GB1406188A - High energy density electrochemical cell - Google Patents

Abstract

1406188 Cathode for high energy density battery J C BOGUE 26 July 1973 35621/73 Heading H1B The cathode of a cell capable of delivering very high current and energy per unit weight and volume comprises a base element, e.g. of stainless steel sheet, having a sintered coating of nickelous ammonium sulphate on which is supported the cathodic active material. The coating greatly enhances the cathode activity. Preferably, the stainless steel base element is initially heated in a hydrogen atmosphere to remove surface oxides and is then sputtered in a vacuum with nickel carbide to form a thin surface coating on which the sintered coating of nickelous ammonium sulphate is subsequently formed. Fig. 20 shows a section through cells forming part of a multi-cell battery, each cell comprising a cathode base plate 113 and a magnesium anode plate 111 each plate having perforations 116 and the shape shown in Fig. 19. The plate 113 is of stainless steel having on both sides the coating of sintered nickelous ammonium sulphate and pasted on both sides with the cathodic active material 114 which enters the holes 116. The paste 114 may comprise mercuric oxide mixed with carbon black and a binder such as carboxymethyl cellulose. Fibrous separation 115 supporting the electrolyte are applied against both surfaces of the magnesium anode plate 111 and enter the holes 116 in the latter. The electrolyte may be an aqueous solution of magnesium perchlorate and lithium perchlorate. In another embodiemnt, Fig. 21, the cathode and anode are both in the form of bent strips 121, 122 entwined together. Reservetype batteries incorporating a cylinder-shaped stack of cells are described with reference to Figs. 1-13 (not shown). The cells of these batteries have cathodes as previously described. The electrolyte is contained in a frangible housing which is broken by release of a spring- biased plunger. Figs. 14, 15 show a reserve-type battery of flat rectangular-pack construction. The battery electrodes 51 are contained in a flexible plastics case 50 together with a thin frangible envelope 53 of glass containing the electrolyte. To activate the battery, metal plates 56 on a hinge 55 are folded over on to the case 50 to break the container 53.