Li Dendrite Growth Research Articles

In Situ Electrochemical Interfacial Manipulation Enabling Lithiophilic Li Metal Anode with Inorganic‐Rich Solid Electrolyte Interphases for Stable Li Metal Batteries

Lithium‐metal anodes (LMAs) are the ultimate choice for realizing high‐energy‐density batteries; however, its use is hindered by problematic Li growth in the form of dendrites. To alleviate dendritic Li growth, the preparation of LMAs with a lithiophilic current collector (CC) is effective; however, applying a lithiophilic CC to LMAs is still challenging due to the manufacturing complexity involved in the separate lithiophilic treatment and lithiation processes. Herein, a facile one‐pot LMA fabrication method by utilizing thiourea (TU) as a precursor is proposed. A lithiophilic Cu2S layer is formed on Cu foam (CF) by the in situ electrochemical oxidation of TU (CuxSCF), and the lithiation of CC is performed via subsequent Li electrodeposition (Li@CuxSCF). The Cu2S on CuxSCF can lead to uniform Li deposition by providing lithiophilic sites, and it is converted to form ionic‐conductive Li2S‐rich solid electrolyte interphase layer. Resultantly, CuxSCF significantly enhances the cycling performance of LMAs compared to CF. Specifically, a LiFePO4/Li@CuxSCF full‐cell lithium‐metal battery (LMB) with a low n/p ratio (1.6) exhibits capacity retention of 95.6% at 0.5 C (220 cycles) and can maintain 85.0% of initial capacity (425 cycles, n/p = 4) at 2.0 C. LMBs with LiNi0.6Co0.2Mn0.2 and LiNi0.8Co0.1Mn0.1 also exhibit improved electrochemical performance.

Regulating Li-ion solvation structure and Electrode-Electrolyte interphases via triple-functional electrolyte additive for Lithium-Metal batteries

LiPF6-based carbonate electrolytes have been widely utilized in commercial Li-ion batteries; however, they encounter significant interfacial stability challenges when implemented in high-energy–density lithium-metal batteries (LMBs). Herein, we introduce innovative N,N-diethylcyclohexanamine (NDA) as a triple-functional electrolyte additive to enhance the stability and compatibility of carbonate electrolytes. Due to the high electronegativity of amino group, NDA additive not only eliminates HF/H2O but also modifies the Li+ solvation structure, effectively reducing the electrolyte decomposition, suppressing the hydrolysis of LiPF6 and inhibiting the transition metal (TM) dissolution. Moreover, NDA facilitates the formation of Li3N-rich solid-/cathode-electrolyte interphase (SEI/CEI) layers thought preferential redox reactions at both the lithium metal anode (LMA) and Ni-rich cathode (LiNi0.8Co0.1Mn0.1O2, NCM811), which restrains the growth of Li dendrites, minimizes parasitic reactions, and promotes rapid Li+ transport. Therefore, the Li/NDA-added/Li symmetric cells exhibit remarkably stable cycling performance, lasting up to 630 h at 0.5 mA cm−2/0.5 mAh cm−2. Compared to the baseline cells, the Li/LiNi0.8Co0.1Mn0.1O2 cells with 0.5 wt% NDA show higher capacity retention after 300 cycles at 1C (85.9 % vs. 49.3 %) and superior rate performance, even at 9C. These unique features of NDA present a promising solution for addressing the interfacial deterioration issue of LMBs.

Fabrication of Single-Ion Conductors Based on Liquid Crystal Polymer Network for Quasi-Solid-State Lithium Ion Batteries.

