New window into problems with lithium batteries

Michigan have found a new way of observing a phenomenon that can be problematic to next-generation lithium batteries.

The researchers at the University of Michigan have fashioned an aperture in a battery to observe the growth of dendrites, which are whiskers of lithium that grow inside batteries and can cause fires.

Lithium sulphur and lithium air batteries — which are sometimes referred to as lithium metal batteries due to their all-metal electrodes — have the potential to store 10 times more energy in the same space as current lithium ion batteries.

However, their all-metal electrodes are prone to forming dendrites, which reduce a battery's performance, raise safety concerns and cut short its lifetime.

While dendrites are widely known to be a problem in lithium metal batteries, which aren't yet on the market, their role in causing problems in current commercially available lithium ion batteries is less understood.

"As researchers try to cram more and more energy in the same amount of space, morphology problems like dendrites become major challenges. While we don't fully know why the Note 7s exploded, dendrites make bad things like that happen," said Kevin Wood, a postdoctoral researcher in mechanical engineering who helped develop the battery window.