Enhancement of ionic conductivity of PEO based polymer electrolyte by the addition of nanosize ceramic powders

The ionic conductivity of polyethylene oxide (PEO) based solid polymer electrolytes (SPEs) has been improved by the addition of nanosize ceramic powders (TiO2 and AL2O3). The PEO based solid polymer electrolytes were prepared by the solution-casting method. Electrochemical measurement shows that the 10 wt% TiO2 PEO-LiClO4 polymer electrolyte has the best ionic conductivity (about 10(-4) S cm(-1) at 40-60 degrees C). The lithium transference number of the 10 wt% TiO2 PEO-LiClO4 polymer electrolyte was measured to be 0.47, which is much higher than that of bare PEO polymer electrolyte. Ac impedance testing shows that the interface resistance of ceramic-added PEO polymer electrolyte is stable. Linear sweep voltammetry measurement shows that the PEO polymer electrolytes are electrochemically stable in the voltage range of 2.0-5.0 V versus a Li/Li+ reference electrode.     

Flattening of Lithium Plating in Carbonate Electrolytes Enabled by All-In-One Separator

The uncontrollable dendritic growth of metallic lithium during repeated cycling in carbonate electrolytes is a crucial obstacle hindering the practical use of Li-metal batteries (LMBs). Among numerous approaches proposed to mitigate the intrinsic constraints of Li metal, the design of a functional separator is an attractive approach to effectively suppress the growth of Li dendrites because direct contact with both the Li metal surface and the electrolyte is maintained. Here, a newly designed all-in-one separator containing bifunctional CaCO₃ nanoparticles (CPP separator) is proposed to achieve the flattening of Li deposits on the Li electrode. Strong interactions between the highly polar CaCO₃ nanoparticles and the polar solvent reduces the ionic radius of the Li⁺-solvent complex, thus increasing the Li⁺ transference number and leading to a reduced concentration overpotential in the electrolyte-filled separator. Furthermore, the integration of CaCO₃ nanoparticles into the separator induces the spontaneous formation of mechanically-strong and lithiophilic CaLi₂ at the Li/separator interface, which effectively decreases the nucleation overpotential toward Li plating. As a result, the Li deposits exhibit dendrite-free planar morphologies, thus enabling excellent cycling performance in LMBs configured with a high-Ni cathode in a carbonate electrolyte under practical operating conditions.     

In Situ Designing a Gradient Li+ Capture and Quasi-Spontaneous Diffusion Anode Protection Layer toward Long-Life Li−O2 Batteries

Lithium metal is the only anode material that can enable the Li−O₂ battery to realize its high theoretical energy density (≈3500 Wh kg⁻¹). However, the inherent uncontrolled dendrite growth and serious corrosion limitations of lithium metal anodes make it experience fast degradation and impede the practical application of Li−O₂ batteries. Herein, a multifunctional complementary LiF/F-doped carbon gradient protection layer on a lithium metal anode by one-step in situ reaction of molten Li with poly(tetrafluoroethylene) (PTFE) is developed. The abundant strong polar C-F bonds in the upper carbon can not only act as Li⁺ capture site to pre-uniform Li⁺ flux but also regulate the electron configuration of LiF to make Li⁺ quasi-spontaneously diffuse from carbon to LiF surface, avoiding the strong Li⁺-adhesion-induced Li aggregation. For LiF, it can behave as fast Li⁺ conductor and homogenize the nucleation sites on lithium, as well as ensure firm connection with lithium. As a result, this well-designed protection layer endows the Li metal anode with dendrite-free plating/stripping and anticorrosion behavior both in ether-based and carbonate ester-based electrolytes. Even applied protected Li anodes in Li−O₂ batteries, its superiority can still be maintained, making the cell achieve stable cycling performance (180 cycles).     

Dual‐Layered Film Protected Lithium Metal Anode to Enable Dendrite‐Free Lithium Deposition

Lithium metal batteries (such as lithium–sulfur, lithium–air, solid state batteries with lithium metal anode) are highly considered as promising candidates for next‐generation energy storage systems. However, the unstable interfaces between lithium anode and electrolyte definitely induce the undesired and uncontrollable growth of lithium dendrites, which results in the short‐circuit and thermal runaway of the rechargeable batteries. Herein, a dual‐layered film is built on a Li metal anode by the immersion of lithium plates into the fluoroethylene carbonate solvent. The ionic conductive film exhibits a compact dual‐layered feature with organic components (ROCO₂Li and ROLi) on the top and abundant inorganic components (Li₂CO₃ and LiF) in the bottom. The dual‐layered interface can protect the Li metal anode from the corrosion of electrolytes and regulate the uniform deposition of Li to achieve a dendrite‐free Li metal anode. This work demonstrates the concept of rational construction of dual‐layered structured interfaces for safe rechargeable batteries through facile surface modification of Li metal anodes. This not only is critically helpful to comprehensively understand the functional mechanism of fluoroethylene carbonate but also affords a facile and efficient method to protect Li metal anodes.     