Single-ion conductive polymer electrolytes can improve the safety of lithium ion batteries (LIBs) by increasing the lithium transference number (tLi+) and avoiding the growth of lithium dendrites. Meanwhile, the self-assembled ordered structure of liquid crystal polymer networks (LCNs) can provide specific channels for the ordered transport of Li ions. Herein, single-ion conductive nematic and cholesteric LCN electrolyte membranes (denoted as NLCN-Li and CLCN-Li) were successfully prepared. NLCN-Li was then coated on commercial Celgard 2325 while CLCN-Li was coated on poly(vinylidene fluoride-hexafluoropropylene) film, coupled with plasticizer, to make NLCN-Li/Cel and CLCN-Li/Pv quasi-solid-state electrolyte membranes, respectively. Their electrochemical properties were evaluated, and it was found that they possessed benign thermal stability and electrolyte/electrode compatibility, high tLi+ up to 0.98 and high electrochemical stability window up to 5.2 V. A small amount (0.5M) of extra Li salt added to the plasticizer could improve the ion conductivity from 1.79 × 10-5 to 5.04 × 10-4 S cm-1, while the tLi+ remained 0.85. The assembled LFP|Li batteries also exhibited excellent cycling and rate performances. The orderliness of the LCN layer played an important role in the distribution and movement of Li ions, thereby affecting the Li deposition and growth of Li dendrites. As the first report of nematic and cholesteric LCN single-ion conductors, this work sheds light on the design and fabrication of ordered quasi-solid-state electrolytes for high-performance and safe LIBs.

Promoting uniform lithium deposition with Janus gel polymer electrolytes enabling stable lithium metal batteries

AbstractLithium metal batteries (LMBs) are desirable candidates owing to their high‐energy advantage for next‐generation batteries. However, the practical application of LMBs continues to be constrained by thorny safety issues with the formation and growth of Li dendrites. Herein, the ZIF‐67 MOFs are in situ coupled onto a single face of 3D porous nanofiber to fabricate an asymmetric Janus membrane, harnessing their anion adsorption capabilities to promote the uniform deposition of Li ions. In addition, the poly(ethylene glycol) diacrylate and trifluoromethyl methacrylate are introduced into nanofiber skeleton to form Janus@GPE, which preferentially reacts with Li metal to form a LiF‐rich stable SEI layer to inhibit Li dendrite growth. Importantly, the synergistic effect of the MOFs and stable solid electrolyte interphase (SEI) layer results in superior cycling performance, achieving a remarkable 2500 h cycling at 1 mA cm−2 in the Li/Janus@GPE/Li configuration. In addition, the Janus@GPE electrolyte has a certain flame retardant, which can self‐extinguish within 3 s, improving the safety performance of the batteries. Consequently, the Li/Janus@GPE/LFP flexible pouch cell exhibits favorable cycling stability (the capacity retention rate of 45 cycles is 91.8% at 0.1 C). This work provides new insights and strategies to improve the safety and practical utility of LMBs.image

Turning waste into wealth: Li2CO3 impurity conversion into ionic conductive and lithiophlic interphase for garnet-based solid-state lithium batteries

Garnet-type solid-state electrolytes (SSEs) show great potential because of high ionic conductivity and steadiness against metallic Li. However, the unstable property of garnet in air and poor interface contact with Li metal dramatically influence the electrochemical performance. In this manuscript, TiO2 gel is coated on the surface of Li6.75La3Zr1.75Ta0.25O12 (LLZTO) pellets by a spin coating process, to remove the surface impurity and in-situ construct an air-stable and lithiophilic LixTiyOz (LTO) layer on the garnet electrolyte surface. The LTO interface layer can enhance interface contact, improve ionic transport and suppress Li dendrite growth. The low interfacial resistance (18.40 Ω cm2) in Li|LTO@LLZTO|Li symmetric cells manifests good wettability. Density functional theory (DFT) calculation results indicate that the modification layer owns higher work of adhesion and interfacial energy, suggesting excellent stability and inhibition in Li dendrite growth. Specifically, the Li symmetric cells with LTO-modified electrolyte show an enhanced critical current density of 0.9 mA cm−2 and outstanding capability to survive long cycling over 5000 h at 0.1 mA cm−2. The assembled LiFePO4-based full cell displays both high reversible capacity and cycling capability. This work provides a promising strategy to take advantage of interfacial Li2CO3 impurities on the garnet electrolytes.

Asymmetrical Functionalization of Polarizable Interface Restructuring Molecules for Rapid and Longer Operative Lithium Metal Batteries.

