WO2020042420A1 - Non-aqueous electrolyte solution for lithium-ion battery and lithium-ion battery using the same - Google Patents

Abstract

A non-aqueous electrolyte solution for a lithium-ion battery and a lithium-ion battery using the same. The electrolyte solution comprises one or more compounds represented by structural formula (I), wherein each of R ₁, R ₂, R ₃, R ₄, R ₅ and R ₆ is independently selected from a hydrogen atom, a halogen atom, or a C1-C5 group. Due to the presence of the compound represented by structural formula 1, the non-aqueous electrolyte solution for the lithium-ion battery further improves the high-temperature cycling performance of the lithium-ion battery and suppresses swelling, while also reducing resistance. A lithium-ion battery prepared from the non-aqueous electrolyte solution has excellent high-temperature resistance and excellent cycling performance, thereby effectively avoiding the issues of lithium-ion batteries such as instability under high temperature conditions, battery swelling, and severe reversible capacity loss of the battery.

Description

Non-aqueous electrolyte for lithium ion battery and lithium ion battery using the electrolyte Technical field

The present invention relates to the technical field of lithium ion batteries, and in particular, to a lithium ion battery non-aqueous electrolyte and a lithium ion battery using the electrolyte.

Background technique

Lithium-ion batteries have the characteristics of high energy density and high power, long cycle life, high safety, wide operating temperature range, and no memory effect. With the vigorous promotion of new energy and a low-carbon economy, the demand for lithium batteries for electric vehicles and energy storage equipment has grown rapidly, making lithium-ion batteries have great application prospects in the new energy field in the future.

In order to improve the performance of lithium-ion batteries, many researchers have improved the performance of batteries by adding different additives to the electrolyte, such as vinylene carbonate, fluoroethylene carbonate, and ethylene ethylene carbonate. When vinylene carbonate is added, the battery is prone to generate gas during high-temperature storage, which causes the battery to swell. Today, the nickel content of the positive electrode materials of high-energy high-density nickel-lithium ion batteries is getting higher and higher, but the high nickel content materials tend to absorb water, which leads to the decline of the electrolyte stability, especially at high potentials, the nickel element of the positive electrode material It will accelerate the decomposition of conventional electrolytes, resulting in reduced battery cycling performance and severe battery inflation at high temperatures. The prior art proposes to improve the cycle performance of batteries and suppress high-temperature weather by adding a monocyclic cyclic acid anhydride derivative to the electrolyte. During the first charging of the battery, other components in the electrolyte can be preferentially reduced to form a film. The formed SE film has good stability and can effectively improve the cycle performance and high temperature performance of the battery. However, the improvement of the cycling performance and the suppression of flatness of the monocyclic cyclic acid anhydride are far from meeting the market requirements. There is a need to further improve the high-temperature cycling performance of batteries, solve their instability under high-temperature conditions, and cause serious problems such as battery inflation and battery reversible capacity loss.

Summary of the Invention

The invention provides a lithium-ion battery non-aqueous electrolyte solution that further improves the high-temperature cycling performance of the battery, suppresses gas inflation, and reduces resistance, and further provides a lithium-ion battery including the lithium-ion battery non-aqueous electrolyte solution.

According to a first aspect of the present invention, the present invention provides a non-aqueous electrolyte solution for a lithium ion battery, including one or more of the compounds shown in Structure 1,

Among them, R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , and R ₆ are each independently selected from hydrogen, a halogen atom, or a group containing 1 to 5 carbon atoms.

Further, the group containing 1 to 5 carbon atoms is selected from a hydrocarbon group, a halogenated hydrocarbon group, an oxygen-containing hydrocarbon group, a silicon-containing hydrocarbon group or a cyano-substituted hydrocarbon group.

Further, each of the R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , and R _{6 is} independently selected from a hydrogen atom, a fluorine atom, a methyl group, an ethyl group, a trimethylsiloxy group, a cyano group, or a trivalent group. Cyanomethyl.

