CN105895955A - Electrolyte and lithium ion battery - Google Patents

Abstract

The present application relates to an electrolyte solution and a lithium ion battery. The electrolyte solution includes an organic solvent, a lithium salt and an additive. The organic solvent contains a methylene disulfonate compound. The additive contains a positive electrode passivation protection agent, And a negative electrode film-forming additive with a higher reduction potential than the methylene disulfonate compound; the electrolyte can obviously improve the overcharge performance of the battery, and can improve the impact resistance of the battery.

Description

A kind of electrolytic solution and lithium ion battery

technical field

The present application relates to the technical field of lithium-ion batteries, in particular to an electrolyte and a lithium-ion battery.

Background technique

Lithium-ion batteries are widely used in consumer electronics products, energy storage and power batteries due to their advantages such as high specific energy, long cycle life, and small self-discharge. With the widespread application of lithium-ion batteries, their use environments have long tended to be diverse, and the requirements for battery safety performance are getting higher and higher. For example, in order to ensure the charging safety of electronic products, the batteries are required to have higher anti-overcharge safety performance when they are overcharged. Anti-collision safety performance.

In view of this, the present application is proposed.

Contents of the invention

The purpose of the present application is to provide an electrolyte and a lithium-ion battery using the electrolyte, so as to improve the overcharge safety performance of the battery and improve the impact safety performance of the battery at the same time.

The concrete technical scheme of this application is:

The application relates to an electrolytic solution, including an organic solvent, a lithium salt and an additive, the organic solvent contains methylene disulfonate compounds, and the additive contains a positive electrode passivation protection agent.

Preferably, the methylene disulfonate compound is selected from at least one of the compounds shown in formulas IA and IB;

Wherein, R ₁₁ to R ₁₆ are each independently selected from a hydrogen atom, a halogen atom, a substituted or unsubstituted C ₁ -C ₁₀ alkyl group, a substituted or unsubstituted C ₂ -C ₁₀ alkenyl group, a substituted or unsubstituted C ₆ -C ₁₀ aryl group; wherein, the substituent is a halogen atom.

Preferably, the methylene disulfonate compound is selected from at least one of the following compounds;

Preferably, the positive electrode passivation protection agent is selected from at least one of the nitrile compounds shown in structural formulas II, III, IV, V, and VI;

in,

R ₂₁ , R ₂₂ , and R ₂₃ are each independently selected from substituted or unsubstituted C ₁ -C ₃ alkylene, substituted or unsubstituted C ₂ -C ₃ alkenylene, substituted or unsubstituted C ₂ -C ₃ alkynylene groups, n is 1-5;

R ₃₁ is selected from substituted or unsubstituted C ₁ -C ₈ alkylene, substituted or unsubstituted C ₂ -C ₈ alkenylene, substituted or unsubstituted C ₂ -C ₈ alkynylene;

R ₄₁ and R ₄₂ are independently selected from substituted or unsubstituted C ₁ -C ₃ alkylene, substituted or unsubstituted C ₂ -C ₃ alkenylene, substituted or unsubstituted C ₂ -C ₃ alkynylene base;

R ₅₁ , R ₆₁ , R ₆₂ , and R ₆₃ are each independently selected from hydrogen, substituted or unsubstituted C ₁ -C ₆ alkyl, substituted or unsubstituted C ₂ -C ₆ alkenyl, substituted or unsubstituted C ₂ ~ C ₆ alkynyl, substituted or unsubstituted phenyl;

Wherein, the substituent is a C ₁ -C ₃ alkyl group.

Preferably, the positive electrode passivation protection agent is selected from adiponitrile, malononitrile, succinonitrile, glutaronitrile, suberonitrile and nitrile compounds shown in formula IIa, IIb, IIc, IIIa, IIIb, IVa at least one;

Preferably, the additive also contains a negative electrode film-forming additive with a reduction potential higher than that of the disulfonic acid methylene ester compound; preferably, the negative electrode film-forming additive is selected from γ-butyrolactone, vinylene carbonate , vinyl ethylene carbonate, succinic anhydride, maleic anhydride, 1,3-propane sultone and ethylene sulfate.

