Electrification of aircraft systems is key for increasing efficiency and reducing climate impact of air transport towards the European net-zero goal. The functional integration of structural capabilities and electrical energy storage in the form of structural batteries (SB) is considered as a low TRL technology with the potential to reduce the impact of battery energy storage on the overall aircraft weight. So far, structural batteries have been mainly studied at material level, largely neglecting their integration into aircraft structures.
The CleanSky2 THT project SOLIFLY is developing further structural batteries for aeronautical applications with two cell concepts, one with coated carbon fibres acting as structural and electrically conductive components, and another with laminate structural electrodes. The project puts particular emphasis on their integration into CFRP laminates that are compatible with aeronautical manufacturing processes.
This report fixes some general considerations about certification requirements on composite material structures and the current trend of certification agencies to move towards a performance-based regulations. This document may represent a reference for structural composite batteries, for which there are still no well-defined certification requirements. Assuming this approach is valid, an airworthy solution for certification of composite structures with embedded structural batteries is given, providing an innovative interpretation of existing regulations, in compliance with current trends.