Silicon(Si)is considered one of the most promising anode materials for next-generation lithium-ion batteries due to its ultrahigh theoretical capacity.However,its application is significantly limited by severe volume ...Silicon(Si)is considered one of the most promising anode materials for next-generation lithium-ion batteries due to its ultrahigh theoretical capacity.However,its application is significantly limited by severe volume expansion,leading to structural degradation and poor cycling stability.Polymer binders play a critical role in addressing these issues by providing mechanical stabilization.Inspired by the mechanically adaptive architecture of spider webs,where stiff radial threads and extensible spiral threads act in synergy,a dual-thread architecture polymer binder(PALT)with energy dissipation ability enabled by integrating rigid and flexible domains is designed.The rigid poly(acrylic acid lithium)(PAALi)segments offer structural reinforcement,while the soft segments(poly(lipoic acid-tannic acid),LT)introduce dynamic covalent bonds and multiple hydrogen bonds that function as reversible sacrificial bonds,enhancing energy dissipation during cycling.Comprehensive experimental and computational analyses demonstrate effectively reduced stress concentration,improved structural integrity,and stable electrochemical performance over prolonged cycling.The silicon anode incorporating the PALT binder exhibits a satisfying capacity loss per cycle of 0.042% during 350 charge/discharge cycles at 3580 m A g^(-1).This work highlights a bioinspired binder design strategy that combines intrinsic rigidity with dynamic stress adaptability to advance the mechanical and electrochemical stability of silicon anodes.展开更多
Silicon(Si)anodes,with a theoretical specific capacity of 4200 mAh g^(-1),hold significant promise for the development of high-energy-density lithium-ion batteries(LIBs).However,practical applications are hindered by ...Silicon(Si)anodes,with a theoretical specific capacity of 4200 mAh g^(-1),hold significant promise for the development of high-energy-density lithium-ion batteries(LIBs).However,practical applications are hindered by sluggish charge transfer kinetics,substantial volume expansion,and an unstable solid elec-trolyte interphase during cycling.To address these challenges,we propose a centimeter-scale Si anode design featuring a three-dimensional continuous network structure of Si nanowires(SiNWs)decorated with high-density Ag nanoparticles(Ag-SiNWs-Net)on both the surface and internally.This architecture effectively mitigates mechanical stress from Si volume changes through the high-aspect-ratio wire network.Additionally,the distribution of Ag nanoparticles on the Si induces electronic structure redistribution,generating built-in electric fields that accelerate charge transfer within the Si,significantly enhancing rate performance and cycling stability.The Ag-SiNWs-Net anode achieves a high reversible capacity of 3780.9 mAh g^(-1)at 0.1 A g^(-1),with an initial coulombic efficiency of 85.1%.Moreover,the energy density of full cells assembled with Ag-SiNWs-Net anodes and LiFePO4 cathodes can be pushed further up to 395.8 Wh kg^(-1).This study offers valuable insights and methodologies for the development of high-capacity and practical Si anodes-.展开更多
There is an urgent need to develop high-areal-capacity silicon(Si)anodes with good cycling stability and rate capability for high-energy-density lithium-ion batteries(LIBs).However,this remains a huge challenge due to...There is an urgent need to develop high-areal-capacity silicon(Si)anodes with good cycling stability and rate capability for high-energy-density lithium-ion batteries(LIBs).However,this remains a huge challenge due to large volume expansion-induced mechanical degradation and electrical connectivity loss in thick electrodes.Here,a three-in-one strategy is proposed to achieve high-areal-capacity silicon anodes by constructing a multi-level interconnected 3D porous and robust conductive network that carbon nanofibers and vertical carbon nanosheets tightly encapsulate on the surface of Si nanoparticles(Si NPs)anchored in porous carbon felts.This network accommodates large volume expansion of Si NPs to significantly improve electrode mechanical stability and creates excellent electrical connectivity to boost charge transport in thick electrodes,revealed through Multiphysics field simulations and in situ electrochemical techniques.Therefore,the designed Si anodes achieve superior long-term stability with a capacity of 8.13 mAh cm^(-2)after 500 cycles and an ultrahigh areal capacity of 45.8 mAh cm^(-2).In particular,Ah-level pouch cells demonstrate an impressive capacity retention of 79.34%after 500 cycles at 1 C.Our study offers novel insights and directions for understanding and optimizing high-areal-capacity silicon-carbon composite anodes.展开更多
This study presents a novel approach to enhance silicon anode performance through barium titanate(BTO)incorporation,with the establishment of a force-electric coupling model.By introducing piezoelectric BTO into silic...This study presents a novel approach to enhance silicon anode performance through barium titanate(BTO)incorporation,with the establishment of a force-electric coupling model.By introducing piezoelectric BTO into silicon matrices,we successfully improved both the mechanical stability and electrochemical kinetics of the anode.The developed force-electric coupling model explains how BTO mitigates stress accumulation during lithiation while optimizing the kinetics of Li^(+)and electron transfer.Experimental verification and multiphysical simulation indicate that Si@BTO effectively eliminates structural degradation during the cycling process and significantly reduces the charge transfer resistance.The force-electric coupling mechanism further facilitates stable solid electrolyte interphase(SEI)formation.When paired with LiFePO_(4)cathodes,Si@BTO maintains 76% capacity retention after 500 cycles at a 10 C rate.This work establishes a basic force-electric coupling model framework and offers insights into the development of advanced silicon anode batteries with exceptional performance.展开更多
Silicon anodes have drawn ever-increasing attention in lithium-ion batteries(LIBs) owing to their extremely high theoretical capacity and abundance in the earth. Despite promising advantages, the wide use of silicon a...Silicon anodes have drawn ever-increasing attention in lithium-ion batteries(LIBs) owing to their extremely high theoretical capacity and abundance in the earth. Despite promising advantages, the wide use of silicon anodes in LIBs is highly hindered by their fast capacity fading and low Coulombic efficiency arising from their substantial volumetric variation(>300%). Herein, we report a novel aqueous hybrid gel binder for silicon anodes via crosslinking sodium carboxymethyl cellulose(NaCMC) by an inorganic crosslinker-sodium borate. Not only this gel polymer binder can chemically bond to silicon nanoparticle, but also the deformable framework of this crosslinked binder is capable of maintaining electrode integrity, thus buffering dramatic volume change of silicon. Consequently, the silicon anode with this gel binder exhibits good cycle life(1211.5 mAh/g after 600 cycles) and high initial Coulombic efficiency(88.95%).展开更多
Silicon(Si)has emerged as a potent anode material for lithium-ion batteries(LIBs),but faces challenges like low electrical conductivity and significant volume changes during lithiation/delithiation,leading to material...Silicon(Si)has emerged as a potent anode material for lithium-ion batteries(LIBs),but faces challenges like low electrical conductivity and significant volume changes during lithiation/delithiation,leading to material pulverization and capacity degradation.Recent research on nanostructured Si aims to mitigate volume expansion and enhance electrochemical performance,yet still grapples with issues like pulverization,unstable solid electrolyte interface(SEI)growth,and interparticle resistance.This review delves into innovative strategies for optimizing Si anodes’electrochemical performance via structural engineering,focusing on the synthesis of Si/C composites,engineering multidimensional nanostructures,and applying non-carbonaceous coatings.Forming a stable SEI is vital to prevent electrolyte decomposition and enhance Li^(+)transport,thereby stabilizing the Si anode interface and boosting cycling Coulombic efficiency.We also examine groundbreaking advancements such as self-healing polymers and advanced prelithiation methods to improve initial Coulombic efficiency and combat capacity loss.Our review uniquely provides a detailed examination of these strategies in real-world applications,moving beyond theoretical discussions.It offers a critical analysis of these approaches in terms of performance enhancement,scalability,and commercial feasibility.In conclusion,this review presents a comprehensive view and a forward-looking perspective on designing robust,high-performance Si-based anodes the next generation of LIBs.展开更多
