Redox-active organic compounds have received much attention as high-capacity electrodes for rechargeable batteries.However,the high solubility in organic electrolytes during charge and discharge processes hinders the ...Redox-active organic compounds have received much attention as high-capacity electrodes for rechargeable batteries.However,the high solubility in organic electrolytes during charge and discharge processes hinders the practical exploitation of organic compounds.This study presents a cobalt-based metal–organic coordination compound with bifunctional coordinated water(Co-MOC-H_(2)O)for sodium-ion storage.The coordinated water enhances interactions between sodium ions and nitrogen atoms in organic ligands through chelation,activating the inert sodium-ion storage sites(C=N).Moreover,the stable hydrogen bonded framework formed by the coordinated water molecules prevents the active organic compounds from dissolving into the electrolyte,thereby enhancing cycling stability.With the bifunctional coordinated water molecules,the Co-MOC-H_(2)O electrode delivers a high capacity of 403 mAh g^(-1)at 0.2 A g^(-1)over 600 cycles and exhibits a capacity retention of 77.9%at 2 A g^(-1)after 1100 cycles.This work highlights the crucial role of the coordinated water molecules in constructing high capacity and long-life sodium-ion storage materials.展开更多
Hierarchical Sb_2S_3 hollow microspheres assembled by nanowires have been successfully synthesized by a simple and practical hydrothermal reaction. The possible formation process of this architecture was investigated ...Hierarchical Sb_2S_3 hollow microspheres assembled by nanowires have been successfully synthesized by a simple and practical hydrothermal reaction. The possible formation process of this architecture was investigated by X-ray diffraction, focused-ion beam-scanning electron microscopy dual-beam system, and transmission electron microscopy. When used as the anode material for lithium-ion batteries, Sb_2S_3 hollow microspheres manifest excellent rate property and enhanced lithium-storage capability and can deliver a discharge capacity of 674 m Ah g^(-1) at a current density of 200 m A g^(-1) after 50 cycles. Even at a high currentdensity of 5000 m A g^(-1), a discharge capacity of541 m Ah g^(-1) is achieved. Sb_2S_3 hollow microspheres also display a prominent sodium-storage capacity and maintain a reversible discharge capacity of 384 m Ah g^(-1) at a current density of 200 m A g^(-1) after 50 cycles. The remarkable lithium/sodium-storage property may be attributed to the synergetic effect of its nanometer size and three-dimensional hierarchical architecture, and the outstanding stability property is attributed to the sufficient interior void space,which can buffer the volume expansion.展开更多
Sodium-ion batteries(SIBs)represent a highly promising class of energy storage devices.Enhancing SIBs performance necessitates innovative anode material development to overcome persistent challenges associated with th...Sodium-ion batteries(SIBs)represent a highly promising class of energy storage devices.Enhancing SIBs performance necessitates innovative anode material development to overcome persistent challenges associated with the large ionic radius of Na^(+),namely significant electrode volumetric expansion and sluggish reaction kinetics.Herein,a macroporous bimetallic(Co,Fe)selenide containing abundant heterojunction interfaces encapsulated into a carbon framework(M-CoSe_(2)/FeSe_(2)@C)is prepared by combining an in-situ crystallization strategy with carbonization-selenization treatment.The structural characterization reveals that the resulting M-CoSe_(2)/FeSe_(2)@C possesses a well-defined porous architecture with internal CoSe_(2)-FeSe_(2) nanoparticles encapsulated by an external carbon matrix.This configuration not only enhances electrical conductivity but also stabilizes the composite structure throughout sodiation/desodiation cycling.Evaluated as an anode in SIBs,the M-CoSe_(2)/FeSe_(2)@C electrode delivers outstanding cycling stability(retaining 455.0 mA h g^(−1) at 0.2 A g^(−1) after 100 cycles)and exceptional rate capability(285.6 mA h g^(−1) at 10 A g^(−1)).These superior properties are primarily attributed to the high density of interphase boundaries generated by the dual-phase configuration.Combined experimental and theoretical investigations demonstrate that these boundaries,particularly regions of high electron density on the FeSe_(2) side,kinetically favor Na^(+)adsorption,thereby accelerating sodium storage kinetics.Furthermore,multi-step electrochemical reaction mechanisms within the composite were elucidated through in-situ and ex-situ characterization analyses.展开更多
基金supported by the National Natural Science Foundation of China(22121005,92372203,92372001,52072186,and 52301278)the National Key Research and Development Program of China(2022YFB2402200)+3 种基金the Science and Technology Plans of Tianjin(23JCYBJC00170)the Fundamental Research Funds for the Central Universities,Nankai University(63241206 and 9242000710)Shanghai Jiao Tong University Shaoxing Research Institute of Renewable Energy and Molecular Engineering(JDSX2023003)the Natural Science Foundation of Jiangsu Province(BK20230937).
