WO2025199693A1 - 一种电解液、包含该电解液的二次电池及电子装置 - Google Patents

一种电解液、包含该电解液的二次电池及电子装置

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Publication number
WO2025199693A1
WO2025199693A1 PCT/CN2024/083614 CN2024083614W WO2025199693A1 WO 2025199693 A1 WO2025199693 A1 WO 2025199693A1 CN 2024083614 W CN2024083614 W CN 2024083614W WO 2025199693 A1 WO2025199693 A1 WO 2025199693A1
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WIPO (PCT)
Prior art keywords
electrolyte
lithium
metal cation
positive electrode
cation salt
Prior art date
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Pending
Application number
PCT/CN2024/083614
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English (en)
French (fr)
Inventor
王美茸
周邵云
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Ningde Amperex Technology Ltd
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Ningde Amperex Technology Ltd
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Priority to PCT/CN2024/083614 priority Critical patent/WO2025199693A1/zh
Publication of WO2025199693A1 publication Critical patent/WO2025199693A1/zh
Pending legal-status Critical Current
Anticipated expiration legal-status Critical

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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
    • H01M10/0567—Liquid materials characterised by the additives
    • 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 field of electrochemical technology, and in particular to an electrolyte, a secondary battery containing the electrolyte, and an electronic device.
  • Secondary batteries such as lithium-ion batteries
  • the purpose of this application is to provide an electrolyte, a secondary battery containing the electrolyte, and an electronic device to improve the cycle performance of the secondary battery.
  • the specific technical solution is as follows:
  • the first aspect of the present application provides an electrolyte, which includes lithium difluorophosphate and a metal cation salt, wherein the valence of the metal cation of the metal cation salt is positive divalent or higher, and the anion group of the metal cation salt includes the anion group represented by formula IA or the anion group represented by formula IB:
  • R1 is selected from a C1 to C3 alkyl group in which all hydrogen atoms are replaced by fluorine
  • R2 and R3 are each independently selected from a fluorine atom or a C1 to C3 alkyl group in which all hydrogen atoms are replaced by fluorine
  • the mass percentage of lithium difluorophosphate is A%
  • the mass percentage of the metal cation salt is B%, 2 ⁇ A ⁇ 8.8, 1 ⁇ A/B ⁇ 2.2.
  • the electrolyte of the present application includes lithium difluorophosphate and a metal cation salt
  • the metal cation salt includes a metal cation with a positive divalent value or higher, has a high positive charge density, has a large electrostatic effect on difluorophosphate, can promote the dissolution of lithium difluorophosphate in the electrolyte, thereby making lithium difluorophosphate have a high solubility, is conducive to the role of lithium difluorophosphate, forms a stable negative electrode solid electrolyte interface film (SEI film) and a positive electrode solid electrolyte interface film (CEI film), thereby improving the cycle performance and high temperature storage performance of the secondary battery.
  • SEI film stable negative electrode solid electrolyte interface film
  • CEI film positive electrode solid electrolyte interface film
  • the electrolyte satisfies at least one of the following characteristics: (1) 2 ⁇ A ⁇ 6; (2) 1.2 ⁇ A/B ⁇ 2.2; (3) 1.8 ⁇ B ⁇ 4. Meeting the above characteristics allows the electrolyte to have good kinetics, which is more conducive to improving the cycle performance and high-temperature storage performance of the secondary battery.
  • the anionic group includes the following groups:
  • the metal cation is MN + , where M includes any one of Al, Sn, In, Ba, or Ga, and 2 ⁇ N ⁇ 3.
  • the anion group and the metal cation are selected within the above range, which is more conducive to improving the cycle performance and high-temperature storage performance of the secondary battery.
  • the metal cation salt includes at least one of aluminum trifluoromethanesulfonate, stannous trifluoromethanesulfonate, indium trifluoromethanesulfonate, barium trifluoromethanesulfonate, bis(trifluoromethylsulfonyl)imide barium (II), bis(trifluoromethylsulfonyl)imide aluminum, bis(trifluoromethylsulfonyl)imide aluminum, or bis(trifluoromethylsulfonyl)imide barium.
  • the metal cation salt within the above range has a high positive charge density and a large electrostatic effect on difluorophosphate, which is more conducive to improving the solubility of lithium difluorophosphate in the electrolyte and forming a stable SEI film and CEI film, thereby further improving the cycle performance and high temperature storage performance of the secondary battery.
  • the electrolyte further includes a carbonate compound, the carbonate compound including at least one of ethylene carbonate, propylene carbonate, dimethyl carbonate, ethyl methyl carbonate, and diethyl carbonate, and the mass percentage of the carbonate compound based on the mass of the electrolyte is D%, 10 ⁇ D ⁇ 87.5.
  • the electrolyte includes lithium difluorophosphate and the above-mentioned metal cation salt
  • further introducing a carbonate compound within the above-mentioned range and regulating the value of D within the above-mentioned range can better exert the dissolution-promoting effect of the metal cation salt, increase the solubility of lithium difluorophosphate in the electrolyte, exert the role of lithium difluorophosphate, and also improve the high-temperature stability of the electrolyte, thereby improving the cycle performance and high-temperature storage performance of the secondary battery.
  • the electrolyte further includes a carboxylate compound
  • the carboxylate compound includes at least one of methyl propionate, ethyl propionate, propyl propionate, ethyl butyrate or 2,2-difluoroethyl acetate
  • the mass percentage of the carboxylate compound is E%, 0.85 ⁇ E ⁇ 62 based on the mass of the electrolyte.
  • the electrolyte includes lithium difluorophosphate and the above-mentioned metal cation salt
  • further introducing a carboxylate compound within the above-mentioned range and regulating the value of E within the above-mentioned range not only facilitates the dissolution-promoting effect of the metal cation salt, but also better plays the role of lithium difluorophosphate to form Stable SEI and CEI films are also beneficial to improving the ion transport capacity of the electrolyte and the dynamics of the electrolyte, thereby improving the cycle performance and high-temperature storage performance of the secondary battery.
  • the electrolyte further includes a first additive, the first additive including at least one of 1,3-propane sultone, 1,3-propylene sultone, vinyl sulfate, 1,3-propylene glycol cyclic sulfate, 2,4-butane sultone, 1,4-butane sultone, vinylene carbonate, or fluoroethylene carbonate.
  • the mass percentage of the first additive, based on the mass of the electrolyte, is X 1 , 0.05 ⁇ X 1 ⁇ 12, and 0.3 ⁇ A/X 1 ⁇ 120.
  • the introduction of the first additive can leverage the synergistic effect of lithium difluorophosphate and the first additive, generating organic fluorine-containing phosphates and inorganic LiF components on the surfaces of the positive and negative electrodes. This helps to increase the organic-inorganic hybrid interface in the SEI and CEI films, further enhancing the stability of the SEI and CEI films, and thereby further improving the cycling performance and high-temperature storage performance of the secondary battery.
  • the electrolyte further includes a second additive, the second additive including at least one of lithium bis(oxalatoborate), lithium tetrafluoroborate, lithium difluorooxalatoborate, lithium bis(fluorosulfonyl imide), lithium bis(trifluoromethanesulfonyl imide), lithium trifluoromethanesulfonate, lithium 4,5-dicyano-2-trifluoromethyl-imidazole, or lithium tetraborate.
  • the mass percentage of the second additive, based on the mass of the electrolyte, is X 2 %, 0.1 ⁇ X 2 ⁇ 8, and 0.3 ⁇ A/X 2 ⁇ 80.
  • the second additive to the electrolyte comprising lithium difluorophosphate and a metal cation salt, and regulating the value of X 2 within the above range, can leverage the synergistic effect of lithium difluorophosphate and the second additive, further enhancing the stability of the SEI and CEI films, and reducing interfacial side reactions on the surfaces of the positive and negative electrode sheets, thereby further improving the cycling performance and high-temperature storage performance of the secondary battery.
  • the second aspect of the present application provides a secondary battery, which includes a positive electrode plate, a negative electrode plate, and the electrolyte provided by the first aspect of the present application.
  • the positive electrode plate includes a positive electrode material layer
  • the positive electrode material layer includes a lithium composite transition metal oxide containing nickel, wherein the molar percentage of nickel to all transition metal elements is C%, and C ⁇ 60.
  • the positive electrode material layer includes a lithium composite transition metal oxide containing nickel and the value of C is regulated within the above range. Since lithium difluorophosphate is oxidized at the positive electrode to form a LiF-rich CEI film, a strong CEI film can be formed, which is beneficial to reducing the dissolution of transition metals.
  • the higher concentration of lithium difluorophosphate system can also play the above-mentioned role of reducing transition metal dissolution for high-nickel system (positive electrode material layer with a high nickel content); at the same time, the CEI film can also reduce the oxidative decomposition catalysis of Ni 4+ in the high-nickel system on the electrolyte, reduce the loss of the electrolyte, and thus improve the cycle performance and high-temperature storage performance of the secondary battery.
  • the third aspect of the present application provides an electronic device, which includes the secondary battery provided by the second aspect of the present application.
  • the secondary battery provided by the second aspect of the present application has good cycle performance and high temperature storage performance, so the electronic device of the present application The device has a long service life.
  • the present application provides an electrolyte, a secondary battery and an electronic device containing the electrolyte.
  • the electrolyte includes lithium difluorophosphate and a metal cation salt, the valence of the metal cation of the metal cation salt is divalent or higher, and the acid radical ion of the metal cation salt includes an anion group shown in formula I-A or an anion shown in formula I-B; based on the mass of the electrolyte, the mass percentage of lithium difluorophosphate is A%, the mass percentage of the metal cation salt is B%, 2 ⁇ A ⁇ 8.8, 1 ⁇ A/B ⁇ 2.2.
  • the present application is explained using a lithium-ion battery as an example of a secondary battery, but the secondary battery of the present application is not limited to a lithium-ion battery.
  • the first aspect of the present application provides an electrolyte, which includes lithium difluorophosphate and a metal cation salt, wherein the valence of the metal cation of the metal cation salt is positive divalent or higher, and the anion group of the metal cation salt includes the anion group represented by formula IA or the anion group represented by formula IB:
  • R1 is selected from a C1 to C3 alkyl group in which all hydrogen atoms are substituted by fluorine
  • R2 and R3 are each independently selected from a fluorine atom or a C1 to C3 alkyl group in which all hydrogen atoms are substituted by fluorine
  • the mass percentage of lithium difluorophosphate is A%
  • the mass percentage of the metal cation salt is B%, 2 ⁇ A ⁇ 8.8, 1 ⁇ A/B ⁇ 2.2, preferably 2 ⁇ A ⁇ 6, 1.2 ⁇ A/B ⁇ 2.2.
  • the value of A can be 2, 2.2, 2.8, 3, 3.5, 4, 4.6, 5, 5.7, 6, 6.4, 7, 7.5, 8, 8.8 or a range consisting of any two of these values
  • the value of A/B can be 1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 2, 2.1, 2.2 or a range consisting of any two of these values.
  • the electrolyte of the present application includes lithium difluorophosphate and a metal cation salt.
  • the metal cation salt includes a metal cation with a positive charge of divalent or higher, has a high positive charge density, has a large electrostatic effect on difluorophosphate, and can promote the dissolution of lithium difluorophosphate in the electrolyte, thereby making lithium difluorophosphate have a high solubility, which is beneficial to the role of lithium difluorophosphate, forming a stable negative electrode solid electrolyte interface film (SEI film) and a positive electrode solid electrolyte interface film (CEI film), thereby improving the cycle performance and high-temperature storage performance of the secondary battery.
  • SEI film stable negative electrode solid electrolyte interface film
  • CEI film positive electrode solid electrolyte interface film
  • a higher concentration of lithium difluorophosphate will significantly increase the viscosity of the electrolyte and affect the transport of ions in the electrolyte, thereby affecting the cycle performance of the secondary battery.
  • the value of A/B is too small, for example, less than 1, the combination of lithium difluorophosphate and metal cation salt is unreasonable, which is not conducive to the synergistic effect between the two, and stable SEI film and CEI film cannot be formed, affecting the cycle performance and high-temperature storage performance of the secondary battery.
  • the metal cation salt includes at least one of aluminum trifluoromethanesulfonate, stannous trifluoromethanesulfonate, indium trifluoromethanesulfonate, barium trifluoromethanesulfonate, bis(trifluoromethylsulfonyl)imide barium (II), bis(trifluoromethylsulfonyl)imide aluminum, bis(trifluoromethylsulfonyl)imide aluminum, or bis(trifluoromethylsulfonyl)imide barium.
  • the electrolyte further includes a carbonate compound, the carbonate compound including at least one of ethylene carbonate (EC), propylene carbonate, dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), and diethyl carbonate (DEC).
  • the mass percentage of the carbonate compound is D%, 10 ⁇ D ⁇ 87.5, for example, the value of D can be 10, 14, 17, 20, 23, 26, 30, 33, 35, 37, 40, 43, 45, 47, 50, 53, 55, 58, 60, 62, 65, 67, 70, 71, 73, 75, 78, 80, 82, 85, 87.5 or a range consisting of any two of these values.
  • the above-mentioned first additive is further introduced, and the value of X 1 is regulated within the above-mentioned range, so that the synergistic effect of lithium difluorophosphate and the above-mentioned first additive can be exerted, and organic fluorine-containing phosphates (such as Li x PF y , Li x PF y O z ) and inorganic LiF and other components can be generated on the surfaces of the positive and negative electrodes, which is beneficial to increasing the organic-inorganic hybrid interface in the SEI film and the CEI film, further enhancing the stability of the SEI film and the CEI film, thereby further improving the cycle performance and high-temperature storage performance of the secondary battery.
  • organic fluorine-containing phosphates such as Li x PF y , Li x PF y O z
  • inorganic LiF and other components can be generated on the surfaces of the positive and negative electrodes, which is beneficial to increasing the organic-inorganic hybrid interface in the
  • the electrolyte further includes a second additive, the second additive including at least one of lithium bis(oxalatoborate), lithium tetrafluoroborate, lithium difluorooxalatoborate, lithium bis(fluorosulfonylimide), lithium bis(trifluoromethanesulfonylimide), lithium trifluoromethanesulfonate, 4,5-dicyano-2-trifluoromethyl-imidazole lithium or lithium tetraborate.
  • the second additive including at least one of lithium bis(oxalatoborate), lithium tetrafluoroborate, lithium difluorooxalatoborate, lithium bis(fluorosulfonylimide), lithium bis(trifluoromethanesulfonylimide), lithium trifluoromethanesulfonate, 4,5-dicyano-2-trifluoromethyl-imidazole lithium or lithium tetraborate.
  • the mass percentage of the second additive is X 2 %, 0.1 ⁇ X 2 ⁇ 8 and 0.3 ⁇ A/X 2 ⁇ 80
  • the value of X 2 can be 0.1, 0.3, 0.5, 0.8, 1, 1.2, 1.4, 1.5, 1.6, 1.8, 2, 2.5, 3, 4, 4.5, 5, 6, 7, 8 or a range consisting of any two values thereof
  • A/X The value of X2 can be 0.3, 0.8, 1, 1.4, 1.5, 1.8, 2, 3, 5, 8, 10, 12, 18, 20, 24, 25, 28, 30, 33, 35, 37, 40, 44, 48, 50, 52, 58, 60, 63, 65, 68, 70, 73, 78, 80, or a range consisting of any two of these values.
  • the above-mentioned second additive is further introduced, and the value of X2 is regulated within the above-mentioned range.
  • the synergistic effect of lithium difluorophosphate and the above-mentioned second additive can be exerted, further enhancing the stability of the SEI film and the CEI film, and reducing the interfacial side reactions on the surfaces of the positive and negative electrode sheets, thereby further improving the cycle performance and high-temperature storage performance of the secondary battery.
  • the electrolyte further includes LiPF6 .
  • This application does not particularly limit the weight percentage of LiPF6 in the electrolyte, as long as the objectives of this application can be achieved.
  • the weight percentage of LiPF6 is 8% to 15%.
  • the weight percentage of LiPF6 can be 8%, 9%, 10%, 11%, 13%, 15%, or a range consisting of any two of these values.
  • the electrolyte includes lithium difluorophosphate, a metal cation salt, a lithium salt, a carbonate compound, and a carboxylate compound.
  • the electrolyte further includes at least one of a first additive and a second additive, wherein the weight percentages of the lithium difluorophosphate, the metal cation salt, the lithium salt, the carbonate compound, the carboxylate compound, the first additive, and the second additive are as described above.
  • Application of the electrolyte having the above characteristics to a secondary battery can improve the cycling performance and high-temperature storage performance of the secondary battery.
  • the electrolyte includes lithium difluorophosphate, a metal cation salt, a lithium salt, and a carbonate compound.
  • the mass percentages of lithium difluorophosphate, the metal cation salt, and the lithium salt are as described above, and the mass percentage (D%) of the carbonate compound can be 71.2% to 87.5%. Applying the electrolyte having the above characteristics to a secondary battery can improve the cycle performance and high-temperature storage performance of the secondary battery.
  • the electrolyte includes lithium difluorophosphate, a metal cation salt, a lithium salt, a first additive, and a carbonate compound.
  • the weight percentages of lithium difluorophosphate, the metal cation salt, the lithium salt, and the first additive are as described above.
  • the weight percentage D% of the carbonate compound can be 59.2% to 87.5%. Applying the electrolyte having the above characteristics to a secondary battery can further improve the cycle performance and high-temperature storage performance of the secondary battery.
  • the electrolyte includes lithium difluorophosphate, a metal cation salt, a lithium salt, a second additive, and a carbonate compound.
  • the weight percentages of lithium difluorophosphate, the metal cation salt, the lithium salt, and the second additive are as described above, and the weight percentage (D%) of the carbonate compound can be 63.2% to 87.5%. Applying the electrolyte having the above characteristics to a secondary battery can further improve the cycle performance and high-temperature storage performance of the secondary battery.
  • the electrolyte includes lithium difluorophosphate, a metal cation salt, a lithium salt, a first additive, a second additive, and a carbonate compound.
  • the weight percentages of lithium difluorophosphate, the metal cation salt, the lithium salt, the first additive, and the second additive are as described above.
  • the weight percentage D% of the carbonate compound can be 51.2% to 87.5%. Applying the electrolyte having the above characteristics to a secondary battery is beneficial for further improving the cycle performance and high-temperature storage performance of the secondary battery.
  • the positive electrode material layer comprises a lithium composite transition metal oxide containing nickel, and the C value is controlled within the aforementioned range. Since lithium difluorophosphate is oxidized at the positive electrode to form a LiF-rich CEI film, a robust CEI film can be produced, which helps reduce transition metal dissolution. A high concentration of lithium difluorophosphate can also reduce transition metal dissolution in high-nickel systems (positive electrode material layers with a high nickel content). Furthermore, the CEI film can reduce the catalytic oxidative decomposition of Ni4 + in the high-nickel system on the electrolyte, reducing electrolyte loss and thus improving the cycling performance and high-temperature storage performance of the secondary battery.
