Electrolytes and lithium ion batteries

Abstract

The application provides an electrolyte and a lithium ion battery. The electrolyte comprises 8-15 parts of lithium salt, 10-90 parts of organic solvent, 0.3-3 parts of isocyanate n-butyl acetate silane compound and 0.05-0.3 parts of glyoxal disulfate in terms of weight fraction. The addition of the isocyanate n-butyl acetate silane compound in the electrolyte of the application helps the isocyanate n-butyl acetate silane compound to generate a dense structure stable passivation film on the silicon-carbon negative electrode preferentially. The addition of the glyoxal disulfate in the electrolyte of the application helps to reduce the interface impedance of the dense SEI film formed by the isocyanate n-butyl acetate silane compound in the electrolyte, thereby helping to further improve the cycle stability of the silicon-carbon negative electrode system lithium ion battery.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium ion batteries, and in particular to an electrolyte and a lithium ion battery. Background Art

[0002] Lithium-ion batteries, with their high operating voltage, lack of memory effect, long cycle life, and environmentally friendly advantages, have become an indispensable source of power for applications such as automotive, consumer electronics, engineering machinery, and aerospace. The electrolyte, often called the "blood" of a lithium-ion battery, typically consists of lithium salts, solvents, and additives. The electrolyte significantly impacts the battery's cycle performance, rate capability, and safety.

[0003] Silicon-carbon anode materials have high capacity, making them the preferred anode material for next-generation high-energy-density lithium batteries. However, silicon-carbon anode materials also have many problems. For example, the volume expansion and contraction of silicon particles during lithium ion insertion and extraction can lead to silicon particle pulverization and shedding, as well as SEI film rupture. This in turn causes the electrolyte to continue to react and consume, resulting in poor cycle performance of lithium batteries using silicon-carbon anode materials. Therefore, a method is urgently needed to address the poor cycle performance of silicon-carbon anode batteries. Summary of the Invention

[0004] The main purpose of the present invention is to provide an electrolyte and a lithium-ion battery to solve the problem of poor cycle stability of lithium-ion batteries with silicon-carbon negative electrode systems in the prior art.

[0005] In order to achieve the above-mentioned object, according to one aspect of the present invention, an electrolyte is provided, which comprises, by weight, 8 to 15 parts of a lithium salt, 10 to 90 parts of an organic solvent, 0.3 to 3 parts of an isocyanate acetate n-butyl silane compound, and 0.05 to 0.3 parts of glyoxal disulfate.

[0006] Furthermore, the electrolyte includes 12 to 14 parts of lithium salt, 70 to 90 parts of organic solvent, 0.5 to 3 parts of isocyanate acetate n-butyl silane compound and 0.05 to 0.2 parts of glyoxal disulfate.

[0007] Furthermore, the mass ratio of the above-mentioned isocyanate acetate n-butyl silane compound to glyoxal disulfate is 1:0.016-0.1.

[0008] Furthermore, the structure of the above-mentioned isocyanate n-butyl acetate silane compound is wherein n is an integer, 1≤n≤10; and / or, R1, R2 and R3 are each independently selected from substituted or unsubstituted C1 to C 10 Alkyl, substituted or unsubstituted C1~C 10Alkoxy, substituted or unsubstituted C2~C 10 Alkynyl, substituted or unsubstituted C6~C 12 any one of aryl, (R4)3SiO-, R4 is selected from substituted or unsubstituted C1~C 10 Any one of the alkyl groups.

[0009] Furthermore, the above R1, R2 and R3 are each independently selected from substituted or unsubstituted C1-C3 alkyl, substituted or unsubstituted C1-C4 alkoxy, substituted or unsubstituted C2-C5 alkynyl, substituted or unsubstituted C6-C8 aryl, (R4)3SiO - Any one of the following, R4 is selected from any one of substituted or unsubstituted C1~C3 alkyl groups.

[0010] Furthermore, the above R1, R2 and R3 are each independently selected from methyl, ethyl, methoxy, ethoxy, ethynyl, phenyl, (CH3)3SiO - 、(CH3CH2)3SiO - Any one of .

[0011] Furthermore, the above-mentioned isocyanate n-butyl acetate silane compound is selected from

[0012]

[0013] Any one or more of .

