WO2021196019A1 - 一种电解液及电化学装置 - Google Patents

一种电解液及电化学装置 Download PDF

Info

Publication number
WO2021196019A1
WO2021196019A1 PCT/CN2020/082574 CN2020082574W WO2021196019A1 WO 2021196019 A1 WO2021196019 A1 WO 2021196019A1 CN 2020082574 W CN2020082574 W CN 2020082574W WO 2021196019 A1 WO2021196019 A1 WO 2021196019A1
Authority
WO
WIPO (PCT)
Prior art keywords
substituted
compound
electrolyte
unsubstituted
formula
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.)
Ceased
Application number
PCT/CN2020/082574
Other languages
English (en)
French (fr)
Inventor
管明明
熊亚丽
郑建明
刘建禹
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.)
Ningde Amperex Technology Ltd
Original Assignee
Ningde Amperex Technology 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 Ningde Amperex Technology Ltd filed Critical Ningde Amperex Technology Ltd
Priority to US17/054,053 priority Critical patent/US12119446B2/en
Priority to CN202080003789.XA priority patent/CN112368872A/zh
Priority to PCT/CN2020/082574 priority patent/WO2021196019A1/zh
Publication of WO2021196019A1 publication Critical patent/WO2021196019A1/zh
Anticipated expiration legal-status Critical
Ceased 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
    • 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
    • H01M10/0568—Liquid materials characterised by the solutes
    • 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
    • H01M10/0569—Liquid materials characterised by the solvents
    • 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
    • H01M10/4235—Safety or regulating additives or arrangements in electrodes, separators or electrolyte
    • 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
    • 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
    • H01M2300/0028—Organic electrolyte characterised by the solvent
    • 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

