GB614126A - Improvements in or relating to electric secondary batteries - Google Patents

Abstract

614,126. Batteries. VARLEY DRY ACCUMULATORS, Ltd., and FULLER, L. July 8, 1946, No. 20389. [Class 53] A layer of plastic material seals the lower end of the metal grid of one or more of the electrodes of an accumulator in which the electrodes with intervening porous separating material form a block which contains the whole of the electrolyte. Fig. 1 shows an accumulator comprising a lead container 10 carrying negative active material 11. An ebonite disc 13 rests on the bottom of the container and a layer 14 of kieselguhr or other porous separating material is applied to the surface of the active material 11. A layer of melted pitch 15 is then poured into the central cavity and the positive conductor 16 having a metal plate 19 at its lower end is lowered into position with the plate 19 embedded in the pitch 15. The positive grid consists of the conductor 16 and a number of uprights 20 connected by circular bands 21 forming a cage. Positive active material 22 is rammed into the remaining space to the height of the layer 11 and covered with additional separating material 23 and a porous ceramic disc 24 and a layer of pitch 25. The battery is fitted into a case 27 and electrolyte introduced through an opening 26. Fig. 3 shows the lower ends of electrodes of the plate type which are separated by layers 32 of aluminium oxide or silicate, kieselguhr or of glass wool sheets pasted with a rubber-kieselguhr mixture as described in Specification 537,377, [Group V]. Before the plates and separators are inserted in the container 33 a quantity of rubber latex is introduced into the container so that when the plate separator block is inserted the lower ends 32a of the separators become. impregnated with latex which after coagulation also forms rubber supports 40 beneath the plates the lower bars of which are thus protected from the action of the electrolyte. Instead of latex, melted pitch, bitumen, waxes, synthetic rubber or synthetic resins may be used and the lower margins of the plates and separators may be coated and impregnated with the sealing composition before insertion in the container. Specification 561,056 also is referred to.