Use of an electrolyte additive, electrolyte and lithium ion battery

Abstract

This invention relates to the field of lithium-ion battery technology, specifically disclosing the application of an electrolyte additive, an electrolyte, and a lithium-ion battery. The electrolyte of this invention contains 0.25-5% hexamethyldisilure by mass. The addition of hexamethyldisilure effectively reduces the generation of flammable gases in lithium-ion batteries under overcharge conditions, ensuring that the battery only bulges and leaks gas under extreme overcharge conditions, without ignition or combustion. Furthermore, the addition of hexamethyldisilure alters the electrolyte decomposition pathway under overcharge conditions, inhibiting the generation of flammable gases (such as H2, CH4, C2H4, etc.) at the source, and fundamentally suppressing the risk of battery fire and explosion.

Description

Technical Field

[0001] This invention relates to the field of lithium-ion battery technology, and in particular to the application of an electrolyte additive, an electrolyte, and a lithium-ion battery. Background Technology

[0002] In recent years, lithium-ion batteries have been widely used in consumer electronics, new energy vehicles, and large-scale electrochemical energy storage power stations due to their high energy density, long cycle life, and stable performance, becoming a key energy storage component supporting the development of modern clean energy systems and portable electronic devices. However, with the continuous expansion of their application scale and the increasing complexity of usage scenarios, the safety issues of lithium-ion batteries under extreme or abuse conditions have gradually become prominent. Among them, combustion and explosion accidents caused by overcharging are frequently reported, seriously threatening the personal safety of users and social property, and have become an important obstacle restricting their further promotion and application.

[0003] Studies have shown that the fundamental cause of lithium-ion battery fires under overcharge conditions lies in the continuous and uncontrolled decomposition of the electrolyte inside the battery under high voltage conditions. When overcharging occurs, the positive electrode potential of the battery rises sharply, exceeding the electrochemical stability window of the electrolyte. This leads to a violent oxidation reaction of the electrolyte components, resulting in the decomposition of large quantities of flammable gases (such as hydrogen, methane, and ethylene) and a significant release of heat. This process further induces a rapid accumulation of temperature and pressure inside the battery. If the heat cannot be dissipated in time, it will trigger a series of chain exothermic reactions, such as the melting of the battery separator and the aggravation of internal short circuits, ultimately leading to thermal runaway of the battery, causing fire or even deflagration.

[0004] Therefore, optimizing the electrolyte system to suppress its decomposition tendency under overcharge conditions, especially reducing the generation of flammable gases, is considered one of the key strategies to improve the overcharge safety of lithium-ion batteries, and has important practical significance for promoting the continuous development of high-safety lithium-ion battery technology. Summary of the Invention

[0005] To address the problems existing in the prior art, this invention provides an application of an electrolyte additive, an electrolyte, and a lithium-ion battery. This invention effectively suppresses the fire phenomenon of lithium-ion batteries during overcharging by introducing a specific additive, hexamethyldisilaurea, into the electrolyte as a fire suppressant.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] In a first aspect, the present invention provides the application of an electrolyte additive in the preparation of lithium-ion battery electrolytes, wherein the electrolyte additive is hexamethyldisilure.

[0008] In a second aspect, the present invention also provides an electrolyte comprising hexamethyldisilure.

[0009] Preferably, it also includes organic solvents and lithium salts.

[0010] Preferably, the mass fraction of hexamethyldisilure in the electrolyte is 0.25-5%.

[0011] Preferably, the organic solvent includes at least one of chain carbonates and cyclic carbonates.

[0012] Preferably, the chain carbonate includes at least one of dimethyl carbonate, diethyl carbonate, and ethyl methyl carbonate;

[0013] The cyclic carbonates include at least one of ethylene carbonate, propylene carbonate, vinylene carbonate, and fluoroethylene carbonate.

[0014] Preferably, the lithium salt includes at least one of lithium hexafluorophosphate, lithium perchlorate, lithium bis(trifluoromethanesulfonyl)imide, lithium tetrafluoroborate, and lithium bis(fluorosulfonyl)imide.

[0015] Preferably, the lithium salt concentration in the electrolyte is 0.8~1.2 mol / L.

[0016] Thirdly, the present invention also provides an application of the electrolyte in the preparation of lithium-ion batteries.

