Lithium ion battery electrolyte and lithium ion battery

Abstract

The invention relates to the technical field of lithium ion batteries, in particular to a lithium ion battery electrolyte and a lithium ion battery. The lithium ion battery electrolyte comprises a lithium supplement agent and an additive, the additive comprises a first additive, and the first additive has any one of the following structural general formula: # imgabs0 #, in which R1, R2 and R3 are identical or different and represent halogen, C1-C7 alkyl or halogen substituted C1-C7 alkyl; r < 5 >-R < 15 > and R < 5 > '-R < 15 >' are the same or different and represent hydrogen, halogen, amino, C1-C7 alkyl or C1-C7 alkyl substituted by halogen. According to the invention, the pyridine ring connected with silyl or silylene is taken as a main body structure, so that HF in the electrolyte can be removed, transition states such as oxygen free radicals / active oxygen released by the lithium supplement agent can be captured, oxygenolysis of the electrolyte is inhibited, a stable CEI film is formed, and the stability of the positive electrode material is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium-ion batteries, and particularly to lithium-ion battery electrolytes and lithium-ion batteries. Background Art

[0002] In recent years, electric vehicles powered by lithium-ion batteries have developed rapidly in terms of energy density, cycle life, safety, and cost control. However, compared with traditional fuel vehicles, the charging time of electric vehicles is relatively long, which limits their further market promotion. As the carrier of ion transport in lithium-ion batteries, the electrolyte plays an ion conduction role between the positive and negative electrodes of the battery, and is an important guarantee for lithium-ion batteries to obtain fast charging ability. Due to the increased electrode thermal effect and polarization under fast charging, the SEI film will accelerate recombination and repair, resulting in continuous decomposition and consumption of the electrolyte at the electrode / electrolyte interface, and the side reactions will intensify. More seriously, the graphite negative electrode reaches the lithium deposition potential in advance, thus inducing rapid battery failure. Research shows that the lithium supplement agent can not only improve the energy density of the battery, but also improve the fast charging performance. The lithium supplement agent can compensate for the irreversible capacity loss caused by the formation of the SEI film on the negative electrode side during the first cycle (i.e., the "formation" stage) of the lithium-ion battery, and greatly improve the energy density of the lithium-ion battery.

[0003] However, there are still certain challenges for the commonly used positive electrode lithium supplement materials in the fast charging battery system: on the one hand, the positive electrode lithium supplement agent usually has strong oxidizing properties, and the released oxygen free radicals / reactive oxygen species and other transition states react with CO generated by the decomposition of the electrolyte to form CO 2 , which makes the main components such as electrolyte additives / solvents ineffective, resulting in the deterioration of battery performance; on the other hand, although the positive electrode lithium supplement agent can compensate for the irreversible capacity loss, the formed SEI layer is often uneven, resulting in poor interface stability, seriously affecting the cycle life of battery fast charging. Therefore, it is urgent to develop a functional electrolyte additive that can effectively capture oxygen free radicals and enhance the electrode / electrolyte interface stability, so as to optimize the influence of the use of the lithium supplement agent on the fast charging cycle performance of the battery. Summary of the Invention

[0004] In order to solve the above technical problems in the prior art, the present invention provides a lithium-ion battery electrolyte and a lithium-ion battery.

[0005] Based on this, the present invention has the following technical solutions: In the first aspect, the present invention provides a lithium-ion battery electrolyte, including a lithium supplement agent and an additive, the additive includes a first additive, the first additive includes a pyridine compound, and the pyridine compound has any one of the following structural general formulas: Wherein, R 1 , R 2 and R3 each independently, identically or differently represent halogen, C 1 ~C 7 alkyl or C alkyl substituted by halogen 1 ~C 7 alkyl; R 5 , R 6 , R 7 , R 8 , R 9 , R 10 , R 11 , R 12 , R 13 , R 14 , R 15 , R 5 ’, R 6 ’, R 7 ’, R 8 ’, R 9 ’, R 10 ’, R 11 ’, R 12 ’, R 13 ’, R 14 ’ and R 15 ’ each independently, identically or differently represent hydrogen, halogen, amino, C 1 ~C 7 alkyl or C alkyl substituted by halogen 1 ~C 7 alkyl.

