With high surface area,open porosity and high efficiency,a catalyst was prepared and firstly employed in electrocatalytic reduction of CO2 and electrosynthesis of dimethyl carbonate（DMC）.The electrochemical property...With high surface area,open porosity and high efficiency,a catalyst was prepared and firstly employed in electrocatalytic reduction of CO2 and electrosynthesis of dimethyl carbonate（DMC）.The electrochemical property for electrocatalytic reduction of CO2 in ionic liquid was studied by cyclic voltammogram（CV）.The effects of various reaction variables like temperature,working potential and cathode materials on the electrocatalytic performance were also investigated.80%yield of DMC was obtained under the optimal reaction conditions.展开更多
Fe3O4/CMK-3 was prepared by impregnation and used as a catalyst for the direct hydroxylation of benzene to phenol with hydro-gen peroxide. The iron species in the prepared catalyst was Fe3O4 because of the partial red...Fe3O4/CMK-3 was prepared by impregnation and used as a catalyst for the direct hydroxylation of benzene to phenol with hydro-gen peroxide. The iron species in the prepared catalyst was Fe3O4 because of the partial reduction of iron(III) to iron(II) on the surface of CMK-3. The high catalytic activity of the catalyst arises from the formation of Fe3O4 on the surface of CMK-3 and the high selectivity for phenol is attributed to the consumption of excess hydroxyl radicals by CMK-3. The effect of temperature,reaction time,volume of H2O2,and amount of catalyst on the catalytic performance of the prepared catalyst were investigated. Under optimized conditions,the catalyst showed excellent catalytic performance for the hydroxylation of benzene to phenol and 18% benzene conversion was achieved with 92% selectivity for phenol and with a TOF value of 8.7 h-1. The stability of catalyst was investigated by determining its activity after the fourth run and it was found to have decreased to 80% of the fresh catalyst's activity.展开更多
Capacitance for electrostatic adsorption forms primarily within a Debye length of the electrode surface. Capacitive carbon electrodes were derivatized with ionic groups by means of adsorbing a surfactant in order to t...Capacitance for electrostatic adsorption forms primarily within a Debye length of the electrode surface. Capacitive carbon electrodes were derivatized with ionic groups by means of adsorbing a surfactant in order to test the theory that attached ionic groups would exclude co-ions and increase coulombic efficiency without the need for an added charge barrier membrane. It has been discovered that capacitive electrodes surface derivatized with ionic groups become polarized and intrinsically more coulombically efficient.展开更多
Rechargeable metal-iodine batteries are an emerging attractive electrochemical energy storage technology that combines metallic anodes with halogen cathodes. Such batteries using aqueous electrolytes represent a viabl...Rechargeable metal-iodine batteries are an emerging attractive electrochemical energy storage technology that combines metallic anodes with halogen cathodes. Such batteries using aqueous electrolytes represent a viable solution for the safety and cost issues associated with organic electrolytes. A hybrid-electrolyte battery architecture has been adopted in a lithium-iodine battery using a solid ceramic membrane that protects the metallic anode from contacting the aqueous electrolyte. Here we demonstrate an eco-friendly, low-cost zinc-iodine battery with an aqueous electrolyte, wherein active I2 is confined in a nanoporous carbon cloth substrate. The electrochemical reaction is confined in the nanopores as a single conversion reaction, thus avoiding the production of I3- intermediates. The cathode architecture fully utilizes the active I2, showing a capacity of 255 mAh·g^-1 and low capacity cycling fading. The battery provides an energy density of -151 Wh·kg^-1 and exhibits an ultrastable cycle life of more than 1,500 cycles.展开更多
Studies on three-dimensional structured carbon templates have focused on how to guide homogeneous lithium metal nucleation and growth for lithium metal anodes(LMAs).However,there is still insufficient evidence for a k...Studies on three-dimensional structured carbon templates have focused on how to guide homogeneous lithium metal nucleation and growth for lithium metal anodes(LMAs).However,there is still insufficient evidence for a key factor to achieve their high electrochemical performance.Here,the effects of nanopores and sulfur doping on carbon-based nanoporous host(CNH)electrode materials for LMAs were investigated using natural polymer-derived CNHs.Homogeneous pore-filling behaviors of lithium metal in the nanopores of the CNH electrode materials were first observed by ex situ scanning electron microscopy analysis,where the protective lithium metal nucleation and growth process led to significantly high Coulombic efficiency(CE)of~99.4%and stable 600 cycles.In addition,a comparison study of CNH and sulfurdoped CNH(S-CNH)electrodes,which differ only in the presence or absence of sulfur,revealed that sulfur doping can cause lower electrochemical series resistance,higher CE value,and better cycling stability in a wide range of current densities and number of cycles.Moreover,S-CNH-based LMAs showed high electrochemical performance in full-cell Li-S battery tests using a sulfur copolymer cathode,where a high energy density of 1370Wh kgelectrode−1 and an excellent power density of 4120Wkgelectrode−1 were obtained.展开更多
