Composite polymer electrolytes(CPEs)offer a promising solution for all-solid-state lithium-metal batteries(ASSLMBs).However,conventional nanofillers with Lewis-acid-base surfaces make limited contribution to improving...Composite polymer electrolytes(CPEs)offer a promising solution for all-solid-state lithium-metal batteries(ASSLMBs).However,conventional nanofillers with Lewis-acid-base surfaces make limited contribution to improving the overall performance of CPEs due to their difficulty in achieving robust electrochemical and mechanical interfaces simultaneously.Here,by regulating the surface charge characteristics of halloysite nanotube(HNT),we propose a concept of lithium-ion dynamic interface(Li^(+)-DI)engineering in nano-charged CPE(NCCPE).Results show that the surface charge characteristics of HNTs fundamentally change the Li^(+)-DI,and thereof the mechanical and ion-conduction behaviors of the NCCPEs.Particularly,the HNTs with positively charged surface(HNTs+)lead to a higher Li^(+)transference number(0.86)than that of HNTs-(0.73),but a lower toughness(102.13 MJ m^(-3)for HNTs+and 159.69 MJ m^(-3)for HNTs-).Meanwhile,a strong interface compatibilization effect by Li^(+)is observed for especially the HNTs+-involved Li^(+)-DI,which improves the toughness by 2000%compared with the control.Moreover,HNTs+are more effective to weaken the Li^(+)-solvation strength and facilitate the formation of Li F-rich solid-electrolyte interphase of Li metal compared to HNTs-.The resultant Li|NCCPE|LiFePO4cell delivers a capacity of 144.9 m Ah g^(-1)after 400 cycles at 0.5 C and a capacity retention of 78.6%.This study provides deep insights into understanding the roles of surface charges of nanofillers in regulating the mechanical and electrochemical interfaces in ASSLMBs.展开更多
High-performance lithium metal batteries benefit from the construction of composite polymer electrolytes(CPEs)which are synthesized by incorporating inorganic fillers into polymer matrices[1].However,the random distri...High-performance lithium metal batteries benefit from the construction of composite polymer electrolytes(CPEs)which are synthesized by incorporating inorganic fillers into polymer matrices[1].However,the random distribution of added fillers within the polymer matrix can lead to tortuous ion pathways and longer transmission distances(Fig.1).As a result,the ion transport capability of CPEs may decrease,while interface contact may deteriorate.Therefore,the organized arrangement of fillers emerges as a crucial consideration in constructing electrolyte membranes.One highly effective approach is the adoption of a vertically aligned filler configuration,where ceramic fillers are constructed to be perpendicular to the electrolyte membrane.If so,the filler/electrolyte interface impedance can be significantly reduced,while continuous ion transport channels along the specified direction are formed,thus significantly enhancing the ion conduction(Fig.1(a))[1].展开更多
Compared to currently commercialized lithium-ion batteries,which use flammable organic liquid electrolytes and low-energy-density graphite anodes,solid-state lithium-metal batteries(SSLMBs)offer enhanced energy densit...Compared to currently commercialized lithium-ion batteries,which use flammable organic liquid electrolytes and low-energy-density graphite anodes,solid-state lithium-metal batteries(SSLMBs)offer enhanced energy density and improved safety,making them promising alternatives for next-generation rechargeable batteries[1].As a crucial component of these batteries,solid-state electrolytes—divided into inorganic solid ceramic electrolytes(SCEs)and organic solid polymer electrolytes(SPEs)—are vital for lithium-ion transport and inhibiting lithium dendrite growth.Among them,SCEs exhibit high ionic conductivity,excellent mechanical properties,and outstanding electrochemical and thermal stability.Nevertheless,their brittleness,interfacial challenges with electrodes,and the requirement for high stacking pressure during battery operation significantly hinder their scalable application.In comparison,SPEs are more favourable for manufacturing due to their flexibility and good interfacial compatibility with electrodes[2].Despite these advantages,SPEs still face significant challenges in achieving practical application.Firstly,typical SPEs,such as poly(ethylene oxide)(PEO),poly(vinylidene fluoride)(PVDF),and poly(ethylene glycol)diacrylate(PEGDA),are characterized by high crystallinity,which causes polymer chains to be tightly packed and rigid.This restricts the segmental motion within the SPEs,resulting in low ionic conductivity.Secondly,compared to lithium ions,anions with large ionic radii and low charge density typically form weaker interactions with the polymer chains,which facilitates their mobility and results in a low lithium-ion transference number(tt).Thirdly,the weak interactions between polymer chains in typical SPEs lead to a low elastic modulus,which in turn compromises their poor mechanical strength.展开更多
Solvation structures fundamentally control the ion-transport dynamics and mechanical properties of polymer electrolytes.However,there is a lack of strategies to rationally regulate the solvation structures and fundame...Solvation structures fundamentally control the ion-transport dynamics and mechanical properties of polymer electrolytes.However,there is a lack of strategies to rationally regulate the solvation structures and fundamental understanding on how they control the electrochemical performances.Herein,by harnessing the electrostatic adsorption of one-dimensional nanofiller(i.e.,surface-charged halloysite nanotubes,d-HNTs),we successfully fabricate a high-performance polymer nanocomposite electrolyte enabled by strong surface adsorption,referred as adsorption-state polymer electrolyte(ASPE).This ASPE shows fast ion transport(0.71±0.05 mS cm^(-1)at room temperature),high mechanical strength and toughness(10.3±0.05 MPa;15.73 MJ m^(-3)),improved lithium-ion transference number,and long cycle life with lithium metal anode,in comparison with the sample without the d-HNT adsorption effect.To fundamentally understand these high performances,an anion-rich asymmetric solvent structure model is further proposed and evidenced by both experiments and simulation studies.Results show that the electrostatic adsorption among the d-HNT,ionic liquid electrolyte,and polymer chain generates a nano filler-supported fast ion-conduction pathway with asymmetric Li+-coordination microenvironment.Meanwhile,the anion-rich asymmetric solvent structure model of ASPE also generates a fast de-solvation and anion-derived stable solid-electrolyte interphase for lithium metal anode.The high performance and understanding of the mechanism for ASPE provide a promising path to develop advanced polymer electrolytes.展开更多
Atomically dispersed Cu-based single-metal-site catalysts(Cu-N-C)have emerged as a frontier for electrocatalytic oxygen reduction reactions(ORR)because they can effectively optimize the D-band center of the Cu active ...Atomically dispersed Cu-based single-metal-site catalysts(Cu-N-C)have emerged as a frontier for electrocatalytic oxygen reduction reactions(ORR)because they can effectively optimize the D-band center of the Cu active site and provide appropriate adsorption/desorption energy for oxygen-containing intermediates.Metal-organic frameworks(MOFs)show excellent prospects in many fields because of their structural regularity and designability,but their direct use for electrocatalysis has been rarely reported due to the low intrinsic conductivity.Here,a MOF material(Cu-TCNQ)with highly regular single-atom copper active centers was successfully prepared using a solution chemical reaction method.Subsequently,Cu-TCNQ and graphene oxide(GO)were directly self-assembled to form a Cu-TCNQ/GO composite,which improved the conductivity of the catalyst while maintained the atomically precise controllability.The resistivity of the Cu-TCNQ/GO decreased by three orders of magnitude(1663.6-2.7 W/cm)compared with pure Cu-TCNQ.The half-wave potential was as high as 0.92 V in 0.1 mol/L KOH,even better than that of commercial 20%Pt/C.In alkaline polymer electrolyte fuel cells(APEFCs),the open-circuit voltage and power density of Cu-TCNQ/GO electrode reached 0.95 V and 320 m W/cm^(2),respectively,which suggests that Cu-TCNQ/GO has a good potential for application as a cathode ORR catalyst.展开更多
