Thermal batteries using cathode-precursor pyrotechnic pellets

A thermal battery which comprises a number of stacked cells, each cell consisting essentially of an anode with a lithium compound, a lithium free pyrotechnic heat source pellet which includes a cathode precursor and an all lithium electrolyte layer separating between the anode and the pyrotechnic heat source pellet. Upon ignition of the heat source, an oxide of the cathode precursor is obtained which is lithiated by the lithium supplied by the all lithium electrolyte ion source.