Two-dimensional materials for flexible energy storage commonly facehuge challenges in limited active surface and hindered charge transport.Herein,wereport an innovative asymmetric pseudocapacitor based on synergistic ...Two-dimensional materials for flexible energy storage commonly facehuge challenges in limited active surface and hindered charge transport.Herein,wereport an innovative asymmetric pseudocapacitor based on synergistic design of modifiedMXene and graphene,integrating gas-induced rapid expansion technology andprecise surface chemical regulation methods.For graphene modification,rapid vaporizationinduces exfoliation and expansion of graphene oxide layers.Subsequently,pseudocapacitiveoxygen-containing groups were selectively introduced through acid oxidation,yielding expanded-and-oxidized graphene(OEG)for positive porous-nanopaperelectrode.For MXene modification,alkali-treated MXene underwent hydrazine assistance to facilitate gas expansion and-NH_(2)grafting,producing MXene-NH_(2)(NOM)for negative porous-nanopaper electrode.Density functional theory calculations show that-COOH moreeffectively modulate graphene’s electronic structure by inducing charge redistribution and creating active sites,thereby enhancing H^(+)adsorption and ion interactions compared to-OH.Meanwhile,-NH_(2)on MXene enable electron delocalization and dynamic Ti-N-H^(+)interactions,speeding up proton adsorption/desorption and boosting both pseudocapacitance and conductivity.Through collaborativeoptimized spatial architecture and surface properties,flexible OEGB and NOMB exhibited of 333.6 and 500.5 F g^(-1)at high mass loading,respectively.The assembled proton pseudocapacitor readily achieved energy and power densities of 58.9 Wh kg^(-1)and 3802 W kg^(-1),respectively,with excellent stability for potential applications.展开更多
Pseudocapacitive transition metal oxides(PTMOs)have the advantages of high areal capacitance and material density suitable for high-energy supercapacitor devices,but they are typically marred by insufficient rate perf...Pseudocapacitive transition metal oxides(PTMOs)have the advantages of high areal capacitance and material density suitable for high-energy supercapacitor devices,but they are typically marred by insufficient rate performance,which in turn deteriorates cyclic stability at high current levels.Using the example of spinel manganese oxide,herein we demonstrate that a pseudocapacitive oxide electrode of remarkable rate performance and cyclic stability may be realized by adopting oxide nanocrystallites,which are derived based on a novel solution chemistry,and carbon additive(CA)nanoparticles with highly uniform of size distributions.Precisely controlling the particle morphology and size distribution of the active material and conductive additive(CA)in the nanometer range can maximize the density of active material-CA-electrolyte three-phase contact points,thus facilitating synchronized electron and cation flow for the completion of surface faradaic reactions.The resultant Mn3O4 pseudocapacitive electrode exhibits rate capability and cycle stability,including 60%capacity retention at 60 A g-1 and no capacity fade over 100000 cycles under dynamic current densities,far superior to the state-of-the-art PTMO electrodes.The electrode design strategy is in general applicable to pseudocapacitors containing poorly conductive active materials.展开更多
The stable operation of supercapacitors at extremely low temperatures is crucial for applications in harsh envi-ronments.Unfortunately,conventional inorganic electrodes suffer from sluggish diffusion kinetics and poor...The stable operation of supercapacitors at extremely low temperatures is crucial for applications in harsh envi-ronments.Unfortunately,conventional inorganic electrodes suffer from sluggish diffusion kinetics and poor cycling stability for proton pseudocapacitors.Here,a redox-active polymer poly(1,5-diaminonaphthalene)is developed and synthesized as an ultrafast,high-mass loading,and durable pseudocapacitive anode.The charge storage of poly(1,5-diaminonaphthalene)depends on the reversible coordination reaction of the C¼N group with Hþ,which enables fast kinetics associated with surface-controlled reactions.The 3D-printed organic electrode delivers a remarkable areal capacitance(8.43 F cm^(-2)at 30.78 mg cm^(-2))and thickness-independent rate per-formance.Furthermore,the 3D-printed proton pseudocapacitor exhibits great low-temperature tolerance and delivers a high energy density of 0.44 mWh cm^(-2)at-60℃,as well as operates well even at-80℃.This work signifies that combining organic material design with 3D hierarchical network electrode construction can provide a promising solution for low-temperature-resistant supercapacitors.展开更多