[0006] A lithium-ion battery electrolyte provided by the present invention, the pyridine compound has any one of the following structural general formulas: .

[0007] A lithium-ion battery electrolyte provided by the present invention, R 1 , R 2 and R 3 each independently, identically or differently represent halogen, C 1 ~C 3 alkyl or C alkyl substituted by halogen 1 ~C 3 alkyl; R 5 , R 6 , R 7 , R 8 , R 9 , R 10 , R 11 , R 12 , R 13 , R 14 , R 15 , R 5 ’, R6 ’, R 7 ’, R 8 ’, R 9 ’, R 10 ’, R 11 ’, R 12 ’, R 13 ’, R 14 ’ and R 15 ’ each independently, identically or differently represent hydrogen, halogen, amino, C 1 ~C 3 alkyl or C alkyl substituted by halogen 1 ~C 3 alkyl; the halogen is fluorine or iodine.

[0008] A lithium ion battery electrolyte provided by the present invention, wherein the 4-position of the pyridine ring is connected to a silyl group or a silylene group, and one or more of the 2-position, 3-position, 5-position and 6-position are connected to halogen, amino or alkyl substituted by halogen; preferably, the alkyl substituted by halogen is selected from -CFH 2 , -CF 2 H or -CF 3 .

[0009] A lithium ion battery electrolyte provided by the present invention, wherein the first additive comprises any one of the following pyridine compounds:

[0010] Preferably, the first additive is selected from one or more of A14 to A24.

[0011] A lithium ion battery electrolyte provided by the present invention, wherein the dosage of the first additive in the lithium ion battery electrolyte is 0.01 to 5 wt%.

[0012] A lithium ion battery electrolyte provided by the present invention, wherein the lithium supplementing agent comprises one or more of lithium-rich lithium ferrite, lithium-rich lithium nickelate, lithium-rich lithium cobaltate, lithium oxide, lithium nitride, lithium peroxide, lithium fluoride, lithium silicate, lithium phosphate, lithium sulfate.

[0013] A lithium ion battery electrolyte provided by the present invention, wherein the dosage of the lithium supplementing agent in the lithium ion battery electrolyte is 0.1 to 10 wt%.

[0014] A lithium ion battery electrolyte provided by the present invention, wherein the mass ratio of the first additive to the lithium supplementing agent is (0.1 to 4):(0.5 to 5).

[0015] According to a lithium-ion battery electrolyte provided by the present invention, a second additive is further included in the additive, and the second additive includes one or more of ethylene carbonate, 1,3-propane sultone, fluoroethylene carbonate, ethylene sulfate, tris(trimethylsilyl) phosphite, tris(trimethylsilyl) borite, allyl sulfonic lactone, methylene methanedisulfonate, ethylene glycol bis(propionitrile) ether, biphenyl, vinylene ethylene carbonate, 1,4-butane sultone, trimethyl phosphate, triphenyl phosphate, tributyl phosphate, trifluoroethyl phosphate, and fluorinated ether.

[0016] According to a lithium-ion battery electrolyte provided by the present invention, the dosage of the second additive in the lithium-ion battery electrolyte is 0.1-5 wt%.

[0017] According to a lithium-ion battery electrolyte provided by the present invention, the mass ratio of the first additive to the second additive is (0.1-4):(1.5-5).

[0018] According to a lithium-ion battery electrolyte provided by the present invention, the lithium salt in the electrolyte includes one or more of lithium hexafluorophosphate, lithium perchlorate, lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium bis(oxalato)borate, lithium difluoro(oxalato)borate, lithium tetrafluoroborate, and lithium difluorophosphate; preferably, the mass of the lithium salt is 10 wt%-30 wt% of the total mass of the lithium-ion battery electrolyte; And / or, the organic solvent in the electrolyte includes one or more of dimethyl carbonate, ethyl methyl carbonate, ethylene carbonate, propylene carbonate, and diethyl carbonate.

