WO2025217829A1 - 一种电化学装置及电子装置 - Google Patents

一种电化学装置及电子装置

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Publication number
WO2025217829A1
WO2025217829A1 PCT/CN2024/088255 CN2024088255W WO2025217829A1 WO 2025217829 A1 WO2025217829 A1 WO 2025217829A1 CN 2024088255 W CN2024088255 W CN 2024088255W WO 2025217829 A1 WO2025217829 A1 WO 2025217829A1
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Prior art keywords
positive electrode
negative electrode
cobalt oxide
electrode material
lithium cobalt
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PCT/CN2024/088255
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English (en)
French (fr)
Inventor
黄星晨
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Ningde Amperex Technology Ltd
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Ningde Amperex Technology Ltd
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Priority to PCT/CN2024/088255 priority Critical patent/WO2025217829A1/zh
Publication of WO2025217829A1 publication Critical patent/WO2025217829A1/zh
Pending legal-status Critical Current
Anticipated expiration legal-status Critical

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—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
    • H01M4/131—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
    • H01M4/36—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

Definitions

  • the present application relates to the field of electrochemical technology, and in particular to an electrochemical device and an electronic device.
  • Electrochemical devices such as lithium-ion batteries, are widely used in wearable devices, smartphones, drones, laptops, electric vehicles and other fields due to their advantages such as high operating voltage, high energy density, environmental friendliness and cycle stability.
  • the purpose of this application is to provide an electrochemical device and an electronic device to improve the energy density, high-temperature cycle performance, and rate performance of the electrochemical device.
  • the specific technical solution is as follows:
  • the first aspect of the present application provides an electrochemical device, which includes a positive electrode plate, a negative electrode plate and a separator, wherein the positive electrode plate includes a positive electrode current collector and a positive electrode material layer arranged on at least one surface of the positive electrode current collector, the positive electrode material layer includes a positive electrode material, the positive electrode material includes lithium cobalt oxide with a P63mc structure, and in the XRD spectrum of the positive electrode material layer, the characteristic peak of the (002) crystal plane of the lithium cobalt oxide with the P63mc structure is located between 17° and 19°; the negative electrode plate includes a negative electrode current collector and a negative electrode material layer arranged on at least one surface of the negative electrode current collector, the negative electrode material layer includes a negative electrode material, and the negative electrode material includes hard carbon and graphite.
  • the positive electrode material includes a lithium cobalt oxide with a P63mc structure, and the characteristic peak of the (002) crystal plane of the lithium cobalt oxide with the P63mc structure is regulated to be between 17° and 19°.
  • the Li-O octahedron of the lithium cobalt oxide with the P63mc structure is connected to the Co-O octahedron on both sides in a co-edge and co-plane manner, respectively. Co is extremely difficult to migrate to the Li site, and a stable structure can be maintained at a higher charging voltage, so that the electrochemical device has a higher energy density while maintaining good high-temperature cycle performance.
  • the interlayer spacing of the Co-O octahedron layer of the lithium cobalt oxide with the P63mc structure is large, which is conducive to the insertion and extraction of Li + , and can improve the rate performance of the electrochemical device.
  • the negative electrode material of the present application includes hard carbon and graphite. The hard carbon can meet the insertion and extraction of Na + , and can form an SEI film of appropriate thickness during the first cycle of charging, thereby reducing the consumption of active lithium. By matching the positive electrode material and the negative electrode material, the high-temperature cycle performance of the electrochemical device can be further improved.
  • the characteristic peak of the (002) crystal plane of the P63mc structure lithium cobalt oxide is located between 18.3° and 18.7°.
  • the mass percentage of the hard carbon is w%, based on the mass of the negative electrode material, with 1 ⁇ w ⁇ 10.
  • the hard carbon can meet the requirements of Na + insertion and extraction, and can form a SEI film of appropriate thickness during the first cycle of charging, thereby reducing the consumption of active lithium, and can achieve a higher energy density of the electrochemical device while further improving the high-temperature cycling performance of the electrochemical device.
  • the lithium cobalt oxide with a P63mc structure comprises LixNayCo1 - abAaBbO2 , wherein A comprises at least one of Mn, Fe, or Ni, B comprises at least one of Al, Mg, Ti, La, Y, Zr, Zn, Cu, Cr, Ca, Ce, or Lu, and 0.779 ⁇ x ⁇ 0.95 , 0 ⁇ y ⁇ 0.001, 0 ⁇ a ⁇ 0.2, and 0 ⁇ b ⁇ 0.02.
  • This configuration further improves the structural stability of the positive electrode material, enabling the electrochemical device to have higher energy density and rate capability while further enhancing the high-temperature cycling performance of the electrochemical device.
  • the positive electrode material further comprises a lithium cobalt oxide with an R-3m structure.