Lithium garnets: Synthesis,structure, Li+ conductivity,Li+ dynamics and applications

Inorganic solid fast Li⁺ conductors based batteries are expected to overcome the limitations over safety concerns of flammable organic polymer electrolytes based Li⁺ batteries. Hence, an all-solid-state Li⁺ battery using non-flammable solid electrolyte have attracted much attention as next-generation battery. Therefore, in the development of all-solid-state lithium rechargeable batteries, it is important to search for a solid electrolyte material that has high Li⁺ conductivity, low electronic conductivity, fast charge transfer at the electrode interface and wide electrochemical window stability against potential electrodes and lithium metal. Hence, significant research effort must be directed towards developing novel fast Li⁺ conductors as electrolytes in all-solid-state lithium batteries. Among the reported inorganic solid Li⁺ conductive oxides, garnet-like structural compounds received considerable attention in recent times for potential application as electrolytes in all-solid-state lithium batteries. The focus of this review is to provide comprehensive overview towards the importance of solid fast lithium ion conductors, advantages of lithium garnets over other ceramic lithium ion conductors and understanding different strategies on synthesis of lithium garnets. Attempts have also been made to understand relationship between the structure, Li⁺ conduction and Li⁺ dynamics of lithium garnets. The status of lithium garnets as solid electrolyte in electrochemical devices like all-solid state lithium battery, lithium-air battery and sensor are also discussed.     

Perovskite‐type Li‐ion solid electrolytes: a review

All-solid-state lithium batteries with inorganic solid electrolytes are recognized as the next-generation battery systems due to their high safety and energy density. To realize the practical applications of all-solid-state lithium battery, it is essential to develop solid electrolytes which exhibit high Li-ion conductivity, low electron conductivity, wide electrochemical window, and low interface resistance between the electrode and the solid electrolyte. Among many solid electrolytes, the perovskite-type lithium-ion solid electrolytes are promising candidates that can be applied to all-solid-state lithium batteries. However, the perovskite-type solid electrolytes still suffer from several significant problems, such as poor stability against lithium metal, high interface resistance, etc. In this review, we have analyzed and summarized the properties of perovskite-type solid electrolytes with two different systems, namely three-component oxide system Li_3xLa_2/3?xTiO₃ (LLTO) and four-component oxide system (Li, Sr)(B, B’)O₃ (B?=?Zr, Hf, Ti, Sn, Ga, etc., B’ = Nb, Ta, etc.). LLTO and (Li, Sr)(B, Ta)O₃ compounds exhibit high Li-ion conductivity of up to >?10^??4 S·cm^??1 at room temperature. Based on the review of academic literature, the ion transportation mechanism, composition design, electrical properties, stability, doping, and application of these solid electrolytes are discussed, which would be helpful for the further development of all-solid-state lithium batteries.

     

Thiol-Branched Solid Polymer Electrolyte Featuring High Strength,Toughness, and Lithium Ionic Conductivity for Lithium-Metal Batteries

Lithium-metal batteries (LMBs) with high energy densities are highly desirable for energy storage, but generally suffer from dendrite growth and side reactions in liquid electrolytes; thus the need for solid electrolytes with high mechanical strength, ionic conductivity, and compatible interface arises. Herein, a thiol-branched solid polymer electrolyte (SPE) is introduced featuring high Li⁺ conductivity (2.26 × 10⁻⁴ S cm⁻¹ at room temperature) and good mechanical strength (9.4 MPa)/toughness (≈500%), thus unblocking the tradeoff between ionic conductivity and mechanical robustness in polymer electrolytes. The SPE (denoted as M-S-PEGDA) is fabricated by covalently cross-linking metal–organic frameworks (MOFs), tetrakis (3-mercaptopropionic acid) pentaerythritol (PETMP), and poly(ethylene glycol) diacrylate (PEGDA) via multiple C S C bonds. The SPE also exhibits a high electrochemical window (>5.4 V), low interfacial impedance (<550 Ω), and impressive Li⁺ transference number (t_Li+ = 0.44). As a result, Li||Li symmetrical cells with the thiol-branched SPE displayed a high stability in a >1300 h cycling test. Moreover, a Li|M-S-PEGDA|LiFePO₄ full cell demonstrates discharge capacity of 143.7 mAh g⁻¹ and maintains 85.6% after 500 cycles at 0.5 C, displaying one of the most outstanding performances for SPEs to date.     

