Currently,there are a limited number of dynamic models available for braided composite plates with large overall motions,despite the incorporation of three-dimensional(3D)braided composites into rotating blade compone...Currently,there are a limited number of dynamic models available for braided composite plates with large overall motions,despite the incorporation of three-dimensional(3D)braided composites into rotating blade components.In this paper,a dynamic model of 3D 4-directional braided composite thin plates considering braiding directions is established.Based on Kirchhoff's plate assumptions,the displacement variables of the plate are expressed.By incorporating the braiding directions into the constitutive equation of the braided composites,the dynamic model of the plate considering braiding directions is obtained.The effects of the speeds,braiding directions,and braided angles on the responses of the plate with fixed-axis rotation and translational motion,respectively,are investigated.This paper presents a dynamic theory for calculating the deformation of 3D braided composite structures undergoing both translational and rotational motions.It also provides a simulation method for investigating the dynamic behavior of non-isotropic material plates in various applications.展开更多
To address the poor mechanical properties of polydimethylsiloxane(PDMS)and enhance the understanding of the reinforcement mechanisms of aerogel network structures in rubber matrices,this study reinforced PDMS using an...To address the poor mechanical properties of polydimethylsiloxane(PDMS)and enhance the understanding of the reinforcement mechanisms of aerogel network structures in rubber matrices,this study reinforced PDMS using an ordered interconnected three-dimensional montmorillonite(MMT)aerogel network.The average pore diameter of the aerogels was successfully reduced from 11.53μm to 2.51μm by adjusting the ratio of poly(vinyl alcohol)(PVA)to MMT via directional freezing.Changes in the aerogel network were observed in field emission scanning electron microscope(FESEM)images.After vacuum impregnation,the aerogel network structure of the composites was observed using FESEM.Tensile tests indicated that as the pore diameter decreased,the elongation at break of the composites first increased to a peak of329.61%before decreasing,while the tensile strength and Young's modulus continuously increased to their maximum values of 6.29 MPa and24.67 MPa,respectively.Meanwhile,FESEM images of the tensile cracks and fracture surfaces showed that with a reduction in aerogel pore diameter,the degrees of crack deflection and interfacial debonding increased,presenting a rougher fracture surface.These phenomena enable the composites to dissipate substantial energy during tension,thus effectively improving the mechanical strength of the composites.The present work elucidates the bearing of ordered three-dimensional aerogel network structures on the performance of rubber matrices and provides crucial theoretical insights and technical guidance for the creation and optimization of high-performance PDMS-based composites.展开更多
MnCO_(3)represents a potentially high-capacity and low-cost anode candidate to replace graphite for enhancing energy density of commercial lithium-ion batteries,but it suffers from poor electrical conductivity and ser...MnCO_(3)represents a potentially high-capacity and low-cost anode candidate to replace graphite for enhancing energy density of commercial lithium-ion batteries,but it suffers from poor electrical conductivity and serious volumetric change,largely hindering its practical applications.展开更多
Silicon-based anode is a promising candidate for all-solid-state batteries(ASSBs).However,it must be further improved because of its tremendous volume change.In this study,various interface treatment strategies for Si...Silicon-based anode is a promising candidate for all-solid-state batteries(ASSBs).However,it must be further improved because of its tremendous volume change.In this study,various interface treatment strategies for SiO/carbon composite anodes in ASSBs were investigated using a multiphysics modeling framework.By evaluating the effects of active(carbon)and inactive coating materials,as well as the geometric and mechanical parameters,this research provides critical insights into optimizing their electrochemical performance and mechanical stability.Computational results indicate that carbon coatings can greatly enhance lithiation kinetics by regulating the interfacial electrochemical potential gradients,reducing the residual lithium concentration,and homogenizing the lithium-ion distribution compared with uncoated or inactive-coated configurations.In addition,thinner carbon coatings further improve capacity retention and stress management by balancing shorter lithium diffusion pathways with mitigated interfacial stress accumulation.Despite their ability to mechanically stabilize the anode,inactive coatings exhibit tradeoffs between lithium transport kinetics and stress modulation,with optimal performance achieved at lower Young’s moduli.Mechanical analyses highlight distinct failure mechanisms at the anode–electrolyte(shear driven)and particle-coating(tension driven)interfaces,emphasizing the need for tailored adhesion strategies.These findings provide actionable guidelines for designing robust SiO-based anodes,emphasizing the interplay among electrochemical efficiency,stress regulation,and interfacial durability in ASSBs.展开更多
In order to search for a suitable anode material used in zinc electrowinning in place of Pb-Ag alloy,Al/Pb-PANI（polyaniline）-WC（tungsten carbide） composite inert anodes were prepared on aluminum alloy substrate by...In order to search for a suitable anode material used in zinc electrowinning in place of Pb-Ag alloy,Al/Pb-PANI（polyaniline）-WC（tungsten carbide） composite inert anodes were prepared on aluminum alloy substrate by double pulse electrodeposition（DPE） of PANI and WC particles with Pb2＋ from an original plating bath.Thereafter,anodic polarization curves,cyclic voltammetry curves and Tafel polarization curves for the composite inert anodes obtained under different PANI concentrations in the original plating bath were measured,and the microstructural features were also investigated by scanning electron microscopy（SEM）.The results show that Al/Pb-PANI-WC composite inert anode obtained under PANI concentration of 20 g/L in the original plating bath possesses uniform microstructures and composition distributions,higher electrocatalytic activity,better reversibility of electrode reaction and corrosion resistance in a synthetic zinc electrowinning electrolyte of 50 g/L Zn2＋,150 g/L H2SO4 at 35 °C.Compared with Pb-1%Ag alloy,the overpotential of oxygen evolutions for the composite inert anode are decreased by 185 mV and 166 mV,respectively,under 500 A/m2 and 1000 A/m2.展开更多
