Stabilizing zinc anode using zeolite imidazole framework functionalized separator for durable aqueous zinc-ion batteries

Aqueous zinc-ion batteries(AZIBs) hold great promise as a viable alternative to lithium-ion batteries owing to their high energy density and environmental friendliness.However,AZIBs are consistently plagued by the formation of zinc dendrites and concurrent side reactions,which significantly diminish their overall service life,In this study,the glass fiber separator(GF) is modified using zeolite imidazole salt framework-8(ZIF-8),enabling the development of efficient AZIBs.ZIF-8,which is abundant in nitrogen content,efficiently regulates the desolvation of [Zn(H_(2)O)_(6)]^(2+) to inhibit hydrogen production.Moreover,it possesses abundant nanochannels that facilitate the uniform deposition of Zn~(2+) via a localized action,thereby hindering the formation of dendrites.The insulating properties of ZIF-8 help prevent Zn^(2+) and water from trapping electron reduction at the layer surface,which reduces corrosion of the zinc anode.Consequently,ZIF-8-GF achieves the even transport of Zn^(2+) and regulates the homogeneous deposition along the Zn(002) crystal surface,thus significantly enhancing the electrochemical performance of the AZIBs,In particular,the Zn|Zn symmetric cell with the ZIF-8-GF separator delivers a stable cycle life at0.5 mA cm^(-2) of 2300 h.The Zn|ZIF-8-GF|MnO_(2) cell exhibits reduced voltage polarization while maintaining a capacity retention rate(93.4%) after 1200 cycles at 1.2 A g^(-1) The unique design of the modified diaphragm provides a new approach to realizing high-performance AZIBs.

A review of electrospun separators for lithium-based batteries: Progress and application prospects

Due to the limitations of the raw materials and processes involved,polyolefin separators used in commercial lithium-ion batteries(LIBs)have gradually failed to meet the increasing requirements of high-end batteries in terms of energy density,power density,and safety.Hence,it is very important to develop next-generation separators for advanced lithium(Li)-based recharge-able batteries including LIBs and Li-S batteries.Nonwoven nanofiber membranes fabricated via electrospinning technology are highly attractive candidates for high-end separators due to their simple processes,low-cost equipment,controllable microporous structure,wide material applicability,and availability of multiple functions.In this review,the electrospinning technologies for separators are reviewed in terms of devices,process and environment,and polymer solution systems.Furthermore,strategies toward the improvement of electrospun separators in advanced LIBs and Li-S batteries are presented in terms of the compositions and the structure of nanofibers and separators.Finally,the challenges and prospects of electrospun separators in both academia and industry are proposed.We anticipate that these systematic discussions can provide information in terms of commercial applications of electrospun separators and offer new perspectives for the design of functional electrospun separators for advanced Li-based batteries.

Converting an O-vacancy-rich oxide into a multifunctional separator modifier for long-lifespan lithium metal batteries

The lithium metal anode is hailed as the desired "holy grail" for the forthcoming generation of highenergy-density batteries,given its astounding theoretical capacity and low potential.Nonetheless,the formation and growth of dendrites seriously compromise battery life and safety.Herein,an yttriastabilized bismuth oxide(YSB) layer is fabricated on the polypropylene(PP) separator,where YSB reacts with Li anode in-situ in the cell to form a multi-component composite interlayer consisting of Li_(3)Bi,Li_(2)O,and Y_(2)O_(3).The interlayer can function not only as a redistributor to regulate Li^(+) distribution but also as an anion adsorber to increase the Li^(+) transference number from 0.37 to 0.79 for suppressing dendrite nucleation and growth.Consequently,compared with the cell with a baseline separator,those with modified separators exhibit prolonged lifespan in both Li/Li symmetrical cells and Li/Cu half-cells.Notably,the full cells coupled with ultrahigh-loading LiFePO_(4) display an excellent cycling performance of 1700 cycles with a high capacity retention of ~80% at 1 C,exhibiting great potential for practical applications.This work provides a feasible and effective new strategy for separator modification towards building a much-anticipated dendrite-free Li anode and realizing long-lifespan lithium metal batteries.

