Lithium-ion batteries are being used in an increasing number of portable gadgets. They are simply the best battery tech we have available today, but they aren't 100% safe. We've all seen what can happen when one of these batteries gets damaged and overheats. Typically there will be a very hot ball of flames that consumes whatever device the battery was inside.
Until we have a replacement for lithium-ion, we need a way to mitigate that risk, and Stanford University looks to have come up with the solution: a lithium-ion battery that can't overheat. And it's all thanks to a human body temperature wearable sensor, which has been tweaked for use in batteries.
The tweaked sensor takes the form of a plastic polymer containing nickel particles(Opens in a new window) that's connected to the battery electrodes. Under normal circumstances electricity is allowed to flow through the nickel particles as they are touching each other. However, if the battery heats up, the polymer expands and at a set temperature the nickel particles separate and break their link. Electricity stops flowing and the battery can't get any hotter.
The polymer is not only useful because it stops overheating, though. It also contracts as the temperature reduces. So while the battery may stop working to prevent an overheat, it will begin to work again once the temperature is back within acceptable limits. That means no expensive battery replacement for the user, unless of course the battery really is damaged and continues to try to overheat.
As the design is reliant on adding a polymer to existing battery designs, it shouldn't be very expensive to implement and mass produce. So hopefully Stanford's invention makes it into commercial batteries quickly, and keeps all our gadgets (and us) safer.
In October, researchers at the University of Cambridge developed a lithium-air battery that packs far more power into the same size pack as lithium-ion, though that design is years away from commercial mass production.
