Broad Electrochemical Window Research Articles

Highly stable and encapsulation-microstructural cathode derived by self-pressurization behavior in Na-halides-based all-solid-state batteries

The emerging halide solid electrolytes (SEs) possess superior (electro)chemical oxidation stabilities compared to sulfide SEs, but the understanding on their good compatibility toward oxide active materials needs to be further studied. Here, we develop a type of Zr-doped Na3YbCl6 chloride SEs. The optimized composition gains a high ionic conductivity and broad electrochemical oxidation window. The in situ and ex situ analyses verify that the chloride as ionic additive in the cathode is highly compatible with NaCrO2. Importantly, it is revealed that the volume change in the cathode can act a position effect on the microstructure evolution. It promotes to form a special core-shell-like structure with homogeneous chloride encapsulating NaCrO2 grains. Such a soft intimate contact promotes a uniform ion transport and mitigate (electro)chemo-mechanical stresses. The prerequisites generating this specific microstructure are proposed. The main capacity loss of the assembled all-solid-state Na batteries (ASSNBs) only occurs in the initial dozens of cycles, induced by the irreversible O3→O'3 phase transition in NaCrO2. The chloride additives with a soft feature and high oxidation-stability allow a high-quality interface in the oxide cathode and an excellent cycling stability of the ASSNBs.

Semi-interpenetrating-network PEO-based polymer electrolytes with fast Li-ion conduction for solid Li-metal batteries

Semi-interpenetrating-network (semi-IPN) PEO-based solid polymer electrolytes (SPEs) are synthesized for the application of Li-metal batteries. Owing to the special semi-IPN structure and synergistic effects of EO segments and PVDF-HFP, the SIN solid electrolytes demonstrate great flexibility, high ionic conductivity of 2.45 × 10−4 S cm−1 at 25 °C, outstanding thermal stability and broad electrochemical window (4.9 V vs. Li+/Li). In addition, SIN owns excellent electrochemical stability with Li-metal with a low over-potential <70 mV after 1400 h Li plating/stripping. Moreover, benefiting from the stable interfacial contact, LiFePO4|SIN|Li cells provide high discharge capacity of 146 mAh g−1 with superior capacity retention of 96.6 % after 500 cycles at 0.1C under room temperature. Hence, the semi-IPN PEO-based SPEs appear to be promising for use in high-performance solid-state Li-metal batteries.

Fast Li+ Transport Polyurethane-Based Single-Ion Conducting Polymer Electrolyte with Sulfonamide Side chains in the Hard Segment for Lithium Metal Batteries.

Single-ion conducting polymer electrolytes (SICPEs) are considered as one of the most promising candidates for achieving lithium metal batteries (LMBs). However, the application of traditional SICPEs is hindered by their low ionic conductivity and poor mechanical stability. Herein, a self-standing and flexible polyurethane-based single-ion conductor membrane was prepared via covalent tethering of the trifluoromethanesulfonamide anion to polyurethane, which was synthesized using a facile reaction of diisocyanates with poly(ethylene oxide) and 3,5-diaminobenzoic acid (or 3,5-dihydroxybenzoic acid). The polymer electrolyte exhibited excellent ionic conductivity, mechanical properties, lithium-ion transference number, thermal stability, and a broad electrochemical window because of the bulky anions and unique two-phase structures with lithium-ion nanochannels in the hard domains. Consequently, the plasticized electrolyte membrane showed exceptional stability and reliability in a Li||Li symmetric battery. The assembled LiFePO4||Li battery exhibited an outstanding capacity (∼180 mA h g-1), Coulombic efficiency (>96%), and capacity retention. This research provides a promising polymer electrolyte for high-performance LMBs.

In-situ constructing efficient gel polymer electrolyte with fluoride-rich interface enabling high-capacity, long-cycling sodium metal batteries

