A paradigm shift in energy storage technology is needed to support the transition towards the climate-neutrality set by the EU’s international commitments under the Paris Agreement, while ensuring the targets of EU’s Action Plan on Critical Raw Materials (CRMs). In this context, GREENCAP joins a multi-disciplinary consortium with 5 Universities, 1 R&D Institute, 5 companies, located in 7 European countries including Italy, Germany, France, Ireland, United Kingdom, Estonia, and Netherlands, to unlock the full potential of supercapacitors (SCs) as electrochemical energy storage systems. We will develop a CRM-free technology exhibiting a battery-like energy density (>20 Wh/kg, >16 Wh/L), together with the distinctive superior power densities and high cycle life of traditional electrochemical double layer capacitors. GREENCAP will exploit layered 2D materials, including graphene and MXenes as electrode materials, and ionic liquids (ILs) as high-voltage electrolyte. The main objectives of GREENCAP are: i) to syntheses/functionalize graphene and MXenes via facile, scalable and sustainable (CRM-free) methodologies, assuring both high surface area and ion accessibility, introducing Faradaic charge storage mechanisms, and improving their quantum capacitance; ii) to produce novel non-/ low-toxic and non-/low-flammable IL-based electrolyte with high conductivities, and a high electrochemical/thermal stability, ensuring SC operation at voltage > 3.5 V within -50°C to +100 °C temperature range, thus eliminating the need for sophisticated cooling systems; iii) to validate the novel SC technology at industrial scale by fabricating cylindrical cells at a TRL 6 while ensuring the creation/existence of the complete value chain from material to cell producers; iv) to produce a novel supercapacitor management system, enabling the full potential of the GREECAP’s SCs in high-end applications, and ensuring their integration into the circular economy.