I’m waiting for the battery of the future, fusion-based, and that will last forever, and the size of a 9 volt battery, and which won’t ever blow up or burn up. The Chinese are working on that, along with the N.Vietnamese and Russians. And that battery is more real than the water-based battery being developed by the Chinese. MIT is also working on a sand-based battery, but, they won’t divulge any details about it, trying to keep the technology from being stolen by the Chinese.
There was a Science Fiction short story (Asimov?) written back in the 60’s I think, where an autonomous robotic space mining ship from an alien civilization landed on Earth by mistake, and landed in a junkyard.
It was supposed to find a Power Source available that would have been built by previously landed robotic ship, but all it found was an old dead battery.
So it proceeded to build a complete mining operation using just the dead battery as a power source......................