  • the characteristic peak of the (003) crystal plane of the R-3m lithium cobalt oxide is located between 18° and 20°; the intensity of the characteristic peak of the (003) crystal plane of the R-3m lithium cobalt oxide is I 1 , and the intensity of the characteristic peak of the (002) crystal plane of the P63mc lithium cobalt oxide is I 2 , with 0 ⁇ I 1 /I 2 ⁇ 20.
  • the positive electrode material comprises a lithium cobalt oxide with an R-3m structure, and the values of the characteristic peak of the (003) crystal plane and I 1 /I 2 of the R-3m lithium cobalt oxide are regulated within the scope of the present application. This can improve the energy density of the electrochemical device while also taking into account the high-temperature cycling performance of the electrochemical device.
  • the R-3m structured lithium cobalt oxide includes LiCo1 -mnAlmCnO2 , wherein C includes at least one of Mg , Ti, La, Y, Zr, or Lu, 0 ⁇ m ⁇ 0.1, and 0 ⁇ n ⁇ 0.05. This configuration can further improve the high-temperature cycling performance of the electrochemical device.
  • the positive electrode material layer further includes a positive electrode binder and a positive electrode conductor.
  • the mass percentage of the positive electrode binder is m 1
  • the mass percentage of the positive electrode conductor is m 2 , satisfying 0 ⁇ m 1 ⁇ 10, and 0 ⁇ m 2 ⁇ 10.
  • the negative electrode material layer further includes a negative electrode binder, a thickener, and a negative electrode conductor.
  • the mass percentage of the negative electrode binder is m3 %
  • the mass percentage of the thickener is m4 %
  • the mass percentage of the negative electrode conductor is m5 %, satisfying 0 ⁇ m3 ⁇ 5, 0 ⁇ m4 ⁇ 5, and 0 ⁇ m5 ⁇ 5.
  • the capacity of the positive electrode plate with metallic lithium as the counter electrode in the potential range of 3.0V to 4.6V is d
  • the capacity of the negative electrode plate with metallic lithium as the counter electrode in the potential range of 0.005V to 0.8V is c, and 1.00 ⁇ c/d ⁇ 1.05.
  • the bonding force between the separator and the positive electrode plate is F N/m, where 1 ⁇ F ⁇ 50.
  • the bonding force between the separator and the positive electrode plate is within the range of the present application, indicating that the separator and the positive electrode plate have high bonding force, which is beneficial to improving the safety performance of the electrochemical device.
  • the upper charging voltage limit of the electrochemical device is 4.5 V to 4.75 V. This indicates that the upper charging voltage limit of the electrochemical device of the present application is high and has a wide range of application scenarios.
  • the second aspect of the present application provides an electronic device, which includes the electrochemical device in any of the above embodiments. Therefore, the electrochemical device provided by the present application has good performance.
  • the present application provides an electrochemical device and an electronic device, the electrochemical device comprising a positive electrode sheet, a negative electrode sheet, and a separator.
  • the positive electrode sheet comprises a positive electrode current collector and a positive electrode material layer disposed on at least one surface of the positive electrode current collector, the positive electrode material layer comprising a positive electrode material, the positive electrode material comprising lithium cobalt oxide having a P63mc structure, and an XRD pattern of the positive electrode material layer showing a characteristic peak of the (002) crystal plane of the lithium cobalt oxide having the P63mc structure located between 17° and 19°.
  • the negative electrode sheet comprises a negative electrode current collector and a negative electrode material layer disposed on at least one surface of the negative electrode current collector, the negative electrode material layer comprising a negative electrode material, the negative electrode material comprising hard carbon and graphite.
  • FIG1 is a diagram showing the high temperature cycle performance test results of the embodiments of the present application and the comparative example
  • FIG2 is a graph showing the rate performance test results of the examples and comparative examples of the present application.
  • FIG3 is an X-ray diffraction pattern of the positive electrode of Example 1-1 of the present application.
  • FIG4 is an X-ray diffraction pattern of the positive electrode of Example 2-2 of the present application.
  • FIG5 is an X-ray diffraction pattern of the positive electrode of Comparative Example 2-1 of the present application.
  • FIG6 is a scanning electron microscope image of the negative electrode of Example 1-1 of the present application.
  • a lithium-ion battery is used as an example of an electrochemical device to explain the present application, but the electrochemical device of the present application is not limited to a lithium-ion battery.
  • the first aspect of the present application provides an electrochemical device comprising a positive electrode plate, a negative electrode plate, and a separator, wherein the positive electrode plate comprises a positive electrode current collector and a positive electrode material layer disposed on at least one surface of the positive electrode current collector, the positive electrode material layer comprising a positive electrode material, the positive electrode material comprising a lithium cobalt oxide with a P63mc structure, and in the XRD pattern of the positive electrode material layer, the characteristic peak of the (002) crystal plane of the lithium cobalt oxide with the P63mc structure is located between 17° and 19°.
