As a promising alternative anode material,silicon(Si)presents a larger capacity than the commercial anode to achieve large capacity lithium-ion batteries.However,the application of pure Si as anode is hampered by limi...As a promising alternative anode material,silicon(Si)presents a larger capacity than the commercial anode to achieve large capacity lithium-ion batteries.However,the application of pure Si as anode is hampered by limitations such as volume expansion,low conductivity and unstable solid electrolyte interphase.To break through these limitations,the core-shell Si@Li4Ti5O12nanocomposite,which was prepared via in-situ self-assembly reaction and decompressive boiling fast concentration method,was proposed in this work.This anode combines the advantages of nano-sized Si particle and pure Li4Ti5O12(LTO)coating layer,improving the performance of the lithium-ion batteries.The Si@Li4Ti5O12 anode displays a high initial discharge/charge specific capacity of 1756/1383 m Ahg^-1 at 500 mAg^-1(representing high initial coulombic efficiency of 78.8%),a large rate capability(specific capacity of 620 mAhg^-1 at4000 mAg^-1),an outstanding cycling stability(reversible specific capacity of 883 mAhg^-1 after 150 cycles)and a low volume expansion rate(only 3.3% after 150 cycles).Moreover,the synthesis process shows the merits of efficiency,simplicity,and economy,providing a reliable method to fabricate large capacity Si@Li4Ti5O12nanocomposite anode materials for practical lithium-ion batteries.展开更多
The main bottleneck against industrial utilization of sodium ion batteries(SIBs)is the lack of high-capacity electrodes to rival those of the benchmark lithium ion batteries(LIBs).Here in this work,we have developed a...The main bottleneck against industrial utilization of sodium ion batteries(SIBs)is the lack of high-capacity electrodes to rival those of the benchmark lithium ion batteries(LIBs).Here in this work,we have developed an economical method for in situ fabrication of nanocomposites made of crystalline few-layer graphene sheets loaded with ultrafine SnO_(2)nanocrystals,using short exposure of microwave to xerogel of graphene oxide(GO)and tin tetrachloride containing minute catalyzing dispersoids of chemically reduced GO(RGO).The resultant nanocomposites(SnO_(2)@MWG)enabled significantly quickened redox processes as SIB anode,which led to remarkable full anode-specific capacity reaching 538 mAh g^(−1)at 0.05 A g^(−1)(about 1.45 times of the theoretical capacity of graphite for the LIB),in addition to outstanding rate performance over prolonged charge–discharge cycling.Anodes based on the optimized SnO_(2)@MWG delivered stable performance over 2000 cycles even at a high current density of 5 A g^(−1),and capacity retention of over 70.4%was maintained at a high areal loading of 3.4 mg cm^(−2),highly desirable for high energy density SIBs to rival the current benchmark LIBs.展开更多
Transition metal oxides as anode materials for high-performance lithium-ion batteries suffer from severe capacity decay,originating primarily from particle pulverization upon volume expansion/shrinkage and the intrins...Transition metal oxides as anode materials for high-performance lithium-ion batteries suffer from severe capacity decay,originating primarily from particle pulverization upon volume expansion/shrinkage and the intrinsically sluggish electron/ion transport.Herein,in-situ encapsulation ofα-Fe_(2)O_(3) nanoparticles into micro-sized ZnFe_(2)O_(4) capsules is facilely fulfilled through a co-precipitation process and followed by heat-treatment at optimal calcination temperature.The porous ZnFe_(2)O_(4) scaffold affords a synergistic confinement effect to suppress the grain growth ofα-Fe2 O3 nanocrystals during the calcination process and to accommodate the stress generated by volume expansion during the charge/discharge process,leading to an enhanced interfacial conductivity and inhibit electrode pulverization and mechanical failure in the active material.With these merits,the preparedα-Fe_(2)O_(3)/Fe_(2)O_(4) composite delivers prolonged cycling stability and improved rate capability with a higher specific capacity than soleα-Fe_(2)O_(3) and Fe_(2)O_(4).The discharge capacity is retained at 700 mAh g-1 after 500 cycles at 200 mA g^(-1) and 940 mAh g^(-1) after 50 cycles at 100 m A g^(-1).This work provides a new perspective in designing transition metal oxides for advanced lithium-ion batteries with superior electrochemical properties.展开更多
ZnO–CuO porous hybrid microspheres were successfully produced through a facile aging process of zinc citrate solid microspheres in copper sulfate solution combined with the subsequent annealing treatment in air atmos...ZnO–CuO porous hybrid microspheres were successfully produced through a facile aging process of zinc citrate solid microspheres in copper sulfate solution combined with the subsequent annealing treatment in air atmosphere. The electrochemical performance investigation suggests that the harvested ZnO–CuO porous hybrid microspheres illustrate much higher specific capacity and better cycling stability than single ZnO counterparts. A reversible capacity of 585 mAh·g^-1 can be acquired for ZnO–CuO porous hybrid microspheres after cycling 500 times at a current density of 200 mA·g^-1. The porous configuration and the incorporation of CuO are responsible for the enhanced lithium storage properties of ZnO–CuO hybrids.展开更多
A facile scalable synthesis of hierarchical Sb/C micro-/nanohybrid has been addressed in this work, which possesses the advantages of both micrometer and nanometer scale structures as lithium-ion battery anode. Difunc...A facile scalable synthesis of hierarchical Sb/C micro-/nanohybrid has been addressed in this work, which possesses the advantages of both micrometer and nanometer scale structures as lithium-ion battery anode. Difunctional methacrylate monomers are used as solvent and carbon source as well. Liquid precursor of antimony（III） n-butoxide is dissolved in the resin monomer solution, and further incorporated into the cross-linking polymer network via photo polymerization. Through calcination in argon/hydrogen atmosphere, antimony nanoparticles are in situ formed by carbothermal reduction, and homogeneously embedded in the in situ formed micrometer sized carbon matrix. The morphology, structure, crys- tallinity, spatial dispersion, composition, and electrochemical performance of the Sb/C micro-/nanohybrid are systemati- cally investigated. The cyclic and rate performance of the Sb/C micro-/nanohybrid anode have been effectively improved compared to the pure carbon anode. A reversible capacity of 362 mAh g-1 is achieved with a reasonable mass loading density after 300 cycles at 66 mA g-1, corresponding to capacity retention of 79%. With reducing mass loading density, the reversible capacity reaches 793 mAh g-1 after 100 cycles. Moreover, the electrochemical performance of Sb/C micro-/nanohybrid as sodium-ion battery anode is also investigated in this study.展开更多
