A wide-temperature-range ether electrolyte with a custom high-voltage-resistant interface layer in alkali metal batteries, its preparation method and application.

Abstract

This invention relates to a wide-temperature-range ether-based electrolyte with a customized high-voltage-resistant interface layer in alkali metal batteries, its preparation method, and its application. The wide-temperature-range ether-based electrolyte comprises a base electrolyte, an anion acceptor additive, and an anion additive containing a specific elemental alkali metal salt. The base electrolyte comprises an alkali metal salt and an ether solvent. In the wide-temperature-range ether-based electrolyte, the concentration of the alkali metal salt is 0.1–1.5 mol·L⁻¹. ‑1 The concentration of the anion acceptor additive is 0.5~5wt%, and the concentration of the alkali metal salt anion additive containing specific elements is 0.1~5wt%. Compared with the prior art, the CEI layer in the wide-temperature-range ether electrolyte of the present invention is more dense and exhibits enhanced chemical and thermal stability, effectively suppressing the positive electrode oxidation reaction and alleviating ion transport limitation, improving the high-temperature, room-temperature, and low-temperature cycle performance of the battery, and increasing the battery's service life.

Description

Technical Field

[0001] This invention relates to the field of alkali metal battery technology, and in particular to a wide-temperature-range ether electrolyte with a customized high-voltage-resistant interface layer in alkali metal batteries, its preparation method, and its application. Background Technology

[0002] Recently, there has been increasing attention on energy storage technology. As energy storage technology extends to devices such as mobile phones, computers, and electric vehicles, the demand for high-energy-density batteries used as energy sources for these electronic devices is also increasing.

[0003] High-capacity metal-based layered oxide cathodes (such as Na(Ni)) 1 / 3 Fe 1 / 3 Mn 1 / 3 Alkali metal batteries (such as lithium metal batteries / sodium metal batteries) composed of alkali metal anodes with high theoretical capacity (O2) are an ideal path to achieve high energy density. However, the core challenges facing this system are: side reactions and dendrite growth between the alkali metal anode and the electrolyte, and interfacial instability between the high-voltage cathode and the electrolyte (especially ether-based electrolytes with good metal compatibility). To solve the interface problems of anode compatibility and high-voltage cathode, researchers have tried surface protection coating of the cathode material or special treatment of the anode material, but these methods almost cannot solve the problems faced by both electrodes simultaneously, and the manufacturing process is cumbersome and increases manufacturing costs. Compared with other solutions, electrolyte design strategies have advantages such as simple operation, low cost, and small scale-up effect. Therefore, developing novel wide-temperature-range, high-voltage-resistant ether-based electrolyte systems is an effective way to achieve high-performance alkali metal batteries.

[0004] Chinese patent application CN108987806A, entitled "Application of Cyclic Boric Anhydride in Battery Electrolytes," discloses the use of cyclic boric anhydride as an electrolyte additive. Although it can improve the electrolyte's pressure resistance, it does not differentiate between the positive electrode, which it can directionally adsorb, and uses a second type of anionic additive containing specific elements to customize the positive electrode-electrolyte interface (CEI), resulting in a relatively thin positive electrode interface. Furthermore, the main solvent used is still carbonate, leading to poor stability against alkali metals. The battery's efficiency and cycle performance are difficult to meet current usage requirements. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art by providing a wide-temperature-range ether electrolyte with a customized high-voltage-resistant interface layer in alkali metal batteries, its preparation method, and its application.

[0006] This invention utilizes neutral anion acceptors and salt anions containing specific elements as additives in battery electrolytes. It employs positive electrode adsorption-anion activation (CDAA) and uses the neutral boron-containing additive trimethoxyboronoxane (TMOBX) as an anion acceptor, examining its directional adsorption characteristics and anion acceptor properties on the NFM positive electrode surface. TMOBX is directionally adsorbed onto the NFM surface and selectively captures anions at the interface, inducing local anion enrichment and promoting their preferential decomposition. By combining this surface-anchored acceptor with an alkali metal salt anion additive containing specific elements (such as sodium bis(oxalato)borate, NaBOB), the type and concentration of anions at the interface can be controlled, thereby achieving rational regulation of the CEI component formed during interface decomposition. The resulting CEI layer is denser and exhibits enhanced chemical and thermal stability, effectively suppressing positive electrode oxidation reactions and alleviating ion transport limitations, improving the battery's high-temperature, room-temperature, and low-temperature cycle performance, and extending battery life.

[0007] The objective of this invention can be achieved through the following technical solutions: One of the technical solutions of the present invention is to provide a wide-temperature-range ether electrolyte with a customized high-voltage-resistant interface layer in an alkali metal battery. The wide-temperature-range ether electrolyte includes a base electrolyte, an anion acceptor additive, and an alkali metal salt anion additive containing a specific element.

[0008] Furthermore, the high-voltage resistant interface layer refers to an inorganic-rich cathode-electrolyte interface layer (CEI).

[0009] Furthermore, the anion acceptor additive and the alkali metal salt anion additive containing specific elements are added to the substrate electrolyte.

[0010] Furthermore, the anion acceptor additive is used to selectively capture anions at the interface, induce local anion enrichment, and promote preferential decomposition of anions.

[0011] Furthermore, in the alkali metal salt anionic additive containing specific elements, the specific elements include one or more of boron, phosphorus, fluorine, nitrogen, and sulfur.

[0012] More preferably, the specific element is boron.

[0013] Different specific elements have different interface functions, thus allowing the interface to be adjusted according to the system, using different specific elements as the main body: Boron (B): Its most typical role is to preferentially form borate / BO-type inorganic interfaces, which often makes the CEI thinner, denser and more continuous, so the trend of increasing the density of CEI is usually to improve it.

[0014] Phosphorus (P): often forms phosphate / NaxPFyOz, with the advantage of both film formation and providing good Na+.+ Conductivity; the trend toward CEI compactness is generally to improve or at least maintain a high degree of homogeneity, but what is more prominent is not the hardest, but rather greater stability and ion conduction.

[0015] Fluorine (F): Most commonly forms NaF-rich CEI, which generally means higher mechanical strength, lower permeability, and stronger passivation ability, so the tendency to increase density is usually significant. However, if the fluorine source is PF6... - Unstable fluorine-containing components may introduce HF / PF5 through side reactions, which may exacerbate the dissolution of transition metals and interface degradation.

