Patent GB-755587-A (GB)
Title: Improvements in or relating to primary electric cells and batteries
IPC: H01M6/46
Filed: 1954-09-21
Abstract: 755,587. Batteries. BURGESS BATTERY CO. Sept. 21, 1954 [Oct. 1, 1953], No. 27269/54. Class 53. A cell of the kind that can be stacked with similar cells to form a battery has a negative electrode, Fig. 4, consisting of a zinc &c. plate 10 fixed by a ring of adhesive 13 to an insulating sheet 11 having an opening through which a conducting button 9 attached to the plate 10 projects. Covering the upper surface of plate 10 is a sheet 12 of absorbent material such as blotting paper which is fixed to the sheet 11 by a ring 14 of adhesive so that the plate 10 is enclosed in an envelope. The contact button 9 may consist of finely divided silver mixed with paraffin wax and is applied to the plate 10 while in the hot and soft condition. The positive electrode, Fig. 8, consists of a plate 16 of carbon or graphite particles mixed with a polyisobutylene or other binder or of a fabric impregnated with a carbonaceous composition and is fixed by a ring 18 of adhesive to an insulating sheet 17 having an opening through which a contact button 21 projects. The two electrodes separated by a cake of manganese dioxide and carbon are assembled to form a cell by the device shown in Fig. 9. The negative electrode is placed in a recess 30 in a jig 32 with the absorbent sheet 12 uppermost and the margins of the two sheets 11, 12 turned upwardly to extend along the interior wall of the recess the sheet 11 being then turned outwardly to lie on the upper surface of the jig. A cake 20 of depolarizer is then placed on the negative electrode. The depolarizer is moistened with a solution of ammonium chloride and zinc chloride and is soft and plastic when placed in position. The sheet 12 absorbs electrolyte from the depolarizer or it may be moistened separately. The positive electrode shown in Fig. 8 is placed on the depolarizer with the sheet 17 resting on the outwardly turned margin of the sheet 11. The elements of the cell are then pressed together by a punch 33 which causes the depolarizer to spread and fill the space enclosed by the sheets 11, 12. The upwardly folded margin of sheet 12 forms a cup which supports the depolarizer. After the pressing operation a heated tubular member 34 replaces the punch 33 at a second station to which the jig is moved. The member 34 is lowered and presses and welds together the overlapping marginal portions of sheets 11 and 17. The jig is then moved to a third station where a heated tubular knife is lowered to sever the excess portions of sheets 11, 17. The completed cell is thus enclosed in an envelope 39 having a rim 38 as shown in Fig. 11. To form the battery shown in Fig. 12 a number of cells are inserted in a casing 42 whereby the rims 38 of the cells are turned upwardly into contact with the casing wall. The casing is made of an outer layer of tough sheet material such as kraft paper and an inner layer of thermoplastic impervious material, the two layers being bonded together by a thermoplastic adhesive. The stack of cells is compressed so that the conductive buttons 9, 21 are firmly pressed together and during this operation the casing is heated so that the inner thermoplastic layer becomes welded to the rims 38 of the cells. Each end of the battery is closed by a metal tray 46 pressed against the conductive button of the end cell, the end of the casing being folded over the rim of the tray and partially covering the bottom. An insulating plate 48 is then placed in the tray with a terminal 49 in contact with the exposed portion of the tray. Specification 755,586 is referred to.