WO2019119766A1 - 一种非水电解液及锂离子电池 - Google Patents

一种非水电解液及锂离子电池 Download PDF

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WO2019119766A1
WO2019119766A1 PCT/CN2018/092979 CN2018092979W WO2019119766A1 WO 2019119766 A1 WO2019119766 A1 WO 2019119766A1 CN 2018092979 W CN2018092979 W CN 2018092979W WO 2019119766 A1 WO2019119766 A1 WO 2019119766A1
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group
carbonate
cyclic
electrolytic solution
lithium
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PCT/CN2018/092979
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English (en)
French (fr)
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石桥
陈群
曹朝伟
胡时光
贠娇娇
黄丰良
黄佳豪
郑仲天
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深圳新宙邦科技股份有限公司
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
    • H01M10/0564—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
    • H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
    • 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

Definitions

  • the invention belongs to the technical field of lithium ion batteries, and particularly relates to a non-aqueous electrolyte and a lithium ion battery.
  • Lithium-ion batteries are widely used in portable electronic products due to their high operating voltage, high safety, long life and no memory effect. With the development of new energy vehicles, lithium-ion batteries have great application prospects in power supply systems for new energy vehicles.
  • the non-aqueous electrolyte lithium ion battery is a key factor affecting the high and low temperature performance of the battery.
  • the additive in the non-aqueous electrolyte is particularly important for the performance of the high-low temperature performance of the battery.
  • the electrolyte reacts on the surface of the carbon negative electrode to produce a compound such as Li 2 CO 3 , LiO, LiOH, etc., thereby forming a passivation film on the surface of the negative electrode, which is called a solid electrolyte interface film (SEI).
  • SEI solid electrolyte interface film
  • the SEI film formed during the initial charging process not only prevents the electrolyte from further decomposing on the surface of the carbon negative electrode, but also acts as a lithium ion tunneling, allowing only lithium ions to pass. Therefore, the SEI film determines the performance of the lithium ion battery.
  • U.S. Patent No. 6,919,141 discloses a lithium ion battery electrolyte containing an unsaturated phosphate compound, which can improve the high temperature performance of the battery, but the electrolyte containing unsaturated phosphate significantly increases the internal resistance of the battery and deteriorates the low temperature performance of the battery.
  • the present invention provides a non-aqueous electrolyte and a lithium ion battery to improve the high temperature cycle performance of the lithium ion battery and the low temperature performance.
  • the present invention provides a nonaqueous electrolyte comprising an organic solvent, a lithium salt and a phosphate compound, the phosphate compound comprising a compound selected from the group consisting of the formula (I):
  • R 1 , R 2 and R 3 are each independently selected from an alkyl group of 1 to 5 carbon atoms, a fluoroalkyl group of 1 to 5 carbon atoms, an aryl group, a fluorine-substituted aromatic group, and 2 to 5 carbons.
  • the atomic unsaturated hydrocarbon group, -Si(C m H 2m+1 ) 3 , m is a natural number of 1 to 3, and at least one of R 1 , R 2 and R 3 is an unsaturated hydrocarbon group, and R 1 , R 2 , R At least one of 3 is a -Si(C m H 2m+1 ) 3 group.
  • the alkyl group having 1 to 5 carbon atoms is selected from the group consisting of methyl, ethyl, propyl, isopropyl, butyl, isobutyl, neobutyl, tert-butyl;
  • the unsaturated hydrocarbon group of 5 carbon atoms is selected from the group consisting of a vinyl group, a propenyl group, an allyl group, a propynyl group, a propargyl group, a methylvinyl group, and a methallyl group.
  • the phosphate compound is present in an amount of 0.1% to 2% by weight based on 100% by mass of the total mass of the nonaqueous electrolyte.
  • the phosphate compound comprises one or more selected from the group consisting of the following compounds 1 to 12:
  • the phosphate compound comprises one or more selected from the group consisting of the following compounds 1, 2, 3, 6 and 11:
  • the organic solvent is a mixture of a cyclic carbonate and a chain carbonate.
  • the cyclic carbonate comprises one or more of ethylene carbonate, propylene carbonate, and butylene carbonate.
  • the chain carbonate comprises one or more of dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate and methyl propyl carbonate.
  • the lithium salt comprises one or more of LiPF 6 , LiBF 4 , LiBOB, LiDFOB, LiN(SO 2 F) 2 .
  • the non-aqueous electrolyte further includes one or more of an unsaturated cyclic carbonate, a fluorinated cyclic carbonate, a cyclic sultone, and a cyclic sulfate.
  • the unsaturated cyclic carbonate comprises one or more of vinylene carbonate, ethylene carbonate, and vinyl methylene carbonate
  • the fluorocyclic carbonate includes fluorocarbonic acid.
  • a lactone and one or more of a propenyl-1,3-sulfonate which includes one or more of a vinyl sulfate and a 4-methylsulfate.
  • the unsaturated cyclic carbonate content is 0.1-5%
  • the fluorinated cyclic carbonate content is 0.1-30%
  • the cyclic sulfonate is 100% by mass of the total mass of the non-aqueous electrolyte.
  • the acid lactone has a mass percentage of 0.1 to 5% and a cyclic sulfate content of 0.1 to 5%.
  • a phosphate compound having the formula shown in the formula (I) is added, and during the first charging, the phosphoric acid compound can act on the surface of the electrode to form an SEI film.
  • An SEI film capable of effectively inhibiting further decomposition of solvent molecules is formed.
  • the structural formula (I) has both a -Si(C m H 2m+1 ) 3 group, an unsaturated bond, and a phosphate group, and the above three functional groups may have a complicated synergistic reaction with LiF to reduce electrode surface passivation.
  • the high-impedance component of the film, LiF facilitates the passage of lithium ions, thereby significantly improving the high-temperature storage of the battery and taking into account its low-temperature properties.
  • the present invention also provides a lithium ion battery comprising a positive electrode, a negative electrode, and a nonaqueous electrolyte as described above.
  • the cathode active material is selected from LiNi x Co y Mn z L ( 1-xyz) O 2, LiCo x 'L (1-x') O 2, LiNi x " At least one of L' y' Mn (2-x"-y') O 4 , Li z ' MPO 4 , wherein L is Al, Sr, Mg, Ti, Ca, Zr, Zn, Si or Fe At least one of, 0 ⁇ x ⁇ 1, 0 ⁇ y ⁇ 1, 0 ⁇ z ⁇ 1, 0 ⁇ x + y + z ⁇ 1, 0 ⁇ x' ⁇ 1, 0.3 ⁇ x" ⁇ 0.6, 0.01 ⁇ y ' ⁇ 0.2, L' is at least one of Co, Al, Sr, Mg, Ti, Ca, Zr, Zn, Si, Fe; 0.5 ⁇ z' ⁇ 1, M is at least one of Fe, Mn, Co Kind
  • the invention discloses a non-aqueous electrolyte comprising an organic solvent, a lithium salt and a phosphate compound, the phosphate compound comprising a compound selected from the formula (I):
  • R 1 , R 2 and R 3 are each independently selected from an alkyl group of 1 to 5 carbon atoms, a fluoroalkyl group of 1 to 5 carbon atoms, an aryl group, a fluorine-substituted aromatic group, and 2 to 5 carbons.
