Sandwich-type composited solid polymer electrolytes to strengthen the interfacial ionic transportation and bulk conductivity for all-solid-state lithium batteries from room temperature to 120℃

The insurmountable charge transfer impedance at the Li metal/solid polymer electrolytes(SPEs)interface at room temperature as well as the ascending risk of short circuits at the operating temperature higher than the melting point,dominantly limits their applications in solid-state batteries(SSBs).Although the inorganic filler such as CeO_(2)nanoparticle content of composite solid polymer electrolytes(CSPEs)can significantly reduce the enormous charge transfer impedance at the Li metal/SPEs interface,we found that the required content of CeO_(2)nanoparticles in SPEs varies for achieving a decent interfacial charge transfer impedance and the bulk ionic conductivity in CSPEs.In this regard,a sandwich-type composited solid polymer electrolyte with a 10%CeO_(2)CSPEs interlayer sandwiched between two 50%CeO_(2)CSPEs thin layers(sandwiched CSPEs)is constructed to simultaneously achieve low charge transfer impedance and superior ionic conductivity at 30℃.The sandwiched CSPEs allow for stable cycling of Li plating and stripping for 1000 h with 129 mV polarized voltage at 0.1 mA cm^(-2)and 30℃.In addition,the LiFePO_(4)/Sandwiched CSPEs/Li cell also exhibits exceptional cycle performance at 30℃and even elevated120℃without short circuits.Constructing multi-layered CSPEs with optimized contents of the inorganic fillers can be an efficient method for developing all solid-state PEO-based batteries with high performance at a wide range of temperatures.

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.

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.

Construction of a High‑Performance Composite Solid Electrolyte Through In‑Situ Polymerization within a Self‑Supported Porous Garnet Framework

Composite solid electrolytes(CSEs)have emerged as promising candidates for safe and high-energy–density solid-state lithium metal batteries(SSLMBs).However,concurrently achieving exceptional ionic conductivity and interface compatibility between the electrolyte and electrode presents a significant challenge in the development of high-performance CSEs for SSLMBs.To overcome these challenges,we present a method involving the in-situ polymerization of a monomer within a self-supported porous Li_(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12)(LLZT)to produce the CSE.The synergy of the continuous conductive LLZT network,well-organized polymer,and their interface can enhance the ionic conductivity of the CSE at room temperature.Furthermore,the in-situ polymerization process can also con-struct the integration and compatibility of the solid electrolyte–solid electrode interface.The synthesized CSE exhibited a high ionic conductivity of 1.117 mS cm^(-1),a significant lithium transference number of 0.627,and exhibited electrochemical stability up to 5.06 V vs.Li/Li+at 30℃.Moreover,the Li|CSE|LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2) cell delivered a discharge capacity of 105.1 mAh g^(-1) after 400 cycles at 0.5 C and 30℃,corresponding to a capacity retention of 61%.This methodology could be extended to a variety of ceramic,polymer electrolytes,or battery systems,thereby offering a viable strategy to improve the electrochemical properties of CSEs for high-energy–density SSLMBs.

Tailoring Practically Accessible Polymer/Inorganic Composite Electrolytes for All-Solid-State Lithium Metal Batteries:A Review

Solid-state electrolytes(SSEs)are widely considered the essential components for upcoming rechargeable lithium-ion batteries owing to the potential for great safety and energy density.Among them,polymer solid-state electrolytes(PSEs)are competitive candidates for replacing commercial liquid electrolytes due to their flexibility,shape versatility and easy machinability.Despite the rapid development of PSEs,their practical application still faces obstacles including poor ionic conductivity,narrow electrochemical stable window and inferior mechanical strength.Polymer/inorganic composite electrolytes(PIEs)formed by adding ceramic fillers in PSEs merge the benefits of PSEs and inorganic solid-state electrolytes(ISEs),exhibiting appreciable comprehensive properties due to the abundant interfaces with unique characteristics.Some PIEs are highly compatible with high-voltage cathode and lithium metal anode,which offer desirable access to obtaining lithium metal batteries with high energy density.This review elucidates the current issues and recent advances in PIEs.The performance of PIEs was remarkably influenced by the characteristics of the fillers including type,content,morphology,arrangement and surface groups.We focus on the molecular interaction between different components in the composite environment for designing high-performance PIEs.Finally,the obstacles and opportunities for creating high-performance PIEs are outlined.This review aims to provide some theoretical guidance and direction for the development of PIEs.

