Electrochemical Stability Window Research Articles

Nonaqueous G-Quadruplex Ionogels.

Supramolecular ionogels, as an emerging class of materials, utilize the intriguing properties of ionic liquids (ILs) and offer a promising method for constructing functional materials in anhydrous solvents. G-Quadruplex, assembled from guanine-rich nucleic acid building blocks, is an important structure closely associated with life and leads to the gelation for constructing versatile materials, such as the electrolytes of supercapacitors. Herein, we design and fabricate G-quadruplex ionogels using an unreported cation. Among the metal acetylacetonates under investigation, iron(III) acetylacetonate is distinctive in its capacity to stabilize G-quadruplexes through a reaction with the solvent ethylammonium nitrate (EAN), resulting in the formation of Fe(acac)2+. The ionogel displays high ionic conductivity (6.43 mS·cm-1), a wide electrochemical stability window (2.86 V), and self-healing properties. The supercapacitor based on the G-quadruplex ionogel electrolyte delivers a gravimetric capacitance of 91.8 F·g-1, a high energy density of 32.6 W h/kg, and a power density of 319.8 W/kg at a current density of 0.2A·g-1. Therefore, the present findings have important implications for deepening the understanding of G-quadruplex structures and metal acetylacetonate complexes and provide an approach to fabricating ionogel electrolytes for high-performance supercapacitors.

Active Water Optimization in Different Electrolyte Systems for Stable Zinc Anodes.

Zinc (Zn) metal, with abundant resources, intrinsic safety, and environmental benignity, presents an attractive prospect as a novel electrode material. However, many substantial challenges remain in realizing the widespread application of aqueous Zn-ion batteries (AZIBs) technologies. These encompass significant material corrosion challenges (This can lead to battery failure in an unloaded state.), hydrogen evolution reactions, pronounced dendrite growth at the anode interface, and a constrained electrochemical stability window. Consequently, these factors contribute to diminished battery lifespan and energy efficiency while restricting high-voltage performance. Although numerous reviews have addressed the potential of electrode and separator design to mitigate these issues to some extent, the inherent reactivity of water remains the fundamental source of these challenges, underscoring the necessity for precise regulation of active water molecules within the electrolyte. In this review, the failure mechanism of AZIBs (unloaded and in charge and discharge state) is analyzed, and the optimization strategy and working principle of water in the electrolyte are reviewed, aiming to provide insights for effectively controlling the corrosion process and hydrogen evolution reaction, further controlling dendrite formation, and expanding the range of electrochemical stability. Furthermore, it outlines the challenges to promote its practical application and future development pathways.

Progress and Challenges of Water‐in‐Salt Electrolytes: Exploring Physical Chemistry Properties and Solid Electrolyte Interphase Formation Mechanisms

“Water‐in‐salt” (WIS) electrolytes endow the possibility of commercial aqueous devices due to the extending electrochemical stability window (ESW). However, there is still a long way to address current issues until future practical applications, such as the high cost of salts, the cathodic limit, and the controversial mechanism of solid‐electrolyte interphase (SEI). In this review, we first introduce cutting‐edge WIS electrolytes and display their current issues. After, the reported tactics of solving issues and achievements in our group are listed, including four sections: 1) physical structure; 2) SEI formation analysis; 3) additives contributions; and 4) devices. In the end, we focus on the current challenges and perspectives of WIS electrolytes for aiming at the practical applications of aqueous energy storage devices.

Nano LiF-Enabled In Situ Synergistic Catalytic Polymeric Electrolytes for Stable Lithium Metal Batteries.

Solid polymer electrolytes (SPEs) with excellent ionic conductivity and a wide electrochemical stability window are critical for high-energy lithium metal batteries (LMBs). However, the widespread application of polymer electrolytes is severely limited by inadequate room-temperature ionic conductivity, sluggish interfacial charge transport, and uncontrolled reactions at the electrode/electrolyte interface. Herein, we present a uniform polymerized 1,3-dioxolane (PDOL) composite solid polymer electrolyte (PDOL-S/F-nano LiF CSE) that satisfies these requirements through the in situ catalytic polymerization effect of nano LiF on the polymerization of 1,3-dioxolane-based electrolytes. The synergistic catalytic effect of well-dispersed nano LiF and lithium tetrafluoroborate (LiBF4) enhances the polymerization of DOL monomers, achieving a conversion rate of up to 83.19% and extending its electrochemical window. Furthermore, the well-dispersed nano LiF forms a stable LiF-rich CEI and SEI, providing exceptional interfacial stability. Based on the PDOL-S/F-nano LiF CSE, the symmetric lithium cell exhibits an ultra-low overpotential of 10 mV at 0.1 mA cm-2 and 0.1 mAh cm-2 and maintains steady cycling for over 1500 h at 0.2 mA cm-2 and 0.2 mAh cm-2. The Li∥LiCoO2 LMB using the PDOL-S/F-nano LiF CSE also delivers a brilliant rate capability and long cycling stability over 200 cycles at 4.4 V (capacity retention of 82.6%). This study provides solutions to the ongoing pain point issues of SPEs and facilitates practical applications of solid-state LMBs.

