CN107293789B - A kind of lithium-ion battery with good circulation effect and electrolyte thereof - Google Patents

Abstract

The invention discloses a lithium-ion battery electrolyte with good circulation effect, which includes an organic solvent, lithium salt and additives; the additive includes a monoisocyanate alkoxysilane compound and a film-forming compound; Lithium-ion battery; the isocyanate-based alkoxysilane compound contained in the electrolytic solution of the present invention is low in cost, easy to synthesize, and can interact with the film-forming compound as an effective water removal agent, and can form stable on the surface of the electrode material. The SEI film improves the structural stability of the positive and negative electrode materials during the charge-discharge cycle and avoids the decomposition of the electrolyte on the electrode surface, so it can effectively improve the cycle performance of lithium-ion batteries at room temperature and high temperature.

Description

A kind of lithium-ion battery with good circulation effect and electrolyte thereof

technical field

The invention relates to the technical field of lithium ion batteries, in particular to a lithium ion battery with good cycle effect and an electrolyte thereof.

Background technique

The electrolyte of lithium-ion batteries is mainly composed of lithium salts, organic solvents and various functional additives, which have an important impact on the performance of lithium-ion batteries such as capacity, internal resistance, cycle, rate, and safety. The solvent of the electrolyte is generally formed by a combination of cyclic carbonate solvents such as EC, PC and chain carbonate solvents such as DMC, DEC, EMC, etc., which have good electrochemical stability, high dielectric constant, low It has the characteristics of high melting point, high flash point, safety and non-toxicity. The electrolyte lithium salt LiPF ₆ is the main lithium salt currently used in commercial electrolytes due to its high solubility in carbonate solvents, high conductivity, and good stability to graphite negative electrodes. However, LiPF ₆ has poor thermal stability. And it is very sensitive to moisture, it can be decomposed to produce PF ₅ , HF and LiF when it encounters traces of water, thus corroding the current collector, SEI film and electrode active materials, causing rapid degradation of battery performance and poor cycle performance. On the other hand, with the increase in the specific energy density of lithium-ion batteries, ternary cathode materials with low cost, high voltage, and high gram capacity, such as nickel-cobalt lithium manganese oxide and nickel-cobalt lithium aluminate, are especially useful in lithium-ion batteries. It is more and more widely used in power lithium-ion batteries, and is considered to be the mainstream cathode material for next-generation lithium-ion batteries. However, the strong water absorption of ternary cathode materials, especially under high voltage and high nickel content, greatly accelerates the decomposition process of conventional electrolytes, resulting in severe gas swelling and poor cycle performance. In addition, silicon-based negative electrodes have a higher gram capacity than commercial graphite negative electrodes, and the risk of lithium precipitation is greatly reduced. Therefore, it is also the main direction for improving the specific energy density of lithium-ion batteries in the future. The large volume expansion makes it difficult for conventional electrolytes to form a stable SEI film on the surface of silicon-based negative electrodes, resulting in poor cycle performance. Therefore, it is imminent to screen and find new electrolyte additive compounds, improve the stability of the electrolyte, and develop a new type of electrolyte that can enable the new type of high specific energy positive and negative electrode materials to achieve long cycle.

At present, there are many related studies on improving the cycle performance of lithium-ion batteries. The main way is to optimize the composition of the electrolyte formula through the screening and evaluation of the electrolyte solvent system and special functional additives to form a more stable SEI film, thereby improving the battery cycle performance. The invention patent with the publication number CN 105355970A reports a ternary positive electrode material lithium-ion battery electrolyte, which is composed of non-aqueous organic solvent, lithium salt and additives, and uses three kinds of fluoroethylene carbonate, sulfur-containing organic matter and fluoroether. The synergistic effect produced by the common use of additives makes the ternary cathode material battery have excellent cycle performance. The publication number is CN 106129473A invention patent, which provides a non-aqueous electrolyte for a silicon-based negative electrode lithium-ion battery with excellent charge-discharge cycle performance. The electrolyte is composed of solvent, lithium salt, unsaturated siloxane additives and fluorosulfonimide salt additives, which can comprehensively improve the high and low temperature and cycle performance of silicon-based negative lithium-ion batteries. However, there is no electrolyte additive that can effectively take into account the characteristics of the positive and negative electrode materials, effectively inhibit the dissolution of metal ions in the positive electrode material, and form a stable SEI film on the surface of the negative electrode material. Therefore, it is necessary to further optimize the electrolyte solvent or additive. The composition of the formula improves the stability of the positive and negative electrode materials, and realizes the improvement of the comprehensive performance of the lithium-ion battery, especially the high-specific energy lithium-ion battery system, especially the cycle performance.