  • the atomic unsaturated hydrocarbon group, -Si(C m H 2m+1 ) 3 , m is a natural number of 1 to 3, and at least one of R 1 , R 2 and R 3 is an unsaturated hydrocarbon group, and R 1 , R 2 , R At least one of 3 is a -Si(C m H 2m+1 ) 3 group.
  • the alkyl group having 1 to 5 carbon atoms includes a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a neobutyl group, a t-butyl group, and various types of pentyl groups.
  • the fluoroalkyl group of 1 to 5 carbon atoms means that one or more hydrogens of the alkyl group are substituted with a fluorine element.
  • the unsaturated hydrocarbon group of 2 to 5 carbon atoms includes a vinyl group, a propenyl group, an allyl group, a propynyl group, a propargyl group, a methylvinyl group, and a methallyl group.
  • a phosphate compound having the formula shown in the formula (I) is added, and during the first charging, the phosphoric acid compound can act on the surface of the electrode to form an SEI film, and can form a compound capable of effectively inhibiting further decomposition of the solvent molecule. SEI film.
  • the structural formula (I) has both a -Si(C m H 2m+1 ) 3 group, an unsaturated bond, and a phosphate group, and the above three functional groups may have a complicated synergistic reaction with LiF to reduce electrode surface passivation.
  • the high-impedance component of the film, LiF facilitates the passage of lithium ions, thereby significantly improving the high-temperature storage of the battery and taking into account its low-temperature properties.
  • the phosphate compound is present in an amount of from 0.1% to 2% by weight based on 100% by mass of the total mass of the nonaqueous electrolyte.
  • the inventors have found through a large number of experiments that when the weight percentage of the phosphate compound in the non-aqueous electrolyte is between 0.1% and 2%, it has a better effect of promoting the formation of the SEI film, when the phosphate compound When the weight percentage in the non-aqueous electrolyte is less than 0.1% or more than 2%, the lifting effect on the SEI film on the electrode is decreased.
  • the phosphate compound comprises one or more selected from the group consisting of compounds 1 to 12 in Table 1, but is not limited thereto:
  • the phosphate compound comprises one or more selected from the group consisting of the following compounds 1, 2, 3, 6 and 11:
  • organic solvent of the nonaqueous electrolyte lithium ion battery for example, a cyclic carbonate, a chain carbonate, a chain ether, a chain carboxylic acid ester or the like can be used.
  • the organic solvent is a mixture of a cyclic carbonate and a chain carbonate for improving battery performance such as charge and discharge characteristics, battery life, and the like.
  • the cyclic carbonate and the chain carbonate have a high solubility to a lithium salt, and the cyclic carbonate and the chain carbonate are also involved in the SEI film formation process of the electrode.
  • the cyclic carbonate includes one or more of ethylene carbonate, propylene carbonate, and butylene carbonate.
  • the chain carbonate includes one or more of dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, and methyl propyl carbonate.
  • the lithium salt comprises one or more of LiPF 6 , LiBF 4 , LiBOB, LiDFOB, LiN(SO 2 F) 2 .
  • the non-aqueous electrolyte further includes one or more of an unsaturated cyclic carbonate, a fluorinated cyclic carbonate, a cyclic sultone, and a cyclic sulfate.
  • the unsaturated cyclic carbonate, the fluorinated cyclic carbonate, the cyclic sultone and the cyclic sulfate can preferentially react with a solvent molecule on the negative electrode to form a passivation film, preventing the electrolyte from being on the electrode surface. Decomposition.
  • the unsaturated cyclic carbonate includes vinylene carbonate (CAS: 872-36-6, abbreviated as VC), ethylene carbonate (CAS: 4427-96-7, abbreviated as VEC), and methylene One or more of vinyl carbonate (CAS: 124222-05-5).
  • the unsaturated cyclic carbonate content is from 0.1 to 5% based on 100% by mass of the total mass of the nonaqueous electrolyte.
  • the fluorinated cyclic carbonate includes fluoroethylene carbonate (CAS: 114435-02-8, abbreviated as FEC), trifluoromethyl ethylene carbonate (CAS: 167951-80-6), and bisfluoroethylene carbonate.
  • FEC fluoroethylene carbonate
  • TEC trifluoromethyl ethylene carbonate
  • bisfluoroethylene carbonate One or more of esters (CAS: 311810-76-1).
  • the fluorinated cyclic carbonate content is from 0.1 to 30% based on 100% by mass of the total mass of the nonaqueous electrolytic solution.
  • the cyclic sultone includes 1,3-propane sultone (CAS: 1120-71-4, abbreviated as PS), 1,4-butane sultone (CAS: 1633-83-6), and One or more of propenyl-1,3-sulfonate (CAS: 21806-61-1).
  • the cyclic sulphonate has a mass percentage of 0.1-5% based on 100% by mass of the total mass of the non-aqueous electrolyte.
  • the cyclic sulfate includes one or more of vinyl sulfate (CAS: 1072-53-3, abbreviated as DTD) and 4-methylsulfate (CAS: 5689-83-8).
  • the cyclic sulfate content is from 0.1 to 5% based on 100% by mass of the total mass of the nonaqueous electrolyte.
  • Another embodiment of the present invention provides a lithium ion battery comprising a positive electrode, a negative electrode, and a nonaqueous electrolyte as described above.
  • the positive electrode includes a positive electrode active material selected from the group consisting of LiNi x Co y Mn z L (1-xyz) O 2 , LiCo x ' L (1-x') O 2 , LiNi x" L' y' At least one of Mn (2-x"-y') O 4 and Li z ' MPO 4 , wherein L is at least one of Al, Sr, Mg, Ti, Ca, Zr, Zn, Si or Fe , 0 ⁇ x ⁇ 1, 0 ⁇ y ⁇ 1, 0 ⁇ z ⁇ 1, 0 ⁇ x+y+z ⁇ 1, 0 ⁇ x' ⁇ 1, 0.3 ⁇ x” ⁇ 0.6, 0.01 ⁇ y' ⁇ 0.2, L' is at least one of Co, Al, Sr, Mg, Ti, Ca, Zr, Zn, Si, and Fe; 0.5 ⁇ z' ⁇ 1, and M is at least one of Fe, Mn, and Co.
  • L is at least one of Al, Sr, Mg, Ti, Ca, Z
  • the positive electrode active material is mixed with a conductive agent and a binder and then coated on a positive electrode current collector to form the positive electrode.
  • the negative electrode includes a negative active material, which may be made of a carbon material, a metal alloy, a lithium-containing oxide, and a silicon-containing material.
  • the negative electrode active material is mixed with a conductive agent and a binder, and then coated on a negative electrode current collector to form the negative electrode.
  • This embodiment is for explaining a nonaqueous electrolyte, a lithium ion battery and a preparation method thereof disclosed by the present invention.
  • the concentration was 1 mol/L, and then 0.2% of the compound 1 based on the total mass of the electrolyte (the compound 1 herein is the compound 1 in Table 1, the same as the following examples) was added.
