WO2023184080A1 - 电化学装置和电子装置 - Google Patents

电化学装置和电子装置 Download PDF

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Publication number
WO2023184080A1
WO2023184080A1 PCT/CN2022/083355 CN2022083355W WO2023184080A1 WO 2023184080 A1 WO2023184080 A1 WO 2023184080A1 CN 2022083355 W CN2022083355 W CN 2022083355W WO 2023184080 A1 WO2023184080 A1 WO 2023184080A1
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Prior art keywords
active material
peak
negative electrode
material layer
negative
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English (en)
French (fr)
Inventor
冯鹏洋
唐佳
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Ningde Amperex Technology Ltd
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Ningde Amperex Technology Ltd
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Priority to EP22933938.7A priority Critical patent/EP4489134A4/en
Priority to CN202280007185.1A priority patent/CN116391284A/zh
Priority to PCT/CN2022/083355 priority patent/WO2023184080A1/zh
Priority to JP2024556176A priority patent/JP2025510736A/ja
Publication of WO2023184080A1 publication Critical patent/WO2023184080A1/zh
Priority to US18/897,304 priority patent/US20250029998A1/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
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H01M4/133—Electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx
    • 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
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H01M4/139—Processes of manufacture
    • H01M4/1393—Processes of manufacture of electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx
    • 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
    • H01M4/362—Composites
    • H01M4/366—Composites as layered products
    • 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
    • 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
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • H01M4/624—Electric conductive fillers
    • H01M4/625—Carbon or graphite
    • 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
    • H01M4/64—Carriers or collectors
    • H01M4/66—Selection of materials
    • 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
    • H01M4/64—Carriers or collectors
    • H01M4/66—Selection of materials
    • H01M4/661—Metal or alloys, e.g. alloy coatings
    • H01M4/662—Alloys
    • 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
    • H01M4/64—Carriers or collectors
    • H01M4/70—Carriers or collectors characterised by shape or form
    • H01M4/75—Wires, rods or strips
    • 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
    • H01M2004/021—Physical characteristics, e.g. porosity, surface area
    • 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
    • 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 energy storage, and specifically to an electrochemical device and an electronic device.
  • Electrochemical devices such as lithium-ion batteries have occupied a mainstream position in the market due to their outstanding advantages such as high energy density, high safety, no memory effect, and long working life.
  • the requirements for the electrochemical devices in them are becoming more and more stringent.
  • batteries are not only required to be lightweight, but also have high capacity and long working life.
  • natural graphite with a high gram capacity is often used as anode material.
  • the large layer porous structure of natural graphite makes it difficult to have both excellent cycle performance and dynamic performance, limiting the high performance of natural graphite. applications in electrochemical devices.
  • this application provides an electrochemical device and an electronic device including the electrochemical device.
  • the electrochemical device of the present application not only has high gram capacity, but also has excellent cycle performance and kinetic performance.
  • the present application provides an electrochemical device, which includes a negative electrode.
  • the negative electrode includes a negative electrode current collector and a negative electrode active material layer.
  • the negative electrode active material layer includes a negative electrode active material, wherein the negative electrode active material layer satisfies 0.1 ⁇ SA/ S002 ⁇ 0.3, SA is the peak area value of the A peak with 2 ⁇ in the range of 42.4° to 43.6° in the XRD pattern of the negative active material layer, and S002 is the peak area value of the 002 peak in the XRD pattern of the negative active material layer.
  • SA is the peak area value of peak A of the negative active material layer has a negative correlation with the thickness of the active material layer.
  • the peak area value S002 of the peak 002 of the negative active material layer is related to the amount of active metal ions such as lithium ions that can be embedded in the negative active material. The greater the S002, the greater the amount of active metal ions that can be embedded, which is beneficial to improving the energy of the electrochemical device. Density, but when S002 is too large, the deformation of the electrochemical device will increase.
  • the electrochemical device can It has high gram capacity and excellent cycle performance and kinetic properties.
  • the SA value is the peak area value of peak A in the XRD pattern of the negative active material layer when the electrochemical device is in a fully discharged state.
  • the S002 value is the peak area value of the 002 peak in the XRD pattern of the negative active material layer when the electrochemical device is in a fully discharged state.
  • the half-maximum width of the A peak is 0.1° to 0.5°.
  • the half-peak width of peak A reflects the thickness of the active material layer. The narrower the half-peak width, the smaller the thickness of the active material layer, which is conducive to the embedding of active metal ions in the active material layer and improves the dynamic performance of the electrochemical device.
  • 2 ⁇ in the XRD pattern of the negative active material layer, 2 ⁇ has a 101 peak in the range of 43.6° to 46.6°, where 0.015 ⁇ S101/S002 ⁇ 0.035, and S101 is the peak area value of the 101 peak.
  • the half-maximum width of the 101 peak is 0.3° to 0.8°.
  • the 101 peak is related to the amount of active metal ions that can be embedded in the active material. The greater the peak intensity of the 101 peak, the narrower the half-peak width, the greater the amount of active metal ions that can be embedded. Therefore, the peak intensity of the 101 peak and the half-peak width are Controlling the peak width within a certain range can be beneficial to obtaining a negative active material with a high amount of embedded active metal ions, and the gram capacity of the active material is increased.
  • the negative electrode current collector is copper foil.
  • the negative electrode current collector contains chromium element, and the chromium element content is 0.008% to 0.020% based on the mass of the negative electrode current collector.
  • the negative electrode current collector contains niobium element, and the content of niobium element is 0.005% to 0.009% based on the mass of the negative electrode current collector.
  • the negative electrode current collector contains sulfur element, and the sulfur element content is 0.001% to 0.006% based on the mass of the negative electrode current collector.
  • Controlling the content of trace elements in the current collector can facilitate the expansion of the negative active material during the process of deintercalation and deintercalation of active metal ions, thereby inhibiting the deformation of the electrochemical device and improving the kinetic performance and cycle performance of the electrochemical device.
  • the thickness of the negative active material layer is H ⁇ m, where 87 ⁇ SA/H ⁇ 300. In some embodiments, the thickness of the negative active material layer is H ⁇ m, and the weight of the negative active material layer per unit area is C g/cm 2 , where 0.003 ⁇ C ⁇ 0.01 and 1.0 ⁇ 10 4 ⁇ C/H ⁇ 1.7.
  • SA is inversely proportional to the thickness of the active material. Generally speaking, the smaller the active material layer H is, the larger the SA is. The reaction to electrical properties is to insert active metal ions faster, and it is not easy to precipitate lithium. However, the thickness of the active material layer is too small.
  • controlling the thickness of the active material layer and the weight of the negative active material layer per unit area within the above range is beneficial to controlling the insertion and extraction speed of active metal ions, increasing the gram capacity of the negative active material, and improving the cycle performance and power of the electrochemical device. academic performance.
  • the negative active material layer satisfies 10 ⁇ S004/S110 ⁇ 25, where S004 is the peak area value of the 004 peak in the XRD pattern of the negative active material layer, and S110 is the peak area value of the 004 peak in the XRD pattern of the negative active material layer.
  • the peak area value of the 110 peak When the ratio of S004/S110 is within the above range, the internal resistance of the active metal ions embedded/extracted from the negative active material is small, and the precipitation of active metal ions can be reduced, which can improve the cycle performance and kinetic performance of the electrochemical device.
  • the negative active material includes natural graphite.
  • the negative active material has a specific surface area (BET) of 2 to 5 g/cm 2 ; in some embodiments, the negative active material has a gram capacity of 360 to 370 mAh/g.
  • the particle size of the negative active material satisfies 1 ⁇ m ⁇ Dv10 ⁇ 10 ⁇ m, 3 ⁇ m ⁇ Dv50 ⁇ 18 ⁇ m, and 8 ⁇ m ⁇ Dv90 ⁇ 35 ⁇ m.
  • the particle size distribution of the negative active material is within the above range, it can ensure that the internal resistance of the active metal ions embedded/extracted from the negative active material is small, the precipitation of active metal ions is reduced, and side reactions with the electrolyte can be reduced, ensuring electrochemical
  • the device has excellent cycle performance and dynamic performance.
  • the present application provides an electronic device including the electrochemical device of the first aspect.
  • the negative electrode of the electrochemical device provided by this application includes a specific negative active material layer, so that the electrochemical device has high capacity and excellent cycle performance and kinetic performance.
  • the present application provides an electrochemical device, which includes a negative electrode.
  • the negative electrode includes a negative electrode current collector and a negative electrode active material layer.
  • the negative electrode active material layer includes a negative electrode active material, wherein the negative electrode active material layer satisfies 0.1 ⁇ SA/ S002 ⁇ 0.3, SA is the peak area value of the A peak with 2 ⁇ in the range of 42.4° to 43.6° in the XRD pattern of the negative active material layer, and S002 is the peak area value of the 002 peak in the XRD pattern of the negative active material layer.
  • the characteristic peak of 2 ⁇ in the range of 25.0° to 27.0° in the XRD pattern of the negative active material layer is the 002 peak.