Silicon-based(Si)materials are promising anodes for lithium-ion batteries(LIBs)because of their ultrahigh theoretical capacity of 4200 mA h g^(−1).However,commercial applications of Si anodes have been hindered by the...Silicon-based(Si)materials are promising anodes for lithium-ion batteries(LIBs)because of their ultrahigh theoretical capacity of 4200 mA h g^(−1).However,commercial applications of Si anodes have been hindered by their drastic volume variation(∼300%)and low electrical conductivity.Here,to tackle the drawbacks,a hierarchical Si anode with double-layer coatings of a SiOx inner layer and a nitrogen(N),boron(B)co-doped carbon(C-NB)outer layer is elaborately designed by copyrolysis of Si-OH structures and a H3BO_(3)-doped polyaniline polymer on the Si surface.Compared with the pristine Si anodes(7mA h g^(−1) at 0.5 A g^(−1) after 340 cycles and 340 mA h g^(−1) at 5 A g^(−1)),the modified Si-based materials(Si@SiOx@C-NB nanospheres)present su perior cycling stability(reversible 1301 mA h g^(−1) at 0.5 A g^(−1) after 340 cycles)as well as excellent rate capability(690mA h g^(−1) at 5 A g^(−1))when used as anodes in LIBs.The unique double-layer coating structure,in which the inner amorphous SiOx layer acts as a buffer matrix and the outer defect-rich carbon enhances the electron diffusion of the whole anode,makes it possible to de liver excellent electrochemical properties.These results indicate that our double-layer coating strategy is a promising approach not only for the devel opment of sustainable Si anodes but also for the design of multielement-doped carbon nanomaterials.展开更多
Silicon(Si)has been investigated as a promising anode material because of its high theoretical capacity(4200 m Ah g^(-1)).However,silicon anode suffers from huge volume changes during repeated charge–discharge cycles...Silicon(Si)has been investigated as a promising anode material because of its high theoretical capacity(4200 m Ah g^(-1)).However,silicon anode suffers from huge volume changes during repeated charge–discharge cycles.In this work,inspired by a remarkable success of the glutinous rice mortar in the Great Wall with ca.2000-year history,amylopectin(AP),the key ingredient responsible for the strong bonding force,is extracted from glutinous rice and utilized as a flexible,aqueous,and resilient binder to address the most challenging drastic volume-expansion and pulverization issues of silicon anode.Additionally,the removal of toxic N-methyl-2-pyrrolidone(NMP)organic solvent makes the electrode fabrication process environmentally friendly and healthy.The as-prepared Si-AP electrode with 60 wt%of Si can uphold a high discharge capacity of 1517.9 m Ah g^(-1)at a rate of 0.1 C after 100 cycles.The cycling stability of the Si-AP has been remarkably improved in comparison with both traditional polyvinylidene fluoride(PVDF)and aqueous carboxymethylcellulose(CMC)binders.Moreover,when the content of silicon in the Si-AP electrode increases to 70 wt%,a high discharge capacity of 1463.1 m Ah g^(-1)can still be obtained after 50 cycles at 0.1°C.These preliminary results suggest that the sustainably available and environmentally benign amylopectin binders could be a promising choice for the construction of highly stable silicon anodes.展开更多
Nowadays,silicon has become a promising anode active material for lithium-ion batteries due to its high specific capacity.However,traditional binder materials cannot effectively restrain the volume expansion of silico...Nowadays,silicon has become a promising anode active material for lithium-ion batteries due to its high specific capacity.However,traditional binder materials cannot effectively restrain the volume expansion of silicon during lithiation/delithiation.Inspired by the growth process of climbing plants,we sequentially crosslink sodium alginate with calcium ions and hyperbranched polyethyleneimine to construct a dual crosslinked network binder.During the sequentially crosslinking,sodium alginate preferentially crosslinks with Ca^(2+)to form the"trellis"network,which restricts the free movement of hyperbranched polyethyleneimine and guides it,like"vine",to gradually anchor on the surrounding"trellis"through hydrogen and ionic bonding.In this dual crosslinked network,the ionic ally crosslinked sodium alginate maintains the anode structural integrity;the anchored hyperbranched polyethyleneimine forms strong multidimensional hydrogen bonds with silicon nanoparticles through its amino-rich branch chains;and the network utilizes the bonding reversibility of hydrogen and ionic bonds to repeatedly eliminate the mechanical stress and self-heal the structure damages caused by the volume change of silicon.Benefited from the multifunction of the dual crosslinked network,the silicon anode has achieved an excellent electrochemical performance with a specific capacity of 2403 mAh·g^(-1)at the current density of500 mA·g^(-1)after 100 cycles.展开更多
Free-standing silicon anodes with high proportion of active materials have aroused great attention;however,the mechanical stability and electrochemical performance are severely suppressed.Herein,to resolve the appeal ...Free-standing silicon anodes with high proportion of active materials have aroused great attention;however,the mechanical stability and electrochemical performance are severely suppressed.Herein,to resolve the appeal issues,a free-standing anode with a"corrugated paper"shape on micro-scale and a topological crosslinking network on the submicron and nano-scale is designed.Essentially,an integrated three-dimensional electrode structure is constructed based on robust carbon nanotubes network with firmly anchored SiNPs via forming interlocking junctions.In which,the hierarchical interlocking structure is achieved by directional induction of the binder,which ensures well integration during cycling so that significantly enhances mechanical stability as well as electronic and ionic conductivity of electrodes.Benefiting from it,this anode exhibits outsta nding performance under harsh service conditions including high Si loading,ultrahigh areal capacity(33.2 mA h cm^(-2)),and high/low temperatures(-15-60℃),which significantly extends its practical prospect.Furthermore,the optimization mechanism of this electrode is explored to verify the crack-healing and structure-integration maintaining along cycling via a unique self-stabilization process.Thus,from both the fundamental and engineering views,this strategy offers a promising path to produce high-performance free-standing electrodes for flexible device applications especially facing volume effect challenges.展开更多
The extreme volume expansion of the silicon(Si) anodes during repeated cycles seriously induces undesirable interfacial side reactions,forming an unstable solid electrolyte interphase(SEI) that degrades the electrode ...The extreme volume expansion of the silicon(Si) anodes during repeated cycles seriously induces undesirable interfacial side reactions,forming an unstable solid electrolyte interphase(SEI) that degrades the electrode integrity and cycle stability in lithium-ion batteries,limiting their practical applications.Despite considerable efforts to stabilize the SEI through surface modification,challenges persist in the development of high-performance Si anodes that effectively regulate intrinsic SEI properties and simultaneously facilitate electron/ion transport.Here,a highly conductive and organic electrolyte-compatible lamellar p-toluenesulfonic acid-doped polyaniline(pTAP) layer is proposed for constructing a robust artificial SEI on Si nanoparticles to achieve fast charging,lo ng-term cycle lifespan and high areal capacity.The spatially uniform pTAP layer,formed through a facile direct-encapsulation approach assisted by enriched hydrogen bonding,contributes to the effective formation of in situ SEI with an even distribution of the LiF-rich phase in its interlamination spaces.Furthermore,the integrated artificial SEI facilitates isotropic ion/electron transport,increased robustness,and effectively dissipates stress from volume changes.Consequently,a notably high rate performance of 570 mA h g^(-1),even at a substantially high current density of 10 A g^(-1),is achieved with excellent cyclic stability by showing a superior capacity over 1430 mA h g^(-1) at 1 A g^(-1) after 250 cycles and a high areal capacity of ca.2 mA h cm^(-2) at 0.5 C in a full cell system.This study demonstrates that the rational design of conductive polymers with SEI modulation for surface protection has great potential for use in high-energy-density Si anodes.展开更多
