Electrochemical cell

A high temperature rechargeable electrochemical cell comprising a cell housing divided by a pair of solid electrolyte separator tubes into two anode compartments each containing alkali metal active anode material, the alkali metal in each anode compartment being electronically connected to the alkali metal in the other anode compartment, and a cathode compartment sandwiched between the anode compartments, the cathode compartment containing cathode material, the cell having an operating temperature at which the alkali metal active anode material is molten, the housing and each separator tube being hollow and tubular in shape and being arranged so that the housing is outermost, a larger of the separator tubes nests within the housing and a smaller of the separator tubes nests within said larger separator tube, an inner of said anode compartments being defined by the interior of the smaller separator tube, the cathode compartment being defined between the separator tubes and an outer of said anode compartments being defined between the larger separator tube and the housing, the cell having an anode comprising the active anode material contained in both anode compartments and the cell having a cathode comprising the cathode material contained in the cathode compartment, the cell further comprising a cathode current collector which is a tube and nests within the larger separator tube with the smaller separator tube nesting within the cathode current collector tube, so that an inner part of the cathode is located between the smaller separator tube and the current collector tube and so that an outer part of the cathode is located between the cathode current collector tube and the larger separator tube, the cathode material comprising a porous electrolyte-permeable electronically conductive matrix and having a charged state in which it has a transition metal halide active cathode material dispersed in finely divided and/or thin layer solid form in the porous interior thereof the matrix being impregnated with an alkali metal aluminum halide molten salt electrolyte having an aluminium:alkali metal atomic ratio of at most 1:1 and being molten at the cell operating temperature:

• and the parts of the cathode compartment containing the inner and outer parts of the cathode being in fluid flow communication with each other.