  • This application relates to the field of energy storage technology, and in particular to an electrolyte and an electrochemical device containing the electrolyte.
  • lithium-ion batteries As we all know, the characteristics of lithium-ion batteries, such as high energy density, long service life, and no memory effect, have attracted wide attention. They are widely used in smart products (including mobile phones, notebooks, cameras and other electronic products), power tools, and electric cars. , And is gradually replacing the traditional nickel-cadmium and nickel-hydrogen batteries. However, with the rapid development of technology and the diversity of usage scenarios, the rapid decay of the capacity of lithium-ion batteries at low temperatures has become a pain point for users.
  • the present invention provides an electrolyte and an electrochemical device.
  • the electrolyte not only improves the low-temperature performance of the battery, but also improves the high-temperature cycle and high-temperature storage performance of the battery.
  • an aspect of the present invention provides an electrolyte.
  • the electrolyte includes a compound of formula I and additive A,
  • the substituent is selected from cyano or halogen
  • X is selected from Li + , Na + , K + or Rb + ;
  • the additive A is selected from at least one of fluoroethylene carbonate, LiPO 2 F 2 or vinylene carbonate.
  • the compound of formula I is selected from at least one of the following compounds:
  • the weight ratio of the compound of formula I to the additive A is 30:1 to 1:200.
  • the compound of formula I accounts for 0.05% to 5% of the total weight of the electrolyte, and the additive A accounts for 0.01% to 16% of the total weight of the electrolyte.
  • the electrolyte further contains a compound of formula II:
  • R 9 is selected from hydrogen, cyano, halogen, substituted or unsubstituted C 1-8 alkyl, or substituted or unsubstituted C 1-8 alkoxy;
  • R 10 to R 12 are each independently selected from a covalent bond, a substituted or unsubstituted C 1-8 alkylene group, or -O-R'-, wherein R'is a substituted or unsubstituted C 1- 8 alkylene;
  • the substituent is selected from cyano or halogen
  • the compound of formula II accounts for 0.05% to 10% of the total weight of the electrolyte.
  • the compound of formula II comprises
  • the electrolyte further comprises a compound of formula III:
  • the compound of formula III accounts for 0.1% to 20% of the total weight of the electrolyte.
  • the compound of formula III comprises
  • the electrolyte further comprises a compound of formula IV,
  • R 41 and R 42 are each independently selected from substituted or unsubstituted C 1-10 alkyl; wherein when substituted, they are substituted with one or more substituents selected from F, Cl or Br;
  • the compound of formula IV accounts for 5% to 50% of the total weight of the electrolyte.
  • the compound of formula IV comprises: At least one of them.
  • the electrochemical device includes a positive electrode, a negative electrode, and any one of the foregoing electrolytes.
  • Another aspect of the present invention provides an electronic device, which includes any one of the electrochemical devices described above.
  • the term "about” is used to describe and illustrate small variations.
  • the term may refer to an example in which the event or situation occurs precisely and an example in which the event or situation occurs very closely.
  • the term can refer to a range of variation less than or equal to ⁇ 10% of the stated value, such as less than or equal to ⁇ 5%, less than or equal to ⁇ 4%, less than or equal to ⁇ 3%, Less than or equal to ⁇ 2%, less than or equal to ⁇ 1%, less than or equal to ⁇ 0.5%, less than or equal to ⁇ 0.1%, or less than or equal to ⁇ 0.05%.
  • a list of items connected by the term "one of” may mean any one of the listed items. For example, if items A and B are listed, then the phrase “one of A and B” means only A or only B. In another example, if items A, B, and C are listed, then the phrase "one of A, B, and C" means only A; only B; or only C.
  • Project A can contain a single element or multiple elements.
  • Project B can contain a single element or multiple elements.
  • Project C can contain a single element or multiple elements.
  • a list of items connected by the terms “at least one of”, “at least one of” or other similar terms can mean any combination of the listed items. For example, if items A and B are listed, then the phrase “at least one of A and B" or “at least one of A or B” means only A; only B; or A and B. In another example, if items A, B, and C are listed, then the phrase “at least one of A, B, and C” or “at least one of A, B, or C” means only A; or only B; C only; A and B (exclude C); A and C (exclude B); B and C (exclude A); or all of A, B, and C.
  • Project A can contain a single element or multiple elements.
  • Project B can contain a single element or multiple elements.
  • Project C can contain a single element or multiple elements.
  • the number after the capital letter “C”, such as “C 1 -C 10 ", “C 3 -C 10 “, etc., after the "C” indicates the number of carbons in a specific functional group. That is, the functional groups may include 1-10 carbon atoms and 3-10 carbon atoms, respectively.
  • C 1 -C 4 alkyl or “C 1-4 alkyl” refers to an alkyl group having 1 to 4 carbon atoms, such as CH 3 -, CH 3 CH 2 -, CH 3 CH 2 CH 2 -, (CH 3 ) 2 CH-, CH 3 CH 2 CH 2 CH 2 -, CH 3 CH 2 CH(CH 3 )- or (CH 3 ) 3 C-.
  • alkyl refers to a linear saturated hydrocarbon structure having 1 to 8 carbon atoms. "Alkyl” is also expected to be a branched or cyclic hydrocarbon structure having 3 to 8 carbon atoms.
  • the alkyl group may be an alkyl group of 1 to 6 carbon atoms, or an alkyl group of 1 to 4 carbon atoms.
  • butyl means to include n-butyl, sec-butyl, isobutyl, and tert-butyl And cyclobutyl
  • propyl includes n-propyl, isopropyl and cyclopropyl.
  • alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, cyclopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, cyclobutyl, n-pentyl, Isopentyl, neopentyl, cyclopentyl, methylcyclopentyl, ethylcyclopentyl, n-hexyl, isohexyl, cyclohexyl, n-heptyl, octyl, cyclopropyl, cyclobutyl, norbornyl Base and so on.
  • the alkyl group may be optionally substituted.
  • alkenyl refers to a monovalent unsaturated hydrocarbon group that can be straight or branched and has at least one and usually 1, 2, or 3 carbon-carbon double bonds. Unless otherwise defined, the alkenyl group usually contains 2-10 carbon atoms, for example, it may be an alkenyl group with 2-8 carbon atoms, an alkenyl group with 2-6 carbon atoms, or an alkenyl group with 2-4 carbon atoms. Alkenyl.
  • Representative alkenyl groups include, for example, vinyl, n-propenyl, isopropenyl, n-but-2-enyl, but-3-enyl, n-hex-3-enyl, and the like. In addition, alkenyl groups may be optionally substituted.
  • alkynyl refers to a monovalent unsaturated hydrocarbon group that can be straight or branched and has at least one and usually 1, 2, or 3 carbon-carbon triple bonds. Unless otherwise defined, the alkynyl group usually contains an alkynyl group of 2 to 10, 2 to 8, 2 to 6, or 2 to 4 carbon atoms. Representative alkynyl groups include, for example, ethynyl, prop-2-ynyl (n-propynyl), n-but-2-ynyl, n-hex-3-ynyl, and the like. In addition, alkynyl groups may be optionally substituted.
  • alkylene means a linear or branched divalent saturated hydrocarbon group.
  • the alkylene group may be an alkylene group of 1-8 carbon atoms, an alkylene group of 1 to 6 carbon atoms, or an alkylene group of 1 to 4 carbon atoms.
  • Representative alkylene groups include, for example, methylene, ethane-1,2-diyl ("ethylene"), propane-1,2-diyl, propane-1,3-diyl, butane -1,4-diyl, pentane-1,5-diyl and so on.
  • the alkylene group may be optionally substituted.
  • alkoxy refers to an alkyl-O- group, for example, it covers alkoxy groups of 1-8 carbon atoms, alkoxy groups of 1-6 carbon atoms, 1-4 An alkoxy group with carbon atoms, or an alkoxy group with 5-8 carbon atoms.
  • Representative examples of alkoxy include, but are not limited to, methoxy, ethoxy, propoxy, 2-propoxy, butoxy, tert-butoxy, pentoxy, and hexoxy.
  • the alkoxy group may be optionally substituted.
  • halogen encompasses F, Cl, Br, and I, preferably F or Cl.
  • the content of each component in the electrolyte is calculated based on the total weight of the electrolyte.
  • Some embodiments of the present invention provide an electrolyte, the electrolyte comprising a compound of formula I and an additive A,
  • the substituent is selected from cyano or halogen
  • X is selected from Li + , Na + , K + or Rb + ;
  • the additive A is selected from at least one of fluoroethylene carbonate (FEC), lithium difluorophosphate (LiPO 2 F 2 ), or vinylene carbonate.
  • formula I can be represented as formula I-1 to I-10:
  • X is selected from Li + , Na + , K + or Rb + .
  • the compound of formula I is selected from at least one of the following compounds:
  • the weight ratio of the compound of formula I to the additive A is 30:1 to 1:200.
  • the compound of formula I accounts for 0.05% to 5% of the total weight of the electrolyte, and the additive A accounts for 0.01% to 16% of the total weight of the electrolyte.
  • the weight ratio of the compound of formula I to the additive A is 20:1 to 1:150, 10:1 to 1:100, 1:1 to 1:50, or 1:1 to 1. :25. In some embodiments, the weight ratio of the compound of formula I to the additive A is about 15:1, about 10:1, about 5:1, about 3:1, about 2:1, about 1:1, About 1:2, about 1:3, about 1:4, about 1:5, about 1:6, about 1:7, about 1:8, about 1:10, about 1:20, about 1:30, About 1:40, about 1:50, about 1:60, about 1:70, about 1:80, about 1:90, about 1:100, about 1:110, about 1:120, about 1:130, About 1:140, about 1:150, about 1:160, about 1:170, about 1:180, or about 1:190. In some embodiments, the weight ratio of the compound of formula I to the additive A is about 3:100, about 9:100, about 3:5, about 3:8, about 5:3, about 1:1.5, About 3:50 or about 3:80.
  • the compound of formula I accounts for 0.1% to 3%, 0.1% to 2.5%, or about 0.1% to about 2% of the total weight of the electrolyte. In some embodiments, the compound of formula I Accounting for about 0.1%, about 0.2%, about 0.3%, about 0.4%, about 0.5%, about 0.6%, about 0.7%, about 0.8%, about 0.9%, about 1%, about 1.2 of the total weight of the electrolyte %, about 1.4%, about 1.6%, about 1.8%, about 2%, about 2.2%, about 2.4%, about 2.6%, about 2.8%, about 3%, about 3.5%, about 4%, or about 5%.
  • the additive A accounts for 0.05% to 15% or 0.1% to 12% of the total weight of the electrolyte. In some embodiments, the additive A accounts for about 0.5%, about 1%, about 1.5%, about 2%, about 2.5%, about 3%, about 3.5%, about 4%, of the total weight of the electrolyte. About 4.5%, about 5%, about 5.5%, about 6%, about 6.5%, about 7%, about 7.5%, about 8%, about 8.5%, about 9%, about 9.5%, about 10%, about 10.5 %, about 11%, about 11.5%, about 12%, about 12.5%, about 13%, about 13.5%, about 14%, about 14.5%, about 15%, about 15.5%, or about 16%.
  • the electrolyte further contains a compound of formula II:
  • R 9 is selected from hydrogen, cyano, halogen, substituted or unsubstituted C 1-8 alkyl, or substituted or unsubstituted C 1-8 alkoxy;
  • R 10 to R 12 are each independently selected from a covalent bond, a substituted or unsubstituted C 1-8 alkylene group, or -O-R'-, wherein R'is a substituted or unsubstituted C 1- 8 alkylene;
  • the substituent when substituted, is selected from cyano or halogen;
  • the compound of formula II accounts for 0.05% to 10% of the total weight of the electrolyte.
  • R 9 is selected from hydrogen, cyano, halogen, or the following substituted or unsubstituted groups: C 1-6 alkyl or C 1-4 alkyl, or C 1-6 alkane Oxy or C 1-4 alkoxy, wherein when substituted, the substituent is selected from cyano or halogen.
  • R 9 is selected from hydrogen, cyano, F, and the following unsubstituted or substituted groups: methyl, ethyl, propyl, isopropyl, methoxy, ethoxy , Propoxy, or isopropoxy, wherein when substituted, it is substituted with one or more substituents selected from cyano and/or F.
  • R 9 is selected from -CN, -F, -CF 3 , -CH 2 CH 2 CN, -OCH 2 CN, or -OCF 2 CN.
  • R 10 to R 12 are each independently selected from a covalent bond, substituted or unsubstituted C 1-6 alkylene or C 1-4 alkylene, or -O-R'-, Wherein R'is substituted or unsubstituted C 1-6 alkylene or C 1-4 alkylene; wherein when substituted, the substituent is selected from cyano and halogen.
  • R 10 to R 12 are each independently selected from the following groups that are covalently bonded, unsubstituted or substituted: methylene, ethylene, propylene, or -O-R'- , Wherein R'is the following unsubstituted or substituted group: methylene, ethylene, or -propylene; wherein when substituted, it is substituted with one or more F.
  • R 10 to R 12 are each independently selected from -CH 2 -, -CH 2 CH 2 -, -CF 2 CH 2 -, -(CH 2 ) 3 -, -OCH 2 -, or -OCF 2 -.
  • the compound of formula II includes at least one of the following compounds:
  • the electrolyte further comprises a compound of formula III:
  • the compound of formula III accounts for about 0.1% to about 20% of the total weight of the electrolyte.
  • the compound of formula III accounts for about 0.5% to about 15% or about 1% to about 10% of the total weight of the electrolyte. In some embodiments, the compound of formula III accounts for about 1%, about 1%, about 2%, about 3%, about 4%, about 5%, about 6%, about 7% of the total weight of the electrolyte. , About 8%, about 9%, about 10%, about 11%, about 12%, about 13%, about 14%, about 15%, about 16%, about 17%, about 18%, about 19% or about 20%.
  • the compound of formula III includes at least one of the following compounds:
  • the electrolyte further comprises a compound of formula IV,
  • R 41 and R 42 are each independently selected from substituted or unsubstituted C 1-10 alkyl; wherein when substituted, they are substituted with one or more substituents selected from F, Cl or Br.
  • R 41 and R 42 are each independently selected from the following substituted or unsubstituted groups: C 1-8 alkyl, C 1-6 alkyl, or C 1-4 alkyl; wherein When substituted, it is substituted by one or more substituents selected from F, Cl or Br.
  • R 41 and R 42 are each independently selected from methyl, ethyl, propyl, butyl, -CF 2 H, -CFH 2 , -CF 3 , -CF 2 CH 3 , CH 2 CF 3 .
  • R 41 is methyl
  • the compound of formula IV includes ethyl acetate, propyl acetate, ethyl difluoroacetate, ethyl trifluoroacetate, propyl acetate, butyl acetate, methyl propionate, ethyl propionate, Ethyl isopropionate, propyl propionate, butyl propionate, isobutyl propionate, pentyl propionate, isoamyl propionate, butyl butyrate, butyl isobutyrate, pentyl butyrate, butyl Of isoamyl acid, ethyl butyrate, ethyl valerate, ethyl isovalerate, ethyl isobutyrate, ethyl valerate, propyl valerate, propyl isovalerate or ethyl isovalerate At least one.
  • the compound of formula IV comprises:
  • the compound of formula IV accounts for 5% to 50% of the total weight of the electrolyte.
  • the compound of formula IV accounts for 10% to 45% or 15% to 40% of the total weight of the electrolyte. In some embodiments, the compound of formula IV accounts for about 10%, about 15%, about 20%, about 25%, about 30%, about 35%, about 40%, about 45% of the total weight of the electrolyte. % Or about 50%.
  • the electrolyte further includes a lithium salt and a non-aqueous organic solvent.
  • the lithium salt includes or is selected from at least one of an organic lithium salt or an inorganic lithium salt.
  • the lithium salt of the present application contains at least one of fluorine, boron, and phosphorus.
  • the lithium salt includes or is selected from lithium hexafluorophosphate (LiPF 6 ), lithium tetrafluoroborate (LiBF 4 ), lithium bisoxalate borate (LiB(C 2 O 4 ) 2 , LiBOB for short), difluorooxalic acid Lithium borate (LiBF 2 (C 2 O 4 ), LiDFOB for short), lithium hexafluoroantimonate (LiSbF 6 ), lithium hexafluoroarsenate (LiAsF 6 ), lithium perfluorobutyl sulfonate (LiC 4 F 9 SO 3 ), lithium perchlorate (LiClO 4 ), lithium aluminate (LiAlO 2 ), lithium tetrachloroaluminate (LiAlCl 4 ), lithium bissulfonimide (LiN(C x F 2x+1 SO 2 ) (C y F 2y+1 SO
  • the concentration of the lithium salt in the electrolyte of the present application is: 0.5 mol/L to 3 mol/L, 0.5 mol/L to 2 mol/L, or 0.8 mol/L to 1.5 mol/L.
  • the non-aqueous organic solvent may include carbonate-based solvents, carboxylate-based solvents, alkoxy-based solvents, sulfone-based solvents, or other aprotic solvents.
  • carbonate-based solvents include dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, methyl propyl carbonate, ethylene propyl carbonate, dipropyl carbonate, ethylene carbonate, propylene carbonate, butylene carbonate, etc.
  • Examples of carboxylic acid ester solvents include ⁇ -butyrolactone, valerolactone, butyrolactone, and the like.
  • alkoxy solvents examples include ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, dibutyl ether, tetrahydrofuran, 2-methyltetrahydrofuran, and the like.
  • sulfone solvents include ethyl vinyl sulfone, methyl isopropyl sulfone, isopropyl sec-butyl sulfone, sulfolane, and the like.
  • the non-aqueous organic solvent in the electrolyte can be a single non-aqueous organic solvent, or a mixture of multiple non-aqueous organic solvents.
  • the performance of the electrochemical device can be Control the mixing ratio.
  • the solvent accounts for 60% to 95% of the weight of the electrolyte.
  • the electrochemical device of the present application includes any device that undergoes an electrochemical reaction, and specific examples thereof include all kinds of primary batteries, secondary batteries, fuel cells, solar cells, or capacitors.