[0016] Nitrogen (N): Commonly found in nitriles, amides, imides, and silicon nitrides, it mainly improves the interface by regulating the solvation structure and film uniformity. The trend for CEI density is usually a gentle increase, making it more uniform, thinner, and capable of lithium transfer, rather than turning the film into a highly inorganic hard shell like B / F.

[0017] Sulfur (S): Commonly found in sulfones, sulfites, sulfonates, etc., it usually improves the polarity, adhesion and ion transport friendliness of CEI; its tendency to increase densification is usually moderate, but generally not as direct and strong as that of B or F.

[0018] Furthermore, the alkali metal salt anion additive containing specific elements is used to combine with the anion acceptor additive to regulate the type and concentration of interfacial anions, thereby achieving regulation of the composition of the positive electrode-electrolyte interface layer formed during the interfacial decomposition process.

[0019] Furthermore, the substrate electrolyte comprises alkali metal salts and ether solvents.

[0020] Furthermore, the alkali metal salt is soluble in an ether solvent.

[0021] Furthermore, in the wide-temperature-range ether electrolyte, the concentration of the alkali metal salt is 0.1-1.5 mol·L⁻¹. -1 .

[0022] Furthermore, in the wide-temperature-range ether electrolyte, the concentration of the anion acceptor additive is 0.5~5wt%.

[0023] Furthermore, in the wide-temperature-range ether electrolyte, the concentration of the specific elemental alkali metal salt anionic additive is 0.1~5wt%.

[0024] Furthermore, the wide-temperature-range ether electrolyte comprises: 0.1-1.5 mol·L⁻¹ -1 An electrolyte additive is prepared by adding 0.5-5 wt% of anion acceptor additive and 0.1-5 wt% of anion additive containing a specific element metal salt to a base electrolyte in which alkali metal salts are dissolved in ether solvents.

[0025] Furthermore, the alkali metal salt is selected from one or more of sodium salts, lithium salts, and potassium salts.

[0026] Furthermore, the anion acceptor additive is trimethoxyboroxane.

[0027] Furthermore, the alkali metal salt anionic additive containing a specific element is selected from one or more of the following: sodium salt anionic additive containing a specific element, lithium salt anionic additive containing a specific element, and potassium salt anionic additive containing a specific element.

[0028] Further, the ether solvent is selected from one or more of tetraethylene glycol dibutyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, ethylene glycol methyl ethyl ether, ethylene glycol diethyl ether, diethylene glycol diethyl ether, diethylene glycol diethyl ether, triethylene glycol diethyl ether, tetraethylene glycol diethyl ether, ethylene glycol dipropyl ether, diethylene glycol dipropyl ether, triethylene glycol dipropyl ether, tetraethylene glycol dipropyl ether, ethylene glycol dibutyl ether, diethylene glycol dibutyl ether, triethylene glycol dibutyl ether, tetrahydrofuran, tetrahydropyran, 1,3-dioxolane, 1,4-dioxane, and 2-methyl-1,3-dioxolane.

[0029] More preferably, the sodium salt is one or more of sodium hexafluorophosphate, sodium bis(oxalato)borate, sodium difluorooxalatoborate, sodium tetrafluoroborate, sodium trifluoromethanesulfonate, sodium trifluoromethanesulfonylimide, and sodium bis(trifluoromethanesulfonyl)imide.

[0030] More preferably, the lithium salt is one or more of lithium hexafluorophosphate, lithium bis(oxalato)borate, lithium difluorooxalato)borate, lithium tetrafluoroborate, lithium trifluoromethanesulfonate, lithium trifluoromethanesulfonylimide, and lithium bis(trifluoromethanesulfonyl)imide.

[0031] More preferably, the potassium salt is one or more of potassium hexafluorophosphate, potassium bis(oxalato)borate, potassium difluorooxalato)borate, potassium tetrafluoroborate, potassium trifluoromethanesulfonate, potassium trifluoromethanesulfonylimide, and potassium bis(trifluoromethanesulfonyl)imide.

[0032] More preferably, the sodium salt anionic additive containing a specific element is selected from one or more of sodium bis(oxalato)borate, sodium difluorooxalatoborate, sodium tetrafluoroborate, sodium trifluoromethanesulfonate, sodium trifluoromethanesulfonylimide, sodium bis(trifluoromethanesulfonyl)imide, and sodium hexafluorophosphate.

[0033] More preferably, the sodium salt and the sodium salt anionic additive containing a specific element are selected from different substances.

[0034] More preferably, the sodium salt anionic additive containing a specific element is sodium bis(oxalato)borate.

[0035] More preferably, the lithium salt anionic additive containing a specific element is selected from one or more of lithium bis(oxalato)borate, lithium difluorooxalato)borate, lithium tetrafluoroborate, lithium trifluoromethanesulfonate, lithium trifluoromethanesulfonylimide, lithium bis(trifluoromethanesulfonyl)imide, and lithium hexafluorophosphate.

[0036] More preferably, the lithium salt and the lithium salt anionic additive containing a specific element are selected from different substances.

[0037] More preferably, the lithium salt anionic additive containing a specific element is lithium bis(oxalato)borate.

[0038] More preferably, the potassium salt anionic additive containing a specific element is selected from one or more of potassium bis(oxalato)borate, potassium difluorooxalatoborate, potassium tetrafluoroborate, potassium trifluoromethanesulfonate, potassium trifluoromethanesulfonylimide, potassium bis(trifluoromethanesulfonyl)imide, and potassium hexafluorophosphate.

[0039] More preferably, the potassium salt and the potassium salt anionic additive containing a specific element are selected from different substances.

[0040] More preferably, the potassium salt anionic additive containing a specific element is potassium bis(oxalate-borate).

[0041] More preferably, the ether solvent is tetraethylene glycol dibutyl ether and / or tetraethylene glycol dimethyl ether.

[0042] More preferably, the sodium salt is sodium hexafluorophosphate.

[0043] More preferably, the lithium salt is lithium hexafluorophosphate.

[0044] More preferably, the potassium salt is potassium hexafluorophosphate.

[0045] The second technical solution of the present invention provides a method for preparing a wide-temperature-range ether electrolyte with a customized high-voltage-resistant interface layer in an alkali metal battery, the preparation method comprising the following steps: Anion acceptor additives, alkali metal salt anion additives containing specific elements, and alkali metal salts are dissolved in an ether solvent in a certain proportion to obtain the wide temperature range ether electrolyte.

