Aluminum alkoxide-five-membered cyclic carbonate electrolyte and preparation method and application thereof

Abstract

The invention belongs to the technical field of lithium ion batteries, and particularly relates to an aluminum alkoxide-five-membered cyclic carbonate electrolyte as well as a preparation method and application thereof. The electrolyte comprises an electrolyte solute, a non-aqueous solvent and an electrolyte additive composition, wherein the electrolyte additive composition comprises an aluminum alkoxide compound and a multi-fluorine derivative of five-membered cyclic carbonate. According to the electrolyte disclosed by the invention, a compact and stable SEI layer can be formed on the battery, the cycling stability of the battery at high temperature and high current rate is effectively improved, and the safety and fast charging performance of the battery are greatly improved.

Description

Technical Field

[0001] This invention belongs to the field of lithium-ion battery technology, specifically relating to an aluminum alkoxide-pentacyclic carbonate electrolyte, its preparation method, and its application. Background Technology

[0002] Lithium-ion rechargeable batteries have become a cornerstone technology in consumer electronics, power batteries, and large-scale energy storage due to their high energy density, long cycle life, and environmental compatibility. To meet the growing demands for high safety and long lifespan, it is crucial to develop electrolyte systems that can simultaneously optimize interface stability and kinetic performance.

[0003] Current commercial electrolytes (mainly LiPF6 carbonate solutions) face severe challenges during cycling: insufficient reduction stability leads to uneven film formation at the anode interface, causing distortion in lithium-ion flux distribution. This interfacial inhomogeneity accelerates localized lithium deposition, promotes dendrite growth, and increases the risk of short circuits. Simultaneously, conventionally formed solid electrolyte interfaces (SEIs) lack sufficient mechanical strength and thermal stability, making it difficult to suppress anode volume expansion or interfacial side reactions at high temperatures, ultimately resulting in capacity decay and safety failure.

[0004] Electrolyte additives, as a core means of regulating interfacial chemistry, can enhance stability by selectively decomposing and constructing functional interfacial layers. However, the solid electrolyte interphase (SEI) films formed by conventional additives often suffer from uneven component distribution and insufficient mechanical strength, leading to localized concentrations of lithium-ion flux. This inhomogeneity causes distortion of lithium deposition morphology and accelerates dendrite penetration into the separator. Simultaneously, during the charging and discharging process at the negative electrode, drastic volume changes exacerbate interfacial stress imbalance, causing repeated SEI rupture and recombination, resulting in continuous consumption of active lithium and electrolyte penetration erosion. The interfacial impedance also continuously increases, ultimately leading to deterioration of cycle performance and safety hazards. To ensure uniform lithium-ion flow and uniform distribution of internal electrode stress under high temperature or high rate conditions, enabling long-term stable operation of lithium-ion secondary batteries, new additives with interactions are needed to improve the mechanical stability and chemical homogeneity of the electrode / electrolyte interface.

[0005] Among them, five-membered cyclic carbonates and their fluorinated derivatives (such as vinylene carbonate VC and fluoroethylene carbonate FEC) are a class of highly efficient film-forming additives. Through their unique molecular configurations, they achieve breakthroughs in interfacial performance: excellent film-forming performance: their cyclic carbonyl groups are preferentially reduced on the negative electrode surface, constructing a dense SEI layer rich in Li2CO3 / LiF, significantly inhibiting continuous electrolyte decomposition and improving the initial coulombic efficiency; excellent thermal stability: the high bond energy (>485kJ / mol) of the CF bond in the fluorinated derivatives endows the SEI with excellent thermomechanical strength, effectively buffering repeated volume changes of the negative electrode and delaying interfacial decomposition under high-temperature cycling; high-rate performance assurance: the formed interfacial layer possesses uniformly high lithium-ion conductivity (>10). -4 (S / cm) ensures rapid and uniform lithium-ion transport and supports high-rate charging and discharging.

[0006] Existing research has confirmed its interface optimization effect on graphite anodes. For example, Chinese invention patent CN120149508A discloses a secondary battery and an electrical device. In this secondary battery, the anode sheet includes a negative electrode current collector and a negative electrode film. The negative electrode film is disposed on at least one side of the negative electrode current collector. The negative electrode film includes a negative electrode active material, which includes a first graphite with a Dv50 particle size of 2.2μm-7.7μm. The electrolyte includes an organic solvent and an organic additive. The organic solvent includes a first solvent, which includes a cyclic carbonate. Based on the total mass of the organic solvent, the mass content of the first solvent is 25%-40%. The organic additive includes a first additive and a second additive. The first additive includes vinylene carbonate, and the second additive includes a ethylene carbonate derivative. Based on the total mass of the electrolyte, the mass percentage of the first additive in the electrolyte is 2%-10%, and the mass percentage of the second additive in the electrolyte is 0.3%-6%.