  • the position of the characteristic peak of the (002) crystal plane of the lithium cobalt oxide with the P63mc structure can be 17°, 17.3°, 17.5°, 17.8°, 18°, 18.3°, 18.5°, 18.8°, 19°, or a range consisting of any two of these values.
  • Figure 3 is an XRD pattern of the lithium cobalt oxide with a P63mc structure in one embodiment of the present application, wherein the position of the characteristic peak of the (002) crystal plane is 18.5°.
  • the negative electrode sheet includes a negative electrode current collector and a negative electrode material layer disposed on at least one surface of the negative electrode current collector.
  • the negative electrode material layer includes a negative electrode material, and the negative electrode material includes hard carbon and graphite.
  • the graphite includes at least one of natural graphite and artificial graphite.
  • the inventors have discovered that the Li-O octahedron of lithium cobalt oxide with a P63mc structure is connected to the Co-O octahedron on both sides with co-edges and co-planarities, respectively. It is extremely difficult for Co to migrate to the Li site.
  • the lithium cobalt oxide with a P63mc structure can still maintain good structural stability under high charging voltage conditions, which can enable the electrochemical device to have a high energy density while maintaining good high-temperature cycle performance.
  • the interlayer spacing of the Co-O octahedron layer of the lithium cobalt oxide with a P63mc structure is large, which is conducive to the insertion and extraction of Li + , and can improve the rate performance of the electrochemical device.
  • the lithium cobalt oxide with a P63mc structure contains a small amount of Na + between the layers, which is doped in the Li layer. During the cycle of the electrochemical device, a small amount of Na + will be extracted from the Li site as the charge and discharge proceeds, and migrate to the negative electrode together with Li + .
  • the negative electrode materials of the present application include hard carbon and graphite.
  • the hard carbon can meet the needs of Na + embedding and extraction, and can form a SEI film of suitable thickness during the first cycle of charging, thereby reducing the consumption of active lithium.
  • the high-temperature cycle performance of the electrochemical device can be further improved by matching the positive electrode material and the negative electrode material.
  • "high charging voltage” refers to a charging upper limit voltage greater than or equal to 4.5V.
  • the characteristic peak of the (002) crystal plane of the lithium cobalt oxide with a P63mc structure is located between 18.3° and 18.7°.
  • the position of the characteristic peak of the (002) crystal plane of the lithium cobalt oxide with a P63mc structure can be 18.3°, 18.4°, 18.5°, 18.6°, 18.7°, or a range consisting of any two of these values.
  • the mass percentage of hard carbon is w%, based on the mass of the negative electrode material. 1 ⁇ w ⁇ 10.
  • the mass percentage of hard carbon can be 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, or a range consisting of any two of these values.
  • the negative electrode material includes hard carbon, which can meet the requirements of Na + insertion and extraction, and can form a SEI film of suitable thickness during the first cycle of charging, thereby reducing the consumption of active lithium. By regulating the mass percentage of hard carbon w% within the scope of this application, the electrochemical device can have a higher energy density while further improving the high-temperature cycle performance of the electrochemical device.
  • the lithium cobalt oxide of P63mc structure includes Li x Na y Co 1-ab A a B b O 2 , wherein A includes at least one of Mn, Fe or Ni, B includes at least one of Al, Mg, Ti, La, Y, Zr, Zn, Cu, Cr, Ca, Ce or Lu, 0.779 ⁇ x ⁇ 0.95, 0 ⁇ y ⁇ 0.001, 0 ⁇ a ⁇ 0.2, and 0 ⁇ b ⁇ 0.02.
  • the value of x can be 0.779, 0.8, 0.82, 0.85, 0.88, 0.9, 0.92, 0.95, or a range consisting of any two of these values;
  • the value of y can be 0.00001, 0.0001, 0.0003, 0.0005, 0.0008, 0.001, or a range consisting of any two of these values;
  • the value of a can be 0.001, 0.01, 0.05, 0.08, 0.1, 0.13, 0.15, 0.18, 0.2, or a range consisting of any two of these values;
  • the value of b can be 0, 0.001, 0.01, 0.013, 0.015, 0.018, 0.02, or a range consisting of any two of these values.
  • the lithium cobalt oxide of P63mc structure may include but is not limited to Li 0.9495 Na 0.0005 Co 0.95 Fe 0.02 Ni 0.01 Mn 0.01 Al 0.01 O 2 , Li 0.9495 Na 0.0005 Co 0.95 Fe 0.04 Al 0.01 O 2 , Li 0.9495 Na 0.0005 Co 0.95 Ni 0.02 Mn 0.02 Al 0.01 O 2 , Li 0.9495 Na 0.0005 Co 0.95 Fe 0.03 Mn 0.01 Cu 0.01 O 2 , Li 0.9495 Na 0.0005 Co 0.95 Fe 0.03 Ni 0.01 Ti 0.01 O 2 , and Li 0.9495 Na 0.0005 Co 0.95 Fe 0.02 Ni 0.01 Mn 0.01 Al 0.01 O 2 , Li 0.937 Na 0.0005 Co 0.9375 Fe 0.03 Ni 0.01 Mn 0.01 Al 0.0125 O 2 , Li 0.9245 Na 0.0005 Co 0.925 Fe 0.04 Ni 0.01 Mn 0.01 Al 0.015 O 2 , Li 0.8 Na 0.0005 Co 0.95 Fe 0.02 Ni 0.01
  • the positive electrode material further comprises a lithium cobalt oxide of R-3m structure.