Lithium metal batteries (LMBs) have been recognized as high-energy storage alternatives; however, problematic surface reactions due to dendritic Li growth are major obstacles to their widespread utilization. Herein, a 3-mercapto-1-propanesulfonic acid sodium salt (MPS) with asymmetrically functionalized thiol and sulfonate groups as polarizable interface-restructuring molecules is proposed to achieve rapid and longer-operating LMBs. Under a harsh condition of 5mA cm-2, Li-Li symmetric cells employing MPS can be cycled over 1200 cycles, outperforming those employing other molecules symmetrically functionalized by thiol or sulfonate groups. The improved performance of the Li|V2O5 full cell is demonstrated by introducing MPS additives. MPS additives offer advantages by flattening the surface, reconfiguring Li nucleation and growth along the stable (110) plane, and forming a durable and conductive solid-electrolyte interface layer (SEI). This study suggests an effective way to develop a new class of electrolyte additives for LMBs by controlling engineering factors, such as functional groups and polarizable properties.

In situ construction of ether-based composite electrolyte with stable electrode interphase for high-performance solid state lithium metal battery

Ether-based polymer electrolyte shows promising potential for application in solid-state lithium batteries owing to its cost-effectiveness, excellent flexibility, and above all, remarkable stability to lithium metal anode. However, it still suffers from challenges related to low ionic conductivity and inferior oxidation resistance. Herein, an ether-based gel composite electrolyte containing Li6.5La3Zr1.5Ta0.5O12 (LLZTO) ceramics (LL-GCE) is fabricated via an in-situ polymerization method which can guarantee good interface contact with electrodes. The ceramics not only activate the interaction between polymers and lithium salts, resulting in significantly enhanced ionic conductivity (7.9 × 10−4 S cm−1), but also collaborate with poly(1,3-dioxolane) (PDOL) to construct favorable anion-rich solvation configurations, which effectively restrict the anion migration with Li+ transference number significantly increased to 0.83. Furthermore, the regulated solvation structures can passivate the electrode surface with a high content of robust LiF components formed on the electrolyte/electrode interphase. Consequently, the composite electrolyte demonstrates excellent abilities to inhibit Li dendrite growth and match with high-voltage cathodes. For instance, the LiFePO4||Li cell using such electrolyte conveys a capacity of 135.4mAh/g and the capacity retention is 99.3 % after 250 cycles at 1C. The LiCoO2||Li full cell also shows excellent cycling performance. This work provides an effective strategy to modify ether-based polymer electrolytes and can boost their development in high-performance solid state lithium metal batteries.

Void Evolution on the Li-Solid Electrolyte Interface in Solid-State Batteries: A Parametric Study Under Varied Mechanical and Electrochemical Conditions

Void growth during the plating and stripping process is an important interfacial phenomenon that hinders the development of Li-metal solid-state batteries (SSBs) because it can potentially result in inter-component delamination or growth of Li dendrites. Behind the void growth is the complex interaction between electrochemistry and mechanics. Voids usually grow from micro- or nanoscale initial imperfections on the Li-solid electrolyte (SE) interface. It is, therefore, important to analyze the stress concentration at the initial void tips, which largely determines the growth/shrinking of the void as well as the consequent changes in the internal resistance and overall battery efficiency. Recently, the development of in situ operando experimental technology has enabled the electro-chemo-mechanical characterization of the void growth phenomenon on the Li-SE interface. In this study, we explore how voids in SSBs evolve with a multi-physics model in COMSOL Multiphysics. Based on this model, we perform a systematic parametric study in the space of the mechanical stack pressure and the applied current density. The simulation results show different deformation patterns and potential failure mechanisms under different combination of stack pressure and current density. To better understand the phenomena, we develop an analytical solution to understand the void deformation induced by the inhomogeneous Li-ion concentration field under stack pressure. This analytical approach offers a complementary and intuitive perspective on the mechanical aspect of our simulation findings. By combining the simulation and analytical solutions, we depict a phase diagram, in which we identify the “safe zone” that will not result in void growth. The new insights of this research hold the promise of guiding the development of stabilized SSB interfaces.

