CN112242563A - High-compaction high-voltage lithium cobalt oxide lithium ion battery electrolyte and lithium ion battery - Google Patents

High-compaction high-voltage lithium cobalt oxide lithium ion battery electrolyte and lithium ion battery Download PDF

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CN112242563A
CN112242563A CN201910651107.5A CN201910651107A CN112242563A CN 112242563 A CN112242563 A CN 112242563A CN 201910651107 A CN201910651107 A CN 201910651107A CN 112242563 A CN112242563 A CN 112242563A
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electrolyte
total mass
additive
lithium
compaction
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潘立宁
朱学全
钟子坊
郭力
黄慧聪
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Shanshan Advanced Materials Quzhou Co ltd
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
    • H01M10/0564—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes the electrolyte being constituted of organic materials only
    • H01M10/0566—Liquid materials
    • H01M10/0567—Liquid materials characterised by the additives
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
    • H01M10/0561—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes the electrolyte being constituted of inorganic materials only
    • H01M10/0563—Liquid materials, e.g. for Li-SOCl2 cells
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
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Abstract

The invention belongs to the technical field of lithium ion batteries, and discloses a high-compaction high-voltage lithium cobaltate lithium ion battery non-aqueous electrolyte and a lithium ion battery. The non-aqueous electrolyte of the high-compaction high-voltage lithium cobalt oxide lithium ion battery comprises a non-aqueous organic solvent, an electrolyte lithium salt and an additive, wherein the additive contains a fluoroether additive with a structure shown in formula (I). The fluoroether additive in the non-aqueous electrolyte of the high-compaction high-voltage lithium cobalt oxide battery has good wettability and oxidation resistance, and can effectively solve the problems of insufficient liquid absorption and overlong activation time of a pole piece and a diaphragm of the high-compaction high-voltage lithium cobalt oxide battery due to overlarge compaction density of a positive pole piece and a negative pole piece, and reduction of cycle performance, low-temperature discharge performance and production efficiency of the lithium cobalt oxide battery.

Description

High-compaction high-voltage lithium cobalt oxide lithium ion battery electrolyte and lithium ion battery
Technical Field
The invention relates to the technical field of lithium ion batteries, in particular to a high-compaction high-voltage lithium cobaltate lithium ion battery non-aqueous electrolyte and a lithium ion battery.
Background
The lithium ion battery has the advantages of high working voltage, high energy density, long service life, wide working temperature range, environmental friendliness and the like, and is widely applied to the fields of 3C digital products, electric tools, electric automobiles, aerospace and the like. With the demand for batteries becoming higher and higher, the development trend of batteries is light, thin and high energy density, especially for 3C digital products, such as mobile phone batteries, tablet computers and camera devices.
In order to increase the energy density of a lithium ion battery, a common measure is to increase the charge cut-off voltage of a positive electrode material, such as a commercial lithium cobalt oxide battery voltage from 4.2V → 4.35V → 4.4V → 4.45V → 4.48V → 4.5V. However, the positive electrode material has certain defects under high voltage, for example, the high-voltage positive electrode active material has strong oxidizability in a lithium-deficient state, and the electrolyte is easily oxidized and decomposed to generate a large amount of gas and heat; in addition, the high-voltage positive electrode active material itself is also unstable in a lithium-deficient state, and is prone to some side reactions, such as oxygen release, transition metal ion elution, and the like.
In addition, the compaction density of the positive and negative pole pieces is increased, the content of active materials in a unit area is increased, the theoretical gram capacity of lithium cobaltate is 278mAh/g, the actual gram capacity is 134mAh/g, and in the commercialized lithium cobaltate battery at present, most battery enterprises improve the energy density of the battery by increasing the compaction density of the positive and negative pole pieces. In a common lithium cobaltate core, the compacted density of the positive plate is 3.5-4.3 g/cm3The positive electrode compaction density of the lithium cobaltate lithium core is improved to 4.1-4.3 g/cm through various technologies by battery enterprises3The level of (c). However, the increase of the compaction density has great negative effects on the liquid absorption amount and the liquid absorption time of the pole piece and the diaphragm, and the liquid absorption amount of the battery core is too small, so that the adverse phenomena of water jumping and the like appear in the later cycle of the battery.
