WO2024114565A1 - 正极材料及其制备方法、正极极片、电池、以及装置 - Google Patents

正极材料及其制备方法、正极极片、电池、以及装置 Download PDF

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WO2024114565A1
WO2024114565A1 PCT/CN2023/134282 CN2023134282W WO2024114565A1 WO 2024114565 A1 WO2024114565 A1 WO 2024114565A1 CN 2023134282 W CN2023134282 W CN 2023134282W WO 2024114565 A1 WO2024114565 A1 WO 2024114565A1
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component
positive electrode
electrode material
battery
mass ratio
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English (en)
French (fr)
Inventor
任瑞丽
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Batterotech Corp Ltd
Battero Tech Corp Ltd
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Batterotech Corp Ltd
Battero Tech Corp Ltd
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Priority to EP23896716.0A priority Critical patent/EP4583197A4/en
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • 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
    • H01M4/364—Composites as mixtures
    • 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
    • H01M10/42—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
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H01M4/131—Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
    • 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
    • H01M4/136—Electrodes based on inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy
    • 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
    • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
    • H01M4/50—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese
    • H01M4/505—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy
    • 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
    • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
    • H01M4/52—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron
    • H01M4/525—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
    • 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
    • H01M4/5825—Oxygenated metallic salts or polyanionic structures, e.g. borates, phosphates, silicates, olivines
    • 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
    • H01M2004/028—Positive 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

  • Embodiments of the present disclosure relate to a positive electrode material and a preparation method thereof, a positive electrode sheet, a battery, and a device.
  • Lithium-ion batteries have the characteristics of high operating voltage, high specific energy, long cycle life and no memory effect, and are widely used in various fields, such as new energy vehicle power systems.
  • Safety and energy density as key indicators of power lithium-ion batteries, have become the research focus in the industrialization process of lithium-ion batteries.
  • Providing a lithium-ion battery with high safety performance while taking into account energy density has become a difficult problem that needs to be solved urgently.
  • At least one embodiment of the present disclosure relates to a positive electrode material, a positive electrode sheet containing the positive electrode material, a battery containing the positive electrode sheet, a device containing the battery, and a method for preparing the positive electrode material.
  • At least one embodiment of the present disclosure provides a positive electrode material, including a positive electrode active material, the positive electrode active material including a first component and a second component, the thermal stability of the first component is higher than the thermal stability of the second component, and the positive electrode material satisfies:
  • ⁇ is the characteristic parameter of the positive electrode material
  • W1 is the mass ratio of the first component to the positive electrode active material
  • W2 is the mass ratio of the second component to the positive electrode active material
  • C1 is the gram capacity of the first component
  • C2 is the gram capacity of the second component
  • the units of C1 and C2 are mA ⁇ h/g
  • U1 is the working voltage of the first component
  • U2 is the working voltage of the second component
  • the units of U1 and U2 are V
  • T is the temperature of the second component at the exothermic peak in the differential scanning calorimetry characterization
  • the unit of T is °C, wherein 0.8 ⁇ 1.03.
  • the temperature of the first component at the exothermic peak in differential scanning calorimetry characterization is greater than 306°C, and the temperature of the second component at the exothermic peak in differential scanning calorimetry characterization is less than or equal to 306°C.
  • the gram capacity of the first component is less than 150 mA ⁇ h/g, and the gram capacity of the second component is greater than or equal to 150 mA ⁇ h/g.
  • the first component includes at least one of olivine material and spinel material;
  • the second component includes a layered structure material, and the layered structure material includes at least one of a ternary material, lithium cobalt oxide, and lithium nickel oxide.
  • the first component includes at least one of lithium iron phosphate, lithium manganese iron phosphate and lithium manganate.
  • the mass ratio of the positive electrode active substance to the positive electrode material is 90wt%-98wt%
  • the mass ratio of the first component to the positive electrode material is 45wt%-49wt%
  • the mass ratio of the second component to the positive electrode material is 45wt%-49wt%.
  • At least one embodiment of the present disclosure provides a positive electrode material further comprising: a positive electrode conductor and a positive electrode binder, wherein the mass ratio of the positive electrode conductor to the positive electrode material is 1wt%-5wt%; the mass ratio of the positive electrode binder to the positive electrode material is 1wt%-5wt%.
  • the first component includes LiMn x Fe (1-x) PO 4 , and 0 ⁇ x ⁇ 0.6, the gram capacity C1 of the first component is 140mA ⁇ h/g to 160mA ⁇ h/g, and the working voltage U1 of the first component is 3.2V or 4.0V.
  • the second component includes LiNizMnyCo(1-zy) O2 , and 0 ⁇ z ⁇ 1, 0 ⁇ y ⁇ 1, 0 ⁇ 1-zy ⁇ 1; the gram capacity C2 of the second component is 150mA ⁇ h/g ⁇ 220mA ⁇ h/g, and the working voltage U2 of the second component is 3.6V ⁇ 3.75V.
  • At least one embodiment of the present disclosure further provides a positive electrode plate, comprising any of the positive electrode materials described above.
  • At least one embodiment of the present disclosure further provides a battery, comprising the positive electrode plate as described above.
  • At least one embodiment of the present disclosure further provides a device, comprising the above-mentioned battery, wherein the battery is configured to serve as a power source for the device.
  • At least one embodiment of the present disclosure further provides a method for preparing a positive electrode material, comprising: mixing a first component and a second component to prepare a positive electrode active material, wherein the thermal stability of the first component is Qualitatively higher than the thermal stability of the second component, and the positive electrode active material satisfies:
  • ⁇ is the characteristic parameter of the positive electrode material
  • W1 is the mass ratio of the first component to the positive electrode active material
  • W2 is the mass ratio of the second component to the positive electrode active material
  • C1 is the gram capacity of the first component
  • C2 is the gram capacity of the second component
  • the units of C1 and C2 are mA ⁇ h/g
  • U1 is the working voltage of the first component
  • U2 is the working voltage of the second component
  • the units of U1 and U2 are V
  • T is the temperature of the second component at the exothermic peak in the differential scanning calorimetry characterization
  • the unit of T is °C, wherein 0.8 ⁇ 1.03.
  • the temperature of the first component at the exothermic peak in the differential scanning calorimetry characterization is greater than 306°C, and the temperature of the second component at the exothermic peak in the differential scanning calorimetry characterization is less than or equal to 306°C.
  • the gram capacity of the first component is less than 150 mA ⁇ h/g, and the gram capacity of the second component is greater than or equal to 150 mA ⁇ h/g.
  • the mass ratio of the positive electrode active substance to the positive electrode material is 90wt%-98wt%
  • the mass ratio of the first component to the positive electrode material is 45wt%-49wt%
  • the mass ratio of the second component to the positive electrode material is 45wt%-49wt%.
  • FIG1 is a schematic diagram of the structure of a positive electrode plate provided in an embodiment of the present disclosure.
  • the positive electrode materials of lithium-ion batteries include lithium iron phosphate and ternary types.
  • the ternary nickel-cobalt-manganese material because nickel has a higher gram capacity and voltage platform, it has obvious advantages over lithium iron phosphate in terms of improving energy density, and can better meet people's needs for long-range travel.
  • the ternary material itself has the defects of poor structural and interface stability, its nature is active, and it is easy to undergo redox reactions with electrolyte solvents.
  • the decomposition temperature of the ternary material is 200°C, its exothermic energy exceeds 800J/g.
  • the decomposition temperature of lithium iron phosphate is 400°C, and its exothermic energy is only 124J/g. Therefore, compared with lithium iron phosphate, the safety of ternary lithium-ion batteries is poor, and it is prone to thermal runaway phenomena such as spontaneous combustion and explosion, which seriously restricts the further promotion and application of new energy vehicles.
  • the structural stability and thermal stability of LiNi 0.8 Co 0.1 Mn 0.1 O 2 materials doped with Mg and Al elements are better than those of undoped materials or materials doped with a single element.
  • the electrochemically inert substances used for surface coating mainly include oxides, fluorides and high molecular polymers.
  • these technical means have improved the thermal stability of ternary materials, their preparation process is complicated, the cost is high, and the consistency of materials is difficult to control.
  • At least one embodiment of the present disclosure provides a positive electrode material, the positive electrode material includes a positive electrode active material.
  • the positive electrode active material includes a first component and a second component, the thermal stability of the first component is higher than the thermal stability of the second component, and the positive electrode material satisfies:
  • ⁇ is the characteristic parameter of the positive electrode material
  • W1 is the mass ratio of the first component to the positive electrode active material
  • W2 is the mass ratio of the second component to the positive electrode active material
  • C1 is the gram capacity of the first component
  • C2 is the gram capacity of the second component
  • the units of C1 and C2 are mA ⁇ h/g
  • U1 is the working capacity of the first component.
  • U1 is the operating voltage of the second component
  • U2 is the operating voltage of the second component
  • the units of U1 and U2 are volts (V)
  • T is the temperature of the second component at the exothermic peak in the differential scanning calorimetry characterization
  • the unit of T is degrees Celsius (°C).
  • Dividing the positive electrode active substance in the positive electrode material into two components can simplify the complexity and facilitate classification and selection among the numerous positive electrode active substances.
  • the embodiment of the present disclosure improves the thermal stability of the positive electrode material by blending the second component with lower thermal stability with the first component with higher thermal stability, thereby achieving higher safety performance.
  • This technical solution has low cost and is easy to implement.
  • the positive electrode material, the positive electrode sheet containing the positive electrode material, the battery containing the positive electrode sheet, the device containing the battery and the preparation method of the positive electrode material are described below with reference to the accompanying drawings and through some embodiments.