Ternary PEO/PVDF-HFP-Based Polymer Electrolytes for Li-Ion Batteries

The impetus to study and develop polymer electrolytes for metal-ion batteries is due to their enhanced safety compared to flammable organic liquid electrolytes, promising ionic conductivity, and broad electrochemical stability window, making them to viable candidates for battery application. In the current work, we present a simple fabrication procedure and a comprehensive physico–chemical study of various PVDF-HFP-based electrolyte formulations with a sufficient addition of PEO polymer, LiTFSI conducting salt, and EMIMTFSI ionic liquid. The ionic conductivity, activation energy for ionic movement and thickness of the resulting polymer electrolyte show a non-linear dependency on the PVDF-HFP/PEO ratio. The electrolyte composition with a 0.35PEO-0.65PVDF-HFP/1LiTFSI/1EMIMTFSI mass fraction exhibits the highest ionic conductivity among the compositions, revealing 7.7×10−5 S cm−1 at 30 °C. Electrochemical tests in half full and full Li-ion batteries with a LiFePO4 cathode and Li4Ti5O12 anode also emphasized this composition as the most promising one, providing an initial capacity in full cells of 120 mAh g−1 and a capacity retention of about 75% after 50 charge/discharge cycles at a 0.1 C current rate. In the PEO/PVDF-HFP polymer blend with EMIMTFSI as a plasticizer, the amount of crystalline parts, which are detrimental to a fast ionic diffusion, is significantly reduced.

High Capacity and Ultralong Lifespan Aqueous Lithium-Bromine Batteries Realized by Low-Cost Concentrated Electrolyte Coupled with Dependable Lithium Titanium Phosphate.

Aqueous halogen batteries are gaining recognition for large-scale energy storage due to their high energy density, safety, environmental sustainability, and cost-effectiveness. However, the limited electrochemical stability window of aqueous electrolytes and the absence of desirable carbonaceous hosts that facilitate halogen redox reactions have hindered the advancement of halogen batteries. Here, a low-cost, high-concentration 26 m Li-B5-C15-O6 aqueous solution incorporating lithium bromide (LiBr), lithium chloride (LiCl), and lithium acetate (LiOAc) was developed for aqueous batteries, which demonstrated an expanded electrochemical stability window of ca. 2.5 V. In addition, the electrochemical performance of the electrolyte in various carbonaceous hosts (graphene, activated carbon, and nitrogen-doped activated carbon (NAc)) was systematically investigated. In-depth analysis using X-ray photoelectron spectroscopy and Raman spectroscopy revealed that the NAc host promoted the redox kinetics of active bromine species and improved the delivery capacity of the battery. Results revealed that the electrolyte in the NAc host achieved a discharge specific capacity exceeding 376 mA h g-1 while maintaining a capacity retention rate of up to 97% after 7800 cycles. When paired with hierarchically porous LTP@C/CNTs anode material, a LTP@C/CNTs-NAc full cell was constructed, which delivered a discharge specific capacity of 238.4 mA h g-1 and an average output voltage of 1.24 V. Moreover, it demonstrated a reversible specific capacity of 158.2 mA h g-1 with near-complete Coulombic efficiency over more than 10,000 cycles.