Preferably, the mass percentage of the negative film-forming additive in the electrolyte is 0.1%-20%; preferably 0.5%-8%.

Preferably, the mass percentage of the methylene disulfonate compound in the electrolyte is 0.1%-30%, preferably 1%-30%.

Preferably, the mass percentage of the anode passivation protection agent in the electrolyte is 0.1%-10%; preferably 0.5%-5%.

The present application also relates to a lithium-ion battery, comprising a positive electrode sheet, a negative electrode sheet, a separator disposed between the positive electrode sheet and the negative electrode sheet, and an electrolyte; the electrolyte is the electrolyte described in any one of the foregoing.

The technical solution provided by the application can achieve the following beneficial effects:

The methylene disulfonate compound of the present application can significantly improve the overcharge performance of the battery due to its oxidation potential lower than that of conventional solvent carbonates and the oxidation reaction forming an insulating layer on the surface of the positive electrode to block the current. At the same time, its excessively high reduction potential can inhibit the formation of a highly resistive and unstable negative electrode passivation film (SEI) by carbonates in the solvent, which can well ensure the stability of the battery interface when the battery is impacted. stability. Moreover, the products formed by the oxidation reaction of methylene disulfonate compounds will increase the impedance of the battery, and will reduce the internal current of the battery cell when it is hit or overcharged. The application adds a positive electrode passivation protection agent, which can inhibit the premature oxidative decomposition of the disulfonic acid methylene ester compound at the positive electrode, thereby preventing the premature consumption of the disulfonic acid methylene ester compound.

detailed description

In order to make the purpose, technical solution and advantages of the application clearer, the technical solution of the application will be clearly and completely described below in conjunction with the embodiments of the application. Obviously, the described embodiments are part of the embodiments of the application, rather than Full examples. All other embodiments obtained by those skilled in the art on the basis of the technical solutions and given embodiments provided in this application without creative efforts shall fall within the scope of protection of this application.

A kind of electrolytic solution that the application relates to comprises organic solvent, lithium salt and additive, and described organic solvent contains disulfonic acid methylene ester compound, contains anode passivation protection agent in the described additive.

It has been found through research that the methylene disulfonate compound can significantly improve the overcharge performance of the battery due to its oxidation potential lower than that of the conventional solvent carbonate and the oxidation reaction forming an insulating layer on the surface of the positive electrode to block the current. At the same time, its high reduction potential can inhibit the reduction and decomposition of the carbonate solvent in the electrolyte to form a highly resistive and unstable negative passivation film (SEI), which can well ensure that the battery is stable when it is hit. The stability of the cell interface. And the products formed by the oxidation reaction of disulfonic acid methylene ester compounds will increase the impedance of the battery, and will reduce the internal current of the battery when it is hit or overcharged. Compared with monosulfonic acid lactone compounds, disulfonic acid Methylene ester is easier to form a film and the film is stable, and it is not easy to decompose and regenerate during the cycle. The addition of the positive electrode passivation protection agent can inhibit the premature oxidative decomposition of the disulfonic acid methylene ester compound at the positive electrode, thereby preventing the premature consumption of the disulfonic acid methylene ester compound.

As an improvement of the electrolyte solution of the present application, the disulfonic acid methylene ester compound of the present application is selected from at least one of the compounds shown in formula IA and IB;

Wherein, R ₁₁ to R ₁₆ are each independently selected from a hydrogen atom, a halogen atom, a substituted or unsubstituted C ₁ -C ₁₀ alkyl group, a substituted or unsubstituted C ₂ -C ₁₀ alkenyl group, a substituted or unsubstituted C ₆ -C ₁₀ aryl group; wherein, the substituent is a halogen atom, such as fluorine atom, chlorine atom, bromine atom and iodine atom.

As an improvement of the electrolyte solution of the present application, R ₁₁ to R ₁₆ are each independently selected from a hydrogen atom, a halogen atom, a C ₁ to C ₆ alkyl group, and a phenyl group.

