NOVELTY - Producing a thin-film lithium battery involves providing a first sheet including a substrate; and applying layers of cathode current collector, cathode material, a separating electrolyte and anode current collector, in a sequential manner, to the substrate; where at least one of the layers contains lithiated compounds, and the configuration of the layer containing lithiated compounds is patterned by a photolithography operation, which involves removal of a photoresist material from the layer containing lithiated compounds using a wet chemical treatment.    USE - For producing a thin-film lithium battery or solid-state battery cell, useful as power supply in portable electronic devices (e.g. computers, mobile phones, tracking systems and scanners) and non-portable electrical appliances.    ADVANTAGE - The method produces thin-film lithium batteries in an efficient and economic manner, with reduced number of steps, and using less complicated equipment as compared to prior art manufacturing techniques. The method produces thin-film lithium batteries without using extra protective layers, in addition to photolithographic masking materials that can be removed using wet chemical treatments. The method enables batteries to be built on substrates similar to those used for manufacturing integrated circuit, thus making the final assembly and integration processes more straightforward and cost efficient. Both wet and dry etching are possible for the films/layers in the battery structure, and several photosensitive materials can be used for patterning the layer containing lithiated compounds. The method produces batteries having sizes of less than or equal to1 mm2 to greater than or equal to2 cm2. Batteries in such sizes give practical amounts of discharge capacity, and are economically practical for manufacturing. Batteries can be produced in square, rectangular, circular or other shapes as required by the application.    DETAILED DESCRIPTION - Producing a thin-film lithium battery involves providing a first sheet including a substrate; and applying layers of cathode current collector, cathode material, a separating electrolyte and anode current collector, in a sequential manner, to the substrate; where at least one of the layers contains lithiated compounds, and the configuration of the layer containing lithiated compounds is patterned by a photolithography operation, which involves removal of a photoresist material from the layer containing lithiated compounds using a wet chemical treatment. The layer containing lithiated compounds is preferably the layer of cathode material containing lithium cobalt oxide, or the electrolyte layer containing lithium phosphorus oxynitride. The patterning of the layer containing lithiated compounds by the photolithography operation, is preferably carried out within 72 hours of initial formation of the layer containing lithiated compounds. During the production of the thin layer lithium battery, at least two of the process steps for applying layers of cathode current collector, cathode material, electrolyte layer and anode current collector, are carried out in different processing apparatus, where the layer containing lithiated compounds is exposed to ordinary air conditions between the process steps. INDEPENDENT CLAIMS are included for the following:    (1) a method for producing lithium batteries involving providing a first sheet that includes a substrate having layers of cathode current collector, cathode material, electrolyte layer and anode current collector, in a sequential manner; performing at least one material removal operation (e.g. laser ablating operation and/or photolithography operation) for removing material through the layers of the substrate, through a first portion of the substrate but not through a second portion of the substrate, to separate several battery cells from one another, with each battery cell attached to at least a single unseparated part of the first sheet; and additionally depositing a second electrically-insulating material (e.g lithium phosphorus oxynitride or a polymer) on the sheet to cover the cells at least on their sides; and    (2) an apparatus for producing lithium batteries, comprising a source of a first sheet that includes a substrate having layers of cathode current collector, cathode material, electrolyte layer and anode current collector, in a sequential manner; and a material removal station (e.g. laser ablating station and/or photolithography station) for removing material through the layer of the substrate, through a first portion of the substrate but not through a second portion of the substrate; and additionally a deposition station for depositing a passivation material on the sheet to cover the cells at least on their sides, and a second material removal station for removing a sub-portion of the second material, to separate several cells from each other.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic cross-section view of a solid-state battery cell having photo-lithographically defined contact areas and/or layers.