WO2024239162A1 - 锂离子二次电池和用电装置 - Google Patents

锂离子二次电池和用电装置 Download PDF

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Publication number
WO2024239162A1
WO2024239162A1 PCT/CN2023/095367 CN2023095367W WO2024239162A1 WO 2024239162 A1 WO2024239162 A1 WO 2024239162A1 CN 2023095367 W CN2023095367 W CN 2023095367W WO 2024239162 A1 WO2024239162 A1 WO 2024239162A1
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Prior art keywords
lithium
ion secondary
secondary battery
electrolyte
carbonate
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PCT/CN2023/095367
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English (en)
French (fr)
Inventor
郭洁
韩昌隆
张翠平
吴则利
王冠
蔡林华
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Contemporary Amperex Technology Co Ltd
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Contemporary Amperex Technology Co Ltd
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Priority to KR1020257039046A priority Critical patent/KR20260003050A/ko
Priority to EP23937841.7A priority patent/EP4715932A4/en
Priority to CN202380009966.9A priority patent/CN119343797A/zh
Priority to JP2025566929A priority patent/JP2026518651A/ja
Priority to PCT/CN2023/095367 priority patent/WO2024239162A1/zh
Publication of WO2024239162A1 publication Critical patent/WO2024239162A1/zh
Priority to US19/390,710 priority patent/US20260074287A1/en
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
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
    • H01M10/0564—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes the electrolyte being constituted of organic materials only
    • H01M10/0566—Liquid materials
    • H01M10/0568—Liquid materials characterised by the solutes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
    • H01M10/0564—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes the electrolyte being constituted of organic materials only
    • H01M10/0566—Liquid materials
    • H01M10/0569—Liquid materials characterised by the solvents
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
    • H01M10/4235—Safety or regulating additives or arrangements in electrodes, separators or electrolyte
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/58—Selection of substances as active materials, active masses, active liquids of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
    • H01M4/583—Carbonaceous material, e.g. graphite-intercalation compounds or CFx
    • H01M4/587—Carbonaceous material, e.g. graphite-intercalation compounds or CFx for inserting or intercalating light metals
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M2004/026—Electrodes composed of, or comprising, active material characterised by the polarity
    • H01M2004/027—Negative electrodes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M2300/00—Electrolytes
    • H01M2300/0017—Non-aqueous electrolytes
    • H01M2300/0025—Organic electrolyte
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M2300/00—Electrolytes
    • H01M2300/0017—Non-aqueous electrolytes
    • H01M2300/0025—Organic electrolyte
    • H01M2300/0028—Organic electrolyte characterised by the solvent
    • H01M2300/0037—Mixture of solvents
    • 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 secondary batteries, and in particular to a lithium-ion secondary battery and an electrical device.
  • secondary batteries have been widely used in energy storage power systems such as hydropower, thermal, wind and solar power stations, as well as in power tools, electric bicycles, electric motorcycles, electric vehicles, military equipment, aerospace and other fields, and the requirements for the electrical performance of secondary batteries are constantly increasing.
  • the performance of the electrolyte has a key impact on the performance of the secondary battery. Therefore, it is necessary to develop electrolytes to improve the performance of secondary batteries to meet the application needs of the new generation of electrochemical systems.
  • the purpose of the present application is to provide a lithium-ion secondary battery, aiming to reduce the DC impedance of the lithium-ion secondary battery and improve the power performance and cycle performance of the lithium-ion secondary battery.
  • the first aspect of the present application provides a lithium ion secondary battery, comprising an electrolyte, wherein the electrolyte comprises an alkali metal ion having an ion radius greater than that of a lithium ion and a film-forming additive;
  • the mass content A of the alkali metal ions and the mass content B of the additive satisfy: 0.10 ⁇ B/A ⁇ 6 ⁇ 10 4 .
  • the electrolyte including alkali metal ions and film-forming additives is conducive to reducing the DC impedance of lithium-ion secondary batteries, improving the metal dendrite phenomenon of lithium-ion secondary batteries, and thus improving the power performance and cycle performance of lithium-ion secondary batteries.
  • the introduction of alkali metal ions with a metal ion radius larger than the radius of lithium ions into the electrolyte facilitates the formation of a good channel for lithium ion transmission during the charge and discharge process of lithium-ion secondary batteries, thereby reducing the lithium ion
  • the introduction of film-forming additives into the electrolyte is conducive to the formation of a uniform and dense inorganic SEI film at the interface between the negative electrode and the electrolyte, which can effectively inhibit metal dendrites and improve the safety of lithium-ion secondary batteries.
  • the inorganic SEI film can further hinder the interface side reactions between the electrolyte and the negative electrode, and improve the cycle performance of lithium-ion secondary batteries.
  • the relationship between the mass content A of alkali metal ions and the mass content B of film-forming additives is controlled to meet 0.10 ⁇ B/A ⁇ 6 ⁇ 10 4 , which can not only reduce the DC impedance of lithium-ion secondary batteries, but also further improve the power performance and cycle performance of batteries.
  • the lithium ion secondary battery includes a negative electrode plate
  • the negative electrode plate includes a current collector and a negative electrode active material layer located on at least one side of the current collector and containing at least a negative electrode active material
  • the porosity C of the negative electrode active material layer and the mass content A of the alkali metal ions in the total mass of the electrolyte satisfy: 10-6 ⁇ A/C ⁇ 0.035, which can be optionally 5 ⁇ 10-5 ⁇ A/C ⁇ 0.025.
  • Controlling the appropriate relationship between the porosity of the negative electrode active material layer and the mass content of alkali metal ions facilitates the electrolyte to better and faster infiltrate the negative electrode plate, so that lithium ions can be better transmitted, the concentration polarization of lithium ions during the transmission process can be improved, the electrical properties of lithium-ion secondary batteries can be enhanced, and the phenomenon of metal dendrites can be improved, taking into account the kinetics and cycle performance of lithium-ion secondary batteries.
  • the mass content A of the alkali metal ions and the mass content B of the film-forming additive satisfy: 0.14 ⁇ B/A ⁇ 2000.
  • the DC impedance of the lithium-ion secondary battery can be further reduced, and the cycle performance of the battery can be improved.
  • the alkali metal ions include one or more of Na + , K + , and Cs + .
  • alkali metal ions are all beneficial to the transmission of lithium ions and improve the power performance of the battery.
  • the mass content A of the alkali metal ions satisfies: 1 ppm ⁇ A ⁇ 7000 ppm, and can be optionally 100 ppm ⁇ A ⁇ 7000 ppm.
  • the electrolyte further includes anions, and the anions include one or more of PO 2 F 2 ⁇ , FSO 3 ⁇ , DFOB ⁇ , BF 4 ⁇ , DFOP ⁇ , BOB ⁇ , and PO 3 F 2 ⁇ .
  • the mass content of the anions is greater than 0 and less than or equal to 5%.
  • the mass content of the anions is greater than 0 and less than or equal to 4%.
  • Controlling the mass content of the introducing anions within an appropriate range can not only improve the cycle performance of lithium-ion secondary batteries, but also help reduce the formation of metal dendrites.
  • the film-forming additive includes one or more of fluorocarbonate compounds, sulfate compounds, and sulfonate compounds.
  • fluorinated carbonate compounds can form an inorganic SEI film rich in LiF and LiCO 3 on the surface of the negative electrode
  • sulfate compounds can form an inorganic SEI film rich in Li 2 SO 4 on the surface of the negative electrode
  • sulfonate compounds can form an inorganic SEI film rich in Li 2 SO 3 on the surface of the negative electrode.
  • the inorganic SEI film can not only inhibit the phenomenon of metal dendrites, but also hinder the reaction between the electrolyte and the positive/negative electrode, improve the stability of lithium-ion secondary batteries, and enhance their cycle performance.
  • the fluorinated carbonate compound includes one or more of fluoroethylene carbonate, 1,2-difluoroethylene carbonate, 1,1-difluoroethylene carbonate, 1,1,2-trifluoroethylene carbonate, 1,1,2,2-tetrafluoroethylene carbonate, 1-fluoro-2-methylethylene carbonate, 1-fluoro-1-methylethylene carbonate, 1,2-difluoro-1-methylethylene carbonate, 1,1,2-trifluoro-2-methylethylene carbonate or trifluoromethylethylene carbonate, and optionally includes fluoroethylene carbonate;
  • the sulfate ester compound includes one or more of 4,4'-vinyl sulfate, vinyl sulfate, diethyl sulfate, dimethyl sulfate and 4,4-bis(1,3,2-dioxathiolane)-2,2,2,2-tetraoxide, and optionally includes one or more of 4,4'-vinyl sulfate and vinyl sulfate; and/or,
  • the sulfonate compound includes one or more of 1,3-propane sultone, propene sultone, and 3-fluoro-1,3-propane sultone, and optionally includes 1,3-propane sultone.
  • the above-mentioned fluorinated carbonate compounds, sulfate compounds, and sulfonate compounds can all form a uniform and dense inorganic SEI film.
  • the mass content B of the film-forming additive satisfies: 0.1% ⁇ B ⁇ 7%, optionally 0.1% ⁇ B ⁇ 6%.
  • a sufficiently dense inorganic SEI film can be formed, the formation of metal dendrites can be inhibited, the interface side reactions can be hindered, and the side reactions of lithium-ion secondary batteries can be reduced.
  • the porosity C of the negative electrode active material layer is 20% to 60%, and can be optionally 20% to 40%.
  • Controlling the porosity of the negative electrode active material layer within an appropriate range can not only improve the wettability of the electrolyte to the negative electrode plate, thereby facilitating better transmission of lithium ions, improve the concentration polarization of lithium ions during transmission, enhance the electrical properties of lithium-ion secondary batteries, and inhibit the phenomenon of dendrites; it can also reduce the risk of increased contact area between the electrolyte and the negative electrode active material due to excessive porosity, and reduce the degree of side reactions.
  • the mass content of the lithium salt is 8% to 20%, and optionally 8% to 15%.
  • Controlling the mass content of lithium salt within an appropriate range is beneficial to promoting the migration of lithium ions and reducing the DC impedance of lithium-ion secondary batteries.
  • the lithium salt includes a first lithium salt and/or a second lithium salt, and the first lithium salt and the second lithium salt each independently include one or more of LiFSI, LiPF 6 , LiBF 4 , LiTFSI, LiClO 4 , LiAsF 6 , LiBOB, LiDFOB, and LiDFOP.
  • the first lithium salt is selected from LiFSI
  • the second lithium salt is selected from LiPF 6 .
  • LiFSI has a large anion that can effectively promote the migration of lithium ions to allow lithium LiFSI has an excellent lithium ion migration number, which reduces its DC impedance and the precipitation of metal dendrites.
  • LiFSI itself is insensitive to water and has good thermal stability, which can further improve the safety of lithium ion secondary batteries.
  • the thermal stability of LiPF 6 film formation is better than that of LiFSI. Therefore, the combination of LiFSI and LiPF 6 can take into account the electrical performance and thermal stability of its lithium ion secondary battery.
  • the mass ratio of LiFSI and LiPF 6 is not less than 0.1 and not more than 5; optionally, the mass ratio of LiFSI and LiPF 6 is not less than 3 and not more than 5.
  • the mass ratio of the first lithium salt to the second lithium salt is controlled within a suitable range so that the lithium ion secondary battery has excellent electrical properties.
  • the electrolyte further comprises a solvent
  • the solvent comprises a cyclic ester solvent and/or a linear ester solvent
  • the cyclic ester solvent includes one or more of ethylene carbonate and propylene carbonate;
  • the linear ester solvent includes one or more of dimethyl carbonate, diethyl carbonate, methyl propyl carbonate, ethyl methyl carbonate, methyl formate, methyl acetate, ethyl acetate, butyl acetate, methyl propionate, methyl butyrate, ethyl butyrate, propyl butyrate, butyl butyrate, isopropyl acetate, and isoamyl acetate.
  • the above solvents can be used in combination with alkali metal salts and film-forming additives to enable lithium-ion secondary batteries to have lower DC impedance and excellent cycle performance.
  • the mass content of the cyclic ester solvent is A, and the mass content of the linear ester solvent is (100%-A). In some embodiments, A is 0-40%, 2%-40% or 5%-35%.
  • the mass content of the cyclic ester solvent is 2% to 40%, optionally 5% to 35%; the mass content of the linear ester solvent is 50% to 100%, optionally 60% to 95%.