Further, the content of the compound represented by the structural formula 1 is 0.1% to 5% with respect to the total mass of the non-aqueous electrolyte solution of the lithium ion battery.

Further, the lithium ion battery non-aqueous electrolyte further includes one or more of vinylene carbonate, ethylene ethylene carbonate, and fluoroethylene carbonate.

Further preferably, the lithium ion battery non-aqueous electrolyte further includes one or more of 1,3-propanesultone, 1,4-butanesultone, and 1,3-propanesultone.

Further, the lithium ion battery non-aqueous electrolyte further includes a lithium salt and a non-aqueous organic solvent, the lithium salt is selected from LiPF ₆ , LiBF ₄ , LiBOB, LiDFOB, LiSbF ₆ , LiAsF ₆ , LiN (SO ₂ CF ₃ ) ₂ , one or more of LiN (SO ₂ C ₂ F ₅ ) ₂ , LiC (SO ₂ CF ₃ ) ₃ or LiN (SO ₂ F) ₂ , the lithium salt relative to the total mass of the non-aqueous electrolyte 0.1% to 15%; the non-aqueous organic solvent is a mixture of a cyclic carbonate and a chain carbonate, and the cyclic carbonate is selected from one of ethylene carbonate, propylene carbonate, or butene carbonate Or more, the chain carbonate is selected from one or more of dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate or methyl propyl carbonate.

According to a second aspect of the present invention, the present invention provides a lithium ion battery including a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode, and further including the lithium ion battery non-aqueous electrolyte solution of the first aspect.

Further, the positive electrode includes a positive electrode active material, and the positive electrode active material is selected from LiCoO ₂ , LiNiO ₂ , LiMn ₂ O ₄ , LiCo _1-y M _y O ₂ , LiNi _1-y M _y O ₂ , LiMn _{2- y} M _y O ₄ or one or more of LiNi _x Co _y Mn _z M _1-xyz O ₂ , wherein M is selected from the group consisting of Fe, Co, Ni, Mn, Mg, Cu, Zn, Al, Sn, B Or Ga, Cr, Sr, V or Ti, and 0≤y≤1, 0≤x≤1, 0≤z≤1, x + y + z≤1.

Further, the positive electrode active material is selected from LiFe _1-x M _x PO ₄ , where M is selected from Mn, Mg, Co, Ni, Cu, Zn, Al, Sn, B, Ga, Cr, Sr, V or Ti One or more of them, and 0 ≦ x <1.

The present invention has the following beneficial effects: The lithium-ion battery non-aqueous electrolyte of the present invention contains a compound represented by the structural formula 1. Due to the existence of the compound represented by the structural formula 1, the high-temperature performance and Low temperature performance is excellent.

detailed description

In order to make the technical problems, technical solutions, and beneficial effects solved by the present invention clearer, the present invention will be further described in detail in combination with the following embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

An embodiment of the present invention discloses a non-aqueous electrolyte solution for a lithium ion battery, which includes a solvent, a lithium salt, a non-aqueous solvent, and a compound additive, and further includes a structure 1 additive, and the structure 1 additive includes at least one structure.

The non-aqueous electrolyte solution of the lithium ion battery of the present invention contains a compound represented by structural formula 1. Its mechanism of action is presumed that during the first charging process, the binary cyclic acid anhydride structure in the molecule of structural formula 1 can preferentially undergo a reduction and decomposition reaction with a solvent molecule. The reaction product forms a passivation film on the electrode surface. The passivation film can inhibit the further decomposition of the solvent molecules. At the same time, because the molecular structure is a binary cyclic acid anhydride structure, the passivation film formed by the reaction product is more linear than a linear carboxylic acid anhydride or a monocyclic The passivation film formed by the acid anhydride is more stable. In addition, since the formed passivation film can effectively prevent the further decomposition of the solvent molecules and lithium salt molecules, it can significantly improve the high temperature cycle of the battery and suppress the gas inflation phenomenon.