[0046] Furthermore, the preparation process of the wide-temperature-range ether electrolyte is carried out under an inert atmosphere.

[0047] Furthermore, the inert atmosphere is one or more of argon, helium, etc.

[0048] Furthermore, the preparation process of the wide-temperature-range ether electrolyte is carried out at 25°C.

[0049] The third technical solution of the present invention is to provide an application of a wide-temperature-range ether electrolyte with a customized high-voltage-resistant interface layer in an alkali metal battery, wherein the wide-temperature-range ether electrolyte is used in an alkali metal battery, and the wide-temperature-range ether electrolyte is used as an electrolyte in an alkali metal battery.

[0050] The fourth technical solution of the present invention provides an alkali metal battery, including a wide-temperature-range ether electrolyte with a customized high-voltage-resistant interface layer in the alkali metal battery, and also includes a positive electrode and a negative electrode.

[0051] Furthermore, the positive electrode includes an active material, which includes a (high-nickel) layered oxide positive electrode material NaNi. 1-x-y Fe x Mn y O2 (NFM) and / or LiNi 1-x-y Co x Mn y O2, where 0 <x<1,0<y<1。

[0052] More preferably, 0.1≤x<0.4, 0.1≤y<0.4.

[0053] More preferably, the active substance includes Na(Ni) 1 / 3 Fe 1 / 3 Mn 1 / 3 O2), sodium copper iron manganese oxide, manganese iron cyanide, lithium nickel cobalt manganese oxide cathode material LiNi a Co b Mn c At least one of O2 (where the sum of a, b, and c is 1).

[0054] Furthermore, the loading amount of the active material in the positive electrode is 0.5–30 mg·cm³. -2 .

[0055] Furthermore, the negative electrode includes one or more of sodium metal, lithium metal, and potassium metal.

[0056] Compared with the prior art, the present invention has the following beneficial effects: 1) This invention provides a wide-temperature-range ether electrolyte with a customized high-voltage-resistant interface layer in alkali metal batteries. It uses the principle of positive electrode adsorption-anion activation, adds anion acceptors and battery electrolytes containing specific elemental alkali metal salt anions, and has high charge-discharge efficiency and good cycle performance. It can meet the charge-discharge requirements of Na||NFM batteries at 30℃ for 1000 charge-discharge cycles at 1C with a capacity retention rate of more than 80%. Compared with the control group (1M NaPF6 in D4), the capacity retention rate decreased to 80% after 50 cycles under the same conditions.

[0057] 2) This invention provides a wide-temperature-range ether electrolyte with a customized high-voltage-resistant interface layer in alkali metal batteries. Under 60°C conditions, it maintains a capacity retention of over 80% after 260 charge-discharge cycles at 1C (compared to only 55 cycles for the control group); under extreme conditions of 80°C, it maintains a capacity retention of over 80% after 100 charge-discharge cycles at 1C (compared to only 30 cycles for the control group). Furthermore, it achieves a low-temperature (-20°C) discharge efficiency of over 85%, which enhances battery storage performance without affecting other battery properties.

[0058] 3) This invention provides a wide-temperature-range ether electrolyte with a customized high-voltage-resistant interface layer in alkali metal batteries, its preparation method and application. The prepared wide-temperature-range ether electrolyte can be used in alkali metal batteries, which have long cycle life, low gas expansion rate, good high-temperature performance, and the battery operating voltage can be higher than 4.2V. Attached Figure Description

[0059] Figure 1 This is a schematic diagram of the charge-discharge cycle of Example 6 and Comparative Example 1.

[0060] Figure 2 This is a TEM image of the CEI layer formed in Example 6.

[0061] Figure 3 This is a TEM image of the CEI layer formed in Comparative Example 1. Detailed Implementation

[0062] The present invention will now be described in detail with reference to specific embodiments. These embodiments are for illustrative purposes only and are not intended to limit the scope of protection of the present invention. Component models, material names, connection structures, control methods, and other features not explicitly stated in this technical solution are considered to be common technical features disclosed in the prior art.

[0063] In the examples below, unless otherwise specified, the reagents used are commercially available products and the methods employed are those known in the art.

[0064] Example 1 This embodiment provides a method for preparing a wide-temperature-range ether electrolyte with a customized high-voltage-resistant interface layer in an alkali metal battery, specifically the preparation of a high-voltage wide-temperature-range alkali metal battery CDAA electrolyte, including the following steps: At room temperature, in an argon-filled glove box (moisture < 0.01 ppm, oxygen < 0.01 ppm), 2,4,6-trimethoxyboroxane was added to tetraethylene glycol dibutyl ether solvent, and then sodium salt NaPF6 was slowly added and stirred until completely dissolved to obtain high-voltage alkali metal battery CDAA electrolyte A1. In high-voltage alkali metal battery CDAA electrolyte A1, the concentration of trimethoxyboroxane was 0.5 wt%, and the concentration of sodium salt NaPF6 was 1 M.

[0065] This embodiment also provides a method for preparing a high-voltage, wide-temperature-range alkali metal battery, comprising the following steps: Na(Ni) was placed in an argon-filled glove box (moisture < 0.01 ppm, oxygen < 0.01 ppm). 1 / 3 Fe 1 / 3 Mn 1 / 3 Using NFM111 (commercially available from KELOD MA-EN-CA-002801) as the positive electrode active material, Super P (commercially available from KELOD) as the conductive agent, and polyvinylidene fluoride (PVDF5130) (molecular weight approximately 1.1 million; commercially available from KELOD) as the binder, these materials are mixed evenly in N-methylpyrrolidone (NMP) at a mass ratio of 8:1:1 (the mass of NMP is 3 times the total mass of NFM, Super P, and PVDF5130). The mixture is then coated onto an aluminum foil current collector, dried, and cut into circular pieces with a diameter of φ10 mm to obtain the positive electrode sheet, which is stored in a glove box for later use. Sodium metal is used as the negative electrode active material. It is removed, dried of kerosene, and the oxide film on the surface is scraped off. It is then rolled into a thin sheet using a stainless steel rod and cut into circular pieces with a diameter of φ12 mm to obtain the negative electrode sheet. A polyethylene (PE) membrane (molecular weight approximately 1 million) (12 μm) was used as the base film, with a 2 μm nano-alumina coating applied to both sides as the separator. The positive electrode, separator, and negative electrode were arranged in sequence, and the prepared electrolyte (CDAA electrolyte A1 for high-voltage alkali metal batteries) was injected. The mixture was then encapsulated and assembled into a CR2032 coin cell. After being left to stand at room temperature for 24 hours, the coin cells were cycle-tested using a Landian battery charge-discharge tester (purchased from Wuhan Landian Electronics Co., Ltd.).