Contents of the invention

The present invention proposes a lithium-ion battery with a good cycle effect and its electrolyte, which can form a stable SEI film on the surface of the electrode material, which improves the structural stability of the positive and negative electrode materials during the charge-discharge cycle and avoids the electrolyte on the electrode. The decomposition of the surface can effectively improve the cycle performance of lithium-ion batteries under normal and high temperature conditions.

The lithium-ion battery electrolyte solution with good cycle effect proposed by the invention includes an organic solvent, a lithium salt and an additive; the additive includes a monoisocyanate-based alkoxysilane compound and a film-forming compound.

Preferably, the monoisocyanatoalkoxysilane compound is selected from at least one of the compounds represented by the general formula I:

in:

In general formula I, R ₁ and R ₂ are each independently selected from C _1-20 alkyl, C _3-20 cycloalkyl, C _2-20 alkenyl, C _2-20 alkynyl, C _3-20 cycloalkenyl , at least one of C _5-26 aryl and C _5-26 heteroaryl;

Further preferably, the hydrogen atoms in R ₁ and R ₂ are partially or completely substituted;

More preferably, the substituent is at least one selected from halogen and cyano;

In general formula I, R ₃ is at least one selected from C _1-20 alkylene, C _2-20 alkenyl, C _2-20 alkynyl, sulfonic acid, boronic acid and phosphorous acid;

Further preferably, some or all of the hydrogen atoms in _R3 are substituted;

More preferably, the substituent is at least one selected from halogen and cyano;

Preferably, R ₁ and R ₂ are each independently selected from at least one of C _1-3 alkyl, C _2-4 alkenyl, C _2-4 alkynyl and C ₆ aryl;

Preferably, R ₃ is at least one selected from C _1-3 alkylene, C _2-4 alkenyl, C _2-4 alkynyl, C ₆ aryl, sulfonic acid, boronic acid and phosphorous acid.

Preferably, the film-forming compound includes vinylene carbonate, vinylethylene carbonate, methylethylene carbonate, inorganic lithium salt, organic lithium salt, pyridine, furan, thiophene, sultone, sulfonyl At least one of imines, phosphates, phosphites, nitriles, sulfones, amides, and acid anhydrides;

Preferably, some or all of the hydrogen atoms in the film-forming compound are substituted;

Further preferably, the substituent is selected from at least one of halogen, cyano, nitro, carboxyl and sulfonic acid;

Preferably, the film-forming compound includes vinylene carbonate, acrylate sultone, ethylene sulfate, dimethyl methanedisulfonate, tris(trimethylsilane) phosphate, tris(trimethylsilane) At least one of phosphoric acid ester, lithium dioxalate borate and lithium difluorooxalate borate.

Preferably, the organic solvent includes at least one of organic carbonates, C _1-10 alkyl ethers, alkylene ethers, cyclic ethers, carboxylates, sulfones, nitriles, dinitriles, and ionic liquids;

Preferably, the organic solvent is selected from ethylene carbonate, propylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, dipropyl carbonate, ethyl methyl carbonate, methyl propyl carbonate, ethylene propylene carbonate Esters, dimethyl ether, diethyl ether, adiponitrile, succinonitrile, glutaronitrile, dimethyl sulfoxide, sulfolane, 1,4-butyrolactone, methyl formate, ethyl acetate, methyl propionate, At least one of ethyl propionate, butyl propionate, and ethyl butyrate;

Preferably, some or all of the hydrogen atoms in the organic solvent are substituted;

Further preferably, the substituent is at least one selected from halogen and cyano.