  • the electrochemical device is a lithium secondary battery, including a lithium metal secondary battery, a lithium ion secondary battery, a lithium polymer secondary battery, or a lithium ion polymer secondary battery.
  • the electrochemical device of the present application is an electrochemical device having a positive electrode having a positive electrode active material capable of occluding and releasing metal ions, and a negative electrode having a negative electrode active material capable of occluding and releasing metal ions. Its characteristics are It consists of any of the above-mentioned electrolytes of the present application.
  • the electrochemical device includes a positive electrode, a negative electrode, a separator, and any one of the foregoing electrolytes.
  • the electrochemical device satisfies (Rb-Ra)/Ra is less than or equal to 1; wherein Ra is the DC resistance of the electrochemical device when the electrochemical device is cycled at 25° C. and 20% charged state for 10 times; Rb is The DC resistance of the electrochemical device when it is cycled 200 times at 25°C and 20% charged.
  • the electrolyte used in the electrochemical device of the present application is any of the above-mentioned electrolytes in the present application.
  • the electrolytic solution used in the electrochemical device of the present application may also include other electrolytic solutions within the scope not departing from the gist of the present application.
  • the negative electrode of the electrochemical device includes a current collector and a negative active material layer formed on the current collector.
  • the negative active material layer includes a negative active material.
  • the negative active material may include a reversible intercalation/deintercalation of lithium ions. Materials, lithium metal, lithium metal alloys, materials capable of doping/undoping lithium, or transition metal oxides.
  • the material that reversibly intercalates/deintercalates lithium ions may be a carbon material.
  • the carbon material may be any carbon-based negative active material commonly used in lithium ion rechargeable electrochemical devices. Examples of carbon materials include crystalline carbon, amorphous carbon, and combinations thereof.
  • the crystalline carbon may be amorphous or plate-shaped, flake-shaped, spherical or fiber-shaped natural graphite or artificial graphite.
  • Amorphous carbon can be soft carbon, hard carbon, mesophase pitch carbonization products, burnt coke, and the like. Both low crystalline carbon and high crystalline carbon can be used as the carbon material.
  • soft carbon and hard carbon may generally be included.
  • As a high crystalline carbon material it may generally include natural graphite, crystalline graphite, pyrolysis carbon, mesophase pitch-based carbon fiber, mesophase carbon microbeads, mesophase pitch, and high-temperature calcined carbon (such as petroleum or coke derived from coal tar pitch) ).
  • the negative active material layer contains a binder
  • the binder may include various binder polymers, such as vinylidene fluoride-hexafluoropropylene copolymer (PVDF-co-HFP), polyvinylidene fluoride, poly Acrylonitrile, polymethyl methacrylate, polyvinyl alcohol, carboxymethyl cellulose, hydroxypropyl cellulose, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, polymers containing ethylene oxide, Polyvinylpyrrolidone, polyurethane, polytetrafluoroethylene, polyethylene, polypropylene, styrene butadiene rubber, acrylic (ester) styrene butadiene rubber, epoxy resin, nylon, etc., but not limited to these.
  • PVDF-co-HFP vinylidene fluoride-hexafluoropropylene copolymer
  • PVDF-co-HFP polyvinylidene
  • the negative active material layer also includes a conductive material to improve electrode conductivity.
  • a conductive material can be used as the conductive material as long as it does not cause a chemical change.
  • conductive materials include: carbon-based materials, such as natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, carbon fibers, etc.; metal-based materials, such as metal powders or metal fibers including copper, nickel, aluminum, silver, etc. ; Conductive polymers, such as polyphenylene derivatives, etc.; or their mixtures.
  • the lithium metal alloy includes lithium and at least one selected from Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Si, Sb, Pb, In, Zn, Ba, Ra, Ge, Al or Sn A metal.
  • materials capable of doping/undoping lithium include Si, SiOx (0 ⁇ x ⁇ 2), Si-C composites, Si-Q alloys (where Q is an alkali metal, alkaline earth metal, group 13 to group 13).
  • Exemplary elements of Q and R include Mg, Ca, Sr, Ba, Ra, Sc, Y, Ti, Zr, Hf, Rf, V, Nb, Ta, Db, Cr, Mo, W, Sg, Tc, Re, Bh, Fe, Pb, Ru, Os, Hs, Rh, Ir, Pd, Pt, Cu, Ag, Au, Zn, Cd, B, Al, Ga, Sn, In, Tl, Ge, P, As, Sb, Bi, S, Se, Te, Po or their combination.
  • the transition metal oxide may be vanadium oxide, lithium vanadium oxide, and the like.
  • the current collector includes, but is not limited to: copper foil, nickel foil, stainless steel foil, titanium foil, nickel foam, copper foam, polymer substrate coated with conductive metal, and any combination thereof.
  • the negative electrode can be prepared by a preparation method known in the art.
  • the negative electrode can be obtained by mixing an active material, a conductive material, and a binder in a solvent to prepare an active material composition, and coating the active material composition on a current collector.
  • the positive electrode of the electrochemical device includes a current collector and a positive electrode active material layer provided on the current collector.
  • the positive active material includes a compound that reversibly intercalates and deintercalates lithium ions (ie, a lithiated intercalation compound).
  • the positive active material may include a composite oxide including lithium and at least one selected from cobalt, manganese, and nickel.
  • the compound may have a coating layer on the surface, or may be mixed with a compound having a coating layer.
  • the coating layer may include oxides of coating elements, hydroxides of coating elements, oxyhydroxides of coating elements, oxycarbonates of coating elements, and alkali carbonates of coating elements ( At least one kind of coating element compound selected from hydroxyl carbonate.
  • the compound used for the coating layer may be amorphous or crystalline.
  • the coating element used for the coating layer may include Mg, Al, Co, K, Na, Ca, Si, Ti, V, Sn, Ge, Ga, B, As, Zr, or a mixture thereof.
  • the coating layer may be formed by any method, as long as it does not negatively affect the properties of the positive electrode active material due to the inclusion of the element in the compound.
  • the method may include any coating method known to those skilled in the art, such as spraying, dipping, and the like.
  • the positive active material layer may include a binder and a conductive material.
  • the binder improves the binding performance between the positive electrode active material particles and the positive electrode active material particles and the current collector.
  • binders include polyvinyl alcohol, carboxymethyl cellulose, hydroxypropyl cellulose, diacetyl cellulose, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, ethylene-containing Oxygen polymers, polyvinylpyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, styrene butadiene rubber, acrylic (ester) styrene butadiene rubber, epoxy resin, nylon, etc.
  • conductive materials are used to provide conductivity to the electrodes.
  • the conductive material may include any conductive material as long as it does not cause a chemical change.
  • Examples of conductive materials include one or a mixture of conductive materials such as: natural graphite; artificial graphite; carbon black; acetylene black; Ketjen black; carbon fiber; metal powder, metal fiber, etc., such as copper, nickel, aluminum, Silver, etc.; or polyphenylene derivatives, etc.
  • the current collector may be aluminum, but is not limited thereto.
  • the positive electrode can be prepared by a preparation method known in the art.
  • the positive electrode can be obtained by mixing an active material, a conductive material, and a binder in a solvent to prepare an active material composition, and coating the active material composition on a current collector.
  • the solvent may include N-methylpyrrolidone and the like, but is not limited thereto.
  • the positive electrode is made by forming a positive electrode material using a positive electrode active material layer including lithium transition metal-based compound powder and a binder on a current collector.
  • the positive active material layer can usually be made by the following operations: dry mixing the positive electrode material and the binder (conducting material and thickener used as needed) to form a sheet, The obtained sheet is press-bonded to the positive electrode current collector, or these materials are dissolved or dispersed in a liquid medium to prepare a slurry, which is coated on the positive electrode current collector and dried.
  • the material of the positive active material layer includes any material known in the art.
  • the porosity of the positive electrode is 8% to 22%. In some embodiments, the porosity of the positive electrode is 8% to 18%, 9% to 17%, 10% to 16%, or 12% to 14%. In some embodiments, the porosity of the positive electrode is about 10%, about 11%, about 12%, about 13%, about 14%, about 15%, about 16%, about 18%, about 20%, or About 22%.
  • the electrochemical device of the present application is provided with a separator between the positive electrode and the negative electrode to prevent short circuits.
  • the material and shape of the isolation membrane used in the electrochemical device of the present application are not particularly limited, and it may be any technology disclosed in the prior art.
  • the isolation membrane includes a polymer or an inorganic substance formed of a material that is stable to the electrolyte of the present application.
  • the separator may include a substrate layer and a surface treatment layer.
  • the substrate layer is a non-woven fabric, film or composite film with a porous structure, and the material of the substrate layer is selected from at least one of polyethylene, polypropylene, polyethylene terephthalate and polyimide.
  • a polypropylene porous film, a polyethylene porous film, a polypropylene non-woven fabric, a polyethylene non-woven fabric, or a polypropylene-polyethylene-polypropylene porous composite film can be selected.
  • a surface treatment layer is provided on at least one surface of the substrate layer.
  • the surface treatment layer may be a polymer layer or an inorganic substance layer, or a layer formed by a mixed polymer and an inorganic substance.
  • the inorganic layer includes inorganic particles and a binder.
  • the inorganic particles are selected from alumina, silica, magnesium oxide, titanium oxide, hafnium dioxide, tin oxide, ceria, nickel oxide, zinc oxide, calcium oxide, zirconium oxide, One or a combination of yttrium oxide, silicon carbide, boehmite, aluminum hydroxide, magnesium hydroxide, calcium hydroxide, and barium sulfate.
  • the binder is selected from polyvinylidene fluoride, vinylidene fluoride-hexafluoropropylene copolymer, polyamide, polyacrylonitrile, polyacrylate, polyacrylic acid, polyacrylate, polyvinylpyrrolidone, polyvinyloxy , Polymethyl methacrylate, polytetrafluoroethylene and polyhexafluoropropylene or a combination of several.
  • the polymer layer contains a polymer, and the material of the polymer is selected from polyamide, polyacrylonitrile, acrylate polymer, polyacrylic acid, polyacrylate, polyvinylpyrrolidone, polyvinyloxy, polyvinylidene fluoride, At least one of poly(vinylidene fluoride-hexafluoropropylene)
  • the isolation membrane of the electrochemical device of the embodiments of the present application includes a polyolefin-based microporous membrane and a coating.
  • the coating includes an organic coating and an inorganic coating, wherein the organic coating is selected from Polyvinylidene fluoride, vinylidene fluoride-hexafluoropropylene copolymer, polyacrylonitrile, polyimide, acrylonitrile-butadiene copolymer, acrylonitrile-styrene-butadiene copolymer, polymethylmethacrylate At least one of ester, polymethyl acrylate, polyethyl acrylate, acrylic-styrene copolymer, polydimethylsiloxane, sodium polyacrylate, sodium carboxymethyl cellulose, and the inorganic coating is selected from SiO 2 One or more of Al 2 O 3 , CaO, TiO 2 , ZnO 2 , MgO, ZrO 2 and SnO 2 ; the polyviny
  • the membrane is selected from polyethylene (PE), ethylene-propylene copolymer, polypropylene (PP), ethylene-butene copolymer, ethylene-hexene copolymer , A single-layer or multi-layer polyolefin microporous film composed of one or more of ethylene-methyl methacrylate copolymers.
  • the electrolyte according to the embodiments of the present application can improve the high-temperature cycle performance, high-temperature storage performance and kinetics of the electrochemical device, and has higher safety, so that the electrochemical device manufactured thereby is suitable for electronic equipment in various fields .
  • the use of the electrochemical device of the present application is not particularly limited, and it can be used for various well-known uses.
  • notebook computers pen-input computers, mobile computers, e-book players, portable phones, portable fax machines, portable copiers, portable printers, headsets, video recorders, LCD TVs, portable cleaners, portable CD players , Mini discs, transceivers, electronic notebooks, calculators, memory cards, portable recorders, radios, backup power supplies, motors, cars, motorcycles, assisted bicycles, bicycles, lighting equipment, toys, game consoles, clocks, power tools, Flashlights, cameras, large household storage batteries or lithium-ion capacitors, etc.
  • SBR styrene-butadiene rubber
  • CMC sodium carboxymethyl cellulose
  • LiCoO 2 lithium cobalt oxide
  • conductive carbon black conductive carbon black
  • conductive paste conductive paste
  • binder polyvinylidene fluoride PVDF
  • NMP pyrrolidone
  • a Disperse the positive electrode active material NCM811 (LiNi 0.8 Mn 0.1 Co 0.1 O 2 ), the conductive agent acetylene black, and the binder polyvinylidene fluoride (PVDF) in an appropriate amount of N-methyl at a weight ratio of 96:2:2.
  • the pyrrolidone (NMP) solvent is fully stirred and mixed to form a uniform positive electrode slurry; the slurry is coated on the positive electrode current collector aluminum foil, dried, and cold pressed to obtain the positive electrode.
  • b Disperse the positive electrode active material NCM523 (LiNi 0.5 Mn 0.3 Co 0.2 O 2 ), conductive carbon black-L, conductive paste, and binder polyvinylidene fluoride (PVDF) at a weight ratio of 96:2:0.8:1.2 Fully stir and mix in an appropriate amount of N-methylpyrrolidone (NMP) solvent to form a uniform positive electrode slurry; coat the slurry on the positive electrode current collector aluminum foil, dry, and cold press to obtain a positive electrode.
  • NMP N-methylpyrrolidone
  • the positive electrode, the separator film, and the negative electrode in order, so that the separator film is located between the positive electrode and the negative electrode for isolation, and then wound to obtain the bare cell; the bare cell is placed in the outer packaging foil, and the prepared electrolysis The liquid is injected into the dried battery, and the preparation of the lithium-ion battery is completed after vacuum packaging, standing, forming, and shaping.
  • the lithium-ion battery that has reached a constant temperature is charged at a constant current of 0.5C to a voltage of 4.45V, then charged at a constant voltage of 4.45V to a current of 0.05C, and then discharged at a constant current of 0.2C to a voltage of 3.4V.
  • the capacity in this step is used as the reference C 2 .
  • Discharge capacity retention rate at -10 degrees Celsius C 3 /C 2 ⁇ 100%
  • Thickness expansion ratio (H 12 -H 11 )/H 11 x 100%
  • the above examples show that the electrolyte provided by the present invention can improve the low-temperature discharge performance, normal-temperature cycle performance, and high-temperature storage performance of electrochemical devices, and reduce the low-temperature impedance of electrochemical devices.
  • Example 3 Prepare the electrolytes of Example 3, Example 18, and Examples 64 to 67 and lithium ion batteries according to the above methods. Please refer to Table 9 and Table 10 for positive electrode porosity, electrolyte composition and test results.
  • references to “some embodiments”, “partial embodiments”, “one embodiment”, “another example”, “examples”, “specific examples” or “partial examples” throughout the specification mean At least one embodiment or example in this application includes the specific feature, structure, material, or characteristic described in the embodiment or example. Therefore, descriptions appearing in various places throughout the specification, such as: “in some embodiments”, “in embodiments”, “in one embodiment”, “in another example”, “in an example “In”, “in a specific example” or “exemplary”, which are not necessarily quoting the same embodiment or example in this application.
  • the specific features, structures, materials or characteristics herein can be combined in one or more embodiments or examples in any suitable manner.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Physics & Mathematics (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • General Physics & Mathematics (AREA)
  • Inorganic Chemistry (AREA)
  • Materials Engineering (AREA)
  • Secondary Cells (AREA)