[0017] Fourthly, the present invention also provides a lithium-ion battery, including the electrolyte described above.

[0018] The application of the electrolyte additive, the electrolyte, and the lithium-ion battery of the present invention have the following advantages over the prior art:

[0019] The electrolyte of this invention contains 0.25-5% hexamethyldisilure by mass. The addition of hexamethyldisilure can effectively reduce the amount of flammable gases generated by lithium-ion batteries under overcharge conditions, so that the battery only bulges and leaks gas under extreme overcharge conditions, without ignition or combustion. The addition of hexamethyldisilure changes the decomposition path of the electrolyte under overcharge conditions, inhibiting the generation of flammable gases (such as H2, CH4, C2H4, etc.) from the source, and can fundamentally suppress the risk of battery fire and explosion, providing an efficient and low-cost safety solution for the power battery and energy storage fields. Attached Figure Description

[0020] Figure 1 Comparison of charge-discharge curves of the pouch cells in Examples 1-3 and Comparative Examples 1-4;

[0021] Figure 2This is a comparison chart of the capacity-voltage curves of the pouch cells in Examples 1-3 and Comparative Examples 1-4 during overcharging;

[0022] Figure 3 This is a comparison chart of the capacity-temperature curves of the pouch batteries in Examples 1-3 and Comparative Examples 1-4 during overcharging;

[0023] Figure 4 The diagram shows the fire state of the pouch batteries in Comparative Examples 1-4 when they are overcharged.

[0024] Figure 5 The diagram shows the fire state of the soft-pack battery during overcharging in Examples 1-3. Detailed Implementation

[0025] The present invention will now be clearly and completely described with reference to specific embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. 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.

[0026] To better understand the invention and not to limit its scope, all figures indicating amounts, percentages, and other numerical values ​​used in this application should, in all cases, be understood to be modified by the word "approximately." Therefore, unless specifically stated otherwise, the numerical parameters listed in the specification and appended claims are approximate values ​​and may vary depending on the desired properties being sought. Each numerical parameter should at least be considered as obtained based on reported significant figures and through conventional rounding methods.

[0027] It should be noted that the order of description of the following embodiments is not intended to limit the preferred order of embodiments. Furthermore, in the description of this application, the term "comprising" means "including but not limited to". Various embodiments of the present invention may exist in the form of a range; it should be understood that the description in the form of a range is merely for convenience and brevity and should not be construed as a rigid limitation on the scope of the invention; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single numerical values ​​within that range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and single digits within the range, such as 1, 2, 3, 4, 5, and 6, regardless of the range. Additionally, whenever a numerical range is referred to herein, it means including any referenced number (fraction or integer) within the referred range.

[0028] This invention provides the application of an electrolyte additive in the preparation of lithium-ion battery electrolytes. The electrolyte additive is hexamethyldisilazane (chemical formula C7H). 20 N2OSi2, CAS No. 18297-63-7).

[0029] The hexamethyldisilure of the present invention, as an electrolyte additive, can effectively reduce the amount of flammable gas generated in lithium-ion batteries under overcharge conditions, so that the battery only bulges and leaks gas under extreme overcharge conditions, without ignition or combustion.

[0030] Based on the same inventive concept, the present invention also provides an electrolyte comprising hexamethyldisilure.

[0031] In some embodiments, organic solvents and lithium salts are also included.

[0032] In some embodiments, the mass fraction of hexamethyldisilazine in the electrolyte is 0.25-5%.

[0033] In some embodiments, the organic solvent includes at least one of chain carbonates and cyclic carbonates.

[0034] In some embodiments, the chain carbonate includes at least one of dimethyl carbonate (DMC), diethyl carbonate (DEC), and ethyl methyl carbonate (EMC);

[0035] Cyclic carbonates include at least one of ethylene carbonate (EC), propylene carbonate (PC), vinylene carbonate (VC), and fluoroethylene carbonate (FEC).

[0036] In some embodiments, the organic solvent includes ethylene carbonate (EC), diethyl carbonate (DEC), and methyl ethyl carbonate (EMC), with the mass ratio of ethylene carbonate (EC), diethyl carbonate (DEC), and methyl ethyl carbonate (EMC) being (2~4): (2~4):(3~5).