Sodium metal batteries (SMBs) are considered feasible candidate for large-scale energy systems. However, complicated reactions between the electrode and electrolyte in liquid electrolyte system lead to poor performance and significant safety issues. Therefore, constructing stable electrode-electrolyte interface is necessary to enhance the comprehensive performance of cells. Utilizing gel polymer electrolytes (GPEs) by in-situ polymerization and moderate additive can effectively address these problems. Herein, a series of fluoroethylene carbonate (FEC) modified GPEs have been successfully prepared by one-step in-situ polymerization, in which trimethylolpropane trimethyl acrylate (TMPTMA) and 1,6-hexanediol diacrylate (HDDA) were used as polymer monomers. As a result, the as-optimized electrolyte, THDP-FEC-2%, exhibited high ionic conductivity (3.77 × 10−3 S cm−1) at 25 °C, high Na+ migration number (0.41), and broad electrochemical window (4.6 V). Encouragingly, the NVP|THDP-FEC-2%|Na cell even exhibited ultra-long cycling stability at high rate (95.31% capacity retention at 5C after 1000 cycles). Such excellent electrochemical performances are attributed to the successful establishment of uniform and dense NaF-rich solid electrolyte interface protection layer. This work is expected to offer interface soft protection layer tuned strategy to construct the ideal interface for high-performance SMBs.

Click-chemistry and ionic cross-linking induced double cross-linking ionogel electrolyte for flexible lithium-ion batteries

With the expansion of portable devices, high-security and flexible energy storage technologies are gaining popularity. However, because of the use of poisonous, flammable, and unstable organic liquid electrolytes in commercial lithium-ion batteries, they cannot provide sufficient protection for the safety and long-term life of portable devices. A thiolate click reaction and ion interaction are used to successfully create a double cross-linking ionogel electrolyte (DC-Ionogel) by sealing 1-ethyl-3methyimidazolium bis (trifluoromethyl) imide (EMIm(TFSI)) in a double cross-linked network. An ion cross-linking network and a covalent cross-linking network are interlaced in the double cross-linked network, which considerably increased the flexibility and stability of the ionogel electrolyte. As a result, DC-Ionogel outperformed in terms of flame retardancy and thermal dimensional stability and outperformed in terms of electrochemical performance, with higher room ionic conductivity (1.79 × 10−3S cm−1) and a broader electrochemical window (5 V). Due to its excellent performance, it is more likely to be used in flexible energy-storage devices.

Skeleton-flesh shape of multipath Li+ transport and compatible interfacial composite solid electrolyte for stable Li-metal batteries

All solid-state battery (ASSB) as the breakthrough of the advanced lithium-ions battery owing to its superior energy density and safety. Solid electrolytes are required to possess excellent electrochemical and safety. However, the low ionic conductivity and the poor interfacial compatibility, respectively, limits the progress of polymer and ceramic electrolyte, which accelerate the development of composite solid electrolyte (CSE). Therefore, we demonstrate a hierarchy structure that PEO(polyethylene)-LLZO@NFPAN-SiO2, which consists of SiO2 particles encapsulated nanofibers (in-situ hydrolyzed by TEOS) and flexible membrane of PEO-LLZO to synergistically elevate the performance of CSE. This CSE exhibits broad electrochemical window (6 V vs. Li) and strong ionic conductivity (3.3 × 10−4 S cm−1, 30 °C), and also shows robust strength (5.1 MPa). The assembled Li-symmetric cells exhibit superior cycling life of 1000 h, with an extremely modest over potential of 45 mV. The full cell exhibits excellent cycle stability, 102 mA h g−1 after 100 cycles at 0.5C, and a high initial Coulomb efficiency of 68 %. Skeleton-flesh structure is constructed by in-situ particle-embedded nanofiber and covered polymer, which strengthened mechanical capability, compatibility, inhibition of lithium dendrites, and introduced multi-Li+ transport pathways, ensuring high safety and superior electrochemical performance for the applications of ASSBs.

3D nanofiber framework based on polyacrylonitrile and siloxane-modified Li6.4La3Zr1.4Ta0.6O12 reinforced poly (ethylene oxide)-based composite solid electrolyte for lithium batteries

The application of solid-state electrolyte in lithium metal batteries is a promising technology to meet the demands for next-generation high-energy-density storage systems. Poly (ethylene oxide) (PEO)-based solid polymer electrolytes have been widely studied, but their electrochemical window is too narrow to be compatible with high-voltage cathodes and their mechanical properties are poor as well. Combination of organic and inorganic compounds is an effective approach to solve this limitation. In this study, Li6.4La3Zr1.4Ta0.6O12 (LLZTO) was surface-modified with a silane coupling agent and compounded with polyacrylonitrile (PAN) to form a 3D nanofiber framework via electrospinning technology, and the PEO-Succinonitrile (SN)-LiTFSI solution was uniformly dispersed in the 3D nanofiber framework to form a continuous Li+ transport path. The prepared composite solid electrolytes (CSEs) showed high ionic conductivity (1.58 × 10−4 S cm−1 at room temperature), a broad electrochemical window (5.1 V, vs. Li/Li+), and an attractive mechanical strength of 49.4 MPa. In addition, solid-state Li/CSE/NCM811 batteries exhibited high coulombic efficiency and significant stable cycling performance.

