For Your Info..
 

Flying with an electric bike.. From FAA..

The short version - you can fly with an electric bike but the battery cannot fly.

Open to interpretation ..
 

Reads to me like you sit with it in your seat it burns you first..
flight crew can put you on fire out, in the seat, ,
where if it's a fire in the cargo hold everybody dies

Solid state lithium batteries should make that problem go away.