[0066] Example 2 This embodiment provides a method for preparing a wide-temperature-range ether electrolyte with a customized high-voltage-resistant interface layer in an alkali metal battery. The difference from Example 1 lies in the preparation of the high-voltage, wide-temperature-range alkali metal battery CDAA electrolyte: At room temperature, in an argon-filled glove box (moisture content < 0.01 ppm, oxygen content < 0.01 ppm), trimethoxyboroxane was added to tetraethylene glycol dibutyl ether solvent, and then sodium salt NaPF6 was slowly added and stirred until completely dissolved to obtain high-voltage alkali metal battery CDAA electrolyte A2. In high-voltage alkali metal battery CDAA electrolyte A2, the concentration of trimethoxyboroxane was 1 wt% and the concentration of sodium salt NaPF6 was 1 M.

[0067] This embodiment also provides a method for preparing a high-voltage, wide-temperature-range alkali metal battery. The high-voltage alkali metal battery CDAA electrolyte A1 of Example 1 is replaced with the high-voltage alkali metal battery CDAA electrolyte A2 of this embodiment, and the steps are the same as in Example 1.

[0068] Example 3 This embodiment provides a method for preparing a wide-temperature-range ether electrolyte with a customized high-voltage-resistant interface layer in an alkali metal battery. The difference from Example 1 lies in the preparation of the high-voltage, wide-temperature-range alkali metal battery CDAA electrolyte: At room temperature, in an argon-filled glove box (moisture < 0.01 ppm, oxygen < 0.01 ppm), trimethoxyboroxane was added to tetraethylene glycol dibutyl ether solvent, and then sodium salt NaPF6 was slowly added and stirred until completely dissolved to obtain high-voltage alkali metal battery CDAA electrolyte A3. In high-voltage alkali metal battery CDAA electrolyte A3, the concentration of trimethoxyboroxane was 1.5 wt%, and the concentration of sodium salt NaPF6 was 1 M.

[0069] This embodiment also provides a method for preparing a high-voltage, wide-temperature-range alkali metal battery. The high-voltage alkali metal battery CDAA electrolyte A1 of Example 1 is replaced with the high-voltage alkali metal battery CDAA electrolyte A3 of this embodiment, and the steps are the same as in Example 1.

[0070] Example 4 This embodiment provides a method for preparing a wide-temperature-range ether electrolyte with a customized high-voltage-resistant interface layer in an alkali metal battery. The difference from Example 1 lies in the preparation of the high-voltage, wide-temperature-range alkali metal battery CDAA electrolyte: At room temperature, in an argon-filled glove box (moisture content < 0.01 ppm, oxygen content < 0.01 ppm), trimethoxyboroxane was added to tetraethylene glycol dibutyl ether solvent, and then sodium salt NaPF6 was slowly added and stirred until it was completely dissolved to obtain high-voltage alkali metal battery CDAA electrolyte A4. In high-voltage alkali metal battery CDAA electrolyte A4, the concentration of trimethoxyboroxane was 2 wt%, and the concentration of sodium salt NaPF6 was 1 M.

[0071] This embodiment also provides a method for preparing a high-voltage, wide-temperature-range alkali metal battery. The high-voltage alkali metal battery CDAA electrolyte A1 of Example 1 is replaced with the high-voltage alkali metal battery CDAA electrolyte A4 of this embodiment, and the steps are the same as in Example 1.

[0072] Example 5 This embodiment provides a method for preparing a wide-temperature-range ether electrolyte with a customized high-voltage-resistant interface layer in an alkali metal battery. The difference from Example 1 lies in the preparation of the high-voltage, wide-temperature-range alkali metal battery CDAA electrolyte: At room temperature, in an argon-filled glove box (moisture content < 0.01 ppm, oxygen content < 0.01 ppm), trimethoxyboroxane was added to tetraethylene glycol dibutyl ether solvent, and then sodium salt NaPF6 was slowly added and stirred until completely dissolved to obtain high-voltage alkali metal battery CDAA electrolyte A5. In high-voltage alkali metal battery CDAA electrolyte A5, the concentration of trimethoxyboroxane was 5 wt%, and the concentration of sodium salt NaPF6 was 1 M.

[0073] This embodiment also provides a method for preparing a high-voltage, wide-temperature-range alkali metal battery. The high-voltage alkali metal battery CDAA electrolyte A1 of Example 1 is replaced with the high-voltage alkali metal battery CDAA electrolyte A5 of this embodiment, and the steps are the same as in Example 1.

[0074] Example 6 This embodiment provides a method for preparing a wide-temperature-range ether electrolyte with a customized high-voltage-resistant interface layer in an alkali metal battery. The difference from Example 1 lies in the preparation of the high-voltage, wide-temperature-range alkali metal battery CDAA electrolyte: At room temperature, in an argon-filled glove box (moisture < 0.01 ppm, oxygen < 0.01 ppm), trimethoxyboroxane and sodium bis(oxalate)borate were added to tetraethylene glycol dibutyl ether solvent, and then sodium salt NaPF6 was slowly added and stirred until completely dissolved to obtain high-voltage alkali metal battery CDAA electrolyte A6. In high-voltage alkali metal battery CDAA electrolyte A6, the concentration of trimethoxyboroxane was 1.5 wt%, the concentration of sodium bis(oxalate)borate was 0.1 wt%, and the concentration of sodium salt NaPF6 was 1 M.

[0075] This embodiment also provides a method for preparing a high-voltage, wide-temperature-range alkali metal battery. The high-voltage alkali metal battery CDAA electrolyte A1 of Example 1 is replaced with the high-voltage alkali metal battery CDAA electrolyte A6 of this embodiment, and the steps are the same as in Example 1.

[0076] Example 7 This embodiment provides a method for preparing a wide-temperature-range ether electrolyte with a customized high-voltage-resistant interface layer in an alkali metal battery. The difference from Example 1 lies in the preparation of the high-voltage, wide-temperature-range alkali metal battery CDAA electrolyte: At room temperature, in an argon-filled glove box (moisture < 0.01 ppm, oxygen < 0.01 ppm), trimethoxyboroxane and sodium difluorooxalate borate were added to tetraethylene glycol dibutyl ether solvent, followed by slow addition of sodium salt NaPF6 and stirring until completely dissolved to obtain high-voltage alkali metal battery CDAA electrolyte A7. In high-voltage alkali metal battery CDAA electrolyte A7, the concentration of trimethoxyboroxane was 1.5 wt%, the concentration of sodium difluorooxalate borate was 0.2 wt%, and the concentration of sodium salt NaPF6 was 1 M.

