In order to meet the objectives of the European Green Deal by 2050 in the aviation sector, the transition towards H2-powered aviation is the solution with the most potential. Although hydrogen-powered aircrafts exist, the current cost of storing and using H2 as a fuel in prolonged flights make their democratization impossible. The main blocking point is the absence of viable storage systems of H2 in aircrafts considering the strict limitations in terms of weight, volume, and cost-efficiency. A sensitivity analysis shows how the economics depend on the tank’s gravimetric index (GI). Today’s technology can barely achieve 20% GI for 500kg of H2, while industry actors need at the very least 35% GI for 500kg of H2 to transition towards H2-powered aviation. OVERLEAF intends to develop a game changer Liquid Hydrogen (LH2) storage tank to enable the transition towards H2-powered aviation. Based on a disruptive design (under patent process) and leveraging innovative materials and technologies, the OVERLEAF solution is expected to boast a GI higher than 60% for 500kg of LH2, with no venting over 24h. Furthermore, the concept is an enabler for using the aircraft’s fuselage as the outer tank, allowing to seamlessly integrate the tank in the aircrafts structure. OVERLEAF will have an interdisciplinary R&D approach focusing on advance materials engineering, testing and combination at lab and at pilot scale, together with appropriate simulation of different design architectures of the hydrogen storage system. The project will be based on three distinctive phases and implemented in 7 Work Packages. The consortium includes multidisciplinary partners from 6 different EU countries and contains all the necessary expertise and know-how to carry-out all tasks needed to achieve OVERLEAF’s ambitious objective.

The core technological approach of the HYDRA project consists of using hybrid electrode technology to overcome the fundamental limits of current Li-ion battery technology in terms of energy, power, safety and cost to enter the age of generation 3b of Li ion batteries. HYDRA, taking its name from the mythological beast, will use a multi-headed integrative approach: In addition to novel material development and scale-up of components and battery cells manufacturing, assisted by modelling, HYDRA will build a synergy with strong investments by the project’s industrial partners and foster reaching and keeping a significant market share for Europe. The necessary competitiveness will be obtained by hybridizing high energy with high power materials. These materials will be implemented at the cell/electrode level, via sustainable, eco-designed scaled-up manufacture and safe electrolyte systems, demonstrated in pilot scale to TRL6, and will be ready for commercialisation 3 years after the project end. To reach this target, HYDRA mobilizes a strong industry commitment: the partners include a strong value-chain of suppliers with global competitiveness for xEV batteries and a direct liaison to the market in sectors such as automotive and maritime transport, ensuring a fast-uptake of results, with an added value of 1BN € in the next decade. Ecological and economical sustainability also keep a strong importance, as HYDRA will be performing life cycle assessments and value-chain analyses on local and global scales. All aspects from raw materials via battery cell production and end-use/market to recycling and 2nd life usage will be evaluated. The HYDRA concept uses abundant electrode materials like iron, manganese and silicon, and eliminates the use of the CRMs cobalt and natural graphite, with a net CRM reduction of >85%. The new materials will be produced in an environmentally friendly, energy-efficient manner, and using water in place of organic solvents.