A porous coral-structured Si/C composite as an anode material was fabricated by coating Si nanoparticles with a carbon layer from polyvinyl alcohol（PVA）, erosion of hydrofluoric（HF） acid, and secondary coating wit...A porous coral-structured Si/C composite as an anode material was fabricated by coating Si nanoparticles with a carbon layer from polyvinyl alcohol（PVA）, erosion of hydrofluoric（HF） acid, and secondary coating with pitch. Three samples with different pitch contents of 30%, 40% and 50% were synthesized. The composition and morphology of the composites were characterized by X-ray diffractometry（XRD） and scanning electron microscopy（SEM）, respectively, and the properties were tested by electrochemical measurements. The results indicated that the composites showed obviously enhanced electrochemical performance compared with that without secondary carbon coating. The second discharge capacity of the composite was 773 m A·h/g at a current density of 100 m A/g, and still retained 669 m A·h/g after 60 cycles with a small capacity fade of less than 0.23%/cycle, while the content of secondary carbon source of pitch was set at 40%. Therefore, the cycle stability of the composite could be excellently improved by regulating carbon content of secondary coating.展开更多
Lithium (Li) metal with an ultrahigh specific theoretical capacity and the lowest reduction potential is strongly considered as a promising anode for high-energy-density batteries. However, uncontrolled lithium dendri...Lithium (Li) metal with an ultrahigh specific theoretical capacity and the lowest reduction potential is strongly considered as a promising anode for high-energy-density batteries. However, uncontrolled lithium dendrites and infinite volume change during repeated plating/stripping cycles hinder its practical applications immensely. Herein, a house-like Li anode (housed Li) was designed to circumvent the above issues. The house matrix was composed of carbon fiber matrix and affords a stable structure to relieve the volume change. An artificial solid electrolyte layer was formed on composite Li metal, just like the roof of a house, which facilitates uniform Li ions diffusion and serves as a physical barrier against electrolyte corrosion. With the combination of solid electrolyte layer and matrix in the composite Li metal anode, both dendrite growth and volume expansion are remarkably inhibited. The housed Li|LiFePO4 batteries exhibited over 95% capacity retention after 500 cycles at 1.0 C in coin cell and 85% capacity retention after 80 cycles at 0.5 C in pouch cell. The rationally combination of solid electrolyte layer protection and housed framework in one Li metal anode sheds fresh insights on the design principle of a safe and long-lifespan Li metal anode for Li metal batteries.展开更多
Silicon （Si） has been considered as one of the most promising anode material for tHe next generation lithium-ion batteries （LIBs） with high energy densities, due to its high theoretical capacity, abundant availabi...Silicon （Si） has been considered as one of the most promising anode material for tHe next generation lithium-ion batteries （LIBs） with high energy densities, due to its high theoretical capacity, abundant availability and environmental friendliness. However. silicon materials with low intrinsic electric and ionic conductivity suffer from huge volume variation during lithiation/delithiation processes leading to the pulverization of Si and subsequently resulting in severe capacity fading of the electrodes. Coupling of Si with carbon （C） realizes a favorable combination of the two materials properties, such as high lithiation capacity of Si and excellent mechanical and conductive properties of C. making silicon/carbon composite （Si/C） ideal candidates for LIBs anodes. In this review, recent progresses of Si/C materials utilized in LIBs are summarized in terms of structural design principles, material synthesis methods, morphological characteristics and electrochemical performances by highlighting the material structures. The mechanisms behind the performance enhancement are also discussed. Moreover, other factors that affect the performance of Si/C anodes, such as prelithiation, electrolyte additives, and binders, are also discussed. We aim to present a full scope of the Si/C-based anodes, and help understand and design future structures of Si/C anodes in LIBs,展开更多
Owing to their very high theoretical capacity, lithium （Li） metal anodes regain widespread attentions for their promising applications for next-generation high-energy-density Li batteries （e.g., lithium-sulfur batt...Owing to their very high theoretical capacity, lithium （Li） metal anodes regain widespread attentions for their promising applications for next-generation high-energy-density Li batteries （e.g., lithium-sulfur batteries, lithium-oxygen batteries, solid-state lithium metal batter- ies）. However, the inherent bottleneck of Li metal anodes, especially the growth of Li dendrites and the related safety concerns, should be well addressed. Owing to their featured micro-/nano-porous structures and intriguing physical properties, nanocarbon materials have been applied as host materials for Li metal anodes. This review summarizes the recent progress in the development of porous nanocarbon materials for safe Li metal anodes. The perspectives regarding the challenges and future development of employing micro-/nano-porous carbon materials in Li metal anodes are also included.展开更多
The development of graphene-based composites with low density,robust absorption,wide bandwidth and thin thickness remained a great challenge in the field of electromagnetic(EM)absorption.In this work,nitrogen-doped re...The development of graphene-based composites with low density,robust absorption,wide bandwidth and thin thickness remained a great challenge in the field of electromagnetic(EM)absorption.In this work,nitrogen-doped reduced graphene oxide/hollow cobalt ferrite(NRGO/hollow CoFe_(2)O_(4))composite aerogels were constructed by a solvothermal and hydrothermal two-step route.Results demonstrated that the as-fabricated composite aerogels had the ultralow density and a unique three-dimensional(3D)network structure,and lots of hollow CoFe_(2)O_(4)microspheres were almost homogeneously distributed on the wrinkled surfaces of lamellar NRGO.Moreover,superior EM absorbing capacity could be achieved by modulating the ferrite structure,addition amounts of hollow CoFe_(2)O_(4)and thicknesses.It was noteworthy that the NRGO/hollow CoFe_(2)O_(4)composite aerogel with the addition amount of ferrite of 15.0 mg pos-sessed the minimum reflection loss of-44.7 dB and maximum absorption bandwidth of 5.2 GHz(from 12.6 to 17.8 GHz)at a very thin thickness of 1.8 mm and filling ratio of 15.0 wt.%.Furthermore,the possible EM attenuation mechanism had been proposed.The results of this work would be helpful for developing RGO-based 3D composites as lightweight,thin and highly efficient EM wave absorbers.展开更多