  • the positive electrode material includes a positive electrode active material.
  • the positive electrode active material includes a first component and a second component, and the thermal stability of the first component is higher than the thermal stability of the second component.
  • the positive electrode material satisfies the following formula:
  • ⁇ is the characteristic parameter of the positive electrode material
  • W1 is the mass ratio of the first component to the positive electrode active material
  • W2 is the mass ratio of the second component to the positive electrode active material
  • C1 is the gram capacity of the first component
  • C2 is the gram capacity of the second component
  • the units of C1 and C2 are mA ⁇ h/g
  • U1 is the working voltage of the first component
  • U2 is the working voltage of the second component
  • the units of U1 and U2 are V
  • T is the temperature of the second component at the exothermic peak in the differential scanning calorimetry characterization
  • the unit of T is °C.
  • the positive electrode material provided by the embodiments of the present disclosure can be used in a secondary battery, for example, a lithium-ion battery, but is not limited thereto.
  • the positive electrode material provided in the embodiment of the present disclosure is to facilitate obtaining a battery with high thermal stability and reduce the probability of thermal runaway when the battery containing the positive electrode material is mechanically abused.
  • the positive electrode active material in the positive electrode material is divided into two components, namely a first component and a second component.
  • the positive electrode active materials of the two components can complement each other in terms of thermal stability, and the first component and the second component are measured by the characteristic ratio, the mass ratio of the first component and the second component to the positive electrode active material, the gram capacity of the first component and the second component, the working voltage of the first component and the second component, and the second component in differential scanning calorimetry.
  • the temperature at the exothermic peak in the characterization is used to construct a formula.
  • the components and contents that satisfy the characteristic ratio ⁇ in the formula are positive electrode materials that meet the requirements.
  • the embodiments of the present disclosure provide suitable positive electrode materials to obtain batteries with high thermal stability and reduce the probability of thermal runaway when the battery containing the positive electrode material is mechanically abused.
  • the parameters are linked, and when the characteristic ratio satisfies 0.8 ⁇ 1.03, the positive electrode material meets the requirements.
  • the heat generation and oxygen release in the battery can be reduced, as well as the probability of thermal runaway when the battery is mechanically abused.
  • the thermal stability of the positive electrode material can be improved to have higher safety performance.
  • the temperature of the first component at the exothermic peak in the differential scanning calorimetry characterization is greater than 306° C.
  • the temperature of the second component at the exothermic peak in the differential scanning calorimetry characterization is less than or equal to 306° C.
  • the temperature of the component at the exothermic peak in the differential scanning calorimetry characterization is determined. That is, the temperature at the exothermic peak in the differential scanning calorimetry characterization is a parameter related to the component, which is a constant when the component is determined.
  • the temperature at the exothermic peak in the differential scanning calorimetry characterization is obtained using a conventional differential scanning calorimeter, and the corresponding national standard (GB) is JB/T 6856-2017.
  • the differential scanning calorimeter model used in the embodiment of the present disclosure is Mettler Toledo DSC 3+. Of course, other differential scanning calorimeters can also be used for measurement.
  • the thermal stability of the second component is lower than that of the first component, and the heat resistance of the second component is lower than that of the first component.
  • the temperature of the first component at the exothermic peak in the differential scanning calorimetry characterization is higher than 306°C
  • the temperature of the second component at the exothermic peak in the differential scanning calorimetry characterization can be 100°C-306°C, but is not limited thereto.
  • the exothermic peak temperature limit of the first component and the second component is 306°C, but is not limited thereto.
  • the thermal stability of the positive electrode material can be improved, so that The battery has higher safety.
  • 0.8 ⁇ 0.9 can be made in order to make the battery have higher thermal stability.
  • 0.85 ⁇ 0.95 can be made in the positive electrode material.
  • 0.8 ⁇ 1 can be made, but it is not limited thereto.
  • the gram capacity of the first component is less than 150 mA ⁇ h/g, and the gram capacity of the second component is greater than or equal to 150 mA ⁇ h/g.
  • the positive electrode active material is further screened, so that the boundary between the first component and the second component is clearer.
  • the gram capacity of each component in the positive active material in the positive electrode material is related to the component.
  • the gram capacity of the component is determined.
  • the gram capacity is measured using the usual test conditions.
  • the gram capacity measurement method can generally include preparing the positive electrode sheet by pulping, coating, drying, and pressing the positive electrode material; using the lithium sheet as the negative electrode, injecting the electrolyte, and then assembling it into a button cell. Then, the measurement is performed using a 0.1C current charge and discharge.
  • the energy density of the first component is less than the energy density of the second component, and the gram capacity of the first component and the second component is limited to 150 mA ⁇ h/g, but is not limited thereto.
  • the overall energy density of the positive electrode material can be improved, so that the energy density of the battery is maintained at a higher level.
  • the temperature of the first component at the exothermic peak in the differential scanning calorimetry characterization is higher than 306°C
  • the temperature of the second component at the exothermic peak in the differential scanning calorimetry characterization is less than or equal to 306°C
  • the gram capacity of the first component is less than 150mAh/g
  • the gram capacity of the second component is greater than or equal to 150mAh/g.
  • energy density refers to the ratio of the energy of a battery to its volume.
  • the first component may include at least one of an olivine material and a spinel material
  • the second component may include a layered structure material
  • the layered structure material includes at least one of a ternary material, lithium cobalt oxide, and lithium nickel oxide.
  • the first component may include at least one of lithium iron phosphate, lithium manganese iron phosphate, and lithium manganate.
  • the thermal stability of the battery can be higher and the safety performance can be higher.
  • the mass ratio of the positive electrode active material to the positive electrode material may be 90wt%-98wt%
  • the mass ratio of the first component to the positive electrode material may be 45wt%-49wt%
  • the mass ratio of the second component to the positive electrode material may be 45wt%-49wt%.
  • the positive electrode active material in the positive electrode material may be 90wt%-95wt%.
  • the positive electrode active material in the positive electrode material may be 92wt%-97wt%.
  • the positive electrode active material in the positive electrode material may be 93wt%-96wt%, but is not limited thereto.
  • the mass ratios of the first component and the second component in the positive electrode material may be substantially equal, but are not limited thereto.
  • the positive electrode material may also include materials other than the positive electrode active material, such as a positive electrode conductor and a positive electrode binder.
  • a positive electrode conductor such as a positive electrode conductor and a positive electrode binder.
  • the mass ratio of the positive electrode conductor to the positive electrode material is 1wt%-5wt%
  • the mass ratio of the positive electrode binder to the positive electrode material is 1wt%-5wt%.
  • the positive electrode conductor and the positive electrode binder account for 2wt%-10wt% of the positive electrode material to form the positive electrode material together with the positive electrode active material.
  • the content of the positive electrode conductor and the positive electrode binder can be equal or approximately equal, but is not limited thereto.
  • the first component may include LiMn x Fe (1- x) PO 4 , and 0 ⁇ x ⁇ 0.6.
  • the gram capacity C1 of the first component may be 140mA ⁇ h/g to 160mA ⁇ h/g, and the operating voltage U1 of the first component may be 3.2V or 4.0V, but is not limited thereto.
  • the second component may include LiNi z Mn y Co (1-zy) O 2 , and 0 ⁇ z ⁇ 1, 0 ⁇ y ⁇ 1, 0 ⁇ 1-zy ⁇ 1.
  • the gram capacity C2 of the second component is 150mA ⁇ h/g to 220mA ⁇ h/g, and the operating voltage U2 of the second component is 3.6V to 3.75V, but is not limited thereto.
  • the gram capacity C2 of the second component is 170mA ⁇ h/g to 220mA ⁇ h/g.
  • the particle size of the first component is smaller than that of the second component.
  • the first component with a small particle size can be distributed between the particles of the second component after mixing, which can inhibit the chain reaction of the second component in the case of thermal runaway, and is conducive to improving and enhancing the thermal stability of the positive electrode material.
  • This technical solution has low cost and is easy to implement.
  • the embodiment of the present disclosure mixes the olivine structure material with the ternary material in a simple mechanical and physical mixing manner, so that the small-sized lithium iron manganese phosphate or lithium iron phosphate is mixed and distributed between the nickel cobalt manganese oxide particles, which can inhibit the chain reaction of the nickel cobalt manganese oxide material in the case of thermal runaway. It is beneficial to improve and enhance its thermal stability. This technical solution has low cost and is easy to implement.
  • FIG1 is a schematic diagram of the structure of a positive electrode plate provided in an embodiment of the present disclosure.
  • an embodiment of the present disclosure further provides a positive electrode sheet 01 , comprising the positive electrode material described in any of the above embodiments.
  • the positive electrode sheet 01 may include a positive electrode material 100 and a positive electrode current collector 200 , wherein the positive electrode material 100 is located on at least one side of the positive electrode current collector 200 .
  • FIG1 illustrates that the positive electrode material 100 is disposed on both sides of the positive electrode current collector 200 , but is not limited thereto.
  • the thermal stability of the positive electrode material can be improved to have higher safety performance.
  • the embodiment of the present disclosure also includes a battery, which includes the positive electrode sheet 01 in the above embodiment.
  • the battery provided by the embodiment of the present disclosure can be a lithium-ion battery, but is not limited thereto.
  • the thermal stability of the positive electrode material can be improved to have higher safety performance.
  • An embodiment of the present disclosure also includes a device, which includes the battery provided in any of the above embodiments, and the battery is configured as a power source for the device.
  • the device provided by the embodiments of the present disclosure may be a car, such as an electric car.