  • the mass contents of the cyclic ester solvent and the linear ester solvent are respectively controlled within a suitable range so that the lithium ion secondary battery has excellent electrical properties and safety.
  • the negative electrode active material layer includes one or more of artificial graphite, natural graphite, soft carbon, hard carbon, silicon-carbon composite, lithium titanate, and silicon-oxygen composite.
  • the negative electrode active material layer including the above negative electrode active material has a suitable porosity.
  • the lithium-ion secondary battery includes a positive electrode plate, and the positive electrode plate includes one or more of a lithium transition metal oxide positive electrode active material and a lithium phosphate positive electrode active material.
  • the second aspect of the present application also includes an electrical device, including the lithium-ion secondary battery described in the first aspect of the present application.
  • FIG1 is a schematic diagram of a lithium-ion secondary battery according to an embodiment of the present application.
  • FIG2 is an exploded view of the lithium-ion secondary battery according to one embodiment of the present application shown in FIG1 ;
  • FIG3 is a schematic diagram of a battery module according to an embodiment of the present application.
  • FIG4 is a schematic diagram of a battery pack according to an embodiment of the present application.
  • FIG5 is an exploded view of the battery pack according to an embodiment of the present application shown in FIG4 ;
  • FIG. 6 is a schematic diagram of an electric device using a lithium-ion secondary battery as a power source according to an embodiment of the present application.
  • the "range” disclosed in this application is defined in the form of a lower limit and an upper limit.
  • a given range is defined by selecting a lower limit and an upper limit.
  • the selected lower limit and upper limit are defined by The boundary of a special range is defined.
  • the scope limited in this way can be including or excluding the end value, and can be arbitrarily combined, that is, any lower limit can be combined with any upper limit to form a range. For example, if the scope of 60-120 and 80-110 is listed for a specific parameter, it is understood that the scope of 60-110 and 80-120 is also expected.
  • the numerical range "ab” represents the abbreviation of any real number combination between a and b, wherein a and b are real numbers.
  • the numerical range "0-5" represents that all real numbers between "0-5" have been fully listed herein, and "0-5" is just the abbreviation of these numerical combinations.
  • a parameter is expressed as an integer ⁇ 2, it is equivalent to disclosing that the parameter is, for example, an integer of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.
  • the method includes steps (a) and (b), which means that the method may include steps (a) and (b) performed sequentially, or may include steps (b) and (a) performed sequentially.
  • the method may further include step (c), which means that step (c) may be added to the method in any order.
  • the method may include steps (a), (b) and (c), or may include steps (a), (c) and (b), or may include steps (c), (a) and (b), etc.
  • the “include” and “comprising” mentioned in this application are open-ended or closed-ended.
  • the “include” and “comprising” may mean that other components not listed may also be included or only the listed components may be included or only the listed components may be included.
  • the term "or” is inclusive.
  • the phrase "A or B” means “A, B, or both A and B”. More specifically, any of the following conditions satisfies the condition "A or B”: A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); or both A and B are true. True (or existent).
  • the metal ion transfer rate seriously affects the battery performance.
  • a low lithium ion transfer rate can lead to undesirable phenomena such as increased DC impedance of lithium batteries and reduced cycle performance.
  • Introducing other metal ions with larger ion radius into the electrolyte can form a good channel for lithium ion transfer during the charge and discharge process, thereby improving power performance.
  • the other introduced metal ions have a larger electrode potential than lithium ions, which makes it easier to deposit and form more active metals during the deposition process, and even worse, form dendrites, which seriously affects the safety of the battery. Therefore, it is necessary to design a new battery that can take into account both power performance and cycle performance.
  • the present application proposes a lithium ion secondary battery, which includes an electrolyte, the electrolyte includes alkali metal ions whose ion radius is larger than that of lithium ions and a film-forming additive; based on the total mass of the electrolyte, the mass content A of the alkali metal ions and the mass content B of the additive satisfy: 0.10 ⁇ B/A ⁇ 6 ⁇ 10 4 .
  • alkali metal ion refers to an ion of an alkali metal, including but not limited to Na + , K + or Cs + .
  • the alkali metal ion can be introduced into the secondary battery by adding an alkali metal salt to the electrolyte.
  • film-forming additive refers to an additive that reacts with metallic lithium to form an inorganic SEI film, including but not limited to fluorocarbonate compounds, sulfate compounds or sulfonate compounds.
  • alkali metal ions whose metal ion radius is larger than that of lithium ions into the electrolyte facilitates the formation of a good channel for lithium ion transmission during the charge and discharge process of the lithium ion secondary battery, thereby reducing the DC impedance of the lithium ion secondary battery.
  • the addition of alkali metal ions is prone to deposit and form metal dendrites during the charge and discharge process of the secondary battery.
  • the introduction of film-forming additives into the electrolyte is conducive to the formation of a uniform and dense inorganic SEI film at the interface between the negative electrode and the electrolyte, which can effectively inhibit metal dendrites, help avoid or reduce the risks and hidden dangers brought by alkali metal ions, and improve the safety of lithium ion secondary batteries; the inorganic SEI film can also further hinder the interface side reactions between the electrolyte and the negative electrode.
  • the introduction of alkali metal ions and film-forming additives helps to improve the power performance and cycle performance of lithium ion secondary batteries at the same time.
  • the mass content A of the alkali metal ion and the mass content B of the film-forming additive satisfy B/A and can be 0.14, 0.2, 0.4, 0.5, 0.8, 1, 5, 10, 50, 100, 500, 1000, 2000, 3000,
  • the mass content of metal ions can be determined by a detection method known to those skilled in the art, such as inductively coupled plasma technology, according to industry detection standards.
  • the alkali metal ion content A and the mass content B of the film-forming additive satisfy: 0.2 ⁇ B/A ⁇ 5 ⁇ 10 4 . In some embodiments, based on the total mass of the electrolyte, the alkali metal ion content A and the mass content B of the film-forming additive satisfy: 0.14 ⁇ B/A ⁇ 2000.
  • the electrolyte including alkali metal ions and film-forming additives is conducive to reducing the DC impedance of lithium-ion secondary batteries, improving the metal dendrite phenomenon of lithium-ion secondary batteries, and thus improving the power performance and cycle performance of lithium-ion secondary batteries.
  • the relationship between the mass content A of alkali metal ions and the mass content B of film-forming additives is controlled to meet 0.10 ⁇ B/A ⁇ 6 ⁇ 10 4 , which can not only reduce the DC impedance of lithium secondary batteries, but also further improve the cycle performance of batteries.
  • a lithium-ion secondary battery includes a negative electrode plate, the negative electrode plate includes a current collector and a negative electrode active material layer located on at least one side of the current collector and containing at least a negative electrode active material, and the porosity C of the negative electrode active material layer and the mass content A of the alkali metal ions in the total mass of the electrolyte satisfy: 10-6 ⁇ A /C ⁇ 0.035, which can be 5 ⁇ 10-5 ⁇ A /C ⁇ 0.035 or 5 ⁇ 10-5 ⁇ A /C ⁇ 0.025.
  • the porosity C of the negative electrode active material layer is related to the alkali metal ion
  • the ratio A/C of the mass content A in the total mass of the electrolyte can be selected as 10-6 , 2 ⁇ 10-6 , 5 ⁇ 10-6 , 7 ⁇ 10-6 , 10-5 , 2 ⁇ 10-5, 5 ⁇ 10-5 , 8 ⁇ 10-5 , 10-4, 2 ⁇ 10-4 , 5 ⁇ 10-4 , 7 ⁇ 10-4 , 0.001, 0.002, 0.005, 0.008, 0.01, 0.015, 0.02 , 0.025, 0.03, 0.035 , or a value in the range consisting of any two of the above points.
  • the porosity of the negative electrode active material layer can be adjusted by the compaction density of the negative electrode film layer. Generally speaking, increasing the compaction density can reduce the porosity of the material layer.
  • the porosity of the negative electrode active material layer can be measured by any known means, including but not limited to BET.
  • BET Bohr's law
  • the electrolyte can better and faster infiltrate the negative electrode plate, so that lithium ions can be better transmitted, the concentration polarization of lithium ions during the transmission process can be improved, the electrical properties of lithium-ion secondary batteries can be enhanced, and the phenomenon of metal dendrites can be improved, taking into account the kinetics and cycle performance of lithium-ion secondary batteries.
  • the alkali metal ions include one or more of Na + , K + , and Cs + . In some embodiments, the alkali metal ions include Na + . In some embodiments, the alkali metal ions include K + . In some embodiments, the alkali metal ions include Cs + . In some embodiments, the alkali metal ions include Na + and Cs + .
  • alkali metal ions are all beneficial to the transmission of lithium ions and improve the power performance of the battery.
  • the mass content A of the alkali metal ions satisfies: 1ppm ⁇ A ⁇ 7000ppm, and can be 100ppm ⁇ A ⁇ 7000ppm. In some embodiments, based on the total mass of the electrolyte, the mass content A of the alkali metal ions can be 1ppm, 5ppm, 10ppm, 50ppm, 100ppm, 500ppm, 1000ppm, 2000ppm, 3000ppm, 4000ppm, 5000ppm, 6000ppm, 7000ppm, or a value in the range consisting of any two of the above points.
  • the alkali metal ions in the electrolyte can participate in the formation of the SEI film and consume some of the alkali metal ions, resulting in a decrease in the mass content of the alkali metal ions in the electrolyte.
  • the mass content of alkali metal ions in the electrolyte may be 1 ppm. Therefore, based on the total mass of the electrolyte, the mass content of alkali metal ions in the range of 1 ppm to 7000 ppm is within the scope protected in the embodiments of the present application.
  • Controlling the alkali metal ions within a suitable range can improve the power performance of the battery.
  • the electrolyte further includes anions, and the anions include one or more of PO 2 F 2 - , FSO 3 - , DFOB - , BF 4 - , DFOP - , BOB - , and PO 3 F 2 - .
  • the anions included in the electrolyte can be introduced together with the alkali metal ions, or introduced into the electrolyte through an electrolyte additive, such as a lithium salt additive containing one of the above anions.
  • the mass content of the anions is greater than 0 and less than or equal to 5%.
  • the mass content of the anions is greater than 0 and less than or equal to 4%.
  • the mass content of the anions can be 0.01%, 0.02%, 0.05%, 0.1%, 0.3%, 0.5%, 0.8%, 1%, 1.3%, 1.5%, 1.8%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, or a value in the range consisting of any two of the above points.
  • the mass content of anions in the electrolyte or the electrolyte of the secondary battery can be detected by detection equipment and methods commonly used in the art, for example, by testing the mass content of anions by nuclear magnetic resonance spectroscopy.
  • the mass content of the anions can be tested using the Oxford Instruments X-Pulse desktop nuclear magnetic resonance spectrometer, for example, according to a commonly used detection method in the art.
  • the above anions help improve the cycle performance and cycle life of secondary batteries.
  • the lone pair electrons contained in the above anions can combine with lithium ions on the surface of the positive electrode sheets, change the Li/Ni mixing, stabilize the structure of the positive electrode sheets, change the charge transfer resistance (Rct) on the surface of the positive electrode sheets, and improve the cycle performance and cycle life of lithium-ion secondary batteries;
  • the above anions can form a dense SEI film on the surface of the negative electrode sheets, improving the life of the battery.
  • Controlling the mass content of the anion in the appropriate range can improve the The cycle performance of the secondary battery also helps to reduce the formation of metal dendrites.
  • the film-forming additive includes one or more of fluorinated carbonate compounds, sulfate compounds, and sulfonate compounds.
  • the film-forming additive comprises a fluorocarbonate compound. In some embodiments, the film-forming additive comprises a sulfate compound. In some embodiments, the film-forming additive comprises a sulfonate compound. In some embodiments, the film-forming additive comprises a fluorocarbonate compound and a sulfate compound. In some embodiments, the film-forming additive comprises a fluorocarbonate compound and a sulfonate compound.
