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This work demonstrates a novel polymerization‐derived polymer electrolyte consisting of methyl methacrylate, lithium bis(trifluoromethanesulfonyl)imide and fluoroethylene carbonate. The polymerization of MMA was initiated by the amino compounds following an anionic catalytic mechanism. LiTFSI plays both roles including the initiator and Li ion source in the polymer electrolyte. Normally, lithium bis(trifluoromethanesulfonyl)imide has difficulty in initiating the polymerization reaction of methyl methacrylate monomer, a very high concentration of lithium bis(trifluoromethanesulfonyl)imide is needed for initiating the polymerization. However, the fluoroethylene carbonate additive can work as a supporter to facilitate the degree of dissociation of lithium bis(trifluoromethanesulfonyl)imide and increase its initiator capacity due to the high dielectric constant. The as‐prepared poly‐methyl methacrylate‐based polymer electrolyte has a high ionic conductivity (1.19 × 10−3 S cm−1), a wide electrochemical stability window (5 V vs Li+/Li), and a high Li ion transference number (tLi+) of 0.74 at room temperature (RT). Moreover, this polymerization‐derived polymer electrolyte can effectively work as an artificial protective layer on Li metal anode, which enabled the Li symmetric cell to achieve a long‐term cycling performance at 0.2 mAh cm−2 for 2800 h. The LiFePO4 battery with polymerization‐derived polymer electrolyte‐modified Li metal anode shows a capacity retention of 91.17% after 800 cycles at 0.5 C. This work provides a facile and accessible approach to manufacturing poly‐methyl methacrylate‐based polymerization‐derived polymer electrolyte and shows great potential as an interphase in Li metal batteries. [ABSTRACT FROM AUTHOR]

Lithium‐sulfur (Li−S) batteries are considered as a most promising rechargeable lithium metal batteries because of their high energy density and low cost. However, the Li−S batteries mainly suffer the capacity decay issue caused by the shutting effect of lithium polysulfides and the safety issues arising from the Li dendrites formation. This review outlines the current issues of Li−S batteries. Furthermore, we comprehensively summarized the challenges encountered by Li anode in Li−S batteries, such as the heterogeneous deposition of the Li anode, the unstable solid electrolyte interface (SEI) layer, and volume expansion. Moreover, research progresses in the stabilization strategies of Li anodes (physical approaches, optimization of electrolyte, surface protection layer, and design of current collector) is discussed in detail. Lastly, the remaining challenges and future research directions of Li metal anode stabilization in Li−S batteries are also present. [ABSTRACT FROM AUTHOR]

It is studied how the treatment of a metal lithium surface with a 1 M LiN(CF3SO2)2 solution in the 1,3-dioxolane/1,2-dimethoxyethane (2 : 1) mixture affects the resistance of the interphases formed by lithium with the polymer and nanocomposite electrolytes based on the 1-ethyl-3-methylimidazolium tetrafluoroborate ionic liquid. The liquid-phase therapy is shown to reduce the resistance at the Li/electrolyte interphase by a factor of 2.5 at room temperature and extend the working temperature range to –30°C. The introduction of TiO2 nanoparticles into the polymer electrolyte, along with the liquid-phase therapy of both the cathode and the Li-anode, provides a high and stable discharge capacity of the Li//LiFePO4 battery for 100 charge–discharge cycles. [ABSTRACT FROM AUTHOR]

Lithium-sulfur batteries have become a research hotspot in the field of energy storage due to their high capacity and low cost. However, lithium metal anodes' short cycle life and safety performance severely limit their commercial application. Here, we used an "in situ" method to form a stable artificial solid electrolyte interface on the surface of the metal lithium, which can control the electrochemical behavior of the interface between the lithium metal and the electrolyte and inhibit the growth of lithium dendrites. The electrochemical performance of lithium-sulfur batteries with protected lithium anode is greatly enhanced. The discharge capacity remains at 1519.6 mAhg−1 after 100 cycles at 0.1 C. In addition, the rate capability of lithium-sulfur batteries is also significantly improved, delivering a reversible capacity of 685.7 mAh g−1 at 0.5 C. [ABSTRACT FROM AUTHOR]

Lithium‐ion secondary batteries (LIB) with high energy density have attracted much attention for electric vehicle (EV) applications. However, LIBs have a safety problem because these batteries contain a flammable organic electrolyte. As such, all‐solid secondary batteries that are not flammable have been extensively reported recently. In this study, we have focused on polymer electrolytes, which is flexible and is expected to address the safety problem. However, the conventional polymer electrolytes have low electrial conductivity at room temperature. Various attempts have been made to solve this problem, such as the addition of inorganic fillers and ionic liquids; however, these composite polymer electrolytes have not yet reached a practical level of lithium‐ion conductivity. In this study, high electrical conductivity and lithium dendrite formation‐free PEO based composite electrolytes are developed with both a filler of Li6,4La3Zr1.4Ta0.6O12 and liquid plasticizers of tetraethylene glycol dimethyl ether and 1,2 dimethoxyethane. The proposed flexible polymer electrolyte shows a high electrical conduciviy of 6.01×10−4 S cm−1 at 25 °C. [ABSTRACT FROM AUTHOR]

Lithium metal shows a great advantage as the most promising anode for its unparalleled theoretical specific capacity and extremely low electrochemical potential. However, uncontrolled lithium dendrite growth and severe side reactions of the reactive intermediates and organic electrolytes still limit the broad application of lithium metal batteries. Herein, we propose 4‐nitrobenzenesulfonyl fluoride (NBSF) as an electrolyte additive for forming a stable organic–inorganic hybrid solid electrolyte interphase (SEI) layer on the lithium surface. The abundance of lithium fluoride and lithium nitride can guarantee the SEI layer's toughness and high ionic conductivity, achieving dendrite‐free lithium deposition. Meanwhile, the phenyl group of NBSF significantly contributes to both the chemical stability of the SEI layer and the good adaptation to volume changes of the lithium anode. The lithium–oxygen batteries with NBSF exhibit prolonged cycle lives and excellent cycling stability. This simple approach is hoped to improve the development of the organic–inorganic SEI layer to stabilize the lithium anodes for lithium–oxygen batteries. [ABSTRACT FROM AUTHOR]