At present, the method for solving the problem of difficult liquid absorption of the pole pieces and the diaphragms in most battery enterprises is to reduce the viscosity of electrolyte and add a novel sizing agent simultaneously, so that the liquid absorption amount of the pole pieces and the diaphragms in the battery core is improved, and the liquid absorption time is shortened. Chinese patent CN109148960A discloses a fluoroether substance, which can improve the stable working capacity of the electrolyte at high voltage and the working capacity of the electrolyte at low temperature and improve the electrochemical performance of a ternary lithium ion battery when the addition amount of the fluoroether additive accounts for 5.0-50.0% of the mass of the electrolyte, but the inventor of the application finds that the electrolyte in the patent has no excellent wettability through a large number of experiments and is not suitable for improving the performance of the ternary lithium ion battery, particularly when the addition amount of the fluoroether additive is more than or equal to 5.0%.
Disclosure of Invention
The invention provides a high-compaction high-voltage lithium cobalt oxide lithium ion battery non-aqueous electrolyte for overcoming the defects of the background technology, wherein an additive in the high-compaction high-voltage lithium cobalt oxide lithium ion battery non-aqueous electrolyte has good wettability and oxidation resistance, and can effectively solve the problems of insufficient liquid absorption and overlong activation time of a pole piece and a diaphragm of the high-compaction high-voltage lithium cobalt oxide lithium ion battery, and reduction of cycle performance, low-temperature discharge performance and production efficiency of the lithium cobalt oxide battery due to overlarge compaction density of the positive pole piece and the negative pole piece.
In order to achieve the above objects, the non-aqueous electrolyte solution for a high-compaction high-voltage lithium cobalt oxide lithium ion battery of the present invention comprises a non-aqueous organic solvent, an electrolyte lithium salt and an additive, wherein the additive comprises a fluoroether additive having a structure of formula (i):
Figure BDA0002135246640000021
wherein R is1And R2Independently selected from any one of alkyl and fluoroalkyl, the number of carbon atoms in the alkyl and fluoroalkyl is less than 4, the carbon chain can be linear chain or branched chain, and R1Containing more than R carbon atoms2The number of carbon atoms contained.
Preferably, the fluoroether additive having the structure of formula (i) is at least one selected from the group consisting of compound (1) to compound (6):
Figure BDA0002135246640000031
the content of the fluoroether additive having the structure represented by formula (I) is 0.5 to 2.0% by mass, for example, 0.5%, 1%, 1.5%, 2% by mass of the total electrolyte.
Further, the electrolyte lithium salt is selected from lithium hexafluorophosphate and lithium difluorosulfonimide (LiFSI), preferably a mixed lithium salt of lithium hexafluorophosphate and lithium difluorosulfonimide.
Preferably, the addition amount of the electrolyte lithium salt accounts for 15.0-18.0% of the total mass of the electrolyte; more preferably, the addition amount of the lithium hexafluorophosphate accounts for 14.5-16% of the total mass of the electrolyte, and the addition amount of the lithium difluorosulfonimide accounts for 0.5-2.0% of the total mass of the electrolyte.
Further, as a refinement, the additive of the present invention further comprises a conventional additive selected from one or more of fluoroethylene carbonate (FEC), 1,3, 6-Hexanetricarbonitrile (HTCN), 1, 3-Propanesultone (PS), Adiponitrile (ADN), vinyl sulfate (DTD), Succinonitrile (SN), and 1, 2-bis (cyanoethoxy) ethane (done).