文摘Redox-active organic compounds have received much attention as high-capacity electrodes for rechargeable batteries.However,the high solubility in organic electrolytes during charge and discharge processes hinders the practical exploitation of organic compounds.This study presents a cobalt-based metal–organic coordination compound with bifunctional coordinated water(Co-MOC-H_(2)O)for sodium-ion storage.The coordinated water enhances interactions between sodium ions and nitrogen atoms in organic ligands through chelation,activating the inert sodium-ion storage sites(C=N).Moreover,the stable hydrogen bonded framework formed by the coordinated water molecules prevents the active organic compounds from dissolving into the electrolyte,thereby enhancing cycling stability.With the bifunctional coordinated water molecules,the Co-MOC-H_(2)O electrode delivers a high capacity of 403 mAh g^(-1)at 0.2 A g^(-1)over 600 cycles and exhibits a capacity retention of 77.9%at 2 A g^(-1)after 1100 cycles.This work highlights the crucial role of the coordinated water molecules in constructing high capacity and long-life sodium-ion storage materials.
基金supported financially by the National Natural Foundation of China(Grant No.51672234)the Research Foundation for Hunan Youth Outstanding People from Hunan Provincial Science and Technology Department(2015RS4030)+1 种基金Hunan 2011 Collaborative Innovation Center of Chemical Engineering&Technology with Environmental Benignity and Effective Resource UtilizationProgram for Innovative Research Cultivation Team in University of Ministry of Education of China(1337304)
文摘Hierarchical Sb_2S_3 hollow microspheres assembled by nanowires have been successfully synthesized by a simple and practical hydrothermal reaction. The possible formation process of this architecture was investigated by X-ray diffraction, focused-ion beam-scanning electron microscopy dual-beam system, and transmission electron microscopy. When used as the anode material for lithium-ion batteries, Sb_2S_3 hollow microspheres manifest excellent rate property and enhanced lithium-storage capability and can deliver a discharge capacity of 674 m Ah g^(-1) at a current density of 200 m A g^(-1) after 50 cycles. Even at a high currentdensity of 5000 m A g^(-1), a discharge capacity of541 m Ah g^(-1) is achieved. Sb_2S_3 hollow microspheres also display a prominent sodium-storage capacity and maintain a reversible discharge capacity of 384 m Ah g^(-1) at a current density of 200 m A g^(-1) after 50 cycles. The remarkable lithium/sodium-storage property may be attributed to the synergetic effect of its nanometer size and three-dimensional hierarchical architecture, and the outstanding stability property is attributed to the sufficient interior void space,which can buffer the volume expansion.
基金support from the National Natural Science Foundation of China(Grant 51573058)funding provided through the Postdoctoral Fellowship Program(Grade C)of the China Postdoctoral Science Foundation(GZC20240629).
文摘Sodium-ion batteries(SIBs)represent a highly promising class of energy storage devices.Enhancing SIBs performance necessitates innovative anode material development to overcome persistent challenges associated with the large ionic radius of Na^(+),namely significant electrode volumetric expansion and sluggish reaction kinetics.Herein,a macroporous bimetallic(Co,Fe)selenide containing abundant heterojunction interfaces encapsulated into a carbon framework(M-CoSe_(2)/FeSe_(2)@C)is prepared by combining an in-situ crystallization strategy with carbonization-selenization treatment.The structural characterization reveals that the resulting M-CoSe_(2)/FeSe_(2)@C possesses a well-defined porous architecture with internal CoSe_(2)-FeSe_(2) nanoparticles encapsulated by an external carbon matrix.This configuration not only enhances electrical conductivity but also stabilizes the composite structure throughout sodiation/desodiation cycling.Evaluated as an anode in SIBs,the M-CoSe_(2)/FeSe_(2)@C electrode delivers outstanding cycling stability(retaining 455.0 mA h g^(−1) at 0.2 A g^(−1) after 100 cycles)and exceptional rate capability(285.6 mA h g^(−1) at 10 A g^(−1)).These superior properties are primarily attributed to the high density of interphase boundaries generated by the dual-phase configuration.Combined experimental and theoretical investigations demonstrate that these boundaries,particularly regions of high electron density on the FeSe_(2) side,kinetically favor Na^(+)adsorption,thereby accelerating sodium storage kinetics.Furthermore,multi-step electrochemical reaction mechanisms within the composite were elucidated through in-situ and ex-situ characterization analyses.