  • the electric car may be any one of an electric pure electric car, a hybrid electric car, and a plug-in hybrid electric car, but is not limited thereto.
  • the electric car may be any one of an electric bus, an electric tram, an electric bicycle, an electric motorcycle, an electric scooter, an electric golf cart, and an electric truck, but is not limited thereto.
  • the device provided by the embodiments of the present disclosure may also be any one of an electric ship, an electric tool, an electronic device, and an energy storage system, but is not limited thereto.
  • the thermal stability of the positive electrode material can be improved to have higher safety performance.
  • At least one embodiment of the present disclosure further provides a method for preparing a positive electrode material, which comprises: mixing a first component and a second component to prepare a positive electrode active material.
  • the first component and the second component are selected according to the following conditions: the thermal stability of the first component is higher than the thermal stability of the second component, and the positive electrode active material satisfies:
  • ⁇ is the characteristic parameter of the positive electrode material
  • W1 is the mass ratio of the first component to the positive electrode active material
  • W2 is the mass ratio of the second component to the positive electrode active material
  • C1 is the gram capacity of the first component
  • C2 is the gram capacity of the second component
  • the units of C1 and C2 are mA ⁇ h/g
  • U1 is the working voltage of the first component
  • U2 is the working voltage of the second component
  • the units of U1 and U2 are V
  • T is the temperature of the second component at the exothermic peak in the differential scanning calorimetry characterization
  • the unit of T is °C.
  • the positive electrode material prepared by this preparation method can enable the battery to meet larger capacity requirements while having higher safety performance, so as to have greater application potential.
  • the temperature of the first component in the positive electrode active material at the exothermic peak in the differential scanning calorimetry characterization can be made greater than 306°C, and the temperature of the second component at the exothermic peak in the differential scanning calorimetry characterization can be made less than or equal to 306°C, but not limited to this.
  • the thermal stability of the second component lower than that of the first component, the heat resistance of the second component is lower than that of the first component.
  • the exothermic peak temperature limit of the first component and the second component can be 306°C.
  • the gram capacity of the first component in the positive electrode active material can be made less than 150 mA ⁇ h/g, and the gram capacity of the second component can be made greater than 150 mA ⁇ h/g, but it is not limited thereto.
  • the energy density of the first component can be made smaller than the energy density of the second component, and the gram capacity of the first component and the second component is limited to 150 mA ⁇ h/g.
  • the overall energy density of the positive electrode material can be improved, so that the battery has a higher energy density.
  • the positive electrode active material may account for 90wt%-98wt% of the positive electrode material
  • the first component may account for 45wt%-49wt% of the positive electrode material
  • the second component may account for 45wt%-49wt% of the positive electrode material.
  • the mass ratio of the positive electrode active material and the first component and the second component therein can be referred to the relevant description in the above embodiments, which will not be elaborated here.
  • the preparation of the positive electrode sheet provided in at least one embodiment of the present disclosure mainly includes the preparation of the positive electrode material, the preparation of the positive electrode current collector, etc. Specifically, the following steps may be included.
  • Step (1) placing the positive electrode material on at least one side of the positive electrode current collector and performing a drying process;
  • the positive electrode current collector 200 may be made of a metal material, such as aluminum foil, but is not limited thereto.
  • Step (2) cold pressing the dried positive electrode sheet.
  • Step (3) cutting the cold pressed positive electrode sheet into a specified size.
  • the positive electrode current collector in the embodiment of the present disclosure may be a composite current collector including multiple materials, for example, the positive electrode current collector may include a support layer and a conductive layer.
  • the conductive layer may be located on both sides of the support layer, but is not limited thereto.
  • the preparation of the battery provided by at least one embodiment of the present disclosure may also include the preparation of a negative electrode sheet, an electrolyte, and a separator.
  • the preparation process of the battery may include the following steps:
  • the preparation method of the positive electrode plate in the battery can refer to the relevant description in the above embodiments, which will not be described here.
  • the negative electrode plate in the battery may include a negative electrode current collector and a negative electrode material.
  • the negative electrode material may be disposed on at least one side of the negative electrode current collector.
  • the negative electrode material may include a negative electrode active material, and the components of the negative electrode active material are not specifically limited.
  • the negative electrode active material may include at least one of artificial graphite, natural graphite, soft carbon, hard carbon, mesophase carbon microspheres, silicon-based materials, tin-based materials, and lithium titanate.
  • the negative electrode current collector may also include other materials, but is not limited thereto, and may be selected according to actual needs.
  • the electrolyte in the battery may include a lithium salt and an organic solvent, but is not limited thereto.
  • the lithium salt may include at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, and lithium perchlorate.
  • the organic solvent may include at least one of a cyclic carbonate, a chain carbonate, and a carboxylic acid ester.
  • the electrolyte may further contain functional additives, such as vinylene carbonate, vinyl sulfate, propane sultone, fluoroethylene carbonate, etc. At least one embodiment of the present disclosure does not limit the material of the electrolyte.
  • the separator of the battery may include a polyethylene film, but is not limited thereto.
  • the positive electrode sheet, the separator and the negative electrode sheet can be stacked in sequence, and the separator is located between the positive electrode sheet and the negative electrode sheet. Then, the stacked structure can be wound to obtain a bare cell. Secondly, the bare cell is placed in the outer packaging shell of the battery, dried, and then injected with the electrolyte. Finally, after vacuum packaging, standing, formation, shaping and other processes, a battery is obtained.
  • the first component of the positive electrode active material of the positive electrode material in the positive electrode plate of the battery may be lithium iron phosphate or lithium manganese iron phosphate, and the second component may be a ternary material.
  • the temperature of the first component at the exothermic peak in the differential scanning calorimetry characterization is 350°C.
  • the second component can be a ternary material with different nickel contents, for example, the second component (ternary material) with a thermal runaway temperature of 264°C has a nickel content of 60%; for example, the second component (ternary material) with a thermal runaway temperature of 306°C has a nickel content of 30%; the second component (ternary material) with a thermal runaway temperature of 225°C has a nickel content of 80%; for example, the second component (ternary material) with a thermal runaway temperature of 290°C has a nickel content of 50%.
  • the negative electrode material in the negative electrode sheet of the battery may include a graphite material (such as artificial graphite or natural graphite).
  • the capacity of the battery may include 90A ⁇ h, 20A ⁇ h, 115A ⁇ h, 137A ⁇ h, 160A ⁇ h, etc., but is not limited thereto.
  • the batteries of the above configurations are subjected to needle penetration tests and hot box tests respectively.
  • the needle puncture test method may include: after fully charging the battery in CC-CV mode, a ⁇ 5mm high temperature resistant steel needle is used to penetrate the battery plate at a speed of 25 ⁇ 5mm/s from a direction perpendicular to the battery plate, and the steel needle stays in the battery for 1 hour.
  • the instrument used in the needle puncture test is a needle puncture extruder, and the model of the needle puncture instrument is: RJD-ZCJY-HLT-20T-1500D.
  • the hot box test method may include: after the battery is fully charged in CC-CV mode, the temperature is raised from ambient temperature to 130°C at a rate of 2°C/min and maintained for 30 minutes; if the battery cell does not lose control, continue The temperature is raised at a rate of 2°C/min until it reaches 220°C and maintained for 30 minutes.
  • the hot box instrument is a thermal abuse hot box, and the hot box model is RJD-VA-1088M.
  • the first component is lithium iron phosphate
  • the second component is a ternary material with a nickel content of 30%
  • the mass ratio of the first component to the positive active material W1 is 10%
  • the temperature T of the second component at the exothermic peak in the differential scanning calorimetry characterization is 306°C
  • the gram capacity C1 of the first component is 140mA ⁇ h/g
  • the gram capacity C2 of the second component is 160mA ⁇ h/g
  • the working voltage U1 of the first component is 3.2V
  • the working voltage U2 of the second component is 3.73V
  • the mass ratio W2 of the second component to the positive active material is 90%
  • the characteristic ratio ⁇ of the positive electrode material of the positive electrode plate of the battery is 1.027
  • the energy density of the battery is 223Wh/kg.
  • the first component is lithium iron phosphate
  • the second component is a ternary material with a nickel content of 50%
  • the mass ratio of the first component to the positive electrode active material W1 is 25%
  • the temperature T of the second component at the exothermic peak in the differential scanning calorimetry characterization is 290°C
  • the gram capacity C1 of the first component is 140mA ⁇ h/g
  • the gram capacity C2 of the second component is 180mA ⁇ h/g
  • the working voltage U1 of the first component is 3.2V
  • the working voltage U2 of the second component is 3.73V
  • the mass ratio W2 of the second component to the positive electrode active material is 75%
  • the characteristic ratio ⁇ of the positive electrode material of the positive electrode plate of the battery is 0.913
  • the energy density of the battery is 239Wh/kg.
  • the needle puncture result for the battery is: no fire; the hot box test result for the battery is: no fire, no explosion.
  • the first component is lithium iron phosphate
  • the second component is a ternary material with a nickel content of 60%
  • the mass ratio of the first component to the positive electrode active material W1 is 40%
  • the temperature T of the second component at the exothermic peak in the differential scanning calorimetry characterization is 264°C
  • the gram capacity C1 of the first component is 140mA ⁇ h/g
  • the gram capacity C2 of the second component is 190mA ⁇ h/g
  • the working voltage U1 of the first component is 3.2V
  • the working voltage U2 of the second component is 3.73V
  • the mass ratio W2 of the second component to the positive electrode active material is 60%
  • the characteristic ratio ⁇ of the positive electrode material of the positive electrode plate of the battery is 0.848
  • the energy density of the battery is 244Wh/kg.