  • the negative electrode plate includes a negative electrode current collector and a negative electrode material layer provided on at least one surface of the negative electrode current collector.
  • the negative electrode material layer can 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 can be the entire area of the negative electrode current collector or a partial area of the negative electrode current collector.
  • the present application has no special restrictions, as long as the purpose of the present application can be achieved.
  • the negative electrode material layer of the present application contains a negative electrode active material.
  • the negative electrode active material may include at least one of natural graphite, artificial graphite, mesophase microcarbon beads (MCMBs), hard carbon, soft carbon, silicon, a silicon-carbon composite, SiO x (0 ⁇ x ⁇ 2), a Li-Sn alloy, a Li-Sn-O alloy, Sn, SnO, SnO 2 , spinel lithium titanate (Li 4 Ti 5 O 12 ) , a Li-Al alloy, or metallic lithium.
  • MCMBs mesophase microcarbon beads
  • the thickness of the negative electrode current collector is 4 to 12 ⁇ m
  • the thickness of the single-sided negative electrode material layer is 30 to 160 ⁇ m.
  • the mass ratio of the negative electrode active material, negative electrode conductive agent, and negative electrode binder in the negative electrode material layer there are no particular limitations on the mass ratio of the negative electrode active material, negative electrode conductive agent, and negative electrode binder in the negative electrode material layer, as long as the objectives of this application are achieved.
  • the negative electrode material layer of the present application may also include a negative electrode conductive agent, a negative electrode binder and a negative electrode dispersant.
  • the present application has no particular restrictions on the negative electrode conductive agent and the negative electrode binder, as long as the purpose of the present application can be achieved.
  • the negative electrode conductive agent may include but is not limited to at least one of conductive carbon black (Super P), carbon nanotubes (CNTs), graphite, carbon fiber, carbon nanowire, graphene, metal materials or conductive polymers, and the above-mentioned carbon nanotubes may include but are not limited to single-walled carbon nanotubes and/or multi-walled carbon nanotubes.
  • the above-mentioned carbon fibers may include but are not limited to vapor-grown carbon fibers (VGCF) and/or nano-carbon fibers.
  • the above-mentioned metal materials may include but are not limited to metal powder and/or metal fibers. Specifically, the metal may include but is not limited to at least one of copper, nickel, aluminum or silver.
  • the above-mentioned conductive polymers may include but are not limited to at least one of polyphenylene derivatives, polyaniline, polythiophene, polyacetylene or polypyrrole.
  • the negative electrode binder may include, but is not limited to, at least one of polyacrylic acid, sodium polyacrylate, potassium polyacrylate, lithium polyacrylate, polyimide, polyvinyl alcohol, carboxymethyl cellulose, sodium carboxymethyl cellulose, lithium carboxymethyl cellulose, polyamide-imide, styrene-butadiene rubber, or polyvinylidene fluoride (PVDF).
  • the negative electrode dispersant may include sodium carboxymethyl cellulose.
  • the preparation method of the negative electrode sheet there is no particular limitation on the preparation method of the negative electrode sheet, as long as the purpose of the present application can be achieved.
  • it can be prepared by the following method: the negative electrode active material, the negative electrode binder, and the negative electrode dispersant are mixed, deionized water is added and stirred evenly, and a negative electrode slurry with a solid content of 50wt% to 75wt% is obtained.
  • the negative electrode slurry is evenly coated on one surface of the negative electrode current collector, and after drying, a negative electrode sheet coated with a negative electrode material layer on one side is obtained.
  • the above coating steps are repeated on the other surface of the negative electrode current collector, and after drying, a negative electrode sheet coated with a negative electrode material layer on both sides is obtained.
  • the negative electrode sheet is obtained by cold pressing and cutting.
  • a positive electrode sheet comprises a positive electrode current collector and a positive electrode material layer disposed on at least one surface of the positive electrode current collector.
  • the positive electrode material layer can be disposed on one surface of the positive electrode current collector in the thickness direction, or on both surfaces of the positive electrode current collector in the thickness direction.
  • the "surface” here can refer to the entire surface of the positive electrode current collector or a portion of the surface of the positive electrode current collector. This application does not specifically limit this, as long as the purpose of this application can be achieved.
  • the present application has no special restrictions 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 (such as an aluminum-carbon composite current collector), etc.
  • the present application has no special restrictions 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 current collector is 5 ⁇ m to 20 ⁇ m
  • the thickness of the single-sided positive electrode material layer is 30 ⁇ m to 120 ⁇ m.
  • the positive electrode material layer of the present application may also include a positive electrode conductive agent and a positive electrode binder.
  • the present application has no special restrictions on the positive electrode conductive agent and the positive electrode binder, as long as the purpose of the present application can be achieved.
  • the positive electrode conductive agent may be the same as the above-mentioned negative electrode conductive agent
  • the positive electrode binder may be the same as the above-mentioned negative electrode binder.
  • the present application has no special restrictions on the mass ratio of the positive electrode active material, the positive electrode conductive agent and the positive electrode binder in the positive electrode material layer, as long as the purpose of the present application can be achieved.
  • the preparation method of the positive electrode sheet there is no particular limitation on the preparation method of the positive electrode sheet, as long as the purpose of the present application can be achieved.
  • it can be prepared by the following method: the positive electrode active material, the positive electrode conductive agent, and the positive electrode binder are mixed, N-methylpyrrolidone (NMP) is added and stirred evenly to obtain a positive electrode slurry with a solid content of 65wt% to 85wt%.
  • NMP N-methylpyrrolidone
  • the positive electrode slurry is evenly coated on one surface of the positive electrode collector, and after drying, a positive electrode sheet coated with a positive electrode material layer on one side is obtained.
  • the above coating steps are repeated on the other surface of the positive electrode collector, and after drying, a positive electrode sheet coated with a positive electrode material layer on both sides is obtained.
  • the positive electrode sheet is obtained by cold pressing and cutting.
  • the secondary battery of the present application also includes a separator.
  • the present application has no particular restrictions on the separator, as long as it can achieve the purpose of the present application.
  • the material of the separator may include but is not limited to polyethylene (PE), polypropylene (PP), polytetrafluoroethylene-based polyolefin (PO) separators, polyester films (such as polyethylene terephthalate (PET) films), cellulose films, polyimide films (PI), polyamide films (PA), spandex or aramid films, etc.
  • At least one of the types of separators may include but is not limited to woven membranes, non-woven membranes (non-woven fabrics), microporous membranes, composite membranes, rolled membranes or spun membranes, etc.
  • the high-temperature storage performance of lithium-ion batteries is evaluated by measuring the thickness expansion rate of lithium-ion batteries when stored at 60°C.
  • the test process is as follows: In a 25°C environment, the lithium-ion battery is charged at a constant current of 0.5C to 4.28V, and then charged at a constant voltage of 4.28V to a current of 0.05C. The thickness of the tested lithium-ion battery is D1 . The lithium-ion battery is then placed in a 60°C oven and taken out after storage for 180 days. The thickness of the lithium-ion battery at this time is D2 .
  • the thickness expansion rate of the lithium-ion battery stored at 60°C ( D2 - D1 )/ D1 ⁇ 100%.
  • the positive electrode active material Li(Ni 0.6 Mn 0.2 Co 0.2 )O 2 , the positive electrode conductive agent conductive carbon black, and the positive electrode binder polyvinylidene fluoride were mixed in a mass ratio of 96:2:2.
  • N-methylpyrrolidone was added and stirred uniformly to obtain a positive electrode slurry with a solid content of 72 wt%.
  • the positive electrode slurry was evenly coated on one surface of a 10 ⁇ m thick positive electrode current collector aluminum foil.
  • the aluminum foil was then dried at 85°C for 4 hours to obtain a positive electrode sheet coated on one side with a positive electrode material layer.
  • the above steps were repeated on the other surface of the aluminum foil to obtain a positive electrode sheet coated on both sides with a positive electrode material layer.
  • the sheet After drying at 85°C under vacuum for 4 hours, the sheet was cold pressed, cut, and slit to obtain a positive electrode sheet measuring 74 mm x 867 mm.
  • the compacted density of the positive electrode material layer was 4.15 g/cm 3
  • the thickness of the single-sided positive electrode material layer was 60 ⁇ m.
  • Graphite the negative electrode active material, styrene-butadiene rubber (SBR), the negative electrode binder, and sodium carboxymethyl cellulose (CMC), the negative electrode thickener, were mixed in a mass ratio of 97.4:1.4:1.2.
  • Deionized water was added and stirred to obtain a negative electrode slurry with a solid content of 54 wt%.
  • the negative electrode slurry was evenly coated on one surface of a 6 ⁇ m thick copper foil for the negative electrode current collector.
  • the foil was then dried at 85°C for 4 hours to obtain a negative electrode sheet coated on one side with a negative electrode material layer.
  • the above steps were repeated on the other surface of the copper foil to obtain a negative electrode sheet coated on both sides with a negative electrode material layer.
  • the sheet After drying at 85°C under vacuum for 4 hours, the sheet was cold pressed, cut, and slit to obtain a negative electrode sheet measuring 78 mm x 875 mm.
  • the compacted density of the positive electrode material layer was 1.75 g/ cm3
  • the thickness of the single-sided positive electrode material layer was 70 ⁇ m.
  • PVDF and alumina ceramic were mixed in a 9:1 mass ratio, and deionized water was added as a solvent to prepare a ceramic layer slurry with a solid content of 25wt%.
  • the mixture was stirred evenly and then evenly coated on one surface of a 16 ⁇ m thick polyethylene porous film substrate. After drying, a separator membrane with a 2 ⁇ m alumina ceramic layer coated on one side was obtained. The above coating steps were then repeated on the other surface of the substrate to obtain a separator membrane with a 2 ⁇ m alumina ceramic layer coated on both sides.
  • Example 1-6 Except for adjusting the mass percentage of each component in the electrolyte according to Table 2, the rest is the same as Example 1-6.
  • Example 1-6 Except for introducing a carboxylate compound into the electrolyte and adjusting relevant parameters according to Table 2, the rest is the same as Example 1-6.
  • Example 3-4 Except for introducing the second additive into the electrolyte and adjusting the relevant parameters according to Table 4, the rest is the same as Example 3-4.
  • the mass percentage of lithium difluorophosphate (A%), the mass percentage of the metal cation salt (B%), or the mass percentage of the second additive ( ⁇ 2 %) is changed according to Table 4, the mass percentage of the carbonate compound changes accordingly, while the mass ratio of EC to DEC and the mass percentage of the lithium salt remain unchanged.
  • Example 1-1 Except for adjusting the parameters according to Table 5, the rest is the same as Example 1-1.
  • the mass percentage of lithium difluorophosphate A% changes according to Table 5
  • the mass percentage of carbonate compound changes accordingly
  • the mass percentage of metal cation salt changes accordingly.
  • the content B%, the mass ratio of EC and DEC, and the mass percentage of lithium salt remain unchanged.
  • the electrolyte was the same as in Example 1-2 except that lithium difluorophosphate was not added, the mass percentage of the carbonate compound was changed accordingly, the mass percentage of the metal cation salt B%, the mass ratio of EC and DEC, and the mass percentage of the lithium salt remained unchanged.
  • Example 1-1 Except for adjusting the parameters according to Table 1, the remainder is the same as Example 1-1.
  • the mass percentage A% of lithium difluorophosphate and the mass percentage B% of the metal cation salt are changed according to Table 1, the mass percentage of the carbonate compound changes accordingly, while the mass ratio of EC to DEC and the mass percentage of the lithium salt remain unchanged.
  • the electrolyte includes lithium difluorophosphate and a metal cation salt, and regulating the values of A and A/B within the scope of this application can make the lithium ion battery have lower impedance, higher cycle capacity retention rate, and lower storage thickness expansion rate, indicating that the lithium ion battery has better cycle performance and high temperature storage performance.
  • Lithium difluorophosphate is not added to the electrolyte of Comparative Example 1, and metal cation salt is not added to the electrolyte of Comparative Example 2 to promote dissolution, and lithium difluorophosphate is not completely dissolved.
  • the lithium-ion battery can have lower impedance, higher cycling capacity retention rate, and lower storage thickness expansion rate, indicating that the lithium-ion battery has lower impedance, better cycling performance, and high-temperature storage performance.
  • the lithium-ion battery can have a lower impedance, a higher cycle capacity retention rate, and a lower storage thickness expansion rate, indicating that the lithium-ion battery has a lower impedance, better cycle performance, and high-temperature storage performance.
  • metal cation salt generally affects the cycling performance and high-temperature storage performance of lithium-ion batteries. As can be seen from Examples 1-2, 1-17, and 1-20, selecting metal cation salts within the scope of this application can result in lithium-ion batteries with lower impedance, higher cycling capacity retention, and lower storage thickness expansion, demonstrating that lithium-ion batteries have lower impedance, better cycling performance, and higher-temperature storage performance.
  • the value of D generally affects the cycling performance and high-temperature storage performance of lithium-ion batteries. As can be seen from Examples 1-6, 1-14 to 1-15, and 2-1 to 2-7, regulating the value of D within the scope of this application can result in lithium-ion batteries having lower impedance, higher cycle capacity retention, and lower storage thickness expansion, indicating that lithium-ion batteries have lower impedance, good cycling performance, and high-temperature storage performance.
  • the type of carbonate compound generally affects the cycling performance and high-temperature storage performance of lithium-ion batteries. As can be seen from Examples 2-6, 2-8, and 2-9, selecting carbonate compounds within the scope of this application can result in lithium-ion batteries with lower impedance, higher cycle capacity retention, and lower storage thickness expansion, demonstrating that lithium-ion batteries have lower impedance, better cycling performance, and higher-temperature storage performance.
  • carboxylate generally affects the cycling performance and high-temperature storage performance of lithium-ion batteries. As can be seen from Examples 2-6, 2-10, and 2-11, selecting carboxylate compounds within the scope of this application can result in lithium-ion batteries with lower impedance, higher cycle capacity retention, and lower storage thickness expansion, demonstrating that lithium-ion batteries have lower impedance, better cycling performance, and higher-temperature storage performance.
  • the inclusion of a first additive in the electrolyte and the value of X1 generally affect the cycling performance and high-temperature storage performance of the lithium-ion battery.
  • the lithium-ion battery can have lower impedance, higher cycle capacity retention, and lower storage thickness expansion, indicating that the lithium-ion battery has lower impedance, good cycling performance, and high-temperature storage performance.
  • A/ X1 generally affects the cycling performance and high-temperature storage performance of lithium-ion batteries. As can be seen from Examples 3-1 to 3-12, regulating the value of A/ X1 within the range of this application can result in lithium-ion batteries with lower impedance, higher cycle capacity retention, and lower storage thickness expansion, indicating that lithium-ion batteries have low impedance, good cycling performance, and high-temperature storage performance.
  • first additive typically affects the cycling performance and high-temperature storage performance of lithium-ion batteries. As can be seen from Examples 3-2, 3-13, and 3-15, selecting a first additive within the scope of this application can result in lithium-ion batteries with lower impedance, higher cycle capacity retention, and lower storage thickness expansion, demonstrating that lithium-ion batteries have lower impedance, good cycling performance, and high-temperature storage performance.
  • the electrolyte includes a second additive and the value of X2 usually affects the cycle performance and high-temperature storage performance of the lithium-ion battery. It can be seen from Examples 1-4, 4-1 to 4-3 that, on the basis of the electrolyte including lithium difluorophosphate and a metal cation salt, a second additive is further introduced, and the value of X2 is regulated within the scope of this application, the lithium-ion battery can have a lower impedance, a higher cycle capacity retention rate and a lower storage thickness expansion rate, indicating that the lithium-ion battery has good cycle performance and high-temperature storage performance.
  • A/ X2 usually affects the cycle performance and high temperature storage performance of lithium-ion batteries. From Examples 4-1 to 4-15, it can be seen that by adjusting the value of A/ X2 within the scope of this application, the lithium-ion battery can have lower impedance, higher cycle capacity retention rate and lower storage thickness expansion rate, which shows that the lithium-ion battery has lower impedance, good Good cycle performance and high temperature storage performance.
  • the type of second additive typically affects the cycling performance and high-temperature storage performance of lithium-ion batteries. As can be seen from Examples 4-6, 4-7, and 4-10, selecting a second additive within the scope of this application can result in lithium-ion batteries with lower impedance, higher cycle capacity retention, and lower storage thickness expansion, demonstrating that lithium-ion batteries have lower impedance, good cycling performance, and high-temperature storage performance.
  • the value of C typically affects the cycling performance and high-temperature storage performance of lithium-ion batteries.
  • Examples 5-5 to 5-10 and Comparative Example 11 by regulating the value of A/B within the range of this application and further regulating the value of C within the range of this application, the lithium-ion battery can have lower impedance, higher cycle capacity retention, and lower storage thickness expansion, demonstrating that the lithium-ion battery has lower impedance, good cycling performance, and high-temperature storage performance.
  • A/C usually affects the cycle performance and high temperature storage performance of lithium ion batteries. It can be seen from Examples 1-4, 1-13, and 5-1 to 5-15 that by regulating the value of A/C within the scope of this application, the lithium-ion battery can have lower impedance, higher cycle capacity retention rate, and lower storage thickness expansion rate, indicating that the lithium-ion battery has lower impedance, good cycle performance, and high-temperature storage performance.