The poor crystallinity and unstable crystal structure of tungsten disulfide(WS2)limit its application in practice.In this paper,a molten salt electrolysis method is proposed to intercalate metal ions into the interlay...The poor crystallinity and unstable crystal structure of tungsten disulfide(WS2)limit its application in practice.In this paper,a molten salt electrolysis method is proposed to intercalate metal ions into the interlayers of layered WS2 to obtain few-layer sheetlike structures.The effect of the molten salt system,applied constant current and electrolysis duration on the exfoliation degree of WS2 bulk has been investigated.The results show that the products electrolyzed in molten LiCl-NaCl-KCl and NaClKCl salts under 25 mA were more transparent and thinner flakes sheets due to the uniform intercalation of Li^+and Na^+with smaller size.The exfoliated WS_(2)was used as an anode material for sodium-ion batteries with a potential of 0.01-2.50 V.In comparison,the WS_(2)-NaCl-25 mA electrode displays a high reversible capacity of 373 mAh·g^(-1)at0.1 A·g^(-1)after cycling for 100 cycles at the same time showing great rate and cycle performance.It also presents a high capacitive ratio of 90.65%at 1.0 mV·s^(-1).The molten salt electrolysis provides a new perspective on the exfoliation of layered material,while demonstrating the great potential of WS2 as an anode material for sodium-ion battery.展开更多
Developing suitable anode materials for potassium-ion batteries(PIBs)remains a great challenge owing to the limited theoretical capacity of active materials and large radius of K+ion(1.38?).To solve these obstacles,by...Developing suitable anode materials for potassium-ion batteries(PIBs)remains a great challenge owing to the limited theoretical capacity of active materials and large radius of K+ion(1.38?).To solve these obstacles,by integrating the principles of multielectron transfer and rational porous crystal framework,we creatively propose the monoclinic Cu_(3)(OH)_(2)V_(2)O_(7)·2H_(2)O(CVO)as a novel anode for PIBs.Furthermore,inspired by the metastable nature of CVO under high temperature/pressure,we skillfully design a facile hydrothermal recrystallization strategy without the phase change and surfactants addition.Thus,for the first time,the porous composite of Cu_(3)(OH)_(2)V_(2)O_(7)·2H_(2)O nanobelts covered in situ by reduced graphene oxide(CVO NBs/r GO)was assembled,greatly improving the deficiencies of CVO.When used as a novel anode for PIBs,CVO NBs/r GO delivers large specific capacity(up to 551.4 m Ah g^(-1)at 50 m A g^(-1)),high-rate capability(215.3 m Ah g^(-1)at 2.5 A g^(-1))and super durability(203.6 m Ah g^(-1)at 500 m A g^(-1)even after 1000 cycles).The outstanding performance can be ascribed to the synergistic merits of desirable structural features of monoclinic CVO nanobelts and the highly conductive graphene 3D network,thus promoting the composite material stability and electrical/ionic conductivity.This work reveals a novel metal vanadate-based anode material for PIBs,would further motivate the subsequent batteries research on M_(3)(OH)_(2)V_(2)O_(7)-n H_(2)O(M;Co,Ni,Cu,Zn),and ultimately expands valuable fundamental understanding on designing other high-performance electrode materials,including the combined strategies of multielectron transfer with rational porous crystal framework,and the composite fabrication of 1D electrode nanostructure with conductive carbon matrix.展开更多
SnS_(2) stands out as a promising lithium storage anode due to its high specific capacity,low voltage plateau,and cost-effectiveness.However,practical applications are hindered by significant limitations,including low...SnS_(2) stands out as a promising lithium storage anode due to its high specific capacity,low voltage plateau,and cost-effectiveness.However,practical applications are hindered by significant limitations,including low electrical conductivity,volumetric expansion,and sulfur dissolution.In this study,carbon-encrusted SnS_(2) nanoparticles are anchored onto few-layered MXene via a straightforward ultrasound-assisted ball milling method,yielding SnS_(2)@C/MXene nanocomposites.Kinetic experiments demonstrate that this innovative ball milling approach facilitates the infiltration of SnS_(2)@C into the distorted sites of MXene,effectively curbing interlayer stacking,expediting ion transfer,and bolstering the pseudocapacitance contribution of the anode.Concurrently,the few-layered MXene intertwines with SnS_(2)@C,effectively mitigating the volume fluctuations of the active SnS_(2)@C.As a lithium-ion battery(LiB)anode,SnS_(2)@C/MXene exhibits a specific capacity of 867.1 mAh g^(−1) after 100 cycles at 0.1 A g^(−1).Moreover,the SnS_(2)@C/MXene anode demonstrates remarkable reversible specific capacities of 1,162.9,1,001.0,838.1,724.8,591.5,and 413.9 mAh g^(−1) under 0.1,0.2,0.5,1,2,and 5 A g^(−1),respectively,surpassing those of recently reported SnSx-based LiB anodes.These findings underscore the significant potential of SnS_(2)@C/MXene nanocomposites for high-performance LiBs.展开更多
In this work,the facile carbon nanotubes(CNTs) modulation strategy was successfully used to fabricate Bi_(5) Nb_(3) O_(15)@CNTs composites as anode materials for lithium-ion battery by a simple solid-state route.The i...In this work,the facile carbon nanotubes(CNTs) modulation strategy was successfully used to fabricate Bi_(5) Nb_(3) O_(15)@CNTs composites as anode materials for lithium-ion battery by a simple solid-state route.The introduction of CNTs does not change the structure of the Bi_(5) Nb_(3) O_(15) materials,the Bi_(5) Nb_(3) O_(15) particles are decorated on a three-dimensional CNTs network,and the high conductive network promotes transfer of electron/ion and relieve the volume change of Bi_(5) Nb_(3) O_(15).The Bi_(5) Nb_(3) O_(15)@CNTs(8 wt%) electrode shows a superior rate capability with charge(discharge) capacities of 490(898.7),379.1(401.6),311.3(326.9),276.5(285.5) and 243.4(252)mAh·g^(-1) at 50,100,200,300 and 500 mA·g^(-1),respectively.However,the Bi_(5) Nb_(3) O_(15) only shows charge(discharge) capacities of 431(772.6),278.6(309.9),193.1(213.7),160.8(171.1),129.9(139.1) mAh·g^(-1) at the corresponding rates,respectively.The excellent rate capability of Bi_(5) Nb_(3) O_(15)@CNTs can be ascribed to the homogeneous distribution of Bi_(5) Nb_(3) O_(15) particles in the CNTs conductive network and the enhancement of conductivity.Hence,the CNTs modulation can be considered as an effective strategy to enhance electrochemical performances of Bi_(5) Nb_(3) O_(15) materials.展开更多
Nb_2O_5/C nanosheets are successfully prepared through a mixing process and followed by heating treatment.Such Nb_2O_5/C based electrode exhibits high rate performance and remarkable cycling ability,showing a high and...Nb_2O_5/C nanosheets are successfully prepared through a mixing process and followed by heating treatment.Such Nb_2O_5/C based electrode exhibits high rate performance and remarkable cycling ability,showing a high and stable specific capacity of ~380mAhg^（-1） at the current density of 50 mAg^（-1）（much higher than the theoretical capacity of Nb_2O_5）.Further more,at a current density of 500mAg^（-1）,the nanocomposites electrode still exhibits a specific capacity of above 150 mAh g^（-1） after 100 cycles.These results suggest the Nb_2O_5/C nanocomposite is a high performance anode material for lithium-ion batteries.展开更多
