High energy density nickel-metal hydride battery using highly functional active materials for positive and negative electrodes

摘要

New active materials were investigated to improve the capabilities of nickel-metal hydride batteries.The use of nickel hydroxide modified with a highly conductive cobalt compound containing sodium as a positive active material led to a remarkable increase in the active material utilization. Furthermore, the addition of Y{sub}2O{sub}3 to the positiveelectrode contributed to a further increase in active material utilization due to an increase in charge acceptance.The high hydrogen capacity and cycle life of a hydrogen absorbing alloy as a negative active material increased with the introduction of a rapid quenching and annealing process. These effects were attributed to the homogeneity of composition and themicro-structure of the alloy.Newly designed cells using these active materials exhibit a 300/1 higher discharge capacity than cells not using them.