A quick idea.
From evolutionary standpoint the universe needs to be optimized for life in order for life to exist this long. Taken this conclusion to use. Then water technology is as essential as water.
Therefor it should not be a surprise if water technology is to be used in batteries as it is probably invented by civilizations and something that can keep them going.
So my guess is that water filtering techniques be it water or some other liquid is essential to ?super batteries.