  • the needle puncture result for the battery is: no fire; the hot box test result for the battery is: no fire, no explosion.
  • the first component is lithium iron phosphate
  • the second component is a ternary material with a nickel content of 80%
  • the mass ratio of the first component to the positive electrode active material W1 is 50%
  • the temperature T of the second component at the exothermic peak in the differential scanning calorimetry characterization is 225°C
  • the gram capacity C1 of the first component is 140mA ⁇ h/g
  • the gram capacity C2 of the second component is 200mA ⁇ h/g
  • the working voltage U1 of the first component is 3.2V
  • the working voltage U2 of the second component is 3.68V
  • the mass ratio W2 of the second component to the positive electrode active material is 50%
  • the characteristic ratio ⁇ of the positive electrode material of the positive electrode plate of the battery is 0.806
  • the energy density of the battery is 247Wh/kg.
  • the needle puncture result for the battery is: no fire; the hot box test result for the battery is: no fire, no explosion.
  • the first component is lithium iron phosphate
  • the second component is a ternary material with a nickel content of 80%
  • the mass ratio of the first component to the positive electrode active material W1 is 10%
  • the temperature T of the second component at the exothermic peak in the differential scanning calorimetry characterization is 225°C
  • the gram capacity C1 of the first component is 140mA ⁇ h/g
  • the gram capacity C2 of the second component is 200mA ⁇ h/g
  • the working voltage U1 of the first component is 3.2V
  • the working voltage U2 of the second component is 3.68V
  • the mass ratio W2 of the second component to the positive electrode active material is 90%
  • the characteristic ratio ⁇ of the positive electrode material of the positive electrode plate of the battery is 0.656
  • the energy density of the battery is 243Wh/kg.
  • the needle puncture result for the battery is: fire; the hot box test result for the battery is: fire and explosion.
  • the first component is lithium iron phosphate
  • the second component is a ternary material with a nickel content of 60%
  • the mass ratio of the first component to the positive electrode active material W1 is 15%
  • the temperature T of the second component at the exothermic peak in the differential scanning calorimetry characterization is 264°C
  • the gram capacity C1 of the first component is 140mA ⁇ h/g
  • the gram capacity C2 of the second component is 190mA ⁇ h/g
  • the working voltage U1 of the first component is 3.2V
  • the working voltage U2 of the second component is 3.73V
  • the mass ratio W2 of the second component to the positive electrode active material is 85%
  • the characteristic ratio ⁇ of the positive electrode material of the positive electrode plate of the battery is 0.791
  • the energy density of the battery is 235Wh/kg.
  • the needle puncture result for the battery is: fire; the hot box test result for the battery is: fire and explosion.
  • the first component is lithium manganese iron phosphate
  • the second component is a ternary material with a nickel content of 30%
  • the mass ratio W1 of the first component to the positive electrode active material is 5%
  • the temperature T of the second component at the exothermic peak in the differential scanning calorimetry characterization is 306°C
  • the gram capacity C1 of the first component is 145 mA ⁇ h/g
  • the gram capacity C2 of the second component is 160 mA ⁇ h/g
  • the working voltage U1 of the first component is 4V
  • the working voltage U2 of the second component is 3.73V
  • the mass ratio W2 of the second component to the positive electrode active material is 95%
  • the characteristic ratio ⁇ of the positive electrode material of the positive electrode sheet of the battery is 1.033
  • the energy density of the battery is 225Wh/kg.
  • the needle puncture result of the battery is: no fire; the hot box test result of the battery is: fire and explosion.
  • the first component is lithium manganese iron phosphate
  • the second component is a ternary material with a nickel content of 80%
  • the mass ratio of the first component to the positive electrode active material W1 is 15%
  • the temperature T of the second component at the exothermic peak in the differential scanning calorimetry characterization is 225°C
  • the gram capacity C1 of the first component is 145mA ⁇ h/g
  • the gram capacity C2 of the second component is 200mA ⁇ h/g
  • the working voltage U1 of the first component is 4V
  • the working voltage U2 of the second component is 3.68V
  • the mass ratio W2 of the second component to the positive electrode active material is 85%
