A fluorine-containing electrolyte additive, an electrolyte and a lithium ion battery

Abstract

This invention belongs to the field of battery technology, specifically relating to a fluorinated electrolyte additive, an electrolyte, and a lithium-ion battery. The fluorine atoms in the additive possess strong electronegativity and extremely weak polarity, resulting in lower unoccupied molecular orbitals and lower highest occupied molecular orbital energies. The additive preferentially forms an SEI layer on the anode and cathode compared to the solvent. This interfacial layer prevents direct contact between the electrodes and the electrolyte, effectively passivating the electrodes. The low-polarity fluorocarbon chain has good affinity with the polypropylene separator, wetting the separator and promoting the formation of lithium-ion batteries. + Successful passage through the separator not only improves the kinetic performance of lithium ions inside the battery, but also promotes the... + Uniform deposition on the Li metal surface reduces the growth of lithium dendrites; the introduction of O, S, N atoms containing lone pairs of electrons can react with trace amounts of water and HF in the electrolyte system, thereby removing harmful substances from the electrolyte system.

Description

Technical Field

[0001] This invention belongs to the field of battery technology, specifically relating to a fluorinated electrolyte additive, an electrolyte, and a lithium-ion battery. Background Technology

[0002] In recent years, due to increasingly serious environmental problems, replacing traditional fossil fuels with clean energy is an effective way to reduce carbon emissions. Lithium-ion batteries, as a clean energy storage solution, have been widely used in various application fields and are expected to flourish in the coming years with the rise of energy storage systems and the electric vehicle industry. Lithium (Li) metal is valued for its extremely high theoretical capacity (3860 mA·h·g). -1 Lithium metal (LiMe) batteries are considered promising anode materials due to their low electrochemical potential and low density. However, two serious problems during cycling have hindered their further commercial application: First, the organic components in the solid electrolyte interphase (SEI) layer formed by the contact between the electrolyte and lithium metal are prone to cracking, leading to re-contact between the lithium electrode and the electrolyte. This uncontrolled growth of the SEI results in continuous loss of lithium source and rapid capacity decay of the lithium metal battery. Second, during continuous plating / stripping, irregular lithium dendrites can grow uncontrollably, potentially puncturing the separator and causing thermal runaway and explosion hazards.

[0003] To suppress lithium dendrite growth and improve the efficiency and safety of lithium metal batteries, researchers have made significant efforts in optimizing electrolyte composition, anode structure design, separator modification, and current collector design. In particular, introducing functional electrolyte additives to form a stable electrode-electrolyte interface layer is considered an economical and practical strategy for addressing the problem of suppressing lithium dendrite growth. The SEI layer functions as a protective film during cycling, not only promoting Li-... +The migration of electrolytes can also prevent side reactions between the electrolyte and the Li anode. Vinylene carbonate is a classic film-forming additive; its main reduction product, polycarbonate, has a high reduction potential (~1.4V) and excellent flexibility, contributing to stable SEI film formation. However, vinylene carbonate film-forming additives have poor high-temperature performance and are generally used in combination with other additives in commercial applications. Fluoroethylene carbonate (FEC) is one of the most widely used SEI film-forming additives. Zhang et al. found that adding FEC additives can form a dense SEI film on the negative electrode; the uniform and dendrite-free morphology improved the coulombic efficiency of the Li||Cu half-cell by 98% after 100 cycles. However, under the catalysis of Lewis acids such as PF5, a by-reaction product of the electrolyte salt LiPF6, especially at high temperatures, FEC produces more acidic substances, leading to more side reactions and a decrease in the cycle performance of lithium-ion batteries. Simultaneously, LiPF6 can react with trace amounts of H2O in the electrolyte to generate HF. Worse still, HF, as a corrosive substance, causes transition metals to leach from the cathode, leading to solvent decomposition. Furthermore, the formation of poorly conductive LiF leads to the consumption of lithium ions, affecting battery kinetics.

[0004] Therefore, it is essential to develop a novel multifunctional electrolyte additive. First, this additive should possess both anodic and cathodic film-forming properties, protecting the positive and negative electrodes from solvent corrosion. Second, the additive should improve membrane wettability, thereby inhibiting lithium dendrite growth. Finally, the additive should have the ability to remove trace amounts of water from the electrolyte, protecting the formed SEI film. Summary of the Invention

[0005] The purpose of this invention is to provide a fluorinated electrolyte additive, an electrolyte solution, and a lithium-ion battery to solve the problem of lithium dendrite formation in current lithium metal batteries.

