The unique synergistic effect of hierarchical core-shell structures demonstrates great potential for designing the next-generation electrode materials for supercapacitors.In this work,we design binderfree MnCo_(2)O_(4...The unique synergistic effect of hierarchical core-shell structures demonstrates great potential for designing the next-generation electrode materials for supercapacitors.In this work,we design binderfree MnCo_(2)O_(4)@NiMoO_(4)heterostructure core-shell nanowire arrays(NWAs)grown over a current collector of nickel foam(NF)achieved through a modified and simple hydrothermal process.The capacitive performance of the core MnCo_(2)O_(4)NWAs was remarkably improved by growing a layer of NiMoO_(4)nanosheets(1244 F g^(-1)at 1 A g^(-1)),which is superior to the capacitance of pristine MnCo_(2)O_(4)(457.85 F g^(-1)at 1 A g^(-1)).Moreover,the prepared MnCo_(2)O_(4)@NiMoO_(4)core-shell NWAs have been used along with commercial activated carbon(AC)to fabricate an asymmetric full supercapacitor device.MnCo_(2)O_(4)@NiMoO_(4)//AC delivers a high energy density(42 W h kg^(-1))at a power density of 852.3 W kg^(-1)and a good cyclability with 93%of the initial capacitance retained at the end of 8000 successive charge/discharge cycles.Therefore,the MnCo_(2)O_(4)@NiMoO_(4)electrode material holds a great promise as a suitable candidate for high performance supercapacitors.展开更多
Supercapacitors, with ultrahigh power density, superior rate capability, long-term cyclability, and exceptional safety, are regarded as one highly competitive candidate of electrochemical energy storage devices,fillin...Supercapacitors, with ultrahigh power density, superior rate capability, long-term cyclability, and exceptional safety, are regarded as one highly competitive candidate of electrochemical energy storage devices,filling the gap between batteries and conventional capacitors. Despite of tremendous effort, elaborated screening of high-performance electrode materials, e.g., graphene, is still intensively required. In this review, we describe the most recent progress in the research and development of graphene-based materials for high-performance and new-concept supercapacitors for the targeted applications in next-generation and smart electronics. First, the design and fabrication of high-performance supercapacitors, including electrical double layer capacitors, pseudocapacitors and hybrid supercapacitors, were summarized in term of the charge storage mechanism. Second, new-concept supercapacitors with multiple functionalities of high-voltage, fiber-shape, microscale and shape-diversity in order to fulfill the requirements of future electronics are reviewed. Accordingly, special emphasis is given to the structure-dependent-performance effects of pores, hybridization, dimensionalities of graphene-based materials on performance of supercapacitors, and tremendous potential of graphene-based planar micro-supercapacitors for the direct seamlessly integration with versatile micro-electronics. Finally, perspectives and challenges of graphene-based supercapacitors are briefly discussed.展开更多
Coordination tuning electronic structure of host materials is a quite effective strategy for activating and improving the intrinsic properties.Herein,halogen anion(X-)-incorporated β-FeOOH(β-FeOOH(X),X=F-,Cl-,and Br...Coordination tuning electronic structure of host materials is a quite effective strategy for activating and improving the intrinsic properties.Herein,halogen anion(X-)-incorporated β-FeOOH(β-FeOOH(X),X=F-,Cl-,and Br-) was investigated with a spontaneous adsorption process,which realized a great improvement of supercapacitor performances by adjusting the coordination geometry.Experiments coupled with theoretical calculations demonstrated that the change of Fe-O bond length and structural distortion of β-FeOOH,which is rooted in halogen ions embedment,led to the relatively narrow band gap.Because of the strong electronegativity of X-,the Fe element in β-FeOOH(X)s presented the unexpected high valence state(3+δ),which is facilitating to adsorb S032-species.Consequently,the designed β-FeOOH(X)s exhibited the good electric conductivity and enhanced the contact between electrode and electrolyte.When used as a negative electrode,the β-FeOOH(F) showed the excellent specific capacity of 391.9 F g-1 at 1 A g-1 current density,almost tenfold improvement compared with initial β-FeOOH,with the superior rate capacity and cyclic stability.This combinational design principle of electronic structure and electrochemical performances provides a promising way to develop advanced electrode materials for supercapacitor.展开更多