  • the positive active material lithium nickel cobalt manganese oxide LiNi 0.5 Co 0.2 Mn 0.3 O 2 , conductive carbon black Super-P and binder polyvinylidene fluoride (PVDF) were mixed at a mass ratio of 93:4:3, and then they were mixed.
  • Dispersion in N-methyl-2-pyrrolidone (NMP) gave a positive electrode slurry.
  • the positive electrode slurry was uniformly coated on both sides of the aluminum foil, dried, calendered and vacuum dried, and the aluminum lead wire was welded by an ultrasonic welder to obtain a positive electrode plate having a thickness of 120-150 ⁇ m.
  • the negative active material artificial graphite, conductive carbon black Super-P, binder styrene butadiene rubber (SBR) and carboxymethyl cellulose (CMC) were mixed at a mass ratio of 94:1:2.5:2.5, and then dispersed.
  • SBR binder styrene butadiene rubber
  • CMC carboxymethyl cellulose
  • a single layer of a three-layer separator having a thickness of 20 ⁇ m is placed between the positive electrode plate and the negative electrode plate, and then a sandwich structure composed of a positive electrode plate, a negative electrode plate and a separator is wound, and the wound body is crushed and placed in an aluminum foil packaging bag. Bake at 85 ° C for 24 h under vacuum to obtain a cell to be injected.
  • the electrolyte prepared in step 1) was injected into the cell, and vacuum-packed and allowed to stand for 24 h.
  • Example 1 The procedures of Example 1 were repeated for Examples 2-15, Comparative Examples 1-8, except that the components of Examples 2-15 and Comparative Examples 1-8 and their contents are shown in Tables 2 and 3.
  • Example 2 is different from Example 1 in that Compound 1 in which 0.5% of the total mass of the electrolyte is used in the electrolytic solution is replaced with 0.2% of Compound 1 based on the total mass of the electrolytic solution.
  • Example 3 is different from Example 1 in that Compound 1 of 1% by mass based on the total mass of the electrolyte was used in the electrolyte to replace 0.2% of Compound 1 based on the total mass of the electrolyte.
  • Example 4 is different from Example 1 in that: Compound 1 in which 1.5% of the total mass of the electrolyte is used in the electrolyte is replaced by 0.2% of Compound 1 based on the total mass of the electrolyte.
  • Example 5 differs from Example 1 in that: Compound 1 of 2% by mass based on the total mass of the electrolyte was used in the electrolyte to replace 0.2% of Compound 1 based on the total mass of the electrolyte.
  • Example 6 is different from Example 1 in that the mass percentage of Compound 1 in the electrolytic solution is 1%, and at the same time, 1% by mass of vinylene carbonate (VC) is added to the electrolytic solution.
  • VC vinylene carbonate
  • Example 7 is different from Example 1 in that the mass percentage of Compound 1 in the electrolytic solution is 1%, and at the same time, 1% by mass of fluoroethylene carbonate (FEC) is added to the electrolytic solution. .
  • FEC fluoroethylene carbonate
  • Example 8 is different from Example 1 in that the mass percentage of Compound 1 in the electrolytic solution is 1%, and at the same time, 1% by mass of propylene sulfate (PS) is added to the electrolytic solution.
  • PS propylene sulfate
  • Example 9 is different from Example 1 in that the mass percentage of the compound 1 in the electrolytic solution is 1%, and at the same time, 1% by mass of ethylene carbonate (DTD) is added to the electrolytic solution.
  • DTD ethylene carbonate
  • Example 10 is different from Example 1 in that the mass percentage of the compound 1 in the electrolytic solution was 1%, and 1 mol/L of LiPF 6 was replaced with 1 mol/L of LiN(SO 2 F) 2 .
  • the eleventh embodiment differs from the first embodiment in that the positive electrode active material is LiNi 0.8 Co 0.15 Al 0.05 O 2 .
  • the positive electrode active material is LiNi 0.8 Co 0.15 Al 0.05 O 2 , and the total amount of the electrolyte solution is replaced by 0.5% of the total mass of the electrolyte. 0.2% of Compound 1 by mass.
  • the positive electrode active material is LiNi 0.8 Co 0.15 Al 0.05 O 2
  • the electrolyte is replaced with 1% of the total mass of the electrolyte. 0.2% of Compound 1 by mass.
  • the positive electrode active material is LiNi 0.8 Co 0.15 Al 0.05 O 2 , and the total amount of the electrolyte is replaced by 1.5% of the total mass of the electrolyte. 0.2% of Compound 1 by mass.
  • the positive electrode active material is LiNi 0.8 Co 0.15 Al 0.05 O 2
  • the total electrolyte solution is replaced by 2% of the total mass of the electrolyte. 0.2% of Compound 1 by mass.
  • Comparative Example 1 was different from Example 1 in that Compound 1 was not added to the electrolytic solution.
  • Comparative Example 2 was different from Example 1 in that Compound 1 was not added to the electrolytic solution, and at the same time, a mass percentage of 0.5% of tripropargyl phosphate was added to the electrolytic solution.
  • Comparative Example 3 was different from Example 1 in that Compound 1 was not added to the electrolytic solution, and at the same time, 1% by mass of vinylene carbonate (VC) was added to the electrolytic solution.
  • VC vinylene carbonate
  • Comparative Example 4 was different from Example 1 in that Compound 1 was not added to the electrolytic solution, and at the same time, 1% by mass of fluoroethylene carbonate (FEC) was added to the electrolytic solution.
  • FEC fluoroethylene carbonate
  • Comparative Example 5 was different from Example 1 in that Compound 1 was not added to the electrolytic solution, and at the same time, 1% by mass of 1,3-propane sultone (PS) was added to the electrolytic solution.
  • PS 1,3-propane sultone
  • Comparative Example 6 was different from Example 1 in that Compound 1 was not added to the electrolytic solution, and at the same time, 1% by mass of polyvinyl sulfate (DTD) was added to the electrolytic solution.
  • DTD polyvinyl sulfate
  • Comparative Example 7 is different from Example 1 in that no compound 1 is added to the electrolyte, and
  • LiFSI lithium bisfluorosulfonimide
  • Comparative Example 8 was different from Example 1 in that the positive electrode active material was LiNi 0.8 Co 0.15 Al 0.05 O 2 and the charge cutoff voltage was 4.2 V, and Compound 1 was not added to the electrolyte.
  • the related performance tests were performed on the lithium ion batteries prepared in the above Examples 1-15 and Comparative Examples 1-8.
  • the test performance includes high temperature cycle performance test and high temperature storage performance test.
  • the specific test methods are as follows:
  • the lithium ion batteries prepared in Examples 1 to 15 and Comparative Examples 1 to 8 were placed in an oven at a constant temperature of 45 ° C, and charged at a constant current of 1 C to 4.4 V (LiNi 0.5 Co 0.2 Mn 0.3 O 2 /artificial graphite battery). Or 4.2V (LiNi 0.8 Co 0.15 Al 0.05 O 2 / artificial graphite battery), and then constant voltage charging until the current drops to 0.02C, and then discharge to 3.0V with a constant current of 1C, so cycle, record the first discharge Capacity and last discharge capacity.
