Electrolyte and battery

Abstract

This invention discloses an electrolyte and a battery. The electrolyte includes an electrolyte salt, a solvent, a first additive, and a second additive. The first additive has the structural formula of (1), and the second additive has the structural formula of (2). The first additive is a vinylpyridine nitrile compound, and the second additive is an unsaturated phosphate ester compound. Vinylpyridine nitrile compounds readily form films at both the positive and negative electrodes, generating stable interfacial films. The interfacial film on the positive electrode side has basic pyridine functional groups, effectively suppressing the attack of HF on the positive electrode material interface. Simultaneously, the unsaturated nitrile structure on the positive electrode side can effectively suppress the dissolution of transition metal ions, significantly reducing the migration of cyano functional groups to the negative electrode. The unsaturated phosphate ester structure can suppress the impedance increase caused by pyridine nitrile compounds. The low-impedance interfacial films generated at the positive and negative electrodes have high stability, improving storage performance. The additives effectively improve the high-temperature cycle performance of the battery, enhancing high-temperature storage and thermal shock performance.

Description

Technical Field

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

[0002] In recent years, with the rapid development of new energy technologies and the continuous expansion of demand, the performance requirements for new energy batteries have become increasingly stringent. Lithium-ion batteries, due to their high energy density and long cycle life, are widely used in electronic devices, electric vehicles, various power tools, and energy storage devices. The performance requirements of lithium-ion batteries vary in different application scenarios. To meet market demands, it is necessary to develop lithium-ion batteries with high energy density, long cycle life, fast charging speed, and high safety performance. One strategy to improve battery energy density is to increase the system voltage. However, as the voltage increases, the high-voltage fast-charging system of lithium-ion batteries exhibits poor high-temperature performance, affecting the safe use of the battery. Summary of the Invention

[0003] The purpose of this invention is to provide an electrolyte and a battery to solve the problem of poor high-temperature performance of lithium-ion batteries.

[0004] In a first aspect, embodiments of the present invention provide an electrolyte, comprising:

[0005] Electrolyte salt, solvent, first additive and second additive, wherein the first additive has a structural formula including structural formula (1) and the second additive has a structural formula including structural formula (2).

[0006] The structural formula (1) is:

[0007]

[0008] Wherein, R1 is selected from a single bond and an alkyl group having 1 to 5 carbon atoms, and R2, R3, and R4 are independently selected from a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 1 to 5 carbon atoms, a nitrile group having 1 to 4 carbon atoms, a halogen-substituted alkyl group having 1 to 5 carbon atoms, a halogen-substituted alkenyl group having 1 to 5 carbon atoms, and a halogen-substituted nitrile group having 1 to 4 carbon atoms;

[0009] Structural formula (2) is selected from at least one of structural formula (2a) and structural formula (2b), and structural formula (2a) and structural formula (2b) are:

[0010]

[0011] Wherein, X1 is selected from alkenyl, and Y1, Y2, Y3, and Y4 are independently selected from one of the following: hydrogen atom, halogen atom, alkyl group with 1 to 5 carbon atoms, alkenyl group with 1 to 5 carbon atoms, nitrile group with 1 to 4 carbon atoms, halogen-substituted alkyl group with 1 to 5 carbon atoms, halogen-substituted alkenyl group with 1 to 5 carbon atoms, and halogen-substituted nitrile group with 1 to 4 carbon atoms.

[0012] Optionally, the first additive is selected from at least one of structural formulas (1-1) to (1-4), wherein structural formulas (1-1) to (1-4) are:

[0013]

[0014] Optionally, the second additive is selected from at least one of structural formulas (2-1) to (2-4), wherein structural formulas (2-1) to (2-4) are:

[0015]

[0016] Optionally, the mass content of the first additive accounts for 0.1% to 10% of the total mass of the electrolyte, preferably 0.5% to 3%.

[0017] Optionally, the mass content of the second additive accounts for 0.1% to 10% of the total mass of the electrolyte, preferably 0.5% to 3%.

[0018] Optionally, the electrolyte further includes:

[0019] The third additive includes at least one selected from fluoroethylene carbonate, vinylene carbonate, 1,3-propanesulfonate lactone, vinyl sulfate, methanedisulfonate methylene, propylene sulfonate lactone, maleic anhydride, diethanolic anhydride, succinic anhydride, succinic anhydride, succinic anhydride, adiponitrile, ethylene glycol bis(propionitrile) ether, and 1,3,6-hexanetrionitrile.

