Silicon(Si)with high theoretical capacity has attracted tremendous attention as the next-generation anode material for Li-ion batteries,but the huge expansion during cycling restricts its practical application.Designi...Silicon(Si)with high theoretical capacity has attracted tremendous attention as the next-generation anode material for Li-ion batteries,but the huge expansion during cycling restricts its practical application.Designing a low-cost,accessible robust network binder is a facile and effective approach to suppress the volume change effect and achieve the commercial application of Si anodes.Different previous studies focused on the network binder macromolecule main chain,this manuscript pays attention to the study of small-molecule cross-linker.Herein,cross-linked network binders using alginate acid and two kinds of cross-linkers,i.e.,D-sorbitol and isosorbide(Alg-DS and Alg-IS binders)are synthesized.It was found that not only the chemical structure of the cross-linker but also the physicochemical property,such as melting point affect greatly the mechanical properties of the network binder.As a result,the Si anode with an Alg-DS binder dried below the melting point of DS shows the best cycling stability with a high capacity of 2249.8 mA·h/g and a retention rate as high as 95.9%after 100 cycles.This study gives a new view to design robust network binders for stable Si anodes.展开更多
Silicon nanowires(Si NWs)have been widely researched as the best alternative to graphite anodes for the next-generation of high-performance lithium-ion batteries(LIBs)owing to their high capacity and low discharge pot...Silicon nanowires(Si NWs)have been widely researched as the best alternative to graphite anodes for the next-generation of high-performance lithium-ion batteries(LIBs)owing to their high capacity and low discharge potential.However,growing binder-free Si NW anodes with adequate mass loading and stable capacity is severely limited by the low surface area of planar current collectors(CCs),and is particularly challenging to achieve on standard pure-Cu substrates due to the ubiquitous formation of Li+inactive silicide phases.Here,the growth of densely-interwoven In-seeded Si NWs is facilitated by a thin-film of copper-silicide(CS)network in situ grown on a Cu-foil,allowing for a thin active NW layer(<10μm thick)and high areal loading(≈1.04 mg/cm^(2))binder-free electrode architecture.The electrode exhibits an average Coulombic efficiency(CE)of>99.6%and stable performance for>900 cycles with≈88.7%capacity retention.More significantly,it delivers a volumetric capacity of≈1086.1 m A h/cm^(3)at 5C.The full-cell versus lithium manganese oxide(LMO)cathode delivers a capacity of≈1177.1 m A h/g at 1C with a stable rate capability.This electrode architecture represents significant advances toward the development of binder-free Si NW electrodes for LIB application.展开更多
The ever-increasing environmental/energy crisis as well as the rapid upgrading of mobile devices had stimulated intensive research attention on promising alternative energy storage and conversion devices.Among these d...The ever-increasing environmental/energy crisis as well as the rapid upgrading of mobile devices had stimulated intensive research attention on promising alternative energy storage and conversion devices.Among these devices,alkali metal ion batteries,such as lithium-ion batteries(LIBs) had attracted increasing research attention due to its several advantages including,environmental friendliness,high power density,long cycle life and excellent reversibility.It had been widely used in consumer electronics,electric vehicles,and large power grids et ac.Silicon-based(silicon and their oxides,carbides) anodes had been widely studied.Its several advantages including low cost,high theoretical capacity,natural abundance,and environmental friendliness,which shows great potential as anodes of LIBs.In this review,we summarized the recently progress in the synthetic method of silicon matrix composites.The empirical method for prelithiation of silicon-based materials were also provided.Further,we also reviewed some novel characterization methods.Finally,the new design,preparation methods and properties of these nano materials were reviewed and compared.We hoped that this review can provide a general overview of recent progress and we briefly highlighted the current challenges and prospects,and will clarify the future trend of silicon anode LIBs research.展开更多
To mitigate the massive volume expansion of Si-based anode during the charge/discharge cycles,we synthesized a superstructure of Si@Co±NC composite via the carbonization of zeolite imidazolate frameworks incorpor...To mitigate the massive volume expansion of Si-based anode during the charge/discharge cycles,we synthesized a superstructure of Si@Co±NC composite via the carbonization of zeolite imidazolate frameworks incorporated with Si nanoparticles.The Si@Co±NC is comprised of Sinanoparticle core and N-doped/Co-incorporated carbon shell,and there is void space between the core and the shell.When using as anode material for LIBs,Si@Co±NC displayed a super performance with a charge/discharge capacity of 191.6/191.4 mA h g^(-1)and a coulombic efficiency of 100.1%at 1000 mA g^(-1)after 3000 cycles,and the capacity loss rate is 0.022%per cycle only.The excellent electrochemical property of Si@Co±NC is because its electronic conductivity is enhanced by doping the carbon shell with N atoms and by incorporating with Co particles,and the pathway of lithium ions transmission is shortened by the hollow structure and abundant mesopores in the carbon shell.Also,the volume expansion of Si nanoparticles is well accommodated in the void space and suppressed by the carbon host matrix.This work shows that,through designing a superstructure for the anode materials,we can synergistically reduce the work function and introduce the confinement effect,thus significantly enhancing the anode materials’electrochemical performance in LIBs.展开更多
The commercialized binder carboxymethyl cellulose sodium(CMC-Na)is considered unsuitable for micro-sized SiO_(x) anode as it cannot endure the large volume change to retain the conductive network during repeated charg...The commercialized binder carboxymethyl cellulose sodium(CMC-Na)is considered unsuitable for micro-sized SiO_(x) anode as it cannot endure the large volume change to retain the conductive network during repeated charge/discharge cycles.Herein,a small amount of silicon nanoparticles(SiNPs)is added during slurry preparation process as“nano-combs”to unfold the convoluted CMC-Na polymer chains so that they undergo a coilto-stretch transition by interaction between polar groups(e.g.,-OH,-COONa)of polymer and SiNPs’large surface.Through maximizing the utilization of binders,a uniform conductive network is constructed with increased interfacial contact with micro-sized SiO_(x).As a result,the SiO_(x) electrode with optimized(10 wt%)SiNPs addition shows significantly improved initial capacity and cycling performance.Through revisiting CMCNa,a currently deemed unqualified binder in SiO_(x) anode,this work gives a brand-new perspective on the failing mechanism of Si-based anode materials and an improving strategy for electrode preparation.展开更多