[0006] This invention is achieved through the following technical solution:

[0007] A fluorinated electrolyte additive, with the following structural formula:

[0008]

[0009] Where X is O, N, or S.

[0010] The present invention also discloses an electrolyte comprising an electrolyte salt, a solvent and the fluorinated electrolyte additive, wherein the mass of the fluorinated electrolyte additive is 0.1%-10% of the total mass of the electrolyte.

[0011] Furthermore, the mass of the fluorinated electrolyte additive is 0.5%-7% of the total mass of the electrolyte.

[0012] Furthermore, the mass of the fluorinated electrolyte additive is 1%-3% of the total mass of the electrolyte.

[0013] Furthermore, the solvent is a mixture of two of the following: ethylene carbonate, dimethyl carbonate, diethyl carbonate, ethylene carbonate, methyl ethyl carbonate, and propylene carbonate.

[0014] Furthermore, the electrolyte salt is one or more of LiPF6, LiBF4, LiSbF6, LiClO4, LiPtCl6, LiN(SO2F)2, LiN(SO2CF3)2, LiN(SO2C2F5)2, LiC(SO2CF3)3, LiB(C2O4)2, LiBF2(C2O4) and LiSO3CF3.

[0015] The present invention also discloses a lithium-ion battery, including a positive electrode, a negative electrode and a separator, wherein the lithium-ion battery further includes the electrolyte, and the electrolyte can improve the wettability of the separator and promote the formation of the solid electrolyte phase (SEI) and the cathode electrolyte phase (CEI).

[0016] Furthermore, the lithium-ion battery achieves a cycle stability of up to 350 hours.

[0017] Furthermore, the active material of the positive electrode is selected from one or more of lithium iron phosphate, lithium manganese oxide, lithium cobalt oxide, nickel-cobalt-manganese ternary materials, and nickel-cobalt-aluminum ternary materials.

[0018] Furthermore, the active material of the negative electrode of the lithium-ion battery is selected from one or more of graphite, lithium, lithium titanate, and silicon-carbon composite materials.

[0019] Compared with the prior art, the present invention has the following beneficial technical effects:

[0020] This invention discloses a fluorinated electrolyte additive, an electrolyte containing the additive, and a lithium-ion battery. Fluorine atoms possess strong electronegativity and extremely weak polarity, resulting in a low unoccupied molecular orbital (LUMO) energy for the fluorinated additive. This allows the additive to be preferentially oxidized at the anode, forming an SEI layer, compared to the solvent. The interface layer prevents direct contact between the electrode and the electrolyte, effectively passivating the electrode, suppressing strong redox reactions at the electrode interface, and reducing irreversible damage to the electrode.

[0021] In addition, the low-polarity CF3 chain has good affinity with the polypropylene separator, which improves the wettability between the electrolyte and the separator, promotes the smooth passage of lithium ions through the separator, not only improves the kinetic performance of lithium ions inside the battery, but also promotes the uniform deposition of lithium ions on the lithium metal surface and reduces the growth of lithium dendrites.

[0022] Finally, the introduction of O, S, and N atoms containing lone pairs of electrons allows them to react with trace amounts of water and HF in the electrolyte system, thereby removing harmful substances. Simultaneously, removing HF protects the formed SEI layer, preventing electrolyte corrosion of the electrode material. Therefore, using these additives as electrolyte additives can significantly improve dendrite growth, cycle stability, and rate performance in lithium-ion batteries. Attached Figure Description

[0023] Figure 1 A schematic diagram of a button cell battery is shown;

[0024] Figure 2 The cycling stability of the Li||Li symmetric battery with the electrolyte of Example 1 of the present invention and the basic electrolyte is plotted with cycle time as the x-axis and voltage as the y-axis.