As an improvement of the electrolyte solution in this application, R ₁₁ and R ₁₂ are independently selected from hydrogen atom, methyl group, ethyl group, fluorine atom, chlorine atom or phenyl group; R ₁₃ , R ₁₄ , R ₁₅ , R ₁₆ each independently selected from a hydrogen atom, a methyl group, a fluorine atom or a chlorine atom.

As an improvement of the electrolyte solution of the present application, wherein R ₁₁ and R ₁₂ are each independently selected from a hydrogen atom, a methyl group, a fluorine atom or a phenyl group; R ₁₃ , R ₁₄ , R ₁₅ , and R ₁₆ are each independently selected from a hydrogen atom atom, methyl group, fluorine atom.

As an improvement of the electrolyte solution of the present application, the disulfonic acid methylene ester compound of the present application is selected from at least one of the compounds shown in the following structural formulas: Ia～Ii:

As an improvement of the electrolyte solution of the present application, the methylene disulfonate compound of the present application is the compound shown in Ia.

As an improvement of the electrolyte solution of the present application, the mass percent content of the methylene disulfonate compound in the electrolyte solution of the present application is 0.1% to 30%. When the content of methylene disulfonate compound was lower than 0.1%, a complete insulating film could not be formed on the surface of the positive electrode, thereby effectively blocking the overcharge current to improve the overcharge performance of the battery; and when methylene disulfonate When the compound content is greater than 30%, the viscosity of the electrolyte is too high, resulting in increased lithium ion migration resistance, and the positive electrode passivation protective film cannot effectively inhibit the oxidation reaction of the electrolyte on the surface of the positive electrode. Further preferably, the mass percent content of the methylene disulfonate compound in the electrolyte is 1%-30%.

As an improvement of the electrolyte solution of the present application, the positive electrode passivation protection agent of the present application is specifically selected from at least one of the nitrile compounds shown in the formula II, III, IV, V, and VI;

in,

R ₂₁ , R ₂₂ , and R ₂₃ are each independently selected from substituted or unsubstituted C ₁ -C ₃ alkylene, substituted or unsubstituted C ₂ -C ₃ alkenylene, substituted or unsubstituted C ₂ -C ₃ alkynylene groups, n is 1-5;

R ₃₁ is selected from substituted or unsubstituted C ₁ -C ₈ alkylene, substituted or unsubstituted C ₂ -C ₈ alkenylene, substituted or unsubstituted C ₂ -C ₈ alkynylene;

R ₄₁ and R ₄₂ are independently selected from substituted or unsubstituted C ₁ -C ₃ alkylene, substituted or unsubstituted C ₂ -C ₃ alkenylene, substituted or unsubstituted C ₂ -C ₃ alkynylene base;

R ₅₁ , R ₆₁ , R ₆₂ , and R ₆₃ are each independently selected from hydrogen, substituted or unsubstituted C ₁ -C ₆ alkyl, substituted or unsubstituted C ₂ -C ₆ alkenyl, substituted or unsubstituted C ₂ ~ C ₆ alkynyl, substituted or unsubstituted phenyl;

Wherein, the substituent is a C ₁ -C ₃ alkyl group.

As an improvement of the electrolyte of the present application,

R ₂₁ , R ₂₂ , and R ₂₃ are selected from C ₁ -C ₃ alkylene, C ₂ -C ₃ alkenylene, and C ₂ -C ₃ alkynylene;

R ₃₁ is selected from C ₁ -C ₈ alkylene, C ₂ -C ₈ alkenylene, C ₂ -C ₈ alkynylene;

R ₄₁ and R ₄₂ are each independently selected from C ₁ -C ₃ alkylene groups.

R ₅₁ , R ₆₁ , R ₆₂ , and R ₆₃ are each independently selected from hydrogen, C ₁ -C ₆ alkyl, C ₂ -C ₆ alkenyl, C ₂ -C ₆ alkynyl, and phenyl.

