The newly invented lithium-ion battery from Stanford researchers will automatically shut off before it overheats and then restart, once it cools and there is no more risk of fire.
Accidental fires associated with lithium-ion batteries have been studied for a while now, with researchers trying to make them safer. According to Stanford News, "a typical lithium-ion battery consists of two electrodes and a liquid or gel electrolyte that carries charged particles between them. Puncturing, shorting or overcharging the battery generates heat. If the temperature reaches about 300 degrees Fahrenheit (150 degrees Celsius), the electrolyte could catch fire and trigger an explosion."
The researchers started 'the battery experiment' by coating the spiky nickel particles with graphene, an atom-thick layer of carbon, and embedding the particles in a thin film of elastic polyethylene. The polyethylene film was attached to one of the battery electrodes so that an electric current could flow through it.
When the researchers heated the battery above 160 F (70 C), the polyethylene film quickly expanded like a balloon would. This caused the spiky particles to physically separate from each other, shutting down the batter. However, as soon as the temperature dropped back down to 160 F (70 C), the polyethylene film shrunk to its previous form and the particles came back into contact, allowing the electric current to start flowing again or in other words, allowing the battery to start generating electricity all over again.
During testing, the battery shut down every time it got too hot and then quickly resumed operating when the temperature cooled. The performance of the battery was not compromised in any way. The temperature threshold can be raised or lowered, depending on requirements, which is done either by changing the number of nanoparticles on the film, or choosing a different type of polymer material.
It is quite an important break-through, as this could very well mean it is the end of that constant fear of having your laptop's (and hoverboard's, computer's or any other electronic, battery-powered device's) battery catch fire.