High-performance batteries with high density and low cost are needed for the development of largescale energy storage fields such as electric vehicles and renewable energy systems.The anode with threedimensional(3D)na...High-performance batteries with high density and low cost are needed for the development of largescale energy storage fields such as electric vehicles and renewable energy systems.The anode with threedimensional(3D)nanoarchitecture is one of the most attractive candidates for high-performance lithiumion batteries(LIBs)and sodium-ion batteries(SIBs)due to its efficient electron/ion transport and high active material mass loading.Although some important breakthroughs have been made in 3D nanoarchitecture anode materials,more improvements are still needed for high cycling stability and high energy density.Herein,the latest research progress of 3D nanoarchitecture anode materials for LIBs and SIBs is reviewed,including nanoporous metal,nanoporous graphene,and their derived foams.Specifically,the storage properties of Li/Na ions,the kinetics of ion/electron transport,and specific chemical interactions are discussed based on the structure design.In addition,the research strategies and structural characteristics of 3D nanoarchitecture anode materials are summarized,providing a reference for the further development of LIBs and SIBs.Meanwhile,the future research directions of LIBs and SIBs have also prospected.展开更多
The coupling between electrochemically active material and conductive matrix is vitally important for high efficiency lithium ion batteries （LIBs）. By introducing oxygen groups into the nanoporous carbon framework, ...The coupling between electrochemically active material and conductive matrix is vitally important for high efficiency lithium ion batteries （LIBs）. By introducing oxygen groups into the nanoporous carbon framework, we accom- plish sustainably enhanced electrochemical performance for a SnO2/carbon LIB. 2-5 nm SnO2 nanoparticles are hydro- thermally grown in different nanoporous carbon frameworks, which are pristine, nitrogen- or oxygen-doped carbons. Compared with pristine and nitrogen-doped carbon hosts, the SnO2/oxygen-doped activated carbon （OAC） composite ex- hibits a higher discharge capacity of 1,122mAhg^-1 at 500 mA g^-1 after 320 cycles operation and a larger lithium storage capacity up to 680 mAhg-I at a high rate of 2,000 mA g^-1. The exceptional electrochemical performance originated from the oxygen groups, which could act as Lewis acid sites to attract electrons effectively from Sn during the charge process, thus accelerating reversible conversion of Sn to SnO2. Meanwhile, SnO2 nanoparticles are effectively bonded with carbon through such oxygen groups, thus preventing the electrochemical sintering and maintaining the cycling stability of the SnO2/OAC composite anode. The high electrochemical performance, low biomass cost, and facile preparation renders the SnO2/OAC composites a promising candidate for anode materials.展开更多
Binary transition metal sulfides are hotly investigated in advanced energy storage devices because of their ultra-high reversible capacity.Nevertheless,the unsatisfied rate capability and cycling stability still hinde...Binary transition metal sulfides are hotly investigated in advanced energy storage devices because of their ultra-high reversible capacity.Nevertheless,the unsatisfied rate capability and cycling stability still hinder their practical application.Herein,hierarchical nanoporous carbon@NiCo_(2)S_(4)(HNCMs@NCS)composites with coreshell flower-like structures were prepared by in situ growing of NiCo_(2)S_(4) nanosheets on HNCMs through a hydro thermal-as sis ted template sacrificial method.Benefiting from a synergistic effect between the NiCo_(2)S_(4)shell with high specific capacity and the HNCMs with unique porous structure,the synthesized flower-like HNCMs@NCS composites exhibit extraordinary electrochemical performances,including a high capacity of 346.9 mAh·g^(-1)at 1 A·g^(-1),superb rate property with86.4%initial capacity at 30 A·g^(-1)and predominant cycle stability with 81.2%capacity retention after 5000 cycles.Furthermore,the resulting HNCMs@NCS cathode was coupled with the chemical-activated HNCMs(AHNCMs)anode to construct a hybrid supercapacitor device.The asfabricated device exhibits superior energy density(49.9 Wh·kg^(-1)at 802 W·kg^(-1))and ultra-high power density(24 kW·kg^(-1)at 29.5 Wh·kg^(-1)).This fascinating result further demonstrates the tremendous prospect of the synthesized HNCMs@NCS composites as high-performance supercapacitor electrode materials.展开更多