As an improvement of the electrolyte solution of the present application, the anode passivation protection agent of the present application is selected from adiponitrile, malononitrile, succinonitrile, glutaronitrile, suberonitrile and those having the formula IIa, IIb, IIc, IIIa, IIIb, At least one of the nitrile compounds shown in IVa;

As an improvement of the electrolyte solution of the present application, the positive electrode passivation protection agent of the present application is selected from ethylene glycol bis (2-cyanoethyl) ether, adiponitrile, succinonitrile, suberonitrile and formula IIa at least one of the compounds.

As an improvement of the application, the mass percent content of the anode passivation protection agent in the electrolyte is 0.1%-10%. When the content of the positive passivation protective agent is lower than 0.1%, the surface of the positive electrode cannot be completely passivated, thereby effectively preventing the side reaction caused by the electron transfer between the electrolyte and the electrode; and when the positive passivation protective agent content is greater than 10% %, a thicker passivation film will be formed on the surface of the positive electrode, resulting in increased lithium ion migration resistance, which is not conducive to the stability of the positive electrode interface of the battery during cycling.

More preferably, the mass percent content of the positive electrode passivation protection agent in the electrolyte is 0.5%-5%.

As an improvement of the electrolyte of the present application, the electrolyte of the present application contains 0.1% to 3% ethylene glycol bis (2-cyanoethyl) ether as a positive passivation protection agent in the electrolyte of the present application; further preferably , The mass percent content of ethylene glycol bis(2-cyanoethyl) ether in the electrolyte solution of the present application is 1% to 3%.

As an improvement of the electrolyte of the present application, the electrolyte of the present application contains adiponitrile with a mass percentage of 0.1% to 5% as a positive electrode passivation protection agent; further preferably, adiponitrile is included in the electrolyte of the present application The mass percentage content is 1%～5%.

As an improvement of the electrolyte solution of the present application, the electrolyte solution of the present application contains a compound represented by formula IIIa with a mass percentage of 0.1% to 10% as a positive electrode passivation protection agent; further preferably, the compound represented by formula IIIa is used in this application The mass percent content in the application electrolyte is 1%-10%.

As an improvement of the electrolyte solution of the present application, the negative electrode film-forming additive with a reduction potential higher than that of the disulfonic acid methylene ester compound contained in the additive of the present application is specifically selected from γ-butyrolactone (GBL), vinylene carbonate , vinyl ethylene carbonate (VEC), succinic anhydride, maleic anhydride, 1,3-propane sultone (PS) and at least one of ethylene sulfate.

As an improvement of the electrolyte solution of the present application, the negative electrode film-forming additive of the present application is preferably at least one of γ-butyrolactone, vinyl ethylene carbonate, succinic anhydride, maleic anhydride and ethylene sulfate.

As an improvement of the electrolyte solution of the present application, the negative electrode film-forming additive of the present application is preferably at least one of γ-butyrolactone, maleic anhydride and vinyl ethylene carbonate.

As an improvement of the electrolyte solution of the present application, the mass percent content of the negative electrode film-forming additive of the present application in the electrolyte solution is 0.1% to 20%. When the content of the negative electrode film-forming additive is lower than 0.1%, a complete SEI film cannot be formed on the surface of the negative electrode, thereby effectively preventing the side reaction caused by the electron transfer between the electrolyte and the electrode; and when the negative electrode film-forming additive content is greater than When it is 20%, a thicker SEI film will be formed on the surface of the negative electrode, resulting in increased lithium ion migration resistance, which is not conducive to the stability of the negative electrode interface of the battery during cycling. Further preferably, the mass percent content of the negative electrode film-forming additive in the electrolyte is 0.5%-8%.

As an improvement of the electrolyte of the present application, the electrolyte of the present application contains γ-butyrolactone with a mass percentage of 0.1% to 10% as a negative electrode film-forming additive; further preferably, γ-butyrolactone is used in this application The mass percent content in the electrolyte is 0.1%-5.0%.

As an improvement of the electrolyte of the present application, the electrolyte of the present application contains maleic anhydride in a mass percentage of 0.1% to 10% as a negative electrode film-forming additive; further preferably, the amount of maleic anhydride in the electrolyte of the present application The mass percentage is 0.1%-5.0%.