  • SA/S002 is 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.2, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, or these values A range consisting of any two of them.
  • the peak area value SA of peak A of the negative active material layer has a negative correlation with the thickness of the active material layer. The larger the SA, the smaller the thickness of the negative active material layer, and the easier it is for active metal ions to embed and detach in the negative active material layer. However, The energy density of electrochemical devices is reduced.
  • the peak area value S002 of peak 002 of the negative active material layer is related to the amount of active metal ions such as lithium ions that can be embedded in the negative active material.
  • the greater the S002, the greater the amount of active metal ions that can be embedded, and the greater the gram capacity of the negative active material. which is beneficial to improving the energy density of the electrochemical device, but when S002 is too large, the deformation rate of the electrochemical device increases, affecting its dynamic performance.
  • SA/S002 is controlled within the above range, it can not only ensure the energy density of the electrochemical device, but also ensure the normal deintercalation of active metal ions in the active material.
  • the electrochemical device can It has high gram capacity and excellent cycle performance and kinetic properties.
  • SA is a range consisting of 7100, 7300, 7500, 7700, 7900, 8000, 8100, 8300, 8500, 8700, 8900, or any two of these values.
  • S002 is a range consisting of 27000, 30000, 34000, 40000, 45000, 50000, 55000, 60000, 65000, 70000, 75000, 80000, 85000, or any two of these values.
  • the SA value is the peak area value of peak A in the XRD pattern of the negative active material layer when the electrochemical device is in a fully discharged state.
  • the S002 value is the peak area value of the 002 peak in the XRD pattern of the negative active material layer when the electrochemical device is in a fully discharged state.
  • the half-maximum width of the A peak is 0.1° to 0.5°. In some embodiments, the half-maximum width of peak A is 0.15°, 0.17°, 0.2°, 0.23°, 0.25°, 0.27°, 0.3°, 0.33°, 0.35°, 0.37°, 0.4°, 0.43°, 0.45 °, 0.47°, or a range consisting of any two of these values.
  • the half-peak width of peak A reflects the thickness of the active material layer. The narrower the half-peak width, the smaller the thickness of the active material layer, which is conducive to the embedding of active metal ions in the active material layer and is conducive to improving the kinetic performance and cycle performance of the electrochemical device. .
  • 2 ⁇ in the XRD pattern of the negative active material layer, 2 ⁇ has a 101 peak in the range of 43.6° to 46.6°, where 0.015 ⁇ S101/S002 ⁇ 0.035, and S101 is the peak area value of the 101 peak.
  • S101/S002 is a range consisting of 0.017, 0.019, 0.02, 0.021, 0.023, 0.025, 0.027, 0.029, 0.030, 0.031, 0.033, or any two of these values.
  • the half-maximum width of the 101 peak is 0.3° to 0.8°.
  • the half-width of the 101 peak is 0.35°, 0.37°, 0.4°, 0.43°, 0.45°, 0.47°, 0.5°, 0.53°, 0.55°, 0.57°, 0.6°, 0.63°, 0.65 °, 0.67°, 0.7°, 0.73°, 0.75°, 0.77°, or a range consisting of any two of these values.
  • the 7101 peak is related to the amount of active metal ions that can be embedded in the active material. The greater the peak intensity of the 101 peak and the narrower the half-peak width, the greater the amount of active metal ions that can be embedded. Therefore, the peak intensity of the 101 peak and the half-peak width are Controlling the peak width within a certain range can be beneficial to obtaining a negative active material with a high amount of embedded active metal ions, and the negative active material has a high gram capacity.
  • the negative electrode current collector is copper foil.
  • the negative electrode current collector contains chromium element. Based on the mass of the negative electrode current collector, the chromium element content is 0.008% to 0.020%, such as 0.009%, 0.01%, 0.011%, 0.012%, 0.012%, 0.014 %, 0.015%, 0.016%, 0.017%, 0.018%, 0.019%, or a range consisting of any two of these values. According to some embodiments of the present application, the negative electrode current collector contains niobium element.
  • the niobium element content is 0.005% to 0.009%, such as 0.0055%, 0.06%, 0.065%, 0.07%, 0.075%, 0.08 %, 0.085%, or a range consisting of any two of these values.
  • the negative electrode current collector contains sulfur element. Based on the mass of the negative electrode current collector, the sulfur element content is 0.001% to 0.006%, such as 0.0015%, 0.02%, 0.0025%, 0.003%, 0.0035%, 0.004 %, 0.0045%, 0.005%, 0.0055%, or a range consisting of any two of these values. Controlling the content of trace elements in the current collector can facilitate the expansion of the negative active material during the lithium deintercalation process, thereby inhibiting the deformation of the electrochemical device and improving the kinetic performance and cycle performance of the electrochemical device.
  • the thickness of the negative active material layer is H ⁇ m, where 87 ⁇ SA/H ⁇ 300. In some embodiments, the thickness of the negative active material layer is H ⁇ m, and the weight of the negative active material layer per unit area is C g/cm 2 , where 0.003 ⁇ C ⁇ 0.01 and 1.0 ⁇ 10 4 ⁇ C/H ⁇ 1.7.
  • SA is inversely proportional to the thickness of the active material. Generally speaking, the smaller the active material layer H is, the larger the SA is. In response to electrical properties, the insertion or detachment of active metal ions is accelerated and is less likely to precipitate. However, the thickness of the active material layer is too small.
  • controlling the thickness of the active material layer and the weight of the negative active material layer per unit area within the above range is beneficial to controlling the insertion and extraction speed of active metal ions, improving the gram capacity of the negative active material and improving the kinetics of the electrochemical device. performance and cycle performance.
  • the negative active material layer satisfies 10 ⁇ S004/S110 ⁇ 25, where S004 is the peak area value of the 004 peak in the XRD pattern of the negative active material layer, and S110 is the peak area value of the 004 peak in the XRD pattern of the negative active material layer.
  • the peak area value of the 110 peak is a range consisting of 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, or any two of these values.
  • the ratio of S004/S110 is related to the particle size of the negative active material. When the particle size of the negative active material decreases, the ratio of S004/S110 decreases accordingly.
  • the internal resistance of the active metal ions embedded/extracted from the negative active material is smaller. And it can reduce the precipitation of active metal ions, reduce the internal resistance of the electrochemical device and improve the capacity retention rate of the electrochemical device under high-rate charge and discharge conditions.
  • the electrochemical device has a lower With internal resistance and high capacity retention rate during high-rate charge and discharge, the electrochemical device has excellent kinetic performance and cycle performance.
  • the negative active material includes natural graphite.
  • the negative active material has a specific surface area (BET) of 2g/cm 2 to 5g/cm 2 , such as 2g/cm 2 , 2.5g/cm 2 , 3/cm 2 , 3.5g/cm 2 , 4g /cm 2 , 4.5g/cm 2 or a range consisting of any two of these values.
  • the negative active material has a gram capacity of 360 to 370 mAh/g.
  • the particle size of the negative active material satisfies 1 ⁇ m ⁇ Dv10 ⁇ 10 ⁇ m, 3 ⁇ m ⁇ Dv50 ⁇ 18 ⁇ m, and 8 ⁇ m ⁇ Dv90 ⁇ 35 ⁇ m.
  • Dv10 means that in the volume-based particle size distribution of the negative active material, 10% of the particles have a particle size smaller than this value.
  • Dv50 indicates that in the volume-based particle size distribution of the negative active material, 50% of the particles have a particle size smaller than this value.
  • Dv90 means that in the volume-based particle size distribution of the negative active material, 90% of the particles have a particle size smaller than this value.
  • Dv10 is a range consisting of 2 ⁇ m, 3 ⁇ m, 4 ⁇ m, 5 ⁇ m, 6 ⁇ m, 7 ⁇ m, 8 ⁇ m, 9 ⁇ m, or any two of these values.
  • Dv50 is a range consisting of 4 ⁇ m, 5 ⁇ m, 6 ⁇ m, 7 ⁇ m, 8 ⁇ m, 9 ⁇ m, 10 ⁇ m, 11 ⁇ m, 12 ⁇ m, 13 ⁇ m, 14 ⁇ m, 15 ⁇ m, 16 ⁇ m, 17 ⁇ m, or any two of these values.
  • Dv90 is a range consisting of 10 ⁇ m, 12 ⁇ m, 14 ⁇ m, 16 ⁇ m, 18 ⁇ m, 20 ⁇ m, 22 ⁇ m, 24 ⁇ m, 26 ⁇ m, 28 ⁇ m, 30 ⁇ m, 32 ⁇ m, 34 ⁇ m, or any two of these values.
  • the ratio of S004/S110 will also decrease accordingly.
  • the internal resistance of the active metal ions embedded/extracted from the negative active material is smaller, and the precipitation of active metal ions is reduced, which can reduce the electrochemical device.
  • the particle size of the negative active material is too small, the specific surface area of the negative active material will be larger, and the contact area with the electrolyte will increase, which can easily cause contact with the electrolyte.