[0077] This embodiment also provides a method for preparing a high-voltage, wide-temperature-range alkali metal battery. The high-voltage alkali metal battery CDAA electrolyte A1 of Example 1 is replaced with the high-voltage alkali metal battery CDAA electrolyte A7 of this embodiment, and the steps are the same as in Example 1.

[0078] Example 8 This embodiment provides a method for preparing a wide-temperature-range ether electrolyte with a customized high-voltage-resistant interface layer in an alkali metal battery. The difference from Example 1 lies in the preparation of the high-voltage, wide-temperature-range alkali metal battery CDAA electrolyte: At room temperature, in an argon-filled glove box (moisture < 0.01 ppm, oxygen < 0.01 ppm), trimethoxyboronoxane and sodium bis(oxalate)borate were added to tetraethylene glycol dibutyl ether solvent, followed by slow addition of sodium salt NaPF6 and stirring until completely dissolved to obtain high-voltage alkali metal battery CDAA electrolyte A8. In high-voltage alkali metal battery CDAA electrolyte A8, the concentration of trimethoxyboronoxane was 1.5 wt%, the concentration of sodium bis(oxalate)borate was 0.1 wt%, and the concentration of sodium salt NaPF6 was 0.1 M.

[0079] This embodiment also provides a method for preparing a high-voltage, wide-temperature-range alkali metal battery. The high-voltage alkali metal battery CDAA electrolyte A1 of Example 1 is replaced with the high-voltage alkali metal battery CDAA electrolyte A8 of this embodiment, and the steps are the same as in Example 1.

[0080] Example 9 This embodiment provides a method for preparing a wide-temperature-range ether electrolyte with a customized high-voltage-resistant interface layer in an alkali metal battery. The difference from Example 1 lies in the preparation of the high-voltage, wide-temperature-range alkali metal battery CDAA electrolyte: At room temperature, in an argon-filled glove box (moisture < 0.01 ppm, oxygen < 0.01 ppm), trimethoxyboroxane and sodium bis(oxalate)borate were added to tetraethylene glycol dimethyl ether solvent, followed by slow addition of sodium salt NaPF6 and stirring until completely dissolved to obtain high-voltage metal battery CDAA electrolyte A9. In high-voltage alkali metal battery CDAA electrolyte A9, the concentration of trimethoxyboroxane was 1.5 wt%, the concentration of sodium bis(oxalate)borate was 0.1 wt%, and the concentration of sodium salt NaPF6 was 0.1 M.

[0081] This embodiment also provides a method for preparing a high-voltage, wide-temperature-range alkali metal battery. The high-voltage alkali metal battery CDAA electrolyte A1 of Example 1 is replaced with the high-voltage alkali metal battery CDAA electrolyte A9 of this embodiment, and the steps are the same as in Example 1.

[0082] Example 10 This embodiment provides a method for preparing a wide-temperature-range ether electrolyte with a customized high-voltage-resistant interface layer in an alkali metal battery. The difference from Example 1 lies in the preparation of the high-voltage, wide-temperature-range alkali metal battery CDAA electrolyte: At room temperature, in an argon-filled glove box (moisture < 0.01 ppm, oxygen < 0.01 ppm), trimethoxyboronoxane and lithium bis(oxalate)borate were added to tetraethylene glycol dibutyl ether solvent, followed by slow addition of lithium salt LiPF6. The mixture was stirred until completely dissolved to obtain high-voltage alkali metal battery CDAA electrolyte A10. In high-voltage alkali metal battery CDAA electrolyte A10, the concentration of trimethoxyboronoxane was 1.5 wt%, the concentration of lithium bis(oxalate)borate was 0.1 wt%, and the concentration of lithium salt LiPF6 was 1 M.

[0083] This embodiment also provides a method for preparing a high-voltage, wide-temperature-range alkali metal battery. The high-voltage alkali metal battery CDAA electrolyte A1 of Example 1 is replaced with the high-voltage alkali metal battery CDAA electrolyte A10 of this embodiment, and the steps are the same as in Example 1.

[0084] Note: Although Examples 1-5 contain only one additive, the second additive containing a specific element alkali metal salt anion includes the main salt sodium hexafluorophosphate (NaPF6). From this perspective, the second additive (containing a specific element alkali metal salt anion) in CDAA electrolytes A1-A5 is actually NaPF6.

[0085] Comparative Example 1: This comparative example provides a method for preparing an electrolyte, which differs from Example 1 in the preparation of the electrolyte: At room temperature, in an argon-filled glove box (moisture content < 0.01 ppm, oxygen content < 0.01 ppm), sodium salt NaPF6 was slowly added to tetraethylene glycol dibutyl ether solvent and stirred until it was completely dissolved to obtain alkali metal battery electrolyte B1. The concentration of sodium salt NaPF6 in alkali metal battery electrolyte B1 was 1 M.

[0086] This comparative example also provides a method for preparing an alkali metal battery, in which the high-voltage alkali metal battery CDAA electrolyte A1 of Example 1 is replaced with the alkali metal battery electrolyte B1 of this comparative example, and the steps are the same as in Example 1.

[0087] Comparative Example 2: This comparative example provides a method for preparing an electrolyte, which differs from Example 1 in the preparation of the electrolyte: At room temperature, in an argon-filled glove box (moisture content < 0.01 ppm, oxygen content < 0.01 ppm), sodium salt NaPF6 was slowly added to tetraethylene glycol dibutyl ether solvent and stirred until it was completely dissolved to obtain alkali metal battery electrolyte B2. The concentration of sodium salt NaPF6 in alkali metal battery electrolyte B2 was 0.7 M.

[0088] This comparative example also provides a method for preparing an alkali metal battery, in which the high-voltage alkali metal battery CDAA electrolyte A1 of Example 1 is replaced with the alkali metal battery electrolyte B2 of this comparative example, and the steps are the same as in Example 1.

