In recent years,the new energy storage system,such as lithium ion batteries(LIBs),has attracted much attention.In order to meet the demand of industrial progress for longer cycle life,higher energy density and cost ef...In recent years,the new energy storage system,such as lithium ion batteries(LIBs),has attracted much attention.In order to meet the demand of industrial progress for longer cycle life,higher energy density and cost efficiency,a quantity of research has been conducted on the commercial application of LIBs.However,it is difficult to achieve satisfying safety and cycling performance simultaneously.There may be thermal runaway(TR),external impact,overcharge and overdischarge in the process of battery abuse,which makes the safety problem of LIBs more prominent.In this review,we summarize recent progress in the smart safety materials design towards the goal of preventing TR of LIBs reversibly from different abuse conditions.Benefiting from smart responsive materials and novel structural design,the safety of LIBs can be improved a lot.We expect to provide a comprehensive reference for the development of smart and safe lithium-based battery materials.展开更多
Silicon(Si)is a promising anode material for lithium‐ion batteries(LIBs)owing to its tremendously high theoretical storage capacity(4200 mAh g−1),which has the potential to elevate the energy of LIBs.However,Si anode...Silicon(Si)is a promising anode material for lithium‐ion batteries(LIBs)owing to its tremendously high theoretical storage capacity(4200 mAh g−1),which has the potential to elevate the energy of LIBs.However,Si anodes exhibit severe volume change during lithiation/delithiation processes,resulting in anode pulverization and delamination with detrimental growth of solid electrolyte interface layers.As a result,the cycling stability of Si anodes is insufficient for commercialization in LIBs.Polymeric binders can play critical roles in Si anodes by affecting their cycling stability,although they occupy a small portion of the electrodes.This review introduces crucial factors influencing polymeric binders'properties and the electrochemical performance of Si anodes.In particular,we emphasize the structure–property relationships of binders in the context of molecular design strategy,functional groups,types of interactions,and functionalities of binders.Furthermore,binders with additional functionalities,such as electrical conductivity and self‐healability,are extensively discussed,with an emphasis on the binder design principle.展开更多
Silicon(Si)is widely used as a lithium‐ion‐battery anode owing to its high capacity and abundant crustal reserves.However,large volume change upon cycling and poor conductivity of Si cause rapid capacity decay and p...Silicon(Si)is widely used as a lithium‐ion‐battery anode owing to its high capacity and abundant crustal reserves.However,large volume change upon cycling and poor conductivity of Si cause rapid capacity decay and poor fast‐charging capability limiting its commercial applications.Here,we propose a multilevel carbon architecture with vertical graphene sheets(VGSs)grown on surfaces of subnanoscopically and homogeneously dispersed Si–C composite nanospheres,which are subsequently embedded into a carbon matrix(C/VGSs@Si–C).Subnanoscopic C in the Si–C nanospheres,VGSs,and carbon matrix form a three‐dimensional conductive and robust network,which significantly improves the conductivity and suppresses the volume expansion of Si,thereby boosting charge transport and improving electrode stability.The VGSs with vast exposed edges considerably increase the contact area with the carbon matrix and supply directional transport channels through the entire material,which boosts charge transport.The carbon matrix encapsulates VGSs@Si–C to decrease the specific surface area and increase tap density,thus yielding high first Coulombic efficiency and electrode compaction density.Consequently,C/VGSs@Si–C delivers excellent Li‐ion storage performances under industrial electrode conditions.In particular,the full cells show high energy densities of 603.5 Wh kg^(−1)and 1685.5 Wh L^(−1)at 0.1 C and maintain 80.7%of the energy density at 3 C.展开更多
Improving the reversibility of anionic redox and inhibiting irreversible oxygen evolution are the main challenges in the application of high reversible capacity Li-rich Mn-based cathode materials.A facile synchronous ...Improving the reversibility of anionic redox and inhibiting irreversible oxygen evolution are the main challenges in the application of high reversible capacity Li-rich Mn-based cathode materials.A facile synchronous lithiation strategy combining the advantages of yttrium doping and LiYO_(2) surface coating is proposed.Yttrium doping effectively suppresses the oxygen evolution during the delithiation process by increasing the energy barrier of oxygen evolution reaction through strong Y–O bond energy.LiYO_(2) nanocoating has the function of structural constraint and protection,that protecting the lattice oxygen exposed to the surface,thus avoiding irreversible oxidation.As an Li^(+) conductor,LiYO_(2) nano-coating can provide a fast Li^(+) transfer channel,which enables the sample to have excellent rate performance.The synergistic effect of Y doping and nano-LiYO_(2) coating integration suppresses the oxygen release from the surface,accelerates the diffusion of Li^(+)from electrolyte to electrode and decreases the interfacial side reactions,enabling the lithium ion batteries to obtain good electrochemical performance.The lithium-ion full cell employing the Y-1 sample(cathode)and commercial graphite(anode)exhibit an excellent specific energy density of 442.9 Wh kg^(-1) at a current density of 0.1C,with very stable safety performance,which can be used in a wide temperature range(60 to-15℃)stable operation.This result illustrates a new integration strategy for advanced cathode materials to achieve high specific energy density.展开更多