  • the side reactions among the electrochemical devices will reduce the first efficiency of the electrochemical device during the first deintercalation of active metal ions, so it needs to be controlled within a certain range to ensure that the electrochemical device has optimal performance.
  • the electrochemical device of the present application also includes a positive electrode.
  • the positive electrode includes a positive electrode current collector and a positive electrode active material layer.
  • the positive electrode active material layer includes a positive electrode active material, a binder and a conductive agent.
  • the positive electrode current collector may be a metal foil or a composite current collector.
  • aluminum foil can be used.
  • the composite current collector can be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, silver alloy, etc.) on a polymer substrate.
  • the positive active material includes lithium cobalt oxide, lithium nickel manganese cobalt oxide, lithium nickel manganese aluminate, lithium iron phosphate, lithium vanadium phosphate, lithium cobalt phosphate, lithium manganese phosphate, lithium iron manganese phosphate, silicon At least one of lithium iron oxide, lithium vanadium silicate, lithium cobalt silicate, lithium manganese silicate, spinel type lithium manganate, spinel type lithium nickel manganate and lithium titanate.
  • the binder includes a binder polymer such as polyvinylidene fluoride, polytetrafluoroethylene, polyolefins, sodium carboxymethylcellulose, lithium carboxymethylcellulose, modified polyvinylidene fluoride At least one of ethylene, modified SBR rubber or polyurethane.
  • the polyolefin binder includes at least one of polyethylene, polypropylene, polyolefin ester, polyvinyl alcohol, or polyacrylic acid.
  • the conductive agent includes carbon-based materials, such as natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black or carbon fiber; metal-based materials, such as metal powder or metal of copper, nickel, aluminum, silver, etc. Fibers; conductive polymers, such as polyphenylene derivatives; or mixtures thereof.
  • the electrochemical device of the present application also includes an isolation membrane.
  • the material and shape of the isolation membrane used in the electrochemical device of the present application are not particularly limited, and it can be any technology disclosed in the prior art.
  • the isolation membrane includes polymers or inorganic substances formed of materials that are stable to the electrolyte of the present application.
  • the isolation film may include a base material layer and a surface treatment layer.
  • the base material layer is a non-woven fabric, film or composite film with a porous structure.
  • the base material layer is made of at least one material selected from the group consisting of polyethylene, polypropylene, polyethylene terephthalate and polyimide.
  • polypropylene porous membrane, polyethylene porous membrane, polypropylene non-woven fabric, polyethylene non-woven fabric or polypropylene-polyethylene-polypropylene porous composite membrane can be used.
  • a surface treatment layer is provided on at least one surface of the base layer.
  • the surface treatment layer may be a polymer layer or an inorganic layer, or may be a layer formed by mixing a polymer and an inorganic layer.
  • the inorganic layer includes inorganic particles and a binder.
  • the inorganic particles are selected from aluminum oxide, silicon oxide, magnesium oxide, titanium oxide, hafnium dioxide, tin oxide, ceria, nickel oxide, zinc oxide, calcium oxide, zirconium oxide, At least one of yttrium oxide, silicon carbide, boehmite, aluminum hydroxide, magnesium hydroxide, calcium hydroxide and barium sulfate.
  • the binder is selected from polyvinylidene fluoride, vinylidene fluoride-hexafluoropropylene copolymer, polyamide, polyacrylonitrile, polyacrylate, polyacrylic acid, polyacrylate, polyvinylpyrrolidone, polyethylene alkoxy , at least one of polymethylmethacrylate, polytetrafluoroethylene and polyhexafluoropropylene.
  • the polymer layer contains a polymer, and the material of the polymer is selected from polyamide, polyacrylonitrile, acrylate polymer, polyacrylic acid, polyacrylate, polyvinylpyrrolidone, polyethylene alkoxy, polyvinylidene fluoride, At least one of poly(vinylidene fluoride-hexafluoropropylene).
  • the electrochemical device of the present application also includes an electrolyte. Electrolytes useful in this application may be electrolytes known in the art.
  • the electrolyte solution includes an organic solvent, a lithium salt, and optional additives.
  • the organic solvent in the electrolyte solution of the present application can be any organic solvent known in the prior art that can be used as a solvent for the electrolyte solution.
  • the electrolyte used in the electrolyte solution according to the present application is not limited, and it can be any electrolyte known in the prior art.
  • the additives of the electrolyte according to the present application may be any additives known in the art that can be used as electrolyte additives.
  • organic solvents include, but are not limited to: ethylene carbonate (EC), propylene carbonate (PC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), dimethyl carbonate (DMC) ), propylene carbonate or ethyl propionate.
  • the organic solvent includes ether solvents, such as at least one of 1,3-dioxane (DOL) and ethylene glycol dimethyl ether (DME).
  • the lithium salt includes at least one of an organic lithium salt or an inorganic lithium salt.
  • lithium salts include, but are not limited to: lithium hexafluorophosphate (LiPF 6 ), lithium tetrafluoroborate (LiBF 4 ), lithium difluorophosphate (LiPO 2 F 2 ), lithium bistrifluoromethanesulfonimide LiN (CF 3 SO 2 ) 2 (LiTFSI), lithium bis(fluorosulfonyl)imide Li(N(SO 2 F) 2 )(LiFSI), lithium bisoxalatoborate LiB(C 2 O 4 ) 2 (LiBOB) or Lithium difluorooxalate borate LiBF 2 (C 2 O 4 ) (LiDFOB).
  • the additive includes at least one of fluoroethylene carbonate and adiponitrile.
  • the electrochemical device of the present application includes, but is not limited to: lithium-ion battery or sodium-ion battery. In some embodiments, the electrochemical device is a lithium-ion battery.
  • the present application further provides an electronic device, which includes the electrochemical device described in the first aspect of the present application.
  • electronic devices of the present application include, but are not limited to, notebook computers, pen-input computers, mobile computers, e-book players, portable telephones, portable fax machines, portable copiers, portable printers, and stereo headsets. , VCR, LCD TV, portable cleaner, portable CD player, mini CD, transceiver, electronic notepad, calculator, memory card, portable recorder, radio, backup power supply, motor, automobile, motorcycle, power-assisted bicycle, bicycle , lighting fixtures, toys, game consoles, clocks, power tools, flashlights, cameras, large household batteries and lithium-ion capacitors, etc.
  • the positive active material lithium cobalt oxide (molecular formula is LiCoO 2 ), the conductive agent acetylene black and the binder polyvinylidene fluoride (abbreviated as PVDF) are mixed in an appropriate amount of N-methylpyrrolidone (abbreviated as PVDF) in a weight ratio of 96:2:2. (NMP) solvent and mix thoroughly to form a uniform positive electrode slurry; apply this slurry on the current collector aluminum foil, dry, cold press, cut into pieces, and weld the tabs to obtain the positive electrode.
  • NMP N-methylpyrrolidone
  • Preparation of negative active material select natural graphite ore, conduct crushing/ball milling and flotation to obtain natural flake graphite, crush the natural flake graphite, preferably a powder with a particle size Dv50 of 3 ⁇ m to 18 ⁇ m, and then perform spheroidization to obtain A material.
  • Material A is mixed with a certain amount of coating agent in a mixing ratio of 50:50 to 90:10. After mixing evenly, it is placed in a high-temperature carbonization furnace and calcined at 1150°C for 4 hours to obtain material B, which is the negative electrode activity used in the experiment.
  • the coating agent is a mixture of 50% to 90% solvent and 10% to 50% carbon material, wherein the solvent includes toluene, ethanol, quinoline or ether, and the carbon material includes carbon nanotubes or graphite ene.
  • the negative active material the binder styrene-butadiene rubber (abbreviated as SBR) and the thickener sodium carboxymethyl cellulose (abbreviated as MMC) in a deionized water solvent at a weight ratio of 95:2:3. It forms a uniform negative electrode slurry; apply this slurry on the current collector copper foil pre-coated with an undercoat (carbon black). The thickness of the undercoat is 1.5 ⁇ m. Dry and use different roller pressures. The coated negative electrode is cold pressed, cut into pieces, and welded.
  • SBR binder styrene-butadiene rubber
  • MMC thickener sodium carboxymethyl cellulose
  • the corresponding peaks and peak area values in the XRD spectrum of the active material layer were adjusted by adjusting the pulverized particle size and the type and content of the coating agent.
  • a polyethylene porous polymer film with a thickness of 7 ⁇ m was used as the isolation membrane.
  • Test method for (002,101,A) crystal plane diffraction peak (hereinafter referred to as "002 peak, 101 peak, A peak"): Use X-ray powder diffractometer (XRD, instrument model: Bruker D8ADVANCE) to test the negative active material layer to obtain XRD Test curve, in which the target material is Cu K ⁇ , the voltage/current is 40KV/40mA, the scanning angle range is 5° to 80°, the scanning step is 0.00836°, and the time of each step is 0.3s.
  • XRD X-ray powder diffractometer
  • the A peak is located at the diffraction angle 2 ⁇ in the range of 42.4°-43.6°
  • the 002 peak is located in the diffraction angle 2 ⁇ in the range of 25.0°-27.0°
  • the 101 peak is located in the diffraction angle 2 ⁇ in the range of 43.6°-46.6°.