  • V LiNi 0.5 Co 0.2 Mn 0.3 O 2 /artificial graphite battery
  • 4.2V LiNi 0.8 Co 0.15 Al 0.05 O 2 / artificial graphite battery
  • Capacity retention rate last discharge capacity / first discharge capacity ⁇ 100%.
  • the lithium ion battery after the formation is charged to 4.4V (LiNi 0.5 Co 0.2 Mn 0.3 O 2 / artificial graphite battery) or 4.2V (LiNi 0.8 Co 0.15 Al 0.05 O 2 / artificial graphite battery) at a normal temperature with a constant current of 1C.
  • the initial discharge capacity of the battery and the initial battery thickness were measured, and then stored in an environment of 60 ° C for 30 days, and then discharged to 3 V at 1 C, and the holding capacity and recovery capacity of the battery and the thickness of the battery after storage were measured. Calculated as follows:
  • Battery capacity retention rate (%) retention capacity / initial capacity ⁇ 100%;
  • Battery capacity recovery rate (%) recovery capacity / initial capacity ⁇ 100%;
  • Thickness expansion ratio (%) (battery thickness after storage - initial battery thickness) / initial battery thickness ⁇ 100%.
  • the lithium ion battery after the formation was charged to 4.4 V (LiNi 0.5 Co 0.2 Mn 0.3 O 2 / artificial graphite battery) or 4.2 V (LiNi 0.8 Co 0.15 Al 0.05 O 2 / artificial) at 25 ° C with a constant current constant voltage.
  • the graphite battery was then discharged to 3.0 V with a constant current of 1 C, and the discharge capacity was recorded.
  • 1C constant current and constant voltage is charged to 4.4V (LiNi 0.5 Co 0.2 Mn 0.3 O 2 / artificial graphite battery) or 4.2V (LiNi 0.8 Co 0.15 Al 0.05 O 2 / artificial graphite battery), and placed in an environment of -20 ° C. After leaving for 12 h, the 0.2 C constant current was discharged to 3.0 V, and the discharge capacity was recorded.
  • Comparative Examples 6 to 9 and Comparative Examples 3 to 6 show that the phosphate compound represented by the formula (I) and vinylene carbonate (VC), fluoroethylene carbonate (FEC), and 1,3-propane.
  • Film-forming additives such as sultone (PS) and vinyl sulphate (DTD) have synergistic effects and can further improve the performance of lithium ion batteries, especially their high temperature cycle performance and high temperature storage performance.

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Abstract

为克服现有锂离子电池中存在钝化膜阻抗大和高、低温性能差的问题，本发明提供了一种非水电解液，包括有机溶剂、锂盐和磷酸酯类化合物，所述磷酸酯类化合物为：PO(OR 1)(OR 2)(OR 3)。其中，R 1、R 2、R 3各自独立地选自1～5个碳原子的烷基、1～5个碳原子的氟代烷基、芳香基、氟取代芳香基、2～5个碳原子的不饱和烃基、-Si(C mH 2m+1) 3，m为1～3的自然数，R 1、R 2、R 3中至少一个为不饱和烃基，且R 1、R 2、R 3中至少一个为-Si(C mH 2m+1) 3基团。同时，本发明还公开了包括上述非水电解液的锂离子电池。本发明提供非水电解液有利于提升锂离子电池的高温循环性能和低温存储性能。

Description

一种非水电解液及锂离子电池 技术领域
本发明属于锂离子电池技术领域，具体涉及一种非水电解液及锂离子电池。
背景技术
锂离子电池因其工作电压高、安全性高、长寿命、无记忆效应等特点，广泛应用于便携式电子产品领域。随着新能源汽车的发展，锂离子电池在新能源汽车用动力电源系统具有巨大的应用前景。
在非水电解液锂离子电池中，非水电解液是影响电池高低温性能的关键因素，特别地，非水电解液中的添加剂对电池高低温性能的发挥尤其重要。在锂离子电池初始充电过程中，电池正极材料中的锂离子脱嵌出来，通过电解液嵌入碳负极中。由于其高反应性，电解液在碳负极表面反应产生Li 2CO 3、LiO、LiOH等化合物，从而在负极表面形成钝化膜，该钝化膜称为固体电解液界面膜(SEI)。在初始充电过程中形成的SEI膜，不仅阻止电解液进一步在碳负极表面分解，而且起到锂离子隧道作用，只允许锂离子通过。因此，SEI膜决定了锂离子电池性能的好坏。