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Abstract

本申请提供了一种电解液、包含该电解液的二次电池及电子装置。电解液包括二氟磷酸锂和金属阳离子盐，金属阳离子盐的金属阳离子的化合价为正二价及以上，金属阳离子盐的酸根离子包括式I-A所示的阴离子基团或者式I-B所示的阴离子；基于电解液的质量，二氟磷酸锂的质量百分含量为A％，金属阳离子盐的质量百分含量为B％，2≤A≤8.8，1≤A/B≤2.2。本申请的电解液包括二氟磷酸锂和金属阳离子盐，有利于发挥二氟磷酸锂的作用，有利于形成稳定的SEI膜和CEI膜，从而改善二次电池的循环性能和高温存储性能。

Description

一种电解液、包含该电解液的二次电池及电子装置 技术领域
本申请涉及电化学技术领域，特别是涉及一种电解液、包含该电解液的二次电池及电子装置。
背景技术
二次电池，例如锂离子电池具有高能量密度、低维护、相对较低的自放电、长循环寿命、无记忆效应、工作电压稳定和环境友好等特性受到人们的广泛关注，被广泛用于便携式电子设备、电动工具和电动汽车等领域。然而随着技术的快速发展以及市场需求的多样性，人们对二次电池也提出了更高的要求。
发明内容
本申请的目的在于提供一种电解液、包含该电解液的二次电池及电子装置，以改善二次电池的循环性能。具体技术方案如下：
本申请的第一方面提供了一种电解液，电解液包括二氟磷酸锂和金属阳离子盐，金属阳离子盐的金属阳离子的化合价为正二价及以上，金属阳离子盐的阴离子基团包括式I-A所示的阴离子基团或者式I-B所示的阴离子基团：
其中，R1选自全部氢原子被氟取代的C1至C3的烷基，R2和R3各自独立地选自氟原子或者全部氢原子被氟取代的C1至C3的烷基；基于电解液的质量，二氟磷酸锂的质量百分含量为A％，金属阳离子盐的质量百分含量为B％，2≤A≤8.8，1≤A/B≤2.2。本申请的电解液包括二氟磷酸锂和金属阳离子盐，金属阳离子盐包括正二价及以上的金属阳离子，具有较高的正电荷密度，对于二氟磷酸根有较大的静电作用，可以促进二氟磷酸锂在电解液中的溶解，从而使得二氟磷酸锂具有较高的溶解度，有利于发挥二氟磷酸锂的作用，形成稳定的负极固态电解质界面膜(SEI膜)和正极固态电解质界面膜(CEI膜)，从而改善二次电池的循环性能和高温存储性能。
在本申请的一些实施方案中，1.5≤B≤5。通过调控B的值在上述范围内，更有利于 提高二氟磷酸锂在电解液中的溶解度，形成稳定的SEI膜和CEI膜，从而进一步改善二次电池的循环性能和高温存储性能。
在本申请的一些实施方案中，电解液满足以下特征中的至少一者：(1)2≤A≤6；(2)1.2≤A/B≤2.2；(3)1.8≤B≤4。满足上述特征，电解液具有良好的动力学，更有利于改善二次电池的循环性能和高温存储性能。
在本申请的一些实施方案中，阴离子基团包括以下基团：
金属阳离子为MN+，M包括Al、Sn、In、Ba或Ga中的任一种，2≤N≤3。阴离子基团和金属阳离子选自上述范围内，更有利于改善二次电池的循环性能和高温存储性能。
在本申请的一些实施方案中，金属阳离子盐包括三氟甲磺酸铝、三氟甲磺酸亚锡、三氟甲磺酸铟、三氟甲磺酸钡、双(三氟甲基磺酰基)亚胺钡(II)、双氟磺酰亚胺铝、双(三氟甲磺酰基)酰亚胺铝或双氟磺酰亚胺钡中的至少一种。上述范围内的金属阳离子盐，具有较高的正电荷密度，对于二氟磷酸根有较大的静电作用，更有利于提高二氟磷酸锂在电解液中的溶解度，形成稳定的SEI膜和CEI膜，从而进一步改善二次电池的循环性能和高温存储性能。
在本申请的一些实施方案中，电解液还包括碳酸酯化合物，碳酸酯化合物包括碳酸亚乙酯、碳酸亚丙酯、碳酸二甲酯、碳酸甲乙酯、碳酸二乙酯中的至少一种，基于电解液的质量，碳酸酯化合物的质量百分含量为D％，10≤D≤87.5。在电解液包括二氟磷酸锂和上述金属阳离子盐的基础上，进一步引入上述范围内的碳酸酯化合物并调控D的值在上述范围内，可以更好地发挥金属阳离子盐的促溶作用，提高二氟磷酸锂在电解液中的溶解度，发挥二氟磷酸锂的作用，还可以提高电解液的高温稳定性，从而改善二次电池的循环性能和高温存储性能。
在本申请的一些实施方案中，电解液还包括羧酸酯化合物，羧酸酯化合物包括丙酸甲酯、丙酸乙酯、丙酸丙酯、丁酸乙酯或乙酸2,2-二氟乙酯中的至少一种，基于电解液的质量，羧酸酯化合物的质量百分含量为E％，0.85≤E≤62。在电解液包括二氟磷酸锂和上述金属阳离子盐的基础上，进一步引入上述范围内的羧酸酯化合物并调控E的值在上述范围内，不仅有利于发挥金属阳离子盐的促溶作用，可以更好的发挥二氟磷酸锂的作用，形成 稳定的SEI膜和CEI膜，还有利于提高电解液的离子传输能力，提高电解液的动力学，从而改善二次电池的循环性能和高温存储性能。
在本申请的一些实施方案中，电解液还包括第一添加剂，第一添加剂包括1,3-丙烷磺内酯、1,3-丙烯磺酸内酯、硫酸乙烯酯、1,3-丙二醇环硫酸酯、2,4-丁烷磺内酯、1,4-丁烷磺内酯、碳酸亚乙烯酯或氟代碳酸乙烯酯中的至少一种，基于电解液的质量，第一添加剂的质量百分含量为X1％，0.05≤X1≤12且0.3≤A/X1≤120。电解液包括二氟磷酸锂和金属阳离子盐的基础上，进一步引入上述第一添加剂，并调控X1的值在上述范围内，可以发挥二氟磷酸锂与上述第一添加剂的协同作用，可以在正极和负极表面生成有机的含氟磷酸盐以及无机的LiF等组分，有利于增加SEI膜和CEI膜中的有机-无机杂化界面，进一步增强SEI膜和CEI膜的稳定性，从而能够进一步改善二次电池的循环性能和高温存储性能。
在本申请的一些实施方案中，电解液还包括第二添加剂，第二添加剂包括双草酸硼酸锂、四氟硼酸锂、二氟草酸硼酸锂、双氟磺酰亚胺锂、双三氟甲磺酰亚胺锂、三氟甲磺酸锂、4,5-二氰基-2-三氟甲基-咪唑锂或四硼酸锂中的至少一种，基于电解液的质量，第二添加剂的质量百分含量为X2％，0.1≤X2≤8且0.3≤A/X2≤80。电解液包括二氟磷酸锂和金属阳离子盐的基础上，进一步引入上述第二添加剂，并调控X2的值在上述范围内，可以发挥二氟磷酸锂与上述第二添加剂的协同作用，进一步增强SEI膜和CEI膜的稳定性，减少正极极片和负极极片表面的界面副反应，从而能够进一步改善二次电池的循环性能和高温存储性能。
本申请的第二方面提供了一种二次电池，其包括正极极片、负极极片和本申请第一方面提供的电解液，正极极片包括正极材料层，正极材料层包括含有镍元素的锂复合过渡金属氧化物，镍元素占所有过渡金属元素的摩尔百分比为C％，C≥60。正极材料层包括含有镍元素的锂复合过渡金属氧化物并调控C的值在上述范围内，由于二氟磷酸锂在正极被氧化，生成富含LiF的CEI膜，可以生成坚固的CEI膜，有利于减少过渡金属的溶出，较高浓度的二氟磷酸锂体系对于高镍体系(镍元素含量较高的正极材料层)也可以发挥上述减少过渡金属溶出的作用；同时，CEI膜还可以减少高镍体系中的Ni4+对于电解液的氧化分解催化，减少电解液的损耗，从而改善二次电池的循环性能和高温存储性能。
在本申请的一些实施方案中，0.021≤A/C≤0.14。调控A/C的值在上述范围内，有利于形成更坚固的CEI膜，更好的发挥其减少过渡金属溶出的作用，减少电解液的氧化分解，从而进一步改善二次电池的循环性能和高温存储性能。
本申请的第三方面提供了一种电子装置，其包括本申请第二方面提供的二次电池。本申请第二方面提供的二次电池具有良好的循环性能和高温存储性能，从而本申请的电子装 置具有较长的使用寿命。
本申请的有益效果：
本申请提供了一种电解液、包含该电解液的二次电池及电子装置。电解液包括二氟磷酸锂和金属阳离子盐，金属阳离子盐的金属阳离子的化合价为正二价及以上，金属阳离子盐的酸根离子包括式I-A所示的阴离子基团或者式I-B所示的阴离子；基于电解液的质量，二氟磷酸锂的质量百分含量为A％，金属阳离子盐的质量百分含量为B％，2≤A≤8.8，1≤A/B≤2.2。本申请的电解液包括二氟磷酸锂和金属阳离子盐，金属阳离子盐包括正二价及以上的金属阳离子，具有较高的正电荷密度，对于二氟磷酸根有较大的静电作用，可以促进二氟磷酸锂在电解液中的溶解，从而使得二氟磷酸锂具有较高的溶解度，有利于发挥二氟磷酸锂的作用，形成稳定的SEI膜和CEI膜，从而改善二次电池的循环性能和高温存储性能。
具体实施方式
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。本领域技术人员基于本申请所获得的所有其他实施例，都属于本申请保护的范围。
需要说明的是，在以下内容中，以锂离子电池作为二次电池的例子来解释本申请，但是本申请的二次电池并不仅限于锂离子电池。
本申请的第一方面提供了一种电解液，电解液包括二氟磷酸锂和金属阳离子盐，金属阳离子盐的金属阳离子的化合价为正二价及以上，金属阳离子盐的阴离子基团包括式I-A所示的阴离子基团或者式I-B所示的阴离子基团：
其中，R1选自全部氢原子被氟取代的C1至C3的烷基，R2和R3各自独立地选自氟原子或者全部氢原子被氟取代的C1至C3的烷基；基于电解液的质量，二氟磷酸锂的质量百分含量为A％，金属阳离子盐的质量百分含量为B％，2≤A≤8.8，1≤A/B≤2.2，优选2≤A≤6，1.2≤A/B≤2.2。例如A的值可以为2、2.2、2.8、3、3.5、4、4.6、5、5.7、6、6.4、7、7.5、8、8.8或为其中任意两个数值组成的范围，A/B的值可以为1、1.2、1.3、1.4、1.5、1.6、 1.7、1.8、2、2.1、2.2或为其中任意两个数值组成的范围。
本申请的电解液包括二氟磷酸锂和金属阳离子盐，金属阳离子盐包括正二价及以上的金属阳离子，具有较高的正电荷密度，对于二氟磷酸根有较大的静电作用，可以促进二氟磷酸锂在电解液中的溶解，从而使得二氟磷酸锂具有较高的溶解度，有利于发挥二氟磷酸锂的作用，形成稳定的负极固态电解质界面膜(SEI膜)和正极固态电解质界面膜(CEI膜)，从而改善二次电池的循环性能和高温存储性能。发明人发现，当A的值过小时，例如小于2，电解液中的二氟磷酸锂的含量过低，不利于形成稳定的SEI膜和CEI膜，从而无法改善二次电池的循环性能和高温存储性能；当A的值过大时，例如大于8.8，电解液中的二氟磷酸锂的含量过高，对于溶剂的要求过高或者二氟磷酸锂无法溶解，并且二氟磷酸锂在电解液中的解离度很低，较高浓度的二氟磷酸锂会显著提升电解液粘度而影响电解液中离子的传输，从而影响二次电池的循环性能。当A/B的值过小时，例如小于1，二氟磷酸锂和金属阳离子盐搭配不合理，不利于发挥二者之间的协同作用，无法形成稳定的SEI膜和CEI膜，影响二次电池的循环性能和高温存储性能，此外，电解液中存在过多含量的金属阳离子盐时，会由于金属阳离子盐自身的稳定性不足，大量在正极和负极表面被氧化或还原，也会影响二次电池的循环性能和高温存储性能；当A/B的值过大时，例如大于2.2，二氟磷酸锂的金属阳离子盐搭配不合理，不利于发挥二者之间的协同作用，并且会导致电解液的粘度增大，会使得电解液的电导率降低，电解液的动力学下降，此外，二氟磷酸锂在电解液中的溶解度过低，甚至无法完全溶解，不能发挥二氟磷酸锂的作用，从而不利于提高二次电池的循环性能和高温存储性能。因此，电解液包括二氟磷酸锂和金属阳离子盐，并调控A和A/B的值在本申请范围内，可以改善二次电池的循环性能和高温存储性能。
在本申请的一些实施方案中，1.5≤B≤5，优选1.8≤B≤4，例如B的值可以为1.5、1.7、1.8、2、2.3、2.5、2.7、3、3.2、3.4、3.5、3.8、4、4.3、4.5、4.7、5或为其中任意两个数值组成的范围。通过调控B的值在上述范围内，更有利于提高二氟磷酸锂在电解液中的溶解度，形成稳定的SEI膜和CEI膜，从而进一步改善二次电池的循环性能和高温存储性能。
在本申请的一些实施方案中，阴离子基团包括以下基团：
金属阳离子为MN+，M包括Al、Sn、In、Ba或Ga中的任一种，2≤N≤3，例如N的值可以为2或3。阴离子基团和金属阳离子选自上述范围内，更有利于改善二次电池的循环性能和高温存储性能。
在本申请的一些实施方案中，金属阳离子盐包括三氟甲磺酸铝、三氟甲磺酸亚锡、三氟甲磺酸铟、三氟甲磺酸钡、双(三氟甲基磺酰基)亚胺钡(II)、双氟磺酰亚胺铝、双(三氟甲磺酰基)酰亚胺铝或双氟磺酰亚胺钡中的至少一种。上述范围内的金属阳离子盐，具有较高的正电荷密度，对于二氟磷酸根有较大的静电作用，更有利于提高二氟磷酸锂在电解液中的溶解度，形成稳定的SEI膜和CEI膜，从而进一步改善二次电池的循环性能和高温存储性能。
