CN114552007B - Non-aqueous electrolyte of lithium ion battery and lithium ion battery - Google Patents

Non-aqueous electrolyte of lithium ion battery and lithium ion battery Download PDF

Info

Publication number
CN114552007B
CN114552007B CN202210151846.XA CN202210151846A CN114552007B CN 114552007 B CN114552007 B CN 114552007B CN 202210151846 A CN202210151846 A CN 202210151846A CN 114552007 B CN114552007 B CN 114552007B
Authority
CN
China
Prior art keywords
lithium ion
ion battery
lithium
nonaqueous electrolyte
equal
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.)
Active
Application number
CN202210151846.XA
Other languages
Chinese (zh)
Other versions
CN114552007A (en
Inventor
杨敏
程梅笑
申海鹏
郑畅
郭营军
李新丽
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.)
Xianghe Kunlun New Energy Materials Co ltd
Original Assignee
Xianghe Kunlun New Energy Materials 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 Xianghe Kunlun New Energy Materials Co ltd filed Critical Xianghe Kunlun New Energy Materials Co ltd
Priority to CN202210151846.XA priority Critical patent/CN114552007B/en
Publication of CN114552007A publication Critical patent/CN114552007A/en
Application granted granted Critical
Publication of CN114552007B publication Critical patent/CN114552007B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01MPROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00Secondary cells; Manufacture thereof
    • H01M10/05Accumulators with non-aqueous electrolyte
    • H01M10/056Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
    • H01M10/0564Accumulators 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
    • H01M10/0566Liquid materials
    • H01M10/0567Liquid materials characterised by the additives
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01MPROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00Secondary cells; Manufacture thereof
    • H01M10/05Accumulators with non-aqueous electrolyte
    • H01M10/052Li-accumulators
    • H01M10/0525Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
    • YGENERAL 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
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02EREDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10Energy storage using batteries

Abstract

The invention provides a non-aqueous electrolyte of a lithium ion battery and the lithium ion battery. The lithium ion battery nonaqueous electrolyte comprises lithium salt, nonaqueous solvent and additive, wherein the additive comprises alkenyl phosphate compound with chain structure and film-forming additive. The alkenyl phosphate compound with the chain structure provided by the invention not only can participate in the formation of a solid electrolyte membrane at a negative electrode interface, but also can reduce the increased internal resistance of the lithium ion battery caused by film formation, so that the battery can maintain excellent electrochemical performance and small impedance growth in the processes of normal temperature circulation, high temperature circulation and high temperature storage.

