Preparation And Electrochemical Performance Of Flexible Carbon-based Hybrid Nanofiber Membrane Electrode

As a novel supercapacitor electrode material,flexible electrode material not only has outstanding charge and discharge performance,but also gains much attention in portable energy store devices with excellent flexible property.In this paper,flexible Co-doped carbon nanofibers(CCNFs)electrode material was synthesized by cobalt acetate and polyacrylonitrile(PAN)as raw materials;in addition,NiCo2O4 was loaded on the surface of Co-doped carbon nanofibers(NCCNFs);and more,a solid-state supercapacitor was assembled using PVA/KOH gel electrolyte and CCNFs membrane.The morphology,structure and electrochemical performance of these composite materials were characterized by XRD,Raman,BET,SEM,TEM,CV,GCD and other characterization methods.First,the spinning solution was prepared using cobalt acetate,PAN and DMF,and then CCNFs was synthesized through electrostatic spinning combining with carbonization.The microstructure,morphology and electrochemical performance of CCNFs were characterized by XRD,Raman,SEM,CV,GCD and other characterization methods.The CCNFs membrane,which was obtained by sintering at 600? for 8h electrospun nanofibers film from the DMF solution of PAN and cobalt acetate with mass ratio of 6:4,not only has excellent electrochemical performance(394 F/gat the current density of 1 A/g,retained 80%of the initial capacitance after 1000 cycles),but also possesses an outstanding flexible property(can bend to 180°for many times).Second,porous NiCo2O4 was loaded on the surface of CCNFs using Co(Ac)2 and Ni(Ac)2 with mass radio of 2:1 through hydrothermal method.The microstructure,morphology and electrochemical performance of NCCNFs were characterized by XRD,Raman,SEM,CV,GCD and other characterization methods.The results indicated that NiCo2O4 was porous and net-like,and that the thickness of NiCo2O4 was about 250nm,which enlarges the surface and the electrochemical properties of the CCNFs.The temperature of the hydrothermal was 95? and the time was 5h.The NCCNFs product shows excellent electrochemical properties with a maximum specific capacitance of 1032 F/gat a current density of 1 A/g and 70%retention after 1000 cycles.In addition,the excellent mechanical flexibility of the initial CCNFs membrane was retained.Finally,PVA/KOH gel was prepared by PVA,H2O and KOH with the mass radio of 1:10 for PVA and H2O,and then solid-state supercapacitor was assembled with two CCNFs membranes as the working electrode and PVA/KOH sol as the solid electrolyte.The solid-state supercapacitor displayed excellent electrochemical properties with an areal capacitance of 18.2 mF/cm2 at a current density of 0.1mA/cm2 and an energy density of 1.69 mWh/cm2.The capacitance remained 97.7%of the initial capacitance after 1000 cycles,indicating a good stability.