CN112786966A - Electrolyte and lithium ion battery - Google Patents

Electrolyte and lithium ion battery Download PDF

Info

Publication number
CN112786966A
CN112786966A CN202110226800.5A CN202110226800A CN112786966A CN 112786966 A CN112786966 A CN 112786966A CN 202110226800 A CN202110226800 A CN 202110226800A CN 112786966 A CN112786966 A CN 112786966A
Authority
CN
China
Prior art keywords
electrolyte
carbonate
lithium ion
ion battery
lithium
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202110226800.5A
Other languages
Chinese (zh)
Inventor
车佩佩
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Envision Power Technology Jiangsu Co Ltd
Envision Ruitai Power Technology Shanghai Co Ltd
Original Assignee
Envision Power Technology Jiangsu Co Ltd
Envision Ruitai Power Technology Shanghai Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Envision Power Technology Jiangsu Co Ltd, Envision Ruitai Power Technology Shanghai Co Ltd filed Critical Envision Power Technology Jiangsu Co Ltd
Priority to CN202110226800.5A priority Critical patent/CN112786966A/en
Publication of CN112786966A publication Critical patent/CN112786966A/en
Pending legal-status Critical Current

Links

Classifications

    • 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
    • H01M2300/00—Electrolytes
    • H01M2300/0017—Non-aqueous electrolytes
    • H01M2300/0025—Organic electrolyte
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Abstract

The invention provides an electrolyte and a lithium ion battery. The electrolyte includes a combination of a lithium salt and an additive; the additive is aromatic sulfonyl fluoride and/or boric acid tri (2,2, 2-trifluoroethyl) ester. The lithium ion battery comprises a positive electrode, a negative electrode, an isolating membrane and the electrolyte; the separator and the electrolyte are located between the positive electrode and the negative electrode. The invention adopts the aromatic sulfonyl fluoride and/or the boric acid tri (2,2, 2-trifluoroethyl) ester as the additive, can effectively inhibit the precipitation of lithium metal, effectively avoids the formation and growth of lithium dendrite in the use process of the lithium ion battery, and ensures that the lithium ion battery has higher safety and longer service life.

