Development of Structural Integrated Supercapacitors With Implemented Electronics for Space Applications

Abstract The market of small cube-like satellite is growing very fast. These satellites are comparatively cheap but are very limited in volume, weight and available energy. Energy is the most decisive factor for the duration of space missions and what kind of application can be run. The research focuses currently on the development of powerful and efficient batteries. Due to the chemical storage processes their lifetime is limited to much less than 30000 cycles. Furthermore, charge cycles and powerful peak power applications such as radar or robotics stress their performance. As result batteries have to be more powerful and bigger or will degrade faster. In contrast, supercapacitors use reversable physical processes of ion movement and orientation for energy storage. This reversible principle allows more than 1 million cycles. Therefore, they can be considered as maintenance-free, ideal for being integrated into composite structures. This approach of combining energy devices and structural elements offers great opportunities to save weight and volume, especially for small satellites. This publication deals with the development of semi-finished thin-film supercapacitors which are integrated into fiber-reinforced plastics composites by autoclave processing. The supercapacitors are manufactured using aluminum collectors coated a with an activated carbon electrode. As electrolyte the ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide is used as electrolyte. Experiments show, that these supercapacitors can also be used as sensors for temperature and mechanical loads. Furthermore, the electronics has to be developed and will be also integrated into the composite to reduce electrical wiring, to improve electrical conductivity and to reduce the overall failure risk. The integrated supercapacitors become a smart component for plug and play application. Within the project Decentralized Electrical supplied Electrical Propulsion (DEEP) a thruster system was developed using also structural integrated supercapacitors. The aim is to test the system on a DLR satellite mission 2030.