Periodic Reporting for period 1 - MATISSE (Multifunctional structures with quasi-solid-state Li-ion battery cells and sensors for the next generation climate neutral aircraft)
Reporting period: 2022-09-01 to 2024-02-29
Air transport is under increasing criticism for its energy intensity and CO2 emissions in the context of climate change. Aviation is likely to remain the fastest growing transport sector, so action is urgently needed if aviation is to play its part in meeting the European Green Deal's target of climate neutrality by 2050.
The transition from fossil-fuel-powered to increasingly electrical aircraft propulsion is contingent upon the development of electric energy storage systems that meet aeronautic requirements. The development of aviation-grade battery technologies and systems for passenger aircraft is in its infancy. While lithium-ion battery technology will remain the dominant technology at the mid-term, its limited energy density at the cell and pack level results in a substantial weight penalty for aircraft integration. Multifunctional structures capable of storing electrical energy or structural batteries (SB) offer the highest degree of integration, thus the lowest weight impact.
The objective of the MATISSE project is to develop and mature SB technology for hybrid electric aircraft applications. This involves integrating lithium-ion cells into aeronautical composite structures, sharing the load-bearing function with the structure and creating an aircraft structural element capable of functioning as a battery module.
MATISSE develops load-bearing quasi-solid-state Li-ion battery cell technology, enabling their functional integration into aerospace-grade solid laminate and sandwich composite structures. Furthermore, the structural battery is made smart by equipping it with on-cell and in-structure sensors, connected to a microchip-based monitoring unit.
MATISSE will deliver a multi-functional energy storage demonstrator in the form of a full-scale wing tip (1.4 m × 0.7 m) to replace the current wingtip assembly installed on the Pipistrel Velis Electro, the first type-certified fully electric light aircraft. This will undergo a comprehensive testing and characterisation campaign, with the objective of qualifying the technology at TRL 4 at the end of the project (2025).
Furthermore, MATISSE will address issues related to flight certification, life-cycle sustainability, and virtual scale-up. This will facilitate the application of structural batteries as an improved performance key enabling technology for next generation commuter and regional hybrid electric aircraft applications.
The transition from fossil-fuel-powered to increasingly electrical aircraft propulsion is contingent upon the development of electric energy storage systems that meet aeronautic requirements. The development of aviation-grade battery technologies and systems for passenger aircraft is in its infancy. While lithium-ion battery technology will remain the dominant technology at the mid-term, its limited energy density at the cell and pack level results in a substantial weight penalty for aircraft integration. Multifunctional structures capable of storing electrical energy or structural batteries (SB) offer the highest degree of integration, thus the lowest weight impact.
The objective of the MATISSE project is to develop and mature SB technology for hybrid electric aircraft applications. This involves integrating lithium-ion cells into aeronautical composite structures, sharing the load-bearing function with the structure and creating an aircraft structural element capable of functioning as a battery module.
MATISSE develops load-bearing quasi-solid-state Li-ion battery cell technology, enabling their functional integration into aerospace-grade solid laminate and sandwich composite structures. Furthermore, the structural battery is made smart by equipping it with on-cell and in-structure sensors, connected to a microchip-based monitoring unit.
MATISSE will deliver a multi-functional energy storage demonstrator in the form of a full-scale wing tip (1.4 m × 0.7 m) to replace the current wingtip assembly installed on the Pipistrel Velis Electro, the first type-certified fully electric light aircraft. This will undergo a comprehensive testing and characterisation campaign, with the objective of qualifying the technology at TRL 4 at the end of the project (2025).
Furthermore, MATISSE will address issues related to flight certification, life-cycle sustainability, and virtual scale-up. This will facilitate the application of structural batteries as an improved performance key enabling technology for next generation commuter and regional hybrid electric aircraft applications.
In the first 18 months of the project, progress was achieved in the structural battery electrochemistry where two approaches for the electrolyte were further developed: AIT’s thermoplast-ionic liquid system with different fillers and KIT’s highly-filled electrolyte system. Their multifunctional (electrical and mechanical) performance and scalability of their production will determine which one will be implemented in the demonstrator cells.
SCP’s integrated cell monitoring unit (CMU-I) enhances their current micro-chip with safety features relevant to aerospace and mission critical applications. An innovative concept to integrate SB cell with sensors and electronics is under development, already producing first prototypes of the smart SB cell.
Concepts to integrate SB cell into solid composite laminates are studied further by ONERA and into sandwich structures by CIRA, investigating with numerical simulation structural and battery damages in bending and under impact. First characterisations of sandwich-SB coupon have been performed to validate the analyses.
Novel composite materials that are highly thermally conductive and manufacturing methods with reduced energy demand are investigated by IAI for their potential for battery integration. IAI has also carried out an assessment of the space and volume that is available in large passenger aircraft for integrating batteries based on two long-haul aircraft that were available at IAI during their conversion into freighters.
Finally, the MATISSE multifunctional demonstrator – a full-scale extended wingtip for the Pipistrel Velis electro – was selected and designed by PVS and the structural material has been selected.
SCP’s integrated cell monitoring unit (CMU-I) enhances their current micro-chip with safety features relevant to aerospace and mission critical applications. An innovative concept to integrate SB cell with sensors and electronics is under development, already producing first prototypes of the smart SB cell.
Concepts to integrate SB cell into solid composite laminates are studied further by ONERA and into sandwich structures by CIRA, investigating with numerical simulation structural and battery damages in bending and under impact. First characterisations of sandwich-SB coupon have been performed to validate the analyses.
Novel composite materials that are highly thermally conductive and manufacturing methods with reduced energy demand are investigated by IAI for their potential for battery integration. IAI has also carried out an assessment of the space and volume that is available in large passenger aircraft for integrating batteries based on two long-haul aircraft that were available at IAI during their conversion into freighters.
Finally, the MATISSE multifunctional demonstrator – a full-scale extended wingtip for the Pipistrel Velis electro – was selected and designed by PVS and the structural material has been selected.
The performance of AIT’s structural battery cells could be significantly enhanced in comparison to the first generation developed in the predecessor project SOLIFLY.
The CMU-I was designed enhanced with safety features relevant to aerospace and mission critical applications.
The innovative smart SB cell concept will enable autonomous sensing once the battery is initially charged, while reducing the weight impact and volume demand.
Integration of structural batteries into solid laminates and sandwich structures offers a multitude of potential avenues for the introduction of multifunctional energy storage into large aircraft with large volumes and surface areas that could be utilized.
The CMU-I was designed enhanced with safety features relevant to aerospace and mission critical applications.
The innovative smart SB cell concept will enable autonomous sensing once the battery is initially charged, while reducing the weight impact and volume demand.
Integration of structural batteries into solid laminates and sandwich structures offers a multitude of potential avenues for the introduction of multifunctional energy storage into large aircraft with large volumes and surface areas that could be utilized.