Preferably, the addition amount of the conventional additive accounts for 0.5-20.0% of the total mass of the electrolyte, wherein when the conventional additive is contained, the addition amount of the fluoroethylene carbonate accounts for 4.0-8.0% of the total mass of the electrolyte; the additive amount of the 1, 3-propane sultone accounts for 3.0-5.5% of the total mass of the electrolyte, the additive amount of the vinyl sulfate accounts for 1.0-2.0% of the total mass of the electrolyte, the additive amount of the nitrile additive accounts for 1.0-4.0% of the total mass of the electrolyte, and the additive amount of the 1, 2-bis (cyanoethoxy) ethane accounts for 1.0-3.0% of the total mass of the electrolyte.
More preferably, the conventional additives are fluoroethylene carbonate accounting for 6.0 percent of the total mass of the electrolyte, 1, 3-propane sultone accounting for 4.5 percent of the total mass of the electrolyte, adiponitrile accounting for 2.0 percent of the total mass of the electrolyte and 1, 2-bis (cyanoethoxy) ethane accounting for 2.0 percent of the total mass of the electrolyte; or fluoroethylene carbonate accounting for 6.0 percent of the total mass of the electrolyte, 1, 3-propane sultone accounting for 4.5 percent of the total mass of the electrolyte, adiponitrile/succinonitrile accounting for 2.0 percent of the total mass of the electrolyte, 1, 2-bis (cyanoethoxy) ethane accounting for 2.0 percent of the total mass of the electrolyte and vinyl sulfate accounting for 1.5 percent of the total mass of the electrolyte; or fluoroethylene carbonate accounting for 6.0 percent of the total mass of the electrolyte, 1, 3-propane sultone accounting for 4.5 percent of the total mass of the electrolyte, 1, 2-bis (cyanoethoxy) ethane accounting for 2.0 percent of the total mass of the electrolyte, 1,3, 6-hexanetricarbonitrile accounting for 1.0 percent of the total mass of the electrolyte and vinyl sulfate accounting for 1.5 percent of the total mass of the electrolyte.
In the present invention, the non-aqueous organic solvent is selected from one or more of Ethylene Carbonate (EC), Propylene Carbonate (PC), diethyl carbonate (DEC), ethyl acetate, n-propyl acetate, Ethyl Propionate (EP), and Propyl Propionate (PP).
Preferably, the non-aqueous organic solvent comprises ethylene carbonate, propylene carbonate, diethyl carbonate, ethyl propionate and propyl propionate; more preferably, the mass ratio of ethylene carbonate, propylene carbonate, diethyl carbonate, ethyl propionate and propyl propionate in the non-aqueous organic solvent is 25: 10: 20: 20: 25.
in order to achieve the purpose of the invention, the invention also provides a high-compaction high-voltage lithium cobalt oxide lithium ion battery which comprises a battery core formed by laminating or winding a positive plate, a separation film and a negative plate, and the electrolyte of the high-compaction high-voltage lithium cobalt oxide lithium ion battery, wherein the positive active material of the positive plate is a lithium cobalt oxide active material, and the compaction density of the positive plate is 4.0-4.3 g/cm3。
Preferably, the negative active material of the negative electrode sheet is artificial graphite, natural graphite, or SiOwThe silicon-carbon composite material is compounded with graphite, wherein w is more than 1 and less than 2, and the compaction density of the negative plate is 1.4-1.75 g/cm3。
Compared with the prior art, the invention has the advantages that:
(1) the fluoroether additive with the structure of formula (I) has high flash point and is resistant to oxidative decomposition, and after the fluoroether additive is added into the electrolyte, the oxidation window of the electrolyte and the comprehensive flash point of the electrolyte can be improved, so that the battery has higher safety;
(2) the additive with the structure of the formula (I) belongs to fluorine compounds, and because fluorine atoms have strong electronegativity and weak polarity, and fluoroether compounds have low viscosity and melting point, after the additive is added into electrolyte according to the additive amount, the surface tension of the electrolyte can be reduced, the wettability of the electrolyte on high-compaction positive and negative plates and diaphragms can be improved, the liquid absorption amount of a battery cell can be improved, the activation time of the battery cell can be reduced, the production efficiency can be improved, and the production cost can be saved;
(3) after the fluoroether compound disclosed by the invention is added into the electrolyte according to the addition amount disclosed by the invention, the fluoroether compound is matched with other additives disclosed by the invention to act synergistically, so that the interface alternating current impedance of a positive electrode material and a negative electrode material of the battery can be reduced, the utilization efficiency of an activated substance is improved, the capacity of the battery is favorably exerted, and the room-temperature cycle performance, the low-temperature charge-discharge performance and the rate capability of the battery are finally improved.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments. Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention. It is to be understood that the following description is only illustrative of the present invention and is not to be construed as limiting the present invention.
