Stanford Creates Battery That Turns Off When It Overheats

Researchers at Stanford University have created a new type of lithium-ion battery that has the ability to shut itself down when it gets too hot. The goal of the researchers was to build a battery that would turn itself off if it got too hot to prevent a risk of fire. Lithium-ion batteries have a long history of catching fire when they overheat.

Scores of notebook computers have caught fire due to overheating batteries and other devices like hover boards have caught fire due to overheating batteries. The new battery that the team has created is able to shutdown when it overheats and then restart when it cools to safe levels.

To create the battery, the researchers invented spiky nickel particles that were then coated with graphene, which is an atom thick layer of carbon. Those particles were then embedded in a thin film of elastic polyethylene. That film is attached to one of the battery electrodes so an electric current can flow through it.

The spiky particles in the film have to physically touch for the current to flow. When the battery gets too hot the elastic film stretches and the particles spread apart stopping the flow of electricity. When the battery is heated above 160 F the film expands like a balloon and the battery shuts down. When temps drop back to 160 F the film shrinks and the battery works again. The temperature where the battery shuts down can be controlled by adding or removing particles in the polyethylene.

SOURCE: Stanford