  • the characteristic ratio ⁇ of the positive electrode material of the positive electrode plate of the battery is 0.663
  • the energy density of the battery is 248Wh/kg.
  • the needle puncture result for the battery is: fire; the hot box test result for the battery is: fire and explosion.
  • the first component is lithium manganese iron phosphate
  • the second component is a ternary material with a nickel content of 60%
  • the mass ratio of the first component to the positive electrode active material W1 is 40%
  • the temperature T of the second component at the exothermic peak in the differential scanning calorimetry characterization is 264°C
  • the gram capacity C1 of the first component is 145mA ⁇ h/g
  • the gram capacity C2 of the second component is 190mA ⁇ h/g
  • the working voltage U1 of the first component is 4V
  • the working voltage U2 of the second component is 3.73V
  • the mass ratio W2 of the second component to the positive electrode active material is 60%
  • the characteristic ratio ⁇ of the positive electrode material of the positive electrode plate of the battery is 0.81
  • the energy density of the battery is 250Wh/kg.
  • the needle puncture result for the battery is: no fire; the hot box test result for the battery is: no fire, no explosion.
  • Table 1 shows Examples 1-9 and corresponding parameters and test results.
  • the battery provided with the positive electrode material can pass the needle penetration test and the hot box test, that is, the result of the battery in the needle penetration test is: no fire, and the result of the hot box test is: no fire and no explosion.
  • the corresponding gram capacity of the second component is different.
  • the corresponding gram capacity is 140mA ⁇ h/g.
  • the corresponding gram capacity is 145mA ⁇ h/g.
  • ⁇ is less than 0.8, the battery fails the needle puncture test and the hot box test.
  • the batteries can pass the puncture test and the hot box test.
  • the numerical range satisfied by ⁇ in the positive electrode material may have a certain fluctuation range.
  • the fluctuation range may be 0.5% to 0.1%, but is not limited to this.
  • the energy density of the battery can be maintained at a high level.
  • the energy density of the battery is greater than 220Wh/Kg.
  • the positive electrode material provided by the embodiments of the present disclosure can enable the battery to meet larger capacity requirements while having higher safety performance and greater application potential.

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Abstract

提供一种正极材料及其制备方法、正极极片、电池、以及装置。正极材料包括正极活性物质，包括第一组分和第二组分。第一组分的热稳定性高于第二组分的热稳定性，正极材料满足：为正极材料的特性参数，W1为第一组分占正极活性物质的质量比，W2为第二组分占正极活性物质的质量比，C1为第一组分的克容量，C2为第二组分的克容量，U1为第一组分的工作电压，U2为第二组分的工作电压，T为第二组分在差示扫描量热法表征中的放热峰值处的温度，0.8≤α≤1.03。本公开实施例通过将热稳定性较高的第一组分与热稳定性较低的第二组分进行掺混，可使正极材料的热稳定性得以提高，以具有较高的安全性能。

Description

正极材料及其制备方法、正极极片、电池、以及装置
本申请要求于2022年11月28日递交的中国专利申请202211505245.0号的优先权，在此全文引用上述中国专利申请公开的内容以作为本申请的一部分。
技术领域
本公开的实施例涉及一种正极材料及其制备方法、正极极片、电池、以及装置。
背景技术
锂离子电池具有工作电压高、比能量大、循环寿命长及无记忆效应等特点，被广泛应用于各个领域，例如新能源汽车动力系统。安全性和能量密度作为动力锂离子电池的关键指标，已成为锂离子电池产业化过程中的研究重点。在兼顾能量密度的前提下，提供一种安全性能高的锂离子电池，成为目前亟待突破的难题。
发明内容
本公开的至少一实施例涉及一种正极材料、含有该正极材料的正极极片、含有该正极极片的电池、含有该电池的装置及该正极材料的制备方法。
本公开的至少一实施例提供一种正极材料，包括正极活性物质，正极活性物质包括第一组分和第二组分，第一组分的热稳定性高于第二组分的热稳定性，正极材料满足：
其中，α为所述正极材料的特性参数，W1为所述第一组分占所述正极活性物质的质量比，W2为所述第二组分占所述正极活性物质的质量比，C1为所述第一组分的克容量，C2为所述第二组分的克容量，C1和C2的单位为mA·h/g，U1为所述第一组分的工作电压，U2为所述第二组分的工作电压，U1和U2的单位为V，T为所述第二组分在差示扫描量热法表征中的放热峰值处的温度，T的单位为℃，其中，0.8≤α≤1.03。
例如，在本公开的至少一实施例提供的正极材料中，所述第一组分在差示扫描量热法表征中的放热峰值处的温度大于306℃，所述第二组分在差示扫描量热法表征中的放热峰值处的温度小于或等于306℃。
例如，在本公开的至少一实施例提供的正极材料中，所述第一组分的克容量小于150mA·h/g，所述第二组分的克容量大于或等于150mA·h/g。
例如，在本公开的至少一实施例提供的正极材料中，所述第一组分包括橄榄石材料和尖晶石材料至少之一；所述第二组分包括层状结构材料，所述层状结构材料包括三元材料、钴酸锂、镍酸锂中的至少之一。
例如，在本公开的至少一实施例提供的正极材料中，所述第一组分包括磷酸铁锂、磷酸锰铁锂及锰酸锂中的至少之一。
例如，在本公开的至少一实施例提供的正极材料中，所述正极活性物质占所述正极材料的质量比为90wt％-98wt％，所述第一组分占所述正极材料的质量比为45wt％～49wt％，所述第二组分占所述正极材料的质量比为45wt％～49wt％。
例如，本公开的至少一实施例提供的正极材料还包括：正极导电剂以及正极粘结剂，其中，所述正极导电剂占所述正极材料的质量比为1wt％-5wt％；所述正极粘结剂占所述正极材料的质量比为1wt％-5wt％。
例如，在本公开的至少一实施例提供的正极材料中，所述第一组分包括LiMnxFe(1-x)PO4，且0≤x≤0.6，所述第一组分的克容量C1为140mA·h/g～160mA·h/g，所述第一组分的工作电压U1为3.2V或4.0V。
例如，在本公开的至少一实施例提供的正极材料中，所述第二组分包括LiNizMnyCo(1-z-y)O2，且0＜z＜1，0＜y＜1，0＜1-z-y＜1；所述第二组分的克容量C2为150mA·h/g～220mA·h/g，所述第二组分的工作电压U2为3.6V～3.75V。
本公开的至少一实施例还提供一种正极极片，包括上述任一项所述的正极材料。
本公开的至少一实施例还提供一种电池，包括如上述的正极极片。
本公开的至少一实施例还提供一种装置，包括上述的电池，所述电池被配置为作为所述装置的电源。
本公开的至少一实施例还提供一种正极材料的制备方法，包括：混合第一组分和第二组分，以制备正极活性物质，其中，所述第一组分的热稳 定性高于所述第二组分的热稳定性，并使所述正极活性物质满足：
其中，α为所述正极材料的特性参数，W1为所述第一组分占所述正极活性物质的质量比，W2为所述第二组分占所述正极活性物质的质量比，C1为所述第一组分的克容量，C2为所述第二组分的克容量，C1和C2的单位为mA·h/g，U1为所述第一组分的工作电压，U2为所述第二组分的工作电压，U1和U2的单位为V，T为所述第二组分在差示扫描量热法表征中的放热峰值处的温度，T的单位为℃，其中，0.8≤α≤1.03。
例如，在本公开的至少一实施例提供的正极材料的制备方法中，所述第一组分在差示扫描量热法表征中的放热峰值处的温度大于306℃，所述第二组分在差示扫描量热法表征中的放热峰值处的温度小于或等于306℃。
例如，在本公开的至少一实施例提供的正极材料的制备方法中，所述第一组分的克容量小于150mA·h/g，所述第二组分的克容量大于或等于150mA·h/g。
