It used to be hydrogen when charging lead acid batteries, for example. NiMH also produces hydrogen once they are full, but that is internally converted back to water via a catalyst (hence they can be charged at 1/10 forever with only getting warm).
Not sure which chemistry would produce hydrogen during a thermal runaway event.
It used to be hydrogen when charging lead acid batteries, for example. NiMH also produces hydrogen once they are full, but that is internally converted back to water via a catalyst (hence they can be charged at 1/10 forever with only getting warm).
Not sure which chemistry would produce hydrogen during a thermal runaway event.