在本申请的一些实施方案中，电解液还包括碳酸酯化合物，碳酸酯化合物包括碳酸亚乙酯(EC)、碳酸亚丙酯、碳酸二甲酯(DMC)、碳酸甲乙酯(EMC)、碳酸二乙酯(DEC)中的至少一种，基于电解液的质量，碳酸酯化合物的质量百分含量为D％，10≤D≤87.5，例如D的值可以为10、14、17、20、23、26、30、33、35、37、40、43、45、47、50、53、55、58、60、62、65、67、70、71、73、75、78、80、82、85、87.5或为其中任意两个数值组成的范围。在电解液包括二氟磷酸锂和上述金属阳离子盐的基础上，进一步引入上述范围内的碳酸酯化合物并调控D的值在上述范围内，可以更好地发挥金属阳离子盐的促溶作用，提高二氟磷酸锂在电解液中的溶解度，发挥二氟磷酸锂的作用，还可以提高电解液的高温稳定性，从而改善二次电池的循环性能和高温存储性能。
在本申请的一些实施方案中，电解液还包括羧酸酯化合物，羧酸酯化合物包括丙酸甲酯、丙酸乙酯(EP)、丙酸丙酯(PP)、丁酸乙酯或乙酸2,2-二氟乙酯中的至少一种，基于电解液的质量，羧酸酯化合物的质量百分含量为E％，0.85≤E≤62，例如E的值可以为0.85、1、2、3、5、8、10、14、17、20、23、26、30、33、35、37、40、43、45、47、50、53、55、58、60、62或为其中任意两个数值组成的范围。在电解液包括二氟磷酸锂和上述金属阳离子盐的基础上，进一步引入上述范围内的羧酸酯化合物并调控E的值在上述范围内，不仅有利于发挥金属阳离子盐的促溶作用，可以更好的发挥二氟磷酸锂的作用，形成稳定的SEI膜和CEI膜，还有利于提高电解液的离子传输能力，提高电解液的动力学，从而改善二次电池的循环性能和高温存储性能。
在本申请的一些实施方案中，电解液还包括第一添加剂，第一添加剂包括1,3-丙烷磺内酯、1,3-丙烯磺酸内酯、硫酸乙烯酯、1,3-丙二醇环硫酸酯、2,4-丁烷磺内酯、1,4-丁烷磺内酯、碳酸亚乙烯酯或氟代碳酸乙烯酯中的至少一种，基于电解液的质量，第一添加剂的质量百分含量为X1％，0.05≤X1≤12且0.3≤A/X1≤120，例如X1的值可以为0.05、0.1、 0.3、0.8、1、3、5、6、8、10、12或为其中任意两个数值组成的范围，A/X1的值可以为0.3、0.5、0.8、1、1.25、1.5、3、5、8、10、12、20、40、50、75、90、100、105、120或为其中任意两个数值组成的范围。电解液包括二氟磷酸锂和金属阳离子盐的基础上，进一步引入上述第一添加剂，并调控X1的值在上述范围内，可以发挥二氟磷酸锂与上述第一添加剂的协同作用，可以在正极和负极表面生成有机的含氟磷酸盐(例如LixPFy、LixPFyOz)以及无机的LiF等组分，有利于增加SEI膜和CEI膜中的有机-无机杂化界面，进一步增强SEI膜和CEI膜的稳定性，从而能够进一步改善二次电池的循环性能和高温存储性能。
在本申请的一些实施方案中，电解液还包括第二添加剂，第二添加剂包括双草酸硼酸锂、四氟硼酸锂、二氟草酸硼酸锂、双氟磺酰亚胺锂、双三氟甲磺酰亚胺锂、三氟甲磺酸锂、4,5-二氰基-2-三氟甲基-咪唑锂或四硼酸锂中的至少一种，基于电解液的质量，第二添加剂的质量百分含量为X2％，0.1≤X2≤8且0.3≤A/X2≤80，例如X2的值可以为0.1、0.3、0.5、0.8、1、1.2、1.4、1.5、1.6、1.8、2、2.5、3、4、4.5、5、6、7、8或为其中任意两个数值组成的范围，A/X2的值可以为0.3、0.8、1、1.4、1.5、1.8、2、3、5、8、10、12、18、20、24、25、28、30、33、35、37、40、44、48、50、52、58、60、63、65、68、70、73、78、80或为其中任意两个数值组成的范围。电解液包括二氟磷酸锂和金属阳离子盐的基础上，进一步引入上述第二添加剂，并调控X2的值在上述范围内，可以发挥二氟磷酸锂与上述第二添加剂的协同作用，进一步增强SEI膜和CEI膜的稳定性，减少正极极片和负极极片表面的界面副反应，从而能够进一步改善二次电池的循环性能和高温存储性能。
本申请中，电解液还包括LiPF6。本申请对电解液中LiPF6的质量百分含量没有特别限制，只要能实现本申请的目的即可。示例性地，基于电解液的质量，LiPF6的质量百分含量为8％至15％，例如LiPF6的质量百分含量可以为8％、9％、10％、11％、13％、15％或为其中任意两个数值组成的范围。
在一些实施方案中，电解液包括二氟磷酸锂、金属阳离子盐、锂盐、碳酸酯化合物和羧酸酯化合物，可选地，电解液还包括第一添加剂和第二添加剂中的至少一种，二氟磷酸锂、金属阳离子盐、锂盐、碳酸酯化合物、羧酸酯化合物、第一添加剂和第二添加剂的质量百分含量如上所述。将具有上述特征的电解液应用于二次电池，可以改善二次电池的循环性能和高温存储性能。
在一些实施方案中，电解液包括二氟磷酸锂、金属阳离子盐、锂盐和碳酸酯化合物，二氟磷酸锂、金属阳离子盐、锂盐的质量百分含量如上所述，碳酸酯化合物的质量百分含量D％可以为71.2％至87.5％。将具有上述特征的电解液应用于二次电池，可以改善二次电池的循环性能和高温存储性能。
在一些实施方案中，电解液包括二氟磷酸锂、金属阳离子盐、锂盐、第一添加剂和碳酸酯化合物，二氟磷酸锂、金属阳离子盐、锂盐、第一添加剂的质量百分含量如上所述，碳酸酯化合物的质量百分含量D％可以为59.2％至87.5％。将具有上述特征的电解液应用于二次电池，有利于进一步改善二次电池的循环性能和高温存储性能。
在一些实施方案中，电解液包括二氟磷酸锂、金属阳离子盐、锂盐、第二添加剂和碳酸酯化合物，二氟磷酸锂、金属阳离子盐、锂盐、第二添加剂的质量百分含量如上所述，碳酸酯化合物的质量百分含量D％可以为63.2％至87.5％。将具有上述特征的电解液应用于二次电池，有利于进一步改善二次电池的循环性能和高温存储性能。
在一些实施方案中，电解液包括二氟磷酸锂、金属阳离子盐、锂盐、第一添加剂、第二添加剂和碳酸酯化合物，二氟磷酸锂、金属阳离子盐、锂盐、第一添加剂、第二添加剂的质量百分含量如上所述，碳酸酯化合物的质量百分含量D％可以为51.2％至87.5％。将具有上述特征的电解液应用于二次电池，有利于进一步改善二次电池的循环性能和高温存储性能。
本申请的第二方面提供了一种二次电池，其包括正极极片、负极极片和本申请第一方面提供的电解液，正极极片包括正极材料层，正极材料层包括含有镍元素的锂复合过渡金属氧化物，镍元素占所有过渡金属元素的摩尔百分比为C％，C≥60，例如C的值可以为60、63、65、68、70、73、78、80、82、85、87.5、90、91、92、95、98、100或为其中任意两个数值组成的范围，在一些实施方案中，60≤C≤100。含有镍元素的锂复合过渡金属氧化物包括但不限于LiNiO2、Li(Ni0.6Mn0.2Co0.2)O2、Li(Ni0.5Mn0.3Co0.2)O2、Li(Ni0.7Mn0.15Co0.15)O2、Li(Ni0.8Mn0.1Co0.1)O2或Li(Ni0.9Mn0.05Co0.05)O2中的至少一种。上述“所有过渡金属元素”中包括镍元素，例如对于LiNiO2，镍元素占所有过渡金属元素的摩尔百分比C％为100％；对于Li(Ni0.6Mn0.2Co0.2)O2，镍元素占所有过渡金属元素的摩尔百分比C％＝0.6/(0.6+0.2+0.2)×100％＝60％。正极材料层包括含有镍元素的锂复合过渡金属氧化物并调控C的值在上述范围内，由于二氟磷酸锂在正极被氧化，生成富含LiF的CEI膜，可以生成坚固的CEI膜，有利于减少过渡金属的溶出，较高浓度的二氟磷酸锂体系对于高镍体系(镍元素含量较高的正极材料层)也可以发挥上述减少过渡金属溶出的作用；同时，CEI膜还可以减少高镍体系中的Ni4+对于电解液的氧化分解催化，减少电解液的损耗，从而改善二次电池的循环性能和高温存储性能。
在本申请的一些实施方案中，0.021≤A/C≤0.14，例如A/C的值可以为0.021、0.03、0.04、0.05、0.06、0.07、0.08、0.09、0.1、0.11、0.12、0.13、0.14或为其中任意两个数值组成的范围。调控A/C的值在上述范围内，有利于形成更坚固的CEI膜，更好的发挥其减 少过渡金属溶出的作用，减少电解液的氧化分解，从而进一步改善二次电池的循环性能和高温存储性能。
本申请对负极极片没有特别限制，只要能够实现本申请目的即可。例如，负极极片包含负极集流体和设置在负极集流体至少一个表面上的负极材料层。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。本申请的负极材料层包含负极活性材料。本申请对负极活性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，负极活性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、SiOx(0＜x≤2)、Li-Sn合金、Li-Sn-O合金、Sn、SnO、SnO2、尖晶石结构的钛酸锂Li4Ti5O12、Li-Al合金或金属锂中的至少一种。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4μm至12μm，单面负极材料层的厚度为30μm至160μm。本申请对负极材料层中负极活性材料、负极导电剂和负极粘结剂的质量比没有特别限制，只要能够实现本申请目的即可。
本申请的负极材料层还可以包含负极导电剂、负极粘结剂和负极分散剂。本申请对负极导电剂和负极粘结剂没有特别限制，只要能够实现本申请目的即可。例如，负极导电剂可以包括但不限于导电炭黑(Super P)、碳纳米管(CNTs)、石墨、碳纤维、碳纳米线、石墨烯、金属材料或导电聚合物中的至少一种，上述碳纳米管可以包括但不限于单壁碳纳米管和/或多壁碳纳米管。上述碳纤维可以包括但不限于气相生长碳纤维(VGCF)和/或纳米碳纤维。上述金属材料可以包括但不限于金属粉和/或金属纤维，具体地，金属可以包括但不限于铜、镍、铝或银中的至少一种。上述导电聚合物可以包括但不限于聚亚苯基衍生物、聚苯胺、聚噻吩、聚乙炔或聚吡咯中的至少一种。负极粘结剂可以包括但不限于聚丙烯酸、聚丙烯酸钠、聚丙烯酸钾、聚丙烯酸锂、聚酰亚胺、聚乙烯醇、羧甲基纤维素、羧甲基纤维素钠、羧甲基纤维素锂、聚酰胺酰亚胺、丁苯橡胶或聚偏氟乙烯(PVDF)中的至少一种。负极分散剂可以包括羧甲基纤维素钠。
本申请中，对负极极片的制备方法没有特别限制，只要能实现本申请的目的即可，例如可以通过以下方法制备：将负极活性材料、负极粘结剂、负极分散剂混合，加入去离子水搅拌均匀，获得固含量为50wt％至75wt％的负极浆料。将负极浆料均匀涂覆于负极集流体的一个表面上，烘干后得到单面涂覆负极材料层的负极极片。然后在负极集流体的另一个表面上重复以上涂布步骤，烘干后得到双面涂布负极材料层的负极极片，涂布完成后， 经冷压、裁切得到负极极片。
在本申请中，正极极片包含正极集流体和设置在正极集流体至少一个表面上的正极材料层。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”可以是正极集流体表面的全部区域，也可以是正极集流体表面的部分区域，本申请没有特别限制，只要能实现本申请目的即可。
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(例如铝碳复合集流体)等。本申请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，单面正极材料层的厚度为30μm至120μm。本申请的正极材料层还可以包含正极导电剂和正极粘结剂。本申请对正极导电剂和正极粘结剂没有特别限制，只要能够实现本申请目的即可。例如，正极导电剂可以与上述负极导电剂相同，正极粘结剂可以与上述负极粘结剂相同。本申请对正极材料层中正极活性材料、正极导电剂和正极粘结剂的质量比没有特别限制，只要能够实现本申请目的即可。