To obtain intrinsic overcharge boundary and investigate overcharge mechanism,here we propose an innovative method,the step overcharge test,to reduce the thermal crossover and distinguish the overcharge thermal behavio...To obtain intrinsic overcharge boundary and investigate overcharge mechanism,here we propose an innovative method,the step overcharge test,to reduce the thermal crossover and distinguish the overcharge thermal behavior,including 5%state of charge(SOC)with small current overcharge and resting until the temperature equilibrium under adiabatic conditions.The intrinsic thermal response and the self-excitation behaviour are analysed through temperature and voltage changes during the step overcharge period.Experimental results show that the deintercalated state of the cathode is highly correlated to self-heating parasitic reactions.Before reaching the upper limit of Negative/Positive(N/P)ratio,the temperature changes little,the heat generation is significantly induced by the reversible heat(endothermic)and ohmic heat,which could balance each other.Following that the lithium metal is gradually deposited on the surface of the anode and reacts with electrolyte upon overcharge,inducing selfheating side reaction.However,this spontaneous thermal reaction could be“self-extinguished”.When the lithium in cathode is completely deintercalated,the boundary point of overcharge is about 4.7 V(~148%SOC,>40℃),and from this point,the self-heating behaviour could be continuously triggered until thermal runaway(TR)without additional overcharge.The whole static and spontaneous process lasts for 115 h and the side reaction heat is beyond 320,000 J.The continuous self-excitation behavior inside the battery is attributed to the interaction between the highly oxidized cathode and the solvent,which leads to the dissolution of metal ions.The dissolved metal ions destroy the SEI(solid electrolyte interphase)film on the surface of the deposited Li of anode,which induces the thermal reaction between lithium metal and the solvent.The interaction between cathode,the deposited Li of anode,and solvent promotes the temperature of the battery to rise slowly.When the temperature of the battery reaches more than 60℃,the reaction between lithium metal and solvent is accelerated.After the temperature rises rapidly to the melting point of the separator,it triggers the thermal runaway of the battery due to the short circuit of the battery.展开更多
Y-doped Li3V2(PO4)3 cathode materials were prepared by a carbothermal reduction(CTR) process.The properties of the Y-doped Li3V2(PO4)3 were investigated by X-ray diffraction(XRD) and electrochemical measuremen...Y-doped Li3V2(PO4)3 cathode materials were prepared by a carbothermal reduction(CTR) process.The properties of the Y-doped Li3V2(PO4)3 were investigated by X-ray diffraction(XRD) and electrochemical measurements.XRD studies showed that the Y-doped Li3V2(PO4)3 had the same monoclinic structure as the undoped Li3V2(PO4)3.The Y-doped Li3V2(PO4)3 samples were investigated on the Li extraction/insertion performances through charge/discharge, cyclic voltammogram(CV), and electrochemical impedance spectra(EIS).The optimal doping content of Y was x=0.03 in Li3V2-xYx(PO4)3 system.The Y-doped Li3V2(PO4)3 samples showed a better cyclic ability.The electrode reaction reversibility was enhanced, and the charge transfer resistance was decreased through the Y-doping.The improved electrochemical perormances of the Y-doped Li3V2(PO4)3 cathode materials were attributed to the addition of Y3+ ion by stabilizing the monoclinic structure.展开更多
Some compounds of LiCo 1- x RE x O 2 (RE=rare earth elements and x =0.01~0.03) were prepared by doping rare earth elements to LiCoO 2 via solid state synthesis. The microstructure characteristics of t...Some compounds of LiCo 1- x RE x O 2 (RE=rare earth elements and x =0.01~0.03) were prepared by doping rare earth elements to LiCoO 2 via solid state synthesis. The microstructure characteristics of the LiCo 1- x RE x O 2 were investigated by XRD. It was found that the lattice parameters c are increased and the lattice volumes are enlarged compared to that of LiCoO 2. Moreover, the performance of LiCo 1- x RE x O 2 as the cathode material in lithium ion battery is improved, especially LiCo 1- x Y x O 2 and LiCo 1- x La x O 2. The initial charge/discharge capacities of LiCo 0.99 Y 0.01 O 2 and LiCo 0.99 La 0.01 O 2 are 174/154 (mAh·g -1 ) and 159/149 (mAh·g -1 ) respectively, while those for LiCoO 2 working in the same way are only 139/131 (mAh·g -1 ).展开更多
A new SnO2-Fe2O3/SWCNTs(single-walled carbon nanotubes) ternary nanocomposite was first synthesized by a facile hydrothermal approach.SnO2 and Fe2O3 nanoparticles(NPs) were homogeneously located on the surface of ...A new SnO2-Fe2O3/SWCNTs(single-walled carbon nanotubes) ternary nanocomposite was first synthesized by a facile hydrothermal approach.SnO2 and Fe2O3 nanoparticles(NPs) were homogeneously located on the surface of SWCNTs,as confirmed by X-ray diffraction(XRD),transmission electron microscope(TEM) and energy dispersive X-ray spectroscopy(EDX).Due to the synergistic effect of different components,the as synthesized SnO2-Fe2O3/SWCNTs composite as an anode material for lithium-ion batteries exhibited excellent electrochemical performance with a high capacity of 692 mAh·g-1 which could be maintained after 50 cycles at 200 mA·g-1.Even at a high rate of2000 mA·g-1,the capacity was still remained at 656 mAh·g-1.展开更多
Along with the extensive application of energy storage devices,the spent lithium-ion batteries(LIBs)are unquestionably classified into the secondary resources due to its high content of several valuable metals.However...Along with the extensive application of energy storage devices,the spent lithium-ion batteries(LIBs)are unquestionably classified into the secondary resources due to its high content of several valuable metals.However,current recycling methods have the main drawback to their tedious process,especially the purification and separation process.Herein,we propose a simplified process to recycle both cathode(LiCoO_(2))and anode(graphite)in the spent LIBs and regenerate newly high-performance anode material,CoO/CoFe2O4/expanded graphite(EG).This process not only has the advantages of succinct procedure and easy control of reaction conditions,but also effectively separates and recycles lithium from transition metals.The 98.43%of lithium is recovered from leachate when the solid product CoO/CoFe2O4/EG is synthesized as anode material for LIBs.And the product exhibits improved cyclic stability(890 mAh g^(-1) at 1 A g^(-1) after 700 cycles)and superior rate capability(208 mAh g^(-1) at 5 A g^(-1)).The merit of this delicate recycling design can be summarized as three aspects:the utilization of Fe impurity in waste LiCoO_(2),the transformation of waste graphite to EG,and the regeneration of anode material.This approach properly recycles the valuable components of spent LIBs,which introduces an insight into the future recycling.展开更多
