Chemical Activation of Metal Hydride Electrodes

Metal hydride (Mm(NiMnCoAl)5) electrodes were chemically activated to improve their caparitiy, electrocatalytic activity, activation characteristics, and high-rate discharge ability. The influences of chemical action on the electochemical properties of metal hydride electrodes and sealed formation of Ni-MH batteries were discussed. Under the action of activator the oxide on the surface of hydrogen storage alloys were reduced and eliminated. The atomic hydrogen could penetrate into the lattice forming hydride. In addition, the specific surface area of MH electrode increased. It was found that the performances of Ni-MH batteries by sealed formation approached to those of the batteries by open formation. The discharge capacity of the AA size Ni-MH battery is about 1050 similar to 1150 mA.h. The capacities at 1C, 3C and 5C rate reach 96.7%, 89.0% and 83.8%of that at 0.2C rate respectively.