The rapid expansion of the photovoltaic industry has generated heavily oxidized waste silicon(wSi),which hinders efficient recycling owing to its small particle size and uncontrolled surface oxidation.This study intro...The rapid expansion of the photovoltaic industry has generated heavily oxidized waste silicon(wSi),which hinders efficient recycling owing to its small particle size and uncontrolled surface oxidation.This study introduces a molten salt electrochemical strategy for converting photovoltaic wSi into NiSi_(2)-silicon nanorods(NiSi_(2)-SiNRs)as high-performance anode materials for lithium-ion batteries.A stable oxidized passivation layer is formed on the wSi surface via controlled oxidation,and further in situ generated highly active NiSi_(2) droplets.The molten salt electric field modulates the surface energy of silicon,while particle integration drives localized directional growth,enabling the self-assembly of NiSi_(2)-SiNRs composites.These NiSi_(2)-SiNRs anodes exhibit rapid ion transport and effective strain buffering.The high aspect ratio of SiNRs and the presence of retained NiSi_(2) facilitate both longitudinal and transverse Li^(+) diffusion.Owing to their robust structural design,the NiSi_(2)-SiNRs anode achieves an excellent initial Coulombic efficiency of 91.61%and retains 72.99%of its capacity after 800 cycles at 2 A·g^(−1).This study establishes a model system for investigating silicide/silicon interfaces in molten salt electrochemical synthesis and provides an effective strategy for upcycling photovoltaic wSi into high-performance lithium-ion battery anodes.展开更多
Silicon(Si)anodes offer an ultrahigh theoretical capacity but face two major barriers to commercialization:severe structural degradation caused by significant volume changes and sluggish ion transport kinetics due to ...Silicon(Si)anodes offer an ultrahigh theoretical capacity but face two major barriers to commercialization:severe structural degradation caused by significant volume changes and sluggish ion transport kinetics due to the discontinuous ionic conductance of conventional binders.To address these challenges,we develop a fully integrated Si anode using sulfonated graphene(SG)as a dual-functional ion-conductive and mechanical reinforcing framework within a conventional carboxymethyl cellulose/styrene-butadiene rubber(CMC/SBR)binder.Thermally activated reactions during electrode fabrication establish covalent sulfonate ester bonds between SG and CMC,elastic carboxylate crosslinks between SBR and CMC,and chemical anchoring between the binders and Si particles,which are all further reinforced by hydrogen bonding.This multi-bonding network not only dissipates mechanical stress and maintains electronic connectivity via embedded C65 carbon but also significantly enhances Li^(+)transport through high intrinsic ionic conductivity of SG,facilitating the formation of a stable solid electrolyte interphase(SEI).The resulting Si@CMC/SBR/SG anode delivers a high initial capacity of 3513.2 mAh g^(-1)and retains 77%capacity after 500 cycles at 2 A g^(-1).It achieves 762 mAh g^(-1)at 4 A g^(-1)and practical areal capacities exceeding 4 mAh cm^(-2).Full-cell tests with NCM811 cathodes confirm 86.2%capacity retention after 100 cycles.This work demonstrates a pragmatic and scalable integration paradigm for durable,high-energy-density Si anodes.展开更多
Polyacrylic acid(PAA)-based binders have been demonstrated to significantly enhance the cycling stability of pure silicon(Si)anodes compared to other binder types.However,there is a notable lack of systematic and in-d...Polyacrylic acid(PAA)-based binders have been demonstrated to significantly enhance the cycling stability of pure silicon(Si)anodes compared to other binder types.However,there is a notable lack of systematic and in-depth investigation into the relationship between the molecular weight(MW)of PAA and its performance in pure Si anodes,leading to an absence of reliable theoretical guidance for designing and optimizing of PAA-based binders for these anodes.Herein,we select a series of PAA with varying MWs as binders for Si nanoparticle(SiNP)anodes to systematically identify the optimal MW of PAA for enhancing the electrochemical performance of SiNP anodes.The actual MWs of the various PAA were confirmed by gel permeation chromatography to accurately establish the relationship between MW and binder performance.Within an ultrawide weight average molecular weight(M_(w))range of 35.9-4850 kDa,we identify that the PAA binder with a M_(w)of 1250 kDa(PAA125)exhibits the strongest mechanical strength and the highest adhesion strength,attributed to its favorable molecular chain orientation and robust interchain interactions.These characteristics enable the SiNP anodes utilizing PAA125 to maintain the best interfacial chemistry and bulk mechanical structure stability,leading to optimal electrochemical performance.Notably,the enhancement in cycling stability of SiNP anode by PAA125 under practical application conditions is further validated by the 1.1 Ah LLNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)/SiNP@PAA125 pouch cell.展开更多
Severe volume changes and poor electrochemical performance are key barriers to the practical use of silicon anodes.In this study,a self-healing,multifunctional supramolecular binder system was introduced,which combine...Severe volume changes and poor electrochemical performance are key barriers to the practical use of silicon anodes.In this study,a self-healing,multifunctional supramolecular binder system was introduced,which combines polymers,ionic liquids,and halometals to achieve dynamic cross linking during volume changes.The addition of specific halometals can adjust the Li+solvation structure and energy,promoting the formation of a stable solid electrolyte interface(SEI)rich in LiF and facilitating Li+desolvation.After 200 cycles,the Si@BF binder(with both ionic liquid and halometal)showed no cracks,indicating excellent structural stability.Additionally,Si||LiFePO_(4)(LFP)full-cell tests at 5 C rate reveal drastic differences:The unmodified binder(the pristine Si)exhibits nearly 0%capacity retention after 400 cycles,the ionic liquid-modified system(Si@B)maintains 11.58%,while Si@BF achieves a remarkable 90.92%retention.Notably,Si@BF retains 78.72%capacity even after 800 cycles.This study offers new insights into dynamic cross-linking systems and solvation-structure regulation,providing references for developing advanced lithium-ion batteries with better performance.展开更多
Silicon,due to its high theoretical capacity and abundant resources,has emerged as a potential anode material for lithium-ion batteries(LIBs).However,it suffers from intrinsic capacity decay and rapid degradation,coup...Silicon,due to its high theoretical capacity and abundant resources,has emerged as a potential anode material for lithium-ion batteries(LIBs).However,it suffers from intrinsic capacity decay and rapid degradation,coupled with huge volume expansion that leads to unstable growth of solid electrolyte interface(SEI).Here,we present a straightforward method to construct yolk-shell(YS)-Si/SiO_(2)-Ti@C materials with YS structure by reducing titanium silicalite-1(TS-1)with magnesium and altering depositing carbon sequence.Besides,the intermediate space can effectively accommodate the expansion of internal silicon nanoparticles.TiO_(2) structural units anchored in the silica alleviate stress-strain in the Si nanoparticles to enhance the cycling stability.The obtained YS-Si/SiO_(2)-Ti@C composites anode exhibits exceptional reversible capacity and cycling stability compared to YS-Si/SiO_(2)@C(without TiO_(2))and commercial Si electrodes.Notably,the YS-Si/SiO_(2)-Ti@C composite anode achieves a high specific capacity(1290 mAh·g^(-1) after 200 cycles at 0.8 A·g^(-1))and a stable SEI film.Specially,the YS-Si/SiO_(2)-Ti@C electrode delivers impressive capacity of 1590,1521,1222,and 646 mAh·g^(-1) at 0.8,2,4,and 8 A·g^(-1),respectively.This study paves an avenue for addressing challenge of drastic volume change in silicon during lithiation/delithiation process to improve cycling stability of LIBs.展开更多