The physical fundamentals and influences upon electrode materials' open-circuit voltage (OCV) and the spatial distribution of electrochemical potential in the full cell are briefly reviewed. We hope to illustrate t...The physical fundamentals and influences upon electrode materials' open-circuit voltage (OCV) and the spatial distribution of electrochemical potential in the full cell are briefly reviewed. We hope to illustrate that a better understanding of these scientific problems can help to develop and design high voltage cathodes and interfaces with low Ohmic drop. OCV is one of the main indices to evaluate the performance of lithium ion batteries (LIBs), and the enhancement of OCV shows promise as a way to increase the energy density. Besides, the severe potential drop at the interfaces indicates high resistance there, which is one of the key factors limiting power density.展开更多
State of charge(SOC)estimation for lithium ion batteries plays a critical role in battery management systems for electric vehicles.Battery fractional order models(FOMs)which come from frequency-domain modelling have p...State of charge(SOC)estimation for lithium ion batteries plays a critical role in battery management systems for electric vehicles.Battery fractional order models(FOMs)which come from frequency-domain modelling have provided a distinct insight into SOC estimation.In this article,we compare five state-of-the-art FOMs in terms of SOC estimation.To this end,firstly,characterisation tests on lithium ion batteries are conducted,and the experimental results are used to identify FOM parameters.Parameter identification results show that increasing the complexity of FOMs cannot always improve accuracy.The model R(RQ)W shows superior identification accuracy than the other four FOMs.Secondly,the SOC estimation based on a fractional order unscented Kalman filter is conducted to compare model accuracy and computational burden under different profiles,memory lengths,ambient temperatures,cells and voltage/current drifts.The evaluation results reveal that the SOC estimation accuracy does not necessarily positively correlate to the complexity of FOMs.Although more complex models can have better robustness against temperature variation,R(RQ),the simplest FOM,can overall provide satisfactory accuracy.Validation results on different cells demonstrate the generalisation ability of FOMs,and R(RQ)outperforms other models.Moreover,R(RQ)shows better robustness against truncation error and can maintain high accuracy even under the occurrence of current or voltage sensor drift.展开更多
With the assistance of nonionic surfactant (OP-10) and surface-selective surfactant (CH3COOH), anatase TiO2 was prepared as an anode material for lithium ion batteries. The morphology, the crystal structure, and t...With the assistance of nonionic surfactant (OP-10) and surface-selective surfactant (CH3COOH), anatase TiO2 was prepared as an anode material for lithium ion batteries. The morphology, the crystal structure, and the electrochemical properties of the prepared anatase TiO2 were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), electrochemical impedance spectroscopy (EIS), and galvanostatic charge and discharge test. The result shows that the prepared anatase TiO2 has high discharge capacity and good cyclic stability. The maximum discharge capacity is 313 mAh.g^-1, and there is no significant capacity decay from the second cycle.展开更多
In spite of silicon has a superior theoretical capacity, the large volume expansion of Si anodes during Li^+ insertion/extraction is the bottle neck that results in fast capacity fading and poor cycling performance. I...In spite of silicon has a superior theoretical capacity, the large volume expansion of Si anodes during Li^+ insertion/extraction is the bottle neck that results in fast capacity fading and poor cycling performance. In this paper, we report a silicon, single-walled carbon nanotube, and ordered mesoporous carbon nanocomposite synthesized by an evaporation-induced self-assembly process, in which silicon nanoparticles and single-walled carbon nanotubes were added into the phenolic resol with F-127 for co-condensation. The ordered mesoporous carbon matrix and single-walled carbon nanotubes network could effectively accommodate the volume change of silicon nanoparticles, and the ordered mesoporous structure could also provide efficient channels for the fast transport of Li-ions. As a consequence, this hybrid material exhibits a reversible capacity of 861 mAh g^(-1) after 150 cycles at a current density of 400 mAg^(-1). It achieves significant improvement in the electrochemical performance when compared with the raw materials and Si nanoparticle anodes.展开更多
Ultrathin MoS2 nanosheets were prepared in high yield using a facile and effective hydrothermal intercalation and exfoliation route. The products were characterized in detail using X-ray diffraction, scanning electron...Ultrathin MoS2 nanosheets were prepared in high yield using a facile and effective hydrothermal intercalation and exfoliation route. The products were characterized in detail using X-ray diffraction, scanning electron microscopy, transmission electron microscopy and Raman spectroscopy. The results show that the high yield of MoS2 nanosheets with good quality was successfully achieved and the dimensions of the immense nanosheets reached 1 μm-2/zm. As anode material for Li-ion batteries, the as-prepared MoS2 nanosheets electrodes exhibited a good initial capacity of 1190 mAh.g-l and excellent cyclic stability at constant current density of 50 mA.g-1. After 50 cycles, it still delivered reversibly sustained high capacities of 750 mAh.g-1.展开更多
TiO2-coated SnO2 (TCS) hollow spheres, which are new anode materials for lithium ion (Li-ion) batteries, were prepared and characterized with X-ray diffraction (XRD), scanning electron microscopy (SEM), transm...TiO2-coated SnO2 (TCS) hollow spheres, which are new anode materials for lithium ion (Li-ion) batteries, were prepared and characterized with X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), cyclic voltammetry (CV), and galvanostatic charge/discharge tests. The results obtained from XRD, SEM, and TEM show that TiO2 can be uniforrrdy coated on the surface of SnO2 hollow spheres with the assistance of anionic surfactant. The cyclic voltammograms indicate that both TiO2 and SnO2 exhibit the activity for Li-ion storage. The charge/discharge tests show that the prepared TCS hollow spheres have a higher reversible coulomb efficiency and a better cycling stability than the uncoated SnO2 hollow spheres.展开更多