The generation of dendrites is a common issue of lithium metal battery, while the failure mechanism is still uncovered especially at low current densities/capacities. To better understand the mechanical factors caused by lithium morphologic evolution in the whole dynamic process of a cycle, this study proposes a failure mechanism of the lithium metal anode under a safe condition of rather low current density/capacity. The anode and the electrolyte fail to maintain effective contact throughout the dynamic cycling process due to the accumulation and extrusion of lithium deposits. To guarantee effective contact, a facile and low‐cost mechanical stamping method for lithium metal anode modification is accordingly presented. The curved lithium electrode can stably cycle for more than 300 cycles at 3 mA cm−2. This study is believed to provide a more in‐depth understanding toward the evolvement of lithium morphology to boost practical use of the lithium metal anodes. [ABSTRACT FROM AUTHOR]

Abstract Lithium‐ion secondary batteries (LIB) with high energy density have attracted much attention for electric vehicle (EV) applications. However, LIBs have a safety problem because these batteries contain a flammable organic electrolyte. As such, all‐solid secondary batteries that are not flammable have been extensively reported recently. In this study, we have focused on polymer electrolytes, which is flexible and is expected to address the safety problem. However, the conventional polymer electrolytes have low electrial conductivity at room temperature. Various attempts have been made to solve this problem, such as the addition of inorganic fillers and ionic liquids; however, these composite polymer electrolytes have not yet reached a practical level of lithium‐ion conductivity. In this study, high electrical conductivity and lithium dendrite formation‐free PEO based composite electrolytes are developed with both a filler of Li6,4La3Zr1.4Ta0.6O12 and liquid plasticizers of tetraethylene glycol dimethyl ether and 1,2 dimethoxyethane. The proposed flexible polymer electrolyte shows a high electrical conduciviy of 6.01×10−4 S cm−1 at 25 °C.

Abstract Lithium metal shows a great advantage as the most promising anode for its unparalleled theoretical specific capacity and extremely low electrochemical potential. However, uncontrolled lithium dendrite growth and severe side reactions of the reactive intermediates and organic electrolytes still limit the broad application of lithium metal batteries. Herein, we propose 4‐nitrobenzenesulfonyl fluoride (NBSF) as an electrolyte additive for forming a stable organic–inorganic hybrid solid electrolyte interphase (SEI) layer on the lithium surface. The abundance of lithium fluoride and lithium nitride can guarantee the SEI layer's toughness and high ionic conductivity, achieving dendrite‐free lithium deposition. Meanwhile, the phenyl group of NBSF significantly contributes to both the chemical stability of the SEI layer and the good adaptation to volume changes of the lithium anode. The lithium–oxygen batteries with NBSF exhibit prolonged cycle lives and excellent cycling stability. This simple approach is hoped to improve the development of the organic–inorganic SEI layer to stabilize the lithium anodes for lithium–oxygen batteries.

Abstract Single lithium-ion conducting polymer electrolytes are promising candidates for next generation safer lithium batteries. In this work, Li+-conducting Nafion membranes have been synthesized by using a novel single-step procedure. The Li-Nafion membranes were characterized by means of small-wide angle X-ray scattering, infrared spectroscopy and thermal analysis, for validating the proposed lithiation method. The obtained membranes were swollen in different organic aprotic solvent mixtures and characterized in terms of ionic conductivity, electrochemical stability window, lithium stripping-deposition ability and their interface properties versus lithium metal. The membrane swollen in ethylene carbonate:propylene carbonate (EC:PC, 1:1 w/w) displays good temperature-activated ionic conductivities (σ ≈ 5.5 × 10–4 S cm−1 at 60 °C) and a more stable Li-electrolyte interface with respect to the other samples. This Li-Nafion membrane was tested in a lithium-metal cell adopting LiFePO4 as cathode material. A specific capacity of 140 mAhg−1, after 50 cycles, was achieved at 30 °C, demonstrating the feasibility of the proposed Li-Nafion membrane.

Single lithium-ion conducting polymer electrolytes are promising candidates for next generation safer lithium batteries. In this work, Li+-conducting Nafion membranes have been synthesized by using a novel single-step procedure. The Li-Nafion membranes were characterized by means of small-wide angle X-ray scattering, infrared spectroscopy and thermal analysis, for validating the proposed lithiation method. The obtained membranes were swollen in different organic aprotic solvent mixtures and characterized in terms of ionic conductivity, electrochemical stability window, lithium stripping-deposition ability and their interface properties versus lithium metal. The membrane swollen in ethylene carbonate:propylene carbonate (EC:PC, 1:1 w/w) displays good temperature-activated ionic conductivities (σ ≈ 5.5 × 10–4 S cm−1 at 60 °C) and a more stable Li-electrolyte interface with respect to the other samples. This Li-Nafion membrane was tested in a lithium-metal cell adopting LiFePO4 as cathode material. A specific capacity of 140 mAhg−1, after 50 cycles, was achieved at 30 °C, demonstrating the feasibility of the proposed Li-Nafion membrane. [ABSTRACT FROM AUTHOR]

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The construction of a heterogeneous structure on an electrode can enhance its absorption energy, thereby improving ionic diffusion and reaction kinetics. Herein, hyperdispersed VO2/V8C7 nano‐heterostructures anchored on carbon nanofibers (VO2/V8C7@CNF), which are further utilized as a lithium anode are successfully developed. The self‐supported VO2/V8C7@CNF electrode features a synergistic effect, resulting from its well‐dispersed nano‐heterostructure, induced hetero‐interfacial electric field, and conspicuous lithiophilicity. This anode thus facilitates rapid Li+ ions diffusion and charge transfer, resulting in high‐rate performance and uniform Li deposition. It exhibits a reversible specific capacity of as high as 674.8 mA h g−1 at a current density of 0.1 A g−1 and maintains a high‐rate capability of 205.3 mA h g−1 at a current density of as high as 5.0 A g−1 even after undergoing 1000 charge/discharge cycles. The Li‐ion nucleation overpotential on this anode is significantly reduced to 27 mV. The hyperdispersed nano‐heterostructure strategy offers a universal blueprint for the fabrication of high‐performance anodes not only for lithium and other batteries. [ABSTRACT FROM AUTHOR]

As the specific energy of traditional lithium-ion batteries (LIBs) approaches theoretical limits, the quest for alternatives intensifies. Lithium metal batteries (LMBs) stand out as a potential solution, promising substantially higher energy densities (∼35% increase in specific energy and ∼50% increase in energy density at the cell level). Historically, challenges with liquid electrolytes (LEs) in LMBs, such as dendrite growth and unstable solid electrolyte interphase (SEI) formation, led to skepticism about their compatibility and most of the focus was on solid-state electrolytes (SSEs) such as polymer electrolytes and recently inorganic electrolytes (oxides, sulphides halides). However, recent strides in LE engineering have repositioned LEs as viable candidates for LMBs, particularly with the strategic use of additives and the careful formulating of solvents. This review delves into the engineering of LEs for LMBs, highlighting their renewed potential and explores the realm of SSEs and report on the recent advancements in both fields. We aim to provide a comprehensive overview of the evolving landscape of LMB research.