Si is a promising anode material for Li ion batteries because of its high specific capacity,abundant reserve,and low cost.However,its rate performance and cycling stability are poor due to the severe particle pulveriz...Si is a promising anode material for Li ion batteries because of its high specific capacity,abundant reserve,and low cost.However,its rate performance and cycling stability are poor due to the severe particle pulverization during the lithiation/delithiation process.The high stress induced by the Li concentration gradient and anisotropic deformation is the main reason for the fracture of Si particles.Here we present a new stress mitigation strategy by uniformly distributing small amounts of Sn and Sb in Si micron-sized particles,which reduces the Li concentration gradient and realizes an isotropic lithiation/delithiation process.The Si8.5Sn0.5Sb microparticles(mean particle size:8.22μm)show over 6000-fold and tenfold improvements in electronic conductivity and Li diffusivity than Si particles,respectively.The discharge capacities of the Si_(8.5)Sn_(0.5)Sb microparticle anode after 100 cycles at 1.0 and 3.0 A g^(-1)are 1.62 and 1.19 Ah g^(-1),respectively,corresponding to a retention rate of 94.2%and 99.6%,respectively,relative to the capacity of the first cycle after activation.Multicomponent microparticle anodes containing Si,Sn,Sb,Ge and Ag prepared using the same method yields an ultra-low capacity decay rate of 0.02%per cycle for 1000 cycles at 1 A g^(-1),corroborating the proposed mechanism.The stress regulation mechanism enabled by the industry-compatible fabrication methods opens up enormous opportunities for low-cost and high-energy-density Li-ion batteries.展开更多
Severe structural fractures and persistent side reactions at the interface with liquid electrolytes have hindered the commercialization of silicon(Si)anodes.Solid-state electrolytes present a promising solution to add...Severe structural fractures and persistent side reactions at the interface with liquid electrolytes have hindered the commercialization of silicon(Si)anodes.Solid-state electrolytes present a promising solution to address these issues.However,the high interfacial resistance of rigid ceramic electrolytes and the limited ionic conductivity of polymer electrolytes remain significant challenges,further complicated by the substantial volume expansion of Si.In this work,we chemically grafted a flame-retardant,self-healing polyurethane-thiourea polymer onto Li_(7)P_(3)S_(11)(SHPUSB-40%LPS)via nucleophilic addition,creating an electrolyte with exceptional ionic conductivity,high elasticity,and strong compatibility with Si anodes.We observed that FSI^(-)was strongly adsorbed onto the LPS surface through electrostatic interactions with sulfur vacancies,enhancing Li^(+)transport.Furthermore,SHPUSB-40%LPS exhibits dynamic covalent disulfide bonds and hydrogen bonds,enabling self-assembly of the electrolyte at the interface.This dynamic bonding provides a self-healing mechanism that mitigates structural changes during Si expansion and contraction cycles.As a result,the Si anode with SHPUSB-40%LPS presents excellent cycling stability,retaining nearly 53.5%of its capacity after 300 cycles.The practical applicability of this design was validated in a 2 Ah all-solid-state Si‖LiNi_(0.6)Mn_(0.2)Co_(0.2)O_(2)pouch cell,which maintained a stable Li-ion storage capacity retention of 76.3%after 350cycles at 0.5C.This novel solid-state electrolyte with selfhealing properties offers a promising strategy to address fundamental interfacial and performance challenges associated with Si anodes.展开更多
Silicon (Si) is a promising anode material for next-generation high-energy lithium-ion batteries (LIBs) due to its high capacity.However,the large volumetric expansion,poor ion conductivity and unstable solid electrol...Silicon (Si) is a promising anode material for next-generation high-energy lithium-ion batteries (LIBs) due to its high capacity.However,the large volumetric expansion,poor ion conductivity and unstable solid electrolyte interface (SEI) lead to rapid capacity fading and low rate performance.Herein,we report Si nitride (SiN) comprising stoichiometric Si_(3)N_(4) and Li-active anazotic SiN_(x) coated porous Si (p-Si@SiN)for high-performance anodes in LIBs.The ant-nest-like porous Si consisting of 3D interconnected Si nanoligaments and bicontinuous nanopores prevents pulverization and accommodates volume expansion during cycling.The Si_(3)N_(4) offers mechanically protective coating to endow highly structural integrity and inhibit superfluous formation of SEI.The fast ion conducting Li_(3)N generated in situ from lithiation of active SiN_(x) facilitates Li ion transport.Consequently,the p-Si@SiN anode has appealing electrochemical properties such as a high capacity of 2180 mAh g^(-1)at 0.5 A g^(-1) with 84%capacity retention after 200cycles and excellent rate capacity with discharge capacity of 721 mAh g^(-1) after 500 cycles at 5.0 A g^(-1).This work provides insights into the rational design of active/inactive nanocoating on Si-based anode materials for fast-charging and highly stable LIBs.展开更多
To effectively enhanced structural stability and cycling performance,a dual carbon protection strategy is proposed to fabricate Si nanoparticles encapsulated in citric acid(CA)-derived inner carbon layer and zeolitic ...To effectively enhanced structural stability and cycling performance,a dual carbon protection strategy is proposed to fabricate Si nanoparticles encapsulated in citric acid(CA)-derived inner carbon layer and zeolitic imidazolate framework-67(ZIF-67) derived outer carbon layer(Si@C-CA@c-ZIF).The results reveal that citric acid-derived carbon facilitates a uniform ZIF-67 coating on the Si surface and serves as the inner carbon precursor to reduce volumetric expansion of Si particles,more importantly,it can enhance the transport of electrons and ions between Si particles and ZIF-67-derived carbon.The ZIF-67-derived outer carbon layer further restricts Si particle expansion and enhances conductivity.Evaluated as anode material for lithium ion batteries,the Si@C-CA@c-ZIF anode demonstrates outstanding lithium storage performance,the high specific capacity is high to 924 m A·h·g^(-1)at 1.0 A·g^(-1) after 10 cycles of activation,and it still maintains a reversible capacity of 703.3 m A·h·g^(-1) after 1000 cycles,along with a capacity retention of 76.1%.This work highlights the effectiveness of the dual carbon framework in addressing the volume expansion and conductivity limitations of Si,with potential applications for other high-capacity anode materials.展开更多
基金the National Natural Science Foundation of China(32201497)for the financial support of this research。
文摘Silicon(Si)is considered one of the most promising anode materials for next-generation lithium-ion batteries due to its ultrahigh theoretical capacity.However,its application is significantly limited by severe volume expansion,leading to structural degradation and poor cycling stability.Polymer binders play a critical role in addressing these issues by providing mechanical stabilization.Inspired by the mechanically adaptive architecture of spider webs,where stiff radial threads and extensible spiral threads act in synergy,a dual-thread architecture polymer binder(PALT)with energy dissipation ability enabled by integrating rigid and flexible domains is designed.The rigid poly(acrylic acid lithium)(PAALi)segments offer structural reinforcement,while the soft segments(poly(lipoic acid-tannic acid),LT)introduce dynamic covalent bonds and multiple hydrogen bonds that function as reversible sacrificial bonds,enhancing energy dissipation during cycling.Comprehensive experimental and computational analyses demonstrate effectively reduced stress concentration,improved structural integrity,and stable electrochemical performance over prolonged cycling.The silicon anode incorporating the PALT binder exhibits a satisfying capacity loss per cycle of 0.042% during 350 charge/discharge cycles at 3580 m A g^(-1).This work highlights a bioinspired binder design strategy that combines intrinsic rigidity with dynamic stress adaptability to advance the mechanical and electrochemical stability of silicon anodes.