Nanostructured metal oxides derived from metal organic frameworks have been shown to be promising materials for application in high energy density lithium ion batteries. In this work, porous nanostructured ZnCo2O4and ...Nanostructured metal oxides derived from metal organic frameworks have been shown to be promising materials for application in high energy density lithium ion batteries. In this work, porous nanostructured ZnCo2O4and Co3O4were synthesized by a facile and cost-effective approach via the calcination of MOF-74 precursors and tested as anode materials for lithium ion batteries. Compared with Co3O4, the electrochemical properties of the obtained porous nanostructured ZnCo2O4exhibit higher specific capacity, more excellent cycling stability and better rate capability. It demonstrates a reversible capacity of 1243.2 m Ah/g after 80 cycles at 100 m A/g and an excellent rate performance with high average discharge specific capacities of 1586.8, 994.6, 759.6 and 509.2 m Ah/g at 200, 400, 600 and 800 m A/g, respectively.The satisfactory electrochemical performances suggest that this porous nanostructured ZnCo2O4is potentially promising for application as an efficient anode material for lithium ion batteries.展开更多
Separators have been gaining increasing attention to improve the performance of lithium ion batteries(LIBs),especially for high safe and long cycle life.However,commercial polyolefin separators still face the problems...Separators have been gaining increasing attention to improve the performance of lithium ion batteries(LIBs),especially for high safe and long cycle life.However,commercial polyolefin separators still face the problems of rapid capacity decay and safety issues due to the poor wettability with electrolytes and low thermal stability.Herein,a novel composite separator is proposed by introducing a surfactant of sodium dodecyl thiosulfate(SDS)into the polytetrafluoroethylene(PTFE)substrate with the binder of polyacrylic acid(PAA)through the suction filtration method.The introduction of PAA/SDS enhances the adsorption energy between PTFE substrate and electrolyte through density functional theory calculations,which improves wettability and electrolyte uptake of the separator significantly.The asachieved composite separator enables the LIBs to own high Li^(+)conductivity(0.64×10^(-3)S cm^(-1))and Li^(+)transference number(0.63),further leading to a high capacity retention of 93.50%after 500 cycles at 1 C.In addition,the uniform and smooth surface morphology of Li metal employed the composite separator after cycling indicates that the lithium dendrites can be successfully inhibited.This work indicates a promising route for the preparation of a novel composite separator for high safe LIBs.展开更多
Surface chemical modification of polyolefin separators for lithium ion batteries is attempted to reduce the thermal shrinkage, which is im- portant for the battery energy density. In this study, we grafted organic/ino...Surface chemical modification of polyolefin separators for lithium ion batteries is attempted to reduce the thermal shrinkage, which is im- portant for the battery energy density. In this study, we grafted organic/inorganic hybrid crosslinked networks on the separators, simply by grafting polymerization and condensation reaction. The considerable silicon-oxygen crosslinked heat-resistance networks are responsible for the reduced thermal shrinkage. The strong chemical bonds between networks and separators promise enough mechanical support even at high temperature. The shrinkage at 150 ℃ for 30 min in the mechanical direction was 38.6% and 4.6% for the pristine and present graft-modified separators, respectively. Meanwhile, the grafting organic-inorganic hybrid crosslink networks mainly occupied part of void in the internal pores of the separators, so the thicknesses of the graft-modified separators were similar with the pristine one. The half cells prepared with the modified separators exhibited almost identical electrochemical properties to those with the commercial separators, thus proving that, in order to enhance the thermal stability of lithium ion battery, this kind of grafting-modified separators may be a better alternative to conventional silica nanoparticle layers-coated polyolefin separators.展开更多
A new composite material was fabricated by intercalating tin nanoparticles into graphite. The tin graphite intercalation compound(Sn-GIC) was prepared by the interactions of tin tetrachloride with KC8 (K-GIC) in t...A new composite material was fabricated by intercalating tin nanoparticles into graphite. The tin graphite intercalation compound(Sn-GIC) was prepared by the interactions of tin tetrachloride with KC8 (K-GIC) in tetrahydrofuran (THF). As the anode of lithium ion batteries, Sn-GIC presents a steady reversible capacity(363 mA·h/g) and a good cycling performance in comparison with Sn and SnO2, it suggests that the association of tin with graphite not only improves the reversible capacities, but also prevents the volume changes resulted from lithium insertion and extraction with tin during a charge-discharge process.展开更多
Herein,we report on the synthesis and lithium storage properties of electrospun one-dimensional(1D) CuFe2O4 nanomaterials.1D CuFe2O4nanotubes and nanorods were fabricated by a single spinneret electrospinning method...Herein,we report on the synthesis and lithium storage properties of electrospun one-dimensional(1D) CuFe2O4 nanomaterials.1D CuFe2O4nanotubes and nanorods were fabricated by a single spinneret electrospinning method followed by thermal decomposition for removal of polymers from the precursor fibers.The as-prepared CuFe2O4 nanotubes with wall thickness of 50 nm presented diameters of 150 nm and lengths up to several millimeters.It was found that phase separation between the electrospun composite materials occured during the electrospinning process,while the as-spun precursor nanofibers composed of polyacrylonitrile(PAN),polyvinylpyrrolidone(PVP) and metal salts might possess a core-shell structure(PAN as the core and PVP/metal salts composite as the shell) and then transformed to a hollow structure after calcination.Moreover,as a demonstration of the functional properties of the 1D nanostructure.CuFe2O4 nanotubes and nanorods were investigated as anodes for lithium ion batteries(LIBs).It was demonstrated that CuFe2O4 nanotubes not only delivered a high reversible capacity of 816 mAh·g-1 at a current density of 200 mA·g-1over 50 cycles,but also showed superior rate capability with respect to counterpart nanorods.Probably,the enhanced electrochemical performance can be attributed to its high specific surface areas as well as the unique hollow structure.展开更多
基金support by,National Key Research and Development Program(2023YFB2503700 and 2023YFC3008804)the Beijing Municipal Science&Technology Commission No.Z231100006123003+1 种基金the National Science Foundation of China(22071133)the Beijing Natural Science Foundation(No.Z220020).