Lithium-selenium(Li-Se)battery has attracted growing attention.Nevertheless,its practical application is still impeded by the shuttle effect of the formed polyselenides.Herein,we report in-situ hydrothermal weaving th...Lithium-selenium(Li-Se)battery has attracted growing attention.Nevertheless,its practical application is still impeded by the shuttle effect of the formed polyselenides.Herein,we report in-situ hydrothermal weaving the three-dimensional(3 D)highly conductive hierarchically interconnected nanoporous web by threading microporous metal organic framework MIL-68(Al)crystals onto multi-walled carbon nanotubes(MWCNTs).Such 3 D hierarchically nanoporous web(3 D MIL-68(Al)@MWCNTs web)with a very high surface area,a large amount of micropores,electrical conductivity and elasticity strongly traps the soluble polyselenides during the electrochemical reaction and significantly facilitates lithium ion diffusion and electron transportation.Molecular dynamic calculation confirmed the strong affinity of MIL-68(Al)for the adsorption of polyselenides,quite suitable for Li-Se battery.Their hexahedral channels(1.56 nm)are more efficient for the confinement of polyselenides and for the diffusion of electrolytes compared to their smaller triangular channels(0.63 nm).All these excellent characteristics of 3 D MIL-68(Al)@MWCNTs web with suitable confinement of a large amount of selenium and the conductive linkage between MIL-68(Al)host by MWCNTs result in a high capacity of 453 m Ah/g at 0.2 C with 99.5%coulombic efficiency after 200 cycles with significantly improved cycle stability and rate performance.The 3 D MIL-68(Al)@MWCNTs web presents a good performance in Li-Se battery in term of the specific capacity and cycling stability and also in terms of rate performance compared with all the metal-organic framework(MOF)based or MOF derived porous carbons used in Li-Se battery.展开更多
基金the National Natural Science Foundation of China(No.20976197) for its financial support of this project
文摘With high surface area,open porosity and high efficiency,a catalyst was prepared and firstly employed in electrocatalytic reduction of CO2 and electrosynthesis of dimethyl carbonate（DMC）.The electrochemical property for electrocatalytic reduction of CO2 in ionic liquid was studied by cyclic voltammogram（CV）.The effects of various reaction variables like temperature,working potential and cathode materials on the electrocatalytic performance were also investigated.80%yield of DMC was obtained under the optimal reaction conditions.
文摘Fe3O4/CMK-3 was prepared by impregnation and used as a catalyst for the direct hydroxylation of benzene to phenol with hydro-gen peroxide. The iron species in the prepared catalyst was Fe3O4 because of the partial reduction of iron(III) to iron(II) on the surface of CMK-3. The high catalytic activity of the catalyst arises from the formation of Fe3O4 on the surface of CMK-3 and the high selectivity for phenol is attributed to the consumption of excess hydroxyl radicals by CMK-3. The effect of temperature,reaction time,volume of H2O2,and amount of catalyst on the catalytic performance of the prepared catalyst were investigated. Under optimized conditions,the catalyst showed excellent catalytic performance for the hydroxylation of benzene to phenol and 18% benzene conversion was achieved with 92% selectivity for phenol and with a TOF value of 8.7 h-1. The stability of catalyst was investigated by determining its activity after the fourth run and it was found to have decreased to 80% of the fresh catalyst's activity.
文摘Capacitance for electrostatic adsorption forms primarily within a Debye length of the electrode surface. Capacitive carbon electrodes were derivatized with ionic groups by means of adsorbing a surfactant in order to test the theory that attached ionic groups would exclude co-ions and increase coulombic efficiency without the need for an added charge barrier membrane. It has been discovered that capacitive electrodes surface derivatized with ionic groups become polarized and intrinsically more coulombically efficient.
基金This work was financially supported by the National Natural Science Foundation of China （Nos. 21171128 and 21603162）, Tianjin Sci. ＆ Tech. Program （No. 17JCYBJC21500）, and the Fundamental Research Funds of Tianjin University of Technology.
