Reasonable design a high-entropy garnet-type solid electrolyte for all-solid-state lithium batteries

Traditional garnet solid electrolyte(Li_(7)La_(3)Zr_(2)O_(12))suffers from low room temperature ionic conductivity,poor air stability,high sintering temperature and energy consumption.Considering the development prospects of high-entropy materials with high structural disorder and strong component controllability in the field of electrochemical energy storage,herein,a novel high-entropy garnet-type oxide solid electrolyte,Li_(5.75)Ga_(0.25)La_(3)Zr_(0.5)Ti_(0.5)Sn_(0.5)Nb_(0.5)O_(12)(LGLZTSNO)was constructed by partially replacing the Li and Zr sites in Li_(7)La_(3)Zr_(2)O_(12)with Ga and Ti/Sn/Nb elements,respectively.The experimental and density functional theory(DFT)calculation results show that the high-entropy LGLZTSNO electrolyte has preferable room temperature ion conductivity,air stability,interface contact performance with lithium anode,and the ability to suppress lithium dendrites.Thanks to the improvement of electrolyte performance,the critical current density of Li/Ag@LGLZTSNO/Li symmetric cell was increased from 0.42 to 1.57 mA cm^(−2),and the interface area specific impedance(IASR)was reduced from 765.2 to 42.3Ωcm^(2).Meanwhile,the Li/Ag@LGLZTSNO/LFP full cell also exhibits excellent rate performance and cycling performance(148 mA h g^(−1)at 0.1 C and 124 mA h g^(−1)at 0.5 C,capacity retention up to 84.8%after 100 cycles at 0.1 C),showing the application prospects of high-entropy LGLZTSNO solid electrolyte in high-performance all solid state lithium batteries.

Atom substitution of the solid-state electrolyte Li_(10)GeP_(2)S_(12)for stabilized all-solid-state lithium metal batteries

Solid-state electrolyte Li_(10)GeP_(2)S_(12)(LGPS)has a high lithium ion conductivity of 12 mS cm^(-1)at room temperature,but its inferior chemical stability against lithium metal anode impedes its practical application.Among all solutions,Ge atom substitution of the solid-state electrolyte LGPS stands out as the most promising solution to this interface problem.A systematic screening framework for Ge atom substitution including ionic conductivity,thermodynamic stability,electronic and mechanical properties is utilized to solve it.For fast screening,an enhanced model Dop Net FC using chemical formulas for the dataset is adopted to predict ionic conductivity.Finally,Li_(10)SrP_(2)S_(12)(LSrPS)is screened out,which has high lithium ion conductivity(12.58 mS cm^(-1)).In addition,an enhanced migration of lithium ion across the LSr PS/Li interface is found.Meanwhile,compared to the LGPS/Li interface,LSrPS/Li interface exhibits a larger Schottky barrier(0.134 eV),smaller electron transfer region(3.103?),and enhanced ability to block additional electrons,all of which contribute to the stabilized interface.The applied theoretical atom substitution screening framework with the aid of machine learning can be extended to rapid determination of modified specific material schemes.

A dynamic database of solid-state electrolyte(DDSE)picturing all-solid-state batteries

All-solid-state batteries(ASSBs)are a class of safer and higher-energy-density materials compared to conventional devices,from which solid-state electrolytes(SSEs)are their essential components.To date,investigations to search for high ion-conducting solid-state electrolytes have attracted broad concern.However,obtaining SSEs with high ionic conductivity is challenging due to the complex structural information and the less-explored structure-performance relationship.To provide a solution to these challenges,developing a database containing typical SSEs from available experimental reports would be a new avenue to understand the structureperformance relationships and find out new design guidelines for reasonable SSEs.Herein,a dynamic experimental database containing>600 materials was developed in a wide range of temperatures(132.40–1261.60 K),including mono-and divalent cations(e.g.,Li^(+),Na^(+),K^(+),Ag^(+),Ca^(2+),Mg^(2+),and Zn^(2+))and various types of anions(e.g.,halide,hydride,sulfide,and oxide).Data-mining was conducted to explore the relationships among different variates(e.g.,transport ion,composition,activation energy,and conductivity).Overall,we expect that this database can provide essential guidelines for the design and development of high-performance SSEs in ASSB applications.This database is dynamically updated,which can be accessed via our open-source online system.

