NOVELTY - Making a nickel hydroxide positive electrode for a battery, involves mixing a hydroxide solution and a strong oxidizing agent with nickel hydroxide at a temperature of at least 90 degrees C to produce a modified nickel hydroxide; separating the modified nickel hydroxide from a mixture; preparing an electrode mixture comprising the modified nickel-hydroxide; and incorporating the electrode mixture into a positive electrode. The nickel hydroxide is a powder comprising nickel hydroxide particles coated with a cobalt compound.    USE - For making positive electrode for galvanic battery cell (claimed); useful in zinc-nickel rechargeable battery for power tools, lawn and gardening tools, and electric vehicles (including hybrid electric vehicles).    ADVANTAGE - The cell comprising nickel hydroxide positive electrode achieves a cycle life of at least 500 cycles at high-rate discharge current, such as 15 C discharge current. Battery cells using the nickel electrodes containing modified nickel hydroxide (or other nickel compound) particles with modified surfaces provide excellent performance in multiple areas e.g. long cycle life when used in high rate applications such as power tools, lawn and gardening tools, and electric vehicles (including hybrid electric vehicles). The positive electrodes possess very high charge efficiencies even when operated at very high charging rates. The positive electrodes have a charge efficiency of at least 90 (preferably greater than or equal to 99)%, when charged at a rate of greater than or equal to 5 C. The nickel-zinc cells provide improved cycle life and electrical performance in service; and exhibit higher battery discharge voltage, higher discharge capacity, lower internal resistance, and high-rate discharge capability. In addition the positive electrodes exhibit very little swelling during cycling, which is a dramatic improvement over unmodified nickel hydroxide positive electrodes. The mechanical stability achieved with the reduced swelling reduces the capacity fade normally exhibited in cells with increasing cycle number. The method provides modified surface structure that facilitates an interfacial reaction between the nickel hydroxide and cobalt metal and/or cobalt compounds in the positive electrode to inhibit cobalt from leaving the positive electrode during contact with electrolyte; and inhibit cobalt (and zinc) compounds in the nickel hydroxide particles from dissolving into the alkaline battery electrolyte at high temperature. The positive electrodes show minimal dissolution of cobalt during cell fabrication, soaking, and cycling. The zinc oxide negative electrode comprises cobalt (less than 10 ppm). In rechargeable nickel-zinc batteries reduced cobalt migration from the positive electrode to the zinc electrode results in a significant reduction in self-discharge and therefore improved reliability. Nickel-zinc batteries show markedly improved capacity retention as they are cycled.    DETAILED DESCRIPTION - Making a nickel hydroxide positive electrode for a battery, involves mixing a hydroxide solution and a strong oxidizing agent with nickel hydroxide at a temperature of at least 90 degrees C to produce a modified nickel hydroxide; separating the modified nickel hydroxide from a mixture; preparing an electrode mixture comprising the modified nickel-hydroxide; and incorporating the electrode mixture into a positive electrode. The nickel hydroxide is a powder comprising nickel hydroxide particles coated with a cobalt compound. The method further involves mixing the nickel hydroxide with a hydroxide and a cobalt salt solution to form the nickel hydroxide particles coated with the cobalt compound. An INDEPENDENT CLAIM is included for a galvanic cell comprising a zinc oxide negative electrode; a nickel hydroxide positive electrode comprising nickel hydroxide particles having a modified surface comprising nickel in a higher oxidation state on average than is present in the bulk of the particles, and cobalt metal and/or a cobalt compound; a separator disposed between the positive electrode and the negative electrode and preventing electrical contact between the electrodes; and an electrolyte in contact with the negative electrode, the positive electrode and the separator.    DESCRIPTION OF DRAWING(S) - The figure shows a flow diagram of a nickel hydroxide stabilization process.