Description

Non-aqueous electrolyte of lithium ion battery and lithium ion battery
Technical Field
The invention belongs to the field of electrolytes, and particularly relates to a non-aqueous electrolyte of a lithium ion battery and the lithium ion battery.
Background
In recent years, lithium ion batteries have been the most widely used chemical energy storage batteries among new energy storage batteries because of their advantages of high energy density, high charge and discharge efficiency, high output voltage, long life, little environmental pollution, and wide application. With the rapid development of the field of lithium ion batteries, people put higher demands on the energy density and safety performance of lithium ion batteries. Therefore, it is important to increase the operating voltage of the existing systems and to develop high specific capacity battery systems to further increase the battery energy density.
In general, the thickness of the solid electrolyte membrane formed in the battery is thinner, and the ionic conductivity of the solid electrolyte membrane is higher, so that the impedance can be reduced to a certain extent, and the electrochemical performance of the battery is improved. However, if conventional film forming additives such as Vinylene Carbonate (VC) are used in lithium ion batteries applied at high voltages, oxidative decomposition reactions occur, so that the cycle performance of the lithium ion batteries is rapidly deteriorated. Many researchers have attempted to use other additives to improve the electrochemical performance of lithium ion batteries, such as ethylene carbonate (VEC) film-forming additives, but they form thicker solid electrolyte films, resulting in increased impedance inside the battery.
CN108470939a discloses a high-rate high-temperature-resistant lithium ion battery electrolyte, which can greatly improve the cycle performance and the high-rate performance of a lithium ion battery by adding a phosphate additive and compounding with other additives, and can well solve the problem of high-temperature gas expansion while improving the energy density, but does not mention the problem of internal impedance growth of the battery.
CN107863556a discloses a non-aqueous electrolyte of a lithium ion battery using a compound of a cyclotriphosphazene compound and a trialkenyl phosphate, which has excellent normal temperature cycle performance and high temperature storage performance, but does not mention the problems of high temperature cycle performance and impedance growth.
Therefore, there is an urgent need to develop a lithium ion battery electrolyte capable of reducing the internal resistance of the battery at high voltage, improving the cycle stability and high temperature performance of the battery.
Disclosure of Invention
Aiming at the defects of the prior art, the invention aims to provide a non-aqueous electrolyte of a lithium ion battery and the lithium ion battery. The alkenyl phosphate compound with the chain structure provided by the invention not only can participate in the formation of a solid electrolyte membrane (SEI) at a negative electrode interface, but also can reduce the increased internal resistance of the lithium ion battery caused by film formation, so that the battery can maintain excellent electrochemical performance and small impedance growth in the processes of normal temperature circulation, high temperature circulation and high temperature storage.
In order to achieve the aim of the invention, the invention adopts the following technical scheme:
In a first aspect, the present invention provides a lithium ion battery nonaqueous electrolyte comprising a lithium salt, a nonaqueous solvent, and an additive comprising an alkenyl phosphate compound having a chain structure represented by formula i and a film-forming additive:
Wherein R is selected from hydrogen, halogen, cyano-substituted or unsubstituted C2-C10 alkyl, substituted or unsubstituted C2-C10 alkenyl, unsubstituted C2-C10 alkynyl, substituted or unsubstituted C6-C30 aryl, amido, sulfonyl, siloxy or boronate.
According to the invention, the alkenyl phosphate compound with the chain structure shown in the formula I is adopted, on one hand, the alkenyl structure of the alkenyl phosphate compound can form a compact SEI film on a battery cathode material, and an electrode-electrolyte interface is stabilized, so that the lithium ion battery is not easily damaged under a high-temperature condition, and the electrochemical performance of the battery is enhanced; on the other hand, the alkenyl phosphate compound can form a high molecular organic matter on the surface of the positive electrode material, and is adsorbed in situ to form a protective film so as to prevent the electrolyte from generating oxidation reaction on the surface of the positive electrode, and the phosphorus atom in the phosphate group can also be used as an anion receptor to capture hydrogen fluoride in the electrolyte, so that the dissolution of transition metal is avoided, and the effect of protecting the electrode is achieved. In addition, in the aspect of reducing impedance, the longer the branched chain of the alkenyl phosphate compound with the chain structure is, the more favorable for reducing the film forming impedance of the electrode slice interface, and the film forming internal resistance of the battery can be obviously reduced by prolonging the length of the branched chain; and the double bond of the alkenyl phosphate compound can carry out crosslinking reaction with molecules of other film forming additives, and plays a synergistic effect with the film forming additives, so that a three-dimensional net film is formed on the surface of the pole piece, and the three-dimensional net film has better ion conductivity than an SEI film formed by singly using the film forming additives and is denser and firmer than an SEI film formed by singly using the alkenyl phosphate compound.
In the present invention, R is selected from hydrogen, halogen, cyano-substituted or unsubstituted C2-C10 alkyl, substituted or unsubstituted C2-C10 alkenyl, unsubstituted C2-C10 alkynyl, substituted or unsubstituted C6-C30 aryl, amide, sulfonyl, siloxy or boronate, for example, ethyl, butyl, benzyl or phenethyl, but not limited to the listed classes, and other non-listed classes within the scope of substituents are equally applicable.
Preferably, the alkenyl phosphate compound having a chain structure represented by formula i is any one of the following compounds:
Preferably, the mass percentage of the alkenyl phosphate compound having the chain structure shown in formula i in the nonaqueous electrolyte solution of the lithium ion battery is 0.01-5.00%, for example, 0.01%,0.05%,0.10%,0.50%,1.00%,2.00% or 5.00%, but not limited to the values listed, and other values not listed in the numerical range are equally applicable.
In the invention, the mass percentage of the alkenyl phosphate compound with the chain structure shown in the formula I in the nonaqueous electrolyte of the lithium ion battery is adjusted, and if the mass percentage is too low, the film formation of the lithium ion battery is not compact and stable enough, so that the effect of the additive in the lithium ion battery is not obvious. On the other hand, more polymer compound is generated, and the volume thickness of the battery is increased, and the impedance is not likely to be suppressed.