基金supported by the National Natural Science Foundation of China(No.61904130)the Key Research and Development Program of Hubei Province(Nos.2023BAB122,2021BAA063,and 2020BAB084)the Key Laboratory of Coal Conversion and New Carbon Materials in Hubei Province(No.WKDM201907)for their invaluable support.
文摘Silicon(Si)anodes,with a theoretical specific capacity of 4200 mAh g^(-1),hold significant promise for the development of high-energy-density lithium-ion batteries(LIBs).However,practical applications are hindered by sluggish charge transfer kinetics,substantial volume expansion,and an unstable solid elec-trolyte interphase during cycling.To address these challenges,we propose a centimeter-scale Si anode design featuring a three-dimensional continuous network structure of Si nanowires(SiNWs)decorated with high-density Ag nanoparticles(Ag-SiNWs-Net)on both the surface and internally.This architecture effectively mitigates mechanical stress from Si volume changes through the high-aspect-ratio wire network.Additionally,the distribution of Ag nanoparticles on the Si induces electronic structure redistribution,generating built-in electric fields that accelerate charge transfer within the Si,significantly enhancing rate performance and cycling stability.The Ag-SiNWs-Net anode achieves a high reversible capacity of 3780.9 mAh g^(-1)at 0.1 A g^(-1),with an initial coulombic efficiency of 85.1%.Moreover,the energy density of full cells assembled with Ag-SiNWs-Net anodes and LiFePO4 cathodes can be pushed further up to 395.8 Wh kg^(-1).This study offers valuable insights and methodologies for the development of high-capacity and practical Si anodes-.
基金supported by the Jiangyin-SUSTech Innovation Fundthe National Natural Science Foundation of China (No. 22309078 and 52302261)+3 种基金the Shenzhen Key Laboratory of Advanced Energy Storage (ZDSYS20220401141000001)the Shenzhen Science and Technology Plan Project(No. SGDX20230116091644003)the Guangdong Basic and Applied Basic Research Foundation (2023B1515120069)the Pico Center at SUSTech Core Research Facilities,which is supported by the Presidential Fund and the Development and Reform Commission of Shenzhen Municipality
文摘There is an urgent need to develop high-areal-capacity silicon(Si)anodes with good cycling stability and rate capability for high-energy-density lithium-ion batteries(LIBs).However,this remains a huge challenge due to large volume expansion-induced mechanical degradation and electrical connectivity loss in thick electrodes.Here,a three-in-one strategy is proposed to achieve high-areal-capacity silicon anodes by constructing a multi-level interconnected 3D porous and robust conductive network that carbon nanofibers and vertical carbon nanosheets tightly encapsulate on the surface of Si nanoparticles(Si NPs)anchored in porous carbon felts.This network accommodates large volume expansion of Si NPs to significantly improve electrode mechanical stability and creates excellent electrical connectivity to boost charge transport in thick electrodes,revealed through Multiphysics field simulations and in situ electrochemical techniques.Therefore,the designed Si anodes achieve superior long-term stability with a capacity of 8.13 mAh cm^(-2)after 500 cycles and an ultrahigh areal capacity of 45.8 mAh cm^(-2).In particular,Ah-level pouch cells demonstrate an impressive capacity retention of 79.34%after 500 cycles at 1 C.Our study offers novel insights and directions for understanding and optimizing high-areal-capacity silicon-carbon composite anodes.
基金the financial support of the National Natural Science Foundation of China(NSFC,No.12074093)。
文摘This study presents a novel approach to enhance silicon anode performance through barium titanate(BTO)incorporation,with the establishment of a force-electric coupling model.By introducing piezoelectric BTO into silicon matrices,we successfully improved both the mechanical stability and electrochemical kinetics of the anode.The developed force-electric coupling model explains how BTO mitigates stress accumulation during lithiation while optimizing the kinetics of Li^(+)and electron transfer.Experimental verification and multiphysical simulation indicate that Si@BTO effectively eliminates structural degradation during the cycling process and significantly reduces the charge transfer resistance.The force-electric coupling mechanism further facilitates stable solid electrolyte interphase(SEI)formation.When paired with LiFePO_(4)cathodes,Si@BTO maintains 76% capacity retention after 500 cycles at a 10 C rate.This work establishes a basic force-electric coupling model framework and offers insights into the development of advanced silicon anode batteries with exceptional performance.
基金supported by the National Natural Science Foundation of China(No.51602250)Thousand Youth Talents Plan Project of China
文摘Silicon anodes have drawn ever-increasing attention in lithium-ion batteries(LIBs) owing to their extremely high theoretical capacity and abundance in the earth. Despite promising advantages, the wide use of silicon anodes in LIBs is highly hindered by their fast capacity fading and low Coulombic efficiency arising from their substantial volumetric variation(>300%). Herein, we report a novel aqueous hybrid gel binder for silicon anodes via crosslinking sodium carboxymethyl cellulose(NaCMC) by an inorganic crosslinker-sodium borate. Not only this gel polymer binder can chemically bond to silicon nanoparticle, but also the deformable framework of this crosslinked binder is capable of maintaining electrode integrity, thus buffering dramatic volume change of silicon. Consequently, the silicon anode with this gel binder exhibits good cycle life(1211.5 mAh/g after 600 cycles) and high initial Coulombic efficiency(88.95%).
基金financially supported by the Jiangsu Distinguished Professors Project(No.1711510024)the funding for Scientific Research Startup of Jiangsu University(Nos.4111510015,19JDG044)+3 种基金the Jiangsu Provincial Program for High-Level Innovative and Entrepreneurial Talents Introductionthe National Natural Science Foundation of China(No.22008091)Natural Science Foundation of Guangdong Province(2023A1515010894)the Open Project of Luzhou Key Laboratory of Fine Chemical Application Technology(HYJH-2302-A).
文摘Silicon(Si)has emerged as a potent anode material for lithium-ion batteries(LIBs),but faces challenges like low electrical conductivity and significant volume changes during lithiation/delithiation,leading to material pulverization and capacity degradation.Recent research on nanostructured Si aims to mitigate volume expansion and enhance electrochemical performance,yet still grapples with issues like pulverization,unstable solid electrolyte interface(SEI)growth,and interparticle resistance.This review delves into innovative strategies for optimizing Si anodes’electrochemical performance via structural engineering,focusing on the synthesis of Si/C composites,engineering multidimensional nanostructures,and applying non-carbonaceous coatings.Forming a stable SEI is vital to prevent electrolyte decomposition and enhance Li^(+)transport,thereby stabilizing the Si anode interface and boosting cycling Coulombic efficiency.We also examine groundbreaking advancements such as self-healing polymers and advanced prelithiation methods to improve initial Coulombic efficiency and combat capacity loss.Our review uniquely provides a detailed examination of these strategies in real-world applications,moving beyond theoretical discussions.It offers a critical analysis of these approaches in terms of performance enhancement,scalability,and commercial feasibility.In conclusion,this review presents a comprehensive view and a forward-looking perspective on designing robust,high-performance Si-based anodes the next generation of LIBs.