Designing Better Li Metal Anodes for Next-Generation Batteries

Li metal batteries have the potential to significantly advance battery technology due to their substantially higher energy densities. However, robust high-capacity Li metal anodes are necessary to realize this approach, and current Li metal anode designs suffer from significant degradation over time due to non-uniform Li plating/stripping during cycling, which can lead to dead Li and/or Li dendrite growth. Carbon scaffold hosts can help mitigate this problem by creating a uniform electric field and providing abundant Li nucleation sites, but the relationship between the host architecture and performance is not well understood. We investigated the effect of scaffold architecture and chemistry on the resulting Li morphology and electrochemical performance using a combined experiment/theory approach. Carbon scaffolds with well-controlled geometries and varied porosities were fabricated using 3D printing and then characterized by SEM, Raman, and XPS before cycling in cells to evaluate their performance as hosts for uniform Li plating/stripping with both liquid and solid electrolytes. Atomistic and mesoscale modeling were used to predict how scaffold chemistry and microstructure affect Li nucleation probability and the formation of current density/stress hotspots that can lead to dendrite growth, and these results were used to help guide scaffold design. This work provides further insight into the relationship between anode architecture and Li metal cycling stability, which will facilitate the development of high-energy-density batteries in the future.Lawrence Livermore National Laboratory is operated by Lawrence Livermore National Security, LLC, for the U.S. Department of Energy, National Nuclear Security Administration under Contract DE-AC52-07NA27344.

Exploring the Nb-Ti-W-O System for Use as Li-Ion Battery Anodes

While much attention in recent years has been given to high performance Li-ion batteries for electrical vehicles, other applications such as medical devices require a unique set of properties that demand a different set of material considerations such as long lifetimes and extremely high safety. Anodes for such batteries must be carefully selected to properly achieve these goals. The most commonly industrially utilized anode material, graphite, is not suitable for medical applications due to particle fracture and Li dendrite growth at high rates. Currently utilized medical device anode materials obtain this high performance by sacrificing energy density.Herein a new set of Nb based materials for use as anodes are presented that do not need to make such a sacrifice as they display high longevity along with high energy densities. The Nb-Ti-W pseudoternary features many promising single-phase compositions that could be used as anodes for such devices. These compositions derive from crystal structures that are found on both the Nb2O5-WO3 and Nb2O5-TiO2 pseudobinaries1, though they posses a more diverse range of chemical compositions. These compositions feature high performance discharge capacities of up to 300 mAh/g. Some materials also display robust capacity retentions of up to 98% after 10 cycles. The materials were also tested at 37 °C to simulate operation within the human body. At these temperatures, improvements were found in electrochemical performance for nearly all compositions, notably demonstrating a large improvement in capacity retention regardless of crystal structure. References (1) Rehman, S.; Sieffert, J. M.; Lang, C. J.; McCalla, E. NbyW1-yOz and NbxTi1-xOz pseudobinaries as anodes for Li-ion batteries. Electrochimica Acta 2023, 439. DOI: 10.1016/j.electacta.2022.141665.

Unlocking the Capability of the Lithium Metal Battery Anode through Organofluorine Additives

Metallic lithium as the anode material in batteries offer extraordinarily high specific capacity and low electrochemical potential, allowing lithium metal batteries (LMBs) to achieve gravimetric energy densities unobtainable by traditional intercalation-based chemistry. However, one must control the morphology and composition of its solid electrolyte interphase (SEI) in order to suppress the growth of separator-piercing Li dendrites and combat electrolyte depletion. Here, we find the usage of small amounts of organofluorine additives to the commercial ethylene carbonate and diethyl carbonate (EC-DEC) electrolyte mixture improves the specific capacity and capacity retention (>99% over 100 cycles at C/3 rate) of LiNi8.15Co1.5Al0.35O2 (NCA) LMB cells. Esters, carboxylic acids, and ketoesters with various degrees of fluorination were explored as potential electrolyte additives. Figure 1

(Invited) Developing Periodically-Aligned Fibrous Structures to Suppress Lithium Dendrites for Anode-Free Batteries

