Lithium-ion hybrid supercapacitors （LIHSs）, also called Li-ion capacitors, are electrochemical energy stor- age devices that combining the advantages of high power density of supercapacitor and high energy density o...Lithium-ion hybrid supercapacitors （LIHSs）, also called Li-ion capacitors, are electrochemical energy stor- age devices that combining the advantages of high power density of supercapacitor and high energy density of Li-ion battery. However, high power density and long cycle life are still challenges for the cul~ rent LIHSs due to the imbalance of charge-storage capacity and electrode kinetics between capacitor-type cathode and battery-type anode. Therefore, great efforts have been made on designing novel cathode materials with high storage capacity and anode material with enhanced kinetic behavior for LIHSs. With unique two-dimensional form and numerous appealing properties, for the past several years, the rational designed graphene and its composites materials exhibit greatly improved electrochemical performance as cathode or anode for LIHSs. Here, we summarized and discussed the latest advances of the state- of-art graphene-based materials for LIHSs applications. The major roles of graphene are highlighted as （1） a superior active material, （2） ultrathin 2D flexible support to remedy the sluggish reaction of the metal compound anode, and （3） good 2D building blocks for constructing macroscopic 3D pOFOUS car- bonjgraphene hybrids. In addition, some high performance aqueous LIHSs using graphene as electrode were also summarized. Finally, the perspectives and challenges are also proposed for further develop- ment of more advanced graphene-based LIHSs.展开更多
Three-dimensional （3D） carbonaceous materials derived from bacterial cellulose （BC） has been introduced as electrode for supercapacitors in recent. Here, we report a simple strategy for the synthesis of functional...Three-dimensional （3D） carbonaceous materials derived from bacterial cellulose （BC） has been introduced as electrode for supercapacitors in recent. Here, we report a simple strategy for the synthesis of functional carbon frameworks through 2,2,6,6-tetramethylpilperidine l-oxyl radical （TEMPO） mediated oxidation of bacterial cellulose （BC） followed by carbonization. TEMPO-mediated oxidation can efficiently convert the hydroxyls on the surface of BC to carboxylate groups to improve electrochemical activity. Because of its high porosity, good hydrophilicity, rich oxygen groups, and continuous ion transport in-between sheet-like porous network, the TEMPO-oxidized BC delivers a much higher gravimetric capacitance （137.3 Fig） at low annealing temperature of 500℃ than that of pyrolysis BC （31 F/g） at the same annealing temperature. The pyrolysis modified BC obtained at 900℃ shows specific capacitance （160.2Fig）, large current stability and long-term stability （84.2% of its initial capacitance retention after 10,000 cycles）.展开更多
Lithium-ion hybrid capacitors(LIHCs) is a promising electrochemical energy storage devices which combines the advantages of lithium-ion batteries and capacitors.Herein,we developed a facile multistep pyrolysis method,...Lithium-ion hybrid capacitors(LIHCs) is a promising electrochemical energy storage devices which combines the advantages of lithium-ion batteries and capacitors.Herein,we developed a facile multistep pyrolysis method,prepared an amorphous structure and a high-level N-doping carbon nanotubes(NCNTs),and by removing the Co catalyst,opening the port of NCNTs,and using NCNTs as anode material.It is shows good performance due to the electrolyte ions enter into the electrode materials and facilitate the charge transfer.Furthermore,we employ the porous carbon material(APDC) as the cathode to couple with anodes of NCNTs,building a LIHCs,it shows a high energy density of 173 Wh/kg at 200 W/kg and still retains 53 Wh/kg at a high power density of 10 kW/kg within the voltage window of 0-4.0 V,as well as outstanding cyclic life keep 80% capacity after 5000 cycles.This work provides an opportunity for the preparation of NCNTs,that is as a promising high-performance anode for LIHCs.展开更多
基金supported by the National Nature Science Foundations of China(Grant No.21673263,21573265)the Independent Innovation Plan Foundations of Qingdao City of China(Grant No.16-5-1-42-jch)the western Young Scholars Foundations of Chinese Academy of Sciences
文摘Lithium-ion hybrid supercapacitors （LIHSs）, also called Li-ion capacitors, are electrochemical energy stor- age devices that combining the advantages of high power density of supercapacitor and high energy density of Li-ion battery. However, high power density and long cycle life are still challenges for the cul~ rent LIHSs due to the imbalance of charge-storage capacity and electrode kinetics between capacitor-type cathode and battery-type anode. Therefore, great efforts have been made on designing novel cathode materials with high storage capacity and anode material with enhanced kinetic behavior for LIHSs. With unique two-dimensional form and numerous appealing properties, for the past several years, the rational designed graphene and its composites materials exhibit greatly improved electrochemical performance as cathode or anode for LIHSs. Here, we summarized and discussed the latest advances of the state- of-art graphene-based materials for LIHSs applications. The major roles of graphene are highlighted as （1） a superior active material, （2） ultrathin 2D flexible support to remedy the sluggish reaction of the metal compound anode, and （3） good 2D building blocks for constructing macroscopic 3D pOFOUS car- bonjgraphene hybrids. In addition, some high performance aqueous LIHSs using graphene as electrode were also summarized. Finally, the perspectives and challenges are also proposed for further develop- ment of more advanced graphene-based LIHSs.
基金supported by the National Nature Science Foundations of China (Nos.21573265 and 21673263)the Independent Innovation Plan Foundations of Qingdao City of China (No.16-5-1-42-jch)the plan of Youth Science foundations of Gansu Province (No.1610RJYA019)
文摘Three-dimensional （3D） carbonaceous materials derived from bacterial cellulose （BC） has been introduced as electrode for supercapacitors in recent. Here, we report a simple strategy for the synthesis of functional carbon frameworks through 2,2,6,6-tetramethylpilperidine l-oxyl radical （TEMPO） mediated oxidation of bacterial cellulose （BC） followed by carbonization. TEMPO-mediated oxidation can efficiently convert the hydroxyls on the surface of BC to carboxylate groups to improve electrochemical activity. Because of its high porosity, good hydrophilicity, rich oxygen groups, and continuous ion transport in-between sheet-like porous network, the TEMPO-oxidized BC delivers a much higher gravimetric capacitance （137.3 Fig） at low annealing temperature of 500℃ than that of pyrolysis BC （31 F/g） at the same annealing temperature. The pyrolysis modified BC obtained at 900℃ shows specific capacitance （160.2Fig）, large current stability and long-term stability （84.2% of its initial capacitance retention after 10,000 cycles）.
基金supported by the Natural Science Foundation of China(No.21872066)the Natural Science Foundation of Gansu(No.18JR3RA274)。
文摘Lithium-ion hybrid capacitors(LIHCs) is a promising electrochemical energy storage devices which combines the advantages of lithium-ion batteries and capacitors.Herein,we developed a facile multistep pyrolysis method,prepared an amorphous structure and a high-level N-doping carbon nanotubes(NCNTs),and by removing the Co catalyst,opening the port of NCNTs,and using NCNTs as anode material.It is shows good performance due to the electrolyte ions enter into the electrode materials and facilitate the charge transfer.Furthermore,we employ the porous carbon material(APDC) as the cathode to couple with anodes of NCNTs,building a LIHCs,it shows a high energy density of 173 Wh/kg at 200 W/kg and still retains 53 Wh/kg at a high power density of 10 kW/kg within the voltage window of 0-4.0 V,as well as outstanding cyclic life keep 80% capacity after 5000 cycles.This work provides an opportunity for the preparation of NCNTs,that is as a promising high-performance anode for LIHCs.