Fluoropolymers promise all-solid-state lithium metal batteries(ASLMBs)but suffer from two critical challenges.The first is the trade-off between ionic conductivity(σ)and lithium anode reactions,closely related to hig...Fluoropolymers promise all-solid-state lithium metal batteries(ASLMBs)but suffer from two critical challenges.The first is the trade-off between ionic conductivity(σ)and lithium anode reactions,closely related to high-content residual solvents.The second,usually consciously overlooked,is the fluoropolymer's inherent instability against alkaline lithium anodes.Here,we propose indium-based metal-organic frameworks(In-MOFs)as a multifunctional promoter to simultaneously address these two challenges,using poly(vinylidene fluoride-hexafluoropropylene)(PVH)as the typical fluoropolymer.In-MOF plays a trio:(1)adsorbing and converting free residual solvents into bonded states to prevent their side reactions with lithium anodes while retaining their advantages on Li~+transport;(2)forming inorganic-rich solid electrolyte interphase layers to prevent PVH from reacting with lithium anodes and promote uniform lithium deposition without dendrite growth;(3)reducing PVH crystallinity and promoting Li-salt dissociation.Therefore,the resulting PVH/In-MOF(PVH-IM)showcases excellent electrochemical stability against lithium anodes,delivering a 5550 h cycling at 0.2 m A cm^(-2)with a remarkable cumulative lithium deposition capacity of 1110 m Ah cm^(-2).It also exhibits an ultrahighσof 1.23×10^(-3)S cm^(-1)at 25℃.Moreover,all-solid-state LiFePO_4|PVH-IM|Li full cells show outstanding rate capability and cyclability(80.0%capacity retention after 280 cycles at 0.5C),demonstrating high potential for practical ASLMBs.展开更多
Immense attention has been focused on developing supercapacitors in the field of energy storage by virtue of their exceptional power density,extended cycling stability and operational safety.However,traditional liquid...Immense attention has been focused on developing supercapacitors in the field of energy storage by virtue of their exceptional power density,extended cycling stability and operational safety.However,traditional liquid electrolytes pose severe challenges in response to leakage,high volatility and low electrochemical stability issues.To address these problems,we have developed a novel composite polymer membrane for gel polymer electrolytes(GPEs).This membrane features an internal fibrous framework composed of shape-memory polymers,while surface dielectric layers of PVDF-HFP cross-linked with modified TiO_(2)nanoparticles are constructed on both sides of the framework.This configuration modulates the Stern layer potential gradient and diffuse layer ionic distribution through dielectric polarization,thereby suppressing electrolyte decomposition at high voltages,mitigating side reactions and facilitating ionic conduction.The resultant quasi-solid-state supercapacitor demonstrates excellent electrochemical stability at a voltage of 3.5 V,achieving an energy density of 43.87 Wh kg^(-1),with a high-power density of 22.66 kW kg^(-1)along with exceptional cyclic stability and mechanical flexibility.The synergistic structural design offers a safe and efficient energy harvesting solution for wearable electronic devices and portable energy storage systems.展开更多
Flexible and stretchable energy storage devices are highly desirable for wearable electronics,particularly in the emerging fields of smart clothes,medical instruments,and stretchable skin.Lithium metal batteries(LMBs)...Flexible and stretchable energy storage devices are highly desirable for wearable electronics,particularly in the emerging fields of smart clothes,medical instruments,and stretchable skin.Lithium metal batteries(LMBs) with high power density and long cycle life are one of the ideal power sources for flexible and stretchable energy storage devices.However,the current LMBs are usually too rigid and bulky to meet the requirements of these devices.The electrolyte is the critical component that determines the energy density and security of flexible and stretchable LMBs.Among various electrolytes,gel polymer electrolytes(GPEs) perform excellent flexibility,safety,and high ionic conductivity compared with traditional liquid electrolytes and solid electrolytes,fulfilling the next generation deformable LMBs.This essay mainly reviews and highlights the recent progress in GPEs for flexible/stretchable LMBs and provides some useful insights for people interested in this field.Additionally,the multifunctional GPEs with self-healing,flame retardant,and temperature tolerance abilities are summarized.Finally,the perspectives and opportunities for flexible and stretchable GPEs are discussed.展开更多
In-situ polymer electrolytes prepared by Li salt-initiated polymerization are promising electrolytes for solid-state Li metal batteries owing to their enhanced interface contact and facile and green preparation proces...In-situ polymer electrolytes prepared by Li salt-initiated polymerization are promising electrolytes for solid-state Li metal batteries owing to their enhanced interface contact and facile and green preparation process.However,conventional in-situ polymer electrolytes suffer from poor interface stability,low mechanical strength,low oxidation stability,and certain flammability.Herein,a silsesquioxane(POSS)-nanocage-crosslinked in-situ polymer electrolyte(POSS-DOL@PI-F)regulated by fluorinated plasticizer and enhanced by polyimide skeleton is fabricated by Li salt initiated in-situ polymerization.Polyimide skeleton and POSS-nanocage-crosslinked network significantly enhance the tensile strength(22.8 MPa)and thermal stability(200℃)of POSS-DOL@PI-F.Fluorinated plasticizer improves ionic conductivity(6.83×10^(-4)S cm^(-1)),flame retardance,and oxidation stability(5.0 V)of POSS-DOL@PI-F.The fluorinated plasticizer of POSS-DOL@PI-F constructs robust LiF-rich solid electrolyte interphases and cathode electrolyte interphases,thereby dramatically enhancing the interface stability of Li metal anodes and LiNi_(0.8)Mn_(0.1)Co_(0.1)O_(2)(NCM811)cathodes.POSS-DOL@PI-F enables stable,long-term(1200 h),and dendrite-free cycle of Li‖Li cells.POSS-DOL@PI-F significantly boosts the performance of Li‖NCM811cells,which display superior cycle stability under harsh conditions of high voltage(4.5 V),high temperature(60℃),low temperature(-20℃),and high areal capacity.This work provides a rational design strategy for safe and efficient polymer electrolytes.展开更多
Despite the growing interest in fast-cha rging solid-state lithium(Li)-metal batteries(SSLMBs),their practical implementation has yet to be achieved,primarily due to an incomplete understanding of the disparate and of...Despite the growing interest in fast-cha rging solid-state lithium(Li)-metal batteries(SSLMBs),their practical implementation has yet to be achieved,primarily due to an incomplete understanding of the disparate and often conflicting requirements of the bulk electrolyte and the electrode-electrolyte interphase.Here,we present a weakly coordinating cationic polymer electrolyte(WCPE)specifically designed to regulate the Li^(+)coordination structure,thereby enabling fast-charging SSLMBs.The WCPE comprises an imidazolium-based polycationic matrix combined with a succinonitrile(SN)-based highconcentration electrolyte.Unlike conventional neutral polymer matrices,the polycationic matrix in the WCPE competes with Li^(+)for interactions with SN,weakening the original coordination between SN and Li^(+).This modulation of SN-Li^(+)interaction improves both Li^(+)conductivity of the WCPE(σ_(Li^(+))=1.29mS cm^(-1))and redox kinetics at the electrode-electrolyte interphase.Consequently,SSLMB cells(comprising LiFePO_(4)cathodes and Li-metal anodes)with the WCPE achieve fast-charging capability(reaching over 80%state of charge within 10 min),outperforming those of previously reported polymer electrolytebased SSLMBs.展开更多
Solid polymer electrolytes(SPEs)offer enhanced safety for next-generation lithium-ion batteries(LIBs)but typically suffer from low lithium-ion transference numbers(t_(Li^(+))),leading to concentration polarization and...Solid polymer electrolytes(SPEs)offer enhanced safety for next-generation lithium-ion batteries(LIBs)but typically suffer from low lithium-ion transference numbers(t_(Li^(+))),leading to concentration polarization and dendritic growth.To address this,we designed a boron-containing SPE(GBOEE)leveraging the electron-deficient nature of boron to immobilize anions.Thermogravimetric analysis revealed the stability of GBOEE up to 284.9℃.The optimized GBOEE-6.7 exhibited a high t_(Li^(+))of 0.49 and an ionic conductivity of 5.75×10^(-5)S·cm^(-1)at 30℃,with a 5.15 V electrochemical window.Symmetric Li//Li cells demonstrated stable cycling for 600 h at 0.05 mA·cm^(-2)with minimal polarization(0.15 V).LiFePO_(4)//Li cells delivered a high initial discharge capacity of 153.4 mAh·g^(-1)and 99.7%capacity retention after 100 cycles at 0.1 C.These results underscore the effectiveness of boron integration in designing high-performance,dendrite-suppressing SPEs for safe lithiummetal batteries(LMBs).展开更多
