GB1354457A - Electro chemical cells - Google Patents

Abstract

1354457 Sealed metal cell casings ESB Inc 29 Jan 1973 4422/73 Heading H1B A cell casing comprises two metallic housing members connected, respectively, to the positive and negative electrodes, an insulating seal between the two members comprising a layer of cured epoxy-polyamide resin in wetting contact with one of the members. The seal prevents leakage of alkaline electrolyte and preferably the seal is in wetting contact with the housing member connected to the negative electrode. ÀIn the embodiment of Fig. 2 the rim of a metal closure disc 10 is coated with an uncured mixture 12 of epoxy resin and polyamide curing agent. When this mixture is applied, especially with a solvent carrier, it wets the surface of the disc 10. The mixture is allowed to cure either at ambient temperature or by heating to reduce the curing time. The wall of the metal casing part 11 is then compressed at 13 around the cured epoxy-polyamide resin. In another embodiment, Fig. 4, the metal closure disc 30 has a layer 32 of cured epoxy-polyamide on its lower surface and its rim is embraced by a plastics grommet 14 which in turn is embraced by the turned over upper edge of the metal casing part (Fig. 3, not shown). A conductor 34 is spot welded through the layer 32 to the disc. In a further embodiment, Fig. 6, the periphery of a steel closure disc 60 has a nickel coating 62 surmounted by a carbon coating 64 on which is provided the uncured mixture 66 of epoxy resin and polyamide curing agent. A nylon grommet 68 is injection moulded on the mixture whereby it is cured. Finally, the grommet 68 is gripped by the metal casing 70. In a modification of Fig. 4, a double seal is provided by a layer 82 of cured epoxy-polyamide resin on the inner surface of the metal cell casing 80, Fig. 7. A similar double seal may be provided with the embodiment of Fig. 6 (Fig. 8, not shown).