  • fluorinated carbonate compounds can form an inorganic SEI film rich in LiF and LiCO 3 on the surface of the negative electrode
  • sulfate compounds can form an inorganic SEI film rich in Li 2 SO 4 on the surface of the negative electrode
  • sulfonate compounds can form an inorganic SEI film rich in Li 2 SO 3 on the surface of the negative electrode.
  • the inorganic SEI film can not only inhibit the phenomenon of metal dendrites, but also hinder the reaction between the electrolyte and the positive/negative electrode, improve the stability of lithium-ion secondary batteries, and enhance their cycle performance.
  • the fluorinated carbonate compound includes one or more of fluoroethylene carbonate, 1,2-difluoroethylene carbonate, 1,1-difluoroethylene carbonate, 1,1,2-trifluoroethylene carbonate, 1,1,2,2-tetrafluoroethylene carbonate, 1-fluoro-2-methylethylene carbonate, 1-fluoro-1-methylethylene carbonate, 1,2-difluoro-1-methylethylene carbonate, 1,1,2-trifluoro-2-methylethylene carbonate or trifluoromethylethylene carbonate, and optionally includes fluoroethylene carbonate;
  • the sulfate ester compound includes one or more of 4,4'-vinyl sulfate, vinyl sulfate, diethyl sulfate, dimethyl sulfate and 4,4-bis(1,3,2-dioxathiolane)-2,2,2,2-tetraoxide, and optionally includes one or more of 4,4'-vinyl sulfate and vinyl sulfate; and/or,
  • the sulfonate compound includes one or more of 1,3-propane sultone, propene sultone, and 3-fluoro-1,3-propane sultone, and optionally includes 1,3-propane sultone.
  • the above-mentioned fluorinated carbonate compounds, sulfate compounds, and sulfonate compounds can all form a uniform and dense inorganic SEI film.
  • the mass of the film-forming additive is based on the total mass of the electrolyte.
  • the amount content B satisfies: 0.1% ⁇ B ⁇ 7%, and can be optionally 0.1% ⁇ B ⁇ 6%.
  • the mass content B of the film-forming additive may be selected to be 0.1%, 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, or a value in the range formed by any two of the above points.
  • the mass content of the film-forming additive By controlling the mass content of the film-forming additive within a suitable range, a sufficiently uniform and dense inorganic SEI film can be formed, dendrites can be inhibited, interface side reactions can be hindered, and side reactions of lithium-ion secondary batteries can be reduced.
  • the porosity C of the negative electrode active material layer is 20% to 60%, and optionally 20% to 40%.
  • the porosity C of the negative electrode active material layer may be 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, or a value in a range consisting of any two of the above points.
  • Controlling the porosity of the negative electrode active material layer within an appropriate range can not only improve the wettability of the electrolyte to the negative electrode plate, thereby facilitating better transmission of lithium ions, improving the concentration polarization of lithium ions during transmission, enhancing the electrical properties of lithium-ion secondary batteries, and inhibiting the phenomenon of dendrites, but also reduce the risk of increased contact area between the electrolyte and the negative electrode active material due to excessive porosity, thereby reducing the degree of side reactions.
  • the mass content of the lithium salt is 8% to 20%, optionally 9% to 18%, or 8% to 15%.
  • the mass content of the lithium salt is 8%, 9%, 10%, 12%, 14%, 15%, 16%, 18%, 20%, or a value in the range formed by any two of the above points.
  • Controlling the mass content of lithium salt within an appropriate range is beneficial to promoting the migration of lithium ions and reducing the DC impedance of lithium-ion secondary batteries.
  • the lithium salt includes a first lithium salt and/or a second lithium salt, and the first lithium salt and the second lithium salt are each independently selected from one of LiFSI, LiPF 6 , LiBF 4 , LiTFSI, LiClO 4 , LiAsF 6 , LiBOB, LiDFOB, and LiDFOP.
  • the lithium salt comprises a first lithium salt. In some embodiments, the lithium salt comprises a second lithium salt. In some embodiments, the lithium salt comprises a first lithium salt and a second lithium salt. In some embodiments, the first lithium salt is selected from LiFSI. In some embodiments, the second lithium salt is selected from LiPF 6 .
  • LiFSI has a larger anion, which can effectively promote the migration of lithium ions, so that the lithium-ion secondary battery has an excellent lithium-ion migration number, reducing its DC impedance and the precipitation of metal dendrites.
  • LiFSI itself is insensitive to water and has good thermal stability, which can further improve the safety of lithium-ion secondary batteries.
  • the film-forming thermal stability of LiPF 6 is better than that of LiFSI. Therefore, the combination of LiFSI and LiPF 6 can take into account the electrical performance and thermal stability of its lithium-ion secondary battery.
  • the mass ratio of the first lithium salt LiFSI and the second lithium salt LiPF6 is not less than 0.1 and not more than 5; optionally, the mass ratio of the first lithium salt LiFSI and the second lithium salt LiPF6 is not less than 3 and not more than 5.
  • the mass ratio of the first lithium salt to the second lithium salt may be 0.1, 0.2, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, or a value in a range consisting of any two of the above points.
  • the lithium-ion secondary battery can have excellent electrical properties.
  • the electrolyte further comprises a solvent
  • the solvent comprises a cyclic ester solvent and/or a linear ester solvent
  • the cyclic ester solvent includes one or more of ethylene carbonate and propylene carbonate;
  • the linear ester solvent includes one or more of dimethyl carbonate, diethyl carbonate, methyl propyl carbonate, ethyl methyl carbonate, methyl formate, methyl acetate, ethyl acetate, butyl acetate, methyl propionate, methyl butyrate, ethyl butyrate, propyl butyrate, butyl butyrate, isopropyl acetate, and isoamyl acetate.
  • the above solvents can be used in combination with alkali metal salts and film-forming additives to enable lithium-ion secondary batteries to have lower DC impedance and excellent cycle performance.
  • the mass content of the cyclic ester solvent is A, and the mass content of the linear ester solvent is (100%-A); wherein the mass content A of the cyclic ester solvent is 0% to 40%, 2% to 40%, or 5% to 35%.
  • the mass of the cyclic ester solvent is based on the total mass of the solvent.
  • the mass content is 2% to 40%, and can be optionally 5% to 35%; the mass content of the linear ester solvent is 50% to 100%, and can be optionally 60% to 95%.
  • the mass content of the cyclic ester solvent can be 0, 0.01%, 1%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, or a value in the range consisting of any two of the above points.
  • the mass content of the linear ester solvent is 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 100%, or a value in the range consisting of any two of the above points.
  • the mass contents of the cyclic ester solvent and the linear ester solvent are respectively controlled within a suitable range so that the lithium ion secondary battery has excellent electrical properties and safety.
  • the positive electrode sheet includes a positive electrode current collector and a positive electrode film layer disposed on at least one surface of the positive electrode current collector, wherein the positive electrode film layer includes a positive electrode active material.
  • the positive electrode current collector has two surfaces opposite to each other in its thickness direction, and the positive electrode film layer is disposed on any one or both of the two opposite surfaces of the positive electrode current collector.
  • the positive electrode current collector may be a metal foil or a composite current collector.
  • aluminum foil may be used as the metal foil.
  • the composite current collector may include a polymer material base and a metal layer formed on at least one surface of the polymer material base.
  • the composite current collector may be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.).
  • PP polypropylene
  • PET polyethylene terephthalate
  • PBT polybutylene terephthalate
  • PS polystyrene
  • PE polyethylene
  • the positive electrode active material may be a positive electrode active material for a battery known in the art.
  • the positive electrode active material may include at least one of the following materials: an olivine-structured lithium-containing phosphate, a lithium transition metal oxide, and their respective modified compounds.
  • the present application is not limited to these materials, and other traditional materials that can be used as positive electrode active materials for batteries may also be used. These positive electrode active materials may be used alone or in combination of two or more.
  • the active material of the positive electrode comprises a lithium transition metal oxide positive electrode.
  • One or more of positive electrode active materials and lithium phosphate positive electrode active materials are included in the active material of the positive electrode.
  • the lithium transition metal oxide has the structural formula shown below: LiNi x Co y N z M 1-xyz O 2 ,
  • N is selected from Mn and Al
  • M is selected from any one of Ni, Mn, Mg, Cu, Zn, Al, Sn, B, Ga, Cr, Sr, V and Ti, 0 ⁇ x ⁇ 1, 0 ⁇ y ⁇ 1, 0 ⁇ z ⁇ 1, x+y+z ⁇ 1.
  • the lithium transition metal oxide includes lithium cobalt oxide (such as LiCoO 2 ), lithium nickel oxide (such as LiNiO 2 ), lithium manganese oxide (such as LiMnO 2 , LiMn 2 O 4 ), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (such as LiNi 1/3 Co 1/3 Mn 1/3 O 2 (also referred to as NCM333), LiNi 0.5 Co 0.2 Mn 0.3 O 2 (also referred to as NCM523), LiNi 0.5 Co 0.25 Mn 0.25 O 2 (also referred to as NCM211), LiNi 0.6 Co 0.2 Mn 0.2 O 2 (also referred to as NCM622), LiNi 0.8 Co 0.1 Mn 0.1 O 2 (also referred to as NCM811), lithium nickel cobalt aluminum oxide (such as LiNi 0.85 Co 0.25 Mn 0.25 O 2 (also referred to as NCM811), and lithium nickel cobalt oxide,
  • the lithium-containing phosphate includes at least one of lithium iron phosphate (such as LiFePO 4 (also referred to as LFP)), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnPO 4 ), a composite material of lithium manganese phosphate and carbon, lithium iron manganese phosphate, and a composite material of lithium iron manganese phosphate and carbon.
  • lithium iron phosphate such as LiFePO 4 (also referred to as LFP)
  • LiMnPO 4 lithium manganese phosphate
  • LiMnPO 4 lithium manganese phosphate
  • LiMnPO 4 lithium manganese phosphate and carbon
  • the positive electrode film layer may further optionally include a binder.
  • the binder may include at least one of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), vinylidene fluoride-tetrafluoroethylene-propylene terpolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, and fluorine-containing acrylate resin.
  • PVDF polyvinylidene fluoride
  • PTFE polytetrafluoroethylene
  • PTFE polytetrafluoroethylene
  • vinylidene fluoride-tetrafluoroethylene-propylene terpolymer vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer
  • the positive electrode film layer may further include a conductive agent, which may include, for example, at least one of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.
  • a conductive agent which may include, for example, at least one of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.
  • the positive electrode sheet can be prepared by the following method: the components for preparing the positive electrode sheet, such as the positive electrode active material, the conductive agent, the binder and any other components are dispersed in a solvent (such as N-methylpyrrolidone) to form a positive electrode slurry; the positive electrode slurry is coated on the positive electrode current collector, and after drying, cold pressing and other processes, The positive electrode plate can be obtained.
  • a solvent such as N-methylpyrrolidone
  • the negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer located on at least one side of the negative electrode current collector and containing at least a negative electrode active material.
  • the negative electrode current collector has two surfaces opposite to each other in its thickness direction, and the negative electrode film layer is disposed on any one or both of the two opposite surfaces of the negative electrode current collector.
  • the negative electrode current collector may be a metal foil or a composite current collector.
  • the metal foil copper foil may be used.
  • the composite current collector may include a polymer material base layer and a metal layer formed on at least one surface of the polymer material substrate.
  • the composite current collector may be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.).
  • PP polypropylene
  • PET polyethylene terephthalate
  • PBT polybutylene terephthalate
  • PS polystyrene
  • PE polyethylene
  • the negative electrode active material may be a negative electrode active material for a battery known in the art.
  • the negative electrode active material may be used alone or in combination of two or more.
  • the negative electrode active material includes one or more of artificial graphite, natural graphite, soft carbon, hard carbon, silicon-carbon composite, lithium titanate, and silicon-oxygen composite.
  • the negative electrode active material layer may further include a binder.
  • the binder may be selected from at least one of styrene-butadiene rubber (SBR), polyacrylic acid (PAA), sodium polyacrylate (PAAS), polyacrylamide (PAM), polyvinyl alcohol (PVA), sodium alginate (SA), polymethacrylic acid (PMAA) and carboxymethyl chitosan (CMCS).