Description

Electrolyte and lithium ion battery
Technical Field
The invention belongs to the technical field of lithium ion batteries, and particularly relates to an electrolyte and a lithium ion battery.
Background
The lithium ion battery has the advantages of high working voltage, long cycle life, small self-discharge, large specific energy, no memory effect, no pollution and the like, so the lithium ion battery is widely applied to the fields of notebook computers, portable tools, mobile communication, electric automobiles and the like. With the increasing demand of the modern society for energy storage of portable electronic devices, electric vehicles and large-scale power grids, the research on lithium batteries with high energy density also draws wide attention of people. In the field of electric automobiles and energy storage, the energy of the lithium ion battery far exceeds that of consumer electronic products, so that the lithium ion battery has higher requirements on safety and service life, and the electrolyte is used as an important component of the lithium ion battery, so how to improve the electrical performance of the lithium ion battery through the electrolyte of the lithium ion battery becomes a key point of research of people.
CN111430796A discloses an electrolyte for lithium ion battery and a lithium ion battery containing the same. The lithium ion battery electrolyte comprises a non-aqueous organic solvent, lithium salt and an additive, wherein the additive comprises the following components in percentage by mass in the lithium ion battery electrolyte: 0.1-2% of 1, 2-bis (difluorophospho-xy) ethane, 0.2-2% of isocyanate compounds, 0.5-3% of cyclic sulfur-containing compounds, 1-3.5% of lithium salt additives and 0.2-15% of other additives. Although the lithium ion battery prepared by the technical scheme has better cycle stability and high and low temperature performance, lithium ions are easy to precipitate at the negative electrode of the battery to form lithium dendrites in the charging and discharging process, so that the safety of the lithium ion battery is reduced and the service life of the lithium ion battery is prolonged.
CN111477956A discloses a lithium ion battery non-aqueous electrolyte additive, a non-aqueous electrolyte and a lithium ion battery. The lithium ion battery comprises a non-aqueous electrolyte, a positive electrode and a negative electrode, wherein the positive electrode is made of a nickel-cobalt-manganese or nickel-cobalt-aluminum ternary material, the non-aqueous electrolyte comprises electrolyte lithium salt, an organic solvent and an additive, the using mass of the additive is 0.1-5% of the total mass of the electrolyte lithium salt and the organic solvent, and the additive comprises a succinimide oligomer and a derivative thereof. According to the technical scheme, the interface of the anode/electrolyte is optimized by using the additive, the surface activity of the anode is reduced, and the polarization of the cathode is reduced.
CN107863558A discloses an electrolyte for lithium ion battery and its application. The electrolyte comprises electrolyte lithium salt dissolved in an organic solvent and an additive; wherein the concentration of the electrolyte lithium salt is 1.0 mol/L; the electrolyte lithium salt comprises bis (trifluorosulfonimide) lithium and lithium difluorooxalato borate, wherein the mass ratio of the substances is (1-9) to 1; the concentration of the additive is 0.01-0.4 mol/L, and the additive is lithium hexafluorophosphate; the organic solvent is ethylene carbonate, acrylic carbonate and methyl ethyl carbonate with the mass ratio of (1-2) to (3-5). The electrolyte provided by the technical scheme can reduce lithium dendrites in the using process, but the electrolyte needs to be used in a specific temperature range, and the application is limited.
For lithium ion batteries, the formation and growth of lithium dendrites on the negative electrode of the battery is a problem that lithium ion batteries need to overcome. On one hand, the lithium dendrite can puncture the isolating membrane to cause the internal short circuit of the battery, thereby generating potential safety hazard; on the other hand, the continued growth of lithium dendrites will lead to deactivation of lithium ions, resulting in a decrease in battery life. In the prior art, in order to reduce the formation of lithium dendrites on a battery cathode, a lithium ion battery needs to be used at a proper charging and discharging rate and temperature to reduce the precipitation of lithium ions, so that the probability of the formation of the lithium dendrites is reduced.
Therefore, how to provide a lithium ion battery with higher safety and longer service life, which can avoid the formation and growth of lithium dendrites, has become a technical problem to be solved.
Disclosure of Invention
In view of the defects of the prior art, the invention aims to provide an electrolyte and a lithium ion battery. According to the invention, the aromatic sulfonyl fluoride and/or the boric acid tris (2,2, 2-trifluoroethyl) ester are/is used as the additive, so that the precipitation of lithium can be effectively inhibited, and the formation and growth of lithium dendrites are effectively avoided in the use process of the lithium ion battery, so that the lithium ion battery has higher safety and longer service life.
In order to achieve the purpose, the invention adopts the following technical scheme:
in a first aspect, the present invention provides an electrolyte comprising a combination of a lithium salt and an additive;
the additive is aromatic sulfonyl fluoride and/or boric acid tri (2,2, 2-trifluoroethyl) ester.
In the invention, the aromatic sulfonyl fluoride and/or the boric acid tris (2,2, 2-trifluoroethyl) ester are/is used as the additive, so that the precipitation of lithium can be effectively inhibited, and the formation and growth of lithium dendrites are effectively avoided in the use process of the lithium ion battery, so that the lithium ion battery has higher safety and longer service life.
In the use process of the lithium ion battery, fluorine-containing groups in the aromatic sulfonyl fluoride can react with lithium metal precipitated from a negative electrode to form a compact and stable LiF layer, and the formation of the LiF layer can prevent the precipitated lithium metal from nucleating on one hand and further grow to form lithium dendrites; on the other hand, the decomposition and consumption of lithium salt in the electrolyte are prevented, and the stability of the SEI film is improved, so that the lithium ion battery has higher safety and longer service life. In a similar way, the fluorine-containing group in the tris (2,2, 2-trifluoroethyl) borate can also react with lithium metal to form a LiF layer, so that the stability of an SEI film is improved, the lithium ion battery has higher safety and longer service life, and meanwhile, the tris (2,2, 2-trifluoroethyl) borate is used as an anion receptor, so that the lithium ion migration rate in the electrolyte can be improved, and the rate capability of the lithium ion battery is improved.
The following is a preferred technical solution of the present invention, but not a limitation to the technical solution provided by the present invention, and the object and advantageous effects of the present invention can be better achieved and achieved by the following preferred technical solution.