S-doped mesoporous graphene modified separator for high performance lithium-sulfur batteries

Due to their low cost,environmental friendliness and high energy density,the lithium-sulfur batteries(LSB)have been regarded as a promising alternative for the next generation of rechargeable battery systems.However,the practical application of LSB is seriously hampered by its short cycle life and high self-charge owing to the apparent shuttle effect of soluble lithium polysulfides.Using MgSO_(4)@MgO composite as both template and dopant,template-guided S-doped mesoporous graphene(SMG)is prepared via the fluidized-bed chemical vapor deposition method.As the polypropylene(PP)modifier,SMG with high specific surface area,abundant mesoporous structures and moderate S doping content offers a wealth of physical and chemical adsorptive sites and reduced interfacial contact resistance,thereby restraining the serious shuttle effects of lithium polysulfides.Consequently,the LSB configured with mesoporous graphene(MG)as S host material and SMG as a separator modifier exhibits an enhanced electrochemical performance with a high average capacity of 955.64 mA h g^(-1) at 1C and a small capacity decay rate of 0.109%per cycle.Additionally,the density functional theory(DFT)calculation models have been rationally constructed and demonstrated that the doped S atoms in SMG possess higher binding energy to lithium polysulfides than that in MG,indicating that the SMG/PP separator can effectively capture soluble lithium polysulfides via chemical binding forces.This work would provide valuable insight into developing a versatile carbon-based separator modifier for LSB.

Effects of Catalysis and Separator Functionalization on High-Energy Lithium–Sulfur Batteries:A Complete Review

Lithium–sulfur(Li-S)batteries have the advantages of high theoretical specific capacity(1675 mAh g^(−1)),rich sulfur resources,low production cost,and friendly environment,which makes it one of the most promising next-generation rechargeable energy storage devices.However,the“shuttle effect”of polysulfide results in the passivation of metal lithium anode,the decrease of battery capacity and coulombic efficiency,and the deterioration of cycle stability.To realize the commercialization of Li-S batteries,its serious“shuttle effect”needs to be suppress.The commercial separators are ineffective to suppress this effect because of its large pore size.Therefore,it is an effective strategy to modify the separator surface and introduce functional modified layer.In addition to the blocking strategy,the catalysis of polysulfide conversion reaction is also an important factor hindering the migration of polysulfides.In this review,the principles of separator modification,functionalization,and catalysis in Li-S batteries are reviewed.Furthermore,the research trend of separator functionalization and polysulfide catalysis in the future is prospected.

Bilayer separator enabling dendrite-free zinc anode with ultralong lifespan >5000 h

Aqueous zinc(Zn)batteries with Zn metal anodes are promising clean energy storage devices with intrinsic safety and low cost.However,Zn dendrite growth severely restricts the use of Zn anodes.To effectively suppress Zn dendrite growth,we propose a bilayer separator consisting of commercial butter paper and glassfiber membrane.The dense cellulose-based butter paper(BP)with low zincophilicity and high mechanical properties prevents the pore-filling behavior of deposited Zn and related separator piercing,effectively suppressing the Zn dendrite growth.As a result,the bilayer separators endow the ZnjjZn symmetrical batteries with a superlong cycling life of Zn anodes(over 5000 h)at 0.5 mA cm^(-2) and the full batteries enhanced capacity retention,demonstrating the advancement of the bilayer separator to afford excellent cyclability of aqueous metal batteries.

Regulating interfacial behavior of zinc metal anode via metal-organic framework functionalized separator

Aqueous zinc ion batteries(AZIBs)are one of the promising energy storage devices.However,uncontrolled dendrite and side reactions have seriously hindered its further application.In this study,the metal-organic framework(MOF)functionalized glass fiber separator(GF-PFC-31)was used to regulate interfacial behavior of zinc metal anode,enabling the development of high-performance AZIBs.In PFC-31,there areπ-πinteractions between two adjacent benzene rings with a spacing of 3.199 A.This spacing can block the passage of[Zn(H_(2)O)_6]^(2+)(8.6 A in diameter)through the GF-PFC-31 separator to a certain extent,which promotes the deposition process of Zn ions.In addition,the sulfonic acid group(-S03H)contained in GF-PFC-31 can form a hydrogen bonding network with H_(2)O,which can provide a desolvation effect and reduce the side reaction.Consequently,GF-PFC-31 separator achieves uniform deposition of Zn ions.The Zn‖GF-PFC-31‖Zn symmetric cell exhibits stable cycle life(3000 h at 1.2 mA cm^(-2),2000 h at 0.3 mA cm^(-2),and 2000 h at 5.0 mA cm^(-2)),and Zn‖GF-PFC-31‖MnO_(2) full cell with GF-PFC-31 separator can cycle for 1000 cycles at 1.2 A g^(-1)with capacity retention rate of 82.5%.This work provides a promising method to achieve high-performance AZIBs.