  • the negative electrode active material layer may further include a conductive agent, which may be selected from at least one of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.
  • a conductive agent which may be selected from at least one of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.
  • the negative electrode active material layer may further optionally include other additives, such as a thickener (eg, sodium carboxymethyl cellulose (CMC-Na)).
  • a thickener eg, sodium carboxymethyl cellulose (CMC-Na)
  • the negative electrode sheet can be prepared by the following method: the components for preparing the negative electrode sheet, such as the negative electrode active material, the conductive agent, the binder and Any other components are dispersed in a solvent (such as deionized water) to form a negative electrode slurry; the negative electrode slurry is coated on a negative electrode current collector, and after drying, cold pressing and other processes, a negative electrode sheet can be obtained.
  • a solvent such as deionized water
  • the lithium-ion secondary battery further includes a separator, which can be any known porous separator with good chemical stability and mechanical stability.
  • the material of the isolation membrane can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene and polyvinylidene fluoride.
  • the isolation membrane can be a single-layer film or a multi-layer composite film. When the isolation membrane is a multi-layer composite film, the materials of each layer can be the same or different.
  • the positive electrode sheet, the negative electrode sheet, and the separator may be formed into an electrode assembly by a winding process or a lamination process.
  • the lithium-ion secondary battery may include an outer package, which may be used to encapsulate the electrode assembly and the electrolyte.
  • the outer packaging of the lithium ion secondary battery can be a hard shell, such as a hard plastic shell, an aluminum shell, a steel shell, etc.
  • the outer packaging of the lithium ion secondary battery can also be a soft package, such as a bag-type soft package.
  • the material of the soft package can be plastic, and as the plastic, polypropylene, polybutylene terephthalate, and polybutylene succinate can be listed.
  • FIG1 is a lithium-ion secondary battery 5 with a square structure as an example.
  • the outer package may include a shell 51 and a cover plate 53.
  • the shell 51 may include a bottom plate and a side plate connected to the bottom plate, and the bottom plate and the side plate enclose a receiving cavity.
  • the shell 51 has an opening connected to the receiving cavity, and the cover plate 53 can be covered on the opening to close the receiving cavity.
  • the positive electrode sheet, the negative electrode sheet and the isolation film can form an electrode assembly 52 through a winding process or a lamination process.
  • the electrode assembly 52 is encapsulated in the receiving cavity.
  • the electrolyte is infiltrated in the electrode assembly 52.
  • the number of electrode assemblies 52 contained in the lithium-ion secondary battery 5 can be one or more, and those skilled in the art can select according to specific actual needs.
  • lithium-ion secondary batteries can be assembled into a battery module.
  • the number of lithium-ion secondary batteries contained in the battery module can be one or more, and the specific number can be selected by those skilled in the art according to the application and capacity of the battery module.
  • FIG3 is a battery module 4 as an example.
  • a plurality of lithium-ion secondary batteries 5 may be arranged in sequence along the length direction of the battery module 4. Of course, they may also be arranged in any other manner. Further, the plurality of lithium-ion secondary batteries 5 may be fixed by fasteners.
  • the battery module 4 may further include a housing having a housing space, and the plurality of lithium-ion secondary batteries 5 are housed in the housing space.
  • the battery modules described above may also be assembled into a battery pack.
  • the battery pack may contain one or more battery modules, and the specific number may be selected by those skilled in the art according to the application and capacity of the battery pack.
  • FIG4 and FIG5 are battery packs 1 as an example.
  • the battery pack 1 may include a battery box and a plurality of battery modules 4 disposed in the battery box.
  • the battery box includes an upper box body 2 and a lower box body 3, and the upper box body 2 can be covered on the lower box body 3 to form a closed space for accommodating the battery modules 4.
  • the plurality of battery modules 4 can be arranged in the battery box in any manner.
  • the present application also provides an electrical device, which includes at least one of the lithium-ion secondary battery, battery module, or battery pack provided in the present application.
  • the lithium-ion secondary battery, battery module, or battery pack can be used as a power source for the electrical device, and can also be used as an energy storage unit for the electrical device.
  • the electrical device may include mobile devices (such as mobile phones, laptops, etc.), electric vehicles (such as pure electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, electric scooters, electric golf carts, electric trucks, etc.), electric trains, ships and satellites, energy storage systems, etc., but are not limited to these.
  • a lithium-ion secondary battery, a battery module or a battery pack may be selected according to its usage requirements.
  • FIG6 is an example of an electric device.
  • the electric device is a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle.
  • a battery pack can be used. or battery modules.
  • a device may be a mobile phone, a tablet computer, a notebook computer, etc. Such a device is usually required to be thin and light, and a lithium-ion secondary battery may be used as a power source.
  • cyclic ester solvent ethylene carbonate and linear ester solvent dimethyl carbonate were mixed in a mass ratio of 25:75 to obtain a mixed solvent. Then, lithium salt lithium hexafluorophosphate and lithium bistrifluoromethanesulfonyl imide (LiFSI and LiPF6 mass ratio of 3: 1 ) were added and dissolved in the mixed solvent to make the mass content of lithium salt 15%, and stirred evenly.
  • LiFSI and LiPF6 mass ratio of 3: 1 lithium salt lithium hexafluorophosphate and lithium bistrifluoromethanesulfonyl imide
  • alkali metal salt NaPO2F2 and film-forming additive 4,4'-vinyl disulfate were added and mixed evenly to obtain an electrolyte; wherein, based on the total mass of the electrolyte, the mass content of alkali metal ion Na + was 30ppm, and the mass content of 4,4'-vinyl disulfate was 2%.
  • 1wt% polyvinylidene fluoride binder is fully dissolved in N-methylpyrrolidone, and then 1wt% carbon black conductive agent and 98wt% lithium transition metal oxide positive electrode active material LiNi 0.5 Co 0.2 Mn 0.3 O 2 are added and stirred to obtain positive electrode slurry.
  • the slurry is evenly coated on the surface of the current collector aluminum foil to prepare a positive electrode film layer, and then transferred to a vacuum drying oven for complete drying.
  • the dried pole piece is rolled and punched to obtain a positive electrode piece.
  • the negative electrode active material artificial graphite, the conductive agent carbon black, the thickener carboxymethyl cellulose (CMC), and the adhesive styrene butadiene rubber (SBR) were mixed in a weight ratio of 96:2:1:1.
  • the mixture was dissolved in deionized water to form negative electrode slurry, and the negative electrode slurry was obtained under the action of a vacuum mixer, and then the slurry was coated on the surface of the copper foil. Finally, it was transferred to a vacuum drying oven for complete drying, and then cut and die-cut, and the compaction density of the electrode film layer was adjusted so that the porosity of the negative electrode active material was 40%, and the negative electrode sheet was obtained.
  • Polypropylene film is used as the isolation film.
  • the positive electrode sheet, the separator, and the negative electrode sheet are stacked in order, the separator is placed between the positive and negative electrode sheets to play an isolating role, the bare cell is welded with the pole ear, and the bare cell is placed in an aluminum shell, and baked at 80°C to remove water, and then the above-mentioned electrolyte is injected and sealed to obtain an uncharged battery.
  • the uncharged battery is then subjected to the processes of static, hot and cold pressing, formation, shaping, and capacity testing in sequence to obtain the lithium-ion secondary battery product of Example 1.
  • Comparative Example 1 The battery preparation method in Comparative Example 1 is basically similar to that in Example 1, but there is no film-forming additive in the electrolyte. The specific parameters are shown in Table 1.
  • the battery preparation method in Comparative Example 2 is basically similar to that in Example 1, but no alkali metal salt is added to the electrolyte.
  • the specific parameters are shown in Table 1.
  • the battery preparation method in Comparative Example 3 is basically similar to that in Example 1, but no alkali metal salt and film-forming additive are added to the electrolyte.
  • the specific parameters are shown in Table 1.
  • the test process of the comparative example and other embodiments is the same as above.
  • the battery after the above cycle of n cycles was disassembled in an argon atmosphere glove box ( H2O ⁇ 0.1ppm, O2 ⁇ 0.1ppm), and the surface morphology of the negative electrode was visually observed to determine whether metal dendrites were generated.
  • the negative electrode sheet without white spots was judged as no metal dendrites
  • the negative electrode sheet with sporadic white spots was judged as slight metal dendrites
  • the negative electrode sheet with dense white spots was judged as severe metal dendrites.
  • the test process of the comparative example and other embodiments is the same as above.
  • Test of alkali metal ions in electrolyte Take 10 ml of the above prepared electrolyte and test it using the Thermo Fisher Scientific ICAP-7400 inductively coupled plasma atomic emission spectrometry. When preparing a secondary battery, take 10 ml of free electrolyte from the secondary battery injection port and test it using the above method.
  • the batteries of the embodiments and comparative examples were prepared according to the above method, and various performance parameters were measured. The results are shown in Tables 1 and 2 below.
  • the lithium ion secondary batteries in Examples 1 to 30 all include an electrolyte, and the electrolyte includes an alkali metal ion having an ion radius greater than that of a lithium ion and a film-forming additive.
  • the mass content A of the alkali metal ion and the mass content B of the additive satisfy: 0.14 ⁇ B/A ⁇ 2000.
  • the electrolyte in the embodiment of the present application includes a film-forming additive 4,4'-disulfated vinyl ester, which is beneficial to increase the number of cycles at which the battery cycle capacity retention rate is 80%.
  • the electrolyte in the embodiment of the present application includes alkali metal ions Na + or K + having an ion radius greater than the radius of lithium ions, which is beneficial to reducing the DC impedance of the battery.
  • the electrolyte in the embodiment of the present application includes both alkali metal ions having an ion radius greater than the radius of lithium ions and film-forming additives, which is beneficial to reducing the DC impedance of the battery and increasing the number of cycles at which the battery cycle capacity retention rate is 80%.
  • the mass content B of the film-forming additive is controlled to meet: 0.1% ⁇ B ⁇ 7%, which is helpful to reduce the DC impedance of the battery and increase the number of battery cycles with a cycle capacity retention rate of 80%.
  • the mass content B of the film-forming additive is further controlled to meet: 0.1% ⁇ B ⁇ 6%, which is beneficial to further reduce the DC impedance of the battery and improve the power performance of the battery.
  • the alkali metal ions in the electrolyte include Na + or K + , which are beneficial to reducing the DC impedance of the battery, increasing the number of cycles with a cycle capacity retention rate of 80%, and improving the metal dendrite condition of the battery.
  • the film-forming additives in the electrolyte include one or more of 4,4'-ethylene disulfate, fluoroethylene carbonate, and 1,3-propane sultone, which can enable the battery to have a low DC impedance, increase the number of battery cycles, and improve the metal dendrites of the battery.
  • controlling the mass content of lithium salt to 8% to 20% based on the total mass of the electrolyte helps improve the DC impedance of the battery and the number of cycles at which the battery cycle capacity retention rate is 80%.
  • the mass ratio of lithium salt LiFSI to lithium salt LiPF 6 is not less than 0.1 and not more than 5, it also helps to improve the metal dendrites of the battery.
  • artificial graphite or silicon-carbon composite can be used as the negative electrode active material layer, and as can be seen from Examples 3 and 28,
  • the preparation of positive electrode sheets using LiNi 0.5 Co 0.2 Mn 0.3 O 2 positive electrode active materials or LiFePO 4 positive electrode active materials is helpful to obtain batteries with low DC impedance, high cycle number and improved metal dendrite condition.