[0019] According to a lithium-ion battery electrolyte provided by the present invention, the mass of the organic solvent is 70 wt%-90 wt% of the total mass of the lithium-ion battery electrolyte.

[0020] In a second aspect, the present invention provides a lithium-ion battery containing the lithium-ion battery electrolyte described above.

[0021] The lithium-ion battery electrolyte and the lithium-ion battery provided by the present invention introduce the second additive. By optimizing the structure of the second additive, with a pyridine ring connected with a silyl group or a silylene group as the main structure, it can not only remove HF in the electrolyte, but also capture transition states such as oxygen free radicals / reactive oxygen species released by the lithium supplement agent, inhibit the oxidative decomposition of the electrolyte, form a stable CEI film, and improve the stability of the positive electrode material. Detailed Embodiments

[0022] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions in the present invention will be clearly and completely described below. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present invention without creative efforts belong to the scope of protection of the present invention.

[0023] To solve the problems of the main components such as electrolyte additives / solvents becoming ineffective caused by the lithium supplement agent and the poor stability of the electrode / electrolyte interface, and to optimize the battery performance, the present invention provides the following technical solutions: In a first aspect, the present invention provides a lithium-ion battery electrolyte, including a lithium supplement agent and an additive. The additive includes a first additive, and the first additive includes a pyridine compound, and the pyridine compound has any of the following structural general formulas: Wherein, R 1 、R 2 and R 3 each independently, identically or differently represent a halogen, an alkyl group of C 1 ~C 7 or an alkyl group of C 1 ~C 7 substituted by a halogen; R 5 、R 6 、R 7 、R 8 、R 9 、R 10 、R 11 、R 12 、R 13 、R 14 、R 15 、R 5 ’、R 6 ’、R 7 ’、R 8 ’、R 9 ’、R 10 ’、R 11 ’、R 12 ’、R 13 ’、R 14 ’and R 15 ’each independently, identically or differently represent hydrogen, a halogen, an amino group, an alkyl group of C 1 ~C 7 or an alkyl group of C 1 ~C 7 substituted by a halogen.

[0024] In the present invention, the first additive contains a pyridine ring structure and can form a rich Li 3The SEI layer of N improves the fast charging performance of the battery; the present invention finds that when a silyl group or a silylene group is connected to the pyridine ring, it can not only remove HF in the electrolyte, but also capture transition states such as oxygen free radicals / reactive oxygen species released by the lithium supplement agent, inhibit the oxidative decomposition of the electrolyte, form a stable CEI film, and improve the stability of the cathode material.

[0025] The present invention further finds that in the first additive, with the pyridine ring connected with a silyl group or a silylene group as the main structure, the simultaneous presence of halogen elements can generate a dense LiX on the negative electrode surface, thereby achieving uniform deposition of lithium and reducing the interfacial impedance; the presence of an amino group can form a strong interaction with PF6− in the lithium salt through hydrogen bonding and induce the formation of LiF, enhancing the mechanical strength of the SEI layer; the silyl functional group can not only participate in the formation of a stable CEI layer and prevent the dissolution of transition metals, but also act as an HF scavenger.

[0026] According to a preferred embodiment provided by the present invention, the pyridine compound has any of the following structural general formulas: 。

[0027] The present invention finds that when the silyl group or the silylene group is connected to the 4-position of the pyridine ring, it is easily reduced and forms a stable SEI layer on the negative electrode surface.

[0028] According to a preferred embodiment provided by the present invention, R 1 、R 2 and R 3 each independently, identically or differently represent halogen, an alkyl group of C 1 ~C 3 or an alkyl group of C 1 ~C 3 substituted by halogen; R 5 、R 6 、R 7 、R 8 、R 9 、R 10 、R 11 、R 12 、R 13 、R 14 、R 15 、R 5 ’、R 6 ’、R 7 ’、R 8 ’、R 9 ’、R 10 ’、R 11 ’、R 12 ’、R 13 ’、R 14 ’and R 15’each independently, identically or differently represents hydrogen, halogen, amino, C 1 ~C 3 alkyl or C substituted by halogen 1 ~C 3 alkyl; the halogen is fluorine or iodine.

