The development of lithium-ion batteries with high-energy densities is substantially hampered by the graphite anode's low theoretical capacity(372 mAh g^(-1)).There is an urgent need to explore novel anode materia...The development of lithium-ion batteries with high-energy densities is substantially hampered by the graphite anode's low theoretical capacity(372 mAh g^(-1)).There is an urgent need to explore novel anode materials for lithium-ion batteries.Silicon(Si),the second-largest element outside of Earth,has an exceptionally high specific capacity(3579 mAh g^(-1)),regarded as an excellent choice for the anode material in high-capacity lithium-ion batteries.However,it is low intrinsic conductivity and volume amplification during service status,prevented it from developing further.These difficulties can be successfully overcome by incorporating carbon into pure Si systems to form a composite anode and constructing a buffer structure.This review looks at the diffusion mechanism,various silicon-based anode material configurations(including sandwich,core-shell,yolk-shell,and other 3D mesh/porous structures),as well as the appropriate binders and electrolytes.Finally,a summary and viewpoints are offered on the characteristics and structural layout of various structures,metal/non-metal doping,and the compatibility and application of various binders and electrolytes for silicon-based anodes.This review aims to provide valuable insights into the research and development of silicon-based carbon anodes for high-performance lithium-ion batteries,as well as their integration with binders and electrolyte.展开更多
Mesoproterozoic magma events in the Bayan Obo rift belt have remained poorly constrained and as a result, the Late Paleoproterozoic–Mesoproterozoic tectonic evolution of the rift belt has remained unclear. By a multi...Mesoproterozoic magma events in the Bayan Obo rift belt have remained poorly constrained and as a result, the Late Paleoproterozoic–Mesoproterozoic tectonic evolution of the rift belt has remained unclear. By a multiple-facetted regional geological investigation of this belt, we have resolved the stratigraphic sequence and geochronology of the Bayan Obo Group and made new discoveries including a three-stage mantle-derived magmatic sequence. Zircon and baddeleyite dating of Xiaonanshan hornblende pyroxenite emplaced into the Bayan Obo Group yields 207Pb/206Pb ages of ca. 1.34 and 1.33 Ga. The geochronological, geochemistry, Hf isotopic analyses place an important constraint on ages of the Late Paleoproterozoic–Mesoproterozoic strata and the evolution of the rift belt. Our field observations and U-Pb dating results suggest that mineralization is genetically related to Mesoproterozoic magmatism in North China Craton, i.e., 1.33–1.34 Ga. The δ34SV-CDT values of sulphide from the ore-bearing ultra-/mafic samples are about 6.2‰, whereas the 206Pb/204Pb, 207Pb/204Pb, and 208Pb/204Pb values vary in the ranges of 17.598–18.115, 15.496–15.501, and 37.478–37.952, respectively. The Late Paleozoic mafic gabbro and acidic granite porphyry intrusions are possible to bimodal magmatic event related to the extensional tectonic setting of the Central Asia in this period.展开更多
Cycling and rate performance of natural graphite is still limited by the sluggish kinetics of lithium ions,which can be improved by surface modifications in previous research.Among these methods,amorphous carbon coati...Cycling and rate performance of natural graphite is still limited by the sluggish kinetics of lithium ions,which can be improved by surface modifications in previous research.Among these methods,amorphous carbon coating has been proved to be mature and efficient.However,the significance of coating uniformity in relation to solid electrolyte interphase(SEI)has been largely overlooked.In this study,the uniformity of amorphous carbon coating is adjusted by the particle size of pitch.When discharged-charged at 1 C,graphite half-cells with such uniform coating show 90.3%of the capacity at 0.1 C,while that is 82.1%for non-uniform coating.Additionally,improved initial coulombic efficiency and cycling stability are demonstrated.These can be attributed to graphite anodes featuring a uniform carbon coating that promotes effective and homogeneous LiF formation within the inorganic matrix.This leads to the establishment of a stabilized SEI,confirmed by time-of-flight secondary ion mass spectrometry(TOF-SIMS).This work provides valuable reference into the rational control of graphite interfaces for high electrochemical performance.展开更多