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Abstract

提供了一种锂离子二次电池（5）和用电装置。锂离子二次电池（5）包括电解液，电解液包括离子半径大于锂离子半径的碱金属离子和成膜添加剂；基于电解液的总质量计，碱金属离子的质量含量A与添加剂的质量含量B满足：0.10≤B/A≤6×10 4。锂离子二次电池（5）具有较低的直流阻抗和优异的循环性能。

Description

锂离子二次电池和用电装置 技术领域
本申请涉及二次电池技术领域，尤其涉及一种锂离子二次电池和用电装置。
背景技术
近年来，二次电池广泛应用于水力、火力、风力和太阳能电站等储能电源系统，以及电动工具、电动自行车、电动摩托车、电动汽车、军事装备、航空航天等多个领域，并且对二次电池的电学性能的要求不断提升。
电解液的性能对二次电池的性能有关键性影响，因此，有必要研发电解液以提高二次电池的性能，以满足新一代电化学体系的应用需要。
发明内容
本申请的目的在于提供一种锂离子二次电池，旨在降低锂离子二次电池的直流阻抗，改善锂离子二次电池的功率性能和循环性能。
为了达到上述目的，本申请的第一方面提供了一种锂离子二次电池，包括电解液，所述电解液包括离子半径大于锂离子半径的碱金属离子和成膜添加剂；
基于所述电解液的总质量计，所述碱金属离子的质量含量A与所述添加剂的质量含量B满足：0.10≤B/A≤6×104。
包括碱金属离子和成膜添加剂的电解液，有利于降低锂离子二次电池的直流阻抗、改善锂离子二次电池的金属枝晶现象，进而提升锂离子二次电池的功率性能和循环性能。一方面，电解液中引入金属离子半径大于锂离子半径的碱金属离子，便于在锂离子二次电池充放电过程中形成可供锂离子传输的良好通道，从而降低其锂离 子二次电池的直流阻抗；另一方面，电解液中引入包括成膜添加剂，有利于在负极极片和电解液之间的界面处形成均匀致密的无机SEI膜，能够有效地抑制金属枝晶，提升锂离子二次电池的安全性，并且无机SEI膜也能够进一步阻碍电解液与负极极片之间的界面副反应，提升锂离子二次电池的循环性能。此外，同时控制碱金属离子的质量含量A和成膜添加剂的质量含量B之间的关系满足0.10≤B/A≤6×104，不仅能够降低锂离子二次电池的直流阻抗，还可以进一步提升电池的功率性能和循环性能。
在任意实施方式中，所述锂离子二次电池包括负极极片，所述负极极片包括集流体和位于所述集流体至少一侧且至少包含负极活性材料的负极活性材料层，所述负极活性材料层的孔隙率C与所述碱金属离子在电解液总质量中的质量含量A之间满足：10-6≤A/C≤0.035，可选为5×10-5≤A/C≤0.025。
控制负极活性材料层的孔隙率和碱金属离子的质量含量之间具有合适的关系式，便于电解液更好更快地浸润负极极片，以使锂离子能够更好的传输，改善锂离子在传输过程中的浓差极化，提升锂离子二次电池的电学性能，以及改善金属枝晶的现象，兼顾锂离子二次电池的动力学和循环性能。
在任意实施方式中，基于所述电解液的总质量计，所述碱金属离子含量A与所述成膜添加剂的质量含量B满足：0.14≤B/A≤2000。
控制碱金属离子的质量含量A与成膜添加剂的质量含量B之间的关系满足上述关系，可以进一步降低锂离子二次电池的直流阻抗，以及提升电池的循环性能。
在任意实施方式中，所述碱金属离子包含Na+、K+、Cs+中的一种或多种。
上述碱金属离子均有利于锂离子的传输，改善电池的功率性能。
在任意实施方式中，基于所述电解液的总质量计，所述碱金属离子的质量含量A满足：1ppm≤A≤7000ppm，可选为100ppm≤A≤7000ppm。
控制碱金属离子在合适的范围内，以提升电池的功率性能。
在任意实施方式中，所述电解液还包括阴离子，所述阴离子包括PO2F2 -、FSO3 -、DFOB-、BF4 -、DFOP-、BOB-、PO3F2-中的一种或多种。
在一些实施方式中，基于所述电解液的总质量计，所述阴离子的质量含量大于0且小于等于5％，可选地，基于所述电解液的总质量计，所述阴离子的质量含量大于0且小于等于4％。
上述阴离子有助于改善二次电池的循环性能和循环寿命。譬如，对于包括锂过渡金属氧化物正极活性材料的正极极片，上述阴离子所含有的孤对电子能够与正极极片表面的锂离子结合，改变Li/Ni混排，稳定正极极片结构，改变正极极片表面电荷转移电阻(Rct)，提升锂离子二次电池的循环性能和循环寿命；对于包括含锂磷酸盐正极活性材料的正极极片，上述阴离子可在负极极片表面形成致密的SEI膜，改善电池的寿命。
控制引阴离子的质量含量在合适的范围内，既能改善锂离子二次电池的循环性能，还有助于减少金属枝晶的形成。
在任意实施方式中，所述成膜添加剂包括氟代碳酸酯类化合物、硫酸酯类化合物、磺酸酯类化合物中的一种或多种。
成膜添加剂的加入有利于形成均匀致密的无机SEI膜，譬如，氟代碳酸酯类化合物能够在负极极片表面形成富含LiF、LiCO3的无机SEI膜，硫酸酯类化合物能够在负极极片表面形成富含Li2SO4的无机SEI膜，磺酸酯类化合物能够在负极极片表面形成富含Li2SO3的无机SEI膜。无机SEI膜既可抑制金属枝晶的现象，又能阻碍电解液和正/负极极片的反应，改善锂离子二次电池的稳定性，提升其循环性能。
在任意实施方式中，所述氟代碳酸酯类化合物包括碳酸氟代亚乙酯、碳酸1,2-二氟亚乙酯、碳酸1,1-二氟亚乙酯、碳酸1,1,2-三氟亚乙酯、碳酸1,1,2,2-四氟亚乙酯、碳酸1-氟-2-甲基亚乙酯、碳酸1-氟-1-甲基亚乙酯、碳酸1,2-二氟-1-甲基亚乙酯、碳酸1,1,2-三氟-2-甲基亚乙酯或碳酸三氟甲基亚乙酯中的一种或多种，可选地包括碳酸氟代亚乙酯；
所述硫酸酯类化合物包括4,4’-联硫酸乙烯酯、硫酸乙烯酯、硫酸二乙酯、硫酸二甲酯和4,4-双(1,3,2-二氧杂硫杂环戊烷)-2,2,2,2-四氧化物中的一种或多种，可选地包括4,4’-联硫酸乙烯酯、硫酸乙烯酯中的一种或多种；和/或，
所述磺酸酯类化合物包括1,3-丙磺酸内酯、丙烯磺酸内酯、3-氟-1,3-丙磺酸内酯中的一种或多种，可选地包括1,3-丙磺酸内酯。
上述氟代碳酸酯类化合物、硫酸酯类化合物、磺酸酯类化合物均可形成均匀致密的无机SEI膜。
在任意实施方式中，基于电解液的总质量计，所述成膜添加剂的质量含量B满足：0.1％≤B≤7％，可选为0.1％≤B≤6％。
控制成膜添加剂的质量含量在合适的范围内，能够形成足够多的致密的无机SEI膜，抑制金属枝晶的生成，阻碍界面副反应，减少锂离子二次电池的副反应。
在任意实施方式中，所述负极活性材料层的孔隙率C为20％～60％，可选为20％～40％。
控制负极活性材料层的孔隙率在合适的范围内，既能够提高电解液对负极极片的浸润性，以便于锂离子更好地传输，改善锂离子在传输过程中的浓差极化，提升锂离子二次电池的电学性能，以及抑制枝晶的现象；还能降低孔隙率过大导致电解液与负极活性材料之间接触面积增加的风险，降低副反应的发生程度。
在任意实施方式中，基于电解液的总质量计，所述锂盐的质量含量为8％～20％，可选为8％～15％。
控制锂盐的质量含量在合适的范围内，有利于促进锂离子的迁移，降低锂离子二次电池的直流阻抗。
在任意实施方式中，所述锂盐包括第一锂盐和/或第二锂盐，所述第一锂盐和第二锂盐各自独立地包括LiFSI、LiPF6、LiBF4、LiTFSI、LiClO4、LiAsF6、LiBOB、LiDFOB、LiDFOP中的一种或多种。在一些实施方式中，所述第一锂盐选自LiFSI，所述第二锂盐选自LiPF6。
LiFSI具有较大的阴离子，可有效地促进锂离子的迁移，以使锂 离子二次电池具有优异的锂离子迁移数，降低其直流阻抗和金属枝晶的析出，并且LiFSI本身对水不敏感，具有较好的热稳定性，能够进一步改善锂离子二次电池的安全性。LiPF6的成膜热稳定性优于LiFSI。故，LiFSI和LiPF6的搭配使用可兼顾其锂离子二次电池的电学性能和热稳定性能。
在一些实施方式中，LiFSI和LiPF6的质量比不低于0.1且不超过5；可选地，LiFSI和LiPF6的质量比不低于3且不超过5。
控制第一锂盐和第二锂盐的质量比在合适的范围内，以使锂离子二次电池具有优异的电学性能。
在任意实施方式中，所述电解液还包括溶剂，所述溶剂包括环状酯类溶剂和/或线性酯类溶剂；
所述环状酯类溶剂包括碳酸乙烯酯、碳酸丙烯酯中的一种或多种；
所述线性酯类溶剂包括碳酸二甲酯、碳酸二乙酯、碳酸甲丙酯、碳酸甲乙酯中、甲酸甲酯、乙酸甲酯、乙酸乙酯、乙酸丁酯、丙酸甲酯、丁酸甲酯、丁酸乙酯、丁酸丙酯、丁酸丁酯、乙酸异丙酯、乙酸异戊酯中的一种或多种。
上述溶剂均可与碱金属盐和成膜添加剂搭配使用，以使锂离子二次电池具有较低的直流阻抗和优异的循环性能。
在一些实施方式中，基于所述溶剂的总质量计，所述环状酯类溶剂的质量含量为A，所述线性酯类溶剂的质量含量为(100％-A)。在一些实施方式中，所述A为0～40％、2％～40％或者5％～35％。
在任意实施方式中，基于溶剂的总质量计，所述环状酯类溶剂的质量含量为2％～40％，可选为5％～35％；所述线性酯类溶剂的质量含量为50％～100％，可选为60％～95％。
分别控制环状酯类溶剂和线性酯类溶剂的质量含量在合适的范围内，以使锂离子二次电池具有优异的电学性能和安全性。
在任意实施方式中，所述负极活性材料层包括人造石墨、天然石墨、软炭、硬炭、硅碳复合物、钛酸锂、硅氧复合物中的一种或多种。
包括上述负极活性材料的负极活性材料层均具有合适的孔隙率。
在任意实施方式中，所述锂离子二次电池包括正极极片，所述正极极片包括锂过渡金属氧化物正极活性材料、含锂磷酸盐正极活性材料中的一种或多种。
本申请第二方面还包括一种用电装置，包括本申请第一方面所述的锂离子二次电池。
附图说明
图1是本申请一实施方式的锂离子二次电池的示意图；
图2是图1所示的本申请一实施方式的锂离子二次电池的分解图；
图3是本申请一实施方式的电池模块的示意图；
图4是本申请一实施方式的电池包的示意图；
图5是图4所示的本申请一实施方式的电池包的分解图；
图6是本申请一实施方式的锂离子二次电池用作电源的用电装置的示意图。
附图标记说明：
1电池包；2上箱体；3下箱体；4电池模块；5锂离子二次电池；
51壳体；52电极组件；53盖板。
具体实施方式
以下，适当地参照附图详细说明具体公开了本申请的锂离子二次电池和用电装置的实施方式。但是会有省略不必要的详细说明的情况。例如，有省略对已众所周知的事项的详细说明、实际相同结构的重复说明的情况。这是为了避免以下的说明不必要地变得冗长，便于本领域技术人员的理解。此外，附图及以下说明是为了本领域技术人员充分理解本申请而提供的，并不旨在限定权利要求书所记载的主题。
本申请所公开的“范围”以下限和上限的形式来限定，给定范围是通过选定一个下限和一个上限进行限定的，选定的下限和上限限 定了特别范围的边界。这种方式进行限定的范围可以是包括端值或不包括端值的，并且可以进行任意地组合，即任何下限可以与任何上限组合形成一个范围。例如，如果针对特定参数列出了60-120和80-110的范围，理解为60-110和80-120的范围也是预料到的。此外，如果列出的最小范围值1和2，和如果列出了最大范围值3，4和5，则下面的范围可全部预料到：1-3、1-4、1-5、2-3、2-4和2-5。在本申请中，除非有其他说明，数值范围“a-b”表示a到b之间的任意实数组合的缩略表示，其中a和b都是实数。例如数值范围“0-5”表示本文中已经全部列出了“0-5”之间的全部实数，“0-5”只是这些数值组合的缩略表示。另外，当表述某个参数为≥2的整数，则相当于公开了该参数为例如整数2、3、4、5、6、7、8、9、10、11、12等。
如果没有特别的说明，本申请的所有实施方式以及可选实施方式可以相互组合形成新的技术方案。
如果没有特别的说明，本申请的所有技术特征以及可选技术特征可以相互组合形成新的技术方案。
如果没有特别的说明，本申请的所有步骤可以顺序进行，也可以随机进行，优选是顺序进行的。例如，所述方法包括步骤(a)和(b)，表示所述方法可包括顺序进行的步骤(a)和(b)，也可以包括顺序进行的步骤(b)和(a)。例如，所述提到所述方法还可包括步骤(c)，表示步骤(c)可以任意顺序加入到所述方法，例如，所述方法可以包括步骤(a)、(b)和(c)，也可包括步骤(a)、(c)和(b)，也可以包括步骤(c)、(a)和(b)等。
如果没有特别的说明，本申请所提到的“包括”和“包含”表示开放式，也可以是封闭式。例如，所述“包括”和“包含”可以表示还可以包括或包含没有列出的其他组分，也可以仅包括或包含列出的组分。
如果没有特别的说明，在本申请中，术语“或”是包括性的。举例来说，短语“A或B”表示“A，B，或A和B两者”。更具体地，以下任一条件均满足条件“A或B”：A为真(或存在)并且B为假(或不存在)；A为假(或不存在)而B为真(或存在)；或A和B都为 真(或存在)。
金属离子传输速率严重影响电池性能。譬如，对于锂电池，较低的锂离子传输速率可以导致锂电池直流阻抗的增加、循环性能的降低等不良现象。电解液中引入离子半径更大的其他金属离子可以在充放电过程中形成良好的通道，供锂离子传输，从而改善功率性能，但引入的其他金属离子由于具有比锂离子更大的电极电势，导致在沉积过程中更易于沉积形成更活泼的金属，更有甚者形成枝晶，严重影响电池的安全性。因此，需要设计一种新的电池，可以兼顾功率性能和循环性能。
[锂离子二次电池]
基于此，本申请提出了一种锂离子二次电池，该锂离子二次包括电解液，电解液包括离子半径大于锂离子半径的碱金属离子和成膜添加剂；基于电解液的总质量计，碱金属离子的质量含量A与添加剂的质量含量B满足：0.10≤B/A≤6×104。
在本文中，术语“碱金属离子”是指碱金属的离子，包括但不限于Na+、K+或Cs+。碱金属离子可以通过向电解液中添加碱金属盐而将碱金属离子引入二次电池中。