Supercapacitors,comprising electrical double-layer capacitors(EDLCs)and pseudocapa-citors,are widely acknowledged as high-power energy storage devices.However,their local structures and fundamental mechanisms remain p...Supercapacitors,comprising electrical double-layer capacitors(EDLCs)and pseudocapa-citors,are widely acknowledged as high-power energy storage devices.However,their local structures and fundamental mechanisms remain poorly understood,and suitable experimental techniques for investigation are also lacking.Recently,nuclear magnetic resonance(NMR)has emerged as a powerful tool for addressing these fundamental issues with high local sensitivity and non-invasiveness.In this paper,we first review the limi-tations of existing characterization methods and highlight the advantages of NMR in investigating mechanisms of supercapacitors.Subsequently,we introduce the basic prin-ciple of ring current effect,NMR-active nuclei,and various NMR techniques employed in exploring energy storage mechanisms including cross polarization(CP)magic angle spinning(MAS)NMR,multiple-quantum(MQ)MAS,two-dimensional exchange spec-troscopy(2D-EXSY)NMR,magnetic resonance imaging(MRI)and pulsed-field gradient(PFG)NMR.Based on this,recent progress in investigating energy storage mechanisms in EDLCs and pseudocapacitors through various NMR techniques is discussed.Finally,an outlook on future directions for NMR research in supercapacitors is offered.展开更多
通过多种电化学测试技术评价了石墨电极在2.3 mol/L H2SO4溶液中的电化学活化工艺及其准电容性能。结果表明,活化工艺宜采用恒电流阶跃技术,最佳工艺参数为:阳极电流密度为200 m A·cm-2,阴极电流密度为-120 m A·cm-2,对应活...通过多种电化学测试技术评价了石墨电极在2.3 mol/L H2SO4溶液中的电化学活化工艺及其准电容性能。结果表明,活化工艺宜采用恒电流阶跃技术,最佳工艺参数为:阳极电流密度为200 m A·cm-2,阴极电流密度为-120 m A·cm-2,对应活化时间分别为300 s和100 s,循环6次。改性后的石墨电极表面形成了多孔、粗糙的三维活性层,单位面积上具有较高的电容量(2.08 F·cm-2)和良好的倍率特性,可作为一种优异的准电容器材料。展开更多
Carbon-based materials are typical and commercially active electrode for supercapacitors due to their advantages such as low cost, good stability and easy availability. In the light of energy storage, supercapacitors ...Carbon-based materials are typical and commercially active electrode for supercapacitors due to their advantages such as low cost, good stability and easy availability. In the light of energy storage, supercapacitors mechanism is classified into EDLCs （electrochemical double layer capacitors） and pseudocapacitors. Multidimensional carbon nanomaterials （active carbon, carbon nanotube, graphene, etc.）, carbon-based composite and corresponding electrolyte are the critical and important factor in the eyes of researcher. In this minireview, we will discuss the storage mechanism and summarize recent developed novel carbon and carbon-based materials in supercapacitors. The techniques to design the novel nanostructure and high performance electrodematerials that facilitate charge transfer to achieve high energy and power densities will also be discussed.展开更多
基金supported by the National Nature Science Foundation of China(No.52402126)Shaanxi Province Qin Chuangyuan general window four chain integration project(No.2024PT-ZCK-09)+3 种基金Shaanxi Province military-civilian integration project(Shaanxi finance office【2024】22nd)Qinchuangyuan introducing high-level innovation and entrepreneurship talent projects(NO.QCYRCXM-2022-343)the China Postdoctoral Science Foundation(Grant Number:2025M772524)National Nature Science Foundation of China(22508239).
文摘Two-dimensional materials for flexible energy storage commonly facehuge challenges in limited active surface and hindered charge transport.Herein,wereport an innovative asymmetric pseudocapacitor based on synergistic design of modifiedMXene and graphene,integrating gas-induced rapid expansion technology andprecise surface chemical regulation methods.For graphene modification,rapid vaporizationinduces exfoliation and expansion of graphene oxide layers.Subsequently,pseudocapacitiveoxygen-containing groups were selectively introduced through acid oxidation,yielding expanded-and-oxidized graphene(OEG)for positive porous-nanopaperelectrode.For MXene modification,alkali-treated MXene underwent hydrazine assistance to facilitate gas expansion and-NH_(2)grafting,producing MXene-NH_(2)(NOM)for negative porous-nanopaper electrode.Density functional theory calculations show that-COOH moreeffectively modulate graphene’s electronic structure by inducing charge redistribution and creating active sites,thereby enhancing H^(+)adsorption and ion interactions compared to-OH.Meanwhile,-NH_(2)on MXene enable electron delocalization and dynamic Ti-N-H^(+)interactions,speeding up proton adsorption/desorption and boosting both pseudocapacitance and conductivity.Through collaborativeoptimized spatial architecture and surface properties,flexible OEGB and NOMB exhibited of 333.6 and 500.5 F g^(-1)at high mass loading,respectively.The assembled proton pseudocapacitor readily achieved energy and power densities of 58.9 Wh kg^(-1)and 3802 W kg^(-1),respectively,with excellent stability for potential applications.