[0007] However, conventional five-membered cyclic carbonates and their fluorinated derivatives (such as VC and FEC) are still not well-suited for high-capacity electrodes, and their interfaces are not stable enough under ultra-fast charging protocols and high-temperature conditions. It is necessary to further use polyfluorinated derivatives of five-membered cyclic carbonates as additives to improve the high-temperature performance of batteries, and to improve the uniformity of the electrode / electrolyte interface and ion transport capability through additives with interactions, so as to achieve safe and stable fast charging and discharging.

[0008] Therefore, it is urgent to deepen the research on the interface regulation mechanism of polyfluorinated derivatives of five-membered cyclic carbonates under complex working conditions, so as to give full play to their core value in improving film uniformity, thermal stability and rate performance, and provide technical support for high-safety and long-life battery systems. Summary of the Invention

[0009] To address the shortcomings of existing technologies, this invention provides an aluminum alkoxide-pentacyclic carbonate electrolyte, its preparation method, and its application.

[0010] This invention is achieved through the following technical solution: This invention provides an aluminum alkoxide-pentacyclic carbonate electrolyte, comprising an electrolyte solute, a non-aqueous solvent, and an electrolyte additive composition; the electrolyte additive composition comprises an aluminum alkoxide compound and a polyfluorinated derivative of the pentacyclic carbonate, the structure of which is shown in Formula 1. ; R1 and R2 are each independently selected from hydrogen atoms, fluorine atoms, or fluorine-containing C1-C6 alkyl groups, C1-C6 saturated alkyl groups, or unsaturated hydrocarbon groups.

[0011] Preferably, the polyfluorinated derivative of the five-membered cyclic carbonate is selected from one or more of difluoroethylene carbonate and trifluoromethylethylene carbonate.

[0012] Preferably, the aluminum alkoxide compound has the following structural formula: ; R3, R4, and R5 are each independently selected from alkyl groups with 1 to 8 carbon atoms.

[0013] More preferably, the aluminum alkoxide compound is selected from one or more of aluminum triethanolamine, aluminum isopropoxide, aluminum n-propoxide, aluminum sec-butoxide, aluminum tert-butoxide, and aluminum isoamyl alcohol.

[0014] The interaction mechanism between aluminum alkoxides and polyfluorinated derivatives of five-membered cyclic carbonates involves a nucleophilic substitution reaction where the nucleophile attacks the electrophilic center. Specifically, the carbonyl oxygen of the polyfluorinated derivative of the five-membered cyclic carbonate, containing an electron-rich group, acts as a nucleophile, attacking the aluminum atom of the aluminum alkoxide. Since the aluminum atom lacks electrons, it can accept electron pairs from other reagents containing lone pairs of electrons, leading to the substitution of the alkoxy group of the aluminum alkoxide by the carbonyl oxygen of the polyfluorinated derivative of the five-membered cyclic carbonate, forming a new covalent bond. Alternatively, the oxygen of the alkoxy group in the aluminum alkoxide initiates a nucleophilic attack on the carbonyl carbon of the polyfluorinated derivative of the five-membered cyclic carbonate, causing a ring-opening polymerization reaction. Through this nucleophilic substitution reaction, the two compounds are tightly linked by covalent bonds.

[0015] Furthermore, aluminum alkoxides can act as crosslinking agents, promoting the formation of three-dimensional polymer networks. This allows inorganic products generated during cycling (such as LiF and Li₂O) to be uniformly distributed at the solid electrolyte interphase (SEI) and cathode electrolyte interphase (CEI), thereby reducing the activation energy for lithium-ion transport, ensuring the consistency of lithium-ion transport, and lowering the internal impedance of the battery. Simultaneously, it promotes uniform lithium deposition at high temperatures and high current densities and suppresses stress cracking and structural degradation of the cathode material.

[0016] Preferably, the mass ratio of the aluminum alkoxide compound to the polyfluorinated derivative of the five-membered cyclic carbonate is 0.1-2:1-20.

[0017] Preferably, the amount of the electrolyte additive composition is 0.1-20% of the total mass of the electrolyte, and more preferably 2-15%.

