Non-Flammable Electrolyte with Lithium Nitrate as the Only Lithium Salt for Boosting Ultra-Stable Cycling and Fire-Safety Lithium Metal Batteries

Lithium metal batteries (LMBs) attract considerable attention for their incomparable energy density. However, safety issues caused by uncontrollable lithium dendrites and highly flammable electrolyte limit large-scale LMBs applications. Herein, a low-cost, thermally stable, and low environmentally-sensitive lithium nitrate (LiNO₃) is proposed as the only lithium salt to incorporate with nonflammable triethyl phosphate and fluoroethylene carbonate (FEC) co-solvent as the electrolyte anticipated to enhance the performance of LMBs. Benefiting from the presence of NO₃⁻ and FEC with strong solvation effect and easily reduced ability, a Li₃N–LiF-rich stable solid electrolyte interphase is constructed. Compared to commercial electrolytes, the proposed electrolyte has a high Coulombic efficiency of 98.31% in Li-Cu test at 1 mA cm⁻² of 1.0 mAh cm⁻² with dendrite-free morphology. Additionally, the electrolyte system shows high voltage stability and cathode electrolyte interphase film-forming properties with stable cycling performances, which exhibit outstanding capacity retention rates of 96.39% and 83.74% after 1000 cycles for LFP//Li and NCM811//Li, respectively. Importantly, the non-flammable electrolyte delays the onset of combustion in lithium metal soft pack batteries by 255 s and reduces the peak heat release by 21.02% under the continuous external high-temperature heating condition. The novel electrolyte can contribute immensely to developing high-electrochemical-performance and high-safety LMBs.     

Functional Separators Regulating Ion Transport Enabled by Metal-Organic Frameworks for Dendrite-Free Lithium Metal Anodes

Developing high energy density lithium secondary batteries is pivotal for satisfying the increasing demand in advanced energy storage systems. Lithium metal batteries (LMBs) have attracted growing attention due to their high theoretical capacity, but the lithium dendrites issue severely fetter their real-world applications. It is found that reducing anion migration near lithium metal prolongs the nucleation time of dendrites, meanwhile, promoting homogeneous lithium deposition suppresses the dendritic growth. Thus, regulating ion transport in LMBs is a feasible and effective strategy for addressing the issues. Based on this, a functional separator is developed to regulate ion transport by utilizing a well-designed metal-organic frameworks (MOFs) coating to functionalize polypropylene (PP) separator. The well-defined intrinsic nanochannels in MOFs and the negatively charged gap channels both restricts the free migration of anions, contributing to a high Li⁺ transference number of 0.68. Meanwhile, the MOFs coating with uniform porous structure promotes homogeneous lithium deposition. Consequently, a highly-stable Li plating/stripping cycling for over 150 h is achieved. Furthermore, implementation of the separator enables LMBs with high discharge capacity, prominent rate performance and good capacity retention. This work is anticipated to aid developement of dendrite-free LMBs by utilizing advanced separators with ion transport management.     

An Ultrarobust Composite Gel Electrolyte Stabilizing Ion Deposition for Long‐Life Lithium Metal Batteries

Lithium metal batteries (LMBs) possessing ultrahigh energy density are promising next‐generation battery systems, but the short cycle life and safety concerns caused by the uncontrollable growth of lithium dendrites impede their broad applications. Herein, to address these issues, an ultrarobust composite gel electrolyte (CGE) that can effectively stabilize ion deposition for LMBs is designed via fabricating a specially structured aerogel as the matrix. The gel electrolyte matrix with a 3D interconnected highly porous structures and good affinity with liquid electrolytes is fabricated via compositing bacterial cellulose (BC) and Li_0.33La_0.557TiO₃ nanowires (LLTO NWs) into an aerogel. The composite aerogel matrix demonstrates excellent wettability and liquid electrolyte uptake (586 ± 5%), and the resulting CGE presents exceptional Young's modulus of 1.15 GPa and an extremely high lithium‐ion transference number of 0.88. More significantly, the synergistic effect from the robust BC skeleton and LLTO NWs enabling stable ion deposition effectively suppresses the growth of lithium dendrites. Armed with the CGE, ultrastable symmetric Li/Li cells demonstrate a long cycle life of 1200 h and highly stable performance even at a high current density of 5 mA cm^?2. Furthermore, half cells with the CGE exhibit remarkable enhancement in capacity, cycling stability, and rate performance.     