In some embodiments, R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ are each independently selected from a hydrocarbon group, an oxygen-containing hydrocarbon group, a silicon-containing hydrocarbon group, a sulfur-containing hydrocarbon group, a cyano-containing hydrocarbon group, or a halogenated hydrocarbon group. .

It should be further explained that in the case where R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , and R ₆ are each independently selected from a group containing a carbon atom, the number of carbon atoms is controlled to 5 or less (including 5) is advantageous. Controlling the number of carbon atoms to less than 5 can reduce the resistance of the battery and take into account both high temperature performance and low temperature performance; however, if a carbon atom-containing group with a carbon number of 6 or more is selected as a substituent, the battery resistance will increase, and The high-temperature performance of the battery and the inhibition of gas inflation have an adverse effect, so the present invention does not select a carbon atom-containing group having 6 or more carbon atoms as a substituent. In the present invention, the optional group containing 1 to 5 carbon atoms is preferably a hydrocarbon group, a halogenated hydrocarbon group, an oxygen-containing hydrocarbon group, a silicon-containing hydrocarbon group, or a cyano-substituted hydrocarbon group, for example, in some preferred embodiments of the present invention. In the examples, fluoro or trifluoromethyl is preferred. In other preferred embodiments of the present invention, R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , and R ₆ are each independently selected from a hydrogen atom and a fluorine atom.

Controlling the content of the compound represented by Structural Formula 1 in the wastewater electrolyte has a favorable effect on the further optimization of high-temperature performance and low-temperature performance. In a preferred embodiment of the present invention, the content of the compound represented by Structural Formula 1 is 0.1% to 5% relative to the total mass of the non-aqueous electrolyte solution of the lithium ion battery. When it is less than 0.1%, it is difficult to sufficiently form a passivation film on the surface of the negative electrode, so that it is difficult to sufficiently improve the high temperature performance of the non-aqueous electrolyte battery, and to suppress the phenomenon of gas inflation. Instead, the internal resistance of the battery is increased, and the battery capacity retention rate is significantly degraded, reducing the battery performance. The study found that the content of the compound represented by Structural Formula 1 is less than 0.1% or more than 5% of the total mass of the non-aqueous electrolyte of the lithium ion battery, compared with the high temperature performance and low temperature performance of the lithium ion battery in the range of 0.1% to 5%. All of them are reduced to different degrees, which indicates that it is of positive significance to control the content of the compound represented by structural formula 1 in the non-aqueous electrolyte.

Exemplary compounds among the compounds represented by Structural Formula 1 are shown in Table 1, but are not limited thereto.

Table 1

The lithium ion battery non-aqueous electrolyte of the present invention may further add additives, such as one or more selected from the group consisting of vinylene carbonate (VC), ethylene ethylene carbonate (VEC), and fluoroethylene carbonate (FEC). ; Can also be selected from one of 1,3-propanesultone (1,3-PS), 1,4-butanesultone (BS), 1,3-propanesultone (PST) or Multiple. These additives can form a more stable SEI film on the surface of the graphite negative electrode, thereby significantly improving the cycling performance of lithium ion batteries. These additives can be added according to the ordinary addition amount in the art, for example, 0.1% to 5%, preferably 0.2% to 3%, and more preferably 0.5% to 2% with respect to the total mass of the electrolytic solution.

The inventors have found through a large number of experiments that the combination of the structural formula 1 compound additive provided by the present invention and the above-mentioned additives can achieve better effects than when they are used alone. It is speculated that there is a synergy between them, that is, the structural formula 1 compound additive and the above-mentioned additive pass Synergies work together to improve battery cycle performance, high-temperature storage, and inhibit flatulence.

In some embodiments, the solvent is a mixture of refill carbonates and chain carbonates.

