May 22, 2020 • 45 mins
How do batteries work? What are the different types of batteries? Why has battery improvement been so slow? Join Lauren and Jonathan to learn more about the science behind batteries.
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Episode Transcript
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Speaker 1 (00:04):
Welcome to text Stuff, a production from I Heart Radio.
Hey there, and welcome to tech Stuff. I'm your host,
Jonathan Strickland. I'm an executive producer with I Heart Radio
and I love all things tech and today it's time
for another classic episode of tech Stuff. This episode originally
(00:26):
published on June third, two thirteen. It is titled The
Evolution of Batteries. So we talk all about how batteries
were first invented and then how they changed over time.
I'm sure you'll get a real charge out of it.
Let's listen. You have something called Moore's law. That's that
observation that in general, microprocessors get twice the number of
(00:49):
discrete elements, or if you prefer to think of it
in another way, microprocessors tend to get twice as powerful
every two years or so. Yeah. This is not exponential growth,
which I have called it in previous episodes, by the way,
and people right in every time and call it. Take
us to task on it, which is important because it's
a misuse of the word exponential. I'm using it's a
(01:11):
colloquial use, but I do not want to go down
that hole again because I'm like you, guys, I get
irritated when people misuse words too. I just wish I
didn't do it as frequently myself, But anyway, it does
double every two years or so, and that's a phenomenal
amount of growth. We're talking about microprocessors that have billions
of discrete elements on them now, and they're all down
(01:32):
at the nano scale. So there's this amazing amount of
technology that's been poured into microprocessors, partially because More's Law
exists and companies strive to to keep up with it,
to maintain it because Moore's Law, as we know it
is not a real physical law. It's more of an observation,
and companies no one wants to be the company that
comes up and says, yeah, we can't do that. You know,
(01:55):
we just got bored. So it means that there's been
a lot of innovation in that space. But mean, while
on the battery front, batteries have in large part remain
more or less the same for decades. I mean, we've
we've seen improvements in battery life, we've seen improvements in
battery efficiency, but there have been some new technologies over
(02:16):
the past fifty years. But even so, it just hasn't
it hasn't at all kept up with the microprocessors assessor side.
This is also, by the way, this ties into our
episodes where we talked about things like the Singularity, where
we talk about how technology doesn't all progress at the
same rate. So while we do see devices getting more
(02:36):
and more sophisticated and powerful, uh, the power supplies aren't
keeping up with that trend. So it may be that
the singularity, if it is ever going to arrive, is
further off than what some people think simply because the
power side of the equation is lagging behind, uh, the
the technological sophistication side. So why is that. Well to
(03:00):
understand that, we kind of have to one talk about
what a battery is and to sort of look at
the history of the development of batteries and talk about
what exactly it does. Now on a very very basic level,
a battery is something that uses electrochemical reactions so that
you can guide electrons through a circuit and have it
(03:21):
do work. And that's about it. Yeah, that's that's really
all a battery is. And it's because there are certain
chemicals that when they have these reactions, they lose electrons
in the process, and if you are able to control
the flow of those electrons. Then you've got a battery.
So batteries date back possibly as long as though more
(03:42):
than two thousand years ago. Yeah, these these clay jars
found in modern day Iraq and you might have might
have heard of them called Bagdad batteries where um, yeah,
clay jars that contained an iron rod en cased in copper.
Tests suggest that the jars were at some point filled
with with with something acidic like vinegar or wine, and
modern day replicas have successfully created an electric charge. They
(04:03):
might have been used for something like a like any
anything from religious rituals and medicinal purposes to even electro plating. Right,
And if you've seen if you're a big MythBusters fan,
you may have seen an episode where they actually showed
these They created one of these batteries and then they
tried to see if they could get enough of a
charge for it to be detectable. Um, so that that's
an indication of that we were familiar with the fact
(04:27):
that certain materials, under certain circumstances could omit this weird energy.
Now at that time we weren't necessarily really aware of
all the things that could do, but that would change
as the centuries would pass. The next big date I
have is quite some time later, which is and that's
when Alessandro Volta, Count Alessandro Volta, he's only one. If
(04:52):
there were more than one, I would killt him. Oh, sorry,
you're talking about a nobility rank. So Count Volta created
a battery by stacking alternating layers of zinc. Lawrence just
checked out at this point zinc, brine, soaked cloth or paper, uh,
and silver. He used these alternating layers kind of a
sandwich here. And we call this a voltaic peel peel
(05:16):
because it's French and uh and and voltaic after volta, yes,
and so uh. The this this peel or pile if
you prefer, because it is a pile oh stuff. When
you put it in this this configuration, you start getting
these chemical reactions that emit electrons. And you could make
the stack taller and taller to get more electrons a
(05:38):
stronger flow of current through this peel. But in order
to do that, you actually had to stack it up
so high that eventually the weight from the top would
start to squish the layers on the bottom, which would
kind of make the brine soak out. And that would
make it less effective, and also the metal itself would
start to corrode fairly quickly from the brine and movement
(06:01):
the electrons. Right. It just wasn't wasn't a practical way
of generating electricity, but it showed the premise and it
gave scientists the idea of there's something here and if
we can figure out other ways of generating the same
kind of energy, we might be able to harness it
for something. Skipping ahead, I mean there there are lots
of different developments in this technology. I have two specific ones.
(06:24):
I think you have a few more. The next really
effective one um was eighty six. Yeah, John Frederick Daniel,
who was an English physicist. He created what we now
call the Daniel cell, which was a you take a
glass jar and on the bottom of the glass jar
you put on in a copper plate, so copper plate
in the bottom of the glass jar, and there's a
(06:45):
wire from the copper plate that comes out of the jar.
Then you pour copper sulfate on top of that copper
plate to about the halfway point of the jar. Then
you suspend a zinc plate in the jar, and then
you pour zinc sulfate solution on top of the zinc plate. Now,
zinc sulfate is less dense than copper sulfate, so zinc
(07:09):
sulfate will float on top of copper sulfate. If you've
ever played with liquids of different densities that had different colors,
then you know what I'm talking about. You can see
that actual level of division. Yeah, it's actually it's one
of my favorite things. I just think it's super cool
when it When I see that, I'm easily amused, I
admit it. But anyway, you also have a wire coming
from the zinc plate uh and exiting the jar. So
(07:32):
a wire attached to this would become that that zinc
plate becomes the negative terminal that's where the electrons are
flowing from, and the copper plate becomes the positive terminal
that's where electrons are flowing too. And so if you
were to connect the two wires together, it would very
quickly burn out this battery. But if you were to
connect it to a circuit, it could actually do uh,
(07:53):
it could or a load as we call it, It It
could actually do work. So again, not terribly practical. It
it was useful for anything that was stationary. But you
know you're talking about a liquid battery here. So it's
not something that you could easily carry around or put
into portable electronics, right right, Yeah, and there's there's a
lot of a lot more elegant ways of getting that
(08:15):
that electrol kind of solution of of you know, just
just a charged molecule then yeah, yeah, And it wouldn't
be until we developed dry cell battery technology that we
started to find practical ways of using it in portable means,
you know. And even then, you know, the batteries weren't
small enough to use in what we consider portable electronics today,
but you could move it around. Uh. The kind of
(08:37):
Daniel cells that that John Frederick Daniel created were useful
for different technologies, things like telephones. It was stuff that
back then you did not carry around. I don't know
if you kids know this, but telephones used to be
these things that were extremely stationary. It's only recently that
we started carrying them around. Uh. Anyway, that's the kind
(08:59):
of battery that became popular for that. Uh. Now, did
you have any other ones who wanted to talk about
before we move onto the basics of batteries. Rechargeable batteries,
The science for that started um started with research around
eighteen fifty nine or so when a French physicist, Gaston
Plant invented the lead acid cell um and that that
was a that was a precursor to to modern day
(09:21):
car batteries. So there you have, you know, the discovery
that this chemical reaction that takes place within a battery,
you get compounds that form out of it, and it
makes the battery over time less effective. That's why batteries die. Eventually,
the active elements that would create the flow of electrons
end up combining with other stuff and for the purposes
(09:42):
of of passing a current through a circuit, they become
a nert. Yeah. Yeah, something either wears out or um
or maybe the the anode or cathode could could dissolve
in the solution. Right, you just essentially what it means
is that you run out of the stuff you need
in order to make it to make this go, right,
and so what what was it? Plant believe? Yes, what
(10:07):
Plant discovered was that for some kinds of solutions, if
you were to pass electric current through the system as
opposed to siphoning it off, you could reverse this process
and yeah, and create a battery that can be used
more than once. Right Now, this does not work for
all batteries, which is why you can't just throw any
(10:27):
regular battery into a recharger and expect it to come
out fine. If you did that to a to a
you know, to adrist cell or something like that, mostly
just explode. Right that these are has to be batteries
that are using specific uh compounds in it for it
to have this this reversible reaction, because not all compounds
will reverse some of them once they're done, they're done
(10:48):
and battery. We will talk about that a little bit
a little bit later, but but let's let's talk about
how how exactly this this circuitry works. Okay, So, if
you've ever looked at a battery, you've seen that there's
a side that is labeled as a plus and one
that's labeled as a minus. So positive and negative. If
you're looking at like a nine volt battery, then they're
next to each other. If you're looking at double a's
(11:10):
or whatever, then it's on one end and the other.