Hierarchical hollow-structured magnetic–dielectric materials are considered to be promising and competitive functional absorbers for microwave absorption(MA).Herein,a hierarchical hollow hydrangea multicomponent meta...Hierarchical hollow-structured magnetic–dielectric materials are considered to be promising and competitive functional absorbers for microwave absorption(MA).Herein,a hierarchical hollow hydrangea multicomponent metal oxides/metal-carbon was designed and successfully produced via a facile self-assembly method and calcination process.Adequate magnetic NiO and Ni nanoparticles were suspended within the hollow hydrangea-like nitrogen-doped carbon matrix(HH N-NiO/Ni/C),constructing a unique hierarchical hollow structured multicomponent magnetic–dielectric MA composite.The annealing temperature and oxidation time were carefully regulated to investigate the complex permittivity and permeability.HH N-NiO/Ni/C delivers exceptional MA properties with maximum reflection loss of–45.8 dB at 1.7 mm thickness and displays a wide effective absorption frequency range of 5.6 GHz.The superior MA performance can be attributed to the following aspects:(1)The hierarchical hollow multicomponent structure offers plentiful of heterojunction interfaces triggering interfacial polarization;(2)nitrogen doped-carbon(N-C)facilitates the conductive loss by the unique electron migration path in the graphitized C and NiO/Ni;(3)magnetic NiO/Ni nanoparticles homogeneously dispersed within N-C form extensive C skeleton and strengthen the magnetic response ability;(4)hierarchical hollow wrinkled structures possess a large interspace and heterogeneous interface improving polarization loss and enhancing multireflection process and the unique structure satisfies magnetic and dielectric loss simultaneously resulting from synergistic effects of different components within the composites.展开更多
基金supported by National Natural Science Foundation of China(No.22205182)National Science Fund for Distinguished Young Scholars(No.52025034)+2 种基金China Postdoctoral Science Foundation(Nos.2022M722594/2024T171170)Guangdong Basic and Applied Basic Research Foundation(No.2024A1515011516)financially supported by Innovation Team of Shaanxi Sanqin Scholars。
文摘The development of lithium-ion batteries with high-energy densities is substantially hampered by the graphite anode's low theoretical capacity(372 mAh g^(-1)).There is an urgent need to explore novel anode materials for lithium-ion batteries.Silicon(Si),the second-largest element outside of Earth,has an exceptionally high specific capacity(3579 mAh g^(-1)),regarded as an excellent choice for the anode material in high-capacity lithium-ion batteries.However,it is low intrinsic conductivity and volume amplification during service status,prevented it from developing further.These difficulties can be successfully overcome by incorporating carbon into pure Si systems to form a composite anode and constructing a buffer structure.This review looks at the diffusion mechanism,various silicon-based anode material configurations(including sandwich,core-shell,yolk-shell,and other 3D mesh/porous structures),as well as the appropriate binders and electrolytes.Finally,a summary and viewpoints are offered on the characteristics and structural layout of various structures,metal/non-metal doping,and the compatibility and application of various binders and electrolytes for silicon-based anodes.This review aims to provide valuable insights into the research and development of silicon-based carbon anodes for high-performance lithium-ion batteries,as well as their integration with binders and electrolyte.
基金financially supported by the National Natural Science Foundation of China (No. 41772227)supported by the Inner Mongolia Mapping Programs (Nos. 1212010811001,1212011120700,DD20160045,1212010510506) administered by China University of Geosciences (Beijing)。
文摘Mesoproterozoic magma events in the Bayan Obo rift belt have remained poorly constrained and as a result, the Late Paleoproterozoic–Mesoproterozoic tectonic evolution of the rift belt has remained unclear. By a multiple-facetted regional geological investigation of this belt, we have resolved the stratigraphic sequence and geochronology of the Bayan Obo Group and made new discoveries including a three-stage mantle-derived magmatic sequence. Zircon and baddeleyite dating of Xiaonanshan hornblende pyroxenite emplaced into the Bayan Obo Group yields 207Pb/206Pb ages of ca. 1.34 and 1.33 Ga. The geochronological, geochemistry, Hf isotopic analyses place an important constraint on ages of the Late Paleoproterozoic–Mesoproterozoic strata and the evolution of the rift belt. Our field observations and U-Pb dating results suggest that mineralization is genetically related to Mesoproterozoic magmatism in North China Craton, i.e., 1.33–1.34 Ga. The δ34SV-CDT values of sulphide from the ore-bearing ultra-/mafic samples are about 6.2‰, whereas the 206Pb/204Pb, 207Pb/204Pb, and 208Pb/204Pb values vary in the ranges of 17.598–18.115, 15.496–15.501, and 37.478–37.952, respectively. The Late Paleozoic mafic gabbro and acidic granite porphyry intrusions are possible to bimodal magmatic event related to the extensional tectonic setting of the Central Asia in this period.
