WO2023087223A1 - Electrolyte, electrochemical device containing same, and electronic device - Google Patents

Electrolyte, electrochemical device containing same, and electronic device Download PDF

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Publication number
WO2023087223A1
WO2023087223A1 PCT/CN2021/131558 CN2021131558W WO2023087223A1 WO 2023087223 A1 WO2023087223 A1 WO 2023087223A1 CN 2021131558 W CN2021131558 W CN 2021131558W WO 2023087223 A1 WO2023087223 A1 WO 2023087223A1
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Prior art keywords
formula
lithium
electrolyte
substituted
unsubstituted
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PCT/CN2021/131558
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French (fr)
Chinese (zh)
Inventor
彭谢学
唐超
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宁德新能源科技有限公司
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Priority to PCT/CN2021/131558 priority Critical patent/WO2023087223A1/en
Priority to CN202180007386.7A priority patent/CN114846668B/en
Publication of WO2023087223A1 publication Critical patent/WO2023087223A1/en

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
    • H01M10/0564—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes the electrolyte being constituted of organic materials only
    • H01M10/0566—Liquid materials
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M2300/00—Electrolytes
    • H01M2300/0017—Non-aqueous electrolytes
    • H01M2300/0025—Organic electrolyte
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Definitions

  • the present application relates to the technical field of electrochemistry, and in particular to an electrolytic solution and electrochemical devices and electronic devices containing the electrolytic solution.
  • Lithium-ion batteries have the advantages of high energy storage density, high open circuit voltage, low self-discharge rate, long cycle life, and good safety. They have been widely used as power sources in cameras, mobile phones, drones, laptops, and smart watches product.
  • the purpose of the present application is to provide an electrolytic solution, an electrochemical device and an electronic device containing the electrolytic solution, so as to improve the high-temperature storage performance and cycle performance of the electrochemical device.
  • the first aspect of the present application provides an electrolyte, which includes the cyano compound represented by formula (I) and formula (II):
  • A is independently selected from formula (I-A) or formula (II-A),
  • n are each independently selected from 0 or 1;
  • R 1 , R 11 , R 12 , R 13 , R 14 , R 15 , R 16 , R 17 , R 18 , R 19 are each independently selected from covalent single bonds, substituted or unsubstituted C 1 to C 10 Alkylene or heterocyclylene, substituted or unsubstituted C 2 to C 10 alkenylene or alkynylene, substituted or unsubstituted C 3 to C 10 allenylene or alicyclic hydrocarbon group, In the substituted or unsubstituted C6 to C10 arylene group, the substituents of each group are independently selected from fluorine, chlorine, bromine or iodine.
  • the compound represented by the formula (I) comprises at least one of the following compounds:
  • the compound represented by the formula (II) comprises at least one of the following compounds:
  • the mass percentage of the compound represented by formula (I) is W 1
  • the mass percentage of the compound represented by formula (II) is W 2 satisfies: 0.01% ⁇ W 1 ⁇ 5%, 0.001% ⁇ W 2 ⁇ 5%, 0.1% ⁇ W 1 +W 2 ⁇ 5%.
  • the electrolyte also includes polynitrile compounds, and the polynitrile compounds include at least one of the following compounds:
  • the mass percentage of the compound represented by the formula (I) is W 1
  • the mass percentage of the compound represented by the formula (II) The percentage content is W 2
  • the mass percentage content of the polynitrile compound is W 3 , satisfying: 0.5% ⁇ W 3 ⁇ 7%, 0.01 ⁇ (W 1 +W 2 )/W 3 ⁇ 1.
  • the electrolytic solution further includes a boron-based lithium salt compound
  • the boron-based lithium salt compound includes lithium tetrafluoroborate (LiBF 4 ), lithium dioxalate borate (LiBOB) or bis At least one of lithium fluorooxalate borate (LiDFOB).
  • the mass percentage W 4 of the boron-based lithium salt compound is 0.1% to 1%.
  • the electrolyte solution further includes a P-O bond compound
  • the P-O bond compound includes lithium difluorophosphate, lithium difluorobisoxalate phosphate, lithium tetrafluorooxalate phosphate, 1, 2-bis((difluorophosphino)oxy)ethane, trimethylphosphate, triphenylphosphate, triisopropylphosphate, 3,3,3-trifluoroethylphosphate, 3, 3,3-trifluoroethyl phosphite, tris(trimethylsilyl) phosphate, 2-(2,2,2-trifluoroethoxy)-1,3,2-dioxaphosphorane2 - at least one of oxides.
  • the mass percentage W 5 of the PO bond compound is 0.1% to 1%.
  • the electrolyte further includes a sulfur-oxygen double bond compound, and the sulfur-oxygen double bond compound includes at least one of the compounds represented by formula (IV):
  • A is selected from at least one of formula (IV-A), formula (IV-B), formula (IV-C), formula (IV-D), and formula (IV-E):
  • R 41 and R 42 are each independently selected from a covalent bond, a substituted or unsubstituted C 1 to C 5 alkyl or alkylene group, a substituted or unsubstituted C 1 to C 6 heterocyclic group, a substituted or unsubstituted Substituted C 2 to C 10 alkenyl or alkynyl, substituted or unsubstituted C 3 to C 10 alicyclic group, and R 41 and R 42 may be connected to form a ring;
  • R 43 is selected from a covalent bond, a substituted or unsubstituted C 1 to C 3 alkylene group, a substituted or unsubstituted C 2 to C 3 alkenylene or alkynylene group;
  • the substituent is selected from halogen, substituted or unsubstituted C1 to C3 alkyl, substituted or unsubstituted C2 to C3 alkenyl, substituted or unsubstituted C2 to C3 alkynyl;
  • heteroatom is selected from at least one of N, O or S;
  • the mass percentage W 6 of the compound represented by the formula (IV) is 0.1% to 8%.
  • the compound represented by formula (IV) comprises at least one of the following compounds:
  • the electrolyte also includes a cyclic carbonate compound, and the cyclic carbonate compound includes at least one of the following compounds:
  • the mass percentage W 7 of the cyclic carbonate compound is 0.1% to 10%
  • the electrolyte solution contains lithium salts, and the lithium salts include lithium hexafluorophosphate, lithium tetrafluoroborate, lithium bisoxalate borate, lithium difluorooxalate borate, lithium hexafluoroantimonate, lithium hexafluoroarsenate, lithium perfluorobutyl sulfonate , lithium perchlorate, lithium aluminate, lithium tetrachloroaluminate, lithium bissulfonylimide (LiN(C x F 2x+1 SO 2 )(C y F 2y+1 SO 2 ), where x is 0 to 10, y is a natural number from 0 to 10), at least one of lithium chloride and lithium fluoride, based on the total mass of the electrolyte, the mass percentage W of the lithium salt is 10% to 8 20%.
  • the lithium salts include lithium hexafluorophosphate, lithium tetrafluoroborate, lithium biso
  • the second aspect of the present application provides an electrochemical device, which includes the electrolyte solution provided in the first aspect of the present application.
  • the third aspect of the present application provides an electronic device, which includes the electrochemical device provided in the second aspect of the present application.
  • the present application provides an electrolytic solution and an electrochemical device and an electronic device containing the electrolytic solution, wherein the electrolytic solution includes cyano compounds represented by formula (I) and formula (II).
  • the electrolytic solution includes cyano compounds represented by formula (I) and formula (II).
  • Adding the cyano compound represented by formula (I) and formula (II) to the electrolyte can not only stabilize the transition metal in the positive and extremely high valence state, but also absorb the oxygen released from the positive electrode and inhibit the continuous decomposition of the electrolyte; it can also be used on the positive and negative electrodes Form an interface protective film to protect the surface of the positive and negative electrodes, thereby significantly improving the high-temperature storage performance and cycle performance of the electrochemical device.
  • An electronic device including the electrochemical device also has good high-temperature storage performance and cycle performance.
  • a lithium-ion battery is used as an example of an electrochemical device to explain the present application, but the electrochemical device of the present application is not limited to the lithium-ion battery. It should be understood by those skilled in the art that the following description is only for illustration and does not limit the protection scope of the present application.
  • the first aspect of the present application provides an electrolyte, which includes the cyano compound represented by formula (I) and formula (II):
  • A is independently selected from formula (I-A) or formula (II-A),
  • n are each independently selected from 0 or 1;
  • R 1 , R 11 , R 12 , R 13 , R 14 , R 15 , R 16 , R 17 , R 18 , R 19 are each independently selected from covalent single bonds, substituted or unsubstituted C 1 to C 10 Alkylene or heterocyclylene, substituted or unsubstituted C 2 to C 10 alkenylene or alkynylene, substituted or unsubstituted C 3 to C 10 allenylene or alicyclic hydrocarbon group, In the substituted or unsubstituted C 6 to C 10 arylene group, the substituents of each group are independently selected from fluorine, chlorine, bromine or iodine.
  • the cyano compounds represented by formula (I) and formula (II) in the present application have different spatial structures of cyano compound molecules with different numbers of cyano groups, and thus have different improvement effects on electrochemical devices.
  • the cyano compound represented by formula (I) and formula (II) is added to the electrolyte, which can stabilize the transition metal in the positive high-valence state, absorb the oxygen released from the positive electrode, and inhibit the continuous decomposition of the electrolyte.
  • the negative electrode forms an interface protective film to protect the surface of the positive and negative electrodes, thereby improving the high-temperature storage performance and cycle performance of the electrochemical device.
  • the compound represented by the formula (I) comprises at least one of the following compounds:
  • the compound represented by the formula (II) comprises at least one of the following compounds:
  • the electrolyte contains at least one of the compounds of formula (I-1) to formula (I-9), so that the compounds represented by formula (I) with different structures act together, In order to further improve the cycle performance and high-temperature storage performance of the electrochemical device without affecting other performances.
  • the electrolyte contains at least one of the compounds of formula (II-1) to formula (II-16), so that the compounds represented by formula (II) with different structures act together, In order to further improve the cycle performance and high-temperature storage performance of the electrochemical device without affecting other performances.
  • the mass percentage of the compound represented by formula (I) is W 1
  • the mass percentage of the compound represented by formula (II) is W 2 satisfies: 0.01% ⁇ W 1 ⁇ 5%, 0.001% ⁇ W 2 ⁇ 5%, 0.1% ⁇ W 1 +W 2 ⁇ 5%.
  • the value of W1 can be 0.01%, 0.05%, 0.1%, 0.5%, 1.5%, 3%, 5% or any value between the above-mentioned any two numerical ranges;
  • the value of W2 can be 0.001%, 0.005%, 0.01%, 0.05%, 0.1%, 0.5%, 1.5%, 3%, 5%, or any value between any two value ranges above;
  • W 1 +W 2 must satisfy 0.1% ⁇ W 1 + W 2 ⁇ 5%
  • the value of W 1 +W 2 can be 0.1%, 0.15%, 0.2%, 0.5%, 1%, 2.1%, 2.5%, 3.5%, 4%, 4.5%, 5% or any of the above Any value between the two value ranges.
  • the electrolyte also includes polynitrile compounds, and the polynitrile compounds include at least one of the following compounds:
  • the cycle performance and high-temperature storage performance of the electrochemical device can be further improved.
  • the mass percentage of the compound represented by the formula (I) is W 1
  • the mass percentage of the compound represented by the formula (II) The percentage content is W 2
  • the mass percentage content of the polynitrile compound is W 3 , satisfying: 0.5% ⁇ W 3 ⁇ 7%, 0.01 ⁇ (W 1 +W 2 )/W 3 ⁇ 1.
  • the value of the mass percent content W of described polynitrile compound can be 0.5%, 1%, 1.5%, 2% , 3%, 4%, 4.5%, 5%, 5.5%, 6, 6.5%, 7% % or any value between any two value ranges above.
  • the electrolytic solution further includes a boron-based lithium salt compound
  • the boron-based lithium salt compound includes lithium tetrafluoroborate (LiBF 4 ), lithium dioxalate borate (LiBOB) or bis At least one of lithium fluorooxalate borate (LiDFOB).
  • LiBF 4 lithium tetrafluoroborate
  • LiBOB lithium dioxalate borate
  • LiDFOB bis At least one of lithium fluorooxalate borate
  • a stable solid electrolyte interface (SEI) film can also be formed on the negative electrode to prevent the transition metals dissolved in the positive electrode from damaging the negative electrode.
  • SEI solid electrolyte interface
  • the mass percentage W 4 of the boron-based lithium salt compound is 0.1% to 1%.
  • the value of W 4 may be 0.1%, 0.2%, 0.3%, 0.5%, 0.8%, 1%, or any value between any two value ranges mentioned above.
  • the mass percentage W of the boron-type lithium salt compound is too high (for example, higher than 1%), it is difficult to be completely consumed in the formation stage of the electrochemical device, and a large amount of gas is generated during the storage of the electrochemical device, which affects the electrochemical device. high temperature storage performance. By controlling the value of W4 within the above range, the cycle performance and high-temperature storage performance of the electrochemical device can be effectively improved.
  • the electrolyte solution further includes a PO bond compound
  • the PO bond compound includes lithium difluorophosphate (LiPO 2 F 2 ), lithium difluorobisoxalate phosphate (LiDFOP) , lithium tetrafluorooxalate phosphate (LiTFOP), 1,2-bis((difluorophosphino)oxy)ethane, trimethyl phosphate, triphenyl phosphate, triisopropyl phosphate, 3,3 ,3-Trifluoroethyl phosphate, 3,3,3-trifluoroethyl phosphite, tris(trimethylsilane) phosphate, 2-(2,2,2-trifluoroethoxy)- At least one of 1,3,2-dioxaphosphane 2-oxides.
  • the contact between the electrolyte and the positive and negative electrodes can be reduced, and gas production
  • the mass percentage W 5 of the PO bond compound is 0.1% to 1%.
  • the electrolyte further includes a sulfur-oxygen double bond compound, and the sulfur-oxygen double bond compound includes at least one of the compounds represented by formula (IV):
  • A is selected from at least one of formula (IV-A), formula (IV-B), formula (IV-C), formula (IV-D), and formula (IV-E):
  • R 41 and R 42 are each independently selected from a covalent bond, a substituted or unsubstituted C 1 to C 5 alkyl or alkylene group, a substituted or unsubstituted C 1 to C 6 heterocyclic group, a substituted or unsubstituted Substituted C 2 to C 10 alkenyl or alkynyl, substituted or unsubstituted C 3 to C 10 alicyclic group, and R 41 and R 42 may be connected to form a ring;
  • R 43 is selected from a covalent bond, a substituted or unsubstituted C 1 to C 3 alkylene group, a substituted or unsubstituted C 2 to C 3 alkenylene or alkynylene group;
  • the substituent is selected from halogen, substituted or unsubstituted C1 to C3 alkyl, substituted or unsubstituted C2 to C3 alkenyl, substituted or unsubstituted C2 to C3 alkynyl;
  • heteroatom is selected from at least one of N, O or S;
  • the mass percentage W 6 of the compound represented by the formula (IV) is 0.1% to 8%.
  • the value of W6 can be 0.1%, 0.3%, 0.5%, 1%, 1.5%, 2%, 3%, 5%, 6%, 7%, 7.5%, 8%, or any two of the above numerical ranges Any value in between, for example, can be 1.5% to 6%.
  • the mass percentage W of the compound represented by formula (IV) is too high (such as higher than 8%), and it is easy to form an acidic substance, corrode the positive electrode electrolyte interface (CEI) film and the positive electrode material layer, and affect the stability of the positive electrode material structure. And then affect the cycle performance of the electrochemical device.