文摘In recent years,the new energy storage system,such as lithium ion batteries(LIBs),has attracted much attention.In order to meet the demand of industrial progress for longer cycle life,higher energy density and cost efficiency,a quantity of research has been conducted on the commercial application of LIBs.However,it is difficult to achieve satisfying safety and cycling performance simultaneously.There may be thermal runaway(TR),external impact,overcharge and overdischarge in the process of battery abuse,which makes the safety problem of LIBs more prominent.In this review,we summarize recent progress in the smart safety materials design towards the goal of preventing TR of LIBs reversibly from different abuse conditions.Benefiting from smart responsive materials and novel structural design,the safety of LIBs can be improved a lot.We expect to provide a comprehensive reference for the development of smart and safe lithium-based battery materials.
基金National Research Foundation,Grant/Award Number:2022R1A2C1092273。
文摘Silicon(Si)is a promising anode material for lithium‐ion batteries(LIBs)owing to its tremendously high theoretical storage capacity(4200 mAh g−1),which has the potential to elevate the energy of LIBs.However,Si anodes exhibit severe volume change during lithiation/delithiation processes,resulting in anode pulverization and delamination with detrimental growth of solid electrolyte interface layers.As a result,the cycling stability of Si anodes is insufficient for commercialization in LIBs.Polymeric binders can play critical roles in Si anodes by affecting their cycling stability,although they occupy a small portion of the electrodes.This review introduces crucial factors influencing polymeric binders'properties and the electrochemical performance of Si anodes.In particular,we emphasize the structure–property relationships of binders in the context of molecular design strategy,functional groups,types of interactions,and functionalities of binders.Furthermore,binders with additional functionalities,such as electrical conductivity and self‐healability,are extensively discussed,with an emphasis on the binder design principle.
基金Guangdong Basic and Applied Basic Research Foundation,Grant/Award Number:2020A1515110762Research Grants Council of the Hong Kong Special Administrative Region,China,Grant/Award Number:R6005‐20Shenzhen Key Laboratory of Advanced Energy Storage,Grant/Award Number:ZDSYS20220401141000001。
文摘Silicon(Si)is widely used as a lithium‐ion‐battery anode owing to its high capacity and abundant crustal reserves.However,large volume change upon cycling and poor conductivity of Si cause rapid capacity decay and poor fast‐charging capability limiting its commercial applications.Here,we propose a multilevel carbon architecture with vertical graphene sheets(VGSs)grown on surfaces of subnanoscopically and homogeneously dispersed Si–C composite nanospheres,which are subsequently embedded into a carbon matrix(C/VGSs@Si–C).Subnanoscopic C in the Si–C nanospheres,VGSs,and carbon matrix form a three‐dimensional conductive and robust network,which significantly improves the conductivity and suppresses the volume expansion of Si,thereby boosting charge transport and improving electrode stability.The VGSs with vast exposed edges considerably increase the contact area with the carbon matrix and supply directional transport channels through the entire material,which boosts charge transport.The carbon matrix encapsulates VGSs@Si–C to decrease the specific surface area and increase tap density,thus yielding high first Coulombic efficiency and electrode compaction density.Consequently,C/VGSs@Si–C delivers excellent Li‐ion storage performances under industrial electrode conditions.In particular,the full cells show high energy densities of 603.5 Wh kg^(−1)and 1685.5 Wh L^(−1)at 0.1 C and maintain 80.7%of the energy density at 3 C.
基金This work was supported by the Fundamental Research Funds for the Central Universities(DUT20LAB123 and DUT20LAB307)the Natural Science Foundation of Jiangsu Province(BK20191167).
文摘Improving the reversibility of anionic redox and inhibiting irreversible oxygen evolution are the main challenges in the application of high reversible capacity Li-rich Mn-based cathode materials.A facile synchronous lithiation strategy combining the advantages of yttrium doping and LiYO_(2) surface coating is proposed.Yttrium doping effectively suppresses the oxygen evolution during the delithiation process by increasing the energy barrier of oxygen evolution reaction through strong Y–O bond energy.LiYO_(2) nanocoating has the function of structural constraint and protection,that protecting the lattice oxygen exposed to the surface,thus avoiding irreversible oxidation.As an Li^(+) conductor,LiYO_(2) nano-coating can provide a fast Li^(+) transfer channel,which enables the sample to have excellent rate performance.The synergistic effect of Y doping and nano-LiYO_(2) coating integration suppresses the oxygen release from the surface,accelerates the diffusion of Li^(+)from electrolyte to electrode and decreases the interfacial side reactions,enabling the lithium ion batteries to obtain good electrochemical performance.The lithium-ion full cell employing the Y-1 sample(cathode)and commercial graphite(anode)exhibit an excellent specific energy density of 442.9 Wh kg^(-1) at a current density of 0.1C,with very stable safety performance,which can be used in a wide temperature range(60 to-15℃)stable operation.This result illustrates a new integration strategy for advanced cathode materials to achieve high specific energy density.
