Onedimensional porous carbons bearing high surface areas and sufficient heteroatom doped functionalities are essential for advanced electrochemical energy storage devices,especially for developing freestanding film el...Onedimensional porous carbons bearing high surface areas and sufficient heteroatom doped functionalities are essential for advanced electrochemical energy storage devices,especially for developing freestanding film electrodes.Here we develop a porous,nitrogenenriched,freestanding hollow carbon nanofiber(PNFHCF)electrode material via filtration of polypyrrole(PPy)hollow nanofibers formed by in situ selfdegraded templateassisted strategy,followed by NH3assisted carbonization.The PNFHCF retains the freestanding film morphology that is composed of threedimensional networks from the entanglement of 1D nanofiber and delivers 3.7fold increase in specific surface area(592 m^(2)g^(-1))compared to the carbon without NH_(3)treatment(FHCF).In spite of the enhanced specific surface area,PNFHCF still exhibits comparable high content of surface N functionalities(8.8%,atom fraction)to FHCF.Such developed hierarchical porous structure without sacrificing N doping functionalities together enables the achievement of high capacity,highrate property and good cycling stability when applied as selfsupporting anode in lithiumion batteries,superior to those of FHCF without NH3 treatment.展开更多
Establishing covalent heterointerfaces with face-to-face contact is promising for advanced energy storage,while challenge remains on how to inhibit the anisotropic growth of nucleated crystals on the matrix.Herein,fac...Establishing covalent heterointerfaces with face-to-face contact is promising for advanced energy storage,while challenge remains on how to inhibit the anisotropic growth of nucleated crystals on the matrix.Herein,faceto-face covalent bridging in-between the 2 D-nanosheets/graphene heterostructure is constructed by intentionally prebonding of laser-manufactured amorphous and metastable nanoparticles on graphene,where the amorphous nanoparticles were designed via the competitive oxidation of Sn-O and Sn-S bonds,and metastable feature was employed to facilitate the formation of the C-S-Sn covalent bonding in-between the heterostructure.The face-to-face bridging of ultrathin SnS;nanosheets on graphene enables the heterostructure huge covalent coupling area and high loading and thus renders unimpeded electron/ion transfer pathways and indestructible electrode structure,and impressive reversible capacity and rate capability for sodium-ion batteries,which rank among the top in records of the SnS_(2)-based anodes.Present work thus provides an alternative of constructing heterostructures with planar interfaces for electrochemical energy storage and even beyond.展开更多
Potassium-ion batteries (PIBs) hold great promise as alternatives to lithium ion batteries in post-lithium age, while face challenges of slow reaction kinetics induced by the inherent characteristics of large-size K+....Potassium-ion batteries (PIBs) hold great promise as alternatives to lithium ion batteries in post-lithium age, while face challenges of slow reaction kinetics induced by the inherent characteristics of large-size K+. We herein show that creating sufficient exposed edges in MoS2 via constructing ordered mesoporous architecture greatly favors for improved kinetics as well as increased reactive sites for K storage. The engineered MoS2 with edge-enriched planes (EE-MoS2) is featured by three-dimensional bicontinuous frameworks with ordered mesopores of ~ 5.0 nm surrounded by thin wall of ~9.0 nm. Importantly, EE-MoS2 permits exposure of enormous edge planes at pore walls, renders its intrinsic layer spacing more accessible for K^+ and accelerates conversion kinetics, thus realizing enhanced capacity and high rate capability. Impressively, EE-MoS2 displays a high reversible charge capacity of 506 mAh·g^−1 at 0.05 A·g^−1, superior cycling capacities of 321 mAh·g^−1 at 1.0 A·g^−1 after 200 cycles and a capacity of 250 mAh·g^−1 at 2.0 A·g^−1, outperforming edge-deficient MoS2 with nonporous bulk structure. This work enlightens the nanoarchitecture design with abundant edges for improving electrochemical properties and provides a paradigm for exploring high-performance PIBs.展开更多
基金the National Natural Science Foundation of China(51972270,51702262,51911530212,51872240,51672225,61805201)the China Postdoctoral Science Foundation(2018T111093,2018M643732,2018BSHYDZZ57)+3 种基金the Natural Science Foundation of Shaanxi Province(2020JZ-07)the Key Research and Development Program of Shaanxi Province(2019TSLGY07-03)the Fundamental Research Funds for the Central Universities(3102019JC005 and 3102019ghxm004)the Research Fund of the State Key Laboratory of Solidification Processing(NPU),China(2019-QZ-03).