Fiber-shaped energy storage devices(FSESDs)with exceptional flexibility for wearable power sources should be applied with solid electrolytes over liquid electrolytes due to short circuits and leakage issue during defo...Fiber-shaped energy storage devices(FSESDs)with exceptional flexibility for wearable power sources should be applied with solid electrolytes over liquid electrolytes due to short circuits and leakage issue during deformation.Among the solid options,polymer electrolytes are particularly preferred due to their robustness and flexibility,although their low ionic conductivity remains a significant challenge.Here,we present a redox polymer electrolyte(HT_RPE)with 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl(HT)as a multi-functional additive.HT acts as a plasticizer that transforms the glassy state into the rubbery state for improved chain mobility and provides distinctive ion conduction pathway by the self-exchange reaction between radical and oxidized species.These synergetic effects lead to high ionic conductivity(73.5 mS cm−1)based on a lower activation energy of 0.13 eV than other redox additives.Moreover,HT_RPE with a pseudocapacitive characteristic by HT enables an outstanding electrochemical performance of the symmetric FSESDs using carbon-based fiber electrodes(energy density of 25.4 W h kg^(−1) at a power density of 25,000 W kg^(−1))without typical active materials,along with excellent stability(capacitance retention of 91.2%after 8,000 bending cycles).This work highlights a versatile HT_RPE that utilizes the unique functionality of HT for both the high ionic conductivity and improved energy storage capability,providing a promising pathway for next-generation flexible energy storage devices.展开更多
Conventional liquid electrolytes in lithium-ion batteries(LIBs)pose significant safety risks and interfacial instability,hindering the development of high-energy-density systems.Solid polymer electrolytes(SPEs),partic...Conventional liquid electrolytes in lithium-ion batteries(LIBs)pose significant safety risks and interfacial instability,hindering the development of high-energy-density systems.Solid polymer electrolytes(SPEs),particularly polyethylene oxide(PEO)-based systems,offer enhanced safety but suffer from low room-temperature ionic conductivity due to high crystallinity,alongside limitations such as poor lithium-ion transference numbers and dendrite growth.To address these challenges,this study develops a novel composite solid electrolyte(PSPH)by synthesizing a polystyrene-polyethylene oxide-polystyrene(PSPEO-PS)triblock copolymer and blending it with poly(vinylidene fluoride-co-hexafluoropropylene)(PVDF-HFP)and lithium bis(trifluoromethylsulfonyl)imide(LiTFSI).The rigid PS segments suppress PEO crystallization,while PVDF-HFP enhances amorphous domain content,promotes LiTFSI dissociation via its high dielectric constant,and improves mechanical strength.The optimized PSPH composition(M_(w,PEO)=35 kg·mol^(-1),w_(PS)=15%,w_(PVDF-HFP)=30%)exhibits a high ionic conductivity of 1.05×10^(-4) S·cm^(-1)at 25℃,a Li^(+)transference number of 0.46,and an extended electrochemical stability window up to 4.8 V.PSPH demonstrates excellent thermal stability(decomposition onset at about 340℃),flexibility,and interfacial compatibility.LiFePO_(4)/PSPH/Li cells delivere a high discharge capacity of 163.7 mAh·g^(-1) at 0.1 C,with 96.2%capacity retention and 99.83%average coulombic efficiency after 200 cycles.Furthermore,Li/PSPH/Li symmetric cells exhibit stable cycling for over 1500 h at 0.05 mA·cm^(-2) with low overpotential(about 0.15 V).These results demonstrate that PSPH is a highly promising electrolyte for enhancing the safety and electrochemical performance of all-solid-state lithium-metal batteries(LMBs).展开更多
Flame-retardant gel polymer electrolyte(FRGPE)with high ionic conductivity and practical safety is essential for the next generation of high energy density sodium metal batteries(SMBs).However,they suffer from serious...Flame-retardant gel polymer electrolyte(FRGPE)with high ionic conductivity and practical safety is essential for the next generation of high energy density sodium metal batteries(SMBs).However,they suffer from serious side reactions and insufficient interfacial stability against sodium metal anode,causing severe performance degradation and even safety issues.Herein,to address these challenges,a fluoroethylene carbonate(FEC)additive confined metal-organic framework(MOF)-based composite gel(AC-MCG)interlayer was constructed upon sodium anode through a facile in-situ UV-induced photopolymerization.The FEC confined in AC-MCG induces the formation of NaF-rich inorganic solid-electrolyte interphase,effectively eliminating the side reactions between the FRGPE and sodium metal anode.Moreover,the MOF with ordered nanochannels can homogenize Na^(+)flux during the plating process and also endow the AC-MCG interlayer with high mechanical strength,thus sufficiently suppressing the growth of sodium dendrites.Benefitting from these merits of the AC-MCG interlayer,a high critical current density of 2.0 mA cm^(-2)and a long-term cycling life for over 4200 h at 0.1 mA cm^(-2)are achieved for the Na/Na symmetric cells.Besides,the solid-state SMBs paired with the constructed AC-MCG interlayer also demonstrated considerable electrochemical performance and practical safety.展开更多
Quasi-solid polymer electrolytes(QSPEs)have been attracted significant attentions due to their benefits for simultaneously improved safety and energy density of batteries.Developing electrolytes capable of forming a s...Quasi-solid polymer electrolytes(QSPEs)have been attracted significant attentions due to their benefits for simultaneously improved safety and energy density of batteries.Developing electrolytes capable of forming a stable solid electrolyte interphase(SEI)layer is a great challenge for QSPE-based lithium(Li)metal batteries(LMBs).Herein,unlike previously reports that the reconstruction of Li^(+)solvation structures in QSPE requires time-consuming bottom-up polymer synthesis,in current study,a facile approach has been developed to reconstruct the Li^(+)solvation structures in QSPE by adjustment of the salt concentrations.The high proportion of Li^(+)-anion complexes can effectively accelerate interfacial Li^(+)diffusion,mitigate the decompositions of organic solvents and induce the formation of a LiF-rich SEI layer,contributing to suppressed Li-dendrite growth.As a result,the Li/QSPE-3/LiFePO_(4)(LFP)cell performs an ultralong lifespan with capacity retention of 77.4%over 3000 cycles at 1 C.With a high-voltage LiCoO_(2)cathode,the cell can stably cycle over 200 cycles at 25℃(capacity retention of∼83.8%).With accelerated ion transport dynamics due to the reconstructed Li^(+)solvation structure,the QSPE-3(the salt concentration is 3 M)is applicable in a wide temperature range.The Li/QSPE-3/LFP full cell exhibits 58.1%and 102.6%of discharge capacity at−15 and 90℃,respectively,compared to those operated at 25℃This study demonstrates a facile yet effective approach on enhancing electrode/electrolyte interfacial stability,enabling the LMBs with simultaneously enhanced safety and high energy density.展开更多
The development of high-performance solid-state electrolytes(SSEs)capable of reconciling high ionic conductivity with robust mechanical strength is crucial for advancing safe lithium-metal batteries(LMBs).In this stud...The development of high-performance solid-state electrolytes(SSEs)capable of reconciling high ionic conductivity with robust mechanical strength is crucial for advancing safe lithium-metal batteries(LMBs).In this study,we synthesized a novel BAB-type triblock copolymer PuPyMA-b-PEO-b-PuPyMA and used it to prepare SSEs.The copolymer design incorporates polyethylene oxide(PEO)segments to achieve ionic conduction,while uracil ketone(uPy)groups are introduced to provide quadruple hydrogen bonding.This molecular architecture leverages microphase separation and supramolecular interactions to optimize performance.The optimized electrolyte,PPMP-30 with w(uPyMA)=30%,n(EO)/n(Li^(+))=25/1,exhibits outstanding comprehensive properties at room temperature:an ionic conductivity of 4.0×10^(-4)S·cm^(-1),a high Li^(+)transference number of 0.41,and an extended electrochemical stability window up to 5.6 V(vs.Li^(+)/Li).Li//Li symmetric cells demonstrate exceptional interfacial stability and lithium dendrite suppression,cycling stably for over 650 h at 0.05 mA·cm^(-2).When assembled into LiFePO_(4)//Li cells,the electrolyte enables a high initial discharge capacity(about 160 mAh·g^(-1)at 0.1 C),excellent cycling stability(85.0%capacity retention after 120 cycles),and good rate capability with significant capacity recovery upon returning to low rates.These results highlight the significant potential of this tetrahedral hydrogen-bonded block copolymer electrolyte in overcoming the ionic conductivity-mechanical strength trade-off for practical solid-state LMBs.展开更多