基金supported by Joint Funds of the National Natural Science Foundation of China(U20A20280)the National Natural Science Foundation of China(21805083,52074119)+3 种基金the Academy of Sciences large apparatus United Fund of China(U1832187)the Scientific Research Fund of Hunan Provincial Education Department(19K058)the Science and Technology Planning Project of Hunan Province(2018TP1017)the High-Tech Leading Plan of Hunan Province(2020GK2072).
文摘Silicon-based(Si)materials are promising anodes for lithium-ion batteries(LIBs)because of their ultrahigh theoretical capacity of 4200 mA h g^(−1).However,commercial applications of Si anodes have been hindered by their drastic volume variation(∼300%)and low electrical conductivity.Here,to tackle the drawbacks,a hierarchical Si anode with double-layer coatings of a SiOx inner layer and a nitrogen(N),boron(B)co-doped carbon(C-NB)outer layer is elaborately designed by copyrolysis of Si-OH structures and a H3BO_(3)-doped polyaniline polymer on the Si surface.Compared with the pristine Si anodes(7mA h g^(−1) at 0.5 A g^(−1) after 340 cycles and 340 mA h g^(−1) at 5 A g^(−1)),the modified Si-based materials(Si@SiOx@C-NB nanospheres)present su perior cycling stability(reversible 1301 mA h g^(−1) at 0.5 A g^(−1) after 340 cycles)as well as excellent rate capability(690mA h g^(−1) at 5 A g^(−1))when used as anodes in LIBs.The unique double-layer coating structure,in which the inner amorphous SiOx layer acts as a buffer matrix and the outer defect-rich carbon enhances the electron diffusion of the whole anode,makes it possible to de liver excellent electrochemical properties.These results indicate that our double-layer coating strategy is a promising approach not only for the devel opment of sustainable Si anodes but also for the design of multielement-doped carbon nanomaterials.
基金financial support from the Australia Research Council Discovery Projects(DP160102627 and DP1701048343)of Australiathe 111 Project(D20015)of China Three Gorges University
文摘Silicon(Si)has been investigated as a promising anode material because of its high theoretical capacity(4200 m Ah g^(-1)).However,silicon anode suffers from huge volume changes during repeated charge–discharge cycles.In this work,inspired by a remarkable success of the glutinous rice mortar in the Great Wall with ca.2000-year history,amylopectin(AP),the key ingredient responsible for the strong bonding force,is extracted from glutinous rice and utilized as a flexible,aqueous,and resilient binder to address the most challenging drastic volume-expansion and pulverization issues of silicon anode.Additionally,the removal of toxic N-methyl-2-pyrrolidone(NMP)organic solvent makes the electrode fabrication process environmentally friendly and healthy.The as-prepared Si-AP electrode with 60 wt%of Si can uphold a high discharge capacity of 1517.9 m Ah g^(-1)at a rate of 0.1 C after 100 cycles.The cycling stability of the Si-AP has been remarkably improved in comparison with both traditional polyvinylidene fluoride(PVDF)and aqueous carboxymethylcellulose(CMC)binders.Moreover,when the content of silicon in the Si-AP electrode increases to 70 wt%,a high discharge capacity of 1463.1 m Ah g^(-1)can still be obtained after 50 cycles at 0.1°C.These preliminary results suggest that the sustainably available and environmentally benign amylopectin binders could be a promising choice for the construction of highly stable silicon anodes.
基金financially supported by the National Natural Science Foundation of China(Nos.52002151 and 51905526)Jiaxing Science and Technology Project(No.2020AY10018)the Key Laboratory of Yam Materials Forming and Composite Processing Technology,Zhejiang Province(open project program,No.MTC2021-10)。
文摘Nowadays,silicon has become a promising anode active material for lithium-ion batteries due to its high specific capacity.However,traditional binder materials cannot effectively restrain the volume expansion of silicon during lithiation/delithiation.Inspired by the growth process of climbing plants,we sequentially crosslink sodium alginate with calcium ions and hyperbranched polyethyleneimine to construct a dual crosslinked network binder.During the sequentially crosslinking,sodium alginate preferentially crosslinks with Ca^(2+)to form the"trellis"network,which restricts the free movement of hyperbranched polyethyleneimine and guides it,like"vine",to gradually anchor on the surrounding"trellis"through hydrogen and ionic bonding.In this dual crosslinked network,the ionic ally crosslinked sodium alginate maintains the anode structural integrity;the anchored hyperbranched polyethyleneimine forms strong multidimensional hydrogen bonds with silicon nanoparticles through its amino-rich branch chains;and the network utilizes the bonding reversibility of hydrogen and ionic bonds to repeatedly eliminate the mechanical stress and self-heal the structure damages caused by the volume change of silicon.Benefited from the multifunction of the dual crosslinked network,the silicon anode has achieved an excellent electrochemical performance with a specific capacity of 2403 mAh·g^(-1)at the current density of500 mA·g^(-1)after 100 cycles.
基金sponsored by the National Natural Science Foundation of China(21905221,21805221)the Suzhou Technological innovation of key industries-research and development of key technologies(SGC2021118)。
文摘Free-standing silicon anodes with high proportion of active materials have aroused great attention;however,the mechanical stability and electrochemical performance are severely suppressed.Herein,to resolve the appeal issues,a free-standing anode with a"corrugated paper"shape on micro-scale and a topological crosslinking network on the submicron and nano-scale is designed.Essentially,an integrated three-dimensional electrode structure is constructed based on robust carbon nanotubes network with firmly anchored SiNPs via forming interlocking junctions.In which,the hierarchical interlocking structure is achieved by directional induction of the binder,which ensures well integration during cycling so that significantly enhances mechanical stability as well as electronic and ionic conductivity of electrodes.Benefiting from it,this anode exhibits outsta nding performance under harsh service conditions including high Si loading,ultrahigh areal capacity(33.2 mA h cm^(-2)),and high/low temperatures(-15-60℃),which significantly extends its practical prospect.Furthermore,the optimization mechanism of this electrode is explored to verify the crack-healing and structure-integration maintaining along cycling via a unique self-stabilization process.Thus,from both the fundamental and engineering views,this strategy offers a promising path to produce high-performance free-standing electrodes for flexible device applications especially facing volume effect challenges.
基金National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) [NRF-2021R1A5A1084921]the “Human Resources Program in Energy Technology” of the Korea Institute of Energy Technology Evaluation and Planning (KETEP), granted financial resource from the Ministry of Trade, Industry & Energy, Republic of Korea [No. 20204010600100]the Materials and Components Technology Development Program of the Ministry of Trade, Industry and Energy (MOTIE, Korea) and Korea Electronics Technology Institute (KETI) [20012224]。
文摘The extreme volume expansion of the silicon(Si) anodes during repeated cycles seriously induces undesirable interfacial side reactions,forming an unstable solid electrolyte interphase(SEI) that degrades the electrode integrity and cycle stability in lithium-ion batteries,limiting their practical applications.Despite considerable efforts to stabilize the SEI through surface modification,challenges persist in the development of high-performance Si anodes that effectively regulate intrinsic SEI properties and simultaneously facilitate electron/ion transport.Here,a highly conductive and organic electrolyte-compatible lamellar p-toluenesulfonic acid-doped polyaniline(pTAP) layer is proposed for constructing a robust artificial SEI on Si nanoparticles to achieve fast charging,lo ng-term cycle lifespan and high areal capacity.The spatially uniform pTAP layer,formed through a facile direct-encapsulation approach assisted by enriched hydrogen bonding,contributes to the effective formation of in situ SEI with an even distribution of the LiF-rich phase in its interlamination spaces.Furthermore,the integrated artificial SEI facilitates isotropic ion/electron transport,increased robustness,and effectively dissipates stress from volume changes.Consequently,a notably high rate performance of 570 mA h g^(-1),even at a substantially high current density of 10 A g^(-1),is achieved with excellent cyclic stability by showing a superior capacity over 1430 mA h g^(-1) at 1 A g^(-1) after 250 cycles and a high areal capacity of ca.2 mA h cm^(-2) at 0.5 C in a full cell system.This study demonstrates that the rational design of conductive polymers with SEI modulation for surface protection has great potential for use in high-energy-density Si anodes.