[0025] Figure 3 SEM images of the Li metal anode surface after cycling tests of Li||Li symmetric cells in the basic electrolyte and TFFE-containing electrolyte, with scale bars of 2 μm and 1 μm, respectively. Figure 3 (a) Represents the SEM image of the Li metal anode surface after cycling tests of a Li||Li symmetric cell in the base electrolyte. Figure 3 (b) Represents the SEM image of the Li metal anode surface after cycling test of a Li||Li symmetric cell in TFFE electrolyte;

[0026] Figure 4 Cyclic performance of Li||NCM622 full cells at 0.5C charge-discharge with 1.0wt% TFFE electrolyte in base and 0.5C charge-discharge conditions; specific discharge capacity and coulombic efficiency in mAh / g versus cycle number;

[0027] Figure 5 The coulombic efficiency of the Li||NCM622 full cell under 0.5C charge-discharge conditions in the base electrolyte and the electrolyte containing 1.0wt% TFFE.

[0028] Figure 6 The coulombic efficiency of the Li||NCM622 full cell under 0.5C charge-discharge conditions in electrolytes containing 1.0 wt% 2-trifluoroacetylfuran and 1.0 wt% 2-trifluoroacetylthiophene.

[0029] Figure 7 This is a comparison chart of the ability of different additives to stabilize LiPF6-based electrolytes in Example 5;

[0030] Figure 8 for Figure 7 Enlarged view of Figure (a);

[0031] Figure 9 for Figure 7 Enlarged view of Figure (b);

[0032] Figure 10 for Figure 7 Enlarged view of Figure (c). Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of the present invention clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention; that is, the described embodiments are only a part of the embodiments of the present invention, and not all of them.

[0034] The components described and illustrated in the accompanying drawings and embodiments of this invention can be arranged and designed in various different configurations. Therefore, the detailed description of the embodiments of the invention provided in the following drawings is not intended to limit the scope of the claimed invention, but merely to illustrate one selected embodiment of the invention. All other embodiments obtained by those skilled in the art based on the accompanying drawings and embodiments of this invention without inventive effort are within the scope of protection of this invention.

[0035] It should be noted that the terms “comprising,” “including,” or any other variations are intended to cover non-exclusive inclusion, such that a process, element, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to the process, element, method, article, or apparatus.

[0036] This invention discloses a fluorinated electrolyte additive, the structural formula of which is:

[0037]

[0038] Where X is O, N, or S.

[0039] An electrolyte is also disclosed, comprising an electrolyte salt, a solvent, and the aforementioned fluorinated electrolyte additive, wherein the mass of the fluorinated electrolyte additive is 0.1%-10% of the total mass of the electrolyte.

[0040] The solvent is a mixture of two of the following: ethylene carbonate, dimethyl carbonate, diethyl carbonate, ethylene carbonate, methyl ethyl carbonate, and propylene carbonate.

[0041] The electrolyte salt is one or more of LiPF6, LiBF4, LiSbF6, LiClO4, LiPtCl6, LiN(SO2F)2, LiN(SO2CF3)2, LiN(SO2C2F5)2, LiC(SO2CF3)3, LiB(C2O4)2, LiBF2(C2O4) and LiSO3CF3.

[0042] This invention discloses a lithium-ion battery, including a positive electrode, a negative electrode, a separator, and an electrolyte, wherein the electrolyte can improve the wettability of the separator and promote the formation of the solid electrolyte phase (SEI) and the cathode electrolyte phase (CEI).

[0043] The active material of the positive electrode is selected from one or more of lithium iron phosphate, lithium manganese oxide, lithium cobalt oxide, nickel-cobalt-manganese ternary materials, and nickel-cobalt-aluminum ternary materials.

[0044] The active material of the negative electrode of the lithium-ion battery is selected from one or more of graphite, lithium, lithium titanate, and silicon-carbon composite materials.

[0045] The preparation of NCM622 cathode material will be used as an example for explanation:

[0046] ① A 14mm diameter Al sheet was polished evenly with fine sandpaper, then ultrasonically cleaned for 15 minutes each with 0.1M NaOH and 0.1% H2C2O4 solutions, and finally soaked in deionized water. After drying in an oven, the Al current collector was obtained and weighed for later use. ② Vinylidene fluoride (PVdF) binder and N-methylpyrrolidone (NMP) dispersant were accurately weighed at a mass ratio of 1:10 and added to a stirring flask for mixing. The mixture was magnetically stirred at room temperature for 24 hours to completely dissolve the PVdF in the NMP, forming a homogeneous binder solution. ③ The positive electrode active material NCM622, conductive agent acetylene black, and binder solution were accurately weighed and ground evenly at a mass ratio of 8:1:1 to obtain a slurry of positive electrode material. ④ The above positive electrode material slurry was evenly coated onto the Al current collector using a glass rod. The loading of the active material was approximately 3.0-3.5 mg / cm³. 2 ⑤ Dry the coated electrode in a vacuum drying oven at 110°C for 3 hours, then compress it into tablets for later use.