Solid-State Electrolyte Design for Lithium Dendrite Suppression

All-solid-state Li metal batteries have attracted extensive attention due to their high safety and high energy density. However, Li dendrite growth in solid-state electrolytes (SSEs) still hinders their application. Current efforts mainly aim to reduce the interfacial resistance, neglecting the intrinsic dendrite-suppression capability of SSEs. Herein, the mechanism for the formation of Li dendrites is investigated, and Li-dendrite-free SSE criteria are reported. To achieve a high dendrite-suppression capability, SSEs should be thermodynamically stable with a high interface energy against Li, and they should have a low electronic conductivity and a high ionic conductivity. A cold-pressed Li₃N–LiF composite is used to validate the Li-dendrite-free design criteria, where the highly ionic conductive Li₃N reduces the Li plating/stripping overpotential, and LiF with high interface energy suppresses dendrites by enhancing the nucleation energy and suppressing the Li penetration into the SSEs. The Li₃N–LiF layer coating on Li₃PS₄ SSE achieves a record-high critical current of >6 mA cm⁻² even at a high capacity of 6.0 mAh cm⁻². The Coulombic efficiency also reaches a record 99% in 150 cycles. The Li₃N–LiF/Li₃PS₄ SSE enables LiCoO₂ cathodes to achieve 101.6 mAh g⁻¹ for 50 cycles. The design principle opens a new opportunity to develop high-energy all-solid-state Li metal batteries.     

固态锂电池用MOF/聚氧化乙烯复合聚合物电解质(英文)

固态聚合物电解质具有柔韧性好和易于加工的优势,可制备各种形状的固态锂电池,杜绝漏液问题。但固态聚合物电解质存在离子电导率低以及对锂金属负极不稳定等问题。本研究以纳米金属–有机框架材料UiO-66为聚合物电解质的填料,用于改善电解质的性能。UiO-66与聚氧化乙烯(poly(ethylene oxide), PEO)链上醚基的氧原子的配位作用以及与锂盐中阴离子的相互作用,可显著提高聚合物电解质的离子电导率(25℃,3.0×10^–5 S/cm;60℃,5.8×10^–4 S/cm),并将锂离子迁移数提高至0.36,电化学窗口拓宽至4.9V。此外,制备的PEO基固态电解质对金属锂具有良好的稳定性,对称电池在60℃、0.15mA·cm^–2电流密度下可稳定循环1000h,锂电池的电化学性能得到显著改善。     

High-Performance Solid Lithium Metal Batteries Enabled by LiF/LiCl/LiIn Hybrid SEI via InCl3-Driven In Situ Polymerization of 1,3-Dioxolane

The use of poly(1,3-dioxolane) (PDOL) electrolyte for lithium batteries has gained attention due to its high ionic conductivity, low cost, and potential for large-scale applications. However, its compatibility with Li metal needs improvement to build a stable solid electrolyte interface (SEI) toward metallic Li anode for practical lithium batteries. To address this concern, this study utilized a simple InCl₃-driven strategy for polymerizing DOL and building a stable LiF/LiCl/LiIn hybrid SEI, confirmed through X-ray photoelectron spectroscopy (XPS) and cryogenic-transmission electron microscopy (Cryo-TEM). Furthermore, density functional theory (DFT) calculations and finite element simulation (FES) verify that the hybrid SEI exhibits not only excellent electron insulating properties but also fast transport properties of Li⁺. Moreover, the interfacial electric field shows an even potential distribution and larger Li⁺ flux, resulting in uniform dendrite-free Li deposition. The use of the LiF/LiCl/LiIn hybrid SEI in Li/Li symmetric batteries shows steady cycling for 2000 h, without experiencing a short circuit. The hybrid SEI also provided excellent rate performance and outstanding cycling stability in LiFePO₄/Li batteries, with a high specific capacity of 123.5 mAh g⁻¹ at 10 C rate. This study contributes to the design of high-performance solid lithium metal batteries utilizing PDOL electrolytes.     

