The market is too small even if the tech is there. Lithium batteries aren't lucrative until you have enough of a kind to build. Somebody will probably build a gas outboard that has no problems with the new fuels. Truth is that's the thing most inflatable owners want and the thing the OB manufacturers are good at.

You want to buy an OB that will perform without problems as long as the inflatable will do the same, I would guess.