Abstract

提供了一种电解液及电化学装置，所述电解液含有联吡啶盐化合物，能够改善电化学装置的低温放电性能和常温循环性能、并降低电化学装置的低温阻抗。

Description

一种电解液及电化学装置 技术领域
本申请涉及储能技术领域，尤其涉及一种电解液和包含该电解液的电化学装置。
背景技术
众所周知，锂离子电池具有高能量密度、长使用寿命、无记忆效应等特性受到人们的广泛关注，被广泛用于智能产品(包括手机、笔记本、相机等电子产品)、电动工具和电动汽车等领域，并正逐步取代传统的镍镉、镍氢电池。然而，随着技术的快速发展以及使用场景的多样性，锂离子电池在低温下容量快速衰减成为用户使用的痛点。
为了改善锂离子电池的循环性能，常见的策略是使用正负极成膜添加剂。然而，高阻抗成膜添加剂往往会导致低温性能严重损失，显著增加电池的阻抗。为了改善锂离子电池的低温性能，常用的方法是提升电解液的动力学。然而，高动力学电解液往往会严重恶化电池的高温循环及高温存储性能。因此，如何开发性能优异的锂离子电池成为业界急需解决的问题。
发明内容
为了解决上述问题，本发明提供了一种电解液和电化学装置。所述电解液在改善电池的低温性能同时也改善了电池的高温循环及高温存储性能。
本发明的一方面提供了一种电解液。在一些实施例中，所述电解液包含式I化合物及添加剂A，
Figure PCTCN2020082574-appb-000001
其中，
R 1至R 8各自独立地选自:H、卤素、-COOX、经取代或未经取代的C 1-8烷基、经取代或未经取代的C 2-10烯基、经取代或未经取代的C 2-10炔基、经取代或未经取代的C 1-8烷氧基、或-R a-S(＝O) 2-R b；其中R a选自经取代或未经取代的C 1-8亚烷基，R b选自卤素或经取代或未经取代的C 1-8烷基，且R 1至R 8中的至少一者为-COOX；
经取代时取代基选自氰基或卤素；
X选自Li +、Na +、K +或Rb +；
添加剂A选自氟代碳酸乙烯酯、LiPO 2F 2或碳酸亚乙烯酯中的至少一种。
在一些实施例中，所述式I化合物选自如下化合物中的至少一种：
Figure PCTCN2020082574-appb-000002
在一些实施例中，所述式I化合物与所述添加剂A的重量比为30:1至1:200。
在一些实施例中，所述式I化合物占所述电解液总重量的0.05％至5％，所述添加剂A占所述电解液总重量的0.01％至16％。
在一些实施例中，所述电解液中进一步包含式Ⅱ化合物：
Figure PCTCN2020082574-appb-000003
其中，
R 9选自氢、氰基、卤素、经取代或未经取代的C 1-8烷基、或经取代或未经取代的C 1-8烷氧基；
R 10至R 12各自独立选自共价键、经取代或未经取代的C 1-8亚烷基、或-O-R'-，其中R'为经取代或未经取代的C 1-8亚烷基；
经取代时取代基选自氰基或卤素；
其中，所述式Ⅱ化合物占所述电解液总重量的0.05％至10％。
在一些实施例中，所述式Ⅱ化合物包含
Figure PCTCN2020082574-appb-000004
Figure PCTCN2020082574-appb-000005
中的至少一种。
在一些实施例中，所述电解液进一步包含式III化合物：
Figure PCTCN2020082574-appb-000006
其中，R 13、R 14及R 15各自独立地选自于经取代或未经取代的C 1-8烷基、或-R c-S(＝O) 2-R d；其中R c选自经取代或未经取代的C 1-8亚烷基，R d选自卤素或者经取代或未经取代的C 1-8烷基；其中经取代时是经一个或多个卤素取代；
其中，所述式III化合物占所述电解液总重量的0.1％至20％。
在一些实施例中，所述式III化合物包含
Figure PCTCN2020082574-appb-000007
Figure PCTCN2020082574-appb-000008
中的至少一种。
在一些实施例中，所述电解液进一步包含式IV化合物，
Figure PCTCN2020082574-appb-000009
R 41和R 42各自独立选自经取代或未经取代的C 1-10烷基；其中经取代时是经一个或多个选自F、Cl或Br的取代基取代；
在一些实施例中，所述式IV化合物占所述电解液总重量的5％至50％。
在一些实施例中，所述式IV化合物包含：
Figure PCTCN2020082574-appb-000010
Figure PCTCN2020082574-appb-000011
中的至少一种。
本发明的另一方面提供了一种电化学装置。所述电化学装置包括正极、负极、以及上述任意一种电解液。
本发明的又一方面提供了一种电子装置，所述电子装置包括如上所述的任意一种电化学装置。
本申请实施例的额外层面及优点将部分地在后续说明中描述、显示、或是经由本申请实施例的实施而阐释。
具体实施方式
本申请的实施例将会被详细的描述在下文中。本申请的实施例不应该被解释为对本申请要求保护范围的限制。除非另外明确指明，本文使用的下述术语具有下文指出的含义。
如本文中所使用，术语“约”用以描述及说明小的变化。当与事件或情形结合使用时，所述术语可指代其中事件或情形精确发生的例子以及其中事件或情形极近似地发生的例子。举例来说，当结合数值使用时，术语可指代小于或等于所述数值的±10％的变化范围，例如小于或等于±5％、小于或等于±4％、小于或等于±3％、小于或等于±2％、小于或等于±1％、小于或等于±0.5％、小于或等于±0.1％、或小于或等于±0.05％。另外，有时在本文中以范围格式呈现量、比率和其它数值。应理解，此类范围格式是用于便利及简洁起见，且应灵活地理解，不仅包含明确地指定为范围限制的数值，而且包含涵盖于所述范围内的所有个别数值或子范围， 如同明确地指定每一数值及子范围一般。
在具体实施方式及权利要求书中，由术语“中的一者”连接的项目的列表可意味着所列项目中的任一者。例如，如果列出项目A及B，那么短语“A及B中的一者”意味着仅A或仅B。在另一实例中，如果列出项目A、B及C，那么短语“A、B及C中的一者”意味着仅A；仅B；或仅C。项目A可包含单个元件或多个元件。项目B可包含单个元件或多个元件。项目C可包含单个元件或多个元件。
在具体实施方式及权利要求书中，由术语“中的至少一者”、“中的至少一种”或其他相似术语所连接的项目的列表可意味着所列项目的任何组合。例如，如果列出项目A及B，那么短语“A及B中的至少一者”或“A或B中的至少一者”意味着仅A；仅B；或A及B。在另一实例中，如果列出项目A、B及C，那么短语“A、B及C中的至少一者”或“A、B或C中的至少一者”意味着仅A；或仅B；仅C；A及B(排除C)；A及C(排除B)；B及C(排除A)；或A、B及C的全部。项目A可包含单个元件或多个元件。项目B可包含单个元件或多个元件。项目C可包含单个元件或多个元件。
在具体实施方式及权利要求书中，在关于碳数的表述即大写字母“C”后面的数字，例如“C 1-C 10”、“C 3-C 10”等中，在“C”之后的数字例如“1”、“3”或“10”表示具体官能团中的碳数。即，官能团分别可包括1-10个碳原子和3-10个碳原子。例如，“C 1-C 4烷基”或“C 1-4烷基”是指具有1-4个碳原子的烷基，例如CH 3-、CH 3CH 2-、CH 3CH 2CH 2-、(CH 3) 2CH-、CH 3CH 2CH 2CH 2-、CH 3CH 2CH(CH 3)-或(CH 3) 3C-。
如本文所用，术语“烷基”是指具有1至8个碳原子的直链饱和烃结构。“烷基”还预期是具有3至8个碳原子的支链或环状烃结构。例如，烷基可为1-6个碳原子的烷基、或1-4个碳原子的烷基。当指定具有具体碳数的烷基时，预期涵盖具有该碳数的所有几何异构体；因此，例如，“丁基”意思是包括正丁基、仲丁基、异丁基、叔丁基和环丁基；“丙基”包括正丙基、异丙基和环丙基。烷基实例包括，但不限于甲基、乙基、正丙基、异丙基、环丙基、正丁基、异丁基、仲丁基、叔丁基、环丁基、正戊基、异戊基、新戊基、环戊基、甲基环戊基、乙基环戊基、正己基、异己基、环己基、正庚基、辛基、环丙基、环丁基、降冰片基等。另外，烷基可以是任选地被取代的。
术语“烯基”是指可为直链或具支链且具有至少一个且通常1个、2个或3个碳碳双键的单价不饱和烃基团。除非另有定义，否则所述烯基通常含有2-10个碳原子，例如可以为2-8个 碳原子的烯基、2-6个碳原子的烯基、或2-4个碳原子的烯基。代表性烯基包括(例如)乙烯基、正丙烯基、异丙烯基、正-丁-2-烯基、丁-3-烯基、正-己-3-烯基等。另外，烯基可以是任选地被取代的。
术语“炔基”是指可为直链或具支链且具有至少一个且通常具有1个、2个或3个碳碳三键的单价不饱和烃基团。除非另有定义，否则所述炔基通常含有2个到10个、2至8个、2至6个、或2至4个碳原子的炔基。代表性炔基包括(例如)乙炔基、丙-2-炔基(正-丙炔基)、正-丁-2-炔基、正-己-3-炔基等。另外，炔基可以是任选地被取代的。
术语“亚烷基”意指直链或具支链的二价饱和烃基。例如，亚烷基可为1-8个碳原子的亚烷基、1-6个碳原子的亚烷基、或1-4个碳原子的亚烷基。代表性亚烷基包括(例如)亚甲基、乙烷-1,2-二基(“亚乙基”)、丙烷-1,2-二基、丙烷-1,3-二基、丁烷-1,4-二基、戊烷-1,5-二基等等。另外，亚烷基可以是任选地被取代的。
术语“烷氧基”术语烷氧基是指烷基-O-的基团，例如其涵盖1-8个碳原子的烷氧基、1-6个碳原子的烷氧基、1-4个碳原子的烷氧基、或5-8个碳原子的烷氧基。烷氧基的代表性实例包括，但不限于，甲氧基、乙氧基、丙氧基、2-丙氧基、丁氧基、叔丁氧基、戊氧基和己氧基。另外，烷氧基可以是任选地被取代的。
当上述取代基经取代时，除另有说明的情况外，是经一个或多个卤素取代。
如本文所用，术语“卤素”涵盖F、Cl、Br及I，优选F或Cl。
如本文中所使用，电解液中各组分的含量均为基于电解液的总重量计算。
一、电解液
本发明的一些实施例提供了一种电解液，所述电解液包含式I化合物及添加剂A，
Figure PCTCN2020082574-appb-000012
其中，
R 1至R 8各自独立地选自:H、卤素、-COOX、经取代或未经取代的C 1-8烷基、经取代或未经取代的C 2-10烯基、经取代或未经取代的C 2-10炔基、经取代或未经取代的C 1-8烷氧基、或-R a-S(＝O) 2-R b；其中R a选自经取代或未经取代的C 1-8亚烷基，R b选自卤素或经取代或未经取代的C 1-8烷基，且R 1至R 8中的至少一者为-COOX；
