Electrolytes For Lithium Metal Batteries Research Articles

Electrospun PAN membrane encapsulated in PEO as a polymer electrolyte for lithium metal batteries

The novel two-step fabrication method of polymer electrolyte membrane was proposed. In the first step, the polyacrylonitrile nano fibrous membrane was prepared with the help of electrospinning. In the second step, the polyethylene oxide solution was prepared along with lithium salt and plasticizers. The solution was poured on the electrospun polyacrylonitrile to get polymer electrolyte membrane in the form of PAN membrane encapsulated in PEO. The polymer electrolyte membrane was boosted by the liquid LiPF6 before assembled in the lithium metal batteries. The polymer electrolyte membrane was compared with the commercial Celgard separator when assembled in coin cell for the application of lithium metal batteries. The polymer electrolyte membrane outperformed and exhibited a good ultimate tensile strength of 20 MPa and the better thermal stability of 97 % at 305 °C. Moreover, the polymer electrolyte membrane also exhibited excellent ionic conductivity of 1.2 mS cm−1, good lithium-ion transference number of 0.57 and uniform lithium plating/stripping cycles for up to 500 cycles without internal short circuiting. The polymer electrolyte membrane represented outstanding rate capability and exhibited the good discharge capacity of 141 mA h g−1 after 100 cycles at 0.5 C rate.

A star polymer POSS-PMMA based gel electrolyte with balanced electrochemical and mechanical properties for lithium metal battery

Gel polymer electrolyte (GPE) is one of the promising candidates to overcome the defects of liquid and solid electrolyte for lithium metal batteries (LMBs). The obstacle for the practical application of GPEs lies in achieving a balance between ion transport, mechanical properties and interface stability. In this work, a star shaped polymer matrix polyhedral oligomeric silsesquioxane-polymethyl methacrylate (POSS-PMMA) is successfully synthesized with POSS as the core via atom transfer radical polymerization (ATRP) method. 1-ethyl-3-methylimidazole bis(trifluoromethanesulfon)imide ([EMIM][TFSI]) and bistrifluoromethanesulfonimide lithium salt (LiTFSI) are blended with the matrix to increase ionic conductivity. Attributed to the star structure and the lithium ion migration channel provided by POSS, the synthesized GPE possesses excellent balanced mechanical and electrochemical properties. To further stabilize the Li/GPE interface, a polymer and plastic crystalline electrolyte (PPCE) is coated as interface modification layer on both sides of GPE. Benefitting from the design, the synthesized GPE reaches a highly stable Li striping/plating cycling for 1000 h at 0.1 mA cm−2 with ionic conductivity of 3.5 × 10−4 S cm−1, Li+ transference number of 0.35, and electrochemical stability window of 4.9 V. Furthermore, the Li||POSS-PMMA-PPCE||LiFePO4 (LFP) full cell shows a high capacity retention of 99.5 % after 100 cycles at 0.2 C under room temperature (RT), and the high voltage Li||POSS-PMMA-PPCE||LiNi1-x-yMnxCoyO2 (NCM811) cell shows a high capacity retention of 88.3 % after 50 cycles at 0.1 C under RT. This work opens up a new frontier to stabilize the Li/GPE interface and enables safe operation of room temperature lithium metal batteries.

The Interaction Between Fluorinated Additives and Imidazolyl Ionic Liquid Electrolytes in Lithium Metal Batteries: A First‐Principles Study

ABSTRACTThis investigation employs first‐principles calculations to explore the interaction between imidazolium ionic liquids (ILs) and fluoride additives on lithium metal surface. Our focus lies in the comprehensive analysis of three distinct categories of fluorinated additives, each differing in their degree of fluorination. The computations reveal that fluorination plays a significant role in determining both the ionic conductivity and the formation of the solid–electrolyte interphase (SEI) film. Specifically, heightened fluorination enhances the oxidative stability of the system but diminishes the strength of solvent binding, resulting in the formation of larger salt/anion clusters and a decrease in ionic conductivity. Conversely, increased fluorination facilitates the interaction between fluorinated additives and the lithium metal surface, thereby aiding in the formation of a stable SEI film characterized by an abundance of inorganic LiF components. This is important as it serves to suppress dendrite growth and mitigate interface side reactions. Considering the combined influences of ionic conductivity and film formation, 1FP is suggested as the optimal candidate for pyridine‐based additive systems, with FEC preferred for cyclic ester‐based additive systems and BC for chain ester‐based additive systems. This study provides theoretical references for the design of ionic liquid‐fluorinated additive electrolyte systems that can protect the lithium metal anode.