Fluorinated Bifunctional Solid Polymer Electrolyte Synthesized under Visible Light for Stable Lithium Deposition and Dendrite-Free All-Solid-State Batteries

Solid polymer electrolytes (SPEs) that can offer flexible processability, highly tunable chemical functionality, and cost effectiveness are regarded as attractive alternatives for liquid electrolytes (LE) to address their safety and energy density limitations. However, it remains a great challenge for SPEs to stabilize Li⁺ deposition at the electrolyte–electrode interface and impede lithium dendrite proliferation compared with LE-based systems. Herein, a design of solid-state fluorinated bifunctional SPE (FB-SPE) that covalently tethers fluorinated chains with polyether-based segments is proposed and synthesized via photo-controlled radical polymerization (photo-CRP). In contrast to the conventional non-fluorinated polyether-derived SPEs, FB-SPE is able to provide conducting Li⁺ transport pathways up to ≈5.0 V, while simultaneously forming a Li F interaction that can enhance Li anode compatibility and prevent Li dendrites growth. As a result, the FB-SPE exhibits outstanding cycling stability in Li||Li symmetrical cells of over 1500 operating hours at as high current density as 0.2 mA cm⁻². A thin and uniform Li deposition layer and LiF-rich SEI at the surface of Li anode are found, and stable cycling with average coulombic efficiencies of 99% is demonstrated in Li||LFP and Li||NCM all-solid-state batteries based on such bifunctional fluorinated SPEs. The interesting fluorine effect and effective self-suppression of lithium dendrites will inform rational molecular design of novel electrolytes and practical development of all-solid-state Li metal batteries.     

Small Molecules,Great Powers: Chemistry of Small Organo-Chalcogenide Molecules in Rechargeable Li-Sulfur Batteries

Small organic chalcogenides molecules are receiving more attention in conjunction with the development of rechargeable lithium metal batteries (LMBs) especially lithium–sulfur (Li−S) batteries due to their abundant resources, reversible redox, high capacities, tunable structures, unique functional adjustability, and strong interaction with congener polysulfides. In this review, the working principles are generalized of small organo-chalcogenide molecules in three important parts of batteries: electrolyte, interface, and cathode. First, in terms of regulating kinetics in electrolyte, small organo-chalcogenide molecules can not only act as redox mediator to accelerate the redox kinetics of sulfur, but also change the inherently slow solid–solid process to form a faster redox pathway, which will bring light to the development of cryogenic Li−S batteries. Second, for interface chemistry, the introduction of small organo-chalcogenide molecules can construct more elastic and stable anodic single-SEI or cathodic/anodic dual-SEI, thus effectively improving the cycling stability of batteries. Third, small organo-chalcogenide molecules can be used as cathode materials in the form of liquid phase, solid phase, or precursor of polymers. Finally, advised optimizations are proposed about further mechanism deciphering, battery configuration design, machine learning, thereby providing direction to bridge the gap between rational modulation and practical battery implementation for small organo-chalcogenide molecules.     

Advanced Liquid Electrolytes for Rechargeable Li Metal Batteries

Rechargeable lithium metal batteries (LMBs) have attracted wide attention for future electric vehicles and next‐generation energy storage because of their exceptionally high specific energy density. Recently, the development of electrode materials for LMBs has been extensively discussed and reviewed in the literature, but there have been very few reports that systematically review the status and progress of electrolytes for such applications. Actually, the viability of practical LMBs critically depends on the development of suitable liquid electrolytes due to the high reactivity of Li metals toward most solvents. This paper provides a systematic summary of the background and recent advances of the electrolytes for LMBs with an emphasis on the thermodynamic and kinetic stabilities at the interfaces. In addition, the emerging advanced characterization techniques for understanding the electrolyte–electrode interfaces are surveyed. Finally, a perspective for future directions is provided.     

