Thanks,very important to me.
Cheapest price though for sodium bis(fluorosulfonyl)imide) looks like $75 / gram
There are other very simple stored energy solutions out there. One I heard of was a library in California. To meet their air conditioning needs they had a huge tank of purified water with coolant lines running through it that distributed to the air conditioning. During nighttime, when power was off-peak and cheaper a refrigeration unit froze the water solid. During peak power, the coolant lines circulated, slowly melting the ice and cooling the library.
Smart and cheaper.
CC