Searching for advanced anode materials with excellent electrochemical properties in sodium-ion battery is essential and imperative for next-generation energy storage system to solve the energy shortage problem.In this...Searching for advanced anode materials with excellent electrochemical properties in sodium-ion battery is essential and imperative for next-generation energy storage system to solve the energy shortage problem.In this work,two-dimensional(2D)ultrathin FePS3 nanosheets,a typical ternary metal phosphosulfide,are first prepared by ultrasonic exfoliation.The novel 2D/2D heterojunction of FePS3 nanosheets@MXene composite is then successfully synthesized by in situ mixing ultrathin MXene nanosheets with FePS3 nanosheets.The resultant FePS3 nanosheets@MXene hybrids can increase the electronic conductivity and specific surface area,assuring excellent surface and interfacial charge transfer abilities.Furthermore,the unique heterojunction endows FePS3 nanosheets@MXene composite to promote the diffusion of Na^+ and alleviate the drastic change in volume in the cyclic process,enhancing the sodium storage capability.Consequently,the few-layered FePS3 nanosheets uniformly coated by ultrathin MXene provide an exceptional reversible capacity of 676.1 mAh g^−1 at the current of 100 mA g^−1 after 90 cycles,which is equivalent to around 90.6% of the second-cycle capacity(746.4 mAh g^−1).This work provides an original protocol for constructing 2D/2D material and demonstrates the FePS3@MXene composite as a potential anode material with excellent property for sodium-ion batteries.展开更多
An A1/Pb-0.3%Ag alloy composite anode was produced via composite casting. Its electrocatalytic activity for the oxygen evolution reaction and corrosion resistance was evaluated by anodic polarization curves and accele...An A1/Pb-0.3%Ag alloy composite anode was produced via composite casting. Its electrocatalytic activity for the oxygen evolution reaction and corrosion resistance was evaluated by anodic polarization curves and accelerated corro- sion test, respectively. The microscopic morphologies of the anode section and anodic oxidation layer during accelerated corrosion test were obtained by scanning electron microscopy. It is found that the composite anode （hard anodizing） dis- plays a more compact interracial combination and a better adhesive strength than plating tin. Compared with industrial Pb-0.3%Ag anodes, the oxygen evolution overpotentials of A1/Pb-0.3%Ag alloy （hard anodizing） and A1/Pb-0.3%Ag alloy （plating tin） at 500 A.m-2 were lower by 57 and 14 mV, respectively. Furthermore, the corrosion rates of Pb-0.3%Ag alloy, A1/Pb-0.3%Ag alloy （hard anodizing）, and A1/Pb-0.3%Ag alloy （plating tin） were 13.977, 9.487, and 11.824 g.m-2.h-1, respectively, in accelerated corrosion test for 8 h at 2000 A-m-2. The anodic oxidation layer of A1/Pb-0.3%Ag alloy （hard anodizing） is more compact than Pb-0.3%Ag alloy and A1/Pb-0.3%Ag alloy （plating tin） after the test.展开更多
The microstructure evolution and electrolysis behavior of(Cu_(52)Ni_(30)Fe_(18))–x Ni Fe_2O_4(x=40wt%,50wt%,60wt%,and 70wt%)composite inert anodes for aluminum electrowinning were studied.Ni Fe_2O_4 was synthesized b...The microstructure evolution and electrolysis behavior of(Cu_(52)Ni_(30)Fe_(18))–x Ni Fe_2O_4(x=40wt%,50wt%,60wt%,and 70wt%)composite inert anodes for aluminum electrowinning were studied.Ni Fe_2O_4 was synthesized by solid-state reaction at 950°C.The dense anode blocks were prepared by ball-milling followed by sintering under a N_2 atmosphere.The phase evolution of the anodes after sintering was determined by scanning electron microscopy and energy-dispersive X-ray spectroscopy.The results indicate that a substitution reaction between Fe in the alloy phase and Ni in the oxide phase occurs during the sintering process.The samples were also examined as inert anodes for aluminum electrowinning in the low-temperature KF–NaF–AlF_3 molten electrolyte for 24 h.The cell voltage during electrolysis and the corrosion scale on the anodes were analyzed.The results confirm that the scale has a self-repairing function because of the synergistic reaction between the alloy phase with Fe added and the oxide phase.The estimated wear rate of the(Cu_(52)Ni_(30)Fe_(18))–50Ni Fe_2O_4 composite anode is 2.02 cm·a^(-1).展开更多
Sodium-ion batteries(SIBs)have attracted significant attention with respect to renewable energy power generation systems because of the abundant reserves of sodium on earth.However,anode materials are presently limite...Sodium-ion batteries(SIBs)have attracted significant attention with respect to renewable energy power generation systems because of the abundant reserves of sodium on earth.However,anode materials are presently limited by low energy density,poor rate performance and inferior cycling stability.In recent years,tin disulfide(SnS_(2))with a particular layered structure has been considered as a promising anode material for SIBs due to its high theoretical capacity and low cost.Herein,a nervoussystem-like structured SnS_(2)/CNTs composite was successfully synthesized via a hydrothermal method.The SnS_(2)sheets were strung with carbon nanotubes(CNTs)to form a hierarchical porous structure,which is effective for electrolyte diffusion and electronic transmission.The large distance of the(001)plane(0.5899 nm)of SnS_(2)favors Na+insertion-extraction dynamics.Benefitting from these structural characteristics,SnS_(2)/CNTs electrodes exhibit high specific capacity,excellent rate performance and superior cycling stability.A high charge capacity of 642 mAh·g^(-1)was released at 0.2 A·g^(-1),and then,a high reversible capacity of 427 mAh·g^(-1)was retained after 100 cycles.Even charged at 2 A·g^(-1),the SnS_(2)/CNTS electrode maintained a capacity of 282 mAh·g^(-1).The nervous-system-like structure of the SnS_(2)/CNTs composite provides a novel strategy for the development of SIBs with high electrochemical performance.展开更多
Cu2O@Cu sub-microspheres composites with a narrow particle size distribution from 300 to 500 nm was successfully fabricated by one-step synthesis through the direct thermal decomposition of copper nitrate （Cu（NO3）2...Cu2O@Cu sub-microspheres composites with a narrow particle size distribution from 300 to 500 nm was successfully fabricated by one-step synthesis through the direct thermal decomposition of copper nitrate （Cu（NO3）2） in octadecylamine （ODA） solvent. As anode materials for lithium ion batteries, the Cu2O@Cu composites obviously possess high specific capacity, excellent cyclic stability and rate capability. The coulombic efficiency is about 84% in the 1 st cycle and increases significantly up to 97.8% during successive cycles at various current densities. Even under a high current density of 500 mA g^-l, the discharge capacity of Cu2O@Cu composites remains up to 200 mAh g^-1. The excellent electrochemical properties are ascribed to the synergistic effect between high electronic conductivity and volume-buffering capacity of metallic copper composited with Cu2O.2017 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science ＆ Technology.展开更多