Ion bridging enables high-voltage polyether electrolytes for quasi-solid-state batteries

Polyether electrolytes have been widely recognized for their favorable compatibility with lithium-metal, yet they are hampered by intrinsically low oxidation thresholds, limiting their potential for realizing high-energy Li-metal batteries. Here, we report a general approach involving the bridge joints between non-lithium metal ions and ethereal oxygen, which significantly enhances the oxidation stability of various polyether electrolyte systems. To demonstrate the feasibility of the ion-bridging strategy, a Zn2+ ion-bridged polyether electrolyte (Zn-IBPE) with an extending electrochemical stability window of over 5 V is prepared, which enables good cyclability in 4.5 V Li||LiCoO2 batteries. Ampere-hour-level quasi-solid-state batteries of SiO-graphite||LiNi0.8Mn0.1Co0.1O2 (10 Ah, N/P ratio of 1.12, 303 Wh kg−1 at 0.1 C based on the total weight of the pouch cells) and 60 μm-Li||LiNi0.9Mn0.05Co0.05O2 (18 Ah, N/P ratio of 2.5, 452 Wh kg−1 at 0.33 C based on the total weight of the pouch cells) pouch cells with Zn-IBPE present elevated electrochemical performance, benefiting from adequate interfacial stability. Nail penetration tests evidence high battery safety enabled by Zn-IBPE in 4 Ah graphite||LiNi0.8Mn0.1Co0.1O2 pouch cells without combustion or smoke. This work offers a pathway for designing high-voltage polymer electrolytes and a general solution for achieving high-performance quasi-solid-state batteries.

Toward Green and Sustainable Zinc-Ion Batteries: The Potential of Natural Solvent-Based Electrolytes.

Zinc-ion batteries (ZIBs) are emerged as a promising alternative for sustainable energy storage, offering advantages such as safety, low cost, and environmental friendliness. However, conventional aqueous electrolytes in ZIBs face significant challenges, including hydrogen evolution reaction (HER) and zinc dendrite formation, compromising their cycling stability and safety. These limitations necessitate innovative electrolyte solutions to enhance ZIB performance while maintaining sustainability. This review explores the potential of natural solvent-based electrolytes derived from renewable and biodegradable resources. Natural deep eutectic solvents (DES), bio-ionic liquids, and biomass-derived organic compounds present unique advantages, including a wider electrochemical stability window, reduced HER activity, and controlled zinc deposition. Examples include DESs based on choline chloride (ChCl), glycerol-based systems, and biomass-derived solvents such as γ-valerolactone (GVL) and aloe vera, demonstrating improved cycling stability and dendrite suppression. Despite their promise, challenges such as high viscosity, cost, and scalability remain critical barriers to commercialization. This review underscores the need for further research to optimize natural solvent formulations, enhance Zn anode compatibility, and integrate these systems into practical applications. By addressing these challenges, natural solvent-based electrolytes can pave the way for safer, high-performance, and environmentally sustainable ZIBs, particularly large-scale energy storage systems.

Tiny‐Ligand Solvation Electrolyte Enabled Fast‐charging Aqueous Batteries

The H‐bond network among H2O molecules enables ultrafast diffusion of H+ and OH‐ via a hopping mechanism, making aqueous batteries attractive competitors for next‐generation fast‐charging energy storages. Ideal aqueous electrolyte for the widely used lithium‐ion batteries is expected to have the wide electrochemical stability window (>5 volts), fast charging (≤15 minutes) without gas evolution, and low cost. However, the hydrogen evolution reaction (HER) associated with narrow voltage window of water (1.23 V) limits their practical applications. Herein, we built a new guideline for designing tiny‐ligand electrolytes by utilizing sterically hindered groups with low binding energy. Cosolvent tetraethyl orthocarbonate (TEOC), with large‐sized ethoxy groups and hydrogen‐bond‐captured ability, forces free H2O and anion TFSI‐ into the Li+ first solvation shell. Hence, inhibition of HER takes place by means of immobilized H2O activity and formation of hydrogen‐bonding networks—C‐O···H between TEOC and H2O. This unique structure with ultra‐small sheath volume thereby facilitates the formation of LiF‐rich SEI and fast ion‐conduction. The lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) in TEOC/H2O electrolyte exhibits wide electrochemical window of 5.7 V, enabling LiMn2O4/Li4Ti5O12 pouch cells to achieve 1200 cycles under rapid 10 C rate. This engineering of tiny‐ligand solvation opens new pathways for developing advanced electrolyte that balance performance with sustainability.