[0047] Fabrication of button cells:

[0048] The coin cell used in this invention for electrochemical performance testing is model CR2025, and its internal structure is as follows: Figure 1As shown, in the symmetrical battery, lithium foil serves as both the positive and negative electrodes. In the full cell, NCM622 is used as the positive electrode material, lithium foil as the negative electrode material, and the separator is Celgard 2300 (composed of polypropylene). The positive electrode, separator, and negative electrode are sequentially placed into the battery casing, and 40 μL of electrolyte is injected. The casing is then sealed using a sealing mold at a pressure of 0.4 MPa.

[0049] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0050] Example 1

[0051] A method for preparing an electrolyte includes the following steps:

[0052] (1) In an argon atmosphere glove box with a moisture content and oxygen content ≤1ppm, 1mol / L of lithium hexafluorophosphate was dissolved in a mixed solvent of ethylene carbonate (EC) and diethyl carbonate (DEC) at a volume ratio of EC:DEC = 1:1 and this was named the basic electrolyte.

[0053] (2) Add 1 wt% of the following additive to the base electrolyte to obtain an electrolyte containing additive.

[0054]

[0055] Where X is O.

[0056] Verification Example 1

[0057] Determination of Cyclic Stability in Li||Li Symmetric Cells

[0058] The cycling stability of Li||Li symmetric cells was determined by cyclic voltammetry electrochemical performance testing. In this method, the electrode voltage was continuously varied, and cycling was performed within a voltage window of -5.0V to 5.0V, with a cutoff capacity of 1 mA / cm². -2 The scanning speed is 0.1 mV / s.

[0059] The effect of introducing additives on battery cycle stability was investigated by comparing a basic electrolyte with that containing 2-trifluoroacetylfuran (TFFE) prepared in Example 1. Figure 2 As shown, the Li||Li symmetric cell with the basic electrolyte exhibited voltage polarization after 75 hours, with significant voltage polarization at 150 hours; while the electrolyte containing TFFE only showed slight voltage polarization after 325 hours, and significant voltage polarization appeared after 350 hours. This is because the electrolyte additive TFFE designed according to this invention can form a passivation protective layer (SEI layer) on the surface of the lithium anode, preventing side reactions between the lithium electrode and the electrolyte, thereby improving the cycle stability of the battery.

[0060] Scanning electron microscopy (SEM) is a fundamental method for characterizing the morphology of electrode materials. This invention characterizes the morphology of a lithium anode from a Li||Li symmetric battery after cycling in a basic electrolyte and an electrolyte containing TFFE for 150 hours. For example... Figure 3 As shown in Figure a, the lithium anode surface exhibits a porous and loose structure after 150 hours of basic electrolyte cycling, possibly due to electrolyte corrosion of the lithium electrode without an SEI layer; conversely, as shown in Figure a... Figure 3 As shown in b, the lithium anode surface structure remains smooth and intact after 150 hours of cycling in an electrolyte containing TFFE. These results demonstrate that the TFFE proposed in this invention has the ability to form an SEI layer, thereby improving the cycle stability of the battery.

[0061] Verification Example 2

[0062] Determination of specific capacity in Li||NCM622 full cells

[0063] Specific capacity was determined in a full cell with a coin cell structure using NCM622 and a lithium anode. Cycling was performed within a voltage window of 4.2V–2.8V, followed by two formation cycles at 0.1C, three conditioning cycles at 0.33C, and then a 1.0C charge / discharge cycle. Measurements at constant current were performed on a Shanghai Chenhua CHI760E at 25℃ ± 0.1℃. Figure 4 The relationship between specific discharge capacity and cycle number of Li||NCM622 full cells is shown, as well as the relationship between CE and cycle number when using the appropriate electrolyte. Figure 5 In the basic electrolyte, the battery exhibited significant capacity decay after 200 cycles, with a capacity retention of only 65.7%. However, the battery containing 1 wt% 2-trifluoroacetylfuran electrolyte showed only a slight capacity reduction after 200 cycles, with a capacity retention of 89.3%. These results indicate that the electrolyte additive provided by this invention can also form a passivation protective layer (CEI) on the positive electrode surface, thereby improving the specific capacity and cycle stability of the battery.