  • S002, S101 and SA are the peak area values of each peak obtained by integrating the 002 peak, 101 peak and A peak respectively.
  • Test method for S004/S110 Test the (004) plane diffraction pattern and (110) plane diffraction line pattern.
  • the test conditions are as follows: X-rays use CuK ⁇ radiation, and the CuK ⁇ radiation is removed by a filter or monochromator.
  • the working voltage of the X-ray tube is (30-35) kV, and the working current is (15-20) mA.
  • the scanning speed of the counter is 1/4(°)/min.
  • the diffraction peak of the (004) plane (the 004 peak in the XRD pattern of the negative active material layer) is located in the range of the diffraction angle 2 ⁇ of 52°-57°, and the diffraction peak of the (110) plane (the XRD pattern of the extremely active material layer)
  • the middle 110 peak is located in the diffraction angle 2 ⁇ in the range of 75°-80°.
  • the peak area value of the 004 peak is recorded as S004, and the peak area value of the 110 peak is recorded as C110, thereby calculating the S004/C110 ratio of the negative active material layer.
  • the peak area values of the 002 peak, 101 peak, A peak, 110 peak and 004 peak in the XRD pattern of the negative active material layer represent the value of each peak area calculated based on the XRD pattern.
  • the negative active material layer Take a certain amount of the negative active material layer, use an organic solvent to dissolve and remove the binder and thickener, and dry to obtain the negative active material powder. Take 1g of the negative active material powder and dissolve it into the dispersant water. Ultrasonic for 5 minutes. The ultrasonic intensity is 53KHz, and then inject the mixed suspension into the Malvern 3000 testing equipment. Each sample is tested three times, and the average value of the test is taken to obtain the values of Dv10, Dv50 and Dv90.
  • ICP-OES Inductively coupled plasma optical emission spectrometer
  • button battery Use the negative active material prepared in the above embodiment to prepare the positive electrode, and assemble the prepared positive electrode, lithium sheet, separator, electrolyte, steel sheet, foam nickel and button battery shell together Obtain the button battery and let it sit for 6 hours before testing.
  • Test process of button battery The assembled button battery is placed on the blue battery tester for testing. The test process is to discharge at 0.05C to the lower limit voltage of 5mV, the upper limit voltage of 2.0V, constant voltage discharge to 50 ⁇ A, and let stand. 5min, charge to the upper limit voltage of 2.0V at 0.1C, let it stand for 5min, record the gram capacity at this time as the gram capacity of the negative active material.
  • the test method for specific surface area refers to GB/T 19587-2017. Take a certain amount of the negative active material layer, use an organic solvent to dissolve and remove the binder and thickener, and obtain the negative active material powder after drying.
  • the specific process is to weigh the negative active material. 1g to 8g (weigh the sample to cover at least 1/3 of the sphere volume) and place it in a 1/2 inch long tube with a bulb (the tube diameter of the sphere part is 12mm). Pre-process at 200°C for 2 hours and then place it in the testing equipment TriStar3030. (American Mike Company), the adsorbed gas used was N 2 (purity: 99.999%), the test conditions were carried out at 77K, and the specific surface area was calculated through the BET calculation method.
  • Judgment of the degree of lithium evolution Judgment based on the state of the negative electrode piece obtained by dismantling the battery after a full charge.
  • the negative electrode piece appears golden yellow as a whole and the area shown as gray is ⁇ 2%, it is judged as no lithium precipitation; when the negative electrode piece Most of the sheet is golden yellow, but gray can be observed in some places. If the gray area is between 2% and 20%, it is judged as slight lithium precipitation; when the negative electrode sheet is gray, some golden yellow can still be observed. , the gray area is between 20% and 60%, it is judged to be lithium precipitation; when most of the negative electrode piece appears gray, and the gray area is >60%, it is judged to be severe lithium precipitation.
  • the DCR mentioned in this application refers to the DC resistance of the lithium-ion battery at 10% state of charge (SOC).
  • EIS test steps Connect the lithium-plated three-electrode battery to the Bio-Logic VMP3B electrochemical workstation produced by the French company Biolog for testing.
  • the frequency range for the test is 30mHz to 50kHz, and the amplitude is 5mV.
  • After collecting the data The data were analyzed using the impedance complex plane diagram to obtain the Rct data.
  • PPG test uses the PPG soft pack battery thickness gauge (manufactured by Shenzhen Aotomei Automation Technology Co., Ltd.) for automatic detection. The test process is to place the battery on the lower panel of the instrument for testing. During the test process, the upper cover lowers at a constant speed. The battery thickness PPGx is measured through pressure sensing, and the mark x corresponds to the number of cycles of the cycle test.
  • MMC test uses a micrometer tester (manufactured by Mitutoyo, Japan, model: MDC-25SX) to measure the thickness of the positive electrode tab of the battery. Measure three points (MMCax, MMCbx, MMCcx). The letters a, b, and c correspond to different tests. Position, the subscript
  • 2C discharge capacity retention rate 2C discharge capacity/0.1C discharge capacity ⁇ 100%.
  • the half-width of the A peak in each example and comparative example in Table 1 is 0.1°, and the half-width of the 101 peak is 0.3°; the thickness of the negative active material layer is 30 ⁇ m, and the negative active material layer per unit area The weight is 0.003g/cm 2 .
  • Example 1-12 when the negative active material layer satisfies 0.1 ⁇ SA/S002 ⁇ 0.3, the gram capacity of the lithium-ion battery can be significantly increased, the cycle expansion rate at 200 cycles and the DC current at 0°C can be significantly reduced. resistance value.
  • the decrease in the cycle expansion rate at 200 cycles indicates that the lithium-ion battery has improved cycle performance, and the decrease in the DC resistance value at 0°C indicates that the lithium-ion battery has improved kinetic properties. Therefore, the lithium-ion batteries of Examples 1-12 have improved cycle performance, kinetic performance, and high gram capacity.
  • the negative active material layer satisfies 7000 ⁇ SA ⁇ 9000 and/or 25000 ⁇ S002 ⁇ 90000, the lithium-ion battery has better overall performance.
  • the SA/S002 ratio in Comparative Example 1 is higher than 0.3.
  • the lithium-ion battery has a lower gram capacity, a higher cycle expansion rate at 200 cycles, and a higher 0°C DCR value; the SA/S002 ratio in Comparative Example 2 Below 0.1, although lithium-ion batteries have higher passenger capacity, the cycle expansion rate is very high at 200 cycles and the 0°C DCR value is high.
  • Examples 26 to 39 describe the relationship between the particle size distribution, BET, and the S004/S110 ratio of the negative active material layer and battery performance.
  • Table 3 when the lithium-ion battery meets: 1 ⁇ m ⁇ Dv10 ⁇ 10 ⁇ m, 3 ⁇ m ⁇ Dv50 ⁇ 18 ⁇ m, 8 ⁇ m ⁇ Dv90 ⁇ 35 ⁇ m, the chromium content is 0.008%-0.02%, the niobium content is 0.005%-0.009%, When the sulfur content is 0.001%-0.006% and/or 10 ⁇ S004/S110 ⁇ 25, it helps to further improve the DC resistance of the lithium-ion battery at 25°C, the separation of the negative electrode plate and the high rate (2C ) discharge capacity retention rate, further improving the cycle performance and dynamic performance of lithium-ion batteries.