Dendrite growth has been the main trouble preventing the practical application of Li metal anodes. Herein, we present how an Fe3O4-PVDF composite network prepared by using electrospinning has been designed to protect lithium metal anodes effectively. In the symmetrical cells test, the cell with the Fe3O4-PVDF composite network maintains good cycle performance after 600 h (500 cycles) at a current density of 1 mA cm−2 and a plating/stripping capacity of 1 mAh cm−2. The bulky Li dendrite is suppressed and a uniform Li deposition remains after long cycling. The characteristics of this engineered separator are further demonstrated in Li-S full cells with a good cycle performance (capacity of 419 mAh g−1 after 300 cycles at 0.5 C). This work provides a new idea for the protection of lithium metal anodes. [ABSTRACT FROM AUTHOR]

Different classes of solid electrolytes for all-solid-state batteries (ASSB) are currently being investigated, with each of them suitable for a different ASSB concept. Their combination in hybrid battery cells enables the use of their individual benefits while mitigating their disadvantages. The cubic stuffed garnet Li7La3Zr2O12 (LLZO), for example, is stable in contact with metallic lithium but has only moderate ionic conductivity, whereas the thiophosphate Li10SnP2S12 (LSPS) is processable using conventional battery manufacturing technologies and has an excellent lithium-ion conductivity but an inferior electrochemical stability. In this work, we, therefore, present a layered hybrid all-solid-state full-cell concept that accommodates a lithium metal anode, a LiNi0.8Co0.1Mn0.1O2-based composite cathode with an LSPS catholyte (LSPS/NCM811) and a sintered monolithic LLZO separator. The electrochemical stability of LLZO and LSPS at cathodic potentials (up to 4.2 V) was investigated via cyclic voltammetry in test cells, as well as by cycling half cells with LSPS or a mixed LSPS/LLZO catholyte. Furthermore, the pressure-dependency of the galvanostatic cycling of a Li | LLZO | LSPS/NCM811 full cell was investigated, as well as the according effect of the Li | LLZO interface in symmetric test cells. An operation pressure of 12.5 MPa was identified as the optimal value, which assures both sufficient inter-layer contact and impeded lithium penetration through the separator and cell short-circuiting. [ABSTRACT FROM AUTHOR]

The development of lithium metal battery is severely restricted by its uncontrolled dendrite growth and volume change. In this work, we designed a controllable lithiophilic Cu3Sn modified commercial Cu foil as current collector via simple industrial electroplating and heat treatment. As a Li‐reservoir substrate for efficient deposition/stripping of Li metal, the introduction of Cu3Sn not only increases multiple active sites for the deposition of Li, but also provides more transfer paths for lithium ions. The Li metal anodes prepared by molten Li on the Cu current collector with dispersed Cu3Sn active sites provide a uniform lithiophilic surface, which could effectively promote a uniform Li deposition/stripping and suppress the formation of lithium dendrites. As a result, the assembled symmetric battery is stable at a low over‐point position for 1600 h without short circuit at 1 mA cm−2 with 1 mAh cm−2, the full battery paired with LiFePO4 still maintains a high‐capacity retention rate of 97.1 % and a coulombic efficiency (CE) of 99.5 % after 400 cycles at a current density of 2 C. This work provides a facile and controllable strategy for the design of current collectors with high lithium affinity for stable lithium metal anode applications. [ABSTRACT FROM AUTHOR]

Lithium metal is the best candidate anode for high specific energy density batteries because of its high specific capacity and low negative potential. However, lithium dendrite formation and growth during the lithium plating and stripping cycles have hindered the use of lithium metal as the anode for practical batteries. Here, a mechanism for the suppression of lithium dendrite formation and growth in a composite separator of Kimwipe paper (KW) and porous polyethylene (PE) for various electrolytes was examined. The Li/KW/PE electrode in an electrolyte of 1 m Li(CFSO3)2N (LiFSI) in 1,4, dioxane (DX)‐1,2 dimethoylethane (DME) (1 : 2 v/v) with a wide electrochemical window was successfully cycled without lithium dendrite short‐circuiting at 5 mA cm−2 and 25 °C for 10 h over 25 cycles. Lithium was deposited into the cellulose fiber network during the lithium plating process, which resulted in the formation of a three‐dimensional (3D) lithium electrode. Whereas, the composite separator of KW and PE was not effective to suppress the lithium dendrite formation and growth with the conventional carbonate based electrolyte of 1 m LiPF6 in ethylene carbonate‐dimethyl carbonate. [ABSTRACT FROM AUTHOR]

Although lithium metal anode has irreplaceable advantages, such as ultra-high specific energy density and ultra-low redox potential, a variety of issues, i.e., short cycle life, low Coulomb efficiency, and tendency to cause fire explosions caused by lithium dendrite growth and high reactivity to the electrolyte, seriously hinder the practical progress of lithium metal anode. This perspective summarizes how 3D lithiophilic materials have stabilized lithium metal anodes in recent years by improving the uneven deposition of lithium metal, alleviating the volume expansion of lithium metal anodes, and limiting dendrite growth. Simultaneously, the issues of the 3D composite lithium anodes in practical application are concluded and the research direction of 3D composite lithium anode is prospected. [ABSTRACT FROM AUTHOR]

The development of lithium-metal batteries has been severely hindered by dendritic lithium dendrites and volume changes. Three-dimensional gradient and two-dimensional lithophilic materials have been shown to improve the electrochemical performance of lithium metal anodes significantly. In this paper, we have exploited the chemical interaction between MXene and ZIF-8 to develop a gradient structure consisting of MXene, MXene/ZIF-8, and MXene+ZIF-8 by in situ growth. In this gradient structure, with the gradual increase of interlayer conductivity, lithium ions can be deposited preferentially and uniformly at the bottom of the conductive bottom during lithium plating, overcoming many deposition problems at the top of 3D structures. It enhanced the electrochemical performances of lithium anodes including a coulombic efficiency of 99 % over 800 cycles at 0.5 mA cm−2 and 99 % over 500 cycles at 1 mAh cm−2, a long cycling life up to 800 h at 1 mA cm−2 and 1 mAh cm−2. The MXene/pt-Li||LiFePO 4 cells exhibited a stable cycling performance with a capacity retention of 94 % after 800 cycles. [ABSTRACT FROM AUTHOR]