Exploring the Possibility of Machine Learning for Predicting Ionic Conductivity of Solid-State Electrolytes.

Unlike conventional liquid electrolytes, solid-state electrolytes (SSEs) have gained increased attention in the domain of all-solid-state lithium-ion batteries (ASSBs) due to their safety features, higher energy/power density, better electrochemical stability, and a broader electrochemical window. SSEs, however, face several difficulties, such as poorer ionic conductivity, complicated interfaces, and unstable physical characteristics. Vast research is still needed to find compatible and appropriate SSEs with improved properties for ASSBs. Traditional trial-and-error procedures to find novel and sophisticated SSEs require vast resources and time. Machine learning (ML), which has emerged as an effective and trustworthy tool for screening new functional materials, was recently used to forecast new SSEs for ASSBs. In this study, we developed an ML-based architecture to predict ionic conductivity by utilizing the characteristics of activation energy, operating temperature, lattice parameters, and unit cell volume of various SSEs. Additionally, the feature set can identify distinct patterns in the data set that can be verified using a correlation map. Because they are more reliable, the ensemble-based predictor models can more precisely forecast ionic conductivity. The prediction can be strengthened even further, and the overfitting issue can be resolved by stacking numerous ensemble models. The data set was split into 70:30 ratios to train and test with eight predictor models. The maximum mean-squared error and mean absolute error in training and testing for the random forest regressor (RFR) model were obtained as 0.001 and 0.003, respectively.

LiNO3-Assisted Succinonitrile-Based Solid-State Electrolyte for Long Cycle Life toward a Li-Metal Anode via an In Situ Thermal Polymerization Method.

Succinonitrile (SN)-based electrolytes have a great potential for the practical application of all-solid-state lithium-metal batteries (ASSLMBs) due to their high room-temperature ionic conductivity, broad electrochemical window, and favorable thermal stability. Nevertheless, the poor mechanical strength and low stability toward Li metal hinder the further application of SN-based electrolytes to ASSLMBs. In this work, the LiNO3-assisted SN-based electrolytes are synthesized via an in situ thermal polymerization method. With this method, the mechanical problem is negligible, and the stability of the electrolyte enhances tremendously toward Li metal due to the addition of LiNO3. The LiNO3-assisted electrolytes exhibit a high ionic conductivity of 1.4 mS cm-1 at 25 °C, a wide electrochemical window (0-4.5 V vs Li+/Li), and excellent interfacial compatibility with Li (stable for over 2000 h at a current density of 0.1 mA cm-1). The LiFePO4/Li cells with the LiNO3-assisted electrolytes present significantly enhanced rate capability and cycling performance compared to the control group. NCM622/Li batteries also exhibit good cycling and rate performances with a voltage range of 3.0 to 4.4 V. Furthermore, ex situ SEM and XPS are employed. A compact interface is observed on Li anode after cycling, and the polymerization of SN is found to be suppressed. This paper will promote the development of practical application of SN-based ASSLMBs.

Achieving stable interface for lithium metal batteries using fluoroethylene carbonate-modified garnet-type Li6.4La3Zr1.4Ta0.6O12 composite electrolyte

Composite polymer electrolytes (CPEs) with Li6.4La3Zr1.4Ta0.6O12 (LLZTO) ceramic oxide electrolytes are attracting significant interest because of the merits of LLZTO. However, inadequate solid-solid contact between electrolytes and electrodes invariably results in high interfacial impedance, which is harmful to CPEs' performance. Herein, fluoroethylene carbonate (FEC) additive which possesses excellent ability in guiding uniform Li+ deposition and suppressing Li dendrite growth was introduced into the electrolyte, and novel CPEs were successfully prepared. It shows a broad electrochemical window of 5.2 V (vs. Li+/Li), low interface impedance, and a high lithium ion migration number of 0.62. As a result, the assembled symmetrical Li/PHTL-FEC-LLZTO/Li cells can run stably for over 500 h at 0.2 mA cm–2. Moreover, the Li metal battery with LiFePO4 (LFP) cathode shows superior cyclic stability with a high initial capacity of 132.9 mAh g–1, and a large retention of 88.5% after 200 cycles at 0.5 C. This excellent electrochemical performance of the battery can be attributed to the employment of FEC additives, which endows promising potential in reducing the interface impedance, promoting lithium uniform deposition, and stabling interface performance in the electrolyte.

