Factors affecting the characteristics of the negative electrodes for nickel-metal hydride batteries

The effects of annealing, pulverization process and particle size on the electrode performance were examined. Annealing flattened the p–c isotherm and improved the cycle life, but decreased the maximum hydrogen absorption content of the alloy and therefore decreased the discharge capacity of the electrode. The initial discharge capacity and maximum discharge capacity of the electrode are higher by using the hydrogen desorption pulverization method. The results of different particle sizes on the characteristics of the electrodes indicated that particles between 200–300 mesh and below 500 mesh has good performance. This may be related to the charge-transfer resistance, contact resistance and other factors which determine the cycle life degradation.