为了提高锂离子电池的各项性能，许多科研者通过往电解液中添加不同的负极成膜添加剂(如碳酸亚乙烯酯，氟代碳酸乙烯酯，碳酸乙烯亚乙酯)来改善SEI膜的质量，从而改善电池的各项性能。例如，在日本特开2000-123867号公报中提出了通过在电解液中添加碳酸亚乙烯酯来提高电池特性。碳酸亚乙烯酯能够优先于溶剂分子在负极表面发生还原分解反应，能在负极表面形成钝化膜，阻止电解液在电极表面进一步分解，从而提高电池的循环性能。但添加碳酸亚乙烯酯后，电池在高温储存中过程中容易产生气体，导致电池发生鼓胀。此外，碳酸亚乙烯酯形成的钝化膜阻抗较大，尤其在低温条件下，容易发生低温充电析锂，影响电池安全性。美国专利US6919141公开了一种含不饱和磷酸酯化合物的锂离子电池电解液，能够改善电池的高温性能，但含不饱和磷酸酯的电解液明显提高电池的内阻，劣化电池的低温性能。
发明内容
针对现有锂离子电池中存在钝化膜阻抗大和高、低温性能难以兼顾的问题，本发明提供了一种非水电解液及锂离子电池，以提升锂离子电池的高温循环性能且兼顾低温性能。
为解决上述技术问题，一方面，本发明提供了一种非水电解液，包括有机溶剂、锂盐和磷酸酯类化合物，所述磷酸酯类化合物包括选自结构式(Ⅰ)所示化合物：
结构式(Ⅰ)
Figure PCTCN2018092979-appb-000001
其中，R 1、R 2、R 3各自独立地选自1～5个碳原子的烷基、1～5个碳原子的氟代烷基、芳香基、氟取代芳香基、2～5个碳原子的不饱和烃基、-Si(C mH 2m+1) 3，m为1～3的自然数，R 1、R 2、R 3中至少一个为不饱和烃基，且R 1、R 2、R 3中至少一个为-Si(C mH 2m+1) 3基团。
可选地，所述含1-5个碳原子的烷基选自甲基、乙基、丙基、异丙基、丁基、异丁基、新丁基、叔丁基；所述2-5个碳原子的不饱和烃基选自乙烯基、丙烯基、烯丙基、丙炔基、炔丙基、甲基乙烯基、甲基烯丙基。
可选地，以所述非水电解液的总质量为100％计，所述磷酸酯类化合物的重量百分含量为0.1％～2％。
可选地，所述磷酸酯类化合物包括选自下列化合物1～12中的一种或多种：
Figure PCTCN2018092979-appb-000002
Figure PCTCN2018092979-appb-000003
更优选地，所述磷酸酯类化合物包括选自下列化合物1、2、3、6和11中的一种或多种：
Figure PCTCN2018092979-appb-000004
可选地，所述有机溶剂为环状碳酸酯和链状碳酸酯的混合物。
可选地，所述环状碳酸酯包括碳酸乙烯酯、碳酸丙烯酯和碳酸丁烯酯中的一种或多种。
可选地，所述链状碳酸酯包括碳酸二甲酯、碳酸二乙酯、碳酸甲乙酯和碳酸甲丙酯中的一种或多种。
可选地，所述锂盐包括LiPF 6、LiBF 4、LiBOB、LiDFOB、LiN(SO 2F) 2中的一种或多种。
可选地，所述非水电解液还包括不饱和环状碳酸酯、氟代环状碳酸酯、环状磺酸内酯和环状硫酸酯中的一种或多种。
可选地，所述不饱和环状碳酸酯包括碳酸亚乙烯酯、碳酸乙烯亚乙酯和亚甲基碳酸乙烯酯中的一种或多种，所述氟代环状碳酸酯包括氟代碳酸乙烯酯、三氟甲基碳酸乙烯酯和双氟代碳酸乙烯酯中的一种或多种，所述环状磺酸内酯包括1,3-丙烷磺内酯、1,4-丁烷磺内酯和丙烯基-1,3-磺酸内酯中的一种或多种，所述环状硫酸酯包括硫酸乙烯酯和4-甲基硫酸乙烯酯中的一种或多种。
可选地，以所述非水电解液的总质量为100％计，不饱和环状碳酸酯含量为0.1-5％，氟代环状碳酸酯含量为0.1-30％，所述环状磺酸内酯的质量百分含量为0.1-5％，环状硫酸酯含量为0.1-5％。
根据本发明提供的非水电解液，加入了具有结构式(Ⅰ)中所示通式的磷酸酯类化合物，在首次充电过程中，所述磷酸类化合物能够对电极表面形成SEI膜的过程产生作用，形成能够有效抑制溶剂分子进一步分解的SEI膜。此外，结构式(Ⅰ)中同时具有-Si(C mH 2m+1) 3基团、不饱和键以及磷酸酯基团，上述三种官能团可能与LiF发生复杂的协同反应，降低电极表面钝化膜中高阻抗成分LiF的含量，有利于锂离子通过，从而能够明显改善电池的高温储存并兼顾其低温性能。
另一方面，本发明还提供了一种锂离子电池，包括正极、负极以及如上所述的非水电解液。
可选地，所述正极包括正极活性材料，所述正极活性材料选自LiNi xCo yMn zL (1-x-y-z)O 2、LiCo x’L (1-x’)O 2、LiNi x”L’ y’Mn (2-x”-y’)O 4、Li z’MPO 4中的至少一种，其中，L为Al、Sr、Mg、Ti、Ca、Zr、Zn、Si或Fe中的至少一种，0≤x≤1，0≤y≤1，0≤z≤1，0＜x+y+z≤1，0<x’≤1，0.3≤x”≤0.6，0.01≤y’≤0.2，L’为Co、Al、Sr、Mg、Ti、Ca、Zr、Zn、Si、Fe中的至少一种；0.5≤z’≤1，M为Fe、Mn、Co中的至少一种。
具体实施方式
为了使本发明所解决的技术问题、技术方案及有益效果更加清楚明白，以下结合实施例，对本发明进行进一步详细说明。应当理解，此处所描述的具体实施例仅仅用以解释本发明，并不用于限定本发明。
本发明公开了一种非水电解液，包括有机溶剂、锂盐和磷酸酯类化合物， 所述磷酸酯类化合物包括选自结构式(Ⅰ)所示化合物：
结构式(Ⅰ)
Figure PCTCN2018092979-appb-000005
其中，R 1、R 2、R 3各自独立地选自1～5个碳原子的烷基、1～5个碳原子的氟代烷基、芳香基、氟取代芳香基、2～5个碳原子的不饱和烃基、-Si(C mH 2m+1) 3，m为1～3的自然数，R 1、R 2、R 3中至少一个为不饱和烃基，且R 1、R 2、R 3中至少一个为-Si(C mH 2m+1) 3基团。
所述1～5个碳原子的烷基包括甲基、乙基、丙基、异丙基、丁基、异丁基、新丁基、叔丁基以及各类戊基。
所述1～5个碳原子的氟代烷基指用氟元素取代所述烷基中的一个或以上的氢。
所述2～5个碳原子的不饱和烃基包括乙烯基、丙烯基、烯丙基、丙炔基、炔丙基、甲基乙烯基和甲基烯丙基。
所述非水电解液中
加入了具有结构式(Ⅰ)中所示通式的磷酸酯类化合物，在首次充电过程中，所述磷酸类化合物能够对电极表面形成SEI膜的过程产生作用，形成能够有效抑制溶剂分子进一步分解的SEI膜。此外，结构式(Ⅰ)中同时具有-Si(C mH 2m+1) 3基团、不饱和键以及磷酸酯基团，上述三种官能团可能与LiF发生复杂的协同反应，降低电极表面钝化膜中高阻抗成分LiF的含量，有利于锂离子通过，从而能够明显改善电池的高温储存并兼顾其低温性能。
在本发明的一些实施例中，以所述非水电解液的总质量为100％计，所述磷酸酯类化合物的重量百分含量为0.1％～2％。
发明人通过大量实验发现，当所述磷酸酯类化合物在非水电解液中的重量百分比处于0.1％～2％之间时具有较好的促进SEI膜形成的作用，当所述磷酸酯类化合物在非水电解液中的重量百分比小于0.1％或大于2％时，其对电极上SEI膜的提升作用均会有所下降。
在本发明的一些实施例中，所述磷酸酯类化合物包括选自表1中化合物1～12中的一种或多种，但不限于此：
表1
Figure PCTCN2018092979-appb-000006
更优选地，所述磷酸酯类化合物包括选自下列化合物1、2、3、6和11中的一种或多种：
Figure PCTCN2018092979-appb-000007