Lithium-sulfur batteries (LSBs) currently face challenges such as low sulfur utilization, inadequate cycling stability, and unstable lithium anode interfaces. In this study, dichloropyrazines (DCPs) are introduced as dual-functional additives into electrolyte and 2,5-DCP exhibits the most promising performance enhancement. This superiority can be attributed to its strong redox activity, lower molecular orbital energy gap, and more negative relative binding energy compared to the other DCP isomers. Specifically, DCPs demonstrate their dual functionality by promoting the formation of a stable organic-inorganic hybrid solid electrolyte interface (SEI) rich in LiCl on lithium anodes. This ensures uniform lithium deposition and suppresses dendrite growth. At sulfur cathodes, density functional theory (DFT) calculations confirm that DCPs facilitate lithium polysulfides (LiPSs) conversion kinetics through Li–N bond formation. LSBs with 2,5-DCP exhibit excellent stability at a 1C rate and retain 86.6 % capacity after 800 cycles. This study demonstrates DCPs' potential as effective dual-functional electrolyte additives in designing high-performance LSBs. Lithium-sulfur batteries (LSBs) exhibit promising theoretical specific energy and specific capacity, but their performance is hindered by sluggish sulfur redox kinetics, poor cycling stability, and unstable lithium anode interface. Based on this, we present a category of dichloropyrazine (DCP) electrolyte additives. The three isomers achieve synergistic effects on lithium anode protection and efficient sulfur redox kinetics in LSBs. Among these three DCP isomers, 2,5-DCP exhibits superior performance enhancement effects on LSBs and demonstrates enhanced redox activity. Consequently, the nucleation overpotential is reduced, leading to an increase in the cycling stability of the battery. [Display omitted] • DCPs synergistically enhance lithium anode durability and accelerate sulfur cathode kinetics. • DFT explains DCPs-LiPS interaction, clarifying isomeric performance variations. • Battery retains 86.6 % capacity after 800 cycles at 1C rate. • Battery shows low overpotential (∼28 mV) after 800 h at 1 mA cm−2. [ABSTRACT FROM AUTHOR]

Dendrite growth has been the main trouble preventing the practical application of Li metal anodes. Herein, we present how an Fe3O4-PVDF composite network prepared by using electrospinning has been designed to protect lithium metal anodes effectively. In the symmetrical cells test, the cell with the Fe3O4-PVDF composite network maintains good cycle performance after 600 h (500 cycles) at a current density of 1 mA cm−2 and a plating/stripping capacity of 1 mAh cm−2. The bulky Li dendrite is suppressed and a uniform Li deposition remains after long cycling. The characteristics of this engineered separator are further demonstrated in Li-S full cells with a good cycle performance (capacity of 419 mAh g−1 after 300 cycles at 0.5 C). This work provides a new idea for the protection of lithium metal anodes.

Different classes of solid electrolytes for all-solid-state batteries (ASSB) are currently being investigated, with each of them suitable for a different ASSB concept. Their combination in hybrid battery cells enables the use of their individual benefits while mitigating their disadvantages. The cubic stuffed garnet Li7La3Zr2O12 (LLZO), for example, is stable in contact with metallic lithium but has only moderate ionic conductivity, whereas the thiophosphate Li10SnP2S12 (LSPS) is processable using conventional battery manufacturing technologies and has an excellent lithium-ion conductivity but an inferior electrochemical stability. In this work, we, therefore, present a layered hybrid all-solid-state full-cell concept that accommodates a lithium metal anode, a LiNi0.8Co0.1Mn0.1O2-based composite cathode with an LSPS catholyte (LSPS/NCM811) and a sintered monolithic LLZO separator. The electrochemical stability of LLZO and LSPS at cathodic potentials (up to 4.2 V) was investigated via cyclic voltammetry in test cells, as well as by cycling half cells with LSPS or a mixed LSPS/LLZO catholyte. Furthermore, the pressure-dependency of the galvanostatic cycling of a Li | LLZO | LSPS/NCM811 full cell was investigated, as well as the according effect of the Li | LLZO interface in symmetric test cells. An operation pressure of 12.5 MPa was identified as the optimal value, which assures both sufficient inter-layer contact and impeded lithium penetration through the separator and cell short-circuiting.

Abstract Lithium metal is the best candidate anode for high specific energy density batteries because of its high specific capacity and low negative potential. However, lithium dendrite formation and growth during the lithium plating and stripping cycles have hindered the use of lithium metal as the anode for practical batteries. Here, a mechanism for the suppression of lithium dendrite formation and growth in a composite separator of Kimwipe paper (KW) and porous polyethylene (PE) for various electrolytes was examined. The Li/KW/PE electrode in an electrolyte of 1 m Li(CFSO3)2N (LiFSI) in 1,4, dioxane (DX)‐1,2 dimethoylethane (DME) (1 : 2 v/v) with a wide electrochemical window was successfully cycled without lithium dendrite short‐circuiting at 5 mA cm−2 and 25 °C for 10 h over 25 cycles. Lithium was deposited into the cellulose fiber network during the lithium plating process, which resulted in the formation of a three‐dimensional (3D) lithium electrode. Whereas, the composite separator of KW and PE was not effective to suppress the lithium dendrite formation and growth with the conventional carbonate based electrolyte of 1 m LiPF6 in ethylene carbonate‐dimethyl carbonate.