[0018] More preferably, the amount of the aluminum alkoxide compound used is 0.1-2% of the total mass of the electrolyte, more preferably 0.1-0.5%; even more preferably 0.5%. The amount of the polyfluorinated derivative of the five-membered cyclic carbonate is 1-10% of the total mass of the electrolyte; preferably 2-6%; more preferably 5%.

[0019] Preferably, the electrolyte solute is selected from one or more of lithium hexafluorophosphate (LiPF6), lithium bis(fluorosulfonyl)imide (LiFSI), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium dioxolaneborate (LiBOB), lithium difluorooxolaneborate (LiDFOB), lithium difluorodioxolane phosphate (LiDFOP), lithium trifluoromethanesulfonate (LiCF3SO3), lithium perchlorate (LiClO4), lithium difluorophosphate (LiPO2F2), lithium tetrafluoroborate (LiBF4), lithium hexafluoroarsenate (LiAsF6), and lithium tetrafluorooxolane phosphate (LiTFOP).

[0020] Preferably, the non-aqueous solvent is selected from one or more of carbonate solvents, carboxylic acid ester solvents, ether solvents, nitrile solvents, and sulfone solvents.

[0021] More preferably, the carbonate solvent includes, but is not limited to, at least one of ethylene carbonate (EC), propylene carbonate (PC), γ-butyrolactone (GBL), butylene carbonate (BC), dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), methyl propyl carbonate (MPC), diethyl carbonate (DEC), ethyl propyl carbonate (EPC), and dipropyl carbonate (DPC).

[0022] More preferably, the carboxylic acid ester solvent includes, but is not limited to, at least one of methyl formate (MF), methyl acetate (MA), ethyl acetate (EA), propyl acetate, butyl acetate, methyl propionate, ethyl propionate (EP), propyl propionate (PP), butyl propionate, methyl butyrate, methyl isobutyrate, ethyl butyrate, methyl trimethylacetate, ethyl trimethylacetate, and 1,4-butyrolactone.

[0023] More preferably, the ether solvent includes, but is not limited to, at least one of 1,3-dioxane (DOL), 1,4-dioxane (DX), crown ether, tetrahydrofuran (THF), 2-methyltetrahydrofuran (2-CH3-THF), 2-trifluoromethyltetrahydrofuran (2-CF3-THF), diethyl ether, dimethoxymethane (DMM), 1,2-dimethoxyethane (DME), and diethylene glycol dimethyl ether (TEGDME).

[0024] More preferably, the nitrile solvent includes, but is not limited to, at least one of acetonitrile (AN), malononitrile, succinic anionyl (SN), glutaronitrile, and adiponitrile (ADN).

[0025] More preferably, the sulfone solvent includes, but is not limited to, at least one of dimethyl sulfone, methyl ethyl sulfone, diethyl sulfone, and sulfolane.

[0026] The present invention also relates to a method for preparing the above-mentioned aluminum alkoxide-five-membered cyclic carbonate electrolyte, comprising the following steps: dissolving the electrolyte solute, the aluminum alkoxide compound and the polyfluorinated derivative of the five-membered cyclic carbonate in a non-aqueous solvent to obtain the aluminum alkoxide-five-membered cyclic carbonate electrolyte.

[0027] This invention also relates to the application of the above-mentioned aluminum alkoxide-pentacyclic carbonate electrolyte or the aluminum alkoxide-pentacyclic carbonate electrolyte prepared by the above preparation method in the preparation of lithium-ion secondary batteries.

[0028] Preferably, the lithium-ion secondary battery is prepared from a positive electrode material, a negative electrode material, and the above-mentioned aluminum alkoxide-pentaneous cyclic carbonate electrolyte.

[0029] More preferably, the cathode material is selected from lithium nickel cobalt manganese oxide (LiNi). x Co y Mn 1-x-y O2), lithium iron phosphate (LiFePO4), lithium nickel cobalt aluminum oxide (LiNi x Co y Al 1-x-y O2), lithium cobalt oxide (LiCoO2), lithium nickel manganese oxide (LiNi 0.5 Mn 1.5 O4) and lithium-rich manganese (Li) 1+x [NiMnCo] 1-x One or more of the following (O2).

[0030] More preferably, the negative electrode material is selected from any one of graphite, lithium metal, copper, silicon-carbon, and silicon.