As used herein, the terms "comprises," "comprising," "includes," "including," "contains," "containing," or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or apparatus that comprises a list of elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, process, method, article, or apparatus.
When an amount, concentration, or other value or parameter is expressed as a range, preferred range, or as a range of upper preferable values and lower preferable values, this is to be understood as specifically disclosing all ranges formed from any pair of any upper range limit or preferred value and any lower range limit or preferred value, regardless of whether ranges are separately disclosed. For example, when a range of "1 to 5" is disclosed, the described range should be interpreted to include the ranges "1 to 4", "1 to 3", "1 to 2 and 4 to 5", "1 to 3 and 5", and the like. When a range of values is described herein, unless otherwise stated, the range is intended to include the endpoints thereof and all integers and fractions within the range.
The singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise. "optional" or "any" means that the subsequently described event or events may or may not occur, and that the description includes instances where the event occurs and instances where it does not.
The indefinite articles "a" and "an" preceding an element or component of the invention are not intended to limit the number requirement (i.e., the number of occurrences) of the element or component. Thus, "a" or "an" should be read to include one or at least one, and the singular form of an element or component also includes the plural unless the number clearly indicates the singular.
Example 1
Preparing an electrolyte: in a glove box filled with argon, ethylene carbonate, propylene carbonate, diethyl carbonate, ethyl propionate and propyl propionate are mixed according to the mass ratio of EC: PC: DEC: EP: PP 25: 10: 20: 20: 25, slowly adding 15.0 wt% of lithium hexafluorophosphate and 1.0 wt% of lithium difluorosulfonimide to the mixed solution, finally adding fluoroether additive (compound 1) accounting for 1.5 wt% of the total mass of the electrolyte, and uniformly stirring to obtain the lithium ion battery electrolyte of the example 1.
Preparing a lithium ion battery:
mixing a positive electrode active material lithium cobaltate, a conductive agent acetylene black and a binder polyvinylidene fluoride (PVDF) according to a mass ratio of 95: 3: 2, fully stirring and uniformly mixing in an N-methyl pyrrolidone solvent system, coating on an aluminum foil, drying, and cold pressing to obtain the positive plate.
Preparing negative active material artificial graphite, conductive agent acetylene black, binder Styrene Butadiene Rubber (SBR), and thickener carboxymethylcellulose sodium (CMC) according to a mass ratio of 96: 2: 1: 1, fully stirring and uniformly mixing in a deionized water solvent system, coating on a copper foil, drying, and cold pressing to obtain the negative plate.
Polyethylene (PE) is used as a base film, and a nano aluminum oxide coating is coated on the base film to be used as an isolating film.
And sequentially laminating the positive plate, the isolating membrane and the negative plate, winding the positive plate, the isolating membrane and the negative plate along the same direction to obtain a bare cell, placing the bare cell in an outer package, injecting the prepared electrolyte, and carrying out processes of packaging, shelving at 45 ℃, high-temperature clamp formation, secondary packaging, capacity grading and the like to obtain the high-compaction lithium iron phosphate lithium ion battery.
Examples 2 to 22
Examples 2 to 22 were the same as example 1 except that the components of the electrolyte were added in the proportions shown in Table 1.