Tiny‐Ligand Solvation Electrolyte Enabled Fast‐charging Aqueous Batteries

The H‐bond network among H2O molecules enables ultrafast diffusion of H+ and OH‐ via a hopping mechanism, making aqueous batteries attractive competitors for next‐generation fast‐charging energy storages. Ideal aqueous electrolyte for the widely used lithium‐ion batteries is expected to have the wide electrochemical stability window (>5 volts), fast charging (≤15 minutes) without gas evolution, and low cost. However, the hydrogen evolution reaction (HER) associated with narrow voltage window of water (1.23 V) limits their practical applications. Herein, we built a new guideline for designing tiny‐ligand electrolytes by utilizing sterically hindered groups with low binding energy. Cosolvent tetraethyl orthocarbonate (TEOC), with large‐sized ethoxy groups and hydrogen‐bond‐captured ability, forces free H2O and anion TFSI‐ into the Li+ first solvation shell. Hence, inhibition of HER takes place by means of immobilized H2O activity and formation of hydrogen‐bonding networks—C‐O···H between TEOC and H2O. This unique structure with ultra‐small sheath volume thereby facilitates the formation of LiF‐rich SEI and fast ion‐conduction. The lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) in TEOC/H2O electrolyte exhibits wide electrochemical window of 5.7 V, enabling LiMn2O4/Li4Ti5O12 pouch cells to achieve 1200 cycles under rapid 10 C rate. This engineering of tiny‐ligand solvation opens new pathways for developing advanced electrolyte that balance performance with sustainability.

Molecular Design of Imino Anion Acceptors Enables Long‐Life Fluoride Ion Batteries

AbstractAnion acceptors (AAs) enable to dissolve metal fluoride salts and achieve reversible fluorination and defluorination in fluoride ion batteries (FIBs). However, most reported strategies only focus on boron‐ and alcohol‐based AAs with strong Lewis acidity and excessive hydrogen bond (HB) strength, which often leads to the uncontrollable mass loss of active materials and the inferior reduction stability of electrolyte. Although amino and imine groups possess preferable anti‐reductive property, their HB strengths are apparently too weak to dissociate fluoride salts. Here a novel strategy is proposed for molecular structure design toward imino AAs by introducing double bonds and pyridine‐N into the five‐membered‐ring of pyrrolidine. Therein the conjugation effect, inductive effect, and α effect are synergistically utilized to enhance the Lewis acidity of imino group. Theoretical calculations and experiments prove that 1,2,4‐triazole AA retains the reduction stability in the maximum extent while increasing the HB strength of imino group. Based on this imino AA, the electrolyte achieves an unprecedented wide electrochemical stability window (5.5 V), enabling highly reversible cycling of fluorination and defluorination for CuF2||Pb full cells (>300 cycles) with a Cu+‐mediated two‐step redox mechanism, for PbF2‐Pb||PbF2‐Pb symmetric cells (1600 h) with low overpotential, and for PbF2||Pb asymmetric cells with high coulombic efficiency.

Confined Biomimetic Catalysts Boost LiNO3-Free Lithium-Sulfur Batteries via Enhanced LiTFSI Decomposition

Lithium-sulfur batteries face a critical challengeLiNO3 limits the electrochemical stability window of electrolyte and poses safety risks. This study presents FePC@NH2-MIL-68, a biomimetic enzyme catalyst stable in ether-based electrolytes, to address these issues, which can replace LiNO3 and facilitate Li-anion decomposition. Theoretical and spectroscopic investigations show it promotes LiTFSI decomposition, forms robust CEI and SEI interfaces, and enhances sulfur conversions. Consequently, the FePC@NH2-MIL-68 cell, without LiNO3 additive, delivers a high discharge capacity of 1549 mAh g−1 at 0.2 C and a low capacity decay rate of 0.067% over 1000 cycles at 1.5 C. Even under high sulfur loading of 7.9 mg cm−2 and low electrolyte-to-sulfur ratio of 5.5 μL mg−1, the cells maintain 720 mAh g−1. This work emphasizes that in developing sulfur conversion catalysts, special attention must be paid to their effects on other lithium salt components, which provides a guidance for new catalysts design for metal-sulfur batteries.

Acidified naphthalene diimide covalent organic frameworks with superior proton conduction for solid-state proton batteries

Naphthalene diimide covalent-organic framework are introduced as a novel solid-state superprotonic conduction electrolyte, demonstrating an expanded electrochemical stability window and stable cycling performance in proton batteries.

In Situ Fabrication of Quasi-Solid Polymer Electrolytes for Lithium Metal Battery via Photopolymerization-Induced Microphase Separation.

