cation of a metal selected from the class consisting of sodium and lithium; wherein O is a oxygen and N is nitrogen and the value for x is 1 to 3 and y is 1 to 4, ?? is 1 to 3 and ?? is 1 to 3; an electrolyte consisting essentially of an ion transport material selected from the class of materials which transport A cations or A' cations; a cathode material in intimate contact with said electrolyte,