[0089] Comparative Example 3: This comparative example provides a method for preparing an electrolyte, which differs from Example 1 in the preparation of the electrolyte: At room temperature, in an argon-filled glove box (moisture content < 0.01 ppm, oxygen content < 0.01 ppm), sodium salt NaPF6 was slowly added to tetraethylene glycol dibutyl ether solvent and stirred until it was completely dissolved to obtain alkali metal battery electrolyte B3. The concentration of sodium salt NaPF6 in alkali metal battery electrolyte B3 was 0.5 M.

[0090] This comparative example also provides a method for preparing an alkali metal battery, in which the high-voltage alkali metal battery CDAA electrolyte A1 of Example 1 is replaced with the alkali metal battery electrolyte B3 of this comparative example, and the steps are the same as in Example 1.

[0091] Comparative Example 4: This comparative example provides a method for preparing an electrolyte, which differs from Example 1 in the preparation of the electrolyte: At room temperature, in an argon-filled glove box (moisture content < 0.01 ppm, oxygen content < 0.01 ppm), sodium salt NaPF6 was slowly added to tetraethylene glycol dibutyl ether solvent and stirred until it was completely dissolved to obtain alkali metal battery electrolyte B4. The concentration of sodium salt NaPF6 in alkali metal battery electrolyte B4 was 0.3 M.

[0092] This comparative example also provides a method for preparing an alkali metal battery, in which the high-voltage alkali metal battery CDAA electrolyte A1 of Example 1 is replaced with the alkali metal battery electrolyte B4 of this comparative example, and the steps are the same as in Example 1.

[0093] Comparative Example 5: This comparative example provides a method for preparing an electrolyte, which differs from Example 1 in the preparation of the electrolyte: At room temperature, in an argon-filled glove box (moisture content < 0.01 ppm, oxygen content < 0.01 ppm), sodium salt NaPF6 was slowly added to tetraethylene glycol dibutyl ether solvent and stirred until it was completely dissolved to obtain alkali metal battery electrolyte B5. The concentration of sodium salt NaPF6 in alkali metal battery electrolyte B5 was 0.1 M.

[0094] This comparative example also provides a method for preparing an alkali metal battery, in which the high-voltage alkali metal battery CDAA electrolyte A1 of Example 1 is replaced with the alkali metal battery electrolyte B5 of this comparative example, and the steps are the same as in Example 1.

[0095] Comparative Example 6: This comparative example provides a method for preparing an electrolyte, which differs from Example 1 in the preparation of the electrolyte: At room temperature, in an argon-filled glove box (moisture < 0.01 ppm, oxygen < 0.01 ppm), sodium bis(oxalate)borate was added to tetraethylene glycol dibutyl ether solvent, and then sodium salt NaPF6 was slowly added and stirred until completely dissolved to obtain alkali metal battery electrolyte B6. In alkali metal battery electrolyte B6, the concentration of sodium bis(oxalate)borate was 0.1 wt%, and the concentration of sodium salt NaPF6 was 1 M.

[0096] This comparative example also provides a method for preparing an alkali metal battery, in which the high-voltage alkali metal battery CDAA electrolyte A1 of Example 1 is replaced with the alkali metal battery electrolyte B6 of this comparative example, and the steps are the same as in Example 1.

[0097] Comparative Example 7: This comparative example provides a method for preparing an electrolyte, which differs from Example 1 in the preparation of the electrolyte: At room temperature, in an argon-filled glove box (moisture < 0.01 ppm, oxygen < 0.01 ppm), sodium difluorooxalate borate was added to tetraethylene glycol dibutyl ether solvent, and then sodium salt NaPF6 was slowly added and stirred until completely dissolved to obtain alkali metal battery electrolyte B7. In alkali metal battery electrolyte B7, the concentration of sodium difluorooxalate borate was 0.2 wt%, and the concentration of sodium salt NaPF6 was 1 M.

[0098] This comparative example also provides a method for preparing an alkali metal battery, in which the high-voltage alkali metal battery CDAA electrolyte A1 of Example 1 is replaced with the alkali metal battery electrolyte B7 of this comparative example, and the steps are the same as in Example 1.

[0099] Comparative Example 8: This comparative example provides a method for preparing an electrolyte, which differs from Example 1 in the preparation of the electrolyte: At room temperature, in a glove box filled with argon (moisture content < 0.01 ppm, oxygen content < 0.01 ppm), 1 M sodium salt NaPF6 was slowly added to tetraethylene glycol dimethyl ether solvent and stirred until it was completely dissolved to obtain alkali metal battery electrolyte B8. The concentration of sodium salt NaPF6 in alkali metal battery electrolyte B8 was 1 M.

[0100] This comparative example also provides a method for preparing an alkali metal battery, in which the high-voltage alkali metal battery CDAA electrolyte A1 of Example 1 is replaced with the alkali metal battery electrolyte B8 of this comparative example, and the steps are the same as in Example 1.

[0101] Comparative Example 9: This comparative example provides a method for preparing an electrolyte, which differs from Example 1 in the preparation of the electrolyte: At room temperature, in an argon-filled glove box (moisture content < 0.01 ppm, oxygen content < 0.01 ppm), lithium salt LiPF6 was slowly added to tetraethylene glycol dibutyl ether solvent and stirred until it was completely dissolved to obtain alkali metal battery electrolyte B9. The concentration of lithium salt LiPF6 in alkali metal battery electrolyte B9 was 1 M.

[0102] This comparative example also provides a method for preparing an alkali metal battery, in which the high-voltage alkali metal battery CDAA electrolyte A1 of Example 1 is replaced with the alkali metal battery electrolyte B9 of this comparative example, and the steps are the same as in Example 1.

[0103] Application Examples In this application embodiment, the test results and analysis are obtained by cyclically testing the button batteries prepared in Examples 1-10 and Comparative Examples 1-8 after they have been left to stand at room temperature for 24 hours using a Landian battery charge-discharge tester (purchased from Wuhan Landian Electronics Co., Ltd.).

[0104] Electrochemical performance The application effects under conditions of 30 ℃, 1 C, and 2-4 V are shown in Table 1a (comparative example) and Table 1b (exemplary example): Table 1a: Battery cycle performance test results of the comparative example under conditions of 30 ℃, 1 C, and 2-4 V.

[0105] Table 1b: Battery cycle performance test results of the example under conditions of 30 °C, 1 C, and 2-4 V.

