I used battery equipment for over 20 years in an underground environment on track haulage, ...
.... If any industry needs and requires better, stronger, lighter, faster to charge, cheaper, efficient batteries, it is the underground mining industry. ...
A bit of a sidetrack here, but I recently saw a Shark Tank episode where Pat Boone and another guy were trying to pitch a car that 'runs on air'. Of course it is only
propelled by (compressed) air, it 'runs' on the energy that was used to compress the air, which is done by an electric motor at a 'charging station' and, since they were marketing these in Hawaii, most of that electricity is being generated by burning oil, and since there are inefficiencies all along the way , the 'air car' is very likely burning more oil than the average mid-size car (and the air car was a tiny clown-car style)!
But of course, there were many supporting comments on the web, many of them touting the brilliance of this 'new invention' (that the oil companies will buy up and bury in the desert or some other tin-foil talk!)!
Turns out their pitch was just licensing the MDI 'product', which was supposed to come to market just about every year since 2000. You can google MDI and air car for more.
But to your comment, reading more on the history of compressed air, compressed air vehicles have been in use in mining operations since the mid-late 1800's. So much for this 'new invention'! For mines, I guess the compressed air provided the advantage of no harmful exhaust, and no combustion. But it is inefficient (largely because you lose much of the heat during compression - that is wasted), so won't replace alternatives except in these niche applications.
But a lot of non-technical people sure were impressed! It runs on air! Crush the big, bad oil companies!
A LOT of money is and has been spent on battery technology since the 80's, and has little to show for it.
Seems to me that battery progress has been steady, but mainly in the lithium area, and it sounds like lithium was not used in mining, due to cost or safety?
So maybe what you are saying is that lead-acid batteries have not improved much? I guess I'd agree. A company in Peoria (former Caterpillar employees), were developing a lead-acid with some kind of carbon foam plates to replace the heavy lead plates. Was said to improve battery characteristics, and reduce weight. But of course there were some obstacles to overcome to get into production. IIRC, their goal was to replace both anode and cathode, I think one was easier (but far less total benefit), but I think they got some military contracts based on that first step.
Here they are: Firefly -
History Of Innovation | Firefly International Energy
-ERD50