本申请中，对正极极片的制备方法没有特别限制，只要能实现本申请的目的即可，例如可以通过以下方法制备：将正极活性材料、正极导电剂、正极粘结剂混合，加入N-甲基吡咯烷酮(NMP)搅拌均匀，获得固含量为65wt％至85wt％的正极浆料。将正极浆料均匀涂覆于正极集流体的一个表面上，烘干后得到单面涂覆正极材料层的正极极片。然后在正极集流体的另一个表面上重复以上涂布步骤，烘干后得到双面涂布正极材料层的正极极片，涂布完成后，经冷压、裁切得到正极极片。
本申请的二次电池还包括隔离膜。本申请对隔离膜没有特别限制，只要能够实现本申请目的即可，例如隔离膜的材料可以包括但不限于聚乙烯(PE)、聚丙烯(PP)、聚四氟乙烯为主的聚烯烃(PO)类隔离膜、聚酯膜(例如聚对苯二甲酸二乙酯(PET)膜)、纤维素膜、聚酰亚胺膜(PI)、聚酰胺膜(PA)、氨纶或芳纶膜等中的至少一种。隔离膜的类型可以包括但不限于织造膜、非织造膜(无纺布)、微孔膜、复合膜、碾压膜或纺丝膜等中的至少一种。本申请的隔离膜可以具有多孔结构，多孔层设置在隔离膜的至少一个表面上，多孔层包括无机颗粒和粘结剂，无机颗粒可以包括氧化铝、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、氢氧化钙或硫酸钡中的至少一种。粘结剂可以包括聚偏氟乙烯、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、羧甲基纤维素纳、聚乙烯吡咯烷酮、聚乙烯醚、聚甲基丙烯酸甲酯、聚四氟乙烯或聚六氟 丙烯中的至少一种。本申请对多孔结构的孔径的尺寸没有特别限制，只要能实现本申请的目的即可，例如，孔径的尺寸可以为0.01μm至1μm。在本申请中，隔离膜的厚度没有特别限制，只要能实现本申请的目的即可，例如隔离膜的厚度可以为5μm至50μm。
本申请对二次电池的种类没有特别限制，其可以包括发生电化学反应的任何装置。例如，二次电池可以包括但不限于：锂金属二次电池、锂离子电池、钠离子电池、锂聚合物二次电池、锂离子聚合物二次电池。本申请对二次电池的形状没有特别限制，只要能够实现本申请目的即可。本申请的二次电池还包括包装袋，本申请对包装袋没有特别限制，只要能够实现本申请目的即可。例如可以采用铝塑膜包装袋。
二次电池的制备过程为本领域技术人员所熟知的，本申请没有特别的限制，例如，可以包括但不限于以下步骤：将正极极片、隔离膜和负极极片按顺序堆叠，焊接极耳后，并根据需要将其进行卷绕、折叠等操作得到卷绕结构的电极组件，将电极组件放入包装袋内，将电解液注入包装袋并封口，得到二次电池；或者，将正极极片、隔离膜和负极极片按顺序堆叠，焊接极耳后，然后用胶带将整个叠片结构的四个角固定好得到叠片结构的电极组件，将电极组件置入包装袋内，将电解液注入包装袋并封口，得到二次电池。此外，也可以根据需要将防过电流元件、导板等置于包装袋中，从而防止二次电池内部的压力上升、过充放电。
本申请的第三方面提供了一种电子装置，其包括本申请第二方面提供的二次电池。本申请第二方面提供的二次电池具有良好的循环性能和高温存储性能，从而本申请的电子装置具有较长的使用寿命。
本申请对电子装置的种类没有特别限定，其可以是用于现有技术中已知的任何电子装置。在一些实施例中，电子装置可以包括但不限于笔记本电脑、笔输入型计算机、移动电脑、电子书播放器、便携式电话、便携式传真机、便携式复印机、便携式打印机、头戴式立体声耳机、录像机、液晶电视、手提式清洁器、便携CD机、迷你光盘、收发机、电子记事本、计算器、存储卡、便携式录音机、收音机、备用电源、电机、汽车、摩托车、助力自行车、自行车、照明器具、玩具、游戏机、钟表、电动工具、闪光灯、照相机、家庭用大型蓄电池和锂离子电容器等。
实施例
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。
测试方法和设备：
电解液中各成分含量的测试：
将锂离子电池以1C恒定电流放电至3V后拆解，收集电解液，并将拆出的正极极片、负极极片、隔离膜进行离心，将离心后得到的液体和上述电解液混合均匀，然后采用气相色谱-质谱联用仪(GC-MS，仪器型号为Agilent 8890)和离子色谱(IC，仪器型号为AQUION离子色谱)进行测试，得到电解液中的各个组分并测试其含量。
镍元素占所有过渡金属元素的摩尔百分比测试：
将锂离子电池以1C恒定电流放电至3V，拆解得到正极极片，用碳酸二甲酯(DMC)清洗上述正极极片，将清洗后的正极极片的正极材料层用刮刀刮下，用混合溶剂溶解，例如取0.4g正极材料层使用10mL王水与2mL的HF混合得到的混合溶剂进行溶解，其中王水由浓硝酸与浓盐酸按照体积比1:1混合得到。然后定容至100mL，然后使用电感耦合等离子光谱发生仪(ICP)测试溶液中的各个过渡金属元素的含量，最后通过计算得到镍元素占所有过渡金属元素的摩尔百分比。
循环性能测试：
通过锂离子电池的容量保持率评价锂离子电池在高电压条件下的循环性能。容量保持率越高，说明锂离子电池的循环性能越好。测试过程为：将锂离子电池置于25℃恒温箱中，静置5min，然后将锂离子电池以1C恒流充电至电压为4.28V，然后以4.28V恒压充电至电流为0.05C，再以1C恒流放电至2.5V，此为一个充放电循环。记录首次放电容量为Q1，反复进行充放电循环800次，停止测试，记录第800次的放电容量为Q2，则锂离子电池的25℃循环容量保持率(％)＝Q2/Q1×100％。
高温存储性能测试：
通过锂离子电池在60℃存储厚度膨胀率来评价锂离子电池的高温存储性能。厚度膨胀率越小，说明锂离子电池的高温存储性能越好。测试过程如下：在25℃环境中，将锂离子电池以0.5C恒流充电至4.28V，再以4.28V恒压充电至电流为0.05C，测试锂离子电池的厚度为D1，然后将锂离子电池放置在60℃烘箱中，存储180天后取出，测试此时锂离子电池的厚度为D2。锂离子电池60℃存储厚度膨胀率＝(D2-D1)/D1×100％。
50％荷电状态(SOC)直流阻抗(DCR)测试：
在25℃环境下，将锂离子电池以0.5C的电流放电至2.5V，静置5分钟，然后以0.5C的电流充电至4.28V，再在4.28V下恒压至0.025C。静置5分钟，使用0.1C的电流放电至2.5V，标记此时的放电容量记为C1。使用0.5C1的容量充电至4.28V，在4.28V电压下恒压至0.025C1，静置5分钟，使用0.1C1的电流放电5小时，此时锂离子电池的电压记为V1，之后采用1C的电流放电1秒，此时锂离子电池的电压记为V2。50％ SOC DCR＝(V1-V2)/(1C-0.1C1)。
实施例1-1
<电解液的制备>
在含水量<10ppm的氩气气氛手套箱中，将碳酸酯化合物碳酸亚乙酯(EC)和碳酸二乙酯(DEC)按照3:7的质量比混合均匀得到基础溶剂，然后向基础溶剂中依次加入LiPF6、二氟磷酸锂、金属阳离子盐三氟甲磺酸铝，溶解并混合均匀，得到电解液。其中，基于所述电解液的质量，LiPF6的质量百分含量为12.5％、二氟磷酸锂的质量百分含量A％、金属阳离子盐的质量百分含量B％如表1所示，余量为基础溶剂。
<正极极片的制备>
将正极活性材料Li(Ni0.6Mn0.2Co0.2)O2、正极导电剂导电炭黑、正极粘结剂聚偏氟乙烯按照质量比为96:2:2进行混合，加入N-甲基吡咯烷酮搅拌均匀，得到固含量为72wt％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一个表面上，将铝箔在85℃下烘干处理4h，得到单面涂覆正极材料层的正极极片。在铝箔的另一个表面上重复以上步骤，即得到双面涂覆正极材料层的正极极片。然后在85℃的真空条件下干燥4h后，经过冷压、裁片、分切得到规格为74mm×867mm的正极极片。其中，正极材料层的压实密度为4.15g/cm3，单面正极材料层的厚度为60μm。
<负极极片的制备>
将负极活性材料石墨、负极粘结剂丁苯橡胶、负极增稠剂羧甲基纤维素钠、按照质量比为97.4:1.4:1.2进行混合，加入去离子水搅拌均匀，获得固含量为54wt％的负极浆料。将负极浆料均匀涂覆于厚度为6μm的负极集流体铜箔的一个表面上，将铜箔在85℃下烘干处理4h，得到单面涂覆负极材料层的负极极片。在铜箔的另一个表面上重复以上步骤，即得到双面涂覆负极材料层的负极极片。然后在85℃的真空条件下干燥4h后，经过冷压、裁片、分切得到规格为78mm×875mm的负极极片。其中，正极材料层的压实密度为1.75g/cm3，单面正极材料层的厚度为70μm。
<隔离膜的制备>
将PVDF和氧化铝陶瓷按照质量比9:1进行混合，加入去离子水作为溶剂，调配成固含量25wt％的陶瓷层浆料，并搅拌均匀，将浆料均匀的涂覆在厚度为16μm的基材聚乙烯多孔薄膜的一个表面，烘干后得到单面涂覆2μm氧化铝陶瓷层的隔离膜。之后，在该基材的另一个表面上重复以上涂覆步骤，得到双面涂覆2μm氧化铝陶瓷层的隔离膜。
<锂离子电池的制备>
将制备的正极极片、隔离膜、负极极片、隔离膜按顺序叠好，使隔离膜处于正极极片和负极极片中间起到隔离的作用，然后卷绕得到电极组件。焊接极耳后将电极组件装入铝 塑膜包装袋中，放置在85℃真空烘箱中干燥12h脱去水分，注入上述配好的电解液，经过真空封装、静置、化成(在45±5℃下、以0.1C倍率恒流充电10min，随后以0.5C倍率恒流充电至4.3V，再恒压充电至电流0.05C，接着以0.5C恒流放电至2.5V)、整形、容量测试、二次封装等工序，得到锂离子电池。
实施例1-2至实施例1-20
除了按照表1调整参数以外，其余与实施例1-1相同。当二氟磷酸锂的质量百分含量A％、金属阳离子盐的质量百分含量B％按照表1变化时，碳酸酯化合物的质量百分含量随之改变，EC和DEC的质量比以及锂盐的质量百分含量保持不变。
实施例2-1
除了按照表2调整电解液中各组分的质量百分含量以外，其余与实施例1-6相同。
实施例2-2至实施例2-11
除了在电解液中引入羧酸酯化合物按照表2调整相关参数以外，其余与实施例1-6相同。
实施例3-1至实施例3-15
除了在电解液中引入第一添加剂并按照表3调整相关参数以外，其余与实施例1-4相同。当二氟磷酸锂的质量百分含量A％、金属阳离子盐的质量百分含量B％或第一添加剂的质量百分含量X1％按照表3变化时，碳酸酯化合物的质量百分含量随之改变，EC和DEC的质量比以及锂盐的质量百分含量保持不变。
实施例4-1至实施例4-3
除了在电解液中引入第二添加剂并按照表4调整第二添加剂的种类及其质量百分含量X2％以外，其余与实施例1-4相同。当第二添加剂的质量百分含量X2％按照表4变化时，碳酸酯化合物的质量百分含量随之改变，二氟磷酸锂的质量百分含量A％、金属阳离子盐的质量百分含量B％、EC和DEC的质量比以及锂盐的质量百分含量保持不变。
实施例4-4至实施例4-15
除了在电解液中引入第二添加剂并按照表4调整相关参数以外，其余与实施例3-4相同。当二氟磷酸锂的质量百分含量A％、金属阳离子盐的质量百分含量B％或第二添加剂的质量百分含量X2％按照表4变化时，碳酸酯化合物的质量百分含量随之改变，EC和DEC的质量比以及锂盐的质量百分含量保持不变。
实施例5-1至实施例5-15
除了按照表5调整参数以外，其余与实施例1-1相同。当二氟磷酸锂的质量百分含量A％按照表5变化时，碳酸酯化合物的质量百分含量随之改变，金属阳离子盐的质量百分 含量B％、EC和DEC的质量比以及锂盐的质量百分含量保持不变。
对比例1
除了在电解液中不加入二氟磷酸锂、碳酸酯化合物的质量百分含量随之改变，金属阳离子盐的质量百分含量B％、EC和DEC的质量比以及锂盐的质量百分含量保持不变以外，其余与实施例1-2相同。
对比例2
除了在电解液中不加入金属阳离子盐、碳酸酯化合物的质量百分含量随之改变，二氟磷酸锂的质量百分含量A％、EC和DEC的质量比以及锂盐的质量百分含量保持不变以外，其余与实施例1-1相同。
对比例3至对比例10
除了按照表1调整参数以外，其余与实施例1-1相同。当二氟磷酸锂的质量百分含量A％、金属阳离子盐的质量百分含量B％按照表1变化时，碳酸酯化合物的质量百分含量随之改变，EC和DEC的质量比以及锂盐的质量百分含量保持不变。
对比例11
除了按照表5调整参数以外，其余与对比例6相同。
各实施例和对比例的制备参数及性能参数如表1至表5所示。
表1