In a more preferred embodiment, the cyclic carbonate includes one or more of ethylene carbonate, propylene carbonate or butene carbonate, and the chain carbonate includes dimethyl carbonate, diethyl carbonate One or more of esters, methyl ethyl carbonate or methyl propyl carbonate.

The lithium salt is selected from LiPF ₆ , LiBF ₄ , LiBOB, LiDFOB, LiSbF ₆ , LiAsF ₆ , LiN (SO ₂ CF ₃ ) ₂ , LiN (SO ₂ C ₂ F ₅ ) ₂ , LiC (SO ₂ CF ₃ ) ₃ Or one or more of LiN (SO ₂ F) ₂ . Preferably, the lithium salt is selected from LiPF ₆ or a mixture of LiPF ₆ and other lithium salts, and the content of the lithium salt can be varied within a wide range. Preferably, in the non-aqueous electrolyte solution of the lithium ion battery, The content of the lithium salt is 0.1% to 15%.

Another embodiment of the present invention provides a lithium ion battery, including a positive electrode, a negative electrode, and the lithium ion battery non-aqueous electrolyte as described above.

The positive electrode includes a positive electrode active material.

In some embodiments, the positive electrode active material includes LiFe _1-x M _x O ₄ , LiCoO ₂ , LiNiO ₂ , LiMn ₂ O ₄ , LiCo _1-y M _y O ₂ , LiNi _1-y M _y O ₂ , One or more of LiMn _2-y M _y O ₄ or LiNi _x Co _y Mn _z M _1-xyz O ₂ , wherein M is selected from Fe, Co, Ni, Mn, Mg, Cu, Zn, Al, One or more of Sn, B, Ga, Cr, Sr, V or Ti, and 0≤y≤1, 0≤x≤1, 0≤z≤1, x + y + z≤1.

The positive electrode further includes a positive electrode current collector for drawing a current, and the positive electrode active material covers the positive electrode current collector.

The negative electrode further includes a negative electrode current collector for drawing a current, and the negative electrode active material covers the negative electrode current collector.

In some embodiments, a separator is further provided between the positive electrode and the negative electrode, and the separator is a conventional separator in the field of lithium ion batteries.

In one embodiment, the positive electrode material is LiNi _0.5 Co _0.2 Mn _0.3 O ₂ , and the negative electrode material is artificial graphite.

Since the lithium ion battery provided by the embodiment of the present invention contains the above-mentioned non-aqueous electrolyte, it can effectively solve the cycle performance problem of the lithium ion battery and improve the high and low temperature cycle performance of the lithium ion battery.

The present invention is described in detail below through specific embodiments. It should be understood that these embodiments are merely exemplary and do not constitute a limitation on the protection scope of the present invention.

Example 1

This embodiment is used to describe the lithium-ion battery non-aqueous electrolyte disclosed in the present invention, a lithium-ion battery and a preparation method thereof, and includes the following operation steps:

1) Preparation of non-aqueous electrolyte:

Mix ethylene carbonate (EC), diethyl carbonate (DEC), and ethyl methyl carbonate (EMC) at a mass ratio of EC: DEC: EMC = 1: 1: 1, and then add lithium hexafluorophosphate (LiPF ₆ ) to the mole The concentration is 1 mol / L, and based on the total weight of the non-aqueous electrolyte solution being 100%, the components are added in a mass percentage content as shown in Example 1 in Table 2.

2) Preparation of positive plate:

The positive electrode active material lithium nickel cobalt manganese oxide LiNi _0.5 Co _0.2 Mn _0.3 O ₂ , conductive carbon black Super-P, and binder polyvinylidene fluoride (PVDF) were mixed at a mass ratio of 93: _{4: 3} , and then they were mixed. It was dispersed in N-methyl-2-pyrrolidone (NMP) to obtain a positive electrode slurry. The slurry is evenly coated on both sides of the aluminum foil, dried, calendered and vacuum-dried, and an aluminum welding wire is welded with an ultrasonic welder to obtain a positive electrode plate with a thickness of 120-150 μm.