Porous carbon materials with a high surface area have attracted considerable attention for their potential application in electrochemical energy storage.In this study,a high-performance capacitive energy storage mater...Porous carbon materials with a high surface area have attracted considerable attention for their potential application in electrochemical energy storage.In this study,a high-performance capacitive energy storage material based on hierarchically porous carbon was successfully prepared from a new nanoscale ZIF(zeolitic imidazolate framework)precursor,JUC160.The effects of the activating reagent KOH on the textural characteristics and supercapacitor performances of ZIF-derived porous carbons have been carefully evaluated.The JUC160-700 sample has a high surface area(SBET=3253 m2 g^(−1)),a hierarchical porous structure with micro-/mesopore frameworks and an appropriate degree of graphitisation,all of which are crucial for the enhancement of electrochemical performance.In electrochemical evaluation,JUC160-700 exhibits an ultra-high capacitance(386 F g^(−1)at 1 A g^(−1)),good rate capability(71.8%retention at 20 A g^(−1))and long-term cycling stability(>99.9%over 10000 cycles).This remarkable performance indicates that ZIF-derived porous carbon could be an ideal electrode material for advanced supercapacitors and other electrochemical energy storage devices.展开更多
Composites of a nickel based compound incorporated with graphene sheets （NiBC-GS） are prepared by a simple flocculation, using hydrazine hydrate as flocculant and reductant, from a homogeneous intermixture of nickel...Composites of a nickel based compound incorporated with graphene sheets （NiBC-GS） are prepared by a simple flocculation, using hydrazine hydrate as flocculant and reductant, from a homogeneous intermixture of nickel dichloride and graphene oxide dispersed in N,N-dimethylformamide. Morphology, microstructure and thermal stability of the obtained products were characterized by field-emission scanning electron microscopy, X-ray diffraction and thermal gravimetric analysis. Furthermore, the electrochemical properties of NiBC-GS, as electrode materials for supercapacitors, were studied by cyclic voltammetry and galvanostatic charge]discharge in 2 mol L 1 KOH solution. It was determined that for NiBC-GS annealed at 250 ~C, a high specific capacitance of 2394 F g 1 was achieved at a current density of 1 A g^-1, with 78% of the value （i.e., 1864 F g^-1） retained after 5000 times of repeated galvanostatic charge/discharge cycling. The high specific capacitance and available charge/discharge stability indicate the synthesized NiBC-GS250 composite is a good candidate as a novel electrode material for supercapacitors.展开更多
The capacitance performances of poly（3,4-ethylenedioxythiophene）-poly（styrenesulfonate）（PEDOT-PSS） supramolecular hydrogels have been investigated systematically. The materials show a specific capacitance of 67 ...The capacitance performances of poly（3,4-ethylenedioxythiophene）-poly（styrenesulfonate）（PEDOT-PSS） supramolecular hydrogels have been investigated systematically. The materials show a specific capacitance of 67 F/g and display excellent rate capability at the scan rate as high as 5000 m V/s in the cyclic voltammogram measurements, accompanied by good cycle stability. On the basis of the measurements of the microscale morphologies, specific areas and electrical conductivities, the mechanisms for the improvement of the electrochemical properties are discussed and ascribed to the novel porous microstructures of the hydrogels and the synergetic effect of the rigid PEDOT and soft PSS components. Furthermore, polyaniline（PAn） is compounded with the PEDOT-PSS hydrogels through an interfacial polymerization process, endowing the hydrogel materials with a higher specific capacitance of 160 F/g at the scan rate of 5000 m V/s. The significance of this work lies in the demonstration of a novel method to solve the problems of conducting polymers in electrochemical applications.展开更多