Converting Nafion into Li+-Conductive Nanoporous Materials

Sulfonated polymers have long been used as proton-conducting materials in fuel cells, and their ionic transport features are highly attractive for electrolytes in lithium-ion/metal batteries (LIBs/LMBs). However, most studies are still based on a preconceived notion of using them directly as polymeric ionic carriers, which precludes exploring them as nanoporous media to construct efficient lithium ions (Li⁺) transport network. Here, effective Li⁺-conducting channels realized by swelling nanofibrous Nafion is demonstrated, which is a classical sulfonated polymer in fuel cells. The sulfonic acid groups, interact with LIBs liquid electrolytes to form porous ionic matrix of Nafion and assist partial desolvation of Li⁺-solvates to further enhance Li⁺ transport. Li-symmetric cells and Li-metal full cells (Li₄Ti₅O₁₂ or high-voltage LiNi_0.6Co_0.2Mn_0.2O₂ as a cathode) with such membrane show excellent cycling performance and stabilized Li-metal anode. The finding provides a strategy to convert the vast sulfonated polymer family into efficient Li⁺ electrolyte, promoting the development of high-energy–density LMBs.     

Weak-Coordination Electrolyte Enabling Fast Li+ Transport in Lithium Metal Batteries at Ultra-Low Temperature

Lithium metal batteries (LMBs) are promising for next-generation high-energy-density batteries owing to the highest specific capacity and the lowest potential of Li metal anode. However, the LMBs are normally confronted with drastic capacity fading under extremely cold conditions mainly due to the freezing issue and sluggish Li⁺ desolvation process in commercial ethylene carbonate (EC)-based electrolyte at ultra-low temperature (e.g., below −30 °C). To overcome the above challenges, an anti-freezing carboxylic ester of methyl propionate (MP)-based electrolyte with weak Li⁺ coordination and low-freezing temperature (below −60 °C) is designed, and the corresponding LiNi_0.8Co_0.1Mn_0.1O₂ (NCM811) cathode exhibits a higher discharge capacity of 84.2 mAh g⁻¹ and energy density of 195.0 Wh kg⁻¹_cathode than that of the cathode (1.6 mAh g⁻¹ and 3.9 Wh kg⁻¹_cathode) working in commercial EC-based electrolytes for NCM811‖ Li cell at −60 °C. Molecular dynamics simulation, Raman spectra, and nuclear magnetic resonance characterizations reveal that rich mobile Li⁺ and the unique solvation structure with weak Li⁺ coordination are achieved in MP-based electrolyte, which collectively facilitate the Li⁺ transference process at low temperature. This work provides fundamental insights into low-temperature electrolytes by regulating solvation structure, and offers the basic guidelines for the design of low-temperature electrolytes for LMBs.     

Interfacial Interaction of Multifunctional GQDs Reinforcing Polymer Electrolytes For All-Solid-State Li Battery

Solid-state polymer electrolytes are highly anticipated for next generation lithium ion batteries with enhanced safety and energy density. However, a major disadvantage of polymer electrolytes is their low ionic conductivity at room temperature. In order to enhance the ionic conductivity, here, graphene quantum dots (GQDs) are employed to improve the poly (ethylene oxide) (PEO) based electrolyte. Owing to the increased amorphous areas of PEO and mobility of Li⁺, GQDs modified composite polymer electrolytes achieved high ionic conductivity and favorable lithium ion transference numbers. Significantly, the abundant hydroxyl groups and amino groups originated from GQDs can serve as Lewis base sites and interact with lithium ions, thus promoting the dissociation of lithium salts and providing more ion pathways. Moreover, lithium dendrite is suppressed, associated with high transference number, enhanced mechanical properties and steady interface stability. It is further observed that all solid-state lithium batteries assembled with GQDs modified composite polymer electrolytes display excellent rate performance and cycling stability.     

Carbonized Polymer Dots with Controllable N,O Functional Groups as Electrolyte Additives to Achieve Stable Li Metal Batteries

Electrolyte additive is an effective strategy to inhibit the uncontrolled growth of Li dendrites for lithium metal batteries (LMBs). However, most of the additives are complex synthesis and prone to decompose in cycling. Herein, in order to guide the homogeneous deposition of Li⁺, carbonized polymer dots (CPDs) as electrolyte additives are successfully designed and synthesized by microwave (M-CPDs) and hydrothermal (H-CPDs) approaches. The controllable functional groups containing N or O (especially pyridinic-N, pyrrolic-N, and carboxyl group) enable CPDs to keep stable in electrolytes for at least 3 months. Meanwhile, the clusters formed between CPDs and Li⁺ through electrostatic interaction effectively guide the uniform Li dispersion and limit the “tip effect” and dendrite formation. Moreover, as lithiophilic groups increase, the strong electrostatic interference for the solvation effect of Li⁺ in the electrolyte is formed, which induces faster Li⁺ diffusion/transfer. As expected, H-CPDs achieve the ultra-even Li⁺ transfer. The corresponding Li//LiFePO₄ full cell delivers a high capacity retention rate of 93.8% after 200 cycles, which is much higher than that of the cells without additives (61.2%) and with M-CPDs (83.7%) as additives. The strategy in this work provides a theoretical direction for CPDs as electrolyte additives used in energy storage devices.     