3) Preparation of negative plate:

Mix the negative active material artificial graphite, conductive carbon black Super-P, binder styrene-butadiene rubber (SBR) and carboxymethyl cellulose (CMC) at a mass ratio of 94: 1: 2.5: 2.5, and disperse them in In ion water, a negative electrode slurry was obtained. The slurry is coated on both sides of the copper foil, dried, calendered and vacuum dried, and a nickel lead wire is welded with an ultrasonic welder to obtain a negative electrode plate with a thickness of 120-150 μm.

4) Preparation of batteries

A three-layer separator with a thickness of 20 μm was placed between the positive electrode plate and the negative electrode plate, and then a sandwich structure composed of the positive electrode plate, the negative electrode plate, and the separator was wound, and the rolled body was crushed and put into an aluminum foil packaging bag. Bake under vacuum at ℃ for 48h to obtain the battery to be filled.

5) Liquid injection and formation of batteries

In a glove box with a dew point controlled below -40 ° C, the prepared electrolyte was injected into the battery cell, vacuum-sealed, and left to stand for 24 hours.

Then, follow the steps below to perform the conventional charge for the first charge: 0.05C constant current charge for 180min, 0.2C constant current charge to 3.95V, secondary vacuum sealing, and then further charge at 4.2C constant current to 4.2V. After leaving at room temperature for 24hr A constant current of 0.2C was discharged to 3.0V to obtain a LiNi _0.5 Co _0.2 Mn _0.3 O ₂ / artificial graphite lithium ion battery.

6) High temperature cycle performance test

The battery was placed in an oven at a constant temperature of 45 ° C, and was charged at a constant current of 1C to 4.2V, then charged at a constant voltage until the current dropped to 0.02C, and then discharged at a constant current of 1C to 3.0V. In this cycle, record the first The discharge capacity of one cycle and the discharge capacity of the last cycle, the capacity retention rate of the high temperature cycle is calculated according to the following formula:

Capacity retention rate = discharge capacity of the last cycle / discharge capacity of the first cycle × 100%

7) High temperature storage performance test

Charge the formed battery to 4.2V with 1C constant current and constant voltage at room temperature, measure the battery's initial discharge capacity and initial battery thickness, and then store at 60 ° C for 30 days, then discharge to 1C to 3V, measure the battery's holding capacity and recovery Capacity and battery thickness after storage. Calculated as follows:

Battery capacity retention rate (%) = retained capacity / initial capacity × 100%;

Battery capacity recovery rate (%) = recovery capacity / initial capacity × 100%;

Thickness expansion ratio (%) = (battery thickness after storage-initial battery thickness) / initial battery thickness × 100%.

8) Low temperature performance test

At 25 ° C, the formed battery was charged to 4.2V with 1C constant current and constant voltage, and then discharged to 3.0V with 1C constant current, and the discharge capacity was recorded. Then 1C constant current and constant voltage was charged to 4.2V, and after being left in an environment of -20 ° C for 12 hours, 0.2C constant current was discharged to 3.0V, and the discharge capacity was recorded.

Low-temperature discharge efficiency at -20 ° C = 0.2C discharge capacity (-20 ° C) / 1C discharge capacity (25 ° C) × 100%.

Example 2

As shown in Table 2, except that 1% of Compound 1 was replaced by 1% of Compound 2 in the preparation of the non-aqueous electrolyte solution, the rest were the same as in Example 1. The data of the high-temperature performance and low-temperature performance obtained in the test are shown in Table 3. .

Example 3

As shown in Table 2, except that 1% of Compound 1 was replaced with 1% of Compound 3 in the preparation of the non-aqueous electrolyte solution, the same as Example 1 was performed. The data of the high temperature performance and low temperature performance obtained in the test are shown in Table 3. .

