Application Of Biomass Carbon - Based Composite Electrode Material In Supercapacitor

In this dissertation, hierarchical porous carbon material from network loofah sponge for high performance supercapacitors, porous carbon@MnO2 and nitrogen-doped porous carbon from carbonised loofah sponge for asymmetric supercapacitors with high energy and power density and carbon material from tea fungus for high performance supercapacitors were reported.Environmentally friendly, low-cost and renewable biomass is a promising raw material for a highperformance supercapacitor electrode material. Herein, high surface area, hierarchical porous carbon materials were obtained by a carbonization and activation process of a loofah sponge. The specific surface area and the pore size distribution of the porous carbon were controlled by adjusting the activation temperature and suitable activation agents. Amazingly, among them, the carbon materials prepared at 800 ℃ the capacity can reach 304 F g-1 with a current density of 1 A g-1, and high capacitance retention. In the two-electrode cell in aqueous and organic electrolyte, the energy density could be up to 10 and 64.4 Wh kg-1 at a power density of 500 W k g-1 and 11.3 KW kg-1, respectively.Porous carbon@MnO2 and Nitrogen-Doped porous carbon from carbonised loofah sponge for preparation of high performance composite electrode materials for asymmetric supercapacitor. In this study, we developed a simple thermal treatment method for PC@MnO2 was synthesized by in situ growth of MnO2 on the surface of loofah sponge-derived PC under hydrothermalconditions. The other part the NPC derived from loofah sponge was synthesized by a urea-assisted hydrothermal method in the PC external and internal. An asymmetric supercapacitor PC@MnO2-12h//NPC was then assembled depending on the loofah sponge-derived PC@MnO2 and N-doped PC. The working voltage of the designed asymmetric device could reach 1.8 V and exhibited excellent performance. A high capacitance of 78.2 F g-1 at a current density of 1 A g-1. A relatively high energy density of 34.7 Wh kg-1 and power density 26.8 kW kg-1 could be obtained. In addition, the device exhibited good electrochemical stability.Preparation of porous carbon materials from tea fungus as carbon source, through carries on the preliminary carbonization, activation, and recalcination. We found that product can reach a high charge storage capacity with 167 F g-1 in 6 M KOH electrolyte with a current density of 0.5 A g-1.