A Universal Room-Temperature 3D Printing Approach Towards porous MOF Based Dendrites Inhibition Hybrid Solid-State Electrolytes

Hybrid solid-state electrolytes (HSSEs) provide new opportunities and inspiration for the realization of safer, higher energy-density metal batteries. The innovative application of 3‑dimensional printing in the electrochemical field, especially in solid-state electrolytes, endows energy storage devices with fascinating characteristics. In this paper, effective dendrite-inhibited PEO/MOFs HSSEs is innovatively developed through universal room-temperature 3‑dimensional printing (RT-3DP) strategy. The prepared HSSEs display enhanced dendrite inhibition due to the porous MOF filler promoting homogeneity of lithium deposition and the formation of C-OCO₃Li, ROLi, LiF mesophases, which further improve the migration of Li⁺ in PEO chain and comprehensive performances. This universal strategy realizes the fabrication of different slurry components (PEO with ZIF-67, MOF-74, UIO-66, ZIF-8 fillers) HSSEs at RT environment, providing new inspirations for the exploration of next-generation advanced solid-state batteries.     

Composite Solid Electrolyte with Continuous and Fast Organic–Inorganic Ion Transport Highways Created by 3D Crimped Nanofibers@functional Ceramic Nanowires

A 3D crimped sulfonated polyethersulfone-polyethylene oxide(C-SPES/PEO) nanofiber membrane and long-range lanthanum cobaltate(LaCoO₃) nanowires are collectively doped into a PEO matrix to acquire a composite solid electrolyte (C-SPES-PEO-LaCoO₃) for all-solid-state lithium metal batteries(ASSLMBs). The 3D crimped structure enables the fiber membrane to have a large porosity of 90%. Therefore, under the premise of strongly guaranteeing the mechanical properties of C-SPES-PEO-LaCoO₃, the ceramic nanowires conveniently penetrated into the 3D crimped SPES nanofiber without being blocked, which can facilitate fast ionic conductivity by forming 3D continuous organic–inorganic ion transport pathways. The as-prepared electrolyte delivers an excellent ionic conductivity of 2.5 × 10⁻⁴ S cm⁻¹ at 30 °C. Density functional theory calculations indicate that the LaCoO₃ nanowires and 3D crimped C-SPES/PEO fibers contribute to Li⁺ movement. Particularly, the LiFePO₄/C-SPES-PEO-LaCoO₃ /Li and NMC811/C-SPES-PEO-LaCoO₃/Li pouch cell have a high initial discharge specific capacity of 156.8 mAh g⁻¹ and a maximum value of 176.7 mAh g⁻¹, respectively. In addition, the universality of the penetration of C-SPES/PEO nanofibers to functional ceramic nanowires is also reflected by the stable cycling performance of ASSLMBs based on the electrolytes, in which the LaCoO₃ nanowires are replaced with Gd-doped CeO₂ nanowires. The work will provide a novel approach to high performance solid-state electrolytes.     

Stabilizing ultrahigh-nickel layered oxide cathodes for high-voltage lithium metal batteries

Rechargeable lithium (Li) metal batteries (LMBs) with ultrahigh-nickel (Ni) layered oxide cathodes offer a great opportunity for applications in electrical vehicles. However, increasing Ni content inherently arouses a tradeoff between specific capacity and electrochemical cyclability due to the aggressive side reactions with electrolyte contributed by the highly reactive Ni species. Here, a protective and stable cathode/electrolyte interphase featuring enriched and evenly-distributed LiF is in situ formed on ultrahigh-Ni cathode LiNi_0.94Co_0.06O₂ (NC) with an advanced ether-based localized high-concentration electrolyte (LHCE), which concurrently shows good compatibility with Li metal anode. Subsequently, the NC cathode can deliver high capacity retentions of 81.4% after 500 cycles at 25 °C and 91.6% after 100 cycles at 60 °C in the voltage range of 2.8–4.4 V in Li||NC cells at 1C cycling rate (1.5 mA cm⁻²). Meanwhile, the conductive electrode/electrolyte interphases formed in LHCE enable a high reversible capacity of about 209 mAh g⁻¹ at 3C charging rate. This work provides an effective approach and important insight from the perspective of in situ ultrahigh-Ni cathode/electrolyte interphase protection for high energy–density, long-lasting LMBs.     