基金supported by the Yunnan Province Basic Research General Program,China(No.202201BE070001-002)the Major Science and Technology Projects in Yunnan Province,China(No.202402AF 080005).
文摘The rapid expansion of the photovoltaic industry has generated heavily oxidized waste silicon(wSi),which hinders efficient recycling owing to its small particle size and uncontrolled surface oxidation.This study introduces a molten salt electrochemical strategy for converting photovoltaic wSi into NiSi_(2)-silicon nanorods(NiSi_(2)-SiNRs)as high-performance anode materials for lithium-ion batteries.A stable oxidized passivation layer is formed on the wSi surface via controlled oxidation,and further in situ generated highly active NiSi_(2) droplets.The molten salt electric field modulates the surface energy of silicon,while particle integration drives localized directional growth,enabling the self-assembly of NiSi_(2)-SiNRs composites.These NiSi_(2)-SiNRs anodes exhibit rapid ion transport and effective strain buffering.The high aspect ratio of SiNRs and the presence of retained NiSi_(2) facilitate both longitudinal and transverse Li^(+) diffusion.Owing to their robust structural design,the NiSi_(2)-SiNRs anode achieves an excellent initial Coulombic efficiency of 91.61%and retains 72.99%of its capacity after 800 cycles at 2 A·g^(−1).This study establishes a model system for investigating silicide/silicon interfaces in molten salt electrochemical synthesis and provides an effective strategy for upcycling photovoltaic wSi into high-performance lithium-ion battery anodes.
基金Opening Project of the National Key Laboratory of Advanced Polymer Materials(Sichuan University)(sklpme2024-1-08)。
文摘Silicon(Si)anodes offer an ultrahigh theoretical capacity but face two major barriers to commercialization:severe structural degradation caused by significant volume changes and sluggish ion transport kinetics due to the discontinuous ionic conductance of conventional binders.To address these challenges,we develop a fully integrated Si anode using sulfonated graphene(SG)as a dual-functional ion-conductive and mechanical reinforcing framework within a conventional carboxymethyl cellulose/styrene-butadiene rubber(CMC/SBR)binder.Thermally activated reactions during electrode fabrication establish covalent sulfonate ester bonds between SG and CMC,elastic carboxylate crosslinks between SBR and CMC,and chemical anchoring between the binders and Si particles,which are all further reinforced by hydrogen bonding.This multi-bonding network not only dissipates mechanical stress and maintains electronic connectivity via embedded C65 carbon but also significantly enhances Li^(+)transport through high intrinsic ionic conductivity of SG,facilitating the formation of a stable solid electrolyte interphase(SEI).The resulting Si@CMC/SBR/SG anode delivers a high initial capacity of 3513.2 mAh g^(-1)and retains 77%capacity after 500 cycles at 2 A g^(-1).It achieves 762 mAh g^(-1)at 4 A g^(-1)and practical areal capacities exceeding 4 mAh cm^(-2).Full-cell tests with NCM811 cathodes confirm 86.2%capacity retention after 100 cycles.This work demonstrates a pragmatic and scalable integration paradigm for durable,high-energy-density Si anodes.
基金funding supports of the National Natural Science Foundation of China(52402315,52172244,51874104,and 52172190)the"Leading Innovative and Entrepreneur Team Introduction Program of Zhejiang"(2023R01007)the Zhejiang Provincial"Jianbing"and"Lingyan"R&D Programs(Grant No.2024C01262)。
文摘Polyacrylic acid(PAA)-based binders have been demonstrated to significantly enhance the cycling stability of pure silicon(Si)anodes compared to other binder types.However,there is a notable lack of systematic and in-depth investigation into the relationship between the molecular weight(MW)of PAA and its performance in pure Si anodes,leading to an absence of reliable theoretical guidance for designing and optimizing of PAA-based binders for these anodes.Herein,we select a series of PAA with varying MWs as binders for Si nanoparticle(SiNP)anodes to systematically identify the optimal MW of PAA for enhancing the electrochemical performance of SiNP anodes.The actual MWs of the various PAA were confirmed by gel permeation chromatography to accurately establish the relationship between MW and binder performance.Within an ultrawide weight average molecular weight(M_(w))range of 35.9-4850 kDa,we identify that the PAA binder with a M_(w)of 1250 kDa(PAA125)exhibits the strongest mechanical strength and the highest adhesion strength,attributed to its favorable molecular chain orientation and robust interchain interactions.These characteristics enable the SiNP anodes utilizing PAA125 to maintain the best interfacial chemistry and bulk mechanical structure stability,leading to optimal electrochemical performance.Notably,the enhancement in cycling stability of SiNP anode by PAA125 under practical application conditions is further validated by the 1.1 Ah LLNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)/SiNP@PAA125 pouch cell.
基金support from the Open Fund of Jiangsu Key Laboratory of Electrochemical Energy Storage Technologies(No.EEST2019-1).
文摘Severe volume changes and poor electrochemical performance are key barriers to the practical use of silicon anodes.In this study,a self-healing,multifunctional supramolecular binder system was introduced,which combines polymers,ionic liquids,and halometals to achieve dynamic cross linking during volume changes.The addition of specific halometals can adjust the Li+solvation structure and energy,promoting the formation of a stable solid electrolyte interface(SEI)rich in LiF and facilitating Li+desolvation.After 200 cycles,the Si@BF binder(with both ionic liquid and halometal)showed no cracks,indicating excellent structural stability.Additionally,Si||LiFePO_(4)(LFP)full-cell tests at 5 C rate reveal drastic differences:The unmodified binder(the pristine Si)exhibits nearly 0%capacity retention after 400 cycles,the ionic liquid-modified system(Si@B)maintains 11.58%,while Si@BF achieves a remarkable 90.92%retention.Notably,Si@BF retains 78.72%capacity even after 800 cycles.This study offers new insights into dynamic cross-linking systems and solvation-structure regulation,providing references for developing advanced lithium-ion batteries with better performance.
基金supported by the National Natural Science Foundation of China(Nos.22371154,U23A20552,52472217,and 52272222)the 111 Project of China(No.D20017)+1 种基金Shandong Province Double-Hundred Talent Plan(No.WST2020003)State Key Laboratory of Heavy Oil Processing(No.SKLHOP202202006).