In a preferred embodiment of the present invention, the lithium salt is LiPF6、LiClO4、LiPO2F2、Li2PO3F、LiBF4、FSO3Li、LiTFMSB、LiN(SO2F)2、LiAsF6、LiN(SO2CF3)2、LiN(SO2C2F5)2Any one or a combination of at least two of LiBOB, LiPFO and lithium tetrafluoro oxalate phosphate, and LiPF is more preferable6、LiBOB、LiBF4、Li2PO3F、LiPO2F2、LiN(SO2CF3)2Or LiN (SO)2C2F5)2Any one or a combination of at least two of them.
In a preferred embodiment of the present invention, the concentration of the lithium salt in the electrolyte is 0.5 to 2mol/L, and may be, for example, 0.5mol/L, 0.6mol/L, 0.7mol/L, 0.8mol/L, 0.9mol/L, 1mol/L, 1.1mol/L, 1.2mol/L, 1.3mol/L, 1.4mol/L, 1.5mol/L, 1.6mol/L, 1.7mol/L, 1.8mol/L, 1.9mol/L, or 2 mol/L.
In a preferred embodiment of the present invention, the additive is contained in the electrolyte in an amount of 0.001 to 3% by mass, for example, 0.001%, 0.005%, 0.01%, 0.05%, 0.1%, 0.2%, 0.5%, 1%, 1.5%, 2%, 2.5%, or 3%.
In the invention, the battery prepared by controlling the content of the additive in the electrolyte within a specific range has longer service life and higher safety. If the content of the additive in the electrolyte is low, the prepared battery has short service life and low safety and does not meet the use requirement; if the content of the additive in the electrolyte is higher, the service life of the prepared battery is shorter, and the battery does not meet the use requirement.
As a preferred technical scheme of the invention, the structural formula of the aryl sulfonyl fluoride is shown as the following formula I:
Figure BDA0002956742820000041
wherein n is an integer of 0 to 5 (for example, 0, 1,2, 3, 4 or 5), and more preferably 1 or 2;
r is selected from substituted or unsubstituted C6～C21Aryl, substituted or unsubstituted C1～C12Straight or branched chain alkyl, halogen, cyano,
Figure BDA0002956742820000042
any one or a combination of at least two of them.
In the present invention, said C6～C21Aryl radicals including C6、C9、C10、C11、C12、C13、C14、C15、C16、C17、C18、C19、C20Or C21Aryl of (a); said C is1～C12Straight or branched chain alkyl includes C1、C2、C3、C4、C5、C6、C7、C8、C9、C10、C11Or C12Linear or branched alkyl.
As a preferred embodiment of the present invention, the aromatic sulfonyl fluoride is selected from
Figure BDA0002956742820000051
Figure BDA0002956742820000052
Any one or a combination of at least two of them.
In a preferred embodiment of the present invention, the percentage by mass of the aromatic sulfonyl fluoride in the electrolyte is 0.001 to 3% (for example, 0.001%, 0.005%, 0.01%, 0.05%, 0.1%, 0.2%, 0.5%, 1%, 1.5%, 2%, 2.5%, or 3%, etc.), and more preferably 0.1 to 2%.
In a preferred embodiment of the present invention, the content of tris (2,2, 2-trifluoroethyl) borate in the electrolyte is 0.002 to 3% by mass (for example, 0.002%, 0.005%, 0.01%, 0.05%, 0.1%, 0.2%, 0.5%, 1%, 1.5%, 2%, 2.5%, or 3%, and more preferably 0.1 to 2%.
As a preferable embodiment of the present invention, the electrolyte further includes an organic solvent.
Preferably, the organic solvent is selected from any one of ethylene carbonate, propylene carbonate, ethyl methyl carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, fluoroethylene carbonate, dipropyl carbonate, 1, 4-butyrolactone, methyl propyl carbonate, ethyl propyl carbonate, methyl propionate, methyl butyrate, ethyl acetate, ethyl propionate or ethyl butyrate or a combination of at least two thereof.
In a second aspect, the present invention provides a lithium ion battery, comprising a positive electrode, a negative electrode, a separator and an electrolyte;
the isolating film and the electrolyte are positioned between the positive electrode and the negative electrode;
the electrolyte is the electrolyte according to the first aspect.
Compared with the prior art, the invention has the following beneficial effects:
according to the invention, aromatic sulfonyl fluoride and/or boric acid tris (2,2, 2-trifluoroethyl) ester are/is used as an additive, so that the precipitation of lithium can be effectively inhibited, the formation and growth of lithium dendrite are effectively avoided in the use process of the lithium ion battery, and the prepared electrolyte has excellent performance. The battery prepared by the electrolyte provided by the invention has longer service life, the discharge capacity of the battery is still greater than 80% of the initial capacity after 2000 circles of cycle test, the safety of the battery is higher, the grades of an overcharge test, an external short circuit test and a heating test are all Lv2, and the battery meets the use requirements.
Detailed Description
The technical solution of the present invention is further illustrated by the following specific examples. It should be understood by those skilled in the art that the examples are only for the understanding of the present invention and should not be construed as the specific limitations of the present invention.
Example 1
This example provides an electrolyte and a method for preparing the same, where the electrolyte includes LiPF6、
Figure BDA0002956742820000061
And an organic solvent;
LiPF in the electrolyte6The concentration of (A) is 1.5 mol/L;
Figure BDA0002956742820000062
the mass percentage content of (A) is 1.5%; the organic solvent consists of dimethyl carbonate, diethyl carbonate and methyl ethyl carbonate according to the mass ratio of 3:5: 2.
The preparation method of the electrolyte comprises the following steps:
in a glove box, uniformly mixing dimethyl carbonate, diethyl carbonate and methyl ethyl carbonateAfter homogenizing, LiPF is added thereto6And
Figure BDA0002956742820000071
and uniformly mixing to obtain the electrolyte.
Example 2
This example provides an electrolyte and a method for preparing the same, where the electrolyte includes LiPF6、
Figure BDA0002956742820000072
Tris (2,2, 2-trifluoroethyl) borate and an organic solvent;
LiPF in the electrolyte6The concentration of (A) is 1.2 mol/L;
Figure BDA0002956742820000073
the content of the boric acid is 1 percent by mass, and the content of the boric acid tris (2,2, 2-trifluoroethyl) ester is 0.1 percent by mass; the organic solvent consists of dimethyl carbonate, diethyl carbonate and methyl ethyl carbonate according to the mass ratio of 4:5: 1.
The preparation method of the electrolyte comprises the following steps:
in a glove box, after uniformly mixing dimethyl carbonate, diethyl carbonate and methyl ethyl carbonate, adding LiPF into the mixture6、
Figure BDA0002956742820000074
And boric acid tri (2,2, 2-trifluoroethyl) ester are uniformly mixed to obtain the electrolyte.
Example 3
The embodiment provides an electrolyte and a preparation method thereof, wherein the electrolyte comprises Li2PO3F、
Figure BDA0002956742820000075
Tris (2,2, 2-trifluoroethyl) borate and an organic solvent;
li in the electrolyte2PO3The concentration of F is 0.5 mol/L;
Figure BDA0002956742820000081
the mass percentage content of the compound is 0.1 percent; the mass percentage content of the boric acid tri (2,2, 2-trifluoroethyl) ester is 2%; the organic solvent consists of dipropyl carbonate, ethyl methyl carbonate and diethyl carbonate according to the mass ratio of 4:3: 3.
The preparation method of the electrolyte comprises the following steps:
in a glove box, after dipropyl carbonate, ethyl methyl carbonate and diethyl carbonate are mixed uniformly, Li is added into the mixture2PO3F. Boric acid tris (2,2, 2-trifluoroethyl) ester and