The photopolymerization-induced microphase separation (photo-PIMS) process involving a reactive polymer block was implemented to fabricate nanostructured quasi-solid polymer electrolytes (QSPEs) for use in lithium metal batteries (LMBs). This innovative one-pot fabrication enhances interfacial properties in LMBs by enabling in situ nanostructuring of QSPE directly onto the electrodes. This process also allows for customization of QSPE structural dimensions by tweaking the architecture and molar mass of poly[(oligo ethylene glycol) methyl ether methacrylate-co-styrene] (P(OEGMA-co-S)) macromolecular chain transfer agent. Bicontinuous nanoscale domains of soft P(OEGMA-co-S)/propylene carbonate/lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) phase and hard poly[isobornyl acrylate-co-(oligo ethylene glycol)diacrylate] phase furnished the QSPEs with respectively high ionic conductivity (0.34 mS cm-1 at 30 °C) and interesting level of mechanical strength (106-107 Pa at 30 °C). The as-prepared QSPE showed decent electrochemical properties and an electrochemical stability window of about 4.2 V vs Li+/Li. This electrolyte enables the Li||SPE||Li symmetric cell to cycle over 350 h at 0.1 mA cm-2 without evidence of dendrite formation. By means of galvanostatic cycling studies on a prototype lithium metal battery with LiNi0.8Mn0.1Co0.1O2 or LiFePO4 positive electrodes, we further demonstrate that the in situ nanostructured QSPE exhibited better performances than the corresponding stacked battery.

Spray-Flame Synthesis (SFS) and Characterization of Li1.3Al0.3-xYxTi1.7(PO4)3 [LA(Y)TP] Solid Electrolytes.

Solid-state electrolytes for lithium-ion batteries, which enable a significant increase in storage capacity, are at the forefront of alternative energy storage systems due to their attractive properties such as wide electrochemical stability window, relatively superior contact stability against Li metal, inherently dendrite inhibition, and a wide range of temperature functionality. NASICON-type solid electrolytes are an exciting candidate within ceramic electrolytes due to their high ionic conductivity and low moisture sensitivity, making them a prime candidate for pure oxidic and hybrid ceramic-in-polymer composite electrolytes. Here, we report on producing pure and Y-doped Lithium Aluminum Titanium Phosphate (LATP) nanoparticles by spray-flame synthesis. The as-synthesized samples consist of an amorphous component and anatase-TiO2 crystalline particles. Brief annealing at 750-1000 °C for one hour was sufficient to achieve the desired phase while maintaining the material's sub-micrometer scale. Rietveld analysis of X-Ray diffraction data demonstrated that the crystal volume increases with Y doping. At the same time, with high Y incorporation, a segregation of the YPO4 phase was observed in addition to the desired LATP phase. Another impurity phase, LiTiOPO4, was observed besides YPO4 and, with higher calcination temperature (1000 °C), the phase fraction for both impurities also increased. The ionic conductivity increased with Y incorporation from 0.1 mS/cm at room temperature in the undoped sample to 0.84 mS/cm in the case of LAY0.1TP, which makes these materials-especially considering the comparatively low sintering temperature-highly interesting for applications in the field of solid-state batteries.

Interfacial Challenges of Halide‐Based All‐Solid‐State Batteries

AbstractAs the demand for high energy density and battery safety grows, all‐solid‐state batteries (ASSBs) have garnered considerable attention as promising energy storage systems by removing flammable liquid electrolytes (LEs). Cutting‐edge sulfide inorganic solid electrolytes (ISEs) such as Li10GeP2S12 and Li6PS5Cl have shown high Li+ conductivity comparable to those of LEs. However, the narrow electrochemical stability windows of sulfide ISEs hinder the development of high‐energy density ASSBs with severe interfacial challenges. Recently, halide ISEs such as Li3YCl6 and Li3InCl6 are attracting increasing attention because of their high Li+ ion conductivity, excellent thermal stability, and high oxidative stability above 4 V. These properties are crucial to developing ASSBs with high energy density, and exceptional cycle and rate performances when employing high‐voltage cathode materials. Nevertheless, recent studies have identified severe interfacial challenges in ASSBs utilizing halide ISEs. Moreover, the safety of ASSBs is assumed to be better than conventional LE batteries but studies find the opposite conclusion when certain types of ISEs are employed, which can be attributed to products from side reactions at the interfaces. The objective here is to summarize the interfacial challenges associated with halide ISEs‐based ASSBs that will guide the development of high‐performance and safe ASSBs.

Toward Long-Life High-Voltage Aqueous Li-Ion Batteries: from Solvation Chemistry to Solid-Electrolyte-Interphase Layer Optimization Against Electron Tunneling Effect.