High‐Power Lithium Metal Batteries Enabled by High‐Concentration Acetonitrile‐Based Electrolytes with Vinylene Carbonate Additive

To enable next‐generation high‐power, high‐energy‐density lithium (Li) metal batteries (LMBs), an electrolyte possessing both high Li Coulombic efficiency (CE) at a high rate and good anodic stability on cathodes is critical. Acetonitrile (AN) is a well‐known organic solvent for high anodic stability and high ionic conductivity, yet its application in LMBs is limited due to its poor compatibility with Li metal anodes even at high salt concentration conditions. Here, a highly concentrated AN‐based electrolyte is developed with a vinylene carbonate (VC) additive to suppress Li⁺ depletion at high current densities. Addition of VC to the AN‐based electrolyte leads to the formation of a polycarbonate‐based solid electrolyte interphase, which minimizes Li corrosion and leads to a very high Li CE of up to 99.2% at a current density of 0.2 mA cm^‐2. Using such an electrolyte, fast charging of Li||NMC333 cells is realized at a high current density of 3.6 mA cm^‐2, and stable cycling of Li||NMC622 cells with a high cathode loading of 4 mAh cm^‐2 is also demonstrated.     

Polymer-Based Solid Electrolytes: Material Selection,Design, and Application

Polymer-based solid electrolytes (PSEs) have attracted tremendous interests for the next-generation lithium batteries in terms of high safety and energy density along with good flexibility. Remarkable performances have been demonstrated in PSEs, which endowed PSEs with the potential to replace liquid electrolytes to meet the market demands. In this review, polymer matrices, different polymer architectures, and functional filler materials used in PSEs are discussed to explore the design concepts, methodologies, working mechanisms, and pros and cons of various PSEs. In addition, their recent notable applications in all-solid-state lithium ion batteries, lithium–sulfur batteries, suppression of lithium dendrites, and flexible lithium batteries are also introduced. Finally, the challenges and future prospects are sketched to provide strategies to explore novel PSEs for high-performance all-solid-state lithium batteries.     

Unlocking the Potential of Lithium Metal Batteries With a Sulfite-Based Electrolyte

Lithium metal batteries (LMBs) have the potential to significantly increase the energy density of advanced batteries in the future. Nonetheless, the dendritic lithium structures and low Coulombic efficiency (CE) of LMBs currently impede their applied implementation. Herein, a sulfite-based electrolyte (SBE/FEC), including 1.0 m lithium bis(fluorosulfonyl)imide in a blend of ethylene sulfite and diethyl sulfite, and 5 wt% fluoroethylene carbonate is proposed. SBE/FEC is a highly efficient inhibitor against the growth of lithium dendrites through the formation of robust solid electrolyte interphase (SEI) layer. Raman spectroscopy and theoretical calculation indicate that in SBE/FEC, a significant portion of FSI⁻ exists in associated complexes, playing a vital role in the creation of LiF-rich passivation. Besides, the sulfite solvents decompose and yield polysulfide complexes in the SEI layer. A direct correlation between the proportion of cation–anion complexes and the contact angle between electrolyte and separator is elucidated through molecular dynamics simulations. The SBE/FEC system exhibits high CEs (98.3%) with Li||Cu cells, along with a steady discharge capacity of ≈137 mA h g⁻¹ in Li||LiFePO₄ cell. This study presents an effective approach for enhancing LMBs with sulfite-based electrolytes, which can lead to high-energy-density next-generation rechargeable batteries.     

Strategies in Structure and Electrolyte Design for High-Performance Lithium Metal Batteries

Lithium metal is the “holy grail” anode for next-generation high-energy rechargeable batteries due to its high capacity and lowest redox potential among all reported anodes. However, the practical application of lithium metal batteries (LMBs) is hindered by safety concerns arising from uncontrollable Li dendrite growth and infinite volume change during the lithium plating and stripping process. The formation of stable solid electrolyte interphase (SEI) and the construction of robust 3D porous current collectors are effective approaches to overcoming the challenges of Li metal anode and promoting the practical application of LMBs. In this review, four strategies in structure and electrolyte design for high-performance Li metal anode, including surface coating, porous current collector, liquid electrolyte, and solid-state electrolyte are summarized. The challenges, opportunities, perspectives on future directions, and outlook for practical applications of Li metal anode, are also discussed.     