Sodium-sulfur(Na-S)batteries are believed as the hopeful energy storage and conversion techniques owing to the high specific capacity and low cost.Nevertheless,unstable sodium(Na)deposition/stripping of Na metal anode...Sodium-sulfur(Na-S)batteries are believed as the hopeful energy storage and conversion techniques owing to the high specific capacity and low cost.Nevertheless,unstable sodium(Na)deposition/stripping of Na metal anode,low intrinsic conductivity of sulfur cathode,and severe shuttling effect of sodium polysulfides(NaPSs)pose significant challenges in the actual reversible capacity and cycle life of Na-S batteries.Herein,a self-supporting electrode made of nitrogen-doped carbon fiber embedded with cobalt nanoparticles(Co/NC-CF)is designed to load sulfur.Meanwhile,gel polymer electrolyte(GPE)with high ion transfer ability is obtained by in-situ polymerization inside the battery.During the polymerization process,an integrated electrode-electrolyte and a continuous ion-electron conduction network in a composite cathode are constructed inside the Na-S battery.It is noteworthy that the designed GPE demonstrates superior ionic conductivity and effective adsorption of NaPSs that can significantly suppress the shuttle effect.Leveraging the synergistic interplay between the designed GPE and self-supporting cathode,the assembled quasi-solid-state(QSS)Na-S battery exhibits great cycling stability.These experimental results are further corroborated by COMSOL Multiphysics simulations and density functional theory(DFT)calculations,which mechanistically validate the enhanced electrochemical performance.The findings of this study offer new and promising perspectives for advancing the development of nextgeneration solid-state batteries.展开更多
Solid polymer electrolytes(SPEs)have garnered considerable interest in the field of lithium metal batteries(LMBs)owing to their exceptional mechanical strength,excellent designability,and heightened safety characteris...Solid polymer electrolytes(SPEs)have garnered considerable interest in the field of lithium metal batteries(LMBs)owing to their exceptional mechanical strength,excellent designability,and heightened safety characteristics.However,their inherently low ion transport efficiency poses a major challenge for their application in LMBs.To address this issue,covalent organic framework(COF)with their ordered ion transport channels,chemical stability,large specific surface area,and designable multifunctional sites has shown promising potential to enhance lithium-ion conduction.Here,we prepared an anionic COF,Tp Pa-COOLi,which can catalyze the ring-opening copolymerization of cyclic lactone monomers for the in situ fabrication of SPEs.The design leverages the high specific surface area of COF to facilitate the absorption of polymerization precursor and catalyze the polymerization within the pores,forming additional COF-polymer junctions that enhance ion transport pathways.The partial exfoliation of COF achieved through these junctions improved its dispersion within the polymer matrix,preserving ion transport channels and facilitating ion transport across COF grain boundaries.By controlling variables to alter the crystallinity of Tp Pa-COOLi and the presence of-COOLi substituents,Tp Pa-COOLi with partial long-range order and-COOLi substituents exhibited superior electrochemical performance.This research demonstrates the potential in constructing high-performance SPEs for LMBs.展开更多
Solid polymer electrolytes(SPEs)have attracted much attention for their safety,ease of packaging,costeffectiveness,excellent flexibility and stability.Poly-dioxolane(PDOL)is one of the most promising matrix materials ...Solid polymer electrolytes(SPEs)have attracted much attention for their safety,ease of packaging,costeffectiveness,excellent flexibility and stability.Poly-dioxolane(PDOL)is one of the most promising matrix materials of SPEs due to its remarkable compatibility with lithium metal anodes(LMAs)and suitability for in-situ polymerization.However,poor thermal stability,insufficient ionic conductivity and narrow electrochemical stability window(ESW)hinder its further application in lithium metal batteries(LMBs).To ameliorate these problems,we have successfully synthesized a polymerized-ionic-liquid(PIL)monomer named DIMTFSI by modifying DOL with imidazolium cation coupled with TFSI^(-)anion,which simultaneously inherits the lipophilicity of DOL,high ionic conductivity of imidazole,and excellent stability of PILs.Then the tridentate crosslinker trimethylolpropane tris[3-(2-methyl-1-aziridine)propionate](TTMAP)was introduced to regulate the excessive Li^(+)-O coordination and prepare a flame-retardant SPE(DT-SPE)with prominent thermal stability,wide ESW,high ionic conductivity and abundant Lit transference numbers(t_(Li+)).As a result,the LiFePO_(4)|DT-SPE|Li cell exhibits a high initial discharge specific capacity of 149.60 mAh g^(-1)at 0.2C and 30℃with a capacity retention rate of 98.68%after 500 cycles.This work provides new insights into the structural design of PIL-based electrolytes for long-cycling LMBs with high safety and stability.展开更多
Solid polymer electrolytes have garnered significant attention for lithium batteries because of their flexibility and safety.However,poor ionic conductivity,lithium dendrite formation,and high impedance hinder their p...Solid polymer electrolytes have garnered significant attention for lithium batteries because of their flexibility and safety.However,poor ionic conductivity,lithium dendrite formation,and high impedance hinder their practical application.In this study,a thin,flexible,3D hybrid solid electrolyte(3DHSE)is prepared by in situ thermal cross-linking polymerization with electrospun 3D nanowebs.The 3DHSE comprises Al-doped Li_(7)La_(3)Zr_(2)O_(12)(ALLZO)embedded in electrospun poly(vinylidene fluoride-cohexafluoropropylene)(PVDF-HFP)nonwoven 3D nanowebs and an in situ cross-linked polyethylene oxide(PEO)-based solid polymer electrolyte.The 3DHSE exhibits high tensile strength(6.55 MPa),a strain of 40.28%,enhanced ionic conductivity(7.86×10^(-4) S cm^(-1)),and a superior lithium-ion transference number(0.76)to that of the PVDF-HFP-based solid polymer electrolyte(PSPE).This enables highly stable lithium plating/stripping cycling for over 900 h at 25℃ with a current density of 0.2 mA cm^(-2).The LiNi_(0.8)Mn_(0.1)Co_(0.1)O_(2)(NCM811)/3DHSE/Li cell has a higher capacity(140.56 mAh g^(-1) at 0.1 C)than the NCM811/PSPE/Li cell(124.88 mAh g^(-1) at 0.1 C)at 25℃.The 3DHSE enhances mechanical properties,stabilizes interfacial contact,improves ion transport,prevents NCM811 cracking,and significantly boosts cycling performance.This study highlights the potential of the 3DHSE as a candidate for advanced lithium polymer battery technology.展开更多
基金the financial support from the National Natural Science Foundation of China(52203123 and 52473248)State Key Laboratory of Polymer Materials Engineering(sklpme2024-2-04)+1 种基金the Fundamental Research Funds for the Central Universitiessponsored by the Double First-Class Construction Funds of Sichuan University。
文摘Composite polymer electrolytes(CPEs)offer a promising solution for all-solid-state lithium-metal batteries(ASSLMBs).However,conventional nanofillers with Lewis-acid-base surfaces make limited contribution to improving the overall performance of CPEs due to their difficulty in achieving robust electrochemical and mechanical interfaces simultaneously.Here,by regulating the surface charge characteristics of halloysite nanotube(HNT),we propose a concept of lithium-ion dynamic interface(Li^(+)-DI)engineering in nano-charged CPE(NCCPE).Results show that the surface charge characteristics of HNTs fundamentally change the Li^(+)-DI,and thereof the mechanical and ion-conduction behaviors of the NCCPEs.Particularly,the HNTs with positively charged surface(HNTs+)lead to a higher Li^(+)transference number(0.86)than that of HNTs-(0.73),but a lower toughness(102.13 MJ m^(-3)for HNTs+and 159.69 MJ m^(-3)for HNTs-).Meanwhile,a strong interface compatibilization effect by Li^(+)is observed for especially the HNTs+-involved Li^(+)-DI,which improves the toughness by 2000%compared with the control.Moreover,HNTs+are more effective to weaken the Li^(+)-solvation strength and facilitate the formation of Li F-rich solid-electrolyte interphase of Li metal compared to HNTs-.The resultant Li|NCCPE|LiFePO4cell delivers a capacity of 144.9 m Ah g^(-1)after 400 cycles at 0.5 C and a capacity retention of 78.6%.This study provides deep insights into understanding the roles of surface charges of nanofillers in regulating the mechanical and electrochemical interfaces in ASSLMBs.