Fiber swelling to improve cycle performance of paper-based separator for lithium-ion batteries application

It is well established that paper-based separators display short-circuit risk in lithium-ion batteries due to their intrinsic micron-sized pores.In this research,we have adjusted pore structure of paper by fiber swelling in liquid electrolyte.Specifically,the paper-based separator is prepared by propionylated sisal fibers through a wet papermaking process.Scanning electron microscope(SEM)and multi-range X-ray nano-computed tomography(CT)images display strong swelling of modified fibers after electrolyte absorption,which can effectively decrease the pore size of separator.Due to the high electrolyte uptake(817 wt%),paper-based separator exhibits ionic conductivity of 2.93 mS cm^(-1).^(7)Li solid-state NMR spectroscopy and Gaussian simulation reveal that the formation of local high Li^(+)ion concentration in the separator and its low absorption energy with Li^(+) ion(62.2 kcal mol^(-1))is conducive to the ionic transportation.In particular,the assembled Li/separator/LiFePO_(4) cell displays wide electrochemical stability window(5.2 V)and excellent cycle performance(capacity retention of 96.6%after 100 cycles at 0.5C)due to the reduced side reactions as well as enhanced electrolyte absorption and retention capacity by propionylation.Our proposed strategy will provide a novel perspective to design high-performance biobased separators to boost the development of clean and sustainable energy economy.

Three-in-one LaNiO_(3) functionalized separator boosting electrochemical stability and redox kinetics for high-performance Li-S battery

The lithium-sulfur(Li-S)battery,as one of the energy storage devices,has been in the limelight due to its high theoretical energy density.However,the poor redox kinetics and the"shuttle effect"of polysulfides severely restrict the use of Li-S batteries in practical applications.Herein,a novel bimetallic LaNiO_(3) functional material with high electrical conductivity and catalytic property is prepared to act as a high-efficiency polysulfide shuttling stopper.The three LaNiO_(3) samples with different physical/chemical characteristics are obtained by controlling the calcination temperature.In conjunction with the high electrical conductivity and excellent catalytic properties of the as-prepared materials,the appropriate chemisorption toward polysulfides offers great potential to enhance electrochemical stability for highperformance Li-S batteries.Particularly,the Li-S cell with the separator modified by such functional material gives a specific capacity of 658 mA h g^(-1) after 500 cycles at a high current density of 2 C.Even with high sulfur loading of 6.05 mg cm^(-2),the Li-S battery still exhibits an areal specific capacity of 2.81 m A h cm^(-2)after 150 cycles.This work paves a new avenue for the rational design of materials for separator modification in high-performance Li-S batteries.

“Three‐in‐one”strategy:Heat regulation and conversion enhancement of a multifunctional separator for safer lithium-sulfur batteries

The safety problems encountered with lithium–sulfur batteries(LSBs)hinder their development for practical applications.Herein,a highly thermally conductive separator was constructed by cross‐weaving super‐aligned carbon nanotubes(SA‐C)on super‐aligned boron nitride@carbon nanotubes(SA‐BC)to create a composite film(SA‐BC/SA‐C).This separator was used to fabricate safe LSBs with improved electrochemical performance.The highly aligned separator structure created a uniform thermal field that could rapidly dissipate heat accumulated during continuous operation due to internal resistance,which prevented the development of extremely high temperatures.The array of boron nitride nanosheets endowed the composite separator with a large number of adsorption sites,while the highly graphitized carbon nanotube skeleton accelerated the catalytic conversion of high‐valence polysulfides into low‐valence polysulfides.The arrayed molecular brush design enabled the regulation of local current density and ion flux,and considerably alleviated the growth of lithium dendrites,thus promoting the smooth deposition of Li metal.Consequently,a battery constructed with the SA‐BC/SA‐C separator showed a good discharge capacity of 685.2 mAh g−1 over 300 cycles(a capacity decay of 0.026%per cycle)at 2 C and 60°C.This“three‐in‐one”multifunctional separator design strategy constitutes a new path forward for overcoming the safety problems of LSBs.