Lithium(Li) metal,possessing an extremely high theoretical specific capacity(3860 mAh/g) and the most negative electrode potential(-3.040 V vs.standard hydrogen electrode),is one the most favorable anode materials for...Lithium(Li) metal,possessing an extremely high theoretical specific capacity(3860 mAh/g) and the most negative electrode potential(-3.040 V vs.standard hydrogen electrode),is one the most favorable anode materials for future high-energy-density batteries.However,the poor cyclability and safety issues induced by extremely unstable interfaces of traditional liquid Li metal batteries have limited their practical applications.Herein,a quasi-solid battery is constructed to offer superior interfacial stability as well as excellent interfacial contact by the incorporation of Li@composite solid electrolyte integrated electrode and a limited amount of liquid electrolyte(7.5 μL/cm2).By combining the inorganic garnet Aldoped Li6.75La3Zr1.75Ta0.25O12(LLZO) with high mechanical strength and ionic conductivity and the o rganic ethylene-vinyl acetate copolymer(EVA) with good flexibility,the composite solid electrolyte film could provide sufficient ion channels,sustained interfacial contact and good mechanical stability at the anode side,which significantly alleviates the thermodynamic corrosion and safety problems induced by liquid electrolytes.This innovative and facile quasi-solid strategy is aimed to promote the intrinsic safety and stability of working Li metal anode,shedding light on the development of next-generation highperformance Li metal batteries.展开更多
Molybdenum disulfide(MoS2)was loaded on biocarbon using waste camellia dregs(CDs)as the carbon source,which was further coated with dopamine hydrochloride to construct biocarbon/MoS2 electrode composites.The electroch...Molybdenum disulfide(MoS2)was loaded on biocarbon using waste camellia dregs(CDs)as the carbon source,which was further coated with dopamine hydrochloride to construct biocarbon/MoS2 electrode composites.The electrochemical lithium storage performance of the composites with different MoS2 contents was investigated.SEM results demonstrated that the composite had a three-dimensional foam-like structure with MoS2 as the interlayer.XRD and HRTEM tests revealed that MoS2 interlayer spacing in the composite was expanded.XPS analysis showed that new Mo—N bonds were formed in the active material.The electrochemical tests showed that the composite with a MoS2 content of 63%had a high initial specific capacity of 1434 mA·h/g at a current density of 100 mA/g.After a long cycle at a high current,it also showed good cycling stability and the capacity retention was nearly 100%.In addition,it had good lithium ion deintercalation ability in the electrochemical kinetics test.展开更多
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
Graphite as a promising anode candidate of K-ion batteries(KIBs)has been increasingly studied currently,but corresponding rate performance and cycling stability are usually inferior to amorphous carbon materials.To pr...Graphite as a promising anode candidate of K-ion batteries(KIBs)has been increasingly studied currently,but corresponding rate performance and cycling stability are usually inferior to amorphous carbon materials.To protect the layer structure and further boost performance,tempura-like carbon/carbon nanocomposite of graphite@pitch-derived S-doped carbon(G@PSC)is designed and prepared by a facile and low-temperature modified molten salt method.This robust encapsulation structure makes their respective advantages complementary to each other,showing mutual promotion of electrochemical performances caused by synergy effect.As a result,the G@PSC electrode is applied in KIBs,delivering impressive rate capabilities(465,408,370,332,290,and 227 m A h g^(-1)at 0.05,0.2,0.5,1,2,and 5 A g^(-1))and ultralong cyclic stability(163 m A g^(-1)remaining even after 8000 cycles at 2 A g^(-1)).On basis of ex-situ studies,the sectionalized K-storage mechanism with adsorption(pseudocapacitance caused by S doping)-intercalation(pitch-derived carbon and graphite)pattern is revealed.Moreover,the exact insights into remarkable rate performances are taken by electrochemical kinetics tests and density functional theory calculation.In a word,this study adopts a facile method to synthesize high-performance carbon/carbon nanocomposite and is of practical significance for development of carbonaceous anode in KIBs.展开更多
Dramatic capacity fading and poor rate performance are two main obstacles that severely hamper the widespread application of the Si anode owing to its large volume variation during cycling and low intrinsic electrical...Dramatic capacity fading and poor rate performance are two main obstacles that severely hamper the widespread application of the Si anode owing to its large volume variation during cycling and low intrinsic electrical conductivity.To mitigate these issues,free-standing N-doped porous carbon nanofibers sheathed pumpkin-like Si/C composites(Si/C-ZIF-8/CNFs)are designed and synthesized by electrospinning and carbonization methods,which present greatly enhanced electrochemical properties for lithium-ion battery anodes.This particular structure alleviates the volume variation,promotes the formation of stable solid electrolyte interphase(SEI)film,and improves the electrical conductivity.As a result,the as-obtained free-standing Si/C-ZIF-8/CNFs electrode delivers a high reversible capacity of 945.5 mAh g^(-1) at 0.2 A g^(-1) with a capacity retention of 64% for 150 cycles,and exhibits a reversible capacity of 538.6 mA h g^(-1) at 0.5 A g^(-1) over 500 cycles.Moreover,the full cell composed of a freestanding Si/C-ZIF-8/CNFs anode and commercial LiNi_(1/3)Co_(1/3)Mn_(1/3)O_(2)(NCM)cathode shows a capacity of 63.4 mA h g^(-1) after 100 cycles at 0.2 C,which corresponds to a capacity retention of 60%.This rational design could provide a new path for the development of high-performance Si-based anodes.展开更多
基金Project supported by the National Natural Science Foundation of China(Nos.12372071 and 12372070)the Aeronautical Science Fund of China(No.2022Z055052001)the Foundation of China Scholarship Council(No.202306830079)。
文摘Currently,there are a limited number of dynamic models available for braided composite plates with large overall motions,despite the incorporation of three-dimensional(3D)braided composites into rotating blade components.In this paper,a dynamic model of 3D 4-directional braided composite thin plates considering braiding directions is established.Based on Kirchhoff's plate assumptions,the displacement variables of the plate are expressed.By incorporating the braiding directions into the constitutive equation of the braided composites,the dynamic model of the plate considering braiding directions is obtained.The effects of the speeds,braiding directions,and braided angles on the responses of the plate with fixed-axis rotation and translational motion,respectively,are investigated.This paper presents a dynamic theory for calculating the deformation of 3D braided composite structures undergoing both translational and rotational motions.It also provides a simulation method for investigating the dynamic behavior of non-isotropic material plates in various applications.
