Preparation And Electrochemical Performance Of Polymer-based Dual Doping Activated Carbon With Hierarchical Porous Structure

With the increasing shortage of energy and environmental pollution,renewable resources such as wind energy and solar energy have been vigorously developed,and their proportion in the world energy system has gradually increased.The demand for energy conversion and energy storage equipment with excellent performance has greatly increased.Supercapacitor is an energy storage device between dielectric capacitor and secondary battery,which has the advantages of both.It is considered to be a promising development direction to meet the requirements of human sustainable development.The electrode material is the core of the supercapacitor and has a crucial influence on its performance.Therefore,the design and preparation of high-performance electrode active materials is the focus of supercapacitor research.Activated carbon has stable physical and chemical properties,well-developed pore structure and high specific surface area.It is the most widely used and most commercialized carbon-based supercapacitor electrode active material with broad development prospects.Through the design and adjustment of the pore structure and surface chemical properties of activated carbon,the preparation of dual-doped activated carbon materials with hierachical porous structure is a great significance for the development of high-performance activated carbon supercapacitors.The purpose of this paper is to construct a high-performance carbon-based supercapacitor electrode material,using polythiophene as a sulfur source,and the polymer composite porous material obtained via thermally induced phase separation method as a precursor to prepare a series of dual doped activated carbon materials with hierarchical porous structure.And using a variety of characterization and testing methods to study the micro-morphology,pore structure characteristics,surface chemical properties and electrochemical performance of the material,and discussed its energy storage mechanism.The specific work content is as follows:?1?Polymethyl methacrylate is used as the polymer porous framework material,and the polythiophene is evenly divided into the Polymethyl methacrylate monolith via thermally induced phase separation method,and carbonized to obtain a hierarchical porous structure and ultra-high Doped activated carbon material with sulfur and oxygen content.Activated carbon materials with high specific surface area(1120-1610 m² g^-1),hierarchical porous structure and high heteroatom content were prepared by adjusting the activation temperature and KOH impregnation ratio during the preparation process.The samples prepared at 700?with a KOH impregnation ratio of 3 have a high specific surface area(1610 m² g^-1)and sulfur and oxygen content?10.63%and 9.33%,respectively?,showing excellent specific capacitance(current density is 0.5 A g^-1,specific capacitance is as high as 290 F g^-1).?2?Using nitrogen-rich polymer polyacrylonitrile as the dispersion medium and nitrogen source,polythiophene is dispersed in the polyacrylonitrile monolith via thermally induced phase separation method,and then carbonized to obtain nitrogen and sulfur co-doping activated carbon with hierarchical porous structure.By adjusting the activation temperature and the KOH impregnation ratio to adjust the morphology of the material,the prepared activated carbon material exhibits a high specific surface area(1570-2550 m² g^-1),a developed graded porous structure,and rich nitrogen and sulfur atom.The samples prepared under the condition of 700?and KOH impregnation ratio of 1 have high specific surface area and microporosity,and their micropore volume is as high.It exhibits excellent electrochemical performance in a three-electrode system.When the current density is 0.5 A g^-1,the specific capacitance is as high as345 F g^-1;when the current density is 20 A g^-1,the specific capacitance remains at 229 F g^-1,is a good carbon-based capacitor electrode material,with potential application value.