Back in the late 70's there was an experimental Beechcraft with a 150 HP electric motor powered by a fuel cell. The fuel tanks were split by rubber diaphragms with hydrogen peroxide on the top side. This was run through the fuel cell and the hydrogen peroxide/lithium pumped from there to the lower side of the tanks. The spent "fuel" could be drained off as fresh H2O2 was pumped in and the lithium rods changed out in about the same time as it would take to fill up with avgas. You could actually be on your again a little sooner because hot starts can be a problem with the original O-360 engine. At cruising altitude, the electric motor still delivers full power, making performance better than the gas burning engine. On top of all that, the motor far outlasted the 2000 hour TBO of the gas engine and the lithium can be extracted from the H2O2, so the "spent" fuel can be recycled.