[0064] The term "specific capacity" refers to the amount of electrons or lithium ions that a material can retain / release per unit mass (e.g., total amount or maximum amount) and can be expressed in units of mAh / g. In some aspects and embodiments, specific capacity can be measured in a constant current discharge / charge analysis, which includes discharging / charging relative to a defined counter electrode at a defined rate within a defined voltage range.

[0065] The term "Coulomb efficiency" is abbreviated as CE and refers to the efficiency of transferring charge in a given cycle.

[0066] Example 2

[0067] Unlike Example 1, 0.1 wt%, 0.5 wt%, 1 wt%, 3 wt%, 5 wt%, 7 wt%, and 10 wt% of 2-trifluoroacetylfuran additive were added to the base electrolyte to obtain electrolytes containing the additive. The electrochemical performance was verified by preparing Li||Li symmetric cells as described above, as shown in Table 1.

[0068] Table 1. Discussion of Additive Dosage

[0069]

[0070] As shown in Table 1, the cycle stability of the Li||Li symmetric battery increases with the amount of additive, reaching a maximum of 350 h at an additive dosage of 1 wt%. Afterward, the cycle stability decreases with further increases in additive dosage. This is because insufficient additive results in an insufficiently dense SEI layer, leading to corrosion of the positive and negative electrodes by the solvent in the electrolyte and a decrease in electrochemical performance; while excessive additive results in an overly thick SEI layer, increasing impedance and further reducing the battery's electrochemical performance.

[0071] Example 3

[0072] Unlike Example 1, X is S, and 1 wt% of 2-trifluoroacetylthiophene additive was added to the base electrolyte to obtain an electrolyte containing the additive. A coin cell was prepared using the cathode and anode as described above. The Li||NCM622 full cells of Comparative Examples 1 and 3 were cycled according to the scheme described in detail above. Figure 6 This includes graphs showing the discharge specific capacity versus cycle time of coin cells maintained at room temperature. (Source: [Insert Source Here]) Figure 6 It can be observed that 2-trifluoromethylfuran and 2-trifluoromethylthiophene show little difference in cycling performance within 200 hours, and both can achieve a specific capacity of over 128 mAh / g.

[0073] Example 4

[0074] Unlike Example 1, X is N, and 1 wt% of 2-trifluoroacetylpyrrole additive was added to the base electrolyte to obtain an additive-containing electrolyte. A coin cell was prepared using the cathode and anode as described above. Comparing the Li||NCM622 full cells of Examples 1 and 4, cycling according to the scheme described in detail above, similar electrochemical performance as in Example 1 was obtained.

[0075] Example 5: Ability of the additive to stabilize LiPF6-based electrolyte

[0076] like Figure 6As shown, 60 mL of basic electrolyte was divided into three equal portions, named ①, ②, and ③. 30 μL of H₂O was added to ①; 30 μL of TFFE was added to ②; and 30 μL of both H₂O and TFFE were added to ③. All three samples were placed in a glove box for 24 hours. 19 The three samples were analyzed using 400 MHz FT-NMR (Bruker, AVANCE IIIHD) to examine the removal efficiency of byproducts. Figure 7 (a) and Figure 8 As shown, the basic electrolyte 19 The F NMR spectrum shows a distinct doublet at 69-72 ppm, corresponding to LiPF6. Peaks near -75, -83, and -154.4 ppm correspond to PO3F2. - PO2F2 - And HF. For example Figure 7 (b) and Figure 9 As shown in the illustration, after the introduction of TFFE additive, PO3F2 - and HF 19 No characteristic peaks were observed in the HF NMR. The ability of TFFE to remove byproducts such as HF from the electrolyte is the fundamental reason for this phenomenon. Meanwhile, in Figure 7 (c) and Figure 10 In the middle, PO2F2 - The peak intensity of PO3F2 decreased significantly, and PO3F2 - The characteristic peaks are not obvious. This phenomenon occurs because the central oxygen atom in TFFE possesses a pair of lone electrons, which can form a complex with an electron donor and with the confirmed electron-withdrawing H₂O. In summary, TFFE can stabilize LiPF₆-based electrolytes by removing trace amounts of H₂O and HF.