[0029] According to a preferred embodiment provided by the present invention, the 4-position of the pyridine ring is connected to a silyl group or a silylene group, and one or more of the 2-position, 3-position, 5-position and 6-position are connected to halogen, amino or alkyl substituted by halogen; preferably, the alkyl substituted by halogen is selected from -CFH 2 , -CF 2 H or -CF 3 .

[0030] According to a preferred embodiment provided by the present invention, the first additive includes any one of the following pyridine compounds:

[0031] .

[0032] Preferably, the first additive is selected from any one or more of A14 to A24; more preferably, the first additive is selected from any one or more of A15 to A24.

[0033] In the present invention, those skilled in the art can prepare or commercially obtain the pyridine compounds disclosed in the prior art, and the preparation method thereof is not limited herein.

[0034] According to a preferred embodiment provided by the present invention, the dosage of the first additive in the lithium-ion battery electrolyte is 0.01 to 5 wt%, preferably, the dosage of the first additive in the lithium-ion battery electrolyte is 0.1 to 1 wt%, for example, it can be any value among 0.1 wt%, 0.2 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt%, 0.6 wt%, 0.7 wt%, 0.8 wt%, 0.9 wt%, 1 wt%, or a numerical range with any two of the above values as endpoints.

[0035] According to a preferred embodiment provided by the present invention, the lithium supplementing agent includes one or more of lithium-rich lithium ferrite, lithium-rich lithium nickelate, lithium-rich lithium cobaltate, lithium oxide, lithium nitride, lithium peroxide, lithium fluoride, lithium silicate, lithium phosphate, lithium sulfate.

[0036] More preferably, the lithium supplementing agent includes one or more of lithium-rich lithium ferrite, lithium-rich lithium nickelate and lithium-rich lithium cobaltate.

[0037] According to a preferred embodiment provided by the present invention, the dosage of the lithium supplement in the lithium-ion battery electrolyte is 0.1-10 wt%, preferably, the dosage of the lithium supplement in the lithium-ion battery electrolyte is 1-5 wt%. For example, it can be any value among 1 wt%, 2 wt%, 3 wt%, 4 wt% and 5 wt%, or a numerical range with any two of the above values as endpoints.

[0038] According to a preferred embodiment provided by the present invention, the mass ratio of the first additive to the lithium supplement is (0.1-4):(0.5-5).

[0039] According to a preferred embodiment provided by the present invention, the additive further includes a second additive, and the second additive includes one or more of ethylene carbonate, 1,3-propane sultone, fluoroethylene carbonate, ethylene sulfate, tris(trimethylsilyl) phosphite, tris(trimethylsilyl) borite, propylene sultone, methylene methanedisulfonate, ethylene glycol bis(propionitrile) ether, biphenyl, vinylene ethylene carbonate, 1,4-butane sultone, trimethyl phosphate, triphenyl phosphate, tributyl phosphate, trifluoroethyl phosphate and fluorinated ether.

[0040] According to a preferred embodiment provided by the present invention, the dosage of the second additive in the lithium-ion battery electrolyte is 0.1-5 wt%; preferably, the dosage of the second additive in the lithium-ion battery electrolyte is 1-5 wt%. For example, it can be any value among 1 wt%, 2 wt%, 3 wt%, 4 wt% and 5 wt%, or a numerical range with any two of the above values as endpoints.

[0041] According to a preferred embodiment provided by the present invention, the mass ratio of the first additive to the second additive is (0.1-4):(1.5-5).

[0042] More preferably, the mass ratio of the first additive to the second additive is (0.1-1):(1.5-5).

[0043] According to a preferred embodiment provided by the present invention, the lithium salt in the electrolyte includes one or more of lithium hexafluorophosphate, lithium perchlorate, lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium bis(oxalato)borate, lithium difluoro(oxalato)borate, lithium tetrafluoroborate and lithium difluorophosphate; preferably, the mass of the lithium salt is 10 wt%-30 wt% of the total mass of the lithium-ion battery electrolyte. For example, it can be any value among 10 wt%, 15 wt%, 20 wt%, 25 wt% and 30 wt%, or a numerical range with any two of the above values as endpoints.