Replacing the conventional carbonate electrolyte by solid-state electrolyte (SSE) will offer improved safety for lithium-ion batteries.To further improve the energy density,Silicon (Si) is attractive for next generati...Replacing the conventional carbonate electrolyte by solid-state electrolyte (SSE) will offer improved safety for lithium-ion batteries.To further improve the energy density,Silicon (Si) is attractive for next generation solid-state battery (SSB) because of its high specific capacity and low cost.High energy density and safe Si-based SSB,however,is plagued by large volume change that leads to poor mechanical stability and slow lithium ions transportation at the multiple interfaces between Si and SSE.Herein,we designed a self-integrated and monolithic Si/two dimensional layered T_(3)C_(2)T_(x)(MXene,T_(x) stands for terminal functional groups) electrode architecture with interfacial nitrogen engineering.During a heat treatment process,the polyacrylonitrile not only converts into amorphous carbon (a-C) that shells Si but also forms robust interfacial nitrogen chemical bonds that anchors Si and MXene.During repeated lithiation and delithiation processes,the robust interfacial engineered Si/MXene configuration enhances the mechanical adhesion between Si and MXene that improves the structure stability but also contributes to form stable solid-electrolyte interphase (SEI).In addition,the N-MXene provides fast lithium ions transportation pathways.Consequently,the Si/MXene with interfacial nitrogen engineering (denoted as Si-N-MXene) deliveres high-rate performance with a specific capacity of 1498 m Ah g^(-1) at a high current of 6.4 A g^(-1).A Si-N-MXene/NMC full cell exhibited a capacity retention of 80.5%after 200 cycles.The Si-N-MXene electrode is also applied to SSB and shows a relative stable cycling over 100 cycles,demonstrating the versatility of this concept.展开更多
Silicon is recognized as the most advantageous next-generation anode material for LIBs in terms of its extremely high theoretical capacity and appropriate operating voltage.However,the application of Si anode is limit...Silicon is recognized as the most advantageous next-generation anode material for LIBs in terms of its extremely high theoretical capacity and appropriate operating voltage.However,the application of Si anode is limited by huge volume expansion emerging with cycling,which in turn induces the collapse of the electrode structure,resulting in rapid capacity decay.Here,we report a strategy using self-swelling artificial laponite to prepare a laponite/MXene/CNT composite framework with both rigidity and flexibility,which can excellently address these challenges of Si anode.The self-swelling artificial laponite participates in the construction of hierarchical and porous structures,providing sufficient buffer space to mitigate the volume expansion of the LixSi alloying reaction.Meanwhile,tough and tightly cross-linked silicate nanosheets can improve the mechanical strength of the framework for strong structural stability.More importantly,the negative charge between the layers of artificial laponite can effectively promote fast Li-ion transport in the electrode.This free-standing silicon anode enables the preparation of high areal capacity electrodes to further enhance the energy density of LIBs and a higher reversible capacity of 2381.8 mAh/g at 0.1 C after 50 cycles with an initial coulombic of 85.6%.This work provides a simple and practical fabrication strategy for developing high-performance Si-based batteries,which can speed up their commercialization.展开更多
Si-based materials have shown great potential as lithium-ion batteries(LIBs)anodes due to their natural reserves and high theoretical capacity.However,the large volume changes during cycles and poor conductivity of Si...Si-based materials have shown great potential as lithium-ion batteries(LIBs)anodes due to their natural reserves and high theoretical capacity.However,the large volume changes during cycles and poor conductivity of Si lead to rapid capacity decay and poor cycling stability,ultimately limiting their commercial applications.Herein,we have skillfully utilized the microporous MCM-22 zeolite as the unique silicon source to produce porous Si(pSi)sheets by a simple magnesiothermic reduction,followed by a carbon coating and further Ti_(3)C_(2)T_(x)MXene assembly,obtaining the ternary pSi@NC@TNSs composite.In the design,porous Si sheets provide more active sites and shorten Li-ion transport paths for electrochemical reactions.The N-doped carbon(NC)layer serves as a bonding layer to couple pSi and Ti_(3)C_(2)T_(x).The conductive network formed by 2D Ti_(3)C_(2)T_(x)and medium NC layer effectively enhances the overall charge transport of the electrode material,and helps to stabilize the electrode structure.Therefore,the as-made pSi@NC@TNSs anode delivers an improved lithium storage performance,exhibiting a high reversible capacity of 925 mAh/g at 0.5 A/g after 100 cycles.This present strategy provides an effective way towards high-performance Si-based anodes for LIBs.展开更多
Single wall carbon nanotube(SWCNT)additives were formulated into(im-Si-graphite composite electrodes and tested in both half cells and full cells with high nickel cathodes.The critical role of small amount of SWCNT ad...Single wall carbon nanotube(SWCNT)additives were formulated into(im-Si-graphite composite electrodes and tested in both half cells and full cells with high nickel cathodes.The critical role of small amount of SWCNT addition(0.2 wt%)was found for significantly improving delithiation capacity,first cycle coulombic efficiency(FCE),and capacity retention.Particularly,Si(10 wt%)-graphite electrode exhibits 560 mAh/g delithiation capacity and 92%FCE at 0.2 C during the first chargedischarge cycle,and 91%capacity retention after 50 cycles(0.5 C)in a half cell.Scanning electron microscope(SEM)was used to illustrate the electrode morphology,compositions and promoting function of the SWCNT additives.In addition,full cells assembled with high nickel-NCM811 cathodes and fim-Si-graphite composite anodes were evaluated for the consistence between half and full cell performance,and the consideration for potential commercial application.Finally,criteria to assess Si-containing anodes are proposed and discussed from an industrial perspective.展开更多