As an improvement of the electrolyte of the present application, the electrolyte of the present application contains vinyl ethylene carbonate (VEC) with a mass percentage of 0.1% to 10% as a negative electrode film-forming additive; further preferably, vinyl ethylene carbonate The mass percentage content of ethyl ester in the electrolyte solution of this application is 0.1%-5.0%.

As a kind of improvement of the electrolytic solution of the present application, the solvent of the electrolytic solution of the present application is selected from gamma-butyrolactone (GBL), ethylene carbonate, propylene carbonate, dimethyl carbonate (DMC), diethyl carbonate ( DEC), ethylene carbonate (EC), propylene carbonate (PC), dipropyl carbonate, ethyl methyl carbonate, methyl formate, ethyl formate, ethyl propionate, propyl propionate, methyl butyrate, Ethyl acetate, N-methylpyrrolidone, N-methylformamide, N-methylacetamide, acetonitrile, sulfolane, dimethyl sulfoxide, ethylene sulfite, propylene sulfite, methyl sulfide, At least one of diethyl sulfite and dimethyl sulfite.

As an improvement of the electrolyte solution of the present application, the lithium salt is optionally selected from at least one of organic lithium salts or inorganic lithium salts.

As an improvement of the electrolyte solution of the present application, the lithium salt contains at least one of fluorine, boron and phosphorus.

As an improvement of the electrolyte solution of the present application, the lithium salt is selected from lithium hexafluorophosphate LiPF ₆ , lithium tetrafluoroborate (LiBF ₄ ), lithium difluorooxalate borate (LiDFOB), lithium bistrifluoromethanesulfonylimide (LiTFSI) , lithium bis(fluorosulfonyl)imide (LiFSI), and the like.

In order to achieve the purpose of the above invention, the present invention also provides a lithium ion battery, including a positive electrode sheet, a negative electrode sheet, a diaphragm and an electrolyte disposed between the positive electrode sheet and the negative electrode sheet; the electrolyte is the electrolytic solution described in the previous paragraph liquid.

In order to realize the object of the above invention, the present invention also provides a lithium ion battery, comprising a positive electrode sheet, a negative electrode sheet, an interval between the positive electrode sheet and the negative electrode sheet, a diaphragm, an electrolyte and a packaging foil; the positive electrode sheet includes a positive electrode current collector and The positive electrode membrane coated on the positive electrode current collector, the negative electrode sheet includes the negative electrode current collector and the negative electrode membrane coated on the negative electrode current collector; the electrolyte is the electrolyte described in the previous paragraph.

As an improvement of the lithium ion battery of the present application, the positive electrode membrane of the present application includes a positive electrode active material, a binder and a conductive agent.

As an improvement of the lithium ion battery of the present application, the positive electrode active material of the present application is selected from at least one of lithium cobaltate LiCoO ₂ , lithium nickel manganese cobalt ternary material, lithium ferrous phosphate, lithium iron phosphate, and lithium manganate ; Preferably a mixture of lithium cobaltate and lithium nickel manganese cobalt ternary material.

As an improvement of the lithium ion battery of the present application, the negative electrode membrane of the present application includes negative electrode active materials, binders and conductive agents.

As an improvement of the lithium ion battery of the present application, the negative electrode active material of the present application is graphite and/or silicon.

Compared with the prior art, the invention provides an electrolyte that can obviously improve the overcharge performance of the battery, and can improve the crash performance of the battery.

The following is an exemplary description of the technical solution of the present application through specific examples:

Preparation of 1#～37# electrolyte and battery:

Solvents: ethylene carbonate (EC), diethyl carbonate (DEC), propylene carbonate (PC);

Lithium salt: LiPF ₆ ;

In the drying room, after mixing EC, PC and DEC, add lithium salt, then add methylene disulfonate compound and additives, mix well, and obtain electrolyte solution, wherein, the addition amount of EC, PC and DEC is such that EC The weight ratio of PC and DEC is EC:PC:DEC=1:1:3, and the amount of lithium salt added is such that the molar concentration of LiPF ₆ in the electrolyte is 1mol/L.

