As technology tries to maintain its dizzying ascent, one dead weight has kept its altitude in check: the battery. Our chips keep getting faster and our data rates keep climbing, but at the end of the day—or worse, by mid-afternoon—those power meters on our screens inevitably turn to red. Every great device, gadget, electric car, and robot would be even greater if batteries didn’t suck so badly. Despite a steady flow of rumors that transformative breakthroughs are just around the corner, progress has moved at the pace of a tar flow.

Steven Levy is Backchannel's founder and Editor in Chief. Sign up to get Backchannel's weekly newsletter.

But earlier this month came news of a potential game changer, from no less a tech luminary than Bill Joy. A long-time investor in clean tech—for years he was involved in venture capital firm Kleiner Perkins’ ill-fated foray into “green” funding—Joy is now serving on the board of Ionic Materials, a battery-tech company in which he has invested. (His personal investment comes on top of the KP funding he oversaw; he is no longer with the venture firm.) Because of Joy’s earlier history as a legendary computer scientist—a co-founder of Sun, a co-inventor of Java, and a visionary who was working on the Internet of Things two decades ago—his views have weight, separate and apart from his financial interest in the company.

As Joy explains it, Ionic’s innovations combine the advantages of the familiar alkaline batteries we buy at the drugstore (cheap, safe, and reliable) with those of the more expensive, fire-prone lithium batteries in our computers and phones (powerful, rechargeable, and more earth-friendly). He claims Ionic’s new approach is a big step to cheaper, safer, and more efficient batteries will not only power our devices and vehicles, but also enable an “energy internet” based on renewable sources.

Joy decoded the breakthrough to Backchannel, and also followed up on his famous WIRED essay about a future techno-apocalypse. The interview is edited for space and clarity.

Steven Levy: You’ve been investing in clean technology as long as anyone. Are you saying that after all of these years, you’ve found your black swan with this new Ionic battery technology?

Bill Joy: Yeah, that’s fair. I think this is a black swan.

What’s the simplest way to describe what’s different about this approach to batteries?

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. Bad things happen with liquids. Films form, things go into [the] solution and run around and react with each other—you have safety issues like the battery catching fire. To be solid instead of liquid is something people have been striving for for 100 years. But in this battery, you have no liquid. You have just a plastic, a polymer, that replaces the liquid, so it’s solid. It’s a pretty big difference from a chemistry standpoint. 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.

Besides safety, what are the other advantages?

Right now the most desirable battery materials are ones we can’t use. 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.

You’re also saying this is going to be cheaper?

That’s another side effect of the fact that it’s not a liquid. We’ve had alkaline batteries since they were invented by Union Carbide about 1960. They use zinc and manganese dioxide. It’s always been cheap; it’s always been safe. The ingredients are abundant. It’s pretty high power, although it’s a little heavy. The only thing it hasn’t been is rechargeable. You could get 20 or 30 cycles and the thing would short out, and that’s just not going to do it for a phone or a car or most rechargeable applications. Everyone kind of gave up. To power mobile devices like camcorders, [the industry] went to lithium chemistry—to get rechargeable batteries, they gave up safety and cost, and that’s where we are now. But with the polymer, all of a sudden, the alkalines become rechargeable. Mechanisms that prevented the rechargeability don’t occur, because there’s no liquid anymore.

How did you get connected with Ionic?