A Durable Solid‐State Na–CO2 Battery with Solid Composite Electrolyte Na3.2Zr1.9Ca0.1Si2PO12–PVDF‐HFP

Na–CO2 batteries are important devices for immobilizing CO2 and storing renewable energy. However, the Na–CO2 batteries with liquid electrolytes have the issues of electrolyte volatilization and poor cyclability. Herein, a composite solid‐state electrolyte consisting of Ca‐doped Na3Zr2Si2PO12 and polyvinylidene fluoride‐co‐hexafluoropropylene (PVDF‐HFP) is synthesized. The solid composite electrolyte Na3.2Zr1.9Ca0.1Si2PO12–PVDF‐HFP shows a high ionic conductivity of 1.32 × 10−4 S cm−1 at room temperature and a broad electrochemical window up to 5.15 V, as well as excellent durability. The assembled solid‐state Na–CO2 battery with this composite electrolyte delivers a high discharge‐specific capacity up to 3320 mA h g−1 and excellent cycling stability.

Composite Electrolytes Prepared by Improving the Interfacial Compatibility of Organic-Inorganic Electrolytes for Dendrite-Free, Long-Life All-Solid Lithium Metal Batteries.

Compared with simplex ceramic or polymer solid electrolytes, composite solid electrolyte (CSE) is more promising for its better interfacial compatibility to electrode and high ionic conductivity simultaneously. Further, the interfacial compatibility within ceramic and polymer is considered to be more and more critical to the overall performance of solid-state batteries. Avoiding the agglomeration of ceramic particles at high loadings can improve the whole intrinsic characteristic and electrochemical performance of CSEs. Herein, we designed a CSE (EO@LLZTO-PEO), which consists of composite particles (EO@LLZTO) as a filler and polyethylene oxide (PEO) as polymer matrix. EO@LLZTO was prepared by chemically grafting polyethylene glycol monomethyl ether methacrylate (MPEG-MAA) on the micro-sized Li6.4La3Zr1.4Ta0.6O12 (LLZTO) particles. By introducing of polymer containing EO segments onto LLZTO, the interfacial compatibility between LLZTO and PEO matrix is highly enhanced, and the intrinsic Li+ complexation capability of MPEG-MAA is improved, even at the high loading of garnet. EO@LLZTO-PEO shows a high ionic conductivity (1.91 mS cm-1), a broad electrochemical window (∼5.2 V vs Li/Li+), and a high lithium ion transference number (0.72). The Li/EO@LLZTO-PEO/Li battery also exhibits a long cycle stability (over 1200 h of cycling). Moreover, all-solid-state batteries with LiFePO4 and LiNi0.8Co0.1Mn0.1O2 (NCM811) cathodes exhibit excellent cycling stability and rate performance. Consequently, enhancing the interfacial compatibility between organic and inorganic electrolytes is identified to be one of the crucial strategies for commercial solid-state lithium batteries.

Screen-printed electrochemical sensors for environmental monitoring of heavy metal ion detection

Abstract Heavy metal ions (HMIs) are known to cause severe damages to the human body and ecological environment. And considering the current alarming situation, it is crucial to develop a rapid, sensitive, robust, economical and convenient method for their detection. Screen printed electrochemical technology contributes greatly to this task, and has achieved global attention. It enabled the mass transmission rate and demonstrated ability to control the chemical nature of the measure media. Besides, the technique offers advantages like linear output, quick response, high selectivity, sensitivity and stability along with low power requirement and high signal-to-noise ratio. Recently, the performance of SPEs has been improved employing the most effective and promising method of the incorporation of different nanomaterials into SPEs. Especially, in electrochemical sensors, the incorporation of nanomaterials has gained extensive attention for HMIs detection as it exhibits outstanding features like broad electrochemical window, large surface area, high conductivity, selectivity and stability. The present review focuses on the recent progress in the field of screen-printed electrochemical sensors for HMIs detection using nanomaterials. Different fabrication methods of SPEs and their utilization for real sample analysis of HMIs using various nanomaterials have been extensively discussed. Additionally, advancement made in this field is also discussed taking help of the recent literature.

