Due to their rapid power delivery,fast charging,and long cycle life,supercapacitors have become an important energy storage technology recently.However,to meet the continuously increasing demands in the fields of port...Due to their rapid power delivery,fast charging,and long cycle life,supercapacitors have become an important energy storage technology recently.However,to meet the continuously increasing demands in the fields of portable electronics,transportation,and future robotic technologies,supercapacitors with higher energy densities without sacrificing high power densities and cycle stabilities are still challenged.Transition metal compounds(TMCs)possessing high theoretical capacitance are always used as electrode materials to improve the energy densities of supercapacitors.However,the power densities and cycle lives of such TMCs-based electrodes are still inferior due to their low intrinsic conductivity and large volume expansion during the charge/discharge process,which greatly impede their large-scale applications.Most recently,the ideal integrating of TMCs and conductive carbon skeletons is considered as an effective solution to solve the above challenges.Herein,we summarize the recent developments of TMCs/carbon hybrid electrodes which exhibit both high energy/power densities from the aspects of structural design strategies,including conductive carbon skeleton,interface engineering,and electronic structure.Furthermore,the remaining challenges and future perspectives are also highlighted so as to provide strategies for the high energy/power TMCs/carbon-based supercapacitors.展开更多
The development of lithium-sulfur batteries(LSBs)is restricted by their poor cycle stability and rate performance due to the low conductivity of sulfur and severe shuttle effect.Herein,an N,O co-doped graphene layered...The development of lithium-sulfur batteries(LSBs)is restricted by their poor cycle stability and rate performance due to the low conductivity of sulfur and severe shuttle effect.Herein,an N,O co-doped graphene layered block(NOGB)with many dents on the graphene sheets is designed as effective sulfur host for high-performance LSB s.The sulfur platelets are physically confined into the dents and closely contacted with the graphene scaffold,ensuring structural stability and high conductivity.The highly doped N and O atoms can prevent the shuttle effect of sulfur species by strong chemical adsorption.Moreover,the micropores on the graphene sheets enable fast Li^+transport through the blocks.As a result,the obtained NOGB/S composite with 76 wt%sulfur content shows a high capacity of 1413 mAh g^-1 at 0.1 C,good rate performance of 433 mAh g^-1 at 10 C,and remarkable stability with 526 mAh g^-1 at after 1000 cycles at 1 C(average decay rate:0.038%per cycle).Our design provides a comprehensive route for simultaneously improving the conductivity,ion transport kinetics,and preventing the shuttle effect in LSBs.展开更多
Carbon-based electric double layer capacitors(EDLCs)hold tremendous potentials due to their high-power performance and excellent cycle stability.However,the practical use of EDLCs is limited by the low energy density ...Carbon-based electric double layer capacitors(EDLCs)hold tremendous potentials due to their high-power performance and excellent cycle stability.However,the practical use of EDLCs is limited by the low energy density in aqueous electrolyte and sluggish diffusion kinetics in organic or/and ionic liquids electrolyte.Herein,3D carbon frameworks(3DCFs)constructed by interconnected nanocages(10-20 nm)with an ultrathin wall of ca.2 nm have been fabricated,which possess high specific surface area,hierarchical porosity and good conductive network.After deoxidization,the deoxidized 3DCF(3DCFDO)exhibits a record low IR drop of 0.064 V at 100 A g^−1 and ultrafast charge/discharge rate up to 10 V s^−1.The related device can be charged up to 77.4%of its maximum capacitance in 0.65 s at 100 A g^−1 in 6 M KOH.It has been found that the 3DCF-DO has a great affinity to EMIMBF4,resulting in a high specific capacitance of 174 F g^−1 at 1 A g^−1,and a high energy density of 34 Wh kg^−1 at an ultrahigh power density of 150 kW kg^−1 at 4 V after a fast charge in 1.11 s.This work provides a facile fabrication of novel 3D carbon frameworks for supercapacitors with ultrafast charge/discharge rate and high energy-power density.展开更多
