US university team develops li-ion battery with inbuilt fire extinguisher
18 January 2017
Researchers from Stanford University in the USA have designed a lithium-ion battery that contains a fire-extinguishing material which is released if the battery gets too hot. The battery contains a shell containing the flame retardant triphenyl phosphate (TPP) which melts when the temperature reaches 150C, releasing the chemical compound.
Flame retardant fibre layers release TTP above 150C - Image: Stanford University
The Stanford University research team's peer-reviewed paper was published by the journal Science Advances. In tests, the team says, battery fires were extinguished in 0.4 seconds.
This methodology ensures the addition of an integrated flame retardant does not reduce the performance of the battery, a problem that affected previous attempts to develop such a capability.
Lithium-ion batteries power many devices but are a known fire hazard. A recent case involved Samsung Galaxy Note 7 smartphones, which were withdrawn at a cost of billions to the South Korean manufacturer after a number exploded or burst into flames.
If a lithium-ion battery cell charges too quickly or a manufacturing error compromises the rigidity of the device a short circuit can result, which can lead to fire.
In February 2016, the US National Transportation Safety Board issued a warning about lithium batteries in aeroplane cargo, describing them as "a fire and explosion ignition source".