文摘Rechargeable metal-iodine batteries are an emerging attractive electrochemical energy storage technology that combines metallic anodes with halogen cathodes. Such batteries using aqueous electrolytes represent a viable solution for the safety and cost issues associated with organic electrolytes. A hybrid-electrolyte battery architecture has been adopted in a lithium-iodine battery using a solid ceramic membrane that protects the metallic anode from contacting the aqueous electrolyte. Here we demonstrate an eco-friendly, low-cost zinc-iodine battery with an aqueous electrolyte, wherein active I2 is confined in a nanoporous carbon cloth substrate. The electrochemical reaction is confined in the nanopores as a single conversion reaction, thus avoiding the production of I3- intermediates. The cathode architecture fully utilizes the active I2, showing a capacity of 255 mAh·g^-1 and low capacity cycling fading. The battery provides an energy density of -151 Wh·kg^-1 and exhibits an ultrastable cycle life of more than 1,500 cycles.
基金National Research Foundation of Korea,Grant/Award Numbers:2019R1A2C1084836,2021R1A4A2001403。
文摘Studies on three-dimensional structured carbon templates have focused on how to guide homogeneous lithium metal nucleation and growth for lithium metal anodes(LMAs).However,there is still insufficient evidence for a key factor to achieve their high electrochemical performance.Here,the effects of nanopores and sulfur doping on carbon-based nanoporous host(CNH)electrode materials for LMAs were investigated using natural polymer-derived CNHs.Homogeneous pore-filling behaviors of lithium metal in the nanopores of the CNH electrode materials were first observed by ex situ scanning electron microscopy analysis,where the protective lithium metal nucleation and growth process led to significantly high Coulombic efficiency(CE)of~99.4%and stable 600 cycles.In addition,a comparison study of CNH and sulfurdoped CNH(S-CNH)electrodes,which differ only in the presence or absence of sulfur,revealed that sulfur doping can cause lower electrochemical series resistance,higher CE value,and better cycling stability in a wide range of current densities and number of cycles.Moreover,S-CNH-based LMAs showed high electrochemical performance in full-cell Li-S battery tests using a sulfur copolymer cathode,where a high energy density of 1370Wh kgelectrode−1 and an excellent power density of 4120Wkgelectrode−1 were obtained.
基金National Natural Science Foundation of China(50730003,50672025,20806024,and 51002051)Fundamental Research Funds for the Central Universities(WA1014016)Research Fund of China 863 program(2008AA062302)~~
基金financially supported by the National Key R&D Program of China(2021YFB3802200)the National Natural Science Foundation of China(No.51801136)+2 种基金the Tianjin Natural Science Foundation of China(No.18JCYBJC41800)the Tianjin science and technology project(Nos.18ZXJMTG00300,20ZYJDJC00100)the Discovery Early Career Researcher Award(DECRA,No.DE180101478)of the Australian Research Council。
文摘High-performance batteries with high density and low cost are needed for the development of largescale energy storage fields such as electric vehicles and renewable energy systems.The anode with threedimensional(3D)nanoarchitecture is one of the most attractive candidates for high-performance lithiumion batteries(LIBs)and sodium-ion batteries(SIBs)due to its efficient electron/ion transport and high active material mass loading.Although some important breakthroughs have been made in 3D nanoarchitecture anode materials,more improvements are still needed for high cycling stability and high energy density.Herein,the latest research progress of 3D nanoarchitecture anode materials for LIBs and SIBs is reviewed,including nanoporous metal,nanoporous graphene,and their derived foams.Specifically,the storage properties of Li/Na ions,the kinetics of ion/electron transport,and specific chemical interactions are discussed based on the structure design.In addition,the research strategies and structural characteristics of 3D nanoarchitecture anode materials are summarized,providing a reference for the further development of LIBs and SIBs.Meanwhile,the future research directions of LIBs and SIBs have also prospected.
基金supported by the National High Technology Research and Development Program of China(2012AA053305 and 2014AA052501)the National Natural Science Foundation of China(21506224)
文摘The coupling between electrochemically active material and conductive matrix is vitally important for high efficiency lithium ion batteries （LIBs）. By introducing oxygen groups into the nanoporous carbon framework, we accom- plish sustainably enhanced electrochemical performance for a SnO2/carbon LIB. 2-5 nm SnO2 nanoparticles are hydro- thermally grown in different nanoporous carbon frameworks, which are pristine, nitrogen- or oxygen-doped carbons. Compared with pristine and nitrogen-doped carbon hosts, the SnO2/oxygen-doped activated carbon （OAC） composite ex- hibits a higher discharge capacity of 1,122mAhg^-1 at 500 mA g^-1 after 320 cycles operation and a larger lithium storage capacity up to 680 mAhg-I at a high rate of 2,000 mA g^-1. The exceptional electrochemical performance originated from the oxygen groups, which could act as Lewis acid sites to attract electrons effectively from Sn during the charge process, thus accelerating reversible conversion of Sn to SnO2. Meanwhile, SnO2 nanoparticles are effectively bonded with carbon through such oxygen groups, thus preventing the electrochemical sintering and maintaining the cycling stability of the SnO2/OAC composite anode. The high electrochemical performance, low biomass cost, and facile preparation renders the SnO2/OAC composites a promising candidate for anode materials.