Supercapacitors(SCs)have attracted extensive attention due to their ultrahigh power density,fast charging/discharging rate,excellent electrochemical stability and environmental friendliness.Currently,the main commerci...Supercapacitors(SCs)have attracted extensive attention due to their ultrahigh power density,fast charging/discharging rate,excellent electrochemical stability and environmental friendliness.Currently,the main commercial electrode materials for SCs are carbon materials in term of low cost,excellent conductivity,large specific surface area and good electrochemical stability.Recently,various dimensional carbon materials including zero dimensional(0D)carbon materials(nanosphere,dot etc.),1D carbon materials(nanotube,nanofiber etc.),2D carbon materials(nanosheet)as well as 3D carbon materials have been developed for SCs.Carbon materials with different spatial dimensions have their unique properties when used as the electrode materials for SCs.In this review,recent advances in the fabrication of different dimensional carbons for SCs are summarized.Several key issues for enhancing the electrochemical properties of carbon-based SCs and some mutual relationships among various influence parameters are reviewed,and challenges and perspectives in this field are also discussed.展开更多
1.Introduction Carbon materials have been widely investigated as the anode materials for Na+storage due to their moderate capacity,good stability,and low cost.The Na+storage mechanisms of carbon are generally classifi...1.Introduction Carbon materials have been widely investigated as the anode materials for Na+storage due to their moderate capacity,good stability,and low cost.The Na+storage mechanisms of carbon are generally classified into diffusion-controlled interlayer insertion/desertion and capacitive-controlled surface adsorption/desorption[1].展开更多
This work presents NiS/graphene/carbon nanotube （NiS/GNS/CNT） composites as electrode material for the supercapacitor application in sea flashing signal systems. NiS nanosheets were closely anchored on the conductiv...This work presents NiS/graphene/carbon nanotube （NiS/GNS/CNT） composites as electrode material for the supercapacitor application in sea flashing signal systems. NiS nanosheets were closely anchored on the conductive GNS-CNT networks. As a result, the NiS/GNS/CNT electrode showed a high specific capacitance of 2 377 F.g^-1 at 2 mV.s^-1 and good cycling stability compared with the pure NiS （1 599F.g^-1）. The enhanced electrochemical performances are attributed to the synergetic effect between the conductive carbon and the pseudo-capacitive NiS. The high performance supercapacitor may provide application in the sea flashing signal system.展开更多
N-doped reduced graphene oxide quantum dots(N-rGQDs) have attracted more and more attention in efficient catalytic degradation of aqueous organic pollutants.However,the synthesis of N-rGQDs is generally a complex and ...N-doped reduced graphene oxide quantum dots(N-rGQDs) have attracted more and more attention in efficient catalytic degradation of aqueous organic pollutants.However,the synthesis of N-rGQDs is generally a complex and high energy required process for the reduction and N-doping steps.In this study,a facile and green fabrication approach of N-rGQDs is established,based on a metal-free Fenton reaction without additional energy-input.The N structures of N-rGQDs play a significant role in the promotion of their catalytic performance.The N-rGQDs with relatively high percentage of aromatic nitrogen(NAr-rGQDs) perform excellent catalytic activities,with which the degradation efficiency of pollutant is enhanced by 25 times.Density functional theory(DFT) calculation also indicates aromatic nitrogen structures with electron-rich sites are prone to transfer electron,presenting a key role in the catalytic reaction.This metal-free Fenton process provides a green and costeffective strategy for one-step fabrication of N-rGQDs with controllable features and potential environmental catalytic applications.展开更多
基金This work was supported by the National Natural Science Foundation of China(Nos.51972342,and 51872056)Taishan Scholar Project of Shandong Province(ts20190922)+3 种基金Key Basic Research Project of Natural Science Foundation of Shandong Province(ZR2019ZD51)Project funded by China Postdoctoral Science Foundation(2019TQ0353 and 2020M672165)Fundamental Research Funds for the Central Universities(20CX06024A)Shandong Provincial Natural Science Foundation,China(ZR201911040344).