LiFePO_(4) as a dual-functional coating for separators in lithium-ion batteries:A new strategy for improving capacity and safety

Lithium-ion batteries(LIBs)require separators with high performance and safety to meet the increasing demands for energy storage applications.Coating electrochemically inert ceramic materials on conventional polyolefin separators can enhance stability but comes at the cost of increased weight and decreased capacity of the battery.Herein,a novel separator coated with lithium iron phosphate(LFP),an active cathode material,is developed via a simple and scalable process.The LFP-coated separator exhibits superior thermal stability,mechanical strength,electrolyte wettability,and ionic conductivity than the conventional polyethylene(PE)separator.Moreover,the LFP coating can actively participate in the electrochemical reaction during the charge-discharge process,thus enhancing the capacity of the battery.The results show that the LFP-coated separator can increase the cell capacity by 26%,and improve the rate capability by 29%at 4 C compared with the conventional PE separator.The LFP-coated separator exhibits only 1.1%thermal shrinkage at 140°C,a temperature even above the melting point of PE.This work introduces a new strategy for designing separators with dual functions for the next-generation LIBs with improved performance and safety.

In Situ Directional Polymerization of Poly(1,3-dioxolane)Solid Electrolyte Induced by Cellulose Paper-Based Composite Separator for Lithium Metal Batteries

In traditional in situ polymerization preparation for solid-state electrolytes,initiators are directly added to the liquid precursor.In this article,a novel cellulose paper-based composite separator is fabricated,which employs alumina as the inorganic reinforcing material and is loaded with polymerization initiator aluminum trifluoromethanesulfonate.Based upon this,a separator-induced in situ directional polymerization technique is demonstrated,and the extra addition of initiators into liquid precursors is no longer required.The polymerization starts from the surface and interior of the separator and extends outward with the gradually dissolving of initiators into the precursor.Compared with its traditional counterpart,the separator-induced poly(1,3-dioxolane)electrolyte shows improved interfacial contact as well as appropriately mitigated polymerization rate,which are conducive to practical applications.Electrochemical measurement results show that the prepared poly(1,3-dioxolane)solid electrolyte possesses an oxidation potential up to 4.4 V and a high Li+transference number of 0.72.After 1000 cycles at 2 C rate(340 mA g^(−1)),the assembled Li||LiFePO_(4)solid battery possesses a 106.8 mAh g^(−1)discharge capacity retention and 83.5%capacity retention ratio,with high average Coulombic efficiency of 99.5%achieved.Our work may provide new ideas for the design and application of in situ polymerization technique for solid electrolytes and solid batteries.

Separator Dependency on Cycling Stability of Lithium Metal Batteries Under Practical Conditions

Development of practical lithium(Li)metal batteries(LMBs)remains challenging despite promises of Li metal anodes(LMAs),owing to Li dendrite formation and highly reactive surface nature.Polyolefin separators used in LMBs may undergo severe mechanical and chemical deterioration when contacting with LMAs.To identify the best polyolefin separator for LMBs,this study investigated the separator-deterministic cycling stability of LMBs under practical conditions,and redefined the key influencing factors,including pore structure,mechanical stability,and chemical affinity,using 12 different commercial separators,including polyethylene(PE),polypropylene(PP),and coated separators.At extreme compression triggered by LMA swelling,isotropic stress release by balancing the machine direction and transverse direction tensile strengths was found to be crucial for mitigating cell short-circuiting.Instead of PP separators,a PE separator that possesses a high elastic modulus and a highly connected pore structure can uniformly regulate LMA swelling.The ceramic coating reinforced short-circuiting resistance,while the cycling efficiency degraded rapidly owing to the detrimental interactions between ceramics and LMAs.This study identified the design principle of separators for practical LMBs with respect to mechanical stability and chemical affinity toward LMAs by elucidating the impacts of separator modification on the cycling performance.

