When I worked at a lithium battery factory, we were taught to call it "out-gassing", and never to think of it as "fire". This is because a fire extinguisher would be worthless against an out-gassing battery. Just as rocket engines contain the perfect ratio of fuel to oxidizer for truly spectacular, and dangerous failures, charged batteries contain all they need to ruin your day. Smothering them in water, foam, or CO2 is not going to slow them down.
This is why you don't see many lithium batteries in steel cases anymore. They figured that the pipe bomb configuration was a bad idea.