POLYMERIC IONIC ELECTROLYTES VS. LIQUID IONIC ELECTROLYTES IN THIN-FILM SUPERCAPACITORS INTEGRATED IN HIGHLY COMPLEX AEROSPACE STRUCTURES

Abstract The latest fear of energy shortage drives the research of highly efficient energy storage and applications with the lowest possible consumption. A lot of research is currently done to develop more powerful and efficient batteries. However, due to the chemical storage processes their lifetime is limited to less than 30000 cycles. In contrast, supercapacitors, as a second way of energy storage, use reversable physical processes for energy storage, allowing more than 1 million cycles. Therefore, they can be considered as maintenance-free and are ideal candidates for being integrated within composite structures. In this publication, semi-finished thin-film supercapacitors are integrated into fiber reinforced plastics composites by autoclave processing. The supercapacitors are manufactured using aluminum collectors with activated carbon. As standard ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide is used on the one hand as liquid and on the other hand as part of a polymeric electrolyte. Intensive electro-mechanical characterizations of the multifunctional composites are carried out. The reduction of parasitic masses and reproducible results are aims of this screening. It can be shown that the electrical conductivity of the supercapacitor and the ionic conductivity between the electrodes play decisive roles. Furthermore, the exact processing of the polymeric electrolyte avoiding leakage into the composite is especially challenging