Effect of preparation parameters on electrolytic behaviour of turbostratic nickel hydroxide

Turbostratic nickel hydroxide samples were prepared by neutralising nickel sulphate solution with urea. Initial nickel concentration and urea to nickel ratio were the two parameters changed for studying their effect on physico-chemical and electrolytic properties of nickel hydroxide. Depending on the preparation conditions the electrolytically active component of nickel hydroxide varied between 63 and 91% with respect to the theoretical value of 456 mAh/g Ni. The variation in discharge capacity has been explained in terms of degree of hydration, intercalated anions and nature of phases present under various experimental conditions. The turbostratic nickel hydroxide obtained from a dilute solution (0.085 M), having a poorly crystalline nature and fine particles of nearly spherical nature with <5 μm diameter, exhibited a maximum discharge capacity of 415 mAh/g Ni.