在本文中，术语“成膜添加剂”是指与金属锂反应可形成无机SEI膜的添加剂，包括但不限于氟代碳酸酯类化合物、硫酸酯类化合物或磺酸酯类化合物。
电解液中引入金属离子半径大于锂离子半径的碱金属离子，便于在锂离子二次电池充放电过程中形成可供锂离子传输的良好通道，从而降低其锂离子二次电池的直流阻抗。但是碱金属离子的加入容易在二次电池充放电过程中沉积形成金属枝晶。向电解液中引入成膜添加剂，有利于在负极极片和电解液之间的界面处形成均匀致密的无机SEI膜，能够有效地抑制金属枝晶，有助于避免或降低碱金属离子带来的风险隐患，改善锂离子二次电池的安全性；无机SEI膜同时能够进一步阻碍电解液与负极极片之间的界面副反应。碱金属离子和成膜添加剂的引入有助于同时提升锂离子二次电池的功率性能和循环性能。
在一些实施方式中，基于电解液的总质量计，碱金属离子的质量含量A与成膜添加剂的质量含量B满足B/A可选为0.14、0.2、0.4、0.5、0.8、1、5、10、50、100、500、1000、2000、3000、
4000、5000、6000、7000、8000、9000、1×104、1.5×104、2×104、2.5×104、3×104、3.5×104、4×104、4.5×104、5×104、5.5×104、6×104、或由上述任意两点构成的范围中的数值。
金属离子质量含量的测定可以采用本领域技术人员公知的检测方法，例如电感耦合等离子体技术，根据行业检测标准进行测定。
在一些实施方式中，基于电解液的总质量计，碱金属离子含量A与成膜添加剂的质量含量B满足：0.2≤B/A≤5×104。在一些实施方式中，基于电解液的总质量计，所述碱金属离子含量A与所述成膜添加剂的质量含量B满足：0.14≤B/A≤2000。包括碱金属离子和成膜添加剂的电解液，有利于降低锂离子二次电池的直流阻抗、改善锂离子二次电池的金属枝晶现象，进而提升锂离子二次电池的功率性能和循环性能。
可以理解的是，由于以碱金属离子的还原态作为电极，其标准电极电势大于锂的标准电极电势，在锂离子二次电池放电过程中，碱金属离子更容易在负极极片侧析出相应的金属，更有甚者形成金属枝晶，严重影响锂离子二次电池的循环性能和安全性。因此，在电解液中加入成膜添加剂，有助于形成致密的无机SEI膜，抑制金属枝晶的形成，提高二次电池的安全性和循环性能。此外，同时控制碱金属离子的质量含量A和成膜添加剂的质量含量B之间的关系满足0.10≤B/A≤6×104，不仅能够降低锂二次电池的直流阻抗，还可以进一步提升电池的循环性能。
在一些实施方式中，锂离子二次电池包括负极极片，负极极片包括集流体和位于集流体至少一侧且至少包含负极活性材料的负极活性材料层，负极活性材料层的孔隙率C与碱金属离子在电解液总质量中的质量含量A之间满足：10-6≤A/C≤0.035，可选为5×10-5≤A/C≤0.035或者5×10-5≤A/C≤0.025。
在一些实施方式中，负极活性材料层的孔隙率C与碱金属离子 在电解液总质量中的质量含量A的比值A/C可选为10-6、2×10-6、5×10-6、7×10-6、10-5、2×10-5、5×10-5、8×10-5、10-4、2×10-4、5×10-4、7×10-4、0.001、0.002、0.005、0.008、0.01、0.015、0.02、0.025、0.03、0.035、或由上述任意两点构成的范围中的数值。
负极活性材料层的孔隙率可以通过负极极片膜层的压实密度进行调整，一般来说，压实密度提高可以降低材料层的孔隙率。
负极活性材料层的孔隙率可以通过任意公知手段测得，包括但不限于BET。作为示例，例如，利用小分子直径的惰性气体如氦气或氮气，通过置换法精确测量得到待测样品的真实体积，并且结合玻尔定律(PV＝nRT)得到待测样品的孔隙率。孔隙率P＝(V11-V12)/V11×100％，其中V11表示负极活性材料层的表观体积，V12表示负极活性材料层的真实体积。
控制负极活性材料层的孔隙率和碱金属离子的质量含量关系式满足合适的范围时，便于电解液更好更快地浸润负极极片，以使锂离子能够更好的传输，改善锂离子在传输过程中的浓差极化，提升锂离子二次电池的电学性能，以及改善金属枝晶的现象，兼顾锂离子二次电池的动力学和循环性能。
在一些实施方式中，碱金属离子包含Na+、K+、Cs+中的一种或多种。在一些实施方式中，碱金属离子包含Na+。在一些实施方式中，碱金属离子包含K+。在一些实施方式中，碱金属离子包含Cs+。在一些实施方式中，碱金属离子包含Na+和Cs+。
上述碱金属离子均有利于锂离子的传输，改善电池的功率性能。
在一些实施方式中，基于电解液的总质量计，碱金属离子的质量含量A满足：1ppm≤A≤7000ppm，可选为100ppm≤A≤7000ppm。在一些实施方式中，基于电解液的总质量计，碱金属离子的质量含量A可选为1ppm、5ppm、10ppm、50ppm、100ppm、500ppm、1000ppm、2000ppm、3000ppm、4000ppm、5000ppm、6000ppm、7000ppm、或由上述任意两点构成的范围中的数值。
可以理解的是，电解液中碱金属离子可参与SEI膜的形成而消耗掉部分碱金属离子，导致电解液中的碱金属离子质量含量降低， 例如，电解液中碱金属离子的质量含量可为1ppm，故，基于电解液的总质量计，碱金属离子的质量含量为1ppm～7000ppm都是本申请实施方式中所保护的范围。
控制碱金属离子在合适的范围内，以提升电池的功率性能。
在一些实施方式中，电解液还包括阴离子，阴离子包括PO2F2 -、FSO3 -、DFOB-、BF4 -、DFOP-、BOB-、PO3F2-中的一种或多种。在一些实施方式中，电解液中包括的所述阴离子可以与碱金属离子一同引入，或者通过电解液添加剂，例如包含上述阴离子之一的锂盐添加剂引入电解液中。
在一些实施方式中，基于电解液的总质量计，阴离子的质量含量大于0且小于等于5％，可选地，基于电解液的总质量计，阴离子的质量含量大于0且小于等于4％。在一些实施方式中，基于电解液的总质量计，阴离子的质量含量可选为0.01％、0.02％、0.05％、0.1％、0.3％、0.5％、0.8％、1％、1.3％、1.5％、1.8％、2％、2.5％、3％、3.5％、4％、4.5％、5％、或由上述任意两点构成的范围中的数值。
电解液或二次电池的电解液中的阴离子质量含量可以通过本领域惯常使用的检测设备和方法进行检测，例如，通过核磁共振波谱法测试阴离子的质量含量。
在一些实施方式中，可以采用牛津仪器公司的台式核磁共振谱仪X-Pulse测试阴离子的质量含量，例如，按照本领域内通用的检测方法进行测试。
上述阴离子有助于改善二次电池的循环性能和循环寿命。譬如，对于包括锂过渡金属氧化物正极活性材料的正极极片，上述阴离子所含有的孤对电子能够与正极极片表面的锂离子结合，改变Li/Ni混排，稳定正极极片结构，改变正极极片表面电荷转移电阻(Rct)，提升锂离子二次电池的循环性能和循环寿命；对于包括含锂磷酸盐正极活性材料的正极极片，上述阴离子可在负极极片表面形成致密的SEI膜，改善电池的寿命。
控制引阴离子的质量含量在合适的范围内，既能改善锂离子二 次电池的循环性能，还有助于减少金属枝晶的形成。
在一些实施方式中，成膜添加剂包括氟代碳酸酯类化合物、硫酸酯类化合物、磺酸酯类化合物中的一种或多种。
在一些实施方式中，成膜添加剂包括氟代碳酸酯类化合物。在一些实施方式中，成膜添加剂包括硫酸酯类化合物。在一些实施方式中，成膜添加剂包括磺酸酯类化合物。在一些实施方式中，成膜添加剂包括氟代碳酸酯类化合物和硫酸酯类化合物。在一些实施方式中，成膜添加剂包括氟代碳酸酯类化合物和磺酸酯类化合物。
成膜添加剂的加入有利于形成均匀致密的无机SEI膜，譬如，氟代碳酸酯类化合物能够在负极极片表面形成富含LiF、LiCO3的无机SEI膜，硫酸酯类化合物能够在负极极片表面形成富含Li2SO4的无机SEI膜，磺酸酯类化合物能够在负极极片表面形成富含Li2SO3的无机SEI膜。无机SEI膜既可抑制金属枝晶的现象，又能阻碍电解液和正/负极极片的反应，改善锂离子二次电池的稳定性，提升其循环性能。
在一些实施方式中，氟代碳酸酯类化合物包括碳酸氟代亚乙酯、碳酸1,2-二氟亚乙酯、碳酸1,1-二氟亚乙酯、碳酸1,1,2-三氟亚乙酯、碳酸1,1,2,2-四氟亚乙酯、碳酸1-氟-2-甲基亚乙酯、碳酸1-氟-1-甲基亚乙酯、碳酸1,2-二氟-1-甲基亚乙酯、碳酸1,1,2-三氟-2-甲基亚乙酯或碳酸三氟甲基亚乙酯中的一种或多种，可选地包括碳酸氟代亚乙酯；
硫酸酯类化合物包括4,4’-联硫酸乙烯酯、硫酸乙烯酯、硫酸二乙酯、硫酸二甲酯和4,4-双(1,3,2-二氧杂硫杂环戊烷)-2,2,2,2-四氧化物中的一种或多种，可选地包括4,4’-联硫酸乙烯酯、硫酸乙烯酯中的一种或多种；和/或，
磺酸酯类化合物包括1,3-丙磺酸内酯、丙烯磺酸内酯、3-氟-1,3-丙磺酸内酯中的一种或多种，可选地包括1,3-丙磺酸内酯。
上述氟代碳酸酯类化合物、硫酸酯类化合物、磺酸酯类化合物均可形成均匀致密的无机SEI膜。
在一些实施方式中，基于电解液的总质量计，成膜添加剂的质 量含量B满足：0.1％≤B≤7％，可选为0.1％≤B≤6％。
在一些实施方式中，基于电解液的总质量计，成膜添加剂的质量含量B可选为0.1％、0.5％、1％、1.5％、2％、2.5％、3％、3.5％、4％、4.5％、5％、5.5％、6％、6.5％、7％、或由上述任意两点构成的范围中的数值。
控制成膜添加剂的质量含量在合适的范围内，能够形成足够多的均匀致密的无机SEI膜，抑制枝晶，阻碍界面副反应，减少锂离子二次电池的副反应。
在一些实施方式中，负极活性材料层的孔隙率C为20％～60％，可选为20％～40％。
在一些实施方式中，负极活性材料层的孔隙率C可选为20％、25％、30％、35％、40％、45％、50％、55％、60％、或由上述任意两点构成的范围中的数值。
控制负极活性材料层的孔隙率在合适的范围内，既能够提高电解液对负极极片的浸润性，以便于锂离子更好的传输，改善锂离子在传输过程中的浓差极化，提升锂离子二次电池的电学性能，以及抑制枝晶的现象，又能降低孔隙率过大导致电解液与负极活性材料之间接触面积增加的风险，减小副反应的发生程度。
在一些实施方式中，基于电解液的总质量计，锂盐的质量含量为8％～20％，可选为9％～18％、8％～15％。
在一些实施方式中，基于电解液的总质量计，锂盐的质量含量为8％、9％、10％、12％、14％、15％、16％、18％、20％、或由上述任意两点构成的范围中的数值。
控制锂盐的质量含量在合适的范围内，有利于促进锂离子的迁移，降低锂离子二次电池的直流阻抗。
在一些实施方式中，锂盐包括第一锂盐和/或第二锂盐，第一锂盐和第二锂盐各自独立地选自LiFSI、LiPF6、LiBF4、LiTFSI、LiClO4、LiAsF6、LiBOB、LiDFOB、LiDFOP中的一种。
在一些实施例中，锂盐包括第一锂盐。在一些实施例中，锂盐包括第二锂盐。在一些实施例中，锂盐包括第一锂盐和第二锂盐。 在一些实施方式中，第一锂盐选自LiFSI。在一些实施方式中，第二锂盐选自LiPF6。
LiFSI具有较大的阴离子，可有效地促进锂离子的迁移，以使锂离子二次电池具有优异的锂离子迁移数，降低其直流阻抗和金属枝晶的析出，并且LiFSI本身对水不敏感，具有较好的热稳定性，能够进一步改善锂离子二次电池的安全性。LiPF6的成膜热稳定性优于LiFSI。故，LiFSI和LiPF6的搭配使用可兼顾其锂离子二次电池的电学性能和热稳定性能。
在一些实施方式中，第一锂盐LiFSI和第二锂盐LiPF6的质量比不低于0.1且不超过5；可选地，所述第一锂盐LiFSI和所述第二锂盐LiPF6的质量比不低于3且不超过5。
在一些实施方式中，第一锂盐和第二锂盐的质量比可选为0.1、0.2、0.5、1、1.5、2、2.5、3、3.5、4、4.5、5、或由上述任意两点构成的范围中的数值。
控制第一锂盐和第二锂盐的质量比满足合适的范围，可以使锂离子二次电池具有优异的电学性能。
在一些实施方式中，电解液还包括溶剂，溶剂包括环状酯类溶剂和/或线性酯类溶剂；
环状酯类溶剂包括碳酸乙烯酯、碳酸丙烯酯中的一种或多种；
线性酯类溶剂包括碳酸二甲酯、碳酸二乙酯、碳酸甲丙酯、碳酸甲乙酯中、甲酸甲酯、乙酸甲酯、乙酸乙酯、乙酸丁酯、丙酸甲酯、丁酸甲酯、丁酸乙酯、丁酸丙酯、丁酸丁酯、乙酸异丙酯、乙酸异戊酯中的一种或多种。
上述溶剂均可与碱金属盐和成膜添加剂搭配使用，可以使锂离子二次电池具有较低的直流阻抗和优异的循环性能。
在一些实施方式中，基于所述溶剂的总质量计，所述环状酯类溶剂的质量含量为A，所述线性酯类溶剂的质量含量为(100％-A)；其中，所述环状酯类溶剂的质量含量A为0％～40％、2％～40％，或者5％～35％。
在一些实施方式中，基于溶剂的总质量计，环状酯类溶剂的质 量含量为2～40％，可选为5％～35％；线性酯类溶剂的质量含量为50％～100％，可选为60％～95％。
在一些实施方式中，基于溶剂的总质量计，环状酯类溶剂的质量含量可选为0、0.01％、1％、5％、10％、15％、20％、25％、30％、35％、40％、或由上述任意两点构成的范围中的数值。基于溶剂的总质量计，线性酯类溶剂的质量含量为50％、55％、60％、65％、70％、75％、80％、85％、90％、95％、100％、或由上述任意两点构成的范围中的数值。
分别控制环状酯类溶剂和线性酯类溶剂的质量含量在合适的范围内，以使锂离子二次电池具有优异的电学性能和安全性。
[正极极片]
正极极片包括正极集流体以及设置在正极集流体至少一个表面的正极膜层，所述正极膜层包括正极活性材料。
