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
Thanks to inexpensive and bountiful potassium resources,potassium ion batteries(PIBs)have come into the spotlight as viable alternatives for next-generation battery systems.However,poor electrochemical kinetics due to...Thanks to inexpensive and bountiful potassium resources,potassium ion batteries(PIBs)have come into the spotlight as viable alternatives for next-generation battery systems.However,poor electrochemical kinetics due to the large size of the K^(+) is a major challenge for PIB anodes.In this paper,an ingenious design of VN nanoparticleassembled hollow microspheres within N-containing intertwined carbon nanofibers(VN-NPs/N-CNFs)via an electrospinning process is reported.Employed as PIB anodes,VN-NPs/N-CNFs exhibit a superb rate property and prolonged cyclability,surpassing that of other reported metal nitride-based anodes.This is ascribed to:(i)the VN NP-assembled hollow microspheres,which shorten the K^(+) diffusion distance,and mitigate volume expansion;and(ii)the interconnected N-CNFs,which supply numerous active sites for K^(+) adsorption and facilitate rapid electron/ion transport.展开更多
The preparation methods of hollow polymer microspheres both at home and abroad are summarized, and their preparation mechanisms and developmental states are presented. These methods include the liquid droplet method, ...The preparation methods of hollow polymer microspheres both at home and abroad are summarized, and their preparation mechanisms and developmental states are presented. These methods include the liquid droplet method, dried-gel droplet method, self-assembly method, microencapsulation method, emulsion polymerization method and the template method. Hollow polystyrene microspheres are the most extensively studied in the research of hollow polymer microspheres. Through comparison of the advantages and disadvantages of different preparation methods, it is concluded that microencapsulation method is most suitable for preparing polystyrene hollow microspheres.展开更多
This article reported the electrochemical behaviors of a novel hollow carbon microspheres/manganese dioxide nanosheets(micro-HC/nano-MnO2) composite prepared by an in situ self-limiting deposition method under hydroth...This article reported the electrochemical behaviors of a novel hollow carbon microspheres/manganese dioxide nanosheets(micro-HC/nano-MnO2) composite prepared by an in situ self-limiting deposition method under hydrothermal condition. The results of scanning electron microscopy reveal that MnO2 nanosheets homogeneously grow onto the surface of micro-HC to form a loose-packed microstructure. The quantity of MnO2 required in the electrode layer has thereby been reduced significantly, and higher specific capacitances have been achieved. The micro-HC/nano-MnO2 electrode presents a high capacitance of 239.0 F g-1 at a current density of 5 m A cm-2, which is a strong promise for high-rate electrochemical capacitive energy storage applications.展开更多
Deep petroleum resources are in a high-temperature environment.However,the traditional deep rock coring method has no temperature preserved measures and ignores the effect of temperature on rock porosity and permeabil...Deep petroleum resources are in a high-temperature environment.However,the traditional deep rock coring method has no temperature preserved measures and ignores the effect of temperature on rock porosity and permeability,which will lead to the distortion of the petroleum resources reserves assessment.Therefore,the hollow glass microspheres/epoxy resin(HGM/EP)composites were innovatively proposed as temperature preserved materials for in-situ temperature-preserved coring(ITP-Coring),and the physical,mechanical,and temperature preserved properties were evaluated.The results indicated that:As the HGM content increased,the density and mechanical properties of the composites gradually decreased,while the water absorption was deficient without hydrostatic pressure.For composites with 50 vol%HGM,when the hydrostatic pressure reached 60 MPa,the water absorption was above 30.19%,and the physical and mechanical properties of composites were weakened.When the hydrostatic pressure was lower than 40 MPa,the mechanical properties and thermal conductivity of composites were almost unchanged.Therefore,the composites with 50 vol%HGM can be used for ITPCoring operations in deep environments with the highest hydrostatic pressure of 40 MPa.Finally,to further understand the temperature preserved performance of composites in practical applications,the temperature preserved properties were measured.An unsteady-state heat transfer model was established based on the test results,then the theoretical change of the core temperature during the coring process was obtained.The above tests results can provide a research basis for deep rock in-situ temperature preserved corer and support accurate assessment of deep petroleum reserves.展开更多
Transition metal nitrides have attracted considerable attention as great potential anode materials due to their excellent metallic conductivity and high theoretical specific capacity.However,their cycling performance ...Transition metal nitrides have attracted considerable attention as great potential anode materials due to their excellent metallic conductivity and high theoretical specific capacity.However,their cycling performance is impeded by their instability caused by the reaction mechanism.Herein,we report the engineering and synthesis of a novel hybrid architecture composed of MoO2.0N0.5 atomic nanoclusters bonded in nanosheets of N-doped carbon hierarchical hollow microspheres(MoO2.0N0.5/NC)as an anode material for sodium-ion batteries.The facile self-templating strategy for the synthesis of MoO2.0N0.5/NC involves chemical polymerization and subsequent one-step calcination treatments.The design is benefi-cial to improve the electrochemical kinetics,buffer the volume variation of electrodes during cycling,and provide more interfacial active sites for sodium uptake.Due to these unique structural and compositional merits,these MoO2.0N0.5/NC exhibits excellent sodium storage performance in terms of superior rate capability and stable long cycle life.The work shows a feasible and effective way to design novel host candidates and solve the long-term cycling stability issues for sodium-ion batteries.展开更多