In this work,via a facile solvothermal route,we synthesized an anode material for lithium ion batteries（LIBs）—SnS2 nanoparticle/graphene（SnS2 NP/GNs） nanocomposite.The nanocomposite consists of SnS2nanoparticles ...In this work,via a facile solvothermal route,we synthesized an anode material for lithium ion batteries（LIBs）—SnS2 nanoparticle/graphene（SnS2 NP/GNs） nanocomposite.The nanocomposite consists of SnS2nanoparticles with an average diameter of 4 nm and graphene nanosheets without restacking.The SnS2 nanoparticles are firmly anchored on the graphene nanosheets.As an anode material for LIBs,the nanocomposite exhibits good Li storage performance especially high rate performance.At the high current rate of 5,10,and 20 A/g,the nanocomposite delivered high capacities of 525,443,and 378 mAh/g,respectively.The good conductivity of the graphene nanosheets and the small particle size of SnS2contribute to the electrochemical performance of SnS2 NP/GNs.展开更多
Anode free lithium metal batteries(AF-LMBs)have conspicuous advantages both in energy density and the compatibility of battery manufacturing process.However,the limited cycle life of AF-LMBs is a crucial factor hinder...Anode free lithium metal batteries(AF-LMBs)have conspicuous advantages both in energy density and the compatibility of battery manufacturing process.However,the limited cycle life of AF-LMBs is a crucial factor hindering its practical application.Fluorinated or nitride artificial inorganic solid electrolyte interphase(SEI)has been found as an effective method to prolong the lifespan of AF-LMBs.Herein,by investigating the impact of nano-sized inorganic gradient layers(LiF or Li3N)on initial Li deposition behavior,we notice that the Li^(+) diffusion barrier and the deposition morphology are highly depended on the thickness of inorganic layers.Thicker protective layers cause larger overpotential as well as more aggregated Li^(+) distribution.This study reveals that the ideal SEI should be synthesized thin and uniformly enough and uncontrollable artificial SEI can cause damage to the lifespan of AF-LMBs.展开更多
In response to the limitations of conventional chemical synthesis methods for the structural modulation of nanomaterials,an innovative high magnetic field-assisted wet chemical synthesis method was proposed to prepare...In response to the limitations of conventional chemical synthesis methods for the structural modulation of nanomaterials,an innovative high magnetic field-assisted wet chemical synthesis method was proposed to prepare NiFe_(2)O_(4)/Fe_(2)O_(3) heterostructures.It is found that the high-energy physical field could induce a more homogeneous morphology of NiFe_(2)O_(4)/Fe_(2)O_(3),accompanied by phase transformation from Fe_(2)O_(3) to NiFe_(2)O_(4).As a result,the optimized structure obtained under the magnetic field endows NiFe_(2)O_(4)/Fe_(2)O_(3) with enhanced performance for the lithium-ion battery anode,as evidenced by an increase of 16%(1200 mA·h/g)in discharge capacity and 24% in ultra-stable cycling performance(capacity retention of 97.1%).These results highlight the feasibility of high magnetic fields in modulating material structure and enhancing lithium storage performance.展开更多
Transition-metal oxides have attracted increased attention in the application of high-performance lithium ion batteries（LIBs）, owing to its higher reversible capacity,better structural stability and high electronic ...Transition-metal oxides have attracted increased attention in the application of high-performance lithium ion batteries（LIBs）, owing to its higher reversible capacity,better structural stability and high electronic conductivity.Herein, CoWO4 nanoparticles wrapped by reduced graphene oxide（CoWO4–RGO） were synthesized via a facile hydrothermal route followed by a subsequent heat-treatment process. When evaluated as the anode of LIB, the synthetic CoWO4–RGO nanocomposite exhibits better Li^＋ storage properties than pure CoWO4 nanostructures synthesized without graphene oxide（GO）. Specifically, it delivers a high initial specific discharge capacity of1100 mAh·g^-1 at a current density of 100 mA·g^-1, and a good reversible performance of 567 mAh·g^-1 remains after the 100th cycle. Moreover, full battery using CoWO4–RGO as anode and commercial LiCoO2 powder as cathode was assembled, which can be sufficient to turn on a 3 V,10 mW blue light emitting diode（LED）. The enhanced electrochemical performance for lithium storage can be attributed to the three-dimensional（3D） structure of the CoWO4–RGO nanocomposite, which can accommodate huge volume changes, and synergetic effect between CoWO4 and reduced graphite oxide（RGO） nanosheets,including an increased conductivity, shortened Li^＋ diffusion path.展开更多
Sustainable transformation and efficient utilization of biomasses and their derived materials are environ-mentally as well as economically compliant strategies.Biomass seaweed-derived nitrogen self-doped porous carbon...Sustainable transformation and efficient utilization of biomasses and their derived materials are environ-mentally as well as economically compliant strategies.Biomass seaweed-derived nitrogen self-doped porous carbon with tailored surface area and pore structures are prepared through carb on izatio n and activation.The in fluence of carb on ization temperature on morphology,surface area,and heteroatom dopants are investigated to optimize sodium-ion storage capability.Seaweed-derived nitrogen selfdoped activated carbon(SAC)as anode materials for sodium-ion batteries exhibits remarkable reversible capacity of 303/192 mAh g^(-1) after 100/500 cycles at current densities of 100/200 mA g^(-1) respectively,and a good rate capability.The interconnected and porous conducting nature along with the heteroatom dopant role in creating defective sites and charge stabilization are favorable for ion storage and diffusion and electron transport,indicating the electrodes can offer improved electrochemical performances.In addition,post-mortem analysis of the cycled carbon electrodes through ex-situ tools demonstrates the sodium-ion storage mechanism.展开更多
Na-ion batteries are considered a promising alternative to Li-ion batteries for large-scale energy storage systems due to their low cost and the natural abundance of Na resource. Great effort is making worldwide to de...Na-ion batteries are considered a promising alternative to Li-ion batteries for large-scale energy storage systems due to their low cost and the natural abundance of Na resource. Great effort is making worldwide to develop high-performance electrode materials for Na-ion batteries,which is critical for Na-ion batteries. This review provides a comprehensive overview of anode materials for Na-ion batteries based on Na-storage mechanism： insertion-based materials, alloy-based materials, conversion-based materials and organic composites. And we summarize the Nastorage mechanism of those anode materials and discuss their failure mechanism. Furthermore, the problems and challenges associated with those anodes are pointed out,and feasible strategies are proposed for designing highperformance anode materials. According to the current state of research, the search for suitable anode materials for Na-ion batteries is still challenging although substantial progress has been achieved. Nevertheless, we believe that high-performance Na-ion batteries would be promising for practical applications in large-scale energy storage systems in the near future.展开更多
