Increasing electrification in the aerospace sector as well as the challenge of powering an entire aircraft electrically places demands for the supply and storage of electrical energy. Energy devices must therefore be powerful and lightweight at the same time for efficient performance of the overall transportation system. One possibility to improve the performance by reducing weight and volume is the combination of structural and energy storing functions. Due to its lay-up, a composite is particularly suitable for this challenge. Of course, batteries are one of the most important components, but when it comes to being integrated in composite structures, their potential is reduced drastically because of their limited lifetime. In contrast, supercapacitors are a very promising technology. Their system features several advantages such as power density and cycle stability. Due to their cycle stability, supercapacitors are the ideal energy device for integration into areas that are difficult to access, such as the lay-up of composite structures. This publication deals with the strategy of structure-compliant integration of pouch supercapacitor cells. The aim is to operate different peak power applications needed for space missions. The material combination has to be optimized to achieve the best possible electromechanical performance. During the development, sets of structural supercapacitors with different scales are built to check their specific capacity. Often the specific properties drop by scaling up, but during this development the specific capacity of 0.24F/cm2 was even kept for the full-size demonstrator. Furthermore, this approach allows the reduction of volume and weight by 70–80% compared to a structure using commercial supercapacitors.