So the negative end the that's where the electrons flow
out of. That's the electrons flow from that end through
a circuit and into the positive end. Uh. Now we
know that you know the uh, the opposite charges attract,
so that's why the negative wants to get to the positive.
(11:30):
And inside the the the battery itself, there is a
chemical called or a compound called an electro light. Now
the electro light has a very important job. It blocks
those electrons from just passing from the negative side to
the positive side directly direct That would burn, burn everything out. Yeah,
that you wouldn't have You wouldn't be able to power anything.
(11:50):
The battery would just you would just have a chemical
reaction inside a canister and it would be dead within
however long it took for those reactions. Yeah. Um. So
it does allow ions to pass through, but not electrons,
and that becomes important. So the negative terminal is connected
to something that's called the anode, the positive terminal is
(12:12):
connected to what we call the cathode, and these together
are the electrodes of a battery. Then you've got the
separator between the anode and the cathode that's presenting that's
preventing those two sides from reacting to each other. And
you have the electro light that allows the electric charge
to flow between cathode and anode, allowing the ions to
pass through. While making sure the electrons don't. And then
(12:33):
you have a collector, which is the part of the
battery that conducts the charge to the outside of the
battery and through whatever the load is, the electronic load,
so the circuit um. So within that anode side, the
negative side, the chemical reaction that takes place is called oxidation.
It's an oxidation reaction. This ends up releasing ions, and
(12:54):
the ions move through the electro light to combine on
UH the other side, and then you've got uh the
release of electrons that go through the circuitry. On the
catholic side, you've got the reduction reaction. That's where the
catholic material and the ions UH combine with the electrons
that are coming in through the circuit that they form
(13:17):
a new compound. And so essentially you've got the anode
freeing up electrons, the cathode accepting electrons, and the electrons
do work along the way. So if you were to
actually connect a wire from the negative terminal to the
positive terminal, you would allow that that pathway to be
open and it would just start to burn up that
battery pretty quickly. Don't do that. It's a waste of batteries.
(13:42):
It's going to heat up that wire. It doesn't do
anything other than kill your battery. But but that's what happens.
It's so when you've got it plugged into something, whenever
you turn the switch on to whatever it is, whether
it's a you know, a lightsaber or a phaser. You know,
I allow all lines of science fiction toys for batteries.
(14:03):
But whenever you turn it on, it opens up that
circuit and that allows the electrons to flow through. And
when you turn it off, then the one of the
gates gets closed essentially, and you no longer the connection
is no longer there. So the battery stops the chemical reaction.
It has to have that pathway open for the chemical
reaction to keep going. Now, there are several different basic
(14:25):
types of batteries that are out there, and we're just
going to cover a couple of them, and we're covering
them based upon the stuff that's inside them, right, because
there's a whole bunch of different substances that you can
use to create these reactions. Like like we said, so yeah, so,
so one basic type is the is alkaline batteries. Uh,
the anode in alkaline batteries tends to be zinc powder.
(14:47):
So the anode again is that negative side that's where
the electrons are coming from. The cathode side has uh,
typically manganese dioxide, and the electrolyte is typically potassium hydroxide.
These are the kind of batteries that you typically find
in double a's, C and D batteries, right, and these
are all examples of This is an example of dry
cell batteries. Yes, which dry cell batteries. One of the
(15:10):
big benefits of those that you don't have to worry
about liquid slashing around inside the battery, so that allows
it to be used in lots of applications. You know,
anything that's liquid obviously you can't shake around too much
or else just gonna disrupt it and you're not gonna
have a working battery. For they're more they're more more volatile. Yeah,
you want that, you want that in a very uh
stationary position. Then you've got zinc carbon batteries. Uh. These
(15:33):
have an anode that has that's a zinc obviously uh,
and then you've got the manganese dioxide cathode. But the
electrolyte in this case is often either ammonium chloride or
zinc chloride. These are often found in triple A, double A,
C and D dry cell batteries. Then you've got lithium
ion batteries. These are the ones that we find in laptops, smartphones, cameras,
(15:54):
that kind of stuff. They are rechargeable batteries and they
have different materials in them. Uh uh. One common version
of lithium ion batteries uses a carbon note and a
lithium cobalt oxide cathode and uh and yeah, these are
the ones that we use when we're recharging our our
various electronics very frequently anyway. Then you've got lead acid batteries.
(16:18):
These are the ones that you often find in cars.
These are more heavy duty, right, they are more volatile.
They do include liquid, Yeah, they include their their their
electrolyte tends to be sulfuric acid. This is one of
the reasons why you want to be really careful with
car batteries because the materials inside them can be very
caustic and and they can damage you, your stuff, your car.
(16:40):
That's why you know you've got to be really careful
with these things. Um. They tend to have uh, lead
dioxide and metallic lead as their electrodes. So yeah, the
rechargeable battery we've already talked about. That's the kind where
if you put the electric current through the battery, you
reverse this uh, this chemical reaction. Uh. It depends upon
(17:02):
what that rechargeable battery is made from, whether how effective
this this process is right, because there's some kinds of
rechargeable batteries that have well they have a memory, and
that memory is not a good one. The memory effect
is what I'm talking about. So I don't know how
many of you are familiar with this, but if you've
(17:25):
ever heard someone say that before you recharge your device,
you should make sure that it's completely that the current
charges completely out. This was due to some some older
types of batteries that have been mostly replaced by lithium
ion batteries. Nickel cadmium is the main culprit here. So
the problem that some people notice with nickel cadmium is
(17:48):
that if you used a nickel cadmium battery for a
while and then you recharged it before you had completely
discharged the original charge, it wouldn't hold as much of
a charge the next time. So let's say that I've
got a device that has a nickel cadmium battery in
it and I run it down to about left like
it's it only has charge left, and I decided to
(18:10):
recharge it. Well, now it's new maximum charge is more
like eight of what it used to be because I
didn't let it go all. It remembers that but doesn't
let me actually consume that power anymore. So, yeah, that
was a problem. Now most batteries now don't have that issue.
(18:30):
I mean, there's still a minor memory effect in some
rechargeable batteries, but it's not nearly as dramatic as it
the older batteries were, right, So so yeah, so if
you are using the lithium ion battery and someone tells
you that thing, you can you can tell them that
we told you no, no, not as big a deal.
And another interesting thing about batteries is what happens if
(18:51):
you place them in series versus in parallel. So in
series it sounds kind of you know, is what it is.
You've you've got them hooked up so that they are
all the charges running through one and then another and
then another yea in the sequence exactly. And uh, if
you do that, you increase the voltage of the output. Now,
(19:11):
if you put them in parallel, you increase the current.
Now you might wonder what's the differences voltage and current
if you're if you're not really familiar with electronics. I
always have to look this up because I I, I
always second guess myself. But voltage measures the energy per
unit charge. And you can think of that is it's
how strong the electrons are pushed through a circuit. So
(19:34):
think of it like water pressure, you know, through a hose.
So the greater the water pressure, the harder that water
is being pushed through the hose. That's essentially your voltage,
it's you know. And then current is the rate at
which electric charge passes through a circuit. Now, voltage will
stay constant, the voltage output will stay constant based upon
(19:55):
whatever kind of battery you have or whether or not
they're in series. Uh. But otherwise it it's going to
remain the same. Current, however, will vary depending upon the
load you place it. Uh, you place on it. So
and that can, like the resistance of a wire, can
affect what the current is. So current is variable. Voltage
(20:17):
is not. And uh, apart from the fact that if
you put them in series, you increase the voltage. But
once you've done that, it does not vary. Um. All right,
Well that's the basis the very basic foundation of batteries. Guys,
We're gonna have to take a quick break. I just
realized the podcast has runned out of batteries, So I'm
(20:40):
gonna go run across the street grab a couple more. Um,
I'll be right back. All right, So we're back. Uh,
And we've learned the basic function of a battery and
how it does what it does. So what's the problem.
Why haven't we made super batteries that last forever and
(21:04):
never need to be recharged and can put out more
energy than uh the generator? Yeah, well, I mean, you know,
there's the first commercial dry cell batteries premiered in and
they haven't really changed all that much since then. Yeah,
we've we've experimented with different materials, but the actual process
(21:25):
has remained very much the same. And there are physical
limits that chemical batteries have, but they can only generate
so much electricity through these reactions. There have been a
few permutations of different things. In addition to those nickel
cadmium batteries that that have the memory effect problem that
we mentioned earlier. There's there was also some some nickel
metal hydride, but they had a really short shelf life.
(21:49):
They would start degrading pretty quickly. Yeah. That's another thing
about some types of batteries is that lithium ion batteries
have that problem as well. Um, they're they're less bad
at it, but they're still not deal right. The idea
being that these these chemical reactions, like the longer the
battery sits idle, the less juice. Yeah, and and and
(22:10):
this doesn't have anything to do with how much you
use it. It's it's from the moment that they're made. Yeah. Yeah.
