A new start-up backed by the credibility (and capital) of Bill Joy, the first-generation Silicon Valley entrepreneur who helped invent the Java programming language and co-founded Sun Microsystems Inc., is claiming to have achieved the first fundamental change in battery construction in decades.
Tech breakthroughs are a dime a dozen, and in battery tech they can be especially exotic, from hot salt storage to designs that claim to pull carbon from the atmosphere. Many breakthroughs fizzle. But Ionic Materials Inc. has been turning heads lately with its promise of a new generation of more powerful, more stable, cheaper electricity storage.
The key difference: Ionic’s batteries are based on a physical solid, rather than a physical liquid. While it may not be apparent to most users, current batteries, whether lead-acid varieties to start motors, alkaline cylinders in flashlights, or lithium-ion cells in electric cars, are all essentially variants of the same design concept using different materials. They all depend on a liquid medium to allow electrons to move from one pole of a battery to the other, creating current.
As Joy explained in an interview with Wired: “In a normal battery, you have some ingredients, like lithium or alkaline, and a separator, like a piece of cloth that you put between them. Then you pour in a liquid so that the ions can move around.” But as Joy also notes, “bad things happen with liquids. Films form. You have safety issues like the battery catching fire.”
Ionic Materials’ claimed breakthrough is to have replaced the liquid with a solid polymer. “To be solid instead of liquid is something people have been striving for for 100 years,” Joy said. “In this battery, you have no liquid. You have just a plastic, a polymer, that replaces the liquid, so it’s solid. It also turns out that this polymer just happens to be essentially a fire-retardant material. So when you build batteries with this polymer, you don’t have a safety problem.”
In addition to being nearly indestructible (Bloomberg reports the company has been testing prototype units by piercing them with nails and shooting bullets at them), the solid-state batteries allow more imaginative use of existing materials, Joy asserted.
“Right now, the most desirable battery materials are ones we can’t use,” the inventor tells Wired. “For example, there are very desirable materials for lithium batteries that would give them more capacity, but they’re not safe in a liquid. Basically, all of a sudden, maybe a half-dozen things that people have been trying to do with lithium batteries that weren’t possible, are possible. You can make better lithium batteries.” Joy believes the new solid matrix will also make cheap alkaline batteries rechargeable for the first time.
The company envisions the first batteries based on its technology coming to market “within two to three years,” according to CEO Mike Zimmerman, and aims to achieve a price as low as US$30 per kilowatt-hour by 2022. That, Bloomberg drily notes, would be “significantly below the current $273 volume-weighted average cost of lithium-ion battery packs.”