Safety glass inspires cheaper and lighter batteries for electric cars

Research inspired by the way safety glass breaks apart could help create safer, cheaper and lighter car batteries.

Researchers from the Materials Science and Technology Division of Oak Ridge National Laboratory in Tennessee modified the design of lithium-ion batteries, adding slits along the electrodes. The technique is designed to mimic safety glass, which is bound together to ensure it fractures into small fragments in the event of an impact rather than creating larger, sharp pieces. 

Lithium-ion batteries are “exceptionally safe”, said the team, but they can short dangerously after an impact. Adding slits should allow batteries to fragment into smaller pieces rather than completely breaking, said researcher and author Nancy Dudney.

“Sometimes the best way to help protect against a dangerous failure is to allow a component to fail or break gracefully and safely,” she said.

If widely replicated, the change means manufacturers could reduce housing materials around large batteries, cutting their weight and improving the overall energy density and cost.

The researchers tested their model against a standard battery by pressing a metal ball into each. The modified battery was heavily distorted but continued to function at 93% of its original capacity. Similar damage to the standard battery caused a full discharge and failure.

The team set out its work in the new journal Joule.

Content published by Professional Engineering does not necessarily represent the views of the Institution of Mechanical Engineers.