  • CEI positive electrode electrolyte interface
  • the sulfur-oxygen double bond compound has strong anti-oxidation ability, can protect the stability of the positive electrode interface, and can also be reduced on the surface of the negative electrode to form a protective film, inhibit the decomposition of the electrolyte, and further enhance the stability of the interface. performance, thereby further improving the high-temperature storage performance and cycle performance of the electrochemical device.
  • the compound represented by formula (IV) comprises at least one of the following compounds:
  • the electrolyte solution of the present application contains at least one of the compound formula (IV-1) to formula (IV-41), so that the sulfur-oxygen double bond compounds with different structures can work together to further Improve cycle performance and high-temperature storage performance of electrochemical devices.
  • the electrolyte also includes a cyclic carbonate compound, and the cyclic carbonate compound includes at least one of the following compounds:
  • the mass percentage W 7 of the cyclic carbonate compound is 0.1% to 10%.
  • the value of W7 can be 0.1%, 0.5%, 1%, 1.5%, 2%, 3%, 5%, 6%, 7%, 8%, 8.5%, 9%, 10%, or any two of the above Any value within a range of values, for example, may be 1% to 6%.
  • the cyclic carbonate compounds can enhance the stability of SEI film formation, and the use of cyclic carbonate compounds can increase the flexibility of the SEI film, further increase the protective effect of the active material, and reduce the interaction between the active material and the electrolyte.
  • the probability of interfacial contact is improved, thereby improving the impedance growth caused by the accumulation of by-products during the cycle, and improving the cycle performance of the electrochemical device.
  • the electrolyte solution contains a lithium salt
  • the lithium salt includes lithium hexafluorophosphate (LiPF 6 ), lithium bissulfonylimide (LiN(C x F 2x+1 SO 2 ) ( C y F 2y+1 SO 2 ), where x is a natural number from 0 to 10, and y is a natural number from 0 to 10), lithium perchlorate (LiClO 4 ), lithium hexafluoroantimonate (LiSbF 6 ), hexafluoroarsenic At least one of lithium salts (LiAsF 6 ), the mass percentage W 8 of the lithium salt is 10% to 20%.
  • the electrolyte solution may contain LiPF 6 , because LiPF 6 can give high ion conductivity and improve the cycle performance of the lithium ion battery.
  • LiPF 6 can give high ion conductivity and improve the cycle performance of the lithium ion battery.
  • the inventors of the present application found that by adjusting the mass percentage of lithium salt within the above range, it is beneficial to improve the electrical conductivity during the cycle of the electrochemical device, thereby improving the cycle performance of the electrochemical device.
  • the electrolyte solution may also contain other non-aqueous solvents.
  • This application has no special restrictions on other non-aqueous solvents, as long as the purpose of this application can be achieved, for example, it may include but not limited to carboxylate compounds, ethers Compound or at least one of other organic solvents.
  • carboxylic acid ester compounds may include but not limited to methyl acetate, ethyl acetate, n-propyl acetate, n-butyl acetate, methyl propionate, ethyl propionate, propyl propionate, butyl propionate, butyl Methyl butyrate, ethyl butyrate, propyl butyrate, butyl butyrate, ⁇ -butyrolactone, 2,2-difluoroethyl acetate, valerolactone, butyrolactone, ethyl 2-fluoroacetate, At least one of ethyl 2,2-difluoroacetate or ethyl trifluoroacetate.
  • the aforementioned ether compounds may include, but are not limited to, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, dibutyl ether, tetrahydrofuran, 2-methyltetrahydrofuran, bis(2,2, At least one of 2-trifluoroethyl) ether, 1,3-dioxane or 1,4-dioxane.
  • the above-mentioned other organic solvents may include but not limited to ethyl vinyl sulfone, methyl isopropyl sulfone, isopropyl sec-butyl sulfone, sulfolane, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, methylpropyl carbonate At least one of ester, ethylene propyl carbonate, dipropyl carbonate, ethylene carbonate, propylene carbonate, butylene carbonate, bis(2,2,2-trifluoroethyl) carbonate.
  • the total content of the above-mentioned other non-aqueous solvents is 5% to 80%, such as 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50% %, 55%, 60%, 65%, 70%, 75%, 80%, or any range therebetween.
  • the second aspect of the present application provides an electrochemical device, which includes the electrolyte solution provided in the first aspect of the present application.
  • the electrochemical device has good cycle performance and high-temperature storage performance.
  • the electrochemical device of the present application also includes an electrode assembly, which may include a separator, a positive electrode, and a negative electrode.
  • the separator is used to separate the positive electrode and the negative electrode to prevent the internal short circuit of the electrochemical device, which allows the electrolyte ions to pass freely to complete the electrochemical charge and discharge process.
  • the present application has no particular limitation on the number of separators, positive electrodes and negative electrodes, as long as the purpose of the present application can be achieved.
  • the present application has no particular limitation on the structure of the electrode assembly, as long as the purpose of the present application can be achieved.
  • the structure of the electrode assembly may include a wound structure or a laminated structure.
  • the positive electrode of the present application is not particularly limited, as long as the purpose of the present application can be achieved.
  • the positive electrode includes a positive electrode current collector and a positive electrode material layer.
  • the present application has no special limitation on the positive electrode current collector, as long as the purpose of the present application can be achieved.
  • the positive electrode current collector may include aluminum foil, aluminum alloy foil, or a composite current collector.
  • the positive electrode material layer of the present application contains the positive electrode material.
  • the present application has no particular limitation on the type of positive electrode material, as long as the purpose of the present application can be achieved.
  • the positive electrode material may include lithium nickel cobalt manganate (811, 622, 523, 111), lithium nickel cobalt aluminate, lithium iron phosphate, lithium-rich manganese-based materials, lithium cobalt oxide, lithium manganate, lithium manganese iron phosphate or At least one of lithium titanate and the like.
  • the positive electrode material may also contain non-metallic elements, for example, non-metallic elements include at least one of fluorine, phosphorus, boron, chlorine, silicon, sulfur, etc., and these elements can further improve the stability of the positive electrode material.
  • there is no particular limitation on the thickness of the positive electrode current collector and the positive electrode material layer as long as the purpose of the present application can be achieved.
  • the thickness of the positive electrode collector is 5 ⁇ m to 20 ⁇ m, preferably 6 ⁇ m to 18 ⁇ m.
  • the thickness of the single-sided positive electrode material layer is 30 ⁇ m to 120 ⁇ m.
  • the positive electrode material layer may be provided on one surface in the thickness direction of the positive electrode current collector, or on two surfaces in the thickness direction of the positive electrode current collector. It should be noted that the "surface” here may refer to the entire area of the positive electrode collector or a partial area of the positive electrode collector. This application is not particularly limited, as long as the purpose of this application can be achieved.
  • the positive electrode sheet may further include a conductive layer, and the conductive layer is located between the positive electrode current collector and the positive electrode material layer.
  • the composition of the conductive layer is not particularly limited, and may be a commonly used conductive layer in the field.
  • the conductive layer includes a conductive agent and a binder.
  • the negative electrode of the present application is not particularly limited, as long as the purpose of the present application can be achieved.
  • the negative electrode includes a negative electrode current collector and a negative electrode material layer.
  • the present application has no particular limitation on the negative electrode collector, as long as the purpose of the present application can be achieved.
  • the negative electrode current collector may include copper foil, copper alloy foil, nickel foil, stainless steel foil, titanium foil, nickel foam, copper foam, or a composite current collector.
  • the negative electrode material layer of the present application contains the negative electrode material.
  • the present application has no particular limitation on the type of negative electrode material, as long as the purpose of the present application can be achieved.
  • the negative electrode material can include natural graphite, artificial graphite, mesophase microcarbon spheres (MCMB), hard carbon, soft carbon, silicon, silicon-carbon composite, SiO x (0 ⁇ x ⁇ 2), and metal lithium, etc. at least one of .
  • MCMB mesophase microcarbon spheres
  • the thickness of the negative electrode current collector and the negative electrode material layer there is no particular limitation on the thickness of the negative electrode current collector and the negative electrode material layer, as long as the purpose of the present application can be achieved.
  • the thickness of the negative electrode current collector is 6 ⁇ m to 10 ⁇ m
  • the thickness of the single-sided negative electrode material layer is 30 ⁇ m to 130 ⁇ m.
  • the negative electrode material layer may be provided on one surface in the thickness direction of the negative electrode current collector, or on two surfaces in the thickness direction of the negative electrode current collector. It should be noted that the "surface” here may be the entire area of the negative electrode collector, or a partial area of the negative electrode collector. This application is not particularly limited, as long as the purpose of this application can be achieved.
  • the negative electrode sheet may further include a conductive layer, and the conductive layer is located between the negative electrode current collector and the negative electrode material layer.
  • the composition of the conductive layer is not particularly limited, and may be a commonly used conductive layer in the field.
  • the conductive layer includes a conductive agent and a binder.
  • the conductive agent mentioned above is not particularly limited, as long as the purpose of the present application can be achieved.
  • the conductive agent can include at least one of conductive carbon black (Super P), carbon nanotubes (CNTs), carbon nanofibers, flake graphite, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes or graphene A sort of.
  • the binder may include polyacryl alcohol, sodium polyacrylate, potassium polyacrylate, lithium polyacrylate, polyimide, polyimide, polyamideimide, styrene-butadiene rubber (SBR), polyvinyl alcohol ( PVA), polyvinylidene fluoride, polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), polyvinyl butyral (PVB), water-based acrylic resin, carboxymethyl cellulose (CMC) or carboxymethyl At least one of base cellulose sodium (CMC-Na) and the like.
  • SBR styrene-butadiene rubber
  • PVA polyvinyl alcohol
  • PVDF polyvinylidene fluoride
  • PVDF polyvinylidene fluoride
  • PTFE polytetrafluoroethylene
  • PVB polyvinyl butyral
  • water-based acrylic resin carboxymethyl cellulose (CMC) or carboxymethyl At least one of base cellulose sodium (CMC-
  • the lithium-ion battery of the present application also includes a separator, and the present application has no special limitation on the separator, as long as the purpose of the present application can be achieved.
  • a separator may include a substrate layer and a surface treatment layer.
  • the substrate layer can be a non-woven fabric, film or composite film with a porous structure, and the material of the substrate layer can include polyethylene (PE), polypropylene (PP), polyethylene terephthalate and polyimide at least one of amines and the like.
  • 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 may be used.
  • at least one surface of the substrate layer is provided with a surface treatment layer, and the surface treatment layer may be a polymer layer or an inorganic layer, or a layer formed by mixing a polymer and an inorganic material.
  • the inorganic layer includes inorganic particles and a binder
  • the inorganic particles are not particularly limited, for example, they can be selected from aluminum oxide, silicon oxide, magnesium oxide, titanium oxide, hafnium oxide, tin oxide, cerium oxide, nickel oxide, oxide At least one of zinc, calcium oxide, zirconia, yttrium oxide, silicon carbide, boehmite, aluminum hydroxide, magnesium hydroxide, calcium hydroxide and barium sulfate.
  • the binder is not particularly limited, for example, it can be selected from polyvinylidene fluoride, copolymer of vinylidene fluoride-hexafluoropropylene, polyamide, polyacrylonitrile, polyacrylate, polyacrylic acid, polyacrylate, polyvinylpyrrolidine At least one of ketone, polyvinyl ether, polymethyl methacrylate, polytetrafluoroethylene and polyhexafluoropropylene.
  • the polymer layer comprises a polymer, and the polymer material includes polyamide, polyacrylonitrile, acrylate polymer, polyacrylic acid, polyacrylate, polyvinylpyrrolidone, polyvinyl ether, polyvinylidene fluoride or poly( at least one of vinylidene fluoride-hexafluoropropylene) and the like.
  • the electrochemical device of the present application is not particularly limited, and it may include any device that undergoes an electrochemical reaction.
  • the electrochemical device may include, but is not limited to, a lithium metal secondary battery, a lithium ion secondary battery (lithium ion battery), a lithium polymer secondary battery, or a lithium ion polymer secondary battery, and the like.
  • the third aspect of the present application provides an electronic device, which includes the electrochemical device provided in the second aspect of the present application.
  • the electronic device has good cycle performance and high-temperature storage performance.
  • the electronic devices of the present application are not particularly limited, and may include but not limited to the following types: notebook computers, pen-input computers, mobile computers, e-book players, portable phones, portable fax machines, portable copiers, portable printers, head-mounted Stereo headphones, VCRs, LCD TVs, portable cleaners, portable CD players, mini-discs, transceivers, electronic organizers, calculators, memory cards, portable tape recorders, radios, backup power supplies, electric motors, automobiles, motorcycles, power-assisted bicycles , bicycles, lighting appliances, toys, game consoles, clocks, electric tools, flashlights, cameras, and large batteries for household use.
  • the storage thickness expansion rate (%) of the lithium-ion battery after high-temperature storage for 24 hours (thickness after storage - initial thickness)/initial thickness ⁇ 100%. If the storage thickness expansion rate exceeds 50%, it is dangerous, so stop the test.
  • Discharge the lithium-ion battery at 0.5C to 3.0V at 45°C, then charge it to 4.5V at 0.5C, and charge it to 0.05C at a constant voltage at 4.5V, test the thickness of the lithium-ion battery and record it as the initial thickness, and place it at 45 In an oven at °C, charge at a constant voltage of 4.5V for 30 days, monitor the thickness change, and record the thickness as the thickness after float charge, and the thickness expansion rate of the lithium ion battery after float charge (%) (thickness after float charge-initial thickness)/initial thickness ⁇ 100%, the float thickness expansion rate exceeding 50% is dangerous, stop the test.
  • the mass percentage of formula (I-1) is 0.1%, the mass percentage of (II-1) is 0.001%, and the mass percentage of lithium salt LiPF 6 is 12.5%.
  • the amount is the mass percentage of the base solvent.
  • the positive electrode material lithium cobaltate (LiCoO 2 ), conductive carbon black, conductive paste, and binder polyvinylidene fluoride (PVDF) in a weight ratio of 97.9:0.4:0.5:1.2, and add N-methyl Pyrrolidone (NMP) was used as a solvent, fully stirred and mixed, and prepared into a positive electrode slurry with a solid content of 75% by weight; the positive electrode slurry was evenly coated on both surfaces of a positive electrode current collector aluminum foil with a thickness of 10 ⁇ m, and baked at 90 ° C. After drying and cold pressing, a positive electrode sheet with a coating thickness of 100 ⁇ m on one side was obtained, and the compacted density of the positive electrode was 4.15 g/cm 3 . Cut the positive electrode sheet for use.
  • NMP N-methyl Pyrrolidone
  • a polyethylene (PE) porous polymer film with a thickness of 5 ⁇ m was used as the separator.
  • the storage thickness expansion rate (%) of the lithium-ion battery after high-temperature storage for 6 hours (thickness after storage - initial thickness)/initial thickness ⁇ 100%. If the storage thickness expansion rate is greater than 50%, it is dangerous, so stop the test.
  • the positive electrode material nickel cobalt lithium manganese oxide NCM811 (molecular formula LiNi 0.8 Mn 0.1 Co 0.1 O 2 ), the conductive agent acetylene black, and the binder polyvinylidene fluoride (PVDF) were mixed in a weight ratio of 96:2:2, and N -Methylpyrrolidone (NMP) is used as a solvent, fully stirred and mixed, and prepared into a positive electrode slurry with a solid content of 75wt%; the positive electrode slurry is coated on both surfaces of a positive electrode current collector aluminum foil with a thickness of 10 ⁇ m, and the condition is 90 ° C. After drying under the hood and cold pressing, a positive electrode sheet with a coating thickness of 100 ⁇ m on one side was obtained, and the compacted density of the positive electrode was 3.50 g/cm 3 . Cut the positive electrode sheet for use.