  • the characteristic peak of the (003) crystal plane of the lithium cobalt oxide of R-3m structure is located between 18° and 20°; the intensity of the characteristic peak of the (003) crystal plane of the lithium cobalt oxide of R-3m structure is I 1 , and the intensity of the characteristic peak of the (002) crystal plane of the lithium cobalt oxide of P63mc structure is I 2 , 0 ⁇ I 1 /I 2 ⁇ 20.
  • the position of the characteristic peak of the (003) crystal plane of the lithium cobalt oxide of R-3m structure is
  • the value of I 1 /I 2 may be 0 , 1, 3, 5, 8, 10 , 13, 15, 18, 20, or a range consisting of any two values.
  • the positive electrode material includes lithium cobalt oxide with an R-3m structure, and the (003) crystal plane characteristic peak and I 1 /I 2 value of the R-3m structure lithium cobalt oxide are regulated within the scope of the present application, which can significantly improve the first discharge mass specific capacity of the electrochemical device, that is, improve the energy density of the electrochemical device while taking into account the high-temperature cycle performance of the electrochemical device.
  • the R-3m lithium cobalt oxide comprises LiCo1 -mnAlmCnO2 , wherein C comprises at least one of Mg, Ti, La, Y, Zr, or Lu, 0 ⁇ m ⁇ 0.1, and 0 ⁇ n ⁇ 0.05.
  • C comprises at least one of Mg, Ti, La, Y, Zr, or Lu, 0 ⁇ m ⁇ 0.1, and 0 ⁇ n ⁇ 0.05.
  • the value of m can be 0.001, 0.01, 0.03, 0.05 , 0.08, 0.1, or a range consisting of any two thereof
  • the value of n can be 0, 0.001, 0.005, 0.01, 0.02, 0.03, 0.04, 0.05, or a range consisting of any two thereof.
  • the lithium cobalt oxide of R-3m structure may include but is not limited to LiCo 0.97 Al 0.03 O 2 , LiCo 0.965 Al 0.03 Mg 0.005 O 2 , LiCo 0.96 Al 0.03 Mg 0.005 Ti 0.005 O 2 , LiCo 0.9 Al 0.1 O 2 , LiCo 0.92 Al 0.03 Mg 0.01 Ti 0.01 La 0.01 Y 0.01 Zr 0.01 O 2 , LiCo 0.999 Al 0.001 O 2 , LiCo 0.99 Al 0.01 O 2 , LiCo 0.95 Co 0.05 O 2 , LiCo 0.969 Al 0.03 Y 0.001 O 2 , LiCo 0.93 Al 0.03 Mg 0.01 Ti 0.01 La 0.01 Y 0.01 O 2 , LiCo 0.9 Al 0.08 Mg 0.005 Ti 0.005 La 0.005 Y 0.005 O 2 etc.
  • the positive electrode material layer further includes a positive electrode binder and a positive electrode conductive agent. Based on the mass of the positive electrode material layer, the mass percentage of the positive electrode binder is m 1 , and the mass percentage of the positive electrode conductive agent is m 2 , satisfying 0 ⁇ m 1 ⁇ 10, and 0 ⁇ m 2 ⁇ 10.
  • the mass percentage of the positive electrode binder m 1 % can be 0.1%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, or a range consisting of any two values therein;
  • the mass percentage of the positive electrode conductive agent m 2 % can be 0.1%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, or a range consisting of any two values therein.
  • the negative electrode material layer further includes a negative electrode binder, a thickener and a negative electrode conductor.
  • the mass percentage of the negative electrode binder is m 3
  • the mass percentage of the thickener is m 4
  • the mass percentage of the conductor is m 5 , satisfying 0 ⁇ m 3 ⁇ 5, 0 ⁇ m 4 ⁇ 5, and 0 ⁇ m 5 ⁇ 5.
  • the mass percentage content m3 % of the negative electrode binder can be 0.1%, 0.5%, 1%, 2%, 3%, 4%, 5% or a range consisting of any two values therein;
  • the mass percentage content m4 % of the thickener can be 0.1%, 0.5%, 1%, 2%, 3%, 4%, 5% or a range consisting of any two values therein;
  • the mass percentage content m5 % of the negative electrode conductive agent can be 0.1%, 0.5%, 1%, 2%, 3%, 4%, 5% or a range consisting of any two values therein.