经取代时取代基选自氰基或卤素；
X选自Li +、Na +、K +或Rb +；
添加剂A选自氟代碳酸乙烯酯(FEC)、二氟磷酸锂(LiPO 2F 2)或碳酸亚乙烯酯中的至少一种。
在一些实施例中，R 1至R 8各自独立地选自:H；卤素；-COOX；经取代或未经取代的下述基团：C 1-6烷基或C 1-4烷基；C 2-8烯基、C 2-6烯基或C 2-4烯基；C 2-8炔基、C 2-6炔基或C 2-4炔基；C 1-6烷氧基或C 1-4烷氧基；或-R a-S(＝O) 2-R b，其中R a选自经取代或未经取代的C 1-6亚烷基或C 1-4亚烷基，R b选自卤素或经取代或未经取代的C 1-6烷基或C 1-4烷基，且R 1至R 8中的至少一者为-COOX；经取代时取代基选自氰基或卤素；X选自Li +、Na +、K +或Rb +。
在一些实施例中，R 1至R 8各自独立地选自:H、F、-COOX、经F或氰基取代或者未经取代的下述基团：甲基、乙基、丙烯基、甲氧基、或-CH 2-S(＝O) 2-F；且R 1至R 8中的至少一者为-COOX；其中X选自Li +、Na +、K +或Rb +。
在一些实施例中，所述式I可表示为式I-1至I-10：
Figure PCTCN2020082574-appb-000013
Figure PCTCN2020082574-appb-000014
Figure PCTCN2020082574-appb-000015
其中X选自Li +、Na +、K +或Rb +。
在一些实施例中，所述式I化合物选自如下化合物中的至少一种：
Figure PCTCN2020082574-appb-000016
Figure PCTCN2020082574-appb-000017
在一些实施例中，所述式I化合物与所述添加剂A的重量比为30:1至1:200。
在一些实施例中，所述式I化合物占所述电解液总重量的0.05％至5％，所述添加剂A占所述电解液总重量的0.01％至16％。
在一些实施例中，所述式I化合物与所述添加剂A的重量比为20:1至1:150、10:1至1:100、1:1至1:50、或1:1至1:25。在一些实施例中，所述式I化合物与所述添加剂A的重量比为约15:1、约10:1、约5:1、约3:1、约2:1、约1:1、约1:2、约1:3、约1:4、约1:5、约1:6、约1:7、约1:8、约1:10、约1:20、约1:30、约1:40、约1:50、约1:60、约1:70、约1:80、约1:90、约1:100、约1:110、约1:120、约1:130、约1:140、约1:150、约1:160、约1:170、约1:180、或约1:190。在一些实施例中，所述式I化合物与所述添加剂A的重量比为约3:100、约9:100、约3:5、约3:8、约5:3、约1:1.5、约3:50或约3:80。
在一些实施例中，所述式I化合物占所述电解液总重量的0.1％至3％、0.1％至2.5％或约 0.1％至约2％，在一些实施例中，所述式I化合物占所述电解液总重量的约0.1％、约0.2％、约0.3％、约0.4％、约0.5％、约0.6％、约0.7％、约0.8％、约0.9％、约1％、约1.2％、约1.4％、约1.6％、约1.8％、约2％、约2.2％、约2.4％、约2.6％、约2.8％、约3％、约3.5％、约4％或约5％。
在一些实施例中，所述添加剂A占所述电解液总重量的0.05％至15％或0.1％至12％。在一些实施例中，所述添加剂A占所述电解液总重量的约0.5％、约1％、约1.5％、约2％、约2.5％、约3％、约3.5％、约4％、约4.5％、约5％、约5.5％、约6％、约6.5％、约7％、约7.5％、约8％、约8.5％、约9％、约9.5％、约10％、约10.5％、约11％、约11.5％、约12％、约12.5％、约13％、约13.5％、约14％、约14.5％、约15％、约15.5％、或约16％。
在一些实施例中，所述电解液中进一步包含式Ⅱ化合物：
Figure PCTCN2020082574-appb-000018
其中，
R 9选自氢、氰基、卤素、经取代或未经取代的C 1-8烷基、或经取代或未经取代的C 1-8烷氧基；
R 10至R 12各自独立选自共价键、经取代或未经取代的C 1-8亚烷基、或-O-R'-，其中R'为经取代或未经取代的C 1-8亚烷基；
其中经取代时取代基选自氰基或卤素；
其中，所述式Ⅱ化合物占所述电解液总重量的0.05％至10％。
在一些实施例中，R 9选自氢、氰基、卤素、或经取代或未经取代的下述基团：C 1-6烷基或C 1-4烷基、或C 1-6烷氧基或C 1-4烷氧基，其中经取代时取代基选自氰基或卤素。
在一些实施例中，R 9选自氢、氰基、F、及未经取代或经取代的下述基团：甲基、乙基、丙基、异丙基、甲氧基、乙氧基、丙氧基、或异丙氧基，其中经取代时是经一个或多个选自氰基和/或F的取代基取代。
在一些实施例中，R 9选自-CN、-F、-CF 3，-CH 2CH 2CN、-OCH 2CN、或-OCF 2CN。
在一些实施例中，R 10至R 12各自独立选自共价键、经取代或未经取代的C 1-6亚烷基或C 1-4亚烷基、或-O-R'-，其中R'为经取代或未经取代的C 1-6亚烷基或C 1-4亚烷基；其中经取代时取代基选自氰基和卤素。
在一些实施例中，R 10至R 12各自独立选自共价键、未经取代或经取代的下述基团：亚甲基、亚乙基、亚丙基、或-O-R'-，其中R'为未经取代或经取代的下述基团：亚甲基、亚乙基、或-亚丙基；其中经取代时是经一个或多个F取代。
在一些实施例中，R 10至R 12各自独立选自-CH 2-、-CH 2CH 2-、-CF 2CH 2-、-(CH 2) 3-、-OCH 2-、或-OCF 2-。
在一些实施例中，所述式Ⅱ化合物包含下述化合物中的至少一种：
Figure PCTCN2020082574-appb-000019
在一些实施例中，所述电解液进一步包含式III化合物：
Figure PCTCN2020082574-appb-000020
其中，R 13、R 14及R 15各自独立地选自于经取代或未经取代的C 1-8烷基、或-R c-S(＝O) 2-R d；其中R c选自经取代或未经取代的C 1-8亚烷基，R d选自卤素或经取代或未经取代的C 1-8烷基；其中经取代时是经一个或多个卤素取代；
其中，所述式III化合物占所述电解液总重量的约0.1％至约20％。
在一些实施例中，R 13、R 14及R 15各自独立地选自于经取代或未经取代的下述基团：C 1-6烷基或C 1-4烷基、或-R c-S(＝O) 2-R d；其中R c选自经取代或未经取代的C 1-6亚烷基或C 1-4亚烷基，R d选自卤素和经取代或未经取代的C 1-6烷基或C 1-4烷基；其中经取代时是经一个或多个卤素取代。
在一些实施例中，R 13、R 14及R 15各自独立地选自于经取代或未经取代的下述基团：甲基、乙基和丙基、或-R c-S(＝O) 2-R d；其中R c选自经取代或未经取代的下述基团：亚甲基、亚乙基和亚丙基，R d选自F和经取代或未经取代的下述基团：甲基、乙基和丙基；其中经取代时是经一个或多个F取代。
在一些实施例中，R 13、R 14及R 15各自独立地选自-CH 3、-CF 3、-CH 2CF 3、-CH 2CH 3、-CH 2CH 2CN、-CH 2CH 2F、-CH 2-S(＝O) 2-F、或-CH 2-S(＝O) 2-CF 3。
在一些实施例中，所述式III化合物占所述电解液总重量的约0.5％至约15％或约1％至约10％。在一些实施例中，所述式III化合物占所述电解液总重量的约1％、约1％、约2％、约3％、约4％、约5％、约6％、约7％、约8％、约9％、约10％、约11％、约12％、约13％、约14％、约15％、约16％、约17％、约18％、约19％或约20％。
在一些实施例中，所述式III化合物包含下述化合物中的至少一种：
Figure PCTCN2020082574-appb-000021
在一些实施例中，所述电解液进一步包含式IV化合物，
Figure PCTCN2020082574-appb-000022
其中，R 41和R 42各自独立选自经取代或未经取代的C 1-10烷基；其中经取代时是经一个或多个选自F、Cl或Br的取代基取代。
在一些实施例中，R 41和R 42各自独立选自经取代或未经取代的下述基团：C 1-8烷基、C 1-6烷基或C 1-4烷基；其中经取代时是经一个或多个选自F、Cl或Br的取代基取代。
在一些实施例中，R 41和R 42各自独立地选自甲基、乙基、丙基、丁基、-CF 2H、-CFH 2、-CF 3、-CF 2CH 3、CH 2CF 3。
在一些实施例中，R 41为甲基。
在一些实施例中，所述式IV化合物包含乙酸乙酯、乙酸丙酯、二氟乙酸乙酯，三氟乙酸乙酯、乙酸丙酯、乙酸丁酯、丙酸甲酯、丙酸乙酯、异丙酸乙酯、丙酸丙酯、丙酸丁酯、丙酸异丁酯、丙酸戊酯、丙酸异戊酯、丁酸丁酯、异丁酸丁酯、丁酸戊酯、丁酸异戊酯、丁 酸乙酯、戊酸乙酯、异戊酸乙酯、异丁酸乙酯、戊酸乙酯、戊酸丙酯、异戊酸丙酯或异戊酸乙酯中的至少一种。
在一些实施例中，所述式IV化合物包含：
Figure PCTCN2020082574-appb-000023
Figure PCTCN2020082574-appb-000024
中的至少一种。
在一些实施例中，所述式IV化合物占所述电解液总重量的5％至50％。
在一些实施例中，所述式IV化合物占所述电解液总重量的10％至45％或15％至40％。在一些实施例中，所述式IV化合物占所述电解液总重量的约10％、约15％、约20％、约25％、约30％、约35％、至约40％、约45％或约50％。
在一些实施例中，所述电解液进一步包括锂盐和非水有机溶剂。
在一些实施例中，所述锂盐包括或选自有机锂盐或无机锂盐中的至少一种。在一些实施例中，本申请锂盐中含有氟元素、硼元素、磷元素中的至少一种。
在一些实施例中，所述锂盐包括或选自六氟磷酸锂(LiPF 6)、四氟硼酸锂(LiBF 4)、双草酸硼酸锂(LiB(C 2O 4) 2，简称LiBOB)、二氟草酸硼酸锂(LiBF 2(C 2O 4)，简称LiDFOB)、六氟锑酸锂(LiSbF 6)、六氟砷酸锂(LiAsF 6)、全氟丁基磺酸锂(LiC 4F 9SO 3)、高氯酸锂(LiClO 4)、铝酸锂(LiAlO 2)、四氯铝酸锂(LiAlCl 4)、双磺酰亚胺锂(LiN(C xF 2x+1SO 2)(C yF 2y+1SO 2)，其中x和y是自然数)、氯化锂(LiCl)、氟化锂(LiI)中的至少一种。