Preferably, the film forming additive comprises any one or a combination of at least two of 1, 3-propane sultone, ethylene carbonate, vinylene carbonate, fluoroethylene carbonate, 1, 4-butane sultone, 2, 4-butane sultone or propylene sultone.
Preferably, the mass percentage of the film forming additive in the nonaqueous electrolyte of the lithium ion battery is 0.10-15.00%, for example, 0.01%,0.05%,1.00%,5.00%,8.00%,10.00% or 15.00%, but not limited to the recited values, and other non-recited values in the numerical range are equally applicable.
In the invention, by adjusting the mass percentage of the film forming additive in the nonaqueous electrolyte of the lithium ion battery, the film cannot be formed when the mass percentage is too low, so that metal ions are dissolved out, and the battery electrode is damaged; otherwise, the interfacial film is continuously increased, resulting in an increase in electrode impedance, and the diffusion of lithium ions is hindered, resulting in capacity fading.
Preferably, the additive further comprises other additives;
Preferably, the other additives include any one or a combination of at least two of lithium difluorophosphate, vinyl sulfate, lithium difluorooxalato borate, lithium difluorobisoxalato phosphate, propylene sulfate, succinonitrile, adiponitrile, succinic anhydride, maleic anhydride, 1-propylphosphoric anhydride, phthalic anhydride, 2-methyl maleic anhydride, 2, 3-dimethyl maleic anhydride, tris (trimethylsilyl) borate, tris (trimethylsilyl) phosphate, ethylene glycol dipropionitrile ether, 1,3, 6-hexanetrinitrile, fluorobenzene, or 1,2, 3-tetrafluoroethyl-2, 3-tetrafluoropropyl ether.
Preferably, the mass percentage of the other additives in the nonaqueous electrolyte of the lithium ion battery is 0.10-15.00%, for example, 0.01%,0.05%,1.00%,5.00%,8.00%,10.00% or 15.00%, but not limited to the recited values, and other non-recited values in the numerical range are equally applicable.
In the invention, by adjusting the mass percentage content of other additives in the nonaqueous electrolyte of the lithium ion battery, the too low mass percentage content can cause poor conductivity of the lithium ion battery, reduce the safety performance of the lithium ion battery and the like; otherwise, more side reactions may occur, causing irreversible changes in the active material, thereby deteriorating electrochemical performance of the lithium ion battery.
Preferably, the lithium salt comprises any one or a combination of at least two of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium trifluoromethanesulfonate, lithium bis-fluorosulfonyl imide, or lithium bis-trifluoromethanesulfonyl imide.
Preferably, the lithium salt content in the nonaqueous electrolyte of the lithium ion battery is 2.00-20.00%, for example, may be 2.00%,3.00%,5.00%,8.00%,10.00%,15.00% or 20.00%, but is not limited to the recited values, and other non-recited values in the numerical range are equally applicable.
Preferably, the nonaqueous solvent comprises any one or a combination of at least two of methyl acetate, ethyl acetate, propyl acetate, ethylene glycol diethyl ether, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, butyl butyrate, acetonitrile, methyl propyl carbonate, sulfolane, dimethyl sulfoxide, tetrahydrofuran, propylene carbonate, diethyl carbonate, dimethyl carbonate, gamma-butyrolactone, methyl ethyl carbonate or ethylene carbonate.
Preferably, the mass percentage of the nonaqueous solvent in the nonaqueous electrolyte solution of the lithium ion battery is 45.00-97.79%, for example, 45.00%,50.00%,60.00%,80.00%,90.00%,95.00% or 97.79%, but not limited to the recited values, and other non-recited values in the numerical range are equally applicable.
In a second aspect, the invention provides a lithium ion battery, which comprises a positive plate, a negative plate, a diaphragm arranged between the positive plate and the negative plate and an electrolyte, wherein the electrolyte is the nonaqueous electrolyte of the lithium ion battery in the first aspect.
Preferably, the positive electrode sheet includes a positive electrode active material and a current collector.
Preferably, the positive electrode active material includes at least one of LiNixCoyMnzL(1-x-y-z)O2、LiCox'L(1-x')O2、LiNix"L'y'Mn(2-x"-y')O4、Liz'MPO4、LiMn2O4; wherein L is at least one of Al, sr, mg, ti, ca, zr, zn, si or Fe; x is more than or equal to 0 and less than or equal to 1, y is more than or equal to 0 and less than or equal to 1, z is more than or equal to 0 and less than or equal to 1, x+y+z is more than or equal to 0 and less than or equal to 1, x ' is more than or equal to 0 and less than or equal to 0.6, y ' is more than or equal to 0.01 and less than or equal to 0.2, and L ' is at least one of Co, al, sr, mg, ti, ca, zr, zn, si or Fe; and z' is more than or equal to 0.5 and less than or equal to 1, and M is at least one of Fe, mn or Co.
Compared with the prior art, the invention has the following beneficial effects:
The invention provides a non-aqueous electrolyte of a lithium ion battery, which adopts an alkenyl phosphate compound with a chain structure shown in a formula I, on one hand, the alkenyl phosphate compound has an alkenyl structure which can form a compact SEI film on a battery cathode material, and an electrode-electrolyte interface is stabilized, so that the lithium ion battery is not easily damaged under a high temperature condition, and the electrochemical performance of the battery is enhanced; on the other hand, the alkenyl phosphate compound can form a high molecular organic matter on the surface of the positive electrode material, and is adsorbed in situ to form a protective film so as to prevent the electrolyte from generating oxidation reaction on the surface of the positive electrode, and the phosphorus atom in the phosphate group can also be used as an anion receptor to capture hydrogen fluoride in the electrolyte, so that the dissolution of transition metal is avoided, and the effect of protecting the electrode is achieved. In addition, in the aspect of reducing impedance, the longer the branched chain of the alkenyl phosphate compound with a chain structure is, the more favorable for reducing the film forming impedance of a pole piece interface, the synergistic effect is exerted with a film forming additive, a three-dimensional net film is formed on the surface of the pole piece, and the ion conductivity of the SEI film is better than that of the SEI film formed by singly using the film forming additive, and the SEI film formed by singly using the alkenyl phosphate compound is more compact and stable.
Drawings
FIG. 1 is a graph showing the cycle performance at 45℃of application example 1, application example 2 and application example 5, and comparative application example 1;
FIG. 2 is a graph showing the circulating performance at 25℃of application example 1, application example 5 and comparative application example 1;
FIG. 3 shows the capacity retention and recovery of application examples 1 to 5 and comparative application example 1 stored at 60℃for 28 days;
FIG. 4 is a graph showing the positive electrode snap AC impedance spectra of application example 1 and comparative application example 5;
