ELECTROCHEMICAL STUDIES ON LANI5-XSNX METAL HYDRIDE ALLOYS

Electrochemical studies mere performed on LaNi5-xSnx with 0 less than or equal to x less than or equal to 0.5. We measured the effect of the Sn substituent on the kinetics of charge-transfer and diffusion durin g hydrogen absorption and desorption, and the cyclic lifetimes of LaNi 5-xSx electrodes in 250 mAh laboratory test cells. We report beneficia l effects of making small substitutions of Sn for Ni in LaNi, on the p erformance of the metal hydride alloy anode in terms of cyclic lifetim e, capacity, and kinetics. The optimal concentration of Sn in LaNi5-xS nx alloys for negative electrodes in alkaline rechargeable secondary c ells was found to lie in the range 0.25 less than or equal to x less t han or equal to 0.3.