The SIMBA project aims at developing a highly cost-effective, safe, all-solid-state-battery with sodium as mobile ionic charge carrier for next generation stationary energy storage applications. Although in many ways Sodium-Ion batteries are like Lithium-ion batteries, there are still several persistent scientific and technical challenges to be addressed in understanding electrochemical processes and degradation mechanisms, electrode, solid-state electrolyte and cell manufacturing. The SIMBA project aims to solve these challenges and pave the way to market introduction.