The Critical Role of Fillers in Composite Polymer Electrolytes for Lithium Battery

With excellent energy densities and highly safe performance,solidstate lithium batteries(SSLBs)have been hailed as promising energy storage devices.Solid-state electrolyte is the core component of SSLBs and plays an essential role in the safety and electrochemical performance of the cells.Composite polymer electrolytes(CPEs)are considered as one of the most promising candidates among all solid-state electrolytes due to their excellent comprehensive performance.In this review,we briefly introduce the components of CPEs,such as the polymer matrix and the species of fillers,as well as the integration of fillers in the polymers.In particular,we focus on the two major obstacles that affect the development of CPEs:the low ionic conductivity of the electrolyte and high interfacial impedance.We provide insight into the factors influencing ionic conductivity,in terms of macroscopic and microscopic aspects,including the aggregated structure of the polymer,ion migration rate and carrier concentration.In addition,we also discuss the electrode-electrolyte interface and summarize methods for improving this interface.It is expected that this review will provide feasible solutions for modifying CPEs through further understanding of the ion conduction mechanism in CPEs and for improving the compatibility of the electrode-electrolyte interface.

Rational Design of High-Performance PEO/Ceramic Composite Solid Electrolytes for Lithium Metal Batteries

Composite solid electrolytes(CSEs)with poly(ethylene oxide)(PEO)have become fairly prevalent for fabricating high-performance solid-state lithium metal batteries due to their high Li~+solvating capability,flexible processability and low cost.However,unsatisfactory room-temperature ionic conductivity,weak interfacial compatibility and uncontrollable Li dendrite growth seriously hinder their progress.Enormous efforts have been devoted to combining PEO with ceramics either as fillers or major matrix with the rational design of two-phase architecture,spatial distribution and content,which is anticipated to hold the key to increasing ionic conductivity and resolving interfacial compatibility within CSEs and between CSEs/electrodes.Unfortunately,a comprehensive review exclusively discussing the design,preparation and application of PEO/ceramic-based CSEs is largely lacking,in spite of tremendous reviews dealing with a broad spectrum of polymers and ceramics.Consequently,this review targets recent advances in PEO/ceramicbased CSEs,starting with a brief introduction,followed by their ionic conduction mechanism,preparation methods,and then an emphasis on resolving ionic conductivity and interfacial compatibility.Afterward,their applications in solid-state lithium metal batteries with transition metal oxides and sulfur cathodes are summarized.Finally,a summary and outlook on existing challenges and future research directions are proposed.

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.

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.

Composite polymer electrolyte reinforced by graphitic carbon nitride nanosheets for room-temperature all-solid-state lithium batteries

By virtue of the flexibility and safety, polyethylene oxide(PEO) based electrolytes are regarded as an appealing candidate for all-solid-state lithium batteries. However, their application is limited by the poor ionic conductivity at room temperature, narrow electrochemical stability window and uncontrolled growth of lithium dendrite. To alleviate these problems, we introduce the ultrathin graphitic carbon nitride nanosheets(GCN) as advanced nanofillers into PEO based electrolytes(GCN-CPE). Benefiting from the high surface area and abundant surface N-active sites of GCN, the GCN-CPE displays decreased crystallinity and enhanced ionic conductivity. Meanwhile, Fourier transform infrared and chronoamperometry studies indicate that GCN can facilitate Li+migration in the composite electrolyte. Additionally, the GCN-CPE displays an extended electrochemical window compared with PEO based electrolytes. As a result, Li symmetric battery assembled with GCN-CPE shows a stable Li plating/stripping cycling performance, and the all-solid-state Li/LiNi_(0.6)Co_(0.2)Mn_(0.2)O_(2)(NCM622) batteries using GCN-CPE exhibit satisfactory cyclability and rate capability in a voltage range of 3-4.2 V at 30 ℃.