基金financially supported by the“Advanced Research Center for Green Materials Science and Technology”from The Featured Area Research Center Program within the framework of the Higher Education Sprout Project by Ministry of Science and Technology in Taiwan under the grants of MOST-108-3017-F-002002,and also of MOST-107-2221-E-002-106-MY3,MOST-108-2119-M-002-010,MOST-107-2923-E-011-002,MOST-108-3116-F-301-001-F
文摘Pseudocapacitive transition metal oxides(PTMOs)have the advantages of high areal capacitance and material density suitable for high-energy supercapacitor devices,but they are typically marred by insufficient rate performance,which in turn deteriorates cyclic stability at high current levels.Using the example of spinel manganese oxide,herein we demonstrate that a pseudocapacitive oxide electrode of remarkable rate performance and cyclic stability may be realized by adopting oxide nanocrystallites,which are derived based on a novel solution chemistry,and carbon additive(CA)nanoparticles with highly uniform of size distributions.Precisely controlling the particle morphology and size distribution of the active material and conductive additive(CA)in the nanometer range can maximize the density of active material-CA-electrolyte three-phase contact points,thus facilitating synchronized electron and cation flow for the completion of surface faradaic reactions.The resultant Mn3O4 pseudocapacitive electrode exhibits rate capability and cycle stability,including 60%capacity retention at 60 A g-1 and no capacity fade over 100000 cycles under dynamic current densities,far superior to the state-of-the-art PTMO electrodes.The electrode design strategy is in general applicable to pseudocapacitors containing poorly conductive active materials.
基金supported by National Natural Science Foundation of China(52072173)International Science and Technology cooperation program of Jiangsu Province(SBZ2022000084)Funding for Outstanding Doctoral Dissertation in NUAA(BCXJ23-10).
文摘The stable operation of supercapacitors at extremely low temperatures is crucial for applications in harsh envi-ronments.Unfortunately,conventional inorganic electrodes suffer from sluggish diffusion kinetics and poor cycling stability for proton pseudocapacitors.Here,a redox-active polymer poly(1,5-diaminonaphthalene)is developed and synthesized as an ultrafast,high-mass loading,and durable pseudocapacitive anode.The charge storage of poly(1,5-diaminonaphthalene)depends on the reversible coordination reaction of the C¼N group with Hþ,which enables fast kinetics associated with surface-controlled reactions.The 3D-printed organic electrode delivers a remarkable areal capacitance(8.43 F cm^(-2)at 30.78 mg cm^(-2))and thickness-independent rate per-formance.Furthermore,the 3D-printed proton pseudocapacitor exhibits great low-temperature tolerance and delivers a high energy density of 0.44 mWh cm^(-2)at-60℃,as well as operates well even at-80℃.This work signifies that combining organic material design with 3D hierarchical network electrode construction can provide a promising solution for low-temperature-resistant supercapacitors.
基金supported by the National Natural Science Foundation of China(Grant No.22075064)National Key Laboratory Projects(No.SYSKT20230056).
文摘Supercapacitors,comprising electrical double-layer capacitors(EDLCs)and pseudocapa-citors,are widely acknowledged as high-power energy storage devices.However,their local structures and fundamental mechanisms remain poorly understood,and suitable experimental techniques for investigation are also lacking.Recently,nuclear magnetic resonance(NMR)has emerged as a powerful tool for addressing these fundamental issues with high local sensitivity and non-invasiveness.In this paper,we first review the limi-tations of existing characterization methods and highlight the advantages of NMR in investigating mechanisms of supercapacitors.Subsequently,we introduce the basic prin-ciple of ring current effect,NMR-active nuclei,and various NMR techniques employed in exploring energy storage mechanisms including cross polarization(CP)magic angle spinning(MAS)NMR,multiple-quantum(MQ)MAS,two-dimensional exchange spec-troscopy(2D-EXSY)NMR,magnetic resonance imaging(MRI)and pulsed-field gradient(PFG)NMR.Based on this,recent progress in investigating energy storage mechanisms in EDLCs and pseudocapacitors through various NMR techniques is discussed.Finally,an outlook on future directions for NMR research in supercapacitors is offered.
文摘通过多种电化学测试技术评价了石墨电极在2.3 mol/L H2SO4溶液中的电化学活化工艺及其准电容性能。结果表明,活化工艺宜采用恒电流阶跃技术,最佳工艺参数为:阳极电流密度为200 m A·cm-2,阴极电流密度为-120 m A·cm-2,对应活化时间分别为300 s和100 s,循环6次。改性后的石墨电极表面形成了多孔、粗糙的三维活性层,单位面积上具有较高的电容量(2.08 F·cm-2)和良好的倍率特性,可作为一种优异的准电容器材料。
基金Acknowledgment This work was financially supported by the National Natural Science Foundation of China （No. 51402040）, China Postdoctoral Science Foundation （2015M582539）, Science and Technology Support Program of Sichuan Province （2016RZ0054） and the National Hi-Tech Research and Development Program （863 Program） of China （No. 2015AA034202）.
文摘Carbon-based materials are typical and commercially active electrode for supercapacitors due to their advantages such as low cost, good stability and easy availability. In the light of energy storage, supercapacitors mechanism is classified into EDLCs （electrochemical double layer capacitors） and pseudocapacitors. Multidimensional carbon nanomaterials （active carbon, carbon nanotube, graphene, etc.）, carbon-based composite and corresponding electrolyte are the critical and important factor in the eyes of researcher. In this minireview, we will discuss the storage mechanism and summarize recent developed novel carbon and carbon-based materials in supercapacitors. The techniques to design the novel nanostructure and high performance electrodematerials that facilitate charge transfer to achieve high energy and power densities will also be discussed.
