Granulation of nano-scale Ni(OH)2 cathode materials for high power Ni-MH batteries

Nano-scale β-Ni(OH)2 and Co(OH)2 were prepared by controlled crystallization, mixed by ball milling and granulated to form about 5μm spherical grains by spray drying granulation. The granulation significantly enhanced the electrochemical performance of nano-scale Ni(OH)2, probably because of good size matching between the active material and the electric conductor. The granulated grains of nano-scale Ni(OH)2 presented high performance at high discharge C-rate, and its specific capacity at 10C exceeded that of conventional spherical micro-scale Ni(OH)2 at 3C. The granulated nano-scale β-Ni(OH)2 is a promising cathode active material for high power Ni-MH batteries.