基金funded by the National Key Research and Development Program of China(2018YFB0104400)supported by the Beijing Natural Science Foundation(2214066)。
文摘To obtain intrinsic overcharge boundary and investigate overcharge mechanism,here we propose an innovative method,the step overcharge test,to reduce the thermal crossover and distinguish the overcharge thermal behavior,including 5%state of charge(SOC)with small current overcharge and resting until the temperature equilibrium under adiabatic conditions.The intrinsic thermal response and the self-excitation behaviour are analysed through temperature and voltage changes during the step overcharge period.Experimental results show that the deintercalated state of the cathode is highly correlated to self-heating parasitic reactions.Before reaching the upper limit of Negative/Positive(N/P)ratio,the temperature changes little,the heat generation is significantly induced by the reversible heat(endothermic)and ohmic heat,which could balance each other.Following that the lithium metal is gradually deposited on the surface of the anode and reacts with electrolyte upon overcharge,inducing selfheating side reaction.However,this spontaneous thermal reaction could be“self-extinguished”.When the lithium in cathode is completely deintercalated,the boundary point of overcharge is about 4.7 V(~148%SOC,>40℃),and from this point,the self-heating behaviour could be continuously triggered until thermal runaway(TR)without additional overcharge.The whole static and spontaneous process lasts for 115 h and the side reaction heat is beyond 320,000 J.The continuous self-excitation behavior inside the battery is attributed to the interaction between the highly oxidized cathode and the solvent,which leads to the dissolution of metal ions.The dissolved metal ions destroy the SEI(solid electrolyte interphase)film on the surface of the deposited Li of anode,which induces the thermal reaction between lithium metal and the solvent.The interaction between cathode,the deposited Li of anode,and solvent promotes the temperature of the battery to rise slowly.When the temperature of the battery reaches more than 60℃,the reaction between lithium metal and solvent is accelerated.After the temperature rises rapidly to the melting point of the separator,it triggers the thermal runaway of the battery due to the short circuit of the battery.
基金supported by Guangxi Natural Science Foundation (0832259)Program to Sponsor Teams for Innovation in the Construction of Talent Highlands in Guangxi Institutions of Higher Learning (GuiJiaoRen [2007]71)Research Funds of the Guangxi Key Laboratory of Environmental Engineering, Protection and Assessment
文摘Y-doped Li3V2(PO4)3 cathode materials were prepared by a carbothermal reduction(CTR) process.The properties of the Y-doped Li3V2(PO4)3 were investigated by X-ray diffraction(XRD) and electrochemical measurements.XRD studies showed that the Y-doped Li3V2(PO4)3 had the same monoclinic structure as the undoped Li3V2(PO4)3.The Y-doped Li3V2(PO4)3 samples were investigated on the Li extraction/insertion performances through charge/discharge, cyclic voltammogram(CV), and electrochemical impedance spectra(EIS).The optimal doping content of Y was x=0.03 in Li3V2-xYx(PO4)3 system.The Y-doped Li3V2(PO4)3 samples showed a better cyclic ability.The electrode reaction reversibility was enhanced, and the charge transfer resistance was decreased through the Y-doping.The improved electrochemical perormances of the Y-doped Li3V2(PO4)3 cathode materials were attributed to the addition of Y3+ ion by stabilizing the monoclinic structure.
文摘Some compounds of LiCo 1- x RE x O 2 (RE=rare earth elements and x =0.01~0.03) were prepared by doping rare earth elements to LiCoO 2 via solid state synthesis. The microstructure characteristics of the LiCo 1- x RE x O 2 were investigated by XRD. It was found that the lattice parameters c are increased and the lattice volumes are enlarged compared to that of LiCoO 2. Moreover, the performance of LiCo 1- x RE x O 2 as the cathode material in lithium ion battery is improved, especially LiCo 1- x Y x O 2 and LiCo 1- x La x O 2. The initial charge/discharge capacities of LiCo 0.99 Y 0.01 O 2 and LiCo 0.99 La 0.01 O 2 are 174/154 (mAh·g -1 ) and 159/149 (mAh·g -1 ) respectively, while those for LiCoO 2 working in the same way are only 139/131 (mAh·g -1 ).
基金supported by the National Key Project on Basic Research(Grant No.2011CB935904)the National Natural Science Foundation of China(Grant No.21171163,91127020)NSF for Distinguished Young Scholars of Fujian Province(Grant No.2013J06006)
文摘A new SnO2-Fe2O3/SWCNTs(single-walled carbon nanotubes) ternary nanocomposite was first synthesized by a facile hydrothermal approach.SnO2 and Fe2O3 nanoparticles(NPs) were homogeneously located on the surface of SWCNTs,as confirmed by X-ray diffraction(XRD),transmission electron microscope(TEM) and energy dispersive X-ray spectroscopy(EDX).Due to the synergistic effect of different components,the as synthesized SnO2-Fe2O3/SWCNTs composite as an anode material for lithium-ion batteries exhibited excellent electrochemical performance with a high capacity of 692 mAh·g-1 which could be maintained after 50 cycles at 200 mA·g-1.Even at a high rate of2000 mA·g-1,the capacity was still remained at 656 mAh·g-1.
基金This work was supported by National Natural Science Foundation of China(51902347,51822812,51772334,51778627).
文摘Along with the extensive application of energy storage devices,the spent lithium-ion batteries(LIBs)are unquestionably classified into the secondary resources due to its high content of several valuable metals.However,current recycling methods have the main drawback to their tedious process,especially the purification and separation process.Herein,we propose a simplified process to recycle both cathode(LiCoO_(2))and anode(graphite)in the spent LIBs and regenerate newly high-performance anode material,CoO/CoFe2O4/expanded graphite(EG).This process not only has the advantages of succinct procedure and easy control of reaction conditions,but also effectively separates and recycles lithium from transition metals.The 98.43%of lithium is recovered from leachate when the solid product CoO/CoFe2O4/EG is synthesized as anode material for LIBs.And the product exhibits improved cyclic stability(890 mAh g^(-1) at 1 A g^(-1) after 700 cycles)and superior rate capability(208 mAh g^(-1) at 5 A g^(-1)).The merit of this delicate recycling design can be summarized as three aspects:the utilization of Fe impurity in waste LiCoO_(2),the transformation of waste graphite to EG,and the regeneration of anode material.This approach properly recycles the valuable components of spent LIBs,which introduces an insight into the future recycling.
基金supported by the National Natural Science Foundation of China(Grant Nos.51325206 and 51372228)National Basic Research Program of China(Grant No.2012CB932900)Shanghai Pujiang Program,China(Grant No.14PJ1403900)
文摘The physical fundamentals and influences upon electrode materials' open-circuit voltage (OCV) and the spatial distribution of electrochemical potential in the full cell are briefly reviewed. We hope to illustrate that a better understanding of these scientific problems can help to develop and design high voltage cathodes and interfaces with low Ohmic drop. OCV is one of the main indices to evaluate the performance of lithium ion batteries (LIBs), and the enhancement of OCV shows promise as a way to increase the energy density. Besides, the severe potential drop at the interfaces indicates high resistance there, which is one of the key factors limiting power density.
