[iams-]

In the united states the main commercial option for non-lithium batteries is Nant who is developing zinc-air batteries (but for usage alongside lithium)

Then there is Redflow out of Australia and Voltstorage in Germany.

Not sure on vanadium flow batteries

[merrymoccasin]

I worked for a vanadium flow battery startup which went out of business. Vanadium provides a higher degree of safety due to the chemistry not being flammable. The chemistry also cycles (charges and discharges) without degradation in energy storage capacity. However, vanadium flow batteries are far less energy dense, have moving parts (pumps), and a poor track record of reliability. There was a lot of interest in vanadium flow batteries when Li-Ion was way more expensive, but now that prices have plummeted (and will continue to do so) I don't see much of a future outside of certain applications.

[ggm]

Redflow is doing good targetting to telecoms for reliable power at the radio mast. Africa, Asia, Latin America rural and remote like them. They struggled to be market viable in Australia head to head with Li-ion on price but if you understand their powerbudget and want a system on standby from binary chemicals they're a good way to go. (Not a shareholder, but been following them for years)