Example 4

As shown in Table 2, except that 1% of Compound 1 was replaced by 1% of Compound 4 in the preparation of the non-aqueous electrolyte solution, the same as Example 1 was performed. The data of the high temperature performance and low temperature performance obtained in the test are shown in Table 3. .

Example 5

As shown in Table 2, except that 1% of Compound 1 was replaced by 1% of Compound 5 in the preparation of the non-aqueous electrolyte solution, the same as Example 1 was performed. The data of the high-temperature performance and low-temperature performance obtained in the test are shown in Table 3. .

Example 6

As shown in Table 2, except that 1% of Compound 1 was replaced with 1% of Compound 6 in the preparation of the non-aqueous electrolyte, the same as Example 1 was performed, and the data of the high temperature performance and low temperature performance obtained in the test are shown in Table 3 .

Comparative Example 1

As shown in Table 2, except that 1% of Compound 1 and 1% of vinylene carbonate were not added in the preparation of the electrolytic solution, the others were the same as in Example 1. The data of the high-temperature performance and low-temperature performance obtained in the test are shown in Table 3. .

Comparative Example 2

As shown in Table 2, except that 1% of the compound 1 was replaced with 1% of maleic anhydride in the preparation of the electrolytic solution, the rest were the same as in Example 1. The data of the high temperature performance and low temperature performance obtained in the test are shown in Table 3.

Comparative Example 3

As shown in Table 2, except that 1% of the compound 1 was replaced with 1% of succinic anhydride in the preparation of the electrolytic solution, the rest were the same as in Example 1. The data of the high temperature performance and low temperature performance obtained in the test are shown in Table 3.

Comparative Example 4

As shown in Table 2, except that 1% of the compound 1 was replaced with 1% of tetrafluorosuccinic anhydride in the preparation of the electrolytic solution, the others were the same as in Example 1. The data of the high temperature performance and low temperature performance obtained in the test are shown in Table 3.

Table 2

Examples / comparative examples	Compound additives and content	Other additives and content
Example 1	Compound 1: 1%	Vinyl carbonate: 1%
Example 2	Compound 2: 1%	Vinyl carbonate: 1%

Example 3	Compound 3: 1%	Vinyl carbonate: 1%
Example 4	Compound 4: 1%	Vinyl carbonate: 1%
Example 5	Compound 5: 1%	Vinyl carbonate: 1%
Example 6	Compound 6: 1%	Vinyl carbonate: 1%
Comparative Example 1	-	-
Comparative Example 2	Maleic anhydride: 1%	Vinyl carbonate: 1%
Comparative Example 3	Succinic anhydride: 1%	Vinyl carbonate: 1%
Comparative Example 4	Tetrafluorosuccinic anhydride: 1%-	Vinyl carbonate: 1%

table 3

Comparing the test results of Examples 1 to 6 and Comparative Examples 1 to 4, it can be seen that compared with compounds added with monocyclic cyclic similar structural units, such as maleic anhydride, succinic anhydride, and tetrafluorosuccinic anhydride, in a non-aqueous electrolyte Adding 1% of compounds 1 to 6 can significantly improve the high-temperature performance and flatness of lithium-ion batteries.

Example 7

As shown in Table 4, except that 1% of Compound 1 was replaced by 0.1% of Compound 1 in the preparation of the non-aqueous electrolyte solution, the same was performed as in Example 1. The data of the high temperature performance and low temperature performance obtained in the test are shown in Table 5. .

Example 8

As shown in Table 4, except that 1% of Compound 1 was replaced by 2% of Compound 1 in the preparation of the non-aqueous electrolyte solution, the same as Example 1 was performed. The data of the high temperature performance and low temperature performance obtained in the test are shown in Table 5. .

Example 9

As shown in Table 4, except that 1% of Compound 1 was replaced with 3% of Compound 1 in the preparation of the non-aqueous electrolyte solution, the same was performed as in Example 1. The data of the high temperature performance and low temperature performance obtained in the test are shown in Table 5. .

