Facile synthesis of nanofiber composite based on biomass-derived material conjugated with nanoparticles of Ni–Co oxides for high-performance supercapacitors

Abstract

Finding renewable, abundant resource, environment-friendly, easy fabrication, low-cost biomass materials that present special physical and electrochemical properties is the first and most important step to design electrochemical energy storage and energy conversion devices. In this regard, we presented nanofibers composite, decorated with nanoparticles of Ni–Co oxides, based on Typha domingensis as an almost universally available biomass source. The surface morphology, crystal structure and electrochemical performance of the composites were studied by X-ray diffraction, energy-dispersive spectroscopy, field emission scanning electron microscope, transmission electron microscopy and electrochemical measurements. The synthesized composite, as an electrode, showed ultrahigh specific capacitance of 1770 F g−1 at current density of 1.0 A g−1 with a remarkable rate capability of 60% after increasing the current density to 66 A g−1. The asymmetric supercapacitors assembly, prepared from prepared composite as the positive electrode and the Vulcan XC-72R as the negative electrode and 6.0 mol L−1 KOH as the electrolyte, shows high specific capacitance (the 142 F g−1 at current density of 1.0 A g−1), excellent rate capability and high energy density up to 101 Wh kg−1 at a power density of 25.6 kW kg−1, over a potential window of 0–1.6 V, as well as excellent cycling stability of 92.1% after 5000 cycles. Two cells in series can easily light up a LED lamp brightly. Such stability and electrochemical performance are a promising choice for biomass-derived materials in terms of high-performance supercapacitors.