In a lab just outside Boston, Tufts University professor and engineer Mike Zimmerman and his team have created what might be the next generation lithium-ion battery that will safely power our phones, cars, and more.
The key to the invention is a solid plastic electrolyte, the substance that bridges the gap between the positive and negative electrodes. In most lithium-ion batteries, the electrolyte is a liquid, and that can make them vulnerable to fire or explosion when hit or pierced. Those vulnerabilities were recently on display in the recalled Samsung Galaxy Note 7 phones, where the battery would spontaneously explode or catch fire because a corner of the battery casing was too small, bending one of the electrodes and increasing the risk of short circuits.
But Zimmerman’s battery can withstand repeated damage without risking explosion or fire. In fact, it can continue to power devices even after most of it has been chopped away.
Solid electrolytes are a holy grail of batteries, allowing for safer batteries that, in this case, can hold more charge for a given size compared with liquid electrolytes. Zimmerman’s solid plastic electrolyte prevents the formation of what are known as dendrites, or tendrils of lithium that spread from the electrode through the electrolyte and can cause dangerous short-circuits.
Zimmerman has formed a company, Ionic Materials, to continue developing and eventually commercialize the design. While the battery shows great promise, he admits that there is still work to be done before it can be used in millions of phones or electric cars. Working in his favor, though, are his production techniques, which are similar to those used in semiconductor packaging, a field with a long and successful history of delivering inexpensive and high-performance computer chips.