例如，在本公开的至少一实施例提供的正极材料的制备方法中，所述正极活性物质占所述正极材料的质量比为90wt％-98wt％，所述第一组分占所述正极材料的质量比为45wt％～49wt％，所述第二组分占所述正极材料的质量比为45wt％～49wt％。
附图说明
为了更清楚地说明本公开实施例的技术方案，下面将对实施例的附图作简单地介绍，显而易见地，下面描述中的附图仅仅涉及本公开的一些实施例，而非对本公开的限制。
图1为本公开的实施例提供的一种正极极片的结构示意图。
具体实施方式
为使本公开实施例的目的、技术方案和优点更加清楚，下面将结合本公开实施例的附图，对本公开实施例的技术方案进行清楚、完整地描述。显然，所描述的实施例是本公开的一部分实施例，而不是全部的实施例。基于所描述的本公开的实施例，本领域普通技术人员在无需创造性劳动的 前提下所获得的所有其他实施例，都属于本公开保护的范围。
除非另外定义，本公开使用的技术术语或者科学术语应当为本公开所属领域内具有一般技能的人士所理解的通常意义。本公开中使用的“第一”、“第二”以及类似的词语并不表示任何顺序、数量或者重要性，而只是用来区分不同的组成部分。同样，“包括”或者“包含”等类似的词语意指出现该词前面的元件或者物件涵盖出现在该词后面列举的元件或者物件及其等同，而不排除其他元件或者物件。
目前，锂离子电池的正极材料包括磷酸铁锂类和三元类。例如，三元镍钴锰材料中由于镍具有较高的克容量和电压平台，在提高能量密度方面，相比磷酸铁锂类优势明显，更能够满足人们的长续航里程出行的需求。但是，三元材料本身存在结构和界面稳定性差的缺陷，其性质活泼，容易与电解液溶剂发生氧化还原反应。同时，由于三元材料的分解温度是200℃，其放热能量超过800J/g。磷酸铁锂的分解温度是400℃，其放热能量仅为124J/g。因此，相比于磷酸铁锂，三元锂离子电池的安全性差，且容易发生自燃、爆炸等热失控现象，进而严重制约了新能源汽车的进一步推广与应用。
由此，构筑高能量密度和高安全的电池体系，已成为当前锂电池研究的热点和重点。针对上述的锂电池安全性差的问题，相关研究中采用了掺杂、表面包覆等手段对三元材料改性。例如，利用Mg、Al元素掺杂的LiNi0.8Co0.1Mn0.1O2材料的结构稳定性和热稳定性优于未掺杂的或利用单一元素掺杂的材料。例如，用于表面包覆的电化学惰性物质主要有氧化物、氟化物以及高分子聚合物等。然而，这些技术手段虽提高了三元材料的热稳定性，但其制备工艺复杂、成本高、材料一致性不易控制。
本公开至少一个实施例提供一种正极材料，该正极材料包括正极活性物质。正极活性物质包括第一组分和第二组分，第一组分的热稳定性高于第二组分的热稳定性，且该正极材料满足：
其中，α为正极材料的特性参数，W1为第一组分占正极活性物质的质量比，W2为第二组分占正极活性物质的质量比，C1为第一组分的克容量，C2为第二组分的克容量，C1和C2的单位为mA·h/g，U1为第一组分的工 作电压，U2为第二组分的工作电压，U1和U2的单位为伏特(V)，T为第二组分在差示扫描量热法表征中的放热峰值处的温度，T的单位为摄氏度(℃)。
在该正极材料中，0.8≤α≤1.03。
将正极材料中的正极活性物质划分为两个组分，可化纷繁为简明，利于在众多的正极活性物质中进行归类和选择。
本公开的实施例通过将热稳定性较低的第二组分与热稳定性较高的第一组分进行掺混，可使得正极材料的热稳定性得以提高，以具有较高的安全性能，该技术方案成本较低，易于实现。
下面结合附图并通过一些实施例对正极材料、含有该正极材料的正极极片、含有该正极极片的电池、含有该电池的装置及该正极材料的制备方法进行说明。
本公开至少一个实施例提供一种正极材料。该正极材料包括正极活性物质。正极活性物质包括第一组分和第二组分，且第一组分的热稳定性高于第二组分的热稳定性。该正极材料满足下述公式：
其中，α为正极材料的特性参数，W1为第一组分占正极活性物质的质量比，W2为第二组分占正极活性物质的质量比，C1为第一组分的克容量，C2为第二组分的克容量，C1和C2的单位为mA·h/g，U1为第一组分的工作电压，U2为第二组分的工作电压，U1和U2的单位为V，T为第二组分在差示扫描量热法表征中的放热峰值处的温度，T的单位为℃。
在该正极材料中，0.8≤α≤1.03。
例如，本公开的实施例所提供的正极材料可用于二次电池。例如，可用于锂离子电池，但不限于此。
本公开的实施例提供的正极材料，为了利于获得热稳定性高的电池，并降低在包含该正极材料的电池发生机械滥用时出现热失控的概率，将正极材料中的正极活性物质划分为两个组分，即第一组分和第二组分，该两个组分的正极活性物质在热稳定性方面可以互相弥补，且通过特性比值、第一组分和第二组分占正极活性物质的质量比、第一组分和第二组分的克容量、第一组分和第二组分的工作电压，以及第二组分在差示扫描量热法 表征中的放热峰值处的温度构建公式，满足该公式中的特性比值α的组分和含量，即为满足要求的正极材料。本公开的实施例为获得热稳定性高的电池，并降低在包含该正极材料的电池发生机械滥用时出现热失控的概率，提供合适的正极材料。在该公式中，各参数联动，当特性比值满足0.8≤α≤1.03时，即满足要求的正极材料。
例如，在正极材料中，通过合理选取第一组分和第二组分，使得在热稳定性较低的第二组分中掺混热稳定性较高的第一组分，可以降低电池出现产热、释氧等情况，以及在电池发生机械滥用时出现热失控的概率。
由此，本公开的实施例通过将热稳定性较低的第二组分与热稳定性较高的第一组分按照一定比例进行掺混，可使得正极材料的热稳定性得以提高，以具有较高的安全性能。
例如，第一组分在差示扫描量热法表征中的放热峰值处的温度大于306℃，第二组分在差示扫描量热法表征中的放热峰值处的温度小于或等于306℃。通过以差示扫描量热法表征中的放热峰值处的温度为306℃作为分界，来区分正极材料中的两个组分，利于正极材料组分的选择和含量的获得。
例如，在正极活性物质的组分确定的情况下，该组分在差示扫描量热法表征中的放热峰值处的温度是确定的。即，差示扫描量热法表征中的放热峰值处的温度是与组分相关的参数，其在组分确定的情况下为定值。在本公开的实施例中，在差示扫描量热法表征中的放热峰值处的温度采用通常的差示扫描量热仪来获得，对应的国标(GB)为JB/T 6856-2017。本公开的实施例采用的差示扫描量热仪型号为梅特勒托利多DSC 3+。当然，也可以采用其他的差示扫描量热仪来测量。
例如，第二组分的热稳定性低于第一组分的热稳定性，第二组分的耐热性能低于第一组分的耐热性能。
例如，第一组分在差示扫描量热法表征中的放热峰值处的温度高于306℃，第二组分在差示扫描量热法表征中的放热峰值处的温度可以为100℃-306℃，但不限于此。例如，第一组分和第二组分的放热峰值温度界限为306℃，但不限于此。
由此，通过将第一组分与第二组分按照上述公式进行掺混，并使得在该正极材料中，0.8≤α≤1.03，正极材料的热稳定性可以得到改善，以使得 电池具有较高的安全性。
例如，为了使得电池具有较高的热稳定性，在该正极材料中，可以使得0.8≤α≤0.9。例如，在该正极材料中，可以使得0.85≤α≤0.95。例如，在该正极材料中，可以使得0.8≤α≤1，但不限于此。
例如，在正极材料中，第一组分的克容量小于150mA·h/g，第二组分的克容量大于或等于150mA·h/g。通过对正极活性物质中各组分的克容量进行进一步限定，进一步筛选正极活性物质，使得第一组分和第二组分的界限更加明晰。
正极材料中的正极活性物质中各组分的克容量与该组分有关，在组分确定的情况下，该组分的克容量是确定的。克容量采用通常的测试条件来测量。本公开的实施例中，克容量的测量方式大致可以包括将正极材料按照制浆、涂布、干燥、压片等步骤，以制备正极极片；以锂片为负极，并注入电解液，进而组装成扣式电池。然后，采用0.1C的电流充放电进行测量。
例如，在正极材料中，第一组分的能量密度小于第二组分的能量密度，且第一组分与第二组分的克容量以150mA·h/g为界限，但不限于此。由此，通过将第一组分与第二组分掺混，可以使得正极材料的整体能量密度得到改善，以使得电池的能量密度维持在较高的水平。
例如，在一些实施例中，第一组分在差示扫描量热法表征中的放热峰值处的温度高于306℃，第二组分在差示扫描量热法表征中的放热峰值处的温度小于或等于306℃，并且第一组分的克容量小于150mAh/g，第二组分的克容量大于或等于150mAh/g。通过在差示扫描量热法表征中的放热峰值处的温度为306℃为分界，且组分的克容量为150mAh/g为分界，进一步筛选正极活性物质，满足该条件的正极活性物质更利于兼顾安全性能和获得大容量的电池。
在本公开的实施例中，能量密度是指电池的能量与其体积之比。
例如，在正极材料的正极活性物质中，第一组分可以包括橄榄石材料和尖晶石材料至少之一。第二组分可以包括层状结构材料，且该层状结构材料包括三元材料、钴酸锂、镍酸锂中的至少之一。
例如，在正极材料的正极活性物质中，第一组分可以包括磷酸铁锂、磷酸锰铁锂及锰酸锂中的至少之一。
在正极材料的正极活性物质中，通过将第一组分和第二组分按照上述公式，以及特定比例、合理地选定为上述材料，可以使得电池的热稳定性较高，具有较高的安全性能。
例如，在正极材料中，正极活性物质占正极材料的质量比可以为90wt％-98wt％。第一组分占正极材料的质量比为45wt％～49wt％，第二组分占正极材料的质量比为45wt％～49wt％。
例如，正极材料中的正极活性物质可以为90wt％-95wt％。例如，正极材料中的正极活性物质可以为92wt％-97wt％。例如，正极材料中的正极活性物质可以为93wt％-96wt％，但不限于此。
例如，第一组分和第二组分占正极材料的质量比可以大致相等，但不限于此。
例如，正极材料还可以包括除正极活性物质以外的材料，例如正极导电剂以及正极粘结剂。例如，正极导电剂占正极材料的质量比为1wt％-5wt％，正极粘结剂占正极材料的质量比为1wt％-5wt％。
例如，正极导电剂以及正极粘结剂占正极材料的2wt％-10wt％，以与正极活性物质共同构成正极材料。例如，在正极材料中，正极导电剂以及正极粘结剂的含量可以相等或大致相等，但不限于此。
例如，在正极材料的正极活性物质中，第一组分可以包括LiMnxFe(1- x)PO4，且0≤x≤0.6。第一组分的克容量C1可以为140mA·h/g～160mA·h/g，第一组分的工作电压U1可以为3.2V或4.0V，但不限于此。
例如，在正极材料的正极活性物质中，第二组分可以包括LiNizMnyCo(1-z-y)O2，且0＜z＜1，0＜y＜1，0＜1-z-y＜1。第二组分的克容量C2为150mA·h/g～220mA·h/g，第二组分的工作电压U2为3.6V～3.75V，但不限于此。进一步例如，第二组分的克容量C2为170mA·h/g～220mA·h/g。
例如，第一组分的粒径小于第二组分的粒径。可以使小粒径的第一组分经混合后分布在第二组分的颗粒之间，可以抑制第二组分在热失控情况下发生连锁反应，有利于改善和提高正极材料的热稳定性，该技术方案成本较低，易于实现。
本公开的实施例以简单的机械物理混合方式将橄榄石结构材料与三元材料进行混合，可以使小粒径的磷酸锰铁锂或磷酸铁锂混合后分布在镍钴锰酸锂颗粒之间，可以抑制镍钴锰酸锂材料在热失控情况下发生连锁反应， 有利于改善和提高其热稳定性，该技术方案成本较低，易于实现。
图1为本公开的实施例提供的一种正极极片的结构示意图。
参考图1，本公开的实施例还提供一种正极极片01，包括上述任一实施例中所述的正极材料。
