ELEKTROCHEMISCHE ZELLE

摘要

A method of making a precursor for an electrochemical cell, comprises loading into a cathode compartment of a cell housing an alkali metal aluminium halide molten salt electrolyte having the formula MAlHal4 an active cathode substance which comprises a transition metal T selected from the group comprising Fe, Ni, Co, Cr, Cu, Mn and mixtures thereof; and as an additive, at least one further substance, X, with X being capable, of reacting at a voltage lower than the voltage required to charge the cell according to the cathode compartment reaction 2MHal+T@@2M+THal2 (1> to generate alkali metal in the anode compartment such that, after substantially all the substance X has reacted, a cell in discharged state results. The additive X is compatible with the molten salt electrolyte, the separator and the active cathode substance. When the substance, X, is an element, it is (a) not Al or Zn, or a mixture of Al and Zn, and (b) not selected from the d-block transition elements of the periodic table of elements, apart from Group IIIB elements and the lanthanides. When the substance, X, is a compound of the formula GxZ where G is an alkali metal, Z an anion and x the valency of Z, then (a) X is selected such that it will not precipitate MHal from the MAlHal4 melts, and (b) X is not a M halide, such as MF; a pseudohalide, such as MCN; M2O or M2CO3.