[0044] According to a preferred embodiment provided by the present invention, the organic solvent in the electrolyte includes one or more of dimethyl carbonate, ethyl methyl carbonate, ethylene carbonate, propylene carbonate, diethyl carbonate, ethyl acetate, ethyl propionate, propyl propionate, methyl acetate, and methyl propionate.

[0045] According to a preferred embodiment provided by the present invention, the mass of the organic solvent is 70wt% - 90wt% of the total mass of the lithium-ion battery electrolyte. For example, it can be any value among 70wt%, 75wt%, 80wt%, 85wt%, and 90wt%, or a numerical range with any two of the above values as endpoints.

[0046] In a second aspect, the present invention provides a lithium-ion battery containing the lithium-ion battery electrolyte described above.

[0047] Unless otherwise specified, all kinds of raw materials used in the examples and comparative examples are commercially available conventional raw materials, and the technical means used are conventional means well-known to those skilled in the art.

[0048] Example 1 This example provides a lithium-ion battery electrolyte, and its preparation method includes the following steps: In a glove box filled with argon, with a moisture content < 0.1ppm and an oxygen content < 0.1ppm, ethylene carbonate (EC), ethyl methyl carbonate (EMC), and dimethyl carbonate (DMC) are mixed in a mass ratio of 1:1:1 to obtain an organic solvent. Then, 10wt% of LiPF based on the total weight of the electrolyte is slowly added to the organic solvent 6 and 5wt% of LiFSI to obtain a mixture of the organic solvent and the lithium salt. Finally, 0.3wt% of a first additive, 1wt% of a lithium supplement agent Li 2 NiO 2 , 1wt% of fluoroethylene carbonate (FEC), 0.5wt% of ethylene carbonate (VC), and 0.5wt% of vinylene sulfate (DTD) are added, and after stirring evenly, the lithium-ion battery electrolyte of this example is obtained.

[0049] In this example, the first additive is .

[0050] This example further provides a lithium-ion battery, including a positive electrode sheet, a negative electrode sheet, a separator spaced between the positive electrode sheet and the negative electrode sheet, and an electrolyte. Among them, the positive electrode sheet uses lithium iron phosphate or a ternary material as the positive electrode active material, the negative electrode sheet uses graphite as the negative electrode active material, the electrolyte is the electrolyte described in the examples and comparative examples, and the separator is a polypropylene separator.

[0051] Example 2 This embodiment provides a lithium-ion battery electrolyte, and the difference from Embodiment 1 is only that: the first additive is replaced with an equal amount of .

[0052] Embodiment 3 This embodiment provides a lithium-ion battery electrolyte, and the difference from Embodiment 1 is only that: the first additive is replaced with an equal amount of .

[0053] Embodiment 4 This embodiment provides a lithium-ion battery electrolyte, and the difference from Embodiment 1 is only that: the addition amount of the first additive is 1.5 wt%.

[0054] Embodiment 5 This embodiment provides a lithium-ion battery electrolyte, and the difference from Embodiment 1 is only that: the first additive is replaced with an equal amount of .

[0055] Embodiment 6 This embodiment provides a lithium-ion battery electrolyte, and the difference from Embodiment 1 is only that: the first additive is replaced with an equal amount of .

[0056] Embodiment 7 This embodiment provides a lithium-ion battery electrolyte, and the difference from Embodiment 1 is only that: the first additive is replaced with an equal amount of .

[0057] Embodiment 8 This embodiment provides a lithium-ion battery electrolyte, and the difference from Embodiment 1 is only that: the first additive is replaced with an equal amount of .

[0058] Embodiment 9 This embodiment provides a lithium-ion battery electrolyte, and the difference from Embodiment 1 is only that: the first additive is replaced with an equal amount of .

[0059] Embodiment 10 This embodiment provides a lithium-ion battery electrolyte, and the difference from Embodiment 1 is only that: the first additive is replaced with an equal amount of .

[0060] Embodiment 11 This embodiment provides a lithium-ion battery electrolyte, and the difference from Embodiment 1 is only that: the first additive is replaced with an equal amount of .

