Development of a High-Performance Battery Cell for the Aviation Industry

In the "batterFLY" collaborative project, five research institutions are working alongside experts from the aviation industry on innovative battery concepts. Their aim is to develop a battery cell that meets the aviation sector’s stringent requirements for service life, energy and power density, and safety, and which supports the drive towards sustainable aviation.    

In this context, Fraunhofer ISE is responsible for safety assessment, carries out abuse tests and provides the project partners with insights into compliance with the strict safety requirements. 

Initial Situation

Electric flight is regarded as a key component of future climate-friendly mobility concepts. At the same time, aviation places particularly high demands on battery systems: in addition to achieving the highest possible energy density, battery cells must also meet high power requirements during take-off and landing, whilst operating safely and reliably over the long term.

However, the current state of the art still shows significant limitations. Conventional lithium-ion batteries lose a noticeable amount of energy density after repeated charge and discharge cycles and are reaching their limits, particularly in aviation applications. At the same time, development processes are often time-consuming, and digital simulation methods have so far been integrated only to a limited extent into material and cell development.

Objective

The batterFLY project combines several innovative approaches to address these challenges. The focus is on developing battery cells with high-silicon, pre-lithiated anodes and nickel-based cathodes. Electrochemical pre-lithiation is intended to significantly improve both the energy density and the lifespan of the silicon anodes.

At the same time, novel electrolyte systems and simulation-based development processes are being employed. Digital models and simulations are incorporated into material, cell and system development right from the early stages. This is intended to shorten development times and ensure that the battery cells are specifically designed to meet the requirements of electric aircraft and subsequent certification processes.

“Aviation places completely different demands on batteries than traditional automotive applications. With batterFLY, we aim to combine materials, cell concepts and digital development approaches in such a way that high-performance yet safe batteries for future electric aircraft become a reality,” explains Prof. Dr Egbert Figgemeier, project coordinator at Helmholtz Institute Münster.

Approach

As energy and power densities increase – which is particularly crucial for the aviation sector – the risk of safety-critical incidents also rises. Fraunhofer ISE is addressing this challenge as part of the "batterFLY" collaborative project by conducting a comprehensive safety assessment of high-performance battery cells for aviation. By developing advanced test procedures and innovative analytical methods – for example, to determine the gas composition during thermal runaway and to identify the chemical reactions taking place – Fraunhofer ISE is helping to make batteries safer for aviation. The research findings are directly incorporated into cell optimisation, thereby strengthening the competitiveness and future viability of German and European aviation technology.

In addition to Forschungszentrum Jülich, the project involves RWTH Aachen University, the Technical University of Munich, the Fraunhofer Institute for Solar Energy Systems ISE and the University of Stuttgart.

The project partners contribute complementary expertise in the fields of battery materials, electrochemistry, simulation, safety research and aeronautical engineering. This creates a close integration of basic research, cell development, safety assessment and aircraft integration.

An advisory industry and application board comprising representatives from the aviation and battery industries is supporting the project and assessing the industrial viability of the technologies developed. Participants include AIR ENERGY Entwicklungs GmbH & CoKG, Customcells Itzehoe GmbH, Lange Aviation GmbH, Pipistrel d.o.o. and Kristl, Seibt & Co. Gesellschaft m.b.H.

The “batterFLY” project is funded by the Federal Ministry of Economic Affairs and Energy (BMWE).