Figure BDA0002956742820000082
and uniformly mixing to obtain the electrolyte.
Example 4
The embodiment provides an electrolyte and a preparation method thereof, wherein the electrolyte comprises a lithium salt,
Figure BDA0002956742820000083
Tris (2,2, 2-trifluoroethyl) borate and an organic solvent;
the lithium salt is formed by LiPO2F2And Li2PO3F is composed of 1:1 by mass, and the concentration of lithium salt in the electrolyte is 1.6 mol/L;
Figure BDA0002956742820000084
the mass percentage content of (A) is 2%; the mass percentage content of the boric acid tri (2,2, 2-trifluoroethyl) ester is 0.002%; the organic solvent consists of dimethyl carbonate, 1, 4-butyrolactone and ethyl acetate according to the mass ratio of 5:3: 2.
The preparation method of the electrolyte comprises the following steps:
in a glove box, after uniformly mixing dimethyl carbonate, 1, 4-butyrolactone and ethyl acetate, LiPO was added thereto2F2、Li2PO3F. Boric acid tris (2,2, 2-trifluoroethyl) ester and
Figure BDA0002956742820000091
and uniformly mixing to obtain the electrolyte.
Example 5
The embodiment provides an electrolyte and a preparation method thereof, wherein the electrolyte comprises lithium tetrafluoro oxalate phosphate,
Figure BDA0002956742820000092
Tris (2,2, 2-trifluoroethyl) borate and an organic solvent;
the concentration of lithium tetrafluoro oxalate phosphate in the electrolyte is 2 mol/L;
Figure BDA0002956742820000093
the mass percentage content of the compound is 0.001 percent; the concentration of the boric acid tris (2,2, 2-trifluoroethyl) ester is 1%; the organic solvent consists of dimethyl carbonate, ethyl methyl carbonate and diethyl carbonate according to the mass ratio of 2:4: 4.
The preparation method of the electrolyte comprises the following steps:
in a glove box, after uniformly mixing dimethyl carbonate, ethyl methyl carbonate and diethyl carbonate, lithium tetrafluoro oxalate phosphate, tris (2,2, 2-trifluoroethyl) borate and ethyl methyl carbonate are added into the mixture
Figure BDA0002956742820000094
And uniformly mixing to obtain the electrolyte.
Example 6
This example provides an electrolyte including LiN (SO) and a method of preparing the same2C2F5)2、
Figure BDA0002956742820000095
And an organic solvent;
LiN (SO) in the electrolyte2C2F5)2The concentration of (A) is 0.8 mol/L;
Figure BDA0002956742820000101
the mass percentage content of (A) is 3%; the organic solvent consists of diethyl carbonate, methyl ethyl carbonate and dipropyl carbonate according to the mass ratio of 4:4: 2.
The preparation method of the electrolyte comprises the following steps:
in a glove box, diethyl carbonate is put inAfter the ester, ethyl methyl carbonate and dipropyl carbonate were mixed uniformly, LiN (SO) was added thereto2C2F5)2And
Figure BDA0002956742820000102
and uniformly mixing to obtain the electrolyte.
Example 7
The embodiment provides an electrolyte and a preparation method thereof, wherein the electrolyte comprises LiBOB, tris (2,2, 2-trifluoroethyl) borate and an organic solvent;
the concentration of LiBOB in the electrolyte is 1.5 mol/L; the mass percentage content of the boric acid tri (2,2, 2-trifluoroethyl) ester is 3 percent; the organic solvent consists of dimethyl carbonate, diethyl carbonate and methyl ethyl carbonate according to the mass ratio of 3:5: 2.
The preparation method of the electrolyte comprises the following steps:
in a glove box, after uniformly mixing dimethyl carbonate, diethyl carbonate and ethyl methyl carbonate, adding LiBOB and tris (2,2, 2-trifluoroethyl) borate into the mixture, and uniformly mixing to obtain the electrolyte.
Example 8
This example provides an electrolyte and a method for preparing the same, which are different from example 1 only in that the electrolyte contains
Figure BDA0002956742820000111
The content of (b) was 0.001% by mass, and the other conditions were the same as in example 1.
Example 9
This example provides an electrolyte and a method for preparing the same, which are different from example 1 only in that the electrolyte contains
Figure BDA0002956742820000112
The content of (b) was 3% by mass, and the other conditions were the same as in example 1.
Example 10
This example provides an electrolyte and a method for preparing the same, which are different from example 1 only in that the electrolyte contains
Figure BDA0002956742820000113
The content of (b) was 0.0005% by mass, and the other conditions were the same as in example 1.
Example 11
This example provides an electrolyte and a method for preparing the same, which are different from example 1 only in that the electrolyte contains
Figure BDA0002956742820000114
The content of (b) was 4% by mass, and the other conditions were the same as in example 1.
Comparative example 1
This comparative example provides an electrolyte and a method of preparing the same, differing from example 1 only in that the electrolyte does not contain
Figure BDA0002956742820000121
Other conditions were the same as in example 1.
Comparative example 2
This comparative example provides an electrolyte and a method for preparing the same, differing from example 1 only in that the electrolyte is used
Figure BDA0002956742820000122
The reaction was replaced with fluorobenzene, and the other conditions were the same as in example 1.
Comparative example 3
This comparative example provides an electrolyte and a method for preparing the same, differing from example 1 only in that the electrolyte is used
Figure BDA0002956742820000123
The bis-fluorosulfonylimide was substituted for the above compound, and the other conditions were the same as in example 1.
Comparative example 4
This comparative example provides an electrolyte and a method for preparing the same, differing from example 1 only in that the electrolyte is used
Figure BDA0002956742820000124
Replacement by phenylmethylsulfonyl fluoride, other conditionsSame as in example 1.
Application examples 1 to 11
Application examples 1 to 11 provide a lithium ion battery, and a preparation method of the lithium ion battery is as follows:
(1) preparing a positive plate: the positive electrode material lithium Nickel Cobalt Manganese (NCM), the conductive agent Super P and the binder polyvinylidene fluoride (PVDF) are fully stirred and uniformly mixed in an N-methyl pyrrolidone solvent system according to the mass ratio of 97:2:1, then the mixture is coated on a positive electrode current collector aluminum foil, and the positive electrode sheet is obtained through drying and rolling.
(2) Preparing a negative plate: the negative electrode material graphite, the conductive agent Super P, the binder Styrene Butadiene Rubber (SBR) and the thickener carboxymethyl cellulose sodium (CMC) are fully stirred and uniformly mixed in a deionized water solvent system according to the mass ratio of 97:1:1.2:0.8, then the mixture is coated on a negative electrode current collector copper foil, and the negative electrode sheet is obtained after drying and rolling.
(3) Preparing an isolating membrane: the polyethylene porous polymer film is used as a separation film.