Organic-Inorganic Hybrid Solid Composite Electrolytes for High Energy Density Lithium Batteries: Combining Manufacturability, Conductivity, and Stability.

The deployment of solid and quasi-solid electrolytes in lithium metal batteries is envisioned to push their energy densities to even higher levels, in addition to providing enhanced safety. This article discusses a set of hybrid solid composite electrolytes which combine functional properties with electrode compatibility and manufacturability. Their anodic stability >5V versus Li+/Li and compatibility with lithium metal stem from the incorporated ionic liquid electrolyte, whereas the organic-inorganic hybrid host structure boosts their conductivity up to 2.7mScm-1 at room temperature. The absence of strong acids enables compatibility with porous NMC811 electrodes. Liquid precursor solutions can be readily impregnated into porous electrodes, facilitating cell assembly. Electrolytes containing TFSI- as the only anion have a superior compatibility toward high-voltage positive electrode materials, whereas electrolytes containing both FSI- and TFSI- have a better compatibility toward lithium metal. Using the former as catholyte and the latter as anolyte, NMC811/Li coin cells retain up to 100% of their initial capacity after 100 cycles (0.2C, 3.0-4.4V vs Li+/Li). Because of their unprecedented combination of functional properties, electrode compatibility, and manufacturability, these hybrid solid composite electrolytes are potential candidates for the further development of lithium metal battery technology.

Exploring Chlorinated Solvents as Electrolytes for Lithium Metal Batteries: A DFT and MD Study

ABSTRACTElectrolytes with fluorinated solvents have been regarded as a promising strategy to stabilize high‐voltage cathodes and the interphase of lithium anode in lithium metal batteries (LMBs). However, the rigorous synthesis approach and high cost have led to a demand for developing cost‐effective solvents with suitable properties for LMBs. Herein, we explored the possibility of using chlorinate solvents as electrolytes using density functional theory (DFT) and classical molecular dynamics (MD) simulation. Taking ether (1,2‐dimethoxyethane [DME], 1,3‐dioxolane [DOL]), carbonate (dimethyl carbonate [DMC], and ethylene carbonate [EC]) as examples, we first compared the energy variation of the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) upon Cl and F substitution. In particular, we found that 1,2‐bis(chloromethoxy)ethane (DME‐2Cl‐2) has the lowest HOMO and the highest LUMO level among the chlorinated DME after coordinating with Li+, enabling a potentially wide voltage stability. Further MD simulation reveals that lithium ions in DME‐2Cl‐2 has a weaker solvation coordination with solvents but stronger interaction with anions than DME and 1,2‐bis(Fluoromethoxy)ethane (DME‐2F‐2), which is more beneficial for forming stable anion‐derived solid electrolyte interphase (SEI). Our findings suggest that chlorinated solvents can be used as promising electrolytes for LMBs.

Solid‐State Electrolytes for Lithium Metal Batteries: State‐of‐the‐Art and Perspectives

AbstractThe use of all‐solid‐state lithium metal batteries (ASSLMBs) has garnered significant attention as a promising solution for advanced energy storage systems. By employing non‐flammable solid electrolytes in ASSLMBs, their safety profile is enhanced, and the use of lithium metal as the anode allows for higher energy density compared to traditional lithium‐ion batteries. To fully realize the potential of ASSLMBs, solid‐state electrolytes (SSEs) must meet several requirements. These include high ionic conductivity and Li+ transference number, smooth interfacial contact between SSEs and electrodes, low manufacturing cost, excellent electrochemical stability, and effective suppression of dendrite formation. This paper delves into the essential requirements of SSEs to enable the successful implementation of ASSLMBs. Additionally, the representative state‐of‐the‐art examples of SSEs developed in the past 5 years, showcasing the latest advancements in SSE materials and highlighting their unique properties are discussed. Finally, the paper provides an outlook on achieving balanced and improved SSEs for ASSLMBs, addressing failure mechanisms and solutions, highlighting critical challenges such as the reversibility of Li plating/stripping and thermal runaway, advanced characterization techniques, composite SSEs, computational studies, and potential and challenges of ASS lithium–sulfur and lithium–oxygen batteries. With this consideration, balanced and improved SSEs for ASSLMBs can be realized.

