Solid-state lithium batteries (ssLBs) promise to significantly enhance the performance and safety compared to conventional Li-ion batteries. These characteristics are advantageous to developing battery systems that can be used for electric vehicles and off grid power systems. Whereas Li-ion batteries rely on a liquid electrolyte, ssLBs utilize solid electrodes and electrolyte, enabling lighter weight, higher energy density, safer batteries. However, faster recharge is challenging. The MASSIF project funded by Marie Skłodowska-Curie Actions programme aims to develop an artificial solid electrolyte interphase between the positive electrode and the electrolyte to reduce the interfacial resistance and optimize the ssLBs and that system can be tailored to enhance the performance of the electric vehicles.