(4) Preparing a lithium ion battery: placing the prepared positive plate, the prepared isolating membrane and the prepared negative plate in sequence to enable the isolating membrane to be positioned between the positive plate and the negative plate, winding to obtain a bare cell, packaging the bare cell in an aluminum plastic film packaging bag, respectively injecting the electrolyte prepared in the embodiments 1-11 into a battery with moisture removed through drying, and obtaining the soft package lithium ion battery with the operating voltage range of 2.8-4.35V through the procedures of packaging, standing, formation, shaping and the like.
Application of comparative examples 1 to 4
Comparative application examples 1 to 4 provide a lithium ion battery, which is different from application example 1 only in that the electrolytes in step (4) are the electrolytes prepared in comparative examples 1 to 4, respectively, and other conditions are the same as in application example 1.
The performance of the lithium ion battery provided by the application example is tested, and the test standard is as follows:
and (3) cycle testing: adopts the 6.4 standard cycle life test in GB/T31484-2015,
the criterion for judging the end of the cycle test is as follows: the cycling test was stopped when the cell had a discharge capacity < 80% of the initial discharge capacity after cycling.
And (4) safety testing: by adopting 8.1.3 overcharge test, 8.1.4 external short circuit test and 8.1.5 heating test in GB/T38031-,
the safety test grade judgment standard is as follows:
lv 0: the experimental process has no phenomenon, and the battery has no functional loss;
lv 1: the passive protection is activated in the experimental process, and the battery is damaged reversibly and needs to be repaired;
lv 2: the battery is damaged in the experimental process, and the battery is irreversibly damaged and needs to be repaired;
lv 3: slight leakage and battery eruption in the experimental process; the weight loss of the electrolyte is less than 50 percent;
lv 4: severe leakage and battery eruption in the experimental process; the electrolyte is not ignited, and the weight loss of the electrolyte is more than 50 percent;
lv 5: cell rupture during the experiment; the battery is not exploded, and the interior of the battery is exposed;
lv 6: the experiment process is on fire; not exploding;
lv 7: explosion in the experimental process; the battery was completely destroyed.
The test results of the battery performance provided by the above application examples and application comparative examples are shown in the following table 1:
TABLE 1
Figure BDA0002956742820000141
Figure BDA0002956742820000151
The results in table 1 show that the aromatic sulfonyl fluoride and/or tris (2,2, 2-trifluoroethyl) borate are/is used as an additive, so that the precipitation of lithium can be effectively inhibited, the formation and growth of lithium dendrites are effectively avoided in the use process of the lithium ion battery, and the lithium ion battery prepared from the electrolyte provided by the invention has long service life, the discharge capacity of the lithium ion battery is still greater than 80% of the initial capacity after 2000 cycles of cycle test, and the safety of the lithium ion battery is high, and the overcharge test, the external short-circuit test and the heating test grades are all Lv2, so that the lithium ion battery meets the use requirements.
Compared with the lithium ion battery (application example 1) prepared from the electrolyte provided by the embodiment 1, if the content of the additive in the electrolyte is low (application example 10), the lithium ion battery (application example 10) prepared from the electrolyte has short service life, after 1812 circles of a cycle test, the discharge capacity of the battery is less than 80% of the initial discharge capacity, the battery does not meet the use requirement, the safety of the battery is poor, and after a charge test, an external short circuit test and a heating test, the lithium ion battery is erupted, and the weight loss of the electrolyte is serious; if the content of the additive in the electrolyte is high (example 11), the service life of the lithium ion battery prepared by the method (application example 11) is short, and after 1536 cycles of cycle test, the discharge capacity of the battery is less than 80% of the initial discharge capacity, so that the battery does not meet the use requirement. Therefore, when the content of the additive in the electrolyte is not in a specific range, the service life and the safety of the lithium ion battery are poor, and the lithium ion battery does not meet the use requirements.
Compared with the lithium ion battery (application example 1) prepared from the electrolyte provided by the example 1, if the electrolyte does not contain the additive (application example 1), the lithium ion battery (application example 1) prepared from the electrolyte has the advantages of short service life, low safety, 1326-circle cycle test frequency, Lv3 grades for overcharge test and external short circuit test, Lv4 grades, and no use requirement; if the additive is fluorobenzene (comparative example 2), the lithium ion battery (applied comparative example 2) prepared by the method has short service life and low safety, the cycle test frequency is 1389 circles, the overcharge test and the external short circuit test are both Lv3, the heating test is both Lv4, and the use requirement is not met; if the additive is bis-fluorosulfonyl imide (comparative example 3), the lithium ion battery (application comparative example 3) prepared by the method has short service life and low safety, the cycle test frequency is 1408 circles, the overcharge test and the external short circuit test are both Lv3, and the heating test is both Lv4, so that the lithium ion battery does not meet the use requirements; if the additive is phenylmethylsulfonyl fluoride (comparative example 4), the lithium ion battery prepared by the method (application comparative example 4) has short service life and low safety, the cycle test frequency is 1421 circles, the overcharge test grade and the external short circuit test grade are both Lv3, and the heating test grade is both Lv4, so that the lithium ion battery does not meet the use requirements. Therefore, the electrolyte provided by the invention adopts the specific additive, so that the prepared lithium ion battery has the advantages of long service life and high safety, and meets the use requirements of the battery.
In conclusion, the invention adopts the aromatic sulfonyl fluoride and/or the boric acid tris (2,2, 2-trifluoroethyl) ester as the additive, can effectively inhibit the precipitation of lithium, and effectively avoids the formation and growth of lithium dendrites in the use process of the lithium ion battery. The battery prepared from the electrolyte provided by the invention has the characteristics of long service life and higher safety, and meets the use requirements.
The applicant states that the present invention is illustrated by the detailed process flow of the present invention through the above examples, but the present invention is not limited to the above detailed process flow, that is, it does not mean that the present invention must rely on the above detailed process flow to be implemented. It should be understood by those skilled in the art that any modification of the present invention, equivalent substitutions of the raw materials of the product of the present invention, addition of auxiliary components, selection of specific modes, etc., are within the scope and disclosure of the present invention.