Regulation of Interphase Layer by Flexible Quasi-Solid Block Polymer Electrolyte to Achieve Highly Stable Lithium Metal Batteries (Adv. Funct. Mater. 27/2023)

Low safety, unstable interfaces, and high reactivity of liquid electrolytes greatly hinder the development of lithium metal batteries (LMBs). Quasi-solid-state electrolytes (QGPEs) with superior mechanical properties and high compatibility can meet the demands of LMBs. Herein, a biodegradable polyacrylonitrile/polylactic acid-block-ethylene glycol polymer (PALE) as membrane skeleton for GPEs is designed and systematically investigated by regulating the length and structure of the cross-linked chain. Benefiting from the enriched affinitive sites of polar functional groups ( CO,  C O C,  CN, and  OH) in highly cross-linked polymer structure, the designed PALE membrane skeleton exhibits flame-retardant property and ultrahigh liquid electrolyte uptake property, and the derived quasi-solid-state PALE GPEs deliver enhanced stretchability and a higher electrochemical stable window of 5.11 V. Besides, the PALE GPEs effectively protect cathodes from corrosion while allowing uniform and fast transfer of Li⁺ ions. Therefore, the Li||Li symmetrical battery and LFP or NCM811||Li full-cell using PALE GPEs exhibit excellent cycling stability coupled with compact and flat inorganic/organic interface layers. And the excellent cycling stability of pouch cells under harsh operating conditions indicates the application possibilities of PALE GPEs in flexible devices with high-energy-density.     

Incombustible Polymer Electrolyte Boosting Safety of Solid-State Lithium Batteries: A Review

Lithium-ion batteries with their portability, high energy density, and reusability are frequently used in today's world. Under extreme conditions, lithium-ion batteries leak, burn, and even explode. Therefore, improving the safety of lithium-ion batteries has become a focus of attention. Researchers believe using a solid electrolyte instead of a liquid one can solve the lithium battery safety issue. Due to the low price, good processability and high safety of the solid polymer electrolytes, increasing attention have been paid to them. However, polymer electrolytes can also decompose and burn under extreme conditions. Moreover, lithium dendrites are formed continuously due to the uneven charge distribution on the surface of the lithium metal anode. A short circuit caused by a lithium dendrite can cause the battery to thermal runaway. As a result, the safety of polymer solid-state batteries remains a challenge. In this review, the thermal runaway mechanism of the batteries is summarized, and the batteries abuse test standard is introduced. In addition, the recent works on the high-safety polymer electrolytes and the solution strategies of lithium anode problems in polymer batteries are reviewed. Finally, the development direction of safe polymer solid lithium batteries is prospected.     

Phosphonium Bromides Regulating Solid Electrolyte Interphase Components and Optimizing Solvation Sheath Structure for Suppressing Lithium Dendrite Growth

Electrolyte additives play important roles in suppressing lithium dendrite growth and improving the electrochemical performance of long-life lithium metal batteries (LMBs), however, it is still challenging to design individual additive for adjusting the solid electrolyte interphase (SEI) components and changing lithium ion solvation sheath in the electrolyte at the same time for optimizing electrochemical performance. Herein, alkyl-triphenyl-phosphonium bromides (alkyl-TPPB) are designed as the electrolyte additive to enhance the stability of metallic Li anode under the guidance of multi-factor principle for electrolyte additive molecule design (EDMD). Both alkyl-TPP cations and Br⁻ anions produce positive influences on suppressing Li dendrite growth and stabilizing the unstable interphase between metallic Li anode/electrolyte. As expected, the optimized solvation sheath structure, and the stable SEI suppress Li dendrite growth. As a result, the Li||Li₄Ti₅O₁₂ cell reveals a long stable life over 1000 cycles with high Coulombic efficiency (99.9%). This work provides an insight on stabilizing SEI and optimizing solvation sheath structure with novel approach to develop long-term stability and safety LMBs.     

Template-Sacrificed Hot Fusion Construction and Nanoseed Modification of 3D Porous Copper Nanoscaffold Host for Stable-Cycling Lithium Metal Anodes

Lithium (Li) metal anodes have been proposed as a promising candidate for high-energy-density electrode materials in secondary batteries. However, the dendrite growth and unstable electrode–electrolyte interfaces during Li plating/stripping are fatal to their practical applications. Herein, the construction of 3D porous Au/Cu nanoscaffold prepared via a convenient template-sacrificed hot fusion construction method and a nanoseed modification process as an effective Li metal hosting material are proposed. The Au/Cu nanoscaffold can spatially guide uniform deposition of Li metal free from the growth of Li dendrites due to the homogenous Li⁺ ion flux and negligible nucleation overpotential. Moreover, the Cu skeleton can relieve volume change and stabilize local current density during cycling processes. Benefiting from these advantages, the symmetric cells based on self-supported Li-filled Au/Cu (Li-Au/Cu) nanoscaffold electrodes present highly stable Li plating/stripping for more than 1000 h with a low voltage hysteresis less than 90 mV and a long lifespan over 1300 h at 1.0 mA cm^–2 in carbonate-based electrolytes. Impressively, the Li-Au/Cu nanoscaffold||LiFePO₄ full cells also exhibit exceptional cycling stability and rate performance. This work provides a promising strategy to construct dendrite-free lithium metal anodes toward high-performance lithium metal batteries.     