[0037] In some embodiments, the organic solvent includes ethylene carbonate (EC), diethyl carbonate (DEC), methyl ethyl carbonate (EMC), vinylene carbonate (VC), and fluoroethylene carbonate (FEC), wherein the mass ratio of ethylene carbonate (EC), diethyl carbonate (DEC), methyl ethyl carbonate (EMC), vinylene carbonate (VC), and fluoroethylene carbonate (FEC) is (25~35):(25~35):(35~40):(2~4):(0.5~1.5).

[0038] In some embodiments, the organic solvent includes ethylene carbonate (EC), dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), vinylene carbonate (VC), and fluoroethylene carbonate (FEC), wherein the mass ratio of ethylene carbonate (EC), dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), vinylene carbonate (VC), and fluoroethylene carbonate (FEC) is (25~35):(25~35):(35~40):(2~4):(0.3~1).

[0039] In some embodiments, the lithium salt includes at least one of lithium hexafluorophosphate (LiPF6), lithium perchlorate (LiClO4), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium tetrafluoroborate (LiBF4), and lithium bis(fluorosulfonyl)imide (LiFSI).

[0040] In some embodiments, the lithium salt concentration in the electrolyte is 0.8~1.2 mol / L.

[0041] The electrolyte described in this application significantly improves battery safety performance by introducing trace amounts (0.25%-5%) of hexamethyldisilazane as an electrolyte additive, using a simple method compatible with existing industrial production processes. It not only effectively alters the electrolyte decomposition pathway and drastically reduces the generation of flammable gases under overcharge conditions, but also fundamentally suppresses the risk of battery fire and deflagration, providing a highly efficient and low-cost safety solution for the power battery and energy storage fields.

[0042] Based on the same inventive concept, the present invention also provides an application of the above-mentioned electrolyte in the preparation of lithium-ion batteries.

[0043] Based on the same inventive concept, the present invention also provides a lithium-ion battery, including the above-mentioned electrolyte, and further including a positive electrode, a negative electrode, and a separator, such that the positive electrode active material can be NCM811 (i.e., lithium nickel cobalt manganese oxide (LiNiO2)). 0.8 Co 0.1 Mn 0.1 The negative electrode active material is graphite, and the separator is polyethylene (PE) separator, polypropylene (PP) separator (such as Celgard 2500 separator), PP / PE / PP three-layer composite separator, polyester non-woven separator, etc.

[0044] Existing technology CN119725753A discloses an electrolyte containing silane additives. The Si-N bond and Si-O-Si bond combination in the two additives can improve the stability of the electrolyte. Although both belong to the field of lithium battery electrolyte additives, there are substantial differences in the technical problems they solve, their mechanisms of action, additive components, and applicable scope. A detailed comparative analysis is as follows:

[0045] The mechanisms of action and the technical problems they address differ: Existing technologies aim to form stable SEI / CEI films on the positive and negative electrode surfaces through the synergistic effect of a first additive (an organofluorine compound containing Si-N bonds) and a second additive (a siloxane containing Si-O-Si bonds), thereby buffering the volume expansion of the silicon negative electrode and improving cycle performance and rate performance. In contrast, this application introduces hexamethyldisilazine to alter the electrolyte decomposition pathway under overcharge conditions, inhibiting the generation of flammable gases (such as H2, CH4, C2H4, etc.) at the source, thus preventing battery fire and explosion. The electrochemical processes (normal cycling vs. overcharge abuse) and intrinsic mechanisms (film protection vs. decomposition pathway regulation) targeted by the two technologies are fundamentally different.

[0046] The chemical structures and functions of the additives differ: Existing technologies employ a compound system of two types of additives: the first additive is a trifluoroacetamide compound containing trimethylsilyl groups, and the second additive is a multifunctional siloxane such as tetra(dimethylvinylsiloxy)silane, whose function depends on the synergistic film-forming and acid-removing functions of Si-N bonds, Si-O-Si bonds, and unsaturated bonds; This application uses a single additive, hexamethyldisilaurea, whose molecular structure is a bis(trimethylsilyl)-substituted urea, which does not contain fluorine or unsaturated bonds. Under overcharge conditions, it achieves a flame-suppressing effect by changing the electrolyte decomposition path. The composition, structural characteristics, and functional implementation paths of the two additives are all different.