基金financially supported by the National Natural Science Foundation of China(Nos.21876164 and U2030203)A Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions。
文摘To address the poor mechanical properties of polydimethylsiloxane(PDMS)and enhance the understanding of the reinforcement mechanisms of aerogel network structures in rubber matrices,this study reinforced PDMS using an ordered interconnected three-dimensional montmorillonite(MMT)aerogel network.The average pore diameter of the aerogels was successfully reduced from 11.53μm to 2.51μm by adjusting the ratio of poly(vinyl alcohol)(PVA)to MMT via directional freezing.Changes in the aerogel network were observed in field emission scanning electron microscope(FESEM)images.After vacuum impregnation,the aerogel network structure of the composites was observed using FESEM.Tensile tests indicated that as the pore diameter decreased,the elongation at break of the composites first increased to a peak of329.61%before decreasing,while the tensile strength and Young's modulus continuously increased to their maximum values of 6.29 MPa and24.67 MPa,respectively.Meanwhile,FESEM images of the tensile cracks and fracture surfaces showed that with a reduction in aerogel pore diameter,the degrees of crack deflection and interfacial debonding increased,presenting a rougher fracture surface.These phenomena enable the composites to dissipate substantial energy during tension,thus effectively improving the mechanical strength of the composites.The present work elucidates the bearing of ordered three-dimensional aerogel network structures on the performance of rubber matrices and provides crucial theoretical insights and technical guidance for the creation and optimization of high-performance PDMS-based composites.
基金supported by the National Natural Science Foundation of China(Nos.52102088 and 22075026)support from Teli Fellowship,Beijing Institute of Technology,and facility support from Analysis&Testing Center,and Experimental Center of Materials Sciences&Engineering at Beijing Institute of Technology.
文摘MnCO_(3)represents a potentially high-capacity and low-cost anode candidate to replace graphite for enhancing energy density of commercial lithium-ion batteries,but it suffers from poor electrical conductivity and serious volumetric change,largely hindering its practical applications.
基金supported by the startup funding from Shanghai Jiao Tong University(Grant No.WH220402052).
文摘Silicon-based anode is a promising candidate for all-solid-state batteries(ASSBs).However,it must be further improved because of its tremendous volume change.In this study,various interface treatment strategies for SiO/carbon composite anodes in ASSBs were investigated using a multiphysics modeling framework.By evaluating the effects of active(carbon)and inactive coating materials,as well as the geometric and mechanical parameters,this research provides critical insights into optimizing their electrochemical performance and mechanical stability.Computational results indicate that carbon coatings can greatly enhance lithiation kinetics by regulating the interfacial electrochemical potential gradients,reducing the residual lithium concentration,and homogenizing the lithium-ion distribution compared with uncoated or inactive-coated configurations.In addition,thinner carbon coatings further improve capacity retention and stress management by balancing shorter lithium diffusion pathways with mitigated interfacial stress accumulation.Despite their ability to mechanically stabilize the anode,inactive coatings exhibit tradeoffs between lithium transport kinetics and stress modulation,with optimal performance achieved at lower Young’s moduli.Mechanical analyses highlight distinct failure mechanisms at the anode–electrolyte(shear driven)and particle-coating(tension driven)interfaces,emphasizing the need for tailored adhesion strategies.These findings provide actionable guidelines for designing robust SiO-based anodes,emphasizing the interplay among electrochemical efficiency,stress regulation,and interfacial durability in ASSBs.
基金Project (51004056) supported by the National Natural Science Foundation of ChinaProject (KKZ6201152009) supported by the Opening Foundation of Key Laboratory of Inorganic Coating Materials, ChinaProjects (2011239, 2011240) supported by Analysis and Measurement Research Fund of Kunming University of Science and Technology,China
文摘In order to search for a suitable anode material used in zinc electrowinning in place of Pb-Ag alloy,Al/Pb-PANI（polyaniline）-WC（tungsten carbide） composite inert anodes were prepared on aluminum alloy substrate by double pulse electrodeposition（DPE） of PANI and WC particles with Pb2＋ from an original plating bath.Thereafter,anodic polarization curves,cyclic voltammetry curves and Tafel polarization curves for the composite inert anodes obtained under different PANI concentrations in the original plating bath were measured,and the microstructural features were also investigated by scanning electron microscopy（SEM）.The results show that Al/Pb-PANI-WC composite inert anode obtained under PANI concentration of 20 g/L in the original plating bath possesses uniform microstructures and composition distributions,higher electrocatalytic activity,better reversibility of electrode reaction and corrosion resistance in a synthetic zinc electrowinning electrolyte of 50 g/L Zn2＋,150 g/L H2SO4 at 35 °C.Compared with Pb-1%Ag alloy,the overpotential of oxygen evolutions for the composite inert anode are decreased by 185 mV and 166 mV,respectively,under 500 A/m2 and 1000 A/m2.
基金Project(11204090)supported by the National Natural Science Foundation of ChinaProject(2013KJCX0050)supported by the Department of Education of Guangdong Province+6 种基金ChinaProjects(2014B0404040672014A0404010052015A0404040432015A090905003201508030033)supported by the Scientific and Technological Plan of Guangdong Province and Guangzhou CityChina
文摘A porous coral-structured Si/C composite as an anode material was fabricated by coating Si nanoparticles with a carbon layer from polyvinyl alcohol（PVA）, erosion of hydrofluoric（HF） acid, and secondary coating with pitch. Three samples with different pitch contents of 30%, 40% and 50% were synthesized. The composition and morphology of the composites were characterized by X-ray diffractometry（XRD） and scanning electron microscopy（SEM）, respectively, and the properties were tested by electrochemical measurements. The results indicated that the composites showed obviously enhanced electrochemical performance compared with that without secondary carbon coating. The second discharge capacity of the composite was 773 m A·h/g at a current density of 100 m A/g, and still retained 669 m A·h/g after 60 cycles with a small capacity fade of less than 0.23%/cycle, while the content of secondary carbon source of pitch was set at 40%. Therefore, the cycle stability of the composite could be excellently improved by regulating carbon content of secondary coating.
