Electrochemical energy storage is of increasing importance to allow large-scale integration of intermittent renewable sources. State-of-the-art lithium-ion batteries suffer from relevant problems, including strategic materials supply (Li), high environmental impact, high cost, low safety. Cheaper and safer batteries based on sodium-ion chemistry can answer to these issues. TRUST aims at developing new materials for next-generation, highly performing and sustainable, all-solid-state, secondary Na-ion batteries. TRUST will explore the entire value chain including: i) computationally-assisted investigation of new materials for both the electrode and the electrolyte compartments; ii) application of advanced in situ and operando characterization tools; iii) “green” fabrication of electrode/electrolyte materials; iv) their assembly to obtain a 100 mAh full-cell prototype in pouch configuration. The project is intended to start at TRL-2/3 and reach TRL-4 in 36 months, and its targets are in sound consonance with EU call HORIZON 2020. TRUST consortium joins six research units from university (UNIPV-leader, UNIMIB, UNIPD, UNIRC, POLITO) and CNR (ICMATE). Great attention will be devoted to the training of young researchers, as well as to gender balance.