[0020] Optionally, the third additive accounts for 0.1% to 15% of the total mass of the electrolyte.

[0021] Optionally, the mass content of the electrolyte salt accounts for 10% to 15% of the total mass of the electrolyte.

[0022] Optionally, the electrolyte salt comprises at least one of lithium hexafluorophosphate, lithium difluorophosphate, lithium difluorobis(oxalato)phosphate, lithium tetrafluoro(oxalato)phosphate, lithium oxalate phosphate, lithium bis(oxalato)borate, lithium difluoro(oxalato)borate, lithium tetrafluoroborate, lithium bis(fluorosulfonyl)imide, and lithium bis(trifluorosulfonyl)imide; and / or

[0023] The solvent includes at least one of ethylene carbonate, propylene carbonate, diethyl carbonate, methyl ethyl carbonate, dimethyl carbonate, ethyl propionate, propyl propionate, ethyl acetate, ethyl butyrate, and γ-butyrolactone.

[0024] Secondly, embodiments of the present invention provide a battery, comprising:

[0025] The electrolyte described in the above embodiments.

[0026] The electrolyte of this invention includes: an electrolyte salt, a solvent, a first additive, and a second additive. The first additive has the structural formula of (1), and the second additive has the structural formula of (2). The first additive is a vinylpyridine nitrile compound, and the second additive is an unsaturated phosphate ester compound. Vinylpyridine nitrile compounds readily form films at both the positive and negative electrodes, generating stable interfacial films. The interfacial film on the positive electrode side has basic pyridine functional groups, which effectively suppress the attack of HF on the interface of the positive electrode material. At the same time, the unsaturated nitrile structure on the positive electrode side can effectively suppress the dissolution of transition metal ions and significantly reduce the migration of cyano functional groups to the negative electrode, thus reducing the damage to the SEI film at the negative electrode interface. The unsaturated phosphate ester structure can effectively suppress the impedance growth caused by pyridine nitrile compounds. In addition, the low-impedance interfacial films generated at the positive and negative electrodes have high stability and good safety, significantly improving storage performance. Under thermal shock conditions, the additives can undergo polymerization to generate stable polymer films covering the surfaces of the positive and negative electrodes, suppressing free radical side reactions and micro-short-circuit heat generation, and improving thermal shock performance. By using the first and second additives in combination, the high-temperature cycle performance of lithium-ion batteries can be effectively improved, as well as their high-temperature storage and thermal shock performance. This results in better cycle, storage, and safety performance, and enhances the safe use of the batteries. Detailed Implementation

[0027] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] The terms "first," "second," etc., used in the specification and claims of this invention are used to distinguish similar objects and are not used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of the invention can be implemented in orders other than those described herein. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0029] The electrolyte of this invention includes:

[0030] Electrolyte salt, solvent, first additive and second additive, wherein the first additive has a structural formula including structural formula (1) and the second additive has a structural formula including structural formula (2).

[0031] The structural formula (1) is:

[0032]

[0033] Wherein, R1 is selected from a single bond and an alkyl group having 1 to 5 carbon atoms; R2, R3, and R4 are independently selected from a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 1 to 5 carbon atoms, a nitrile group having 1 to 4 carbon atoms, a halogen-substituted alkyl group having 1 to 5 carbon atoms, a halogen-substituted alkenyl group having 1 to 5 carbon atoms, and a halogen-substituted nitrile group having 1 to 4 carbon atoms; when R1 is selected from a single bond, the carbon atom containing R3 can be directly attached to a carbon atom on a heterocycle.

[0034] Structural formula (2) is selected from at least one of structural formula (2a) and structural formula (2b), and structural formula (2a) and structural formula (2b) are:

[0035]

[0036] Wherein, X1 is selected from alkenyl, and Y1, Y2, Y3, and Y4 are independently selected from one of the following: hydrogen atom, halogen atom, alkyl group with 1 to 5 carbon atoms, alkenyl group with 1 to 5 carbon atoms, nitrile group with 1 to 4 carbon atoms, halogen-substituted alkyl group with 1 to 5 carbon atoms, halogen-substituted alkenyl group with 1 to 5 carbon atoms, and halogen-substituted nitrile group with 1 to 4 carbon atoms.