We have developed electrospinning-based manufacturing capability for dendrite-free anode-free and anode-less batteries. Electrospinning is a widely used, feasible manufacturing approach to create nano- and micro-porous layers of functional fibers. By tailoring fiber compositions, the electrospun layers can afford a wide variety of functionalities applicable to biomedical templates, separation membranes, and energy storage. Its manufacturing capability is, however, limited to producing randomly oriented fibrous structures. Topology and tortuosity of the electrospun fibrous layers are poorly controlled, making it difficult to systematically investigate structure-property relationships for any given applications, especially electrochemical systems.In this presentation, we will demonstrate how to improve the controllability of fiber construction geometry by electrospinning. Unlike conventional electrospinning, our approach employs a mobile stage that allows precise alignment of fibers. Produced fibrous structures will be used to construct current collectors of the anode-free batteries, one of the proposed beyond-lithium (Li)-ion battery systems for high energy density. While direct, yet reversible, Li plating and stripping on and from the current collector has proven difficult due to uncontrolled dendrite growth, we found that the flat copper foil reinforced by the three-dimensional fibrous structure can enhance Li storage efficiency over an extended number of cycles, outperforming the planar case. We will discuss the effect of fiber compositions and controlled geometrical configurations on stabilizing Li plating and stripping morphologies to suppress Li dendrite growth and provide a fundamental design principle to construct anode-free and anode-less battery cells. Battery manufacturing advanced by this work will offer a systematic strategy to develop next-generation energy storage systems for a sustainable energy future.

In Situ Polymerization of Ultra-Thin and Defect-Free Polyamide Layer for Effectively Impeding the Polysulfides Shuttle.

Lithium-sulfur (Li-S) batteries present significant potential for next-generation high-energy-density devices. Nevertheless, obstacles such as the polysulfide shuttle and Li-dendrite growth severely impede their commercial production. It is still hard to eliminate gaps between individual particles on separators that serve as potential conduits for polysulfide shuttling. Herein, the synthesis of a nanoscale thickness and defect-free cross-linked polyamide (PA) layer on a polypropylene (PP) separator is presented through in situ polymerization. The PA modification layer can effectively impede the diffusion of polysulfides with a thickness of only 1.5nm, as evidenced by the results of cyclic voltammetry (CV) and time-of-flight (TOF) testing. Therefore, the Li/Li symmetric battery assembled with the functional separator exhibits an overpotential of merely 12mV after 1000 h of cycling under test conditions of 1mA cm-2-1 mAh cm-2. Furthermore, the capacity degradation rate of the Li-S battery is only 0.06% per cycle over 450 cycles at 1 C, while the Li-S pouch cell retains 87.63% of its capacity after 50 cycles. This work will significantly advance the preparation and application of molecules in Li-S batteries, and it will also stimulate further research on defect-free modification of separators.

Nucleation, growth and dissolution of Li metal dendrites and the formation of dead Li in Li-ion batteries investigated by operando electrochemical liquid cell scanning transmission electron microscopy

Li metal dendrites, which can form on the anode of Li-ion batteries during charging, not only accelerate their aging but may also pose a safety hazard when causing a short-circuit within the battery. Therefore, a fundamental understanding of the mechanisms governing the early stages of Li plating, the progression into dendrites, and the formation of dead Li, is imperative. Here, we employ operando electrochemical liquid cell scanning transmission electron microscopy (ec-LC-STEM) to monitor, in real-time, nanoscale processes occurring at the anode-electrolyte interface of a Li-ion battery during charge/discharge. Our results indicate that Li metal dendrites nucleate as spherical Li nanoparticles beneath the solid electrolyte interphase (SEI) and subsequently grow until dendritic Li metal is formed. During discharge, Li dendrites undergo incomplete dissolution, leading to the formation of dead Li. Interestingly, the SEI layers play a pivotal role in both the growth and the dissolution processes. Our findings reveal that the growth of Li dendrites is a multi-step process: (i) nucleation, (ii) root growth, and (iii) tip growth. We elucidate that the formation of dead Li is associated with the morphology of the initially developed dendrites and the structure of the SEI layer. The thinning of the inhomogeneously thick Li whiskers leads to the contraction of the root before the tip, ultimately resulting in the creation of electrically isolated Li metal. This work sheds light on dendritic Li growth as well as on the formation of dead Li and provides significant insights for future electrode designs.