  • the capacity of the positive electrode plate with metallic lithium as the counter electrode in the potential range of 3.0V to 4.6V is d
  • the capacity of the negative electrode plate with metallic lithium as the counter electrode in the potential range of 0.005V to 0.8V is c, and 1.00 ⁇ c/d ⁇ 1.05.
  • the value of c/d can be 1.01, 1.02, 1.03, 1.04, 1.05, or a range consisting of any two of these values.
  • the negative electrode capacity is slightly greater than the positive electrode capacity, which can enable the electrochemical device to have a higher energy density and good high-temperature cycling performance while also having good safety performance.
  • the bonding force between the separator and the positive electrode sheet is F N/m, 1 ⁇ F ⁇ 50.
  • the bonding force F between the separator and the positive electrode sheet can be 1 N/m, 10 N/m, 20 N/m, 30 N/m, 40 N/m, 50 N/m, or a range consisting of any two of these values.
  • the bonding force between the separator and the positive electrode sheet is within the range of the present application, indicating that the separator and the positive electrode sheet have high bonding force, which is beneficial to improving the energy density and safety performance of the electrochemical device.
  • the upper charge voltage limit of the electrochemical device is 4.5V to 4.75V.
  • the upper charge voltage limit can be 4.5V, 4.55V, 4.6V, 4.65V, 4.7V, 4.75V, or a range consisting of any two of these values.
  • the upper charge voltage limit of the electrochemical device is 4.5V to 4.75V, indicating that the electrochemical device of the present application has a high upper charge voltage limit and a wide range of application scenarios.
  • the preparation method of the lithium cobalt oxide with a P63mc structure, LixNayCo1 - abAaBbO2 may include, but is not limited to, the following steps: using a cobalt source material, a source material A, and a source material B as raw materials, and preparing the raw materials according to the stoichiometric ratio of the lithium cobalt oxide with a P63mc structure, LixNayCo1-abAaBbO2 ; dissolving the raw materials in water in a reaction kettle, stirring under a nitrogen atmosphere, and adding an alkaline source solution to the reaction kettle during stirring, and adjusting the pH of the solution in the reaction kettle to 10 to 12.
  • Stirring is continued for 10 to 14 hours, filtering to obtain a precipitate, washing with deionized water three times, and vacuum drying at 60°C to 100°C for 20 to 26 hours to obtain a precursor powder.
  • the precursor and the sodium source material are ball-milled and mixed uniformly.
  • the ball-milled mixture is then placed in a muffle furnace and heat-treated at 700° C. to 900° C. for 20 to 24 hours under an air atmosphere. A sample is taken out, crushed, ground, and sieved.
  • the cobalt source material may include, but is not limited to, at least one of cobalt sulfate, cobalt carbonate, cobalt chloride, or cobalt nitrate
  • the A source material may include, but is not limited to, at least one of manganese sulfate, manganese nitrate, manganese chloride, ferric chloride, ferric sulfate, ferric nitrate, nickel chloride, nickel nitrate, or nickel sulfate
  • the B source material may include, but is not limited to, at least one of aluminum nitrate, magnesium sulfate, copper sulfate, or titanium dioxide
  • the alkali source may include, but is not limited to, at least one of sodium hydroxide or am
  • the present application does not particularly limit the preparation method of the lithium cobalt oxide with an R-3m structure, as long as the purpose of the present application can be achieved.
  • the preparation method of the lithium cobalt oxide with an R-3m structure LiCo 1-mn Al m C n O 2 may include, but is not limited to, the following steps: LiCoO 2 (CAS No.: 12190-79-3), an aluminum source material, and a carbon source material are uniformly mixed, transferred to a corundum crucible, sintered at 950° C. to 1050° C.
  • the aluminum source material and the carbon source material are not particularly limited in this application and can be selected based on actual needs, as long as they can achieve the objectives of this application.
  • the aluminum source material may include, but is not limited to, aluminum oxide
  • the carbon source material may include, but is not limited to, at least one of magnesium sulfate, titanium dioxide, or lanthanum trioxide.
  • the positive electrode sheet of the present application includes a positive electrode current collector and a positive electrode material layer arranged on at least one surface of the positive electrode current collector.
  • the present application has no special restrictions on the positive electrode current collector, as long as the purpose of the present application can be achieved.
  • the positive electrode current collector may include aluminum foil, aluminum alloy foil or a composite current collector (such as an aluminum-carbon composite current collector), etc.
  • there is no special restriction on the thickness of the positive electrode current collector and the positive electrode material layer as long as the purpose of the present application can be achieved.
  • the thickness of the positive electrode current collector is 5 ⁇ m to 20 ⁇ m.
  • the thickness of the single-sided positive electrode material layer is 30 ⁇ m to 120 ⁇ m.
  • the positive electrode material layer can be arranged on one surface in the thickness direction of the positive electrode current collector, or on two surfaces in the thickness direction of the positive electrode current collector. It should be noted that the "surface” here can be the entire area of the positive electrode current collector or a partial area of the positive electrode current collector.