[0037] The electrolyte salt may include at least one of lithium hexafluorophosphate, lithium difluorophosphate, lithium difluorobis(oxalato)phosphate, lithium tetrafluoro(oxalato)phosphate, lithium oxalate phosphate, lithium bis(oxalato)borate, lithium difluoro(oxalato)borate, lithium tetrafluoroborate, lithium bis(fluorosulfonyl)imide, and lithium bis(trifluorosulfonyl)imide. For example, the electrolyte salt may include lithium hexafluorophosphate, and the electrolyte salt may include lithium hexafluorophosphate and lithium bis(fluorosulfonyl)imide. The type and content of the electrolyte can be selected according to actual needs. The solvent may include at least one of ethylene carbonate, propylene carbonate, diethyl carbonate, methyl ethyl carbonate, dimethyl carbonate, ethyl propionate, propyl propionate, ethyl acetate, ethyl butyrate, and γ-butyrolactone. For example, the solvent may include dimethyl carbonate and ethyl propionate, and the solvent may include ethyl propionate, propyl propionate, and ethyl acetate. The type and content of the solvent can be selected according to actual needs.

[0038] In the electrolyte of this invention, the first additive is a vinylpyridine nitrile compound, and the second additive is an unsaturated phosphate ester compound. Vinylpyridine nitrile compounds readily form films on both the positive and negative electrodes, generating stable interfacial films. The positive electrode-side interfacial film possesses basic pyridine functional groups, effectively suppressing the attack of HF on the positive electrode material interface. Simultaneously, the unsaturated nitrile structure on the positive electrode side effectively inhibits the dissolution of transition metal ions and significantly reduces the migration of cyano functional groups to the negative electrode, minimizing damage to the SEI film at the negative electrode interface. The unsaturated phosphate ester structure effectively suppresses the impedance increase caused by pyridine nitrile compounds. Furthermore, the low-resistance interfacial films formed on both the positive and negative electrodes exhibit high stability and good safety, significantly improving storage performance. Under thermal shock conditions, the additives undergo polymerization to form stable polymer films covering the positive and negative electrode surfaces, suppressing free radical side reactions and micro-short-circuit heat generation, thus improving thermal shock performance. The combined use of the first and second additives effectively improves the high-temperature cycle performance of lithium-ion batteries, enhances high-temperature storage and thermal shock performance, resulting in better cycle, storage, and safety performance, and improving the battery's safe operation.

[0039] In some embodiments, the first additive may be selected from at least one of structural formulas (1-1) to (1-4), and structural formulas (1-1) to (1-4) may be:

[0040]

[0041] The first additive may be selected from one or more of structural formulas (1-1) to (1-4). For example, the first additive may be selected from structural formula (1-1), structural formula (1-3), or structural formula (1-4). The first additive may be selected from multiple structural formulas (1-1) to (1-4). For example, the first additive may be selected from structural formula (1-1) and structural formula (1-3), or the first additive may be selected from structural formula (1-1) and structural formula (1-4). The combination of multiple first additives with different structural formulas can have a better effect.

[0042] Optionally, the second additive may be selected from at least one of structural formulas (2-1) to (2-4), wherein structural formulas (2-1) to (2-4) may be:

[0043]

[0044] The second additive can be selected from one of the structural formulas (2-1) to (2-4). For example, the second additive can be selected from structural formula (2-1), structural formula (2-3), or structural formula (2-4). The second additive can be selected from multiple structural formulas (2-1) to (2-4). For example, the second additive can be selected from structural formula (2-1) and structural formula (2-3), the second additive can be selected from structural formula (2-1) and structural formula (2-4), the second additive can be selected from structural formula (2-3) and structural formula (2-4). The combination of multiple second additives with different structural formulas can have a better effect.

[0045] In some embodiments, the mass content of the first additive may be 0.1% to 10% of the total mass of the electrolyte. Preferably, the mass content of the first additive may be 0.5% to 3% of the total mass of the electrolyte. For example, the mass content of the first additive may be 0.1%, 3%, 5% or 10% of the total mass of the electrolyte, and the mass content of the first additive may be reasonably selected according to actual conditions.

[0046] In other embodiments, the mass content of the second additive can be 0.1% to 10% of the total mass of the electrolyte. Preferably, the mass content of the second additive can be 0.5% to 3% of the total mass of the electrolyte. For example, the mass content of the second additive can be 0.1%, 4%, 7%, or 10% of the total mass of the electrolyte, and the mass content of the second additive can be reasonably selected according to actual conditions. For example, in the electrolyte, the mass content of the first additive can be 0.1% of the total mass of the electrolyte, and the mass content of the second additive can be 10% of the total mass of the electrolyte; the mass content of the first additive can be 5% of the total mass of the electrolyte, and the mass content of the second additive can be 7% of the total mass of the electrolyte. The specific types and mass contents of the first and second additives can be reasonably selected according to actual conditions.