Ultrathin poly(cyclocarbonate-ether)-based composite electrolyte reinforced with high-strength functional skeleton

Composite polymer electrolytes(CPEs)are considered to be the most promising to break through the performance and safety limitations of traditional lithium-ion batteries because of their excellent electrochemical and mechanical properties.Aiming at the performance limitations of the most common polyether matrix such as poly(ethylene oxide)(PEO),a novel poly(cyclocarbonate-ether)polymer matrix was prepared by in-situ thermal curing,the weaker interaction between its C=O bond and Li^(+)can promote the rapid transport of Li^(+).Adding ionic liquid and active filler LLZTO to the matrix can synergistically reduce the crystallinity of matrix and promote the dissociation of lithium salts.In addition,a 3D functional skeleton made of polyacrylonitrile(PAN)and lithium fluoride(LiF)can greatly improve the mechanical strength of polymer matrix after cold pressing,and Li F is also conducive to interface stability.The thickness of the optimal sample(VP6L/CPL)was only 25μm,and its ionic conductivity,lithium ion transference number,and electrochemical stability window were as high as 7.17×10^(-4)S cm^(-1)(25℃),0.54 and 5.4 V,respectively,while the mechanical strength reaches 6.1 MPa,which can fully inhibit the growth of lithium dendrites.The excellent electrochemical performance and mechanical strength enable the assembled Li|VP6L/CPL|Li battery to be continuously charged for over 200 h and cycled stably for more than 2300 h,and Li|VP6L/CPL|LFP battery can be stably cycled for more than 400 and 550 cycles at 1 C(40℃)and 0.5 C(25℃),respectively.

Optimized CeO_(2) Nanowires with Rich Surface Oxygen Vacancies Enable Fast Li-Ion Conduction in Composite Polymer Electrolytes

Low-cost and flexible solid polymer electrolytes are promising in all-solid-state Li-metal batteries with high energy density and safety.However,both the low room-temperature ionic conductivities and the small Li^(+)transference number of these electrolytes significantly increase the internal resistance and overpotential of the battery.Here,we introduce Gd-doped CeO_(2) nanowires with large surface area and rich surface oxygen vacancies to the polymer electrolyte to increase the interaction between Gd-doped CeO_(2) nanowires and polymer electrolytes,which promotes the Li-salt dissociation and increases the concentration of mobile Li ions in the composite polymer electrolytes.The optimized composite polymer electrolyte has a high Li-ion conductivity of 5×10^(-4)4 S cm^(-1) at 30℃ and a large Li+transference number of 0.47.Moreover,the composite polymer electrolytes have excellent compatibility with the metallic lithium anode and high-voltage LiNi_(0.8)Mn _(0.1)Co_(0.1)O_(2)(NMC)cathode,providing the stable cycling of all-solid-state batteries at high current densities.

Laminar Composite Solid Electrolyte with Poly(Ethylene Oxide)-Threaded Metal-Organic Framework Nanosheets for High-Performance All-Solid-State Lithium Battery