fig. 5 shows the ac impedance change rates of application examples 1 to 3 and comparative application example 1 stored at 60 ℃ for 28 days.
Detailed Description
The technical scheme of the invention is further described below by combining the attached drawings and the specific embodiments. It will be apparent to those skilled in the art that the examples are merely to aid in understanding the invention and are not to be construed as a specific limitation thereof.
Example 1
The present example provides a lithium ion battery nonaqueous electrolyte comprising an alkenyl phosphate compound ii (purchased from santa chemical company, songarland) in an amount of 0.50% by mass, ethylene carbonate in an amount of 1.00% by mass, and an additive of lithium difluorophosphate in an amount of 0.50% by mass, lithium hexafluorophosphate in an amount of 12.5% by mass, and a nonaqueous solvent of ethylene carbonate in an amount of 26.00% by mass, diethyl carbonate in an amount of 8.50% by mass, and methyl carbonate in an amount of 51.00% by mass, respectively, based on 100% by mass of the nonaqueous electrolyte.
The preparation method of the nonaqueous electrolyte of the lithium ion battery comprises the following steps:
In a glove box filled with nitrogen, based on 100% of the total mass of the nonaqueous electrolyte, uniformly mixing 26.00% of ethylene carbonate, 8.50% of diethyl carbonate and 51.00% of methyl ethylene carbonate battery grade organic solvent, adding 12.5% of lithium hexafluorophosphate into the nonaqueous solvent, adding 0.50% of alkenyl phosphate compound II (purchased from Shimadzu Santa chemical Co., ltd.) and finally adding 1.00% of ethylene carbonate and 0.50% of lithium difluorophosphate to obtain the nonaqueous electrolyte of the lithium ion battery.
Example 2
The present example provides a lithium ion battery nonaqueous electrolyte comprising alkenyl phosphate compound iii (purchased from santa chemical company, ston) in an amount of 1.00% by mass, fluoroethylene carbonate in an amount of 15.00% by mass, and lithium bis (trifluoromethylsulfonamide) in an amount of 2.50% by mass, lithium hexafluorophosphate in an amount of 12.5% by mass, and a nonaqueous solvent of ethylene carbonate in an amount of 21.00% by mass, diethyl carbonate in an amount of 8% by mass, and methyl carbonate in an amount of 40.00% by mass, respectively, based on 100% by mass of the total nonaqueous electrolyte.
The preparation method of the nonaqueous electrolyte of the lithium ion battery comprises the following steps:
The preparation method of the nonaqueous electrolyte for lithium ion batteries in this example is the same as in example 1.
Example 3
The present example provides a lithium ion battery nonaqueous electrolyte comprising an alkenyl phosphate compound iv (purchased from santa chemical company, ma) in an amount of 0.01% by mass, 1, 3-propane sultone in an amount of 5.00% by mass, and an additive of lithium difluorobis (oxalato) phosphate in an amount of 2.50% by mass, lithium hexafluorophosphate in an amount of 13.5% by mass, a nonaqueous solvent of ethylene carbonate in an amount of 25.65% by mass, diethyl carbonate in an amount of 11.32% by mass, and methyl carbonate in an amount of 42.02% by mass, respectively, based on 100% by mass of the nonaqueous electrolyte.
The preparation method of the nonaqueous electrolyte of the lithium ion battery comprises the following steps:
The preparation method of the nonaqueous electrolyte for lithium ion batteries in this example is the same as in example 1.
Example 4
The present example provides a lithium ion battery nonaqueous electrolyte comprising an alkenyl phosphate compound v (purchased from santa chemical company, songarland) in an amount of 3.00% by mass, ethylene carbonate in an amount of 0.30% by mass, and an additive of lithium difluorooxalato borate in an amount of 0.20% by mass, lithium hexafluorophosphate in an amount of 13.5% by mass, and a nonaqueous solvent of ethylene carbonate in an amount of 25.00% by mass, diethyl carbonate in an amount of 10.00% by mass, and methyl carbonate in an amount of 48.00% by mass, respectively, based on 100% by mass of the nonaqueous electrolyte.
The preparation method of the nonaqueous electrolyte of the lithium ion battery comprises the following steps:
The preparation method of the nonaqueous electrolyte for lithium ion batteries in this example is the same as in example 1.
Example 5
The present example provides a lithium ion battery nonaqueous electrolyte comprising alkenyl phosphate compound vi (purchased from santa chemical company, ston) in an amount of 1.50% by mass, ethylene carbonate in an amount of 0.05% by mass, and an additive of lithium bis (fluorosulfonyl) imide in an amount of 1.00% by mass, lithium hexafluorophosphate in an amount of 20.0% by mass, and a nonaqueous solvent of 30.2% by mass of ethylene carbonate, diethyl carbonate in an amount of 7.25% by mass, and methyl carbonate in an amount of 40.00% by mass, respectively, based on 100% by mass of the nonaqueous electrolyte.
The preparation method of the nonaqueous electrolyte of the lithium ion battery comprises the following steps:
The preparation method of the nonaqueous electrolyte for lithium ion batteries in this example is the same as in example 1.
Example 6
The present example provides a lithium ion battery nonaqueous electrolyte comprising an alkenyl phosphate compound vii (purchased from santa chemical company, ma) in an amount of 5.00% by mass, ethylene carbonate in an amount of 0.50% by mass, and an additive of lithium difluorooxalato borate in an amount of 2.00% by mass, lithium hexafluorophosphate in an amount of 12.5% by mass, a nonaqueous solvent of ethylene carbonate in an amount of 24.00% by mass, diethyl carbonate in an amount of 8.00% by mass, and methyl carbonate in an amount of 48.00% by mass, respectively, based on 100% by mass of the nonaqueous electrolyte.
The preparation method of the nonaqueous electrolyte of the lithium ion battery comprises the following steps:
The preparation method of the nonaqueous electrolyte for lithium ion batteries in this example is the same as in example 1.
Example 7
The present example provides a lithium ion battery nonaqueous electrolyte comprising an alkenyl phosphate compound ii (purchased from santa chemical company, songarland) in an amount of 0.05% by mass, ethylene carbonate in an amount of 1.55% by mass, and an additive of lithium difluorooxalato borate in an amount of 4.90% by mass, lithium hexafluorophosphate in an amount of 13.5% by mass, a nonaqueous solvent of ethylene carbonate in an amount of 24.00% by mass, diethyl carbonate in an amount of 8.00% by mass, and methyl carbonate in an amount of 48.00% by mass, respectively, based on 100% by mass of the nonaqueous electrolyte.
The preparation method of the nonaqueous electrolyte of the lithium ion battery comprises the following steps:
The preparation method of the nonaqueous electrolyte for lithium ion batteries in this example is the same as in example 1.
Example 8