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Abstract

提供一种电化学装置，该电化学装置包括负极，负极包括负极集流体和负极活性材料层，负极活性材料层包括负极活性材料，其中，负极活性材料层满足0.1≤SA/S002≤0.3，SA为负极活性材料层的XRD图谱中2θ在42.4°至43.6°范围内的A峰的峰面积值，S002为负极活性材料层的XRD图谱中002峰的峰面积值。本申请的电化学装置在具有高克容量的同时，兼具优异的循环性能及动力学性能。还提供包括该电化学装置的电子装置。

Description

电化学装置和电子装置 技术领域
本申请涉及储能领域，具体涉及一种电化学装置和电子装置。
背景技术
电化学装置如锂离子电池凭借其具有能量密度高、安全性高、无记忆效应和工作寿命长等突出的优点已经在市场上占据主流地位。随着消费电子类的产品如笔记本电脑、手机、平板电脑、移动电源和无人机等的普及，对其中的电化学装置的要求越来越严格。例如，不仅要求电池轻便，而且还要求电池拥有高容量和较长的工作寿命。
以锂离子电池为例，常使用具有较高克容量的天然石墨作为负极材料，但天然石墨的大片层多孔结构使其难以兼具优异的循环性能及动力学性能，限制了天然石墨在高性能的电化学装置中的应用。
发明内容
针对现有技术的不足，本申请提供了一种电化学装置及包括该电化学装置的电子装置。本申请的电化学装置在具有高克容量的同时，兼具优异的循环性能及动力学性能。
在第一方面，本申请提供一种电化学装置，其包括负极，该负极包括负极集流体和负极活性材料层，负极活性材料层包括负极活性材料，其中，负极活性材料层满足0.1≤SA/S002≤0.3，SA为负极活性材料层的XRD图谱中2θ在42.4°至43.6°范围内的A峰的峰面积值，S002为负极活性材料层的XRD图谱中002峰的峰面积值。负极活性材料层A峰的峰面积值SA与活性材料层的厚度呈负相关关系，SA越大，说明负极活性材料层厚度越小，活性金属离子如锂离子越容易在负极活性材料层中嵌入和脱出，但电化学装置的能量密度会降低。负极活性材料层002峰的峰面积值S002与负极活性材料的可嵌入活性金属离子如锂离子的量相关，S002越大，可嵌活性金属离子的量越大，有利于提高电化学装置的能量密度，但是S002过大时，电化学装置的变形会增大。本申请的发明人经过广泛研究后发现，将SA/S002控制在上述范围内时，既能保证电化学装置的能量密度，又能确保活性金属离子在活性材料中正常脱嵌，电化学装置在具有高克容量的同时， 兼具优异的循环性能及动力学性能。
根据本申请的一些实施方式，7000≤SA≤9000。根据本申请的一些实施方式，25000≤S002≤90000。本申请中，SA值为当电化学装置处于满放状态时，负极活性材料层的XRD图谱A峰的峰面积值。S002值为当电化学装置处于满放状态时，负极活性材料层的XRD图谱中的002峰的峰面积值。
根据本申请的一些实施方式，A峰的半峰宽为0.1°至0.5°。A峰的半峰宽反馈的是活性材料层厚度，半峰宽越窄，代表活性材料层厚度较小，有利于活性材料层嵌入活性金属离子，提升电化学装置的动力学性能。
根据本申请的一些实施方式，负极活性材料层的XRD图谱中，2θ在43.6°至46.6°范围内有101峰，其中0.015≤S101/S002≤0.035，S101为101峰的峰面积值。
根据本申请的一些实施方式，101峰的半峰宽为0.3°至0.8°。101峰与活性材料的可嵌活性金属离子的量相关，101峰的峰强越大，半峰宽越窄，其可嵌活性金属离子的量则越大，因此将101峰的峰强和半峰宽控制在一定的范围内可有利于得到具有高嵌活性金属离子的量的负极活性材料，活性材料克容量提高。
根据本申请的一些实施方式，负极集流体为铜箔。
根据本申请的一些实施方式，负极集流体包含铬元素，基于负极集流体的质量，铬元素含量为0.008％至0.020％。根据本申请的一些实施方式，负极集流体包含铌元素，基于负极集流体的质量，铌元素含量为0.005％至0.009％。根据本申请的一些实施方式，负极集流体包含硫元素，基于负极集流体的质量，硫元素含量为0.001％至0.006％。控制集流体中微量元素的含量可有利于负极活性材料在脱嵌活性金属离子过程中的延展，进而抑制电化学装置的变形，提升电化学装置的动力学性能和循环性能。
根据本申请的一些实施方式，负极活性材料层的厚度为Hμm，其中，87≤SA/H≤300。在一些实施方式中，负极活性材料层的厚度为Hμm，单位面积负极活性材料层的重量为C g/cm 2，其中，0.003≤C≤0.01，1.0≤10 4×C/H≤1.7。SA与活性材料的厚度呈反比，一般情况下，活性材料层H越小，SA越大，反应到电性能为嵌活性金属离子速度加快，不容易析锂。但活性材料层的厚度过小，在相同的活性材料层重量下(C g/cm 2相同)，施加在极片上的压力越大，活性金属离子更难嵌入到活性材料层中，电化学装置的内阻较大。因此控制活性材料层的厚度与单位面积负极活性材料层的重量在上述范围内，有利于控制活性金属离子的嵌入和脱出速度，提高负极活性材料的克容量及提升电化学装置的循环性能和动力学性能。
根据本申请的一些实施方式，负极活性材料层满足10≤S004/S110≤25，其中，S004为负极活性材料层的XRD图谱中004峰的峰面积值，S110为负极活性材料层的XRD图谱中110峰的峰面积值。S004/S110的比值在上述范围内时，活性金属离子嵌入/脱出负极活性材料的内阻较小，且可以减少活性金属离子析出，能够提升电化学装置的循环性能和动力学性能。
根据本申请的一些实施方式，负极活性材料包含天然石墨。在一些实施方式中，负极活性材料的比表面积(BET)为2g/cm 2至5g/cm 2；在一些实施方式中，负极活性材料的克容量为360mAh/g至370mAh/g。
在一些实施方式中，负极活性材料的粒径满足1μm≤Dv10≤10μm，3μm≤Dv50≤18μm，8μm≤Dv90≤35μm。负极活性材料的粒径分布在上述范围内时，可保证活性金属离子嵌入/脱出负极活性材料的内阻较小，活性金属离子析出减少，同时可减少与电解液间的副反应，保证电化学装置具有较优的循环性能和动力学性能。
在第二方面，本申请提供了一种电子装置，其包括第一方面的电化学装置。
本申请提供的电化学装置的负极包括特定的负极活性材料层，使得电化学装置在具有高容量的同时，兼具优异的循环性能及动力学性能。
具体实施方式
下面结合具体实施方式，进一步阐述本申请。应理解，这些具体实施方式仅用于说明本申请而不用于限制本申请的范围。
一、电化学装置
在第一方面，本申请提供一种电化学装置，其包括负极，该负极包括负极集流体和负极活性材料层，负极活性材料层包括负极活性材料，其中，负极活性材料层满足0.1≤SA/S002≤0.3，SA为负极活性材料层的XRD图谱中2θ在42.4°至43.6°范围内的A峰的峰面积值，S002为负极活性材料层的XRD图谱中002峰的峰面积值。
本申请中，负极活性材料层的XRD图谱中2θ在25.0°至27.0°范围内的特征峰为002峰。
在一些实施方式中，SA/S002为0.11、0.12、0.13、0.14、0.15、0.16、0.17、0.18、0.19、0.2、0.21、0.22、0.23、0.24、0.25、0.26、0.27、0.28、0.29或这些值中任意两者组成的范围。负极活性材料层A峰的峰面积值SA与活性材料层的厚度呈负相关关系，SA 越大，负极活性材料层厚度越小，活性金属离子越容易在负极活性材料层中嵌入和脱出，但电化学装置的能量密度会降低。负极活性材料层002峰的峰面积值S002与负极活性材料的可嵌活性金属离子如锂离子的量相关，S002越大，可嵌入活性金属离子的量越大，负极活性材料的克容量越大，有利于提高电化学装置的能量密度，但是S002过大时，电化学装置的变形率增加，影响其动力学性能。本申请的发明人经过广泛研究后发现，将SA/S002控制在上述范围内时，既能保证电化学装置的能量密度，又能确保活性金属离子在活性材料中正常脱嵌，电化学装置在具有高克容量的同时，兼具优异的循环性能及动力学性能。
根据本申请的一些实施方式，7000≤SA≤9000。在一些实施方式中，SA为7100、7300、7500、7700、7900、8000、8100、8300、8500、8700、8900或这些值中任意两者组成的范围。根据本申请的一些实施方式，25000≤S002≤90000。在一些实施方式中，S002为27000、30000、34000、40000、45000、50000、55000、60000、65000、70000、75000、80000、85000或这些值中任意两者组成的范围。本申请中，SA值为当电化学装置处于满放状态时，负极活性材料层的XRD图谱A峰的峰面积值。S002值为当电化学装置处于满放状态时，负极活性材料层的XRD图谱中的002峰的峰面积值。
