Long life thin film battery and method therefor

A long-life, thin film rechargeable battery, comprising:

• a support substrate having a support surface;
• a cathode current collector spaced-apart from an anode current collector deposited on the support surface of the substrate;
• a cathode layer deposited on a portion of the cathode current collector;
• a solid electrolyte layer deposited on the cathode material, substrate and a first portion of the anode current collector;
• an anode layer deposited on the electrolyte layer, and a second portion of the anode current collector to provide a thin film battery stack;
• a planarization material applied over the thin film battery stack to provide a relatively smooth planarization layer having a surface roughness of no more than about 1.0 nanometers root mean square, and the planarization material in the planarization layer is substantially non-reactive with the anode layer;
• one or more barrier layers applied over the planarization layer, the barrier layers being selected from the group consisting of metal materials, ceramic materials, and polymeric materials;
• whereby the planarization layer and the one or more barrier layers are effective to provide a thin film battery having an extended life.