Developing laminar composite solid electrolyte with ultrathin thickness and continuous conduction channels in vertical direction holds great promise for all-solid-state lithium batteries.Herein,a thin,laminar solid electrolyte is synthesized by filtrating–NH 2 functionalized metal-organic framework nanosheets and then being threaded with poly(ethylene oxide)chains induced by the hydrogen-bonding interaction from–NH_(2) groups.It is demonstrated that the threaded poly(ethylene oxide)chains lock the adjacent metal-organic framework nanosheets,giving highly enhanced structural stability(Young’s modulus,1.3 GPa)to 7.5-μm-thick laminar composite solid electrolyte.Importantly,these poly(ethylene oxide)chains with stretching structure serve as continuous conduction pathways along the chains in pores.It makes the non-conduction laminar metal-organic framework electrolyte highly conductive:3.97×10^(−5) S cm^(−1) at 25℃,which is even over 25 times higher than that of pure poly(ethylene oxide)electrolyte.The assembled lithium cell,thus,acquires superior cycling stability,initial discharge capacity(148 mAh g^(−1) at 0.5 C and 60℃),and retention(94% after 150 cycles).Besides,the pore size of nanosheet is tailored(24.5–40.9˚A)to evaluate the mechanisms of chain conformation and ion transport in confined space.It shows that the confined pore only with proper size could facilitate the stretching of poly(ethylene oxide)chains,and meanwhile inhibit their disorder degree.Specifically,the pore size of 33.8˚A shows optimized confinement effect with trans-poly(ethylene oxide)and cis-poly(ethylene oxide)conformation,which offers great significance in ion conduction.Our design of poly(ethylene oxide)-threaded architecture provides a platform and paves a way to the rational design of next-generation high-performance porous electrolytes.

A critical review on composite solid electrolytes for lithium batteries:Design strategies and interface engineering

The rapid development of new energy vehicles and 5G communication technologies has led to higher demands for the safety,energy density,and cycle performance of lithium-ion batteries as power sources.However,the currently used liquid carbonate compounds in commercial lithium-ion battery electrolytes pose potential safety hazards such as leakage,swelling,corrosion,and flammability.Solid electrolytes can be used to mitigate these risks and create a safer lithium battery.Furthermore,high-energy density can be achieved by using solid electrolytes along with high-voltage cathode and metal lithium anode.Two types of solid electrolytes are generally used:inorganic solid electrolytes and polymer solid electrolytes.Inorganic solid electrolytes have high ionic conductivity,electrochemical stability window,and mechanical strength,but suffer from large solid/solid contact resistance between the electrode and electrolyte.Polymer solid electrolytes have good flexibility,processability,and contact interface properties,but low room temperature ionic conductivity,necessitating operation at elevated temperatures.Composite solid electrolytes(CSEs) are a promising alternative because they offer light weight and flexibility,like polymers,as well as the strength and stability of inorganic electrolytes.This paper presents a comprehensive review of recent advances in CSEs to help researchers optimize CSE composition and interactions for practical applications.It covers the development history of solid-state electrolytes,CSE properties with respect to nanofillers,morphology,and polymer types,and also discusses the lithium-ion transport mechanism of the composite electrolyte,and the methods of engineering interfaces with the positive and negative electrodes.Overall,the paper aims to provide an outlook on the potential applications of CSEs in solid-state lithium batteries,and to inspire further research aimed at the development of more systematic optimization strategies for CSEs.

Performance Evaluation of Composite Electrolyte with GQD for All-Solid-State Lithium Batteries

The use a stabilized lithium structure as cathode material for batteries could be a fundamental alternative in the development of next-generation energy storage devices.However,the lithium structure severely limits battery life causes safety concerns due to the growth of lithium(Li)dendrites during rapid charge/discharge cycles.Solid electrolytes,which are used in highdensity energy storage devices and avoid the instability of liquid electrolytes,can be a promising alternative for next-generation batteries.Nevertheless,poor lithium ion conductivity and structural defects at room temperature have been pointed out as limitations.In this study,through the application of a low-dimensional graphene quantum dot(GQD)layer structure,stable operation characteristics were demonstrated based on Li^(+)ion conductivity and excellent electrochemical performance.Moreover,the device based on the modified graphene quantum dots(GQDs)in solid state exhibited retention properties of 95.3%for 100 cycles at 0.5 C and room temperature(RT).Transmission electronmicroscopy analysis was performed to elucidate the Li^(+)ion action mechanism in the modified GQD/electrolyte heterostructure.The low-dimensional structure of theGQD-based solid electrolyte has provided an important strategy for stably-scalable solid-state lithium battery applications at room temperature.It was demonstrated that lithiated graphene quantum dots(Li-GQDs)inhibit the growth of Li dendrites by regulating the modified Li^(+)ion flux during charge/discharge cycling at current densities of 2.2–5.5 mA cm,acting as a modified Li diffusion heterointerface.A full Li GQDbased device was fabricated to demonstrate the practicality of the modified Li structure using the Li–GQD hetero-interface.This study indicates that the low-dimensional carbon structure in Li–GQDs can be an effective approach for stabilization of solid-state Li matrix architecture.