Claims (10)

1. An electrolyte, characterized in that the electrolyte comprises a combination of a lithium salt and an additive;
the additive is aromatic sulfonyl fluoride and/or boric acid tri (2,2, 2-trifluoroethyl) ester.
2. The electrolyte of claim 1, wherein the lithium salt is selected from LiPF6、LiClO4、LiPO2F2、Li2PO3F、LiBF4、FSO3Li、LiTFMSB、LiN(SO2F)2、LiAsF6、LiN(SO2CF3)2、LiN(SO2C2F5)2Any one or a combination of at least two of LiBOB, LiPFO and lithium tetrafluoro oxalate phosphate, and LiPF is more preferable6、LiBOB、LiBF4、Li2PO3F、LiPO2F2、LiN(SO2CF3)2Or LiN (SO)2C2F5)2Any one or a combination of at least two of them.
3. The electrolyte of claim 1 or 2, wherein the concentration of the lithium salt in the electrolyte is 0.5-2 mol/L.
4. The electrolyte according to any one of claims 1 to 3, wherein the additive is contained in the electrolyte in an amount of 0.001 to 3% by mass.
5. The electrolyte of any one of claims 1-4, wherein the aryl sulfonyl fluoride has the formula I:
Figure FDA0002956742810000011
wherein n is an integer of 0 to 5, and more preferably 1 or 2;
r is selected from substituted or unsubstituted C6～C21Aryl, substituted or unsubstituted C1～C12Straight or branched alkyl, halogen, cyano or
Figure FDA0002956742810000012
Any one or a combination of at least two of them.
6. The electrolyte of any one of claims 1-5, wherein the aryl sulfonyl fluoride is selected from the group consisting of
Figure FDA0002956742810000021
Any one or at least two ofA combination of species.
7. The electrolyte according to any one of claims 1 to 6, wherein the mass percentage of the aromatic sulfonyl fluoride in the electrolyte is 0.001 to 3%, and more preferably 0.1 to 2%.
8. The electrolyte according to any one of claims 1 to 7, wherein the tris (2,2, 2-trifluoroethyl) borate is present in the electrolyte in an amount of 0.002 to 3% by mass, and more preferably in an amount of 0.1 to 2% by mass.
9. The electrolyte of any one of claims 1-8, further comprising an organic solvent;
preferably, the organic solvent is selected from any one of ethylene carbonate, propylene carbonate, ethyl methyl carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, fluoroethylene carbonate, dipropyl carbonate, 1, 4-butyrolactone, methyl propyl carbonate, ethyl propyl carbonate, methyl propionate, methyl butyrate, ethyl acetate, ethyl propionate or ethyl butyrate or a combination of at least two thereof.
10. The lithium ion battery is characterized by comprising a positive electrode, a negative electrode, a separation film and electrolyte;
the isolating film and the electrolyte are positioned between the positive electrode and the negative electrode;
the electrolyte is according to any one of claims 1 to 9.
CN202110226800.5A 2021-03-01 2021-03-01 Electrolyte and lithium ion battery Pending CN112786966A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202110226800.5A CN112786966A (en) 2021-03-01 2021-03-01 Electrolyte and lithium ion battery

