Lithium-based batteries have become extremely common and attractive due to their high capacity, low weight and long shelf life. In an effort to enhance performance while ensuring safety, lithium-based solid-state electrolytes (the charge carrying medium) made of various materials, in particular glass, have gained interest. However, preparation of thin films with the desired characteristics via a technique called sputtering has been problematic. European researchers supported by EU funding of the HI-Condelec project set out to develop solid electrolytes (glass and crystalline materials) together with the necessary thin film technology enabling very high conductivity with enhanced chemical and mechanical stability. Powerful computational tools were developed to fully investigate and characterise materials behaviour from the atomic to the glass structure scale, as properties of bulk materials have been shown to be quite different from those of thin films of the same compounds. In addition, researchers developed similar tools for investigating stability of thin film electrolytes produced by sputtering as well as the stack integration process itself. Experimental studies enabled determination of sputtering process parameters and investigation of ionic conductances in prepared materials. The HI-Condelec project team was therefore able to identify basic structure-property relationships, process parameters and conditions leading to development of novel optimal compositions and an exploitable electrolyte for micro-batteries. HI-Condelec significantly advanced understanding of properties and process parameters for producing solid-state thin film electrolytes via sputtering and produced a micro-battery electrolyte ready for up scaling. Solid thin film electrolytes hold promise for miniature energy storage devices as well as smart windows or displays, among others. Exploitation of results could have important impact on the electronics and other industries with benefits for manufacturers and consumers alike.