  • the present application has no special restrictions, as long as the purpose of the present application can be achieved.
  • the conductive agent may include but is not limited to at least one of conductive carbon black (Super P), carbon nanotubes (CNTs), carbon fibers, flake graphite, graphene, metal materials or conductive polymers.
  • the above-mentioned carbon nanotubes may include but are not limited to single-walled carbon nanotubes and/or multi-walled carbon nanotubes.
  • the above-mentioned carbon fibers may include but are not limited to vapor-grown carbon fibers (VGCF) and/or nano-carbon fibers.
  • the above-mentioned metal materials may include but are not limited to metal powder and/or metal fibers.
  • the metal may include but is not limited to at least one of copper, nickel, aluminum or silver.
  • the above-mentioned conductive polymers may include but are not limited to at least one of polyphenylene derivatives, polyaniline, polythiophene, polyacetylene or polypyrrole.
  • the binder may include but is not limited to polyacrylic acid, sodium polyacrylate, potassium polyacrylate, lithium polyacrylate, polyimide, polyvinyl alcohol, At least one of carboxymethyl cellulose, sodium carboxymethyl cellulose, lithium carboxymethyl cellulose, polyimide, polyamide-imide, styrene-butadiene rubber or polyvinylidene fluoride.
  • the negative electrode sheet of the present application includes a negative electrode current collector and a negative electrode material layer disposed on at least one surface of the negative electrode current collector.
  • the negative electrode material layer can be disposed on one surface of the negative electrode current collector in the thickness direction, or on both surfaces of the negative electrode current collector in the thickness direction.
  • the "surface” here can be the entire area of the negative electrode current collector or a part of the negative electrode current collector. This application has no special restrictions, as long as the purpose of this application can be achieved. This application has no special restrictions on the negative electrode current collector, as long as the purpose of this application can be achieved.
  • the negative electrode current collector can include but is not limited to copper foil, copper alloy foil, nickel foil, titanium foil, foamed nickel, foamed copper or a composite current collector.
  • the thickness of the negative electrode current collector and the negative electrode material layer there is no special restriction on the thickness of the negative electrode current collector and the negative electrode material layer, as long as the purpose of this application can be achieved.
  • the thickness of the negative electrode current collector is 4 ⁇ m to 15 ⁇ m
  • the thickness of the single-sided negative electrode material layer is 30 ⁇ m to 130 ⁇ m.
  • the present application does not particularly limit the types of the negative electrode binder, thickener, and negative electrode conductor in the negative electrode material layer, as long as the purpose of the present application can be achieved.
  • the conductive agent and binder can be at least one of the above-mentioned conductive agents and binders.
  • the thickener can include, but is not limited to, at least one of sodium carboxymethyl cellulose or lithium carboxymethyl cellulose.
  • the material of the isolation membrane may include but is not limited to polyethylene (PE), polypropylene (PP)-based polyolefins (PO), polyesters (such as polyethylene terephthalate (PET) film), cellulose, polyimide (PI), polyamide (PA), spandex or aramid.
  • the type of isolation membrane may include at least one of a woven membrane, a non-woven membrane (non-woven fabric), a microporous membrane, a composite membrane, a rolled membrane or a spun membrane.
  • the isolation membrane of the present application may have a porous structure, and the porous layer is provided on at least one surface of the isolation membrane, and the porous layer includes inorganic particles and a binder.
  • the inorganic particles may include at least one of aluminum oxide, silicon oxide, magnesium oxide, titanium oxide, hafnium dioxide, tin oxide, cerium dioxide, nickel oxide, zinc oxide, calcium oxide, zirconium oxide, yttrium oxide, silicon carbide, boehmite, aluminum hydroxide, magnesium hydroxide, calcium hydroxide or barium sulfate.
  • the binder may include at least one of polyvinylidene fluoride, a copolymer of vinylidene fluoride and hexafluoropropylene, polyamide, polyacrylonitrile, polymethyl acrylate, polyethyl acrylate, polybutyl acrylate, polyacrylic acid, polyacrylate, sodium carboxymethyl cellulose, polyvinyl pyrrolidone, polyvinyl ether, polymethyl methacrylate, polytetrafluoroethylene, or polyhexafluoropropylene.
  • the present application does not particularly limit the size of the pores of the porous structure, as long as the purpose of the present application can be achieved.
  • the pore size can be 0.01 ⁇ m to 1 ⁇ m.
  • the thickness of the isolation membrane is not particularly limited, as long as the purpose of the present application can be achieved.
  • the thickness can be 3 ⁇ m to 30 ⁇ m.
  • the electrochemical device of the present application further includes an electrolyte, which includes a lithium salt and a non-aqueous solvent.