And also you may have heard stories about, well, if
you want to keep your batteries from the grading, you
should put them in the refrigerator. Don't do that. Don't
do that because that actually it actually slows down the
chemical processes that happen when you Yeah, when you're when
(22:32):
you're trying to use the battery, and you're going to
not get as much juice as you thought you were
because the chemicals themselves are too cold to have those
chemical reactions happen at the correct rate. They're still going
to happen, but you're gonna get a easily amount of
juice out of it. Right, So, so far lithium ion batteries,
especially for small uses, have have been have been pretty
(22:53):
pretty rad um. However, they are very sensitive to high
temperatures um, you know, which is occasionally why they wind
up exploding, bursting into flame. Let's let's also point out
that lithium is an alkali metal, so and we'll we'll
talk about a little bit. We're gonna talk about a
a a possible future type of battery that people are
(23:15):
working on right now where that's really an issue. Both
lithium and sodium are being considered for new types of batteries,
but both of them are alkali metals. The big problem,
there are several problems, but the big problem I would
say with that is alkali metals belong to a class
where they tend to be let's say, reactive when they
(23:36):
come into contact with water. So, if you've ever heard
stories about sodium and water, or if you've ever seen
anyone demonstrate what happens when sodium encounters water, uh, you know,
it's explosive. The same thing is true of lithium. All right,
this is where we get a little chemistry lesson. Everyone
go and get your periodic table of elements. I'll wait now,
(23:57):
if you look at the left hand side of that
table of elements, you're gonna see that down the line,
you're gonna have lithium and you're gonna have sodium that
are both in that same line, as well as potassium
and some other alkali metals. That means that those elements
share common characteristics, and one of those is when water
comes in contacts, sometimes things go boom. So first of all,
(24:19):
never never ever play with these I don't if you
get hold of sodium or lithium, never play with that.
And water, this is seriously dangerous stuff. Also, probably just
just don't. I mean, because because water is in the
air around us in in great enough quantities that hypothetically
it can burst into flame. I know of someone I didn't.
(24:41):
This is a friend of a friend's story, so it's
possibly apocryphal, So so it could be urban legend. I
admit that. But I know of someone who pocketed some
sodium from his chemistry class and then was walking around
with it in his pocket, and and his body was
(25:02):
giving off moisture, and so he began to feel a
burning sensation in his pants and immediately ran to the
bathroom and pulled the sodium mountain threw it into the toilet,
which then exploded. Yeah, again, could be apocryphal. This is
it was a story about a high school student who
went to a rival school, so it could have very
(25:22):
well been one of those stories where ha ha, the
people who go to that school are so dumb, so
much more dumb than the people who go to my school,
which is saying something. I'm just kidding. I love all
my classmates Spartans, but anyway, you were the Spartans, I
was the Spartans. Spartans Spartans together. This is tech stuff.
So but the point, the point being that these these
(25:45):
these elements have serious drawbacks to him. And that's one
of the reasons why the another reason why battery improvement
has gone so slowly, because we have to find safe
ways to handle this stuff so that it doesn't come
into contact with water and and just blow up. Right.
Part of that in lithium ion batteries specifically, is that
they have to have a very small, very simple onboard
(26:06):
computer to to manage the way that all of the
bits flow around in there, and uh and and that
that makes them pretty expensive lithium is already pretty expensive,
but it makes them even more expensive than they would
already be. Now, we have seen some improvements with battery
life in recent years, but a lot of that doesn't
come from improvements in the batteries. It's coming in improvements
in the actual electronics. We are finding more efficient ways
(26:30):
to generate the stuff we want. So your smartphones, if
you've got a smartphone recently that has a decent battery life,
it may not be that the battery is so much better.
It's just that the people who designed the hardware and software,
we're able to maximize performance while being as efficient as possible.
So you're still working with the same basic amount of Yeah,
(26:53):
but I don't need as much of it to do
the stuff you are doing exactly. Speaking of that juice though, Um,
the problem with batteries, and the reason that that that
gasoline has not been ousted completely by batteries, is that
gasoline has an energy density of something like thirteen thousand
watt hours per kilogram, which is which is just a
measure of how much of juice it has, how much
(27:15):
how much how much work you can get out of
a given amount of gasoline. Sure, Um, the best lithium
ion batteries only hold about two hundred what hours per kilogram,
with of a of a hypothetical in a perfect world
situation four hundred possible, so still vastly underpowered when you
compare it to gasoline. Right now, there are some people
(27:40):
out there, very very smart people working on batteries that
would have much higher densities power densities for their batteries
if they can get the batteries to work, if they
can get the the components to to to play nicely,
to not explode, and to work on larger scales and
to work after more than three charges. There are a
lot of barriers that are in place, and we'll talk
(28:03):
about some specific uh cases, but keep in mind there
have been dozens, if not hundreds of different experiments and
trying to improve battery technology, and most of them just
have not panned out. They might have seen promising at
the beginning, but when you get to a point where
you're thinking, all right, how are we going to scale
this up where we can actually manufacture it or create
(28:24):
a battery large enough to do something useful, and then
things start to break down. So one of the ones
I wanted to talk about where these things called micro batteries.
And this was something that UH that we received from
that initial request to talk about battery improvements. And this
is a story about a team of researchers from the
(28:45):
University of Illinois UH talking about a particular type of
battery that uses these very tiny electrodes and lots and
lots of them, and their three dimensional electrodes, and it
was almost like these troads are kind of intertwined together,
so they're very close together, which allows the ions to
pass very very quickly. It also allows electrons to flow
(29:09):
very quickly, and the idea being that you would be
able to release quite a bit of energy in a
short amount of time, faster than you could with most batteries,
and you could also recharge the battery way faster, right,
because that thoroughput speed has a lot to do with
how effective a battery is. Yeah, And in fact, according
to several articles that were posted about this technology, BBC
(29:30):
did one as well as some other outlets. The claim
was that such a battery would be reached could be
recharged one thousand times faster than competing technology. So you
could turn your you know, plug your smartphone in let's
say your smartphone has one of these batteries in it,
and you plugged it in. After a second, it's fully recharged.
(29:51):
You don't have to leave it there for hours for
it to charge up, which is that's a very attractive thing.
So you're thinking, well, if it can release lots of
energy and if it can be recharged in a blink
of an eye, where's the problem. Well, mostly the problem
comes in from the manufacturing side and the scalability as
(30:12):
well as, uh, the fact that it's not the most
reliable technology. Ours Technica actually ran a great article where
they really looked into this and and dove deeper than
a lot of the other outlets did to kind of
take a look at this technology with a skeptical eye,
just to make sure that it really did measure up
to the hype, because we've seen this before with battery technology, right.
(30:36):
And this isn't to say that they want the team
won't figure out a way of of solving the problems
that they face, But here are some of the problems.
One of them is that it's really hard to manufacture
these things. The way that the team was doing it,
they were using this uh this essentially gold to make
these little three dimensional um electrodes sort of, and then
(30:56):
they used polystyrene uh, little little old tiny poly styring pills,
essentially packing them in there, twisting the electrodes around, coding
it in nickel in a well in a combination of
nickel and tin and then uh nickelton alloy actually, and
then coding the rest of it with manganese oxy hydroxide uh,
(31:21):
and then melting away the poly styrene so it it's gone,
then immersing the whole thing to a liquid that was
heated to three degrees celsius or five degrees fahrenheit. And
so it's what even the team has referred to as
a boutique manufacturing approach, meaning that it's very detailed, it's painstaking,
(31:42):
it is not automated. Extremely expensive. Yeah, it's not time
consuming exactly. Not something that's scalable to mass manufacturing methods
right now, certainly. Right. That's not to say that they
wouldn't find some other way of doing it. They may
find a way of doing it where it doesn't require
this series of painstaking steps in order to get the
result that they want, but uh, it's not ideal. Another
(32:07):
problem is that the electrolyte they're using is combustible, so
that's always a concern. If you get it too hot,
it could burst into flames. Uh um or you know,
if you were to get it close to a flame,
it could catch fire. And on top of all that, uh,
the battery loses about five percent of its capacity with
each charge discharge cycle, So after fifteen cycles it would
(32:30):
be down to about two thirds of its original capacity.
And uh, if you were to do a full discharge
full charge, it might be even worse than that. So
while it would recharge very quickly, it would have a
little less juice each time. And so after you recharge
it twenty times, you have to charge, Yeah, you have
(32:51):
to buy a new battery, new battery, right, So uh
that raises lots of problems to waste problems. For example,
like even if you were to say, well that's acceptable
because I want to be able to charge my phone
in a second, you can do that twenty times, and
then you have to go buy a new battery. And
especially when the when the technology to create it is
so so detailed and expensive, and to be fair, you
wouldn't even you wouldn't even go twenty times, right because
(33:13):
each time you would have less juice and so your
your phone would be less and less useful over time.
So after after your phone doesn't last more than a
couple of hours, you think, well, I gotta get a
new battery. So that might be six or seven recharges,
depending upon how hard you are on electronics. If you're me,
then you'd be like, all right, recharge it, give me
(33:34):
a new battery, yea. Lauren and I have more to
say about the evolution of batteries in just a moment,
but first let's take another quick break. So so that
that's the downside to this micro battery technology. That's not
(33:55):
to say again that they won't find ways around that.
