So in 1986, Asahi executive Isao Kuribayashi flew to Boston on a top secret mission, carrying three jars containing cathode, anode and electrolyte materials.He handed them to a tiny firm called Battery Engineering, working out of a converted truck garage, and he asked them to turn the materials
cryptic. It shows a road map for batteries. We're right down here today. We're with lithium metal oxide anodes and graphite anodes , so it would be an anode and a cathode. And this shows you by the time you get out to about 2019, we don't even know what kinds of anodes you're going to get based on the kinds of energy densities that road map projects. So I told you we're
They were called so often, they threatened to start charging the lab for the special chemicals needed to extinguish the burning lithium. - The problem was the anode . Whittingham's design used pure lithium, which worked brilliantly, until it didn't.
At the same time, nearby cobalt atoms will give up an electron to balance out the charge, and those electrons then go through the wire to the anode to meet with the ions. If Goodenough could find an anode that would replace lithium metal, the battery would become safe enough to leave the lab and actually power real world devices.
graphite anodes , so it would be an anode and a cathode. And this shows you by the time you get out to about 2019, we don't even know what kinds of anodes you're going to get based on the kinds of energy densities that road map projects. So I told you we're have to get up toward gasoline. We're talking about 2019 and 2021 getting closer to gasoline. But we don't even know what the materials are going to be. So if you
of titanium disulfide. And then when you recharge it, they have to leave again cleanly without incident, without getting stuck, make their way all the way back to the anode . Amazingly, despite just being an early prototype, Whittingham's battery came close to that 99%.
to the anode to meet with the ions. If Goodenough could find an anode that would replace lithium metal, the battery would become safe enough to leave the lab and actually power real world devices. Goodenough was so excited about the potential of his design that he reached out to battery companies across the US, the UK and Europe, but incredibly, no one was interested.
It worked safely and reliably, but Yoshino wasn't satisfied. The material he used for the anode , the polyacetylene had an extremely low density. I mean, it couldn't pack in enough lithium, so the energy density of the battery was terrible.
Instead they form a thin protective layer known as the solid electrolyte interface, or SEI. It's a kind of chemical shield protecting both the graphite anode and the electrolyte from further reactions. But crucially, lithium-ions can still slip through it.
To test it, Ruska first boiled electrons off a tungsten filament, the same kind of filament you'd find in an incandescent light bulb. He accelerated these free electrons through a positively charged anode down to his electromagnetic lens. As an electron approaches the lens, the magnetic field exerts a force on it.
a lithium battery, you drive the lithium back over into the cathode side. And that's how battery cycles. It's very simple. And this is an advanced idea that we're working on which involves different kinds of cathodes and anodes . But fundamentally it breathes. And it breathes because it takes the lithium ion and combines it with oxygen and makes lithium peroxide. The challenge there
But for months, Yoshino struggled. Obviously, since he removed lithium metal from the anode , he had to get lithium-ions from somewhere else and he couldn't figure it out. And then just as he was losing hope, on the last workday of 1982 while cleaning out his office, he stumbled upon a 1980 paper by John B. Goodenough.
This was the missing piece. He sketched out the reaction between lithium cobalt oxide and his lithium free anode , and then built a test cell using the two materials. It worked safely and reliably, but Yoshino wasn't satisfied.
from anything else. And if it burst into fireworks, then at least it's in a container. It starts around 80 degrees Celsius when the protective SEI layer on the anode starts to break down.
get you that 400 mile vehicle. I won't get through the details but it involves a different way to think about batteries. Batteries always look this way, there's a cathode and anode . And the anode and cathode are differently charged. And lithium in a lithium battery shuttle back and forth usually through a liquid. When you charge it, the lithium go over to this cathode. And when you discharge it, the lithium filters back into the anode . When you charge it back up like in
There, hydrogen ions in the lemon juice want those electrons, so they receive them and turn into hydrogen gas. You've got one side that gives up electrons, that's the anode , and you've got one that receives them, that's the cathode. - But why do you need the lemon at all?
His new chemistry delivered nearly double, a huge 2.4 volts per cell. He now had a working prototype, a metallic lithium anode on one side, a titanium disulfide cathode on the other, his new liquid electrolyte in between. There was also a thin porous separator that kept the electrodes apart, so they couldn't touch and short circuit.
Here's how it works. When you close the circuit, lithium atoms at the anode give up their electrons. Those electrons travel through the external circuit toward the cathode, generating a current that powers whatever's connected.