[0047] In some embodiments of the present invention, the electrolyte may further include:

[0048] The third additive may include at least one of the following: fluoroethylene carbonate (FEC), vinylene carbonate (VC), 1,3-propanesulfonate lactone (PS), vinyl sulfate (DTD), methanedisulfonate methylene (MMDS), propenesulfonate lactone (PST), maleic anhydride, diethanolamine anhydride, succinic anhydride, succinic anhydride, succinic anhydride (SN), adiponitrile (ADN), ethylene glycol bis(propionitrile) ether (DENE), and 1,3,6-hexanetrionitrile (HTCN). For example, the third additive may include fluoroethylene carbonate or 1,3-propanesulfonate lactone; the third additive may include both fluoroethylene carbonate and 1,3-propanesulfonate lactone. The specific type and content of the additive can be selected according to actual needs.

[0049] In some embodiments, the mass content of the third additive may be 0.1% to 15% of the total mass of the electrolyte. For example, the mass content of the third additive may be 0.1%, 5%, 10% or 15% of the total mass of the electrolyte. The mass content of the third additive can be reasonably selected according to actual conditions.

[0050] Optionally, the mass content of the electrolyte salt can account for 10% to 15% of the total mass of the electrolyte. For example, the mass content of the electrolyte salt can account for 15% of the total mass of the electrolyte.

[0051] The electrolyte salt can be a lithium salt electrolyte, and may include at least one of lithium hexafluorophosphate, lithium difluorophosphate, lithium difluorobis(oxalato)phosphate, lithium tetrafluoro(oxalato)phosphate, lithium oxalate phosphate, lithium bis(oxalato)borate, lithium difluoro(oxalato)borate, lithium tetrafluoroborate, lithium bis(fluorosulfonyl)imide, and lithium bis(trifluorosulfonyl)imide. For example, the electrolyte salt may be lithium hexafluorophosphate, and may include lithium hexafluorophosphate and lithium bis(fluorosulfonyl)imide. The specific type and content of the electrolyte salt can be selected according to actual needs.

[0052] The solvent may include at least one of ethylene carbonate (EC), propylene carbonate (PC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), dimethyl carbonate (DMC), ethyl propionate (EP), propyl propionate (PP), ethyl acetate (EA), ethyl butyrate (EB), and γ-butyrolactone (GBL). For example, the solvent may include ethylene carbonate, propylene carbonate, and ethyl acetate; or it may include ethylene carbonate, diethyl carbonate, ethyl propionate, and propyl propionate. The solvent may be an organic solvent, and its content may be 20% to 60% of the total mass of the electrolyte. The specific type and content of the solvent can be selected according to actual needs.

[0053] The battery of this invention includes:

[0054] The electrolyte described in the above embodiments. Batteries using the electrolyte described in the above embodiments have better cycle life, storage performance, and safety performance, thus improving the safe use of the battery.

[0055] The battery can be a lithium-ion battery, and the battery can include a positive electrode, a negative electrode, a separator disposed between the positive electrode and the negative electrode, and the electrolyte described in the above embodiments.

[0056] The present invention will be further illustrated below through some specific embodiments.

[0057] Example 1

[0058] Positive electrode preparation:

[0059] Lithium cobalt oxide (LCO), polyvinylidene fluoride (PVDF), conductive carbon black, and single-walled carbon nanotubes were mixed in a weight ratio of 97.2:1.5:1.2:0.1. N-methylpyrrolidone (NMP) was added, and the mixture was stirred under vacuum until it formed a homogeneous and fluid positive electrode slurry. The positive electrode slurry was uniformly coated onto a current collector aluminum foil. The coated aluminum foil was baked in ovens at different temperature gradients, and then dried in an oven at 120°C for 8 hours. Finally, it was rolled and slit to obtain the desired positive electrode sheet.

[0060] Negative electrode preparation:

[0061] A certain proportion of graphite (anode active material), sodium carboxymethyl cellulose (CMC-Na) (thickener), styrene-butadiene rubber (binder), and acetylene black (conductive agent) were mixed in a weight ratio of 97:1:1:1. Deionized water was added, and the mixture was stirred in a vacuum mixer to obtain a cathode slurry. The cathode slurry was uniformly coated onto a high-strength carbon-coated copper foil to obtain an electrode sheet. The obtained electrode sheet was dried at room temperature and then transferred to an 80°C oven for 10 hours. After that, it was rolled and slit to obtain a cathode sheet.