Charge-Delocalized Triptycene-Based Ionic Porous Organic Polymers as Quasi-Solid-State Electrolytes for Lithium Metal Batteries.

Ideal solid electrolytes for lithium (Li) metal batteries should conduct Li+ rapidly with low activation energy, exhibit a high Li+ transference number, form a stable interface with the Li anode, and be electrochemically stable. However, the lack of solid electrolytes that meet all of these criteria has remained a considerable bottleneck in the advancement of lithium metal batteries. In this study, we present a design strategy combining all of those requirements in a balanced manner to realize quasi-solid-state electrolyte-enabled Li metal batteries (LMBs). We prepared Li+-coordinated triptycene-based ionic porous organic polymers (Li+@iPOPs). The Li+@iPOPs with imidazolates and phenoxides exhibited a high conductivity of 4.38 mS cm-1 at room temperature, a low activation energy of 0.627 eV, a high Li+ transference number of 0.95, a stable electrochemical window of up to 4.4 V, excellent compatibility with Li metal electrodes, and high stability during Li deposition/stripping cycles. The high performance is attributed to charge delocalization in the backbone, mimicking the concept of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), which facilitates the diffusion of coordinated Li+ through the porous space of the triptycene-based iPOPs. In addition, Li metal batteries assembled using Li+@Trp-Im-O-POPs as quasi-solid-state electrolytes and a LiFePO4 cathode showed an initial capacity of 114 mAh g-1 and 86.7% retention up to 200 cycles.

Bespoke Dual‐Layered Interface Enabled by Cyclic Ether in Localized High‐Concentration Electrolytes for Lithium Metal Batteries

AbstractLithium metal anodes (LMAs) are regarded as a highly promising candidate for next‐generation batteries owing to their exceptional energy density. Nevertheless, the instability of the interphase poses significant safety and degradation challenges for LMAs, thereby impeding their feasibility for commercial application. Herein, based on the lessons learned from the stable solid‐electrolyte‐interface (SEI) layer formed with ethylene carbonate (EC) solvents for graphite anodes, the effects of cyclic‐ethers are systematically investigated in localized high concentration electrolytes (LHCEs) using tetrahydrofuran (THF), 1,3‐dioxolane (DOL), and 1,4‐epoxybuta‐1,3‐diene (Furan) as co‐solvents. When using DME and THF as co‐solvents, the most stable interface, a LiF‐rich SEI layer with a polymeric outer‐layer, is formed, elongating the cyclability of the Li | Li symmetric cells up to 1200 h at 1 mA cm−2 and 1 mAh cm−2. This research gives useful insight into how to enhance the mechanical strength of the SEI layer with polymeric compounds by incorporating cyclic‐ether co‐solvents in LHCEs.

Local fluorinated functional units enhance Li+ transport in acrylate-based polymer electrolytes for lithium metal batteries

Fluorinated polymer matrix emerges as a promising candidate owing to their enhanced anti-oxidation ability, but their application is plagued by the relatively low ion conduction ability and the ambiguous ionic conduction mechanism in the fluorinated polymer electrolytes (PEs). Herein, a series of acrylate-based electrolytes with different fluorinated functional units (fluorinated-FUs) of poly(ethyl methacrylate) electrolyte (0F PE), poly(trifluoroethyl methacrylate) electrolyte (3F PE) and poly(hexafluorobutyl methacrylate) electrolyte (6F PE) were investigated. Beneficial from the long fluorinated-FUs in the side chain, the 6F PE exhibits improved both ionic conductivity of 4.0×10−4 S cm−1 and Li+ transference number of 0.65 at 25 °C, which are superior to those of the 0F PE and the 3F PE. The enhanced ion conduction mechanism was clarified via combining the theoretical calculations and experimental data, where the integration of local fluorinated-FUs provides additional coordinating sites for the continuous Li+ migration and regulates the ion transporting pathways. This work demonstrates that the regulation of local fluorinated-FUs can provide a promising strategy for achieving high performance PEs applied in solid-state batteries.

High-Concentrated Binary-Salt Ether Electrolytes for High-Voltage Lithium Metal Batteries with Ni-Rich Cathode.