基金Beijing Municipal Natural Science Foundation of China(Grant No.3182035)National Natural Science Foundation of China(Grant No.51877009).
文摘State of charge(SOC)estimation for lithium ion batteries plays a critical role in battery management systems for electric vehicles.Battery fractional order models(FOMs)which come from frequency-domain modelling have provided a distinct insight into SOC estimation.In this article,we compare five state-of-the-art FOMs in terms of SOC estimation.To this end,firstly,characterisation tests on lithium ion batteries are conducted,and the experimental results are used to identify FOM parameters.Parameter identification results show that increasing the complexity of FOMs cannot always improve accuracy.The model R(RQ)W shows superior identification accuracy than the other four FOMs.Secondly,the SOC estimation based on a fractional order unscented Kalman filter is conducted to compare model accuracy and computational burden under different profiles,memory lengths,ambient temperatures,cells and voltage/current drifts.The evaluation results reveal that the SOC estimation accuracy does not necessarily positively correlate to the complexity of FOMs.Although more complex models can have better robustness against temperature variation,R(RQ),the simplest FOM,can overall provide satisfactory accuracy.Validation results on different cells demonstrate the generalisation ability of FOMs,and R(RQ)outperforms other models.Moreover,R(RQ)shows better robustness against truncation error and can maintain high accuracy even under the occurrence of current or voltage sensor drift.
基金supported by the National Natural Science Foundation of China(No.20873046)the Specialized Research Fund for the Doctoral Program of Higher Education of China(No.200805740004)the Project of Guangdong Province(No.2009B050700039)
文摘With the assistance of nonionic surfactant (OP-10) and surface-selective surfactant (CH3COOH), anatase TiO2 was prepared as an anode material for lithium ion batteries. The morphology, the crystal structure, and the electrochemical properties of the prepared anatase TiO2 were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), electrochemical impedance spectroscopy (EIS), and galvanostatic charge and discharge test. The result shows that the prepared anatase TiO2 has high discharge capacity and good cyclic stability. The maximum discharge capacity is 313 mAh.g^-1, and there is no significant capacity decay from the second cycle.
基金supported by the National Natural Science Foundation of China(NO.91434203,21276257,91534109)"Strategic Priority Research Program" of the Chinese Academy of Sciences(Grant No.XDA09010103)External Cooperation Program of BIC of the Chinese Academy of Sciences(Grant No.GJHZ201306)
文摘In spite of silicon has a superior theoretical capacity, the large volume expansion of Si anodes during Li^+ insertion/extraction is the bottle neck that results in fast capacity fading and poor cycling performance. In this paper, we report a silicon, single-walled carbon nanotube, and ordered mesoporous carbon nanocomposite synthesized by an evaporation-induced self-assembly process, in which silicon nanoparticles and single-walled carbon nanotubes were added into the phenolic resol with F-127 for co-condensation. The ordered mesoporous carbon matrix and single-walled carbon nanotubes network could effectively accommodate the volume change of silicon nanoparticles, and the ordered mesoporous structure could also provide efficient channels for the fast transport of Li-ions. As a consequence, this hybrid material exhibits a reversible capacity of 861 mAh g^(-1) after 150 cycles at a current density of 400 mAg^(-1). It achieves significant improvement in the electrochemical performance when compared with the raw materials and Si nanoparticle anodes.
基金supported by the Grants from National Natural Science Foundation of China(No.51172191,51002129 and 11074211)the National Basic Research Program of China(2012CB921303)the Hunan Provincial Innovation Foundation for Graduate(No.CX2012B265)
文摘Ultrathin MoS2 nanosheets were prepared in high yield using a facile and effective hydrothermal intercalation and exfoliation route. The products were characterized in detail using X-ray diffraction, scanning electron microscopy, transmission electron microscopy and Raman spectroscopy. The results show that the high yield of MoS2 nanosheets with good quality was successfully achieved and the dimensions of the immense nanosheets reached 1 μm-2/zm. As anode material for Li-ion batteries, the as-prepared MoS2 nanosheets electrodes exhibited a good initial capacity of 1190 mAh.g-l and excellent cyclic stability at constant current density of 50 mA.g-1. After 50 cycles, it still delivered reversibly sustained high capacities of 750 mAh.g-1.
基金financially supported by the National Natural Science Foundation of China (No.20873046)the Specialized Research Fund for the Doctoral Program of HigherEducation (No.200805740004)Natural Science Foundation of Guangdong Province (No.10351063101000001)
文摘TiO2-coated SnO2 (TCS) hollow spheres, which are new anode materials for lithium ion (Li-ion) batteries, were prepared and characterized with X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), cyclic voltammetry (CV), and galvanostatic charge/discharge tests. The results obtained from XRD, SEM, and TEM show that TiO2 can be uniforrrdy coated on the surface of SnO2 hollow spheres with the assistance of anionic surfactant. The cyclic voltammograms indicate that both TiO2 and SnO2 exhibit the activity for Li-ion storage. The charge/discharge tests show that the prepared TCS hollow spheres have a higher reversible coulomb efficiency and a better cycling stability than the uncoated SnO2 hollow spheres.