  • NMP N -Methylpyrrolidone
  • Example 1 From Example 1 to Example 17, Example 48, Comparative Example 1, and Comparative Example 2, it can be seen that the application of the cyano compound represented by formula (I) and formula (II) in the electrolyte can significantly improve the lithium The cycle performance, float charge performance and high temperature storage performance of ion batteries.
  • Example 18 to Example 47 it can be seen that adding at least one of different types of sulfur-oxygen double bond compounds or polynitrile compounds in the electrolyte of the present application can further improve the performance of lithium-ion batteries. Cycle performance, float charge performance and high temperature storage performance; adding different types of boron lithium salt compounds can improve the cycle performance of lithium-ion batteries.
  • Example 48 to Example 50 it can be seen that adding different mass percentages of lithium salts to the electrolyte of the present application can improve the cycle performance and high-temperature storage performance of lithium-ion batteries. It can be seen from Example 48, Example 51 to Example 66 that adding at least one of different types of sulfur-oxygen double bond compounds, P-O bond compounds or cyclic carbonate compounds into the electrolyte solution of the present application, all It can further improve the cycle performance and high-temperature storage performance of lithium-ion batteries.

Abstract

An electrolyte, an electrochemical device containing same, and an electronic device, wherein the electrolyte comprises cyano compounds represented by formula (I) and formula (II).

Description

一种电解液和包含该电解液的电化学装置、电子装置An electrolytic solution and an electrochemical device and an electronic device containing the electrolytic solution 技术领域technical field
本申请涉及电化学技术领域，具体涉及一种电解液和包含该电解液的电化学装置、电子装置。The present application relates to the technical field of electrochemistry, and in particular to an electrolytic solution and electrochemical devices and electronic devices containing the electrolytic solution.
背景技术Background technique
锂离子电池具有储能密度大、开路电压高、自放电率低、循环寿命长、安全性好等优点，现已作为电源广泛应用于相机、手机、无人机、笔记本电脑和智能手表等电子产品。Lithium-ion batteries have the advantages of high energy storage density, high open circuit voltage, low self-discharge rate, long cycle life, and good safety. They have been widely used as power sources in cameras, mobile phones, drones, laptops, and smart watches product.
随着锂离子电池的使用范围不断扩大，市场对锂离子电池提出了更高的要求，例如要求锂离子电池在具有高能量密度的同时，还具有更长的寿命和更好的循环性能。但在提升锂离子电池能量密度的同时，往往会加速电解液的分解，从而影响锂离子电池的使用寿命和循环性能。因此，有鉴于此，开发一种合适的电解液成为本领域技术人员亟待解决的技术问题。With the continuous expansion of the use of lithium-ion batteries, the market has put forward higher requirements for lithium-ion batteries, such as requiring lithium-ion batteries to have longer life and better cycle performance while having high energy density. However, while increasing the energy density of lithium-ion batteries, the decomposition of electrolyte is often accelerated, thereby affecting the service life and cycle performance of lithium-ion batteries. Therefore, in view of this, developing a suitable electrolyte has become a technical problem to be solved urgently by those skilled in the art.
发明内容Contents of the invention
本申请的目的在于提供一种电解液和包含该电解液的电化学装置、电子装置，以改善电化学装置的高温存储性能和循环性能。The purpose of the present application is to provide an electrolytic solution, an electrochemical device and an electronic device containing the electrolytic solution, so as to improve the high-temperature storage performance and cycle performance of the electrochemical device.
本申请第一方面提供了一种电解液，其包括式(Ⅰ)和式(Ⅱ)表示的氰基化合物：The first aspect of the present application provides an electrolyte, which includes the cyano compound represented by formula (I) and formula (II):
Figure PCTCN2021131558-appb-000001
Figure PCTCN2021131558-appb-000001
其中，in,
A 1独立地选自式(Ⅰ-A)或式(Ⅱ-A)， A is independently selected from formula (I-A) or formula (II-A),
Figure PCTCN2021131558-appb-000002
Figure PCTCN2021131558-appb-000002
Figure PCTCN2021131558-appb-000003
表示与相邻原子的结合位点；
Figure PCTCN2021131558-appb-000003
Indicates the binding site with adjacent atoms;
m或n各自独立地选自0或1；m or n are each independently selected from 0 or 1;
R 1、R 11、R 12、R 13、R 14、R 15、R 16、R 17、R 18、R 19各自独立地选自共价单键、取代或未取代的的C 1至C 10的亚烷基或亚杂环基、取代或未取代的C 2至C 10的亚烯基或亚炔基、取代或未取代的C 3至C 10的亚连烯基或亚脂环烃基、取代或未取代的C 6至C 10的亚芳基，各基团的取代基各自独立地选自氟、氯、溴或碘。 R 1 , R 11 , R 12 , R 13 , R 14 , R 15 , R 16 , R 17 , R 18 , R 19 are each independently selected from covalent single bonds, substituted or unsubstituted C 1 to C 10 Alkylene or heterocyclylene, substituted or unsubstituted C 2 to C 10 alkenylene or alkynylene, substituted or unsubstituted C 3 to C 10 allenylene or alicyclic hydrocarbon group, In the substituted or unsubstituted C6 to C10 arylene group, the substituents of each group are independently selected from fluorine, chlorine, bromine or iodine.
在本申请第一方面的一些实施方式中，所述式(Ⅰ)表示的化合物包含以下化合物中的至少一种：In some embodiments of the first aspect of the present application, the compound represented by the formula (I) comprises at least one of the following compounds:
Figure PCTCN2021131558-appb-000004
Figure PCTCN2021131558-appb-000004
所述式(Ⅱ)表示的化合物包含以下化合物中的至少一种：The compound represented by the formula (II) comprises at least one of the following compounds:
Figure PCTCN2021131558-appb-000005
Figure PCTCN2021131558-appb-000005
Figure PCTCN2021131558-appb-000006
Figure PCTCN2021131558-appb-000006
在本申请第一方面的一些实施方式中，基于所述电解液的总质量，式(Ⅰ)表示的化合物的质量百分含量为W 1,式(Ⅱ)表示的化合物的质量百分含量为W 2，满足：0.01％≤W 1≤5％，0.001％≤W 2≤5％，0.1％≤W 1+W 2≤5％。 In some embodiments of the first aspect of the present application, based on the total mass of the electrolyte, the mass percentage of the compound represented by formula (I) is W 1 , and the mass percentage of the compound represented by formula (II) is W 2 satisfies: 0.01%≤W 1 ≤5%, 0.001%≤W 2 ≤5%, 0.1%≤W 1 +W 2 ≤5%.
在本申请第一方面的一些实施方式中，所述电解液还包含多腈类化合物，所述多腈类化合物包含以下化合物中的至少一种：In some embodiments of the first aspect of the present application, the electrolyte also includes polynitrile compounds, and the polynitrile compounds include at least one of the following compounds:
Figure PCTCN2021131558-appb-000007
Figure PCTCN2021131558-appb-000007
Figure PCTCN2021131558-appb-000008
Figure PCTCN2021131558-appb-000008
在本申请第一方面的一些实施方式中，基于所述电解液的总质量，所述式(Ⅰ)表示的化合物的质量百分含量为W 1,所述式(Ⅱ)表示的化合物的质量百分含量为W 2，所述多腈类化合物的质量百分含量为W 3，满足：0.5％≤W 3≤7％，0.01≤(W 1+W 2)/W 3≤1。 In some embodiments of the first aspect of the present application, based on the total mass of the electrolyte, the mass percentage of the compound represented by the formula (I) is W 1 , and the mass percentage of the compound represented by the formula (II) The percentage content is W 2 , and the mass percentage content of the polynitrile compound is W 3 , satisfying: 0.5%≤W 3 ≤7%, 0.01≤(W 1 +W 2 )/W 3 ≤1.
在本申请第一方面的一些实施方式中，所述电解液还包含硼类锂盐化合物，所述硼类锂盐化合物包括四氟硼酸锂(LiBF 4)、二草酸硼酸锂(LiBOB)或二氟草酸硼酸锂(LiDFOB)中的至少一种。 In some embodiments of the first aspect of the present application, the electrolytic solution further includes a boron-based lithium salt compound, and the boron-based lithium salt compound includes lithium tetrafluoroborate (LiBF 4 ), lithium dioxalate borate (LiBOB) or bis At least one of lithium fluorooxalate borate (LiDFOB).
在本申请第一方面的一些实施方式中，基于所述电解液的总质量，所述硼类锂盐化合物的质量百分含量W 4为0.1％至1％。 In some embodiments of the first aspect of the present application, based on the total mass of the electrolyte, the mass percentage W 4 of the boron-based lithium salt compound is 0.1% to 1%.
在本申请第一方面的一些实施方式中，所述电解液还包含P-O键类化合物，所述P-O键类化合物包括二氟磷酸锂、二氟双草酸磷酸锂、四氟草酸磷酸锂、1,2-双((二氟膦基)氧基)乙烷、三甲基磷酸酯、三苯基磷酸酯、三异丙基磷酸酯、3,3,3-三氟乙基磷酸酯、3,3,3-三氟乙基亚磷酸酯、三(三甲基硅烷)磷酸酯、2-(2,2,2-三氟乙氧基)-1,3,2-二氧杂膦烷2-氧化物中的至少一种。In some embodiments of the first aspect of the present application, the electrolyte solution further includes a P-O bond compound, and the P-O bond compound includes lithium difluorophosphate, lithium difluorobisoxalate phosphate, lithium tetrafluorooxalate phosphate, 1, 2-bis((difluorophosphino)oxy)ethane, trimethylphosphate, triphenylphosphate, triisopropylphosphate, 3,3,3-trifluoroethylphosphate, 3, 3,3-trifluoroethyl phosphite, tris(trimethylsilyl) phosphate, 2-(2,2,2-trifluoroethoxy)-1,3,2-dioxaphosphorane2 - at least one of oxides.
在本申请第一方面的一些实施方式中，基于所述电解液的总质量，所述P-O键类化合物的质量百分含量W 5为0.1％至1％。 In some embodiments of the first aspect of the present application, based on the total mass of the electrolyte, the mass percentage W 5 of the PO bond compound is 0.1% to 1%.
在本申请第一方面的一些实施方式中，所述电解液还包含硫氧双键类化合物，所述硫氧双键类化合物包括式(Ⅳ)表示的化合物中的至少一种：In some embodiments of the first aspect of the present application, the electrolyte further includes a sulfur-oxygen double bond compound, and the sulfur-oxygen double bond compound includes at least one of the compounds represented by formula (IV):
Figure PCTCN2021131558-appb-000009
Figure PCTCN2021131558-appb-000009
其中，A 4选自式(Ⅳ-A)、式(Ⅳ-B)、式(Ⅳ-C)、式(Ⅳ-D)、式(Ⅳ-E)中的至少一种： Wherein, A is selected from at least one of formula (IV-A), formula (IV-B), formula (IV-C), formula (IV-D), and formula (IV-E):
Figure PCTCN2021131558-appb-000010
Figure PCTCN2021131558-appb-000011
Figure PCTCN2021131558-appb-000010
Figure PCTCN2021131558-appb-000011
Figure PCTCN2021131558-appb-000012
表示与相邻原子的结合位点；
Figure PCTCN2021131558-appb-000012
Indicates the binding site with adjacent atoms;
R 41和R 42各自独立地选自共价键、取代或未取代的C 1至C 5的烷基或亚烷基、取代或未取代的C 1至C 6的杂环基、取代或未取代的C 2至C 10的烯基或炔基、取代或未取代的C 3至C 10的脂环基，并且R 41和R 42可以连接成环； R 41 and R 42 are each independently selected from a covalent bond, a substituted or unsubstituted C 1 to C 5 alkyl or alkylene group, a substituted or unsubstituted C 1 to C 6 heterocyclic group, a substituted or unsubstituted Substituted C 2 to C 10 alkenyl or alkynyl, substituted or unsubstituted C 3 to C 10 alicyclic group, and R 41 and R 42 may be connected to form a ring;
R 43选自共价键、取代或未取代的C 1至C 3的亚烷基、取代或未取代的C 2至C 3的亚烯基或亚炔基； R 43 is selected from a covalent bond, a substituted or unsubstituted C 1 to C 3 alkylene group, a substituted or unsubstituted C 2 to C 3 alkenylene or alkynylene group;
其中，取代基选自卤素、取代或未取代C 1至C 3的烷基、取代或未取代C 2至C 3的烯基、取代或未取代C 2至C 3的炔基； Wherein, the substituent is selected from halogen, substituted or unsubstituted C1 to C3 alkyl, substituted or unsubstituted C2 to C3 alkenyl, substituted or unsubstituted C2 to C3 alkynyl;
其中，所述杂原子选自N、O或S中的至少一种；Wherein, the heteroatom is selected from at least one of N, O or S;
基于所述电解液的总质量，所述式(Ⅳ)表示的化合物的质量百分含量W 6为0.1％至8％。 Based on the total mass of the electrolyte, the mass percentage W 6 of the compound represented by the formula (IV) is 0.1% to 8%.
在本申请第一方面的一些实施方式中，式(Ⅳ)表示的化合物包含以下化合物中的至少一种：In some embodiments of the first aspect of the present application, the compound represented by formula (IV) comprises at least one of the following compounds:
Figure PCTCN2021131558-appb-000013
Figure PCTCN2021131558-appb-000013
Figure PCTCN2021131558-appb-000014
Figure PCTCN2021131558-appb-000014
在本申请第一方面的一些实施方式中，所述电解液还包含环状碳酸酯类化合物，所述环状碳酸酯类化合物包括以下化合物中的至少一种：In some implementations of the first aspect of the present application, the electrolyte also includes a cyclic carbonate compound, and the cyclic carbonate compound includes at least one of the following compounds:
Figure PCTCN2021131558-appb-000015
Figure PCTCN2021131558-appb-000015
基于所述电解液的总质量，所述环状碳酸酯类化合物的质量百分含量W 7为0.1％至10％； Based on the total mass of the electrolyte, the mass percentage W 7 of the cyclic carbonate compound is 0.1% to 10%;
所述电解液包含锂盐，所述锂盐包括六氟磷酸锂、四氟硼酸锂、双草酸硼酸锂、二氟草酸硼酸锂、六氟锑酸锂、六氟砷酸锂、全氟丁基磺酸锂、高氯酸锂、铝酸锂、四氯铝酸锂、双磺酰亚胺锂(LiN(C xF 2x+1SO 2)(C yF 2y+1SO 2)，其中x是0至10的自然数，y是0至10的自然数)、氯化锂、氟化锂中的至少一种，基于所述电解液的总质量，所述锂盐的质量百分含量W 8为10％至20％。 The electrolyte solution contains lithium salts, and the lithium salts include lithium hexafluorophosphate, lithium tetrafluoroborate, lithium bisoxalate borate, lithium difluorooxalate borate, lithium hexafluoroantimonate, lithium hexafluoroarsenate, lithium perfluorobutyl sulfonate , lithium perchlorate, lithium aluminate, lithium tetrachloroaluminate, lithium bissulfonylimide (LiN(C x F 2x+1 SO 2 )(C y F 2y+1 SO 2 ), where x is 0 to 10, y is a natural number from 0 to 10), at least one of lithium chloride and lithium fluoride, based on the total mass of the electrolyte, the mass percentage W of the lithium salt is 10% to 8 20%.
本申请第二方面提供了一种电化学装置，其包含本申请第一方面提供的电解液。The second aspect of the present application provides an electrochemical device, which includes the electrolyte solution provided in the first aspect of the present application.
