E-mobility systems require the provision of efficient, lightweight and durable battery solutions. Here, novel solutions for efficient energy storage are needed, which aim at combining the performance of supercapacitors with structural capabilities realized by the use of functional carbon fibers. To achieve functional carbon fibers, different additives are used to modify carbon fibers starting with the precursor. Polyacrylonitrile blends with nanocellulose, graphene or polycyclic aromatic hydrocarbon have been spun using solvent wet spinning. Different ratios of post-drawing were performed to investigate the influence on the mechanical properties of the precursor fibers. They were characterized by tensile tests and morphological investigations.