In anode free batteries(AFBs), the current collector acts as anode simultaneously and has large volume expansion which is generally considered as a negative effect decreasing the structural stability of a battery. Mor...In anode free batteries(AFBs), the current collector acts as anode simultaneously and has large volume expansion which is generally considered as a negative effect decreasing the structural stability of a battery. Moreover, despite many studies on the fast lithium diffusion in the current collector materials of AFB such as copper and aluminum, the involved Li diffusion mechanism in these materials remains poorly understood. Through first-principles calculation and stress-assisted diffusion equations, here we study the Li diffusion mechanism in several current collectors and related alloys and clarify the effect of volume expansion on Li diffusion respectively. It is suggested that due to the lower Li migration barriers in aluminum and tin, they should be more suitable to be used as AFB anodes, compared to copper, silver, and lead. The Li diffusion facilitation in copper with a certain number of vacancies is proposed to explain why the use of copper with a thickness≤100 nm as the protective coating on the anode improves the lifetime of the batteries. We show that the volume expansion has a positive effect on Li diffusion via mechanical–electrochemical coupling. Namely, the volume expansion caused by Li diffusion will further induce stress which in turn affects the diffusion. These findings not only provide in-depth insight into the operating principle of AFBs, but also open a new route toward design of improved anode through utilizing the positive effect of mechanical–electrochemical coupling.展开更多
Rational designing and controlling of nanostructures is a key factor in realizing appropriate properties required for the high-performance energy fields. In the present study, hollow Sn O2@C nanoparticles（NPs） with ...Rational designing and controlling of nanostructures is a key factor in realizing appropriate properties required for the high-performance energy fields. In the present study, hollow Sn O2@C nanoparticles（NPs） with a mean size of 50 nm have been synthesized in large-scale via a facile hydrothermal approach.The morphology and composition of as-obtained products were studied by various characterized techniques. As an anode material for lithium ion batteries（LIBs）, the as-prepared hollow Sn O2@C NPs exhibit significant improvement in cycle performances. The discharge capacity of lithium battery is as high as 370 m Ah g 1, and the current density is 3910 m A g 1（5 C） after 573 cycles. Furthermore, the capacity recovers up to 1100 m Ah g 1at the rate performances in which the current density is recovered to 156.4 m A g 1（0.2 C）. Undoubtedly, sub-100 nm Sn O2@C NPs provide significant improvement to the electrochemical performance of LIBs as superior-anode nanomaterials, and this carbon coating strategy can pave the way for developing high-performance LIBs.展开更多
Despite carbonaceous materials are widely employed as commercial negative electrodes for lithium ion battery, an urge requirement for new electrode materials that meet the needs of high energy density, long cycle life...Despite carbonaceous materials are widely employed as commercial negative electrodes for lithium ion battery, an urge requirement for new electrode materials that meet the needs of high energy density, long cycle life, low cost and safety is still underway. A number of cobalt-based compounds（Co（OH）_2, Co_3O_4, CoN, CoS,CoP, NiCo_2O_4, etc.） have been developed over the past years as promising anode materials for lithium ion batteries（LIBs） due to their high theoretical capacity, rich redox reaction and adequate cyclability. The LIBs performances of the cobalt-based compounds have been significantly improved in recent years, and it is anticipated that these materials will become a tangible reality for practical applications in the near future. However, the different types of cobalt-based compounds will result in diverse electrochemical performance. This review briefly analyzes recent progress in this field, especially highlights the synthetic approaches and the prepared nanostructures of the diverse cobalt-based compounds and their corresponding performances in LIBs, including the storage capacity, rate capability, cycling stability and so on.展开更多
As anode materials for lithium-ion batteries, SiO2 is of great interest because of its high capacity, low cost and environmental affinity. A facile approach has been developed to fabricate SiO2@C hollow spheres by hyd...As anode materials for lithium-ion batteries, SiO2 is of great interest because of its high capacity, low cost and environmental affinity. A facile approach has been developed to fabricate SiO2@C hollow spheres by hydrolysis of tetraethyl orthosilicate（TEOS） to form SiO2 shells on organic sphere templates followed by calcinations in air to remove the templates, and then the SiO2 shells are covered by carbon layers.Electron microscopy investigations confirm hollow structure of the SiO2@C. The SiO2@C hollow spheres with different SiO2 contents display gradual increase in specific capacity with discharge/charge cycling,among which the SiO2@C with SiO2 content of 67 wt% exhibits discharge/charge capacities of 653.4/649.6 mAh g^（-1） over 160 cycles at current density of 0.11 mA cm^（-2）. The impedance fitting of the electrochemical impedance spectroscopy shows that the SiO2@C with SiO2 content of 67 wt% has the lowest charge transfer resistance, which indicates that the SiO2@C hollow spheres is promising anode candidate for lithium-ion batteries.展开更多
基金the financial support from the National Natural Science Foundation of China (51876052, 51676128)
文摘As a promising alternative anode material,silicon(Si)presents a larger capacity than the commercial anode to achieve large capacity lithium-ion batteries.However,the application of pure Si as anode is hampered by limitations such as volume expansion,low conductivity and unstable solid electrolyte interphase.To break through these limitations,the core-shell Si@Li4Ti5O12nanocomposite,which was prepared via in-situ self-assembly reaction and decompressive boiling fast concentration method,was proposed in this work.This anode combines the advantages of nano-sized Si particle and pure Li4Ti5O12(LTO)coating layer,improving the performance of the lithium-ion batteries.The Si@Li4Ti5O12 anode displays a high initial discharge/charge specific capacity of 1756/1383 m Ahg^-1 at 500 mAg^-1(representing high initial coulombic efficiency of 78.8%),a large rate capability(specific capacity of 620 mAhg^-1 at4000 mAg^-1),an outstanding cycling stability(reversible specific capacity of 883 mAhg^-1 after 150 cycles)and a low volume expansion rate(only 3.3% after 150 cycles).Moreover,the synthesis process shows the merits of efficiency,simplicity,and economy,providing a reliable method to fabricate large capacity Si@Li4Ti5O12nanocomposite anode materials for practical lithium-ion batteries.