本申请第三方面提供了一种电子装置，其包含本申请第二方面提供的电化学装置。The third aspect of the present application provides an electronic device, which includes the electrochemical device provided in the second aspect of the present application.
本申请提供了一种电解液和包含该电解液的电化学装置、电子装置，其中，电解液包括式(Ⅰ)和式(Ⅱ)表示的氰基化合物。在电解液中添加式(Ⅰ)和式(Ⅱ)表示的氰基化合物，不仅可以稳定正极高价态的过渡金属，同时可以吸收正极释放的氧，抑制电解液持续分解；还可以在正、负极形成界面保护膜，保护正、负极表面，从而显著改善电化学装置的高温 存储性能和循环性能。包含该电化学装置的电子装置，也具有良好的高温存储性能和循环性能。The present application provides an electrolytic solution and an electrochemical device and an electronic device containing the electrolytic solution, wherein the electrolytic solution includes cyano compounds represented by formula (I) and formula (II). Adding the cyano compound represented by formula (I) and formula (II) to the electrolyte can not only stabilize the transition metal in the positive and extremely high valence state, but also absorb the oxygen released from the positive electrode and inhibit the continuous decomposition of the electrolyte; it can also be used on the positive and negative electrodes Form an interface protective film to protect the surface of the positive and negative electrodes, thereby significantly improving the high-temperature storage performance and cycle performance of the electrochemical device. An electronic device including the electrochemical device also has good high-temperature storage performance and cycle performance.
具体实施方式Detailed ways
为使本申请的目的、技术方案、及优点更加清楚明白，以下举实施例，对本申请进一步详细说明。显然，所描述的实施例仅仅是本申请一部分实施例，而不是全部的实施例。本领域普通技术人员基于本申请中的实施例所获得的所有其他实施例，都属于本申请保护的范围。In order to make the purpose, technical solution, and advantages of the present application clearer, the following examples are given to further describe the present application in detail. Apparently, the described embodiments are only some of the embodiments of this application, not all of them. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments in this application belong to the protection scope of this application.
需要说明的是，本申请中，以锂离子电池作为电化学装置的例子来解释本申请，但是本申请的电化学装置并不仅限于锂离子电池。本领域技术人员应当理解，以下说明仅为举例说明，并不限定本申请的保护范围。It should be noted that, in the present application, a lithium-ion battery is used as an example of an electrochemical device to explain the present application, but the electrochemical device of the present application is not limited to the lithium-ion battery. It should be understood by those skilled in the art that the following description is only for illustration and does not limit the protection scope of the present application.
以下，举出实施例及对比例来对本申请的实施方式进行更具体地说明。各种的试验及评价按照下述的方法进行。另外，只要无特别说明，“份”、“％”为质量基准。Hereinafter, the embodiment of the present application will be described more specifically with reference to examples and comparative examples. Various tests and evaluations were performed according to the following methods. In addition, unless otherwise specified, "part" and "%" are based on mass.
本申请第一方面提供了一种电解液，其包括式(Ⅰ)和式(Ⅱ)表示的氰基化合物：The first aspect of the present application provides an electrolyte, which includes the cyano compound represented by formula (I) and formula (II):
Figure PCTCN2021131558-appb-000016
Figure PCTCN2021131558-appb-000016
其中，in,
A 1独立地选自式(Ⅰ-A)或式(Ⅱ-A)， A is independently selected from formula (I-A) or formula (II-A),
Figure PCTCN2021131558-appb-000017
Figure PCTCN2021131558-appb-000017
Figure PCTCN2021131558-appb-000018
表示与相邻原子的结合位点；
Figure PCTCN2021131558-appb-000018
Indicates the binding site with adjacent atoms;
m或n各自独立地选自0或1；m or n are each independently selected from 0 or 1;
R 1、R 11、R 12、R 13、R 14、R 15、R 16、R 17、R 18、R 19各自独立地选自共价单键、取代或未取代的的C 1至C 10的亚烷基或亚杂环基、取代或未取代的C 2至C 10的亚烯基或亚炔基、取代或未取代的C 3至C 10的亚连烯基或亚脂环烃基、取代或未取代的C 6至C 10的亚芳基， 各基团的取代基各自独立地选自氟、氯、溴或碘。 R 1 , R 11 , R 12 , R 13 , R 14 , R 15 , R 16 , R 17 , R 18 , R 19 are each independently selected from covalent single bonds, substituted or unsubstituted C 1 to C 10 Alkylene or heterocyclylene, substituted or unsubstituted C 2 to C 10 alkenylene or alkynylene, substituted or unsubstituted C 3 to C 10 allenylene or alicyclic hydrocarbon group, In the substituted or unsubstituted C 6 to C 10 arylene group, the substituents of each group are independently selected from fluorine, chlorine, bromine or iodine.
本申请式(Ⅰ)和式(Ⅱ)表示的氰基化合物，含有不同氰基个数的氰基化合物分子的空间结构不同，对电化学装置的改善效果也不同。本申请在电解液中添加式(Ⅰ)和式(Ⅱ)表示的氰基化合物，能够稳定正极高价态的过渡金属，可以吸收正极释放出来的氧，抑制电解液持续分解，还可以在正、负极形成界面保护膜，保护正、负极表面，从而改善电化学装置的高温存储性能和循环性能。The cyano compounds represented by formula (I) and formula (II) in the present application have different spatial structures of cyano compound molecules with different numbers of cyano groups, and thus have different improvement effects on electrochemical devices. In the present application, the cyano compound represented by formula (I) and formula (II) is added to the electrolyte, which can stabilize the transition metal in the positive high-valence state, absorb the oxygen released from the positive electrode, and inhibit the continuous decomposition of the electrolyte. The negative electrode forms an interface protective film to protect the surface of the positive and negative electrodes, thereby improving the high-temperature storage performance and cycle performance of the electrochemical device.
在本申请第一方面的一些实施方式中，所述式(Ⅰ)表示的化合物包含以下化合物中的至少一种：In some embodiments of the first aspect of the present application, the compound represented by the formula (I) comprises at least one of the following compounds:
Figure PCTCN2021131558-appb-000019
Figure PCTCN2021131558-appb-000019
所述式(Ⅱ)表示的化合物包含以下化合物中的至少一种：The compound represented by the formula (II) comprises at least one of the following compounds:
Figure PCTCN2021131558-appb-000020
Figure PCTCN2021131558-appb-000020
Figure PCTCN2021131558-appb-000021
Figure PCTCN2021131558-appb-000021
在本申请第一方面的一些实施方式中，电解液包含化合物式(Ⅰ-1)至式(Ⅰ-9)中的至少一种，使具有不同结构的式(Ⅰ)表示的化合物共同作用，以在不影响其他性能的同时，进一步改善电化学装置的循环性能和高温存储性能。In some embodiments of the first aspect of the present application, the electrolyte contains at least one of the compounds of formula (I-1) to formula (I-9), so that the compounds represented by formula (I) with different structures act together, In order to further improve the cycle performance and high-temperature storage performance of the electrochemical device without affecting other performances.
在本申请第一方面的一些实施方式中，电解液包含化合物式(Ⅱ-1)至式(Ⅱ-16)中的至少一种，使具有不同结构的式(Ⅱ)表示的化合物共同作用，以在不影响其他性能的同时，进一步改善电化学装置的循环性能和高温存储性能。In some embodiments of the first aspect of the present application, the electrolyte contains at least one of the compounds of formula (II-1) to formula (II-16), so that the compounds represented by formula (II) with different structures act together, In order to further improve the cycle performance and high-temperature storage performance of the electrochemical device without affecting other performances.
在本申请第一方面的一些实施方式中，基于所述电解液的总质量，式(Ⅰ)表示的化合物的质量百分含量为W 1,式(Ⅱ)表示的化合物的质量百分含量为W 2，满足：0.01％≤W 1≤5％，0.001％≤W 2≤5％，0.1％≤W 1+W 2≤5％。例如，W 1的值可以为0.01％、0.05％、0.1％、0.5％、1.5％、3％、5％或上述任两个数值范围间的任一数值；W 2的值可以为0.001％、0.005％、0.01％、0.05％、0.1％、0.5％、1.5％、3％、5％或上述任两个数值范围间的任一数值；其中W 1+W 2要满足0.1％≤W 1+W 2≤5％，W 1+W 2的值可以为0.1％、0.15％、0.2％、0.5％、1％、2.1％、2.5％、3.5％、4％、4.5％、5％或上述任两个数值范围间的任一数值。其中，式(Ⅰ) 表示的氰基化合物的质量百分含量W 1和式(Ⅱ)表示的化合物的质量百分含量W 2的值，若过低，无法抑制电解液的持续分解；若过高，氰基化合物容易在正、负极表面富集，形成较大的空间阻抗，将影响锂离子的传输，从而影响电化学装置的电化学性能。 In some embodiments of the first aspect of the present application, based on the total mass of the electrolyte, the mass percentage of the compound represented by formula (I) is W 1 , and the mass percentage of the compound represented by formula (II) is W 2 satisfies: 0.01%≤W 1 ≤5%, 0.001%≤W 2 ≤5%, 0.1%≤W 1 +W 2 ≤5%. For example, the value of W1 can be 0.01%, 0.05%, 0.1%, 0.5%, 1.5%, 3%, 5% or any value between the above-mentioned any two numerical ranges; the value of W2 can be 0.001%, 0.005%, 0.01%, 0.05%, 0.1%, 0.5%, 1.5%, 3%, 5%, or any value between any two value ranges above; where W 1 +W 2 must satisfy 0.1%≤W 1 + W 2 ≤5%, the value of W 1 +W 2 can be 0.1%, 0.15%, 0.2%, 0.5%, 1%, 2.1%, 2.5%, 3.5%, 4%, 4.5%, 5% or any of the above Any value between the two value ranges. Wherein, if the value of the mass percent content W of the cyano compound represented by formula ( I ) and the mass percent composition W of the compound represented by formula ( II ) is too low, the continuous decomposition of the electrolyte cannot be suppressed; High, cyano compounds are easy to enrich on the surface of the positive and negative electrodes, forming a large steric impedance, which will affect the transmission of lithium ions, thereby affecting the electrochemical performance of the electrochemical device.
本申请通过将W 1+W 2控制在上述范围内，有利于式(Ⅰ)和式(Ⅱ)表示的氰基化合物发挥协同作用，能够稳定正极高价态的过渡金属，吸收正极释放的氧，抑制电解液的分解，可以在正、负极形成界面保护膜，保护正、负极表面，从而有效改善电化学装置的高温存储性能和循环性能。 In the present application, by controlling W 1 +W 2 within the above range, it is beneficial for the cyano compounds represented by formula (I) and formula (II) to play a synergistic effect, and can stabilize the transition metal in a positive high-valence state, and absorb the oxygen released by the positive electrode. Inhibiting the decomposition of the electrolyte can form an interface protective film on the positive and negative electrodes to protect the surface of the positive and negative electrodes, thereby effectively improving the high-temperature storage performance and cycle performance of the electrochemical device.
在本申请第一方面的一些实施方式中，所述电解液还包含多腈类化合物，所述多腈类化合物包含以下化合物中的至少一种：In some embodiments of the first aspect of the present application, the electrolyte also includes polynitrile compounds, and the polynitrile compounds include at least one of the following compounds:
Figure PCTCN2021131558-appb-000022
Figure PCTCN2021131558-appb-000022
通过选择上述多腈类化合物，可以进一步提升电化学装置的循环性能和高温存储性能。By selecting the above-mentioned polynitrile compounds, the cycle performance and high-temperature storage performance of the electrochemical device can be further improved.
在本申请第一方面的一些实施方式中，基于所述电解液的总质量，所述式(Ⅰ)表示的化合物的质量百分含量为W 1,所述式(Ⅱ)表示的化合物的质量百分含量为W 2，所述多腈类化合物的质量百分含量为W 3，满足：0.5％≤W 3≤7％，0.01≤(W 1+W 2)/W 3≤1。所述多腈类化合物的质量百分含量W 3的值可以为0.5％、1％、1.5％、2％、3％、4％、4.5％、5％、5.5％、6、6.5％、7％或上述任两个数值范围间的任一数值。本申请的发明人发现，当(W 1+W 2)/W 3过高时(例如高于1％)，会使得式(Ⅰ)与式(Ⅱ)的含量总和过大或者会使得多腈类化合物含量过少。式(Ⅰ)与式(Ⅱ)的含量总和过高，不仅会使得电解液粘度增加，而且会在正、负极表面形成阻抗大的界面膜。多腈类化合物含量过少，不能对正极起到很好的保护效果。以上这些都会影响电化学装置的电化学性能。通过控制(W 1+W 2)/W 3的值在上述范围内， 能够提升电化学装置的循环性能和高温存储性能。 In some embodiments of the first aspect of the present application, based on the total mass of the electrolyte, the mass percentage of the compound represented by the formula (I) is W 1 , and the mass percentage of the compound represented by the formula (II) The percentage content is W 2 , and the mass percentage content of the polynitrile compound is W 3 , satisfying: 0.5%≤W 3 ≤7%, 0.01≤(W 1 +W 2 )/W 3 ≤1. The value of the mass percent content W of described polynitrile compound can be 0.5%, 1%, 1.5%, 2% , 3%, 4%, 4.5%, 5%, 5.5%, 6, 6.5%, 7% % or any value between any two value ranges above. The inventors of the present application have found that when (W 1 +W 2 )/W 3 is too high (for example, higher than 1%), the sum of the contents of formula (I) and formula (II) will be too large or polynitrile The compound content is too low. If the total content of formula (I) and formula (II) is too high, not only will the viscosity of the electrolyte increase, but also an interface film with high impedance will be formed on the surface of the positive and negative electrodes. If the content of polynitrile compounds is too small, it cannot protect the positive electrode well. All of the above will affect the electrochemical performance of the electrochemical device. By controlling the value of (W 1 +W 2 )/W 3 within the above range, the cycle performance and high-temperature storage performance of the electrochemical device can be improved.
在本申请第一方面的一些实施方式中，所述电解液还包含硼类锂盐化合物，所述硼类锂盐化合物包括四氟硼酸锂(LiBF 4)、二草酸硼酸锂(LiBOB)或二氟草酸硼酸锂(LiDFOB)中的至少一种。在电化学装置中，随着脱锂量的增加，正极表面的氧自由基相对更加活泼，硼原子可以与氧自由基形成稳定的共价键，有效抑制氧自由基的损耗。此外，通过在电解液中添加硼类锂盐化合物，还可以在负极形成稳定的固体电解质界面(SEI)膜，防止正极中溶解出来的过渡金属对负极的破坏。由此，电解液中硼类锂盐化合物的添加，能进一步改善电化学装置的循环性能和高温存储性能。 In some embodiments of the first aspect of the present application, the electrolytic solution further includes a boron-based lithium salt compound, and the boron-based lithium salt compound includes lithium tetrafluoroborate (LiBF 4 ), lithium dioxalate borate (LiBOB) or bis At least one of lithium fluorooxalate borate (LiDFOB). In electrochemical devices, as the amount of delithiation increases, the oxygen radicals on the surface of the positive electrode are relatively more active, and boron atoms can form stable covalent bonds with oxygen radicals, effectively inhibiting the loss of oxygen radicals. In addition, by adding a boron lithium salt compound to the electrolyte, a stable solid electrolyte interface (SEI) film can also be formed on the negative electrode to prevent the transition metals dissolved in the positive electrode from damaging the negative electrode. Thus, the addition of the boron-type lithium salt compound in the electrolyte can further improve the cycle performance and high-temperature storage performance of the electrochemical device.
