High temperature secondary batteries

A high temperature battery which comprises:

• a cathode composed at least partly of one of sulphur and a metal sulphide,
• an anode which contains one of an alkali metal, an alkaline earth metal, an alloy of an alkali metal and an alloy of an alkaline earth metal, the cathodic material in excess electrochemically of the anodic material, and
• disposed between the anode and cathode, an electrolyte containing at least a potassium halide, said halide selected from one of chloride, bromide and iodide, is included in each of the anode, cathode and the electrolyte, wherein the battery is a lithium aluminium iron sulphide battery with a ternary halide electrolyte, magnesia is added to the anode, cathode and electrolyte, the ratio of the weight of magnesia in the electrolyte to the weight of the electrolyte is in the range of 1:0.5 to 0.7, the ratio of the weight of lithium aluminium alloy to the weight of magnesia in the lithium aluminium alloy being 1:21, the ratio of the weight of iron sulphide to the weight of magnesia in the iron sulphide being 1:0.25.

A high temperature battery which comprises:

• a cathode composed at least partly of one of sulphur and a metal sulphide,
• an anode which contains one of an alkali metal, an alkaline earth metal, an alloy of an alkali metal and an alloy of an alkaline earth metal, the cathodic material in excess electrochemically of the anodic material, and
• disposed between the anode and cathode, an electrolyte containing at least a potassium halide, said halide selected from one of chloride, bromide and iodide, is included in each of the anode, cathode and the electrolyte, wherein lithium aluminate is added to the electrolyte.