| It is of great significance to research and develop novel energy storage devices for dealing with the current environmental pollution and energy shortage problems.Compared with traditional chemical batteries,supercapacitors have the characteristics of faster charging,higher power density,longer service life and more environmentally friendly,which have been generally recognized by the society.What counts is the quality of its electrode materials directly affects the future development of supercapacitors.The carbon materials with rich channels take up a vital position in the field of energy storage materials because of the advantages of large pore volume,sufficient resources and stable thermoelectric mechanical properties.The existence of nanopores and cavities provides favorable conditions for electrolyte ion transmission and storage.In this paper,the carbon-based composite materials prepared by different methods were studied,and the combination of different morphologies was realized,which showed excellent electrochemical performance.The main contents of this research are shown below:1)The“co-assembly”method was used to anchor the nitrogen-containing polymer polystyrene/polyacrylonitrile(PSPAN)on the resin sheet to prepare a hollow carbon sphere/carbon sheet composite(HCS/S).During the preparation process,PSPAN,as a core,is pyrolyzed into small organic nitrogen-containing gases under high temperature,creating large cavities,and the ionic liquid guides the resin and the silica polymer to form a sheet.The prepared carbon composite exhibits uniform pore size,high specific surface area,and high nitrogen doping content.In the electrochemical test,HCS/S-2 exhibits a specific capacitance of 219 F g-1 at a current density of 0.5 A g-1.After simulating high-frequency charge and discharge in the equivalent circuit,its electrochemical stability maintained91.2%.The“co-assembly”strategy opens up a new approach for the development of carbon-based composite electrode materials with multiple morphologies.2)The nitrogen-doped porous carbon/fiber carbon composites(PC/PNFs)were successfully prepared.The conductive polymer polypyrrole fibers(PPy)are co-assembled with resin and silicate polymers through the electrostatic force of the ionic liquid.After removing silica,PC/PNFs with different morphologies were obtained.The PC/PNFs-2retains the hollow tubular morphology of PPy,having a high nitrogen doping content(4.76%),a large cavity(30-40 nm)structure and a large specific surface area(1385 m2 g-1).In the electrochemical test,PC/PNFs-2 has a high specific capacitance of 226.2 F g-1 in a real symmetrical electrode.It can maintain an initial capacitance of 81.5%even at a current density of 10 A g-1.The initial capacitance of PC/PNFs-2 attenuates only 7.5%after simulating long-term charge/discharge,proving its excellent durability and stability,indicating that the composite of conductive polymers and carbon-based materials has great potential in the application of supercapacitors.3)The core-shell separated“yolk-shell”porous carbon composites(YS-PCS)were successfully prepared by the silica-assisted coating strategy using phenol formaldehyde resin polymer as the core,dense silica as the intermediate template layer,and silicate resin hybrid as the carbon source.The organic amine as a catalyst can easily promote the hydrolysis of silane to form Si O2.After adjusting the amount of silane used,the thickness of the YS-PCS's shell layer is differentiated,the YS-PCS-0.6 structural unit has fluffy shell,with a large specific surface area and a mesoporous structure.As the electrode materials,YS-PCS-0.6 exhibits a specific capacitance of 210 F g-1 at 0.5 A g-1 as a symmetrical electrode,and the capacitance can still maintain 75.8%under high current density.The capacitance remains 90.6%after simulating high-frequency charging and discharging.The core-shell separated spherical porous carbon composite material has high application value in the field of high-performance electrode materials. |
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