Crystallographic and electrochemical characterization of TiV4-xNix alloys for nickel-metal hydride batteries

Crystallographic and electrochemical characterization of novel TiV4-xNix hydrogen storage alloys, which are body-centered cubic solid solutions of titanium in vanadium, was firstly investigated. Crystal structure of TiV4-xNix (0 less than or equal to x less than or equal to 1) alloys changed in two steps depending on the amount of absorbed hydrogen in the same manner as a V metal. In charge-discharge cycling tests, the maximum discharge capacity of the TiV4-xNix electrodes was observed to be ca. 350 mA h g(-1) at around x = 0.4-0.6 under the condition of charge and discharge current densities of 50 mA h g(-1) and operating temperature of 30 degrees C.