基金funded by the Zhengzhou Materials Genome Institute,the National Talents Program of China,and Key Innovation Projects of the Zhengzhou Municipal City of China.
文摘The main bottleneck against industrial utilization of sodium ion batteries(SIBs)is the lack of high-capacity electrodes to rival those of the benchmark lithium ion batteries(LIBs).Here in this work,we have developed an economical method for in situ fabrication of nanocomposites made of crystalline few-layer graphene sheets loaded with ultrafine SnO_(2)nanocrystals,using short exposure of microwave to xerogel of graphene oxide(GO)and tin tetrachloride containing minute catalyzing dispersoids of chemically reduced GO(RGO).The resultant nanocomposites(SnO_(2)@MWG)enabled significantly quickened redox processes as SIB anode,which led to remarkable full anode-specific capacity reaching 538 mAh g^(−1)at 0.05 A g^(−1)(about 1.45 times of the theoretical capacity of graphite for the LIB),in addition to outstanding rate performance over prolonged charge–discharge cycling.Anodes based on the optimized SnO_(2)@MWG delivered stable performance over 2000 cycles even at a high current density of 5 A g^(−1),and capacity retention of over 70.4%was maintained at a high areal loading of 3.4 mg cm^(−2),highly desirable for high energy density SIBs to rival the current benchmark LIBs.
基金financially supported by the National Natural Science Foundation of China(No.51702217)the Shenzhen Government’s Plan of Science and Technology(No.JCYJ20190808121407676)+1 种基金the Natural Science Foundation of Guangdong(No.2020A1515011127)the Shenzhen University Initiative Research Program(No.2019005)。
文摘Transition metal oxides as anode materials for high-performance lithium-ion batteries suffer from severe capacity decay,originating primarily from particle pulverization upon volume expansion/shrinkage and the intrinsically sluggish electron/ion transport.Herein,in-situ encapsulation ofα-Fe_(2)O_(3) nanoparticles into micro-sized ZnFe_(2)O_(4) capsules is facilely fulfilled through a co-precipitation process and followed by heat-treatment at optimal calcination temperature.The porous ZnFe_(2)O_(4) scaffold affords a synergistic confinement effect to suppress the grain growth ofα-Fe2 O3 nanocrystals during the calcination process and to accommodate the stress generated by volume expansion during the charge/discharge process,leading to an enhanced interfacial conductivity and inhibit electrode pulverization and mechanical failure in the active material.With these merits,the preparedα-Fe_(2)O_(3)/Fe_(2)O_(4) composite delivers prolonged cycling stability and improved rate capability with a higher specific capacity than soleα-Fe_(2)O_(3) and Fe_(2)O_(4).The discharge capacity is retained at 700 mAh g-1 after 500 cycles at 200 mA g^(-1) and 940 mAh g^(-1) after 50 cycles at 100 m A g^(-1).This work provides a new perspective in designing transition metal oxides for advanced lithium-ion batteries with superior electrochemical properties.
基金financially supported by the National Key Research Program of China(No.2016YFA0202602)the National Natural Science Foundation of China(Nos.51371154 and 51571167)the Natural Science Foundation of Fujian Province of China(No.2017J05087)
文摘ZnO–CuO porous hybrid microspheres were successfully produced through a facile aging process of zinc citrate solid microspheres in copper sulfate solution combined with the subsequent annealing treatment in air atmosphere. The electrochemical performance investigation suggests that the harvested ZnO–CuO porous hybrid microspheres illustrate much higher specific capacity and better cycling stability than single ZnO counterparts. A reversible capacity of 585 mAh·g^-1 can be acquired for ZnO–CuO porous hybrid microspheres after cycling 500 times at a current density of 200 mA·g^-1. The porous configuration and the incorporation of CuO are responsible for the enhanced lithium storage properties of ZnO–CuO hybrids.
基金funded by the Natural Science Foundation of China(No.51702335)open project of the Beijing National Laboratory for Molecular Science(No.20140138)+1 种基金the CASEU S&T cooperation partner program(No.174433KYSB20150013)the Key Laboratory of Bio-based Polymeric Materials of Zhejiang Province
文摘A facile scalable synthesis of hierarchical Sb/C micro-/nanohybrid has been addressed in this work, which possesses the advantages of both micrometer and nanometer scale structures as lithium-ion battery anode. Difunctional methacrylate monomers are used as solvent and carbon source as well. Liquid precursor of antimony（III） n-butoxide is dissolved in the resin monomer solution, and further incorporated into the cross-linking polymer network via photo polymerization. Through calcination in argon/hydrogen atmosphere, antimony nanoparticles are in situ formed by carbothermal reduction, and homogeneously embedded in the in situ formed micrometer sized carbon matrix. The morphology, structure, crys- tallinity, spatial dispersion, composition, and electrochemical performance of the Sb/C micro-/nanohybrid are systemati- cally investigated. The cyclic and rate performance of the Sb/C micro-/nanohybrid anode have been effectively improved compared to the pure carbon anode. A reversible capacity of 362 mAh g-1 is achieved with a reasonable mass loading density after 300 cycles at 66 mA g-1, corresponding to capacity retention of 79%. With reducing mass loading density, the reversible capacity reaches 793 mAh g-1 after 100 cycles. Moreover, the electrochemical performance of Sb/C micro-/nanohybrid as sodium-ion battery anode is also investigated in this study.