The present example provides a lithium ion battery nonaqueous electrolyte comprising an alkenyl phosphate compound ii (purchased from santa chemical company, ston) in an amount of 3.50% by mass, an additive of fluoroethylene carbonate in an amount of 5.00% by mass and lithium bis (trifluoromethylsulfonamide) in an amount of 2.00% by mass, lithium hexafluorophosphate in an amount of 13.5% by mass, and a nonaqueous solvent of ethylene carbonate in an amount of 24.00% by mass, diethyl carbonate in an amount of 9.50% by mass and methyl carbonate in an amount of 42.50% by mass, respectively, based on 100% by mass of the total nonaqueous electrolyte.
The preparation method of the nonaqueous electrolyte of the lithium ion battery comprises the following steps:
The preparation method of the nonaqueous electrolyte for lithium ion batteries in this example is the same as in example 1.
Example 9
The present example provides a lithium ion battery nonaqueous electrolyte comprising an alkenyl phosphate compound ii (purchased from santa chemical company, songarland) in an amount of 4.00% by mass, 1, 3-propane sultone in an amount of 2.45% by mass, and lithium difluorophosphate as an additive in an amount of 0.05% by mass, lithium hexafluorophosphate in an amount of 13.5% by mass, and a nonaqueous solvent of ethylene carbonate in an amount of 24.00% by mass, diethyl carbonate in an amount of 8.00% by mass, and methyl carbonate in an amount of 48.00% by mass, respectively, based on 100% by mass of the nonaqueous electrolyte.
The preparation method of the nonaqueous electrolyte of the lithium ion battery comprises the following steps:
The preparation method of the nonaqueous electrolyte for lithium ion batteries in this example is the same as in example 1.
Example 10
The present example provides a lithium ion battery nonaqueous electrolyte comprising an alkenyl phosphate compound ii (purchased from santa chemical company, songarland) in an amount of 0.50% by mass, an additive of vinylene carbonate in an amount of 1.00% by mass and lithium difluorophosphate in an amount of 0.50% by mass, lithium hexafluorophosphate in an amount of 12.5% by mass, a nonaqueous solvent of ethylene carbonate in an amount of 26.00% by mass, diethyl carbonate in an amount of 8.50% by mass and methyl carbonate in an amount of 51.00% by mass, respectively, based on 100% by mass of the nonaqueous electrolyte.
The preparation method of the nonaqueous electrolyte of the lithium ion battery comprises the following steps:
The preparation method of the nonaqueous electrolyte for lithium ion batteries in this example is the same as in example 1.
Example 11
The present example provides a lithium ion battery nonaqueous electrolyte comprising an alkenyl phosphate compound ii (purchased from santa chemical company, ston) in an amount of 0.50% by mass, ethylene carbonate in an amount of 1.50% by mass, lithium hexafluorophosphate in an amount of 12.5% by mass, ethylene carbonate in an amount of 26.00% by mass, diethyl carbonate in an amount of 8.50% by mass, and a nonaqueous solvent of methyl ethylene carbonate in an amount of 51.00% by mass, respectively, based on 100% by mass of the nonaqueous electrolyte.
The preparation method of the nonaqueous electrolyte of the lithium ion battery comprises the following steps:
The preparation method of the nonaqueous electrolyte for lithium ion batteries in this example is the same as in example 1.
Comparative example 1
The comparative example is different from example 1 in that in the preparation of the nonaqueous electrolytic solution for lithium ion battery, the alkenyl phosphate compound II is not added, the mass percentage of ethylene carbonate is 1.50%, based on 100% of the total mass of the nonaqueous electrolytic solution, and the other is the same as in example 1.
Comparative example 2
The comparative example differs from example 1 in that ethylene carbonate was not added in the preparation of the nonaqueous electrolytic solution for a lithium ion battery, and the mass percentage of the alkenyl phosphate compound II was 1.50% based on 100% of the total mass of the nonaqueous electrolytic solution, and the other was the same as in example 1.
Comparative example 3
The comparative example is different from example 1 in that in the preparation of the nonaqueous electrolytic solution for a lithium ion battery, the alkenyl phosphate compound II and ethylene carbonate are not added, and the mass percentage of lithium hexafluorophosphate is 14% based on 100% of the total mass of the nonaqueous electrolytic solution, and the other is the same as in example 1.
Comparative example 4
The present comparative example was different from example 1 in that in the preparation of the nonaqueous electrolytic solution for a lithium ion battery, an alkenyl phosphate compound, ethylene carbonate and lithium difluorophosphate were not added, based on 100% of the total mass of the nonaqueous electrolytic solution, and the mass percentage of lithium hexafluorophosphate was 14.5%, all of which were the same as in example 1.
Comparative example 5
This comparative example is different from example 1 in that in the preparation of the nonaqueous electrolytic solution for lithium ion battery, the alkenyl phosphate compound II is replaced with a phosphate compound A (available from Santa chemical Co., ltd.) having the following structure, and the other is the same as in example 1.
The contents of the components of the nonaqueous electrolytic solutions for lithium ion batteries provided in examples 1 to 11 and comparative examples 1 to 5 are shown in table 1:
TABLE 1
Application example 1-application example 11 and comparative application example 1-comparative application example 5
The lithium ion batteries provided in examples 1 to 11 and comparative examples 1 to 5 were prepared from the nonaqueous electrolytic solutions of lithium ion batteries as follows:
preparing a positive electrode: mixing LiNi 0.5Co0.2Mn0.3O2 powder, binder polyvinylidene fluoride (PVDF) and conductive agent acetylene black according to the weight ratio of 97.5:1.5:1.5, adding N-methyl pyrrolidone (NMP), stirring the mixture by using a vacuum stirrer to obtain positive electrode slurry, uniformly coating the positive electrode slurry on aluminum foil, putting the coated aluminum foil into an oven for baking and drying, and rolling and cutting to obtain the required positive electrode sheet.
Preparing a negative electrode: mixing graphite anode material, conductive carbon black (Super P) conductive agent, sodium carboxymethylcellulose (CMC) dispersant and Styrene Butadiene Rubber (SBR) binder according to a weight ratio of 95.7:1:1.3:2 to prepare anode slurry according to a certain process; and then uniformly coating the graphite negative electrode sheet on an aluminum foil, putting the coated aluminum foil into an oven for baking and drying, and rolling and slitting to obtain the required graphite negative electrode sheet.
Preparation of a diaphragm: the polypropylene material is used as a lithium ion battery diaphragm.
Preparing a lithium ion battery: winding the positive plate, the diaphragm and the negative plate prepared by the method to prepare a bare cell; and (3) putting the obtained bare cell into a packaging aluminum foil, drying the bare cell, injecting the electrolyte, and carrying out the procedures of vacuum packaging, standing, formation, shaping, sorting and the like to obtain the nickel-cobalt-manganese battery, wherein the discharge interval is 2.75V-4.40V.