Lithium cobalt oxide is arranged so that the cobalt and oxygen atoms form tightly bonded layers, with lithium-ions nestled in between. This means that your supply of lithium-ions doesn't just have to come from the dangerous lithium metal on the anode side, it's already there prebuilt into the cathode. So theoretically, you don't even need lithium metal at all.
So the plastic conducts electricity like a metal. And that got Yoshino thinking, what if polyacetylene could work as a battery anode ? During charging, it could absorb lithium-ions and electrons, and then during discharge, it would give up those electrons to the circuit, just like lithium metal does.
from anything else. And if it burst into fireworks, then at least it's in a container. So that's a roll off the cathode, separates that anode .
And what happens is that the lithium begins to shuttle. The lithium leaves the cathode, goes over to the anode , leaving all that space open. And in that nanosecond when that happens, oxygen somehow is lost.
One of the things that we revealed in the book is that the most expensive component of an auto battery today is something called a separator. It's a thin sheet of plastic, very smart plastic, but something that looks like thin sheet of plastic that separates between the anode and the cathode. This intellectual property makes up about 10 to 12 percent of the cost of the battery. The IP actually belongs to Exxon Chemicals.
And this process is reversible. When you apply a voltage to recharge, the extra electrons are stripped from the titanium and pulled back to the anode . The lithium-ions are forced out of the titanium disulfide layers into the electrolyte, and they too migrate to the anode where metallic lithium reforms.
When you apply a voltage to recharge, the extra electrons are stripped from the titanium and pulled back to the anode . The lithium-ions are forced out of the titanium disulfide layers into the electrolyte, and they too migrate to the anode where metallic lithium reforms. What Whittingham had created here was a rechargeable battery, one that worked reliably cycle after cycle with incredible consistency.
What you're seeing here is a piece of copper, which we're gradually plating with lithium. So this is analogous to the first generation lithium metal batteries, which use lithium metal as the anode . On this side, we have a piece of lithium.
- And that dendrite can just keep growing, and eventually it's gonna poke through the separator and reach to the other side. Now the electrons are gonna have a shortcut, so instead of going through the circuit, they race straight from the anode to the cathode using the dendrite, and that sudden surge of electrons cause intense heating, and that can trigger a chain reaction inside the battery, leading to a fire, or even an explosion.
And now back to Goodenough's design, a breakthrough with nowhere to go, yet. While Goodenough's battery design was gathering dust, 10,000 kilometers away in Japan, a 34-year-old chemist named Akira Yoshino was trying to find a safer battery anode , one that didn't require lithium metal.
Then he dropped a heavy iron rod onto it. It exploded violently. Then he ran the same test again, but this time with his new design, using carbon as the anode . He charged the cell, placed it in the rig, and dropped the rod but nothing happened.
- But what's crazy is that even after all this, these batteries should never have worked. See, when you charge the battery for the first time, lithium-ions move from the cathode to the graphite anode . And here, they react with the electrolyte to form this weird complex patchwork of compounds that build up on the anode 's surface.
See, when you charge the battery for the first time, lithium-ions move from the cathode to the graphite anode . And here, they react with the electrolyte to form this weird complex patchwork of compounds that build up on the anode 's surface. These parasitic side reactions should keep going on indefinitely, using up all the lithium and destroying the cell but they don't.
from anything else. And if it burst into fireworks, then at least it's in a container. It's so obvious when you see it, but I don't think anyone intuitively thinks that it's a rolled up like sheet of anode and cathode inside.
from anything else. And if it burst into fireworks, then at least it's in a container. - At roughly 130 degrees Celsius, the polymer separator is gonna melt, and now the anode and cathode can come into direct contact,
And big temperature swings cause expansion and contraction of this metal, and so that can eventually break these connections. Also, inside the batteries, a liquid electrolyte solution allows lithium ions to move between the cathode and anode during charging and discharging. But if this solution freezes, JPL fears that the whole thing will stop working entirely.
this way, there's a cathode and anode . And the anode and cathode are differently charged. And lithium in a lithium battery shuttle back and forth usually through a liquid. When you charge it, the lithium go over to this cathode. And when you discharge it, the lithium filters back into the anode . When you charge it back up like in a lithium battery, you drive the lithium back over into the cathode side. And that's how battery cycles. It's very simple. And this is an advanced idea that we're working
are much more complicated than a transistor built on silicon. And so, what I have on this little patch, I applogize, it's pretty cryptic. It shows a road map for batteries. We're right down here today. We're with lithium metal oxide anodes and graphite anodes , so it would be an anode and a cathode. And this shows you by the time you get out to about 2019, we don't even know what