Engineers are brilliant at finding ways of fixing problems. But
it's not going to be the revolutionary battery technology that
we're all going to see in our smartphones in the
next few months. It'll it'll at least be a couple
of years before we can see this rolled out in
any way, assuming that they find a way to fix
these problems. Right. One of the other ones that I
(34:18):
wanted to talk about our lithium air batteries, and this
is where we're getting into those alkali metals and the
concern about how they react with water exactly. You know,
they could hypothetically store up to four times as as
much as as lithium ion batteries, as much power as
lithium ion batteries, but they work in the um. Lithium
(34:39):
combines with with oxygen that's trapped by a carbon surface.
Carbon nanotubes are are popular right now and um and
the resulting interplay of these lithium ions and electrons induces
the flow of current UM. Yeah, you get a get a.
One of the by products you get out of this
is lithium peroxide, which is a problem because as it umulates,
(35:00):
it starts to make it more difficult to recharge the battery. Right.
So they they've only recently figured well, they they've had
a bunch of of barriers to to making this work.
That is, that is one of them. They're they're starting to.
For a long time, they didn't understand why the electrochemical
reactions were going so poorly in these things, and it
(35:21):
wasn't until uh that that researchers at M I T
and Sandia National Labs announced that they were starting to
be able to observe the reactions at all to figure
out why this isn't work. And that's when they started
seeing this lithium peroxide forming that was inhibiting the flow
of electricity. And uh, they did discover that if the
(35:43):
electricity were flowing, that the lithium peroxide was starting to
reduce around the trouble spots, and they figured that if
they could improve the electron flow of the battery overall,
then they might be able to get around this problem.
So that recharging does become an issue, right. Uh, that
that explosion thing that we mentioned earlier is still at
(36:05):
issue because when when you're dealing with you know, these
these carbon surfaces are allowing air to basically breathe into
the battery, and since water happens in air, yeah, you
have to find either a way of coding the lithium
inside the battery so that the water would not react
with the surface of lithium, or you have to find
a way of filtering the water out entirely, so that
(36:27):
membrane at the top end, Yeah, hydrophobic membrane, that's what
we'd like to call that. It's scared of water. It
pushes water out. So uh, yeah, it's that that's an issue. Now,
there is a potential alternative to lithium air batteries called
sodium air batteries that are even they are, they may
not be able to hold as much energy as a
(36:50):
lithium battery. It's a lower theoretical energy density, but a
higher practical energy density at at the current moment exactly,
So current moment dear. So yeah, no, it's it always happens.
You can't get around it. But yeah, that's so that's
a possibility. But again, remember sodium is probably that alkali
metal groups, so against same issues. You get that water
(37:13):
in contact with sodium and battery goal boom, yeah instead
of instead of zap zap. Right. Uh. There's there's also
research being done into what's being called solid state batteries UM,
which are kind of kind of the lithium ion um
solution to dry cell batteries. It's it's using um thin
layers of solid electrolyte instead of instead of the liquid
(37:36):
that most lithium ions use. UM. Yeah. And then there's
a I read on Wired this interesting idea of spray
can batteries where each of the each of the elements
that you would find within a battery, the cathodeena, the electrolyte,
all that is represented by a different can of uh,
sprayable material, so you could actually spray this material onto
(37:59):
different surfaces and make a battery that way. And the
idea being that this would allow you to create batteries
in devices that would incorporate the battery designed directly into
the device, so you wouldn't have this blocky battery compartment. Now,
it's not saying that these batteries would be particularly efficient
or powerful compared to what we have now, just that
(38:19):
this would give us more opportunity to explore different ways
of shaping batteries so that they are part of our
electronics and not just you know again, not just some
clunky thing that you have to find make room, make
room for it, right, right, and and also not so heavy. Um,
what would be terrific. That reminds me of the nanocomposite
(38:40):
paper batteries that some people are are working on. These
are These are composed of cellulose and um an aligned
carbon nanotubes woven together UM and and they're they're they're small,
they're flat, they're flexible, they're implantable. Um. They could hypothetically
be put into medical devices. Yeah, these could actually use
biological fluid as ionic fluid, So it ends up turning
(39:03):
your body's fluids into the electrolyte it needs. This is
just making me think of idiocracy. It's electrolyte. It's the
thing that plants crave. Um. I was doing the hand
gesture and everything for those of you are fans of
that movie. Then there's also uh, you know, the Verge
reported on bacteria that are able to transfer electricity, and
(39:24):
scientists had known about this for a while, but they
weren't sure about what the mechanism was, like how did
it transfer electricity? And they discovered that that there were
proteins on the bacteria surface that we're responsible for electron transfer. Uh.
The bacteria is uh, this is this is going to
be a train wreck of a pronunciation in front of me.
(39:46):
Luck she wa nella oneidnisis. But anyway attaches to rusty
iron and other materials and breaks those down and in
the process of breaking down these materials, it releases electrons.
So why are we interested in this? Because by studying
biological organisms that can emit electricity as part of some
(40:11):
process where it's consuming something, we might be able to
create biological batteries. Right, And these are these are a
little bit more of fuel cell really than a battery.
But and and to explain the difference, a fuel cell
is a device that you put fuel into and then
there's a chemical reaction that generates electricity, and then you
(40:33):
refill the fuel cell. So and you know, with a battery,
what you're doing is you're using an electric uh or
electrochemical reaction to harness electricity, and then you either have
to reverse the reaction in order to get the battery
to do it again, or you have to replace the battery.
Fuel cell, you just refill it with fuel. So hydrogen
fuel cells are the ones that most people know about
(40:56):
because those the ones that we've talked about for things
like cars. Hydrogen fuel cell ells use hydrogen, which is
the most plentiful element on Earth, although you have to
break it up from other stuff. It doesn't, it doesn't,
it's not so plentiful in its pure state. It's usually
it's it's in water, which is very plentiful, and hydrocarbons
as well, also very plentiful. But you have to separate
(41:18):
the hydrogen outfast, which requires energy a lot of energy.
But once you've got it, assuming that you've assuming that
you found some sort of a hydrogen mine where it's
not going to take you too much energy to get
it free. Um, you put hydrogen on one side of
a a membrane UM that has a catalyst on it,
usually something really expensive like platinum, and then on the
(41:39):
other side of the membrane you've got oxygen. The membrane
allows the hydrogen ions to pass through, but not hydrogen atoms.
It has to lose the electrons for it to pass through.
The electrons go through a circuit just like it would
with a battery and combine on the other side. So
the hydrogen ions passed through the membrane and that meets
up with the oxygen and says, hey, you wanna you
(42:01):
wanna go do something? I got my buddy here, my
buddy here, and I would love to take you out
to dinner. And so the two hydrogen take out the
one oxygen to dinner. Meanwhile, the electrons come back over
through the circuit and recombined, and then you get water.
So the output of a hydrogen based fuel cell is water, electricity,
and heat, which is why everything pretty Yeah, I think
(42:24):
this is why we would love to use it to
fuel cars because instead of giving off all these different
ghouse Yeah, now water vapor is technically a greenhouse gas,
but it's water vapor. It's not carbon dioxide, it's not
methane or anything like that. So that's why they're very attractive.
But they are you know, they're similar to batteries, but
there there is a difference. I do I do have
(42:48):
a have a bio battery that I was just reading
about research last November at m I T. Harvard and
the Massachusetts Eye and Ear Infirmary. Um. Okay, so so
mammals have in their inner ears chamber that's filled with
ions and um uh. These these ions produce an electrical
potential which drives neural signals. And what this means is
(43:12):
that this is the chamber in your ear that that
lets the vibration of your ear drum be converted into
an electrochemical signal that your brain can read and then
interprets the sound and interprets a sound. Um and so
but but but you've got this this inner chamber that's
just hanging out with ions in it, which is a
potential battery. UM. And these researchers put, UM, put some
(43:35):
electrodes in there along with a very low power electronic device,
and UM the chamber produced enough power with these electrodes
to power the device to wire wirelessly transmit data. That's
pretty cool to to an external drive. Now again we're
talking about you know, we're not talking about stuff that's
that's advancing the power of batteries, but we are looking
(43:59):
at brand new applications that could that are really exciting. Yeah,
it's just but again, this isn't the thing that's going
to make your cell phone last longer. Probably probably not.
It's it's really really really low power, but it would
it would mostly be great for for medical advances in
um hearing aids. Yeah. So anyway, anyway, the advances we're
(44:22):
talking about for the most part, are again just refining
the technology that we already have. It may turn out
that we just have to find a different means of
generating electricity that goes away from this electrochemical model entirely
for us to get beyond this this bottleneck. Or if
one of these other like the if the lithium air
or sodium air batteries work out, or if the micro
(44:44):
battery works out, maybe maybe that will be that that
would be a huge leap ahead. And if either of those,
if any of those were any any more efficient chemical combination. Right.
So there, we're not saying it's impossible. We're just saying
that it's been several decades AIDS and we've only seen
incremental improvements. So don't be surprised if that stays the same.
(45:06):
If it doesn't stay the same, if we do have
this huge leap, that's gonna be awesome for everybody, and
that's what everyone wants. Just you know, be prepared to wait. Guys,
I hope you enjoyed this classic episode of text Stuff.
If you have any suggestions for future tech stuff topics,
reach out to me on Twitter or on Facebook. We
use the same handle at both locations. It is text
(45:29):
Stuff H s W. And I'll talk to you again
really soon. Text Stuff is an I Heart Radio production.
For more podcasts from my Heart Radio, visit the i
Heart Radio app, Apple Podcasts, or wherever you listen to
your favorite shows.