12.6μm-Thick Asymmetric Composite Electrolyte with Superior Interfacial Stability for Solid-State Lithium-Metal Batteries

Solid-state lithium metal batteries(SSLMBs)show great promise in terms of high-energy-density and high-safety performance.However,there is an urgent need to address the compatibility of electrolytes with high-voltage cathodes/Li anodes,and to minimize the electrolyte thickness to achieve highenergy-density of SSLMBs.Herein,we develop an ultrathin(12.6μm)asymmetric composite solid-state electrolyte with ultralight areal density(1.69 mg cm^(−2))for SSLMBs.The electrolyte combining a garnet(LLZO)layer and a metal organic framework(MOF)layer,which are fabricated on both sides of the polyethylene(PE)separator separately by tape casting.The PE separator endows the electrolyte with flexibility and excellent mechanical properties.The LLZO layer on the cathode side ensures high chemical stability at high voltage.The MOF layer on the anode side achieves a stable electric field and uniform Li flux,thus promoting uniform Li^(+)deposition.Thanks to the well-designed structure,the Li symmetric battery exhibits an ultralong cycle life(5000 h),and high-voltage SSLMBs achieve stable cycle performance.The assembled pouch cells provided a gravimetric/volume energy density of 344.0 Wh kg^(−1)/773.1 Wh L^(−1).This simple operation allows for large-scale preparation,and the design concept of ultrathin asymmetric structure also reveals the future development direction of SSLMBs.

Lithiophilic Li-Si alloy-solid electrolyte interface enabled by high-concentration dual salt-reinforced quasi-solid-state electrolyte

Solid polymer electrolytes(SPEs)are urgently required to achieve practical solid-state lithium metal batteries(LMBs)and lithium-ion batteries(LIBs),Herein,we proposed a mechanism for modulating interfacial conduction and anode interfaces in high-concentration SPEs by LiDFBOP.Optimized electrolyte exhibits superior ionic conductivity and remarkable interface compatibility with salt-rich clusters:(1)polymer-plastic crystal electrolyte(P-PCE,TPU-SN matrix)dissociates ion pairs to facilitate Li+transport in the electrolyte and regulates Li^(+)diffusion in the SEI.The crosslinking structure of the matrix compensates for the loss of mechanical strength at high-salt concentrations;(2)dual-anion TFSI^(-)_(n)-DFBOP^(-)_(m)in the Li^(+)solvation sheath facilitates facile Li^(+)desolvation and formation of salt-rich clusters and is conducive to the formation of Li conductive segments of TPU-SN matrix;(3)theoretical calculations indicate that the decomposition products of LiDFBOP form SEI with lower binding energy with LiF in the SN system,thereby enhancing the interfacial electrochemical redox kinetics of SPE and creating a solid interface SEI layer rich in LiF.As a result,the optimized electrolyte exhibits an excellent ionic conductivity of9.31×10^(-4)S cm^(-1)at 30℃and a broadened electrochemical stability up to 4.73 V.The designed electrolyte effectively prevents the formation of Li dendrites in Li symmetric cells for over 6500 h at0.1 mA cm^(-2).The specific Li-Si alloy-solid state half-cell capacity shows 711.6 mAh g^(-1)after 60 cycles at 0.3 A g^(-1).Excellent rate performance and cycling stability are achieved for these solid-state batteries with Li-Si alloy anodes and NCM 811 cathodes.NCM 811‖Prelithiated silicon-based anode solid-state cell delivers a discharge capacity of 195.55 mAh g^(-1)and a capacity retention of 97.8%after 120 cycles.NCM 811‖Li solid-state cell also delivers capacity retention of 84.2%after 450 cycles.