Rational design and low-cost fabrication of multifunctional separators enabling high sulfur utilization in long-life lithium-sulfur batteries

The lithium-sulfur(Li-S)battery with an ultrahigh theoretical energy density has emerged as a promising rechargeable battery system.However,the practical applications of Li-S batteries are severely plagued by the sluggish reaction kinetics of sulfur species and notorious shuttling of soluble lithium polysulfides(LiPSs)intermediates that result in low sulfur utilization.The introduction of functional layers on separators has been considered as an effective strategy to improve the sulfur utilization in Li-S batteries by achieving effective regulation of LiPSs.Herein,a promising self-assembly strategy is proposed to achieve the low-cost fabrication of hollow and hierarchically porous Fe_(3)O_(4)nanospheres(p-Fe_(3)O_(4)-NSs)assembled by numerous extremely-small primary nanocrystals as building blocks.The rationally-designed p-Fe_(3)O_(4)-NSs are utilized as a multifunctional layer on the separator with highly efficient trapping and conversion features toward LiPSs.Results demonstrate that the nanostructured p-Fe_(3)O_(4)-NSs provide chemical adsorption toward LiPSs and kinetically promote the mutual transformation between LiPSs and Li_(2)S_(2)/Li_(2)S during cycling,thus inhibiting the LiPSs shuttling and boosting the redox reaction kinetics via a chemisorption-catalytic conversion mechanism.The enhanced wettability of the p-Fe_(3)O_(4)-NSs-based separator with the electrolyte enables fast transportation of lithium ions.Benefitting from these alluring properties,the functionalized separator with p-Fe_(3)O_(4)-NSs endows the battery with an admirable rate performance of 877 mAh g^(−1)at 2 C,an ultra-durable cycling performance of up to 2176 cycles at 1 C,and a promising areal capacity of 4.55 mAh cm^(−2)under high-sulfur-loading and lean-electrolyte conditions(4.29 mg cm^(−2),electrolyte/ratio:8μl mg^(−1)).This study will offer fresh insights on the rational design and low-cost fabrication of multifunctional separator to strengthen electrochemical reaction kinetics by regulating LiPSs conversion for developing efficient and long-life Li-S batteries.

Thermal Stability and Electrochemical Properties of Separators for Lithium-ion Batteries

The mechanical properties,contact angle,thermomechanical and electrochemical properties of PE,PVDF,and ceramic separators were compared.The experimental results show that the PE separator has the largest porosity,the PVDF separator has the best mechanical properties,wettability,and heat resistance.Three kinds of separators were assembled into lithium-ion batteries for electrochemical tests.Among them,the PE separator has the best rate performance,and the ceramic separator has poor performance in charge-discharge cycles.At the same time,the PE and ceramic separators were tested with different amounts of electrolytes at room temperature and a high temperature,and it is found that the capacity of the PE separator is higher at room temperature,while the performance of the ceramic separator is better at a high temperature.The amount of electrolyte also has a certain influence on its electrochemical performance.

Efficient utilization of glass fiber separator for low-cost sodium-ion batteries

The separator is a key component of sodium-ion battery,which greatly affects the electrochemical performances and safety characteristics of the battery.Conventional glass fiber separator cannot meet the requirements of large-scale application because of high cost and poor mechanical properties.Herein,the novel composite separators are prepared by a simple slurry sieving process using glass fiber separator scraps and ordinary qualitative filter paper as raw materials.As the composite mass ratio is 1:1,the composite separator has excellent comprehensive properties,including tensile strength of 15.8 MPa,porosity of 74.3%,ionic conductivity of 1.57×10^(-3)S·cm^(-1)and thermal stability at 210℃.The assembled sodium-ion battery shows superior cycling performance(capacity retention of 94.1%after 500 cycles at 1C)and rate capacity(retention rate of 87.3%at 10C),and it maintains fine interface stability.The above results provide some new ideas for the separator design of high-performance and low-cost sodium-ion batteries.

A surfactant-modified composite separator for high safe lithium ion battery

Separators have been gaining increasing attention to improve the performance of lithium ion batteries(LIBs),especially for high safe and long cycle life.However,commercial polyolefin separators still face the problems of rapid capacity decay and safety issues due to the poor wettability with electrolytes and low thermal stability.Herein,a novel composite separator is proposed by introducing a surfactant of sodium dodecyl thiosulfate(SDS)into the polytetrafluoroethylene(PTFE)substrate with the binder of polyacrylic acid(PAA)through the suction filtration method.The introduction of PAA/SDS enhances the adsorption energy between PTFE substrate and electrolyte through density functional theory calculations,which improves wettability and electrolyte uptake of the separator significantly.The asachieved composite separator enables the LIBs to own high Li^(+)conductivity(0.64×10^(-3)S cm^(-1))and Li^(+)transference number(0.63),further leading to a high capacity retention of 93.50%after 500 cycles at 1 C.In addition,the uniform and smooth surface morphology of Li metal employed the composite separator after cycling indicates that the lithium dendrites can be successfully inhibited.This work indicates a promising route for the preparation of a novel composite separator for high safe LIBs.