[0061] Embodiment 12 This embodiment provides a lithium-ion battery electrolyte, which is only different from that of Embodiment 1 in that: the first additive is replaced with an equal amount of .

[0062] Embodiment 13 This embodiment provides a lithium-ion battery electrolyte, which is only different from that of Embodiment 1 in that: the first additive is replaced with an equal amount of .

[0063] Embodiment 14 This embodiment provides a lithium-ion battery electrolyte, which is only different from that of Embodiment 1 in that: the first additive is replaced with an equal amount of .

[0064] Embodiment 15 This embodiment provides a lithium-ion battery electrolyte, which is only different from that of Embodiment 1 in that: the organic solvent is replaced with an equal amount of ethylene carbonate (EC), ethyl methyl carbonate (EMC), and dimethyl carbonate (DMC) with a mass ratio of 2:3:1; the lithium supplement agent is 2 wt% Li 5 FeO 4 ; and it does not contain DTD.

[0065] Embodiment 16 This embodiment provides a lithium-ion battery electrolyte, which is only different from that of Embodiment 1 in that the addition amount of the lithium salt is 12.5 wt% of LiPF 6 .

[0066] Embodiment 17 This embodiment provides a lithium-ion battery electrolyte, which is only different from that of Embodiment 1 in that: the second additive is replaced with 1 wt% of fluoroethylene carbonate (FEC).

[0067] Embodiment 18 This embodiment provides a lithium-ion battery electrolyte, which is only different from that of Embodiment 1 in that: the lithium salt is replaced with 7 wt% of LiPF 6 and 8 wt% LiFSI.

[0068] Embodiment 19 This embodiment provides a lithium-ion battery electrolyte, which is only different from that of Embodiment 1 in that: the solvent is ethylene carbonate (EC), ethyl methyl carbonate (EMC), dimethyl carbonate (DMC), and ethyl acetate (EA) in a ratio of 1:1:1:1.

[0069] Embodiment 20 This embodiment provides a lithium-ion battery electrolyte, and the difference from Embodiment 1 is only that: the solvents are ethylene carbonate (EC), ethyl methyl carbonate (EMC), dimethyl carbonate (DMC), and ethyl propionate (EP) in a ratio of 1:1:1:1.

[0070] Comparative Example 1 This comparative example provides a lithium-ion battery electrolyte, and the difference from Embodiment 1 is only that: is replaced with an equal amount of .

[0071] Test Example The present invention further tests the battery performance prepared in the above embodiments and comparative examples, and the test results are shown in Table 2: Table 2

[0072] It can be seen from a comparison of Embodiments 1 to 3, Embodiments 5 to 8 with Embodiments 10 to 14 that when a silyl group or a silylene group is connected to the 4th position of the pyridine ring compared with other positions, the battery has better cycling performance; it can be seen from a comparison of Embodiment 4 with Embodiment 1 that when the dosage of the first additive is within 1.5%, it is more conducive to improving the battery performance. It can be seen from a comparison of Embodiment 9 with Embodiments 1 to 3, Embodiments 5 to 8 that when an amino group is connected to the pyridine ring, the halogen atom and the alkyl group connected to the silyl group are substituted by fluorine atoms, the battery performance is better; compared with Embodiment 17 and Embodiment 1, when the mass ratio of the first additive to the second additive exceeds the range defined in the present invention, it will affect the cycling and rate performance of the battery.

[0073] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent substitutions on some of the technical features; and these modifications or substitutions do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A lithium ion battery electrolyte, characterized in that: It includes a lithium supplement and an additive, wherein the additive includes a first additive, the first additive includes a pyridine compound, and the pyridine compound has any of the following general structural formulas: wherein R1, R2 and R3 are independently, identically or differently, halogen, C1-C7 alkyl or C1-C7 alkyl substituted by halogen; R5, R6, R7, R8, R9, R 10 , R 11 , R 12 , R 13 , R 14 , R 15 , R5', R6', R7', R8', R9', R 10 '、R 11 '、R 12 '、R 13 '、R 14 ' and R 15 'Each independently, the same or different represents hydrogen, halogen, amino, C1~C7 alkyl or C1~C7 alkyl substituted by halogen.