基金supported by the National Key Research and Development Program (2016YFA0202500, 2015CB932500, and 2016YFA0200102)the National Natural Science Foundation of China (21676160, 21825501, 21805161, and 21808125)China Postdoctoral Science Foundation (2017M620773, 2018M631480, and BX201700125)
文摘Lithium (Li) metal with an ultrahigh specific theoretical capacity and the lowest reduction potential is strongly considered as a promising anode for high-energy-density batteries. However, uncontrolled lithium dendrites and infinite volume change during repeated plating/stripping cycles hinder its practical applications immensely. Herein, a house-like Li anode (housed Li) was designed to circumvent the above issues. The house matrix was composed of carbon fiber matrix and affords a stable structure to relieve the volume change. An artificial solid electrolyte layer was formed on composite Li metal, just like the roof of a house, which facilitates uniform Li ions diffusion and serves as a physical barrier against electrolyte corrosion. With the combination of solid electrolyte layer and matrix in the composite Li metal anode, both dendrite growth and volume expansion are remarkably inhibited. The housed Li|LiFePO4 batteries exhibited over 95% capacity retention after 500 cycles at 1.0 C in coin cell and 85% capacity retention after 80 cycles at 0.5 C in pouch cell. The rationally combination of solid electrolyte layer protection and housed framework in one Li metal anode sheds fresh insights on the design principle of a safe and long-lifespan Li metal anode for Li metal batteries.
文摘Silicon （Si） has been considered as one of the most promising anode material for tHe next generation lithium-ion batteries （LIBs） with high energy densities, due to its high theoretical capacity, abundant availability and environmental friendliness. However. silicon materials with low intrinsic electric and ionic conductivity suffer from huge volume variation during lithiation/delithiation processes leading to the pulverization of Si and subsequently resulting in severe capacity fading of the electrodes. Coupling of Si with carbon （C） realizes a favorable combination of the two materials properties, such as high lithiation capacity of Si and excellent mechanical and conductive properties of C. making silicon/carbon composite （Si/C） ideal candidates for LIBs anodes. In this review, recent progresses of Si/C materials utilized in LIBs are summarized in terms of structural design principles, material synthesis methods, morphological characteristics and electrochemical performances by highlighting the material structures. The mechanisms behind the performance enhancement are also discussed. Moreover, other factors that affect the performance of Si/C anodes, such as prelithiation, electrolyte additives, and binders, are also discussed. We aim to present a full scope of the Si/C-based anodes, and help understand and design future structures of Si/C anodes in LIBs,
基金financially supported by the National Key Research and Development Program(Nos.2016YFA0202500,2015CB932500)the National Natural Scientific Foundation of China(Nos.21676160,21561130151)
文摘Owing to their very high theoretical capacity, lithium （Li） metal anodes regain widespread attentions for their promising applications for next-generation high-energy-density Li batteries （e.g., lithium-sulfur batteries, lithium-oxygen batteries, solid-state lithium metal batter- ies）. However, the inherent bottleneck of Li metal anodes, especially the growth of Li dendrites and the related safety concerns, should be well addressed. Owing to their featured micro-/nano-porous structures and intriguing physical properties, nanocarbon materials have been applied as host materials for Li metal anodes. This review summarizes the recent progress in the development of porous nanocarbon materials for safe Li metal anodes. The perspectives regarding the challenges and future development of employing micro-/nano-porous carbon materials in Li metal anodes are also included.
基金supported by the Foundation of Provincial Natural Science Research Project of Anhui Colleges(No.KJ2021ZD0047)the Anhui Provincial Natural Science Foundation(No.2008085J27)+1 种基金the China Postdoctoral Science Foundation(No.2019M652160)the Research Foundation of the Institute of Environment-friendly Materials and Occupational Health(Wuhu),Anhui University of Science and Technology(No.ALW2020YF05).
文摘The development of graphene-based composites with low density,robust absorption,wide bandwidth and thin thickness remained a great challenge in the field of electromagnetic(EM)absorption.In this work,nitrogen-doped reduced graphene oxide/hollow cobalt ferrite(NRGO/hollow CoFe_(2)O_(4))composite aerogels were constructed by a solvothermal and hydrothermal two-step route.Results demonstrated that the as-fabricated composite aerogels had the ultralow density and a unique three-dimensional(3D)network structure,and lots of hollow CoFe_(2)O_(4)microspheres were almost homogeneously distributed on the wrinkled surfaces of lamellar NRGO.Moreover,superior EM absorbing capacity could be achieved by modulating the ferrite structure,addition amounts of hollow CoFe_(2)O_(4)and thicknesses.It was noteworthy that the NRGO/hollow CoFe_(2)O_(4)composite aerogel with the addition amount of ferrite of 15.0 mg pos-sessed the minimum reflection loss of-44.7 dB and maximum absorption bandwidth of 5.2 GHz(from 12.6 to 17.8 GHz)at a very thin thickness of 1.8 mm and filling ratio of 15.0 wt.%.Furthermore,the possible EM attenuation mechanism had been proposed.The results of this work would be helpful for developing RGO-based 3D composites as lightweight,thin and highly efficient EM wave absorbers.
基金support funding is from the National Natural Science Foundation of China(51871119 and 51901100)China Jiangsu Specially Appointed Professor,Jiangsu Provincial Founds for Natural Science Foundation(BK20170793 and BK20180015)+2 种基金China Postdoctoral Science Foundation(2018M640481 and 2019T120426)Jiangsu Postdoctoral Research Fund(2019K003 and 2019K201)Jiangsu-Innovate UK Business Competition(BZ2017061)
文摘Searching for advanced anode materials with excellent electrochemical properties in sodium-ion battery is essential and imperative for next-generation energy storage system to solve the energy shortage problem.In this work,two-dimensional(2D)ultrathin FePS3 nanosheets,a typical ternary metal phosphosulfide,are first prepared by ultrasonic exfoliation.The novel 2D/2D heterojunction of FePS3 nanosheets@MXene composite is then successfully synthesized by in situ mixing ultrathin MXene nanosheets with FePS3 nanosheets.The resultant FePS3 nanosheets@MXene hybrids can increase the electronic conductivity and specific surface area,assuring excellent surface and interfacial charge transfer abilities.Furthermore,the unique heterojunction endows FePS3 nanosheets@MXene composite to promote the diffusion of Na^+ and alleviate the drastic change in volume in the cyclic process,enhancing the sodium storage capability.Consequently,the few-layered FePS3 nanosheets uniformly coated by ultrathin MXene provide an exceptional reversible capacity of 676.1 mAh g^−1 at the current of 100 mA g^−1 after 90 cycles,which is equivalent to around 90.6% of the second-cycle capacity(746.4 mAh g^−1).This work provides an original protocol for constructing 2D/2D material and demonstrates the FePS3@MXene composite as a potential anode material with excellent property for sodium-ion batteries.