Fast Li+ Transport via Silica Network-Driven Nanochannels in Ionomer-in-Framework for Lithium Metal Batteries

For the development of all-solid-state lithium metal batteries (LMBs), a high-porous silica aerogel (SA)-reinforced single-Li⁺ conducting nanocomposite polymer electrolyte (NPE) is prepared via two-step selective functionalization. The mesoporous SA is introduced as a mechanical framework for NPE as well as a channel for fast lithium cation migration. Two types of monomers containing weak-binding imide anions and Li⁺ cations are synthesized and used to prepare NPEs, where these monomers are grafted in SA to produce SA-based NPEs (SANPEs) as ionomer-in-framework. This hybrid SANPE exhibits high ionic conductivities (≈10⁻³ S cm⁻¹), high modulus (≈10⁵ Pa), high lithium transference number (0.84), and wide electrochemical window (>4.8 V). The resultant SANPE in the lithium symmetric cell possesses long-term cyclic stability without short-circuiting over 800 h under 0.2 mA cm⁻². Furthermore, the LiFePO₄|SANPE|Li solid-state batteries present a high discharge capacity of 167 mAh g⁻¹ at 0.1 C, good rate capability up to 1 C, wide operating temperatures (from −10 to 40 °C), and a stable cycling performance with 97% capacity retention and 100% coulombic efficiency after 75 cycles at 1 C and 25 °C. The SANPE demonstrates a new design principle for solid-state electrolytes, allowing for a perfect complex between inorganic silica and organic polymer, for high-energy-density LMBs.     

Synergistic Effect of Crosslinked Organic–Inorganic Composite Protective Layer for High Performance Lithium Metal Batteries

Maintaining a stable interface of lithium metal anodes (LMAs) by implementing a protective layer is a promising approach in extending the cycle life of lithium metal batteries (LMBs). Nevertheless, designing a protective layer with desired physicochemical properties is still a challenging task. Herein, an inorganic–organic composite protective layer consisting of fluorinated graphene oxide (FGO) (inorganic part) and polyacrylic acid (PAA) (organic part) that are in situ crosslinked via poly(ethylene glycol) diglycidyl ether (PEGDE) into a robust network is reported. The mechanical strength of FGO and the elasticity of the polymeric network jointly suppress the unwanted dendritic Li growth while fluorine-functional groups in FGO induce an LiF-enriched interface. This balanced inorganic–organic composite protective layer facilitates charge transfer kinetics for enhanced lithium-ion diffusion at the interface. Utilizing this protective layer, LMB full-cells with LiFePO₄ demonstrate negligible capacity loss for 100 cycles even under an extreme negative/positive capacity (N/P) ratio of 1.0. This study uncovers the possibility of highly robust, reliable LMBs by a sophisticatedly designed protective layer of widely used inorganic and organic components.     

Safe,Stable Cycling of Lithium Metal Batteries with Low‐Viscosity,Fire‐Retardant Locally Concentrated Ionic Liquid Electrolytes

Ionic liquid (IL) electrolytes with concentrated Li salt can ensure safe, high‐performance Li metal batteries (LMBs) but suffer from high viscosity and poor ionic transport. A locally concentrated IL (LCIL) electrolyte with a non‐solvating, fire‐retardant hydrofluoroether (HFE) is presented. This rationally designed electrolyte employs lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), 1‐methyl‐1‐propyl pyrrolidinium bis(fluorosulfonyl)imide (P13FSI) and 1,1,2,2‐tetrafluoroethyl 2,2,3,3‐tetrafluoropropyl ether (TTE) as the IL and HFE, respectively (1:2:2 by mol). Adding TTE enables a Li‐concentrated IL electrolyte with low viscosity and good separator wettability, facilitating Li‐ion transport to the Li metal anode. The non‐flammability of TTE contributes to excellent thermal stability. Furthermore, synergy between the dual (FSI/TFSI) anions in the LCIL electrolyte can help modify the solid electrolyte interphase, increasing Li Coulombic efficiency and decreasing dendritic Li deposition. LMBs (Li||LiCoO₂) employing the LCIL electrolyte exhibit good rate capability (≈89 mAh g^?1 at 1.8 mA cm^?2, room temperature) and long‐term cycling (≈80% retention after 400 cycles).     

