IN-SITU ELECTROLYTE PREPARATION IN FLOW BATTERY

A method of in-situ electrolyte preparation in a flow battery includes providing a vanadium-based electrolyte solution having vanadium ions of predominantly vanadium V to a first electrode and a second electrode of at least one cell of a flow battery. The vanadium V at the first electrode is converted to vanadium V and the vanadium V at the second electrode is converted to vanadium V by providing electrical energy to the electrodes. A reducing agent is then provided to the vanadium V at the second electrode to reduce the V to vanadium V. The vanadium V at the first electrode is then converted to vanadium V and the vanadium V at the second electrode is then converted to vanadium V by providing electrical energy to the electrodes. A simple method to produce predominantly vanadium V electrolyte from a V source, such as VO, is also taught.