To conquer inherently low conductivity,volume swelling,and labile solid electrolyte interphase(SEI)films of Si anode in lithium ion battery(LIBs),it is widely accepted that appropriate structure design of Si-C hybrids...To conquer inherently low conductivity,volume swelling,and labile solid electrolyte interphase(SEI)films of Si anode in lithium ion battery(LIBs),it is widely accepted that appropriate structure design of Si-C hybrids performs effectively,especially for nanosize Si particles.Herein,inspired by the sturdy construction of high-rise buildings,a mansion-like 3D structured Si@SiO_(2)/PBC/RGO(SSPBG)with separated rooms is developed based on 0D core-shell Si@SiO_(2),1D pyrolytic bacterial cellulose(PBC)and 2D reduced graphene oxide(RGO).Therefore,these hierarchical protectors operate synergistically to inhibit the inevitable volume changes during electrochemical process.Specifically,tightly coated SiO_(2)shell as the first protective layer could buffer the volume expansion and reduce detrimental pulverization of Si NPs.Furthermore,flexible spring-like PBC and ultra-fine RGO sheets perform as securer barriers and skeleton which will counteract the microstructure strain and accelerate electron transfer at the same time.Remarkably,the self-supporting electrode realizes a distinguished performance of 901 mAh g^(-1)at 2 A g^(-1)for 500 cycles.When matched with LiFePO4 cathodes,high stability of more than 100 cycles has been realized for the full batteries.展开更多
The low yield of MXene is normally related to the delaminating step,contributing to the key technical challenges in moving toward industrial applications.Here,a shearing-force-driven strategy is proposed for re-exfoli...The low yield of MXene is normally related to the delaminating step,contributing to the key technical challenges in moving toward industrial applications.Here,a shearing-force-driven strategy is proposed for re-exfoliating waste MXene residue to prepare oxidatively stable MXene composites in a low-cost manner,where the strong shear stress in the assisted solvent,such as carbon nanotubes(CNTs),chitosan(CS),and polyacrylamide(PAM)aqueous solutions,acts on the surface of MXene(Ti_(3)C_(2)T_(x))through coordination between hydroxyl and Ti atoms,resulting in a rapid and efficient exfoliation of waste Ti_(3)C_(2)T_(x)residue under stirring.Furthermore,this formed coordinate bond helps to stabilize the low-valent Ti atoms on the surface of MXene,thereby enhancing the oxidative stability of Ti_(3)C_(2)T_(x).Besides,the CNT@MXene composite is selected to construct a free-standing membrane to encapsulate Si nanoparticles,achieving a high and reversible capacity after 50 cycles.This work supports the concept of valorizing waste and adopts a fluid shear forceassisted method to re-exfoliate waste residues,which greatly reduces the cost of processing and improves the chemical stability of MXene.More importantly,this work has uncovered a new direction for the commercialization of MXene composites and has significantly improved the realworld applications of MXene-based materials.展开更多
Silicon(Si)holds promise as an anode material for lithium-ion batteries(LIBs)as it is widely avail-able and characterized by high specific capacity and suitable working potential.However,the relatively low electrical ...Silicon(Si)holds promise as an anode material for lithium-ion batteries(LIBs)as it is widely avail-able and characterized by high specific capacity and suitable working potential.However,the relatively low electrical conductivity of Si and the significantly high extent of volume expansion realized dur-ing lithiation hinder its practical application.We prepared N-doped carbon polyhedral micro cage en-capsulated Si nanoparticles derived from Co-Mo bimetal metal-organic framework(MOFs)(denoted as Si/CoMo@NCP)and explored their lithium storage performance as anode materials to address these prob-lems.The Si/CoMo@NCP anode exhibited a high reversible lithium storage capacity(1013 mAh g^(−1)at 0.5 A g^(−1)after 100 cycles),stable cycle performance(745 mAh g^(−1)at 1 A g^(−1)after 400 cycles),and excellent rate performance(723 mAh g^(−1)at 2 A g^(−1)).Also,the constructed the full-cell NCM 811//Si/CoMo@NCP exhibited well reversible capacity.The excellent electrochemical performances of Si/CoMo@NCP were at-tributed to two unique properties.The encapsulation of NCP with doped nitrogen and porous structural carbon improves the electrical conductivity and cycling stability of the molecules.The introductions of metallic cobalt and its oxides help to improve the rate capability and lithiation capacity of the materials following multi-electron reaction mechanisms.展开更多
Silicon/carbon composites are promising alternatives to current graphite anodes in commercial lithiumion batteries(LIBs)because of their high capacity and excellent safety.Nevertheless,the unsatisfactory fastcharging ...Silicon/carbon composites are promising alternatives to current graphite anodes in commercial lithiumion batteries(LIBs)because of their high capacity and excellent safety.Nevertheless,the unsatisfactory fastcharging capability and cycle stability of Si/C composites caused by slow charge transport capability and huge volume change under industrial electrode conditions severely hamper their development.Here,a novel Si/C anode was fabricated by homogeneously depositing amorphous C-Si nanolayers on graphite(C-Si@graphite).C-Si nanolayers with uniformly dispersed sub-nanometer Si particles in 3D carbon skeleton significantly boost electron and Li-ion transport and efficiently relieve Si's agglomeration and volume change.As a result,the tailored C-Si@graphite electrodes show an excellent rate capacity(760.3 mAh·g^(-1)at 5.0C)and long cycle life of over 1000 cycles at 1.0C and800 cycles at 2.0C under industrial electrode conditions.In addition,the assembled full cells(C-Si@graphite,anode;Li[Ni_(0.8)Co_(0.1)Mn_(0.1)]O_(2),cathode)present superior fastcharging capability(240.4 Wh·kg^(-1),charging for16.2 min,3.0C)and long cycle life(80.7%capacity retention after 500 cycles at 1.0C),demonstrating the massive potential of C-Si@graphite for practical application.展开更多