An upgraded polymeric composite with interparticle chemical bonding microstructure toward lithium-ion battery separators with enhanced safety and electrochemical performances

A composite separator of SiC/PVDF-HFP was synthesized for lithium-ion batteries with high thermal and mechanical stabilities.Benefiting from the nanoscale,high hardness,and melting point of SiC,SiC/PVDFHFP with highly uniform microstructure was obtained.This polarization caused by barrier penetration was significantly restrained.Due to the Si-F bond between SiC and PVDF-HFP,the structural stability has been obviously enhanced,which could suppress the growth of lithium(Li) dendrite.Furthermore,some 3D reticulated Si nanowires are found on the surface of Li anode,which also greatly inhibit Li dendrites and result in irregular flakes of Li metal.Especially,the shrinkage of 6% SiC/PVDF-HFP at 150℃ is only 5%,which is notably lower than those of PVDF-HFP and Celgard2500.The commercial LiFePO_(4) cell assembled with 6% SiC/PVDF-HFP possesses a specific capacity of 157.8 mA h g^(-1) and coulomb efficiency of 98% at 80℃.In addition,the tensile strength and modulus of 6% SiC/PVDF-HFP could reach 14.6 and 562 MPa,respectively.And a small deformation(1000 nm) and strong deformation recovery are obtained under a high additional load(2.3 mN).Compared with PVDF-HFP and Celgard2500,the symmetric Li cell assembled with 6% SiC/PVDF-HFP has not polarized after 900 cycles due to its excellent mechanical stabilities.This strategy provides a feasible solution for the composite separator of high-safety batteries with a high temperature and impact resistance.

Research status and prospect of separators for magnesium-sulfur batteries

Magnesium-sulfur(Mg-S)batteries have attracted wide research attention in recent years,and are considered as one of the major candidates to replace lithium-ion batteries due to the high theoretical energy density,low costs of active materials,and high safety.However,there are still significant challenges that need to be overcome before they can reach the large-scale practical applications.The key issue is the dissolution and shuttle effect of magnesium polysulfides(Mg-PSs),which leads to severe capacity degradation and shortens cycling life,greatly limiting the development of Mg-S batteries.In order to overcome these challenges,great efforts have been made in cathode materials,electrolytes,and separators.Herein,we review the investigations on suppressing the shuttle effect of Mg-PSs via the modification of separators,including schemes such as coating the functional materials that can hold Mg-PSs on the surface of polyolefin-based or glass fiber(GF)separators,forming gel polymer separators via cross-linking polymerization reactions,and developing gel polymer electrolytes coupled with GF separators.Furthermore,an outlook is proposed for the future design on separator exploitation to accelerate the development of Mg-S battery technology.

Dependence of lithium metal battery performances on inherent separator porous structure regulation

Boosting of rechargeable lithium metal batteries(LMBs) holds challenges because of lithium dendrites germination and high-reactive surface feature.Separators may experience structure-determined chemical deterioration and worsen Li plating-stripping behaviors when smoothly shifting from lithium-ion batteries(LIBs) to LMBs.This study precisely regulations the crystal structure of β-polypropylene and separator porous construction to investigate the intrinsic porous structure and mechanical properties determined electrochemical performances and cycling durability of LMBs.Crystal structure characterizations,porous structure analyses,and electrochemical cycling tests uncover appropriate annealing thermal stimulation concentrates β-lamellae thickness and enhances lamellae thermal stability by rearranging molecular chain in inferior β-lamellae,maximally homogenizing biaxial tensile deformation and resultant porous constructions.These even pores with high connectivity lower ion migration barriers,alleviate heterogeneous Li^(+) flux dispersion,stabilize reversible Li plating-stripping behaviors,and hinder coursing and branching of Li dendrites,endowing steady cell cycling durability,especially at higher currents due to the highlighted uncontrollable cumulation of dead Li,which offers new insights for the current pursuit of high-power density battery and fast charging technology.The suggested separator structure-chemical nature functions in ensuring cyclic cell stability and builds reliable relationships between separator structure design and practical LMBs applications.