基金financially supported by the Fundamental Research Funds for the Central Universities(Nos.N2025034 and N2025035)Xingliao Project(No.XLYC1807042)the Program of the Ministry of Education of China for Introducing Talents of Discipline to Universities(No.B16009)。
文摘The poor crystallinity and unstable crystal structure of tungsten disulfide(WS2)limit its application in practice.In this paper,a molten salt electrolysis method is proposed to intercalate metal ions into the interlayers of layered WS2 to obtain few-layer sheetlike structures.The effect of the molten salt system,applied constant current and electrolysis duration on the exfoliation degree of WS2 bulk has been investigated.The results show that the products electrolyzed in molten LiCl-NaCl-KCl and NaClKCl salts under 25 mA were more transparent and thinner flakes sheets due to the uniform intercalation of Li^+and Na^+with smaller size.The exfoliated WS_(2)was used as an anode material for sodium-ion batteries with a potential of 0.01-2.50 V.In comparison,the WS_(2)-NaCl-25 mA electrode displays a high reversible capacity of 373 mAh·g^(-1)at0.1 A·g^(-1)after cycling for 100 cycles at the same time showing great rate and cycle performance.It also presents a high capacitive ratio of 90.65%at 1.0 mV·s^(-1).The molten salt electrolysis provides a new perspective on the exfoliation of layered material,while demonstrating the great potential of WS2 as an anode material for sodium-ion battery.
基金supported by the National Natural Science Foundation of China(52072118,51772089)the Youth 1000 Talent Program of China+3 种基金the Research and Development Plan of Key Areas in Hunan Province(2019GK2235)the Key Research and Development Program of Ningxia(2020BDE03007)the China Postdoctoral Science Foundation(2019M653649)the Guangdong Basic and Applied Basic Research Fund(2019A1515110518,2019A1515111188,2020B0909030004)。
文摘Developing suitable anode materials for potassium-ion batteries(PIBs)remains a great challenge owing to the limited theoretical capacity of active materials and large radius of K+ion(1.38?).To solve these obstacles,by integrating the principles of multielectron transfer and rational porous crystal framework,we creatively propose the monoclinic Cu_(3)(OH)_(2)V_(2)O_(7)·2H_(2)O(CVO)as a novel anode for PIBs.Furthermore,inspired by the metastable nature of CVO under high temperature/pressure,we skillfully design a facile hydrothermal recrystallization strategy without the phase change and surfactants addition.Thus,for the first time,the porous composite of Cu_(3)(OH)_(2)V_(2)O_(7)·2H_(2)O nanobelts covered in situ by reduced graphene oxide(CVO NBs/r GO)was assembled,greatly improving the deficiencies of CVO.When used as a novel anode for PIBs,CVO NBs/r GO delivers large specific capacity(up to 551.4 m Ah g^(-1)at 50 m A g^(-1)),high-rate capability(215.3 m Ah g^(-1)at 2.5 A g^(-1))and super durability(203.6 m Ah g^(-1)at 500 m A g^(-1)even after 1000 cycles).The outstanding performance can be ascribed to the synergistic merits of desirable structural features of monoclinic CVO nanobelts and the highly conductive graphene 3D network,thus promoting the composite material stability and electrical/ionic conductivity.This work reveals a novel metal vanadate-based anode material for PIBs,would further motivate the subsequent batteries research on M_(3)(OH)_(2)V_(2)O_(7)-n H_(2)O(M;Co,Ni,Cu,Zn),and ultimately expands valuable fundamental understanding on designing other high-performance electrode materials,including the combined strategies of multielectron transfer with rational porous crystal framework,and the composite fabrication of 1D electrode nanostructure with conductive carbon matrix.
基金supported by the Applied Basic Research Program of Yunnan Province,China(No.202101AU07110).
文摘SnS_(2) stands out as a promising lithium storage anode due to its high specific capacity,low voltage plateau,and cost-effectiveness.However,practical applications are hindered by significant limitations,including low electrical conductivity,volumetric expansion,and sulfur dissolution.In this study,carbon-encrusted SnS_(2) nanoparticles are anchored onto few-layered MXene via a straightforward ultrasound-assisted ball milling method,yielding SnS_(2)@C/MXene nanocomposites.Kinetic experiments demonstrate that this innovative ball milling approach facilitates the infiltration of SnS_(2)@C into the distorted sites of MXene,effectively curbing interlayer stacking,expediting ion transfer,and bolstering the pseudocapacitance contribution of the anode.Concurrently,the few-layered MXene intertwines with SnS_(2)@C,effectively mitigating the volume fluctuations of the active SnS_(2)@C.As a lithium-ion battery(LiB)anode,SnS_(2)@C/MXene exhibits a specific capacity of 867.1 mAh g^(−1) after 100 cycles at 0.1 A g^(−1).Moreover,the SnS_(2)@C/MXene anode demonstrates remarkable reversible specific capacities of 1,162.9,1,001.0,838.1,724.8,591.5,and 413.9 mAh g^(−1) under 0.1,0.2,0.5,1,2,and 5 A g^(−1),respectively,surpassing those of recently reported SnSx-based LiB anodes.These findings underscore the significant potential of SnS_(2)@C/MXene nanocomposites for high-performance LiBs.
基金financially supported by the Key Program for International S&T Cooperation Projects of China (No.2017YFE0124300)the National Natural Science Foundation of China (Nos.U1960107 and 22179019)+2 种基金the "333" Talent Project of Hebei Province (No.A202005018)the Fundamental Research Funds for the Central Universities (No.N2123001)the Natural Science Foundation of Hebei Province of China (No.B2020501003)。
文摘In this work,the facile carbon nanotubes(CNTs) modulation strategy was successfully used to fabricate Bi_(5) Nb_(3) O_(15)@CNTs composites as anode materials for lithium-ion battery by a simple solid-state route.The introduction of CNTs does not change the structure of the Bi_(5) Nb_(3) O_(15) materials,the Bi_(5) Nb_(3) O_(15) particles are decorated on a three-dimensional CNTs network,and the high conductive network promotes transfer of electron/ion and relieve the volume change of Bi_(5) Nb_(3) O_(15).The Bi_(5) Nb_(3) O_(15)@CNTs(8 wt%) electrode shows a superior rate capability with charge(discharge) capacities of 490(898.7),379.1(401.6),311.3(326.9),276.5(285.5) and 243.4(252)mAh·g^(-1) at 50,100,200,300 and 500 mA·g^(-1),respectively.However,the Bi_(5) Nb_(3) O_(15) only shows charge(discharge) capacities of 431(772.6),278.6(309.9),193.1(213.7),160.8(171.1),129.9(139.1) mAh·g^(-1) at the corresponding rates,respectively.The excellent rate capability of Bi_(5) Nb_(3) O_(15)@CNTs can be ascribed to the homogeneous distribution of Bi_(5) Nb_(3) O_(15) particles in the CNTs conductive network and the enhancement of conductivity.Hence,the CNTs modulation can be considered as an effective strategy to enhance electrochemical performances of Bi_(5) Nb_(3) O_(15) materials.
