Electrical power subsystems designed for space applications face uniquely harsh environments over their lifetime. Yet, today they are required to cope with new trends driven by the fast-growing space business: increasingly energy-hungry payloads, longer mission durations, ever more stringent safety requirements, lower satellite and launchers masses and smaller volumes. In order to pave the way for a competitive European space industry, the ECLIPSE project (European Consortium for Lithium-Sulphur Power for Space Environments) was brought to life by the European Commission under the H2020 framework. With a total budget of 1 Million Euros, ECLIPSE will prepare the next evolution of spacecraft and launchers battery technology by the end of 2017.
The current state-of-the-art of energy storage for space applications is exemplified by the Lithium-Ion technology, which has been used extensively in spacecraft electrical systems over the last 15 years. However, Lithium-Ion technology seems to be approaching the end of its product lifecycle, as ongoing Li-Ion developments have failed to yield significant improvements in performance. Fortunately, the next generation battery technology is around the corner; this time its chemistry is based on the Lithium-Sulphur process.
This technology could therefore represent the new breakthrough technology for energy storage on board spacecraft systems. In the future, Lithium-Sulphur technology could enable the production of batteries with an energy density twice as high as Lithium-Ion, a significant advancement in the field of inspace energy storage.
The main objective of the ECLIPSE project is to demonstrate the feasibility of the optimized Lithium-Sulphur cell technology so that it can make its way towards space applications. Using a new battery technology on a satellite or a launcher is only possible once a Technology Readiness Level (TRL) of 5 has been successfully demonstrated on three main levels: at cell, at battery and at system level.
In order to meet its key objectives, ECLIPSE will need to overcome certain challenges at these levels:
- At cell level: Maximising the high energy density (>400 Wh/kg) offered by the Lithium-Sulphur chemistry.
- At battery and cell encapsulation level: Building a prototype battery module and checking its suitability for the space environment.
- At system level: Creating an electrical model of the cell that takes into account ageing effects. The detailed cell design, the experimental results and the assessment of system-level impacts will also have to be developed.
Even if ECLIPSE’s Li-S prototypes have not reached the performances targets at cell level, ECLIPSE activities helped to improve the technology performances compared to the state of the art at the beginning of the project. The project has led to patents, publications, innovations for future activities and also reinforcement of partnership between industry and research in order to prepare future European battery technology for space.