[0077] Example 6

[0078] Unlike Example 1, the choice of electrolyte salt in the basic electrolyte is different. In an argon atmosphere glove box with a moisture content and oxygen content ≤1ppm, 1mol / L lithium tetrafluoroborate (LiBF4) was dissolved in a mixed solvent of EC and DEC at a volume ratio of EC:DEC = 1:1, and this was named basic electrolyte 2;

[0079] Adding 1 wt% TFFE additive to the base electrolyte 2 yielded an additive-containing electrolyte. A Li||Li symmetric battery was prepared to investigate the effect of the additive on the battery's electrochemical performance. Cyclic stability tests revealed little difference in the cyclic stability between the base electrolyte 2 and the TFFE-containing electrolyte.

[0080] Example 7

[0081] In an argon atmosphere glove box with a moisture content and oxygen content ≤1ppm, 1mol / L LiPtCl6 was dissolved in a mixed solvent of EC and DEC at a volume ratio of EC:DEC = 1:1, and this was named basic electrolyte 3.

[0082] Adding 1 wt% TFFE additive to the basic electrolyte 3 yielded an electrolyte containing the additive. The effect of the additive on the electrochemical performance of a Li||Li symmetric battery was investigated.

[0083] Cyclic stability tests revealed little difference in cyclic stability between the base electrolyte 3 and the electrolyte containing TFFE.

[0084] Example 8

[0085] In an argon atmosphere glove box with a moisture content and oxygen content ≤1ppm, 1mol / L lithium hexafluorophosphate was dissolved in a mixed solvent of ethylene carbonate and ethylene carbonate at a mass ratio of 3:7. This mixture was named Basic Electrolyte 4.

[0086] Adding 1 wt% TFFE additive to the basic electrolyte 4 yielded an electrolyte containing the additive. The effect of the additive on the electrochemical performance of a Li||Li symmetric battery was investigated.

[0087] Cyclic stability tests revealed little difference in cyclic stability between the base electrolyte 4 and the electrolyte containing TFFE.

[0088] The above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the protection scope of the claims of the present invention.

Claims

1. A fluorine-containing electrolyte additive characterized by comprising Its structural formula is: ； Where X is O.

2. An electrolyte, characterized by It includes an electrolyte salt, a solvent, and the fluorinated electrolyte additive as described in claim 1, wherein the mass of the fluorinated electrolyte additive is 7%-10% of the total mass of the electrolyte.

3. The electrolyte according to claim 2, characterized in that, The solvent is a mixture of two of the following: ethylene carbonate, dimethyl carbonate, diethyl carbonate, ethylene carbonate, methyl ethyl carbonate, and propylene carbonate.

4. The electrolyte of claim 2, wherein, The electrolyte salt is one or more of LiPF6, LiBF4, LiSbF6, LiClO4, LiPtCl6, LiN(SO2F)2, LiN(SO2CF3)2, LiN(SO2C2F5)2, LiC(SO2CF3)3, LiB(C2O4)2, LiBF2(C2O4) and LiSO3CF3.

5. A lithium-ion battery comprising a positive electrode, a negative electrode, and a separator, characterized in that, The lithium-ion battery further includes the electrolyte according to any one of claims 2-4, wherein the electrolyte can improve the wettability of the separator and promote the formation of the solid electrolyte phase (SEI) and the cathode electrolyte phase (CEI).

6. The lithium-ion battery of claim 5, wherein, The active material of the positive electrode is selected from one or more of lithium iron phosphate, lithium manganese oxide, lithium cobalt oxide, nickel-cobalt-manganese ternary materials, and nickel-cobalt-aluminum ternary materials.

7. The lithium-ion battery of claim 5, wherein, The active material of the negative electrode of the lithium-ion battery is selected from one or more of graphite, lithium, lithium titanate, and silicon-carbon composite materials.

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