[0047] The applicable objects and battery systems differ: Existing technologies are specifically designed for silicon-carbon anode systems, utilizing additives to form a high-toughness SEI film to alleviate the volume expansion of silicon anodes; the embodiments in this application all use graphite anode systems to verify the overcharge safety performance of hexamethyldisilure in conventional lithium-ion batteries. The applicable anode material systems and the core failure problems to be solved (volume expansion vs. overcharge thermal runaway) are significantly different.

[0048] In summary, this application differs clearly from existing technologies in terms of the technical problems it solves, its mechanism of action, additive composition, applicable battery systems, and the path to achieving safety functions.

[0049] The electrolyte and lithium-ion battery of the present invention are further illustrated below with specific embodiments. This section further illustrates the content of the present invention in conjunction with specific embodiments, but should not be construed as limiting the present invention. Unless otherwise specified, the technical means used in the embodiments are conventional means well known to those skilled in the art. Unless otherwise specified, the reagents, methods, and equipment used in the present invention are conventional reagents, methods, and equipment in the art.

[0050] Example 1

[0051] This embodiment provides an electrolyte comprising hexamethyldisilazine, an organic solvent, and a lithium salt;

[0052] The mass fraction of hexamethyldisilazane in the electrolyte is 0.5%;

[0053] The organic solvents include ethylene carbonate (EC), diethyl carbonate (DEC), and methyl ethyl carbonate (EMC), with a mass ratio of 3:3:4.

[0054] The lithium salt is LiPF6, and the concentration of lithium salt in the electrolyte is 1.0 mol / L.

[0055] This embodiment also provides a lithium-ion battery, wherein the electrolyte from Example 1 is injected into a 1Ah soft-pack battery, the positive electrode active material of the soft-pack battery is NCM811, the negative electrode active material is graphite, and the separator is Celgard 2500 separator, thus obtaining a lithium-ion battery.

[0056] Example 2

[0057] This embodiment provides an electrolyte comprising hexamethyldisilazine, an organic solvent, and a lithium salt;

[0058] The mass fraction of hexamethyldisilazane in the electrolyte is 0.25%;

[0059] The organic solvents include ethylene carbonate (EC), diethyl carbonate (DEC), methyl ethyl carbonate (EMC), vinylene carbonate (VC), and fluoroethylene carbonate (FEC), with a mass ratio of 30:30:36:3:1.

[0060] The lithium salt is LiClO4, and the concentration of lithium salt in the electrolyte is 0.8 mol / L.

[0061] This embodiment also provides a lithium-ion battery, wherein the electrolyte from Example 2 is injected into a 1Ah soft-pack battery, the positive electrode active material of the soft-pack battery is NCM811, the negative electrode active material is graphite, and the separator is Celgard 2500 separator, thus obtaining a lithium-ion battery.

[0062] Example 3

[0063] This embodiment provides an electrolyte comprising hexamethyldisilazine, an organic solvent, and a lithium salt;

[0064] The mass fraction of hexamethyldisilazane in the electrolyte is 5%;

[0065] The organic solvents include ethylene carbonate (EC), dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), vinylene carbonate (VC), and fluoroethylene carbonate (FEC), with a mass ratio of 30:30:36.5:3:0.5.

[0066] The lithium salts are LiFSI and LiBF4, with the concentration of LiFSI in the electrolyte being 0.8 mol / L and the concentration of LiBF4 being 0.4 mol / L.

[0067] This embodiment also provides a lithium-ion battery, wherein the electrolyte from Example 3 is injected into a 1Ah soft-pack battery, the positive electrode active material of the soft-pack battery is NCM811, the negative electrode active material is graphite, and the separator is Celgard 2500 separator, thus obtaining a lithium-ion battery.

[0068] Comparative Example 1

[0069] This comparative example provides an electrolyte that is the same as in Example 1, except that the electrolyte does not contain hexamethyldisilazine, while the other components are the same as in Example 1.

[0070] This comparative example also provides a lithium-ion battery, in which the electrolyte from Comparative Example 1 is injected into a 1Ah pouch cell. The positive electrode active material of the pouch cell is NCM811, the negative electrode active material is graphite, and the separator is Celgard 2500 separator, thus obtaining a lithium-ion battery.

[0071] Comparative Example 2

[0072] This comparative example provides an electrolyte that is the same as in Example 2, except that the electrolyte does not contain hexamethyldisilure, while the other components are the same as in Example 2.