The manufacturing method of the button half-cell comprises the following steps:
And preparing the prepared electrolyte into a positive plate I electrolyte I lithium plate positive button type half cell by using the positive and negative electrodes of the same type of soft package cell.
Test conditions
The lithium ion batteries prepared in application examples 1 to 11 and comparative application examples 1 to 5 were subjected to normal temperature cycle, high temperature storage performance and high temperature cycle performance tests, respectively, as follows:
(1) And (3) normal temperature circulation: the soft package battery prepared in the above way is placed in a constant temperature chamber at 25 ℃ after being formed, is charged to 4.40V by constant current and constant voltage, the cut-off current is 0.05C, and is discharged to 2.75V by constant current, and the capacity retention rate is calculated after 400 weeks of circulation.
The calculation formula of 400-week normal temperature cycle is as follows:
capacity retention (%) =discharge capacity after 400 weeks of cycling/first discharge capacity×100%
(2) High temperature cycle: the soft package battery prepared by the method is placed in an environment of 45 ℃ after being formed, is charged to 4.40V by constant current and constant voltage, has cut-off current of 0.05C, is discharged to 2.75V by constant current, and the capacity retention rate is calculated after 200 weeks of circulation.
The calculation formula of the 200-week high-temperature cycle is as follows:
Capacity retention (%) =discharge capacity after 200 weeks of cycle/first discharge capacity×100%
(3) High temperature storage test: the battery after formation is charged to 4.40V at 25 ℃ with a constant current and constant voltage of 1C, the cut-off current is 0.05C, then the 1C constant current is discharged to 2.75V, the initial discharge capacity of the battery is measured and recorded, the initial alternating current impedance is measured and recorded by an alternating current impedance tester, then the 1C constant current and constant voltage is charged to 4.40V, the cut-off current is 0.05C, then the full-charged battery is put into an oven at 60 ℃ for 28 days, then the 1C constant current is discharged to 2.75V, the holding capacity of the battery is measured and recorded, then the 1C constant current and constant voltage is charged to 4.40V, the cut-off battery is 0.05C, then the recovery capacity is measured and recorded, the alternating current impedance is measured and recorded in the full-charged state, and the data is measured every 7 days.
The capacity retention rate and the capacity recovery rate are calculated as follows:
battery capacity retention (%) =retention capacity/initial capacity ×100%
Battery capacity recovery rate (%) =recovery capacity/initial capacity ×100%
Battery ac impedance increase rate (%) = (ac impedance after 7 days-initial ac impedance)/initial ac impedance × 100%
(4) Alternating current impedance (EIS) test: the same positive electrode of the soft-package battery is used for preparing the lithium cobaltate I electrolyte I lithium sheet button battery, and 3-4 ml of electrolyte is injected. And placing the button cell on an electrochemical workstation for AC impedance test, wherein the frequency range is 0.10-1 multiplied by 10 6 HZ.
As can be seen from fig. 1, the capacity retention rates of the lithium ion batteries prepared in application example 1, application example 2 and application example 5 at 45 ℃ are much higher than those of the lithium ion batteries provided in comparative application example 1; fig. 2 shows that the capacity retention rate of the lithium ion batteries prepared in application example 1 and application example 5 is much higher than that of the lithium ion battery provided in comparative application example 1 at 25 ℃; as shown in fig. 3, the capacity retention rate and recovery rate of the lithium ion batteries prepared in application examples 1 to 5 at 60 ℃ were much higher than those of the lithium ion battery provided in comparative application example 1.
The test results are shown in table 2:
TABLE 2
As can be seen from the data of table 2, the lithium ion battery nonaqueous electrolyte containing the alkenyl phosphate compound additive with a chain structure is adopted in the invention, the prepared lithium ion battery has higher capacity retention rate and lower alternating current impedance growth rate (except application example 10) in normal temperature circulation, high temperature circulation and high temperature storage, and the comparative example without the additive has obviously bad effect, for example, the capacity retention rate of the lithium ion battery in comparative application example 1 is 74.86% after the lithium ion battery is circulated for 400 weeks at the normal temperature of 25 ℃, and the circulation performance at 45 ℃ and the high temperature storage performance at 60 ℃ are not as good as application example 1; the lithium ion battery prepared by the electrolyte of the comparative application example 3 only adopting other additives has the same comprehensive performance as that of the application example 1, and the comparative application example 4 is a common electrolyte without any additive, so that the electrochemical performance is the worst; the capacity retention rate of the short-chain phosphate compound A adopted in the comparative application example 5 after being circulated for 200 weeks at 45 ℃ is below 85%, and other performances are far lower than the capacity retention rate of the lithium ion batteries provided in the application examples 1 to 9, so that the lithium ion battery prepared by the non-aqueous electrolyte of the lithium ion battery provided by the invention has the characteristics of high circulation capacity retention rate, high storage capacity retention rate and high recovery rate under high temperature conditions.
Application example 10 shows that the lithium ion battery using Vinylene Carbonate (VC) at high voltage is significantly inferior to the lithium ion battery prepared using other application examples in normal temperature cycle, high temperature cycle, and high temperature storage. As can be seen by comparing fig. 4 and 5, the lithium ion battery containing the alkenyl phosphate compound additive has a smaller resistance increase, which indicates that the alkenyl phosphate compound contributes to the formation of a dense SEI film on the electrode surface, improving the performance degradation and resistance increase performance of the lithium ion battery under the cycle and high temperature storage. Therefore, the electrolyte can be applied to lithium ion batteries under high voltage, so that the batteries have excellent capacity retention rate and small impedance increase.
The applicant states that the process of the invention is illustrated by the above examples, but the invention is not limited to, i.e. does not mean that the invention must be carried out in dependence on the above process steps. It should be apparent to those skilled in the art that any modification of the present invention, equivalent substitution of selected raw materials, addition of auxiliary components, selection of specific modes, etc. fall within the scope of the present invention and the scope of disclosure.

