Researchers at the Chicago College of Engineering have discovered a way of preventing Lithium-Ion batteries from failing and potentially catching fire - which is good news for the e-bike industry and us customers, of course.
When an e-bike battery catches fire, it's because the battery's cathode (usually a lithium cobalt) decomposes and releases oxygen. When the oxygen mixes with the decomposed electrolyte and enough heat is involved, it causes a spontaneous combustion. The researchers discovered that applying a minute layer of graphene (measured in nanometers) over the cathode actually blocks the release of oxygen.
As well as this, the strength, durability and extremely high conductivity of graphene means that the cathode and anode of the battery will get an increased lifespan - the lower internal resistance leads to a higher long-term capacity.
The discovery has impressed beyond the e-bike world, with Tesla reportedly experimenting with the new method. Researcher Shahbazian-Yassar said: “Graphene is the ideal material for blocking the release of oxygen into the electrolyte.
“It is impermeable to oxygen, electrically conductive, flexible, and is strong enough to withstand conditions within the battery. It is only a few nanometers thick so there would be no extra mass added to the battery. Our research shows that its use in the cathode can reliably reduce the release of oxygen and could be one way that the risk for fire in these batteries — which power everything from our phones to our cars — could be significantly reduced."
Although scientists knew it existed, graphene wasn't technically discovered until 2004 when it was isolated as an atom by researchers at the University of Manchester. In its short lifespan it's already made its way onto bike frames, tyres and clothing, with the potential improvements in battery safety for e-vehicles becoming graphene's latest useful application.