[0062] Electrolyte preparation:

[0063] In a glove box filled with inert gas (H2O < 10 ppm, O2 < 5 ppm), ethylene carbonate (EC), ethyl methyl carbonate (PC), and diethyl carbonate (DEC) were mixed in a mass ratio of 1:2:4. Then, lithium hexafluorophosphate (LiPF6) at 13.75 wt% of the total electrolyte weight was slowly added to the mixed solution. After passing the tests for moisture and free acid, a basic electrolyte was obtained. Different amounts of additives, fluoroethylene carbonate (FEC), and 1,3,6-hexanetrionitrile (HTCN) were added to the basic electrolyte to obtain a new electrolyte. Fluoroethylene carbonate accounted for 8% of the electrolyte mass, and 1,3,6-hexanetrionitrile accounted for 2% of the electrolyte mass.

[0064] Battery manufacturing:

[0065] Stack the prepared positive electrode, separator (9-micron thick PP film), and negative electrode in sequence, ensuring that the separator is between the positive and negative electrodes to provide isolation. Place the bare cell in the aluminum-plastic film outer packaging, inject the prepared electrolyte into the dried battery, and then encapsulate, let stand, form, shape, and perform capacity testing to complete the preparation of the lithium-ion soft pack battery.

[0066] Batteries of Examples 2-31 and Comparative Examples 1-3 were prepared according to the preparation method described above. The difference between Examples 2-31 and Comparative Examples 1-3 and Example 1 is the type and content of additives in the electrolyte. The specific additives and their contents are shown in Table 1.

[0067] Table 1. Additive components of the electrolyte in the examples and comparative examples.

[0068]

[0069]

[0070]

[0071] Battery performance testing

[0072] The lithium-ion batteries and their electrolytes obtained in Examples 1-31 and Comparative Examples 1-3 were subjected to relevant performance tests.

[0073] (1) High-temperature cycle performance test: At 45℃, the battery after capacity grading was charged to 4.48V at a constant current and constant voltage of 0.7C, with a cutoff current of 0.05C, and then discharged to 3.0V at a constant current of 0.5C. This cycle was repeated for 500 charge-discharge cycles. The capacity retention rate at the 500th cycle was calculated using the following formula:

[0074] 500-week cycle capacity retention (%) = (500-week cycle discharge capacity / initial cycle discharge capacity) × 100%.

[0075] (2) 60℃ High Temperature Storage Test:

[0076] The battery was charged and discharged once at 0.5C at room temperature. Then, it was fully charged using a constant current and constant voltage method. The battery thickness d1 before high-temperature storage was measured using vernier calipers (connecting the two diagonals of the battery with a straight line; the intersection of the two diagonals is the battery thickness test point). The battery was then stored in a 60℃ constant temperature chamber. During storage, the battery was removed and the thermal thickness d2 after storage was measured. The battery thickness expansion rate after 60℃ storage was calculated using the following formula:

[0077] Thickness expansion rate after storage at 60℃ = (d2-d1) / d1*100%;

[0078] If the thickness expansion rate is greater than 20% after storage at 60℃, the product is considered to have failed, and the failure time is recorded.

[0079] (3) Thermal shock performance: Under 25℃ ambient conditions, discharge to 3.0V with a given current of 0.2C; rest for 5 minutes; charge to 4.48V with a charging current of 0.2C. When the cell voltage reaches 4.48V, switch to 4.48V constant voltage charging until the charging current is less than or equal to the given cutoff current of 0.05C; after resting for 1 hour, put the cell into an oven. The oven temperature rises to 135±2℃ at a rate of 5±2℃ / min and is maintained for 30 minutes before stopping. The judgment criterion is that the cell does not catch fire or explode.

[0080] The battery test results in the examples and comparative examples are shown in Table 2.

[0081] Table 2 Battery test results in the examples and comparative examples.

