Preparation And Electrochemical Performance Of Heteroatom-doped Carbon Materials For Supercapacitors

The supercapacitor has high power density, long cycle life performance accompanied with the characteristic of wide working temperature range, good safety and stability, which is widely used in various fields. Supercapacitor with a high energy storage is a research hotspot in recent years. The electrode materials for capacitor performance is very important, in which carbon materials as a kind of widely used electrode material, because of its large specific surface area, porosity developed and friendly environment, low price and other excellent properties has attracted wide attention, which was considered to be the most development potential of the supercapacitor electrode materials.The specific surface area, pore structure, conductivity and surface chemical properties of the carbon electrode materials can influence the performance of carbon based supercapacitor. In order to improve the energy storage of capacitor, the heteroatoms were introduced into the carbon skeleton structure to improve the structure and the surface chemical properties of carbons in order to optimize the electrochemical performance of supercapacitors. This paper systematically studied the preparation, surface modification and electrochemical performance in aqueous solution and organic electrolyte of the carbon electrode materials with nitrogen, phosphorous co-doped.The scanning electron microscope, N2adsorption, X ray photoelectron spectroscopy, Fourier transform infrared spectroscopy technology were used to characterize the structure and surface chemistry of the prepared carbon materials. Cyclic voltammetry, galvanostatic charge/discharge cycling, AC impedance and long cycle life tests were used to study their electrochemical performance. This paper mainly contained three sections:reviewe, experiments and conclutions. The main research contents and results are as follows:(1) The nitrogen-contained polymers were prepared by the Mannich rapid reaction in phenolic amine polymerization system using different nitrogen containing precursors as nitrogen sources and catalysts. The surface area of carbons prepared after carbonization with three-dimensional network structure was in the range of550-650m2g"1. The existence of nitrogen improved the wettability and capacitance of the carbons.(2) Phosphoric acid activation increase the specific surface area and pore volume of the nitrogen and phosphoric co-doped carbon materials with pore size distribution<2nm. In aqueous electrolyte, the capacitance values of nitrogen and phosphorus codoped carbons is larger than nitrogen doped carbons by almost100F g"(3) In organic electrolyte, the capacitance, energy density and power density of nitrogen and phosphoric co-doped carbon materials are larger than nitrogen doped carbons. With the nitrogen content increase, the capacitance performance improved more obviously. Nitrogen and phosphoric co-doped carbon material has good adaptability with organic electrolyte.