在本申请第一方面的一些实施方式中，基于所述电解液的总质量，所述硼类锂盐化合物的质量百分含量W 4为0.1％至1％。例如，W 4的值可以为0.1％、0.2％、0.3％、0.5％、0.8％、1％或上述任两个数值范围间的任一数值。硼类锂盐化合物的质量百分含量W 4过高(例如高于1％)，在电化学装置化成阶段难以被完全消耗，在电化学装置的存储过程中分解产生大量气体，影响电化学装置的高温存储性能。通过将W 4的值控制在上述范围内，能够有效改善电化学装置的循环性能和高温存储性能。 In some embodiments of the first aspect of the present application, based on the total mass of the electrolyte, the mass percentage W 4 of the boron-based lithium salt compound is 0.1% to 1%. For example, the value of W 4 may be 0.1%, 0.2%, 0.3%, 0.5%, 0.8%, 1%, or any value between any two value ranges mentioned above. The mass percentage W of the boron-type lithium salt compound is too high (for example, higher than 1%), it is difficult to be completely consumed in the formation stage of the electrochemical device, and a large amount of gas is generated during the storage of the electrochemical device, which affects the electrochemical device. high temperature storage performance. By controlling the value of W4 within the above range, the cycle performance and high-temperature storage performance of the electrochemical device can be effectively improved.
在本申请第一方面的一些实施方式中，所述电解液还包含P-O键类化合物，所述P-O键类化合物包括二氟磷酸锂(LiPO 2F 2)、二氟双草酸磷酸锂(LiDFOP)、四氟草酸磷酸锂(LiTFOP)、1,2-双((二氟膦基)氧基)乙烷、三甲基磷酸酯、三苯基磷酸酯、三异丙基磷酸酯、3,3,3-三氟乙基磷酸酯、3,3,3-三氟乙基亚磷酸酯、三(三甲基硅烷)磷酸酯、2-(2,2,2-三氟乙氧基)-1,3,2-二氧杂膦烷2-氧化物中的至少一种。通过在电解液中添加P-O键类化合物，能够减少电解液与正、负极接触，起到抑制产气的作用，从而有效改善电化学装置的循环性能和高温存储性能。 In some implementations of the first aspect of the present application, the electrolyte solution further includes a PO bond compound, and the PO bond compound includes lithium difluorophosphate (LiPO 2 F 2 ), lithium difluorobisoxalate phosphate (LiDFOP) , lithium tetrafluorooxalate phosphate (LiTFOP), 1,2-bis((difluorophosphino)oxy)ethane, trimethyl phosphate, triphenyl phosphate, triisopropyl phosphate, 3,3 ,3-Trifluoroethyl phosphate, 3,3,3-trifluoroethyl phosphite, tris(trimethylsilane) phosphate, 2-(2,2,2-trifluoroethoxy)- At least one of 1,3,2-dioxaphosphane 2-oxides. By adding PO bond compounds in the electrolyte, the contact between the electrolyte and the positive and negative electrodes can be reduced, and gas production can be suppressed, thereby effectively improving the cycle performance and high-temperature storage performance of the electrochemical device.
在本申请第一方面的一些实施方式中，基于所述电解液的总质量，所述P-O键类化合物的质量百分含量W 5为0.1％至1％。通过将W 5的值控制在上述范围内，能够有效改善电化学装置的循环性能和高温存储性能。 In some embodiments of the first aspect of the present application, based on the total mass of the electrolyte, the mass percentage W 5 of the PO bond compound is 0.1% to 1%. By controlling the value of W5 within the above range, the cycle performance and high-temperature storage performance of the electrochemical device can be effectively improved.
在本申请第一方面的一些实施方式中，所述电解液还包含硫氧双键类化合物，所述硫氧双键类化合物包括式(Ⅳ)表示的化合物中的至少一种：In some embodiments of the first aspect of the present application, the electrolyte further includes a sulfur-oxygen double bond compound, and the sulfur-oxygen double bond compound includes at least one of the compounds represented by formula (IV):
Figure PCTCN2021131558-appb-000023
Figure PCTCN2021131558-appb-000023
其中，A 4选自式(Ⅳ-A)、式(Ⅳ-B)、式(Ⅳ-C)、式(Ⅳ-D)、式(Ⅳ-E)中的至少一种： Wherein, A is selected from at least one of formula (IV-A), formula (IV-B), formula (IV-C), formula (IV-D), and formula (IV-E):
Figure PCTCN2021131558-appb-000024
Figure PCTCN2021131558-appb-000024
Figure PCTCN2021131558-appb-000025
表示与相邻原子的结合位点；
Figure PCTCN2021131558-appb-000025
Indicates the binding site with adjacent atoms;
R 41和R 42各自独立地选自共价键、取代或未取代的C 1至C 5的烷基或亚烷基、取代或未取代的C 1至C 6的杂环基、取代或未取代的C 2至C 10的烯基或炔基、取代或未取代的C 3至C 10的脂环基，并且R 41和R 42可以连接成环； R 41 and R 42 are each independently selected from a covalent bond, a substituted or unsubstituted C 1 to C 5 alkyl or alkylene group, a substituted or unsubstituted C 1 to C 6 heterocyclic group, a substituted or unsubstituted Substituted C 2 to C 10 alkenyl or alkynyl, substituted or unsubstituted C 3 to C 10 alicyclic group, and R 41 and R 42 may be connected to form a ring;
R 43选自共价键、取代或未取代的C 1至C 3的亚烷基、取代或未取代的C 2至C 3的亚烯基或亚炔基； R 43 is selected from a covalent bond, a substituted or unsubstituted C 1 to C 3 alkylene group, a substituted or unsubstituted C 2 to C 3 alkenylene or alkynylene group;
其中，取代基选自卤素、取代或未取代C 1至C 3的烷基、取代或未取代C 2至C 3的烯基、取代或未取代C 2至C 3的炔基； Wherein, the substituent is selected from halogen, substituted or unsubstituted C1 to C3 alkyl, substituted or unsubstituted C2 to C3 alkenyl, substituted or unsubstituted C2 to C3 alkynyl;
其中，所述杂原子选自N、O或S中的至少一种；Wherein, the heteroatom is selected from at least one of N, O or S;
基于所述电解液的总质量，所述式(Ⅳ)表示的化合物的质量百分含量W 6为0.1％至8％。例如，W 6的值可以为0.1％、0.3％、0.5％、1％、1.5％、2％、3％、5％、6％、7％、7.5％、8％或上述任两个数值范围间的任一数值，例如，可以为1.5％至6％。式(Ⅳ)表示的化合物的质量百分含量W 6过高(例如高于8％)，易形成酸性物质，腐蚀正极电解液界面(CEI)膜及正极材料层，影响正极材料结构的稳定，进而影响电化学装置的循环性能。通过将硫氧双键类化合物的质量百分含量W 6控制在上述范围内，更利于改善电化学装置的循环稳定性，进一步改善电化学装置的循环性能和存储性能。 Based on the total mass of the electrolyte, the mass percentage W 6 of the compound represented by the formula (IV) is 0.1% to 8%. For example, the value of W6 can be 0.1%, 0.3%, 0.5%, 1%, 1.5%, 2%, 3%, 5%, 6%, 7%, 7.5%, 8%, or any two of the above numerical ranges Any value in between, for example, can be 1.5% to 6%. The mass percentage W of the compound represented by formula (IV) is too high (such as higher than 8%), and it is easy to form an acidic substance, corrode the positive electrode electrolyte interface (CEI) film and the positive electrode material layer, and affect the stability of the positive electrode material structure. And then affect the cycle performance of the electrochemical device. By controlling the mass percentage W 6 of the sulfur-oxygen double bond compound within the above range, it is more beneficial to improve the cycle stability of the electrochemical device, and further improve the cycle performance and storage performance of the electrochemical device.
本申请中，所述硫氧双键类化合物的抗氧化能力较强，可以保护正极界面的稳定，还可以在负极表面还原，形成一层保护膜，抑制电解液的分解，进一步增强界面的稳定性，从而进一步改善电化学装置的高温存储性能和循环性能。In the present application, the sulfur-oxygen double bond compound has strong anti-oxidation ability, can protect the stability of the positive electrode interface, and can also be reduced on the surface of the negative electrode to form a protective film, inhibit the decomposition of the electrolyte, and further enhance the stability of the interface. performance, thereby further improving the high-temperature storage performance and cycle performance of the electrochemical device.
在本申请第一方面的一些实施方式中，式(Ⅳ)表示的化合物包含以下化合物中的至少一种：In some embodiments of the first aspect of the present application, the compound represented by formula (IV) comprises at least one of the following compounds:
Figure PCTCN2021131558-appb-000026
Figure PCTCN2021131558-appb-000026
本申请的电解液包含化合物式(Ⅳ-1)至式(Ⅳ-41)中的至少一种，使具有不同结构的硫氧双键类化合物共同作用，以在不影响其他性能的同时，进一步改善电化学装置的循环性能和高温存储性能。The electrolyte solution of the present application contains at least one of the compound formula (IV-1) to formula (IV-41), so that the sulfur-oxygen double bond compounds with different structures can work together to further Improve cycle performance and high-temperature storage performance of electrochemical devices.
在本申请第一方面的一些实施方式中，所述电解液还包含环状碳酸酯类化合物，所述环状碳酸酯类化合物包括以下化合物中的至少一种：In some implementations of the first aspect of the present application, the electrolyte also includes a cyclic carbonate compound, and the cyclic carbonate compound includes at least one of the following compounds:
Figure PCTCN2021131558-appb-000027
Figure PCTCN2021131558-appb-000027
Figure PCTCN2021131558-appb-000028
Figure PCTCN2021131558-appb-000028
基于所述电解液的总质量，所述环状碳酸酯类化合物的质量百分含量W 7为0.1％至10％。例如，W 7的值可以为0.1％、0.5％、1％、1.5％、2％、3％、5％、6％、7％、8％、8.5％、9％、10％或上述任两个数值范围间的任一数值，例如，可以为1％至6％。通过将W 7控制在上述范围内，能够有效改善电化学装置的循环性能和存储性能。 Based on the total mass of the electrolyte, the mass percentage W 7 of the cyclic carbonate compound is 0.1% to 10%. For example, the value of W7 can be 0.1%, 0.5%, 1%, 1.5%, 2%, 3%, 5%, 6%, 7%, 8%, 8.5%, 9%, 10%, or any two of the above Any value within a range of values, for example, may be 1% to 6%. By controlling W 7 within the above range, the cycle performance and storage performance of the electrochemical device can be effectively improved.
本申请中，所述环状碳酸酯类化合物，能够增强SEI成膜稳定性，使用环状碳酸酯类化合物可以增加SEI膜的柔性，进一步增加做活性材料的保护作用，降低活性材料与电解液的界面接触几率，从而改善循环过程中副产物累积产生的阻抗增长，提高电化学装置的循环性能。In the present application, the cyclic carbonate compounds can enhance the stability of SEI film formation, and the use of cyclic carbonate compounds can increase the flexibility of the SEI film, further increase the protective effect of the active material, and reduce the interaction between the active material and the electrolyte. The probability of interfacial contact is improved, thereby improving the impedance growth caused by the accumulation of by-products during the cycle, and improving the cycle performance of the electrochemical device.
在本申请第一方面的一些实施方式中，所述电解液包含锂盐，所述锂盐包括六氟磷酸锂(LiPF 6)、双磺酰亚胺锂(LiN(C xF 2x+1SO 2)(C yF 2y+1SO 2)，其中x是0至10的自然数，y是0至10的自然数)、高氯酸锂(LiClO 4)、六氟锑酸锂(LiSbF 6)、六氟砷酸锂(LiAsF 6)中的至少一种，所述锂盐的质量百分含量W 8为10％至20％。优选地，所述电解液可以包含LiPF 6，因为LiPF 6可以给出高的离子导电率，并改善锂离子电池的循环性能。不限于任何理论，本申请的发明人发现，通过调控锂盐的质量百分含量在上述范围，在电化学装置循环过程中，有利于提高电导率，从而提高电化学装置的循环性能。 In some implementations of the first aspect of the present application, the electrolyte solution contains a lithium salt, and the lithium salt includes lithium hexafluorophosphate (LiPF 6 ), lithium bissulfonylimide (LiN(C x F 2x+1 SO 2 ) ( C y F 2y+1 SO 2 ), where x is a natural number from 0 to 10, and y is a natural number from 0 to 10), lithium perchlorate (LiClO 4 ), lithium hexafluoroantimonate (LiSbF 6 ), hexafluoroarsenic At least one of lithium salts (LiAsF 6 ), the mass percentage W 8 of the lithium salt is 10% to 20%. Preferably, the electrolyte solution may contain LiPF 6 , because LiPF 6 can give high ion conductivity and improve the cycle performance of the lithium ion battery. Without being limited to any theory, the inventors of the present application found that by adjusting the mass percentage of lithium salt within the above range, it is beneficial to improve the electrical conductivity during the cycle of the electrochemical device, thereby improving the cycle performance of the electrochemical device.
在本申请中，电解液还可以包含其他非水溶剂，本申请对其他非水溶剂没有特别限制，只要能实现本申请的目的即可，例如可以包括但不限于羧酸酯类化合物、醚类化合物或其它有机溶剂中的至少一种。上述羧酸酯类化合物可以包括但不限于乙酸甲酯、乙酸乙酯、乙酸正丙酯、乙酸正丁酯、丙酸甲酯、丙酸乙酯、丙酸丙酯、丙酸丁酯、丁酸甲酯、丁酸乙酯、丁酸丙酯、丁酸丁酯、γ-丁内酯、乙酸2,2-二氟乙酯、戊内酯、丁内酯、2-氟乙酸乙酯、2,2-二氟乙酸乙酯或三氟乙酸乙酯中的至少一种。上述醚类化合物可以包括但不限于乙二醇二甲醚、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、双(2,2,2-三氟乙基)醚、1,3-二氧六环或1,4-二氧六环中的至少一种。上述其它有机溶剂可以包括但不限于乙基乙烯基砜、甲基异丙基砜、异丙基仲丁基砜、环丁砜、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、二(2,2,2-三氟乙基)碳酸酯中的至少一种。基于电解液的总质量，上 述其他非水溶剂的总含量5％至80％，例如5％、10％、15％、20％、25％、30％、35％、40％、45％、50％、55％、60％、65％、70％、75％、80％或其间的任何范围。In this application, the electrolyte solution may also contain other non-aqueous solvents. This application has no special restrictions on other non-aqueous solvents, as long as the purpose of this application can be achieved, for example, it may include but not limited to carboxylate compounds, ethers Compound or at least one of other organic solvents. The above-mentioned carboxylic acid ester compounds may include but not limited to methyl acetate, ethyl acetate, n-propyl acetate, n-butyl acetate, methyl propionate, ethyl propionate, propyl propionate, butyl propionate, butyl Methyl butyrate, ethyl butyrate, propyl butyrate, butyl butyrate, γ-butyrolactone, 2,2-difluoroethyl acetate, valerolactone, butyrolactone, ethyl 2-fluoroacetate, At least one of ethyl 2,2-difluoroacetate or ethyl trifluoroacetate. The aforementioned ether compounds may include, but are not limited to, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, dibutyl ether, tetrahydrofuran, 2-methyltetrahydrofuran, bis(2,2, At least one of 2-trifluoroethyl) ether, 1,3-dioxane or 1,4-dioxane. The above-mentioned other organic solvents may include but not limited to ethyl vinyl sulfone, methyl isopropyl sulfone, isopropyl sec-butyl sulfone, sulfolane, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, methylpropyl carbonate At least one of ester, ethylene propyl carbonate, dipropyl carbonate, ethylene carbonate, propylene carbonate, butylene carbonate, bis(2,2,2-trifluoroethyl) carbonate. Based on the total mass of the electrolyte, the total content of the above-mentioned other non-aqueous solvents is 5% to 80%, such as 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50% %, 55%, 60%, 65%, 70%, 75%, 80%, or any range therebetween.
