In order to meet the demands of new-generation electric vehicles that require high power output(over 15 kW/kg),it is crucial to increase the energy density of car-bon-based supercapacitors to a level comparable to tha...In order to meet the demands of new-generation electric vehicles that require high power output(over 15 kW/kg),it is crucial to increase the energy density of car-bon-based supercapacitors to a level comparable to that of batteries,while maintaining a high power density.We re-port a porous carbon material produced by immersing pop-lar wood(PW)sawdust in a solution of KOH and graphene oxide(GO),followed by carbonization.The resulting mater-ial has exceptional properties as an electrode for high-en-ergy supercapacitors.Compared to the material prepared by the direct carbonization of PW,its electrical conductivity was in-creased from 0.36 to 26.3 S/cm.Because of this and a high microporosity of over 80%,which provides fast electron channels and a large ion storage surface,when used as the electrodes for a symmetric supercapacitor,it gave a high energy density of 27.9 Wh/kg@0.95 kW/kg in an aqueous electrolyte of 1.0 mol/L Na_(2)SO_(4).The device also had battery-level energy storage with maximum energy densities of 73.9 Wh/kg@2.0 kW/kg and 67.6 Wh/kg@40 kW/kg,an ultrahigh power density,in an organic electrolyte of 1.0 mol/L TEABF4/AN.These values are comparable to those of 30−45 Wh/kg for Pb-acid batteries and 30−55 Wh/kg for aqueous lithium batteries.This work indicates a way to prepare carbon materials that can be used in supercapacit-ors with ultrahigh energy and power densities.展开更多
基金This study was supported by the National Natural Science Foundation(No·30472061,No·306724709)the Teaching and Research Award Program for Outstanding Young Teachers(No·2002383)
文摘In order to meet the demands of new-generation electric vehicles that require high power output(over 15 kW/kg),it is crucial to increase the energy density of car-bon-based supercapacitors to a level comparable to that of batteries,while maintaining a high power density.We re-port a porous carbon material produced by immersing pop-lar wood(PW)sawdust in a solution of KOH and graphene oxide(GO),followed by carbonization.The resulting mater-ial has exceptional properties as an electrode for high-en-ergy supercapacitors.Compared to the material prepared by the direct carbonization of PW,its electrical conductivity was in-creased from 0.36 to 26.3 S/cm.Because of this and a high microporosity of over 80%,which provides fast electron channels and a large ion storage surface,when used as the electrodes for a symmetric supercapacitor,it gave a high energy density of 27.9 Wh/kg@0.95 kW/kg in an aqueous electrolyte of 1.0 mol/L Na_(2)SO_(4).The device also had battery-level energy storage with maximum energy densities of 73.9 Wh/kg@2.0 kW/kg and 67.6 Wh/kg@40 kW/kg,an ultrahigh power density,in an organic electrolyte of 1.0 mol/L TEABF4/AN.These values are comparable to those of 30−45 Wh/kg for Pb-acid batteries and 30−55 Wh/kg for aqueous lithium batteries.This work indicates a way to prepare carbon materials that can be used in supercapacit-ors with ultrahigh energy and power densities.