Severe volume expansion and inherently poor lithium ion transmission are two major problems of silicon anodes.To address these issues,we proposed a pomegranate-type Si/C composite anode with highly dispersed tiny sili...Severe volume expansion and inherently poor lithium ion transmission are two major problems of silicon anodes.To address these issues,we proposed a pomegranate-type Si/C composite anode with highly dispersed tiny silicon particles as the core assisted by small amount of SiC.Skillfully exploiting the high heat from magnesiothermic reduction,SiC can assist the good dispersion of silicon and provide good interface compatibility and chemical stability.The silicon anchored to the carbon shell provides multipoint contact mode,that together with the carbon shell frame,significantly promoting the transfer of dual charge.Besides,the pomegranate-type microcluster structure also improves the tap density of the electrode,reduces the direct contact area between active material and electrolyte,and enhances the electrochemical performance.展开更多
The application of Si as the anode materials for lithium-ion batteries(LIBs) is still severely hindered by the rapid capacity decay due to the structural damage caused by large volume change(> 300%) during cycling....The application of Si as the anode materials for lithium-ion batteries(LIBs) is still severely hindered by the rapid capacity decay due to the structural damage caused by large volume change(> 300%) during cycling. Herein, a three-dimensional(3 D) aerogel anode of Si@carbon@graphene(SCG) is rationally constructed via a polydopamine-assisted strategy. Polydopamine is coated on Si nanoparticles to serve as an interface linker to initiate the assembly of Si and graphene oxide, which plays a crucial role in the successful fabrication of SCG aerogels. After annealing the polydopamine is converted into N-doped carbon(N-carbon) coatings to protect Si materials. The dual protection from N-carbon and graphene aerogels synergistically improves the structural stability and electronic conductivity of Si, thereby leading to the significantly improved lithium storage properties. Electrochemical tests show that the SCG with optimized graphene content delivers a high capacity(712 m Ah/g at 100 m A/g) and robust cycling stability(402 m Ah/g at 1 A/g after 1500 cycles). Furthermore, the full cell using SCG aerogels as anode exhibits a reversible capacity of 187.6 m Ah/g after 80 cycles at 0.1 A/g. This work provides a plausible strategy for developing Si anode in LIBs.展开更多
Porous Si can be synthesized from diverse silica(SiO_(2))via magnesiothermic reduction technology and widely employed as potential anode material in lithium ion batteries.However,concerns regarding the influence of re...Porous Si can be synthesized from diverse silica(SiO_(2))via magnesiothermic reduction technology and widely employed as potential anode material in lithium ion batteries.However,concerns regarding the influence of residual silicon oxide(SiO_(x))component on resulted Si anode after reduction are still lacked.In this work,we intentionally fabricate a cauliflower-like silicon/silicon oxide(CF-Si/SiO_(x))particles from highly porous SiO_(2)spheres through insufficient magnesiothermic reduction,where residual SiO_(x)component and internal space play an important role in preventing the structural deformation of secondary bulk and restraining the expansion of Si phase.Moreover,the hierarchically structured CF-Si/SiO_(x)exhibits uniformly-dispersed channels,which can improve ion transport and accommodate large volume expansion,simultaneously.As a result,the CF-Si/SiO_(x)-700 anode shows excellent electrochemical performance with a specific capacity of^1,400 mA·h·g^(−1)and a capacity retention of 98%after 100 cycles at the current of 0.2 A·g^(−1).展开更多
Inspired by the natural corn structure,a Si@hollow graphene shell@graphene(Si@GS@G)anode material was prepared in which silicon nanoparticles were preliminarily anchored onto the surface of an elastic graphene shell a...Inspired by the natural corn structure,a Si@hollow graphene shell@graphene(Si@GS@G)anode material was prepared in which silicon nanoparticles were preliminarily anchored onto the surface of an elastic graphene shell and further constrained using graphene sheets.Hollow graphene oxide shells with abundant surficial hydrogen bonds,which were synthesized using a novel bottom-up method,were used as an intermediate material to anchor positively charged silicon nanoparticles via electrostatic attraction and achieve a rational spatial distribution.The inner hollow graphene shell anchorage and outer graphene constraint synergistically constituted a porous and robust conductive corn-like structure.The as-fabricated Si@GS@G anode afforded efficient electron and ion transport pathways and improved structural stability,thereby enhancing Li+storage capability(505 mAh·g^(−1)at 10 A·g^(−1))and extending the lifespan compared to the single hollow graphene shell or graphene sheet-protected Si anode(72%capacity retention after 500 cycles).The improved kinetics of the Si@GS@G anode were investigated using electro impedance spectroscopy,galvanostatic intermittent titration,and pseudocapacitance contribution rate analysis,and the structural evolution was analyzed using ex situ electron microscopy.This study proposes a novel hollow graphene oxide shell as an activated intermediate material for designing a porous electrode structure that facilitates an enhanced electrochemical performance.展开更多
基金This work was supported by the National Natural Science Foundation of China(Nos.51772162,51802171)the Taishan Scholars Program of China,the Natural Science Foundation of Shandong Province,China(No.ZR2018BB031)+1 种基金the Youth Innovation of Shandong Higher Education Institutions,China(No.2019KJC004)the Outstanding Youth Foundation of Shandong Province,China(No.ZR2019JQ14).
文摘Silicon(Si)with high theoretical capacity has attracted tremendous attention as the next-generation anode material for Li-ion batteries,but the huge expansion during cycling restricts its practical application.Designing a low-cost,accessible robust network binder is a facile and effective approach to suppress the volume change effect and achieve the commercial application of Si anodes.Different previous studies focused on the network binder macromolecule main chain,this manuscript pays attention to the study of small-molecule cross-linker.Herein,cross-linked network binders using alginate acid and two kinds of cross-linkers,i.e.,D-sorbitol and isosorbide(Alg-DS and Alg-IS binders)are synthesized.It was found that not only the chemical structure of the cross-linker but also the physicochemical property,such as melting point affect greatly the mechanical properties of the network binder.As a result,the Si anode with an Alg-DS binder dried below the melting point of DS shows the best cycling stability with a high capacity of 2249.8 mA·h/g and a retention rate as high as 95.9%after 100 cycles.This study gives a new view to design robust network binders for stable Si anodes.