[0031] Compared with the prior art, the present invention has the following beneficial effects: (1) The lithium secondary battery made using the electrolyte containing the additives of the present invention can operate stably at high temperatures above 45°C and high rates above 3C, which greatly improves the environmental adaptability and charging efficiency of the battery, and improves the safety and stability of the battery.

[0032] (2) The polyfluorinated derivatives of the five-membered cyclic carbonate in the compound additive of the present invention can undergo ring-opening polymerization under the initiation of aluminum alkoxide compounds and further crosslink to form a three-dimensional network polymer structure, thereby enhancing the uniformity and stability of the SEI and CEI layers, reducing the battery impedance, improving the rate performance of the battery, and suppressing the volume expansion of the negative electrode during cycling. At the same time, the fluorine atoms in the fluorinated derivatives of the five-membered cyclic carbonate have high electronegativity and can attract the surrounding electron cloud to form stable chemical bonds, thereby enhancing the thermal stability of the electrolyte and the SEI and CEI layers and improving the high-temperature performance of the battery. Detailed Implementation

[0033] The present invention will be further described in detail below with reference to specific embodiments. The following embodiments are not intended to limit the present invention, but only to illustrate the present invention. Unless otherwise specified, the experimental methods used in the following embodiments are generally performed under conventional conditions. Unless otherwise specified, the materials and reagents used in the following embodiments are commercially available.

[0034] The aluminum alkoxide additive (aluminum triethanolamine) used in the comparative examples of this invention was prepared according to the method disclosed in "Transformation of bulk alloys to oxide nanowires" (Lei, D. et al. Science. 355: 267-271 (2017)). The specific preparation process is as follows: (1) First, lithium powder and aluminum powder were used as materials for synthesizing LiAl alloy. 0.085g of lithium powder and 0.3g of aluminum powder (atomic ratio Li:Al=1:1, 10% excess Li) were added to a graphite crucible lined with graphite paper. After heating at 800℃ for 30min, the graphite crucible was removed from the muffle furnace and the graphite plunger was immediately pressed down to obtain LiAl alloy.

[0035] (2) Take 0.115g of LiAl alloy and put it into 20mL of anhydrous ethanol. Place it at 60℃ for 30h and obtain uniform aluminum triethanolamine (its morphology is nanowires with a diameter of 20-200nm) through chemical desalting process.

[0036] Preparation of positive electrode sheet: positive electrode active material LiN i0.8 Co 0.1 Mn 0.1 O2 (NCM811), conductive agent Super P, and binder polyvinylidene fluoride (PVDF) are added to N-methyl-2-pyrrolidone (NMP) in a mass ratio of 94:3:3 and stirred evenly to form a positive electrode slurry. The positive electrode slurry is then evenly coated onto the positive electrode current collector aluminum foil, and after baking, rolling, and cutting, a positive electrode sheet is obtained.

[0037] The negative electrode sheet was purchased from Tianjin Zhongneng Lithium Industry Co., Ltd.

[0038] The negative electrode shell, positive electrode shell, stainless steel sheet, gasket, and spring were purchased from Dongguan Kelude Experimental Equipment Technology Co., Ltd., model number CR2032.

[0039] The diaphragm was purchased from Dongguan Kelude Experimental Equipment Technology Co., Ltd., model Celgard 2500.

[0040] Example 1 A method for preparing an aluminum alkoxide-five-membered cyclic carbonate electrolyte: Ethylene carbonate (EC) and diethyl carbonate (DEC) were mixed evenly at a volume ratio of 1:1 to serve as the electrolyte solvent; LiPF6 was added to a concentration of 1M and mixed evenly; 0.5% by mass of aluminum triethanolamine and 5% by mass of ethylene difluorocarbonate (DFEC) were added and mixed evenly.

[0041] Example 2 The only difference from Example 1 is that the electrolyte additive uses 0.5% aluminum triethanolamine and 5% ethylene trifluoromethyl carbonate (TFPC) by mass percentage of the electrolyte.

[0042] Example 3 The only difference from Example 1 is that the electrolyte additive uses 0.5% aluminum isopropoxide and 5% ethylene difluorocarbonate (DFEC) by mass percentage of the electrolyte.

[0043] Example 4 The only difference from Example 1 is that the electrolyte additive uses 0.1% aluminum triethanolamine and 1% ethylene difluorocarbonate (DFEC) by mass of the electrolyte.

[0044] Example 5 The only difference from Example 1 is that the electrolyte additive uses 2% aluminum triethanolamine and 10% ethylene difluorocarbonate (DFEC) by mass of the electrolyte.

