SILICA ELECTROLYTE ELEMENT FOR SECONDARY LITHIUM BATTERY

A film of linear organosilsesquioxane polymer, or "ladder" organosiloxane, coated upon the surface of an LiMn2O4 secondary battery electrode (19) and cured to a glassy layer is subjected to plasma oxidation to remove pendant organic groups comprising the coated polymer. The resulting ultrathin silica separator layer (17) is replete with minute pores which take up and retain by capillarity a typical LiCIO4 electrolyte solution. A counter-electrode (15) placed in intimate contact with the silica electrolyte element completes a secondary battery structure (10) in which lithium ions readily migrate through the electrolyte during repeated discharge/charge cycles without loss of element integrity or efficacy.