Self‐Discharge Mechanism of Nickel‐Hydrogen Batteries Using Metal Hydride Anodes

The self‐discharge mechanism of nickel‐hydrogen batteries using metal hydride anodes has been investigated and discussed by dividing the capacity loss during the storage in open‐circuit conditions into two parts, i.e. , reversible and irreversible ones. The reversible capacity loss was attributed to the desorption of hydrogen from the metal hydride anode and the irreversible capacity loss to the deterioration of the hydrogen‐absorbing alloy. Microencapsulation of the alloy with a thin copper layer was found to improve the self‐discharge characteristics.