基金financially supported by the National Natural Science Foundation of China(No.51004056)the Opening Foundation of the Key Laboratory of Inorganic Coating Materials,Chinese Academy of Sciences(No.KKZ6201152009)+2 种基金the Specialized Research Fund for the Doctoral Program of Higher Education(No.20125314110011)the Applied Basic Research Foundation of Yunnan Province,China(No.2010ZC052)the Analysis and Testing Foundation of Kunming University of Science and Technology(Nos.2010203 and 2011173)
文摘An A1/Pb-0.3%Ag alloy composite anode was produced via composite casting. Its electrocatalytic activity for the oxygen evolution reaction and corrosion resistance was evaluated by anodic polarization curves and accelerated corro- sion test, respectively. The microscopic morphologies of the anode section and anodic oxidation layer during accelerated corrosion test were obtained by scanning electron microscopy. It is found that the composite anode （hard anodizing） dis- plays a more compact interracial combination and a better adhesive strength than plating tin. Compared with industrial Pb-0.3%Ag anodes, the oxygen evolution overpotentials of A1/Pb-0.3%Ag alloy （hard anodizing） and A1/Pb-0.3%Ag alloy （plating tin） at 500 A.m-2 were lower by 57 and 14 mV, respectively. Furthermore, the corrosion rates of Pb-0.3%Ag alloy, A1/Pb-0.3%Ag alloy （hard anodizing）, and A1/Pb-0.3%Ag alloy （plating tin） were 13.977, 9.487, and 11.824 g.m-2.h-1, respectively, in accelerated corrosion test for 8 h at 2000 A-m-2. The anodic oxidation layer of A1/Pb-0.3%Ag alloy （hard anodizing） is more compact than Pb-0.3%Ag alloy and A1/Pb-0.3%Ag alloy （plating tin） after the test.
基金financially supported by the Major Science and Technology Programs of CHALCO(ZB2013CBBCe1)the Zhengzhou Non-ferrous Metals Research Institute Co.Ltd.of CHALCO for supporting this work
文摘The microstructure evolution and electrolysis behavior of(Cu_(52)Ni_(30)Fe_(18))–x Ni Fe_2O_4(x=40wt%,50wt%,60wt%,and 70wt%)composite inert anodes for aluminum electrowinning were studied.Ni Fe_2O_4 was synthesized by solid-state reaction at 950°C.The dense anode blocks were prepared by ball-milling followed by sintering under a N_2 atmosphere.The phase evolution of the anodes after sintering was determined by scanning electron microscopy and energy-dispersive X-ray spectroscopy.The results indicate that a substitution reaction between Fe in the alloy phase and Ni in the oxide phase occurs during the sintering process.The samples were also examined as inert anodes for aluminum electrowinning in the low-temperature KF–NaF–AlF_3 molten electrolyte for 24 h.The cell voltage during electrolysis and the corrosion scale on the anodes were analyzed.The results confirm that the scale has a self-repairing function because of the synergistic reaction between the alloy phase with Fe added and the oxide phase.The estimated wear rate of the(Cu_(52)Ni_(30)Fe_(18))–50Ni Fe_2O_4 composite anode is 2.02 cm·a^(-1).
基金financially supported by the National Natural Science Foundation of China(Nos.51704124,51762017 and 11602094)the Key Planned Science and Technology Project of Xiangxi Tujia&Miao Autonomous Prefecture(No.2018GX2001)+2 种基金the Program of Youth Talent Support for Hunan Province(No.2018RS3098)the Key Program of Hunan Provincial Education Department(No.18A285)the Natural Science Foundation of Hunan Province(Nos.2018JJ3415 and 2019JJ50485)。
文摘Sodium-ion batteries(SIBs)have attracted significant attention with respect to renewable energy power generation systems because of the abundant reserves of sodium on earth.However,anode materials are presently limited by low energy density,poor rate performance and inferior cycling stability.In recent years,tin disulfide(SnS_(2))with a particular layered structure has been considered as a promising anode material for SIBs due to its high theoretical capacity and low cost.Herein,a nervoussystem-like structured SnS_(2)/CNTs composite was successfully synthesized via a hydrothermal method.The SnS_(2)sheets were strung with carbon nanotubes(CNTs)to form a hierarchical porous structure,which is effective for electrolyte diffusion and electronic transmission.The large distance of the(001)plane(0.5899 nm)of SnS_(2)favors Na+insertion-extraction dynamics.Benefitting from these structural characteristics,SnS_(2)/CNTs electrodes exhibit high specific capacity,excellent rate performance and superior cycling stability.A high charge capacity of 642 mAh·g^(-1)was released at 0.2 A·g^(-1),and then,a high reversible capacity of 427 mAh·g^(-1)was retained after 100 cycles.Even charged at 2 A·g^(-1),the SnS_(2)/CNTS electrode maintained a capacity of 282 mAh·g^(-1).The nervous-system-like structure of the SnS_(2)/CNTs composite provides a novel strategy for the development of SIBs with high electrochemical performance.
基金financially supported by the National Program on Key Basic Research Project (2014CB643403)National Key Research and Development Program of China (2017YFB0102900)the Shanghai Pujiang Program (17PJD016)
文摘Cu2O@Cu sub-microspheres composites with a narrow particle size distribution from 300 to 500 nm was successfully fabricated by one-step synthesis through the direct thermal decomposition of copper nitrate （Cu（NO3）2） in octadecylamine （ODA） solvent. As anode materials for lithium ion batteries, the Cu2O@Cu composites obviously possess high specific capacity, excellent cyclic stability and rate capability. The coulombic efficiency is about 84% in the 1 st cycle and increases significantly up to 97.8% during successive cycles at various current densities. Even under a high current density of 500 mA g^-l, the discharge capacity of Cu2O@Cu composites remains up to 200 mAh g^-1. The excellent electrochemical properties are ascribed to the synergistic effect between high electronic conductivity and volume-buffering capacity of metallic copper composited with Cu2O.2017 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science ＆ Technology.
