Ti-Mn alloy is one of the potential materials for the negative electrode of Ni/MH rechargeable battery because of its large hydrogen storage capacity. However, it is impossible to absorb the hydrogen electrochemically in the KOH solution because it doesn't have a catalytic element for charge transfer reaction.
Ti-Mn alloy was sintered with Ni powder to provide a catalytic effect on charge transfer reaction at the surface of Ti-Mn alloy. The sintering condition was 900℃, 25min, 100wt.% of Ni powder. After sintering, Ti-Mn alloy could absorb or desorb the hydrogen in the KOH solution. During sintering new phase such as TiNi and $TiNi_3$, was formed, which have the catalytic effect on the charge transfer reaction. As the amount of TiNi and $TiNi_3$ formed was increased, the rate capability was improved and the exchange current density was increased. Ni powder and $TiNi_3$ in the electrode can't absorb the hydrogen, which didn't contribute to the dischrage capacity of the electrode. To avoid this shortcoming of the sintering process, Ti-Mn alloy was sintered with Ni rich hydride compound ($LaNi_5$, TiNi, etc) which had catalytic effect and could absorb the hydrogen. By sintering Ti-Mn alloy with Ni rich hydride powder, Ti-Mn alloy could be hydrogenated electrochemically in KOH solution and its discharge capacity was higher than that of Ti-Mn alloy sintered with Ni powder.
For developing anode materials of Ni/MH rechargeable battery, it may be suggested for new process to use the metal hydride, by surface modification of it, which has a large storage capacity, but can't be discharge in the KOH solution.