注：表1中，“/”表示无相关参数或不存在对应的物质，表1中“-”表示锂离子电池的性能数据无法测得。
从实施例1-1至实施例1-20、对比例1至对比例10可以看出，电解液包括二氟磷酸锂和金属阳离子盐，并调控A和A/B的值在本申请范围内，可以使得锂离子电池具有较低的阻抗、更高的循环容量保持率以及更低的存储厚度膨胀率，说明锂离子电池具有更好的循环性能和高温存储性能。对比例1的电解液未加入二氟磷酸锂，对比例2的电解液未加入金属阳离子盐促溶，二氟磷酸锂不完全溶解，对比例3至对比例10的锂离子电池，A或A/B中的至少一者未在本申请范围内其中，其中对比例4、对比例9至对比例10的A/B值过大，由于二氟磷酸锂和金属阳离子盐的搭配不合理，二氟磷酸锂不完全溶解，对比例2、对比例4、对比例9至对比例10无法测得锂离子电池的性能数据。对比例5的锂离子电池虽然存储厚度膨胀率较低，但是其循环容量保持率更低，说明锂离子电池的循环性能和高温存储性能无法兼顾。对比例1、对比例3、对比例6至对比例8的锂离子电池，循环容量保持率更低、存储厚度膨胀率更高，说明锂离子电池的循环性能和高温存储性能较差。
从实施例1-1至实施例1-16、对比例3至对比例5可以看出，当A的值过小时，例如对比例3，锂离子电池的循环容量保持率更低、存储厚度膨胀率更高；当A的值过大时，例如对比例4和对比例5，对比例4的二氟磷酸锂不完全溶解，无法测得锂离子电池的性能数据，虽然对比例5的锂离子电池的存储厚度膨胀率较低，但是其循环容量保持率更低 说明锂离子电池的循环性能和高温存储性能无法兼顾。从而，调控A的值在本申请范围内，可以使得锂离子电池具有较低的阻抗、更高的循环容量保持率以及更低的存储厚度膨胀率，说明锂离子电池具有较低的阻抗、更好的循环性能和高温存储性能。
从实施例1-1至实施例1-16、对比例6至对比例10可以看出，当A/B的值过小时，例如对比例6至对比例8，锂离子电池的循环容量保持率更低、存储厚度膨胀率更高；当A/B的值过大时，例如对比例9至对比例10，由于二氟磷酸锂和金属阳离子盐的搭配不合理，二氟磷酸锂不完全溶解，无法测得锂离子电池的性能数据。从而，调控A/B的值在本申请范围内，可以使得锂离子电池具有较低的阻抗、更高的循环容量保持率以及更低的存储厚度膨胀率，说明锂离子电池具有较低的阻抗、更好的循环性能和高温存储性能。
B的值通常会影响锂离子电池的循环性能和高温存储性能。从实施例1-1至实施例1-4、实施例1-10至实施例1-16可以看出，调控B的值在本申请范围内，可以使得锂离子电池具有较低的阻抗、较高的循环容量保持率以及较低的存储厚度膨胀率，说明锂离子电池具有较低的阻抗、良好的循环性能和高温存储性能。
金属阳离子盐的种类通常会影响锂离子电池的循环性能和高温存储性能。从实施例1-2、实施例1-17至实施例1-20可以看出，选用在本申请范围内的金属阳离子盐，可以使得锂离子电池具有较低的阻抗、较高的循环容量保持率以及较低的存储厚度膨胀率，说明锂离子电池具有较低的阻抗、良好的循环性能和高温存储性能。
表2

