Stanford researchers develop first self-cooling lithium-ion battery
13 Jan 2016
Researchers at Stanford University have developed the first lithium-ion battery that shuts down when it reaches higher temperatures and restarts once it had cooled.
According to the researchers, the key was implementing polyethylene film (See: New battery shuts down at high temperatures, restarts when it cools).
The researchers used graphene-coated spiky nickel particles and drawing on nanotechnology. They installed an elastic polyethylene thin film on one of the electrodes to allow the flow of current.
When the temperature reached 160 F plus, the film expanded causing the spiky particles to spread apart, thus making the film nonconductive to electricity and shutting down its system. The opposite scenario happens when the battery starts cooling, the film shrinks and the spiky particles stick together allowing electric current to pass.
To conduct electricity, the spiky particles had to physically touch one another, but during thermal expansion, polyethylene stretched. That caused the particles to spread apart, making the film non-conductive so that electricity could no longer flow through the battery.
Stanford News reported that the lithium-ion batteries were composed of two electrodes and a gel or liquid electrolyte, which served as the carrier of the charged particles.
Stanford's latest technology is therefore seen to be useful in preventing fires commonly associated with household devices powered by batteries, such as computers and hoverboards.
Research conducted earlier had also sought to address the overheating issue of batteries. Yi Cui, a Stanford engineer and the current study's co-author, invented a smart battery that signaled caution before overheating. Cui added flame retardants to the electrolyte. The technology was, however, irreversible which made the battery unusable after it had overheated.
According to commentators, the new research held the promise of faster battery performance and improved safety.
This new research, therefore, holds promise of faster battery performance and improved safety. According to Cui, in spite of a lot of effort invested, the ultimate goal was always toward battery safety.