I'm not knowledgeable enough to say, but there are problems with these kind of batteries overheating, especially on recharging. Pumping electricity through a material produces heat. If it has nowhere to go then you end up with a fire and toxic fumes. The solution on airplanes being to put the battery in a sealed metal box with a pipe to vent any toxic fumes to the outside of the hull.

https://en.wikipedia.org/wiki/Boeing_787_Dreamliner_battery_...