Thin film battery and method for making same

A thin-film electrochemical cell comprising:

• a) a substrate;
• b) a first and a second electrically conductive film deposited on the surface of said substrate, said first and second films separated horizontally and said first film larger than said second film;
• c) a third film of electrically conductive material deposited over said first film;
• d) a fourth film of an electrolyte overlapping said third film to extend upon said first film and to partially extend upon said substrate separating said first and second films, said electrolyte having the composition Li.sub.x PO.sub.y Nz where x has an approximate value of 2.8, 2y=3z has an approximate value of 7.8 and z has a value between 0.16 and 0.46;
• and
• e) a fifth film of electrically conductive and chemically active material deposited over the remainder of said substrate separating said first and second films and over substantially all of said second and said fourth films, said fifth film being electrochemically stable in contact with said fourth film.