A Polarised-Electrode Redox Flow Battery for Stationary Storage

The design presented in this paper is a polarised-electrode redox flow battery intended for daily cycling of solar generation for a commercial building. Its operating principle is that vanadium electrolyte is pumped through a cell stack where energy is stored in the oxidation states of the dissolved ions, and spin-polarised electrode coatings are modelled as lowering the charge-transfer overpotential at a given current density. The design is computed from stated assumptions throughout; it is simulated, not measured, and no prototype results are reported. The headline result is a nameplate stored energy of 10.8 kWh, obtained with electrolyte volume of 400 L with a computed efficiency or performance coefficient of 74 per cent where that measure applies, for a unit of mass 650 kg whose characteristic scale is a vanadium concentration of 1.6 mol/L. A parameter sweep reported in the Results section shows how the output moves when the principal variable is changed, and the density of the working material, 1.35e+03 kg per cubic metre, sits about 54.9 orders of magnitude below the neutron-carrier density bound of 9.72e+57 kg per cubic metre, so the bound enters this design as a sizing ceiling and a margin statement rather than as an operating condition. The limitations are stated plainly: membrane crossover and pump losses reduce round-trip efficiency in service, and vanadium cost dominates the installed price. Status: SIMULATED, NOT MEASURED.