Mussel‐Inspired, Biomimetics‐Assisted Self‐Assembly of Co 3 O 4 on Carbon Fibers for Flexible Supercapacitors

Carbon nanofiber (CNF) composites could be promising materials for flexible supercapacitors. However, it is still a challenge to grow uniformly active materials on the surface of fibers and maintain flexibility. Herein, Co 3 O 4 nanoparticle‐decorated CNFs have been produced through the combination of electrospinning technology and a polydopamine‐assisted self‐assembly strategy. The free ‐ standing hybrid electrode exhibited a high capacitance of 418 F g −1 at a current density of 0.5 A g −1 in 2 M KOH solution. In addition, the as ‐ fabricated symmetric supercapacitors (SCs) presented excellent electrochemical performance with a capacitance of 55 F g −1 , an energy density of 14.97 W h kg −1 , and a power density of 5660 W kg −1 . Notably, the symmetric SC device exhibited remarkable electrochemical stability and flexibility (93 % capacitance retention after 2000 cycles and 97 % after bending 100 times to 60°).