微波辅助氮掺杂与孔结构调控提升炭电极超级电容器性能OA

Nitrogen-rich biomass-based porous carbon materials were prepared from soybean straw by introducing the bifunctional template C3 N4 through green liquefaction technology and microwave hydrothermal doping technology.This study primarily examined the effects of three different doping methods—solid-solid doping,hydrothermal doping,and microwave hydrothermal doping—on the structure and properties of porous carbon materials.The results indicated that microwave hydrothermal technology was more conducive to the balanced conversion of nitrogen bonding forms into graphitic nitrogen(N-Q),pyridine nitrogen(N-6),and oxidized nitrogen(N-X).Meanwhile,as nonmetallic heteroatoms were deeply incorporated into carbon materials at the molecular level,these nitrogen-containing groups were more effective on enhancing electrical conductivity and could promote redox reactions in which nitrogen served as an active site.In the three-electrode system,tested at a current density of 0.5 A/g,the specific capacitance of samples prepared via microwave hydrothermal doping(Carbon-M)reached as high as 261.55 F/g,which was significantly higher than 157.60 F/g for solid-solid doping(Carbon-S)and 143.45 F/g for hydrothermal doping(Carbon-H).When the current density was increased from 0.5 A/g to 10 A/g,Carbon-M's specific capacitance remained at 193.64 F/g,with a capacity retention rate of 74.04%.After 10 000 long-term cycles,the capacitance retention remained at 93.2%,demonstrating excellent stability.In a two-electrode system,the material exhibits a specific capacitance of 21.2 F/g at 1 A/g.Notably,the energy density retained 69%of its initial value even with a 20-fold increase in power density,showing excellent energy retention.This suggests that the preparation method holds great promise for advanced energy storage applications.