Development of a Pasted Nickel Electrode with High Active Material Utilization

The authors discuss the development of a high-performance and low-cost pasted nickel electrode made from a metal fiber substrate. The electrode is designed so that it exhibits active material utilization close to 100%, with an energy density as high as 170 mAh/g or 520 mAh/cm/sup 3/. This high active material utilization, even with a metal fiber substrate, which is a poor current collector compared with a conventional sintered nickel powder plaque, has been made possible by adding CoO which dissolves and precipitates on the surface of nickel hydroxide particles as {Beta}-Co(OH)/sub 2/ during standing and then is converted to CoOOH during the subsequent charging, which provides a good electrical path between the nickel hydroxide particles and the metal fiber substrate. Thus-formed CoOOH is not reduced in the subsequent discharges of the electrode and serves as a good current collector to ensure a high active material utilization throughout the life of the electrode.