Regulating the horizontal confined deposition of lithium metal by Co-Nx modified honeycomb-like carbon nanosheets

The uncontrollable Li dendrite growth as well as the severe volume expansion of Li metal anodes during cycling significantly impedes the practical applications of high-energy-density Li metal batteries. In this work, an innovative modulation strategy has been developed by constructing honeycomb-like nitrogen-doped carbon nanosheets with uniformly anchored cobalt nanoparticles (denoted as Co@HNC) for regulating the Li deposition behavior and meanwhile alleviating volume change during cycling. On one hand, the lithiophilic Co-Nx sites can largely reduce the energy barrier of Li nucleation and subsequently guide horizontal confined Li deposition in the honeycomb-like holes of Co@HNC, which is verified by the density functional theory calculations and in-situ optical microscopy observations. On the other hand, the honeycomb-like carbon framework with good structural integrity can endure the huge volume change during repeated Li plating/stripping processes. Consequently, the optimized Co@HNC electrode delivered a promoted cycling life for over 600 times with high Coulombic efficiency of 98.5 % at 1 mA cm−2. When matched with the high-mass-loading LiFePO4 (20 mg cm−2) or high-voltage LiNi0.8Mn0.1Co0.1O2 cathode, the Li@Co@HNC anode exhibited outstanding cycling stability and rate capability under low negative/positive capacity ratio, demonstrating its great potential in practical applications of high-energy-density lithium metal batteries.

Triple-doped Argyrodite Sulfide Electrolyte with Improved Air Stability and Lithium Compatibility for All-Solid-State Li-Metal Batteries

The shift to electric vehicles has highlighted challenges associated with lithium-ion batteries, and the need for safer and higher-energy–density all-solid-state batteries. However, sulfide-based solid electrolytes face problems with moisture reactivity and poor Li metal compatibility. In this study, we synthesized a Li5.4Al0.1P1−xSbxS4.7−2.5xO2.5xCl1.3 electrolyte, employing a dual-doping strategy inspired by the “hard and soft acids and bases” theory to enhance ionic conductivity, air stability, and Li metal compatibility. Sb–O dopants were introduced into Cl–Al-doped argyrodite solid electrolytes, achieving an optimized electrolyte with controlled dopant concentration. The electrolyte exhibited high ionic conductivity, excellent air stability, and Li metal compatibility. The all-solid-state Li metal battery showed promising initial discharge capacity. The improved air stability of Sb–O-doped electrolytes is attributed to the formation of Sb–S and P–O bonds, which reduces H2S emission by 78 % upon moisture exposure, effectively suppressing reactions with moisture. Enhanced Li metal compatibility induces the formation of Li–Sb alloy at the anode interface, inhibiting the growth of Li-dendrites. The Li symmetric cell demonstrates high critical current density and outstanding cycling stability. This study offers a sulfide electrolyte design for all-solid-state Li metal batteries, showcasing its potential for practical application with high air stability and Li metal compatibility.

Giant dielectric ceramic of Li0.3Ti0.02Ni0.68O with abundant oxygen vacancies enabling high lithium-ion conductivity in composite solid-state electrolyte

The low ionic conductivity of composite solid-state electrolytes due to the lack of free Li-ions and Li dendrite growth induced by the low transference number seriously hinder their application. Herein, we find that the giant dielectric ceramic of Li0.3Ti0.02Ni0.68O (LTNO) with ultra-high dielectric constant can greatly promote the dissociation of Li salt to generate abundant movable Li-ions and realize a high room-temperature ionic conductivity (4.09 × 10–4 S cm−1) as well as a low activation energy (0.16 eV). The oxygen vacancies on the surface of LTNO can effectively immobilize the anions to achieve a high Li transference number (0.61). Furthermore, the enhanced dielectric properties of the composite electrolyte induce homogenous Li plating/stripping to suppress the growth of Li dendrites. As a result, the Li||Li symmetric cells exhibit long lifespan of 2400 h and 1150 h at 0.1 mA cm−2 and 0.2 mA cm−2, respectively. The Li||LiNi0.8Co0.1Mn0.1O2 solid-state full cells show a high capacity retention of 83% after 430 cycles at 2C. This work highlights the critical role of high dielectric property and oxygen defects of fillers in composite solid-state electrolytes, and provides a demonstration for the application of giant dielectric materials in solid-state Li metal batteries.