2. The lithium ion battery electrolyte according to claim 1, characterized in that: The pyridine compound has any of the following general structural formulas: 。 3. The lithium ion battery electrolyte according to claim 1 or 2, characterized in that: R1, R2 and R3 independently, identically or differently, represent halogen, C1-C3 alkyl or C1-C3 alkyl substituted by halogen; R5, R6, R7, R8, R9, R 10 , R 11 , R 12 , R 13 , R 14 , R 15 , R5', R6', R7', R8', R9', R 10 '、R 11 '、R 12 '、R 13 '、R 14 ' and R 15 'Each independently, identically or differently, represents hydrogen, halogen, amino, C1~C3 alkyl or C1~C3 alkyl substituted by halogen; the halogen is fluorine or iodine; Preferably, position 4 of the pyridine ring is connected to a silyl group or a silene group, and one or more of positions 2, 3, 5 and 6 are connected to a halogen, an amino group or an alkyl group substituted by a halogen; preferably, the alkyl group substituted by a halogen is selected from -CFH2, -CF2H or -CF3.

4. The lithium ion battery electrolyte according to any one of claims 1 to 3, characterized in that The first additive includes any of the following pyridine compounds: Preferably, the first additive is selected from any one or more of A14-A24.

5. The lithium ion battery electrolyte according to any one of claims 1 to 4, characterized in that The amount of the first additive in the lithium ion battery electrolyte is 0.01-5wt%.

6. The lithium ion battery electrolyte according to any one of claims 1 to 5, characterized in that The lithium supplement agent includes one or more of lithium-rich lithium iron oxide, lithium-rich lithium nickel oxide, lithium-rich lithium cobalt oxide, lithium oxide, lithium nitride, lithium peroxide, lithium fluoride, lithium silicate, lithium phosphate, and lithium sulfate; preferably, the amount of the lithium supplement agent in the lithium-ion battery electrolyte is 0.1~10wt%.

7. The lithium ion battery electrolyte according to claim 6, characterized in that: The mass ratio of the first additive to the lithium supplement is (0.1-4): (0.5-5).

8. The lithium ion battery electrolyte according to any one of claims 1 to 7, characterized in that The additive also includes a second additive, wherein the second additive includes one or more of ethylene carbonate, 1,3-propane sultone, fluoroethylene carbonate, vinyl sulfate, tri-(trimethylsilane) phosphite, tri-(trimethylsilane) borate, propylene sultone, methylene disulfonate, ethylene glycol bis(propionitrile) ether, biphenyl, ethylene carbonate, 1,4-butane sultone, trimethyl phosphate, triphenyl phosphate, tributyl phosphate, trifluoroethyl phosphate and fluorine-containing ether; Preferably, the amount of the second additive in the lithium-ion battery electrolyte is 0.1-5wt%; Preferably, the mass ratio of the first additive to the second additive is (0.1-4):(1.5-5).

9. The lithium ion battery electrolyte according to any one of claims 1 to 7, characterized in that The lithium salt in the electrolyte includes: one or more of lithium hexafluorophosphate, lithium perchlorate, lithium bis(trifluoromethanesulfonyl imide), lithium trifluoromethanesulfonate, lithium bis(oxalatoborate), lithium difluorooxalatoborate, lithium tetrafluoroborate and lithium difluorophosphate; preferably, the mass of the lithium salt is 10wt% to 30wt% of the total mass of the lithium ion battery electrolyte; Preferably, the organic solvent in the electrolyte includes one or more of dimethyl carbonate, ethyl methyl carbonate, ethylene carbonate, propylene carbonate, diethyl carbonate, ethyl acetate, ethyl propionate, propyl propionate, methyl acetate and methyl propionate; preferably, the mass of the organic solvent is 70wt%~90wt% of the total mass of the lithium ion battery electrolyte.

10. A lithium ion battery, characterized in that: It contains the lithium ion battery electrolyte according to any one of claims 1 to 9.

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