基金financially supported by the National Natural Science Foundation of China(No.52174247)the Distinguish Young Scientists of Hunan province(No.2022JJ10024)+2 种基金"Hejian"Innovative Talent Project of Hunan Province(No.2022RC1088)the Natural Science Foundation of Hunan Province(Nos.2021JJ30212 and 2021JJ30216)the Scientific Research and Innovation Foundation of Hunan University of Technology(No.CX2209)。
文摘Binary transition metal sulfides are hotly investigated in advanced energy storage devices because of their ultra-high reversible capacity.Nevertheless,the unsatisfied rate capability and cycling stability still hinder their practical application.Herein,hierarchical nanoporous carbon@NiCo_(2)S_(4)(HNCMs@NCS)composites with coreshell flower-like structures were prepared by in situ growing of NiCo_(2)S_(4) nanosheets on HNCMs through a hydro thermal-as sis ted template sacrificial method.Benefiting from a synergistic effect between the NiCo_(2)S_(4)shell with high specific capacity and the HNCMs with unique porous structure,the synthesized flower-like HNCMs@NCS composites exhibit extraordinary electrochemical performances,including a high capacity of 346.9 mAh·g^(-1)at 1 A·g^(-1),superb rate property with86.4%initial capacity at 30 A·g^(-1)and predominant cycle stability with 81.2%capacity retention after 5000 cycles.Furthermore,the resulting HNCMs@NCS cathode was coupled with the chemical-activated HNCMs(AHNCMs)anode to construct a hybrid supercapacitor device.The asfabricated device exhibits superior energy density(49.9 Wh·kg^(-1)at 802 W·kg^(-1))and ultra-high power density(24 kW·kg^(-1)at 29.5 Wh·kg^(-1)).This fascinating result further demonstrates the tremendous prospect of the synthesized HNCMs@NCS composites as high-performance supercapacitor electrode materials.
基金supported by the National Postdoctoral Program(2020M672782)National Natural Science Foundation of China(No.U1663225)+2 种基金Changjiang Scholars and Innovative Research Team in University(No.IRT15R52)National 111 project from the Ministry of Science and Technologythe Ministry of Education of China and the National Key R&D Program of China(No.2016YFA0202602)。
文摘Lithium-selenium(Li-Se)battery has attracted growing attention.Nevertheless,its practical application is still impeded by the shuttle effect of the formed polyselenides.Herein,we report in-situ hydrothermal weaving the three-dimensional(3 D)highly conductive hierarchically interconnected nanoporous web by threading microporous metal organic framework MIL-68(Al)crystals onto multi-walled carbon nanotubes(MWCNTs).Such 3 D hierarchically nanoporous web(3 D MIL-68(Al)@MWCNTs web)with a very high surface area,a large amount of micropores,electrical conductivity and elasticity strongly traps the soluble polyselenides during the electrochemical reaction and significantly facilitates lithium ion diffusion and electron transportation.Molecular dynamic calculation confirmed the strong affinity of MIL-68(Al)for the adsorption of polyselenides,quite suitable for Li-Se battery.Their hexahedral channels(1.56 nm)are more efficient for the confinement of polyselenides and for the diffusion of electrolytes compared to their smaller triangular channels(0.63 nm).All these excellent characteristics of 3 D MIL-68(Al)@MWCNTs web with suitable confinement of a large amount of selenium and the conductive linkage between MIL-68(Al)host by MWCNTs result in a high capacity of 453 m Ah/g at 0.2 C with 99.5%coulombic efficiency after 200 cycles with significantly improved cycle stability and rate performance.The 3 D MIL-68(Al)@MWCNTs web presents a good performance in Li-Se battery in term of the specific capacity and cycling stability and also in terms of rate performance compared with all the metal-organic framework(MOF)based or MOF derived porous carbons used in Li-Se battery.
