Study on Electrode Potential of Zinc Nickel Single-Flow Battery during Charge

In this study of zinc nickel single-flow batteries (ZNB), the ion concentration of the convection area and the electrode surface of the battery runner were investigated first. Then, the relationships between the electrode over-potential (or equilibrium potential) and the charge time were studied. This was based on the electrochemical reaction rate equation and the equilibrium potential equation, from which a mathematical model of the stack voltage (as affected by the internal parameters of the battery) was obtained. By comparison with experimental data, it was determined that the relative error of the simulated stack voltage of a 300 Ah battery was restricted to <0.62% while charging under the condition of 100 A constant-current charging. This shows that the mathematical model can accurately describe the dynamic characteristics of the battery stack voltage, and is very accurate for predicting the stack voltage of the battery during charging under 100 A constant-current charging conditions.