Addressing lithium‐dendrite problem caused by uneven lithium (Li) plating/stripping is crucial for improving cycle‐life and safety of Li‐metal batteries. Here we describe a simple chemical substitution method of 2Li+Mg(PF6)2=Mg+2LiPF6 to construct a highly stable Li−Mg alloy on Li metal anode. The self‐grown Li−Mg alloy exhibits homogeneous β‐phase bulk structure with flat and dense surface morphology. Systematic studies reveal that the obtained Li−Mg film acts as ion redistributor and surface stabilizer to protect Li metal anode by its low strain, fast conductivity, superior lithophilicity and excellent stability. Compared to the bare Li metal, symmetric cells assembled using Li−Mg‐protected Li exhibit better cycling performance with lower charge‐discharge overpotential. Notably, this Li−Mg film demonstrates great potential for Li‐metal batteries, it can effectively suppress Li‐dendrite growth and work effectively in LiFePO4//Li and LiNi0.8Co0.1Mn0.1O2//Li cells. This work provides a simple and effective strategy to construct Li‐ion redistributor and surface protector to guard Li anodes operating in high‐energy Li batteries. [ABSTRACT FROM AUTHOR]

Lithiated Cu current collectors with a lean Li supply have been extensively explored as prospective composite anodes for constructing lithium metal batteries (LMBs) but suffer from low Coulombic efficiencies (CE) and uncontrollable dendrite growth. Herein, two hexaazanonaphthalene (HATN)-based compounds comprising rich conjugated aromatic rings and redox-active C═N groups are synthesized and exploited to modify the Cu surface for mediating smooth Li plating/stripping. Compared to the HATN compound interlinked through flexible sigma bonds, the one conjugated through dual sp 2 -carbon manifests a more rigid backbone, improved electric conductivity, and enhanced mesoporosity. As a result, Cu electrodes modified with the latter demonstrate enhanced CE and suppressed dendrites in both half and symmetric cells, apart from a stable operation over 250 cycles in the LiFePO 4 full cells with a capacity retention of 94.9% at 1 C. This study signifies the tailoring of intramolecular conjugation and chain configuration of lithiophilic macromolecules to facilitate reversible Li deposition on Cu for achieving high-performance LMBs.

Sulfide solid electrolytes (SSE) are considered promising alternatives to conventional liquid electrolytes due to their high safety that is inaccessible to common liquid electrolytes and favorable ionic conductivity. Nonetheless, the poor interfacial contacts and stability between SSEs and Li anode, as well as the inhomogeneous dendrite growth severely limit their practical applications. Herein, a trinity artificial solid electrolyte interphase composed of ethyl cellulose, graphene oxide and phosphoric acid was in-situ fabricated on the surface of the Li anode. This Li anode is denoted as EGPL (ethyl-cellulose-graphene-oxide-phosphoric-acid-modified-lithium). The artificial interphase can effectively benefit the uniform deposition of lithium, promote the transport of lithium ions and improve interfacial stability. Therefore, the all-solid-state batteries incorporated with EGPL anode and LiCoO2cathode can maintain 94.6% of initial capacity over 100 cycles at 0.2C, and also deliver excellent rate performance. This work provides a novel approach for the interfacial modification of lithium anodes for applications in all-solid-state batteries.

The uncontrollable growth of dendrites, infinite volume changes, low Coulombic efficiencies, and poor charging/discharging rates in lithium metal anodes have seriously hampered the further development of lithium metal batteries. Trapping lithium (Li) into rationally designed three‐dimensional (3D) structured Li metal anodes in order to construct a 3D‐Li framework is an effective approach to suppress the growth of Li dendrites. However, material inconsistencies and high costs still seriously limit practical applications. In this study, we describe the use of commercial low‐cost graphite fiber (GF) as a suitable conformal scaffold for preparing a lithiophilic SnO2@GF material using facile infiltration method. The lithiophilic 3D porous conductive framework allows homogeneous Li deposition on the surface of a structured electrode and accommodates the volume change during Li plating/stripping, leading to a significant boost in both the charging/discharging rates and cycling stability. This study highlights the significance of interface‐related science and engineering in designing high‐performance Li metal anodes, but also highlights the need for greater dedication to the construction of highly stable lithium anodes and high‐energy density Li metal batteries in a low‐cost manner. [ABSTRACT FROM AUTHOR]

Rechargeable Lithium‐sulfur batteries (LSBs) have been considered as a potential candidate for next‐generation energy storage technologies because of ultrahigh‐energy density (2600 Wh kg−1) and being lightweight. However, the practical applications of LSBs are currently limited by lithium polysulfides (LiPSs) shuttle, continuous electrolyte decomposition, and lithium anode corrosion. These challenges are mainly related to the cathode structure framework, the reactive nature of lithium anode, and the redox reactions occurring at the electrode‐electrolyte interfaces. Proper cathode architecture design, development of novel electrolytes, and anode protection have been developed to improve the electrochemical performance of LSBs. In this review, the working principles and challenges of LSBs are briefly introduced. The strategies to overcome the challenges of LSBs, such as electrode design and modification, development of novel electrolytes, separator modification/functional interlayer insertion, and protection of lithium anode are systematically discussed. The advanced in situ/operando characterization techniques deployed to reveal the redox chemistries of LSBs also summarized. Finally, a summary and future perspective for developing electrode structure, electrolyte engineering, functional interlayers/separators, and anode protection for the practical application of LSBs are provided. [ABSTRACT FROM AUTHOR]

Lithium dendrite growth has long been considered an obstacle to the practical application of lithium metal battery, which could be efficiently suppressed by increasing the lithiophilicity of Cu collector. Therefore, herein we developed a facile way to prepare LiCuO/Cu composite current collector, which shows better wettability with EC/EDC electrolyte than pure Cu2O layer. X‐ray diffraction (XRD) analysis shows that there is a large amount of LiCuO on the surface of the anode. The nucleation overpotential of LiCuO/Cu composite current collector is only 26 mV in the electrodeposition curve. At a current density of 1 mA/cm2, the Li−Cu cell with the as‐prepared LiCuO/Cu anode, can keep more than 85 % Coulombic efficiency for more than 125 cycles. Impedance spectra of electrodes image show that the impedance of LiCuO/Cu composite current collector is only 60 Ω at the initial stage, which can promote the transfer of Li+ at the collector surface and thus inhibit the formation of lithium dendrites on the electrode surface. [ABSTRACT FROM AUTHOR]

Lithium metal batteries are regarded as promising alternatives to lithium ion batteries due to their high specific capacity. However, lithium dendrite growth during cycling causes safety problem and rapid capacity loss. Here, we report a composite Li anode composed (LYF) of metallic Li and trace amounts (1–2 wt%) of two-dimensional YFδ. The lithiophilic nature of YFδ enables its homogeneous dispersion in metallic lithium. The LYF electrode exhibits lower resistance, higher chemical and mechanical stability, and longer cycle life compared to bare Li electrode due to uniform Li stripping and plating with YFδ incorporation, which was confirmed by in-situ optical microscope observation. X-ray photoelectron spectroscopy reveals that LiF can in-situ form on the LYF electrode with reactions between Li and YFδ during cycling. The spontaneous reactions are clarified by density functional theory calculations. A quasi-solid-state cell with LYF anode, LiFePO4 cathode and cathode-supported solid electrolyte layer has been constructed with a soft interface constructed between Li anode and solid electrolyte by in-situ thermal polymerization. The cell shows a high initial discharge capacity of 147 mAh g−1 at 0.5 C at 60 °C and sustains a stable cycling over 50 cycles with the in-situ formed LiF-rich layer and soft interface.