基金supported by the National Natural Science Foundation of China(Nos.51402103 and 51302079)
文摘Nb_2O_5/C nanosheets are successfully prepared through a mixing process and followed by heating treatment.Such Nb_2O_5/C based electrode exhibits high rate performance and remarkable cycling ability,showing a high and stable specific capacity of ~380mAhg^（-1） at the current density of 50 mAg^（-1）（much higher than the theoretical capacity of Nb_2O_5）.Further more,at a current density of 500mAg^（-1）,the nanocomposites electrode still exhibits a specific capacity of above 150 mAh g^（-1） after 100 cycles.These results suggest the Nb_2O_5/C nanocomposite is a high performance anode material for lithium-ion batteries.
基金financially supported by the National Natural Science Foundation of China (No. 21475085)the key scientific research project of high schools in Henan Province (Nos. 16A430025 & 17A480009)
文摘In this work,via a facile solvothermal route,we synthesized an anode material for lithium ion batteries（LIBs）—SnS2 nanoparticle/graphene（SnS2 NP/GNs） nanocomposite.The nanocomposite consists of SnS2nanoparticles with an average diameter of 4 nm and graphene nanosheets without restacking.The SnS2 nanoparticles are firmly anchored on the graphene nanosheets.As an anode material for LIBs,the nanocomposite exhibits good Li storage performance especially high rate performance.At the high current rate of 5,10,and 20 A/g,the nanocomposite delivered high capacities of 525,443,and 378 mAh/g,respectively.The good conductivity of the graphene nanosheets and the small particle size of SnS2contribute to the electrochemical performance of SnS2 NP/GNs.
基金supported by the National Natural Scientific Foundation of China(No.22379014)Shanxi key research and development program(No.202102060301011)。
文摘Anode free lithium metal batteries(AF-LMBs)have conspicuous advantages both in energy density and the compatibility of battery manufacturing process.However,the limited cycle life of AF-LMBs is a crucial factor hindering its practical application.Fluorinated or nitride artificial inorganic solid electrolyte interphase(SEI)has been found as an effective method to prolong the lifespan of AF-LMBs.Herein,by investigating the impact of nano-sized inorganic gradient layers(LiF or Li3N)on initial Li deposition behavior,we notice that the Li^(+) diffusion barrier and the deposition morphology are highly depended on the thickness of inorganic layers.Thicker protective layers cause larger overpotential as well as more aggregated Li^(+) distribution.This study reveals that the ideal SEI should be synthesized thin and uniformly enough and uncontrollable artificial SEI can cause damage to the lifespan of AF-LMBs.
基金supported by the National Natural Science Foundation of China(No.52274294)the Fundamental Research Funds for the Central Universities,China(No.N2124007-1)the Fund of the State Key Laboratory of Solidification Processing in Northwestern Polytechnical University,China(No.SKLSP202101)。
文摘In response to the limitations of conventional chemical synthesis methods for the structural modulation of nanomaterials,an innovative high magnetic field-assisted wet chemical synthesis method was proposed to prepare NiFe_(2)O_(4)/Fe_(2)O_(3) heterostructures.It is found that the high-energy physical field could induce a more homogeneous morphology of NiFe_(2)O_(4)/Fe_(2)O_(3),accompanied by phase transformation from Fe_(2)O_(3) to NiFe_(2)O_(4).As a result,the optimized structure obtained under the magnetic field endows NiFe_(2)O_(4)/Fe_(2)O_(3) with enhanced performance for the lithium-ion battery anode,as evidenced by an increase of 16%(1200 mA·h/g)in discharge capacity and 24% in ultra-stable cycling performance(capacity retention of 97.1%).These results highlight the feasibility of high magnetic fields in modulating material structure and enhancing lithium storage performance.
基金financially supported by the National Natural Science Foundation of China(Nos.21631004,21371053,21401048 and 21173072)the International Science and Technology Cooperation Program of China(No.2014DFR41110)+1 种基金the University Nursing Program for Young Scholars with Creative Talents in Heilongjiang Province(No.UNPYSCT-2016016)the Harbin Science and Technology Innovation Talents Research Foundation(No.2015RAQXJ057)
文摘Transition-metal oxides have attracted increased attention in the application of high-performance lithium ion batteries（LIBs）, owing to its higher reversible capacity,better structural stability and high electronic conductivity.Herein, CoWO4 nanoparticles wrapped by reduced graphene oxide（CoWO4–RGO） were synthesized via a facile hydrothermal route followed by a subsequent heat-treatment process. When evaluated as the anode of LIB, the synthetic CoWO4–RGO nanocomposite exhibits better Li^＋ storage properties than pure CoWO4 nanostructures synthesized without graphene oxide（GO）. Specifically, it delivers a high initial specific discharge capacity of1100 mAh·g^-1 at a current density of 100 mA·g^-1, and a good reversible performance of 567 mAh·g^-1 remains after the 100th cycle. Moreover, full battery using CoWO4–RGO as anode and commercial LiCoO2 powder as cathode was assembled, which can be sufficient to turn on a 3 V,10 mW blue light emitting diode（LED）. The enhanced electrochemical performance for lithium storage can be attributed to the three-dimensional（3D） structure of the CoWO4–RGO nanocomposite, which can accommodate huge volume changes, and synergetic effect between CoWO4 and reduced graphite oxide（RGO） nanosheets,including an increased conductivity, shortened Li^＋ diffusion path.
基金supported by the Next Generation Engineering Researcher Program of National Research Foundation of Korea(NRF)funded by the Ministry of Science and ICT(2017H1D8A2031138).
文摘Sustainable transformation and efficient utilization of biomasses and their derived materials are environ-mentally as well as economically compliant strategies.Biomass seaweed-derived nitrogen self-doped porous carbon with tailored surface area and pore structures are prepared through carb on izatio n and activation.The in fluence of carb on ization temperature on morphology,surface area,and heteroatom dopants are investigated to optimize sodium-ion storage capability.Seaweed-derived nitrogen selfdoped activated carbon(SAC)as anode materials for sodium-ion batteries exhibits remarkable reversible capacity of 303/192 mAh g^(-1) after 100/500 cycles at current densities of 100/200 mA g^(-1) respectively,and a good rate capability.The interconnected and porous conducting nature along with the heteroatom dopant role in creating defective sites and charge stabilization are favorable for ion storage and diffusion and electron transport,indicating the electrodes can offer improved electrochemical performances.In addition,post-mortem analysis of the cycled carbon electrodes through ex-situ tools demonstrates the sodium-ion storage mechanism.