Preferably, the general formula of the lithium salt is:

Li[F _6-x P(C _y F _2y+1 ) _x ], where x is an integer of 0-6, and y is an integer of 1-20;

Li[B(R ₄ ) ₄ ], wherein each R ₄ is independently selected from F, Cl, Br, I, C _1-4 alkyl, C _2-4 alkenyl and C _2-4 alkynyl;

Li[B(R ₅ ) ₂ (OR ₆ O)], wherein R ₅ and R ₆ are selected from C _1-6 alkyl, C _2-6 alkenyl and C _2-6 alkynyl;

Li[B(OR ₆ O) ₂ ], where (OR ₆ O) is derived from 1,2-diol, 1,3-diol, 1,2-dicarboxylic acid, 1,3-dicarboxylic acid, 1 , a divalent group of 2-hydroxycarboxylic acid or 1,3-hydroxycarboxylic acid, wherein the divalent group forms a 5- or 6-membered ring with the central R atom via two oxygen atoms;

And at least one of the salts of Li[X(C _n F _2n+1 SO ₂ )m], wherein m and n are as defined below: n is an integer of 1-20; when X is oxygen or sulfur, m=1 ; When X is nitrogen or phosphorus, m=2; when X is carbon or silicon, m=3;

Further preferably, the lithium salt is LiPF ₆ , LiClO ₄ , LiAsF ₆ , LiBF ₄ , lithium tetrafluoro(oxalate)phosphate, lithium bisoxalate borate, lithium difluorooxalate borate, lithium bistrifluoromethanesulfonylimide, At least one of lithium bisfluorosulfonyl imides;

More preferably, the lithium salt is LiPF ₆ .

Preferably, based on the total weight of the electrolyte, the mass concentration of the organic solvent is 80-90%, the mass concentration of the lithium salt is 8-15%, and the mass concentration of the isocyanate alkoxysilane compound is 0.1- 10%, the mass concentration of the film-forming compound is 0.1-10%;

Further preferably, the mass concentration of the organic solvent is 80-85%, the mass concentration of the lithium salt is 10-14%, the mass concentration of the isocyanate alkoxysilane compound is 0.5-5%, and the other components The mass concentration of membrane compound is 0.5-5%.

The present invention also proposes a lithium-ion battery with good cycle effect, which includes a positive electrode containing a cathode active material, a negative electrode containing an anode active material, a diaphragm, and the lithium-ion battery electrolyte with a good cycle effect.

Preferably, the cathode active material includes a material capable of occluding and releasing lithium ions;

Further preferably, the cathode active material is a lithiated transition metal phosphate with an olivine structure, a lithium ion intercalated transition metal oxide with a layered structure, and a lithiated transition metal mixed oxide with a spinel structure. at least one.

Preferably, the anode active material comprises a material capable of occluding and releasing lithium ions;

Further preferably, the anode active material is at least one of carbonaceous materials, titanium oxides, silicon, lithium, lithium alloys and materials capable of forming lithium alloys.

Preferably, the diaphragm is one or more composite films of polyethylene, polypropylene, polyvinylidene fluoride.

In the above-mentioned lithium-ion battery with good cycle effect, the specific lithium-ion separator used is not limited by the specific type, and can be all types of separators used in existing lithium-ion batteries, including but not limited to polyethylene, polypropylene, polybias Tetrafluoroethylene and their composite films.

Compared with prior art, the beneficial effect of the present invention is:

(1) Monoisocyanate-based alkoxysilane compound is used as a new type of electrolyte additive in this solution, which is simple to synthesize, low in cost, has little toxicity and side effects, and is very suitable for use as a commercial additive;

(2) The isocyanate-based alkoxysilane compound has strong reactivity. It can be used as a film-forming additive at the same time as a water-removing agent to remove trace moisture in the electrolyte, avoiding the production of acidic substances such as HF, and significantly improving electrolysis. Liquid storage stability;

(3) Monoisocyanate-based alkoxysilane compounds are easy to work together with other film-forming additives, and can form a stable SEI film on the electrode surface through cross-linking coupling, which can significantly improve the structural stability and battery cycle performance of positive and negative electrode materials .

Detailed ways

In the following examples and comparative examples, the reagents, materials and instruments used can be obtained by common methods unless otherwise specified, and the reagents involved can be obtained by conventional synthesis methods.