在一些实施例中，本申请的电解液中锂盐的浓度为：0.5mol/L至3mol/L、0.5mol/L至2mol/L或0.8mol/L至1.5mol/L。
所述非水有机溶剂可以包含碳酸酯类溶剂、羧酸酯类溶剂、烷氧类溶剂、砜类溶剂或其它非质子溶剂。碳酸酯类溶剂的示例包含碳酸二甲酯、碳酸二乙酯、碳酸甲乙酯、碳酸甲丙酯、碳酸乙丙酯、碳酸二丙酯、碳酸乙烯酯、碳酸丙烯酯、碳酸丁烯酯等。羧酸酯类溶剂的示例包含γ-丁内酯、戊内酯、丁内酯等。烷氧类溶剂的示例包含乙二醇二甲醚、二乙二醇二甲醚、四乙二醇二甲醚、二丁醚、四氢呋喃、2-甲基四氢呋喃等。砜类溶剂的示例包含有乙基乙烯基砜、甲基异丙基砜、异丙基仲丁基砜、环丁砜等。
根据本申请的实施例，所述电解液中非水有机溶剂可以使用单非水有机溶剂，也可以使用多种非水有机溶剂混合，当使用混合溶剂时，可以根据期望的电化学装置性能进行控制混合比。
在一些实施例中，其中所述溶剂占所述电解液重量的60％至95％。
二、电化学装置
本申请的电化学装置包括发生电化学反应的任何装置，它的具体实例包括所有种类的一次电池、二次电池、燃料电池、太阳能电池或电容器。特别地，该电化学装置是锂二次电池，包括锂金属二次电池、锂离子二次电池、锂聚合物二次电池或锂离子聚合物二次电池。在一些实施例中，本申请的电化学装置是具备具有能够吸留、放出金属离子的正极活性物质的正极以及具有能够吸留、放出金属离子的负极活性物质的负极的电化学装置，其特征在于，包含本申请的上述任何电解液。
在一些实施例中，所述电化学装置包括正极、负极、隔离膜、以及上述任意一种电解液。
在一些实施例中，其中所述电化学装置满足(Rb-Ra)/Ra小于或等于1；其中Ra是电化学装置在25℃且20％充电状态下循环10次时的直流电阻；Rb是电化学装置在25℃且20％充电状态下循环200次时的直流电阻。
电解液
本申请的电化学装置中使用的电解液为本申请的上述任何电解液。此外，本申请的电化学装置中使用的电解液还可包含不脱离本申请的主旨的范围内的其它电解液。
负极
根据本申请的实施例的电化学装置的负极包括集流体和形成在集流体上的负极活性物质 层，负极活性物质层包括负极活性物质，负极活性物质可以包括可逆地嵌入/脱嵌锂离子的材料、锂金属、锂金属合金、能够掺杂/脱掺杂锂的材料或过渡金属氧化物。可逆地嵌入/脱嵌锂离子的材料可以是碳材料。碳材料可以是在锂离子可再充电电化学装置中通常使用的任何碳基负极活性物质。碳材料的示例包括结晶碳、非晶碳和它们的组合。结晶碳可以是无定形的或板形的、小片形的、球形的或纤维形的天然石墨或人造石墨。非晶碳可以是软碳、硬碳、中间相沥青碳化产物、烧制焦炭等。低结晶碳和高结晶碳均可以用作碳材料。作为低结晶碳材料，可通常包括软碳和硬碳。作为高结晶碳材料，可通常包括天然石墨、结晶石墨、热解碳、中间相沥青基碳纤维、中间相碳微珠、中间相沥青和高温锻烧炭(如石油或衍生自煤焦油沥青的焦炭)。
负极活性物质层包含有粘合剂，且该粘合剂可以包括各种粘合剂聚合物，如二氟乙烯一六氟丙烯共聚物(PVDF-co-HFP)，聚偏二氟乙烯、聚丙烯睛、聚甲基丙烯酸甲醋、聚乙烯醇、羧甲基纤维素、羟丙基纤维素、聚氯乙烯、羧化的聚氯乙烯、聚氟乙烯、含亚乙基氧的聚合物、聚乙烯吡咯烷酮、聚氨酯、聚四氟乙烯、聚乙烯、聚丙烯、丁苯橡胶、丙烯酸(酯)化的丁苯橡胶、环氧树脂、尼龙等，但不限于此等。
负极活性物质层还包括导电材料来改善电极导电率。可以使用任何导电的材料作为该导电材料，只要它不引起化学变化即可。导电材料的示例包括：碳基材料，例如天然石墨、人造石墨、炭黑、乙炔黑、科琴黑、碳纤维等；金属基材料，例如包括铜、镍、铝、银等的金属粉或金属纤维；导电聚合物，例如聚亚苯基衍生物等；或它们的混合物。
其中，锂金属合金包括锂和从Na、K、Rb、Cs、Fr、Be、Mg、Ca、Sr、Si、Sb、Pb、In、Zn、Ba、Ra、Ge、Al或Sn中选择的至少一种金属。能够掺杂/脱掺杂锂的材料的示例包括Si、SiOx(0<x<2)、Si-C复合物、Si-Q合金(其中，Q是碱金属、碱土金属、第13族至第16族元素、过渡元素、稀土元素或它们的组合，但不为Si)、Sn、SnOz、Sn-C复合物、Sn-R(其中，R是碱金属、碱土金属、第13族至第16族元素、过渡元素、稀土元素或它们的组合，但不为Sn)等。Q和R的示例性元素包括Mg、Ca、Sr、Ba、Ra、Sc、Y、Ti、Zr、Hf、Rf、V、Nb、Ta、Db、Cr、Mo、W、Sg、Tc、Re、Bh、Fe、Pb、Ru、Os、Hs、Rh、Ir、Pd、Pt、Cu、Ag、Au、Zn、Cd、B、Al、Ga、Sn、In、Tl、Ge、P、As、Sb、Bi、S、Se、Te、Po或它们的组合。过渡金属氧化物可以为氧化钒、氧化锂钒等。
在一些实施例中，集流体包括，但不限于：铜箔、镍箔、不锈钢箔、钛箔、泡沫镍、泡 沫铜、覆有导电金属的聚合物基底和它们的任意组合。
负极可以通过本领域公知的制备方法制备。例如，负极可以通过如下方法获得：在溶剂中将活性材料、导电材料和粘合剂混合，以制备活性材料组合物，并将该活性材料组合物涂覆在集流体上。
正极
根据本申请的实施例的电化学装置的正极包括集流体和设置在集流体上的正极活性物质层。
在一些实施例中，正极活性物质包括可逆地嵌入和脱嵌锂离子的化合物(即，锂化插层化合物)。正极活性物质可以包括包含锂以及从钴、锰和镍中选择的至少一种的复合氧化物。具体地讲，可以使用下面的化合物：使用LiCoO 2、LiNiO 2、LiMnO 2、LiMn 2O 4、Li(Ni aCo bMn c)O 2(0<a<1，0<b<1，0<c<1，a+b+c＝1)、LiMn 2O 4LiNi 1-yCo yO 2、LiCo l-yMn yO 2、LiNi l-yMn yO 2(0<y<1)、Li(Ni aMn bCo c)04(0<a<2，0<b<2，0<c<2，a+b+c＝2)、LiMn 2-zNi zO 4、LiMn 2-zCo zO 4(0<z<2)、Li(Ni aCo bAl c)O 2(0<a<1，0<b<1，0<c<1，a+b+c＝1)、LiCoPO 4和LiFePO 4中的至少一种或两种以上的混合物，除上述氧化物外，还可以使用硫化物、硒化物和卤化物等。
在一些实施例中，该化合物可以具有位于表面上的包覆层，或者可以与具有包覆层的化合物混合。包覆层可以包括从包覆元素的氧化物、包覆元素的氢氧化物、包覆元素的羟基氧化物、包覆元素的碳酸氧盐(oxycarbonate)和包覆元素的碱式碳酸盐(hydroxyl carbonate)中选择的至少一种包覆元素化合物。用于包覆层的化合物可为非晶的或结晶的。用于包覆层的包覆元素可以包括Mg、Al、Co、K、Na、Ca、Si、Ti、V、Sn、Ge、Ga、B、As、Zr或它们的混合物。可以通过任何方法形成包覆层，只要不会因为在该化合物中包括所述元素而对正极活性物质的性质产生负面影响即可。例如，该方法可以包括对本领域技术人员来讲已知的任何包覆方法，例如喷涂、浸渍等。
在一些实施例中，正极活性物质层可以包括粘结剂和导电材料。粘结剂改善正极活性物质颗粒彼此间以及正极活性物质颗粒与集流体的粘结性能。粘结剂的非限制性示例包括聚乙烯醇、羧甲基纤维素、羟丙基纤维素、二乙酰基纤维素、聚氯乙烯、羧化的聚氯乙烯、聚氟乙烯、含亚乙基氧的聚合物、聚乙烯吡咯烷酮、聚氨酯、聚四氟乙烯、聚偏二氟乙烯、聚乙烯、聚丙烯、丁苯橡胶、丙烯酸(酯)化的丁苯橡胶、环氧树脂、尼龙等。
在一些实施例中，导电材料用于为电极提供导电性。导电材料可以包括任何导电的材料，只要它不引起化学变化即可。导电材料的示例包括诸如下述的导电材料中的一种或混合物：天然石墨；人造石墨；炭黑；乙炔黑；科琴黑；碳纤维；金属粉、金属纤维等，例如铜、镍、铝、银等；或聚亚苯基衍生物等。
在一些实施例中，集流体可以是铝，但不限于此。
正极可以通过本领域公知的制备方法制备。例如，正极可以通过如下方法获得：在溶剂中将活性材料、导电材料和粘合剂混合，以制备活性材料组合物，并将该活性材料组合物涂覆在集流体上。在一些实施例中，溶剂可以包括N-甲基吡咯烷酮等，但不限于此。
在一些实施例中，正极通过在集流体上使用包括锂过渡金属系化合物粉体和粘结剂的正极活性物质层形成正极材料而制成。
在一些实施例中，正极活性物质层通常可以通过如下操作来制作：将正极材料和粘结剂(根据需要而使用的导电材料和增稠剂等)进行干式混合而制成片状，将得到的片压接于正极集流体，或者使这些材料溶解或分散于液体介质中而制成浆料状，涂布在正极集流体上并进行干燥。在一些实施例中，正极活性物质层的材料包括任何本领域公知的材料。
在一些实施例中，所述正极的孔隙率为8％至22％。在一些实施例中，所述正极的孔隙率为8％至18％、9％至17％、10％至16％或12％至14％。在一些实施例中，所述正极的孔隙率为约10％、约11％、约12％、约13％、约14％、约15％、约16％、约18％、约20％、或约22％。
隔离膜
在一些实施例中，本申请的电化学装置在正极与负极之间设有隔离膜以防止短路。本申请的电化学装置中使用的隔离膜的材料和形状没有特别限制，其可为任何现有技术中公开的技术。在一些实施例中，隔离膜包括由对本申请的电解液稳定的材料形成的聚合物或无机物等。
例如隔膜可包括基材层和表面处理层。基材层为具有多孔结构的无纺布、膜或复合膜，基材层的材料选自聚乙烯、聚丙烯、聚对苯二甲酸乙二醇酯和聚酰亚胺中的至少一种。具体的，可选用聚丙烯多孔膜、聚乙烯多孔膜、聚丙烯无纺布、聚乙烯无纺布或聚丙烯-聚乙烯- 聚丙烯多孔复合膜。
基材层的至少一个表面上设置有表面处理层，表面处理层可以是聚合物层或无机物层，也可以是混合聚合物与无机物所形成的层。
无机物层包括无机颗粒和粘结剂，无机颗粒选自氧化铝、氧化硅、氧化镁、氧化钛、二氧化铪、氧化锡、二氧化铈、氧化镍、氧化锌、氧化钙、氧化锆、氧化钇、碳化硅、勃姆石、氢氧化铝、氢氧化镁、氢氧化钙和硫酸钡中的一种或几种的组合。粘结剂选自聚偏氟乙烯、偏氟乙烯-六氟丙烯的共聚物、聚酰胺、聚丙烯腈、聚丙烯酸酯、聚丙烯酸、聚丙烯酸盐、聚乙烯呲咯烷酮、聚乙烯烷氧、聚甲基丙烯酸甲酯、聚四氟乙烯和聚六氟丙烯中的一种或几种的组合。
聚合物层中包含聚合物，聚合物的材料选自聚酰胺、聚丙烯腈、丙烯酸酯聚合物、聚丙烯酸、聚丙烯酸盐、聚乙烯呲咯烷酮、聚乙烯烷氧、聚偏氟乙烯、聚(偏氟乙烯-六氟丙烯)中的至少一种
