High performance supercapacitor based on Ni3S2/carbon nanofibers and carbon nanofibers electrodes derived from bacterial cellulose

The Ni3S2 nanoparticles have been successfully grown on the carbon nanofibers (CNFs) derived from bacterial cellulose via a hydrothermal method, which the as-prepared composite exhibited high specific capacitance (883 F g(-1), at 2 A g(-1)), much more than CNFs (108 F g(-1) at 2 A g(-1)), and good cycle stability. The asymmetric supercapacitor was designed to contain the CNFs coated Ni3S2 nanoparticles (Ni3S2/CNFs) as positive electrode and CNFs as negative electrode in 2 M KOH electrolyte. Due to the synergistic effects of the two electrodes, asymmetric cell showed superior electrochemical performances. The optimized asymmetric supercapacitor gave a operating potential of 1.7 V in 2 M KOH aqueous solution, exhibiting a high specific capacitance of 56.6 F g(-1) at 1 A g(-1) and considerably high energy density of 25.8 Wh kg(-1) at a power density of 425 W kg(-1). Meanwhile, Ni3S2/CNFs//CNFs asymmetric supercapacitor showed excellent cycling stability with 97% specific capacitance retained after 2500 cycles. (C) 2014 Elsevier B.V. All rights reserved.