Deep oil and gas reservoirs are under high-temperature conditions,but traditional coring methods do not consider temperature-preserved measures and ignore the influence of temperature on rock porosity and permeability...Deep oil and gas reservoirs are under high-temperature conditions,but traditional coring methods do not consider temperature-preserved measures and ignore the influence of temperature on rock porosity and permeability,resulting in distorted resource assessments.The development of in situ temperaturepreserved coring(ITP-Coring)technology for deep reservoir rock is urgent,and thermal insulation materials are key.Therefore,hollow glass microsphere/epoxy resin thermal insulation materials(HGM/EP materials)were proposed as thermal insulation materials.The materials properties under coupled hightemperature and high-pressure(HTHP)conditions were tested.The results indicated that high pressures led to HGM destruction and that the materials water absorption significantly increased;additionally,increasing temperature accelerated the process.High temperatures directly caused the thermal conductivity of the materials to increase;additionally,the thermal conduction and convection of water caused by high pressures led to an exponential increase in the thermal conductivity.High temperatures weakened the matrix,and high pressures destroyed the HGM,which resulted in a decrease in the tensile mechanical properties of the materials.The materials entered the high elastic state at 150℃,and the mechanical properties were weakened more obviously,while the pressure led to a significant effect when the water absorption was above 10%.Meanwhile,the tensile strength/strain were 13.62 MPa/1.3%and 6.09 MPa/0.86%at 100℃ and 100 MPa,respectively,which meet the application requirements of the self-designed coring device.Finally,K46-f40 and K46-f50 HGM/EP materials were proven to be suitable for ITP-Coring under coupled conditions below 100℃ and 100 MPa.To further improve the materials properties,the interface layer and EP matrix should be optimized.The results can provide references for the optimization and engineering application of materials and thus technical support for deep oil and gas resource development.展开更多
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the National Natural Science Foundation of China(No.51631004)the Project of Talent Development in Jilin Province,the Natural Science Foundation of Jilin Province(No.20200201073JC)+2 种基金the Program for JLU Science and Technology Innovative Research Team(No.2017TD-09)the Graduate Innovation Fund of Jilin University(No.101832020CX146)the Fundamental Research Funds for the Central Universities for their financial support.
文摘Thanks to inexpensive and bountiful potassium resources,potassium ion batteries(PIBs)have come into the spotlight as viable alternatives for next-generation battery systems.However,poor electrochemical kinetics due to the large size of the K^(+) is a major challenge for PIB anodes.In this paper,an ingenious design of VN nanoparticleassembled hollow microspheres within N-containing intertwined carbon nanofibers(VN-NPs/N-CNFs)via an electrospinning process is reported.Employed as PIB anodes,VN-NPs/N-CNFs exhibit a superb rate property and prolonged cyclability,surpassing that of other reported metal nitride-based anodes.This is ascribed to:(i)the VN NP-assembled hollow microspheres,which shorten the K^(+) diffusion distance,and mitigate volume expansion;and(ii)the interconnected N-CNFs,which supply numerous active sites for K^(+) adsorption and facilitate rapid electron/ion transport.
文摘The preparation methods of hollow polymer microspheres both at home and abroad are summarized, and their preparation mechanisms and developmental states are presented. These methods include the liquid droplet method, dried-gel droplet method, self-assembly method, microencapsulation method, emulsion polymerization method and the template method. Hollow polystyrene microspheres are the most extensively studied in the research of hollow polymer microspheres. Through comparison of the advantages and disadvantages of different preparation methods, it is concluded that microencapsulation method is most suitable for preparing polystyrene hollow microspheres.
基金supported by the National Natural Science Foundation of China (51203071, 51363014 and 51362018)China Postdoctoral Science Foundation (2014M552509)+1 种基金the Key Project of Chinese Ministry of Education (212183)the Natural Science Funds for Distinguished Young Scholars of Gansu Province (1111RJDA012)
文摘This article reported the electrochemical behaviors of a novel hollow carbon microspheres/manganese dioxide nanosheets(micro-HC/nano-MnO2) composite prepared by an in situ self-limiting deposition method under hydrothermal condition. The results of scanning electron microscopy reveal that MnO2 nanosheets homogeneously grow onto the surface of micro-HC to form a loose-packed microstructure. The quantity of MnO2 required in the electrode layer has thereby been reduced significantly, and higher specific capacitances have been achieved. The micro-HC/nano-MnO2 electrode presents a high capacitance of 239.0 F g-1 at a current density of 5 m A cm-2, which is a strong promise for high-rate electrochemical capacitive energy storage applications.
