We were talking about using batteries for mass storage of power to power the power grid; which is storage capacity. sziehr’s comment was literally “It’s how I store for the no sun periods”. Cost isn’t really the issue; it’s having the capacity to actually store the necessary power which is storage which we haven’t really advanced on.

Edit: Since you responded then immediately blocked me in a sad attempt to avoid having your points addressed I’ll just add my reply here.

Not really. Cost is an issue and a big one, but not really the main one. Or at least not the only major one. Part of the cost issue is from not simply the battery, but the inefficiency. You need way more power than what you want to store and a battery for one house would be huge. And the batteries don’t last that long.
Building fleets of battery farms across the world to store energy just isn’t really feasible and no matter how cheap you make them they simply aren’t efficient enough to deal with things like intercontinental flights.
We’ve seen this with things like California where they built 4 massive battery farms just 2 years ago and still has to utilize rolling black outs.

As to your other comment:
Being Stationary doesn’t really change the game that much. Yes it ignores the weight/size issue for planes but space is still at a premium. Maybe you live in North Dakota and have all the space in the world but I’m not sure how you expect England or Spain or India to have the space to build massive fleets of battery farms.

For your Cathode thing, cool? Not sure what you think you’re proving but the Cathode is just one part and it’s Metal Oxide, not Lithium.

And I said the minerals for batteries, not one single mineral and the sites I linked you spell it out. Focusing on Lithium is meaningless except to pretend like you’re right when you’re not.