Abstract: High energy density, self-healing cathodes for use in solid state or quasi-solid state electrochemical cells having active metal, e.g. lithium, one or more of materials existing in the solid or liquid state at ordinary temperatures and selected from the group of oxides of phosphorous and boron, halides of phosphorous and boron chalcogenides of phosphorous and boron and oxyhalides of phosphorous and boron, said mass having induced therein a useable degree of electronic conductivity. One example of a means of including a useable amount of electronic conductivity is the inclusion in the cathode mass of a charge transfer complex of a polymer of the type of poly-2-vinyl pyridine.