Advanced high-performance Generation 4a, 4b (solid-state) Li-ion batteries supporting electro mobility and other applications (Batteries Partnership) The overarching R&I challenges lie in the development of solid-state electrolytes, cathode materials and anode materials enabling higher thermal and electrochemical stability while targeting higher energy / power densities, fast charging, cyclability and improved safety. These new materials should contribute in the control of thermal runaway at early stage, and create non-propagation designs. Developments should range from using conventional materials to using Li metal-based anode materials, aiming at reducing the amount of cobalt used in the production in addition to the other expected outcomes listed above. Projects should be aligned with ongoing H2020 projects on the subject, especially from H2020-LC-BAT-2020 call and their publicly-available results.For Generation 4a (solid state with conventional materials) projects are expected to cover all bullets: Developing low direct current resistance active materials; Reducing thickness of the anode; Developing thin solid electrolyte with high ionic conductivity; Developing concepts/strategies for manufacturing new solid electrolyte interlayers; Improving interface design to ensure efficient charge-transfer and electrochemical stability and improved cell mechanical stability; Proposed approach is expected to have no negative impact on energy densities, safety, and cyclability; Development of coating strategies for current collectors. For Generation 4b (solid state with Li metal-based anode materials) projects are expected to cover one or several bullets: New materials and/or chemistries to increase the energy densities beyond the state of the art of batteries used in electro mobility applications. At the anode side, lithium metal appears as the most appealing choice in terms of gravimetric energy density. Improved reversibility, homogeneity and density of electrodeposition process by doping or coating strategies. Solutions for manufacturing and handling Li metal sheet in dry atmosphere. Novel solutions for low cost manufacturing strategies such as solvent-free electrode manufacturing and solid electrolyte deposition. Another technology (anode-less), could also be developed by designing current collectors for reversible electrodeposition of lithium. Current collector coating strategies which regulate lithium deposition and improve cycling performance can also be developed. Solid-state electrolytes and lithium metal anodes open the way to new cathode chemistries reaching high energy density such as lithium-free cathode in combination with lithium metal or Li-excess cathode exhibiting high irreversible capacity in the anode-less configuration. Improving interface design to ensure efficient charge-transfer and electromechanical stability and improved cell mechanical stability. Bipolar cell design concepts and processing. This topic implements the co-programmed European Partnership on ‘Towards a competitive European industrial battery value chain for stationary applications and e-mobility’.