The Nickel Positive Electrode II. Semiconduction and Electrode Performance

The anodic oxidation of nickel hydroxide in pure l ithium hydroxide elec-trolytes produces an n-type semiconductor. The anodic oxidation involves l ithium migration into the active material. The beta phase is characterized at room temperature by Seebeck coefficients near--100 ~v/ ~ and electrical conductivities of 1 mho/cm. This is in contrast to the positive Seebeck co-efficient for l ithium nickelate. The nickel hydroxide positive electrode is con-sidered to involve a divalent Ni(OH)2 and a trivalent nickelate discharge and charge state. The designation beta phase was used by Tuomi (1) to describe the oxidized state without giving an explicit chemical composition formulation. Variations in the electro-chemical processing conditions can modify the beta phase structural characteristics. The beta phase, how