[0045] Comparative Example 1 The only difference from Example 1 is that no electrolyte additive is added.

[0046] Comparative Example 2 The only difference from Example 1 is that the electrolyte additive uses 0.5% by mass of aluminum triethanolamine.

[0047] Comparative Example 3 The only difference from Example 1 is that the electrolyte additive uses 5% by weight of ethylene difluorocarbonate (DFEC) in the electrolyte.

[0048] Comparative Example 4 The only difference from Example 1 is that the electrolyte additive uses 5.5% aluminum triethanolamine by mass of the electrolyte.

[0049] Comparative Example 5 The only difference from Example 1 is that the electrolyte additive uses 5.5% by mass of ethylene difluorocarbonate (DFEC).

[0050] Comparative Example 6 The only difference from Example 1 is that the electrolyte additive uses 0.5% aluminum triethanolamine and 5% fluoroethylene carbonate (FEC) by mass percentage of the electrolyte.

[0051] Comparative Example 7 The only difference from Example 1 is that the electrolyte additive uses 0.5% aluminum triethanolamine and 5% vinylene carbonate (VC) by mass percentage of the electrolyte.

[0052] Comparative Example 8 The only difference from Example 1 is that the electrolyte additive uses 0.5% aluminum triethanolamine and 5% ethylene ethylene carbonate (VEC) by mass percentage of the electrolyte.

[0053] Comparative Example 9 The only difference from Example 1 is that the electrolyte additive uses 0.5% aluminum triethanolamine and 5% propylene carbonate (PC) by mass of the electrolyte.

[0054] Test case Assembly and testing of the full-cell Li||NCM811: The coin cell was assembled in the following order: negative electrode shell, negative electrode sheet, 30μL electrolyte, separator, 30μL electrolyte, positive electrode sheet, gasket, spring contact, and positive electrode shell. The cell was left to stand at 45℃ for 8 hours and activated for 3 cycles at a current density of 0.5C. It was then charged to 4.3V at 3C and discharged to 3.0V to obtain the first-cycle discharge specific capacity and initial coulombic efficiency at 3C. The cell was cycled 50 times under the same conditions to obtain the discharge specific capacity at the 50th cycle, and the capacity retention rate was calculated as: capacity retention rate = discharge specific capacity at the 50th cycle / discharge specific capacity at the first cycle.

[0055] At 45℃, the impedance of the activated battery and the battery after 50 cycles were tested using the potential-controlled AC impedance method. A small amplitude perturbation of 10mV was applied to the battery, and the impedance of the battery in the frequency range of 100k-1Hz was measured. The impedance values ​​are denoted as R0 and R1, respectively. 50 .

[0056] The test results of the full-cell cycle performance and impedance of different electrolytes in the above embodiments are shown in Table 1.

[0057]

[0058] As shown in Table 1, without electrolyte additives, the battery capacity rapidly decays at high temperatures and high current rates, and the battery impedance increases significantly. When only aluminum alkoxide compounds are added to the electrolyte, the initial coulombic efficiency of the battery is improved to some extent, but the cycle stability is not improved, and the battery still decays rapidly at high temperatures and high current rates. When only polyfluorinated derivatives of five-membered cyclic carbonates are added, the cycle stability of the battery is improved, but the impedance remains high. However, when both aluminum alkoxide compounds and polyfluorinated derivatives of five-membered cyclic carbonates are added to the electrolyte, the high-temperature performance and fast-charging performance of the battery are significantly improved. At 45℃ and 3C current rate, its capacity retention rate can reach 87.4%, which is 50.7 percentage points higher than the control group without additives; in addition, the battery impedance is also significantly lower than that without additives. Comparative Examples 6, 7, 8, and 9 used conventional five-membered cyclic carbonates and their fluorinated derivatives, such as fluoroethylene carbonate, vinylene carbonate, ethylene ethylene carbonate, and propylene carbonate, as common additives. Although their impedance was reduced, their capacity still decayed rapidly, and some capacity retention rates were even lower than those of Comparative Example 1, which did not use additives. This indicates that although conventional five-membered cyclic carbonates and their fluorinated derivatives can improve the film-forming performance of the battery, the electrode / electrolyte interface layer is not stable under high temperature and high current rate conditions. In contrast, aluminum alkoxide compounds and polyfluorinated derivatives of five-membered cyclic carbonates have a good synergistic effect, generating dense and stable SEI and CEI layers. This inhibits the decomposition of the electrolyte and the repeated breakage and recombination of the SEI / CEI layer under high temperature and high current, reduces the battery impedance, and effectively improves the battery's high-temperature adaptability, charging efficiency, and safety.