Composite electrolyte with self‐inserted structure and all‐trans F conformation provides fast Li+ transport for solid‐state Li metal batteries

AbstractSolid‐state Li metal battery has attracted increasing interests for its potentially high energy density and excellent safety assurance, which is a promising candidate for next generation battery system. However, the low ionic conductivity and Li+ transport number of solid‐state polymer electrolytes limit their practical application. Herein, a composite polymer electrolyte with self‐inserted structure is proposed using the layered double hydroxides (LDHs) as dopant to achieve a fast Li+ transport channel in poly(vinylidene‐co‐trifluoroethylene) [P(VDF‐TrFE)] based polymer electrolyte. In such a composite electrolyte, P(VDF‐TrFE) polymer has an all‐trans conformation, in which all fluorine atoms locate on one side of the polymer chain, providing fast Li+ transport highways. Meanwhile, the LDH can immobilize the anions of Li salts based on the electrostatic interactions, promoting the dissociation of Li salts, thereby enhancing the ionic conductivity (6.4 × 10−4 S cm−1) and Li+ transference number (0.76). The anion immobilization effect can realize uniform electric field distribution at the anode surface and suppress the dendritic Li growth. Moreover, the hydrogen bonding interaction between LDH and polymer chains also endows the composite electrolyte with strong mechanical properties. Thus, at room temperature, the Li || Li symmetric cells can be stably cycled over 1000 h at a current density of 0.2 mA cm−2, and the full cells with LiFePO4 cathode deliver a high capacity retention (>95%) after 200 cycles. This work offers a promising route to construct solid‐state polymer electrolytes with fast Li+ transport.image

Review on Artificial Interphases for Lithium Metal Anodes: From a Mechanical Perspective

AbstractLithium (Li) metal is a promising candidate for next‐generation high‐energy‐density rechargeable batteries. However, the solid electrolyte interphase (SEI) inevitably suffers from mechanical fracture owing to the large morphological change during Li cycling, leading to the uncontrollable growth of Li dendrites, low Coulombic efficiency, and short cycle life. The fabrication of an artificial interphase is an effective strategy for improving the performances of Li metal anodes. The ideal artificial interphase should provide sufficient mechanical robustness to suppress dendritic Li growth and accommodate large volume changes during Li deposition‐dissolution cycles. In this review, we focus on the fabrication of mechanically robust artificial interphases for stabilizing Li‐metal anodes, including the underlying mechanism of SEI fracture, quantitative requirements for mechanical properties, measurements of mechanical properties, and recent progress in the fabrication of mechanically stable artificial interphases.

An Ion‐Management Membrane with Vertically Aligned Uniform Electronegative Nanochannels Toward Dendrite‐Free Lithium Metal Anodes

AbstractLithium (Li) metal anodes have received sustained attention due to their remarkable theoretical specific capacities and low electrochemical potentials. However, the nucleation and growth of Li dendrites during cycling have hindered their application in Li metal batteries (LMBs). As an indispensable battery component, separators offer an ideal platform for mitigating Li dendrites. Herein, an ion‐management membrane (IMM) concept utilizing polydopamine (PDA)‐modified polyetherimide track‐etched membranes (PEITEMs) is proposed. The PDA@PEITEM‐based IMM features vertically aligned uniform electronegative nanochannels, serving as ion distributors and “Li‐ion guides” to simultaneously smooth ion concentration fluctuations and accelerate Li+ selective conduction. The IMM's unique structural and chemical properties yield exceptional ionic conductivity (0.73 mS cm−1) and high Li+ transfer number (0.80) while minimizing Li+ concentration fluctuations. When employed in Li/Cu cells, the IMM facilitates a Coulombic efficiency exceeding 96% over 100 cycles at 0.5 mA cm−2. Moreover, it extends the cycle lifespan of Li/Li cells to 1 200 h at 1.0 mA cm−2. For Li/LiFePO4 cells, this approach enables a specific capacity of 146 mAh g−1, maintaining capacity retention of 79.84% after 1 000 cycles. This novel strategy for constructing free‐standing functional separators is convenient, efficient, and scalable, providing valuable insights into multifunctional separators for dendrite‐free LMBs.