Journal of Power Sources, Vol.114, No.2, 352-356, 2003
Investigation of MmFe(2) electrode for nickel-metal hydride battery applications
An electrochemical investigation is made on a Mischmetal-iron (MmFe(2)) alloy for its suitability as an electrode for nickel-metal hydride (Ni-MH) batteries. Change-discharge characteristics, kinetics and life-cycle are studied. The charging capacity is around 350 mAh g(-1), which corresponds to a hydrogen concentration of 2.62 hydrogen atoms per formula unit and 25 activation cycles are required to attain the maximum capacity. Studies with the ac impedance method show that the kinetics are controlled by the charge-transfer mechanism. The MmFe(2) electrode can withstand prolonged charge-discharge with no deterioration in performance and high-rate capacity.