Abstract
A model of the self‐discharge process of a nickel‐hydrogen cell is presented. The model includes three electrochemical reactions on the nickel electrode (reduction of nickel oxyhydroxide, oxidation of hydrogen, and oxidation of hydroxyl ion to form oxygen) and two electrochemical reactions on the hydrogen electrode (reduction of oxygen and oxidation of hydrogen). The self‐discharge pressure profile of the nickel‐hydrogen battery that consists of two characteristic regions is explained reasonably well with the model. The model can be used to predict the capacity retention of a nickel‐hydrogen cell during open‐circuit conditions at different temperatures. © 2000 The Electrochemical Society. All rights reserved.