Figure PCTCN2018092979-appb-000008
作为非水电解液锂离子电池的有机溶剂，可以采用如：环状碳酸酯、链状碳酸酯、链状醚、链状羧酸酯等。
在本发明的一些实施例中，为提高充放电特性、电池寿命等电池性能整体，所述有机溶剂为环状碳酸酯和链状碳酸酯的混合物。
所述环状碳酸酯和所述链状碳酸酯对锂盐具有较高的溶解性，且所述环状碳酸酯和链状碳酸酯也参与到电极的SEI膜成膜过程。
所述环状碳酸酯包括碳酸乙烯酯、碳酸丙烯酯和碳酸丁烯酯中的一种或多种。
所述链状碳酸酯包括碳酸二甲酯、碳酸二乙酯、碳酸甲乙酯和碳酸甲丙酯中的一种或多种。
在本发明的一些实施例中，所述锂盐包括LiPF 6、LiBF 4、LiBOB、LiDFOB、LiN(SO 2F) 2中的一种或多种。
在本发明的一些实施例中，所述非水电解液还包括不饱和环状碳酸酯、氟代环状碳酸酯、环状磺酸内酯和环状硫酸酯中的一种或多种。
所述不饱和环状碳酸酯、氟代环状碳酸酯、环状磺酸内酯和环状硫酸酯能够优先于溶剂分子在负极上发生还原反应，形成钝化膜，阻止电解液在电极表面的分解。
其中，所述不饱和环状碳酸酯包括碳酸亚乙烯酯(CAS：872-36-6，缩写为VC)、碳酸乙烯亚乙酯(CAS：4427-96-7，缩写为VEC)和亚甲基碳酸乙烯酯(CAS：124222-05-5)中的一种或多种。优选的，以所述非水电解液的总质量为100％计，不饱和环状碳酸酯含量为0.1-5％。
所述氟代环状碳酸酯包括氟代碳酸乙烯酯(CAS：114435-02-8，缩写为FEC)、三氟甲基碳酸乙烯酯(CAS：167951-80-6)和双氟代碳酸乙烯酯(CAS：311810-76-1)中的一种或多种。优选的，以所述非水电解液的总质量为100％计，氟代环状碳酸酯含量为0.1-30％。
所述环状磺酸内酯包括1,3-丙烷磺内酯(CAS：1120-71-4，缩写为PS)、1,4- 丁烷磺内酯(CAS：1633-83-6)和丙烯基-1,3-磺酸内酯(CAS：21806-61-1)中的一种或多种。优选的，以所述非水电解液的总质量为100％计，所述环状磺酸内酯的质量百分含量为0.1-5％
所述环状硫酸酯包括硫酸乙烯酯(CAS：1072-53-3，缩写为DTD)和4-甲基硫酸乙烯酯(CAS：5689-83-8)中的一种或多种。优选的，以所述非水电解液的总质量为100％计，环状硫酸酯含量为0.1-5％。
本发明的另一实施例提供了一种锂离子电池，包括正极、负极以及如上所述的非水电解液。
所述正极包括正极活性材料，所述正极活性材料选自LiNi xCo yMn zL (1-x-y-z)O 2、LiCo x’L (1-x’)O 2、LiNi x”L’ y’Mn (2-x”-y’)O 4、Li z’MPO 4中的至少一种，其中，L为Al、Sr、Mg、Ti、Ca、Zr、Zn、Si或Fe中的至少一种，0≤x≤1，0≤y≤1，0≤z≤1，0＜x+y+z≤1，0<x’≤1，0.3≤x”≤0.6，0.01≤y’≤0.2，L’为Co、Al、Sr、Mg、Ti、Ca、Zr、Zn、Si、Fe中的至少一种；0.5≤z’≤1，M为Fe、Mn、Co中的至少一种。
具体的，所述正极活性材料与导电剂、粘结剂混合后涂布于正极集流体上，以形成所述正极。
所述负极包括负极活性材料，所述负极活性材料可由碳材料、金属合金、含锂氧化物及含硅材料制得。
具体的，所述负极活性材料与导电剂、粘结剂混合后涂布于负极集流体上，形成所述负极。
以下通过实施例对本发明进行进一步的说明。
实施例1
本实施例用于说明本发明公开的一种非水电解液、锂离子电池及其制备方法。
实施例1
1)电解液的制备
将碳酸乙烯酯(EC)、碳酸二乙酯(DEC)和碳酸甲乙酯(EMC)按质量比为EC:DEC:EMC＝1:1:1进行混合，然后加入六氟磷酸锂(LiPF 6)至摩尔浓度为1mol/L，再加入按电解液的总质量计0.2％的化合物1(此处化合物1即为表1中的化合物1，以下实施例类同)。
2)正极板的制备
按93:4:3的质量比混合正极活性材料锂镍钴锰氧化物LiNi 0.5Co 0.2Mn 0.3O 2，导电碳黑Super-P和粘结剂聚偏二氟乙烯(PVDF)，然后将它们分散在N-甲基-2-吡咯烷酮(NMP)中，得到正极浆料。将正极浆料均匀涂布在铝箔的两面上，经过烘干、压延和真空干燥，并用超声波焊机焊上铝制引出线后得到正极板，正极板的厚度在120-150μm。
3)负极板的制备
按94:1:2.5:2.5的质量比混合负极活性材料人造石墨，导电碳黑Super-P，粘结剂丁苯橡胶(SBR)和羧甲基纤维素(CMC)，然后将它们分散在去离子水中，得到负极浆料。将浆料涂布在铜箔的两面上，经过烘干、压延和真空干燥，并用超声波焊机焊上镍制引出线后得到负极板，负极板的厚度在120-150μm。
4)电芯的制备
在正极板和负极板之间放置单层厚度为20μm的三层隔膜，然后将正极板、负极板和隔膜组成的三明治结构进行卷绕，再将卷绕体压扁后放入铝箔包装袋，在85℃下真空烘烤24h，得到待注液的电芯。
5)电芯的注液和化成
在露点控制在-40℃以下的手套箱中，将步骤1)制备的电解液注入电芯中，经真空封装，静置24h。
然后按以下步骤进行首次充电的常规化成：0.05C恒流充电180min,0.2C恒流充电至3.95V，二次真空封口，然后进一步以0.2C的电流恒流充电至4.4V，常温搁置24hr后，以0.2C的电流恒流放电至3.0V。
实施例2-15，对比例1-8
实施例2-15，对比例1-8重复实施例1的步骤，不同的是，实施例2-15及对比例1-8中各组分及其含量如表2和表3所示。
其中，实施例2与实施例1的不同之处在于：所述电解液中采用按电解液的总质量计0.5％的化合物2替换按电解液的总质量计0.2％的化合物1。
实施例3与实施例1的不同之处在于：所述电解液中采用按电解液的总质量计1％的化合物3替换按电解液的总质量计0.2％的化合物1。
实施例4与实施例1的不同之处在于：所述电解液中采用按电解液的总质量计1.5％的化合物6替换按电解液的总质量计0.2％的化合物1。
实施例5与实施例1的不同之处在于：所述电解液中采用按电解液的总质量计2％的化合物11替换按电解液的总质量计0.2％的化合物1。
实施例6与实施例1的不同之处在于：所述电解液中化合物1的质量百分比为1％，同时，所述电解液中加入有质量百分比为1％的碳酸亚乙烯酯(VC)。
实施例7与实施例1的不同之处在于：所述电解液中化合物1的质量百分比为1％，同时，所述电解液中加入有质量百分比为1％的氟代碳酸乙烯酯(FEC)。
实施例8与实施例1的不同之处在于：所述电解液中化合物1的质量百分比为1％，同时，所述电解液中加入有质量百分比为1％的亚硫酸丙烯酯(PS)。
实施例9与实施例1的不同之处在于：所述电解液中化合物1的质量百分比为1％，同时，所述电解液中加入有质量百分比为1％的硫酸亚乙酯(DTD)。
实施例10与实施例1的不同之处在于：所述电解液中化合物1的质量百分比为1％，采用1mol/L的LiN(SO 2F) 2替换按1mol/L的LiPF 6。
实施例11与实施例1的不同之处在于：正极活性材料采用LiNi 0.8Co 0.15Al 0.05O 2。
实施例12与实施例1的不同之处在于：正极活性材料采用LiNi 0.8Co 0.15Al 0.05O 2，所述电解液中采用按电解液的总质量计0.5％的化合物2替换按电解液的总质量计0.2％的化合物1。