The incompatibility of ether electrolytes with a cathode dramatically limits its application in high-voltage Li metal batteries. Herein, we report a new highly concentrated binary salt ether-based electrolyte (HCBE, 1.25 M LiTFSI + 2.5 M LiFSI in DME) that enables stable cycling of high-voltage lithium metal batteries with the Ni-rich (NCM83, LiNi0.83Co0.12Mn0.05O2) cathode. Experimental characterizations and density functional theory (DFT) calculations reveal the special solvation structure in HCBE. A solvation structure rich in aggregates (AGGs) can effectively broaden the electrochemical window of the ether electrolyte. The anions in HCBE preferentially decompose under high voltage, forming a CEI film rich in inorganic components to protect the electrolyte from degradation. Thus, the high-energy-density Li||NCM83 cell has a capacity retention of ≈95% after 150 cycles. Significantly, the cells in HCBE have a high and stable average Coulombic efficiency of over 99.9%, much larger than that of 1 M LiPF6 + EC + EMC + DMC (99%). The result emphasizes that the anionic-driven formation of a cathode electrolyte interface (CEI) can reduce the number of interface side reactions and effectively protect the cathode. Furthermore, the Coulombic efficiency of Li||Cu using the HCBE is 98.5%, underscoring the advantages of using ether-based electrolytes. This work offers novel insights and approaches for the design of high-performance electrolytes for lithium metal batteries.

Deep Eutectic Solvent‐Based Solid Polymer Electrolytes for High‐Voltage and High‐Safety Lithium Metal Batteries

AbstractSolid‐state electrolytes (SSE) exhibit great promise in enhancing the safety of Li metal batteries by replacing flammable liquid electrolytes. However, the practical application of SSE is hampered mainly due to the poor electrode–electrolyte interface, low ion conductivity, and inferior electrochemical stability. Herein, superior nonflammable solid polymer electrolytes are elaborately designed by in situ encapsulating succinonitrile (SN)‐based deep eutectic solvent (DES) into the ethoxylated trimethylolpropane triacrylate (ETPTA) matrix (DES‐ETPTA). Benefiting from strong polarity and high anti‐oxidation capability, as‐prepared DES‐ETPTA electrolyte shows high ionic conductivity (9.55 × 10−4 S cm−1 at 30 °C), high Li+ transference number (0.68), and good electrochemical stability. As a result, the assembled LiFePO4 || Li full cells based on the designed DES‐ETPTA electrolyte deliver a high reversible capacity and capacity retention at −10 °C and room temperature. Furthermore, considering the compatibility with high‐voltage layered oxide cathode, the electrochemical stability of the ETPTA is further improved through the decoration of cyanoacrylate (CA) with strong electron‐withdrawing characteristic of C≡N. Consequently, the constructed 4.5 V LiCoO2 || Li full cells using DES‐ETPTA‐CA electrolyte deliver a high reversible capacity of 144 mAh g−1 and a superior retention rate of 93% after 200 cycles at 0.5 C. This work paves a new pathway to design high‐safety and high‐voltage solid polymer electrolytes for lithium metal batteries.

Ultralong Cycling and Interfacial Regulation of Bilayer Heterogeneous Composite Solid-State Electrolytes in Lithium Metal Batteries.

Under the background of "carbon neutral", lithium-ion batteries (LIB) have been widely used in portable electronic devices and large-scale energy storage systems, but the current commercial electrolyte is mainly liquid organic compounds, which have serious safety risks. In this paper, a bilayer heterogeneous composite solid-state electrolyte (PLPE) was constructed with the 3D LiX zeolite nanofiber (LiX-NF) layer and in-situ interfacial layer, which greatly extends the life span of lithium metal batteries (LMB). LiX-NF not only offers a continuous fast path for Li+, but also zeolite's Lewis acid-base interaction can immobilize large anions, which significantly improves the electrochemical performance of the electrolyte. In addition, the in-situ interfacial layer at the electrode-electrolyte interface can effectively facilitate the uniform deposition of Li+ and inhibit the growth of lithium dendrites. As a result, the Li/Li battery assembled with PLPE can be stably cycled for more than 2500 h at 0.1 mA cm-2. Meanwhile, the initial discharge capacity of the LiFePO4/PLPE/Li battery can be 162.43 mAh g-1 at 0.5 C, and the capacity retention rate is 82.74% after 500 cycles. These results emphasize that this bilayer heterogeneous composite solid-state electrolyte has distinct properties and shows excellent potential for application in LMB.