Example 1

Preparation of Electrolyte 1 and Experimental Battery 1

(1) Preparation of Electrolyte 1

In an argon glove box with moisture content ≤ 10ppm, mix ethylene carbonate (EC) and ethyl methyl carbonate (EMC) uniformly according to the mass ratio EC:EMC=3:7, then slowly add lithium salt, namely lithium hexafluorophosphate, and wait After the lithium salt is completely dissolved, add propyl isocyanate triethoxysilane with a mass fraction of 0.5% and vinylene carbonate with a mass fraction of 1%, and stir evenly to obtain electrolyte 1, wherein lithium hexafluorophosphate accounts for the mass of the entire electrolyte The concentration is 14%.

(2) Preparation of positive electrode sheet

Mix the positive electrode active material silicon-based negative electrode material, conductive agent acetylene black, and binder polytetrafluoroethylene according to the mass ratio NMC811: acetylene black: polytetrafluoroethylene = 95: 2.5: 2.5, add N-methylpyrrolidone, fully Stir and mix to form a uniform positive electrode slurry, which is evenly coated on a 15-micron thick aluminum foil, and dried to obtain a positive electrode sheet.

(3) Negative sheet preparation

Negative electrode active material silicon-based negative electrode material, conductive agent acetylene black, binder styrene-butadiene rubber, thickener sodium carboxymethyl cellulose according to the mass ratio of silicon-based negative electrode material: acetylene black: styrene-butadiene rubber: thickener = 95 : 2:2:1 for mixing, add deionized water, stir and mix well to form a uniform negative electrode slurry and evenly coat it on the 8 micron thick copper foil, and get the negative electrode sheet after drying.

(4) Preparation of Experimental Battery 1

In a dry environment with the dew point controlled below -40°C, stack the positive electrode sheet prepared in step (2), the separator sheet, and the negative electrode sheet prepared in step (3) in order to ensure that the separator completely separates the positive and negative electrode sheets, and then polarize The sheet is wound into a roll core, and packaged in a fixed-size aluminum-plastic film with glued tabs to form a pouch battery to be injected, and then inject the electrolyte prepared in step (1) into the pouch battery , followed by sealing, formation, aging, and capacity separation to obtain an experimental battery 1 for testing.

Example 2

Electrolyte 2 and experimental battery 2 were prepared.

The difference from Example 1 is that in the preparation process of the electrolyte, 1% propyl isocyanate trimethoxysilane and 1% vinylene carbonate are added after the lithium salt is completely dissolved.

Example 3

Electrolyte 3 and experimental battery 3 were prepared.

The difference from Example 1 is that in the electrolyte preparation process, 3% propyl isocyanate triethoxysilane and 1% vinylene carbonate are added after the lithium salt is completely dissolved.

Example 4

Electrolyte 4 and experimental battery 4 were prepared.

The difference from Example 1 is that in the preparation process of the electrolyte, 1% vinyl isocyanate trimethoxysilane and 1% vinylene carbonate are added after the lithium salt is completely dissolved.

Example 5

Electrolyte 5 and experimental battery 5 were prepared.

The difference from Example 1 is that in the electrolyte preparation process, 3% isocyanate sulfonate triethoxysilane and 1% vinylene carbonate are added after the lithium salt is completely dissolved.

Example 6

Electrolyte 6 and experimental battery 6 were prepared.

The difference from Example 1 is that in the electrolyte preparation process, 3% isocyanate phosphite triethoxysilane and 1% vinylene carbonate are added after the lithium salt is completely dissolved.

Example 7

Electrolyte 7 and experimental battery 7 were prepared.

The difference from Example 1 is that in the preparation process of the electrolyte, 3% triethoxysilane borate isocyanate and 1% vinylene carbonate are added after the lithium salt is completely dissolved.

Example 8

Electrolyte solution 8 and experimental battery 8 were prepared.

The difference from Example 1 is that: 1% propyl isocyanate triethoxysilane and 1% acrylic sultone are added after the lithium salt is completely dissolved during the preparation of the electrolyte.

Example 9

Electrolyte 9 and experimental battery 9 were prepared.

The difference from Example 1 is that in the preparation process of the electrolyte, 1% propyl isocyanate triethoxysilane and 1% lithium difluorooxalate borate are added after the lithium salt is completely dissolved.

Example 10

Electrolyte solution 10 and experimental battery 10 were prepared.