在一些实施例中，本申请的实施例的电化学装置的隔离膜包括聚烯烃类微多孔膜和涂层，所述的涂层包括有机涂层和无机涂层，其中，有机涂层选自聚偏氟乙烯、偏氟乙烯-六氟丙烯共聚物、聚丙烯腈、聚酰亚胺、丙烯腈-丁二烯共聚物、丙烯腈-苯乙烯-丁二烯共聚物、聚甲基丙烯酸甲酯、聚丙烯酸甲酯、聚丙烯酸乙酯、丙烯酸-苯乙烯共聚物、聚二甲基硅氧烷、聚丙烯酸钠、羧甲基纤维素钠中的至少一种，无机涂层选自SiO 2、Al 2O 3、CaO、TiO 2、ZnO 2、MgO、ZrO 2以及SnO 2中的一种或几种；所述聚合物粘结剂选自聚偏二氟乙烯。
根据本申请的实施例的电化学装置的隔离膜，所述的隔膜选自聚乙烯(PE)、乙烯-丙烯共聚物、聚丙烯(PP)、乙烯-丁烯共聚物、乙烯-己烯共聚、乙烯-甲基丙烯酸甲酯共聚物中的一种或多种组成的单层或多层的聚烯烃类微多孔膜。
三、应用
根据本申请实施例的电解液，能够改善电化学装置的高温循环性能、高温存储性能和动力学，且具有更高的安全性，使得由此制造的电化学装置适用于各种领域的电子设备。
本申请的电化学装置的用途没有特别限定，可以用于公知的各种用途。例如：笔记本电脑、笔输入型计算机、移动电脑、电子书播放器、便携式电话、便携式传真机、便携式复印 机、便携式打印机、头戴式立体声耳机、录像机、液晶电视、手提式清洁器、便携CD机、迷你光盘、收发机、电子记事本、计算器、存储卡、便携式录音机、收音机、备用电源、电机、汽车、摩托车、助力自行车、自行车、照明器具、玩具、游戏机、钟表、电动工具、闪光灯、照相机、家庭用大型蓄电池或锂离子电容器等。
四、实施例
以下，举出实施例和比较例对本申请进一步具体地进行说明，但只要不脱离其主旨，则本申请并不限定于这些实施例。
1.锂离子电池的制备
(1)负极的制备
将人造石墨、丁苯橡胶(SBR)、羧甲基纤维素钠(CMC)按重量比97.4:1.4:1.2分散于适量的去离子水中，充分搅拌形成均匀的负极浆料；将负极浆料涂覆负极集流体铜箔上，然后经过烘干、冷压，得到负极。
(2)正极的制备
对比例1至6和实施例1至实施例67中正极的制备方法如下：
称取正极活性物质钴酸锂(LiCoO 2)、导电碳黑、导电浆料、粘结剂聚偏二氟乙烯(PVDF)按重量比97.9:0.4:0.5:1.2分散在适量的N-甲基吡咯烷酮(NMP)溶剂中充分搅拌混合，使其形成均匀的正极浆料；将此浆料涂覆于正极集流体铝箔上，烘干、冷压，得到正极。设置辊压强度，调整所述正极孔隙率介于8-22％之间。
其它类型正极的制备
除上述方法，还可以采用其它方法制备适用于本发明技术方案的正极。例如，可以选用下述a或b方法：
a.将正极活性物质NCM811(LiNi 0.8Mn 0.1Co 0.1O 2)、导电剂乙炔黑、粘结剂聚偏二氟乙烯(PVDF)按重量比96:2:2分散在适量的N-甲基吡咯烷酮(NMP)溶剂中充分搅拌混合，使其形成均匀的正极浆料；将此浆料涂覆于正极集流体铝箔上，烘干、冷压，得到正极。
b.将正极活性物质NCM523(LiNi 0.5Mn 0.3Co 0.2O 2)、导电碳黑-L、导电浆料、粘结剂聚偏二氟乙烯(PVDF)按重量比96:2:0.8:1.2分散在适量的N-甲基吡咯烷酮(NMP)溶剂中充分搅拌混合，使其形成均匀的正极浆料；将此浆料涂覆于正极集流体铝箔上，烘干、冷压，得到正极。
(3)电解液的制备
在含水量<10ppm的氩气气氛手套箱中，将碳酸乙烯酯(EC)、碳酸丙烯酯(PC)、碳酸二乙酯(DEC)按照3:3:4的质量比混合均匀，再将充分干燥的锂盐LiPF 6溶解于上述非水溶剂，最后加入一定量的添加剂，配成电解液。添加物质的种类和量如下表中所示，各物质的含量基于电解液的总重量计算得到。其中LiPF 6的浓度为1mol/L。
(4)隔离膜的制备
选用12微米厚的聚乙烯隔离膜。
(5)锂离子电池的制备
将正极、隔离膜、负极按顺序叠好，使隔离膜处于正极和负极之间起到隔离的作用，然后卷绕得到裸电池；将裸电池置于外包装箔中，将上述制备好的电解液注入到干燥后的电池中，经过真空封装、静置、化成、整形等工序，即完成锂离子电池的制备。
2.锂离子电池的性能测试
(Ⅰ)循环测试：
将锂离子电池置于25摄氏度恒温箱中，静置30分钟，使锂离子电池达到恒温；0.7C恒流充电至4.45V，恒压充电至电流为0.05C；0.7C放电至3.0V，以此步容量为基准C 0；此步骤循环1000次，记录1000次循环容量为C 1，计算容量保持率。
1000次循环后容量保持率＝C 1/C 0×100％
(Ⅱ)低温放电测试
将锂离子电池置于高低温箱中，调整炉温至25摄氏度，静置5分钟，使锂离子电池达到恒温。将达到恒温的锂离子电池以0.5C恒流充电至电压4.45V，然后以4.45V恒压充电至电流为0.05C，接着以0.2C恒流放电至电压为3.4V，此步容量作为基准C 2。25摄氏 度条件下将电池以0.5C恒流充电至4.45V，然后以4.45V恒压充电至电流为0.05C。调节炉温至-10摄氏度，电池在箱内静置60分钟后，在以0.2C的电流恒流放电至电压为3.4V，记录此时放出的容量C 3。
-10摄氏度下的放电容量保持率＝C 3/C 2×100％
(Ⅲ)直流阻抗(DCR)测试(0摄氏度下)
1)将锂离子电池在0摄氏度高低温箱中静置4小时；
2)0.1C恒流充至4.45V，恒压截止至0.05C,静置10分钟；
3)0.1C放电到3.4V，静置5分钟(此步得到实际容量)。
4)静置5分钟，0.1C恒流充至4.45V，恒压截止至0.05C(用第3步得到的实际容量计算)。
5)静置10分钟。
6)0.1C放电8小时(用第3步得到的实际容量计算)，记录此时的电压为V 1。
7)1C放电1秒(容量以电池标注容量计算)，记录此时的电压为V 2。
8)计算电池20％充电状态(SOC)对应的直流阻抗，单位为毫欧姆(mOhm)：
20％SOC直流阻抗＝(V 1-V 2)/1C
(Ⅳ)85℃存储电池膨胀率
将锂离子电池在25℃下以0.5C放电至3.0V，再以0.7C充电至4.45V，4.45V下恒压充电至0.05C，用千分尺测试并记录电池的厚度记为H 11,放置到85℃烘箱当中，4.45V恒压24小时，24小时结束后用千分尺测试并记录电池的厚度，记为H 12。
厚度膨胀率＝(H 12-H 11)/H 11x 100％
A.按照上述方法制备实施例1至23和对比例1至6的电解液以及锂离子电池。电解液成分及测试结果请见表1和表2。
表1
Figure PCTCN2020082574-appb-000025
注：“/”代表未添加，实施例1至实施例23、对比例1至对比例6的正极孔隙率为14％
表2
Figure PCTCN2020082574-appb-000026
通过实施例1-23和对比例1-6可以看出，电解液中同时添加特定含量的式I化合物及添加剂A与未加入这两种化合物的情况或仅加入这两者之一的情况相比，可以在有效改善电池低温放电容量和降低阻抗的同时改善循环性能。
B.按照上述方法制备实施例3及24至36的电解液以及锂离子电池。电解液成分及测试结果请见表3和表4。
表3
Figure PCTCN2020082574-appb-000027
注：“/”代表未添加；实施例20至36和对比例10至13的正极孔隙率为14％
表4
Figure PCTCN2020082574-appb-000028
通过表3和表4的实施例可以看出，在含有式I化合物及添加剂A的电解液中进一步加入式Ⅱ化合物(添加剂B)可在改善高温存储性能的同时改善电池阻抗和循环性能。
C.按照上述方法制备实施例3及实施例37至50的电解液以及锂离子电池。电解液成分及测试结果请见表5和表6。
表5
Figure PCTCN2020082574-appb-000029
注：“/”代表未添加；实施例37至50的正极孔隙率为14％
表6
Figure PCTCN2020082574-appb-000030
通过表5和表6的实施例可以看出，在含有式I化合物及添加剂A的电解液中进一步加入式III化合物(添加剂C)或进一步加入式II化合物(添加剂B)和式III化合物(添加剂C)均可提升高温存储性能、同时改善循环性能和降低电池阻抗。
D.按照上述方法制备实施例3及实施例51至63的电解液以及锂离子电池。电解液成分及测试结果请见表7和表8。
表7
Figure PCTCN2020082574-appb-000031
表8
Figure PCTCN2020082574-appb-000032
通过表7和表8的实施例可以看出，在含有式I化合物及添加剂A的电解液中进一步加 入式IV化合物(添加剂D)、或进一步加入式IV化合物(添加剂D)与式II化合物(添加剂B)或式III化合物(添加剂C)中至少一者的组合，可以提升高温存储性能、同时改善循环性能和降低电池低温阻抗。
综上，以上实施例表明本发明提供的电解液能够改善电化学装置的低温放电性能、常温循环性能、高温存储性能、并降低电化学装置的低温阻抗。
E.按照上述方法制备实施例3、实施例18、实施例64至67的电解液以及锂离子电池。正极孔隙率、电解液成分及测试结果请见表9和表10。
表9
Figure PCTCN2020082574-appb-000033
表10
Figure PCTCN2020082574-appb-000034
通过表9和表10实施例可以看出，控制正极孔隙率在合适范围内可进一步改善电化学装置的循环性能和高温存储性能。
以上所述，仅是本发明的几个实施例，并非对本发明做任何形式的限制，虽然本发明以 较佳实施例揭示如上，然而并非用以限制本发明，任何熟悉本专业的技术人员，在不脱离本发明技术方案的范围内，利用上述揭示的技术内容做出些许的变动或修饰均等同于等效实施案例，均属于技术方案范围内。
整个说明书中对“一些实施例”、“部分实施例”、“一个实施例”、“另一举例”、“举例”、“具体举例”或“部分举例”的引用，其所代表的意思是在本申请中的至少一个实施例或举例包含了该实施例或举例中所描述的特定特征、结构、材料或特性。因此，在整个说明书中的各处所出现的描述，例如：“在一些实施例中”、“在实施例中”、“在一个实施例中”、“在另一个举例中”，“在一个举例中”、“在特定举例中”或“举例”，其不必然是引用本申请中的相同的实施例或示例。此外，本文中的特定特征、结构、材料或特性可以以任何合适的方式在一个或多个实施例或举例中结合。尽管已经演示和描述了说明性实施例，本领域技术人员应该理解上述实施例不能被解释为对本申请的限制，并且可以在不脱离本申请的精神、原理及范围的情况下对实施例进行改变，替代和修改。

