Dry solid polymer electrolytes on the basis of poly (ethylene oxide) are one of the most promising membranes to enable Lithium-ion batteries with solid organic-inorganic hybrid electrolytes. Crucial for their success is the oxidation stability of the PEO at the cathode interface as well as the internal interface resistance between PEO and the ceramic (Li7-xLa3Zr2-xTaxO12) in the hybrid electrolyte. For both cases the exact knowledge of the interface formation like occurring reactions and the formation of electrical double layers are inevitable, but not accessible via post mortem analysis. Therefore, this work will provide a new approach to study PEO+LiTFSI interfaces between LiCoO2 cathodes, ceramic Garnet electrolytes and Lithium metal anodes on basis of the surface science approach. Due to their soft nature, it is impossible to deposit ceramics on polymers at elevated temperatures or by using plasma deposition techniques like sputtering. Therefore, it is necessary to deposit the polymer and the salt thin film on top of the ceramic cathode. Conventional processes outside the vacuum like spin coating are accompanied by a large number of contaminations and due to this a new thermal evaporation process under ultra-high vacuum conditions for PEO on basis of its oligomer PEG 2000 g/mol together with LiTFSI is established. With a direct deposition on top the substrates and subsequent analysis by photoelectron spectroscopy inside the cluster tool the interface formation process can be studied. Additional techniques like differential scanning calorimetry, thermo-gravimetric analysis, mass spectroscopy and scanning electron microscopy are used to ensure that the physical properties of the PEG + LiTFSI thin films are identical to their PEO bulk membrane counterpart. Additionally, LiF coatings on top of LLZ(T)O are introduced and their influence on the interface resistance systematically studied. Furthermore, the 2D coating process is expanded by the use of a vibrational stage inside the deposition chamber to enable the coating of 3D particle systems. All relevant interfaces of the model cell LiCoO2/PEG+LiTFSI/LLZ(T)O (+LiF)/Lithium are discussed on the basis of the XPS results like detected reaction products and the formation of space charge layers. In particular of interest is the origin and the influence on the interface resistance. The key points of the discussion are the possibility of electron and Li+-ion transfer along the interface as well as the appearance of parasitic states inside the band gap and resulting from this the possible oxidation and reduction reactions.