[0082]

[0083]

[0084] As shown in Table 2, the test results of Comparative Examples 1-3 and Examples 1-31 indicate that additives can effectively improve the high-temperature cycle performance, high-temperature storage performance, and thermal shock performance of lithium-ion batteries. The unsaturated pyridine structure in the first additive can form a stable interfacial film on the electrode, while the weakly basic pyridine group can help suppress the damage of HF to the electrode interface, improving electrode stability. Therefore, both cycle performance and storage performance are improved. The unsaturated phosphate ester structure can effectively suppress the impedance increase caused by pyridine nitrile compounds, resulting in a low-impedance interfacial film with high stability and good safety, significantly improving storage performance. Under thermal shock conditions, the additive can undergo a polymerization reaction to form a stable polymer film covering the positive and negative electrode surfaces, suppressing free radical side reactions and micro-short-circuit heat generation, thus improving thermal shock performance. Through the combined use of additives, the high-temperature cycle performance of lithium-ion batteries can be improved, as well as their high-temperature storage and thermal shock performance, resulting in better cycle, storage, and safety performance, and enhancing the safe use of the battery.

[0085] The embodiments of the present invention have been described above. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of the present invention.

Claims

1. An electrolyte, characterized by, include: Electrolyte salt, solvent, first additive and second additive, wherein the first additive has a structural formula including structural formula (1) and the second additive has a structural formula including structural formula (2). The structural formula (1) is: ； Wherein, R1 is selected from a single bond and an alkyl group having 1 to 5 carbon atoms, and R2, R3, and R4 are independently selected from a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 1 to 5 carbon atoms, a nitrile group having 1 to 4 carbon atoms, a halogen-substituted alkyl group having 1 to 5 carbon atoms, a halogen-substituted alkenyl group having 1 to 5 carbon atoms, and a halogen-substituted nitrile group having 1 to 4 carbon atoms; Structural formula (2) is selected from at least one of structural formula (2a) and structural formula (2b), and structural formula (2a) and structural formula (2b) are: ； Wherein, X1 is selected from alkenyl, and Y1, Y2, Y3, and Y4 are independently selected from one of hydrogen atom, halogen atom, alkyl group with 1 to 5 carbon atoms, alkenyl group with 1 to 5 carbon atoms, nitrile group with 1 to 4 carbon atoms, halogen-substituted alkyl group with 1 to 5 carbon atoms, halogen-substituted alkenyl group with 1 to 5 carbon atoms, and halogen-substituted nitrile group with 1 to 4 carbon atoms; The first additive accounts for 0.1% to 10% of the total mass of the electrolyte; The second additive accounts for 0.1% to 10% of the total mass of the electrolyte.

2. The electrolyte according to claim 1, characterized in that, The first additive is selected from at least one of structural formulas (1-1) to (1-4), and structural formulas (1-1) to (1-4) are as follows: 。 3. The electrolyte of claim 1, wherein The second additive is selected from at least one of structural formulas (2-1) to (2-4), wherein structural formulas (2-1) to (2-4) are: 。 4. The electrolyte according to any one of claims 1 to 3, characterized in that, The mass content of the first additive accounts for 0.5%-3% of the total mass of the electrolyte.

5. The electrolyte according to any one of claims 1 to 3, characterized in that, The second additive accounts for 0.5%-3% of the total mass of the electrolyte.

6. The electrolyte of claim 1, wherein Also includes: The third additive includes at least one selected from fluoroethylene carbonate, vinylene carbonate, 1,3-propanesulfonate lactone, vinyl sulfate, methanedisulfonate methylene, propylene sulfonate lactone, maleic anhydride, diethanolic anhydride, succinic anhydride, succinic anhydride, succinic anhydride, adiponitrile, ethylene glycol bis(propionitrile) ether, and 1,3,6-hexanetrionitrile.

7. The electrolyte according to claim 6, characterized in that The third additive accounts for 0.1% to 15% of the total mass of the electrolyte.

8. The electrolyte according to claim 1, characterized in that, The electrolyte salt accounts for 10% to 15% of the total mass of the electrolyte.

9. The electrolyte according to claim 1, characterized in that, The electrolyte salt comprises at least one of lithium hexafluorophosphate, lithium difluorophosphate, lithium difluorobis(oxalate) phosphate, lithium tetrafluoro(oxalate) phosphate, lithium oxalate phosphate, lithium bis(oxalate) borate, lithium difluoro(oxalate) borate, lithium tetrafluoroborate, lithium bis(fluorosulfonyl)imide, and lithium bis(trifluorosulfonyl)imide; and / or The solvent includes at least one of ethylene carbonate, propylene carbonate, diethyl carbonate, methyl ethyl carbonate, dimethyl carbonate, ethyl propionate, propyl propionate, ethyl acetate, ethyl butyrate, and γ-butyrolactone.

10. A battery, characterized in that, include: The electrolyte according to any one of claims 1-9.

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