Flow battery

A flow battery is a storage component that works somewhat like a fuel cell: its active materials are liquid electrolytes kept in tanks outside the reactor. In use, the electrolytes move back and forth between the reactor and the storage tanks, so the system relies on pumps, other fluid handling equipment and flow controls. Two commercial types exist: zinc bromine and vanadium redox. A vanadium redox battery holds vanadium salts in a sulfuric acid electrolyte, and charging or discharging changes the oxidation state of the vanadium. In a zinc bromine battery, charging stores energy as zinc metal in the cell and as polybromide in the cathode reservoir. On discharge the zinc is oxidized and the bromine is reduced to bromide. During maintenance, wear the right protection when handling or topping up electrolyte, and watch for exposed pump parts or fans that are missing their guards.

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• sentence 2: support check: partial - The passages say the electrolytes are transferred between reactor and tanks, and they list 706.43 Flow Controls and 706.44 Pumps and Other Fluid Handling Equipment. They do not say the electrolytes move back and forth, or that the system relies on those items.
• sentence 5: support check: partial - The passages mention corrosive electrolyte handling and replenishing during maintenance, and missing guards on pump parts and fans. The PPE instruction appears only for vented lead-acid batteries, not flow batteries, and the guard point is a hazard under abnormal conditions, not a maintenance instruction. -->