A method for the preparation of the nickel electrodes for galvanic accumulators, in which the pores with metal oxide or electrically conductive plates. - hydroxide be filled

摘要

1,262,342. Battery electrodes. YARDNEY INTERNATIONAL CORP. 30 Jan., 1969 [2 Feb., 1968], No. 5141/69. Heading H1B. [Also in Division C7] The pores of a porous conductive plaque, e.g. of Ni or Ni alloy are filled with nickel hydroxide by cathodically impregnating the plaque immersed with an anode, e.g. of Ni in an electrolyte bath comprising aqueous nickel nitrate solution, preferably containing between 700 and 1150 g./l. of Ni(NO 3 ) 2 .6H 2 O, and a wetting agent, e.g. " Carbowax " (Registered Trade Mark), having a pH of between 0 and 3, at at least 60‹ C., the initial current density being in excess of 1À5 A/sq. inch of the apparent area of the plaque, until the amount of nickel hydroxide in the pores is equivalent to a loading of at least 6 A hr./cu. inch. The voltage of the current supply is maintained constant relative to a Ag/AgCl reference electrode. The impregnated plaque may be soaked in a solution containing 5-45% KOH, cathodically polarized in the KOH solution, and/or anodically treated to convert the Ni(OH) 2 to a higher hydroxide. During impregnation, nitrate inside the pores is reduced to ammonia. The bath may further include Co(NO 3 ) 2 ; nitric acid may be added to maintain the pH. The plaque is suitable for use as an anode in a Ni-Cd cell or battery.