Bordeaux, September 10, 2025
The European project L.I.M.E. (Lithium-based Innovation for Modular Energy) has officially launched under the umbrella of Europe’s Clean Aviation program, with a €5 million grant awarded to the consortium led by Exoes, Ascendance Flight Technologies, Basquevolt, and RWTH Aachen University. This recognition reflects strong support from major aircraft manufacturers including Airbus, ATR, and Daher.
The L.I.M.E. (Lithium-based Innovation for Modular Energy) project aims to develop a next-generation battery system for an ultra-efficient hybrid-electric aircraft concept. The system will be designed to meet CS-23 and CS-25 certification standards, with a focus on safety, modularity, and integration into future hybrid-electric propulsion architectures.
This initiative is part of Clean Aviation’s broader mission to accelerate the decarbonization of air transport and contribute to the European Union’s climate goals.
The project addresses six key objectives for the aerospace industry:
- Safety & End-User-Centric Design: Design a battery system that meets stringent certification standards and user requirements for aviation, especially CS25 applications.
- Disruptive Battery Innovation: Push the boundaries of current technology with a battery system surpassing existing capabilities in cell technology, thermal management, and composite casing.
- TRL4 Prototyping: Manufacture and test a TRL4 prototype including cell blocks, battery management, and thermal systems, followed by ground demonstrations.
- Digital Twin Agility: Utilize high-fidelity digital twins to optimize development, reduce costs, and minimize physical prototyping, ensuring rapid design validation.
- Roadmap to Entry Into Service: Support integration studies and create an industrialization plan to prepare the battery system for service in regional aircrafts, specifically targeting the ATR 42/72 for entry into service by 2035.
- Maximize European Impact: Advance critical aviation technology to benefit European society, economy, and competitiveness by disseminating research and results widely
Exoes, a French company specializing in high-voltage battery systems, thermal management and hazardous testing, is responsible for the design, prototyping, and testing of the cell blocks. The company brings its expertise in high-performance battery and cooling technologies and system integration to ensure performance, safety, and certification readiness.
About Exoes
Founded in 2009, Exoes is a French company specializing in the design, prototyping, and testing of advanced battery systems for sustainable mobility. With deep expertise in HV battery development, thermal management, safety and system integration, Exoes supports its customers in their transition to low-carbon powertrains. Active in several sectors – including aerospace, automotive and rail – EXOES operates a dedicated battery production line and test centers, and also offers turnkey custom test equipment solutions.
“Being selected by Clean Aviation with the support of Airbus, ATR and Daher, leader in their respective field, is a major milestone for Exoes. It validates our technological roadmap and confirms the relevance of our high-performance battery systems for the future of clean aviation. Together with our partners, we are proud to contribute to the emergence of a European battery ecosystem that meets the highest standards of safety, performance, and certification and will decrease the aviation emissions.”
Arnaud Desrentes, CEO, Exoes
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