[0014] Furthermore, the organic solvent is selected from organic carbonate compounds, ionic liquids, alkylene ether compounds, aromatic ether compounds, C 1-10 Any one or more of alkyl ether compounds, cyclic ether compounds, carboxylate compounds, sulfone compounds, and nitrile compounds; preferably, the organic solvent is selected from any one or more of ethylene carbonate, propylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, 1,4-butyrolactone, ethyl methyl carbonate, methyl propionate, propyl acetate, n-butyl acetate, isobutyl acetate, n-amyl acetate, dimethyl ether, phenylene sulfide, acetonitrile, glutaronitrile, and sulfolane; further, preferably, the organic solvent is a combination of ethylene carbonate, dimethyl carbonate, and ethyl methyl carbonate, and the mass ratio of ethylene carbonate, dimethyl carbonate, and ethyl methyl carbonate is 15-25:35-45:35-45.

[0015] Furthermore, the lithium salt is selected from any one or more of lithium hexafluorophosphate, lithium hexafluoroarsenate, lithium tetrafluoroborate, lithium perchlorate, lithium nitrate, lithium bis(oxalatoborate), lithium difluorooxalatoborate, lithium trifluoromethanesulfonate, lithium bis(pentafluoroethylsulfonylimide), lithium bis(trifluoromethylsulfonylimide), lithium bis(fluorosulfonylimide), lithium difluoro(bisoxalato)phosphate and lithium tetrafluoro(oxalato)phosphate; preferably, the lithium salt is lithium hexafluorophosphate.

[0016] According to another aspect of the present invention, a lithium-ion battery is provided, comprising a positive electrode sheet, an electrolyte, a separator and a silicon-carbon negative electrode sheet, wherein the electrolyte is the electrolyte described above.

[0017] Applying the technical solution of the present application, adding isocyanate acetate n-butyl silane compounds to the electrolyte of the present application helps the isocyanate acetate n-butyl silane compounds to preferentially form a dense and stable passivation film on the silicon-carbon negative electrode, thereby helping to reduce the reactivity of the negative electrode surface to inhibit the occurrence of electrolyte side reactions; the Si-O bond in the isocyanate acetate n-butyl silane compound has the characteristics of high bond energy, which helps to make the isocyanate in the isocyanate acetate n-butyl silane compound undergo polymerization to form a polymer-like solid electrolyte membrane, which has good ionic conductivity, strong flexibility and stability, and can inhibit the continuous consumption of electrolyte caused by silicon particle expansion during the cycle, reduce interfacial impedance, and thus help to improve the cycle stability of the silicon-carbon negative electrode system lithium ion battery. Adding glyoxal disulfate to the electrolyte of the present application helps to reduce the interfacial impedance of the dense SEI film formed by the isocyanate acetate n-butyl silane compound in the electrolyte, thereby helping to further improve the cycle stability of the silicon-carbon negative electrode system lithium ion battery. It is preferred to control the composition and weight fraction of the electrolyte within the above range, which helps to give full play to the synergistic effect between the components and promote the formation of the passivation film, thereby helping to further improve the cycle stability of the silicon-carbon negative electrode system lithium-ion battery. DETAILED DESCRIPTION

[0018] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the embodiments.

[0019] As analyzed in the background technology of this application, lithium-ion batteries with silicon-carbon negative electrode systems in the prior art have the problem of poor cycle stability. In order to solve this problem, this application provides an electrolyte and a lithium-ion battery.

[0020] In a typical embodiment of the present application, an electrolyte is provided, which includes, by weight, 8 to 15 parts of a lithium salt, 10 to 90 parts of an organic solvent, 0.3 to 3 parts of an isocyanate acetate n-butyl silane compound, and 0.05 to 0.3 parts of glyoxal disulfate.

[0021] Adding isocyanate acetate n-butyl silane compounds to the electrolyte of the present application helps the isocyanate acetate n-butyl silane compounds to preferentially form a dense and stable passivation film on the silicon-carbon negative electrode, thereby helping to reduce the reactivity of the negative electrode surface to inhibit the occurrence of electrolyte side reactions; the Si-O bond in the isocyanate acetate n-butyl silane compounds has the characteristics of high bond energy, which helps to make the isocyanate in the isocyanate acetate n-butyl silane compounds undergo polymerization to form a polymer-like solid electrolyte membrane, which has good ionic conductivity, strong flexibility and stability, and can inhibit the continuous consumption of electrolyte caused by silicon particle expansion during the cycle, reduce interfacial impedance, and thus help to improve the cycle stability of the silicon-carbon negative electrode system lithium ion battery. Adding glyoxal disulfate to the electrolyte of the present application helps to reduce the interfacial impedance of the dense SEI film formed by the isocyanate acetate n-butyl silane compounds in the electrolyte, thereby helping to further improve the cycle stability of the silicon-carbon negative electrode system lithium ion battery. It is preferred to control the composition and weight fraction of the electrolyte within the above range, which helps to give full play to the synergistic effect between the components and promote the formation of the passivation film, thereby helping to further improve the cycle stability of the silicon-carbon negative electrode system lithium-ion battery.

