Thermodynamic behavior of Ni–Cd and Ni–H2 batteries over wide ranges of temperatures (0–200°C), KOH concentrations (0.1–20 mol kg−1) and H2 pressure (0.1–500 bar)

For simulating the full discharged and charged states of nickel–cadmium and nickel–hydrogen batteries, thermodynamic characteristics such as the equilibrium Ee and thermoneutral ET potentials of the cells have been calculated over wide ranges of temperatures (0°–200°C), potassium hydroxide concentrations (0.1–20 mol kg−1) and hydrogen pressures (0.1–500 bar). The effects of non-ideality of the hydrogen gas phase and potassium hydroxide aqueous solution were taken into account by using available thermodynamic and experimental data. The effect of temperature, potassium hydroxide concentration, and hydrogen pressures on Ee and ET have been analyzed.