Protection of sealed NiCd cells from cell voltage reversal: I. experimental conditions for the formation of cadmium bridges

A common polyamide separator, used as the electrolyte carrier in sealed Ni/Cd cells, can also function as a carrier for the Cd/Cd 2+ system, the deposition method being the same as that in the preparation of sintered Cd electrodes. A separator thus treated is suitable for sealed Ni/Cd cells. If it is cycled at least once in an excess of alkaline electrolyte prior to sealing, and if the cell capacity is limited by the positive electrode, the explosion hazard of the sealed cell due to voltage reversal can be eliminated by a proper choice of separator and cadmium loading. Cadmium bridges formed in the separator under these conditions prevent gas formation on either electrode, their properties depending on the quality of the separator and its loading with cadmium.