Welcome to text Stuff, a production from I Heart Radio.
Hey there, and welcome to tech Stuff. I'm your host,
Jonathan Strickland. I'm an executive producer with I Heart Radio
and I love all things tech and today it's time
for another classic episode of tech Stuff. This episode originally
(00:26):
published on June third, two thirteen. It is titled The
Evolution of Batteries. So we talk all about how batteries
were first invented and then how they changed over time.
I'm sure you'll get a real charge out of it.
Let's listen. You have something called Moore's law. That's that
observation that in general, microprocessors get twice the number of
(00:49):
discrete elements, or if you prefer to think of it
in another way, microprocessors tend to get twice as powerful
every two years or so. Yeah. This is not exponential growth,
which I have called it in previous episodes, by the way,
and people right in every time and call it. Take
us to task on it, which is important because it's
a misuse of the word exponential. I'm using it's a
(01:11):
colloquial use, but I do not want to go down
that hole again because I'm like you, guys, I get
irritated when people misuse words too. I just wish I
didn't do it as frequently myself, But anyway, it does
double every two years or so, and that's a phenomenal
amount of growth. We're talking about microprocessors that have billions
of discrete elements on them now, and they're all down
(01:32):
at the nano scale. So there's this amazing amount of
technology that's been poured into microprocessors, partially because More's Law
exists and companies strive to to keep up with it,
to maintain it because Moore's Law, as we know it
is not a real physical law. It's more of an observation,
and companies no one wants to be the company that
comes up and says, yeah, we can't do that. You know,
(01:55):
we just got bored. So it means that there's been
a lot of innovation in that space. But mean, while
on the battery front, batteries have in large part remain
more or less the same for decades. I mean, we've
we've seen improvements in battery life, we've seen improvements in
battery efficiency, but there have been some new technologies over
(02:16):
the past fifty years. But even so, it just hasn't
it hasn't at all kept up with the microprocessors assessor side.
This is also, by the way, this ties into our
episodes where we talked about things like the Singularity, where
we talk about how technology doesn't all progress at the
same rate. So while we do see devices getting more
(02:36):
and more sophisticated and powerful, uh, the power supplies aren't
keeping up with that trend. So it may be that
the singularity, if it is ever going to arrive, is
further off than what some people think simply because the
power side of the equation is lagging behind, uh, the
the technological sophistication side. So why is that. Well to
(03:00):
understand that, we kind of have to one talk about
what a battery is and to sort of look at
the history of the development of batteries and talk about
what exactly it does. Now on a very very basic level,
a battery is something that uses electrochemical reactions so that
you can guide electrons through a circuit and have it
(03:21):
do work. And that's about it. Yeah, that's that's really
all a battery is. And it's because there are certain
chemicals that when they have these reactions, they lose electrons
in the process, and if you are able to control
the flow of those electrons. Then you've got a battery.
So batteries date back possibly as long as though more
(03:42):
than two thousand years ago. Yeah, these these clay jars
found in modern day Iraq and you might have might
have heard of them called Bagdad batteries where um, yeah,
clay jars that contained an iron rod en cased in copper.
Tests suggest that the jars were at some point filled
with with with something acidic like vinegar or wine, and
modern day replicas have successfully created an electric charge. They
(04:03):
might have been used for something like a like any
anything from religious rituals and medicinal purposes to even electro plating. Right,
And if you've seen if you're a big MythBusters fan,
you may have seen an episode where they actually showed
these They created one of these batteries and then they
tried to see if they could get enough of a
charge for it to be detectable. Um, so that that's
an indication of that we were familiar with the fact
(04:27):
that certain materials, under certain circumstances could omit this weird energy.
Now at that time we weren't necessarily really aware of
all the things that could do, but that would change
as the centuries would pass. The next big date I
have is quite some time later, which is and that's
when Alessandro Volta, Count Alessandro Volta, he's only one. If
(04:52):
there were more than one, I would killt him. Oh, sorry,
you're talking about a nobility rank. So Count Volta created
a battery by stacking alternating layers of zinc. Lawrence just
checked out at this point zinc, brine, soaked cloth or paper, uh,
and silver. He used these alternating layers kind of a
sandwich here. And we call this a voltaic peel peel
(05:16):
because it's French and uh and and voltaic after volta, yes,
and so uh. The this this peel or pile if
you prefer, because it is a pile oh stuff. When
you put it in this this configuration, you start getting
these chemical reactions that emit electrons. And you could make
the stack taller and taller to get more electrons a
(05:38):
stronger flow of current through this peel. But in order
to do that, you actually had to stack it up
so high that eventually the weight from the top would
start to squish the layers on the bottom, which would
kind of make the brine soak out. And that would
make it less effective, and also the metal itself would
start to corrode fairly quickly from the brine and movement
(06:01):
the electrons. Right. It just wasn't wasn't a practical way
of generating electricity, but it showed the premise and it
gave scientists the idea of there's something here and if
we can figure out other ways of generating the same
kind of energy, we might be able to harness it
for something. Skipping ahead, I mean there there are lots
of different developments in this technology. I have two specific ones.
(06:24):
I think you have a few more. The next really
effective one um was eighty six. Yeah, John Frederick Daniel,
who was an English physicist. He created what we now
call the Daniel cell, which was a you take a
glass jar and on the bottom of the glass jar
you put on in a copper plate, so copper plate
in the bottom of the glass jar, and there's a
(06:45):
wire from the copper plate that comes out of the jar.
Then you pour copper sulfate on top of that copper
plate to about the halfway point of the jar. Then
you suspend a zinc plate in the jar, and then
you pour zinc sulfate solution on top of the zinc plate. Now,
zinc sulfate is less dense than copper sulfate, so zinc
(07:09):
sulfate will float on top of copper sulfate. If you've
ever played with liquids of different densities that had different colors,
then you know what I'm talking about. You can see
that actual level of division. Yeah, it's actually it's one
of my favorite things. I just think it's super cool
when it When I see that, I'm easily amused, I
admit it. But anyway, you also have a wire coming
from the zinc plate uh and exiting the jar. So
(07:32):
a wire attached to this would become that that zinc
plate becomes the negative terminal that's where the electrons are
flowing from, and the copper plate becomes the positive terminal
that's where electrons are flowing too. And so if you
were to connect the two wires together, it would very
quickly burn out this battery. But if you were to
connect it to a circuit, it could actually do uh,
(07:53):
it could or a load as we call it, It It
could actually do work. So again, not terribly practical. It
it was useful for anything that was stationary. But you
know you're talking about a liquid battery here. So it's
not something that you could easily carry around or put
into portable electronics, right right, Yeah, and there's there's a
lot of a lot more elegant ways of getting that
(08:15):
that electrol kind of solution of of you know, just
just a charged molecule then yeah, yeah, And it wouldn't
be until we developed dry cell battery technology that we
started to find practical ways of using it in portable means,
you know. And even then, you know, the batteries weren't
small enough to use in what we consider portable electronics today,
but you could move it around. Uh. The kind of
(08:37):
Daniel cells that that John Frederick Daniel created were useful
for different technologies, things like telephones. It was stuff that
back then you did not carry around. I don't know
if you kids know this, but telephones used to be
these things that were extremely stationary. It's only recently that
we started carrying them around. Uh. Anyway, that's the kind
(08:59):
of battery that became popular for that. Uh. Now, did
you have any other ones who wanted to talk about
before we move onto the basics of batteries. Rechargeable batteries,
The science for that started um started with research around
eighteen fifty nine or so when a French physicist, Gaston
Plant invented the lead acid cell um and that that
was a that was a precursor to to modern day
(09:21):
car batteries. So there you have, you know, the discovery
that this chemical reaction that takes place within a battery,
you get compounds that form out of it, and it
makes the battery over time less effective. That's why batteries die. Eventually,
the active elements that would create the flow of electrons
end up combining with other stuff and for the purposes
(09:42):
of of passing a current through a circuit, they become
a nert. Yeah. Yeah, something either wears out or um
or maybe the the anode or cathode could could dissolve
in the solution. Right, you just essentially what it means
is that you run out of the stuff you need
in order to make it to make this go, right,
and so what what was it? Plant believe? Yes, what
(10:07):
Plant discovered was that for some kinds of solutions, if
you were to pass electric current through the system as
opposed to siphoning it off, you could reverse this process
and yeah, and create a battery that can be used
more than once. Right Now, this does not work for
all batteries, which is why you can't just throw any
(10:27):
regular battery into a recharger and expect it to come
out fine. If you did that to a to a
you know, to adrist cell or something like that, mostly
just explode. Right that these are has to be batteries
that are using specific uh compounds in it for it
to have this this reversible reaction, because not all compounds
will reverse some of them once they're done, they're done
(10:48):
and battery. We will talk about that a little bit
a little bit later, but but let's let's talk about
how how exactly this this circuitry works. Okay, So, if
you've ever looked at a battery, you've seen that there's
a side that is labeled as a plus and one
that's labeled as a minus. So positive and negative. If
you're looking at like a nine volt battery, then they're
next to each other. If you're looking at double a's
(11:10):
or whatever, then it's on one end and the other.
So the negative end the that's where the electrons flow
out of. That's the electrons flow from that end through
a circuit and into the positive end. Uh. Now we
know that you know the uh, the opposite charges attract,
so that's why the negative wants to get to the positive.