基金funded by the Science Foundation Ireland (SFI)under the Principal Investigator Program under contract No.11PI-1148,16/IA/4629 and SFI 16/M-ERA/3419funding under the European Union’s Horizon 2020 Research and Innovation Program+7 种基金grant agreement No.814464 (Si-DRIVE project)IRCLA/2017/285 and SFI Research Centres AMBER,Ma REI and CONFIRM 12/RC/2302_P2,12/RC/2278_P2,and 16/RC/3918SFI for SIRG grant No.18/SIRG/5484support from the Sustainable Energy Authority of Ireland through the Research Development and Demonstration Funding Program (Grant No.19/RDD/548)Enterprise Ireland through the Innovation Partnership Program (Grant No.IP 20190910)support from the SFI Research Centre Ma REI (award reference No.12/RC/2302_P2)support from the SFI Industry RD&I Fellowship Program (21/IRDIF/9876)the EU Horizon 2020 research and innovation program under the Marie Sklodowska-Curie Individual Fellowship Grant (843621)。
文摘Silicon nanowires(Si NWs)have been widely researched as the best alternative to graphite anodes for the next-generation of high-performance lithium-ion batteries(LIBs)owing to their high capacity and low discharge potential.However,growing binder-free Si NW anodes with adequate mass loading and stable capacity is severely limited by the low surface area of planar current collectors(CCs),and is particularly challenging to achieve on standard pure-Cu substrates due to the ubiquitous formation of Li+inactive silicide phases.Here,the growth of densely-interwoven In-seeded Si NWs is facilitated by a thin-film of copper-silicide(CS)network in situ grown on a Cu-foil,allowing for a thin active NW layer(<10μm thick)and high areal loading(≈1.04 mg/cm^(2))binder-free electrode architecture.The electrode exhibits an average Coulombic efficiency(CE)of>99.6%and stable performance for>900 cycles with≈88.7%capacity retention.More significantly,it delivers a volumetric capacity of≈1086.1 m A h/cm^(3)at 5C.The full-cell versus lithium manganese oxide(LMO)cathode delivers a capacity of≈1177.1 m A h/g at 1C with a stable rate capability.This electrode architecture represents significant advances toward the development of binder-free Si NW electrodes for LIB application.
基金financially supported by the International Science & Technology Cooperation Program of China under 2019YFE0100200the NSAF (Grant No. U1930113)+2 种基金the Beijing Natural Science Foundation (Grant No. L182022)the 13th Five-Year Plan of Advance Research and Sharing Techniques by the Equipment Department (41421040202)the SAST (2018-114).
文摘The ever-increasing environmental/energy crisis as well as the rapid upgrading of mobile devices had stimulated intensive research attention on promising alternative energy storage and conversion devices.Among these devices,alkali metal ion batteries,such as lithium-ion batteries(LIBs) had attracted increasing research attention due to its several advantages including,environmental friendliness,high power density,long cycle life and excellent reversibility.It had been widely used in consumer electronics,electric vehicles,and large power grids et ac.Silicon-based(silicon and their oxides,carbides) anodes had been widely studied.Its several advantages including low cost,high theoretical capacity,natural abundance,and environmental friendliness,which shows great potential as anodes of LIBs.In this review,we summarized the recently progress in the synthetic method of silicon matrix composites.The empirical method for prelithiation of silicon-based materials were also provided.Further,we also reviewed some novel characterization methods.Finally,the new design,preparation methods and properties of these nano materials were reviewed and compared.We hoped that this review can provide a general overview of recent progress and we briefly highlighted the current challenges and prospects,and will clarify the future trend of silicon anode LIBs research.
基金financial supports by the National Natural Science Foundation of China(No.51772295)support of GTIIT for the collaboration,and the start-up fund provided by GTIIT
文摘To mitigate the massive volume expansion of Si-based anode during the charge/discharge cycles,we synthesized a superstructure of Si@Co±NC composite via the carbonization of zeolite imidazolate frameworks incorporated with Si nanoparticles.The Si@Co±NC is comprised of Sinanoparticle core and N-doped/Co-incorporated carbon shell,and there is void space between the core and the shell.When using as anode material for LIBs,Si@Co±NC displayed a super performance with a charge/discharge capacity of 191.6/191.4 mA h g^(-1)and a coulombic efficiency of 100.1%at 1000 mA g^(-1)after 3000 cycles,and the capacity loss rate is 0.022%per cycle only.The excellent electrochemical property of Si@Co±NC is because its electronic conductivity is enhanced by doping the carbon shell with N atoms and by incorporating with Co particles,and the pathway of lithium ions transmission is shortened by the hollow structure and abundant mesopores in the carbon shell.Also,the volume expansion of Si nanoparticles is well accommodated in the void space and suppressed by the carbon host matrix.This work shows that,through designing a superstructure for the anode materials,we can synergistically reduce the work function and introduce the confinement effect,thus significantly enhancing the anode materials’electrochemical performance in LIBs.
基金support from the National Key R&D Program of China(2016YFB0700600,2020YFB0704500)China Postdoctoral Science Foundation(2019M660317)+1 种基金Engineering and Physical Sciences Research Council,UK(EP/S000933/1)Shenzhen Science and Technology Program(Grant No.RCBS20200714114820077).