Revealing the specific role of sulfide and nano-alumina in composite solid-state electrolytes for performance-reinforced ether-nitrile copolymers

Composite solid-state electrolytes represent a critical pathway that balances the interface compatibility and lithium-ion conductivity in all-solid-state batteries.The quest for stable and highly ion-conductive combinations between polymers and fillers is vital,but blind attempts are often made due to a lack of understanding of the mechanisms involved in the interaction between polymers and fillers.Herein,we employ in-situ polymerization to prepare a polymer based on an ether-nitrile copolymer with high cathode stability as the foundation and discuss the performance enhancement mechanisms of argyrodite and nano-alumina.With 1%content of sulfide interacting with the polymer at the two-phase interface,the local enhancement of lithium-ion migration capability can be achieved,avoiding the reduction in capacity due to the low ion conductivity of the passivation layer during cycling.The capacity retention after 50cycles at 0.5 C increases from 83.5%to 94.4%.Nano-alumina,through anchoring the anions and interface inhibition functions,eventually poses an initial discharge capacity of 136.8 m A h g^(-1)at 0.5 C and extends the cycling time to 1000 h without short-circuiting in lithium metal batteries.Through the combined action of dual fillers on the composite solid-state electrolyte,promising insights are provided for future material design.

Incorporation of Ionic Conductive Polymers into Sulfide Electrolyte-Based Solid-State Batteries to Enhance Electrochemical Stability and Cycle Life

Sulfide-based inorganic solid electrolytes are promising materials for high-performance safe solid-state batteries.The high ion conductivity,mechanical characteristics,and good processability of sulfide-based inorganic solid electrolytes are desirable properties for realizing high-performance safe solid-state batteries by replacing conventional liquid electrolytes.However,the low chemical and electrochemical stability of sulfide-based inorganic solid electrolytes hinder the commercialization of sulfide-based safe solid-state batteries.Particularly,the instability of sulfide-based inorganic solid electrolytes is intensified in the cathode,comprising various materials.In this study,carbonate-based ionic conductive polymers are introduced to the cathode to protect cathode materials and suppress the reactivity of sulfide electrolytes.Several instruments,including electrochemical spectroscopy,X-ray photoelectron spectroscopy,and scanning electron microscopy,confirm the chemical and electrochemical stability of the polymer electrolytes in contact with sulfide-based inorganic solid electrolytes.Sulfide-based solid-state cells show stable electrochemical performance over 100 cycles when the ionic conductive polymers were applied to the cathode.

A three-dimensional co-continuous network structure polymer electrolyte with efficient ion transport channels enabling ultralong-life all solid-state lithium metal batteries

Solid polymer electrolytes(SPEs)have emerged as one of the most promising candidates for the construction of solid-state lithium batteries due to their excellent flexibility,scalability,and interface compatibility with electrodes.Herein,a novel all-solid polymer electrolyte(PPLCE)was fabricated by the copolymer network of liquid crystalline monomers and poly(ethylene glycol)dimethacrylate(PEGDMA)acts as a structural frame,combined with poly(ethylene glycol)diglycidyl ether short chain interspersed serving as mobile ion transport entities.The preparaed PPLCEs exhibit excellent mechanical property and out-standing electrochemical performances,which is attributed to their unique three-dimensional cocontinuous structure,characterized by a cross-linked semi-interpenetrating network and an ionic liquid phase,resulting in a distinctive nanostructure with short-range order and long-range disorder.Remarkably,the addition of PEGDMA is proved to be critical to the comprehensive performance of the PPLCEs,which effectively modulates the microscopic morphology of polymer networks and improves the mechanical properties as well as cycling stability of the solid electrolyte.When used in a lithiumion symmetrical battery configuration,the 6 wt%-PPLCE exhibites super stability,sustaining operation for over 2000 h at 30 C,with minimal and consistent overpotential of 50 mV.The resulting Li|PPLCE|LFP solid-state battery demonstrates high discharge specific capacities of 160.9 and 120.1 mA h g^(-1)at current densities of 0.2 and 1 C,respectively.Even after more than 300 cycles at a current density of 0.2 C,it retaines an impressive 73.5%capacity.Moreover,it displayes stable cycling for over 180 cycles at a high current density of 0.5C.The super cycle stability may promote the application for ultralong-life all solid-state lithium metal batteries.