Rechargeable Lithium Metal Batteries with an In-Built Solid-State Polymer Electrolyte and a High Voltage/Loading Ni-Rich Layered Cathode

Solid-state batteries enabled by solid-state polymer electrolytes (SPEs) are under active consideration for their promise as cost-effective platforms that simultaneously support high-energy and safe electrochemical energy storage. The limited oxidative stability and poor interfacial charge transport in conventional polymer electrolytes are well known, but difficult challenges must be addressed if high-voltage intercalating cathodes are to be used in such batteries. Here, ether-based electrolytes are in situ polymerized by a ring-opening reaction in the presence of aluminum fluoride (AlF₃) to create SPEs inside LiNi_0.6Co_0.2 Mn_0.2O₂ (NCM) || Li batteries that are able to overcome both challenges. AlF₃ plays a dual role as a Lewis acid catalyst and for the building of fluoridized cathode–electrolyte interphases, protecting both the electrolyte and aluminum current collector from degradation reactions. The solid-state NCM || Li metal batteries exhibit enhanced specific capacity of 153 mAh g⁻¹ under high areal capacity of 3.0 mAh cm⁻². This work offers an important pathway toward solid-state polymer electrolytes for high-voltage solid-state batteries.     

The Synergetic Effect of Lithium Bisoxalatodifluorophosphate and Fluoroethylene Carbonate on Dendrite Suppression for Fast Charging Lithium Metal Batteries

Fluorinated solid‐electrolyte interphase (SEI) derived from fluoroethylene carbonate (FEC) is particularly favored for dendrite suppression in lithium metal batteries because of the high Young's modulus (≈64.9 Gpa) and low electronic conductivity (10^?31 S cm^?1) of LiF. However, the transportation ability of Li⁺ in this fluorinated SEI under high current densities is limited by the low ionic conductivity of LiF (≈10^?12 S cm^?1). Herein, by rational design, 0.1 m lithium bisoxalatodifluorophosphate (LiDFBOP) is adopted to modify fluorinated SEI in FEC based electrolyte for fast charging lithium metal batteries. Benefiting from the synergetic effect of LiDFBOP and FEC, a fluorinated SEI rich in LiF and Li_xPO_yF_z species can be yielded, which can further improve the stability and ionic conductivity of SEI for fast Li⁺ transportation. Meanwhile, the average coulombic efficiency for Li plating/stripping is improved from 92.0% to 96.7%, thus promoting stable cycling of Li||Li symmetrical batteries with dendrite free morphologies, even at high current densities (3.0 mA cm^?2) and high plating/stripping capacities (3.0 mAh cm^?2). More attractively, in practical Li||LiNi_0.6Co_0.2Mn_0.2O₂ batteries, the cycling life at 1C and rate capacities at 6C are also significantly improved. Therefore, the synergetic effect of LiDFBOP and FEC provides great potential for achieving advanced lithium metal batteries with fast charging ability.     

High‐Voltage Lithium‐Metal Batteries Enabled by Localized High‐Concentration Electrolytes

Rechargeable lithium‐metal batteries (LMBs) are regarded as the “holy grail” of energy‐storage systems, but the electrolytes that are highly stable with both a lithium‐metal anode and high‐voltage cathodes still remain a great challenge. Here a novel “localized high‐concentration electrolyte” (HCE; 1.2 m lithium bis(fluorosulfonyl)imide in a mixture of dimethyl carbonate/bis(2,2,2‐trifluoroethyl) ether (1:2 by mol)) is reported that enables dendrite‐free cycling of lithium‐metal anodes with high Coulombic efficiency (99.5%) and excellent capacity retention (>80% after 700 cycles) of Li||LiNi_1/3Mn_1/3Co_1/3O₂ batteries. Unlike the HCEs reported before, the electrolyte reported in this work exhibits low concentration, low cost, low viscosity, improved conductivity, and good wettability that make LMBs closer to practical applications. The fundamental concept of “localized HCEs” developed in this work can also be applied to other battery systems, sensors, supercapacitors, and other electrochemical systems.