Water is pursued as an electrolyte solvent for its non-flammable nature compared to traditional organic solvents, yet its narrow electrochemical stability window (ESW) limits its performance. Solvation chemistry design is widely adopted as the key to suppress the reactivity of water, thereby expanding the ESW. In this study, an acetamide-based ternary eutectic electrolyte achieved an ESW ranging from 1.4 to 5.1V. The electrolyte confines water molecules within the primary solvation sheath of Li-ions, reducing the free water and breaking the hydrogen bond network. Despite this, initial capacity retention is suboptimal due to inadequate formation of solid-electrolyte-interphase (SEI) layers. To address this, additional hydrogen evolution reaction is induced by widening the operation voltage range, thereby optimizing the SEI layer to mitigate the electron tunneling effect. This approach resulted in a denser LiF-rich SEI layer, effectively preventing water decomposition and improving long-term cycle stability. The optimized SEI layer reduced the electron tunneling barrier, achieving a discharge capacity of 152 mAh g-1 at 1 C and maintaining 76% of its capacity (116 mAh g-1) after 1000 cycles. This study highlights the critical role of both solvation structure and SEI layer optimization in enhancing the performance of high-voltage aqueous Li-ion batteries.

Coordination Regulation Enabling Deep Eutectic Electrolyte for Fast-Charging High-Voltage Lithium Metal Batteries.

The safety and cycle stability of lithium metal batteries (LMBs) under conditions of high cut-off voltage and fast charging put forward higher requirements for electrolytes. Here, a sulfonate-based deep eutectic electrolyte (DEE) resulting from the eutectic effect between solid sultone and lithium bis(trifluoromethanesulfonyl)imide without any other additives is reported. The intermolecular coordination effect triggers this eutectic phenomenon, as evidenced with nuclear magnetic resonance, and thus the electrochemical behavior of the DEE can be controlled by jointly regulating the coordination effects of F···H and Li···O intermolecular interactions. The DEE with a properly coordinated environment of Li+ presents a low motion barrier and a high transport rate of localized Li+, leading to a 10 C fast-charging LiFePO4||Li battery with a capacity retention of 95.1% after 500 cycles. Meanwhile, the strengthened α-H···F coordination broadens the electrochemical stability window of the DEE, thus enabling the cycle stability of high-capacity and high-voltage cathode materials in LMBs, e.g., a cycle stability at 4.5 V in the LiNi0.88Co0.07Mn0.05O2||Li battery with a capacity retention of 81.0% after 500 cycles, and an excellent compatibility in 4.5 V LiCoO2||Li and 4.8 V Li1.13Mn0.517Ni0.256Co0.097O2||Li batteries. The practical applicability of the carefully designed DEE is underscored through successful implementation in pouch cells.

Synergy of In Situ Heterogeneous Interphases with Hydrogen Bond Reconstruction Enabling Highly Reversible Zn Anode at −40 °C

AbstractAqueous Zn2+ ion batteries (AZIBs) are considered promising candidates for large‐scale energy storage systems. However, the critical technical bottlenecks, including Zn dendrite, corrosion reactions, and poor low‐temperature performance, significantly impede their commercialization. Here, γ‐valerolactone (γ‐GVL), a bioactive polar biomass‐based green solvent derived from lignocellulose, is introduced into electrolyte as a co‐solvent to improve the electrochemical stability of Zn anode and enhance its low‐temperature cycling performance. The non‐toxic γ‐GVL, serving as a strong hydrogen‐bonding ligand, coordinates with H2O to reconstruct the electrolyte's hydrogen bond network, broadening the electrochemical stability window and enhancing the anti‐frost properties of aqueous electrolytes. Moreover, γ‐GVL facilitates in situ formation of a heterogeneous solid‐electrolyte interphase (SEI) composed of ZnF2 and ZnS inorganic components. The heterogeneous interphases maintain superior ionic conductivity for Zn2+ transportation and hydrophobicity for H2O repulsion, synergistically enabling highly stable and dendrite‐free Zn deposition. Consequently, Zn||Zn cells exhibit improved cycling performance across a wide temperature range, achieving an extended cycle life of 5060 h at 25 °C and 2300 h at −40 °C. Zn||VO2 full cells show enhanced low‐temperature cyclability, retaining 97.0% capacity after 300 cycles at −20 °C, demonstrating substantial potential for advancing the commercialization of low‐temperature aqueous electrolytes.

Effect of ether introduction and ether chain length on electrochemical stability window feature of imidazolium ionic liquids with different anions: experimental and DFT studies

Effect of ether introduction and ether chain length on electrochemical stability window feature of imidazolium ionic liquids with different anions: experimental and DFT studies