基金Project(52377220)supported by the National Natural Science Foundation of ChinaProject(kq2208265)supported by the Natural Science Foundation of Changsha,Hunan Province,ChinaProject supported by State Key Laboratory of Powder Metallurgy(Central South University,Changsha,China)。
文摘Cycling and rate performance of natural graphite is still limited by the sluggish kinetics of lithium ions,which can be improved by surface modifications in previous research.Among these methods,amorphous carbon coating has been proved to be mature and efficient.However,the significance of coating uniformity in relation to solid electrolyte interphase(SEI)has been largely overlooked.In this study,the uniformity of amorphous carbon coating is adjusted by the particle size of pitch.When discharged-charged at 1 C,graphite half-cells with such uniform coating show 90.3%of the capacity at 0.1 C,while that is 82.1%for non-uniform coating.Additionally,improved initial coulombic efficiency and cycling stability are demonstrated.These can be attributed to graphite anodes featuring a uniform carbon coating that promotes effective and homogeneous LiF formation within the inorganic matrix.This leads to the establishment of a stabilized SEI,confirmed by time-of-flight secondary ion mass spectrometry(TOF-SIMS).This work provides valuable reference into the rational control of graphite interfaces for high electrochemical performance.
基金the China Academy of Launch Vehicle Technology(Nos.5120200522 and 5120210234)the National Natural Science Foundation of China(No.21875190)+1 种基金Foundation of Aeronautics Science Fund(No.2020Z056053002)Fundamental Research Funds for the Central Universities(construction and low-frequency microwave absorption properties of metamaterials).
文摘Hierarchical hollow-structured magnetic–dielectric materials are considered to be promising and competitive functional absorbers for microwave absorption(MA).Herein,a hierarchical hollow hydrangea multicomponent metal oxides/metal-carbon was designed and successfully produced via a facile self-assembly method and calcination process.Adequate magnetic NiO and Ni nanoparticles were suspended within the hollow hydrangea-like nitrogen-doped carbon matrix(HH N-NiO/Ni/C),constructing a unique hierarchical hollow structured multicomponent magnetic–dielectric MA composite.The annealing temperature and oxidation time were carefully regulated to investigate the complex permittivity and permeability.HH N-NiO/Ni/C delivers exceptional MA properties with maximum reflection loss of–45.8 dB at 1.7 mm thickness and displays a wide effective absorption frequency range of 5.6 GHz.The superior MA performance can be attributed to the following aspects:(1)The hierarchical hollow multicomponent structure offers plentiful of heterojunction interfaces triggering interfacial polarization;(2)nitrogen doped-carbon(N-C)facilitates the conductive loss by the unique electron migration path in the graphitized C and NiO/Ni;(3)magnetic NiO/Ni nanoparticles homogeneously dispersed within N-C form extensive C skeleton and strengthen the magnetic response ability;(4)hierarchical hollow wrinkled structures possess a large interspace and heterogeneous interface improving polarization loss and enhancing multireflection process and the unique structure satisfies magnetic and dielectric loss simultaneously resulting from synergistic effects of different components within the composites.
基金supported by the National Natural Science Foundation of China(22209006 and 21935001)the Natural Science Foundation of Shandong Province(ZR2022QE009)+1 种基金the Fundamental Research Funds for the Central Universities(buctrc202307)the National Key Beijing Natural Science Foundation(Z210016)。
