Carbon fiber(CF)sequentially undergoes thermal activation(TCF),electrochemical oxidation activation(EOTCF),electrochemical reduction activation(E_(RO)TCF)and a secondary thermal activation process to form a highly act...Carbon fiber(CF)sequentially undergoes thermal activation(TCF),electrochemical oxidation activation(EOTCF),electrochemical reduction activation(E_(RO)TCF)and a secondary thermal activation process to form a highly activated CF(TE_(RO)TCF)electrode material.E_(O)TCF undergoes a thermal activation process to form TE_(O)TCF.E_(RO)TCF,T_(EO)TCF and TE_(RO)TCF show specific capacitance values of 1455,1438 and 1426 mF cm^(-2) at 1 mA cm^(-2) and capacitance retention values of 0.97%,35.62%,and 59.61% when the current density increases from 1 to 20 mA cm^(-2).E_(RO)TCF,TE_(O)TCF and TE_(RO)TCF show similar capacitance values,but much superior to CF(709 mF cm^(-2)).TE_(RO)TCF shows much higher rate capability than E_(RO)TCF and TE_(O)TCF.Carbonyl,epoxy and hydroxyl groups are introduced on the TCF by electrochemical oxidation activation.Carbonyl groups existing at the edge of the basal plane contribute towards improving the specific capacitance of CF.Hydroxyl and epoxy groups on the basal plane of the carbon skeleton lead to the destruction of the conjugated system.The electrochemical reduction and secondary thermal activation cause the removal of the non-electroactive epoxy and hydroxyl groups for recovering the sp^(2) structure,accordingly enhancing the rate capability of CF.All-solid-state flexible supercapacitors using two TE_(RO)TCF electrodes achieve 26.0μW h cm^(-2) at 125.0μW cm^(-2) and good cycling performance.So,CF with thermal and electrochemical activation treatment shows highly enhanced capacitance for highperformance supercapacitor application.展开更多
基金supported by the National Natural Science Foundation of China(No.21373047)the Graduate Innovation Program of Jiangsu Province(KYCX18_0080)+1 种基金the Fundamental Research Funds for the Central Universities(2242018K41024)the Priority Academic Program Development of Jiangsu Higher Education Institutions.
文摘Carbon fiber(CF)sequentially undergoes thermal activation(TCF),electrochemical oxidation activation(EOTCF),electrochemical reduction activation(E_(RO)TCF)and a secondary thermal activation process to form a highly activated CF(TE_(RO)TCF)electrode material.E_(O)TCF undergoes a thermal activation process to form TE_(O)TCF.E_(RO)TCF,T_(EO)TCF and TE_(RO)TCF show specific capacitance values of 1455,1438 and 1426 mF cm^(-2) at 1 mA cm^(-2) and capacitance retention values of 0.97%,35.62%,and 59.61% when the current density increases from 1 to 20 mA cm^(-2).E_(RO)TCF,TE_(O)TCF and TE_(RO)TCF show similar capacitance values,but much superior to CF(709 mF cm^(-2)).TE_(RO)TCF shows much higher rate capability than E_(RO)TCF and TE_(O)TCF.Carbonyl,epoxy and hydroxyl groups are introduced on the TCF by electrochemical oxidation activation.Carbonyl groups existing at the edge of the basal plane contribute towards improving the specific capacitance of CF.Hydroxyl and epoxy groups on the basal plane of the carbon skeleton lead to the destruction of the conjugated system.The electrochemical reduction and secondary thermal activation cause the removal of the non-electroactive epoxy and hydroxyl groups for recovering the sp^(2) structure,accordingly enhancing the rate capability of CF.All-solid-state flexible supercapacitors using two TE_(RO)TCF electrodes achieve 26.0μW h cm^(-2) at 125.0μW cm^(-2) and good cycling performance.So,CF with thermal and electrochemical activation treatment shows highly enhanced capacitance for highperformance supercapacitor application.