作为示例，正极集流体具有在其自身厚度方向相对的两个表面，正极膜层设置在正极集流体相对的两个表面的其中任意一者或两者上。
在一些实施方式中，所述正极集流体可采用金属箔片或复合集流体。例如，作为金属箔片，可采用铝箔。复合集流体可包括高分子材料基层和形成于高分子材料基层至少一个表面上的金属层。复合集流体可通过将金属材料(铝、铝合金、镍、镍合金、钛、钛合金、银及银合金等)形成在高分子材料基材(如聚丙烯(PP)、聚对苯二甲酸乙二醇酯(PET)、聚对苯二甲酸丁二醇酯(PBT)、聚苯乙烯(PS)、聚乙烯(PE)等的基材)上而形成。
在一些实施方式中，正极活性材料可采用本领域公知的用于电池的正极活性材料。作为示例，正极活性材料可包括以下材料中的至少一种：橄榄石结构的含锂磷酸盐、锂过渡金属氧化物及其各自的改性化合物。但本申请并不限定于这些材料，还可以使用其他可被用作电池正极活性材料的传统材料。这些正极活性材料可以仅单独使用一种，也可以将两种以上组合使用。
在一些实施方式中，正极的活性材料包括锂过渡金属氧化物正 极活性材料、含锂磷酸盐正极活性材料中的一种或多种。
在一些实施方式中，锂过渡金属氧化物具有如下所示的结构式：
LiNixCoyNzM1-x-y-zO2，
其中N选自Mn和Al，M选自Ni、Mn、Mg、Cu、Zn、Al、Sn、B、Ga、Cr、Sr、V和Ti中的任意一种，0＜x＜1，0≤y≤1，0≤z≤1，x+y+z≤1。
在一些实施方式中，锂过渡金属氧化物包括锂钴氧化物(如LiCoO2)、锂镍氧化物(如LiNiO2)、锂锰氧化物(如LiMnO2、LiMn2O4)、锂镍钴氧化物、锂锰钴氧化物、锂镍锰氧化物、锂镍钴锰氧化物(如LiNi1/3Co1/3Mn1/3O2(也可以简称为NCM333)、LiNi0.5Co0.2Mn0.3O2(也可以简称为NCM523)、LiNi0.5Co0.25Mn0.25O2(也可以简称为NCM211)、LiNi0.6Co0.2Mn0.2O2(也可以简称为NCM622)、LiNi0.8Co0.1Mn0.1O2(也可以简称为NCM811)、锂镍钴铝氧化物(如LiNi0.85Co0.15Al0.05O2)及其改性化合物等中的至少一种。
在一些实施方式中，含锂磷酸盐包括磷酸铁锂(如LiFePO4(也可以简称为LFP))、磷酸铁锂与碳的复合材料、磷酸锰锂(如LiMnPO4)、磷酸锰锂与碳的复合材料、磷酸锰铁锂、磷酸锰铁锂与碳的复合材料中的至少一种。
在一些实施方式中，正极膜层还可选地包括粘结剂。作为示例，所述粘结剂可以包括聚偏氟乙烯(PVDF)、聚四氟乙烯(PTFE)、偏氟乙烯-四氟乙烯-丙烯三元共聚物、偏氟乙烯-六氟丙烯-四氟乙烯三元共聚物、四氟乙烯-六氟丙烯共聚物及含氟丙烯酸酯树脂中的至少一种。
在一些实施方式中，正极膜层还可选地包括导电剂。作为示例，所述导电剂可以包括超导碳、乙炔黑、炭黑、科琴黑、碳点、碳纳米管、石墨烯及碳纳米纤维中的至少一种。
在一些实施方式中，可以通过以下方式制备正极极片：将上述用于制备正极极片的组分，例如正极活性材料、导电剂、粘结剂和任意其他的组分分散于溶剂(例如N-甲基吡咯烷酮)中，形成正极浆料；将正极浆料涂覆在正极集流体上，经烘干、冷压等工序后， 即可得到正极极片。
[负极极片]
负极极片包括负极集流体和位于负极集流体至少一侧且至少包含负极活性材料的负极活性材料层。
作为示例，负极集流体具有在其自身厚度方向相对的两个表面，负极膜层设置在负极集流体相对的两个表面中的任意一者或两者上。
在一些实施方式中，所述负极集流体可采用金属箔片或复合集流体。例如，作为金属箔片，可以采用铜箔。复合集流体可包括高分子材料基层和形成于高分子材料基材至少一个表面上的金属层。复合集流体可通过将金属材料(铜、铜合金、镍、镍合金、钛、钛合金、银及银合金等)形成在高分子材料基材(如聚丙烯(PP)、聚对苯二甲酸乙二醇酯(PET)、聚对苯二甲酸丁二醇酯(PBT)、聚苯乙烯(PS)、聚乙烯(PE)等的基材)上而形成。
在一些实施方式中，负极活性材料可采用本领域公知的用于电池的负极活性材料。负极活性材料可以仅单独使用一种，也可以将两种以上组合使用。
在一些实施方式中，负极活性材料包括人造石墨、天然石墨、软炭、硬炭、硅碳复合物、钛酸锂、硅氧复合物中的一种或多种。
在一些实施方式中，负极活性材料层还可选地包括粘结剂。所述粘结剂可选自丁苯橡胶(SBR)、聚丙烯酸(PAA)、聚丙烯酸钠(PAAS)、聚丙烯酰胺(PAM)、聚乙烯醇(PVA)、海藻酸钠(SA)、聚甲基丙烯酸(PMAA)及羧甲基壳聚糖(CMCS)中的至少一种。
在一些实施方式中，负极活性材料层还可选地包括导电剂。导电剂可选自超导碳、乙炔黑、炭黑、科琴黑、碳点、碳纳米管、石墨烯及碳纳米纤维中的至少一种。
在一些实施方式中，负极活性材料层还可选地包括其他助剂，例如增稠剂(如羧甲基纤维素钠(CMC-Na))等。
在一些实施方式中，可以通过以下方式制备负极极片：将上述用于制备负极极片的组分，例如负极活性材料、导电剂、粘结剂和 任意其他组分分散于溶剂(例如去离子水)中，形成负极浆料；将负极浆料涂覆在负极集流体上，经烘干、冷压等工序后，即可得到负极极片。
[隔离膜]
在一些实施方式中，锂离子二次电池中还包括隔离膜。可以选用任意公知的具有良好的化学稳定性和机械稳定性的多孔结构隔离膜。
在一些实施方式中，隔离膜的材质可选自玻璃纤维、无纺布、聚乙烯、聚丙烯及聚偏二氟乙烯中的至少一种。隔离膜可以是单层薄膜，也可以是多层复合薄膜。在隔离膜为多层复合薄膜时，各层的材料可以相同或不同。
在一些实施方式中，正极极片、负极极片和隔离膜可通过卷绕工艺或叠片工艺制成电极组件。
在一些实施方式中，锂离子二次电池可包括外包装。该外包装可用于封装上述电极组件及电解液。
在一些实施方式中，锂离子二次电池的外包装可以是硬壳，例如硬塑料壳、铝壳、钢壳等。锂离子二次电池的外包装也可以是软包，例如袋式软包。软包的材质可以是塑料，作为塑料，可列举出聚丙烯、聚对苯二甲酸丁二醇酯以及聚丁二酸丁二醇酯等。
本申请对锂离子二次电池的形状可以是圆柱形、方形或其他任意的形状。例如，图1是作为一个示例的方形结构的锂离子二次电池5。
在一些实施方式中，参照图2，外包装可包括壳体51和盖板53。其中，壳体51可包括底板和连接于底板上的侧板，底板和侧板围合形成容纳腔。壳体51具有与容纳腔连通的开口，盖板53能够盖设于所述开口，以封闭所述容纳腔。正极极片、负极极片和隔离膜可经卷绕工艺或叠片工艺形成电极组件52。电极组件52封装于所述容纳腔内。电解液浸润于电极组件52中。锂离子二次电池5所含电极组件52的数量可以为一个或多个，本领域技术人员可根据具体实际需求进行选择。
在一些实施方式中，锂离子二次电池可以组装成电池模块，电池模块所含锂离子二次电池的数量可以为一个或多个，具体数量本领域技术人员可根据电池模块的应用和容量进行选择。
图3是作为一个示例的电池模块4。参照图3，在电池模块4中，多个锂离子二次电池5可以是沿电池模块4的长度方向依次排列设置。当然，也可以按照其他任意的方式进行排布。进一步可以通过紧固件将该多个锂离子二次电池5进行固定。
可选地，电池模块4还可以包括具有容纳空间的外壳，多个锂离子二次电池5容纳于该容纳空间。
在一些实施方式中，上述电池模块还可以组装成电池包，电池包所含电池模块的数量可以为一个或多个，具体数量本领域技术人员可根据电池包的应用和容量进行选择。
图4和图5是作为一个示例的电池包1。参照图4和图5，在电池包1中可以包括电池箱和设置于电池箱中的多个电池模块4。电池箱包括上箱体2和下箱体3，上箱体2能够盖设于下箱体3，并形成用于容纳电池模块4的封闭空间。多个电池模块4可以按照任意的方式排布于电池箱中。
另外，本申请还提供一种用电装置，所述用电装置包括本申请提供的锂离子二次电池、电池模块、或电池包中的至少一种。锂离子二次电池、电池模块、或电池包可以用作所述用电装置的电源，也可以用作所述用电装置的能量存储单元。所述用电装置可以包括移动设备(例如手机、笔记本电脑等)、电动车辆(例如纯电动车、混合动力电动车、插电式混合动力电动车、电动自行车、电动踏板车、电动高尔夫球车、电动卡车等)、电气列车、船舶及卫星、储能系统等，但不限于此。
作为所述用电装置，可以根据其使用需求来选择锂离子二次电池、电池模块或电池包。
图6是作为一个示例的用电装置。该用电装置为纯电动车、混合动力电动车、或插电式混合动力电动车等。为了满足该用电装置对锂离子二次电池的高功率和高能量密度的需求，可以采用电池包 或电池模块。
作为另一个示例的装置可以是手机、平板电脑、笔记本电脑等。该装置通常要求轻薄化，可以采用锂离子二次电池作为电源。
实施例
以下，说明本申请的实施例。下面描述的实施例是示例性的，仅用于解释本申请，而不能理解为对本申请的限制。实施例中未注明具体技术或条件的，按照本领域内的文献所描述的技术或条件或者按照产品说明书进行。所用试剂或仪器未注明生产厂商者，均为可以通过市购获得的常规产品。
一、制备方法
实施例1
1)电解液
在氩气气氛手套箱中(H2O<0.1ppm，O2<0.1ppm)，将环状酯类溶剂碳酸乙烯酯与线性酯类溶剂碳酸二甲酯按照质量比25:75混合均匀，得到混合溶剂。然后加入锂盐六氟磷酸锂和双三氟甲烷磺酰亚胺锂(LiFSI与LiPF6质量比为3:1)溶解于上述混合溶剂中使锂盐的质量含量为15％，搅拌均匀，随后加入碱金属盐NaPO2F2和成膜添加剂4,4’-联硫酸乙烯酯，混合均匀后得到电解液；其中，基于电解液的总质量计，碱金属离子Na+的质量含量为30ppm，4,4’-联硫酸乙烯酯的质量含量为2％。
2)正极极片的制备
将1wt％聚偏二氟乙烯粘结剂充分溶解于N-甲基吡咯烷酮中，再加入1wt％炭黑导电剂与98wt％锂过渡金属氧化物正极活性材料LiNi0.5Co0.2Mn0.3O2搅拌混合均匀，得到正极浆料。将浆料均匀涂敷在集流体铝箔表面以制备正极膜层，然后转移到真空干燥箱中完全干燥。将干燥后的极片进行辊压、冲切，得到正极极片。
3)负极极片的制备
将负极活性材料人造石墨、导电剂碳黑、增稠剂羧甲基纤维素(CMC)、粘接剂丁苯橡胶(SBR)按照重量比96:2:1:1的比例进行 混合溶于去离子水中制成负极浆料，在真空搅拌机作用下获得负极浆料，再将浆料涂布在铜箔表面。最后转移到真空干燥箱中完全干燥，之后分切、模切，调整极片膜层的压实密度使负极活性材料的孔隙率为40％，得到负极极片。
4)隔离膜
以聚丙烯膜作为隔离膜。
5)电池的制备
将正极极片、隔离膜、负极极片按顺序叠好，隔离膜处于正、负极片之间起到隔离的作用，给裸电芯焊接极耳，并将裸电芯装入铝壳中，并在80℃下烘烤除水，随即注入上述电解液并封口，得到不带电的电池。不带电的电池再依次经过静置、热冷压、化成、整形、容量测试等工序，获得实施例1的锂离子二次电池产品。
实施例2～30
实施例2～30中的电池制备方法与实施例1基本相似，但是调整电解液、正极活性材料、负极活性材料的制备参数，具体参数如表1所示。
对比例1
对比例1中的电池制备方法与实施例1基本相似，但是电解液中没有成膜添加剂，具体参数如表1所示。
对比例2
对比例2中的电池制备方法与实施例1基本相似，但是电解液中没有加入碱金属盐，具体参数如表1所示。
对比例3
对比例3中的电池制备方法与实施例1基本相似，但是电解液中没有加入碱金属盐和成膜添加剂，具体参数如表1所示。
对比例4～5
对比例4～5中的电池制备方法与实施例1基本相似，但是调整了B/A的范围，具体参数如表1所示。
对比例6～7
对比例6～7中的电池制备方法与实施例28基本相似，但是调整 了B/A的范围，具体参数如表1所示。
二、性能测试
1、负极极片性能测试
1)负极活性材料层孔隙率测试
利用惰性气体氦气或氮气，通过置换法精确测量得到待测样品的真实体积，结合玻尔定律(pV＝nRT，p为压强，V为气体体积，T为温度，n为气体的物质的量，R为摩尔气体常数)得到待测样品的孔隙率。孔隙率P＝(V11-V12)/V11×100％，其中V11表示负极活性材料层的表观体积，V12表示负极活性材料层的真实体积。
2、电池性能测试
1)直流阻抗(DCR)测试
在-25℃下，调整单体电池荷电状态至50％SOC，静置30min，记录此时的电池电压为U1(V)，采用0.36C放电10s，记录此时的电池电压为U2(V)，对应电池的放电电流I(mA)为0.36×电池设计容量(mAh)。直流阻抗DCR(mΩ)＝(U1-U2)/I。
2)循环性能测试
循环性能测试过程如下：在25℃下，将制备的电池以2C恒定电流充电至4.25V，之后以4.25V恒压充电至电流降到0.05C，静置5min后，以1C恒定电流放电至2.5V，此为电池的首次充电/放电循环，此次的放电容量记为电池首次循环的放电容量(C1)；对上述同一个电池重复以上步骤，循环第n次后电池的过程容量(Cn)，循环n圈后的容量保持率＝Cn/C1×100％。记录循环容量保持率为80％的循环圈数。对比例以及其他实施例的测试过程同上。
3)金属枝晶测试
将上述循环n圈后的电池在氩气气氛手套箱中(H2O<0.1ppm，O2<0.1ppm)进行拆解，目视观察负极极片表面形貌，确定是否有金属枝晶生成。负极极片无白点判定为金属枝晶情况无、负极极片有零星白点判定为金属枝晶情况轻微、负极极片有密密麻麻白点判定为金属枝晶情况严重。对比例以及其他实施例的测试过程同上。
3、碱金属离子质量含量的测定
电解液中碱金属离子的测试：取10ml上述制备的电解液，采用Thermo Fisher Scientific公司型号为ICAP-7400的电感耦合等离子体原子发射光谱法进行测试。当制备为二次电池时，从二次电池注液口取10ml游离电解液，采用上述方法检测。
三、各实施例、对比例测试结果分析
按照上述方法分别制备各实施例和对比例的电池，并测量各项性能参数，结果见下表1和表2。
表1