本申请第二方面提供了一种电化学装置，其包含本申请第一方面提供的电解液。该电化学装置具有良好的循环性能和高温存储性能。The second aspect of the present application provides an electrochemical device, which includes the electrolyte solution provided in the first aspect of the present application. The electrochemical device has good cycle performance and high-temperature storage performance.
本申请的电化学装置还包括电极组件，电极组件可以包含隔膜、正极和负极。隔膜用以分隔正极和负极，以防止电化学装置内部短路，其允许电解质离子自由通过，完成电化学充放电过程。本申请对隔膜、正极和负极的数量没有特别限制，只要能够实现本申请目的即可。本申请对电极组件的结构没有特别限制，只要能够实现本申请目的即可。例如，电极组件的结构可以包括卷绕结构或叠片结构。The electrochemical device of the present application also includes an electrode assembly, which may include a separator, a positive electrode, and a negative electrode. The separator is used to separate the positive electrode and the negative electrode to prevent the internal short circuit of the electrochemical device, which allows the electrolyte ions to pass freely to complete the electrochemical charge and discharge process. The present application has no particular limitation on the number of separators, positive electrodes and negative electrodes, as long as the purpose of the present application can be achieved. The present application has no particular limitation on the structure of the electrode assembly, as long as the purpose of the present application can be achieved. For example, the structure of the electrode assembly may include a wound structure or a laminated structure.
本申请的正极没有特别限制，只要能够实现本申请目的即可。例如，正极包含正极集流体和正极材料层。本申请对正极集流体没有特别限制，只要能够实现本申请目的即可。例如，正极集流体可以包含铝箔、铝合金箔或复合集流体等。本申请的正极材料层包含正极材料。本申请对正极材料的种类没有特别限制，只要能够实现本申请目的即可。例如，正极材料可以包含镍钴锰酸锂(811、622、523、111)、镍钴铝酸锂、磷酸铁锂、富锂锰基材料、钴酸锂、锰酸锂、磷酸锰铁锂或钛酸锂等中的至少一种。在本申请中，正极材料还可以包含非金属元素，例如非金属元素包括氟、磷、硼、氯、硅、硫等中的至少一种，这些元素能进一步提高正极材料的稳定性。在本申请中，对正极集流体和正极材料层的厚度没有特别限制，只要能够实现本申请目的即可。例如，正极集流体的厚度为5μm至20μm，优选为为6μm至18μm。单面正极材料层的厚度为30μm至120μm。在本申请中，正极材料层可以设置于正极集流体厚度方向上的一个表面上，也可以设置于正极集流体厚度方向上的两个表面上。需要说明，这里的“表面”可以是正极集流体的全部区域，也可以是正极集流体的部分区域，本申请没有特别限制，只要能实现本申请目的即可。任选地，正极极片还可以包含导电层，导电层位于正极集流体和正极材料层之间。导电层的组成没有特别限制，可以是本领域常用的导电层。导电层包括导电剂和粘结剂。The positive electrode of the present application is not particularly limited, as long as the purpose of the present application can be achieved. For example, the positive electrode includes a positive electrode current collector and a positive electrode material layer. The present application has no special limitation on the positive electrode current collector, as long as the purpose of the present application can be achieved. For example, the positive electrode current collector may include aluminum foil, aluminum alloy foil, or a composite current collector. The positive electrode material layer of the present application contains the positive electrode material. The present application has no particular limitation on the type of positive electrode material, as long as the purpose of the present application can be achieved. For example, the positive electrode material may include lithium nickel cobalt manganate (811, 622, 523, 111), lithium nickel cobalt aluminate, lithium iron phosphate, lithium-rich manganese-based materials, lithium cobalt oxide, lithium manganate, lithium manganese iron phosphate or At least one of lithium titanate and the like. In the present application, the positive electrode material may also contain non-metallic elements, for example, non-metallic elements include at least one of fluorine, phosphorus, boron, chlorine, silicon, sulfur, etc., and these elements can further improve the stability of the positive electrode material. In the present application, there is no particular limitation on the thickness of the positive electrode current collector and the positive electrode material layer, as long as the purpose of the present application can be achieved. For example, the thickness of the positive electrode collector is 5 μm to 20 μm, preferably 6 μm to 18 μm. The thickness of the single-sided positive electrode material layer is 30 μm to 120 μm. In the present application, the positive electrode material layer may be provided on one surface in the thickness direction of the positive electrode current collector, or on two surfaces in the thickness direction of the positive electrode current collector. It should be noted that the "surface" here may refer to the entire area of the positive electrode collector or a partial area of the positive electrode collector. This application is not particularly limited, as long as the purpose of this application can be achieved. Optionally, the positive electrode sheet may further include a conductive layer, and the conductive layer is located between the positive electrode current collector and the positive electrode material layer. The composition of the conductive layer is not particularly limited, and may be a commonly used conductive layer in the field. The conductive layer includes a conductive agent and a binder.
本申请的负极没有特别限制，只要能够实现本申请目的即可。例如，负极包含负极集流体和负极材料层。本申请对负极集流体没有特别限制，只要能够实现本申请目的即可。例如，负极集流体可以包含铜箔、铜合金箔、镍箔、不锈钢箔、钛箔、泡沫镍、泡沫铜或复合集流体等。本申请的负极材料层包含负极材料。本申请对负极材料的种类没有特别限制，只要能够实现本申请目的即可。例如，负极材料可以包含天然石墨、人造石墨、中间相微碳球(MCMB)、硬碳、软碳、硅、硅-碳复合物、SiO x(0<x<2)、及金属锂等中的至少一种。在本申请中，对负极集流体和负极材料层的厚度没有特别限制，只要能够实现本 申请目的即可。例如，负极集流体的厚度为6μm至10μm，单面负极材料层的厚度为30μm至130μm。在本申请中，负极材料层可以设置于负极集流体厚度方向上的一个表面上，也可以设置于负极集流体厚度方向上的两个表面上。需要说明，这里的“表面”可以是负极集流体的全部区域，也可以是负极集流体的部分区域，本申请没有特别限制，只要能实现本申请目的即可。任选地，负极极片还可以包含导电层，导电层位于负极集流体和负极材料层之间。导电层的组成没有特别限制，可以是本领域常用的导电层。导电层包括导电剂和粘结剂。 The negative electrode of the present application is not particularly limited, as long as the purpose of the present application can be achieved. For example, the negative electrode includes a negative electrode current collector and a negative electrode material layer. The present application has no particular limitation on the negative electrode collector, as long as the purpose of the present application can be achieved. For example, the negative electrode current collector may include copper foil, copper alloy foil, nickel foil, stainless steel foil, titanium foil, nickel foam, copper foam, or a composite current collector. The negative electrode material layer of the present application contains the negative electrode material. The present application has no particular limitation on the type of negative electrode material, as long as the purpose of the present application can be achieved. For example, the negative electrode material can include natural graphite, artificial graphite, mesophase microcarbon spheres (MCMB), hard carbon, soft carbon, silicon, silicon-carbon composite, SiO x (0<x<2), and metal lithium, etc. at least one of . In the present application, there is no particular limitation on the thickness of the negative electrode current collector and the negative electrode material layer, as long as the purpose of the present application can be achieved. For example, the thickness of the negative electrode current collector is 6 μm to 10 μm, and the thickness of the single-sided negative electrode material layer is 30 μm to 130 μm. In the present application, the negative electrode material layer may be provided on one surface in the thickness direction of the negative electrode current collector, or on two surfaces in the thickness direction of the negative electrode current collector. It should be noted that the "surface" here may be the entire area of the negative electrode collector, or a partial area of the negative electrode collector. This application is not particularly limited, as long as the purpose of this application can be achieved. Optionally, the negative electrode sheet may further include a conductive layer, and the conductive layer is located between the negative electrode current collector and the negative electrode material layer. The composition of the conductive layer is not particularly limited, and may be a commonly used conductive layer in the field. The conductive layer includes a conductive agent and a binder.
上述导电剂没有特别限制，只要能够实现本申请目的即可。例如，导电剂可以包括导电炭黑(Super P)、碳纳米管(CNTs)、碳纳米纤维、鳞片石墨、乙炔黑、炭黑、科琴黑、碳点、碳纳米管或石墨烯中的至少一种。例如，粘结剂可以包括聚丙烯醇、聚丙烯酸钠、聚丙烯酸钾、聚丙烯酸锂、聚酰亚胺、聚酰亚胺、聚酰胺酰亚胺、丁苯橡胶(SBR)、聚乙烯醇(PVA)、聚偏氟乙烯、聚偏二氟乙烯(PVDF)、聚四氟乙烯(PTFE)、聚乙烯醇缩丁醛(PVB)、水性丙烯酸树脂、羧甲基纤维素(CMC)或羧甲基纤维素钠(CMC-Na)等中的至少一种。The conductive agent mentioned above is not particularly limited, as long as the purpose of the present application can be achieved. For example, the conductive agent can include at least one of conductive carbon black (Super P), carbon nanotubes (CNTs), carbon nanofibers, flake graphite, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes or graphene A sort of. For example, the binder may include polyacryl alcohol, sodium polyacrylate, potassium polyacrylate, lithium polyacrylate, polyimide, polyimide, polyamideimide, styrene-butadiene rubber (SBR), polyvinyl alcohol ( PVA), polyvinylidene fluoride, polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), polyvinyl butyral (PVB), water-based acrylic resin, carboxymethyl cellulose (CMC) or carboxymethyl At least one of base cellulose sodium (CMC-Na) and the like.
本申请的锂离子电池还包括隔膜，本申请对隔膜没有特别限制，只要能够实现本申请目的即可。例如，隔膜可以包括基材层和表面处理层。基材层可以为具有多孔结构的无纺布、膜或复合膜，基材层的材料可以包括聚乙烯(PE)、聚丙烯(PP)、聚对苯二甲酸乙二醇酯和聚酰亚胺等中的至少一种。任选地，可以使用聚丙烯多孔膜、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。任选地，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。例如，无机物层包括无机颗粒和粘结剂，无机颗粒没有特别限制，例如可以选自氧化铝、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、氢氧化钙和硫酸钡等中的至少一种。粘结剂没有特别限制，例如可以选自聚偏氟乙烯、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、聚乙烯醚、聚甲基丙烯酸甲酯、聚四氟乙烯和聚六氟丙烯等中的至少一种。聚合物层中包含聚合物，聚合物的材料包括聚酰胺、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、聚乙烯醚、聚偏氟乙烯或聚(偏氟乙烯-六氟丙烯)等中的至少一种。The lithium-ion battery of the present application also includes a separator, and the present application has no special limitation on the separator, as long as the purpose of the present application can be achieved. For example, a separator may include a substrate layer and a surface treatment layer. The substrate layer can be a non-woven fabric, film or composite film with a porous structure, and the material of the substrate layer can include polyethylene (PE), polypropylene (PP), polyethylene terephthalate and polyimide at least one of amines and the like. Optionally, 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 may be used. Optionally, at least one surface of the substrate layer is provided with a surface treatment layer, and the surface treatment layer may be a polymer layer or an inorganic layer, or a layer formed by mixing a polymer and an inorganic material. For example, the inorganic layer includes inorganic particles and a binder, and the inorganic particles are not particularly limited, for example, they can be selected from aluminum oxide, silicon oxide, magnesium oxide, titanium oxide, hafnium oxide, tin oxide, cerium oxide, nickel oxide, oxide At least one of zinc, calcium oxide, zirconia, yttrium oxide, silicon carbide, boehmite, aluminum hydroxide, magnesium hydroxide, calcium hydroxide and barium sulfate. The binder is not particularly limited, for example, it can be selected from polyvinylidene fluoride, copolymer of vinylidene fluoride-hexafluoropropylene, polyamide, polyacrylonitrile, polyacrylate, polyacrylic acid, polyacrylate, polyvinylpyrrolidine At least one of ketone, polyvinyl ether, polymethyl methacrylate, polytetrafluoroethylene and polyhexafluoropropylene. The polymer layer comprises a polymer, and the polymer material includes polyamide, polyacrylonitrile, acrylate polymer, polyacrylic acid, polyacrylate, polyvinylpyrrolidone, polyvinyl ether, polyvinylidene fluoride or poly( at least one of vinylidene fluoride-hexafluoropropylene) and the like.
本申请的电化学装置没有特别限制，其可以包括发生电化学反应的任何装置。在一些实施例中，电化学装置可以包括但不限于：锂金属二次电池、锂离子二次电池(锂离子电池)、锂聚合物二次电池或锂离子聚合物二次电池等。The electrochemical device of the present application is not particularly limited, and it may include any device that undergoes an electrochemical reaction. In some embodiments, the electrochemical device may include, but is not limited to, a lithium metal secondary battery, a lithium ion secondary battery (lithium ion battery), a lithium polymer secondary battery, or a lithium ion polymer secondary battery, and the like.
本申请第三方面提供了一种电子装置，其包含本申请第二方面提供的电化学装置。该电子装置具有良好的循环性能和高温存储性能。The third aspect of the present application provides an electronic device, which includes the electrochemical device provided in the second aspect of the present application. The electronic device has good cycle performance and high-temperature storage performance.
本申请的电子装置没有特别限制，其可以包括但不限于以下种类：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、和家庭用大型蓄电池等。The electronic devices of the present application are not particularly limited, and may include but not limited to the following types: notebook computers, pen-input computers, mobile computers, e-book players, portable phones, portable fax machines, portable copiers, portable printers, head-mounted Stereo headphones, VCRs, LCD TVs, portable cleaners, portable CD players, mini-discs, transceivers, electronic organizers, calculators, memory cards, portable tape recorders, radios, backup power supplies, electric motors, automobiles, motorcycles, power-assisted bicycles , bicycles, lighting appliances, toys, game consoles, clocks, electric tools, flashlights, cameras, and large batteries for household use.
以下，基于实施例对本申请进行具体地说明，但本申请并不限于这些实施例。Hereinafter, although this application is demonstrated concretely based on an Example, this application is not limited to these Examples.
实施例1至实施例47、对比例1的测试方法和设备：The test method and equipment of embodiment 1 to embodiment 47, comparative example 1:
循环性能测试：Cycle performance test:
在25℃条件下，将锂离子电池以0.7C充电至4.5V，4.5V条件下恒压充电至0.05C。之后以0.7C的电流放电至3.0V，并以0.7C充电和1C放电的流程，循环进行800圈。容量保持率＝(第800次循环的放电容量/初始放电容量)×100％。At 25°C, the lithium-ion battery was charged at 0.7C to 4.5V, and at 4.5V at a constant voltage to 0.05C. Then discharge to 3.0V with a current of 0.7C, and charge at 0.7C and discharge at 1C for 800 cycles. Capacity retention=(discharge capacity at the 800th cycle/initial discharge capacity)×100%.