(11:30):
And inside the the the battery itself, there is a
chemical called or a compound called an electro light. Now
the electro light has a very important job. It blocks
those electrons from just passing from the negative side to
the positive side directly direct That would burn, burn everything out. Yeah,
that you wouldn't have You wouldn't be able to power anything.
(11:50):
The battery would just you would just have a chemical
reaction inside a canister and it would be dead within
however long it took for those reactions. Yeah. Um. So
it does allow ions to pass through, but not electrons,
and that becomes important. So the negative terminal is connected
to something that's called the anode, the positive terminal is
(12:12):
connected to what we call the cathode, and these together
are the electrodes of a battery. Then you've got the
separator between the anode and the cathode that's presenting that's
preventing those two sides from reacting to each other. And
you have the electro light that allows the electric charge
to flow between cathode and anode, allowing the ions to
pass through. While making sure the electrons don't. And then
(12:33):
you have a collector, which is the part of the
battery that conducts the charge to the outside of the
battery and through whatever the load is, the electronic load,
so the circuit um. So within that anode side, the
negative side, the chemical reaction that takes place is called oxidation.
It's an oxidation reaction. This ends up releasing ions, and
(12:54):
the ions move through the electro light to combine on
UH the other side, and then you've got uh the
release of electrons that go through the circuitry. On the
catholic side, you've got the reduction reaction. That's where the
catholic material and the ions UH combine with the electrons
that are coming in through the circuit that they form
(13:17):
a new compound. And so essentially you've got the anode
freeing up electrons, the cathode accepting electrons, and the electrons
do work along the way. So if you were to
actually connect a wire from the negative terminal to the
positive terminal, you would allow that that pathway to be
open and it would just start to burn up that
battery pretty quickly. Don't do that. It's a waste of batteries.
(13:42):
It's going to heat up that wire. It doesn't do
anything other than kill your battery. But but that's what happens.
It's so when you've got it plugged into something, whenever
you turn the switch on to whatever it is, whether
it's a you know, a lightsaber or a phaser. You know,
I allow all lines of science fiction toys for batteries.
(14:03):
But whenever you turn it on, it opens up that
circuit and that allows the electrons to flow through. And
when you turn it off, then the one of the
gates gets closed essentially, and you no longer the connection
is no longer there. So the battery stops the chemical reaction.
It has to have that pathway open for the chemical
reaction to keep going. Now, there are several different basic
(14:25):
types of batteries that are out there, and we're just
going to cover a couple of them, and we're covering
them based upon the stuff that's inside them, right, because
there's a whole bunch of different substances that you can
use to create these reactions. Like like we said, so yeah, so,
so one basic type is the is alkaline batteries. Uh,
the anode in alkaline batteries tends to be zinc powder.
(14:47):
So the anode again is that negative side that's where
the electrons are coming from. The cathode side has uh,
typically manganese dioxide, and the electrolyte is typically potassium hydroxide.
These are the kind of batteries that you typically find
in double a's, C and D batteries, right, and these
are all examples of This is an example of dry
cell batteries. Yes, which dry cell batteries. One of the
(15:10):
big benefits of those that you don't have to worry
about liquid slashing around inside the battery, so that allows
it to be used in lots of applications. You know,
anything that's liquid obviously you can't shake around too much
or else just gonna disrupt it and you're not gonna
have a working battery. For they're more they're more more volatile. Yeah,
you want that, you want that in a very uh
stationary position. Then you've got zinc carbon batteries. Uh. These
(15:33):
have an anode that has that's a zinc obviously uh,
and then you've got the manganese dioxide cathode. But the
electrolyte in this case is often either ammonium chloride or
zinc chloride. These are often found in triple A, double A,
C and D dry cell batteries. Then you've got lithium
ion batteries. These are the ones that we find in laptops, smartphones, cameras,
(15:54):
that kind of stuff. They are rechargeable batteries and they
have different materials in them. Uh uh. One common version
of lithium ion batteries uses a carbon note and a
lithium cobalt oxide cathode and uh and yeah, these are
the ones that we use when we're recharging our our
various electronics very frequently anyway. Then you've got lead acid batteries.
(16:18):
These are the ones that you often find in cars.
These are more heavy duty, right, they are more volatile.
They do include liquid, Yeah, they include their their their
electrolyte tends to be sulfuric acid. This is one of
the reasons why you want to be really careful with
car batteries because the materials inside them can be very
caustic and and they can damage you, your stuff, your car.
(16:40):
That's why you know you've got to be really careful
with these things. Um. They tend to have uh, lead
dioxide and metallic lead as their electrodes. So yeah, the
rechargeable battery we've already talked about. That's the kind where
if you put the electric current through the battery, you
reverse this uh, this chemical reaction. Uh. It depends upon
(17:02):
what that rechargeable battery is made from, whether how effective
this this process is right, because there's some kinds of
rechargeable batteries that have well they have a memory, and
that memory is not a good one. The memory effect
is what I'm talking about. So I don't know how
many of you are familiar with this, but if you've
(17:25):
ever heard someone say that before you recharge your device,
you should make sure that it's completely that the current
charges completely out. This was due to some some older
types of batteries that have been mostly replaced by lithium
ion batteries. Nickel cadmium is the main culprit here. So
the problem that some people notice with nickel cadmium is
(17:48):
that if you used a nickel cadmium battery for a
while and then you recharged it before you had completely
discharged the original charge, it wouldn't hold as much of
a charge the next time. So let's say that I've
got a device that has a nickel cadmium battery in
it and I run it down to about left like
it's it only has charge left, and I decided to
(18:10):
recharge it. Well, now it's new maximum charge is more
like eight of what it used to be because I
didn't let it go all. It remembers that but doesn't
let me actually consume that power anymore. So, yeah, that
was a problem. Now most batteries now don't have that issue.
(18:30):
I mean, there's still a minor memory effect in some
rechargeable batteries, but it's not nearly as dramatic as it
the older batteries were, right, So so yeah, so if
you are using the lithium ion battery and someone tells
you that thing, you can you can tell them that
we told you no, no, not as big a deal.
And another interesting thing about batteries is what happens if
(18:51):
you place them in series versus in parallel. So in
series it sounds kind of you know, is what it is.
You've you've got them hooked up so that they are
all the charges running through one and then another and
then another yea in the sequence exactly. And uh, if
you do that, you increase the voltage of the output. Now,
(19:11):
if you put them in parallel, you increase the current.
Now you might wonder what's the differences voltage and current
if you're if you're not really familiar with electronics. I
always have to look this up because I I, I
always second guess myself. But voltage measures the energy per
unit charge. And you can think of that is it's
how strong the electrons are pushed through a circuit. So
(19:34):
think of it like water pressure, you know, through a hose.
So the greater the water pressure, the harder that water
is being pushed through the hose. That's essentially your voltage,
it's you know. And then current is the rate at
which electric charge passes through a circuit. Now, voltage will
stay constant, the voltage output will stay constant based upon
(19:55):
whatever kind of battery you have or whether or not
they're in series. Uh. But otherwise it it's going to
remain the same. Current, however, will vary depending upon the
load you place it. Uh, you place on it. So
and that can, like the resistance of a wire, can
affect what the current is. So current is variable. Voltage
(20:17):
is not. And uh, apart from the fact that if
you put them in series, you increase the voltage. But
once you've done that, it does not vary. Um. All right,
Well that's the basis the very basic foundation of batteries. Guys,
We're gonna have to take a quick break. I just
realized the podcast has runned out of batteries, So I'm
(20:40):
gonna go run across the street grab a couple more. Um,
I'll be right back. All right, So we're back. Uh,
And we've learned the basic function of a battery and
how it does what it does. So what's the problem.
Why haven't we made super batteries that last forever and
(21:04):
never need to be recharged and can put out more
energy than uh the generator? Yeah, well, I mean, you know,
there's the first commercial dry cell batteries premiered in and
they haven't really changed all that much since then. Yeah,
we've we've experimented with different materials, but the actual process
(21:25):
has remained very much the same. And there are physical
limits that chemical batteries have, but they can only generate
so much electricity through these reactions. There have been a
few permutations of different things. In addition to those nickel
cadmium batteries that that have the memory effect problem that
we mentioned earlier. There's there was also some some nickel
metal hydride, but they had a really short shelf life.
(21:49):
They would start degrading pretty quickly. Yeah. That's another thing
about some types of batteries is that lithium ion batteries
have that problem as well. Um, they're they're less bad
at it, but they're still not deal right. The idea
being that these these chemical reactions, like the longer the
battery sits idle, the less juice. Yeah, and and and
(22:10):
this doesn't have anything to do with how much you
use it. It's it's from the moment that they're made. Yeah. Yeah.
