lithium is most definitly profitable in thousands of applications including boats, and light aircraft, now. The intercontinental heavy aircraft, and marine segment is not there yet, but there is a lot of progress bieng made every day, and every single major player in the transpotation sector is watching closely, as the chance of a disruptive battery technology de-stealthing is significant

Aircraft getting lighter as they burn off fuel is a feature. Lithium energy storage doesn’t get lighter as it discharges, meaning the aircraft doesn’t get more efficient as stored energy decreases and the landing weights/speeds are higher than a comparable fossil fueled aircraft.

I’m more hopeful that synthetic jet fuel will be a practical solution than batteries for long-range flight.

> meaning the aircraft doesn’t get more efficient as stored energy decreases

While I read that, I imagined booster packs detaching from airplanes when they reach cruise height. In my mind they look like heavy quadcopters stuck to the wings. They would cycle back to the airport for charging before assisting the next climb.

the thing with all of that obvious engineering detail, is that it is old, very old, and liquid fueled heat engines have very little room for improvement, while, electricity storage mediums, have vast potential for improvement. Solid state batteries are already bieng investigated for use as structural components, and super capacitors have the potential to weigh very little, and are only waiting for a technology that allows for higher and higher internal surface area, something that many other technologys can make use of, and is bieng sought after by many research teams. Jet A will remain Jet A, and hot section components in jet engines are more or less stuck where they are ,and the best theoretical improvements, are not large. So there is a certain inevitability about how this plays out.