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202110226800.5A CN112786966A (en) 2021-03-01 2021-03-01 Electrolyte and lithium ion battery

Publications (1)

Publication Number Publication Date
CN112786966A true CN112786966A (en) 2021-05-11

Family

ID=75762060

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202110226800.5A Pending CN112786966A (en) 2021-03-01 2021-03-01 Electrolyte and lithium ion battery

Country Status (1)

Country Link
CN (1) CN112786966A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115863768A (en) * 2023-02-22 2023-03-28 安徽盟维新能源科技有限公司 Electrolyte and lithium metal battery containing same

Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1385919A (en) * 2001-05-11 2002-12-18 三星Sdi株式会社 Electrolytic solution for lithium secondary cell and lithium cell containing same
CN103633368A (en) * 2013-10-28 2014-03-12 山东海容电源材料有限公司 Flame-retardant additive for electrolyte and flame-retardant lithium ion battery electrolyte
CN105206875A (en) * 2015-10-29 2015-12-30 哈尔滨工业大学 Electrolyte for improving cycle performance of anode materials of lithium-ion batteries
US20160372791A1 (en) * 2015-06-22 2016-12-22 Johnson Controls Technology Company Electrolyte formulations for lithium ion batteries
CN107732302A (en) * 2017-10-11 2018-02-23 西安交通大学 A kind of nonaqueous electrolytic solution and its preparation method and application
CN109301162A (en) * 2013-03-27 2019-02-01 三菱化学株式会社 Nonaqueous electrolytic solution and the nonaqueous electrolyte battery for using the nonaqueous electrolytic solution
CN110718715A (en) * 2019-10-23 2020-01-21 东莞维科电池有限公司 Battery electrolyte additive, battery electrolyte and lithium ion battery
CN110931872A (en) * 2019-12-11 2020-03-27 多氟多新能源科技有限公司 Lithium ion battery electrolyte additive and lithium ion battery electrolyte
CN111146499A (en) * 2019-12-20 2020-05-12 东莞市杉杉电池材料有限公司 Lithium ion battery electrolyte and lithium ion battery containing same
CN111342138A (en) * 2020-03-12 2020-06-26 河南电池研究院有限公司 High-film-forming-property lithium ion battery electrolyte and using method thereof
CN111630702A (en) * 2018-01-25 2020-09-04 三井化学株式会社 Nonaqueous electrolyte for battery and lithium secondary battery
CN111769326A (en) * 2020-06-18 2020-10-13 合肥国轩高科动力能源有限公司 Ternary cathode material lithium ion battery electrolyte

