摘要 |
1474720 Ni-Zn alkaline batteries MATSUSHITA ELECTRIC INDUSTRIAL CO Ltd 24 Dec 1974 55786/74 Heading H1B In a nickel zinc alkaline storage battery, separators comprise an electrolyte-absorbent layer 18, 19 of non-woven cellulose cloth next to the negative electrode 12, a cellulose membrane 20, 21 permeable to H<SP>+</SP> and OH<SP>-</SP> ions but not to Zn(OH) 4 <SP>--</SP> ions, and a microporous polyethylene or polypropylene film 22, 23; and the alkaline electrolyte is held in the separator, there being no excess electrolyte. 5-15 wt. per cent fine powder Ca(OH) 2 is preferably dispersed in the microporous film 22, 23. The cell is sealed and may include a gas phase reaction catalyst 24 for recombining oxygen and hydrogen evolved during charging (examples given), a pressure release safety valve 26, and an auxiliary electrode 28 for suppressing excess oxygen evolution towards the end of charging (examples given). The electrolyte is preferably 1À7-2À1 ml per Ah of negative electrode active material of 5-7 mol/l aqueous KOH; negative electrode; paste of ZnO powder and aqueous polyvinyl alcohol on a copper net. |