The difference from Example 1 is that in the electrolyte preparation process, propyl isocyanate triethoxysilane with a mass fraction of 1% and tri(trimethylsilane with a mass fraction of 1% are added after the lithium salt is completely dissolved. ) borate.

Comparative example 1

Electrolyte solution 11 and experimental battery 11 were prepared.

The difference from Example 1 is that only vinylene carbonate with a mass fraction of 1% is added after the lithium salt is completely dissolved during the preparation of the electrolyte, and no propyl isocyanate triethoxysilane is added.

Comparative example 2

Electrolyte solution 12 and experimental battery 12 were prepared.

The difference from Example 1 is that only 1% acrylic acid sultone with a mass fraction of 1% is added after the lithium salt is completely dissolved in the electrolyte preparation process, and no propyl isocyanate triethoxysilane is added.

Comparative example 3

Electrolyte solution 13 and experimental battery 13 were prepared.

The difference from Example 1 is that only lithium difluorooxalate borate with a mass fraction of 1% is added after the lithium salt is completely dissolved during the preparation of the electrolyte, and no propyl isocyanate triethoxysilane is added.

Comparative example 4

Electrolyte 14 and experimental battery 14 were prepared.

The difference from Example 1 is that only 1% propene sultone with a mass fraction of 1% is added after the lithium salt is completely dissolved in the electrolyte preparation process, and no propyl isocyanate triethoxysilane is added.

Comparative example 5

Electrolyte solution 15 and experimental battery 15 were prepared.

The difference from Example 1 is that only 1% propyl isocyanate triethoxysilane is added after the lithium salt is completely dissolved during the preparation of the electrolyte, and no other film-forming additives are added.

Comparative example 6

Electrolyte 16 and experimental cell 16 were prepared.

The difference from Example 1 is that no additives are added after the lithium salt is completely dissolved during the preparation of the electrolyte.

The composition and content of lithium salt, organic solvent and additives in the electrolyte solutions of Examples 1-10 and Comparative Examples 1-6 are shown in Table 1 below.

The composition and content of the lithium salt of table 1 embodiment and comparative example electrolyte, organic solvent and additive

Test example 1: Electrolyte and battery performance test

(1) Storage stability test of electrolyte

The obtained electrolyte solutions in Examples 1-10 and Comparative Examples 1-6 were placed in a 25°C constant temperature storage box under the same conditions, and left to stand for 1 week, and were detected and recorded by Karl analytical moisture tester and acid-base titration method respectively. The changes of moisture and acidity values of the electrolyte before and after standing, see Table 2 for relevant comparative data.

(2) 25°C charge-discharge cycle test of the experimental battery

Place the divided experimental battery in a constant temperature box at 25°C and connect it to the charge-discharge tester. Charge it to 4.2V with a constant current and constant voltage of 1C, and set the cut-off current to 0.01C; Flow discharge to 2.8V, carry out cyclic charge and discharge test in this way, record each discharge capacity, and calculate the battery capacity retention rate of the 50th week, 100th week and 200th week respectively. Weekly capacity retention (%)=discharge capacity of the Nth week/discharge capacity of the first week*100%.

(3) 55°C charge-discharge cycle test of the experimental battery

Place the divided experimental battery in a constant temperature box at 55°C and connect it to a charge-discharge tester. Charge it to 4.2V with a constant current and constant voltage of 1C, and set the cut-off current to 0.01C; Flow discharge to 2.8V, carry out cyclic charge and discharge test in this way, record each discharge capacity, and calculate the battery capacity retention rate of the 50th week, 100th week and 200th week respectively. Weekly capacity retention (%)=discharge capacity of the Nth week/discharge capacity of the first week*100%.