Tuning composite solid-state electrolyte interface to improve the electrochemical performance of lithium-oxygen battery

Thin and flexible composite solid-state electrolyte(SSE) is considered to be a prospective candidate for lithium-oxygen(Li-O_(2)) batteries with the aim to address the problems of unsatisfied safety, terrible durability as well as inferior electrochemical performance. Herein, in order to improve the safety and durability, a succinonitrile(SN) modified composite SSE is proposed. In this SSE, SN is introduced for eliminating the boundary between ceramic particles, increasing the amorphous region of polymer and ensuring fast ionic transport. Subsequently, the symmetric battery based on the proposed SSE achieves a long cycle life of 3000 h. Moreover, the elaborate cathode interface through the SN participation effectively reduces the barriers to the combination between lithium ions and electrons, facilitating the corresponding electrochemical reactions.As a result, the solid-state Li-O_(2)battery based on this SSE and tuned cathode interface achieves improved electrochemical performance including large specific capacity over 12,000 m Ah g^(-1), enhanced rate capacity as well as stable cycle life of 54 cycles at room temperature. This ingenious design provides a new orientation for the evolution of solid-state Li-O_(2)batteries.

Enhanced ionic conductivity in a novel composite electrolyte based on Gd-doped SnO_(2) nanotubes for ultra-long-life all-solid-state lithium metal batteries

All-solid-state electrolytes are exceedingly attractive because of the outstanding inherent safety and energy density compared to liquid electrolytes.Whereas,it is still formidable to simultaneously design solid electrolytes with favorable electrode/electrolyte interface compatibility and high ionic conductivity in a simple and scalable manner.Hence,the oxygen-vacancy-rich Gd-doped SnO_(2) nanotubes(GDS NTs)are innovatively prepared and applied to the electrolyte of all-solid-state lithium metal batteries for the first time.The addition of GDS NTs can validly construct long-range co ntinuous ion transport networks in the poly(ethylene oxide)(PEO)-based system and greatly improve the mechanical properties of the electrolyte.Compared to the PEO-based electrolyte,the composite electrolyte displays a higher lithium ion conductivity of 2.41×10^(-4) S cm^(-1) at 30℃,a higher lithium ion transference number up to 0.62 and a wider electrochemical window of 5 V at 50℃.In addition,the composite electrolyte manifests outstanding compatibility with high-voltage LiNi_(0.8)Mn_(0.1)Co_(0.1)O_(2)(NMC811)cathode,LiFePO4 cathode and lithium metal anode.The assembled Li/Li symmetric battery exhibits stable Li plating/stripping cycling performance,which can cycle steadily for 1500 h at a capacity of 0.3 mA h cm^(-2).And Li/LiFePO4 battery still maintains a high capacity of 131.54 mA h g^(-1) at 0.5C after 800 cycles,which has a superior capacity retention rate of 93.2%.The obtained novel composite electrolyte has promising application prospects in the field of all-solid-state lithium metal cells.