[0022] In order to further improve the cycle stability of lithium-ion batteries with silicon-carbon negative electrode systems, in one embodiment of the present application, the above-mentioned electrolyte preferably includes 12 to 14 parts of lithium salt, 70 to 90 parts of organic solvent, 0.5 to 3 parts of isocyanate acetate n-butyl silane compound and 0.05 to 0.2 parts of glyoxal disulfate.

[0023] In one embodiment of the present application, the mass ratio of the above-mentioned isocyanate n-butyl acetate silane compound to glyoxal disulfate is 1:0.016-0.1.

[0024] It is preferred to control the mass ratio of isocyanate acetate n-butyl silane compound to glyoxal disulfate within the above range, thereby helping to further reduce the interfacial impedance of the dense SEI film formed by the isocyanate acetate n-butyl silane compound in the electrolyte, thereby helping to further improve the cycle stability of the silicon-carbon negative electrode system lithium ion battery.

[0025] In one embodiment of the present application, the structure of the above-mentioned isocyanate n-butyl acetate silane compound is wherein n is an integer, 1≤n≤10; and / or, R1, R2 and R3 are each independently selected from substituted or unsubstituted C1 to C 10 Alkyl, substituted or unsubstituted C1~C 10 Alkoxy, substituted or unsubstituted C2~C 10Alkynyl, substituted or unsubstituted C6~C 12 any one of alkylaryl, (R4)3SiO-, R4 is selected from substituted or unsubstituted C1~C 10 Any one of the alkyl groups.

[0026] In order to further improve the cycle stability of the silicon-carbon negative electrode system lithium ion battery, in one embodiment of the present application, it is preferred that the above-mentioned R1, R2 and R3 are each independently selected from substituted or unsubstituted C1-C3 alkyl, substituted or unsubstituted C1-C4 alkoxy, substituted or unsubstituted C2-C5 alkynyl, substituted or unsubstituted C6-C8 alkylaryl, (R4)3SiO - Any one of the following, R4 is selected from any one of substituted or unsubstituted C1~C3 alkyl groups.

[0027] In order to further improve the cycle stability of the silicon-carbon negative electrode system lithium ion battery, in one embodiment of the present application, it is preferred that the above R1, R2 and R3 are each independently selected from methyl, ethyl, methoxy, ethoxy, ethynyl, phenyl, (CH3)3SiO - 、(CH3CH2)3SiO - Any one of .

[0028] In order to further improve the cycle stability of silicon-carbon negative electrode system lithium ion batteries, in one embodiment of the present application, it is preferred that the above-mentioned isocyanate acetate n-butyl silane compound is selected from

[0029] Any one or more of .

[0030] In one embodiment of the present application, the organic solvent is selected from organic carbonate compounds, ionic liquids, alkylene ether compounds, aromatic ether compounds, C 1-10 Any one or more of alkyl ether compounds, cyclic ether compounds, carboxylate compounds, sulfone compounds, and nitrile compounds; preferably, the organic solvent is selected from any one or more of ethylene carbonate, propylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, 1,4-butyrolactone, ethyl methyl carbonate, methyl propionate, propyl acetate, n-butyl acetate, isobutyl acetate, n-amyl acetate, dimethyl ether, phenylene sulfide, acetonitrile, glutaronitrile, and sulfolane; further, preferably, the organic solvent is a combination of ethylene carbonate, dimethyl carbonate, and ethyl methyl carbonate, and the mass ratio of ethylene carbonate, dimethyl carbonate, and ethyl methyl carbonate is 15-25:35-45:35-45.

[0031] It is preferable to control the type of organic solvent within the above range, which helps to improve the solubility of lithium salt, isocyanate acetate n-butyl silane compound and glyoxal disulfate in the organic solvent, thereby helping to improve the stability of the electrolyte.

[0032] In one embodiment of the present application, the lithium salt is selected from any one or more of lithium hexafluorophosphate, lithium hexafluoroarsenate, lithium tetrafluoroborate, lithium perchlorate, lithium nitrate, lithium bis(oxalatoborate), lithium difluorooxalatoborate, lithium trifluoromethanesulfonate, lithium bis(pentafluoroethylsulfonylimide), lithium bis(trifluoromethylsulfonylimide), lithium bis(fluorosulfonylimide), lithium difluoro(bis(oxalato)phosphate and lithium tetrafluoro(oxalato)phosphate; preferably, the lithium salt is lithium hexafluorophosphate.