TABLE 1 composition ratios of the components of the electrolytes of examples 1 to 22
Figure BDA0002135246640000071
Figure BDA0002135246640000081
Effects of the embodiment
The electrolytes of examples 18 and 1-13 were tested for electrolyte viscosity and wetting, respectively, as follows:
1) and (3) testing the viscosity of the electrolyte: sucking the solution into the ball 1 through the B tube by using a liquid sucking ball, removing the liquid sucking ball, opening a sleeve clamp at the top end of the C tube to enable the ball D to be communicated with the atmosphere, and enabling the liquid to freely flow out under the action of self gravity. When the liquid level reaches the scale a, the timing is started according to a stop second table, and when the liquid level falls to the scale b, the time of the solution between the scales a and b flowing through the capillary is measured according to the stop second table. Repeatedly operating for three times, wherein the difference between the data of the three times is not more than 1s, and taking an average value, namely the outflow time t1And converting the obtained time into the viscosity of the electrolyte.
2) And (3) testing the infiltration of electrolytes of positive and negative pole pieces: after the positive and negative pole pieces of the high-compaction high-voltage cobalt acid lithium battery pass through the pair rollers, the protection is carried outThe positive plate is proved to have the compaction density of 4.0-4.3 g/cm3Within the range, the compaction density of the negative plate is 1.4-1.75 g/cm3Within the range, the electrode punching sheets of the electricity cutting sheets are used, wherein the positive and negative electrode sheets are circular, and the diameter of the positive and negative electrode sheets is 20 mm; vacuum baking the prepared positive and negative electrode plates at 85 deg.C for 24h, placing the baked positive and negative electrode plates in a glove box, dripping quantitative electrolyte on the positive and negative electrode plates with a liquid-transferring gun, and recording the liquid-absorbing time t of the positive electrode plate2Soaking time t of negative plate3。
The test results are shown in table 2.
TABLE 2 electrolyte viscosity test and wetting test results
Test item Viscosity test of electrolyte/mm2/S Positive plate wetting test/t2(s) Cathode plate wetting test/t3(s)
Example 1 2.6109 23.97 62.63
Example 2 2.6547 25.07 65.71
Example 3 2.6678 27.18 67.14
Example 4 2.6976 27.98 67.78
Example 5 2.8965 28.43 68.33
Example 6 2.6743 26.37 66.28
Example 7 2.7200 40.06 83.15
Example 8 2.6576 25.68 65.74
Example 9 2.6334 24.43 63.24
Example 10 2.6899 30.76 69.13
Example 11 2.7798 42.34 85.67
Example 12 3.0495 45.98 87.09
Example 13 3.6578 60.32 90.89
Example 18 2.8251 40.88 83.56
The following performance tests were performed on the batteries of examples 1-6 and 14-22, respectively, and the test results are shown in table 3:
1) and (3) testing the normal-temperature cycle performance: and at the temperature of 25 ℃, charging the battery with the capacity divided to 4.45V at a constant current and a constant voltage of 0.5C, stopping the current at 0.05C, then discharging the battery to 3.0V at a constant current of 0.7C, and circulating the battery according to the above steps, and calculating the capacity retention rate of 500 cycles after 500 cycles of charging/discharging. The calculation formula is as follows:
the 500 th cycle capacity retention ratio (%) (500 th cycle discharge capacity/first cycle discharge capacity) × 100%.
2) Testing the residual rate of the storage capacity at constant temperature of 85 ℃: firstly, the battery is circularly charged and discharged for 1 time (4.45V-3.0V) at the normal temperature at 0.5C, and the discharge capacity C before the battery is stored is recorded0Then the battery is charged to a full state of 4.45V at constant current and constant voltage, and then the battery is put at a constant temperature of 85 DEG CStoring for 4h in the box, and taking out the battery after the storage is finished; after the battery is cooled for 24 hours at room temperature, the battery is discharged to 3.0V at constant current of 0.5C again, and the discharge capacity C after the battery is stored is recorded1And calculating the capacity residual rate of the battery after being stored for 4 hours at the constant temperature of 85 ℃, wherein the calculation formula is as follows:
after being stored for 4 hours at constant temperature of 85 ℃, the capacity residual rate is C1/C0*100％。
3) The high-compaction high-voltage lithium cobalt oxide battery is tested for 45 ℃ cycle performance: and (3) charging the battery with the capacity divided to 4.45V at a constant current and a constant voltage of 0.5C and stopping the current at 0.05C at 45 ℃, then discharging the battery to 3.0V at a constant current of 0.7C, and circulating the battery according to the steps, and calculating the capacity retention rate of the battery in the cycle of 300 after 300 cycles of charging/discharging. The calculation formula is as follows:
the 300 th cycle capacity retention (%) was (300 th cycle discharge capacity/first cycle discharge capacity) × 100%.
