The Secret to Better Rechargeable Batteries Is in Their Sandwich

The next wave of smartphone and car batteries could pack big power in a small size.

December 04, 2017 Ian Chaffee

Tired of your cellphone battery dying right when you really need it? USC researchers may have uncovered a secret to creating rechargeable batteries that could last longer.

Lithium-sulfur batteries are better at storing energy than the lithium-ion batteries common in today’s electronic devices. But they only can be recharged 50 to 100 times. The USC Dornsife College of Letters, Arts and Sciences’ Sri Narayan and Derek Moy found a way around that. Their “sandwich” approach could speed engineers toward smaller, longer-lasting batteries.

Narayan and Moy created a “mixed conduction membrane” (MCM), a small piece of non-porous, fabricated material placed between two layers of porous separators. Soaked in electrolytes, the MCM is sandwiched between the battery’s two electrodes.

The MCM allows the lithium ions to move and generate a current, but it also acts as a buffer to significantly reduce cycle strain over time.

In addition to their use in cell phones and computers, smaller lithium-sulfur batteries could reduce the weight of future electric vehicles.

The researchers found that the MCM extended battery life four times longer than that of lithium-sulfur batteries without it.