[0033] It is preferable to control the type of lithium salt within the above range, which helps to further improve the ion transport rate of the electrolyte and the stability of the electrolyte.

[0034] In another typical embodiment of the present application, a lithium-ion battery is provided, comprising a positive electrode sheet, an electrolyte, a separator and a silicon-carbon negative electrode sheet, wherein the electrolyte is the aforementioned electrolyte.

[0035] Since the electrolyte in the lithium-ion battery is the electrolyte of the present application, the lithium-ion battery has excellent cycle stability.

[0036] The beneficial effects of the present application will be further illustrated below with reference to embodiments.

[0037] Example 1

[0038] Preparation of electrolyte

[0039] In a glove box filled with argon (oxygen <0.1 ppm, moisture <0.1 ppm), ethylene carbonate (EC), dimethyl carbonate (DMC) and ethyl methyl carbonate (EMC) were mixed in a mass ratio of 20:40:40 to obtain an organic solvent. 13 parts of lithium hexafluorophosphate were slowly added to 86.45 parts of the organic solvent, and after complete dissolution, 0.5 parts of additive 1 and 0.05 parts of glyoxal disulfate were added. After complete dissolution, the electrolyte was uniformly stirred to obtain the electrolyte. The structural formula of additive 1 is:

[0040] Preparation of positive electrode materials

[0041] Mix 92% NCM811, 3% conductive agent SP, 2% single-walled carbon nanotubes, and 3% binder PVDF in a mass ratio, add solvent N-methylpyrrolidone and stir to form a uniform slurry, apply it on a 12-micron thick aluminum foil, roll and cut it to obtain the positive electrode material.

[0042] Preparation of negative electrode materials

[0043] 85% silicon carbon, 10% single-walled carbon nanotubes and 5% binder SBR were mixed evenly in a mass ratio, and deionized water was added as a solvent. The slurry was then coated on an 8-micron copper foil, dried, and rolled and cut to obtain a negative electrode material.

[0044] Battery preparation

[0045] In a dry environment with a dew point controlled below -60°C, the positive electrode sheet, diaphragm, and negative electrode sheet are stacked in order to ensure that the diaphragm completely separates the positive and negative electrode sheets, and the negative electrode completely covers the positive electrode. The battery cells are made by stacking the sheets, and then encapsulated in an aluminum-plastic film with glue ears after hot pressing. After baking until the moisture content is qualified, the prepared electrolyte is injected into the soft-pack battery cell, followed by sealing, formation, secondary sealing, aging, and capacity separation to obtain an experimental battery for testing.

[0046] Example 2

[0047] The difference from Example 1 is that the weight portion of additive 1 is 1 part, and an experimental battery is finally obtained.

[0048] Example 3

[0049] The difference from Example 1 is that the weight portion of the additive 1 is 2 parts, and an experimental battery is finally obtained.

[0050] Example 4

[0051] The difference from Example 1 is that the weight portion of the additive 1 is 3 parts, and an experimental battery is finally obtained.

[0052] Example 5

[0053] The difference from Example 1 is that the weight portion of the additive 1 is 1 part, and the weight portion of glyoxal disulfate is 0.1 part, and finally an experimental battery is obtained.

[0054] Example 6

[0055] The difference from Example 1 is that the weight portion of glyoxal disulfate is 0.1 parts, and an experimental battery is finally obtained.

[0056] Example 7

[0057] The difference from Example 1 is that the weight portion of glyoxal disulfate is 0.2 parts, and an experimental battery is finally obtained.

[0058] Example 8

[0059] The difference from Example 1 is that the weight portion of the additive 1 is 1 part, and the weight portion of glyoxal disulfate is 0.2 parts, and finally an experimental battery is obtained.

[0060] Example 9

[0061] The difference from Example 1 is that the weight portion of the additive 1 is 0.3 parts, and the weight portion of glyoxal disulfate is 0.3 parts, and finally an experimental battery is obtained.

[0062] Example 10

[0063] The difference from Example 1 is that By replacing additive 1, an experimental battery was finally obtained.

[0064] Example 11

[0065] The difference from Example 1 is that By replacing additive 1, an experimental battery was finally obtained.

[0066] Example 12

[0067] The difference from Example 1 is that By replacing additive 1, an experimental battery was finally obtained.

