Low Temperature Characteristics of Hydrogen Storage Alloy LaMm-Ni4.1Al0.3Mn0.4Co0.45 for Ni-MH Batteries

Nickel hydride batteries (Ni-MH) are known of their good performance and high reliability at temperatures below 0 C, which is significantly dependent on electrolyte composition. Here we present the low temperature characteristics of pristine AB5-type alloy, LaMm-Ni4.1Al0.3Mn0.4Co0.45, determined in various alkali metal hydroxide solutions. We found that the ombination of KOH with NaOH showed a significant eect of enhancement of low temperature performance of the electrode material and diusion of hydrogen in the alloy. This 6M binary mixed NaOH/KOH electrolyte, comprising 4M KOH component and 2M NaOH component, made it possible to maintain 81.7% and 61.0% of maximum capacity at 20 C and 30 C, respectively, enhancing the hydrogen storage properties of the alloy after reheating to room temperature