Berkeley Startup Develops Ultra-Thin Printable Rechargeable Batteries

A startup out of UC Berkley has developed an ultra-thin, flexible, rechargeable battery that can be printed using conventional screen printing technology. Imprint Energy has developed an innovative new battery technology, ZincPoly, which drops the traditional battery electrolyte in order to use stable zinc for a cheap and non-toxic alternative to lithium.

“A lot of these batteries need a lot of plastic housing or metal housing,” Imprint Energy CEO Christine Ho told MIT Technology Review. “They need protective circuitry. Because you’re doing everything you can to tame a very, very wild and reactive system. What’s interesting about Imprint’s approach is we’re using an inherently more stable chemistry that doesn’t need that hermetic sealing. [That results in] the packaging being much more simplistic and thinner. What’s nice about zinc batteries is the materials are really cost-effective and easy to acquire. They’re also nontoxic.”

Zinc is often eschewed in battery manufacture as it usually relies on a corrosive water-based electrolyte and, as such, is not rechargeable. Imprint Energy’s ZincPoly technology, though, removes the electrolyte and instead utilises a complementary layer array.

“Batteries are stacked; they look like a stacked sandwich,” Ho explains. “The middle layer, like the jelly in the jelly sandwich, is called the electrolyte. What I realized was that if we eliminated that and replaced it with something that is stable with the zinc system and rechargeable, we could open up a whole new market space. I looked at lots of different materials, literally throwing everything in a bucket and hoping that it worked. We started to get some really interesting results with one of these material sets we were looking at. We could basically take this material and cast it into a solid film. So you could cut it, you could stretch it and whatnot, but inside it had ions that moved.”

The thin, flexible batteries are designed for use in wearable tech and on-body applications, and similar technology could be used in the next generation of flexible smartphones.