| 摘要 |
PURPOSE:To stabilize the initial cycle performance and to retain high capacity for a long time by impregnating nickel salt in a porous nickel substrate and conducting alkali treatment to fill active material, and immersing the substrate in an alkaline solution in which cobalt hydroxide is dissolved, then heating the substrate in an air atmosphere. CONSTITUTION:A nickel nitrate aqueous solution is impregnated in a sintered porous nickel substrate having a porosity of 80%. The substrate is immersed in a sodium hydroxide aqueous solution receiving alkali treatment to convert nickel nitrate into nickel hydroxide for activation, then washed and dried. After this impregnation process is repeated several times, the substrate is immersed in hot, concentrated alkaline solution obtained by dissolving cobalt hydroxide in 30% sodium hydroxide aqueous solution and heating at 80 deg.C, and heated in the air at 150 deg.C for 30 minutes. A nickel positive electrode containing 1 wt% cobalt based on nickel active material is formed. By this process, formation of gamma-NiOOH in the positive electrode is prevented. |