[0106] The test results in Tables 1a and 1b show that: Comparing Comparative Examples 1, 2, 3, 4, and 5, it can be seen that when the NaPF6 concentration is increased from 0.1 / 0.3 / 0.5 / 0.7 M to 1.0 M (solvent: tetraethylene glycol dibutyl ether), the battery exhibits significantly higher cycle capacity retention and coulombic efficiency. This is because the electrolyte at a concentration of 1.0 mol / L also has higher ionic conductivity, which can effectively enhance the NaPF6 concentration. + This increases flux and significantly reduces interfacial impedance. Therefore, most subsequent embodiments use 1.0 M as the sodium salt concentration.

[0107] Comparing Comparative Examples 1, 6, and 7, it can be seen that when using sodium salt anions containing specific elements as additives alone, the cycle performance of the battery is only slightly improved. This is because sodium salt anions containing specific elements alone cannot be directionally decomposed on the positive electrode surface to form a stable CEI. The positive electrode interface is still a loose decomposition product of organic ethers. At the same time, ethers undergo severe decomposition under high voltage, which affects the cycle performance of the battery.

[0108] Comparing Comparative Examples 1 and 8, it can be seen that the battery using tetraethylene glycol dimethyl ether electrolyte performs worse than the battery using tetraethylene glycol dibutyl ether electrolyte in terms of average coulombic efficiency and cycle performance. This is because with the increase of nonpolar carbon chain length, there is a greater steric hindrance effect, which affects the Na+. + Its solubility is reduced, but its high-pressure resistance is better.

[0109] Comparing Comparative Example 1 with Examples 1, 2, 3, 4, and 5, it can be seen that when the anion acceptor additive trimethoxyboroxane is added, and the second anion additive containing a specific element sodium salt is sodium hexafluorophosphate, which is the same as the main salt, the average coulombic efficiency and cycle performance of the battery are significantly improved. This is because trimethoxyboroxane is directionally adsorbed on the NFM surface and selectively captures anions at the interface, inducing local anion enrichment and promoting its preferential decomposition, forming a dense, inorganic-rich CEI layer dominated by anion decomposition products. This interfacial film can exist stably under high voltage, inhibiting the decomposition of the electrolyte, thereby improving the battery efficiency and cycle performance, which is a significant improvement.

[0110] Comparing Examples 1, 2, 3, 4, and 5, it can be seen that the concentration of added trimethoxyboroxane should not be excessive, and 1.5 wt% is optimal.

[0111] Comparing Examples 3, 6, and 7, it is evident that the average coulombic efficiency and cycle performance of batteries assembled with electrolytes containing 0.1 wt% sodium difluorooxalate borate and 0.2 wt% sodium difluorooxalate borate were significantly improved. This is because the combination of surface-anchored anion acceptor trimethoxyboronoxane with anion additives containing specific elements (such as boron) allows for the artificial control of the type and concentration of interfacial anions, thereby enabling rational regulation of the CEI components formed during interfacial decomposition. The resulting boron-containing CEI layer is denser and exhibits enhanced chemical and thermal stability, effectively suppressing cathode oxidation and alleviating ion transport limitations, ultimately achieving excellent electrochemical performance.

[0112] Comparing Comparative Example 5 and Example 8, it can be seen that at a salt concentration of 0.1 M, the CDAA electrolyte strategy can still significantly improve the average coulombic efficiency and cycle performance of the battery.

[0113] Comparing Comparative Example 8 and Example 9, it can be seen that when the solvent is changed from tetraethylene glycol dibutyl ether to tetraethylene glycol dimethyl ether, the CDAA electrolyte strategy still shows a significant improvement in the average coulombic efficiency and cycle performance of the battery, indicating that this strategy can be widely applied under the condition of chain ether solvents.

[0114] Therefore, in subsequent testing experiments, Comparative Example 1 and Example 6 with the best performance were selected for testing under extreme conditions such as high and low temperatures and ultra-high pressure.

[0115] High temperature performance The application effects under conditions of 60 ℃, 1 C, and 2-4 V are shown in Table 2a below: Table 2a Battery cycle performance test results under 60 ℃, 1 C, 2-4 V conditions

[0116] The application effects under conditions of 80 ℃, 1 C, and 2-4 V are shown in Table 2b below: Table 2b shows the battery cycle performance test results under the conditions of 80 ℃, 1 C, and 2-4 V.

[0117] The test results in Tables 2a and 2b show that: Under high-temperature conditions, the average coulombic efficiency and cycle performance of the cells in the embodiment are significantly better than those in the comparative example, especially in terms of coulombic efficiency. This is because the CEI layer formed by the CDAA electrolyte strategy is more dense (e.g., ...). Figure 2 , 3As shown, compared with Comparative Example 1, the CEI layer formed in Example 6 is more dense. Even with increased reactivity at high temperatures, it still maintains enhanced chemical and thermal stability, effectively suppressing cathode oxidation and alleviating ion transport limitations. Especially at extreme high temperatures of 80°C (the melting point of sodium metal is about 97°C), the battery using the CDAA electrolyte strategy can still cycle stably for 100 cycles.

[0118] Low temperature performance The application effects under conditions of -20 ℃, 0.1 C, and 2-4 V are shown in Table 3 below: Table 3. Battery cycle performance test results under conditions of -20 ℃, 0.1 C, and 2-4 V.

[0119] The test results in Table 3 show that: Under low-temperature conditions, the battery in this embodiment exhibits a better discharge capacity than the comparative example, with a capacity retention rate of 86.03% relative to 30°C. This is because the anion acceptor trimethoxyboronyl hexacyclohexane attracts hexafluorophosphate anions on the positive electrode surface, increasing the degree of dissociation of sodium hexafluorophosphate, improving ionic conductivity, and enhancing kinetic performance at low temperatures, thus resulting in a higher capacity retention rate relative to room temperature.

[0120] Ultra-high pressure performance The application effects under conditions of 30 ℃, 1 C, and 2-4.2 V are shown in Table 4 below: Table 4. Battery cycle performance test results under the conditions of 30 ℃, 1 C, and 2-4.2 V.

[0121] The test results in Table 4 show that: Under high cutoff voltage conditions, the battery cycle performance of Example 6 is far superior to that of the comparative example, which can only cycle stably for 38 cycles. After using the CDAA strategy, Example 6 can cycle stably for more than 200 cycles.

[0122] Lithium metal battery performance Table 5. Cycle performance test results of lithium metal batteries under the conditions of 30 ℃, 1 C, and 2.6-4.3 V.