[0073] This comparative example also provides a lithium-ion battery. The electrolyte from Comparative Example 2 is injected into a 1Ah pouch cell. The positive electrode active material of the pouch cell is NCM811, the negative electrode active material is graphite, and the separator is Celgard 2500 separator, thus obtaining a lithium-ion battery.

[0074] Comparative Example 3

[0075] This comparative example provides an electrolyte that is the same as in Example 3, except that the electrolyte does not contain hexamethyldisilure, while the other components are the same as in Example 3.

[0076] This comparative example also provides a lithium-ion battery. The electrolyte from Comparative Example 3 is injected into a 1Ah pouch cell. The positive electrode active material of the pouch cell is NCM811, the negative electrode active material is graphite, and the separator is Celgard 2500 separator, thus obtaining a lithium-ion battery.

[0077] Comparative Example 4

[0078] This comparative example provides an electrolyte that is the same as in Example 2, except that hexamethyldisilazane is replaced with N,O-bis(trimethylsilyl)trifluoroacetamide, with the same mass fraction of 0.25%. All other components are the same as in Example 2.

[0079] This comparative example also provides a lithium-ion battery. The electrolyte from Comparative Example 4 is injected into a 1Ah pouch cell. The positive electrode active material of the pouch cell is NCM811, the negative electrode active material is graphite, and the separator is Celgard 2500 separator, thus obtaining a lithium-ion battery.

[0080] Performance testing

[0081] Constant current charge and discharge test

[0082] Constant current charge-discharge tests were performed on the pouch cells in Examples 1-3 and Comparative Examples 1-4 above. The test method was as follows: the pouch cells were charged at 1A at 25°C until they reached 4.2V; then left to stand for 5 minutes; subsequently discharged at 1A until they reached 3.0V. Capacity-voltage data were collected.

[0083] Constant current overcharge fire test

[0084] Referring to GB / T 36276-2023 (Lithium-ion Batteries for Power Storage, 6.7.1.1.1) for test methods of battery safety runaway, with I=P rc / U nom (i.e., 1A, P) rc U represents the rated charging power. nom The pouch cells in Examples 1-3 and Comparative Examples 1-4 were charged with constant current (indicating nominal voltage), and the voltage, apparent temperature changes, and fire conditions were recorded.

[0085] Collection of overcharge gases from pouch batteries

[0086] With I=P rc / U nom The pouch cells in Examples 1-3 and Comparative Examples 1-4 were overcharged with a current of (1A) to 130% SOC (meaning overcharged to 1.3 times the rated capacity). At this point, the pouch cells were bulging. The bulging gas was collected and analyzed by gas chromatography.

[0087] Figure 1 The above are comparison graphs of the charge and discharge curves of the pouch cells in Examples 1-3 and Comparative Examples 1-4.

[0088] Figure 2 The graphs show a comparison of the capacity-voltage curves of the pouch cells during overcharging in Examples 1-3 and Comparative Examples 1-4.

[0089] Figure 3 The chart shows a comparison of the capacity-temperature curves of the pouch cells during overcharging in Examples 1-3 and Comparative Examples 1-4.

[0090] Figure 4 The diagram shows the fire state of the pouch batteries in Comparative Examples 1-4 when they are overcharged.

[0091] Figure 5 The diagram shows the fire state of the soft-pack battery during overcharging in Examples 1-3.

[0092] Table 1 shows a comparison of gas chromatographic analysis of the bulging gases of the pouch batteries in Examples 1-3 and Comparative Examples 1-4. The data in Table 1 are the volume concentrations of each gas. Other untested gases include some low molecular weight alkanes, alkenes, alkynes, and volatile electrolyte solvents.

[0093] Table 1 - Gas Analysis of Bulges in Different Pouch Batteries

[0094]

[0095] Combination Figure 1 The charge-discharge curves of the pouch cells in Examples 1-3 and Comparative Examples 1-3 show that adding hexamethyldisilure additive with a mass fraction of 0.5%-5% has no significant effect on the normal charge-discharge behavior of the cells.

