A vanadium one, which (as mentioned in the piece) is symmetric.
The 'Just Have a Think' channel did a video on the Swiss battery here - https://www.youtube.com/watch?v=CPAFeTvjVzY
The advantage of vanadium batteries, as I understand it, is that leakage does not corrupt the system. The vanadium gets converted to the right chemical species on either side.
The advantage of vanadium batteries, as I understand it, is that leakage does not corrupt the system. The vanadium gets converted to the right chemical species on either side.