Electric accumulator with a solid electrolyte

In an electric accumulator comprising an anode compartment containing an anode formed from at least one metal selected from the group consisting of metals belonging to Groups Ia, IIa, IIb and IIIb of the periodic table of elements;

• a cathode compartment containing a cathode formed at least partly from a transition metal, and an electrolyte which is maintained in a molten state;
• the anode compartment and cathode compartment being separated from each other by a wall impervious to fluids and formed from sodium beta aluminate;
• the improvement consisting in that the anode compartment contains a porous matrix adjacent said anode and at least one anode metal salt having a melting point not exceeding about 200.degree. C and being selected from the group consisting of compounds of the general formulas:
• Me(B R.sub.4).sub.n, Me(Al R.sub.4).sub.n, Me(B R.sub.3 H).sub.n, Me(Al R.sub.3 H).sub.n and Me Al X.sub.4 (in which Me represents a metal selected from the group consisting of metals belonging to Groups Ia, IIa, IIb and IIIb of the periodic table of elements, R represents an alkyl or aryl group and n is 1, 2 or 3, according to the valency of the metal Me and X is a halogen atoms) and mixtures of at least two of these compounds, said salt being maintained in a molten state and permeating said porous matrix;
• the electrolyte being selected from the group consisting of the same group as the anode metal salt and the eutectic mixture NaCl-AlCl.sub.3.