Lithium battery separator: 16 micron thick polypropylene separator (model A273, provided by Celgard);

Positive plate: Lithium cobaltate (LiCoO ₂ ), binder polyvinylidene fluoride, and conductive agent acetylene black are mixed according to the weight ratio of LiCoO ₂ : polyvinylidene fluoride: acetylene black = 96:2:2, and then N -Methylpyrrolidone (NMP), and then stirred under the action of a vacuum mixer until the system becomes uniform and transparent to obtain the positive electrode slurry; the positive electrode slurry is evenly coated on an aluminum foil with a thickness of 12 μm; the aluminum foil is dried at room temperature and then transferred Dry in an oven at 120° C. for 1 hour, and then cold press and cut to obtain positive electrode sheets.

Negative plate: Graphite, acetylene black, thickener sodium carboxymethyl cellulose (CMC), and binder styrene-butadiene rubber are graphite in weight ratio: acetylene black: binder styrene-butadiene rubber: sodium carboxymethyl cellulose (CMC)=95:2:2:1 mixed, after adding deionized water, under the agitation of vacuum mixer, obtain negative electrode slurry; Negative electrode slurry is evenly coated on copper foil; After drying at room temperature, it was transferred to an oven at 120° C. for 1 hour, and then subjected to cold pressing and slitting to obtain negative electrode sheets.

A polyethylene microporous membrane coated with aluminum oxide is interposed between the positive electrode sheet and the negative electrode sheet, and wound to form a winding core. Insert the winding core into the cell shell, bake, inject liquid, form, and seal; thereby make a lithium-ion battery.

By adjusting the types and contents of methylene disulfonate compounds and additives, different electrolytes of Comparative Examples 1# to 37# were obtained, and then different lithium-ion batteries were obtained. The specific parameters are shown in Table 1.

Table 1 Parameter list of 1#～37# electrolyte components

Among them, 1#-10# electrolytes and batteries are used as comparative examples of this application, and 11#-37# electrolytes and batteries are examples of this application.

The lithium-ion secondary battery obtained above was subjected to an overcharge test and an impact test, and the test results are shown in Table 2.

Overcharge test: Discharge to 3.0V at 25°C with a constant current of 0.5C, then charge to 10V with a constant current of 0.55C, charge at a constant voltage of 10V for 7 hours, measure the surface temperature of the battery at the same time, and observe the state of the battery after the test. If the battery catches fire, it is judged as NG; if there is no fire, it is judged as OK.

Impact test: At 25°C, charge the lithium-ion battery with a constant current of 0.5C to 4.35V, then stand still for 1h, place a rod with a diameter of 15.8mm across the center of the sample, and a weight of 9.1±0.46kg Falling onto the sample from a height of 610±25mm; if the battery catches fire, it is judged as NG; if there is no fire, it is judged as OK;

Table 2 Comparative Example 1#～10# and Example 11#～37# lithium battery overcharge test and impact test results

From the relevant results in the above table 2, it can be known that compared with batteries 1#, 4#, 5# and 7#, the state presented by the overcharge test is compared with the electrolyte solution containing methylene disulfonate compounds After the battery has been charged and impact tested, the battery as a whole is not prone to fire.

The positive electrode passivation additive and the negative electrode film-forming additive are used together with methylene disulfonate. Compared with using alone, the overcharge and impact effects of the battery will be improved, and the effect will increase with the increase in the amount of methylene disulfonate. will enhance. Compared with 1,3-propane sultone (PS), the effect of methylene disulfonate is much better.

The electrolyte solution and the secondary lithium battery were prepared according to the methods of the foregoing examples, and the components and contents of the electrolyte solution are shown in Table 3.

Table 3 38#～47# electrolyte additives and content

The properties of the 38# to 47# electrolytes and lithium-ion batteries prepared according to this example are similar to those of the previous example, and will not be repeated due to space limitations.