基金National Natural Science Foundation of China(grant number 51827901)funded by the Program for Guangdong Introducing Innovative and Enterpreneurial Teams(No.2019ZT08G315)Shenzhen Basic Research Program(General Program)(No.JCYJ20190808153416970)
文摘Deep petroleum resources are in a high-temperature environment.However,the traditional deep rock coring method has no temperature preserved measures and ignores the effect of temperature on rock porosity and permeability,which will lead to the distortion of the petroleum resources reserves assessment.Therefore,the hollow glass microspheres/epoxy resin(HGM/EP)composites were innovatively proposed as temperature preserved materials for in-situ temperature-preserved coring(ITP-Coring),and the physical,mechanical,and temperature preserved properties were evaluated.The results indicated that:As the HGM content increased,the density and mechanical properties of the composites gradually decreased,while the water absorption was deficient without hydrostatic pressure.For composites with 50 vol%HGM,when the hydrostatic pressure reached 60 MPa,the water absorption was above 30.19%,and the physical and mechanical properties of composites were weakened.When the hydrostatic pressure was lower than 40 MPa,the mechanical properties and thermal conductivity of composites were almost unchanged.Therefore,the composites with 50 vol%HGM can be used for ITPCoring operations in deep environments with the highest hydrostatic pressure of 40 MPa.Finally,to further understand the temperature preserved performance of composites in practical applications,the temperature preserved properties were measured.An unsteady-state heat transfer model was established based on the test results,then the theoretical change of the core temperature during the coring process was obtained.The above tests results can provide a research basis for deep rock in-situ temperature preserved corer and support accurate assessment of deep petroleum reserves.
基金supports provided by the National Natural Science Foundation of China(U21A2077,21971145,21871164)the Taishan Scholar Project Foundation of Shandong Province(ts20190908)+2 种基金the Natural Science Foundation of Shandong Province(ZR2021ZD05,ZR2019MB024)Young Scholars Program of Shandong University(2017WLJH15)and Anhui Kemi Machinery Technology Co.,Ltd.for providing a Teflon-lined stainless steel autoclave.
文摘Transition metal nitrides have attracted considerable attention as great potential anode materials due to their excellent metallic conductivity and high theoretical specific capacity.However,their cycling performance is impeded by their instability caused by the reaction mechanism.Herein,we report the engineering and synthesis of a novel hybrid architecture composed of MoO2.0N0.5 atomic nanoclusters bonded in nanosheets of N-doped carbon hierarchical hollow microspheres(MoO2.0N0.5/NC)as an anode material for sodium-ion batteries.The facile self-templating strategy for the synthesis of MoO2.0N0.5/NC involves chemical polymerization and subsequent one-step calcination treatments.The design is benefi-cial to improve the electrochemical kinetics,buffer the volume variation of electrodes during cycling,and provide more interfacial active sites for sodium uptake.Due to these unique structural and compositional merits,these MoO2.0N0.5/NC exhibits excellent sodium storage performance in terms of superior rate capability and stable long cycle life.The work shows a feasible and effective way to design novel host candidates and solve the long-term cycling stability issues for sodium-ion batteries.
基金supported by the Sichuan Science and Technology Program (Grant Nos.2023NSFSC0004,2023NSFSC0790)the National Natural Science Foundation of China (Grant Nos.51827901,52304033)the Sichuan University Postdoctoral Fund (Grant No.2024SCU12093)。
文摘Deep oil and gas reservoirs are under high-temperature conditions,but traditional coring methods do not consider temperature-preserved measures and ignore the influence of temperature on rock porosity and permeability,resulting in distorted resource assessments.The development of in situ temperaturepreserved coring(ITP-Coring)technology for deep reservoir rock is urgent,and thermal insulation materials are key.Therefore,hollow glass microsphere/epoxy resin thermal insulation materials(HGM/EP materials)were proposed as thermal insulation materials.The materials properties under coupled hightemperature and high-pressure(HTHP)conditions were tested.The results indicated that high pressures led to HGM destruction and that the materials water absorption significantly increased;additionally,increasing temperature accelerated the process.High temperatures directly caused the thermal conductivity of the materials to increase;additionally,the thermal conduction and convection of water caused by high pressures led to an exponential increase in the thermal conductivity.High temperatures weakened the matrix,and high pressures destroyed the HGM,which resulted in a decrease in the tensile mechanical properties of the materials.The materials entered the high elastic state at 150℃,and the mechanical properties were weakened more obviously,while the pressure led to a significant effect when the water absorption was above 10%.Meanwhile,the tensile strength/strain were 13.62 MPa/1.3%and 6.09 MPa/0.86%at 100℃ and 100 MPa,respectively,which meet the application requirements of the self-designed coring device.Finally,K46-f40 and K46-f50 HGM/EP materials were proven to be suitable for ITP-Coring under coupled conditions below 100℃ and 100 MPa.To further improve the materials properties,the interface layer and EP matrix should be optimized.The results can provide references for the optimization and engineering application of materials and thus technical support for deep oil and gas resource development.
