One of the critical challenges for the electrification of aviation is the storage of the necessary electrical energy. The use of conventional batteries would introduce considerable additional masses and volumes into the overall aircraft system at the expense of performance. The project "Structural energy storage focussing on battery cells with load bearing properties" investigates the small-scale integration of battery materials into the fibre composites used in aircraft construction. For this purpose, the resin used in fibre composites will be replaced by battery materials to enable the storage of electrical energy while retaining the mechanical properties.
The schematic structure of an energy-storing fiber composite structure is shown in the figure below. The matrix polymer normally used in fibre composites is replaced here by the materials of a battery. Carbon fibres impregnated with active material, a solid state electrolyte and other additives form the cathode. In addition to their load-bearing properties, the carbon fibres used can also act as current collector. Sulfur is a suitable active material for this type of battery due to its high gravimetric energy density and the high carbon content already present in the carbon fibers. The separator of the battery consists of electrically insulating glass fibers which are impregnated with a solid-state electrolyte. Pure metallic lithium is used as the anode.