Although the present application is disclosed as above with preferred embodiments, it is not used to limit the claims. Any person skilled in the art can make some possible changes and modifications without departing from the concept of the present application. Therefore, the present application The scope of protection shall be based on the scope defined by the claims of the present application.

Claims (10)

1. An electrolytic solution, comprising organic solvent, lithium salt and additive, is characterized in that, described organic solvent contains disulfonic acid methylene ester compound, contains anode passivation protection agent in the described additive. 2. The electrolyte according to claim 1, wherein the methylene disulfonate compound is selected from at least one of the compounds shown in formula IA and IB; Wherein, R ₁₁ to R ₁₆ are each independently selected from a hydrogen atom, a halogen atom, a substituted or unsubstituted C ₁ -C ₁₀ alkyl group, a substituted or unsubstituted C ₂ -C ₁₀ alkenyl group, a substituted or unsubstituted C ₆ -C ₁₀ aryl group; wherein, the substituent is a halogen atom. 3. The electrolytic solution according to claim 2, wherein the methylene disulfonate compound is selected from at least one of the following compounds; 4. The electrolyte solution according to claim 1, wherein the positive electrode passivation protection agent is selected from at least one of the nitrile compounds shown in structural formulas II, III, IV, V, and VI; in, R ₂₁ , R ₂₂ , and R ₂₃ are each independently selected from substituted or unsubstituted C ₁ -C ₃ alkylene, substituted or unsubstituted C ₂ -C ₃ alkenylene, substituted or unsubstituted C ₂ -C ₃ alkynylene groups, n is 1-5; R ₃₁ is selected from substituted or unsubstituted C ₁ -C ₈ alkylene, substituted or unsubstituted C ₂ -C ₈ alkenylene, substituted or unsubstituted C ₂ -C ₈ alkynylene; R ₄₁ and R ₄₂ are independently selected from substituted or unsubstituted C ₁ -C ₃ alkylene, substituted or unsubstituted C ₂ -C ₃ alkenylene, substituted or unsubstituted C ₂ -C ₃ alkynylene base; R ₅₁ , R ₆₁ , R ₆₂ , and R ₆₃ are each independently selected from hydrogen, substituted or unsubstituted C ₁ -C ₆ alkyl, substituted or unsubstituted C ₂ -C ₆ alkenyl, substituted or unsubstituted C ₂ ~ C ₆ alkynyl, substituted or unsubstituted phenyl; Wherein, the substituent is a C ₁ -C ₃ alkyl group. 5. The electrolytic solution according to claim 4, wherein the positive electrode passivation protection agent is selected from the group consisting of adiponitrile, malononitrile, succinonitrile, glutaronitrile, suberonitrile and formula IIa, IIb, IIc , at least one of the nitrile compounds shown in IIIa, IIIb, and IVa; 6. The electrolytic solution according to claim 1, characterized in that, the additive also contains a negative electrode film-forming additive with a reduction potential higher than that of the disulfonic acid methylene ester compound; preferably, the negative electrode film-forming additive The additive is at least one selected from gamma-butyrolactone, vinylene carbonate, vinylethylene carbonate, succinic anhydride, maleic anhydride, 1,3-propane sultone and ethylene sulfate. 7 . The electrolyte solution according to claim 6 , wherein the mass percentage of the negative electrode film-forming additive in the electrolyte solution is 0.1%-20%; preferably 0.5%-8%. 8. The electrolyte solution according to claim 1, characterized in that the mass percentage of the methylene disulfonate compound in the electrolyte solution is 0.1% to 30%; preferably 1% to 30% %. 9. The electrolyte solution according to claim 1, characterized in that, the mass percentage of the positive electrode passivation protection agent in the electrolyte solution is 0.1%-10%; preferably 0.5%-5%. 10. A lithium ion battery, comprising a positive electrode sheet, a negative electrode sheet, a diaphragm and an electrolyte disposed between the positive electrode sheet and the negative electrode sheet at intervals; it is characterized in that the electrolyte solution is any one of claims 1 to 9 electrolyte.