Example 10

As shown in Table 4, except that 1% of Compound 1 was replaced by 5% of Compound 1 in the preparation of the non-aqueous electrolyte, the same as Example 1 was performed, and the data of the high temperature performance and low temperature performance obtained in the test are shown in Table 5 .

Table 4

Examples	Compound additives and content	Other additives and content
Example 7	Compound 1: 0.1%	Vinyl carbonate: 1%
Example 8	Compound 1: 2%	Vinyl carbonate: 1%
Example 9	Compound 1: 3%	Vinyl carbonate: 1%

Example 10

Compound 1: 5%

Vinyl carbonate: 1%

table 5

Comparing the test results of Examples 7 to 10 and Comparative Examples 1 to 4, it can be seen that the lithium ion prepared by adding 0.1% of Compound 1 or 5% of Compound 1 to the non-aqueous electrolyte compared with 2% or 3% of Compound 1 The battery has slightly deteriorated high-temperature performance and low-temperature performance. It means that too little or too much addition will cause the high-temperature performance and low-temperature performance of lithium-ion batteries to deteriorate.

Example 11

As shown in Table 6, except that 1% vinylene carbonate was replaced by 1% ethylene ethylene carbonate in the preparation of the non-aqueous electrolyte solution, the data were the same as those in Example 1, and the high-temperature performance and low-temperature performance data were obtained. See Table 7.

Example 12

As shown in Table 6, except that 1% vinylene carbonate was replaced with 1% fluoroethylene carbonate in the preparation of the non-aqueous electrolyte solution, the data were the same as those in Example 1, and the high-temperature performance and low-temperature performance data were obtained. See Table 7.

Comparative Example 5

As shown in Table 6, it is the same as Example 1 except that 1% of Compound 1 is not added in the preparation of the electrolytic solution. Table 7 shows the data of the high-temperature performance and low-temperature performance.

Comparative Example 6

As shown in Table 6, except that 1% of Compound 1 was not added in the preparation of the electrolytic solution, and 1% of vinylene carbonate was replaced with 1% of ethylene ethylene carbonate, the rest was the same as in Example 1. The performance and low temperature performance data are shown in Table 7.

Comparative Example 7

As shown in Table 6, except that 1% of Compound 1 was not added in the preparation of the electrolytic solution, and 1% of vinylene carbonate was replaced with 1% of fluoroethylene carbonate, the rest was the same as in Example 1. The performance and low temperature performance data are shown in Table 7.

Table 6

Examples / comparative examples	Compound additives and content	Other additives and content
Example 11	Compound 1: 1%	Ethylene ethylene carbonate: 1%
Example 12	Compound 1: 1%	Fluorinated ethylene carbonate: 1%
Comparative Example 5	-	Vinyl carbonate: 1%
Comparative Example 6	-	Ethylene ethylene carbonate: 1%
Comparative Example 7	-	Fluorinated ethylene carbonate: 1%

Table 7

By comparing the test results of Examples 1, 11, and 12 with Comparative Examples 5-7, it can be known that the addition of the compound additive provided by the present invention can further optimize and improve the high-temperature performance and gas bloating of the lithium ion battery.

In summary, the compound additive provided by the present invention can effectively improve the high temperature performance and bulging of lithium ion batteries on the basis of adding additives such as vinylene carbonate, ethylene ethylene carbonate, or fluoroethylene carbonate. In addition, it can be further optimized to make each performance more optimized.

The above description is only the preferred embodiments of the present invention, and does not limit the present invention in any form. Any person skilled in the industry can smoothly implement the present invention as described above; however, anyone familiar with the present invention Those skilled in the art, without departing from the scope of the technical solution of the present invention, can use the technical content disclosed above to make equivalent changes, modifications, and evolutions, which are all equivalent embodiments of the present invention. Any modification, modification, and evolution of the equivalent technology to the above embodiments by the essential technology of the present invention still fall within the protection scope of the technical solution of the present invention.