Solid-state batteries (SSBs) involving argyrodite-type sulfide electrolytes are considered as promising candidates for the state-of-art lithium-ion batteries (LIBs) due to their superior safety, energy and power density. However, the incompatibility between the argyrodite-type sulfide and lithium anode has plagued the development of the sulfide-based SSBs. Herein, we introduced a poly-dioxolane-based (PDOL) interlayer at the lithium anode, which is ring-opening polymerized via poly(acrylamide-2-methyl-1-propane-sulfonate) (PAMPS) loaded on the separator. The in-situ polymerized PDOL interlayer could match with the solvent-sensitive lithium argyrodite while enabling a stable and tight lithium interface. The symmetric lithium cell with the PDOL interlayer exhibits over-1200-hour dendrite-free lithium deposition and stripping at 0.5 mA cm-2, and the critical current density reaches 2.7 mA cm-2. The as-cycled lithium interface is further investigated via the depth-profiling X-ray photoelectron spectroscopy, and solid electrolyte interphase (SEI) is determined to be composed of ether polymer as well as inorganic compounds like LiC, Li 2 O, LiF, and Li 2 S. The Li|LiCoO 2 SSB with PDOL interlayer presents a high discharge capacity of 120.7 mAh g-1 at 0.1 C and a capacity retention rate of 95.4% after 200 cycles. The rational design of the PDOL interlayer at the lithium anode opens a new alternative for high-performance SSBs. [Display omitted] • An effective PDOL-based interlayer is first synthesized via a novel in-situ polymerization method. • The composition of the unique robust hybrid SEI layer that consist of inorganic compounds in ether polymer matrix has been elegantly analyzed. • The PDOL interlayer enables the symmetric lithium cells over-1200-hour cycling at 0.5 mA cm-‍‍‍2 and a critical current density of 2.7 mA cm-2. • The Li/LiCoO 2 battery with the PDOL interlayer presents a high initial discharge capacity of 120.7 mAh g-1 and a capacity retention rate of 95.4% after 200 cycles. [ABSTRACT FROM AUTHOR]

All-solid-state batteries (ASSBs) employing solid electrolytes (SE) are currently gaining attention as next-generation energy storage devices. Solid electrolytes exhibit higher energy densities and operation across a wide temperature range than liquid electrolytes. The solid electrolyte acts as a separator, providing higher mechanical strength than polymer separators. This helps prevent cell deterioration and short circuit issues caused by lithium dendrite growth during charge – discharge cycles. Consequently, lithium metal, previously challenging to apply in conventional lithium-ion batteries, can be utilized as an anode electrode material. Sulfide-based solid electrolytes offer advantageous mechanical properties and high ionic conductivity. However, their narrow chemical/electrochemical stability window poses challenges. During the charging-discharging process of a battery with a lithium metal anode, a reduction decomposition reaction of the solid electrolyte occurs. On the other hand, Lithium Fluoride (LiF) exhibits low electronic conductivity due to a wide band gap but has a broad electrochemical stability window. In this study, we prepared a mixture of Li 5.3 PS 4.3 Cl 1.7 with InF 3 to generate an artificial solid electrolyte interphase (SEI) containing LiF. We confirmed the structural properties using powder X-ray diffraction (XRD). The XRD pattern showed the maintenance of the argyrodite structure, with only an increase in the peak intensity corresponding to InF 3. The optimized solid electrolyte-based ASSB demonstrated a higher initial discharge capacity of 172.8 mAh/g, a coulombic efficiency of 78.54 %, and a capacity retention rate of 93.6 %, outperforming ASSBs based on the bare solid electrolyte (Li 5.3 PS 4.3 Cl 1.7). • Li 5.3 PS 4.3 Cl 1.7 is synthesized through high energy dry ball-milling. • Li 5.3 PS 4.3 Cl 1.7 and InF 3 are mixed through simple hand grinding. • The optimized solid electrolyte has an ionic conductivity of 5.46mS/cm at RT. • The all-solid-state battery show a higher specific capacity of 172.8 mAh/g. • The all-solid-state battery shows a higher capacity retention of 93.58 %. [ABSTRACT FROM AUTHOR]

Although metallic lithium is regarded as the most potential anode candidate for next-generation batteries, its applications are greatly restricted by the uncontrollable growth of lithium dendrites and unstable anode/electrolyte interface. Herein, MXene/MOFs heterojunction nanosheets are developed through a convenient self-assembly process by harnessing the chemical interactions between MXene and Ni-MOFs monolayers. In this heterojunction, not only the MXene interlayer induces uniform lithium nucleation, but also MOFs monolayers act as stable interfaces to promote Li ion transport and homogenize the subsequent lithium deposition. Moreover, the MXene/MOFs substrate mitigates the volume change of lithium anodes. Consequently, 2D MXene/MOFs heterojunction nanosheets as confinement hosts effectively suppress lithium dendrites and exhibit enhanced electrochemical performances including a coulombic efficiency of 99 % over 300 cycles at 0.5 mA cm−2 and 1 mAh cm−2, and a long cycling life up to 500 h at 1 mA cm−2 and 1 mAh cm−2. The MXene/MOFs-Li||LiFePO 4 cells exhibit a stable cycling performance with a capacity retention of 91 % after 600 cycles. MXene/MOFs heterojunction nanosheets were developed through a convenient self-assembly process between MXene and Ni-MOFs monolayers. In this unique structure, MXene induced uniform lithium nucleation and MOFs acted as stable interface layer to protect subsequent lithium deposition. And the variable interlamination gaps mitigated the volume change of lithium anodes. Consequently, this heterojunction exhibited superior electrochemical performances including high coulombic efficiency and cycling stability. [Display omitted] [ABSTRACT FROM AUTHOR]