[0123] As shown in Table 5, the test results indicate that: In lithium metal batteries, the CDAA electrolyte strategy still shows significant performance improvement and can be further extended to alkaline light metal-based batteries.

[0124] The above embodiments are merely preferred embodiments of the present invention. The present invention cannot list all embodiments. Any technical solution that adopts one of the above embodiments, or any equivalent changes made based on the above embodiments, are within the protection scope of the present invention.

[0125] As described in the above embodiments of the present invention, other additives, electrolytes and batteries obtained by using the same or similar methods and components are all within the protection scope of the present invention.

[0126] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A wide-temperature-range ether electrolyte with a custom high-voltage-resistant interface layer in alkali metal batteries, characterized in that, The wide-temperature-range ether electrolyte includes a base electrolyte, an anion acceptor additive, and an anion additive containing a specific element alkali metal salt; the anion acceptor additive and the anion additive containing a specific element alkali metal salt are added to the base electrolyte; The substrate electrolyte comprises alkali metal salts and ether solvents; The alkali metal salt is soluble in ether solvents; In the wide-temperature-range ether electrolyte, the concentration of the alkali metal salt is 0.1-1.5 mol·L⁻¹. -1 ; In the wide-temperature-range ether electrolyte, the concentration of the anion acceptor additive is 0.5~5 wt%; The concentration of the specific elemental alkali metal salt anionic additive in the wide-temperature-range ether electrolyte is 0.1~5wt%.

2. The wide-temperature-range ether electrolyte with a customized high-voltage-resistant interface layer in an alkali metal battery according to claim 1, characterized in that, The alkali metal salt is selected from one or more of sodium salt, lithium salt, and potassium salt; The anion acceptor additive is 2,4,6-trimethoxyboroxane; The alkali metal salt anionic additive containing a specific element is selected from one or more of the following: sodium salt anionic additive containing a specific element, lithium salt anionic additive containing a specific element, and potassium salt anionic additive containing a specific element. The ether solvent is selected from one or more of tetraethylene glycol dibutyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, ethylene glycol methyl ethyl ether, ethylene glycol diethyl ether, diethylene glycol diethyl ether, diethylene glycol diethyl ether, triethylene glycol diethyl ether, tetraethylene glycol diethyl ether, ethylene glycol dipropyl ether, diethylene glycol dipropyl ether, triethylene glycol dipropyl ether, tetraethylene glycol dipropyl ether, ethylene glycol dibutyl ether, diethylene glycol dibutyl ether, triethylene glycol dibutyl ether, tetrahydrofuran, tetrahydropyran, 1,3-dioxolane, 1,4-dioxane, and 2-methyl-1,3-dioxolane.

3. The wide-temperature-range ether electrolyte with a customized high-voltage-resistant interface layer in an alkali metal battery according to claim 2, characterized in that, The sodium salt is one or more of sodium hexafluorophosphate, sodium bis(oxalato)borate, sodium difluorooxalatoborate, sodium tetrafluoroborate, sodium trifluoromethanesulfonate, sodium trifluoromethanesulfonylimide, and sodium bis(trifluoromethanesulfonyl)imide. The lithium salt is one or more of lithium hexafluorophosphate, lithium bis(oxalato)borate, lithium difluorooxalato)borate, lithium tetrafluoroborate, lithium trifluoromethanesulfonate, lithium trifluoromethanesulfonylimide, and lithium bis(trifluoromethanesulfonyl)imide. The potassium salt is one or more of potassium hexafluorophosphate, potassium bis(oxalato)borate, potassium difluorooxalatoborate, potassium tetrafluoroborate, potassium trifluoromethanesulfonate, potassium trifluoromethanesulfonylimide, and potassium bis(trifluoromethanesulfonyl)imide. The sodium salt anionic additive containing a specific element is selected from one or more of sodium bis(oxalato)borate, sodium difluorooxalatoborate, sodium tetrafluoroborate, sodium trifluoromethanesulfonate, sodium trifluoromethanesulfonylimide, sodium bis(trifluoromethanesulfonyl)imide, and sodium hexafluorophosphate. The specific element lithium salt anionic additive is selected from one or more of lithium bis(oxalato)borate, lithium difluorooxalatoborate, lithium tetrafluoroborate, lithium trifluoromethanesulfonate, lithium trifluoromethanesulfonylimide, lithium bis(trifluoromethanesulfonyl)imide, and lithium hexafluorophosphate. The specific element potassium salt anionic additive is selected from one or more of potassium bis(oxalato)borate, potassium difluorooxalatoborate, potassium tetrafluoroborate, potassium trifluoromethanesulfonate, potassium trifluoromethanesulfonylimide, potassium bis(trifluoromethanesulfonyl)imide, and potassium hexafluorophosphate. The ether solvent is tetraethylene glycol dibutyl ether and / or tetraethylene glycol dimethyl ether.

4. The wide-temperature-range ether electrolyte with a customized high-voltage-resistant interface layer in an alkali metal battery according to claim 3, characterized in that, The sodium salt is sodium hexafluorophosphate; The lithium salt is lithium hexafluorophosphate; The potassium salt is potassium hexafluorophosphate.

5. A method for preparing a wide-temperature-range ether electrolyte with a customized high-voltage-resistant interface layer in an alkali metal battery as described in any one of claims 1-4, characterized in that, The preparation method includes the following steps: Anion acceptor additives, alkali metal salt anion additives containing specific elements, and alkali metal salts are dissolved in an ether solvent in a certain proportion to obtain the wide temperature range ether electrolyte.

6. The application of a wide-temperature-range ether electrolyte with a customized high-voltage-resistant interface layer in alkali metal batteries as described in any one of claims 1-4, characterized in that, The wide-temperature-range ether electrolyte is used in alkali metal batteries.

7. An alkali metal battery, characterized in that, The electrolyte includes a wide-temperature-range ether electrolyte with a customized high-voltage-resistant interface layer in an alkali metal battery as described in any one of claims 1-4, and also includes a positive electrode and a negative electrode.

8. An alkali metal battery according to claim 7, characterized in that, The positive electrode includes an active material, which includes a high-nickel layered oxide positive electrode material NaNi. 1-x-y Fe x Mn y O2, where 0 <x<1,0<y<1。 9. An alkali metal battery according to claim 8, characterized in that, The loading of the active material in the positive electrode is 0.5–30 mg·cm³. -2 .

10. An alkali metal battery according to claim 7, characterized in that, The negative electrode includes one or more of sodium metal, lithium metal, and potassium metal.

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