注：表2中，“/”表示无相关参数或不存在对应的物质，碳酸酯化合物为EC+DEC、EC+EMC或EC+DMC，两种化合物的质量比均为3:7。
D的值通常会影响锂离子电池的循环性能和高温存储性能。从实施例1-6、实施例1-14至实施例1-15、实施例2-1至实施例2-7可以看出，调控D的值在本申请范围内，可以使得锂离子电池具有更低的阻抗、较高的循环容量保持率以及较低的存储厚度膨胀率，说明锂离子电池具有更低的阻抗、良好的循环性能和高温存储性能。
碳酸酯化合物的种类通常会影响锂离子电池的循环性能和高温存储性能。从实施例2-6、实施例2-8至实施例2-9可以看出，选用在本申请范围内的碳酸酯化合物，可以使得锂离子电池具有较低的阻抗、较高的循环容量保持率以及较低的存储厚度膨胀率，说明锂离子电池具有较低的阻抗、良好的循环性能和高温存储性能。
E的值通常会影响锂离子电池的循环性能和高温存储性能。从实施例2-1至实施例2-7可以看出，电解液中进一步加入羧酸酯化合物并调控E的值在本申请范围内，可以使得锂离子电池具有较低的阻抗、较高的循环容量保持率以及较低的存储厚度膨胀率，说明锂离子电池具有较低的阻抗、良好的循环性能和高温存储性能。
羧酸酯的种类通常会影响锂离子电池的循环性能和高温存储性能。从实施例2-6、实施例2-10至实施例2-11可以看出，选用在本申请范围内的羧酸酯化合物，可以使得锂离子电池具有较低的阻抗、较高的循环容量保持率以及较低的存储厚度膨胀率，说明锂离子电池具有较低的阻抗、良好的循环性能和高温存储性能。
表3