基金supported by the National Natural Science Foundation of China(No.51972293)Hangzhou Key Research Program Project(2023SZD0099)LingYan Project(2024C01090).
文摘High-performance lithium metal batteries benefit from the construction of composite polymer electrolytes(CPEs)which are synthesized by incorporating inorganic fillers into polymer matrices[1].However,the random distribution of added fillers within the polymer matrix can lead to tortuous ion pathways and longer transmission distances(Fig.1).As a result,the ion transport capability of CPEs may decrease,while interface contact may deteriorate.Therefore,the organized arrangement of fillers emerges as a crucial consideration in constructing electrolyte membranes.One highly effective approach is the adoption of a vertically aligned filler configuration,where ceramic fillers are constructed to be perpendicular to the electrolyte membrane.If so,the filler/electrolyte interface impedance can be significantly reduced,while continuous ion transport channels along the specified direction are formed,thus significantly enhancing the ion conduction(Fig.1(a))[1].
基金supported by the University of Wollongong,Wollongong,Australiafinancial support from the National Natural Science Foundation of China(22272086)Natural Science Foundation of Sichuan Province(2023NSFSC0009).
文摘Compared to currently commercialized lithium-ion batteries,which use flammable organic liquid electrolytes and low-energy-density graphite anodes,solid-state lithium-metal batteries(SSLMBs)offer enhanced energy density and improved safety,making them promising alternatives for next-generation rechargeable batteries[1].As a crucial component of these batteries,solid-state electrolytes—divided into inorganic solid ceramic electrolytes(SCEs)and organic solid polymer electrolytes(SPEs)—are vital for lithium-ion transport and inhibiting lithium dendrite growth.Among them,SCEs exhibit high ionic conductivity,excellent mechanical properties,and outstanding electrochemical and thermal stability.Nevertheless,their brittleness,interfacial challenges with electrodes,and the requirement for high stacking pressure during battery operation significantly hinder their scalable application.In comparison,SPEs are more favourable for manufacturing due to their flexibility and good interfacial compatibility with electrodes[2].Despite these advantages,SPEs still face significant challenges in achieving practical application.Firstly,typical SPEs,such as poly(ethylene oxide)(PEO),poly(vinylidene fluoride)(PVDF),and poly(ethylene glycol)diacrylate(PEGDA),are characterized by high crystallinity,which causes polymer chains to be tightly packed and rigid.This restricts the segmental motion within the SPEs,resulting in low ionic conductivity.Secondly,compared to lithium ions,anions with large ionic radii and low charge density typically form weaker interactions with the polymer chains,which facilitates their mobility and results in a low lithium-ion transference number(tt).Thirdly,the weak interactions between polymer chains in typical SPEs lead to a low elastic modulus,which in turn compromises their poor mechanical strength.
基金financial support from the National Natural Science Foundation of China(52203123)the Sichuan Science and Technology Program(2023NSFSC0991)+2 种基金the State Key Laboratory of Polymer Materials Engineering(sklpme 2023-1-05 and sklpme 2024-2-04)the Fundamental Research Funds for the Central Universitiespartially sponsored by the Double First-Class Construction Funds of Sichuan University。
文摘Solvation structures fundamentally control the ion-transport dynamics and mechanical properties of polymer electrolytes.However,there is a lack of strategies to rationally regulate the solvation structures and fundamental understanding on how they control the electrochemical performances.Herein,by harnessing the electrostatic adsorption of one-dimensional nanofiller(i.e.,surface-charged halloysite nanotubes,d-HNTs),we successfully fabricate a high-performance polymer nanocomposite electrolyte enabled by strong surface adsorption,referred as adsorption-state polymer electrolyte(ASPE).This ASPE shows fast ion transport(0.71±0.05 mS cm^(-1)at room temperature),high mechanical strength and toughness(10.3±0.05 MPa;15.73 MJ m^(-3)),improved lithium-ion transference number,and long cycle life with lithium metal anode,in comparison with the sample without the d-HNT adsorption effect.To fundamentally understand these high performances,an anion-rich asymmetric solvent structure model is further proposed and evidenced by both experiments and simulation studies.Results show that the electrostatic adsorption among the d-HNT,ionic liquid electrolyte,and polymer chain generates a nano filler-supported fast ion-conduction pathway with asymmetric Li+-coordination microenvironment.Meanwhile,the anion-rich asymmetric solvent structure model of ASPE also generates a fast de-solvation and anion-derived stable solid-electrolyte interphase for lithium metal anode.The high performance and understanding of the mechanism for ASPE provide a promising path to develop advanced polymer electrolytes.
基金supported by the National Key Research and Development Program of China(No.2022YFB3807500)the National Natural Science Foundation of China(No.22220102003)+1 种基金the Beijing Natural Science Foundation(No.JL23003)“Double-First-Class”construction projects(Nos.XK180301 and XK1804-02)。
文摘Atomically dispersed Cu-based single-metal-site catalysts(Cu-N-C)have emerged as a frontier for electrocatalytic oxygen reduction reactions(ORR)because they can effectively optimize the D-band center of the Cu active site and provide appropriate adsorption/desorption energy for oxygen-containing intermediates.Metal-organic frameworks(MOFs)show excellent prospects in many fields because of their structural regularity and designability,but their direct use for electrocatalysis has been rarely reported due to the low intrinsic conductivity.Here,a MOF material(Cu-TCNQ)with highly regular single-atom copper active centers was successfully prepared using a solution chemical reaction method.Subsequently,Cu-TCNQ and graphene oxide(GO)were directly self-assembled to form a Cu-TCNQ/GO composite,which improved the conductivity of the catalyst while maintained the atomically precise controllability.The resistivity of the Cu-TCNQ/GO decreased by three orders of magnitude(1663.6-2.7 W/cm)compared with pure Cu-TCNQ.The half-wave potential was as high as 0.92 V in 0.1 mol/L KOH,even better than that of commercial 20%Pt/C.In alkaline polymer electrolyte fuel cells(APEFCs),the open-circuit voltage and power density of Cu-TCNQ/GO electrode reached 0.95 V and 320 m W/cm^(2),respectively,which suggests that Cu-TCNQ/GO has a good potential for application as a cathode ORR catalyst.
