Coated cathode current collector in alkali metal aluminium halide high temperature storage cell

In a high temperature electrochemical power storage cell (10) which has a cathode compartment containing a molten alkali metal aluminium halide molten salt electrolyte and a cathode which comprises an electronically conductive electrolyte-permeable porous matrix (26), the matrix having dispersed therein, an active cathode substance Thal2 in which Hal is the halide of the electrolyte and T is a transition metal selected from Fe, Ni, Co, Cr, Mn and mixtures thereof, the matrix being impregnated with said molten electrolyte, the matrix comprises the transition metal T of the active cathode substance in porous form and the cathode includes, embedded in the matrix, a metallic current collector (22) having a coating (30) thereon which is chemically and electrochemically inert in the cell environment and is electronically conductive, the metal of the current collector being no more noble than any transition metal of the active cathode substance. Halogenation of the current collector upon charging is avoided by the provision of the coating, enabling e.g. a nickel rather than an expensive, more noble metal, to be used as the current collector when the active metal of the cathode is nickel.