Claims (10)

1. A non-aqueous electrolyte solution for a lithium ion battery, which is characterized by comprising one or more of the compounds shown in Structure 1,

   

   Among them, R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , and R ₆ are each independently selected from hydrogen, a halogen atom, or a group containing 1 to 5 carbon atoms.
2. The non-aqueous electrolyte solution for a lithium ion battery according to claim 1, wherein the group containing 1 to 5 carbon atoms is selected from the group consisting of a hydrocarbon group, a halogenated hydrocarbon group, an oxygen-containing hydrocarbon group, a silicon-containing hydrocarbon group, or a cyano-containing group. Substituted hydrocarbyl.
3. The non-aqueous electrolyte solution for a lithium ion battery according to claim 1 or 2, wherein each of R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , and R _{6 is} independently selected from a hydrogen atom and a fluorine atom. , Methyl, ethyl, trimethylsiloxy, cyano or tricyanomethyl.
4. The non-aqueous electrolyte solution for a lithium ion battery according to claim 3, wherein the content of the compound represented by the structural formula 1 is 0.1% to 5% relative to the total mass of the non-aqueous electrolyte solution for the lithium ion battery.
5. The non-aqueous electrolyte solution for a lithium-ion battery according to claim 4, wherein the non-aqueous electrolyte solution for a lithium-ion battery further comprises one of vinylene carbonate, ethylene ethylene carbonate, and fluoroethylene carbonate. Or more.
6. The non-aqueous electrolyte solution for a lithium-ion battery according to claim 4, wherein the non-aqueous electrolyte solution for a lithium-ion battery further comprises 1,3-propanesultone, 1,4-butanesultone, 1 One or more of 3-propene sultone.
7. The lithium-ion battery non-aqueous electrolyte according to claim 5 or 6, wherein the lithium-ion battery non-aqueous electrolyte further comprises a lithium salt and a non-aqueous organic solvent, and the lithium salt is selected from the group consisting of LiPF ₆ and LiBF. ₄ , LiBOB, LiDFOB, LiSbF ₆ , LiAsF ₆ , LiN (SO ₂ CF ₃ ) ₂ , LiN (SO ₂ C ₂ F ₅ ) ₂ , LiC (SO ₂ CF ₃ ) ₃ or LiN (SO ₂ F) ₂ One or more kinds of the lithium salt with respect to the total mass of the non-aqueous electrolyte is 0.1% to 15%; the non-aqueous organic solvent is a mixture of a cyclic carbonate and a chain carbonate, and the cyclic carbonate One or more selected from the group consisting of ethylene carbonate, propylene carbonate, or butene carbonate, and the chain carbonate is selected from dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, or methyl propyl carbonate One or more.
8. A lithium ion battery includes a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode, and further comprises a non-aqueous electrolyte solution for a lithium ion battery according to any one of claims 1 to 7.
9. The lithium ion battery according to claim 8, wherein the positive electrode comprises a positive electrode active material, and the positive electrode active material is selected from the group consisting of LiCoO ₂ , LiNiO ₂ , LiMn ₂ O ₄ , LiCo _1-y M _y O ₂ , One or more of LiNi _1-y M _y O ₂ , LiMn _2-y M _y O ₄ or LiNi _x Co _y Mn _z M _1-xyz O ₂ , wherein M is selected from Fe, Co, Ni, Mn One or more of Mg, Cu, Zn, Al, Sn, B, Ga, Cr, Sr, V or Ti, and 0≤y≤1, 0≤x≤1, 0≤z≤1, x + y + z≤1.
10. The lithium ion battery according to claim 9, wherein the positive electrode active material is selected from LiFe _1-x M _x PO ₄ , and M is selected from Mn, Mg, Co, Ni, Cu, Zn, Al, Sn Or B, Ga, Cr, Sr, V or Ti, and 0≤x <1.