Claims (13)

1. A lithium ion battery nonaqueous electrolyte, characterized in that the lithium ion battery nonaqueous electrolyte comprises a lithium salt, a nonaqueous solvent and an additive, wherein the additive comprises an alkenyl phosphate compound with a chain structure shown in formula ii or formula iv and a film-forming additive:
The mass percentage of the alkenyl phosphate compound with the chain structure shown in the formula II or the formula IV in the nonaqueous electrolyte of the lithium ion battery is 1-5.00%.
2. The lithium ion battery nonaqueous electrolyte according to claim 1, wherein the film-forming additive comprises any one or a combination of at least two of 1, 3-propane sultone, ethylene carbonate, fluoroethylene carbonate, 1, 4-butane sultone, 2, 4-butane sultone, or propylene sultone.
3. The nonaqueous electrolyte for lithium ion batteries according to claim 1, wherein the mass percentage of the film-forming additive in the nonaqueous electrolyte for lithium ion batteries is 0.10-15.00%.
4. The lithium ion battery nonaqueous electrolyte according to claim 1, wherein the additive further comprises other additives.
5. The non-aqueous electrolyte for lithium ion batteries according to claim 4, wherein the other additives comprise any one or a combination of at least two of lithium difluorophosphate, vinyl sulfate, lithium difluorooxalate borate, lithium difluorobisoxalate phosphate, propylene sulfate, succinonitrile, adiponitrile, succinic anhydride, maleic anhydride, 1-propylphosphoric anhydride, phthalic anhydride, 2-methyl maleic anhydride, 2, 3-dimethylmaleic anhydride, tris (trimethylsilyl) borate, tris (trimethylsilyl) phosphate, ethylene glycol dipropionylether, 1,3, 6-hexanetrinitrile, fluorobenzene, or 1,2, 3-tetrafluoroethyl-2, 3-tetrafluoropropyl ether.
6. The nonaqueous electrolyte for lithium ion batteries according to claim 4, wherein the mass percentage of other additives in the nonaqueous electrolyte for lithium ion batteries is 0.10-15.00%.
7. The lithium ion battery nonaqueous electrolyte according to claim 1, wherein the lithium salt comprises any one or a combination of at least two of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium trifluoromethane sulfonate, lithium bis-fluoro-sulfonyl imide, or lithium bis-fluoro-methyl-sulfonyl imide.
8. The nonaqueous electrolyte for lithium ion batteries according to claim 1, wherein the mass percentage of lithium salt in the nonaqueous electrolyte for lithium ion batteries is 2.00-20.00%.
9. The nonaqueous electrolyte for lithium ion batteries according to claim 1, wherein the nonaqueous solvent comprises any one or a combination of at least two of methyl acetate, ethyl acetate, propyl acetate, ethylene glycol diethyl ether, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, butyl butyrate, acetonitrile, methyl propyl carbonate, sulfolane, dimethyl sulfoxide, tetrahydrofuran, propylene carbonate, diethyl carbonate, dimethyl carbonate, γ -butyrolactone, methyl ethyl carbonate, or ethylene carbonate.
10. The nonaqueous electrolyte for lithium ion batteries according to claim 1, wherein the nonaqueous solvent in the nonaqueous electrolyte for lithium ion batteries is 45.00 to 97.79% by mass.
11. A lithium ion battery, characterized in that the lithium ion battery comprises a positive electrode plate, a negative electrode plate, a diaphragm arranged between the positive electrode and the negative electrode, and an electrolyte, wherein the electrolyte is the non-aqueous electrolyte of the lithium ion battery of any one of claims 1-10.
12. The lithium ion battery of claim 11, wherein the positive electrode sheet comprises a positive electrode active material and a current collector.
13. The lithium ion battery of claim 12, wherein the positive electrode active material comprises at least one of LiNixCoyMnzL(1-x-y-z)O2、LiCox'L(1-x')O2、LiNix"L'y'Mn(2-x"-y')O4、Liz'MPO4、LiMn2O4; wherein L is at least one of Al, sr, mg, ti, ca, zr, zn, si or Fe; x is more than or equal to 0 and less than or equal to 1, y is more than or equal to 0 and less than or equal to 1, z is more than or equal to 0 and less than or equal to 1, x+y+z is more than or equal to 0 and less than or equal to 1, x ' is more than or equal to 0 and less than or equal to 0.6, y ' is more than or equal to 0.01 and less than or equal to 0.2, and L ' is at least one of Co, al, sr, mg, ti, ca, zr, zn, si or Fe; and z' is more than or equal to 0.5 and less than or equal to 1, and M is at least one of Fe, mn or Co.
CN202210151846.XA 2022-02-18 2022-02-18 Non-aqueous electrolyte of lithium ion battery and lithium ion battery Active CN114552007B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202210151846.XA CN114552007B (en) 2022-02-18 2022-02-18 Non-aqueous electrolyte of lithium ion battery and lithium ion battery