Direct application of metallic lithium (Li) as the anode in rechargeable lithium metal batteries (LMBs) is still hindered by some annoying issues such as lithium dendrites formation, low Coulombic efficiency, and safety concerns arising therefrom. Herein, an advanced composite separator is prepared by facilely blade coating lightweight and thin functional layers on commercial 12 µm polyethylene separator to stabilize the Li anode. The composite separator simultaneously improves the Li ion transport and lithium deposition behaviors with uniform lithium ion distribution properties, enabling the dendrite‐free Li deposition. As a result, the lithium anode can stably cycle up to 3000 cycles with the high capacity of 3.5 mAh cm−2. Moreover, the composite separator exhibits wide compatibility in LMBs (Li–S and Li‐ion battery) and delivers stable cycling performance and high Coulombic efficiency both in coin and lab‐level soft‐pack cells. Thus, this cost‐effective modification strategy exhibits great application potential in high‐energy LMBs. [ABSTRACT FROM AUTHOR]

Lithium–sulfur (Li–S) batteries are regarded as the most promising next‐generation energy storage systems due to their high energy density and cost‐effectiveness. However, their practical applications are seriously hindered by several inevitable drawbacks, especially the shuttle effects of soluble lithium polysulfides (LiPSs) which lead to rapid capacity decay and short cycling lifespan. This review specifically concentrates on the shuttle path of LiPSs and their interaction with the corresponding cell components along the moving way, systematically retrospect the recent advances and strategies toward polysulfides diffusion suppression. Overall, the strategies for the shuttle effect inhibition can be classified into four parts, including capturing the LiPSs in the sulfur cathode, reducing the dissolution in electrolytes, blocking the shuttle channels by functional separators, and preventing the chemical reaction between LiPSs and Li metal anode. Herein, the fundamental aspect of Li–S batteries is introduced first to give an in‐deep understanding of the generation and shuttle effect of LiPSs. Then, the corresponding strategies toward LiPSs shuttle inhibition along the diffusion path are discussed step by step. Finally, general conclusions and perspectives for future research on shuttle issues and practical application of Li–S batteries are proposed. [ABSTRACT FROM AUTHOR]

Design of prototype for a solid-state lithium battery with LiFePO4 cathode and nanocomposite polymer gel electrolyte is developed. The concept of an asymmetric solid-state electrolyte was used for better compatibility of the solid electrolyte/electrode interface. According to the concept, a silica-nanoparticle-based transition layer is used facing the lithium anode; a liquid electrolyte layer; facing the cathode. The composition of the liquid electrolyte is optimized. 1 M lithium bis-trifluoromethanesulfonyl imide solution in a dioxolane/dimethoxyethane mixture (2 : 1) is shown to be the best electrolyte for the forming of a transition ion-conducting layer between the nanocomposite polymer gel electrolyte and the LiFePO4 cathode; 1 M LiBF4 in gamma-butyrolactonee, for the synthesis of a cross-linked polymer gel electrolyte, as an inert liquid medium for the radical-polymerization reaction. Comparative tests of Li/LiFePO4 battery prototypes showed the maximal capacity of the LiFePO4 cathode to be as large as 170 mA h g–1 when using a nanocomposite polymer gel electrolyte based on polyethylene glycol diacrylate with 6 wt % SiO2 with asymmetric interface. [ABSTRACT FROM AUTHOR]

Solid electrolyte interphase (SEI) plays a critical role in determining the interfacial stability, which in turn impacts the plating/stripping process of the lithium metal anode. Substantial research has been focused on the composition of SEI and its contribution to the interfacial stability. Herein, we illustrate the significance of SEI structure, in a comprehensive comparison of a diluted electrolyte (1 M LiTFSI‐PC) and a super‐concentrated electrolyte (8 M LiTFSI‐PC). Illustrated by in situ optical and atomic force microscope observation, homogeneous plating on lithium anode is achieved in the concentrated electrolyte. However, x‐ray photoelectron spectroscopy and molecular dynamics simulations reveal that, contrary to the general understanding, the components of SEI is nearly identical for lithium anode cycled in both two electrolytes. Detailed characterizations demonstrate the structure of SEI is quite different. In concentrated electrolyte, a compact structure of SEI layer can be obtained, mainly due to the reduced solubility and outstanding formation kinetics of the interfacial layer. This work provided a new understanding to the excellent performance of super‐concentrated electrolyte in lithium metal battery. [ABSTRACT FROM AUTHOR]

Abstract Direct application of metallic lithium (Li) as the anode in rechargeable lithium metal batteries (LMBs) is still hindered by some annoying issues such as lithium dendrites formation, low Coulombic efficiency, and safety concerns arising therefrom. Herein, an advanced composite separator is prepared by facilely blade coating lightweight and thin functional layers on commercial 12 µm polyethylene separator to stabilize the Li anode. The composite separator simultaneously improves the Li ion transport and lithium deposition behaviors with uniform lithium ion distribution properties, enabling the dendrite‐free Li deposition. As a result, the lithium anode can stably cycle up to 3000 cycles with the high capacity of 3.5 mAh cm−2. Moreover, the composite separator exhibits wide compatibility in LMBs (Li–S and Li‐ion battery) and delivers stable cycling performance and high Coulombic efficiency both in coin and lab‐level soft‐pack cells. Thus, this cost‐effective modification strategy exhibits great application potential in high‐energy LMBs.

Abstract Lithium–sulfur (Li–S) batteries are regarded as the most promising next‐generation energy storage systems due to their high energy density and cost‐effectiveness. However, their practical applications are seriously hindered by several inevitable drawbacks, especially the shuttle effects of soluble lithium polysulfides (LiPSs) which lead to rapid capacity decay and short cycling lifespan. This review specifically concentrates on the shuttle path of LiPSs and their interaction with the corresponding cell components along the moving way, systematically retrospect the recent advances and strategies toward polysulfides diffusion suppression. Overall, the strategies for the shuttle effect inhibition can be classified into four parts, including capturing the LiPSs in the sulfur cathode, reducing the dissolution in electrolytes, blocking the shuttle channels by functional separators, and preventing the chemical reaction between LiPSs and Li metal anode. Herein, the fundamental aspect of Li–S batteries is introduced first to give an in‐deep understanding of the generation and shuttle effect of LiPSs. Then, the corresponding strategies toward LiPSs shuttle inhibition along the diffusion path are discussed step by step. Finally, general conclusions and perspectives for future research on shuttle issues and practical application of Li–S batteries are proposed.