Flexible Fluidic-Type Strain Sensors for Wearable and Robotic Applications Fabricated with Novel Conductive Liquids: A Review

Flexible strain sensors with high sensitivity, wide sensing range, and excellent long-term stability are highly anticipated due to their promising potential in user-friendly electronic skins, interactive wearable systems, and robotics. Fortunately, there have been more flexible sensing materials developed during the past few decades, and some important milestones have been reached. Among the various strain sensing approaches, liquid-type (fluidic type) sensing has attracted great attention due to its appealing qualities, including its high flexibility, broad electrochemical window, variety in design, minimal saturated vapor pressure, and outstanding solubility. This review provides the comprehensive and systematic development of fluidic-type flexible strain sensors, especially in the past 10 years, with a focus on various types of liquids used, fabrication methods, channel structures, and their wide-range applications in wearable devices and robotics. Furthermore, it is believed that this work will be of great help to young researchers looking for a detailed study on fluidic strain sensors.

MXene‐Ti3C2 Armored Layer for Aluminum Current Collector Enable Stable High‐Voltage Lithium‐Ion Battery

AbstractElevating operating voltage (above 4.5 V) is a consequential approach to increasing the energy density of lithium‐ion batteries (LIBs). Unfortunately, the corrosion of cathode aluminum (Al) current collector at high voltage limits the application of high‐voltage LIBs. In this report, for the first time, MXene‐Ti3C2Tx nanosheets are proposed as an armored layer for Al current collector to conquer the corrosion under high operating voltage over 4.5 V versus Li+/Li. The MXene armored layer is fabricated via a self‐assembly procedure, which exhibits ultra‐thinness less than 100 nm, attaches to Al substrate homogeneously, and ensures the electron conduction of current collector by virtue of outstanding conductivity. More importantly, the obtained MXene‐Al can be stabilized under a broad electrochemical window of 2–5.5 V versus Li/Li+ in commercial LiPF6‐carbonates electrolyte. As a consequence, the execution of MXene‐Al current collector to ternary cathode LiCo1/3Ni1/3Mn1/3O2 (NCM333) can significantly enhance electrochemical performance. Under a high cut‐off voltage of 4.5 V, the discharge capacity retention is increased from 21% to 81.4% after 300 cycles at 0.5 C with the protection of MXene armored layer. This work proposes an effective strategy for developing stable high‐voltage LIBs and contributes to the MXene application in energy‐related field.

High-Voltage Redox Mediator of an Organic Electrolyte for Supercapacitors by Lewis Base Electrocatalysis.

Redox electrolytes for supercapacitors (SCs) have recently sparked widespread interest. Due to the redox reactions within electrolytes, they can achieve high capacitance and long cycle stability. However, the energy density of SCs with redox electrolytes is limited by the narrow applied electrochemical window due to the irreversible side reaction of redox mediators at high potential. To overcome this issue, a redox mediator with a high redox potential, tetrachloridehydroquinone (TCHQ), is added to organic electrolytes to obtain a broad electrochemical window. TCHQ is designed to undergo a dehydrogenation reaction catalyzed by N-doped activated carbon to provide capacitance. The pyrrole N atoms have the highest electrocatalytic activity based on the theoretical calculation of reaction overpotential with predicted reaction pathways due to their Lewis basicity. Benefitting from that, TCHQ shows promising reversibility with a larger electrochemical window (up to 2.7 V). As a result, a higher energy density is obtained when compared to commercial SCs. This study proposes a strategy for designing redox mediators and interfaces of SCs with high energy density and a calculation method of dehydrogenation reaction electrocatalysis.

Organic Ammonium Ion Battery: A New Strategy for a Nonmetallic Ion Energy Storage System

AbstractNonmetallic ammonium (NH4+) ion batteries are promising candidates for large‐scale energy storage systems, which have the merit of low molar mass, sustainability, non‐toxicity and non‐dendrite. Herein, for the first time, we introduce the novel organic ammonium ion batteries (OAIBs). Significantly, a manganese‐based Prussian white analogue (noted as MnHCF) as cathode exhibits a reversible capacity of 104 mAh g−1with 98 % retention over 100 cycles. We further demonstrate the electrochemical performance of the NH4+ion full cell, which delivers a reversible capacity of 45 mAh g−1with a broad electrochemical window. Combining ex situ XPS, ex situ XRD results and electrochemical properties, the NH4+ion storage mechanism of MnHCF in a non‐aqueous electrolyte is clearly revealed. This work verifies the feasibility of employing NH4+ions as charge carriers in organic energy storage systems and provides new insights for designing organic nonmetallic ion batteries with broad electrochemical windows and high energy density.