PDOL-Based Solid Electrolyte Toward Practical Application:Opportunities and Challenges

Polymer solid-state lithium batteries(SSLB)are regarded as a promising energy storage technology to meet growing demand due to their high energy density and safety.Ion conductivity,interface stability and battery assembly process are still the main challenges to hurdle the commercialization of SSLB.As the main component of SSLB,poly(1,3-dioxolane)(PDOL)-based solid polymer electrolytes polymerized in-situ are becoming a promising candidate solid elec-trolyte,for their high ion conductivity at room temperature,good battery elec-trochemical performances,and simple assembly process.This review analyzes opportunities and challenges of PDOL electrolytes toward practical application for polymer SSLB.The focuses include exploring the polymerization mechanism of DOL,the performance of PDOL composite electrolytes,and the application of PDOL.Furthermore,we provide a perspective on future research directions that need to be emphasized for commercialization of PDOL-based electrolytes in SSLB.The exploration of these schemes facilitates a comprehensive and profound understanding of PDOL-based polymer electrolyte and provides new research ideas to boost them toward practical application in solid-state batteries.

Synergistic coupling among Mg_(2)B_(2)O_(5),polycarbonate and N,Ndimethylformamide enhances the electrochemical performance of PVDF-HFP-based solid electrolyte

Polymer solid electrolytes(SPEs)based on the[solvate-Li+]complex structure have promising prospects in lithium metal batteries(LMBs)due to their unique ion transport mechanism.However,the solvation structure may compromise the mechanical performance and safety,hindering practical application of SPEs.In this work,a composite solid electrolyte(CSE)is designed through the organic-inorganic syner-gistic interaction among N,N-dimethylformamide(DMF),polycarbonate(PC),and Mg_(2)B_(2)O_(5) in poly(vinylidene fluoride-co-hexafluoropropylene)(PVDF-HFP).Flame-retardant Mg_(2)B_(2)O_(5) nanowires provide non-flammability to the prepared CSEs,and the addition of PC improves the dispersion of Mg_(2)B_(2)O_(5) nanowires.Simultaneously,the organic-inorganic synergistic action of PC plasticizer and Mg_(2)B_(2)O_(5) nanowires pro-motes the dissociation degree of LiTFSI and reduces the crystallinity of PVDF-HFP,enabling rapid Li ion transport.Additionally,Raman spectroscopy and DFT calculations confirm the coordination between Mg atoms in Mg_(2)B_(2)O_(5) and N atoms in DMF,which exhibits Lewis base-like behavior attacking adjacent C-F and C-H bonds in PVDF-HFP while inducing dehydrofluorination of PVDF-HFP.Based on the syner-gistic coupling of Mg_(2)B_(2)O_(5),PC,and DMF in the PVDF-HFP matrix,the prepared CSE exhibits superior ion conductivity(9.78×10^(-4) s cm^(-1)).The assembled Li symmetric cells cycle stably for 3900 h at a current density of 0.1 mA cm^(-2) without short circuit.The LFP||Li cells assembled with PDL-Mg_(2)B_(2)O_(5)/PC CSEs show excellent rate capability and cycling performance,with a capacity retention of 83.3%after 1000 cycles at 0.5 C.This work provides a novel approach for the practical application of organic-inorganic Synergistic CSEs in LMBs.

Corrosion behavior of composite coatings containing hydroxyapatite particles on Mg alloys by plasma electrolytic oxidation: A review

Mg and its alloys have been introduced as promising biodegradable materials for biomedical implant applications due to their excellent biocompatibility, mechanical behavior, and biodegradability. However, their susceptibility to rapid corrosion within the body poses a significant challenge and restricts their applications. To overcome this issue, various surface modification techniques have been developed to enhance the corrosion resistance and bioactivity of Mg-based implants. PEO is a potent technique for producing an oxide film on a surface that significantly minimizes the tendency to corrode. However, the inevitable defects due to discharges and poor biological activity during the coating process remain a concern. Therefore, adding suitable particles during the coating process is a suitable solution. Hydroxyapatite(HAp)has attracted much attention in the development of biomedical applications in the scientific community. HAp shows excellent biocompatibility due to its similarity in chemical composition to the mineral portion of bone. Therefore, its combination with Mg-based implants through PEO has shown significant improvements in their corrosion resistance and bioactivity. This review paper provides a comprehensive overview of the recent advances in the preparation, characterization, corrosion behavior and bioactivity applications of HAp particles on Mg-based implants by PEO.