| 摘要 |
An accumulator plate is produced by forming a coating of black nickel hydroxide NiO(OH) on a porous Ni plate by electrolytic oxidation in a continuously circulated NaHCO3 solution at a pH of from 7.9 to 8.5 using a pulsating direct current with the Ni plate always the anode. The NaHCO3 solution may have a concentration of 80 to 135 g/l and a temperature of 50 to 70 DEG C. The pH may be maintained constant by adding CO2 as necessary. The pulsating D.C. may have a frequency of between 4 and 1/4 cycles per second and its pulses of higher current density may last for 0.2 to 1 second. It may have a square, sinusoidal or saw-tooth wave form. The maximum current density may be reduced after the electrolysis has been proceeding for some time. The porous Ni plate may contain an inner metal grid of or coated with Ni, e.g. a plate produced by a process as described in Specification 1,024,371. |