文摘Due to their rapid power delivery,fast charging,and long cycle life,supercapacitors have become an important energy storage technology recently.However,to meet the continuously increasing demands in the fields of portable electronics,transportation,and future robotic technologies,supercapacitors with higher energy densities without sacrificing high power densities and cycle stabilities are still challenged.Transition metal compounds(TMCs)possessing high theoretical capacitance are always used as electrode materials to improve the energy densities of supercapacitors.However,the power densities and cycle lives of such TMCs-based electrodes are still inferior due to their low intrinsic conductivity and large volume expansion during the charge/discharge process,which greatly impede their large-scale applications.Most recently,the ideal integrating of TMCs and conductive carbon skeletons is considered as an effective solution to solve the above challenges.Herein,we summarize the recent developments of TMCs/carbon hybrid electrodes which exhibit both high energy/power densities from the aspects of structural design strategies,including conductive carbon skeleton,interface engineering,and electronic structure.Furthermore,the remaining challenges and future perspectives are also highlighted so as to provide strategies for the high energy/power TMCs/carbon-based supercapacitors.
基金supported by the National Natural Science Foundation of China(Nos.51672055,51972342,51872656,and 51702275)the Taishan Scholar Project of Shandong Province(ts20190922)+3 种基金the Key Basic Research Project of Natural Science Foundation of Shandong Province(ZR2019ZD51)the Xinjiang Tianshan Xuesong Project(2018XS28)the Scientific Research Program of the Higher Education Institution of Xinjiang(XJEDU2017S003)the Xinjiang Tianchi Doctoral Project。
文摘The development of lithium-sulfur batteries(LSBs)is restricted by their poor cycle stability and rate performance due to the low conductivity of sulfur and severe shuttle effect.Herein,an N,O co-doped graphene layered block(NOGB)with many dents on the graphene sheets is designed as effective sulfur host for high-performance LSB s.The sulfur platelets are physically confined into the dents and closely contacted with the graphene scaffold,ensuring structural stability and high conductivity.The highly doped N and O atoms can prevent the shuttle effect of sulfur species by strong chemical adsorption.Moreover,the micropores on the graphene sheets enable fast Li^+transport through the blocks.As a result,the obtained NOGB/S composite with 76 wt%sulfur content shows a high capacity of 1413 mAh g^-1 at 0.1 C,good rate performance of 433 mAh g^-1 at 10 C,and remarkable stability with 526 mAh g^-1 at after 1000 cycles at 1 C(average decay rate:0.038%per cycle).Our design provides a comprehensive route for simultaneously improving the conductivity,ion transport kinetics,and preventing the shuttle effect in LSBs.
基金the financial support from the National Natural Science Foundation of China(51672033,U1610255,U1703251).
文摘Carbon-based electric double layer capacitors(EDLCs)hold tremendous potentials due to their high-power performance and excellent cycle stability.However,the practical use of EDLCs is limited by the low energy density in aqueous electrolyte and sluggish diffusion kinetics in organic or/and ionic liquids electrolyte.Herein,3D carbon frameworks(3DCFs)constructed by interconnected nanocages(10-20 nm)with an ultrathin wall of ca.2 nm have been fabricated,which possess high specific surface area,hierarchical porosity and good conductive network.After deoxidization,the deoxidized 3DCF(3DCFDO)exhibits a record low IR drop of 0.064 V at 100 A g^−1 and ultrafast charge/discharge rate up to 10 V s^−1.The related device can be charged up to 77.4%of its maximum capacitance in 0.65 s at 100 A g^−1 in 6 M KOH.It has been found that the 3DCF-DO has a great affinity to EMIMBF4,resulting in a high specific capacitance of 174 F g^−1 at 1 A g^−1,and a high energy density of 34 Wh kg^−1 at an ultrahigh power density of 150 kW kg^−1 at 4 V after a fast charge in 1.11 s.This work provides a facile fabrication of novel 3D carbon frameworks for supercapacitors with ultrafast charge/discharge rate and high energy-power density.