The detection and result of table 2 embodiment 1-10 and comparative example 1-6

From the experimental batteries 1-10 in Examples 1-10 and the batteries 11-16 in Comparative Examples 1-6, it can be seen that when the electrolyte is stored for one week under normal conditions, due to the addition of monoisocyanate alkoxysilanes Additive, the moisture content in the electrolyte is significantly lower than that of the same period last year, indicating that the additive can act as a water remover in the electrolyte, which is conducive to improving the stability of the electrolyte. In addition, when the electrolyte is stored under normal conditions for a week, the acidity in the electrolyte also decreases significantly. During the storage process of ordinary electrolyte, water reacts with lithium hexafluorophosphate to release HF, which will erode the structure of positive and negative materials and seriously reduce the battery cycle performance. , and the addition of monoisocyanate-based alkoxysilane additives will reduce the HF acid content in the electrolyte. Comparing the capacity retention rates of batteries 1-16 at 25°C and 55°C, we can see that the addition of 1% monoisocyanatoalkoxysilane and film-forming compound is significantly better than adding a single additive or no additive. The improvement effect of the cycle performance, the relevant cycle data are shown in Table 2, which shows that the monoisocyanate alkoxysilane can interact with the organic film-forming components on the electrode surface, and form a stable SEI film through synergistic effect, which finally effectively improves the battery life. Normal and high temperature cycle performance.

The above is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto, any person familiar with the technical field within the technical scope disclosed in the present invention, according to the technical solution of the present invention Any equivalent replacement or change of the inventive concepts thereof shall fall within the protection scope of the present invention.

Claims (19)

1. a kind of good lithium-ion battery electrolytes of circulating effect, which is characterized in that including organic solvent, lithium salts and additive； The additive includes monoisocyanates base alkoxysilane compound containing trialkylsilyl group in molecular structure and film forming compound；

The monoisocyanates base alkoxysilane compound containing trialkylsilyl group in molecular structure is as shown in the following general formula I:

Wherein:

R in general formula I₁、R₂、R₃It is independently selected from C_1-20Alkyl, C_3-20Naphthenic base, C_2-20Alkenyl, C_2-20Alkynyl, C_3-20Cyclenes Base, C_6-26Aryl and C_6-26Heteroaryl is at least one；R in general formula I₄Selected from C_2-20Alkenyl, C_2-20Alkynyl, sulfonic group, boronate and Phosphorous acidic group is at least one；

On the basis of the total weight of electrolyte, the organic solvent mass concentration is 80-90%, and the lithium salts mass concentration is 8- 15%, the monoisocyanates base alkoxysilane compound containing trialkylsilyl group in molecular structure mass concentration is 0.1-10%, and the film forming compound quality is dense Degree is 0.1-10%.

2. the good lithium-ion battery electrolytes of circulating effect according to claim 1, which is characterized in that R in general formula I₁、R₂、 R₃In hydrogen moiety or all be substituted；Substituent group is selected from halogen and cyano is at least one.

3. the good lithium-ion battery electrolytes of circulating effect according to claim 1, which is characterized in that R in general formula I₄In Hydrogen moiety is all substituted；Substituent group is selected from halogen and cyano is at least one.

4. the good lithium-ion battery electrolytes of circulating effect according to claim 1 or 2, which is characterized in that R in general formula I₁、 R₂、R₃It is independently selected from C_1-3Alkyl, C_2-4Alkenyl, C_2-4Alkynyl and C₆Aryl is at least one.

5. the good lithium-ion battery electrolytes of circulating effect according to claim 1 or 3, which is characterized in that R in general formula I₄ Selected from C_2-4Alkenyl, C_2-4Alkynyl, sulfonic group, boronate and phosphorous acidic group are at least one.

6. the good lithium-ion battery electrolytes of circulating effect according to claim 1, which is characterized in that the film forming chemical combination Object include vinylene carbonate base ester, vinyl ethylene carbonate, methyl ethyl, pyridine, furans, thiophene, sultones, At least one of sulfimide, phosphate, phosphite ester, nitrile, sulfone class, amide, acid anhydrides.

7. the good lithium-ion battery electrolytes of circulating effect according to claim 6, which is characterized in that the film forming chemical combination Hydrogen moiety or all substituted in object, it is at least one that substituent group is selected from halogen, cyano, nitro, carboxyl and sulfonic group.

8. the good lithium-ion battery electrolytes of circulating effect according to claim 6, which is characterized in that the film forming chemical combination Object includes vinylene carbonate, acrylic acid sultones, ethyl sulfate, methane-disulfonic acid dimethyl ester, three (trimethyl silanes) At least one of phosphate, dioxalic acid lithium borate and difluorine oxalic acid boracic acid lithium.

9. the good lithium-ion battery electrolytes of circulating effect according to claim 1, which is characterized in that the organic solvent Including organic carbonate, C_1-10At least one of alkyl ether, alkylene ether, cyclic ethers, carboxylate, sulfone, nitrile, ionic liquid.