高温存储性能测试：High temperature storage performance test:
将锂离子电池在25℃下以0.5C恒流充电至4.5V，然后恒压充电至电流为0.05C，测试锂离子电池的厚度并记为初始厚度，放置到85℃烘箱当中24h，监控此时厚度，记为存储后厚度。锂离子电池高温存储24h后的存储厚度膨胀率(％)＝(存储后厚度-初始厚度)/初始厚度×100％，存储厚度膨胀率超过50％有危险性，停止测试。Charge the lithium-ion battery at 25°C with a constant current of 0.5C to 4.5V, and then charge it with a constant voltage until the current is 0.05C. Test the thickness of the lithium-ion battery and record it as the initial thickness. Place it in an oven at 85°C for 24 hours, and monitor it. When the thickness is recorded as the thickness after storage. The storage thickness expansion rate (%) of the lithium-ion battery after high-temperature storage for 24 hours = (thickness after storage - initial thickness)/initial thickness × 100%. If the storage thickness expansion rate exceeds 50%, it is dangerous, so stop the test.
浮充性能测试：Float charge performance test:
将锂离子电池在45℃下以0.5C放电至3.0V，再以0.5C充电至4.5V，4.5V下恒压充电至0.05C，测试锂离子电池的厚度并记为初始厚度，放置到45℃烘箱当中，4.5V恒压充电30天，监控厚度变化，厚度记为浮充后厚度，锂离子电池的浮充厚度膨胀率(％)＝(浮充后厚度-初始厚度)/初始厚度×100％，浮充厚度膨胀率超过50％有危险性，停止测试。Discharge the lithium-ion battery at 0.5C to 3.0V at 45°C, then charge it to 4.5V at 0.5C, and charge it to 0.05C at a constant voltage at 4.5V, test the thickness of the lithium-ion battery and record it as the initial thickness, and place it at 45 In an oven at ℃, charge at a constant voltage of 4.5V for 30 days, monitor the thickness change, and record the thickness as the thickness after float charge, and the thickness expansion rate of the lithium ion battery after float charge (%)=(thickness after float charge-initial thickness)/initial thickness× 100%, the float thickness expansion rate exceeding 50% is dangerous, stop the test.
实施例1Example 1
<电解液的制备><Preparation of Electrolyte Solution>
在含水量小于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)、丙酸乙酯(EP)、丙酸丙酯(PP)，按照1:1:1:1:1的质量比混合均匀，形成基础溶剂。再向上述基础溶剂中加入式(Ⅰ)表示的化合物式(Ⅰ-1)、式(Ⅱ)表示的化合物式(Ⅱ-1)和充分干燥的锂盐LiPF 6，并搅拌均匀使锂盐溶解。基于电解液的总质量，式(Ⅰ-1)的质量百分含量为0.1％，(Ⅱ-1)的质量百分含量为0.001％，锂盐LiPF 6的质量百分含量为12.5％，余量为基础溶剂的质量百分含量。 In an argon atmosphere glove box with a water content of less than 10ppm, ethylene carbonate (EC), propylene carbonate (PC), diethyl carbonate (DEC), ethyl propionate (EP), propyl propionate (PP) ), mixed uniformly according to the mass ratio of 1:1:1:1:1 to form the base solvent. Then add compound formula (I-1) represented by formula (I), compound formula (II-1) represented by formula (II) and fully dried lithium salt LiPF 6 into the above basic solvent, and stir evenly to dissolve the lithium salt . Based on the total mass of the electrolyte, the mass percentage of formula (I-1) is 0.1%, the mass percentage of (II-1) is 0.001%, and the mass percentage of lithium salt LiPF 6 is 12.5%. The amount is the mass percentage of the base solvent.
<正极极片的制备><Preparation of positive electrode sheet>
将正极材料钴酸锂(LiCoO 2)、导电剂导电碳黑、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进行混合，加入N-甲基吡咯烷酮(NMP)作为溶剂，充分搅拌混合，调配成固含量为75wt％的正极浆料；将正极浆料均匀涂覆于厚度为10μm的正极集流体铝箔的两个表面上，90℃条件下烘干，冷压后得到单面涂层厚度为100μm的正极极片，正极压实密度为4.15g/cm 3。将正极极片裁切待用。 Mix the positive electrode material lithium cobaltate (LiCoO 2 ), conductive carbon black, conductive paste, and binder polyvinylidene fluoride (PVDF) in a weight ratio of 97.9:0.4:0.5:1.2, and add N-methyl Pyrrolidone (NMP) was used as a solvent, fully stirred and mixed, and prepared into a positive electrode slurry with a solid content of 75% by weight; the positive electrode slurry was evenly coated on both surfaces of a positive electrode current collector aluminum foil with a thickness of 10 μm, and baked at 90 ° C. After drying and cold pressing, a positive electrode sheet with a coating thickness of 100 μm on one side was obtained, and the compacted density of the positive electrode was 4.15 g/cm 3 . Cut the positive electrode sheet for use.
<负极极片的制备><Preparation of Negative Electrode Sheet>
将负极材料石墨、粘结剂丁苯橡胶(SBR)、增稠剂羧甲基纤维素钠(CMC)按照重量比97.4:1.4:1.2混合，然后加入去离子水作为溶剂，充分搅拌混合，调配成固含量为70wt％的负极浆料；将负极浆料均匀涂覆于厚度为8μm的负极集流体铜箔的两个表面上，90℃条件下烘干，冷压后得到单面涂层厚度为150μm的负极极片，负极的压实密度为1.80g/cm 3。将负极极片裁切待用。 Mix the negative electrode material graphite, the binder styrene-butadiene rubber (SBR), and the thickener sodium carboxymethylcellulose (CMC) according to the weight ratio of 97.4:1.4:1.2, then add deionized water as a solvent, fully stir and mix, and prepare A negative electrode slurry with a solid content of 70wt% is formed; the negative electrode slurry is evenly coated on both surfaces of the negative electrode current collector copper foil with a thickness of 8 μm, dried at 90 ° C, and the thickness of the single-sided coating is obtained after cold pressing It is a negative electrode sheet of 150 μm, and the compacted density of the negative electrode is 1.80 g/cm 3 . Cut the negative electrode sheet for use.
<隔膜的制备><Preparation of separator>
采用厚度为5μm的聚乙烯(PE)多孔聚合物薄膜作为隔膜。A polyethylene (PE) porous polymer film with a thickness of 5 μm was used as the separator.
<锂离子电池的制备><Preparation of lithium ion battery>
将正极极片、隔膜、负极极片按顺序叠好，使隔膜处于正极极片和负极极片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。Stack the positive electrode sheet, separator, and negative electrode sheet in order, so that the separator is between the positive electrode sheet and the negative electrode sheet to play the role of isolation, and then wind up to obtain a bare cell; place the bare cell in the outer packaging foil, The above prepared electrolyte solution is injected into the dried battery, and the preparation of the lithium-ion battery is completed through processes such as vacuum packaging, standing still, chemical formation, and shaping.
实施例2至实施例17Example 2 to Example 17
<电解液的制备>、<正极极片的制备>、<负极极片的制备>、<隔膜的制备>及<锂离子电池的制备>的制备步骤均与实施例1相同，相关制备参数和性能参数的变化如表1所示。<Preparation of Electrolyte>, <Preparation of Positive Electrode>, <Preparation of Negative Electrode>, <Preparation of Diaphragm> and <Preparation of Lithium-ion Battery> are all the same as in Example 1, and the relevant preparation parameters and The changes in performance parameters are shown in Table 1.
实施例18至实施例47Example 18 to Example 47
<电解液的制备><Preparation of Electrolyte Solution>
除了向基础溶剂中加入式(Ⅰ)表示的化合物、式(Ⅱ)表示的化合物外，还加入硫氧双键类化合物、多腈类化合物或硼类锂盐化合物中的至少一种，相关制备参数和性能参数的变化如表2所示，其余与实施例1相同。In addition to adding the compound represented by formula (I) and the compound represented by formula (II) to the base solvent, at least one of sulfur-oxygen double bond compound, polynitrile compound or boron lithium salt compound is added, and the related preparation The changes of parameters and performance parameters are shown in Table 2, and all the other are the same as in Example 1.
<正极极片的制备>、<负极极片的制备>、<隔膜的制备>及<锂离子电池的制备>的制备步骤均与实施例1相同。The preparation steps of <Preparation of Positive Electrode>, <Preparation of Negative Electrode>, <Preparation of Diaphragm> and <Preparation of Lithium-ion Battery> are all the same as in Example 1.
对比例1Comparative example 1
<电解液的制备><Preparation of Electrolyte Solution>
除了不向基础溶剂中加入式(Ⅰ)表示的化合物、式(Ⅱ)表示的化合物外，其余与实施例1相同，相关制备参数和性能参数的变化如表1所示。Except that the compound represented by formula (I) and compound represented by formula (II) was not added to the base solvent, the rest was the same as that of Example 1, and the changes of relevant preparation parameters and performance parameters are shown in Table 1.
<正极极片的制备>、<负极极片的制备>、<隔膜的制备>及<锂离子电池的制备>的制备步骤均与实施例1相同。The preparation steps of <Preparation of Positive Electrode>, <Preparation of Negative Electrode>, <Preparation of Diaphragm> and <Preparation of Lithium-ion Battery> are all the same as in Example 1.
实施例48至实施例66、对比例2的测试方法和设备：The testing method and equipment of embodiment 48 to embodiment 66, comparative example 2:
循环性能测试：Cycle performance test:
在25℃条件下，将锂离子电池以1C充电至4.2V，4.2V条件下恒压充电至0.05C。之后以1C的电流放电至2.8V，并以1C充电和4C放电的流程，循环进行800圈。容量保持率＝(第800次循环的放电容量/初始放电容量)×100％。At 25°C, the lithium-ion battery was charged at 1C to 4.2V, and at 4.2V at a constant voltage to 0.05C. Then discharge to 2.8V with a current of 1C, and cycle through 800 cycles of charging at 1C and discharging at 4C. Capacity retention=(discharge capacity at the 800th cycle/initial discharge capacity)×100%.
高温存储性能测试：High temperature storage performance test:
将锂离子电池在25℃下以0.5C恒流充电至4.2V，然后恒压充电至电流为0.05C，测试锂离子电池的厚度并记为初始厚度；放置到85℃烘箱当中6h，监控此时厚度，记为存储后厚度。锂离子电池高温存储6h后的存储厚度膨胀率(％)＝(存储后厚度-初始厚度)/初始厚度×100％，存储厚度膨胀率大于50％有危险性，停止测试。Charge the lithium-ion battery at 25°C with a constant current of 0.5C to 4.2V, and then charge it with a constant voltage until the current is 0.05C. Test the thickness of the lithium-ion battery and record it as the initial thickness; place it in an oven at 85°C for 6 hours, and monitor this When the thickness is recorded as the thickness after storage. The storage thickness expansion rate (%) of the lithium-ion battery after high-temperature storage for 6 hours = (thickness after storage - initial thickness)/initial thickness × 100%. If the storage thickness expansion rate is greater than 50%, it is dangerous, so stop the test.
实施例48Example 48
<电解液的制备><Preparation of Electrolyte Solution>
在含水量小于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，形成基础溶剂。再向上述基础溶剂中 加入式(Ⅰ)表示的化合物式(Ⅰ-1)、式(Ⅱ)表示的化合物式(Ⅱ-1)和充分干燥的锂盐LiPF 6，并搅拌均匀使锂盐溶解。基于电解液的总质量，式(Ⅰ-1)的质量百分含量为0.5％，(Ⅱ-1)的质量百分含量为0.5％，锂盐LiPF 6的质量百分含量为12.5％，余量为基础溶剂的质量百分含量。 In an argon atmosphere glove box with a water content of less than 10ppm, mix ethylene carbonate (EC), propylene carbonate (PC), and diethyl carbonate (DEC) uniformly in a mass ratio of 3:3:4 to form a base solvent. Then add compound formula (I-1) represented by formula (I), compound formula (II-1) represented by formula (II) and fully dried lithium salt LiPF 6 into the above basic solvent, and stir evenly to dissolve the lithium salt . Based on the total mass of the electrolyte, the mass percentage of formula (I-1) is 0.5%, the mass percentage of (II-1) is 0.5%, and the mass percentage of lithium salt LiPF 6 is 12.5%. The amount is the mass percentage of the base solvent.
<正极极片的制备><Preparation of positive electrode sheet>
将正极材料镍钴锰酸锂NCM811(分子式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进行混合，加入N-甲基吡咯烷酮(NMP)作为溶剂，充分搅拌混合，调配成固含量为75wt％的正极浆料；将正极浆料涂覆于厚度为10μm的正极集流体铝箔的两个表面上，90℃条件下烘干，冷压后得到单面涂层厚度为100μm的正极极片，正极压实密度为3.50g/cm 3。将正极极片裁切待用。 The positive electrode material nickel cobalt lithium manganese oxide NCM811 (molecular formula LiNi 0.8 Mn 0.1 Co 0.1 O 2 ), the conductive agent acetylene black, and the binder polyvinylidene fluoride (PVDF) were mixed in a weight ratio of 96:2:2, and N -Methylpyrrolidone (NMP) is used as a solvent, fully stirred and mixed, and prepared into a positive electrode slurry with a solid content of 75wt%; the positive electrode slurry is coated on both surfaces of a positive electrode current collector aluminum foil with a thickness of 10 μm, and the condition is 90 ° C. After drying under the hood and cold pressing, a positive electrode sheet with a coating thickness of 100 μm on one side was obtained, and the compacted density of the positive electrode was 3.50 g/cm 3 . Cut the positive electrode sheet for use.
<负极极片的制备>、<隔膜的制备>及<锂离子电池的制备>的制备步骤均与实施例1相同。The preparation steps of <Preparation of Negative Electrode Sheet>, <Preparation of Diaphragm> and <Preparation of Lithium-ion Battery> are all the same as in Example 1.
实施例49至实施例51Example 49 to Example 51
<电解液的制备>、<正极极片的制备>、<负极极片的制备>、<隔膜的制备>及<锂离子电池的制备>的制备步骤均与实施例48相同，相关制备参数和性能参数的变化如表3所示。<Preparation of Electrolyte>, <Preparation of Positive Electrode>, <Preparation of Negative Electrode>, <Preparation of Diaphragm> and <Preparation of Lithium-ion Battery> are all the same as in Example 48, and the relevant preparation parameters and The changes in performance parameters are shown in Table 3.
实施例52至实施例66Example 52 to Example 66
<电解液的制备><Preparation of Electrolyte Solution>
除了向基础电解液中加入式(Ⅰ)表示的化合物、式(Ⅱ)表示的化合物外，还加入硫氧双键类化合物、P-O键类化合物或环状碳酸酯类化合物中的至少一种，相关制备参数和性能参数的变化如表3所示，其余与实施例48相同。In addition to adding the compound represented by the formula (I) and the compound represented by the formula (II) to the basic electrolyte, at least one of the sulfur-oxygen double bond compound, the P-O bond compound or the cyclic carbonate compound is added, The changes of relevant preparation parameters and performance parameters are shown in Table 3, and the rest are the same as in Example 48.
<正极极片的制备>、<负极极片的制备>、<隔膜的制备>及<锂离子电池的制备>的制备步骤均与实施例48相同。The preparation steps of <Preparation of Positive Electrode>, <Preparation of Negative Electrode>, <Preparation of Separator> and <Preparation of Lithium-ion Battery> were the same as in Example 48.
对比例2Comparative example 2
<电解液的制备><Preparation of Electrolyte Solution>
除了不向基础电解液中加入式(Ⅰ)表示的化合物、式(Ⅱ)表示的化合物外，其余与实施例48相同，相关制备参数和性能参数的变化如表3所示。Except that the compound represented by formula (I) and compound represented by formula (II) is not added to the basic electrolyte, the rest is the same as that of Example 48, and the changes of relevant preparation parameters and performance parameters are shown in Table 3.