In this study,cobalt-doped nickel sulfide nanomaterials are synthesized.The experimental results show that cobalt is successfully doped into the lattice of NiS_(2).Co-doping causes the hollow sphere sulphides to break...In this study,cobalt-doped nickel sulfide nanomaterials are synthesized.The experimental results show that cobalt is successfully doped into the lattice of NiS_(2).Co-doping causes the hollow sphere sulphides to break down and favors the formation of Ni_(x)Co_(1-x)S_(2)nanostructures with high-density active edge sites.The Ni_(0.75)Co_(0.25)S_(2)sample exhibits a high specific capacitance of 2141.9 F g^(-1)at a current density of 2 A g^(-1)due to its fluffy characteristics and edge site-enriched nanostructure.The asymmetric supercapacitor based on Ni_(0.75)Co_(0.25)S_(2)exhibits a high energy density(54.9 Wh kg^(-1))and stable cycling durability with 85.1%capacitance retention after 4000 cycles.展开更多
Single crystals of cobalt coordination compounds were obtained by one-pot hydrothermal reaction.Nickel ion exchange was used to produce the Ni–Co hetero-metal compound with tunable chemical composition.Using a nickel...Single crystals of cobalt coordination compounds were obtained by one-pot hydrothermal reaction.Nickel ion exchange was used to produce the Ni–Co hetero-metal compound with tunable chemical composition.Using a nickel-exchanged compound as the precursor,we developed a simple chemical reaction to synthesize large-scale 3D hierarchical Ni_(x)Co_(3−x)S_(4)(x=0.15–0.42)microflowers under ambient conditions.展开更多
Development of high volumetric capacitance,high rate performance and low-cost electrode materials for supercapacitors is still a significant challenge.Among the various promising candidates,carbon nanofibers(CNFs)with...Development of high volumetric capacitance,high rate performance and low-cost electrode materials for supercapacitors is still a significant challenge.Among the various promising candidates,carbon nanofibers(CNFs)with heteroatom functionalization have attracted increasing attention.Herein,a type of nonporous CNFs combined with a heteroatom functionalization strategy is proposed for high performance supercapacitor electrodes.Tri-heteroatom functionalization of nonporous carbon nanofibers was carried out by tetraethyl orthosilicate(TEOS)and phosphorus(H3PO4)activation of polyacrylonitrile(PAN)through electrospinning and subsequent thermal treatment.The optimal electrode material showed a high gravimetric capacitance of 243.7 F g^(-1) at 0.5 A g^(-1),superior rate capability with ~83% retention at rates ranging from 0.5 A g^(-1) to 30 A g^(-1) and excellent cycle stability(capacitance retention rate>100% after 8000 cycles at a high current density of 30 A g^(-1)).It is worth noting that the nonporous CNF also possesses a high packing density,which presents a maximum volumetric capacitance of 253.4 F cm^(-3) at 0.5 A g^(-1) and 209 F cm^(-3) at 30 A g^(-1).The current synthetic strategy of preparing nonporous carbon architectures with multi-heteroatom doping offers an eco-friendly,feasible,and cost-effective way for constructing high-performance electrode materials employed in supercapacitors.展开更多
基金National Natural Science Fund for Distinguished Young Scholars(51425204)National Natural Science Foundation of China(51832004,51521001)+2 种基金National Key R&D Program of China(2016YFA0202603)Programme of Introducing Talents of Discipline to Universities(B17034)Yellow Crane Talent(Science&Technology)Program of Wuhan City。
文摘The unique synergistic effect of hierarchical core-shell structures demonstrates great potential for designing the next-generation electrode materials for supercapacitors.In this work,we design binderfree MnCo_(2)O_(4)@NiMoO_(4)heterostructure core-shell nanowire arrays(NWAs)grown over a current collector of nickel foam(NF)achieved through a modified and simple hydrothermal process.The capacitive performance of the core MnCo_(2)O_(4)NWAs was remarkably improved by growing a layer of NiMoO_(4)nanosheets(1244 F g^(-1)at 1 A g^(-1)),which is superior to the capacitance of pristine MnCo_(2)O_(4)(457.85 F g^(-1)at 1 A g^(-1)).Moreover,the prepared MnCo_(2)O_(4)@NiMoO_(4)core-shell NWAs have been used along with commercial activated carbon(AC)to fabricate an asymmetric full supercapacitor device.MnCo_(2)O_(4)@NiMoO_(4)//AC delivers a high energy density(42 W h kg^(-1))at a power density of 852.3 W kg^(-1)and a good cyclability with 93%of the initial capacitance retained at the end of 8000 successive charge/discharge cycles.Therefore,the MnCo_(2)O_(4)@NiMoO_(4)electrode material holds a great promise as a suitable candidate for high performance supercapacitors.
