A high-throughput experimental approach is developed to assess the correlations between chemical composition, structure and conduction properties of inorganic solid ionic conductors. This approach covers the preparation of a large number of samples by combinatorial synthesis, followed by fast characterization of the material library. The approach is primarily based on combinatorial synthesis by magnetron co-sputtering and the characterization of thin film samples where lithium phosphorus oxynitride (LiPON) is chosen as a case study. A library of 76 LiPON materials is prepared in one experiment from the reactive co-sputtering of LiPO3 and Li3PO4 in a N2 atmosphere. A specific sample design allows conducting thickness and impedance measurements, Raman spectroscopy, then fast and spatially-resolved chemical analysis by Laser-Induced Breakdown Spectroscopy (LIBS) on each material. Particular developments are devoted to this technique to achieve quantitative analysis of lithium in thin films. The materials cover a wide range of compositions with 0.95