Yeah! The thing about flow batteries is that if we manage to find good chemistries, they have the potential to be very cheap energy storage compared to ordinary batteries. High energy, low power, low cost.

Ie the small electrodes cost something but the big bag of fluid might be cheap.

Say, vitamin- like substances consisting of extremely common elements like hydrogen, oxygen, nitrogen, carbon etc could be used to store energy in a flow battery. Even with quite low performance, they could be very cheap compared to things like cobalt, nickel, manganese or lithium.

Or what about quinones? And sodium, sulphur, sodium are cheap too. There are a lot of very cheap chemistries that could be explored!