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 5 μm 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 10 C exceeded that of conventional spherical micro-scale Ni(OH)2 at 3 C. The granulated nano-scale β-Ni(OH)2 is a promising cathode active material for high power Ni-MH batteries.