[0068] Example 13

[0069] The difference from Example 1 is that the mass ratio of ethylene carbonate, dimethyl carbonate and ethyl methyl carbonate is 25:35:35, and an experimental battery is finally obtained.

[0070] Example 14

[0071] The difference from Example 1 is that the mass ratio of ethylene carbonate, dimethyl carbonate and ethyl methyl carbonate is 15:45:45, and an experimental battery is finally obtained.

[0072] Example 15

[0073] The difference from Example 1 is that the mass ratio of ethylene carbonate, dimethyl carbonate and ethyl methyl carbonate is 10:50:50, and an experimental battery is finally obtained.

[0074] Comparative Example 1

[0075] The difference from Example 1 is that 2 parts of vinyl sulfate (VC) are used to replace 0.5 parts of Additive 1 and 0.05 parts of glyoxal disulfate, and finally an experimental battery is obtained.

[0076] Comparative Example 2

[0077] The difference from Example 1 is that 0.5 parts of Additive 1 and 0.05 parts of glyoxal disulfate are replaced by 1 part of fluoroethylene carbonate (FEC), and finally an experimental battery is obtained.

[0078] Comparative Example 3

[0079] The difference from Example 1 is that 0.5 parts of Additive 1 and 0.05 parts of glyoxal disulfate are replaced by 1 part of ethylene sulfate (DTD), and finally an experimental battery is obtained.

[0080] Comparative Example 4

[0081] The difference from Example 1 is that the weight portion of the additive 1 is 1 part, and glyoxal disulfate is not added, and finally an experimental battery is obtained.

[0082] Electrical performance test

[0083] After soaking for 24 hours, the soft-pack batteries were formed and capacitated using a battery test cabinet. The formation process involved charging at a constant current of 0.02C to 3.2V, then charging at a constant current of 0.1C to 3.7V. The batteries were then aged at 45°C for 24 hours. The capacitated batteries were charged at a constant current and voltage of 0.1C to 4.25V, with a cutoff current of 0.05C, and discharged at a constant current of 0.1C to 2.75V. The capacitated batteries were then charged and discharged at a constant current and voltage of 0.33C to 4.25V, with a cutoff current of 0.05C, and discharged at a constant current of 0.33C to 2.75V. The capacitated batteries were then cycled for 800 cycles at a constant current and voltage of 1C / 1C, with a voltage range of 2.75-4.25V. After cycling, the battery impedance was measured using an internal resistance meter, and the battery thickness was measured using a vernier caliper. The internal resistance growth rate was equal to the difference between the pre- and post-cycle internal resistance divided by the pre-cycle internal resistance, and the thickness growth rate was equal to the difference between the pre- and post-cycle internal resistance divided by the pre-cycle thickness. Comparing the internal resistance growth rate and thickness growth rate of the battery, the specific results are shown in Table 1.

[0084] Table 1

[0085]

[0086]

[0087] By comparing the results of the examples and the comparative examples, it can be seen that the electrolyte to which the additives isocyanate acetate n-butyl silane compound and glyoxal disulfate provided by the present invention are added significantly improves the initial efficiency and capacity retention rate after cycling in the test of soft-pack batteries, reduces the cycle internal resistance and the increase in battery thickness, and suppresses the impedance growth caused by the reaction of the electrolyte with the lithiated silicon negative electrode during the cycle by protecting the silicon negative electrode from particle breakage caused by repeated lithium insertion and deintercalation and reducing the interface impedance to a certain extent, thereby improving the cycle stability of the battery.

[0088] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects:

[0089] Adding isocyanate acetate n-butyl silane compounds to the electrolyte of the present application helps the isocyanate acetate n-butyl silane compounds to preferentially form a dense and stable passivation film on the silicon-carbon negative electrode, thereby helping to reduce the reactivity of the negative electrode surface to inhibit the occurrence of electrolyte side reactions; the Si-O bond in the isocyanate acetate n-butyl silane compounds has the characteristics of high bond energy, which helps to make the isocyanate in the isocyanate acetate n-butyl silane compounds undergo polymerization to form a polymer-like solid electrolyte membrane, which has good ionic conductivity, strong flexibility and stability, and can inhibit the continuous consumption of electrolyte caused by silicon particle expansion during the cycle, reduce interfacial impedance, and thus help to improve the cycle stability of the silicon-carbon negative electrode system lithium ion battery. Adding glyoxal disulfate to the electrolyte of the present application helps to reduce the interfacial impedance of the dense SEI film formed by the isocyanate acetate n-butyl silane compounds in the electrolyte, thereby helping to further improve the cycle stability of the silicon-carbon negative electrode system lithium ion battery. It is preferred to control the composition and weight fraction of the electrolyte within the above range, which helps to give full play to the synergistic effect between the components and promote the formation of the passivation film, thereby helping to further improve the cycle stability of the silicon-carbon negative electrode system lithium-ion battery.