基金financially supported by the National Natural Science Foundation of China(Grant 51572259)National Key R&D Program of China(Grant 2016YBF0100100 and2016YFA0200200)+2 种基金Natural Science Foundation of Liaoning Province(Grant 201602737)Thousand Youth Talents Plan of China,DICP(DICP ZZBS201708)Exploratory Research Projects of Shaanxi Yanchang Petroleum(Group)CO.,LTD&DICP
文摘Supercapacitors, with ultrahigh power density, superior rate capability, long-term cyclability, and exceptional safety, are regarded as one highly competitive candidate of electrochemical energy storage devices,filling the gap between batteries and conventional capacitors. Despite of tremendous effort, elaborated screening of high-performance electrode materials, e.g., graphene, is still intensively required. In this review, we describe the most recent progress in the research and development of graphene-based materials for high-performance and new-concept supercapacitors for the targeted applications in next-generation and smart electronics. First, the design and fabrication of high-performance supercapacitors, including electrical double layer capacitors, pseudocapacitors and hybrid supercapacitors, were summarized in term of the charge storage mechanism. Second, new-concept supercapacitors with multiple functionalities of high-voltage, fiber-shape, microscale and shape-diversity in order to fulfill the requirements of future electronics are reviewed. Accordingly, special emphasis is given to the structure-dependent-performance effects of pores, hybridization, dimensionalities of graphene-based materials on performance of supercapacitors, and tremendous potential of graphene-based planar micro-supercapacitors for the direct seamlessly integration with versatile micro-electronics. Finally, perspectives and challenges of graphene-based supercapacitors are briefly discussed.
基金supported by the National Natural Science Foundation of China(Nos.2177060378,21627813,and 21521005)the Program for Changjiang Scholars,Innovative Research Teams in Universities(No.IRT1205)the Fundamental Research Funds for the Central Universities(Nos.12060093063 and XK1803-05).
文摘Coordination tuning electronic structure of host materials is a quite effective strategy for activating and improving the intrinsic properties.Herein,halogen anion(X-)-incorporated β-FeOOH(β-FeOOH(X),X=F-,Cl-,and Br-) was investigated with a spontaneous adsorption process,which realized a great improvement of supercapacitor performances by adjusting the coordination geometry.Experiments coupled with theoretical calculations demonstrated that the change of Fe-O bond length and structural distortion of β-FeOOH,which is rooted in halogen ions embedment,led to the relatively narrow band gap.Because of the strong electronegativity of X-,the Fe element in β-FeOOH(X)s presented the unexpected high valence state(3+δ),which is facilitating to adsorb S032-species.Consequently,the designed β-FeOOH(X)s exhibited the good electric conductivity and enhanced the contact between electrode and electrolyte.When used as a negative electrode,the β-FeOOH(F) showed the excellent specific capacity of 391.9 F g-1 at 1 A g-1 current density,almost tenfold improvement compared with initial β-FeOOH,with the superior rate capacity and cyclic stability.This combinational design principle of electronic structure and electrochemical performances provides a promising way to develop advanced electrode materials for supercapacitor.
基金supported by the National Natural Science Foundation of China(21571076,21390394,21571079)the“111”project(B07016).
文摘Porous carbon materials with a high surface area have attracted considerable attention for their potential application in electrochemical energy storage.In this study,a high-performance capacitive energy storage material based on hierarchically porous carbon was successfully prepared from a new nanoscale ZIF(zeolitic imidazolate framework)precursor,JUC160.The effects of the activating reagent KOH on the textural characteristics and supercapacitor performances of ZIF-derived porous carbons have been carefully evaluated.The JUC160-700 sample has a high surface area(SBET=3253 m2 g^(−1)),a hierarchical porous structure with micro-/mesopore frameworks and an appropriate degree of graphitisation,all of which are crucial for the enhancement of electrochemical performance.In electrochemical evaluation,JUC160-700 exhibits an ultra-high capacitance(386 F g^(−1)at 1 A g^(−1)),good rate capability(71.8%retention at 20 A g^(−1))and long-term cycling stability(>99.9%over 10000 cycles).This remarkable performance indicates that ZIF-derived porous carbon could be an ideal electrode material for advanced supercapacitors and other electrochemical energy storage devices.
基金financially supported by National Natural Science Foundation of China(No.51075384)
文摘Composites of a nickel based compound incorporated with graphene sheets （NiBC-GS） are prepared by a simple flocculation, using hydrazine hydrate as flocculant and reductant, from a homogeneous intermixture of nickel dichloride and graphene oxide dispersed in N,N-dimethylformamide. Morphology, microstructure and thermal stability of the obtained products were characterized by field-emission scanning electron microscopy, X-ray diffraction and thermal gravimetric analysis. Furthermore, the electrochemical properties of NiBC-GS, as electrode materials for supercapacitors, were studied by cyclic voltammetry and galvanostatic charge]discharge in 2 mol L 1 KOH solution. It was determined that for NiBC-GS annealed at 250 ~C, a high specific capacitance of 2394 F g 1 was achieved at a current density of 1 A g^-1, with 78% of the value （i.e., 1864 F g^-1） retained after 5000 times of repeated galvanostatic charge/discharge cycling. The high specific capacitance and available charge/discharge stability indicate the synthesized NiBC-GS250 composite is a good candidate as a novel electrode material for supercapacitors.