Claims (12)

  1. 一种电解液，其包含式I化合物及添加剂A，
    Figure PCTCN2020082574-appb-100001
    其中，
    R 1至R 8各自独立地选自:H、卤素、-COOX、经取代或未经取代的C 1-8烷基、经取代或未经取代的C 2-10烯基、经取代或未经取代的C 2-10炔基、经取代或未经取代的C 1-8烷氧基或-R a-S(＝O) 2-R b；其中R a选自经取代或未经取代的C 1-8亚烷基，R b选自卤素或经取代或未经取代的C 1-8烷基，且R 1至R 8中的至少一者为-COOX；
    经取代时取代基选自氰基或卤素；
    X选自Li +、Na +、K +或Rb +；
    添加剂A选自氟代碳酸乙烯酯、LiPO 2F 2或碳酸亚乙烯酯中的至少一种。
  2. 根据权利要求1所述的电解液，其中所述式I化合物选自如下化合物中的至少一种：
    Figure PCTCN2020082574-appb-100002
    Figure PCTCN2020082574-appb-100003
  3. 根据权利要求1所述的电解液，其中所述式I化合物与所述添加剂A的重量比为30:1至1:200。
  4. 根据权利要求1所述的电解液，其中所述式I化合物占所述电解液总重量的0.05％至5％，所述添加剂A占所述电解液总重量的0.01％至16％。
  5. 根据权利要求1所述的电解液，其进一步包含式Ⅱ化合物：
    Figure PCTCN2020082574-appb-100004
    其中，
    R 9选自氢、氰基、卤素、经取代或未经取代的C 1-8烷基、或经取代或未经取代的C 1-8烷氧基；
    R 10至R 12各自独立选自共价键、经取代或未经取代的C 1-8亚烷基、或-O-R'-，其中R'为经取代或未经取代的C 1-8亚烷基；
    经取代时取代基选自氰基或卤素；
    其中，所述式Ⅱ化合物占所述电解液总重量的0.05％至10％。
  6. 根据权利要求5所述的电解液，其中所述式Ⅱ化合物包含
    Figure PCTCN2020082574-appb-100005
    Figure PCTCN2020082574-appb-100006
    中的至少一种。
  7. 根据权利要求1所述的电解液，其进一步包含式III化合物：
    Figure PCTCN2020082574-appb-100007
    其中，R 13、R 14及R 15各自独立地选自于经取代或未经取代的C 1-8烷基、或-R c-S(＝O) 2-R d；其中R c选自经取代或未经取代的C 1-8亚烷基，R d选自卤素、或经取代或未经取代的C 1-8烷基；其中经取代时是经一个或多个卤素取代；
    其中，所述式III化合物占所述电解液总重量的0.1％至20％。
  8. 根据权利要求7所述的电解液，其中所述式III化合物包含:
    Figure PCTCN2020082574-appb-100008
    Figure PCTCN2020082574-appb-100009
    中的至少一种。
  9. 根据权利要求1-8中任一权利要求所述的电解液，其进一步包含式IV化合物，
    Figure PCTCN2020082574-appb-100010
    R 41和R 42各自独立选自经取代或未经取代的C 1-10烷基；其中经取代时是经一个或多个选自F、Cl或Br的取代基取代，其中，所述式IV化合物占所述电解液总重量的5％至50％。
  10. 根据权利要求9所述的电解液，其中所述式Ⅳ化合物包含：
    Figure PCTCN2020082574-appb-100011
    Figure PCTCN2020082574-appb-100012
    中的至少一种。
  11. 一种电化学装置，其包括正极、负极以及根据权利要求1-10中任一权利要求所述的电解液。
  12. 一种电子装置，其包括根据权利要求11所述的电化学装置。
PCT/CN2020/082574 2020-03-31 2020-03-31 一种电解液及电化学装置 Ceased WO2021196019A1 (zh)

Priority Applications (3)

Application Number Priority Date Filing Date Title
US17/054,053 US12119446B2 (en) 2020-03-31 2020-03-31 Electrolyte and electrochemical device
CN202080003789.XA CN112368872A (zh) 2020-03-31 2020-03-31 一种电解液及电化学装置
PCT/CN2020/082574 WO2021196019A1 (zh) 2020-03-31 2020-03-31 一种电解液及电化学装置

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/CN2020/082574 WO2021196019A1 (zh) 2020-03-31 2020-03-31 一种电解液及电化学装置

Publications (1)

Publication Number Publication Date
WO2021196019A1 true WO2021196019A1 (zh) 2021-10-07

Family

ID=74535026

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2020/082574 Ceased WO2021196019A1 (zh) 2020-03-31 2020-03-31 一种电解液及电化学装置

Country Status (3)

Country Link
US (1) US12119446B2 (zh)
CN (1) CN112368872A (zh)
WO (1) WO2021196019A1 (zh)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116072971B (zh) * 2023-04-03 2023-07-18 宁德新能源科技有限公司 电解液和电化学装置

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0765863A (ja) * 1993-08-24 1995-03-10 Fuji Photo Film Co Ltd 非水電池
CN101640290A (zh) * 2008-08-01 2010-02-03 三洋电机株式会社 非水电解质二次电池
CN102324565A (zh) * 2011-09-05 2012-01-18 厦门华戎能源科技有限公司 一种电解液添加剂及含有该添加剂的电解液和锂离子电池
CN105914401A (zh) * 2016-06-27 2016-08-31 宁德时代新能源科技股份有限公司 一种电解液以及包含该电解液的锂离子电池

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106207258B (zh) * 2016-08-30 2019-06-25 中盐安徽红四方锂电有限公司 一种低温锂电池的电解液
CN107946636A (zh) 2017-10-26 2018-04-20 北京大学深圳研究生院 一种固体电解质材料、固态电池及其应用
CN109687022B (zh) 2018-12-25 2020-12-01 杉杉新材料（衢州）有限公司 一种含氟溶剂和吡啶类添加剂的电解液及使用该电解液的锂离子电池
CN111933946B (zh) * 2019-03-18 2022-03-18 宁德新能源科技有限公司 电化学装置及包含其的电子装置
CN112234209B (zh) 2019-06-03 2021-11-23 宁德新能源科技有限公司 电化学装置
CN110190332B (zh) * 2019-06-20 2020-02-11 东莞东阳光科研发有限公司 高镍三元正极材料体系电池用电解液及锂离子电池

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0765863A (ja) * 1993-08-24 1995-03-10 Fuji Photo Film Co Ltd 非水電池
CN101640290A (zh) * 2008-08-01 2010-02-03 三洋电机株式会社 非水电解质二次电池
CN102324565A (zh) * 2011-09-05 2012-01-18 厦门华戎能源科技有限公司 一种电解液添加剂及含有该添加剂的电解液和锂离子电池
CN105914401A (zh) * 2016-06-27 2016-08-31 宁德时代新能源科技股份有限公司 一种电解液以及包含该电解液的锂离子电池

Also Published As

Publication number Publication date
CN112368872A (zh) 2021-02-12
US20230104300A1 (en) 2023-04-06
US12119446B2 (en) 2024-10-15

Similar Documents

Publication Publication Date Title
CN110994018B (zh) 一种电解液及电化学装置
KR102677615B1 (ko) 전해액 및 전기화학장치
WO2021223181A1 (zh) 一种电解液及电化学装置
CN113078361B (zh) 一种电解液及电化学装置
WO2022133836A1 (zh) 电解液、电化学装置及电子装置
CN111370695A (zh) 负极活性材料及使用其的电化学装置和电子装置
WO2021218267A1 (zh) 一种电解液及电化学装置
CN112400249A (zh) 一种电解液及电化学装置
CN111430795B (zh) 一种电化学装置及包括其的电子装置
CN110854432A (zh) 电解液以及使用其的电化学装置和电子装置
CN112335090A (zh) 电解液和使用其的电化学装置
CN111697267A (zh) 电解液和包含电解液的电化学装置及电子装置
CN116508189B (zh) 电解液及包括其的电化学装置和电子装置
CN112103561A (zh) 一种电解液及电化学装置
WO2023078059A1 (zh) 电解液以及使用其的电化学装置和电子装置
CN112055910B (zh) 一种电解液及电化学装置
WO2021128203A1 (zh) 一种电解液及电化学装置
US12119446B2 (en) Electrolyte and electrochemical device
CN117175013A (zh) 一种电解液及使用其的电化学装置和电子装置
CN116454400A (zh) 电化学装置和包括其的电子装置
WO2021195965A1 (zh) 一种电化学装置及包括其的电子装置
CN116053461B (zh) 电化学装置和包括其的电子装置
JP7515960B2 (ja) 非水電解液およびそれを含むリチウム二次電池
CN118117164A (zh) 电解液及电化学装置
CN116979145A (zh) 电解液、电化学装置及电子装置

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 20929165

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 20929165

Country of ref document: EP

Kind code of ref document: A1