Organic Ammonium Ion Battery: A New Strategy for a Nonmetallic Ion Energy Storage System.

Nonmetallic ammonium (NH4 + ) ion batteries are promising candidates for large-scale energy storage systems, which have the merit of low molar mass, sustainability, non-toxicity and non-dendrite. Herein, for the first time, we introduce the novel organic ammonium ion batteries (OAIBs). Significantly, a manganese-based Prussian white analogue (noted as MnHCF) as cathode exhibits a reversible capacity of 104 mAh g-1 with 98 % retention over 100 cycles. We further demonstrate the electrochemical performance of the NH4 + ion full cell, which delivers a reversible capacity of 45 mAh g-1 with a broad electrochemical window. Combining ex situ XPS, ex situ XRD results and electrochemical properties, the NH4 + ion storage mechanism of MnHCF in a non-aqueous electrolyte is clearly revealed. This work verifies the feasibility of employing NH4 + ions as charge carriers in organic energy storage systems and provides new insights for designing organic nonmetallic ion batteries with broad electrochemical windows and high energy density.

Polyether sulfone and Li6.4La3Zr1.4Ta0.6O12 based polymer-in-ceramic electrolyte with enhanced conductivity at low temperature for solid state lithium batteries

Developing solid state lithium batteries (SSLBs) is an essential step to overcome current safety and energy density issues of traditional Li-ion batteries. As the core component of SSLBs, a solid electrolyte with high ionic conductivity, great physical and chemical properties is still under exploration. Herein, a novel “polymer in ceramic” composite polymer-ceramic electrolytes (CPEs) is reported, which is composed of a polyether sulfone (PESF) polymer and cubic Li6.4La3Zr1.4Ta0.6O12 (LLZTO) ceramic with high contents (up to 80 wt. %). The as-prepared PESF-LLZTO CPEs possess good heat resistance and high mechanical strength to maintain structural integrity. The optimized 0.2PESF-0.8LLZTO CPEs exhibits an excellent ionic conductivity of 4.13×10−4 S cm−1 with a tLi+value as high as 0.64 at 20 °C after wetted by trace wetting agent (6.0 ul cm−2). More impressively, the ionic conductivity is still reached 1.49×10−4 S cm−1 at -10 °C and 9.42×10−4 S cm−1 at 80oC. Meanwhile, the 0.2PESF-0.8LLZTO CPEs shows a broad electrochemical window (≤4.8 V vs. Li+/Li) and an excellent compatibility with Li metal. Density functional theory calculations and 6Li solid-state NMR characterizations suggest that strong interactions among LLZTO, PESF and wetting agents contribute to the enhanced conductivity. As a proof for practical application, the Li||0.2PESF-0.8LLZTO CPEs||LiFePO4 full cells deliver a specific discharge capacity of 133.2 mAh g−1 at 2.0 C, and successfully run over 80 cycles at 0.5 C without capacity attenuation at 20 °C. The full cell also demonstrates a possibility for the application at low temperature down to -10oC and high temperature up to 60oC. This work brings a new perspective for high-performance SSLBs.

Ether-Water Hybrid Electrolyte Contributing to Excellent Mg Ion Storage in Layered Sodium Vanadate.

Magnesium ion batteries have potential for large-scale energy storage. However, the high charge density of Mg2+ ions establishes a strong intercalation energy barrier in host materials, causing sluggish diffusion kinetics and structural degradation. Here, we report that the kinetic and dissolution issues connected to cathode materials can be resolved simultaneously using a tetraethylene glycol dimethyl ether (TEGDME)-water hybrid electrolyte. The lubricating and shielding effect of water solvent could boost the swift transport of Mg2+, contributing to a high diffusion coefficient within the sodium vanadate (NaV8O20·nH2O) cathode. Meanwhile, the organic TEGDME component can coordinate with water to diminish its activity, thus providing the hybrid electrolyte with a broad electrochemical window of 3.9 V. More importantly, the TEGDME preferentially amassed at the interface, leading to a robust cathode electrolyte interface layer that suppresses the dissolution of vanadium species. Consequently, the NaV8O20·nH2O cathode achieved a specific capacity of 351 mAh g-1 at 0.3 A g-1 and a long cycle life of 1000 cycles in this hybrid electrolyte. A mechanism study revealed the reversible interaction of Mg2+ during cycles. This organic water hybrid electrolyte is effective for overcoming the difficulty of multivalent ion storage.