Mussel-Inspired, Biomimetics-Assisted Self-Assembly of Co3O4 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, Co3O4 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 Fg(-1) at a current density of 0.5 Ag-1 in 2 M KOH solution. In addition, the as-fabricated symmetric supercapacitors (SCs) presented excellent electrochemical performance with a capacitance of 55 Fg(-1), an energy density of 14.97 Whkg(-1), and a power density of 5660 Wkg(-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 608).