Theoretical Analysis of the Discharge Performance of a NiOOH / H 2 Cell

A mathematical model is presented for the discharge of a NiOOH/H2 cell. This model includes diffusion and migration in the electrolyte phase as well as proton diffusion and ohmic drop across the solid active material in the porous nickel electrode. A theoretical analysis of the cell performance is presented for different design parameters using this model. It is predicted that proton diffusion in the solid active material is the main factor in limiting the cell voltage and the utilization of the active material. It is also predicted that use of a thick nickel electrode is an effective method for increasing electrode capacity per unit area. This model can be used to predict the two-discharge-plateau behavior of a nickel electrode.