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202210151846.XA CN114552007B (en) 2022-02-18 2022-02-18 Non-aqueous electrolyte of lithium ion battery and lithium ion battery

Publications (2)

Publication Number Publication Date
CN114552007A CN114552007A (en) 2022-05-27
CN114552007B true CN114552007B (en) 2024-04-30

Family

ID=81676017

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202210151846.XA Active CN114552007B (en) 2022-02-18 2022-02-18 Non-aqueous electrolyte of lithium ion battery and lithium ion battery

Country Status (1)

Country Link
CN (1) CN114552007B (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114824486A (en) * 2022-06-29 2022-07-29 天鹏锂能技术(淮安)有限公司 Electrolyte for lithium ion battery, preparation method of electrolyte and lithium ion battery
CN116864811B (en) * 2023-08-30 2023-11-28 香河昆仑新能源材料股份有限公司 Battery electrolyte with excellent high-temperature performance and lithium ion battery

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2015043298A (en) * 2013-08-26 2015-03-05 旭化成株式会社 Nonaqueous electrolytic solution, and lithium ion secondary battery using nonaqueous electrolytic solution
CN109193029A (en) * 2018-08-21 2019-01-11 东莞市杉杉电池材料有限公司 A kind of nickelic ternary non-aqueous electrolyte for lithium ion cell and the nickelic ternary lithium ion battery containing the electrolyte
CN109818058A (en) * 2019-01-17 2019-05-28 安徽屹盛机电科技有限公司 A kind of jetting machine lithium battery electrolytes
CN109860706A (en) * 2018-12-19 2019-06-07 珠海光宇电池有限公司 A kind of nonaqueous electrolytic solution and the lithium ion battery containing the electrolyte
CN110021785A (en) * 2019-04-15 2019-07-16 杉杉新材料(衢州)有限公司 A kind of ternary high-voltage lithium-ion battery electrolyte and ternary high-voltage lithium ion batteries
CN111342131A (en) * 2020-03-04 2020-06-26 河南省法恩莱特新能源科技有限公司 4.4V high-voltage manganese-based ternary lithium ion battery electrolyte and preparation method thereof
CN109762115B (en) * 2019-01-14 2021-10-01 上海安缔诺科技有限公司 Resin composition and application thereof

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2015043298A (en) * 2013-08-26 2015-03-05 旭化成株式会社 Nonaqueous electrolytic solution, and lithium ion secondary battery using nonaqueous electrolytic solution
CN109193029A (en) * 2018-08-21 2019-01-11 东莞市杉杉电池材料有限公司 A kind of nickelic ternary non-aqueous electrolyte for lithium ion cell and the nickelic ternary lithium ion battery containing the electrolyte
CN109860706A (en) * 2018-12-19 2019-06-07 珠海光宇电池有限公司 A kind of nonaqueous electrolytic solution and the lithium ion battery containing the electrolyte
CN109762115B (en) * 2019-01-14 2021-10-01 上海安缔诺科技有限公司 Resin composition and application thereof
CN109818058A (en) * 2019-01-17 2019-05-28 安徽屹盛机电科技有限公司 A kind of jetting machine lithium battery electrolytes
CN110021785A (en) * 2019-04-15 2019-07-16 杉杉新材料(衢州)有限公司 A kind of ternary high-voltage lithium-ion battery electrolyte and ternary high-voltage lithium ion batteries
CN111342131A (en) * 2020-03-04 2020-06-26 河南省法恩莱特新能源科技有限公司 4.4V high-voltage manganese-based ternary lithium ion battery electrolyte and preparation method thereof

Also Published As

Publication number Publication date
CN114552007A (en) 2022-05-27

Similar Documents

Publication Publication Date Title
US7294436B2 (en) Nonaqueous electrolytic solution and lithium secondary batteries
JP3558007B2 (en) Non-aqueous electrolyte and lithium secondary battery using the same
CN109473719B (en) Lithium ion battery electrolyte and lithium ion battery containing same
CN111525190B (en) Electrolyte and lithium ion battery
CN110752406B (en) Electrolyte and application thereof
CN114552007B (en) Non-aqueous electrolyte of lithium ion battery 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
CN110911748B (en) Lithium secondary battery electrolyte and lithium secondary battery
EP3996180A1 (en) Electrolytic solution, and preparation method therefor and application thereof
CN111934015A (en) Non-aqueous electrolyte of lithium ion battery and lithium ion battery containing non-aqueous electrolyte
CN114512721A (en) Lithium ion battery non-aqueous electrolyte and lithium ion battery
CN109473717B (en) Electrolyte suitable for high-voltage high-nickel power battery and high-voltage high-nickel power battery
CN114039094A (en) Non-aqueous electrolyte of lithium ion battery and lithium ion battery
CN112072179A (en) Electrolyte, lithium ion battery and vehicle
CN112615056B (en) Additive composition for preparing electrolyte, electrolyte containing additive composition and lithium ion secondary battery
CN110970663A (en) Non-aqueous electrolyte and lithium ion battery
EP4243146A1 (en) Lithium ion battery non-aqueous electrolyte and lithium ion battery
CN110556579B (en) Electrolyte and lithium ion battery containing same
CN115133125A (en) Method for improving solubility of lithium salt additive and electrolyte containing lithium salt additive
CN112038697A (en) Lithium ion battery non-aqueous electrolyte and lithium ion battery
JP2009283473A (en) Nonaqueous electrolyte solution and lithium secondary battery using the same
CN111613834A (en) Electrolyte and high-nickel power battery
CN111146497A (en) Additive for battery electrolyte, lithium ion battery electrolyte and lithium ion battery
JP4432397B2 (en) Nonaqueous electrolyte and lithium secondary battery using the same

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
GR01 Patent grant