Patent Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1385919A (en) * 2001-05-11 2002-12-18 三星Sdi株式会社 Electrolytic solution for lithium secondary cell and lithium cell containing same
CN109301162A (en) * 2013-03-27 2019-02-01 三菱化学株式会社 Nonaqueous electrolytic solution and the nonaqueous electrolyte battery for using the nonaqueous electrolytic solution
CN103633368A (en) * 2013-10-28 2014-03-12 山东海容电源材料有限公司 Flame-retardant additive for electrolyte and flame-retardant lithium ion battery electrolyte
US20160372791A1 (en) * 2015-06-22 2016-12-22 Johnson Controls Technology Company Electrolyte formulations for lithium ion batteries
CN105206875A (en) * 2015-10-29 2015-12-30 哈尔滨工业大学 Electrolyte for improving cycle performance of anode materials of lithium-ion batteries
CN107732302A (en) * 2017-10-11 2018-02-23 西安交通大学 A kind of nonaqueous electrolytic solution and its preparation method and application
CN111630702A (en) * 2018-01-25 2020-09-04 三井化学株式会社 Nonaqueous electrolyte for battery and lithium secondary battery
CN110718715A (en) * 2019-10-23 2020-01-21 东莞维科电池有限公司 Battery electrolyte additive, battery electrolyte and lithium ion battery
CN110931872A (en) * 2019-12-11 2020-03-27 多氟多新能源科技有限公司 Lithium ion battery electrolyte additive and lithium ion battery electrolyte
CN111146499A (en) * 2019-12-20 2020-05-12 东莞市杉杉电池材料有限公司 Lithium ion battery electrolyte and lithium ion battery containing same
CN111342138A (en) * 2020-03-12 2020-06-26 河南电池研究院有限公司 High-film-forming-property lithium ion battery electrolyte and using method thereof
CN111769326A (en) * 2020-06-18 2020-10-13 合肥国轩高科动力能源有限公司 Ternary cathode material lithium ion battery electrolyte

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115863768A (en) * 2023-02-22 2023-03-28 安徽盟维新能源科技有限公司 Electrolyte and lithium metal battery containing same
CN115863768B (en) * 2023-02-22 2023-04-25 安徽盟维新能源科技有限公司 Electrolyte and lithium metal battery containing same

Similar Documents

Publication Publication Date Title
CN109585925B (en) Electrolyte and lithium ion battery using same
CN106505249B (en) Lithium ion battery electrolyte and lithium ion battery containing same
CN109768326B (en) Electrolyte and electrochemical energy storage device
CN107871889B (en) Electrolyte solution and secondary battery
CN111525190B (en) Electrolyte and lithium ion battery
EP3972029A1 (en) Lithium secondary battery electrolyte, preparation method therefor and lithium secondary battery
CN112701349B (en) Electrolyte solution, electrochemical device and electronic apparatus including the same
CN111883830A (en) Lithium ion battery electrolyte, battery cathode and electrochemical energy storage device
CN108987802B (en) Non-aqueous electrolyte for high-voltage lithium ion battery
CN113381072A (en) Electrolyte and battery containing the same
CN105789703A (en) Lithium difluoborate containing sulfonate group and battery employing lithium salt
JP2021534555A (en) Lithium ion secondary battery
CN110911748B (en) Lithium secondary battery electrolyte and lithium secondary battery
US20200136183A1 (en) Electrolyte and lithium ion battery
CN113130990A (en) Electrolyte and secondary battery using same
CN112928328A (en) Lithium ion battery electrolyte containing silane sulfonamide compound and lithium ion secondary battery
CN109473717B (en) Electrolyte suitable for high-voltage high-nickel power battery and high-voltage high-nickel power battery
CN112531213A (en) Non-aqueous electrolyte with high-temperature characteristics and normal-temperature cycle, application thereof and lithium ion battery
CN112786966A (en) Electrolyte and lithium ion battery
CN114464889A (en) Non-aqueous electrolyte for high-voltage lithium ion battery and lithium ion battery thereof
CN114188605A (en) Lithium ion battery electrolyte for silicon-carbon cathode and lithium ion battery containing electrolyte
CN111600073B (en) Lithium ion battery electrolyte
CN112803072A (en) Lithium battery electrolyte and lithium battery
CN113871715A (en) Lithium iron phosphate battery
CN111613834A (en) Electrolyte and high-nickel power battery

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
RJ01 Rejection of invention patent application after publication
RJ01 Rejection of invention patent application after publication

Application publication date: 20210511