根据本申请的一些实施方式，A峰的半峰宽为0.1°至0.5°。在一些实施方式中，A峰的半峰宽为0.15°、0.17°、0.2°、0.23°、0.25°、0.27°、0.3°、0.33°、0.35°、0.37°、0.4°、0.43°、0.45°、0.47°或这些值中任意两者组成的范围。A峰的半峰宽反馈的是活性材料层厚度，半峰宽越窄，活性材料层厚度较小，有利于活性材料层嵌入活性金属离子，有利于提升电化学装置的动力学性能和循环性能。
根据本申请的一些实施方式，负极活性材料层的XRD图谱中，2θ在43.6°至46.6°范围内有101峰，其中，0.015≤S101/S002≤0.035，S101为101峰的峰面积值。在一些实施方式中，S101/S002为0.017、0.019、0.02、0.021、0.023、0.025、0.027、0.029、0.030、0.031、0.033或这些值中任意两者组成的范围。
根据本申请的一些实施方式，101峰的半峰宽为0.3°至0.8°。在一些实施方式中，101峰的半峰宽为0.35°、0.37°、0.4°、0.43°、0.45°、0.47°、0.5°、0.53°、0.55°、0.57°、0.6°、0.63°、0.65°、0.67°、0.7°、0.73°、0.75°、0.77°或这些值中任意两者组成的范围。7101峰与活性材料的可嵌入活性金属离子的量相关，101峰的峰强越大，半峰宽越窄，其可嵌入活性金属离子的量则越大，因此将101峰的峰强和半峰宽控制在一定的范围内可有利于得到具有高嵌活性金属离子的量的负极活性材料，负极活性材料具有较高的克容量。
根据本申请的一些实施方式，负极集流体为铜箔。
根据本申请的一些实施方式，负极集流体包含铬元素，基于负极集流体的质量，铬元素含量为0.008％至0.020％，例如为0.009％、0.01％、0.011％、0.012％、0.012％、0.014％、0.015％、0.016％、0.017％、0.018％、0.019％或这些值中任意两者组成的范围。根据本申请的一些实施方式，负极集流体包含铌元素，基于负极集流体的质量，铌元素含量为0.005％至0.009％，例如为0.0055％、0.06％、0.065％、0.07％、0.075％、0.08％、0.085％、或这些值中任意两者组成的范围。根据本申请的一些实施方式，负极集流体包含硫元素，基于负极集流体的质量，硫元素含量为0.001％至0.006％，如为0.0015％、0.02％、0.0025％、0.003％、0.0035％、0.004％、0.0045％、0.005％、0.0055％或这些值中任意两者组成的范围。控制集流体中微量元素的含量可有利于负极活性材料在脱嵌锂过程中的延展，进而抑制电化学装置的变形，提升电化学装置的动力学性能和循环性能。
根据本申请的一些实施方式，负极活性材料层的厚度为Hμm，其中，87≤SA/H≤300。在一些实施方式中，负极活性材料层的厚度为Hμm，单位面积负极活性材料层的重量为C g/cm 2，其中，0.003≤C≤0.01，1.0≤10 4×C/H≤1.7。SA与活性材料的厚度呈反比，一般情况下，活性材料层H越小，SA越大，反应到电性能则是活性金属离子嵌入或脱出速度加快，不容易析出。但活性材料层的厚度过小，在相同的活性材料层重量下(C g/cm 2相同)，施加在极片上的压力越大，活性金属离子如锂离子更难嵌入到活性材料层中，嵌入内阻增大。因此控制活性材料层的厚度与单位面积负极活性材料层的重量在上述范围内，有利于控制活性金属离子的嵌入和脱出速度，有利于提高负极活性材料的克容量及提升电化学装置的动力学性能和循环性能。
根据本申请的一些实施方式，负极活性材料层满足10≤S004/S110≤25，其中，S004为负极活性材料层的XRD图谱中004峰的峰面积值，S110为负极活性材料层的XRD图谱中110峰的峰面积值。在一些实施方式中，S004/S110为11、12、13、14、15、16、17、18、19、20、21、22、23、24或这些值中任意两者组成的范围。S004/S110的比值与负极活性材料的粒径相关，当负极活性材料的粒径减小时，S004/S110的比值相应减小，此时活性金属离子嵌入/脱出负极活性材料的内阻较小，且可以减少活性金属离子析出，能够降低电化学装置的内阻和提高电化学装置在大倍率充放电条件下的容量保持率，当S004/S110的比值满足上述范围时，电化学装置具有较低内阻和较高的大倍率充放电时的容量保持率，电化学装置具有较优的动力学性能和循环性能。
根据本申请的一些实施方式，负极活性材料包含天然石墨。在一些实施方式中，负极 活性材料的比表面积(BET)为2g/cm 2至5g/cm 2，例如2g/cm 2、2.5g/cm 2、3/cm 2、3.5g/cm 2、4g/cm 2、4.5g/cm 2或这些值中任意两者组成的范围。在一些实施方式中，负极活性材料的克容量为360mAh/g至370mAh/g。
在一些实施方式中，负极活性材料的粒径满足1μm≤Dv10≤10μm，3μm≤Dv50≤18μm，8μm≤Dv90≤35μm。本申请中，Dv10表示负极活性材料在体积基准的粒度分布中，10％的颗粒粒径小于该值。Dv50表示负极活性材料在体积基准的粒度分布中，50％的颗粒粒径小于该值。Dv90表示负极活性材料在体积基准的粒度分布中，90％的颗粒粒径小于该值。
在一些实施方式中，Dv10为2μm、3μm、4μm、5μm、6μm、7μm、8μm、9μm或这些值中任意两者组成的范围。在一些实施方式中，Dv50为4μm、5μm、6μm、7μm、8μm、9μm、10μm、11μm、12μm、13μm、14μm、15μm、16μm、17μm或这些值中任意两者组成的范围。在一些实施方式中，Dv90为10μm、12μm、14μm、16μm、18μm、20μm、22μm、24μm、26μm、28μm、30μm、32μm、34μm或这些值中任意两者组成的范围。随着负极活性材料粒径减小，S004/S110的比值也会相应减小，此时活性金属离子嵌入/脱出负极活性材料的内阻较小，且活性金属离子析出减少，可降低电化学装置的内阻和提高电化学装置的大倍率充放电时的容量保持率；但负极活性材料粒径过小时，负极活性材料的比表面积偏大，与电解液的接触面积增多，易引发与电解液间的副反应，在首次脱嵌活性金属离子的过程中降低电化学装置的首效，故需要将其控制在一定的范围内，保证电化学装置具有较优性能。
本申请的电化学装置还包括正极，正极包括正极集流体和正极活性材料层，正极活性材料层包括正极活性材料、粘结剂和导电剂。
根据本申请的一些实施方式，正极集流体可以采用金属箔片或复合集流体。例如，可以使用铝箔。复合集流体可以通过将金属材料(铜、铜合金、镍、镍合金、钛、钛合金、银及银合金等)形成在高分子基材上而形成。
根据本申请的一些实施方式，正极活性材料包括钴酸锂、镍锰钴酸锂、镍锰铝酸锂、磷酸铁锂、磷酸钒锂、磷酸钴锂、磷酸锰锂、磷酸锰铁锂、硅酸铁锂、硅酸钒锂、硅酸钴锂、硅酸锰锂、尖晶石型锰酸锂、尖晶石型镍锰酸锂和钛酸锂中的至少一种。在一些实施例中，粘结剂包括粘合剂聚合物，例如聚偏氟乙烯、聚四氟乙烯、聚烯烃类、羧甲基纤维素钠、羧甲基纤维素锂、改性聚偏氟乙烯、改性SBR橡胶或聚氨酯中的至少一种。在一些实施例中，聚烯烃类粘结剂包括聚乙烯、聚丙烯、聚烯酯、聚烯醇或聚丙烯酸中的至少 一种。在一些实施例中，导电剂包括碳基材料，例如天然石墨、人造石墨、炭黑、乙炔黑、科琴黑或碳纤维；金属基材料，例如铜、镍、铝、银等的金属粉或金属纤维；导电聚合物，例如聚亚苯基衍生物；或它们的混合物。
本申请的电化学装置还包括隔离膜，本申请的电化学装置中使用的隔离膜的材料和形状没有特别限制，其可为任何现有技术中公开的技术。在一些实施例中，隔离膜包括由对本申请的电解液稳定的材料形成的聚合物或无机物等。
例如隔离膜可包括基材层和表面处理层。基材层为具有多孔结构的无纺布、膜或复合膜，基材层的材料选自聚乙烯、聚丙烯、聚对苯二甲酸乙二醇酯和聚酰亚胺中的至少一种。具体的，可选用聚丙烯多孔膜、聚乙烯多孔膜、聚丙烯无纺布、聚乙烯无纺布或聚丙烯-聚乙烯-聚丙烯多孔复合膜。
基材层的至少一个表面上设置有表面处理层，表面处理层可以是聚合物层或无机物层，也可以是混合聚合物与无机物所形成的层。无机物层包括无机颗粒和粘结剂，无机颗粒选自氧化铝、氧化硅、氧化镁、氧化钛、二氧化铪、氧化锡、二氧化铈、氧化镍、氧化锌、氧化钙、氧化锆、氧化钇、碳化硅、勃姆石、氢氧化铝、氢氧化镁、氢氧化钙和硫酸钡中的至少一种。粘结剂选自聚偏氟乙烯、偏氟乙烯-六氟丙烯的共聚物、聚酰胺、聚丙烯腈、聚丙烯酸酯、聚丙烯酸、聚丙烯酸盐、聚乙烯呲咯烷酮、聚乙烯烷氧、聚甲基丙烯酸甲酯、聚四氟乙烯和聚六氟丙烯中的至少一种。聚合物层中包含聚合物，聚合物的材料选自聚酰胺、聚丙烯腈、丙烯酸酯聚合物、聚丙烯酸、聚丙烯酸盐、聚乙烯呲咯烷酮、聚乙烯烷氧、聚偏氟乙烯、聚(偏氟乙烯-六氟丙烯)中的至少一种。