Data-Driven Viewpoint for Developing Next-Generation Mg-Ion Solid-State Electrolytes

Magnesium(Mg)is a promising alternative to lithium(Li)as an anode material in solid-state batteries due to its abundance and high theoretical volumetric capacity.However,the sluggish Mg-ion conduction in the lattice of solidstate electrolytes(SSEs)is one of the key challenges that hamper the development of Mg-ion solid-state batteries.Though various Mg-ion SSEs have been reported in recent years,key insights are hard to be derived from a single literature report.Besides,the structure-performance relationships of Mg-ion SSEs need to be further unraveled to provide a more precise design guideline for SSEs.In this viewpoint article,we analyze the structural characteristics of the Mg-based SSEs with high ionic conductivity reported in the last four decades based upon data mining-we provide big-data-derived insights into the challenges and opportunities in developing next-generation Mg-ion SSEs.

Anion competition for Li^(+)solvated coordination environments in poly(1,3 dioxolane)electrolyte to enable high-voltage lithium metal solid-state batteries

Gel-based polymer electrolytes are limited by the polarity of the residual solvent,which restricts the coupling-breaking behaviour during Li^(+)conduction,resulting in the Li^(+)transport kinetics being greatly affected.Here,we designed anion competitive gel polymer electrolyte(ACPE)by introducing lithium difluoro(oxalato)borate(LiDFOB)anion into the 1,3-dioxolane(DOL)in situ polymerisation system.ACPE enhances the ionic dipole interaction between Li^(+)and the solvent molecules and synergizes with Li^(+)across the solvation site of the polymer ethylene oxide(EO)unit,combination that greatly improves the Li^(+)transport efficiency.As a result,ACPE exhibits 1.12 mS cm^(−1)ionic conductivity and 0.75 Li^(+)transfer number at room temperature.Additionally,this intra-polymer solvation sheath allows preferential desolvation of DFOB−,which contributes to the formation of kinetically stable anion-derived interphase and effectively mitigates side reactions.Our results demonstrate that the assembled Li||NCM622 solid-state battery exhibits lifespan of over 300 cycles with average Coulombic efficiency of 98.8%and capacity retention of 80.3%.This study introduces a novel approach for ion migration and interface design,paving the way for high-safety and high-energy-density batteries.

A gel polymer electrolyte based on IL@NH_(2)-MIL-53(Al)for high-performance all-solid-state lithium metal batteries

Solid polymer composite electrolytes possess the benefits of superior compatibility with electrodes and good thermal characteristics for more secure energy storage equipment.Herein,a new gel polymer electrolyte(GPE)containing NH_(2)-MIL-53(Al),[PP_(13)][TFSI],LiTFSI,and PVDF-HFP was prepared using a simple method of solution casting.The effects of encapsulating different ratios of ionic liquid([PP_(13)][TFSI])into the micropores of functionalized metal-organic frameworks(NH_(2)-MIL-53(Al))on the electrochemical properties were compared.XRD,SEM,nitrogen adsorption-desorption isotherms,and electrochemical measurements were conducted.This GPE demonstrates a superior ionic conductivity of 8.08×10^(-4)S·cm^(-1)at 60℃and can sustain a discharge specific capacity of 156.6 mA·h·g^(-1)at 0.2 C for over 100 cycles.This work might offer a potential approach to alleviate the solid-solid contact with the solid-state electrolyte and electrodes and broaden a new window for the creation of all-solid-state batteries.