And also you may have heard stories about, well, if
you want to keep your batteries from the grading, you
should put them in the refrigerator. Don't do that. Don't
do that because that actually it actually slows down the
chemical processes that happen when you Yeah, when you're when
(22:32):
you're trying to use the battery, and you're going to
not get as much juice as you thought you were
because the chemicals themselves are too cold to have those
chemical reactions happen at the correct rate. They're still going
to happen, but you're gonna get a easily amount of
juice out of it. Right, So, so far lithium ion batteries,
especially for small uses, have have been have been pretty
(22:53):
pretty rad um. However, they are very sensitive to high
temperatures um, you know, which is occasionally why they wind
up exploding, bursting into flame. Let's let's also point out
that lithium is an alkali metal, so and we'll we'll
talk about a little bit. We're gonna talk about a
a a possible future type of battery that people are
(23:15):
working on right now where that's really an issue. Both
lithium and sodium are being considered for new types of batteries,
but both of them are alkali metals. The big problem,
there are several problems, but the big problem I would
say with that is alkali metals belong to a class
where they tend to be let's say, reactive when they
(23:36):
come into contact with water. So, if you've ever heard
stories about sodium and water, or if you've ever seen
anyone demonstrate what happens when sodium encounters water, uh, you know,
it's explosive. The same thing is true of lithium. All right,
this is where we get a little chemistry lesson. Everyone
go and get your periodic table of elements. I'll wait now,
(23:57):
if you look at the left hand side of that
table of elements, you're gonna see that down the line,
you're gonna have lithium and you're gonna have sodium that
are both in that same line, as well as potassium
and some other alkali metals. That means that those elements
share common characteristics, and one of those is when water
comes in contacts, sometimes things go boom. So first of all,
(24:19):
never never ever play with these I don't if you
get hold of sodium or lithium, never play with that.
And water, this is seriously dangerous stuff. Also, probably just
just don't. I mean, because because water is in the
air around us in in great enough quantities that hypothetically
it can burst into flame. I know of someone I didn't.
(24:41):
This is a friend of a friend's story, so it's
possibly apocryphal, So so it could be urban legend. I
admit that. But I know of someone who pocketed some
sodium from his chemistry class and then was walking around
with it in his pocket, and and his body was
(25:02):
giving off moisture, and so he began to feel a
burning sensation in his pants and immediately ran to the
bathroom and pulled the sodium mountain threw it into the toilet,
which then exploded. Yeah, again, could be apocryphal. This is
it was a story about a high school student who
went to a rival school, so it could have very
(25:22):
well been one of those stories where ha ha, the
people who go to that school are so dumb, so
much more dumb than the people who go to my school,
which is saying something. I'm just kidding. I love all
my classmates Spartans, but anyway, you were the Spartans, I
was the Spartans. Spartans Spartans together. This is tech stuff.
So but the point, the point being that these these
(25:45):
these elements have serious drawbacks to him. And that's one
of the reasons why the another reason why battery improvement
has gone so slowly, because we have to find safe
ways to handle this stuff so that it doesn't come
into contact with water and and just blow up. Right.
Part of that in lithium ion batteries specifically, is that
they have to have a very small, very simple onboard
(26:06):
computer to to manage the way that all of the
bits flow around in there, and uh and and that
that makes them pretty expensive lithium is already pretty expensive,
but it makes them even more expensive than they would
already be. Now, we have seen some improvements with battery
life in recent years, but a lot of that doesn't
come from improvements in the batteries. It's coming in improvements
in the actual electronics. We are finding more efficient ways
(26:30):
to generate the stuff we want. So your smartphones, if
you've got a smartphone recently that has a decent battery life,
it may not be that the battery is so much better.
It's just that the people who designed the hardware and software,
we're able to maximize performance while being as efficient as possible.
So you're still working with the same basic amount of Yeah,
(26:53):
but I don't need as much of it to do
the stuff you are doing exactly. Speaking of that juice though, Um,
the problem with batteries, and the reason that that that
gasoline has not been ousted completely by batteries, is that
gasoline has an energy density of something like thirteen thousand
watt hours per kilogram, which is which is just a
measure of how much of juice it has, how much
(27:15):
how much how much work you can get out of
a given amount of gasoline. Sure, Um, the best lithium
ion batteries only hold about two hundred what hours per kilogram,
with of a of a hypothetical in a perfect world
situation four hundred possible, so still vastly underpowered when you
compare it to gasoline. Right now, there are some people
(27:40):
out there, very very smart people working on batteries that
would have much higher densities power densities for their batteries
if they can get the batteries to work, if they
can get the the components to to to play nicely,
to not explode, and to work on larger scales and
to work after more than three charges. There are a
lot of barriers that are in place, and we'll talk
(28:03):
about some specific uh cases, but keep in mind there
have been dozens, if not hundreds of different experiments and
trying to improve battery technology, and most of them just
have not panned out. They might have seen promising at
the beginning, but when you get to a point where
you're thinking, all right, how are we going to scale
this up where we can actually manufacture it or create
(28:24):
a battery large enough to do something useful, and then
things start to break down. So one of the ones
I wanted to talk about where these things called micro batteries.
And this was something that UH that we received from
that initial request to talk about battery improvements. And this
is a story about a team of researchers from the
(28:45):
University of Illinois UH talking about a particular type of
battery that uses these very tiny electrodes and lots and
lots of them, and their three dimensional electrodes, and it
was almost like these troads are kind of intertwined together,
so they're very close together, which allows the ions to
pass very very quickly. It also allows electrons to flow
(29:09):
very quickly, and the idea being that you would be
able to release quite a bit of energy in a
short amount of time, faster than you could with most batteries,
and you could also recharge the battery way faster, right,
because that thoroughput speed has a lot to do with
how effective a battery is. Yeah, And in fact, according
to several articles that were posted about this technology, BBC
(29:30):
did one as well as some other outlets. The claim
was that such a battery would be reached could be
recharged one thousand times faster than competing technology. So you
could turn your you know, plug your smartphone in let's
say your smartphone has one of these batteries in it,
and you plugged it in. After a second, it's fully recharged.
(29:51):
You don't have to leave it there for hours for
it to charge up, which is that's a very attractive thing.
So you're thinking, well, if it can release lots of
energy and if it can be recharged in a blink
of an eye, where's the problem. Well, mostly the problem
comes in from the manufacturing side and the scalability as
(30:12):
well as, uh, the fact that it's not the most
reliable technology. Ours Technica actually ran a great article where
they really looked into this and and dove deeper than
a lot of the other outlets did to kind of
take a look at this technology with a skeptical eye,
just to make sure that it really did measure up
to the hype, because we've seen this before with battery technology, right.
(30:36):
And this isn't to say that they want the team
won't figure out a way of of solving the problems
that they face, But here are some of the problems.
One of them is that it's really hard to manufacture
these things. The way that the team was doing it,
they were using this uh this essentially gold to make
these little three dimensional um electrodes sort of, and then
(30:56):
they used polystyrene uh, little little old tiny poly styring pills,
essentially packing them in there, twisting the electrodes around, coding
it in nickel in a well in a combination of
nickel and tin and then uh nickelton alloy actually, and
then coding the rest of it with manganese oxy hydroxide uh,
(31:21):
and then melting away the poly styrene so it it's gone,
then immersing the whole thing to a liquid that was
heated to three degrees celsius or five degrees fahrenheit. And
so it's what even the team has referred to as
a boutique manufacturing approach, meaning that it's very detailed, it's painstaking,
(31:42):
it is not automated. Extremely expensive. Yeah, it's not time
consuming exactly. Not something that's scalable to mass manufacturing methods
right now, certainly. Right. That's not to say that they
wouldn't find some other way of doing it. They may
find a way of doing it where it doesn't require
this series of painstaking steps in order to get the
result that they want, but uh, it's not ideal. Another
(32:07):
problem is that the electrolyte they're using is combustible, so
that's always a concern. If you get it too hot,
it could burst into flames. Uh um or you know,
if you were to get it close to a flame,
it could catch fire. And on top of all that, uh,
the battery loses about five percent of its capacity with
each charge discharge cycle, So after fifteen cycles it would
(32:30):
be down to about two thirds of its original capacity.
And uh, if you were to do a full discharge
full charge, it might be even worse than that. So
while it would recharge very quickly, it would have a
little less juice each time. And so after you recharge
it twenty times, you have to charge, Yeah, you have
(32:51):
to buy a new battery, new battery, right, So uh
that raises lots of problems to waste problems. For example,
like even if you were to say, well that's acceptable
because I want to be able to charge my phone
in a second, you can do that twenty times, and
then you have to go buy a new battery. And
especially when the when the technology to create it is
so so detailed and expensive, and to be fair, you
wouldn't even you wouldn't even go twenty times, right because
(33:13):
each time you would have less juice and so your
your phone would be less and less useful over time.
So after after your phone doesn't last more than a
couple of hours, you think, well, I gotta get a
new battery. So that might be six or seven recharges,
depending upon how hard you are on electronics. If you're me,
then you'd be like, all right, recharge it, give me
(33:34):
a new battery, yea. Lauren and I have more to
say about the evolution of batteries in just a moment,
but first let's take another quick break. So so that
that's the downside to this micro battery technology. That's not
(33:55):
to say again that they won't find ways around that.
Engineers are brilliant at finding ways of fixing problems. But
it's not going to be the revolutionary battery technology that
we're all going to see in our smartphones in the
next few months. It'll it'll at least be a couple
of years before we can see this rolled out in
any way, assuming that they find a way to fix
these problems. Right. One of the other ones that I
(34:18):
wanted to talk about our lithium air batteries, and this
is where we're getting into those alkali metals and the
concern about how they react with water exactly. You know,
they could hypothetically store up to four times as as
much as as lithium ion batteries, as much power as
lithium ion batteries, but they work in the um. Lithium
(34:39):
combines with with oxygen that's trapped by a carbon surface.