[0090] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. An electrolyte, characterized in that: In parts by weight, the electrolyte comprises: 8-15 parts of lithium salt; 10-90 parts of an organic solvent; 0.3 to 3 parts of isocyanate n-butyl acetate silane compound; and 0.05-0.3 parts of glyoxal disulfate; The structure of the isocyanate n-butyl acetate silane compound is: ； wherein n is an integer, 1≤n≤10; and / or, R1, R2 and R3 are each independently selected from substituted or unsubstituted C1~C 10 Alkyl, substituted or unsubstituted C1~C 10 Alkoxy, substituted or unsubstituted C2~C 10 Alkynyl, substituted or unsubstituted C6~C 12 any one of aryl, (R4)3SiO-, R4 is selected from substituted or unsubstituted C1~C 10 Any one of the alkyl groups.

2. The electrolyte according to claim 1, characterized in that The electrolyte comprises: 12-14 parts of lithium salt; 70-90 parts of organic solvent; 0.5 to 3 parts of isocyanate n-butyl acetate silane compound; and 0.05~0.2 parts of glyoxal disulfate.

3. The electrolyte according to claim 1 or 2, characterized in that The mass ratio of the isocyanate acetate n-butyl silane compound to the glyoxal disulfate is 1:0.016-0.

1.

4. The electrolyte according to claim 1, characterized in that The R1, the R2 and the R3 are each independently selected from any one of a substituted or unsubstituted C1~C3 alkyl group, a substituted or unsubstituted C1~C4 alkoxy group, a substituted or unsubstituted C2~C5 alkynyl group, a substituted or unsubstituted C6~C8 aryl group, and (R4)3SiO-, and R4 is selected from any one of a substituted or unsubstituted C1~C3 alkyl group.

5. The electrolyte according to claim 4, characterized in that The R1, the R2 and the R3 are each independently selected from any one of methyl, ethyl, methoxy, ethoxy, ethynyl, phenyl, (CH3)3SiO-, and (CH3CH2)3SiO-.

6. The electrolyte according to claim 5, characterized in that The isocyanate n-butyl acetate silane compound is selected from 、 、 and Any one or more of .

7. The electrolyte according to claim 1 or 2, characterized in that The organic solvent is selected from organic carbonate compounds, ionic liquids, alkylene ether compounds, aromatic ether compounds, C 1-10 Any one or more of alkyl ether compounds, cyclic ether compounds, carboxylate compounds, sulfone compounds, and nitrile compounds.

8. The electrolyte according to claim 7, characterized in that The organic solvent is selected from any one or more of ethylene carbonate, propylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, 1,4-butyrolactone, ethyl methyl carbonate, methyl propionate, propyl acetate, n-butyl acetate, isobutyl acetate, n-amyl acetate, dimethyl ether, phenylene sulfide, acetonitrile, glutaronitrile and sulfolane.

9. The electrolyte according to claim 8, characterized in that The organic solvent is a composition of ethylene carbonate, dimethyl carbonate and ethyl methyl carbonate, and the mass ratio of the ethylene carbonate, the dimethyl carbonate and the ethyl methyl carbonate is 15-25:35-45:35-45.

10. The electrolyte according to claim 1 or 2, characterized in that The lithium salt is selected from any one or more of lithium hexafluorophosphate, lithium hexafluoroarsenate, lithium tetrafluoroborate, lithium perchlorate, lithium nitrate, lithium bis(oxalatoborate), lithium difluorooxalatoborate, lithium trifluoromethanesulfonate, lithium bis(pentafluoroethylsulfonylimide), lithium bis(trifluoromethylsulfonylimide), lithium bis(fluorosulfonylimide), lithium difluoro(bisoxalato)phosphate and lithium tetrafluoro(oxalato)phosphate.

11. The electrolyte according to claim 10, characterized in that The lithium salt is lithium hexafluorophosphate.

12. A lithium-ion battery comprising a positive electrode, an electrolyte, a separator and a silicon-carbon negative electrode, characterized in that: The electrolyte is the electrolyte according to any one of claims 1 to 11.

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