The European L.I.M.E. (Lithium-based Innovation for Modular Energy) project has officially launched under Europe s Clean Aviation programme, securing a 5 million grant for a consortium led by Exoes, Ascendance Flight Technologies, Basquevolt, and RWTH Aachen University.
Support from aerospace heavyweights including Airbus, ATR, and Daher reinforces the initiative s credibility, especially as it pursues development of a next-generation battery architecture built around lightweight composite casings to enhance structural integrity, reduce mass, and enable safer integration into hybrid-electric aircraft systems.

The L.I.M.E. 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.