Perspective on Recent Advances of Functional Electrolytes for Lithium Metal Batteries

Perspective on Recent Advances of Functional Electrolytes for Lithium Metal Batteries

PFAS-Free Locally Concentrated Ionic Liquid Electrolytes for Lithium Metal Batteries

PFAS-Free Locally Concentrated Ionic Liquid Electrolytes for Lithium Metal Batteries

In Situ Characterizations of the Dynamics of Cathode Electrolyte Interfaces at Different Current Densities.

LiNi0.8Mn0.1Co0.1O2 with high nickel content plays a critical role in enabling lithium metal batteries (LMBs) to achieve high specific energy density, making them a prominent choice for electric vehicles (EVs). However, ensuring the long-term cycling stability of the cathode electrolyte interfaces (CEIs), particularly at fast-charge conditions, remains an unsolved challenge. The decay mechanism associated with CEIs and electrolytes in LMB at high current densities is still not fully understood. To address this issue, in situ Fourier transform infrared (FTIR) is employed to observe the dynamic process of formation/disappearance/regeneration of CEIs during charge and discharge cycles. These dynamic processes further exacerbate the instability of CEIs as current density increases, leading to rupture and dissolution of CEIs and subsequent deterioration in battery performance because of continuous electrolyte reactions. Additionally, the dynamic changes occurring within individual components of CEIs at different cycling stages and various current densities are also discussed. The results demonstrate that excellent capacity retention at small current density is attributed to enrichment of inorganic compounds (Li2CO3, LiF, etc.) and rendering better stability and smaller expansion of CEIs. The key to achieving excellent electrochemical performance at high current densities lies on protecting CEIs, mainly inorganic components.

Anion‐Derived Solid Electrolyte Interphase Enabled by Diluent Modulated Dimethyl Carbonate‐Based Localized High Concentration Electrolytes for Lithium Metal Batteries

AbstractCarbonate‐based electrolytes generally suffer from low Coulombic efficiency and poor cycling stability in lithium metal batteries. In this work, localized high concentration electrolytes (LHCEs) based on dimethyl carbonate (DMC) with varying diluent additions are designed. LHCEs demonstrate higher Li+ transference numbers and a greater proportion of contact ion pairs (CIPs) and ion pair aggregates (AGGs) in the solvation structures, facilitating the formation of anion‐derived solid electrolyte interphase (SEI). Furthermore, LHCEs enhance the Coulombic efficiency of Li||Cu cells and improve the anodic stability against lithium. One of these LHCEs, prepared with appropriate diluent addition, exhibits excellent capacity retention in Li||NCM622 cells at 0.5 C after 150 cycles, thus presenting promising possibilities for the development of high energy density lithium metal batteries.

Design and electrochemical properties of novel fluorinated electrolytes for lithium metal batteries

Synthesis and electrochemical study of novel trifluorinated diethers, namely, α-methoxy-ω-(2,2,2-trifluoroethoxy)- alkanes, as potential candidates for new-generation electrolyte solvents for lithium-metal batteries are presented. The trifluoro diethers were tested in cell configurations implying cathodes with high nickel content and revealed Coulombic efficiencies exceeding 99.9% and specific discharge capacity retention up to 99% over 55 cycles for potentials up to 4.5 V. This study opens up new prospects in targeted design of organic ether molecules as lithium-metal batteries electrolyte components.

Synergistic effect of Ti3C2Tx MXene/PAN nanofiber and LLZTO particles on high-performance PEO-based solid electrolyte for lithium metal battery