基金supported by National Key Research and Development Program(No.2016YFA0202500)National Natural Science Foundation of China(Nos.21776019,21808124)Beijing Natural Science Foundation(No.L182021)。
文摘Lithium(Li) metal,possessing an extremely high theoretical specific capacity(3860 mAh/g) and the most negative electrode potential(-3.040 V vs.standard hydrogen electrode),is one the most favorable anode materials for future high-energy-density batteries.However,the poor cyclability and safety issues induced by extremely unstable interfaces of traditional liquid Li metal batteries have limited their practical applications.Herein,a quasi-solid battery is constructed to offer superior interfacial stability as well as excellent interfacial contact by the incorporation of Li@composite solid electrolyte integrated electrode and a limited amount of liquid electrolyte(7.5 μL/cm2).By combining the inorganic garnet Aldoped Li6.75La3Zr1.75Ta0.25O12(LLZO) with high mechanical strength and ionic conductivity and the o rganic ethylene-vinyl acetate copolymer(EVA) with good flexibility,the composite solid electrolyte film could provide sufficient ion channels,sustained interfacial contact and good mechanical stability at the anode side,which significantly alleviates the thermodynamic corrosion and safety problems induced by liquid electrolytes.This innovative and facile quasi-solid strategy is aimed to promote the intrinsic safety and stability of working Li metal anode,shedding light on the development of next-generation highperformance Li metal batteries.
基金The authors are grateful for the financial supports from the National Natural Science Foundation of China(50702020,81171461)the Natural Science Foundation of Hunan Province,China(2017JJ2040)the Young Teacher Promotion Fund by Hunan University,China,the Fundamental Research Funds of the Central Universities,China.
文摘Molybdenum disulfide(MoS2)was loaded on biocarbon using waste camellia dregs(CDs)as the carbon source,which was further coated with dopamine hydrochloride to construct biocarbon/MoS2 electrode composites.The electrochemical lithium storage performance of the composites with different MoS2 contents was investigated.SEM results demonstrated that the composite had a three-dimensional foam-like structure with MoS2 as the interlayer.XRD and HRTEM tests revealed that MoS2 interlayer spacing in the composite was expanded.XPS analysis showed that new Mo—N bonds were formed in the active material.The electrochemical tests showed that the composite with a MoS2 content of 63%had a high initial specific capacity of 1434 mA·h/g at a current density of 100 mA/g.After a long cycle at a high current,it also showed good cycling stability and the capacity retention was nearly 100%.In addition,it had good lithium ion deintercalation ability in the electrochemical kinetics test.
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the financial support from the National Natural Science Foundation of China(No.91963118)the 111 Project(No.B13013)supported by the Open Project Program of Key Laboratory of Preparation and Application of Environmental Friendly Materials(Jilin Normal University),Ministry of Education,China(No.2020004)。
文摘Graphite as a promising anode candidate of K-ion batteries(KIBs)has been increasingly studied currently,but corresponding rate performance and cycling stability are usually inferior to amorphous carbon materials.To protect the layer structure and further boost performance,tempura-like carbon/carbon nanocomposite of graphite@pitch-derived S-doped carbon(G@PSC)is designed and prepared by a facile and low-temperature modified molten salt method.This robust encapsulation structure makes their respective advantages complementary to each other,showing mutual promotion of electrochemical performances caused by synergy effect.As a result,the G@PSC electrode is applied in KIBs,delivering impressive rate capabilities(465,408,370,332,290,and 227 m A h g^(-1)at 0.05,0.2,0.5,1,2,and 5 A g^(-1))and ultralong cyclic stability(163 m A g^(-1)remaining even after 8000 cycles at 2 A g^(-1)).On basis of ex-situ studies,the sectionalized K-storage mechanism with adsorption(pseudocapacitance caused by S doping)-intercalation(pitch-derived carbon and graphite)pattern is revealed.Moreover,the exact insights into remarkable rate performances are taken by electrochemical kinetics tests and density functional theory calculation.In a word,this study adopts a facile method to synthesize high-performance carbon/carbon nanocomposite and is of practical significance for development of carbonaceous anode in KIBs.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.21965034,21703185,U1903217,51901013,and 21666037)the Xinjiang Autonomous Region Major Projects(2017A02004)+4 种基金the Leading Project Foundation of Science Department of Fujian Province(Grant No.2018H0034)the Resource Sharing Platform Construction Project of Xinjiang Province(PT1909)the Nature Science Foundation of Xinjiang Province(2017D01C074)the Opening Project of National Joint Engineering Research Center for Abrasion Control and Molding of Metal Materials,Henan University of Science and Technology(No.HKDNM201906)the Young Scholar Science Foundation of Xinjiang Educational Institutions(XJEDU2016S030)。
文摘Dramatic capacity fading and poor rate performance are two main obstacles that severely hamper the widespread application of the Si anode owing to its large volume variation during cycling and low intrinsic electrical conductivity.To mitigate these issues,free-standing N-doped porous carbon nanofibers sheathed pumpkin-like Si/C composites(Si/C-ZIF-8/CNFs)are designed and synthesized by electrospinning and carbonization methods,which present greatly enhanced electrochemical properties for lithium-ion battery anodes.This particular structure alleviates the volume variation,promotes the formation of stable solid electrolyte interphase(SEI)film,and improves the electrical conductivity.As a result,the as-obtained free-standing Si/C-ZIF-8/CNFs electrode delivers a high reversible capacity of 945.5 mAh g^(-1) at 0.2 A g^(-1) with a capacity retention of 64% for 150 cycles,and exhibits a reversible capacity of 538.6 mA h g^(-1) at 0.5 A g^(-1) over 500 cycles.Moreover,the full cell composed of a freestanding Si/C-ZIF-8/CNFs anode and commercial LiNi_(1/3)Co_(1/3)Mn_(1/3)O_(2)(NCM)cathode shows a capacity of 63.4 mA h g^(-1) after 100 cycles at 0.2 C,which corresponds to a capacity retention of 60%.This rational design could provide a new path for the development of high-performance Si-based anodes.