基金the financial support from the 261 Project of MIITNatural Science Foundation of Jiangsu Province(No.BK20240179)。
文摘Fluoropolymers promise all-solid-state lithium metal batteries(ASLMBs)but suffer from two critical challenges.The first is the trade-off between ionic conductivity(σ)and lithium anode reactions,closely related to high-content residual solvents.The second,usually consciously overlooked,is the fluoropolymer's inherent instability against alkaline lithium anodes.Here,we propose indium-based metal-organic frameworks(In-MOFs)as a multifunctional promoter to simultaneously address these two challenges,using poly(vinylidene fluoride-hexafluoropropylene)(PVH)as the typical fluoropolymer.In-MOF plays a trio:(1)adsorbing and converting free residual solvents into bonded states to prevent their side reactions with lithium anodes while retaining their advantages on Li~+transport;(2)forming inorganic-rich solid electrolyte interphase layers to prevent PVH from reacting with lithium anodes and promote uniform lithium deposition without dendrite growth;(3)reducing PVH crystallinity and promoting Li-salt dissociation.Therefore,the resulting PVH/In-MOF(PVH-IM)showcases excellent electrochemical stability against lithium anodes,delivering a 5550 h cycling at 0.2 m A cm^(-2)with a remarkable cumulative lithium deposition capacity of 1110 m Ah cm^(-2).It also exhibits an ultrahighσof 1.23×10^(-3)S cm^(-1)at 25℃.Moreover,all-solid-state LiFePO_4|PVH-IM|Li full cells show outstanding rate capability and cyclability(80.0%capacity retention after 280 cycles at 0.5C),demonstrating high potential for practical ASLMBs.
基金financially supported by the Key Research and Development Program of Shaanxi(No.2022GXLH-01-23)the Fundamental Research Funds for the Central Universities,CHD(No.300102384106)+1 种基金the Innovation Capability Support Program of Shaanxi(No.2022KXJ-144)the National Natural Science Foundation of China(No.22209101)
文摘Immense attention has been focused on developing supercapacitors in the field of energy storage by virtue of their exceptional power density,extended cycling stability and operational safety.However,traditional liquid electrolytes pose severe challenges in response to leakage,high volatility and low electrochemical stability issues.To address these problems,we have developed a novel composite polymer membrane for gel polymer electrolytes(GPEs).This membrane features an internal fibrous framework composed of shape-memory polymers,while surface dielectric layers of PVDF-HFP cross-linked with modified TiO_(2)nanoparticles are constructed on both sides of the framework.This configuration modulates the Stern layer potential gradient and diffuse layer ionic distribution through dielectric polarization,thereby suppressing electrolyte decomposition at high voltages,mitigating side reactions and facilitating ionic conduction.The resultant quasi-solid-state supercapacitor demonstrates excellent electrochemical stability at a voltage of 3.5 V,achieving an energy density of 43.87 Wh kg^(-1),with a high-power density of 22.66 kW kg^(-1)along with exceptional cyclic stability and mechanical flexibility.The synergistic structural design offers a safe and efficient energy harvesting solution for wearable electronic devices and portable energy storage systems.
基金financial support from National Natural Science Foundation of China(Nos.22005186 and 51877132) was acknowledged。
文摘Flexible and stretchable energy storage devices are highly desirable for wearable electronics,particularly in the emerging fields of smart clothes,medical instruments,and stretchable skin.Lithium metal batteries(LMBs) with high power density and long cycle life are one of the ideal power sources for flexible and stretchable energy storage devices.However,the current LMBs are usually too rigid and bulky to meet the requirements of these devices.The electrolyte is the critical component that determines the energy density and security of flexible and stretchable LMBs.Among various electrolytes,gel polymer electrolytes(GPEs) perform excellent flexibility,safety,and high ionic conductivity compared with traditional liquid electrolytes and solid electrolytes,fulfilling the next generation deformable LMBs.This essay mainly reviews and highlights the recent progress in GPEs for flexible/stretchable LMBs and provides some useful insights for people interested in this field.Additionally,the multifunctional GPEs with self-healing,flame retardant,and temperature tolerance abilities are summarized.Finally,the perspectives and opportunities for flexible and stretchable GPEs are discussed.
基金supported by the National Natural Science Foundation of China(22375116,22001057)the Science Foundation of High-Level Talents of Wuyi University(2019AL017,2021AL002)Tianjin Lishen Battery Co.,Ltd。
文摘In-situ polymer electrolytes prepared by Li salt-initiated polymerization are promising electrolytes for solid-state Li metal batteries owing to their enhanced interface contact and facile and green preparation process.However,conventional in-situ polymer electrolytes suffer from poor interface stability,low mechanical strength,low oxidation stability,and certain flammability.Herein,a silsesquioxane(POSS)-nanocage-crosslinked in-situ polymer electrolyte(POSS-DOL@PI-F)regulated by fluorinated plasticizer and enhanced by polyimide skeleton is fabricated by Li salt initiated in-situ polymerization.Polyimide skeleton and POSS-nanocage-crosslinked network significantly enhance the tensile strength(22.8 MPa)and thermal stability(200℃)of POSS-DOL@PI-F.Fluorinated plasticizer improves ionic conductivity(6.83×10^(-4)S cm^(-1)),flame retardance,and oxidation stability(5.0 V)of POSS-DOL@PI-F.The fluorinated plasticizer of POSS-DOL@PI-F constructs robust LiF-rich solid electrolyte interphases and cathode electrolyte interphases,thereby dramatically enhancing the interface stability of Li metal anodes and LiNi_(0.8)Mn_(0.1)Co_(0.1)O_(2)(NCM811)cathodes.POSS-DOL@PI-F enables stable,long-term(1200 h),and dendrite-free cycle of Li‖Li cells.POSS-DOL@PI-F significantly boosts the performance of Li‖NCM811cells,which display superior cycle stability under harsh conditions of high voltage(4.5 V),high temperature(60℃),low temperature(-20℃),and high areal capacity.This work provides a rational design strategy for safe and efficient polymer electrolytes.
基金supported by the Basic Science Research Program(RS-2024-00344021,RS-2023-00261543,and RS-202300257666)through the National Research Foundation of Korea(NRF),the National Research Council of Science(000)Korea Institute for Advancement of Technology(KIAT)grant funded by the Korea Government(MOTIE)(RS-2024-00420590,HRD Program for Industrial Innovation)The computational resources were provided by KITSI(KSC-2024-CRE-0143)。
文摘Despite the growing interest in fast-cha rging solid-state lithium(Li)-metal batteries(SSLMBs),their practical implementation has yet to be achieved,primarily due to an incomplete understanding of the disparate and often conflicting requirements of the bulk electrolyte and the electrode-electrolyte interphase.Here,we present a weakly coordinating cationic polymer electrolyte(WCPE)specifically designed to regulate the Li^(+)coordination structure,thereby enabling fast-charging SSLMBs.The WCPE comprises an imidazolium-based polycationic matrix combined with a succinonitrile(SN)-based highconcentration electrolyte.Unlike conventional neutral polymer matrices,the polycationic matrix in the WCPE competes with Li^(+)for interactions with SN,weakening the original coordination between SN and Li^(+).This modulation of SN-Li^(+)interaction improves both Li^(+)conductivity of the WCPE(σ_(Li^(+))=1.29mS cm^(-1))and redox kinetics at the electrode-electrolyte interphase.Consequently,SSLMB cells(comprising LiFePO_(4)cathodes and Li-metal anodes)with the WCPE achieve fast-charging capability(reaching over 80%state of charge within 10 min),outperforming those of previously reported polymer electrolytebased SSLMBs.
基金supported by the 2024 Capital Construction Funds within the Provincial Budget of Jilin Provincial Development and Reform Commission[2024C018-2].
文摘Solid polymer electrolytes(SPEs)offer enhanced safety for next-generation lithium-ion batteries(LIBs)but typically suffer from low lithium-ion transference numbers(t_(Li^(+))),leading to concentration polarization and dendritic growth.To address this,we designed a boron-containing SPE(GBOEE)leveraging the electron-deficient nature of boron to immobilize anions.Thermogravimetric analysis revealed the stability of GBOEE up to 284.9℃.The optimized GBOEE-6.7 exhibited a high t_(Li^(+))of 0.49 and an ionic conductivity of 5.75×10^(-5)S·cm^(-1)at 30℃,with a 5.15 V electrochemical window.Symmetric Li//Li cells demonstrated stable cycling for 600 h at 0.05 mA·cm^(-2)with minimal polarization(0.15 V).LiFePO_(4)//Li cells delivered a high initial discharge capacity of 153.4 mAh·g^(-1)and 99.7%capacity retention after 100 cycles at 0.1 C.These results underscore the effectiveness of boron integration in designing high-performance,dendrite-suppressing SPEs for safe lithiummetal batteries(LMBs).