基金financially supported by the Fund for Innovative Research Groups of the National Natural Science Foundation of China (No.NSFC51621001)the National Natural Science Foundation of China (No.51671089)+1 种基金Guangdong Natural Science Funds for Distinguished Young Scholar (No.2017B030306004)the Fundamental Research Funds for the Central Universities (No.2017ZD011)
文摘Na-ion batteries are considered a promising alternative to Li-ion batteries for large-scale energy storage systems due to their low cost and the natural abundance of Na resource. Great effort is making worldwide to develop high-performance electrode materials for Na-ion batteries,which is critical for Na-ion batteries. This review provides a comprehensive overview of anode materials for Na-ion batteries based on Na-storage mechanism： insertion-based materials, alloy-based materials, conversion-based materials and organic composites. And we summarize the Nastorage mechanism of those anode materials and discuss their failure mechanism. Furthermore, the problems and challenges associated with those anodes are pointed out,and feasible strategies are proposed for designing highperformance anode materials. According to the current state of research, the search for suitable anode materials for Na-ion batteries is still challenging although substantial progress has been achieved. Nevertheless, we believe that high-performance Na-ion batteries would be promising for practical applications in large-scale energy storage systems in the near future.
基金National Natural Science Foundation of China(Grant Nos.11874254,51802187,and 51622207)Shanghai Sailing Program,China(Grant No.18YF1408700)+3 种基金Shanghai Pujiang Program,China(Grant No.2019PJD016)Open Project of the State Key Laboratory of Advanced Special Steel,Shanghai University,China(Grant No.SKLASS2018-01)the Project of the State Key Laboratory of Advanced Special Steel,Shanghai University,China(Grant No.SKLASS2019-Z023)the Science and Technology Commission of Shanghai Municipality,China(Grant No.19DZ2270200).
文摘In anode free batteries(AFBs), the current collector acts as anode simultaneously and has large volume expansion which is generally considered as a negative effect decreasing the structural stability of a battery. Moreover, despite many studies on the fast lithium diffusion in the current collector materials of AFB such as copper and aluminum, the involved Li diffusion mechanism in these materials remains poorly understood. Through first-principles calculation and stress-assisted diffusion equations, here we study the Li diffusion mechanism in several current collectors and related alloys and clarify the effect of volume expansion on Li diffusion respectively. It is suggested that due to the lower Li migration barriers in aluminum and tin, they should be more suitable to be used as AFB anodes, compared to copper, silver, and lead. The Li diffusion facilitation in copper with a certain number of vacancies is proposed to explain why the use of copper with a thickness≤100 nm as the protective coating on the anode improves the lifetime of the batteries. We show that the volume expansion has a positive effect on Li diffusion via mechanical–electrochemical coupling. Namely, the volume expansion caused by Li diffusion will further induce stress which in turn affects the diffusion. These findings not only provide in-depth insight into the operating principle of AFBs, but also open a new route toward design of improved anode through utilizing the positive effect of mechanical–electrochemical coupling.
基金the Program for the NSFC (Nos. 51302325, 51201115, 51471121)New Century Excellent Talents in University (No. NCET-12-0553)+4 种基金Program for Shenghua Overseas Talent (No. 1681-7607030005) from Central South UniversityHubei Provincial Natural Science Foundation (No. 2014CFB261)the partial financial support from the Open-End Fund for the Valuable and Precision Instruments of Central South University (No. CSUZC2014032)Fundamental Research Funds for the Central Universities (No. 2042015kf0184)Wuhan University
文摘Rational designing and controlling of nanostructures is a key factor in realizing appropriate properties required for the high-performance energy fields. In the present study, hollow Sn O2@C nanoparticles（NPs） with a mean size of 50 nm have been synthesized in large-scale via a facile hydrothermal approach.The morphology and composition of as-obtained products were studied by various characterized techniques. As an anode material for lithium ion batteries（LIBs）, the as-prepared hollow Sn O2@C NPs exhibit significant improvement in cycle performances. The discharge capacity of lithium battery is as high as 370 m Ah g 1, and the current density is 3910 m A g 1（5 C） after 573 cycles. Furthermore, the capacity recovers up to 1100 m Ah g 1at the rate performances in which the current density is recovered to 156.4 m A g 1（0.2 C）. Undoubtedly, sub-100 nm Sn O2@C NPs provide significant improvement to the electrochemical performance of LIBs as superior-anode nanomaterials, and this carbon coating strategy can pave the way for developing high-performance LIBs.
基金financially supported by the‘‘1000 Talents Recruitment Program’’of Chinese government,University of Science and Technology Beijingthe Fundamental Research Funds for the Central Universities(No.FRF-TP-16-070A1)
文摘Despite carbonaceous materials are widely employed as commercial negative electrodes for lithium ion battery, an urge requirement for new electrode materials that meet the needs of high energy density, long cycle life, low cost and safety is still underway. A number of cobalt-based compounds（Co（OH）_2, Co_3O_4, CoN, CoS,CoP, NiCo_2O_4, etc.） have been developed over the past years as promising anode materials for lithium ion batteries（LIBs） due to their high theoretical capacity, rich redox reaction and adequate cyclability. The LIBs performances of the cobalt-based compounds have been significantly improved in recent years, and it is anticipated that these materials will become a tangible reality for practical applications in the near future. However, the different types of cobalt-based compounds will result in diverse electrochemical performance. This review briefly analyzes recent progress in this field, especially highlights the synthetic approaches and the prepared nanostructures of the diverse cobalt-based compounds and their corresponding performances in LIBs, including the storage capacity, rate capability, cycling stability and so on.
基金supported by the National Natural Science Foundation of China (Grant No. 51472083)
文摘As anode materials for lithium-ion batteries, SiO2 is of great interest because of its high capacity, low cost and environmental affinity. A facile approach has been developed to fabricate SiO2@C hollow spheres by hydrolysis of tetraethyl orthosilicate（TEOS） to form SiO2 shells on organic sphere templates followed by calcinations in air to remove the templates, and then the SiO2 shells are covered by carbon layers.Electron microscopy investigations confirm hollow structure of the SiO2@C. The SiO2@C hollow spheres with different SiO2 contents display gradual increase in specific capacity with discharge/charge cycling,among which the SiO2@C with SiO2 content of 67 wt% exhibits discharge/charge capacities of 653.4/649.6 mAh g^（-1） over 160 cycles at current density of 0.11 mA cm^（-2）. The impedance fitting of the electrochemical impedance spectroscopy shows that the SiO2@C with SiO2 content of 67 wt% has the lowest charge transfer resistance, which indicates that the SiO2@C hollow spheres is promising anode candidate for lithium-ion batteries.