表2

根据上述结果可知，实施例1～30中的锂离子二次电池均包括电解液，电解液包括离子半径大于锂离子半径的碱金属离子和成膜添加剂。其中，基于电解液的总质量计，碱金属离子的质量含量A与添加剂的质量含量B满足：0.14≤B/A≤2000。
从实施例1～27与对比例1的对比可见，本申请实施例中电解液包括成膜添加剂4,4’-联硫酸乙烯酯，有利于提高电池循环容量保持率为80％的循环圈数。从实施例1～27与对比例2的对比可见，本申请实施例中电解液包括离子半径大于锂离子半径的碱金属离子Na+或K+，有利于降低电池的直流阻抗。从实施例1～27与对比例3的对比可见，本申请实施例中电解液同时包括离子半径大于锂离子半径的碱金属离子和成膜添加剂，有利于降低电池的直流阻抗、提高电池循环容量保持率为80％的循环圈数。
从实施例1～16、实施例22～27与对比例4～5，实施例28～29与对比例6～7的对比可见，基于电解液的总质量计，控制碱金属离子的质量含量A与添加剂的质量含量B满足：0.14≤B/A≤2000，有利于提升电池循环容量保持率为80％的循环圈数。
从实施例1～8和实施例23～25中可见，基于电解液的总质量计，控制碱金属离子的质量含量A与添加剂的质量含量B满足：0.2≤B/A≤2000，可以降低电池的直流阻抗、提高循环容量保持率为80％的电池循环圈数，兼顾电池的功率性能和循环性能。
从实施例3、实施例15～16和实施例26～27中可见，控制负极活性材料层的孔隙率C与碱金属离子在电解液总质量中的质量含量A之间满足：5×10-5≤A/C≤0.035，电池的直流阻抗和循环容量保持率为80％的循环圈数均有所改善。从实施例3、15～16、26与实施例27的 对比可见，控制负极活性材料层的孔隙率C与碱金属离子在电解液总质量中的质量含量A之间满足：5×10-5≤A/C≤0.025，进一步有利于提升电池循环容量保持率为80％的循环圈数。
从实施例2～4与实施例1的对比可见，基于电解液的总质量计，控制碱金属离子的质量含量A满足100ppm≤A≤7000ppm，进一步降低电池的直流阻抗、提高电池循环容量保持率为80％的循环圈数、以及改善电池的金属枝晶。
从实施例5～8中可见，基于电解液的总质量计，控制成膜添加剂的质量含量B满足：0.1％≤B≤7％，有助于降低电池直流阻抗和提高循环容量保持率为80％的电池循环圈数。从实施例5～7与实施例8的对比可见，基于电解液的总质量计，进一步控制成膜添加剂的质量含量B满足：0.1％≤B≤6％，有利于进一步降低电池的直流阻抗，改善电池的功率性能。
从实施例3、9中可见，电解液中的碱金属离子包括Na+或K+，均有利于降低电池的直流阻抗和提高电池循环容量保持率为80％的循环圈数、并改善电池的金属枝晶状况。
从实施例3、实施例12～14中可见，电解液中的成膜添加剂包括4,4’-联硫酸乙烯酯、碳酸氟代亚乙酯、1,3-丙磺酸内酯中的一种或多种，可以使电池获得有低的直流阻抗，提高电池的循环圈数、以及改善电池的金属枝晶。
从实施例3、实施例15～16中可见，控制负极活性材料层的孔隙率C为20％～60％，可以减少电池的直流阻抗和改善电池循环容量保持率为80％的循环圈数。
从实施例3、17～18中可见，基于电解液的总质量计，控制锂盐的质量含量为8％～20％，有助于改善电池的直流阻抗和电池循环容量保持率为80％的循环圈数。从实施例3、实施例19～20中可见，锂盐LiFSI与锂盐LiPF6的质量比不低于0.1且不超过5时，还有助于改善电池的金属枝晶。
从实施例3、21中可见，可以使用人造石墨或硅碳复合物作为负极活性材料层，从实施例3、28中可见，可以使用 LiNi0.5Co0.2Mn0.3O2正极活性材料或LiFePO4正极活性材料制备正极极片，有助于获得直流阻抗低、循环圈数高、金属枝晶状况改善的电池。
从实施例28～29中可见，基于溶剂的总质量计，控制环状酯类溶剂的质量含量为5％～35％，线性酯类溶剂的质量含量为65％～95％，有助于改善电池的直流阻抗和循环圈数。
需要说明的是，本申请不限定于上述实施方式。上述实施方式仅为示例，在本申请的技术方案范围内具有与技术思想实质相同的构成、发挥相同作用效果的实施方式均包含在本申请的技术范围内。此外，在不脱离本申请主旨的范围内，对实施方式施加本领域技术人员能够想到的各种变形、将实施方式中的一部分构成要素加以组合而构筑的其它方式也包含在本申请的范围内。

Claims (18)

  1. 一种锂离子二次电池，其特征在于，包括电解液，所述电解液包括离子半径大于锂离子半径的碱金属离子和成膜添加剂；
    基于所述电解液的总质量计，所述碱金属离子的质量含量A与所述成膜添加剂的质量含量B满足：0.10≤B/A≤6×104。
  2. 根据权利要求1所述的锂离子二次电池，其特征在于，所述锂离子二次电池包括负极极片，所述负极极片包括集流体和位于所述集流体至少一侧且至少包含负极活性材料的负极活性材料层，所述负极活性材料层的孔隙率C与所述碱金属离子在电解液总质量中的质量含量A之间满足：10-6≤A/C≤0.035，可选为5×10-5≤A/C≤0.025。
  3. 根据权利要求1或2所述的锂离子二次电池，其特征在于，基于所述电解液的总质量计，所述碱金属离子含量A与所述成膜添加剂的质量含量B满足：0.14≤B/A≤2000。
  4. 根据权利要求1至3中任一项所述的锂离子二次电池，其特征在于，所述碱金属离子包含Na+、K+、Cs+中的一种或多种。
  5. 根据权利要求1至4中任一项所述的锂离子二次电池，其特征在于，基于所述电解液的总质量计，所述碱金属离子的质量含量A满足：1ppm≤A≤7000ppm，可选为100ppm≤A≤7000ppm。
  6. 根据权利要求1至5中任一项所述的锂离子二次电池，其特征在于，所述电解液还包括阴离子，所述阴离子包括PO2F2 -、FSO3 -、DFOB-、BF4 -、DFOP-、BOB-、PO3F2-中的一种或多种。
  7. 根据权利要求1至6中任一项所述的锂离子二次电池，其特 征在于，所述成膜添加剂包括氟代碳酸酯类化合物、硫酸酯类化合物、磺酸酯类化合物中的一种或多种。
  8. 根据权利要求7所述的锂离子二次电池，其特征在于，所述氟代碳酸酯类化合物包括碳酸氟代亚乙酯、碳酸1,2-二氟亚乙酯、碳酸1,1-二氟亚乙酯、碳酸1,1,2-三氟亚乙酯、碳酸1,1,2,2-四氟亚乙酯、碳酸1-氟-2-甲基亚乙酯、碳酸1-氟-1-甲基亚乙酯、碳酸1,2-二氟-1-甲基亚乙酯、碳酸1,1,2-三氟-2-甲基亚乙酯或碳酸三氟甲基亚乙酯中的一种或多种，可选地包括碳酸氟代亚乙酯；
    所述硫酸酯类化合物包括4,4’-联硫酸乙烯酯、硫酸乙烯酯、硫酸二乙酯、硫酸二甲酯和4,4-双(1,3,2-二氧杂硫杂环戊烷)-2,2,2,2-四氧化物中的一种或多种，可选地包括4,4’-联硫酸乙烯酯、硫酸乙烯酯中的一种或多种；和/或，
    所述磺酸酯类化合物包括1,3-丙磺酸内酯、丙烯磺酸内酯、3-氟-1,3-丙磺酸内酯中的一种或多种，可选地包括1,3-丙磺酸内酯。
  9. 根据权利要求1至8中任一项所述的锂离子二次电池，其特征在于，基于所述电解液的总质量计，所述成膜添加剂的质量含量B满足：0.1％≤B≤7％，可选为0.1％≤B≤6％。
  10. 根据权利要求2至9中任一项所述的锂离子二次电池，其特征在于，所述负极活性材料层的孔隙率C为20％～60％，可选为20％～40％。
  11. 根据权利要求1至10中任一项所述的锂离子二次电池，其特征在于，基于电解液的总质量计，所述锂盐的质量含量为8％～20％，可选为8％～15％。
  12. 根据权利要求1至11中任一项所述的锂离子二次电池，其特征在于，所述锂盐包括第一锂盐、第二锂盐或二者的组合，所述 第一锂盐和所述第二锂盐各自独立地选自LiFSI、LiPF6、LiBF4、LiTFSI、LiClO4、LiAsF6、LiBOB、LiDFOB、LiDFOP中的一种。
  13. 根据权利要求12所述的锂离子二次电池，其特征在于，所述第一锂盐选自LiFSI，所述第二锂盐选自LiPF6；
    所述第一锂盐和所述第二锂盐的质量比不低于0.1且不超过5；可选地，所述第一锂盐和所述第二锂盐的质量比不低于3且不超过5。
  14. 根据权利要求1至13中任一项所述的锂离子二次电池，其特征在于，所述电解液还包括溶剂，所述溶剂包括环状酯类溶剂和/或线性酯类溶剂；
    所述环状酯类溶剂包括碳酸乙烯酯、碳酸丙烯酯中的一种或多种；
    所述线性酯类溶剂包括碳酸二甲酯、碳酸二乙酯、碳酸甲丙酯、碳酸甲乙酯中、甲酸甲酯、乙酸甲酯、乙酸乙酯、乙酸丁酯、丙酸甲酯、丁酸甲酯、丁酸乙酯、丁酸丙酯、丁酸丁酯、乙酸异丙酯、乙酸异戊酯中的一种或多种。
  15. 根据权利要求14所述的锂离子二次电池，其特征在于，基于所述溶剂的总质量计，所述环状酯类溶剂的质量含量为A，所述线性酯类溶剂的质量含量为(100％-A)；
    其中，所述环状酯类溶剂的质量含量A为2％～40％，可选为5％～35％。
  16. 根据权利要求2至15中任一项所述的锂离子二次电池，其特征在于，所述负极活性材料包括人造石墨、天然石墨、软炭、硬炭、硅碳复合物、钛酸锂、硅氧复合物中的一种或多种。
  17. 根据权利要求1至16中任一项所述的锂离子二次电池，其特征在于，所述锂离子二次电池包括正极极片，所述正极极片包括 锂过渡金属氧化物正极活性材料、含锂磷酸盐正极活性材料中的一种或多种。
  18. 一种用电装置，其特征在于，包括权利要求1至17中任一项所述的锂离子二次电池。
PCT/CN2023/095367 2023-05-19 2023-05-19 锂离子二次电池和用电装置 Ceased WO2024239162A1 (zh)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN120089879A (zh) * 2025-01-24 2025-06-03 宁德时代新能源科技股份有限公司 锂离子电池及用电装置

Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103346349A (zh) * 2013-06-27 2013-10-09 宁德新能源科技有限公司 锂离子电池及其电解液
CN105186034A (zh) * 2015-07-28 2015-12-23 珠海市赛纬电子材料有限公司 以碳酸丙烯酯为主溶剂的电解液及锂离子电池
CN105845983A (zh) * 2016-04-15 2016-08-10 宁德时代新能源科技股份有限公司 一种电解液及含有该电解液的锂离子电池
CN106159324A (zh) * 2016-07-05 2016-11-23 上海枭源能源科技有限公司 非水电解液及使用该非水电解液的锂二次电池
CN107403958A (zh) * 2016-05-19 2017-11-28 宁德新能源科技有限公司 电解液及锂离子电池
KR20190050265A (ko) * 2017-11-02 2019-05-10 솔브레인 주식회사 전해액 첨가제 및 이를 포함하는 리튬 이차 전지
CN110854432A (zh) * 2019-11-05 2020-02-28 宁德新能源科技有限公司 电解液以及使用其的电化学装置和电子装置
CN113782725A (zh) * 2021-09-09 2021-12-10 宁德新能源科技有限公司 电化学装置和电子设备
CN115298875A (zh) * 2022-03-29 2022-11-04 宁德新能源科技有限公司 电解液、电化学装置及电子装置
CN115810796A (zh) * 2021-09-26 2023-03-17 宁德时代新能源科技股份有限公司 一种电解液、包括其的二次电池及该二次电池的制备方法

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20200212486A1 (en) * 2018-12-28 2020-07-02 Battelle Memorial Institute Electrolytes for wide-temperature range lithium ion batteries
CN110911752A (zh) * 2019-12-06 2020-03-24 广州天赐高新材料股份有限公司 一种低内阻的锂二次电池电解液及锂二次电池
CN111477962B (zh) * 2020-05-29 2021-07-20 珠海市赛纬电子材料股份有限公司 一种锂离子电池非水电解液及含该非水电解液的锂离子电池
CN113078358A (zh) * 2021-03-17 2021-07-06 东莞市杉杉电池材料有限公司 一种锂离子电池非水电解液及其锂离子电池
WO2022246798A1 (zh) * 2021-05-28 2022-12-01 宁德时代新能源科技股份有限公司 锂离子二次电池、电池模块、电池包、以及用电装置
CN113851724B (zh) * 2021-09-22 2022-08-02 宁德新能源科技有限公司 电化学装置和电子装置

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103346349A (zh) * 2013-06-27 2013-10-09 宁德新能源科技有限公司 锂离子电池及其电解液
CN105186034A (zh) * 2015-07-28 2015-12-23 珠海市赛纬电子材料有限公司 以碳酸丙烯酯为主溶剂的电解液及锂离子电池
CN105845983A (zh) * 2016-04-15 2016-08-10 宁德时代新能源科技股份有限公司 一种电解液及含有该电解液的锂离子电池
CN107403958A (zh) * 2016-05-19 2017-11-28 宁德新能源科技有限公司 电解液及锂离子电池
CN106159324A (zh) * 2016-07-05 2016-11-23 上海枭源能源科技有限公司 非水电解液及使用该非水电解液的锂二次电池
KR20190050265A (ko) * 2017-11-02 2019-05-10 솔브레인 주식회사 전해액 첨가제 및 이를 포함하는 리튬 이차 전지
CN110854432A (zh) * 2019-11-05 2020-02-28 宁德新能源科技有限公司 电解液以及使用其的电化学装置和电子装置
CN113782725A (zh) * 2021-09-09 2021-12-10 宁德新能源科技有限公司 电化学装置和电子设备
CN115810796A (zh) * 2021-09-26 2023-03-17 宁德时代新能源科技股份有限公司 一种电解液、包括其的二次电池及该二次电池的制备方法
CN115298875A (zh) * 2022-03-29 2022-11-04 宁德新能源科技有限公司 电解液、电化学装置及电子装置

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP4715932A4 *

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN120089879A (zh) * 2025-01-24 2025-06-03 宁德时代新能源科技股份有限公司 锂离子电池及用电装置

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