NOVELTY - An apparatus (A1) comprises a first battery cell having a negative electrode, a positive electrode, and an electrolyte structure. The negative electrode includes a lithium phosphorus oxynitride (LiPON) layer (114) covering at least a portion of the negative electrode. The positive electrode includes a cathode material and a LiPON layer covering at least a portion of the positive electrode. The electrolyte structure includes a polymer electrolyte material sandwiched between the LiPON layer of the negative electrode and the LiPON layer of the positive electrode.    USE - For making thin-film (e.g. lithium) battery useful in electronic device (claimed) e.g. cellular phone, compass, digital camera.    ADVANTAGE - The LiPON electrolyte layer serves as a hard coating on the negative electrode preventing the formation of lithium dendrites. At both electrodes, the LiPON layer also provides an improvement in environmental resistance to water vapor and oxygen, especially during manufacture before the battery is completed and otherwise sealed. The soft electrolyte layer conducts ions across the gap between hard electrolyte layers and/or fills pinholes, thin spots, and other defects in the hard electrolyte layers. The hard-soft-hard combination of electrolyte layer provides a low-cost, high-quality, high-reliability, highly rechargeable battery system.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following:    (1) preparation of thin-film batteries involving providing a first sheet containing an anode material and a LiPON layer covering the anode material; providing a second sheet containing a cathode material such as lithium and a LiPON layer covering the cathode material; and sandwiching a polymer electrolyte material between the LiPON layer covering the anode material of the first sheet and the LiPON layer covering the cathode material of the first cathode sheet; and    (2) an apparatus (A2) comprising a first sheet that includes a LiPON layer covering a first face of the first sheet; a second sheet that includes a cathode material that includes lithium and a LiPON layer covering the cathode material on a second face of the second sheet; and unit for passing lithium ions between the LiPON layer on the first face of the first sheet and the LiPON layer on the second face of the second sheet to form a first battery cell.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic cross-section view of the parallel-connected screen-cathode current-collector contact lithium-battery.    cathode material (112)    LiPON layer (114)    battery (500)    cathode current-collector contact (521)    anode current-collector contact. (522)