  • the lithium salt may include but is not limited to at least one of LiPF 6 , LiBF 4 , LiAsF 6 , LiClO 4 , LiB(C 6 H 5 ) 4 , LiCH 3 SO 3 , LiCF 3 SO 3 , LiN(SO 2 CF 3 ) 2 , LiC(SO 2 CF 3 ) 3 , Li 2 SiF 6 , lithium bis(oxalatoborate) (LiBOB) or lithium difluoroborate.
  • LiPF 6 LiBF 4
  • LiAsF 6 LiClO 4
  • LiB(C 6 H 5 ) 4 LiCH 3 SO 3 , LiCF 3 SO 3 , LiN(SO 2 CF 3 ) 2 , LiC(SO 2 CF 3 ) 3 , Li 2 SiF 6 , lithium bis(oxalatoborate) (LiBOB) or lithium difluoroborate.
  • LiPF 6 LiBF 4
  • LiAsF 6 LiClO 4
  • non-aqueous solvents can include but are not limited to at least one of carbonate compounds, carboxylate compounds, ether compounds or other organic solvents.
  • carbonate compounds can include but are not limited to at least one of linear carbonate compounds, cyclic carbonate compounds or fluorinated carbonate compounds.
  • linear carbonate compounds can include but are not limited to at least one of dimethyl carbonate (DMC), diethyl carbonate (DEC), dipropyl carbonate (DPC), methyl propyl carbonate (MPC), ethyl propyl carbonate (EPC) or methyl ethyl carbonate (MEC).
  • cyclic carbonates can include but are not limited to at least one of ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate (BC) or vinyl ethylene carbonate (VEC).
  • the fluorinated carbonate compound may include, but is not limited to, at least one of fluoroethylene carbonate (FEC), 1,2-difluoroethylene carbonate, 1,1-difluoroethylene carbonate, 1,1,2-trifluoroethylene carbonate, 1,1,2,2-tetrafluoroethylene carbonate, 1-fluoro-2-methylethylene carbonate, 1-fluoro-1-methylethylene carbonate, 1,2-difluoro-1-methylethylene carbonate, 1,1,2-trifluoro-2-methylethylene carbonate, or trifluoromethylethylene carbonate.
  • FEC fluoroethylene carbonate
  • the above-mentioned carboxylate compound may include, but is not limited to, at least one of methyl formate, methyl acetate, ethyl acetate, n-propyl acetate, tert-butyl acetate, methyl propionate, ethyl propionate, propyl propionate, ⁇ -butyrolactone, decanoic acid lactone, valerolactone, or caprolactone.
  • the above-mentioned ether compound may include but is not limited to at least one of dibutyl ether, tetraglyme, diglyme, 1,2-dimethoxyethane, 1,2-diethoxyethane, 1-ethoxy-1-methoxyethane, 2-methyltetrahydrofuran or tetrahydrofuran.
  • the above-mentioned other organic solvents may include but are not limited to at least one of dimethyl sulfoxide, 1,2-dioxolane, sulfolane, methyl sulfolane, 1,3-dimethyl-2-imidazolidinone, N-methyl-2-pyrrolidone, dimethylformamide, acetonitrile, trimethyl phosphate, triethyl phosphate or trioctyl phosphate.
  • the present application does not particularly limit the content of the non-aqueous solvent in the electrolyte, as long as the purpose of the present application can be achieved.
  • the electrochemical device of the present application also includes a housing for accommodating a positive electrode sheet, a separator, a negative electrode sheet, and an electrolyte, as well as other components known in the field of electrochemical devices.
  • This application does not limit the above-mentioned other components.
  • This application does not particularly limit the housing, and it can be a housing known in the art, as long as it can achieve the purpose of this application.
  • the housing can be a hard shell housing or a flexible shell.
  • the material of the hard shell housing can be metal.
  • the flexible shell can be a metal plastic film, such as an aluminum plastic film, a steel plastic film, etc.
  • the preparation process of the electrochemical device of the present application is well known to those skilled in the art, and is not particularly limited in the present application.
  • it may include but is not limited to the following steps: stacking the positive electrode sheets, the separator and the negative electrode sheets in order, and winding, folding and other operations as needed to obtain an electrode assembly with a wound structure, placing the electrode assembly in a shell, injecting the electrolyte into the shell and sealing it to obtain an electrochemical device.
  • an overcurrent protection device may be provided as needed. The flow element, guide plate, etc. are placed in the shell to prevent the pressure inside the electrochemical device from rising and overcharging and discharging.
  • the second aspect of the present application provides an electronic device, which includes the electrochemical device in any of the above embodiments. Therefore, the electrochemical device provided by the present application has good performance.
  • the present application does not particularly limit the type of electronic device, and it can be any electronic device known in the prior art.