文摘The commercialized binder carboxymethyl cellulose sodium(CMC-Na)is considered unsuitable for micro-sized SiO_(x) anode as it cannot endure the large volume change to retain the conductive network during repeated charge/discharge cycles.Herein,a small amount of silicon nanoparticles(SiNPs)is added during slurry preparation process as“nano-combs”to unfold the convoluted CMC-Na polymer chains so that they undergo a coilto-stretch transition by interaction between polar groups(e.g.,-OH,-COONa)of polymer and SiNPs’large surface.Through maximizing the utilization of binders,a uniform conductive network is constructed with increased interfacial contact with micro-sized SiO_(x).As a result,the SiO_(x) electrode with optimized(10 wt%)SiNPs addition shows significantly improved initial capacity and cycling performance.Through revisiting CMCNa,a currently deemed unqualified binder in SiO_(x) anode,this work gives a brand-new perspective on the failing mechanism of Si-based anode materials and an improving strategy for electrode preparation.
基金supported by the National Natural Science Foundation of China(51902165,12004145,52072323)the Natural Science Foundation of Jiangsu Province(BK20200800)+2 种基金the Natural Science Foundation of Jiangxi Province(20192ACBL20048)the Jiangxi Provincial Natural Science Foundation(20212BAB214032)the Nanjing Science&Technology Innovation Project for Personnel Studying Abroad。
文摘Replacing the conventional carbonate electrolyte by solid-state electrolyte (SSE) will offer improved safety for lithium-ion batteries.To further improve the energy density,Silicon (Si) is attractive for next generation solid-state battery (SSB) because of its high specific capacity and low cost.High energy density and safe Si-based SSB,however,is plagued by large volume change that leads to poor mechanical stability and slow lithium ions transportation at the multiple interfaces between Si and SSE.Herein,we designed a self-integrated and monolithic Si/two dimensional layered T_(3)C_(2)T_(x)(MXene,T_(x) stands for terminal functional groups) electrode architecture with interfacial nitrogen engineering.During a heat treatment process,the polyacrylonitrile not only converts into amorphous carbon (a-C) that shells Si but also forms robust interfacial nitrogen chemical bonds that anchors Si and MXene.During repeated lithiation and delithiation processes,the robust interfacial engineered Si/MXene configuration enhances the mechanical adhesion between Si and MXene that improves the structure stability but also contributes to form stable solid-electrolyte interphase (SEI).In addition,the N-MXene provides fast lithium ions transportation pathways.Consequently,the Si/MXene with interfacial nitrogen engineering (denoted as Si-N-MXene) deliveres high-rate performance with a specific capacity of 1498 m Ah g^(-1) at a high current of 6.4 A g^(-1).A Si-N-MXene/NMC full cell exhibited a capacity retention of 80.5%after 200 cycles.The Si-N-MXene electrode is also applied to SSB and shows a relative stable cycling over 100 cycles,demonstrating the versatility of this concept.
基金supported by the National Natural Science Foundation of China(No.51871113)Natural Science Foundation of Jiangsu Province(No.BK20200047).
文摘Silicon is recognized as the most advantageous next-generation anode material for LIBs in terms of its extremely high theoretical capacity and appropriate operating voltage.However,the application of Si anode is limited by huge volume expansion emerging with cycling,which in turn induces the collapse of the electrode structure,resulting in rapid capacity decay.Here,we report a strategy using self-swelling artificial laponite to prepare a laponite/MXene/CNT composite framework with both rigidity and flexibility,which can excellently address these challenges of Si anode.The self-swelling artificial laponite participates in the construction of hierarchical and porous structures,providing sufficient buffer space to mitigate the volume expansion of the LixSi alloying reaction.Meanwhile,tough and tightly cross-linked silicate nanosheets can improve the mechanical strength of the framework for strong structural stability.More importantly,the negative charge between the layers of artificial laponite can effectively promote fast Li-ion transport in the electrode.This free-standing silicon anode enables the preparation of high areal capacity electrodes to further enhance the energy density of LIBs and a higher reversible capacity of 2381.8 mAh/g at 0.1 C after 50 cycles with an initial coulombic of 85.6%.This work provides a simple and practical fabrication strategy for developing high-performance Si-based batteries,which can speed up their commercialization.
基金financially supported by the Natural Science Foundation of Shanghai(No.23ZR1423800)Shuguang Program from Shanghai Education Development Foundation and Shanghai Municipal Education Commission(No.18SG35)Key Laboratory of Advanced Energy Materials Chemistry(Ministry of Education),Nankai University.
文摘Si-based materials have shown great potential as lithium-ion batteries(LIBs)anodes due to their natural reserves and high theoretical capacity.However,the large volume changes during cycles and poor conductivity of Si lead to rapid capacity decay and poor cycling stability,ultimately limiting their commercial applications.Herein,we have skillfully utilized the microporous MCM-22 zeolite as the unique silicon source to produce porous Si(pSi)sheets by a simple magnesiothermic reduction,followed by a carbon coating and further Ti_(3)C_(2)T_(x)MXene assembly,obtaining the ternary pSi@NC@TNSs composite.In the design,porous Si sheets provide more active sites and shorten Li-ion transport paths for electrochemical reactions.The N-doped carbon(NC)layer serves as a bonding layer to couple pSi and Ti_(3)C_(2)T_(x).The conductive network formed by 2D Ti_(3)C_(2)T_(x)and medium NC layer effectively enhances the overall charge transport of the electrode material,and helps to stabilize the electrode structure.Therefore,the as-made pSi@NC@TNSs anode delivers an improved lithium storage performance,exhibiting a high reversible capacity of 925 mAh/g at 0.5 A/g after 100 cycles.This present strategy provides an effective way towards high-performance Si-based anodes for LIBs.
文摘Single wall carbon nanotube(SWCNT)additives were formulated into(im-Si-graphite composite electrodes and tested in both half cells and full cells with high nickel cathodes.The critical role of small amount of SWCNT addition(0.2 wt%)was found for significantly improving delithiation capacity,first cycle coulombic efficiency(FCE),and capacity retention.Particularly,Si(10 wt%)-graphite electrode exhibits 560 mAh/g delithiation capacity and 92%FCE at 0.2 C during the first chargedischarge cycle,and 91%capacity retention after 50 cycles(0.5 C)in a half cell.Scanning electron microscope(SEM)was used to illustrate the electrode morphology,compositions and promoting function of the SWCNT additives.In addition,full cells assembled with high nickel-NCM811 cathodes and fim-Si-graphite composite anodes were evaluated for the consistence between half and full cell performance,and the consideration for potential commercial application.Finally,criteria to assess Si-containing anodes are proposed and discussed from an industrial perspective.