Table 3 results of cell performance test of some examples
Figure BDA0002135246640000101
As can be seen from the comparison of the viscosity and the pole piece wetting performance test results of the electrolyte solutions of example 18 and examples 1 to 6 in Table 2: the fluoroether additive with the structure shown in the formula (I) can obviously reduce the viscosity of the electrolyte and reduce the infiltration time of the positive and negative electrode plates, wherein after the compound (1) is added into the electrolyte, the viscosity of the electrolyte is minimum, and the infiltration time of the electrolyte to the positive and negative electrode plates is minimum.
In addition, as can be seen from the comparison of the electrolyte viscosity and the pole piece wetting performance test results of the example 1 and the examples 7 to 13 in the table 3: when the addition amount of the fluoroether additive with the structure shown in the formula (I) is 0.5-2.0%, the viscosity of the electrolyte can be reduced, and the infiltration time of the electrolyte to a positive electrode sheet and a negative electrode sheet can be reduced, wherein the optimal addition amount of the fluoroether additive compound (1) with the structure shown in the formula (I) is 1.5%. For a high-compaction high-voltage cobalt acid lithium battery, the viscosity of the electrolyte is reduced, the infiltration time of the positive and negative electrode plates is reduced, the production efficiency of the battery can be improved, and the quality of the battery is improved.
In summary, the test results show that the addition amount of the fluoroether additive in the invention is 0.5% -2.0%, and the addition amounts in other ranges cannot achieve the electrolyte impregnating compound and viscosity effect in the invention, and can not achieve good electrochemical performance, when the addition amount is too small, the liquid absorption amount of the high-compaction high-voltage lithium cobaltate core is too small, the cycle performance of the battery in later cycle is deteriorated due to insufficient electrolyte, and the addition amount is too large, so that the viscosity of the electrolyte is too large, the lithium ion is not beneficial to the migration between the positive electrode and the negative electrode in the battery, and the electrochemical performance of the battery is also deteriorated. The fluoroether additive with the formula (I) can correspondingly improve the cycle performance and the high-temperature performance of the battery after being added into the electrolyte, and the reason is that the substance improves the liquid absorption of a high-compaction high-voltage cobalt acid lithium battery.
It will be readily understood by those skilled in the art that the above embodiments may be modified and adapted by persons skilled in the art based on the disclosure and teachings of the above specification, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present invention should be included within the scope of the present invention. Furthermore, although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.

Claims (10)

1. A high-compaction high-voltage lithium cobalt oxide lithium ion battery non-aqueous electrolyte, comprising a non-aqueous organic solvent, an electrolytic lithium salt and an additive, wherein the additive comprises a fluoroether additive having the structure of formula (i):
Figure FDA0002135246630000011
wherein R is1And R2Independently selected from any one of alkyl and fluorinated alkyl, the number of carbon atoms in the alkyl and the fluorinated alkyl is less than 4, and the number of carbon atoms in the alkyl and the fluorinated alkyl is less than 4The chain may be straight or branched, and R1Containing more than R carbon atoms2The number of carbon atoms contained.
2. The high-compaction high-voltage lithium cobalt oxide lithium ion battery nonaqueous electrolyte solution of claim 1, wherein the fluoroether-based additive having the structure of formula (i) is at least one selected from the group consisting of compound (1) to compound (6):
Figure FDA0002135246630000012
the content of the fluoroether additive having the structure represented by formula (I) is 0.5 to 2.0% by mass, for example, 0.5%, 1%, 1.5%, 2% by mass of the total electrolyte.