基金financially supported by the National Natural Science Foundation of China(Nos.21174059 and 21374046)China Postdoctoral Science Foundation(No.2013M530249)+1 种基金Program for Changjiang Scholars and Innovative Research Teams in Universities,Open Project of State Key Laboratory of Superamolecular Structure and Materials(No.SKLSSM201416)the Testing Foundation of Nanjing University
文摘The capacitance performances of poly（3,4-ethylenedioxythiophene）-poly（styrenesulfonate）（PEDOT-PSS） supramolecular hydrogels have been investigated systematically. The materials show a specific capacitance of 67 F/g and display excellent rate capability at the scan rate as high as 5000 m V/s in the cyclic voltammogram measurements, accompanied by good cycle stability. On the basis of the measurements of the microscale morphologies, specific areas and electrical conductivities, the mechanisms for the improvement of the electrochemical properties are discussed and ascribed to the novel porous microstructures of the hydrogels and the synergetic effect of the rigid PEDOT and soft PSS components. Furthermore, polyaniline（PAn） is compounded with the PEDOT-PSS hydrogels through an interfacial polymerization process, endowing the hydrogel materials with a higher specific capacitance of 160 F/g at the scan rate of 5000 m V/s. The significance of this work lies in the demonstration of a novel method to solve the problems of conducting polymers in electrochemical applications.
基金supported by grants from the National Natural Science Foundation of China(Grant No.U1662119)Key research and development program of Binzhou University(Grant No.2017ZDL03).
文摘In this study,cobalt-doped nickel sulfide nanomaterials are synthesized.The experimental results show that cobalt is successfully doped into the lattice of NiS_(2).Co-doping causes the hollow sphere sulphides to break down and favors the formation of Ni_(x)Co_(1-x)S_(2)nanostructures with high-density active edge sites.The Ni_(0.75)Co_(0.25)S_(2)sample exhibits a high specific capacitance of 2141.9 F g^(-1)at a current density of 2 A g^(-1)due to its fluffy characteristics and edge site-enriched nanostructure.The asymmetric supercapacitor based on Ni_(0.75)Co_(0.25)S_(2)exhibits a high energy density(54.9 Wh kg^(-1))and stable cycling durability with 85.1%capacitance retention after 4000 cycles.
基金supported by the National Science Foundation of China(grant no.21001090,21443003 and 21103153)Program for Innovative Research Team(in Science and Technology)in University of Henan Province(grant no.2012IRTSTHN021)Education Department of Henan Province(grant no.13A150648).
文摘Single crystals of cobalt coordination compounds were obtained by one-pot hydrothermal reaction.Nickel ion exchange was used to produce the Ni–Co hetero-metal compound with tunable chemical composition.Using a nickel-exchanged compound as the precursor,we developed a simple chemical reaction to synthesize large-scale 3D hierarchical Ni_(x)Co_(3−x)S_(4)(x=0.15–0.42)microflowers under ambient conditions.
基金financially supported by National Natural Science Foundation of China(No.51072013,51272021,51402010,51142004 and 51772016).
文摘Development of high volumetric capacitance,high rate performance and low-cost electrode materials for supercapacitors is still a significant challenge.Among the various promising candidates,carbon nanofibers(CNFs)with heteroatom functionalization have attracted increasing attention.Herein,a type of nonporous CNFs combined with a heteroatom functionalization strategy is proposed for high performance supercapacitor electrodes.Tri-heteroatom functionalization of nonporous carbon nanofibers was carried out by tetraethyl orthosilicate(TEOS)and phosphorus(H3PO4)activation of polyacrylonitrile(PAN)through electrospinning and subsequent thermal treatment.The optimal electrode material showed a high gravimetric capacitance of 243.7 F g^(-1) at 0.5 A g^(-1),superior rate capability with ~83% retention at rates ranging from 0.5 A g^(-1) to 30 A g^(-1) and excellent cycle stability(capacitance retention rate>100% after 8000 cycles at a high current density of 30 A g^(-1)).It is worth noting that the nonporous CNF also possesses a high packing density,which presents a maximum volumetric capacitance of 253.4 F cm^(-3) at 0.5 A g^(-1) and 209 F cm^(-3) at 30 A g^(-1).The current synthetic strategy of preparing nonporous carbon architectures with multi-heteroatom doping offers an eco-friendly,feasible,and cost-effective way for constructing high-performance electrode materials employed in supercapacitors.