Unprecedented Improvement of Single Li‐Ion Conductive Solid Polymer Electrolyte Through Salt Additive

Solid‐state lithium metal (Li°) batteries (SSLMBs) are believed to be the most promising technologies to tackle the safety concerns and the insufficient energy density encountered in conventional Li‐ion batteries. Solid polymer electrolytes (SPEs) inherently own good processability and flexibility, enabling large‐scale preparation of SSLMBs. To minimize the growth of Li° dendrites and cell polarization in SPE‐based SSLMBs, an additive‐containing single Li‐ion conductive SPE is reported. The characterization results show that a small dose of electrolyte additive (2 wt%) substantially increases the ionic conductivity of single Li‐ion conductive SPEs as well as the interfacial compatibility between electrode and SPE, allowing the cycling of SPE‐based cells with good electrochemical performance. This work may provide a paradigm shift on the design of highly cationic conductive electrolytes, which are essential for developing safe and high‐performance rechargeable batteries.     

Juggling Formation of HF and LiF to Reduce Crossover Effects in Carbonate Electrolyte with Fluorinated Cosolvents for High-Voltage Lithium Metal Batteries

Fluorinated solvents emerge as a promising strategy to improve performance of lithium metal batteries (LMBs). However, most of them are prone to produce corrosive HF and deteriorate electrode interface, inducing cathode-to-anode detrimental crossover of transition metal-ions. Here, fluorinated aromatic hydrocarbons in dimethyl carbonate (DMC)-based diluted highly concentrated electrolyte (DHCE) are employed to juggle formation of HF and LiF, enabling stable cycling of high-voltage LiNi_0.7Co_0.1Mn_0.2O₂ (NCM712) and LiCoO₂ (LCO). The nature of aromatics in this carbonate-based DHCE makes them difficult to undergo β-hydrogen assisted defluorination, evidencing by the high energy barrier and high bond energy of β-sites hydrogen. The advanced DHCE restrains HF formation but strengthens LiF formation, which not only suppresses impedance growth, transition-metal dissolution, and stress crack on the cathode, but achieves highly reversible Li stripping/plating with an outstanding average Coulombic efficiency up to 99.3%. The Li||NCM712 cell and Li||LCO cell both exhibits superior cycling stability at high operation voltage. Even under stringent conditions, the 4.4 V Li||NCM712 full battery retains >95% of the initial capacity over 100 cycles, advancing practical high-voltage LMBs. This study designs an efficient electrolyte that generates robust electrode/electrolyte interphases and restrains by-products formation spontaneously, thus shedding new light on electrolyte toward applicable LMBs.     

Effect of the Anion Activity on the Stability of Li Metal Anodes in Lithium‐Sulfur Batteries

With the significant progress made in the development of cathodes in lithium‐sulfur (Li‐S) batteries, the stability of Li metal anodes becomes a more urgent challenge in these batteries. Here the systematic investigation of the stability of the anode/electrolyte interface in Li‐S batteries with concentrated electrolytes containing various lithium salts is reported. It is found that Li‐S batteries using LiTFSI‐based electrolytes are more stable than those using LiFSI‐based electrolytes. The decreased stability is because the N–S bond in the FSI^? anion is fairly weak and the scission of this bond leads to the formation of lithium sulfate (LiSO_x) in the presence of polysulfide species. In contrast, in the LiTFSI‐based electrolyte, the lithium metal anode tends to react with polysulfide to form lithium sulfide (LiS_x), which is more reversible than LiSO_x formed in the LiFSI‐based electrolyte. This fundamental difference in the bond strength of the salt anions in the presence of polysulfide species leads to a large difference in the stability of the anode‐electrolyte interface and performance of the Li‐S batteries with electrolytes composed of these salts. Therefore, anion selection is one of the key parameters in the search for new electrolytes for stable operation of Li‐S batteries.