基金Jiangsu provincial financial support of Fundamental Conditions and Science and Technology for people’s livelihood for Jiangsu key laboratory of Advanced Metallic Materials(grant number BM2007204)the National Natural Science Foundation of China(grant number 21475021,21427807)+1 种基金the Natural Science Foundation of Jiangsu Province(grant number BK20141331)the Fundamental Research Funds for the Central Universities(grant number2242016K40083)
文摘Nanostructured metal oxides derived from metal organic frameworks have been shown to be promising materials for application in high energy density lithium ion batteries. In this work, porous nanostructured ZnCo2O4and Co3O4were synthesized by a facile and cost-effective approach via the calcination of MOF-74 precursors and tested as anode materials for lithium ion batteries. Compared with Co3O4, the electrochemical properties of the obtained porous nanostructured ZnCo2O4exhibit higher specific capacity, more excellent cycling stability and better rate capability. It demonstrates a reversible capacity of 1243.2 m Ah/g after 80 cycles at 100 m A/g and an excellent rate performance with high average discharge specific capacities of 1586.8, 994.6, 759.6 and 509.2 m Ah/g at 200, 400, 600 and 800 m A/g, respectively.The satisfactory electrochemical performances suggest that this porous nanostructured ZnCo2O4is potentially promising for application as an efficient anode material for lithium ion batteries.
基金supported by the Science Foundation of the National Key Laboratory of Science and Technology on Advanced Composites in Special Environmentsthe National Natural Science Foundation of China(12002109)+1 种基金the China Postdoctoral Science Foundation(2020M670898)the Heilongjiang Postdoctoral Fund(LBH-Z20060)。
文摘Separators have been gaining increasing attention to improve the performance of lithium ion batteries(LIBs),especially for high safe and long cycle life.However,commercial polyolefin separators still face the problems of rapid capacity decay and safety issues due to the poor wettability with electrolytes and low thermal stability.Herein,a novel composite separator is proposed by introducing a surfactant of sodium dodecyl thiosulfate(SDS)into the polytetrafluoroethylene(PTFE)substrate with the binder of polyacrylic acid(PAA)through the suction filtration method.The introduction of PAA/SDS enhances the adsorption energy between PTFE substrate and electrolyte through density functional theory calculations,which improves wettability and electrolyte uptake of the separator significantly.The asachieved composite separator enables the LIBs to own high Li^(+)conductivity(0.64×10^(-3)S cm^(-1))and Li^(+)transference number(0.63),further leading to a high capacity retention of 93.50%after 500 cycles at 1 C.In addition,the uniform and smooth surface morphology of Li metal employed the composite separator after cycling indicates that the lithium dendrites can be successfully inhibited.This work indicates a promising route for the preparation of a novel composite separator for high safe LIBs.
基金supported by the MOST(Grant No.2013CB934000,2014DFG71590,2011CB935902,2010DFA72760,2011CB711202,2013AA050903,2011AA11A257 and 2011AA11A254)China Postdoctoral Science Foundation(Grant No.2013M530599 and 2013M540929)+2 种基金Tsinghua University Initiative Scientific Research Program(Grant No.2010THZ08116,2011THZ08139,2011THZ01004 and 2012THZ08129)the State Key Laboratory of Automotive Safety and Energy(No.ZZ2012-011)Suzhou(Wujiang)Automotive Research Institute,Tsinghua University,Project No.2012WJ-A-01
文摘Surface chemical modification of polyolefin separators for lithium ion batteries is attempted to reduce the thermal shrinkage, which is im- portant for the battery energy density. In this study, we grafted organic/inorganic hybrid crosslinked networks on the separators, simply by grafting polymerization and condensation reaction. The considerable silicon-oxygen crosslinked heat-resistance networks are responsible for the reduced thermal shrinkage. The strong chemical bonds between networks and separators promise enough mechanical support even at high temperature. The shrinkage at 150 ℃ for 30 min in the mechanical direction was 38.6% and 4.6% for the pristine and present graft-modified separators, respectively. Meanwhile, the grafting organic-inorganic hybrid crosslink networks mainly occupied part of void in the internal pores of the separators, so the thicknesses of the graft-modified separators were similar with the pristine one. The half cells prepared with the modified separators exhibited almost identical electrochemical properties to those with the commercial separators, thus proving that, in order to enhance the thermal stability of lithium ion battery, this kind of grafting-modified separators may be a better alternative to conventional silica nanoparticle layers-coated polyolefin separators.
基金Supported by the Fund of the Science and Technology Department of Jilin Province, China(No. 2005415).
文摘A new composite material was fabricated by intercalating tin nanoparticles into graphite. The tin graphite intercalation compound(Sn-GIC) was prepared by the interactions of tin tetrachloride with KC8 (K-GIC) in tetrahydrofuran (THF). As the anode of lithium ion batteries, Sn-GIC presents a steady reversible capacity(363 mA·h/g) and a good cycling performance in comparison with Sn and SnO2, it suggests that the association of tin with graphite not only improves the reversible capacities, but also prevents the volume changes resulted from lithium insertion and extraction with tin during a charge-discharge process.
基金supported by funding from the National Research Foundation,Clean Energy Research Project(Grant Number:NRF2009EWT-CERP001036)
文摘Herein,we report on the synthesis and lithium storage properties of electrospun one-dimensional(1D) CuFe2O4 nanomaterials.1D CuFe2O4nanotubes and nanorods were fabricated by a single spinneret electrospinning method followed by thermal decomposition for removal of polymers from the precursor fibers.The as-prepared CuFe2O4 nanotubes with wall thickness of 50 nm presented diameters of 150 nm and lengths up to several millimeters.It was found that phase separation between the electrospun composite materials occured during the electrospinning process,while the as-spun precursor nanofibers composed of polyacrylonitrile(PAN),polyvinylpyrrolidone(PVP) and metal salts might possess a core-shell structure(PAN as the core and PVP/metal salts composite as the shell) and then transformed to a hollow structure after calcination.Moreover,as a demonstration of the functional properties of the 1D nanostructure.CuFe2O4 nanotubes and nanorods were investigated as anodes for lithium ion batteries(LIBs).It was demonstrated that CuFe2O4 nanotubes not only delivered a high reversible capacity of 816 mAh·g-1 at a current density of 200 mA·g-1over 50 cycles,but also showed superior rate capability with respect to counterpart nanorods.Probably,the enhanced electrochemical performance can be attributed to its high specific surface areas as well as the unique hollow structure.