Fast ion-conducting high-entropy garnet solid-state electrolytes with excellent air stability

The garnet-type electrolyte is one of the most promising solid-state electrolytes(SSEs)due to its high ionic conductivity(σ)and wide electrochemical window.However,such electrolyte generates lithium carbonate(Li_(2)CO_(3))in air,leading to an increase in impedance,which greatly limits their practical applications.In turn,high-entropy ceramics(HECs)can improve phase stability due to high-entropy effect.Herein,high-entropy garnet(HEG)Li_(6.2)La_(3)(Zr_(0.2)Hf_(0.2)Ti_(0.2)Nb_(0.2)Ta_(0.2))_(2)O_(12)(LL(ZrHfTiNbTa)O)SSEs were synthesized by the solid-state reaction method.X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),electrochemical impedance spectroscopy(EIS),and scanning electron microscopy(SEM)characterizations indicated that the LL(ZrHfTiNbTa)O electrolyte has excellent air stability.Room-temperature conductivity of LL(ZrHfTiNbTa)O can be maintained at~1.42×10^(-4)S/cm after exposure to air for 2 months.Single-element-doped garnets were synthesized to explain the role of different elements and the mechanism of air stabilization.In addition,a lithium(Li)/LL(ZrHfTiNbTa)O/Li symmetric cell cycle is stable over 600 h,and the critical current density(CCD)is 1.24 mA/cm^(2),indicating remarkable stability of the Li/LL(ZrHfTiNbTa)O interface.Moreover,the LiFePO_(4)/LL(ZrHfTiNbTa)O/Li cell shows excellent rate performance at 30℃.These results suggest that HECs can be one of the strategies for improving the performance of SSEs in the future due to their unique effects.

Green recycling of short-circuited garnet-type electrolyte for high-performance solid-state lithium batteries

Solid-state lithium batteries(SSLBs)solve safety issues and are potentially energy-dense alternatives to next-generation energy storage systems.Battery green recycling routes are responsible for the widespread use of SSLBs due to minimizing environmental contamination,reducing production costs,and providing a sustainable solution for resources,e.g.,saving rare earth elements(La,Ta,etc.).Herein,a solid-state recycling strategy is proposed to achieve green recycling of the crucial component solidstate electrolytes(SSEs)in spent SSLBs.The short-circuited garnet Li_(6.5)La_(3)Zr_(1.5)Ta_(0.5)O_(12)(LLZTO)is broken into fine particles and mixed with fresh particles to improve sintering activity and achieve high packing density.The continuous Li absorption process promotes sufficient grain fusion and guarantees the transformation from tetragonal phase to pure cubic phase for high-performance recycled LLZTO.The Li-ion conductivity reaches 5.80×10^(-4)S cm-1with a relative density of 95.9%.Symmetric Li cell with asrecycled LLZTO shows long-term cycling stability for 700 h at 0.3 mA cm^(-2)without any voltage hysteresis.Full cell exhibits an excellent cycling performance with a discharge capacity of 141.5 mA h g^(-1)and a capacity retention of 92.1%after 400 cycles(0.2C).This work develops an environmentally friendly and economically controllable strategy to recycle SSE from spent SSLBs,guiding future directions of SSLBs large-scale industrial application and green recycling study.

Recent advances in solving Li_(2)CO_(3) problems in garnet-based solid-state battery: A systematic review(2020-2023)

Garnet solid electrolytes are one of the most promising electrolytes for solid-state batteries.However,Li_(2)CO_(3) is a critical issue that hinders the practical application of garnet-based solid-state lithium-ion batteries.There are two sources of Li_(2)CO_(3) contamination.The main one is the aging of garnet electrolytes in the atmosphere.Garnet electrolytes can react with H_(2)O and CO_(2) in the air to form Li_(2)CO_(3),which reduces ion conductivity,increases electrode/garnet electrolyte interface resistance,and deteriorates the electrochemical performance of the battery.Various strategies,such as elemental doping,grain boundary manipulation,and interface engineering,have been suggested to address these issues.The other is the passivation layer(Li_(2)CO_(3),Li_3N,LiOH,Li_(2)O) formed on the surface of the lithium foil after long-term storage,which is ignored by most researchers.To better understand the current strategies and future trends to address the Li_(2)CO_(3) problem,this perspective provides a systematic review of journals published in this field from 2020-2023.