基金supported by the National Natural Science Foundation of China(51802171,52072197)Outstanding Youth Foundation of Shandong Province(ZR2019JQ14)+1 种基金Taishan Scholar Young Talent Program(tsqn201909114)Major Basic Research Program of Natural Science Foundation of Shandong Province(ZR2020ZD09)。
文摘To conquer inherently low conductivity,volume swelling,and labile solid electrolyte interphase(SEI)films of Si anode in lithium ion battery(LIBs),it is widely accepted that appropriate structure design of Si-C hybrids performs effectively,especially for nanosize Si particles.Herein,inspired by the sturdy construction of high-rise buildings,a mansion-like 3D structured Si@SiO_(2)/PBC/RGO(SSPBG)with separated rooms is developed based on 0D core-shell Si@SiO_(2),1D pyrolytic bacterial cellulose(PBC)and 2D reduced graphene oxide(RGO).Therefore,these hierarchical protectors operate synergistically to inhibit the inevitable volume changes during electrochemical process.Specifically,tightly coated SiO_(2)shell as the first protective layer could buffer the volume expansion and reduce detrimental pulverization of Si NPs.Furthermore,flexible spring-like PBC and ultra-fine RGO sheets perform as securer barriers and skeleton which will counteract the microstructure strain and accelerate electron transfer at the same time.Remarkably,the self-supporting electrode realizes a distinguished performance of 901 mAh g^(-1)at 2 A g^(-1)for 500 cycles.When matched with LiFePO4 cathodes,high stability of more than 100 cycles has been realized for the full batteries.
基金financially supported by the National Natural Science Foundation of China(No.52102470)the Natural Science Foundation of Jiangsu Province(No.BK20200047)+1 种基金General Project of Natural Science Research in Jiangsu Universities(22KJB15003)Scientific Research Project for Doctor Degree Teachers of Jiangsu Normal University(21XSRX003)。
文摘The low yield of MXene is normally related to the delaminating step,contributing to the key technical challenges in moving toward industrial applications.Here,a shearing-force-driven strategy is proposed for re-exfoliating waste MXene residue to prepare oxidatively stable MXene composites in a low-cost manner,where the strong shear stress in the assisted solvent,such as carbon nanotubes(CNTs),chitosan(CS),and polyacrylamide(PAM)aqueous solutions,acts on the surface of MXene(Ti_(3)C_(2)T_(x))through coordination between hydroxyl and Ti atoms,resulting in a rapid and efficient exfoliation of waste Ti_(3)C_(2)T_(x)residue under stirring.Furthermore,this formed coordinate bond helps to stabilize the low-valent Ti atoms on the surface of MXene,thereby enhancing the oxidative stability of Ti_(3)C_(2)T_(x).Besides,the CNT@MXene composite is selected to construct a free-standing membrane to encapsulate Si nanoparticles,achieving a high and reversible capacity after 50 cycles.This work supports the concept of valorizing waste and adopts a fluid shear forceassisted method to re-exfoliate waste residues,which greatly reduces the cost of processing and improves the chemical stability of MXene.More importantly,this work has uncovered a new direction for the commercialization of MXene composites and has significantly improved the realworld applications of MXene-based materials.
基金the National Natural Science Foundation of China(NSFC,No.21203116)the Innovation Capability Support Plan of Shaanxi Province(Grant No.2022WGZJ-25)the Foundation of Shaanxi University of Science and Tech-nology(Grant No.210210031 and 210210032).
文摘Silicon(Si)holds promise as an anode material for lithium-ion batteries(LIBs)as it is widely avail-able and characterized by high specific capacity and suitable working potential.However,the relatively low electrical conductivity of Si and the significantly high extent of volume expansion realized dur-ing lithiation hinder its practical application.We prepared N-doped carbon polyhedral micro cage en-capsulated Si nanoparticles derived from Co-Mo bimetal metal-organic framework(MOFs)(denoted as Si/CoMo@NCP)and explored their lithium storage performance as anode materials to address these prob-lems.The Si/CoMo@NCP anode exhibited a high reversible lithium storage capacity(1013 mAh g^(−1)at 0.5 A g^(−1)after 100 cycles),stable cycle performance(745 mAh g^(−1)at 1 A g^(−1)after 400 cycles),and excellent rate performance(723 mAh g^(−1)at 2 A g^(−1)).Also,the constructed the full-cell NCM 811//Si/CoMo@NCP exhibited well reversible capacity.The excellent electrochemical performances of Si/CoMo@NCP were at-tributed to two unique properties.The encapsulation of NCP with doped nitrogen and porous structural carbon improves the electrical conductivity and cycling stability of the molecules.The introductions of metallic cobalt and its oxides help to improve the rate capability and lithiation capacity of the materials following multi-electron reaction mechanisms.
基金financially supported by Guangdong Basic and Applied Basic Research Foundation (No.2020A1515110762)。
文摘Silicon/carbon composites are promising alternatives to current graphite anodes in commercial lithiumion batteries(LIBs)because of their high capacity and excellent safety.Nevertheless,the unsatisfactory fastcharging capability and cycle stability of Si/C composites caused by slow charge transport capability and huge volume change under industrial electrode conditions severely hamper their development.Here,a novel Si/C anode was fabricated by homogeneously depositing amorphous C-Si nanolayers on graphite(C-Si@graphite).C-Si nanolayers with uniformly dispersed sub-nanometer Si particles in 3D carbon skeleton significantly boost electron and Li-ion transport and efficiently relieve Si's agglomeration and volume change.As a result,the tailored C-Si@graphite electrodes show an excellent rate capacity(760.3 mAh·g^(-1)at 5.0C)and long cycle life of over 1000 cycles at 1.0C and800 cycles at 2.0C under industrial electrode conditions.In addition,the assembled full cells(C-Si@graphite,anode;Li[Ni_(0.8)Co_(0.1)Mn_(0.1)]O_(2),cathode)present superior fastcharging capability(240.4 Wh·kg^(-1),charging for16.2 min,3.0C)and long cycle life(80.7%capacity retention after 500 cycles at 1.0C),demonstrating the massive potential of C-Si@graphite for practical application.
