GB1423486A - Thermals battery - Google Patents

Abstract

1423486 Thermal battery YUASA BATTERY CO Ltd 5 April 1974 [14 Sept 1973] 15158/74 Heading H1B A thermal battery comprises fusible heat reservoir arranged in a stack of alternately arranged thermal cells 1 and heat-generating pellets 2 surrounded by a heat insulator 10 within a stainless steel case 11. Each cell, Fig. 2, not shown, comprises an anode layer and a cathode layer separated by a solid electrolyte layer which becomes molten when heat is applied thereto by the pellets 2. The pellets 2 are connected by a strip 6 of similar material which is ignited by a squib 7 having ignition terminals 14. To improve the discharge performance of the battery the fusible heat reservoir 4 is provided at the centre of the stack, the melting point of the reservoir, preferably 500- 600‹C, being higher than that of the cell electrolyte. Preferably, the pellets 2 adjacent the reservoir 4 have a higher calorific value than the other pellets. The discharge capacity of the cells 1 is improved by incorporating barium nitrate or lithium chromate in the electrolyte, the preferred electrolyte being a eutectic mixture of potassium chloride and lithium chloride. Heat reservoir plates 5, e.g. if steel, are provided at the stack ends. The insulator 10 may be of glass or asbestos. The cathode material of the cells may be lead chromate or calcium chromate and the anode material may be magnesium or calcium. The pellets 2 may comprise a mixture of zirconium and barium chromate.