基金supported by Korea Institute of Science and Technology(KIST)Institutional Program and Open Research Program(ORP)This work was also supported by grant from the National Research Foundation(NRF)of Korea government(RS-2024-00433159 and RS-2023-00208313)from ITECH R&D program of MOTIE/KEIT(RS-2023-00257573).
文摘Fiber-shaped energy storage devices(FSESDs)with exceptional flexibility for wearable power sources should be applied with solid electrolytes over liquid electrolytes due to short circuits and leakage issue during deformation.Among the solid options,polymer electrolytes are particularly preferred due to their robustness and flexibility,although their low ionic conductivity remains a significant challenge.Here,we present a redox polymer electrolyte(HT_RPE)with 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl(HT)as a multi-functional additive.HT acts as a plasticizer that transforms the glassy state into the rubbery state for improved chain mobility and provides distinctive ion conduction pathway by the self-exchange reaction between radical and oxidized species.These synergetic effects lead to high ionic conductivity(73.5 mS cm−1)based on a lower activation energy of 0.13 eV than other redox additives.Moreover,HT_RPE with a pseudocapacitive characteristic by HT enables an outstanding electrochemical performance of the symmetric FSESDs using carbon-based fiber electrodes(energy density of 25.4 W h kg^(−1) at a power density of 25,000 W kg^(−1))without typical active materials,along with excellent stability(capacitance retention of 91.2%after 8,000 bending cycles).This work highlights a versatile HT_RPE that utilizes the unique functionality of HT for both the high ionic conductivity and improved energy storage capability,providing a promising pathway for next-generation flexible energy storage devices.
基金supported by the 2024 Capital Construction Funds within the Provincial Budget of Jilin Provincial Development and Reform Commission[2024C018-2].
文摘Conventional liquid electrolytes in lithium-ion batteries(LIBs)pose significant safety risks and interfacial instability,hindering the development of high-energy-density systems.Solid polymer electrolytes(SPEs),particularly polyethylene oxide(PEO)-based systems,offer enhanced safety but suffer from low room-temperature ionic conductivity due to high crystallinity,alongside limitations such as poor lithium-ion transference numbers and dendrite growth.To address these challenges,this study develops a novel composite solid electrolyte(PSPH)by synthesizing a polystyrene-polyethylene oxide-polystyrene(PSPEO-PS)triblock copolymer and blending it with poly(vinylidene fluoride-co-hexafluoropropylene)(PVDF-HFP)and lithium bis(trifluoromethylsulfonyl)imide(LiTFSI).The rigid PS segments suppress PEO crystallization,while PVDF-HFP enhances amorphous domain content,promotes LiTFSI dissociation via its high dielectric constant,and improves mechanical strength.The optimized PSPH composition(M_(w,PEO)=35 kg·mol^(-1),w_(PS)=15%,w_(PVDF-HFP)=30%)exhibits a high ionic conductivity of 1.05×10^(-4) S·cm^(-1)at 25℃,a Li^(+)transference number of 0.46,and an extended electrochemical stability window up to 4.8 V.PSPH demonstrates excellent thermal stability(decomposition onset at about 340℃),flexibility,and interfacial compatibility.LiFePO_(4)/PSPH/Li cells delivere a high discharge capacity of 163.7 mAh·g^(-1) at 0.1 C,with 96.2%capacity retention and 99.83%average coulombic efficiency after 200 cycles.Furthermore,Li/PSPH/Li symmetric cells exhibit stable cycling for over 1500 h at 0.05 mA·cm^(-2) with low overpotential(about 0.15 V).These results demonstrate that PSPH is a highly promising electrolyte for enhancing the safety and electrochemical performance of all-solid-state lithium-metal batteries(LMBs).
基金supported by the National Natural Science Foundation of China(No.52203261,No.52473213)the China Postdoctoral Science Foundation(2023731330)the Central Laboratory,School of Chemical and Material Engineering,Jiangnan University。
文摘Flame-retardant gel polymer electrolyte(FRGPE)with high ionic conductivity and practical safety is essential for the next generation of high energy density sodium metal batteries(SMBs).However,they suffer from serious side reactions and insufficient interfacial stability against sodium metal anode,causing severe performance degradation and even safety issues.Herein,to address these challenges,a fluoroethylene carbonate(FEC)additive confined metal-organic framework(MOF)-based composite gel(AC-MCG)interlayer was constructed upon sodium anode through a facile in-situ UV-induced photopolymerization.The FEC confined in AC-MCG induces the formation of NaF-rich inorganic solid-electrolyte interphase,effectively eliminating the side reactions between the FRGPE and sodium metal anode.Moreover,the MOF with ordered nanochannels can homogenize Na^(+)flux during the plating process and also endow the AC-MCG interlayer with high mechanical strength,thus sufficiently suppressing the growth of sodium dendrites.Benefitting from these merits of the AC-MCG interlayer,a high critical current density of 2.0 mA cm^(-2)and a long-term cycling life for over 4200 h at 0.1 mA cm^(-2)are achieved for the Na/Na symmetric cells.Besides,the solid-state SMBs paired with the constructed AC-MCG interlayer also demonstrated considerable electrochemical performance and practical safety.
基金supported by the Natural Science Foundation of China(22379073,52373275)the Natural Science Foundation of Tianjin,China(18JCZDJC31400)the Ministry of Education Innovation Team(IRT13022).
文摘Quasi-solid polymer electrolytes(QSPEs)have been attracted significant attentions due to their benefits for simultaneously improved safety and energy density of batteries.Developing electrolytes capable of forming a stable solid electrolyte interphase(SEI)layer is a great challenge for QSPE-based lithium(Li)metal batteries(LMBs).Herein,unlike previously reports that the reconstruction of Li^(+)solvation structures in QSPE requires time-consuming bottom-up polymer synthesis,in current study,a facile approach has been developed to reconstruct the Li^(+)solvation structures in QSPE by adjustment of the salt concentrations.The high proportion of Li^(+)-anion complexes can effectively accelerate interfacial Li^(+)diffusion,mitigate the decompositions of organic solvents and induce the formation of a LiF-rich SEI layer,contributing to suppressed Li-dendrite growth.As a result,the Li/QSPE-3/LiFePO_(4)(LFP)cell performs an ultralong lifespan with capacity retention of 77.4%over 3000 cycles at 1 C.With a high-voltage LiCoO_(2)cathode,the cell can stably cycle over 200 cycles at 25℃(capacity retention of∼83.8%).With accelerated ion transport dynamics due to the reconstructed Li^(+)solvation structure,the QSPE-3(the salt concentration is 3 M)is applicable in a wide temperature range.The Li/QSPE-3/LFP full cell exhibits 58.1%and 102.6%of discharge capacity at−15 and 90℃,respectively,compared to those operated at 25℃This study demonstrates a facile yet effective approach on enhancing electrode/electrolyte interfacial stability,enabling the LMBs with simultaneously enhanced safety and high energy density.
基金supported by the 2024 Capital Construction Funds within the Provincial Budget of Jilin Provincial Development and Reform Commission[2024C018-2].