文摘Onedimensional porous carbons bearing high surface areas and sufficient heteroatom doped functionalities are essential for advanced electrochemical energy storage devices,especially for developing freestanding film electrodes.Here we develop a porous,nitrogenenriched,freestanding hollow carbon nanofiber(PNFHCF)electrode material via filtration of polypyrrole(PPy)hollow nanofibers formed by in situ selfdegraded templateassisted strategy,followed by NH3assisted carbonization.The PNFHCF retains the freestanding film morphology that is composed of threedimensional networks from the entanglement of 1D nanofiber and delivers 3.7fold increase in specific surface area(592 m^(2)g^(-1))compared to the carbon without NH_(3)treatment(FHCF).In spite of the enhanced specific surface area,PNFHCF still exhibits comparable high content of surface N functionalities(8.8%,atom fraction)to FHCF.Such developed hierarchical porous structure without sacrificing N doping functionalities together enables the achievement of high capacity,highrate property and good cycling stability when applied as selfsupporting anode in lithiumion batteries,superior to those of FHCF without NH3 treatment.
基金This work was financially supported by the project of National Key R&D Program for International Cooperation(2021YFE0115100)the National Natural Science Foundation of China(Nos.51872240,51972270 and 52172101)+5 种基金Shaanxi Province Key Research and Development Program(2021ZDLGY14-08)Natural Science Foundation of Shaanxi Province(2020JZ-07)the Research Fund of the State Key Laboratory of Solidification Processing(NPU),China(2021-TS-03)the Fundamental Research Funds for the Central Universities(3102019JC005)the Research Fund of the State Key Laboratory of Solid Lubrication(CAS),China(LSL-2007)Open access funding provided by Shanghai Jiao Tong University
文摘Establishing covalent heterointerfaces with face-to-face contact is promising for advanced energy storage,while challenge remains on how to inhibit the anisotropic growth of nucleated crystals on the matrix.Herein,faceto-face covalent bridging in-between the 2 D-nanosheets/graphene heterostructure is constructed by intentionally prebonding of laser-manufactured amorphous and metastable nanoparticles on graphene,where the amorphous nanoparticles were designed via the competitive oxidation of Sn-O and Sn-S bonds,and metastable feature was employed to facilitate the formation of the C-S-Sn covalent bonding in-between the heterostructure.The face-to-face bridging of ultrathin SnS;nanosheets on graphene enables the heterostructure huge covalent coupling area and high loading and thus renders unimpeded electron/ion transfer pathways and indestructible electrode structure,and impressive reversible capacity and rate capability for sodium-ion batteries,which rank among the top in records of the SnS_(2)-based anodes.Present work thus provides an alternative of constructing heterostructures with planar interfaces for electrochemical energy storage and even beyond.
基金the National Natural Science Foundation of China(Nos.51972270,51702262,51872240,51911530212,and 51672225)the Natural Science Foundation of Shaanxi Province(No.2020JZ-07)+2 种基金the Key Research and Development Program of Shaanxi Province(No.2019TSLGY07-03)the Fundamental Research Funds for the Central Universities(Nos.3102019[C005 and 3102019ghxm004),the Research Fund of the State Key Laboratory of Solidification Processing(NPU),China(2019-QZ-03)the Top International University Visiting Program for Outstanding Young Scholars of North-western Polytechnical University.We would like to thank the Analytical&Testing Center of Northwestern Polytechnical University for XPS characterizations.G.I.acknowledges the sponsorship from China Scholarship Council(CSC).H.W.acknowledges the support from the 1000 Youth Talent Program of China.F X.acknowledges support by the Alexander von Humboldt Foundation.
文摘Potassium-ion batteries (PIBs) hold great promise as alternatives to lithium ion batteries in post-lithium age, while face challenges of slow reaction kinetics induced by the inherent characteristics of large-size K+. We herein show that creating sufficient exposed edges in MoS2 via constructing ordered mesoporous architecture greatly favors for improved kinetics as well as increased reactive sites for K storage. The engineered MoS2 with edge-enriched planes (EE-MoS2) is featured by three-dimensional bicontinuous frameworks with ordered mesopores of ~ 5.0 nm surrounded by thin wall of ~9.0 nm. Importantly, EE-MoS2 permits exposure of enormous edge planes at pore walls, renders its intrinsic layer spacing more accessible for K^+ and accelerates conversion kinetics, thus realizing enhanced capacity and high rate capability. Impressively, EE-MoS2 displays a high reversible charge capacity of 506 mAh·g^−1 at 0.05 A·g^−1, superior cycling capacities of 321 mAh·g^−1 at 1.0 A·g^−1 after 200 cycles and a capacity of 250 mAh·g^−1 at 2.0 A·g^−1, outperforming edge-deficient MoS2 with nonporous bulk structure. This work enlightens the nanoarchitecture design with abundant edges for improving electrochemical properties and provides a paradigm for exploring high-performance PIBs.
