Sodium-ion batteries offer enhanced cost-effectiveness and sustainability, challenging the dominance of lithium batteries in the stationary energy storage sector. The SPRINT project will gather 8 industries, 2 SMEs and 8 academic partners (incl. one associated partner) for 46 months to optimise and demonstrate two sustainable, techno-economically viable and safe quasi-solid-state sodium-ion batteries better meeting the requirements of stationary energy storage applications. This will be achieved relying on abundant, non-toxic, safe, and competitive materials available in EU supply chains brought to scale within SPRINT, i.e. optimised NFP cathode materials relying on novel synthesis; hard-carbon materials derived from a validated forest residues supply chain in Northern Europe; and quasi-solid-state polymer and polymer composite electrolytes with a solvent-free synthesis, and which are major advancements vs. flammable liquid electrolytes. Strategic interface optimisations will be leveraged to meet end-users’ requirements in terms of cells’ cycle life. SPRINT also aims to bring to scale dry electrode processing (incl. using PFAS-free binders) to enhance the sustainability of battery manufacturing. Batteries encompassing such solutions will be demonstrated on two demonstration sites in Austria (portfolio hybridisation, balancing services) and Lithuania (residential PV, increased grid capacity for EV chargers), and SPRINT will also engage with international use-case providers (e.g. Morrocco, Tunisia, Kenya, Sierra Leone, etc.). All in all, it is foreseen that SPRINT will reduce costs (0.04€/kWh/cycle), enhance energy density (>200Wh/kg & >420Wh/L) and power metrics (>500 W/kg), improve cells' cycle life (projected >5,000 cycles), while ensuring safe operation (leak-free technology) for a high market penetration. The Consortium will accompany all solutions to commercialisation, supported by the created Exploitation Board to facilitate their uptake.