Flexible electrolyte offers protection against battery fires

A new chewing gum-like material could help prevent lithium ion batteries catching fire, according to its inventors.

Researchers from Washington State University in the US developed the flexible material as an alternative to the hazardous liquid electrolyte commonly used in rechargeable lithium ion batteries in electronic devices, which can leak or even catch fire.

The engineers claim the material performs almost as well as standard liquid electrolytes, unlike previous experiments to create solid electrolytes, which didn’t conduct electricity well and were difficult to connect to the battery’s anode and cathode.  

Problems with lithium ion batteries are becoming increasingly well known thanks in part to several incidents of battery fire on board Boeing 787 Dreamliner, and the Civil Aviation Authority (CAA) has begun warning of the dangers of taking poorly constructed, cheap batteries onto aircraft.

Prof Katie Zong, who led the Washington researchers, said in a statement that while commercial battery makers have ways to address safety concerns, for example temperature sensors and flame retardant additives, they ‘can’t solve the safety problem fundamentally’.

The new material combines liquid electrolyte, the substance that allows ions to pass between the two sides of the battery, with solid particles of wax or a similar material. If the battery gets too hot then the material melts and breaks the circuit.

The researchers now plan to test the material in real batteries. Because the electrolyte is also flexible and lightweight, they believe it could be useful in future flexible electronic devices.

Last year, researchers at Oak Ridge National Laboratory in Tennessee detailed their attempt to create a solid electrolyte by altering the nanostructure of the material to make it more conductive, although this limited the battery’s power.