Enhanced High-Temperature Cycling Stability of Garnet-Based All Solid-State Lithium Battery Using a Multi-Functional Catholyte Buffer Layer

The pursuit of safer and high-performance lithium-ion batteries(LIBs)has triggered extensive research activities on solid-state batteries,while challenges related to the unstable electrode-electrolyte interface hinder their practical implementation.Polymer has been used extensively to improve the cathode-electrolyte interface in garnet-based all-solid-state LIBs(ASSLBs),while it introduces new concerns about thermal stability.In this study,we propose the incorporation of a multi-functional flame-retardant triphenyl phos-phate additive into poly(ethylene oxide),acting as a thin buffer layer between LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM811)cathode and garnet electro-lyte.Through electrochemical stability tests,cycling performance evaluations,interfacial thermal stability analysis and flammability tests,improved thermal stability(capacity retention of 98.5%after 100 cycles at 60℃,and 89.6%after 50 cycles at 80℃)and safety characteristics(safe and stable cycling up to 100℃)are demonstrated.Based on various materials characterizations,the mechanism for the improved thermal stability of the interface is proposed.The results highlight the potential of multi-functional flame-retardant additives to address the challenges associated with the electrode-electrolyte interface in ASSLBs at high temperature.Efficient thermal modification in ASSLBs operating at elevated temperatures is also essential for enabling large-scale energy storage with safety being the primary concern.

A gel polymer electrolyte with IL@UiO-66-NH_(2) as fillers for high-performance all-solid-state lithium metal batteries

All solid-state electrolytes have the advantages of good mechanical and thermal properties for safer energy storage,but their energy density has been limited by low ionic conductivity and large interfacial resistance caused by the poor Li~+transport kinetics due to the solid-solid contacts between the electrodes and the solid-state electrolytes.Herein,a novel gel polymer electrolyte(UPP-5)composed of ionic liquid incorporated metal-organic frameworks nanoparticles(IL@MOFs)is designed,it exhibits satisfying electrochemical performances,consisting of an excellent electrochemical stability window(5.5 V)and an improved Li^(+)transference number of 0.52.Moreover,the Li/UPP-5/LiFePO_(4) full cells present an ultra-stable cycling performance at 0.2C for over 100 cycles almost without any decay in capacities.This study might provide new insight to create an effective Li^(+)conductive network for the development of all-solid-state lithium-ion batteries.

Elucidating Ion Transport Phenomena in Sulfide/Polymer Composite Electrolytes for Practical Solid-State Batteries

Despite the enormous interest in inorganic/polymer composite solid-state electrolytes(CSEs)for solid-state batteries(SSBs),the underlying ion transport phenomena in CSEs have not yet been elucidated.Here,we address this issue by formulating a mechanistic understanding of bi-percolating ion channels formation and ion conduction across inorganic-polymer electrolyte interfaces in CSEs.A model CSE is composed of argyrodite-type Li_6PS_5Cl(LPSCl)and gel polymer electrolyte(GPE,including Li~+-glyme complex as an ion-conducting medium).The percolation threshold of the LPSCl phase in the CSE strongly depends on the elasticity of the GPE phase.Additionally,manipulating the solvation/desolvation behavior of the Li~+-glyme complex in the GPE facilitates ion conduction across the LPSCl-GPE interface.The resulting scalable CSE(area=8×6(cm×cm),thickness~40μm)can be assembled with a high-mass-loading LiNi_(0.7)Co_(0.15)Mn_(0.15)O_(2)cathode(areal-mass-loading=39 mg cm~(-2))and a graphite anode(negative(N)/positive(P)capacity ratio=1.1)in order to fabricate an SSB full cell with bi-cell configuration.Under this constrained cell condition,the SSB full cell exhibits high volumetric energy density(480 Wh L_(cell)~(-1))and stable cyclability at 25℃,far exceeding the values reported by previous CSE-based SSBs.