Abstract Solid electrolyte interphase (SEI) plays a critical role in determining the interfacial stability, which in turn impacts the plating/stripping process of the lithium metal anode. Substantial research has been focused on the composition of SEI and its contribution to the interfacial stability. Herein, we illustrate the significance of SEI structure, in a comprehensive comparison of a diluted electrolyte (1 M LiTFSI‐PC) and a super‐concentrated electrolyte (8 M LiTFSI‐PC). Illustrated by in situ optical and atomic force microscope observation, homogeneous plating on lithium anode is achieved in the concentrated electrolyte. However, x‐ray photoelectron spectroscopy and molecular dynamics simulations reveal that, contrary to the general understanding, the components of SEI is nearly identical for lithium anode cycled in both two electrolytes. Detailed characterizations demonstrate the structure of SEI is quite different. In concentrated electrolyte, a compact structure of SEI layer can be obtained, mainly due to the reduced solubility and outstanding formation kinetics of the interfacial layer. This work provided a new understanding to the excellent performance of super‐concentrated electrolyte in lithium metal battery.

[Display omitted] Electrolytes are widely considered as a key component in Li–O 2 batteries (LOBs) because they greatly affect the discharge-charge reaction kinetics and reversibility. Herein, we report that 1,3-dimethyl-2-imidazolidinone (DMI) is an excellent electrolyte solvent for LOBs. Comparing with conventional ether and sulfone based electrolytes, it has higher Li 2 O 2 and Li 2 CO 3 solubility, which on the one hand depresses cathode passivation during discharge, and on the other hand promotes the liquid-phase redox shuttling during charge, and consequently lowers the overpotential and improves the cyclability of the battery. However, despite the many advantages at the cathode side, DMI is not stable with bare Li anode. Thus, we have developed a pretreatment method to grow a protective artificial solid-state electrolyte interface (SEI) to prevent the unfavorable side-reactions on Li. The SEI film was formed via the reaction between fluorine-rich organic reagents and Li metal. It is composed of highly Li+-conducting Li x BO y , LiF, Li x NO y , Li 3 N particles and some organic compounds, in which Li x BO y serves as a binder to enhance its mechanical strength. With the protective SEI, the coulombic efficiency of Li plating/stripping in DMI electrolyte increased from 20% to 98.5% and the fixed capacity cycle life of the assembled LOB was elongated to 205 rounds, which was almost fivefold of the cycle life in dimethyl sulfoxide (DMSO) or tetraglyme (TEGDME) based electrolytes. Our work demonstrates that molecular polarity and ionic solvation structure are the primary issues to be considered when designing high performance Li–O 2 battery electrolytes, and cross-linked artificial SEI is effective in improving the anodic stability. [ABSTRACT FROM AUTHOR]

Developing high‐areal‐capacity and dendrite‐free lithium (Li) anodes is of significant importance for the practical applications of the Li‐metal secondary batteries. Herein, an effective strategy to stabilize the high‐areal‐capacity Li electrodeposition by modifying the Li metal with a stretchable ionic conductive elastomer (ICE) is demonstrated. The ICE layer prepared via an instant photocuring process shows a promising Li+‐ion conductivity at room temperature. When being used in Li‐metal batteries, the thin ICE coating (~0.27 μm) acts as both a stretchable constraint to minimize the Li loss and a protective layer to facilitate the uniform flux of Li ions. With this ICE‐modifying strategy, the reversibility and cyclability of the Li anodes under high‐areal‐capacity condition in carbonate electrolyte are significantly improved, leading to a stable Li stripping/plating for 500 h at an ultrahigh areal capacity of 20 mAh cm−2 in commercial carbonate electrolyte. When coupled with industry‐level thick LiFePO4 electrodes (20.0 mg cm−2), the cells with ICE‐Li anodes show significantly enhanced rate and cycling capability. [ABSTRACT FROM AUTHOR]

Lithium (Li) metal batteries (LMBs) have garnered significant research attention due to their high energy density. However, uncontrolled Li dendrite growth and the continuous accumulation of "dead Li" directly lead to poor electrochemical performance in LMBs, along with serious safety hazards. These issues have severely hindered their commercialization. In this study, a lithiophilic layer of Sn-Cu 2 O is constructed on the surface of copper foam (CF) grown with Cu nanowire arrays (SCCF) through a combination of electrodeposition and plasma reduction. Sn-Cu 2 O, with excellent lithiophilicity, reduces the Li nucleation barrier and promotes uniform Li deposition. Simultaneously, the high surface area of the nanowires reduces the local current density, further suppressing the Li dendrite growth. Therefore, at 1 mA cm -2 , the half cells and symmetric cells achieve high Coulombic efficiency (CE) and stable operation for over 410 cycles and run smoothly for more than 1350 h. The full cells using an LFP cathode demonstrate a capacity retention rate of 90.6% after 1000 cycles at 5 C, with a CE as high as 99.79%, suggesting excellent prospects for rapid charging and discharging and long-term cyclability. This study provides a strategy for modifying three-dimensional current collectors for Li metal anodes, offering insights into the construction of stable, safe, and fast-charging LMBs.

Although lithium metal anode has irreplaceable advantages, such as ultra-high specific energy density and ultra-low redox potential, a variety of issues, i.e., short cycle life, low Coulomb efficiency, and tendency to cause fire explosions caused by lithium dendrite growth and high reactivity to the electrolyte, seriously hinder the practical progress of lithium metal anode. This perspective summarizes how 3D lithiophilic materials have stabilized lithium metal anodes in recent years by improving the uneven deposition of lithium metal, alleviating the volume expansion of lithium metal anodes, and limiting dendrite growth. Simultaneously, the issues of the 3D composite lithium anodes in practical application are concluded and the research direction of 3D composite lithium anode is prospected.

Optimization of the synthesis procedure for a layer of lithium carbonate on the surface of a lithium electrode has been carried out. As a result, a number of samples without additives and with the addition of polyvinylidene fluoride were obtained. Testing in air showed that the sample with a layer of lithium carbonate doped with polyvinylidene fluoride performed better in air than samples of pure lithium and lithium coated with a layer of lithium carbonate. Possible causes of this phenomenon are described. [ABSTRACT FROM AUTHOR]