文摘The development of high-performance solid-state electrolytes(SSEs)capable of reconciling high ionic conductivity with robust mechanical strength is crucial for advancing safe lithium-metal batteries(LMBs).In this study,we synthesized a novel BAB-type triblock copolymer PuPyMA-b-PEO-b-PuPyMA and used it to prepare SSEs.The copolymer design incorporates polyethylene oxide(PEO)segments to achieve ionic conduction,while uracil ketone(uPy)groups are introduced to provide quadruple hydrogen bonding.This molecular architecture leverages microphase separation and supramolecular interactions to optimize performance.The optimized electrolyte,PPMP-30 with w(uPyMA)=30%,n(EO)/n(Li^(+))=25/1,exhibits outstanding comprehensive properties at room temperature:an ionic conductivity of 4.0×10^(-4)S·cm^(-1),a high Li^(+)transference number of 0.41,and an extended electrochemical stability window up to 5.6 V(vs.Li^(+)/Li).Li//Li symmetric cells demonstrate exceptional interfacial stability and lithium dendrite suppression,cycling stably for over 650 h at 0.05 mA·cm^(-2).When assembled into LiFePO_(4)//Li cells,the electrolyte enables a high initial discharge capacity(about 160 mAh·g^(-1)at 0.1 C),excellent cycling stability(85.0%capacity retention after 120 cycles),and good rate capability with significant capacity recovery upon returning to low rates.These results highlight the significant potential of this tetrahedral hydrogen-bonded block copolymer electrolyte in overcoming the ionic conductivity-mechanical strength trade-off for practical solid-state LMBs.
基金supported by the National Natural Science Foundation of China(No.52130101)the Project of Science and Technology Development Plan of Jilin Province in China(Nos.20210402058GH and 20220201114GX)。
文摘Sodium-sulfur(Na-S)batteries are believed as the hopeful energy storage and conversion techniques owing to the high specific capacity and low cost.Nevertheless,unstable sodium(Na)deposition/stripping of Na metal anode,low intrinsic conductivity of sulfur cathode,and severe shuttling effect of sodium polysulfides(NaPSs)pose significant challenges in the actual reversible capacity and cycle life of Na-S batteries.Herein,a self-supporting electrode made of nitrogen-doped carbon fiber embedded with cobalt nanoparticles(Co/NC-CF)is designed to load sulfur.Meanwhile,gel polymer electrolyte(GPE)with high ion transfer ability is obtained by in-situ polymerization inside the battery.During the polymerization process,an integrated electrode-electrolyte and a continuous ion-electron conduction network in a composite cathode are constructed inside the Na-S battery.It is noteworthy that the designed GPE demonstrates superior ionic conductivity and effective adsorption of NaPSs that can significantly suppress the shuttle effect.Leveraging the synergistic interplay between the designed GPE and self-supporting cathode,the assembled quasi-solid-state(QSS)Na-S battery exhibits great cycling stability.These experimental results are further corroborated by COMSOL Multiphysics simulations and density functional theory(DFT)calculations,which mechanistically validate the enhanced electrochemical performance.The findings of this study offer new and promising perspectives for advancing the development of nextgeneration solid-state batteries.
基金the National Natural Science Foundation of China(grant nos.52020105012 and 523B2025)the Innovation and Talent Recruitment Base of New Energy Chemistry and Device(B21003)the Analysis and Testing Center of HUST for the assistance in analysis and testing。
文摘Solid polymer electrolytes(SPEs)have garnered considerable interest in the field of lithium metal batteries(LMBs)owing to their exceptional mechanical strength,excellent designability,and heightened safety characteristics.However,their inherently low ion transport efficiency poses a major challenge for their application in LMBs.To address this issue,covalent organic framework(COF)with their ordered ion transport channels,chemical stability,large specific surface area,and designable multifunctional sites has shown promising potential to enhance lithium-ion conduction.Here,we prepared an anionic COF,Tp Pa-COOLi,which can catalyze the ring-opening copolymerization of cyclic lactone monomers for the in situ fabrication of SPEs.The design leverages the high specific surface area of COF to facilitate the absorption of polymerization precursor and catalyze the polymerization within the pores,forming additional COF-polymer junctions that enhance ion transport pathways.The partial exfoliation of COF achieved through these junctions improved its dispersion within the polymer matrix,preserving ion transport channels and facilitating ion transport across COF grain boundaries.By controlling variables to alter the crystallinity of Tp Pa-COOLi and the presence of-COOLi substituents,Tp Pa-COOLi with partial long-range order and-COOLi substituents exhibited superior electrochemical performance.This research demonstrates the potential in constructing high-performance SPEs for LMBs.
基金financially supported by the National Key R&D Program of China(Grant No.2022YFE0207300)National Natural Science Foundation of China(Grant Nos.22179142 and 22075314)+1 种基金Jiangsu Funding Program for Excellent Postdoctoral Talent(Grant No.2024ZB051 and 2023ZB836)the technical support for Nano-X from Suzhou Institute of Nano-Tech and Nano-Bionics,Chinese Academy of Sciences(SINANO).
文摘Solid polymer electrolytes(SPEs)have attracted much attention for their safety,ease of packaging,costeffectiveness,excellent flexibility and stability.Poly-dioxolane(PDOL)is one of the most promising matrix materials of SPEs due to its remarkable compatibility with lithium metal anodes(LMAs)and suitability for in-situ polymerization.However,poor thermal stability,insufficient ionic conductivity and narrow electrochemical stability window(ESW)hinder its further application in lithium metal batteries(LMBs).To ameliorate these problems,we have successfully synthesized a polymerized-ionic-liquid(PIL)monomer named DIMTFSI by modifying DOL with imidazolium cation coupled with TFSI^(-)anion,which simultaneously inherits the lipophilicity of DOL,high ionic conductivity of imidazole,and excellent stability of PILs.Then the tridentate crosslinker trimethylolpropane tris[3-(2-methyl-1-aziridine)propionate](TTMAP)was introduced to regulate the excessive Li^(+)-O coordination and prepare a flame-retardant SPE(DT-SPE)with prominent thermal stability,wide ESW,high ionic conductivity and abundant Lit transference numbers(t_(Li+)).As a result,the LiFePO_(4)|DT-SPE|Li cell exhibits a high initial discharge specific capacity of 149.60 mAh g^(-1)at 0.2C and 30℃with a capacity retention rate of 98.68%after 500 cycles.This work provides new insights into the structural design of PIL-based electrolytes for long-cycling LMBs with high safety and stability.
基金supported by the National Research Foundation of Korea(NRF)(no.:NRF-2020M3H4A3081874)the National Research Council of Science&Technology(NST)grant by the Korea government(MSIT)(no.:GTL24011-000)the Korea Research Institute of Chemical Technology(KRICT),Republic of Korea(no.KS2422-20).
文摘Solid polymer electrolytes have garnered significant attention for lithium batteries because of their flexibility and safety.However,poor ionic conductivity,lithium dendrite formation,and high impedance hinder their practical application.In this study,a thin,flexible,3D hybrid solid electrolyte(3DHSE)is prepared by in situ thermal cross-linking polymerization with electrospun 3D nanowebs.The 3DHSE comprises Al-doped Li_(7)La_(3)Zr_(2)O_(12)(ALLZO)embedded in electrospun poly(vinylidene fluoride-cohexafluoropropylene)(PVDF-HFP)nonwoven 3D nanowebs and an in situ cross-linked polyethylene oxide(PEO)-based solid polymer electrolyte.The 3DHSE exhibits high tensile strength(6.55 MPa),a strain of 40.28%,enhanced ionic conductivity(7.86×10^(-4) S cm^(-1)),and a superior lithium-ion transference number(0.76)to that of the PVDF-HFP-based solid polymer electrolyte(PSPE).This enables highly stable lithium plating/stripping cycling for over 900 h at 25℃ with a current density of 0.2 mA cm^(-2).The LiNi_(0.8)Mn_(0.1)Co_(0.1)O_(2)(NCM811)/3DHSE/Li cell has a higher capacity(140.56 mAh g^(-1) at 0.1 C)than the NCM811/PSPE/Li cell(124.88 mAh g^(-1) at 0.1 C)at 25℃.The 3DHSE enhances mechanical properties,stabilizes interfacial contact,improves ion transport,prevents NCM811 cracking,and significantly boosts cycling performance.This study highlights the potential of the 3DHSE as a candidate for advanced lithium polymer battery technology.