例如，参考图1，正极极片01可以包括正极材料100和正极集流体200，正极材料100位于正极流体200的至少一侧，图1以正极集流体200的两侧分别设置有正极材料100进行说明，但不限于此。
在本公开的实施例所提供的正极极片中，通过在正极材料的正极活性物质中将热稳定性较低的第二组分与热稳定性较高的第一组分按照一定比例进行掺混，可使得正极材料的热稳定性得以提高，以具有较高的安全性能。
本公开的实施例还包括一种电池，该电池包括上述实施例中的正极极片01。例如，本公开的实施例提供的电池可以为锂离子电池，但不限于此。例如，关于该电池中的正极材料的各项组成参数请参考上述相关说明，在此不作赘述。
在本公开的实施例所提供的电池中，通过在正极材料的正极活性物质中将热稳定性较高的第一组分与热稳定性较低的第二组分按照一定比例进行掺混，可使得正极材料的热稳定性得以提高，以具有较高的安全性能。
本公开的实施例还包括一种装置，该装置包括上述任一实施例中所提供的电池，且电池被配置为该装置的电源。
例如，本公开的实施例提供的装置可以汽车，例如电动汽车。例如，电动汽车可以为电动纯电动车、混合动力电动车、插电式混合动力电动车中的任意一种，但不限于此。例如，电动汽车可以为电动大巴、电动有轨电车、电动自行车、电动摩托车、电动踏板车、电动高尔夫球车、电动卡车中的任意一种，但不限于此。例如，本公开的实施例提供的装置还可以为电动船舶、电动工具、电子设备及储能系统中的任意一种，但不限于此。
在本公开的实施例所提供的装置中，通过在正极材料的正极活性物质中将热稳定性较低的第二组分与热稳定性较高的第一组分按照一定比例进行掺混，可使得正极材料的热稳定性得以提高，以具有较高的安全性能。
本公开的至少一个实施例还提供一种正极材料的制备方法。该制备方法包括：混合第一组分和第二组分，以制备正极活性物质。
例如，在制备正极材料的过程中，第一组分和第二组分按照以下条件进行选取：第一组分的热稳定性高于第二组分的热稳定性，并使正极活性物质满足：
其中，α为正极材料的特性参数，W1为第一组分占正极活性物质的质量比，W2为第二组分占正极活性物质的质量比，C1为第一组分的克容量，C2为第二组分的克容量，C1和C2的单位为mA·h/g，U1为第一组分的工作电压，U2为第二组分的工作电压，U1和U2的单位为V，T为第二组分在差示扫描量热法表征中的放热峰值处的温度，T的单位为℃。
在制备该正极材料时，需满足：0.8≤α≤1.03。
在制备正极材料的过程中，通过合理地选取第一组分和第二组分，并使得在热稳定性较低的第二组分中掺混热稳定性较高的第一组分，可以降低电池出现产热、释氧等情况，以及在电池发生机械滥用时出现热失控的概率。
因此，通过该制备方法所制备的正极材料，可以使电池在能够满足较大的容量需求的同时，具有较高的安全性能，以具有较大的应用潜力。
例如，在本公开的一些实施例中，在制备正极材料时，可以使得正极活性物质中的第一组分在差示扫描量热法表征中的放热峰值处的温度大于306℃，第二组分在差示扫描量热法表征中的放热峰值处的温度小于或等于306℃，但不限于此。
例如，通过使得第二组分的热稳定性低于第一组分的热稳定性，则第二组分的耐热性能低于第一组分的耐热性能。例如，可以使得第一组分和第二组分的放热峰值温度界限可以为306℃。由此，通过将第二组分与第一组分进行掺混，可以使得正极材料的热稳定性得到改善，以使得电池具有较高的安全性能。
例如，在制备正极材料时，可以使得正极活性物质中第一组分的克容量小于150mA·h/g，第二组分的克容量大于150mA·h/g，但不限于此。
例如，在制备正极材料时，可以使得第一组分的能量密度小于第二组分的能量密度，且第一组分与第二组分的克容量以150mA·h/g为界限。由此，通过将第一组分与第二组分掺混，可以使得正极材料的整体能量密度得到改善，以使得电池具有较高的能量密度。
例如，在制备正极材料时，可以使得正极活性物质占正极材料的质量比为90wt％-98wt％。第一组分占正极材料的质量比为45wt％～49wt％，第二组分占正极材料的质量比为45wt％～49wt％。
例如，在制备正极材料时，关于正极活性物质及其中的第一组分和第二组分的质量比可参见上述实施例中的相关说明，在此不作赘述。
例如，对于本公开至少一个实施例所提供的正极极片，在其制备时，主要包括正极材料的制备、正极集流体的制备等。具体可以包括以下步骤。
步骤(1)、将正极材料设置正极集流体的至少一侧，并进行干燥处理；例如，正极集流体200可采用金属材料，例如铝箔，但不限于此。
步骤(2)、将经过干燥处理的正极极片进行冷压处理。
步骤(3)、将冷压后的正极极片分切后裁剪至规定尺寸。
需要说明的是，本公开的实施例中的正极集流体可以为包括多种材料的复合集流体，例如，正极集流体可以包括支撑层和导电层。例如，导电层可以位于支撑层的两侧，但不限于此。
例如，对于本公开至少一个实施例所提供的电池的制备，还可以包括制备负极极片、电解液以隔离膜等。例如，该电池的制备工艺可以包括下述步骤：
(1)正极极片的制备
例如，关于电池中的正极极片的制备方法可以参见上述实施例中的相关说明，在此不作赘述。
(2)负极极片的制备
例如，电池中的负极极片可以包括负极集流体以及负极材料。例如，可以将负极材料设置在负极集流体的至少一侧。例如，负极材料可以包括负极活性物质，且负极活性物质的组分不受具体限制。例如，负极活性物质可以包括人造石墨、天然石墨、软碳、硬碳、中间相碳微球、硅基材料、锡基材料、钛酸锂中的至少之一。例如，负极集流体还可以包括其他材料，但不限于此，可根据实际需求进行选择。
(3)电解液的制备
例如，电池中的电解液可以包括锂盐以及有机溶剂，但不限于此。例如，锂盐可以包括六氟磷酸锂、四氟硼酸锂、高氯酸锂中的至少一种。例如，有机溶剂可包括环状碳酸酯、链状碳酸酯、羧酸酯中的至少一种。例 如，电解液中还可含有功能添加剂，例如碳酸亚乙烯酯、硫酸乙烯酯、丙磺酸内酯、氟代碳酸乙烯酯等，本公开的至少一个实施例对于电解液的材料不作限制。
(4)隔离膜的制备
例如，电池的隔离膜可以包括聚乙烯膜，但不限于此。
(5)电池的封装
例如，电池进行封装时可以首先将正极极片、隔离膜以及负极极片依次层叠设置，并使得隔离膜位于正极极片与负极极片之间。然后，可以将上述层叠设置后的结构卷绕以得到裸电芯。其次，将该裸电芯设置在电池的外包装壳内，并进行干燥处理，进而注入上述电解液。最终，经过真空封装、静置、化成、整形等工序，得到电池。
针对本公开至少一个实施例所提供的电池，下面以实施例的形式对其特性进行说明。
例如，在电池性能测试过程中，电池的正极极片中的正极材料的正极活性物质的第一组分可以为磷酸铁锂或磷酸锰铁锂，第二组分可以为三元材料。
例如，第一组分在差示扫描量热法表征中的放热峰值处的温度为350℃。例如，第二组分可以为不同镍含量的三元材料，例如，热失控温度为264℃的第二组分(三元材料)中镍含量为60％；例如，热失控温度为306℃的第二组分(三元材料)中镍含量为30％；热失控温度为225℃的第二组分(三元材料)中镍含量为80％；例如，热失控温度为290℃的第二组分(三元材料)中镍含量为50％。例如，电池的负极极片中的负极材料可以包括石墨材料(例如人造石墨或天然石墨)。例如，电池的容量可包括90A·h、20A·h、115A·h、137A·h、160A·h等，但不限于此。
例如，针对上述配置的电池分别进行针刺测试和热箱测试。
例如，针刺测试方法可以包括：将电池以CC-CV的方式充满电后，用Φ5mm的耐高温钢针，以25±5mm/s的速度，从垂直于电池极板的方向贯穿，使钢针停留在电池中1h。例如，针刺测试时采用的仪器为针刺挤压机，针刺仪器的型号为：RJD-ZCJY-HLT-20T-1500D。
例如，热箱测试方法可以包括：将电池以CC-CV的方式充满电后，以2℃/min速率由环境温度升至130℃，保持30min；若电芯不失控，则继续 以2℃/min速率升温，直至220℃，保持30min。例如，热箱仪器为：热滥用温箱，热箱型号为：RJD-VA-1088M。
实施例1
实施例1提供的正极极片所包含的正极材料的正极活性物质中，第一组分为磷酸铁锂，第二组分为镍含量为30％的三元材料，第一组分占正极活性物质的质量比例W1为10％，第二组分在差示扫描量热法表征中的放热峰值处的温度T为306℃，第一组分的克容量C1为140mA·h/g，第二组分的克容量C2为160mA·h/g，第一组分的工作电压U1为3.2V，第二组分的工作电压U2为3.73V，第二组分占正极活性物质的质量比例W2为90％，该电池的正极极片的正极材料的特性比值α为1.027，电池的能量密度为223Wh/kg。针对该电池的针刺结果为：未起火；针对该电池的热箱试验结果为：未起火、未爆炸。
实施例2
实施例2提供的正极极片所包含的正极材料中，第一组分为磷酸铁锂，第二组分为镍含量为50％的三元材料，第一组分占正极活性物质的质量比例W1为25％，第二组分在差示扫描量热法表征中的放热峰值处的温度T为290℃，第一组分的克容量C1为140mA·h/g，第二组分的克容量C2为180mA·h/g，第一组分的工作电压U1为3.2V，第二组分的工作电压U2为3.73V，第二组分占正极活性物质的质量比例W2为75％，该电池的正极极片的正极材料的特性比值α为0.913，电池的能量密度为239Wh/kg。针对该电池的针刺结果为：未起火；针对该电池的热箱试验结果为：未起火、未爆炸。
实施例3
实施例3提供的正极极片所包含的正极材料中，第一组分为磷酸铁锂，第二组分为镍含量为60％的三元材料，第一组分占正极活性物质的质量比例W1为40％，第二组分在差示扫描量热法表征中的放热峰值处的温度T为264℃，第一组分的克容量C1为140mA·h/g，第二组分的克容量C2为190mA·h/g，第一组分的工作电压U1为3.2V，第二组分的工作电压U2为3.73V，第二组分占正极活性物质的质量比例W2为60％，该电池的正极极片的正极材料的特性比值α为0.848，电池的能量密度为244Wh/kg。针对该电池的针刺结果为：未起火；针对该电池的热箱试验结果为：未起火、未爆炸。
实施例4
实施例4提供的正极极片所包含的正极材料中，第一组分为磷酸铁锂，第二组分为镍含量为80％的三元材料，第一组分占正极活性物质的质量比例W1为50％，第二组分在差示扫描量热法表征中的放热峰值处的温度T为225℃，第一组分的克容量C1为140mA·h/g，第二组分的克容量C2为200mA·h/g，第一组分的工作电压U1为3.2V，第二组分的工作电压U2为3.68V，第二组分占正极活性物质的质量比例W2为50％，该电池的正极极片的正极材料的特性比值α为0.806，电池的能量密度为247Wh/kg。针对该电池的针刺结果为：未起火；针对该电池的热箱试验结果为：未起火、未爆炸。
实施例5
实施例5提供的正极极片所包含的正极材料中，第一组分为磷酸铁锂，第二组分为镍含量为80％的三元材料，第一组分占正极活性物质的质量比例W1为10％，第二组分在差示扫描量热法表征中的放热峰值处的温度T为225℃，第一组分的克容量C1为140mA·h/g，第二组分的克容量C2为200mA·h/g，第一组分的工作电压U1为3.2V，第二组分的工作电压U2为3.68V，第二组分占正极活性物质的质量比例W2为90％，该电池的正极极片的正极材料的特性比值α为0.656，电池的能量密度为243Wh/kg。针对该电池的针刺结果为：起火；针对该电池的热箱试验结果为：起火、爆炸。