注：表3中，“/”表示无相关参数或不存在对应的物质，“FEC+1,3-PS”的质量百分含量为“2.5+0.5”表示FEC的质量百分含量为2.5％，1,3-PS的质量百分含量为0.5％，二者之和为X1％，其余类似表述以此类推。
电解液包括第一添加剂以及X1的值通常会影响锂离子电池的循环性能和高温存储性能。从实施例1-4、实施例3-1至实施例3-6、实施例3-12可以看出，电解液包括二氟磷酸和金属阳离子盐的基础上，进一步引入第一添加剂，并调控X1的值在本申请范围内，可以使得锂离子电池具有较低的阻抗、较高的循环容量保持率以及较低的存储厚度膨胀率，说明锂离子电池具有较低的阻抗、良好的循环性能和高温存储性能。
A/X1的值通常会影响锂离子电池的循环性能和高温存储性能。从实施例3-1至实施例3-12可以看出，调控A/X1的值在本申请范围内，可以使得锂离子电池具有较低的阻抗、较高的循环容量保持率以及较低的存储厚度膨胀率，说明锂离子电池具有较低的阻抗、良好的循环性能和高温存储性能。
第一添加剂的种类通常会影响锂离子电池的循环性能和高温存储性能。从实施例3-2、实施例3-13至实施例3-15可以看出，选用本申请范围内的第一添加剂，可以使得锂离子电池具有较低的阻抗、较高的循环容量保持率以及较低的存储厚度膨胀率，说明锂离子电池具有较低的阻抗、良好的循环性能和高温存储性能。
表4

注：表4中，“/”表示无相关参数或不存在对应的物质，“LiBF4+LiDFOB+LiBOB”的质量百分含量为“0.2+0.2+0.2”表示LiBF4的质量百分含量为0.2％，LiDFOB的质量百分含量为0.2％，LiBOB的质量百分含量为0.2％，三者之和为X2％，其余类似表述以此类推。
电解液包括第二添加剂以及X2的值通常会影响锂离子电池的循环性能和高温存储性能。从实施例1-4、实施例4-1至实施例4-3可以看出，电解液包括二氟磷酸锂和金属阳离子盐的基础上，进一步引入第二添加剂，并调控X2的值在本申请范围内，可以使得锂离子电池具有较低的阻抗、较高的循环容量保持率以及较低的存储厚度膨胀率，说明锂离子电池具有良好的循环性能和高温存储性能。从实施例3-4、实施例4-4至实施例4-13可以看出，电解液包括二氟磷酸锂、金属阳离子盐和第一添加剂的基础上，进一步引入第二添加剂，并调控X2的值在本申请范围内，可以使得锂离子电池具有较低的阻抗、较高的循环容量保持率以及较低的存储厚度膨胀率，说明锂离子电池具有较低的阻抗、良好的循环性能和高温存储性能。
A/X2的值通常会影响锂离子电池的循环性能和高温存储性能。从实施例4-1至实施例4-15可以看出，调控A/X2的值在本申请范围内，可以使得锂离子电池具有较低的阻抗、较高的循环容量保持率以及较低的存储厚度膨胀率，说明锂离子电池具有较低的阻抗、良 好的循环性能和高温存储性能。
第二添加剂的种类通常会影响锂离子电池的循环性能和高温存储性能。从实施例4-6至实施例4-7、实施例4-10可以看出，选用本申请范围内的第二添加剂，可以使得锂离子电池具有较低的阻抗、较高的循环容量保持率以及较低的存储厚度膨胀率，说明锂离子电池具有较低的阻抗、良好的循环性能和高温存储性能。
表5
C的值通常会影响锂离子电池的循环性能和高温存储性能。从实施例5-5至实施例5-10、对比例11可以看出，调控A/B的值在本申请范围内的基础上，进一步调控C的值在本申请范围内，可以使得锂离子电池具有较低的阻抗、较高的循环容量保持率以及较低的存储厚度膨胀率，说明锂离子电池具有较低的阻抗、良好的循环性能和高温存储性能。
A/C的值通常会影响锂离子电池的循环性能和高温存储性能。从实施例1-1至实施例 1-4、实施例1-13、实施例5-1至实施例5-15可以看出，调控A/C的值在本申请范围内，可以使得锂离子电池具有较低的阻抗、较高的循环容量保持率以及较低的存储厚度膨胀率，说明锂离子电池具有较低的阻抗、良好的循环性能和高温存储性能。
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。

Claims (12)

  1. 一种电解液，所述电解液包括二氟磷酸锂和金属阳离子盐，所述金属阳离子盐的金属阳离子的化合价为正二价及以上，所述金属阳离子盐的阴离子基团包括式I-A所示的阴离子基团或者式I-B所示的阴离子基团：
    其中，R1选自全部氢原子被氟取代的C1至C3的烷基，R2和R3各自独立地选自氟原子或者全部氢原子被氟取代的C1至C3的烷基；
    基于所述电解液的质量，二氟磷酸锂的质量百分含量为A％，所述金属阳离子盐的质量百分含量为B％，2≤A≤8.8，1≤A/B≤2.2。
  2. 根据权利要求1所述的电解液，其中，1.5≤B≤5。
  3. 根据权利要求1所述的电解液，其满足以下特征中的至少一者：
    (1)2≤A≤6；
    (2)1.2≤A/B≤2.2；
    (3)1.8≤B≤4。
  4. 根据权利要求1至3中任一项所述的电解液，其中，所述阴离子基团包括以下基团：
    所述金属阳离子为MN+，M包括Al、Sn、In、Ba或Ga中的任一种，2≤N≤3。
  5. 根据权利要求1至3中任一项所述的电解液，其中，所述金属阳离子盐包括三氟甲磺酸铝、三氟甲磺酸亚锡、三氟甲磺酸铟、三氟甲磺酸钡、双(三氟甲基磺酰基)亚胺钡(II)、双氟磺酰亚胺铝、双(三氟甲磺酰基)酰亚胺铝或双氟磺酰亚胺钡中的至少一种。
  6. 根据权利要求1至3中任一项所述的电解液，其中，所述电解液还包括碳酸酯化合物，所述碳酸酯化合物包括碳酸亚乙酯、碳酸亚丙酯、碳酸二甲酯、碳酸甲乙酯、碳酸二 乙酯中的至少一种，
    基于所述电解液的质量，所述碳酸酯化合物的质量百分含量为D％，10≤D≤87.5。
  7. 根据权利要求1至3中任一项所述的电解液，其中，所述电解液还包括羧酸酯化合物，所述羧酸酯化合物包括丙酸甲酯、丙酸乙酯、丙酸丙酯、丁酸乙酯或乙酸2,2-二氟乙酯中的至少一种，
    基于电解液的质量，所述羧酸酯化合物的质量百分含量为E％，0.85≤E≤62。
  8. 根据权利要求1至3中任一项所述的电解液，其中，所述电解液还包括第一添加剂，所述第一添加剂包括1,3-丙烷磺内酯、1,3-丙烯磺酸内酯、硫酸乙烯酯、1,3-丙二醇环硫酸酯、2,4-丁烷磺内酯、1,4-丁烷磺内酯、碳酸亚乙烯酯或氟代碳酸乙烯酯中的至少一种，
    基于所述电解液的质量，所述第一添加剂的质量百分含量为X1％，0.05≤X1≤12且0.3≤A/X1≤120。
  9. 根据权利要求1至3中任一项所述的电解液，其中，所述电解液还包括第二添加剂，所述第二添加剂包括双草酸硼酸锂、四氟硼酸锂、二氟草酸硼酸锂、双氟磺酰亚胺锂、双三氟甲磺酰亚胺锂、三氟甲磺酸锂、4,5-二氰基-2-三氟甲基-咪唑锂或四硼酸锂中的至少一种，
    基于所述电解液的质量，所述第二添加剂的质量百分含量为X2％，0.1≤X2≤8且0.3≤A/X2≤80。
  10. 一种二次电池，其包括正极极片、负极极片和权利要求1至9中任一项所述的电解液，所述正极极片包括正极材料层，所述正极材料层包括含有镍元素的锂复合过渡金属氧化物，所述镍元素占所有过渡金属元素的摩尔百分比为C％，C≥60。
  11. 根据权利要求10所述的二次电池，其中，0.021≤A/C≤0.14。
  12. 一种电子装置，其包括权利要求10或11中所述的二次电池。
PCT/CN2024/083614 2024-03-25 2024-03-25 一种电解液、包含该电解液的二次电池及电子装置 Pending WO2025199693A1 (zh)

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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111066192A (zh) * 2017-08-10 2020-04-24 三菱化学株式会社 非水系电解液二次电池
CN111108642A (zh) * 2017-09-22 2020-05-05 三菱化学株式会社 非水系电解液、非水系电解液二次电池及能源装置
US20210194056A1 (en) * 2019-12-19 2021-06-24 Enevate Corporation Silicon-based energy storage devices with electrolyte containing sulfonate or carboxylate salt based compounds
WO2023216139A1 (zh) * 2022-05-11 2023-11-16 宁德时代新能源科技股份有限公司 二次电池及其制备方法、电池模块、电池包和用电装置
CN117410582A (zh) * 2023-09-20 2024-01-16 蜂巢能源科技股份有限公司 一种半固态电池及其制备方法与应用

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111066192A (zh) * 2017-08-10 2020-04-24 三菱化学株式会社 非水系电解液二次电池
CN111108642A (zh) * 2017-09-22 2020-05-05 三菱化学株式会社 非水系电解液、非水系电解液二次电池及能源装置
US20210194056A1 (en) * 2019-12-19 2021-06-24 Enevate Corporation Silicon-based energy storage devices with electrolyte containing sulfonate or carboxylate salt based compounds
WO2023216139A1 (zh) * 2022-05-11 2023-11-16 宁德时代新能源科技股份有限公司 二次电池及其制备方法、电池模块、电池包和用电装置
CN117410582A (zh) * 2023-09-20 2024-01-16 蜂巢能源科技股份有限公司 一种半固态电池及其制备方法与应用

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