10. the good lithium-ion battery electrolytes of circulating effect according to claim 1, which is characterized in that described organic molten Agent is selected from ethylene carbonate, propene carbonate, butylene, dimethyl carbonate, diethyl carbonate, dipropyl carbonate, carbonic acid Methyl ethyl ester, methyl propyl carbonate, ethyl propyl carbonic acid ester, dimethyl ether, diethyl ether, adiponitrile, succinonitrile, glutaronitrile, dimethyl sulfoxide, ring Fourth sulfone, 1,4-butyrolactone, methyl formate, ethyl acetate, methyl propionate, ethyl propionate, butyl propionate, in ethyl butyrate at least It is a kind of.

11. the good lithium-ion battery electrolytes of circulating effect according to claim 9 or 10, which is characterized in that described to have Hydrogen moiety or all substituted in solvent, it is at least one that substituent group is selected from halogen, cyano.

12. the good lithium-ion battery electrolytes of circulating effect according to claim 1, which is characterized in that the lithium salts General formula are as follows:

Li[F_6-xP(C_yF_2y+1)_x], wherein x is the integer of 0-6, and y is the integer of 1-20；

Li[B(R₄)₄], wherein R₄It is selected from F, Cl, Br, I, C each, independently of the other_1-4Alkyl, C_2-4Alkenyl and C_2-4Alkynyl；

Li[B(R₅)₂(OR₆O)], wherein R₅、R₆It is selected from C each, independently of the other_1-6Alkyl, C_2-6Alkenyl and C_2-6Alkynyl；

Li[B(OR₆O)₂], wherein (OR₆O 1,2- glycol, 1,3- glycol, 1,2- dicarboxylic acids, 1,3- dicarboxylic acids, 1,2-) are derived from Hydroxycarboxylic acid or 1, the bivalent group of 3- hydroxycarboxylic acid, wherein the bivalent group is via two oxygen atoms and center R atom shape At 5- or 6-membered ring；

And Li [X (C_nF_2n+1SO₂) m] and salt at least one, wherein m and n are defined below: n be 1-20 integer；When X is oxygen Or when sulphur, m=1；When X is nitrogen or phosphorus, m=2；When X is carbon or silicon, m=3.

13. the good lithium-ion battery electrolytes of circulating effect according to claim 1, which is characterized in that the lithium salts is LiPF₆、LiClO₄、LiAsF₆、LiBF₄, tetrafluoro (oxalic acid) lithium phosphate, di-oxalate lithium borate, difluorine oxalic acid boracic acid lithium, double trifluoros At least one of sulfonyl methane imine lithium, double fluorine sulfimide lithiums.

14. the good lithium-ion battery electrolytes of circulating effect according to claim 13, which is characterized in that the lithium salts is LiPF₆。

15. the good lithium-ion battery electrolytes of circulating effect according to claim 1, which is characterized in that described organic molten The mass concentration of agent is 80-85%, and the lithium salts mass concentration is 10-14%, the monoisocyanates base alkoxyl silicone alkanisation Conjunction amount of substance concentration is 0.5-5%, and the film forming compound mass concentration is 0.5-5%.

16. a kind of good lithium ion battery of circulating effect, which is characterized in that including containing active material of cathode anode, contain anode The cathode of active material, diaphragm and the good lithium ion battery battery of circulating effect described in any one of -15 according to claim 1 Solve liquid.

17. the good lithium ion battery of circulating effect according to claim 16, which is characterized in that the wherein cathode activity Material is the lithiated transition metal phosphate with olivine structural, the insertion transiting metal oxidation of the lithium ion with layer structure At least one of object and the lithiated transition metal mixed oxide with spinel structure.

18. the good lithium ion battery of circulating effect according to claim 16, which is characterized in that the wherein anode activity Material is at least one of carbonaceous material, titanium oxide, silicon, lithium, lithium alloy and the material for being capable of forming lithium alloy.

19. the good lithium ion battery of the described in any item circulating effects of 6-18 according to claim 1, which is characterized in that it is described every Film is polyethylene, polypropylene, the one or more kinds of composite membranes for gathering inclined tetrafluoroethene.