Carbon nanotubes are are popular right now and um and
the resulting interplay of these lithium ions and electrons induces
the flow of current UM. Yeah, you get a get a.
One of the by products you get out of this
is lithium peroxide, which is a problem because as it umulates,
(35:00):
it starts to make it more difficult to recharge the battery. Right.
So they they've only recently figured well, they they've had
a bunch of of barriers to to making this work.
That is, that is one of them. They're they're starting to.
For a long time, they didn't understand why the electrochemical
reactions were going so poorly in these things, and it
(35:21):
wasn't until uh that that researchers at M I T
and Sandia National Labs announced that they were starting to
be able to observe the reactions at all to figure
out why this isn't work. And that's when they started
seeing this lithium peroxide forming that was inhibiting the flow
of electricity. And uh, they did discover that if the
(35:43):
electricity were flowing, that the lithium peroxide was starting to
reduce around the trouble spots, and they figured that if
they could improve the electron flow of the battery overall,
then they might be able to get around this problem.
So that recharging does become an issue, right. Uh, that
that explosion thing that we mentioned earlier is still at
(36:05):
issue because when when you're dealing with you know, these
these carbon surfaces are allowing air to basically breathe into
the battery, and since water happens in air, yeah, you
have to find either a way of coding the lithium
inside the battery so that the water would not react
with the surface of lithium, or you have to find
a way of filtering the water out entirely, so that
(36:27):
membrane at the top end, Yeah, hydrophobic membrane, that's what
we'd like to call that. It's scared of water. It
pushes water out. So uh, yeah, it's that that's an issue. Now,
there is a potential alternative to lithium air batteries called
sodium air batteries that are even they are, they may
not be able to hold as much energy as a
(36:50):
lithium battery. It's a lower theoretical energy density, but a
higher practical energy density at at the current moment exactly,
So current moment dear. So yeah, no, it's it always happens.
You can't get around it. But yeah, that's so that's
a possibility. But again, remember sodium is probably that alkali
metal groups, so against same issues. You get that water
(37:13):
in contact with sodium and battery goal boom, yeah instead
of instead of zap zap. Right. Uh. There's there's also
research being done into what's being called solid state batteries UM,
which are kind of kind of the lithium ion um
solution to dry cell batteries. It's it's using um thin
layers of solid electrolyte instead of instead of the liquid
(37:36):
that most lithium ions use. UM. Yeah. And then there's
a I read on Wired this interesting idea of spray
can batteries where each of the each of the elements
that you would find within a battery, the cathodeena, the electrolyte,
all that is represented by a different can of uh,
sprayable material, so you could actually spray this material onto
(37:59):
different surfaces and make a battery that way. And the
idea being that this would allow you to create batteries
in devices that would incorporate the battery designed directly into
the device, so you wouldn't have this blocky battery compartment. Now,
it's not saying that these batteries would be particularly efficient
or powerful compared to what we have now, just that
(38:19):
this would give us more opportunity to explore different ways
of shaping batteries so that they are part of our
electronics and not just you know again, not just some
clunky thing that you have to find make room, make
room for it, right, right, and and also not so heavy. Um,
what would be terrific. That reminds me of the nanocomposite
(38:40):
paper batteries that some people are are working on. These
are These are composed of cellulose and um an aligned
carbon nanotubes woven together UM and and they're they're they're small,
they're flat, they're flexible, they're implantable. Um. They could hypothetically
be put into medical devices. Yeah, these could actually use
biological fluid as ionic fluid, So it ends up turning
(39:03):
your body's fluids into the electrolyte it needs. This is
just making me think of idiocracy. It's electrolyte. It's the
thing that plants crave. Um. I was doing the hand
gesture and everything for those of you are fans of
that movie. Then there's also uh, you know, the Verge
reported on bacteria that are able to transfer electricity, and
(39:24):
scientists had known about this for a while, but they
weren't sure about what the mechanism was, like how did
it transfer electricity? And they discovered that that there were
proteins on the bacteria surface that we're responsible for electron transfer. Uh.
The bacteria is uh, this is this is going to
be a train wreck of a pronunciation in front of me.
(39:46):
Luck she wa nella oneidnisis. But anyway attaches to rusty
iron and other materials and breaks those down and in
the process of breaking down these materials, it releases electrons.
So why are we interested in this? Because by studying
biological organisms that can emit electricity as part of some
(40:11):
process where it's consuming something, we might be able to
create biological batteries. Right, And these are these are a
little bit more of fuel cell really than a battery.
But and and to explain the difference, a fuel cell
is a device that you put fuel into and then
there's a chemical reaction that generates electricity, and then you
(40:33):
refill the fuel cell. So and you know, with a battery,
what you're doing is you're using an electric uh or
electrochemical reaction to harness electricity, and then you either have
to reverse the reaction in order to get the battery
to do it again, or you have to replace the battery.
Fuel cell, you just refill it with fuel. So hydrogen
fuel cells are the ones that most people know about
(40:56):
because those the ones that we've talked about for things
like cars. Hydrogen fuel cell ells use hydrogen, which is
the most plentiful element on Earth, although you have to
break it up from other stuff. It doesn't, it doesn't,
it's not so plentiful in its pure state. It's usually
it's it's in water, which is very plentiful, and hydrocarbons
as well, also very plentiful. But you have to separate
(41:18):
the hydrogen outfast, which requires energy a lot of energy.
But once you've got it, assuming that you've assuming that
you found some sort of a hydrogen mine where it's
not going to take you too much energy to get
it free. Um, you put hydrogen on one side of
a a membrane UM that has a catalyst on it,
usually something really expensive like platinum, and then on the
(41:39):
other side of the membrane you've got oxygen. The membrane
allows the hydrogen ions to pass through, but not hydrogen atoms.
It has to lose the electrons for it to pass through.
The electrons go through a circuit just like it would
with a battery and combine on the other side. So
the hydrogen ions passed through the membrane and that meets
up with the oxygen and says, hey, you wanna you
(42:01):
wanna go do something? I got my buddy here, my
buddy here, and I would love to take you out
to dinner. And so the two hydrogen take out the
one oxygen to dinner. Meanwhile, the electrons come back over
through the circuit and recombined, and then you get water.
So the output of a hydrogen based fuel cell is water, electricity,
and heat, which is why everything pretty Yeah, I think
(42:24):
this is why we would love to use it to
fuel cars because instead of giving off all these different
ghouse Yeah, now water vapor is technically a greenhouse gas,
but it's water vapor. It's not carbon dioxide, it's not
methane or anything like that. So that's why they're very attractive.
But they are you know, they're similar to batteries, but
there there is a difference. I do I do have
(42:48):
a have a bio battery that I was just reading
about research last November at m I T. Harvard and
the Massachusetts Eye and Ear Infirmary. Um. Okay, so so
mammals have in their inner ears chamber that's filled with
ions and um uh. These these ions produce an electrical
potential which drives neural signals. And what this means is
(43:12):
that this is the chamber in your ear that that
lets the vibration of your ear drum be converted into
an electrochemical signal that your brain can read and then
interprets the sound and interprets a sound. Um and so
but but but you've got this this inner chamber that's
just hanging out with ions in it, which is a
potential battery. UM. And these researchers put, UM, put some
(43:35):
electrodes in there along with a very low power electronic device,
and UM the chamber produced enough power with these electrodes
to power the device to wire wirelessly transmit data. That's
pretty cool to to an external drive. Now again we're
talking about you know, we're not talking about stuff that's
that's advancing the power of batteries, but we are looking
(43:59):
at brand new applications that could that are really exciting. Yeah,
it's just but again, this isn't the thing that's going
to make your cell phone last longer. Probably probably not.
It's it's really really really low power, but it would
it would mostly be great for for medical advances in
um hearing aids. Yeah. So anyway, anyway, the advances we're
(44:22):
talking about for the most part, are again just refining
the technology that we already have. It may turn out
that we just have to find a different means of
generating electricity that goes away from this electrochemical model entirely
for us to get beyond this this bottleneck. Or if
one of these other like the if the lithium air
or sodium air batteries work out, or if the micro
(44:44):
battery works out, maybe maybe that will be that that
would be a huge leap ahead. And if either of those,
if any of those were any any more efficient chemical combination. Right.
So there, we're not saying it's impossible. We're just saying
that it's been several decades AIDS and we've only seen
incremental improvements. So don't be surprised if that stays the same.
(45:06):
If it doesn't stay the same, if we do have
this huge leap, that's gonna be awesome for everybody, and
that's what everyone wants. Just you know, be prepared to wait. Guys,
I hope you enjoyed this classic episode of text Stuff.
If you have any suggestions for future tech stuff topics,
reach out to me on Twitter or on Facebook. We
use the same handle at both locations. It is text
(45:29):
Stuff H s W. And I'll talk to you again
really soon. Text Stuff is an I Heart Radio production.
For more podcasts from my Heart Radio, visit the i
Heart Radio app, Apple Podcasts, or wherever you listen to
your favorite shows.
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Stuff You Should Know
If you've ever wanted to know about champagne, satanism, the Stonewall Uprising, chaos theory, LSD, El Nino, true crime and Rosa Parks, then look no further. Josh and Chuck have you covered.