Abstract: A high temperature rechargeable electrochemical cell comprises a housing in the form of a canister which is polygonal in cross-section so that it has a plurality of peripherally spaced corners. A solid electrolyte separator which is a conductor of sodium ions, separates the interior of the housing into an anode compartment containing an anode and a cathode compartment containing a cathode. The separator is tubular or cup-shaped, having a closed end and an open end, and having a plurality of peripherally spaced radially outwardly projecting ribs or lobes corresponding in number to the corners of the housing. The separator is concentrically located in the housing, with each lobe of the separator being peripherally aligned with, and projecting towards, one of said corners of the housing. Anchoring components anchoring the separator in position relative to the housing, are provided.

Abstract: A high temperature rechargeable electrochemical cell has a housing containing an anode and a cathode, and divided by a sodium ion-conducting solid electrolyte separator into an anode compartment and a cathode compartment, containing respectively molten sodium active anode material and active cathode material. The separator is tubular, having a closed end and an open end, and a plurality of circumferentially spaced radially outwardly projecting ribs or lobes. The housing is a tubular canister which is polygonal in cross-section, so that it has a plurality of circumferentially spaced corners corresponding in number to the number of lobes of the separator. The separator is concentrically located in the housing, each lobe of the separator being circumferentially aligned with, and projecting radially from the separator towards, one of said corners.

Abstract: A method of making an electrochemical cell comprises loading into the cathode compartment of a cell housing comprising an anode compartment separated from a cathode compartment by a separator which is a solid conductor of ions of alkali metal M or is a micromolecular sieve which contains alkali metal M sorbed therein; an alkali metal aluminium halide molten salt electrolyte having the formula MAlHal.sub.4 wherein M is the alkali metal of the anode and Hal is a halide; Cu as an active cathode substance; and an alkali metal halide MHal wherein M and Hal are respectively an alkali metal and a halide; thereby to make an electrochemical cell precursor.

Abstract: A method of making an electrochemical cell comprises loading into a cathode compartment of a cell housing comprising an anode compartment separated from a cathode compartment by a separator which is a solid conductor of ions of alkali metal M or is a micromolecular sieve which contains alkali metal M sorbed therein, an alkali metal aluminium halide molten salt electrolyte having the formula MAlHal.sub.4 wherein M is the alkali metal of the separator and Hal is a halide; an alkali metal halide MHal wherein M and Hal are respectively an alkali metal and a halide; a transition metal T selected from the group comprising Fe, Ni, Co, Cr, Mn and mixtures thereof, as an active cathode substance; and a current collector comprising at least one of copper, a copper-based substance, and a copper-coated substance, thereby to make an electrochemical cell precursor.

Abstract: The invention provides a cathode for an electrochemical cell, a cell incorporating the cathode, and a method of rendering the cathode resistant to a drop in capacity associated with cell cycling. The invention involves dispersing a transition metal, other than Ni, Fe, Cr, Co or Mn, in the active cathode substance, the cathode comprising an electronically conductive porous matrix impregnated with sodium aluminium halide molten salt electrolyte containing chloride ions. Said active cathode substance is an chlorinated nickel-containing substance dispersed in the matrix.