Preparation Of Porous Carbon Matrix Materials And Its Application In Supercapacitors

With the increase of energy consumption and the decrease of non-renewable energy,the study of sustainable energy is imminent.Among them,electrochemical energy as a kind of efficient clean energy has attracted much attention.Electrochemical supercapacitors have been widely concerned by researchers due to their characteristics of high power density,fast charge-discharge rate and long cycle life.Among them,the key to determine the electrochemical performance of supercapacitor lies in the selection of electrode materials,so the preparation of effective electrode materials becomes the focus of further improving the performance of supercapacitor.Porous carbon materials have great application value in adsorption,catalysis,energy storage and conversion due to their large specific surface area and abundant pore structure,and are effective alternative materials for electrode materials.This thesis mainly studies the design and synthesis of porous carbon skeleton material structure,and discusses its influence as a precursor of carbon material on the electrochemical performance of supercapacitors,including the following contents:1.A covalent organic framework containing oxygen sulfur atoms（OSC）was designed and synthesized to prepare high-performance conductive porous carbon materials（OSC-T）by using OSC as a carbon material precursor.The optimized OSC-T supercapacitor has the advantages of high specific capacitance,superior energy and power density and robust cycle stability.The optimized electrode material OSC-T-800has high specific surface area and microporosity,and has a specific capacitance of 430F g^-1 at a current density of 0.5 A g^-1.When the power density is 250 W kg^-1,the energy density is 60 Wh kg^-1.In the case of a higher power density of 5000 W kg^-1,it still maintains a high energy density of 20 Wh kg^-1.After 1000 cycles at 5 A g^-1,the capacity retention rate and coulomb efficiency were maintained at 99.4%and 99.21%respectively.Under the condition of 10 A g^-1,the capacity retention rate is maintained at 98.13%and the coulombic efficiency is maintained at 99.25%.2.A series of conjugated microporous polymers（CMPs）materials were designed and synthesized through a one-step coupling reaction.As the precursor of carbon material CMP-XYZ-Ts,CMPS were applied to the electrode of supercapacitor to explore the influence of the structure on the electrochemical performance.The results show that when the carbonization temperature is 800℃,the electrochemical performance of the carbon material is the best,and the specific capacitance can reach375 F g^-1 at the current density of 0.5 A g^-1.When the precursor and KOH are mixed at a mass ratio of 1:2,the resistance of carbon material is lower and the electric storage capacity is stronger.CMP-XYZ-800 can maintain a high energy density of 28.8 Wh kg^-1 when the power density is as high as 5000 W kg^-1.After 1000 cycles of constant current charge-discharge for CMP-XYZ-800 with current density of 5 A g^-1,the sample still has 98.8%capacitance retention rate and 99.66%coulomb efficiency.After 10000cycles of 10 A g^-1 current density,the capacitance retention rate is maintained at 96.3%and the coulombic efficiency is maintained at 98.26%.