本申请的电化学装置还包括电解液。可用于本申请的电解液可以为现有技术中已知的电解液。
根据本申请的一些实施方式，电解液包括有机溶剂、锂盐和可选的添加剂。本申请的电解液中的有机溶剂可为现有技术中已知的任何可作为电解液的溶剂的有机溶剂。根据本申请的电解液中使用的电解质没有限制，其可为现有技术中已知的任何电解质。根据本申请的电解液的添加剂可为现有技术中已知的任何可作为电解液添加剂的添加剂。在一些实施例中，有机溶剂包括，但不限于：碳酸乙烯酯(EC)、碳酸丙烯酯(PC)、碳酸二乙酯(DEC)、碳酸甲乙酯(EMC)、碳酸二甲酯(DMC)、碳酸亚丙酯或丙酸乙酯。在一些实施例中，有机溶剂包括醚类溶剂，例如包括1，3-二氧五环(DOL)和乙二醇二甲醚(DME)中的至少一种。在一些实施例中，锂盐包括有机锂盐或无机锂盐中的至少一种。在一些实施例中，锂盐包括，但不限于：六氟磷酸锂(LiPF 6)、四氟硼酸锂(LiBF 4)、 二氟磷酸锂(LiPO 2F 2)、双三氟甲烷磺酰亚胺锂LiN(CF 3SO 2) 2(LiTFSI)、双(氟磺酰)亚胺锂Li(N(SO 2F) 2)(LiFSI)、双草酸硼酸锂LiB(C 2O 4) 2(LiBOB)或二氟草酸硼酸锂LiBF 2(C 2O 4)(LiDFOB)。在一些实施例中，添加剂包括氟代碳酸乙烯酯和己二腈中的至少一种。
根据本申请的一些实施方式，本申请的电化学装置包括，但不限于：锂离子电池或钠离子电池。在一些实施例中，电化学装置是锂离子电池。
二、电子装置
本申请进一步提供了一种电子装置，其包括本申请第一方面所述的电化学装置。
本申请的电子设备或装置没有特别限定。在一些实施例中，本申请的电子设备包括但不限于，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。
在下述实施例及对比例中，所使用到的试剂、材料以及仪器如没有特殊的说明，均可商购获得。
实施例及对比例
正极的制备
将正极活性材料钴酸锂(分子式为LiCoO 2)、导电剂乙炔黑和粘结剂聚偏二氟乙烯(简写为PVDF)按重量比96:2:2在适量的N-甲基吡咯烷酮(简写为NMP)溶剂中充分搅拌混合，使其形成均匀的正极浆料；将此浆料涂覆于集流体铝箔上，烘干、冷压、裁片、焊接极耳，得到正极。
负极的制备
负极活性材料的制备：选取天然石墨矿石，进行粉碎/球磨以及浮选，得到天然鳞片石墨，将天然鳞片石墨进行粉碎，优选粒径Dv50为3μm至18um的粉体，然后进行球形化处理，得到A料。A料与一定量的包覆剂混合，混合比例为50：50～90：10，混合均匀后置于高温碳化炉中1150℃煅烧4h，得到料B，料B即为实验中所用的负极活性材料石 墨，其中，包覆剂为由50％至90％的溶剂和10％至50％的碳材料的混合物，其中，溶剂包括甲苯、乙醇、喹啉或乙醚，碳材料包括碳纳米管或石墨烯。
将负极活性材料、粘结剂丁苯橡胶(简写为SBR)和增稠剂羧甲基纤维素钠(简写为ΜMC)按照重量比95:2:3在去离子水溶剂中充分搅拌混合，使其形成均匀的负极浆料；将此浆料涂覆于预先涂覆有底涂层(炭黑)的集流体铜箔上，底涂层的厚度为1.5μm，烘干、采用不同辊压压力对涂布好的负极进行冷压、裁片、焊接。
本申请的实施例及对比例中，通过调整粉碎的粒径以及包覆剂的种类和含量来调整活性材料层的XRD谱图中相应的峰值与峰面积值。
电解液的制备
在干燥氩气环境下，将碳酸乙烯酯(EC)，碳酸丙烯酯(PC)，碳酸二乙酯(DEC)(重量比1：1：1)混合均匀形成基础溶剂，向基础溶剂中加入干燥的锂盐LiPF 6混合均匀，再加入氟代碳酸乙烯酯和己二腈，混合均匀得到电解液，其中基于电解液的质量，氟代碳酸乙烯酯的质量含量为3％，己二腈的质量含量为2％，LiPF 6的质量含量为12.5％，其余为DEC。
隔离膜的制备
以厚度7μm的聚乙烯多孔聚合物薄膜作为隔离膜。
锂离子电池的制备
将正极、隔离膜和负极按顺序叠好，使隔离膜处于正极和负极中间，然后卷绕、置于外包装箔中，并注入上述制备好的电解液，经过真空封装、静置、化成、整形等工序，得到锂离子电池。
测试方法
1、X射线粉末衍射(XRD)测试
(002,101,A)晶面衍射峰(以下简称为“002峰,101峰,A峰”)的测试方法：采用X射线粉末衍射仪(XRD，仪器型号:Bruker D8ADVANCE)测试负极活性材料层得到XRD测试曲线，其中，靶材为Cu Kα，电压/电流为40KV/40mA，扫描角度范围为5°至80°，扫描步长为0.00836°，每步长时间为0.3s。其中，A峰位于衍射角2θ的范围为42.4°-43.6°处，002峰位于衍射角2θ的范围为25.0°-27.0°处，101峰位于衍射角2θ的范围为43.6°-46.6°处，S002、S101和SA为分别通过对002峰、101峰和A峰积分所得的各峰的峰面积值。
S004/S110的测试方法：按照中华人民共和国机械行业标准JB/T 4220-2011《人造石 墨的点阵参数测定方法》测试负极活性材料层的X射线衍射图谱中的(004)面衍射线图形和(110)面衍射线图形。试验条件如下：X射线采用CuKα辐射，CuKα辐射由滤波片或单色器除去。X射线管的工作电压为(30-35)kV，工作电流为(15-20)mA。计数器的扫描速度为1/4(°)/min。其中，(004)面的衍射峰(负极活性材料层的XRD图谱中004峰)位于衍射角2θ的范围为52°-57°处，(110)面的衍射峰(极活性材料层的XRD图谱中110峰)位于衍射角2θ的范围为75°-80°处。积分计算004峰的峰面积值记为S004，积分计算110峰的峰面积值记为C110，以此计算负极活性材料层的S004/C110的比值。
本申请中，负极活性材料层的XRD图谱中的002峰、101峰、A峰、110峰和004峰的峰面积值表示根据XRD图谱计算得到的各个峰面积的数值。
2、负极活性材料粒径测试
取一定量负极活性材料层，使用有机溶剂溶解除去粘结剂和增稠剂，干燥后得到负极活性物质粉末，取1g的负极活性物质粉末将其溶入分散剂水中，超声5min，超声强度为53KHz，然后将混合后的悬浮液注入马尔文3000测试设备中，每个样品测试三遍，取测试平均值得到Dv10，Dv50和Dv90的数值。
3、元素分析测试
称取负极空箔区的负极集流体铜箔0.5g，将负极集流体铜箔与10mL HNO 3溶液混合，采用微波消解的方式将集流体中的微量元素溶于溶液中，消解后的溶液引入ICP光源中。采用电感耦合等离子体发射光谱仪(ICP-OES)设备根据试样物质中气态原子被激发后其外层电子由激发态返回到基态时，辐射跃迁所发射的特征辐射能来检测不同物质含量。
4、克容量测试
(1)扣式电池的制备：使用上述实施例中制备的负极活性材料制备正极，将制备好的正极，锂片，隔离膜，电解液，钢片，泡沫镍以及扣式电池壳组装在一起得到扣式电池，测试前静置6h。
(2)扣式电池的测试流程：组装后的扣式电池置于蓝电测试仪上进行测试，测试流程为在0.05C放电至下限电压5mV，上限电压2.0V恒压放电至50μA，静置5min，在0.1C充电至上限电压2.0V，静置5min，记录此时克容量为负极活性材料的克容量。
5、BET测试
比表面积的测试方法参照GB/T 19587-2017，取一定量负极活性材料层，使用有机溶剂溶解除去粘结剂和增稠剂，干燥后得到负极活性物质粉末，具体流程为称量负极活性物质1g至8g(样品称量最少没过球体体积的1/3)置于1/2inch带球泡长管中(圆球体部分 的管径为12mm)，200℃前处理2h后置于测试设备TriStar3030(美国麦克公司)中进行测试，所用吸附气体为N 2(纯度：99.999％)，测试条件在77K下进行，并通过BET的计算方法测试计算比表面积。
6、负极极片析锂程度测试
取被测锂离子电池在0℃测试温度下，静置5分钟，以0.7C的电流恒流充电至4.45V，再以4.45V的电压恒压充电至0.05C；静置5分钟，再以0.5C的电流恒流放电至3.0V，静置5分钟。重复上述充放电流程10次后，将电池满充，于干燥房内拆解，拍照记录负极的状态。
析锂程度判定：根据满充拆解电池得到的负极极片的状态来判定，当负极极片整体显示为金黄色且显示为灰色的面积<2％，则判定为不析锂；当负极极片大部分为金黄色，但有部分位置可观察到灰色，灰色面积在2％至20％之间，则判定为轻微析锂；当负极极片部分为灰色，但仍可观察到部分金黄色，灰色面积在20％至60％，则判定为析锂；当负极极片大部分显示为灰色，灰色面积＞60％时，则判定为严重析锂。