实施例13与实施例1的不同之处在于：正极活性材料采用LiNi 0.8Co 0.15Al 0.05O 2，所述电解液中采用按电解液的总质量计1％的化合物3替换按电解液的总质量计0.2％的化合物1。
实施例14与实施例1的不同之处在于：正极活性材料采用LiNi 0.8Co 0.15Al 0.05O 2，所述电解液中采用按电解液的总质量计1.5％的化合物6替换按电解液的总质量计0.2％的化合物1。
实施例15与实施例1的不同之处在于：正极活性材料采用LiNi 0.8Co 0.15Al 0.05O 2，所述电解液中采用按电解液的总质量计2％的化合物11替换按电解液的总质量计0.2％的化合物1。
对比例1与实施例1的不同之处在于：所述电解液中不加入化合物1。
对比例2与实施例1的不同之处在于：所述电解液中不加入化合物1，同时，所述电解液中加入有质量百分比为0.5％的磷酸三炔丙酯。
对比例3与实施例1的不同之处在于：所述电解液中不加入化合物1，同时，所述电解液中加入有质量百分比为1％的碳酸亚乙烯酯(VC)。
对比例4与实施例1的不同之处在于：所述电解液中不加入化合物1，同时，所述电解液中加入有质量百分比为1％的氟代碳酸乙烯酯(FEC)。
对比例5与实施例1的不同之处在于：所述电解液中不加入化合物1，同时，所述电解液中加入有质量百分比为1％的1,3-丙烷磺内酯(PS)。
对比例6与实施例1的不同之处在于：所述电解液中不加入化合物1，同时，所述电解液中加入有质量百分比为1％的硫酸乙烯酯(DTD)。
对比例7与实施例1的不同之处在于：所述电解液中不加入化合物1，同时，
所述电解液中加入有质量百分比为1％的双氟磺酰亚胺锂(LiFSI)。
对比例8与实施例1的不同之处在于：正极活性材料采用LiNi 0.8Co 0.15Al 0.05O 2，充电截止电压为4.2V，所述电解液中不加入化合物1。
性能测试
对上述实施例1-15、对比例1-8制备得到的锂离子电池进行相关的性能测试。测试的性能包括高温循环性能测试和高温储存性能测试，各项的具体测试方法如下：
一、高温循环性能测试
将实施例1～15及对比例1～8制备的锂离子电池置于恒温45℃的烘箱中，以1C的电流恒流充电至4.4V(LiNi 0.5Co 0.2Mn 0.3O 2/人造石墨电池)或4.2V(LiNi 0.8Co 0.15Al 0.05O 2/人造石墨电池)，再恒压充电至电流下降至0.02C，然后以1C的电流恒流放电至3.0V，如此循环，记录第一次的放电容量和最后一次的放电容量。
按下式计算高温循环的容量保持率：
容量保持率＝最后一次的放电容量/第一次的放电容量×100％。
二、高温储存性能测试
将化成后的锂离子电池在常温下用1C恒流恒压充至4.4V(LiNi 0.5Co 0.2Mn 0.3O 2/人造石墨电池)或4.2V(LiNi 0.8Co 0.15Al 0.05O 2/人造石墨电池)，测量电池初始放电容量及初始电池厚度，然后在60℃环境中储存30天后，以1C放电至3V，测量电池的保持容量和恢复容量及储存后电池厚度。计算公式如下：
电池容量保持率(％)＝保持容量/初始容量×100％；
电池容量恢复率(％)＝恢复容量/初始容量×100％；
厚度膨胀率(％)＝(储存后电池厚度-初始电池厚度)/初始电池厚度×100％。
三、低温性能测试
在25℃下，将化成后的锂离子电池用1C恒流恒压充至4.4V(LiNi 0.5Co 0.2Mn 0.3O 2/人造石墨电池)或4.2V(LiNi 0.8Co 0.15Al 0.05O 2/人造石墨电池)，然后用1C恒流放电至3.0V，记录放电容量。然后1C恒流恒压充至4.4V(LiNi 0.5Co 0.2Mn 0.3O 2/人造石墨电池)或4.2V(LiNi 0.8Co 0.15Al 0.05O 2/人造石墨电池)，置于-20℃的环境中搁置12h后，0.2C恒流放电至3.0V，记录放电容量。
-20℃的低温放电效率值＝0.2C放电容量(-20℃)/1C放电容量(25℃)×100％。
得到的测试结果填入表2和表3。
表2实施例1～10及对比例1～7中相应锂离子电池的性能
Figure PCTCN2018092979-appb-000009
Figure PCTCN2018092979-appb-000010
表3实施例11～15及对比例8中相应锂离子电池的性能
Figure PCTCN2018092979-appb-000011
Figure PCTCN2018092979-appb-000012
对比实施例1～15和对比例1～8的测试结果可看出，在非水电解液中添加本发明中结构式(Ⅰ)所示磷酸酯类化合物，能够有效提升锂离子电池的高温循环性能、高温存储性能并兼顾低温性能。
对比实施例6～9和对比例3～6的测试结果可知，结构式(Ⅰ)所示磷酸酯类化合物与碳酸亚乙烯酯(VC)、氟代碳酸乙烯酯(FEC)、1,3-丙烷磺内酯(PS)、硫酸乙烯酯(DTD)等成膜添加剂具有协同作用，能够进一步提高锂离子电池的性能，尤其是其高温循环性能和高温存储性能。
以上所述仅为本发明的较佳实施例而已，并不用以限制本发明，凡在本发明的精神和原则之内所作的任何修改、等同替换和改进等，均应包含在本发明的保护范围之内。

Claims (10)

  1. 一种非水电解液，其特征在于，包括有机溶剂、锂盐和磷酸酯类化合物，所述磷酸酯类化合物包括选自结构式(Ⅰ)所示化合物：
    Figure PCTCN2018092979-appb-100001
    其中，R 1、R 2、R 3各自独立地选自1～5个碳原子的烷基、1～5个碳原子的氟代烷基、芳香基、氟取代芳香基、2～5个碳原子的不饱和烃基、-Si(C mH 2m+1) 3，m为1～3的自然数，R 1、R 2、R 3中至少一个为不饱和烃基，且R 1、R 2、R 3中至少一个为-Si(C mH 2m+1) 3基团。
  2. 根据权利要求1所述的非水电解液，其特征在于，所述含1-5个碳原子的烷基选自甲基、乙基、丙基、异丙基、丁基、异丁基、新丁基、叔丁基；所述2-5个碳原子的不饱和烃基选自乙烯基、丙烯基、烯丙基、丙炔基、炔丙基、甲基乙烯基、甲基烯丙基。
  3. 根据权利要求1所述的非水电解液，其特征在于，以所述非水电解液的总质量为100％计，所述磷酸酯类化合物的重量百分含量为0.1％～2％。
  4. 根据权利要求1所述的非水电解液，其特征在于，所述磷酸酯类化合物包括选自下列化合物中的一种或多种：
    Figure PCTCN2018092979-appb-100002
    Figure PCTCN2018092979-appb-100003
  5. 根据权利要求1所述的非水电解液，其特征在于，所述非水电解液还包括不饱和环状碳酸酯、氟代环状碳酸酯、环状磺酸内酯、环状硫酸酯中的一种或多种。
  6. 根据权利要求5所述的非水电解液，其特征在于，所述不饱和环状碳酸酯包括碳酸亚乙烯酯、碳酸乙烯亚乙酯、亚甲基碳酸乙烯酯中的一种或多种；所述氟代环状碳酸酯包括氟代碳酸乙烯酯、三氟甲基碳酸乙烯酯、双氟代碳酸乙烯酯中的一种或多种；所述环状磺酸内酯包括1,3-丙烷磺内酯、1,4-丁烷磺内酯、丙烯基-1,3-磺酸内酯中的一种或多种；所述环状硫酸酯包括硫酸乙烯酯、4-甲基硫酸乙烯酯中的一种或多种。