实施例6
实施例6提供的正极极片所包含的正极材料中，第一组分为磷酸铁锂，第二组分为镍含量为60％的三元材料，第一组分占正极活性物质的质量比例W1为15％，第二组分在差示扫描量热法表征中的放热峰值处的温度T为264℃，第一组分的克容量C1为140mA·h/g，第二组分的克容量C2为190mA·h/g，第一组分的工作电压U1为3.2V，第二组分的工作电压U2为3.73V，第二组分占正极活性物质的质量比例W2为85％，该电池的正极极片的正极材料的特性比值α为0.791，电池的能量密度为235Wh/kg。针对该电池的针刺结果为：起火；针对该电池的热箱试验结果为：起火、爆炸。
实施例7
实施例7提供的正极极片所包含的正极材料中，第一组分为磷酸锰铁锂，第二组分为镍含量为30％的三元材料，第一组分占正极活性物质的质量比例W1为5％，第二组分在差示扫描量热法表征中的放热峰值处的温度T为306℃，第一组分的克容量C1为145mA·h/g，第二组分的克容量C2为160 mA·h/g，第一组分的工作电压U1为4V，第二组分的工作电压U2为3.73V，第二组分占正极活性物质的质量比例W2为95％，该电池的正极极片的正极材料的特性比值α为1.033，电池的能量密度为225Wh/kg。针对该电池的针刺结果为：未起火；针对该电池的热箱试验结果为：起火、爆炸。
实施例8
实施例8提供的正极极片所包含的正极材料中，第一组分为磷酸锰铁锂，第二组分为镍含量为80％的三元材料，第一组分占正极活性物质的质量比例W1为15％，第二组分在差示扫描量热法表征中的放热峰值处的温度T为225℃，第一组分的克容量C1为145mA·h/g，第二组分的克容量C2为200mA·h/g，第一组分的工作电压U1为4V，第二组分的工作电压U2为3.68V，第二组分占正极活性物质的质量比例W2为85％，该电池的正极极片的正极材料的特性比值α为0.663，电池的能量密度为248Wh/kg。针对该电池的针刺结果为：起火；针对该电池的热箱试验结果为：起火、爆炸。
实施例9
实施例9提供的正极极片所包含的正极材料中，第一组分为磷酸锰铁锂，第二组分为镍含量为60％的三元材料，第一组分占正极活性物质的质量比例W1为40％，第二组分在差示扫描量热法表征中的放热峰值处的温度T为264℃，第一组分的克容量C1为145mA·h/g，第二组分的克容量C2为190mA·h/g，第一组分的工作电压U1为4V，第二组分的工作电压U2为3.73V，第二组分占正极活性物质的质量比例W2为60％，该电池的正极极片的正极材料的特性比值α为0.81，电池的能量密度为250Wh/kg。针对该电池的针刺结果为：未起火；针对该电池的热箱试验结果为：未起火、未爆炸。
表1示出了的实施例1-9及对应参数及测试结果。
表1

例如，根据表1可知，当正极材料满足：
且0.8≤α≤1.03时，
设置有该正极材料的电池能够通过针刺测试和热箱测试，即电池在针刺试验时的结果为：未起火，且在热箱试验的结果为：未起火、未爆炸。
如表1所示，对于正极材料的正极活性物质中的第二组分，当镍含量不同时，第二组分所对应的克容量不同。例如，当第一组分采用磷酸铁锂时，对应的克容量为140mA·h/g。例如，当第一组分采用磷酸锰铁锂时，对应的克容量为145mA·h/g。如表1中的实施例5-6、以及实施例8，当α小于0.8时，电池未能通过针刺测试和热箱测试。
如表1中的实施例1-4、以及实施例7和实施例9，电池均能通过针刺测试和热箱测试。在此，需要说明的是，在本公开的实施例中，正极材料中的α所满足的数值范围，可以具有一定的波动范围，例如，该波动范围可以为0.5％～0.1％，但不限于此。同时，当电池在通过针刺测试和热箱测试的情况下，电池的能量密度可以保持在一个较高的水平。例如，根据实施例1-4、以及实施例7和实施例9，电池的能量密度均大于220Wh/Kg。
由此，本公开的实施例所提供的正极材料，可以使电池能够满足较大的容量需求的同时，具有较高的安全性能，应用潜力较大。
在不冲突的情况下，本公开的同一实施例及不同实施例中的特征可以相互组合。
以上所述，仅为本公开的具体实施方式，但本公开的保护范围并不局限于此，任何熟悉本技术领域的技术人员在本公开揭露的技术范围内，可轻易想到变化或替换，都应涵盖在本公开的保护范围之内。因此，本公开的保护范围应以所述权利要求的保护范围为准。

Claims (16)

  1. 一种正极材料，包括正极活性物质，
    所述正极活性物质包括第一组分和第二组分，所述第一组分的热稳定性高于所述第二组分的热稳定性，所述正极材料满足：
    其中，α为所述正极材料的特性参数，W1为所述第一组分占所述正极活性物质的质量比，W2为所述第二组分占所述正极活性物质的质量比，C1为所述第一组分的克容量，C2为所述第二组分的克容量，C1和C2的单位为mA·h/g，U1为所述第一组分的工作电压，U2为所述第二组分的工作电压，U1和U2的单位为V，T为所述第二组分在差示扫描量热法表征中的放热峰值处的温度，T的单位为℃，
    其中，0.8≤α≤1.03。
  2. 根据权利要求1所述的正极材料，其中，
    所述第一组分在差示扫描量热法表征中的放热峰值处的温度大于306℃，所述第二组分在差示扫描量热法表征中的放热峰值处的温度小于或等于306℃。
  3. 根据权利要求1或2所述的正极材料，其中，所述第一组分的克容量小于150mA·h/g，所述第二组分的克容量大于或等于150mA·h/g。
  4. 根据权利要求1～3任一项所述的正极材料，其中，
    所述第一组分包括橄榄石材料和尖晶石材料至少之一；
    所述第二组分包括层状结构材料，所述层状结构材料包括三元材料、钴酸锂、镍酸锂中的至少之一。
  5. 根据权利要求1～4任一项所述的正极材料，其中，所述第一组分包括磷酸铁锂、磷酸锰铁锂及锰酸锂中的至少之一。
  6. 根据权利要求1～5任一项所述的正极材料，其中，所述正极活性物质占所述正极材料的质量比为90wt％-98wt％，
    所述第一组分占所述正极材料的质量比为45wt％～49wt％，所述第二组分占所述正极材料的质量比为45wt％～49wt％。
  7. 根据权利要求1～6任一项所述的正极材料，还包括：正极导电剂以 及正极粘结剂，其中，
    所述正极导电剂占所述正极材料的质量比为1wt％-5wt％；
    所述正极粘结剂占所述正极材料的质量比为1wt％-5wt％。
  8. 根据权利要求1～7任一项所述的正极材料，其中，所述第一组分包括LiMnxFe(1-x)PO4，且0≤x≤0.6，
    所述第一组分的克容量C1为140mA·h/g～160mA·h/g，所述第一组分的工作电压U1为3.2V或4.0V。
  9. 根据权利要求1～8任一项所述的正极材料，其中，所述第二组分包括LiNizMnyCo(1-z-y)O2，且0＜z＜1，0＜y＜1，0＜1-z-y＜1；
    所述第二组分的克容量C2为150mA·h/g～220mA·h/g，所述第二组分的工作电压U2为3.6V～3.75V。
  10. 一种正极极片，包括如权利要求1～9任一项所述的正极材料。
  11. 一种电池，包括如权利要求10所述的正极极片。
  12. 一种装置，包括如权利要求11所述的电池，所述电池被配置为作为所述装置的电源。
  13. 一种正极材料的制备方法，包括：
    混合第一组分和第二组分，以制备正极活性物质，
    其中，所述第一组分的热稳定性高于所述第二组分的热稳定性，并使所述正极活性物质满足：
    其中，α为所述正极材料的特性参数，W1为所述第一组分占所述正极活性物质的质量比，W2为所述第二组分占所述正极活性物质的质量比，C1为所述第一组分的克容量，C2为所述第二组分的克容量，C1和C2的单位为mA·h/g，U1为所述第一组分的工作电压，U2为所述第二组分的工作电压，U1和U2的单位为V，T为所述第二组分在差示扫描量热法表征中的放热峰值处的温度，T的单位为℃，
    其中，0.8≤α≤1.03。
  14. 根据权利要求13所述的正极材料的制备方法，其中，
    所述第一组分在差示扫描量热法表征中的放热峰值处的温度大于306℃，所述第二组分在差示扫描量热法表征中的放热峰值处的温度小于或等于 306℃。
  15. 根据权利要求13或14所述的正极材料的制备方法，其中，所述第一组分的克容量小于150mA·h/g，所述第二组分的克容量大于或等于150mA·h/g。
  16. 根据权利要求13～15任一项所述的正极材料的制备方法，其中，所述正极活性物质占所述正极材料的质量比为90wt％-98wt％，
    所述第一组分占所述正极材料的质量比为45wt％～49wt％，所述第二组分占所述正极材料的质量比为45wt％～49wt％。
PCT/CN2023/134282 2022-11-28 2023-11-27 正极材料及其制备方法、正极极片、电池、以及装置 Ceased WO2024114565A1 (zh)

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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101295780A (zh) * 2007-04-28 2008-10-29 深圳市比克电池有限公司 锂离子二次电池正极活性材料组合物及电池
CN112447964A (zh) * 2019-09-02 2021-03-05 宁德时代新能源科技股份有限公司 正极活性材料、正极极片及锂离子二次电池
CN115312762A (zh) * 2022-08-24 2022-11-08 上海兰钧新能源科技有限公司 活性物质、正极材料、正极、电池、电池装置和方法
CN115377358A (zh) * 2022-09-29 2022-11-22 欣旺达电动汽车电池有限公司 二次电池和用电设备
CN115692678A (zh) * 2022-11-28 2023-02-03 上海兰钧新能源科技有限公司 正极材料及其制备方法、正极极片、电池、以及装置

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101295780A (zh) * 2007-04-28 2008-10-29 深圳市比克电池有限公司 锂离子二次电池正极活性材料组合物及电池
CN112447964A (zh) * 2019-09-02 2021-03-05 宁德时代新能源科技股份有限公司 正极活性材料、正极极片及锂离子二次电池
CN115312762A (zh) * 2022-08-24 2022-11-08 上海兰钧新能源科技有限公司 活性物质、正极材料、正极、电池、电池装置和方法
CN115377358A (zh) * 2022-09-29 2022-11-22 欣旺达电动汽车电池有限公司 二次电池和用电设备
CN115692678A (zh) * 2022-11-28 2023-02-03 上海兰钧新能源科技有限公司 正极材料及其制备方法、正极极片、电池、以及装置

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP4583197A4

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