3. The high-compaction high-voltage lithium cobalt oxide lithium ion battery nonaqueous electrolyte solution of claim 1, wherein the electrolyte lithium salt is selected from lithium hexafluorophosphate, lithium difluorosulfonimide, preferably a mixed lithium salt of lithium hexafluorophosphate and lithium difluorosulfonimide.
4. The high-compaction high-voltage lithium cobalt oxide lithium ion battery nonaqueous electrolyte solution of claim 3, wherein the addition amount of the electrolyte lithium salt accounts for 15.0-18.0% of the total mass of the electrolyte solution; preferably, the addition amount of the lithium hexafluorophosphate accounts for 14.5-16% of the total mass of the electrolyte, and the addition amount of the lithium difluorosulfonimide accounts for 0.5-2.0% of the total mass of the electrolyte.
5. The high-compaction high-voltage lithium cobalt oxide lithium ion battery nonaqueous electrolyte solution of claim 1, wherein the additive further comprises a conventional additive selected from one or more of fluoroethylene carbonate, 1,3, 6-hexanetricarbonitrile, 1, 3-propanesultone, adiponitrile, vinyl sulfate, succinonitrile, 1, 2-bis (cyanoethoxy) ethane; preferably, the addition amount of the conventional additive accounts for 0.5-20.0% of the total mass of the electrolyte, wherein when the conventional additive is contained, the addition amount of the fluoroethylene carbonate accounts for 4.0-8.0% of the total mass of the electrolyte; the additive amount of the 1, 3-propane sultone accounts for 3.0-5.5% of the total mass of the electrolyte, the additive amount of the vinyl sulfate accounts for 1.0-2.0% of the total mass of the electrolyte, the additive amount of the nitrile additive accounts for 1.0-4.0% of the total mass of the electrolyte, and the additive amount of the 1, 2-bis (cyanoethoxy) ethane accounts for 1.0-3.0% of the total mass of the electrolyte.
6. The high-compaction high-voltage lithium cobalt oxide lithium ion battery nonaqueous electrolyte solution of claim 5, wherein the conventional additives are fluoroethylene carbonate accounting for 6.0% of the total mass of the electrolyte solution, 1, 3-propane sultone accounting for 4.5% of the total mass of the electrolyte solution, adiponitrile accounting for 2.0% of the total mass of the electrolyte solution, and 1, 2-bis (cyanoethoxy) ethane accounting for 2.0% of the total mass of the electrolyte solution; or fluoroethylene carbonate accounting for 6.0 percent of the total mass of the electrolyte, 1, 3-propane sultone accounting for 4.5 percent of the total mass of the electrolyte, adiponitrile/succinonitrile accounting for 2.0 percent of the total mass of the electrolyte, 1, 2-bis (cyanoethoxy) ethane accounting for 2.0 percent of the total mass of the electrolyte and vinyl sulfate accounting for 1.5 percent of the total mass of the electrolyte; or fluoroethylene carbonate accounting for 6.0 percent of the total mass of the electrolyte, 1, 3-propane sultone accounting for 4.5 percent of the total mass of the electrolyte, 1, 2-bis (cyanoethoxy) ethane accounting for 2.0 percent of the total mass of the electrolyte, 1,3, 6-hexanetricarbonitrile accounting for 1.0 percent of the total mass of the electrolyte and vinyl sulfate accounting for 1.5 percent of the total mass of the electrolyte.
7. The high-compaction high-voltage lithium cobalt oxide lithium ion battery nonaqueous electrolyte of claim 1, wherein the nonaqueous organic solvent is selected from one or more of ethylene carbonate, propylene carbonate, diethyl carbonate, ethyl acetate, n-propyl acetate, ethyl propionate, and propyl propionate.