文摘Silicon,due to its high theoretical capacity and abundant resources,has emerged as a potential anode material for lithium-ion batteries(LIBs).However,it suffers from intrinsic capacity decay and rapid degradation,coupled with huge volume expansion that leads to unstable growth of solid electrolyte interface(SEI).Here,we present a straightforward method to construct yolk-shell(YS)-Si/SiO_(2)-Ti@C materials with YS structure by reducing titanium silicalite-1(TS-1)with magnesium and altering depositing carbon sequence.Besides,the intermediate space can effectively accommodate the expansion of internal silicon nanoparticles.TiO_(2) structural units anchored in the silica alleviate stress-strain in the Si nanoparticles to enhance the cycling stability.The obtained YS-Si/SiO_(2)-Ti@C composites anode exhibits exceptional reversible capacity and cycling stability compared to YS-Si/SiO_(2)@C(without TiO_(2))and commercial Si electrodes.Notably,the YS-Si/SiO_(2)-Ti@C composite anode achieves a high specific capacity(1290 mAh·g^(-1) after 200 cycles at 0.8 A·g^(-1))and a stable SEI film.Specially,the YS-Si/SiO_(2)-Ti@C electrode delivers impressive capacity of 1590,1521,1222,and 646 mAh·g^(-1) at 0.8,2,4,and 8 A·g^(-1),respectively.This study paves an avenue for addressing challenge of drastic volume change in silicon during lithiation/delithiation process to improve cycling stability of LIBs.
基金This work was supported by the General Research Fund scheme of the Hong Kong Research Grants Council(Project No.15227121)the Hong Kong Polytechnic University(ZVGH).
文摘Si is a promising anode material for Li ion batteries because of its high specific capacity,abundant reserve,and low cost.However,its rate performance and cycling stability are poor due to the severe particle pulverization during the lithiation/delithiation process.The high stress induced by the Li concentration gradient and anisotropic deformation is the main reason for the fracture of Si particles.Here we present a new stress mitigation strategy by uniformly distributing small amounts of Sn and Sb in Si micron-sized particles,which reduces the Li concentration gradient and realizes an isotropic lithiation/delithiation process.The Si8.5Sn0.5Sb microparticles(mean particle size:8.22μm)show over 6000-fold and tenfold improvements in electronic conductivity and Li diffusivity than Si particles,respectively.The discharge capacities of the Si_(8.5)Sn_(0.5)Sb microparticle anode after 100 cycles at 1.0 and 3.0 A g^(-1)are 1.62 and 1.19 Ah g^(-1),respectively,corresponding to a retention rate of 94.2%and 99.6%,respectively,relative to the capacity of the first cycle after activation.Multicomponent microparticle anodes containing Si,Sn,Sb,Ge and Ag prepared using the same method yields an ultra-low capacity decay rate of 0.02%per cycle for 1000 cycles at 1 A g^(-1),corroborating the proposed mechanism.The stress regulation mechanism enabled by the industry-compatible fabrication methods opens up enormous opportunities for low-cost and high-energy-density Li-ion batteries.
基金supported financially by the National Natural Science Foundation of China(No.52172202)Science and Technology Program of Guangzhou,China(No.SL2024A03J00326)+1 种基金Key Research and Development project of High-Level Scientific and Technological Talent Introduction for Luliang City(No.2023RC27)the Basic Research Program(Free Exploration Category)Project for Shanxi Province(No.202303021222251)
文摘Severe structural fractures and persistent side reactions at the interface with liquid electrolytes have hindered the commercialization of silicon(Si)anodes.Solid-state electrolytes present a promising solution to address these issues.However,the high interfacial resistance of rigid ceramic electrolytes and the limited ionic conductivity of polymer electrolytes remain significant challenges,further complicated by the substantial volume expansion of Si.In this work,we chemically grafted a flame-retardant,self-healing polyurethane-thiourea polymer onto Li_(7)P_(3)S_(11)(SHPUSB-40%LPS)via nucleophilic addition,creating an electrolyte with exceptional ionic conductivity,high elasticity,and strong compatibility with Si anodes.We observed that FSI^(-)was strongly adsorbed onto the LPS surface through electrostatic interactions with sulfur vacancies,enhancing Li^(+)transport.Furthermore,SHPUSB-40%LPS exhibits dynamic covalent disulfide bonds and hydrogen bonds,enabling self-assembly of the electrolyte at the interface.This dynamic bonding provides a self-healing mechanism that mitigates structural changes during Si expansion and contraction cycles.As a result,the Si anode with SHPUSB-40%LPS presents excellent cycling stability,retaining nearly 53.5%of its capacity after 300 cycles.The practical applicability of this design was validated in a 2 Ah all-solid-state Si‖LiNi_(0.6)Mn_(0.2)Co_(0.2)O_(2)pouch cell,which maintained a stable Li-ion storage capacity retention of 76.3%after 350cycles at 0.5C.This novel solid-state electrolyte with selfhealing properties offers a promising strategy to address fundamental interfacial and performance challenges associated with Si anodes.
基金financially supported by the National Natural Science Foundation of China (U2004210, 51974208, U2003130, 21875080, 52002297)the Outstanding Youth Foundation of Natural Science Foundation of Hubei Province (2020CFA099)+2 种基金the Special Project of Central Government for Local Science and Technology Development of Hubei Province (2019ZYYD024)the Innovation group of Natural Science Foundation of Hubei Province (2019CFA020)the City University of Hong Kong Strategic Research Grants (7005505)。
文摘Silicon (Si) is a promising anode material for next-generation high-energy lithium-ion batteries (LIBs) due to its high capacity.However,the large volumetric expansion,poor ion conductivity and unstable solid electrolyte interface (SEI) lead to rapid capacity fading and low rate performance.Herein,we report Si nitride (SiN) comprising stoichiometric Si_(3)N_(4) and Li-active anazotic SiN_(x) coated porous Si (p-Si@SiN)for high-performance anodes in LIBs.The ant-nest-like porous Si consisting of 3D interconnected Si nanoligaments and bicontinuous nanopores prevents pulverization and accommodates volume expansion during cycling.The Si_(3)N_(4) offers mechanically protective coating to endow highly structural integrity and inhibit superfluous formation of SEI.The fast ion conducting Li_(3)N generated in situ from lithiation of active SiN_(x) facilitates Li ion transport.Consequently,the p-Si@SiN anode has appealing electrochemical properties such as a high capacity of 2180 mAh g^(-1)at 0.5 A g^(-1) with 84%capacity retention after 200cycles and excellent rate capacity with discharge capacity of 721 mAh g^(-1) after 500 cycles at 5.0 A g^(-1).This work provides insights into the rational design of active/inactive nanocoating on Si-based anode materials for fast-charging and highly stable LIBs.
基金financially supported by Industry foresight and common key technology research in Carbon Peak and Carbon Neutrality Special Project from Zhenjiang city (CG2023003)National Natural Science Foundation of China (22379056,22409076)。
文摘To effectively enhanced structural stability and cycling performance,a dual carbon protection strategy is proposed to fabricate Si nanoparticles encapsulated in citric acid(CA)-derived inner carbon layer and zeolitic imidazolate framework-67(ZIF-67) derived outer carbon layer(Si@C-CA@c-ZIF).The results reveal that citric acid-derived carbon facilitates a uniform ZIF-67 coating on the Si surface and serves as the inner carbon precursor to reduce volumetric expansion of Si particles,more importantly,it can enhance the transport of electrons and ions between Si particles and ZIF-67-derived carbon.The ZIF-67-derived outer carbon layer further restricts Si particle expansion and enhances conductivity.Evaluated as anode material for lithium ion batteries,the Si@C-CA@c-ZIF anode demonstrates outstanding lithium storage performance,the high specific capacity is high to 924 m A·h·g^(-1)at 1.0 A·g^(-1) after 10 cycles of activation,and it still maintains a reversible capacity of 703.3 m A·h·g^(-1) after 1000 cycles,along with a capacity retention of 76.1%.This work highlights the effectiveness of the dual carbon framework in addressing the volume expansion and conductivity limitations of Si,with potential applications for other high-capacity anode materials.
