Originally Posted by
rickair7777
You can't really extinguish it, you just have to keep it cool while it discharges it's energy.
I'm splitting hairs here, but it
could be extinguished if it were cooled sufficiently. Cool it far enough that the energy dissipation is too low to permit the temperature to increase to the flashpoint of the battery or surrounding materials: no fire.
That said, I know of no airline that carries liquid nitrogen fire extinguishers.