COF-based single Li^(+)solid electrolyte accelerates the ion diffusionandrestrains dendritegrowthin quasi-solid-state organic batteries

A solid-state electrolyte(SSE),which is a solid ionic conductor and electroninsulating material,is known to play a crucial role in adapting a lithium metal anode to a high-capacity cathode in a solid-state battery.Among the various SSEs,the single Li-ion conductor has advantages in terms of enhancing the ion conductivity,eliminating interfacial side reactions,and broadening the electrochemical window.Covalent organic frameworks(COFs)are optimal platforms for achieving single Li-ion conduction behavior because of wellordered one-dimensional channels and precise chemical modification features.Herein,we study in depth three types of Li-carboxylate COFs(denoted LiOOC-COFn,n=1,2,and 3)as single Li-ion conducting SSEs.Benefiting from well-ordered directional ion channels,the single Li-ion conductor LiOOC-COF3 shows an exceptional ion conductivity of 1.36×10^(-5) S cm^(-1) at room temperature and a high transference number of 0.91.Moreover,it shows excellent electrochemical performance with long-term cycling,high-capacity output,and no dendrites in the quasi-solid-state organic battery,with the organic small molecule cyclohexanehexone(C_(6)O_(6))as the cathode and the Li metal as the anode,and enables effectively avoiding dissolution of the organic electrode by the liquid electrolyte.

The effects of amino groups and open metal sites of MOFs on polymer-based electrolytes for all-solid-state lithium metal batteries

Metal-organic frameworks(MOFs) are becoming more and more popular as the fillers in polymer electrolytes in recent years. In this study, a series of MOFs(NH_(2)-MIL-101(Fe), MIL-101(Fe), activated NH_(2)-MIL-101(Fe) and activated MIL-101(Fe)) were synthesized and added to PEO-based solid composite electrolytes(SCEs). Furthermore, the role of the —NH_(2) groups and open metal sites(OMSs) were both examined. Different ratios of MOFs vs polymers were also studied by the electrochemical characterizations. At last, we successfully designed a novel solid composite electrolyte containing activated NH_(2)-MIL-101(Fe),PEO, Li TFSI and PVDF for the high-performance all-solid-state lithium-metal batteries. This work might provide new insight to understand the interactions between polymers and functional groups or OMSs of MOFs better.

Polymer dispersed ionic liquid electrolytes with high ionic conductivity for ultrastable solid-state lithium batteries

Solid polymer electrolytes(SPEs)have emerged as one of the most promising candidates for building solid-state lithium batteries due to their excellent flexibility,scalability,and interfacial compatibility with electrodes.However,the low ionic conductivity and poor cyclic stability of SPEs do not meet the requirements for practical applications of lithium batteries.Here,a novel polymer dispersed ionic liquid-based solid polymer electrolyte(PDIL-SPE)is fabricated using the in situ polymerization-induced phase separation(PIPS)method.The as-prepared PDIL-SPE possesses both outstanding ionic conductivity(0.74 mS cm^(-1) at 25℃)and a wide electrochemical window(up to 4.86 V),and the formed unique three-dimensional(3D)co-continuous structure of polymer matrix and ionic liquid in PDIL-SPE can promote the transport of lithium ions.Also,the 3D co-continuous structure of PDIL-SPE effectively accommodates the severe volume expansion for prolonged lithium plating and stripping processes over 1000 h at 0.5 mA cm^(-2) under 25℃.Moreover,the LiFePO_(4)//Li coin cell can work stably over 150 cycles at a 1 C rate under room temperature with a capacity retention of 90.6%from 111.1 to 100.7 mAh g^(-1).The PDIL-SPE composite is a promising material system for enabling the ultrastable operation of solid-state lithium-metal batteries.