  7. 根据权利要求5或6所述的非水电解液，其特征在于，以所述非水电解液的总质量为100％计，不饱和环状碳酸酯含量为0.1-5％，氟代环状碳酸酯含量 为0.1-30％，所述环状磺酸内酯的质量百分含量为0.1-5％，环状硫酸酯含量为0.1-5％。
  8. 根据权利要求1所述的非水电解液，其特征在于，所述有机溶剂为环状碳酸酯和链状碳酸酯的混合物；锂盐选自LiPF 6、LiBF 4、LiBOB、LiDFOB、LiN(SO 2F) 2中的一种或两种以上。
  9. 一种锂离子电池，其特征在于，包括正极、负极以及如权利要求1～8中任意一项所述的非水电解液。
  10. 根据权利要求9所述的锂离子电池，其特征在于，所述正极包括正极活性材料，所述正极活性材料选自LiNi xCo yMn zL (1-x-y-z)O 2、LiCo x’L (1-x’)O 2、LiNi x”L’ y’Mn (2-x”-y’)O 4、Li z’MPO 4中的至少一种，其中，L为Al、Sr、Mg、Ti、Ca、Zr、Zn、Si或Fe中的至少一种，0≤x≤1，0≤y≤1，0≤z≤1，0＜x+y+z≤1，0<x’≤1，0.3≤x”≤0.6，0.01≤y’≤0.2，L’为Co、Al、Sr、Mg、Ti、Ca、Zr、Zn、Si、Fe中的至少一种；0.5≤z’≤1，M为Fe、Mn、Co中的至少一种。
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Families Citing this family (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112310466B (zh) * 2019-07-31 2023-03-10 深圳新宙邦科技股份有限公司 锂离子电池非水电解液及包含该电解液的锂离子电池
CN112563570B (zh) * 2019-09-10 2022-04-12 杉杉新材料（衢州）有限公司 一种三盐体系的锂离子电池非水电解液及锂离子电池
CN111048837B (zh) * 2019-12-17 2021-07-13 桑顿新能源科技(长沙)有限公司 一种高温型锂离子电池电解液及锂离子电池
CN113130890B (zh) * 2019-12-31 2023-01-17 深圳新宙邦科技股份有限公司 一种锂离子电池
CN113745658B (zh) * 2020-05-28 2023-09-08 深圳新宙邦科技股份有限公司 一种非水电解液及锂离子电池
CN111900472A (zh) * 2020-06-30 2020-11-06 远景动力技术(江苏)有限公司 一种锂离子电池非水电解液
CN111883841A (zh) * 2020-08-05 2020-11-03 香河昆仑化学制品有限公司 一种锂离子电池非水电解液及锂离子电池
CN114447425A (zh) * 2020-11-06 2022-05-06 三明市海斯福化工有限责任公司 一种非水电解液及电池
CN112271337A (zh) * 2020-11-25 2021-01-26 深圳新宙邦科技股份有限公司 一种非水电解液及锂离子电池
KR20220099852A (ko) * 2021-01-07 2022-07-14 삼성에스디아이 주식회사 리튬 전지용 전해질 및 이를 포함하는 리튬 전지
CN113078360B (zh) * 2021-03-25 2022-10-21 宁德新能源科技有限公司 一种电解液及包含该电解液的电化学装置
CN115911515A (zh) * 2021-08-09 2023-04-04 深圳新宙邦科技股份有限公司 一种非水电解液及电池
CN114315903B (zh) * 2021-12-30 2023-10-10 欣旺达动力科技股份有限公司 一种环状双磷酸酯类化合物、其制备方法及其应用
CN114552004A (zh) * 2022-01-21 2022-05-27 深圳新宙邦科技股份有限公司 一种非水电解液及二次电池
CN114639872B (zh) * 2022-02-21 2024-04-05 深圳新宙邦科技股份有限公司 一种锂离子电池

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104300174A (zh) * 2014-10-11 2015-01-21 深圳新宙邦科技股份有限公司 一种锂离子电池非水电解液及锂离子电池
CN105161763A (zh) * 2015-08-03 2015-12-16 深圳新宙邦科技股份有限公司 一种锂离子电池非水电解液及锂离子电池
JP2017069146A (ja) * 2015-10-02 2017-04-06 旭化成株式会社 化合物、添加剤、電解液及びリチウムイオン二次電池
CN106898817A (zh) * 2015-12-18 2017-06-27 比亚迪股份有限公司 锂离子电池电解液及锂离子电池
CN107275676A (zh) * 2017-08-04 2017-10-20 广州天赐高新材料股份有限公司 一种用于硅基锂二次电池的电解液和硅基锂二次电池

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4538886B2 (ja) * 1999-03-16 2010-09-08 住友化学株式会社 非水電解液およびこれを用いたリチウム二次電池
JP5549438B2 (ja) * 2009-07-30 2014-07-16 三菱化学株式会社 非水系電解液及びそれを用いた非水系電解液二次電池
CN105556732B (zh) * 2013-10-04 2018-04-03 旭化成株式会社 电解液和锂离子二次电池
KR20160091077A (ko) * 2015-01-23 2016-08-02 삼성에스디아이 주식회사 유기전해액 및 상기 전해액을 채용한 리튬전지
JP2017182917A (ja) * 2016-03-28 2017-10-05 株式会社カネカ リチウムイオン二次電池及びその製造方法、ならびに組電池

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104300174A (zh) * 2014-10-11 2015-01-21 深圳新宙邦科技股份有限公司 一种锂离子电池非水电解液及锂离子电池
CN105161763A (zh) * 2015-08-03 2015-12-16 深圳新宙邦科技股份有限公司 一种锂离子电池非水电解液及锂离子电池
JP2017069146A (ja) * 2015-10-02 2017-04-06 旭化成株式会社 化合物、添加剤、電解液及びリチウムイオン二次電池
CN106898817A (zh) * 2015-12-18 2017-06-27 比亚迪股份有限公司 锂离子电池电解液及锂离子电池
CN107275676A (zh) * 2017-08-04 2017-10-20 广州天赐高新材料股份有限公司 一种用于硅基锂二次电池的电解液和硅基锂二次电池

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