| 摘要 |
PURPOSE:To improve coulomb efficiency and energy efficiency by limiting optimum concentrations of ZnBr2 and NH4Cl in an electrolyte of a zinc-bromine battery to values lower than conventional values from a specific mutual relationship between the concentrations of the two ingredients. CONSTITUTION:While a liquid resistance is increased by reducing the amount of addition of a conductivity increasing agent NH4Cl, the liquid resistance changes little within a certain range and therefore a voltage efficiency can be maintained to a conventional value. When the concentration of NH4Cl is decreased on the other hand, the concentration of ZnBr2 can be lower than the conventional value. As the lowering of the concentration of ZnBr2 lowers the bromine solubility in the electrolyte, self-discharge between zinc decreases and coulomb efficiency increases. As a result, concentrations of ZnBr2 and NH4Cl are limited to 1.8-2.8mol/l and 1.5-3.5mol/l respectively, lower than conventional values. This improves both coulomb efficiency and energy efficiency. |