Solid polymer electrolytes (SPEs) have been considered the most promising separators for all-solid-state lithium metal batteries (ASSLMBs) due to their ease of processing and low cost. However, the practical applications of SPEs in ASSLMBs are limited by their low ionic conductivities and mechanical strength. Herein, we developed a three-dimensional (3D) interconnected MXene (Ti3C2Tx) network and Li6.4La3Zr1.4Ta0.6O12 (LLZTO) particles synergistically reinforced polyethylene oxide (PEO)-based SPE, where the association of Li+ with ether-oxygen in PEO could be significantly weakened through the Lewis acid-base interactions between the electron-absorbing group (Ti–F, −O–) of Ti3C2Tx and Li+. Besides, the TFSI− in lithium salts could be immobilized by hydrogen bonds from the Ti–OH of Ti3C2Tx. The 3D interconnected Ti3C2Tx network not only alleviated the agglomeration of inorganic fillers (LLZTO), but also improved the mechanical strength of composite solid electrolyte (CSE). Consequently, the assembled Li||CSE||Li symmetric battery showed excellent cycling stability at 35 ℃ (stable cycling over 3000 h at 0.1 mA cm−2, 0.1 mAh cm−2) and −2 ℃ (stable cycling over 2500 h at 0.05 mA cm−2, 0.05 mAh cm−2). Impressively, the LiFePO4||CSE||Li battery showed a high discharge capacity of 145.3 mAh/g at 0.3 C after 300 cycles at 35 ℃. This rational structural design provided a new strategy for the preparation of high-performance solid-state electrolytes for lithium metal batteries.

Rational Lithium Salt Molecule Tuning for Fast Charging/Discharging Lithium Metal Battery.

The electrolytes for lithium metal batteries (LMBs) are plagued by a low Li+ transference number (T+) of conventional lithium salts and inability to form a stable solid electrolyte interphase (SEI). Here, we synthesized a self-folded lithium salt, lithium 2-[2-(2-methoxy ethoxy)ethoxy]ethanesulfonyl(trifluoromethanesulfonyl) imide (LiETFSI), and comparatively studied with its structure analogue, lithium 1,1,1-trifluoro-N-[2-[2-(2-methoxyethoxy)ethoxy)]ethyl]methanesulfonamide (LiFEA). The special anion chemistry imparts the following new characteristics: i) In both LiFEA and LiETFSI, the ethylene oxide moiety efficiently captures Li+, resulting in a self-folded structure and high T+ around 0.8. ii) For LiFEA, a Li-N bond (2.069 Å) is revealed by single crystal X-ray diffraction, indicating that the FEA anion possesses a high donor number (DN) and thus an intensive interphase "self-cleaning" function for an ultra-thin and compact SEI. iii) Starting from LiFEA, an electron-withdrawing sulfone group is introduced near the N atom. The distance of Li-N is tuned from 2.069 Å in LiFEA to 4.367 Å in LiETFSI. This alteration enhances ionic separation, achieves a more balanced DN, and tunes the self-cleaning intensity for a reinforced SEI. Consequently, the fast charging/discharging capability of LMBs is progressively improved. This rationally tuned anion chemistry reshapes the interactions among Li+, anions, and solvents, presenting new prospects for advanced LMBs.

Rational Lithium Salt Molecule Tuning for Fast Charging/Discharging Lithium Metal Battery

AbstractThe electrolytes for lithium metal batteries (LMBs) are plagued by a low Li+ transference number (T+) of conventional lithium salts and inability to form a stable solid electrolyte interphase (SEI). Here, we synthesized a self‐folded lithium salt, lithium 2‐[2‐(2‐methoxy ethoxy)ethoxy]ethanesulfonyl(trifluoromethanesulfonyl) imide (LiETFSI), and comparatively studied with its structure analogue, lithium 1,1,1‐trifluoro‐N‐[2‐[2‐(2‐methoxyethoxy)ethoxy)]ethyl]methanesulfonamide (LiFEA). The special anion chemistry imparts the following new characteristics: i) In both LiFEA and LiETFSI, the ethylene oxide moiety efficiently captures Li+, resulting in a self‐folded structure and high T+ around 0.8. ii) For LiFEA, a Li−N bond (2.069 Å) is revealed by single crystal X‐ray diffraction, indicating that the FEA anion possesses a high donor number (DN) and thus an intensive interphase “self‐cleaning” function for an ultra‐thin and compact SEI. iii) Starting from LiFEA, an electron‐withdrawing sulfone group is introduced near the N atom. The distance of Li−N is tuned from 2.069 Å in LiFEA to 4.367 Å in LiETFSI. This alteration enhances ionic separation, achieves a more balanced DN, and tunes the self‐cleaning intensity for a reinforced SEI. Consequently, the fast charging/discharging capability of LMBs is progressively improved. This rationally tuned anion chemistry reshapes the interactions among Li+, anions, and solvents, presenting new prospects for advanced LMBs.