8. The high-compaction high-voltage lithium cobalt oxide lithium ion battery nonaqueous electrolyte of claim 1, wherein the nonaqueous organic solvent comprises ethylene carbonate, propylene carbonate, diethyl carbonate, ethyl propionate, and propyl propionate; more preferably, the mass ratio of ethylene carbonate, propylene carbonate, diethyl carbonate, ethyl propionate and propyl propionate in the non-aqueous organic solvent is 25: 10: 20: 20: 25.
9. a high-compaction high-voltage lithium cobalt oxide lithium ion battery, which comprises a cell formed by laminating or winding a positive plate, a separation film and a negative plate, and the high-compaction high-voltage lithium cobalt oxide lithium ion battery electrolyte according to any one of claims 1 to 8, wherein the positive active material of the positive plate is a lithium cobalt oxide active material, and the compaction density of the positive plate is 4.0 to 4.3g/cm3。
10. The high-compaction high-voltage lithium cobalt oxide lithium ion battery of claim 9, wherein the negative active material of the negative plate is artificial graphite, natural graphite, SiOwThe silicon-carbon composite material is compounded with graphite, wherein w is more than 1 and less than 2, and the compaction density of the negative plate is 1.4-1.75 g/cm3。
CN201910651107.5A 2019-07-18 2019-07-18 High-compaction high-voltage lithium cobalt oxide lithium ion battery electrolyte and lithium ion battery Pending CN112242563A (en)

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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113889671A (en) * 2021-09-30 2022-01-04 厦门海辰新能源科技有限公司 Electrolyte and lithium ion battery
WO2023082869A1 (en) * 2021-11-09 2023-05-19 宁德时代新能源科技股份有限公司 Secondary battery, method for preparing secondary battery, battery module, battery pack, and power consumption apparatus
WO2023104038A1 (en) * 2021-12-07 2023-06-15 深圳新宙邦科技股份有限公司 Secondary battery
CN116864807A (en) * 2023-08-01 2023-10-10 新亚杉杉新材料科技(衢州)有限公司 Lithium cobaltate high-voltage lithium ion battery nonaqueous electrolyte and lithium ion battery

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105826607A (en) * 2016-05-25 2016-08-03 宁德新能源科技有限公司 Electrolyte and lithium ion battery containing electrolyte
CN109148960A (en) * 2018-10-10 2019-01-04 杉杉新材料（衢州）有限公司 A kind of lithium ion battery nonaqueous electrolytic solution and the lithium ion battery using the electrolyte
CN110010970A (en) * 2019-04-24 2019-07-12 杉杉新材料（衢州）有限公司 A kind of high-pressure solid ferric phosphate lithium ion battery nonaqueous electrolytic solution and lithium ion battery

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105826607A (en) * 2016-05-25 2016-08-03 宁德新能源科技有限公司 Electrolyte and lithium ion battery containing electrolyte
CN109148960A (en) * 2018-10-10 2019-01-04 杉杉新材料（衢州）有限公司 A kind of lithium ion battery nonaqueous electrolytic solution and the lithium ion battery using the electrolyte
CN110010970A (en) * 2019-04-24 2019-07-12 杉杉新材料（衢州）有限公司 A kind of high-pressure solid ferric phosphate lithium ion battery nonaqueous electrolytic solution and lithium ion battery

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113889671A (en) * 2021-09-30 2022-01-04 厦门海辰新能源科技有限公司 Electrolyte and lithium ion battery
CN113889671B (en) * 2021-09-30 2022-12-27 厦门海辰储能科技股份有限公司 Electrolyte and lithium ion battery
WO2023082869A1 (en) * 2021-11-09 2023-05-19 宁德时代新能源科技股份有限公司 Secondary battery, method for preparing secondary battery, battery module, battery pack, and power consumption apparatus
WO2023104038A1 (en) * 2021-12-07 2023-06-15 深圳新宙邦科技股份有限公司 Secondary battery
CN116864807A (en) * 2023-08-01 2023-10-10 新亚杉杉新材料科技(衢州)有限公司 Lithium cobaltate high-voltage lithium ion battery nonaqueous electrolyte and lithium ion battery

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