[0096] Figure 2 and Figure 3 The capacity-voltage curves, capacity-temperature curves, and fire states of the pouch cells in Examples 1-3 and Comparative Examples 1-4 during overcharging are shown in the comparison. The results show that Comparative Examples 1-3 began to heat up when overcharged to approximately 1.25 Ah (i.e., 125% SOC), and ignited after the temperature rose to approximately 260 °C (approximately 150% SOC), ultimately leaving only metal parts and burning residue. Figure 4 As shown; in contrast, although Examples 1-3 with added hexamethyldisilazane also experienced temperature rise during overcharging, they only exhibited bulging and gas leakage when thermal runaway occurred, without open flame, and the battery structure remained relatively intact, as shown. Figure 5 As shown, this demonstrates that hexamethyldisilure can effectively suppress the risk of battery fire under overcharge conditions.

[0097] Furthermore, Table 1 summarizes the volume concentrations of various components (C2H4, C2H6, C2H2, CH4, CO, CO2, H2, O2, N2) in the bulging gas of the pouch batteries in Examples 1-3 and Comparative Examples 1-4 after overcharging to 130% SOC. The data shows that after adding 0.5-5% hexamethyldisilure, the volume concentrations of the four combustible gases C2H4, C2H6, CH4, and H2 in Examples 1-3 were significantly lower than those in Comparative Examples 1-3. This indicates that hexamethyldisilure can alter the decomposition pathway of the electrolyte under overcharge conditions, inhibit the generation of combustible gases, thereby reducing the risk of fire and explosion of the battery under extreme overcharge conditions and improving battery safety.

[0098] Furthermore, based on existing publicly available technologies, the applicant compared the core additive N,O-bis(trimethylsilyl)trifluoroacetamide (i.e., Comparative Example 4) in the published patent CN119725753A with Example 2. Although the charge / discharge capacity of the pouch battery in Comparative Example 4 is similar to that of the pouch battery in Example 2 (…),… Figure 1 However, its voltage polarization during overcharging ( Figure 2 ) and rate of temperature rise ( Figure 3 The values ​​of both were greater than those of Example 2. Secondly, although Comparative Example 4 did not ignite during overcharging, it produced a large amount of white smoke (…). Figure 4 However, it still poses certain safety hazards, and its effect on suppressing thermal runaway due to overcharging of lithium-ion batteries is not as good as that in Example 2. Furthermore, in Comparative Example 4, the volume concentration of the four combustible gases C2H4, C2H6, CH4, and H2 in the bulging gas of the soft-pack battery reached 32.195%, while in Example 2, the volume concentration of these four combustible gases was only 28.431%. The content of these four combustible gases in Example 2 was significantly lower than that in Comparative Example 4.

[0099] It is understood that the technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0100] The above are merely preferred embodiments of this application, and only specifically describe the technical principles of this application. These descriptions are only for explaining the principles of this application and should not be construed as limiting the scope of protection of this application in any way. Based on this explanation, any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application, as well as other specific embodiments of this application that can be conceived by those skilled in the art without creative effort, should be included within the scope of protection of this application.

Claims

1. The application of an electrolyte additive in the preparation of lithium-ion battery electrolytes, characterized in that, The electrolyte additive is hexamethyldisilure.

2. An electrolyte, characterized in that, Including hexamethyldisilure.

3. The electrolyte as described in claim 2, characterized in that, It also includes organic solvents and lithium salts.

4. The electrolyte as described in claim 3, characterized in that, The electrolyte contains 0.25-5% hexamethyldisilamide by mass.

5. The electrolyte as described in claim 3, characterized in that, The organic solvent includes at least one of chain carbonates and cyclic carbonates.

6. The electrolyte as described in claim 5, characterized in that, The chain carbonate includes at least one of dimethyl carbonate, diethyl carbonate, and ethyl methyl carbonate; The cyclic carbonates include at least one of ethylene carbonate, propylene carbonate, vinylene carbonate, and fluoroethylene carbonate.

7. The electrolyte as described in claim 3, characterized in that, The lithium salt includes at least one of lithium hexafluorophosphate, lithium perchlorate, lithium bis(trifluoromethanesulfonyl)imide, lithium tetrafluoroborate, and lithium bis(fluorosulfonyl)imide.

8. The electrolyte as described in claim 3, characterized in that, The concentration of lithium salt in the electrolyte is 0.8~1.2 mol / L.

9. The application of the electrolyte as described in any one of claims 2 to 8 in the preparation of lithium-ion batteries.

10. A lithium-ion battery, characterized in that, Includes the electrolyte as described in any one of claims 2 to 8.

Images