7、直流电阻(DCR)测试
在25℃下，将锂离子电池以1.5C恒流充电至4.45V，再以4.45V恒压充电至0.05C，静置30分钟。以0.1C放电10秒，记录电压值为U1，以1C放电360秒，记录电压值为U2。重复充放电步骤5次。“1C”是在1小时内将锂离子电池容量完全放完的电流值。
通过下式计算锂离子电池在25℃下的直流电阻R：
R＝(U2-U1)/(1C-0.1C)。
采用上述测试锂离子电池在25℃下的直流电阻R的方法步骤测试锂离子电池在0℃下的直流电阻，区别仅在于操作温度为0℃。
除非有特别说明，本申请所述的DCR指的是锂离子电池在10％荷电状态(SOC)下的直流电阻。
8、电化学阻抗谱(EIS)测试
a)三电极电池的制备和镀锂，如上述锂离子电池的制备方式一致，在锂离子电池的制备过程中将铜丝接入电池作为参比电极，负极以20μA的电流分别镀锂6h，镀锂完毕后测试EIS。
b)EIS测试步骤：将镀锂的三电极电池接入由法国比奥罗杰公司生产的Bio-Logic VMP3B电化学工作站进行测试，测试用频率范围为30mHz至50kHz，振幅为5mV，采集数据后采用阻抗复平面图对数据进行分析，得到Rct的数据。
9、锂离子电池循环膨胀率测试
取被测锂离子电池在45℃测试温度下，静止5分钟，记录电池的初始厚度(PPG0和MMC0)，然后以0.7C的电流将锂离子电池恒流充电至4.45V，再以4.45V的电压恒压充电至0.05C，记录电池厚度(PPG1和MMC1)；静置5分钟，再以0.5C的电流恒流放电至3.0V，静止5分钟。重复上述充放电流程500次，前200次，每充放电50次记录电池厚度，后300-500次循环，每100次循环记录电池厚度(PPGx和MMCx，x代表循环圈数)，并记录每一次充放电的残余容量。
PPG测试：PPG测试使用PPG软包电池测厚仪(深圳奥拓美自动化科技有限公司制造)进行自动检测，测试流程为将电池放置于仪器测试下面板上，在测试过程中上盖板匀速下降，通过压力传感测得电池厚度PPGx，标x对应循环测试的圈数。
MMC测试：MMC测试使用千分尺测试仪(日本Mitutoyo制造，型号：MDC-25SX)测量电池正极极耳处厚度，测量三个点(MMCax、MMCbx、MMCcx)，字母a，b，c对应不同测试的位置，下标x对应循环测试的圈数，MMCx＝(MMCax+MMCbx+MMCcx)/3，MMC反弹＝(MMCx-MMC0)/MMC×100％。
根据记录的电池厚度计算锂离子电池45℃循环膨胀率＝[PPGx/(Max(MMCax、MMCbx、MMCcx))-1]×100％，Max(MMCax、MMCbx、MMCcx)代表取三个测试点中的最大值。
10、2C放电容量保持率测试
将锂离子电池在2℃下静止5分钟后以0.7C的电流恒流充电至4.45V，再以4.45V的恒压充电至0.05C，静置5分钟，然后以0.5C恒流放电至3.0V，静止5分钟。重复上述充放电过程，以0.1C进行放电，记录锂离子电池的0.1C放电容量，然后以2C进行放电，记录锂离子电池的2C放电容量。通过下式锂离子电池的2C放电容量保存率：
2C放电容量保持率＝2C放电容量/0.1C放电容量×100％。
测试结果
表1
Figure PCTCN2022083355-appb-000001
注：表1中各实施例和对比例的A峰的半峰宽均为0.1°、101峰的半峰宽均为0.3°；负极活性材料层的厚度为30μm，单位面积负极活性材料层的重量为0.003g/cm 2。
如实施例1-12所示，当负极活性材料层满足0.1≤SA/S002≤0.3时，可明显提高锂离子电池的克容量、显著降低循环200圈时的循环膨胀率以及0℃时的直流电阻值。200圈时的循环膨胀率的降低表明锂离子电池具有改善的循环性能，0℃时的直流电阻值降低表明锂离子电池具有改善的动力学性能。因此，实施例1-12的锂离子电池具有改善的循环性能、动力学性能和高的克容量。当负极活性材料层满足7000≤SA≤9000和/或25000≤S002≤90000时，锂离子电池具有更优的综合性能。
对比例1中的SA/S002的比值高于0.3，锂离子电池的克容量较低、200圈时循环膨胀率较高且0℃DCR的值较高；对比例2中的SA/S002的比值低于0.1，锂离子电池虽具有较高的客容量，但200圈时循环膨胀率很高且0℃DCR的值较高。
表2
Figure PCTCN2022083355-appb-000002
注：表2中实施例及对比例的其余参数与实施例2相同
如表2所示，当满足A峰的半峰宽为0.1°-0.5°、101峰的半峰宽为0.3°-0.8°、30μm≤H≤80μm、87≤SA/H≤300、C为0.003g/cm 2至0.01g/cm 2和/或1.0≤10 4×C/H≤1.7时，有助于进一步改善锂离子电池的阻抗、负极极片的析理情况和提高锂离子电池的克容量，可进一步提升锂离子电池的循环性能和动力学性能。
表3
Figure PCTCN2022083355-appb-000003
注：表3中实施例及对比例的其余参数与实施例15相同
实施例26至实施例39描述的是负极活性材料的粒径分布、BET以及负极活性材料层的S004/S110的比值与电池性能的关系。如表3所示，当锂离子电池满足：1μm≤Dv10≤10μm、3μm≤Dv50≤18μm、8μm≤Dv90≤35μm、铬元素含量为0.008％-0.02％、铌元素含量为0.005％-0.009％、硫元素含量为0.001％-0.006％和/或10≤S004/S110≤25时，有助于进一步改善锂离子电池的在25℃下的直流电阻、负极极片的析理情况和高倍率(2C) 放电容量保持率，进一步提升锂离子电池的循环性能和动力学性能。
尽管已经演示和描述了说明性实施例，本领域技术人员应该理解上述实施例不能被解释为对本申请的限制，并且可以在不脱离本申请的精神、原理及范围的情况下对实施例进行改变，替代和修改。

Claims (10)

  1. 一种电化学装置，包括负极，所述负极包括负极集流体和负极活性材料层，所述负极活性材料层包括负极活性材料，其中，所述负极活性材料层满足0.1≤SA/S002≤0.3，SA为负极活性材料层的XRD图谱中2θ在42.4°至43.6°范围内的A峰的峰面积值，S002为负极活性材料层的XRD图谱中002峰的峰面积值。
  2. 根据权利要求1所述的电化学装置，其中，7000≤SA≤9000和/或25000≤S002≤90000。
  3. 根据权利要求1所述的电化学装置，其中，所述A峰的半峰宽为0.1°至0.5°。
  4. 根据权利要求1所述的电化学装置，其中，所述负极活性材料层的XRD图谱中，2θ在43.6°至46.6°范围内有101峰，其中0.015≤S101/S002≤0.035，S101为所述101峰的峰面积值；和/或所述101峰的半峰宽为0.3°至0.8°。
  5. 根据权利要求1所述的电化学装置，其中，所述负极满足条件(a)至(d)中的至少一者：
    (a)所述负极集流体为铜箔；
    (b)所述负极集流体包含铬元素，基于所述负极集流体的质量，所述铬元素含量为0.008％至0.020％；
    (c)所述负极集流体包含铌元素，基于所述负极集流体的质量，所述铌元素含量为0.005％至0.009％；
    (d)所述负极集流体包含硫元素，基于所述负极集流体的质量，所述硫元素含量为0.001％至0.006％。
  6. 根据权利要求1所述的电化学装置，其中，所述负极活性材料层的厚度为Hμm，其中，87≤SA/H≤300。
  7. 根据权利要求1所述的电化学装置，其中，所述负极活性材料层的厚度为Hμm，单位面积负极活性材料层的重量为C g/cm 2，其中，0.003≤C≤0.01，1.0≤10 4×C/H≤1.7。
  8. 根据权利要求1所述的电化学装置，其中，所述负极活性材料层满足10≤S004/S110≤25，其中，S004为所述负极活性材料层的XRD图谱中004峰的峰面积值，S110为所述负极活性材料层的XRD图谱中110峰的峰面积值。
  9. 根据权利要求1所述的电化学装置，其中，所述负极满足条件(e)至(h)中的至少一者：
    (e)所述负极活性材料包含天然石墨；
    (f)所述负极活性材料的比表面积为2g/cm 2至5g/cm 2；
    (g)所述负极活性材料的克容量为360mAh/g至370mAh/g；
    (h)所述负极活性材料的粒径满足1μm≤Dv10≤10μm，3μm≤Dv50≤18μm，8μm≤Dv90≤35μm。
  10. 一种电子装置，包括权利要求1至9中任一项所述的电化学装置。
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