OK, so my perception may be wrong indeed.

I'm really nitpicking the theoretical aspect here, I guess. Is Lithion-ion really different from a first principle perspective? Is any battery technology not based on electrolyte principles?

See, when I look at a vapor engine, and compare it with an electrical engine, I really do have two different first principles driving motion, two different conversions of energy. When I look at a regular / convection oven (heated resistors) and compare it with a microwave oven, again two fundamentally different ways of heating a solid. Magnetic induction compared with thermodynamic heat conduction. X-ray compared with MRI. All of these are breakthroughs, using different first principles to complete the task.

I fail to see how battery technology is not all based on one and the same fundamental principle. Quoting your second link:

> “Batteries are electrochemical devices that store electrical energy by directly converting it to a chemical form.”

I'm not sure we were talking about the same thing, because your I read comment and it seems to fit my view, actually substantiates it. Am I misunderstanding these concepts?

Edit: FWIW, I was heavy daily user of portable music devices in the 1990s, and while new battery tech gave you an extra hour or so every iteration, none of it was life changing, it was a slow increment, not orders of magnitudes — a sign that we're operating on the same principles, just with more efficiency. My point was that current battery life is fantastically aided by improvements on the consumption side, much more than on the source side. I'm not claiming there's none in the latter, not at all.

Edit 2: TL;DR: I believe there is no fundamentally new physics in "battery" (storing energy), it's been the same thing for centuries (and reportedly was invented but not used in Ancient times). Unlike many other technologies like engines, ovens, body imaging, etc. Please don't hesitate to teach me more.

Batteries are always based on chemistry. But since you said that portable device batteries today are little-changed from 40 years ago, I wanted to point out that the lithium ion battery is newer than that, and still improving.

That's why cordless saws and leaf blowers are practical now but weren't practical 40 years ago. Better batteries made them work. They didn't benefit from Moore's Law.

Ah, fair point about these tools. I think I understand better what you meant. Point very well taken, and thanks for the informed perspective.