[0059] The above detailed description is a specific description of one of the feasible embodiments of the present invention. This embodiment is not intended to limit the patent scope of the present invention. All equivalent implementations or modifications that do not depart from the present invention should be included within the scope of the technical solution of the present invention.

Claims

1. An aluminum alkoxide-pentacyclic carbonate electrolyte, characterized in that, The electrolyte comprises an electrolyte solute, a non-aqueous solvent, and an electrolyte additive composition; the electrolyte additive composition comprises an aluminum alkoxide compound and a polyfluorinated derivative of a five-membered cyclic carbonate, the structure of which is shown in Formula 1. ； R1 and R2 are each independently selected from hydrogen atoms, fluorine atoms, or fluorine-containing C1-C6 alkyl groups, C1-C6 saturated alkyl groups, or unsaturated hydrocarbon groups.

2. The aluminum alkoxide-pentacyclic carbonate electrolyte according to claim 1, characterized in that, The polyfluorinated derivatives of the five-membered cyclic carbonate are selected from one or more of difluoroethylene carbonate and trifluoromethylethylene carbonate.

3. The aluminum alkoxide-pentacyclic carbonate electrolyte according to claim 1, characterized in that, The aluminum alkoxide compound has the following structural formula: ； R3, R4, and R5 are each independently selected from alkyl groups with 1 to 8 carbons; The aluminum alkoxide compound is selected from one or more of aluminum triethanolamine, aluminum isopropoxide, aluminum n-propoxide, aluminum sec-butoxide, aluminum tert-butoxide, and aluminum isopentoxide.

4. The aluminum alkoxide-pentacyclic carbonate electrolyte according to claim 3, characterized in that, The mass ratio of the aluminum alkoxide compound to the polyfluorinated derivative of the five-membered cyclic carbonate is 0.1-2:1-20.

5. The aluminum alkoxide-pentacyclic carbonate electrolyte according to claim 1, characterized in that, The amount of the electrolyte additive composition is 0.1-20% of the total mass of the electrolyte, preferably 2-15%.

6. The aluminum alkoxide-pentacyclic carbonate electrolyte according to claim 5, characterized in that, The amount of the aluminum alkoxide compound used is 0.1-2% of the total mass of the electrolyte, preferably 0.1-0.5%; more preferably 0.5%. The amount of the polyfluorinated derivative of the five-membered cyclic carbonate is 1-10% of the total mass of the electrolyte; preferably 2-6%; more preferably 5%.

7. The aluminum alkoxide-pentacyclic carbonate electrolyte according to claim 5 or 6, characterized in that, The electrolyte solute is selected from one or more of lithium hexafluorophosphate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium dioxalate borate, lithium difluorooxalate borate, lithium difluorodioxalate phosphate, lithium trifluoromethanesulfonate, lithium perchlorate, lithium difluorophosphate, lithium tetrafluoroborate, lithium hexafluoroarsenate, and lithium tetrafluorooxalate phosphate; the non-aqueous solvent is selected from one or more of carbonate solvents, carboxylic acid ester solvents, ether solvents, nitrile solvents, and sulfone solvents.

8. A method for preparing the aluminum alkoxide-pentacyclic carbonate electrolyte according to any one of claims 1-7, characterized in that, Includes the following steps: The aluminum alkoxide-five-membered cyclic carbonate electrolyte is obtained by dissolving the electrolyte solute, aluminum alkoxide compound, and polyfluorinated derivative of five-membered cyclic carbonate in a non-aqueous solvent.

9. The application of the aluminum alkoxide-pentacyclic carbonate electrolyte according to any one of claims 1-7 or the electrolyte prepared by the preparation method according to claim 8 in the preparation of lithium-ion secondary batteries.

10. The application according to claim 9, characterized in that, The lithium-ion secondary battery is prepared from a positive electrode material, a negative electrode material, and the aluminum alkoxide-pentaneous cyclic carbonate electrolyte according to any one of claims 1-7; The cathode material is selected from one or more of lithium nickel cobalt manganese oxide, lithium iron phosphate, lithium nickel cobalt aluminum oxide, lithium cobalt oxide, lithium nickel manganese oxide, and lithium-rich manganese. The negative electrode material is selected from any one of graphite, lithium metal, copper, silicon-carbon, and silicon.

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