GB1286537A - Thermal battery - Google Patents

Abstract

1286537 Thermal battery EAGLE-PICHER INDUSTRIES Inc 21 Aug 1969 [16 Sept 1968] 41851/69 Heading HlB Short circuits are prevented in a thermal battery which uses a normally solid-state electrolyte which can be rendered molten by an internally contained heat source, by means of electrically insulative rings each arranged with a central portion encircling the periphery of the solid electrolyte between each anode and cathode couple and with integral inwardly turned spaced lips overlying a marginal edge portion on opposite sides of the electrolyte. In a preferred embodiment the insulative ring additionally encloses the peripheral edge of only one of the opposite polarity electrodes with which it is associated. In the embodiment shown the insulative ring 70, preferably of asbestos, has a U-shaped cross-section 71-73 which encloses the depolarizer 62, preferably of CaCrO 4 , Na 2 CrO 4 or K z CrO 4 , and the electrolyte 19, preferably comprising eutectic LiCI and KC1, and kaolin, of each electrochemical couple 14. Each cathode 15 has a current collector 60 preferably of Ni or steel and each anode 17 preferably comprises a sheet of Ca or Mg, 66, and a current collector 68, and the couples 14 are connected serially. Heat sources 20 preferably a mixture of powdered Fe 2 O 7 and Al are located between each couple 14, and an igniter, e.g. an electrically actuated match or percussion actuated primer is located in the cover so that when actuated an intense flame which ignites the heat sources is directed down the centre of the stacked couples via central apertures in the collectors 60, 68 and each couple 14, thereby melting the electrolyte.