Boeing claims to have eliminated the risk of combustion, but not ignition.
If combustion occurs within a battery, says Boeing, it would be snuffed out in a microsecond for lack of oxygen.
It was “vaporized electrolyte which looks like smoke but is not the result of combustion.”
early 15c., from Old French combustion (13c.), from Latin combustionem (nominative combustio) "a burning," noun of action from past participle stem of Latin comburere "to burn up, consume," from com-, intensive prefix (see com-), + *burere, faulty separation of amburere "to burn around," actually ambi-urere, from urere "to burn, singe," from PIE root *eus- "to burn" (see ember).
combustion com·bus·tion (kəm-bŭs'chən)
The process of burning.
A chemical change, especially oxidation, accompanied by the production of heat and light.