<正极极片的制备>、<负极极片的制备>、<隔膜的制备>及<锂离子电池的制备>的制备步骤均与实施例48相同。The preparation steps of <Preparation of Positive Electrode>, <Preparation of Negative Electrode>, <Preparation of Separator> and <Preparation of Lithium-ion Battery> were the same as in Example 48.
Figure PCTCN2021131558-appb-000029
Figure PCTCN2021131558-appb-000029
Figure PCTCN2021131558-appb-000030
Figure PCTCN2021131558-appb-000030
Figure PCTCN2021131558-appb-000031
Figure PCTCN2021131558-appb-000031
Figure PCTCN2021131558-appb-000032
Figure PCTCN2021131558-appb-000032
Figure PCTCN2021131558-appb-000033
Figure PCTCN2021131558-appb-000033
从实施例1至实施例17、实施例48、对比例1、对比例2可以看出，本申请在电解液中添加式(Ⅰ)和式(Ⅱ)表示的氰基化合物，能够明显改善锂离子电池的循环性能、浮充性能和高温存储性能。From Example 1 to Example 17, Example 48, Comparative Example 1, and Comparative Example 2, it can be seen that the application of the cyano compound represented by formula (I) and formula (II) in the electrolyte can significantly improve the lithium The cycle performance, float charge performance and high temperature storage performance of ion batteries.
从实施例1至实施例8可以看出，随着式(Ⅰ)和式(Ⅱ)表示的化合物质量百分含量W 1+W 2的增加，锂离子电池的容量保持率呈先增加后降低的趋势，本申请通过将W 1+W 2控制在0.1％至5％范围内，能够使锂离子电池具有较好的循环性能、浮充性能和高温存储性能。 From Examples 1 to 8, it can be seen that with the increase of the mass percentage W 1 + W 2 of the compounds represented by formula (I) and formula (II), the capacity retention rate of lithium-ion batteries first increases and then decreases In this application, by controlling W 1 +W 2 within the range of 0.1% to 5%, the lithium-ion battery can have better cycle performance, float charge performance and high-temperature storage performance.
从实施例12、实施例18至实施例47可以看出，本申请电解液中加入不同种类的硫氧双键类化合物或多腈类化合物中的至少一种，均能够进一步提升锂离子电池的循环性能、浮充性能和高温存储性能；加入不同种类的硼类锂盐化合物，能够提升锂离子电池的循环性能。From Example 12, Example 18 to Example 47, it can be seen that adding at least one of different types of sulfur-oxygen double bond compounds or polynitrile compounds in the electrolyte of the present application can further improve the performance of lithium-ion batteries. Cycle performance, float charge performance and high temperature storage performance; adding different types of boron lithium salt compounds can improve the cycle performance of lithium-ion batteries.
从实施例48至实施例50可以看出，本申请电解液中加入不同质量百分含量的锂盐，均能够改善锂离子电池的循环性能和高温存储性能。从实施例48、实施例51至实施例66可以看出，本申请电解液中加入不同种类的硫氧双键类化合物、P-O键类化合物或环状碳酸酯类化合物中的至少一种，均能够进一步提升锂离子电池的循环性能和高温存储性能。From Example 48 to Example 50, it can be seen that adding different mass percentages of lithium salts to the electrolyte of the present application can improve the cycle performance and high-temperature storage performance of lithium-ion batteries. It can be seen from Example 48, Example 51 to Example 66 that adding at least one of different types of sulfur-oxygen double bond compounds, P-O bond compounds or cyclic carbonate compounds into the electrolyte solution of the present application, all It can further improve the cycle performance and high-temperature storage performance of lithium-ion batteries.
以上所述仅为本申请的较佳实施例，并不用以限制本申请，凡在本申请的精神和原则之内，所做的任何修改、等同替换、改进等，均应包含在本申请保护的范围之内。The above are only preferred embodiments of the application, and are not intended to limit the application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the application shall be included in the protection of the application. within the range.

Claims (14)

  1. 一种电解液，其包括式(Ⅰ)和式(Ⅱ)表示的氰基化合物：A kind of electrolytic solution, it comprises the cyano compound represented by formula (I) and formula (II):
    Figure PCTCN2021131558-appb-100001
    Figure PCTCN2021131558-appb-100001
    其中，in,
    A 1独立地选自式(Ⅰ-A)或式(Ⅱ-A)， A is independently selected from formula (I-A) or formula (II-A),
    Figure PCTCN2021131558-appb-100002
    Figure PCTCN2021131558-appb-100002
    Figure PCTCN2021131558-appb-100003
    表示与相邻原子的结合位点；
    Figure PCTCN2021131558-appb-100003
    Indicates the binding site with adjacent atoms;
    m或n各自独立地选自0或1；m or n are each independently selected from 0 or 1;
    R 1、R 11、R 12、R 13、R 14、R 15、R 16、R 17、R 18、R 19各自独立地选自共价单键、取代或未取代的的C 1至C 10的亚烷基或亚杂环基、取代或未取代的C 2至C 10的亚烯基或亚炔基、取代或未取代的C 3至C 10的亚连烯基或亚脂环烃基、取代或未取代的C 6至C 10的亚芳基，各基团的取代基各自独立地选自氟、氯、溴或碘。 R 1 , R 11 , R 12 , R 13 , R 14 , R 15 , R 16 , R 17 , R 18 , R 19 are each independently selected from covalent single bonds, substituted or unsubstituted C 1 to C 10 Alkylene or heterocyclylene, substituted or unsubstituted C 2 to C 10 alkenylene or alkynylene, substituted or unsubstituted C 3 to C 10 allenylene or alicyclic hydrocarbon group, In the substituted or unsubstituted C6 to C10 arylene group, the substituents of each group are independently selected from fluorine, chlorine, bromine or iodine.
  2. 根据权利要求1所述的电解液，其中，所述式(Ⅰ)表示的化合物包含以下化合物中的至少一种：The electrolyte solution according to claim 1, wherein the compound represented by the formula (I) comprises at least one of the following compounds:
    Figure PCTCN2021131558-appb-100004
    Figure PCTCN2021131558-appb-100004
    Figure PCTCN2021131558-appb-100005
    Figure PCTCN2021131558-appb-100005
    所述式(Ⅱ)表示的化合物包含以下化合物中的至少一种：The compound represented by the formula (II) comprises at least one of the following compounds:
    Figure PCTCN2021131558-appb-100006
    Figure PCTCN2021131558-appb-100006
    Figure PCTCN2021131558-appb-100007
    Figure PCTCN2021131558-appb-100007
  3. 根据权利要求1所述的电解液，其中，基于所述电解液的总质量，式(Ⅰ)表示的化合物的质量百分含量为W 1,式(Ⅱ)表示的化合物的质量百分含量为W 2，满足：0.01％≤W 1≤5％，0.001％≤W 2≤5％，0.1％≤W 1+W 2≤5％。 The electrolyte according to claim 1, wherein, based on the total mass of the electrolyte, the mass percentage of the compound represented by formula (I) is W 1 , and the mass percentage of the compound represented by formula (II) is W 2 satisfies: 0.01%≤W 1 ≤5%, 0.001%≤W 2 ≤5%, 0.1%≤W 1 +W 2 ≤5%.
  4. 根据权利要求1所述的电解液，其中，所述电解液还包含多腈类化合物，所述多腈类化合物包含以下化合物中的至少一种：The electrolytic solution according to claim 1, wherein the electrolytic solution also comprises polynitrile compounds, and the polynitrile compounds comprise at least one of the following compounds:
    Figure PCTCN2021131558-appb-100008
    Figure PCTCN2021131558-appb-100008
  5. 根据权利要求4所述的电解液，其中，基于所述电解液的总质量，所述式(Ⅰ)表示的化合物的质量百分含量为W 1,所述式(Ⅱ)表示的化合物的质量百分含量为W 2，所述多腈类化合物的质量百分含量为W 3，满足：0.5％≤W 3≤7％，0.01≤(W 1+W 2)/W 3≤1。 The electrolyte according to claim 4, wherein, based on the total mass of the electrolyte, the mass percentage of the compound represented by the formula (I) is W 1 , and the mass of the compound represented by the formula (II) The percentage content is W 2 , and the mass percentage content of the polynitrile compound is W 3 , satisfying: 0.5%≤W 3 ≤7%, 0.01≤(W 1 +W 2 )/W 3 ≤1.
  6. 根据权利要求1所述的电解液，其中，所述电解液还包含硼类锂盐化合物，所述硼类锂盐化合物包括四氟硼酸锂、二草酸硼酸锂或二氟草酸硼酸锂中的至少一种。The electrolytic solution according to claim 1, wherein the electrolytic solution further comprises a boron-type lithium salt compound, and the boron-type lithium salt compound comprises at least one of lithium tetrafluoroborate, lithium dioxalate borate or lithium difluorooxalate borate A sort of.
  7. 根据权利要求6所述的电解液，其中，基于所述电解液的总质量，所述硼类锂盐化合物的质量百分含量W 4为0.1％至1％。 The electrolytic solution according to claim 6, wherein, based on the total mass of the electrolytic solution, the mass percentage W 4 of the boron lithium salt compound is 0.1% to 1%.
  8. 根据权利要求1所述的电解液，其中，所述电解液还包含P-O键类化合物，所述P-O键类化合物包括二氟磷酸锂、二氟双草酸磷酸锂、四氟草酸磷酸锂、1,2-双((二氟膦基)氧基)乙烷、三甲基磷酸酯、三苯基磷酸酯、三异丙基磷酸酯、3,3,3-三氟乙基磷酸酯、3,3,3- 三氟乙基亚磷酸酯、三(三甲基硅烷)磷酸酯、2-(2,2,2-三氟乙氧基)-1,3,2-二氧杂膦烷2-氧化物中的至少一种。The electrolytic solution according to claim 1, wherein the electrolytic solution further comprises a P-O bond compound, and the P-O bond compound includes lithium difluorophosphate, lithium difluorobisoxalate phosphate, lithium tetrafluorooxalate phosphate, 1, 2-bis((difluorophosphino)oxy)ethane, trimethylphosphate, triphenylphosphate, triisopropylphosphate, 3,3,3-trifluoroethylphosphate, 3, 3,3-Trifluoroethylphosphite, tris(trimethylsilane)phosphate, 2-(2,2,2-trifluoroethoxy)-1,3,2-dioxaphosphorane2 - at least one of oxides.
  9. 根据权利要求8所述的电解液，其中，基于所述电解液的总质量，所述P-O键类化合物的质量百分含量W 5为0.1％至1％。 The electrolyte solution according to claim 8, wherein, based on the total mass of the electrolyte solution, the mass percentage W 5 of the PO bond compound is 0.1% to 1%.
  10. 根据权利要求1所述的电解液，其中，所述电解液还包含硫氧双键类化合物，所述硫氧双键类化合物包括式(Ⅳ)表示的化合物中的至少一种：The electrolytic solution according to claim 1, wherein the electrolytic solution further comprises a sulfur-oxygen double bond compound, and the sulfur-oxygen double bond compound includes at least one of the compounds represented by formula (IV):
    Figure PCTCN2021131558-appb-100009
    Figure PCTCN2021131558-appb-100009
    其中，A 4选自式(Ⅳ-A)、式(Ⅳ-B)、式(Ⅳ-C)、式(Ⅳ-D)、式(Ⅳ-E)中的至少一种： Wherein, A is selected from at least one of formula (IV-A), formula (IV-B), formula (IV-C), formula (IV-D), and formula (IV-E):
    Figure PCTCN2021131558-appb-100010
    Figure PCTCN2021131558-appb-100010
    Figure PCTCN2021131558-appb-100011
    表示与相邻原子的结合位点；
    Figure PCTCN2021131558-appb-100011
    Indicates the binding site with adjacent atoms;
    R 41和R 42各自独立地选自共价键、取代或未取代的C 1至C 5的烷基或亚烷基、取代或未取代的C 1至C 6的杂环基、取代或未取代的C 2至C 10的烯基或炔基、取代或未取代的C 3至C 10的脂环基，并且R 41和R 42可以连接成环； R 41 and R 42 are each independently selected from a covalent bond, a substituted or unsubstituted C 1 to C 5 alkyl or alkylene group, a substituted or unsubstituted C 1 to C 6 heterocyclic group, a substituted or unsubstituted Substituted C 2 to C 10 alkenyl or alkynyl, substituted or unsubstituted C 3 to C 10 alicyclic group, and R 41 and R 42 may be connected to form a ring;
    R 43选自共价键、取代或未取代的C 1至C 3的亚烷基、取代或未取代的C 2至C 3的亚烯基或亚炔基； R 43 is selected from a covalent bond, a substituted or unsubstituted C 1 to C 3 alkylene group, a substituted or unsubstituted C 2 to C 3 alkenylene or alkynylene group;
    其中，取代基选自卤素、取代或未取代C 1至C 3的烷基、取代或未取代C 2至C 3的烯基、取代或未取代C 2至C 3的炔基； Wherein, the substituent is selected from halogen, substituted or unsubstituted C1 to C3 alkyl, substituted or unsubstituted C2 to C3 alkenyl, substituted or unsubstituted C2 to C3 alkynyl;
    其中，所述杂原子选自N、O或S中的至少一种；Wherein, the heteroatom is selected from at least one of N, O or S;
    基于所述电解液的总质量，所述式(Ⅳ)表示的化合物的质量百分含量W 6为0.1％至8％。 Based on the total mass of the electrolyte, the mass percentage W 6 of the compound represented by the formula (IV) is 0.1% to 8%.
  11. 根据权利要求10所述的电解液，其中，式(Ⅳ)表示的化合物包含以下化合物中的至少一种：The electrolyte solution according to claim 10, wherein the compound represented by formula (IV) comprises at least one of the following compounds:
    Figure PCTCN2021131558-appb-100012
    Figure PCTCN2021131558-appb-100012
  12. 根据权利要求1所述的电解液，其中，所述电解液还包含环状碳酸酯类化合物，所述环状碳酸酯类化合物包括以下化合物中的至少一种：The electrolytic solution according to claim 1, wherein the electrolytic solution further comprises a cyclic carbonate compound, and the cyclic carbonate compound comprises at least one of the following compounds:
    Figure PCTCN2021131558-appb-100013
    Figure PCTCN2021131558-appb-100013
    基于所述电解液的总质量，所述环状碳酸酯类化合物的质量百分含量W 7为0.1％至10％； Based on the total mass of the electrolyte, the mass percentage W 7 of the cyclic carbonate compound is 0.1% to 10%;
    所述电解液包含锂盐，所述锂盐包括六氟磷酸锂、双磺酰亚胺锂(LiN(C xF 2x+1SO 2)(C yF 2y+1SO 2)，其中x是0至10的自然数，y是0至10的自然数)、高氯酸锂、六氟锑酸锂、六氟砷酸锂中的至少一种，基于所述电解液的总质量，所述锂盐的质量百分含量W 8为10％至20％。 The electrolyte contains lithium salts including lithium hexafluorophosphate, lithium bissulfonimide (LiN(C x F 2x+1 SO 2 )(C y F 2y+1 SO 2 ), where x is 0 to 10 a natural number, y is a natural number from 0 to 10), at least one of lithium perchlorate, lithium hexafluoroantimonate, and lithium hexafluoroarsenate, based on the total mass of the electrolyte, the mass of the lithium salt is 100% The component content W 8 is 10% to 20%.
  13. 一种电化学装置，其包含权利要求1至12中任一项所述的电解液。An electrochemical device comprising the electrolytic solution according to any one of claims 1 to 12.
  14. 一种电子装置，其包含权利要求13的电化学装置。An electronic device comprising the electrochemical device of claim 13.
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