基金supported by National Natural Science Foundation of China 51702043(51702043,51672055,51972342,51902345,51872656)Fundamental Research Funds for the Central Universities(20 C×06024 A,19 C×05001 A)+1 种基金Taishan Scholar Project of Shandong Province(ts20190922)Key Basic Research Projects of Natural Science Foundation of Shandong Province(ZR2019ZD51).
文摘Supercapacitors(SCs)have attracted extensive attention due to their ultrahigh power density,fast charging/discharging rate,excellent electrochemical stability and environmental friendliness.Currently,the main commercial electrode materials for SCs are carbon materials in term of low cost,excellent conductivity,large specific surface area and good electrochemical stability.Recently,various dimensional carbon materials including zero dimensional(0D)carbon materials(nanosphere,dot etc.),1D carbon materials(nanotube,nanofiber etc.),2D carbon materials(nanosheet)as well as 3D carbon materials have been developed for SCs.Carbon materials with different spatial dimensions have their unique properties when used as the electrode materials for SCs.In this review,recent advances in the fabrication of different dimensional carbons for SCs are summarized.Several key issues for enhancing the electrochemical properties of carbon-based SCs and some mutual relationships among various influence parameters are reviewed,and challenges and perspectives in this field are also discussed.
基金supported by the National Natural Science Foundation of China(Nos.51972342,5187205652062046,and 51702275)the Taishan Scholar Project of Shandong Province(ts20190922)+3 种基金the Key Basic Research Projects of Natural Science Foundation of Shandong province(ZR2019ZD51)the CAS Key aboratory of Carbon Materials(KLCMKFJJ2012)the Science Foundation of Xinjiang Autonomous Region(2020D01C019)the Fundamental Research Funds for the Central Universities(20CX05010A)。
文摘1.Introduction Carbon materials have been widely investigated as the anode materials for Na+storage due to their moderate capacity,good stability,and low cost.The Na+storage mechanisms of carbon are generally classified into diffusion-controlled interlayer insertion/desertion and capacitive-controlled surface adsorption/desorption[1].
基金Foundation item： Supported by the National Natural Science Foundation of China （Nos. 51077014, 21003028 and 51202043）： the Fundamental Research funds for the Central Universities, the Program for New Century Excellent Talents in University （NCET-10-0050）, and the Excellent Youth Foundation of Heilongjiang Province of China.
文摘This work presents NiS/graphene/carbon nanotube （NiS/GNS/CNT） composites as electrode material for the supercapacitor application in sea flashing signal systems. NiS nanosheets were closely anchored on the conductive GNS-CNT networks. As a result, the NiS/GNS/CNT electrode showed a high specific capacitance of 2 377 F.g^-1 at 2 mV.s^-1 and good cycling stability compared with the pure NiS （1 599F.g^-1）. The enhanced electrochemical performances are attributed to the synergetic effect between the conductive carbon and the pseudo-capacitive NiS. The high performance supercapacitor may provide application in the sea flashing signal system.
基金funding by National Natural Science Foundation of China (No. 51978643)Youth Innovation Promotion Association of CAS (Y201814)The National Youth Talent Support Program of China。
文摘N-doped reduced graphene oxide quantum dots(N-rGQDs) have attracted more and more attention in efficient catalytic degradation of aqueous organic pollutants.However,the synthesis of N-rGQDs is generally a complex and high energy required process for the reduction and N-doping steps.In this study,a facile and green fabrication approach of N-rGQDs is established,based on a metal-free Fenton reaction without additional energy-input.The N structures of N-rGQDs play a significant role in the promotion of their catalytic performance.The N-rGQDs with relatively high percentage of aromatic nitrogen(NAr-rGQDs) perform excellent catalytic activities,with which the degradation efficiency of pollutant is enhanced by 25 times.Density functional theory(DFT) calculation also indicates aromatic nitrogen structures with electron-rich sites are prone to transfer electron,presenting a key role in the catalytic reaction.This metal-free Fenton process provides a green and costeffective strategy for one-step fabrication of N-rGQDs with controllable features and potential environmental catalytic applications.