基金the Shenzhen Science and Technology Projects(No.JCYJ20180306172957494)National Natural Science Foundation of China(No.5187224)for financial support.
文摘Severe volume expansion and inherently poor lithium ion transmission are two major problems of silicon anodes.To address these issues,we proposed a pomegranate-type Si/C composite anode with highly dispersed tiny silicon particles as the core assisted by small amount of SiC.Skillfully exploiting the high heat from magnesiothermic reduction,SiC can assist the good dispersion of silicon and provide good interface compatibility and chemical stability.The silicon anchored to the carbon shell provides multipoint contact mode,that together with the carbon shell frame,significantly promoting the transfer of dual charge.Besides,the pomegranate-type microcluster structure also improves the tap density of the electrode,reduces the direct contact area between active material and electrolyte,and enhances the electrochemical performance.
基金financially supported by the National Natural Science Foundation of China (Nos. 51972182 and 61971252)the Shandong Provincial Natural Science Foundation (Nos. ZR2020JQ27 and ZR2019BF008)the Youth Innovation Team Project of Shandong Provincial Education Department (No. 2020KJN015)。
文摘The application of Si as the anode materials for lithium-ion batteries(LIBs) is still severely hindered by the rapid capacity decay due to the structural damage caused by large volume change(> 300%) during cycling. Herein, a three-dimensional(3 D) aerogel anode of Si@carbon@graphene(SCG) is rationally constructed via a polydopamine-assisted strategy. Polydopamine is coated on Si nanoparticles to serve as an interface linker to initiate the assembly of Si and graphene oxide, which plays a crucial role in the successful fabrication of SCG aerogels. After annealing the polydopamine is converted into N-doped carbon(N-carbon) coatings to protect Si materials. The dual protection from N-carbon and graphene aerogels synergistically improves the structural stability and electronic conductivity of Si, thereby leading to the significantly improved lithium storage properties. Electrochemical tests show that the SCG with optimized graphene content delivers a high capacity(712 m Ah/g at 100 m A/g) and robust cycling stability(402 m Ah/g at 1 A/g after 1500 cycles). Furthermore, the full cell using SCG aerogels as anode exhibits a reversible capacity of 187.6 m Ah/g after 80 cycles at 0.1 A/g. This work provides a plausible strategy for developing Si anode in LIBs.
基金supported by the National Natural Science Foundation of China(No.51872157)Shenzhen Technical Plan Project(Nos.JCYJ20170817161753629 and JCYJ20180508152135822)+4 种基金the Shenzhen Graphene Manufacturing Innovation Center(No.201901161513)Shenzhen Key Lab of Security Research of Power Batteries(No.ZDSYS201707271615073)Guangdong Technical Plan Project(Nos.2015TX01N011 and 2017B090907005)Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program(No.2017BT01N111)the Special Fund Project for Strategic Emerging Industry Development of Shenzhen(No.20170428145209110).
文摘Porous Si can be synthesized from diverse silica(SiO_(2))via magnesiothermic reduction technology and widely employed as potential anode material in lithium ion batteries.However,concerns regarding the influence of residual silicon oxide(SiO_(x))component on resulted Si anode after reduction are still lacked.In this work,we intentionally fabricate a cauliflower-like silicon/silicon oxide(CF-Si/SiO_(x))particles from highly porous SiO_(2)spheres through insufficient magnesiothermic reduction,where residual SiO_(x)component and internal space play an important role in preventing the structural deformation of secondary bulk and restraining the expansion of Si phase.Moreover,the hierarchically structured CF-Si/SiO_(x)exhibits uniformly-dispersed channels,which can improve ion transport and accommodate large volume expansion,simultaneously.As a result,the CF-Si/SiO_(x)-700 anode shows excellent electrochemical performance with a specific capacity of^1,400 mA·h·g^(−1)and a capacity retention of 98%after 100 cycles at the current of 0.2 A·g^(−1).
基金the National Natural Science Foundation of China(Nos.52071225 and 51672181)the Czech Republic through ERDF“Institute of Environmental Technology-Excellent Research”(No.CZ.02.1.01/0.0/0.0/16_019/0000853)M.H.R.acknowledges the Sino-German Research Institute for their support(Project GZ 1400).
文摘Inspired by the natural corn structure,a Si@hollow graphene shell@graphene(Si@GS@G)anode material was prepared in which silicon nanoparticles were preliminarily anchored onto the surface of an elastic graphene shell and further constrained using graphene sheets.Hollow graphene oxide shells with abundant surficial hydrogen bonds,which were synthesized using a novel bottom-up method,were used as an intermediate material to anchor positively charged silicon nanoparticles via electrostatic attraction and achieve a rational spatial distribution.The inner hollow graphene shell anchorage and outer graphene constraint synergistically constituted a porous and robust conductive corn-like structure.The as-fabricated Si@GS@G anode afforded efficient electron and ion transport pathways and improved structural stability,thereby enhancing Li+storage capability(505 mAh·g^(−1)at 10 A·g^(−1))and extending the lifespan compared to the single hollow graphene shell or graphene sheet-protected Si anode(72%capacity retention after 500 cycles).The improved kinetics of the Si@GS@G anode were investigated using electro impedance spectroscopy,galvanostatic intermittent titration,and pseudocapacitance contribution rate analysis,and the structural evolution was analyzed using ex situ electron microscopy.This study proposes a novel hollow graphene oxide shell as an activated intermediate material for designing a porous electrode structure that facilitates an enhanced electrochemical performance.