  • the electronic device can include, but is not limited to, a laptop computer, a pen-type computer, a mobile computer, an electronic book player, a portable phone, a portable fax machine, a portable copier, a portable printer, a head-mounted stereo headset, a video recorder, an LCD television, a portable cleaner, a portable CD player, a mini-disc, a transceiver, an electronic notepad, a calculator, a memory card, a portable recorder, a radio, a backup power supply, a motor, a car, a motorcycle, a power-assisted bicycle, a bicycle, a lighting fixture, a toy, a game console, a clock, a power tool, a flashlight, a camera, a large household battery, and a lithium-ion capacitor.
  • the positive electrode was disassembled to obtain the positive electrode sheet. After soaking in ethylene carbonate (EC) for 30 minutes, it was rinsed with ethylene carbonate three times and naturally dried under an argon atmosphere to obtain the treated positive electrode sheet. A 3cm ⁇ 3cm treated positive electrode sheet was taken for XRD (X-ray diffraction) testing.
  • the positive electrode sheet was placed on the sample stage of the XRD test instrument (model Bruker, D8). Cu target K ⁇ radiation was used, a scanning rate of 10°/min, and a scanning angle range of 10° to 71° to obtain the XRD diffraction pattern. The corresponding diffraction peak was read and the position of the diffraction peak was recorded.
  • the negative electrode sheet was disassembled and soaked in ethylene carbonate (EC) for 30 minutes. The sheet was then rinsed three times with EC and air-dried under an argon atmosphere to obtain the treated negative electrode sheet. The treated negative electrode sheet was sectioned using an ion beam to obtain a cross-section along its thickness. The cross-section was observed using a scanning electron microscope (SEM) at a magnification of 1000X and an image area of 125 ⁇ m ⁇ 85 ⁇ m. In the SEM backscattered mode, the hard carbon particles appeared as angular, blocky particles, while the graphite particles appeared as lamellar particles.
  • SEM scanning electron microscope
  • the area of the hard carbon and graphite particles was calculated for at least 50 images using ImageJ image analysis software.
  • the area of the hard carbon particles was divided by the area of the hard carbon and graphite particles combined, and the arithmetic average was taken to determine the mass percentage of the hard carbon.
  • the lithium-ion battery was fully discharged to 3.0V at a constant current of 0.2C and then disassembled, retaining the positive electrode with the isolation film on one side.
  • the side of the positive electrode sheet without the separator attached was attached to a steel plate with double-sided tape.
  • a 180° peel test was performed using a tensile testing machine. The steel plate was secured in the lower fixture, while the separator was clamped in the upper fixture. The test was performed at a constant rate of 50 mm/min, stretching the separator 50 mm apart from the positive electrode sheet to a 180° angle. Stress and displacement data were obtained.
  • the bond strength between the separator and the positive electrode sheet stress/displacement.
  • the mass of the positive electrode active material (weight of the positive electrode disc - weight of the aluminum foil) / ( ⁇ ⁇ 22 ⁇ 22) ⁇ length of the positive electrode disc ⁇ width of the positive electrode disc ⁇ (1 - mass fraction of conductive carbon black - mass fraction of binder).
  • the mass of the negative electrode active material (weight of the negative electrode disc - weight of the copper foil) / ( ⁇ ⁇ 22 ⁇ 22) ⁇ length of the negative electrode sheet ⁇ width of the negative electrode sheet ⁇ (1 - mass fraction of conductive carbon - mass fraction of binder - mass fraction of dispersant).
  • 14mm diameter discs were taken from the positive and negative electrode sheets, and lithium sheets were used as counter electrodes to make button batteries to test the first discharge mass specific capacity of the positive and negative electrode materials.
  • Positive electrode sheet capacity d positive electrode material mass specific capacity ⁇ positive electrode active material mass
  • Negative electrode sheet capacity c negative electrode material mass specific capacity ⁇ negative electrode active material mass
  • Lithium-ion batteries were placed in a 25°C environment and charged at a constant current of 0.2C to 4.55V. They were then charged at a constant voltage of 4.55V until the current dropped below 0.05C. The batteries were then discharged at a constant current of 0.2C to 3.0V. The initial discharge capacity was recorded.
  • the lithium-ion battery test equipment used was Land CT2001A.
  • Initial mass specific capacity initial discharge capacity / mass of the positive electrode active material.
  • the initial mass specific capacity of a lithium-ion battery is used to evaluate the energy density of a lithium-ion battery. A larger initial mass specific capacity indicates a higher energy density, while a smaller initial mass specific capacity indicates a lower energy density.
  • the lithium-ion battery was placed in a 25°C environment and first discharged at a constant current of 0.2C to 3.0V, then at a constant current of 0.5C.
  • Charge at a constant current to 4.55V then charge at a constant voltage of 4.55V to a current of 0.05C, and then discharge at a constant current of 0.2C to 3.0V.
  • the discharge capacity at this time is recorded as C1 .
  • Charge at a constant current of 0.5C to 4.55V then charge at a constant voltage of 4.55V to a current of 0.05C, and then discharge at a constant current of 0.5C to 3.0V.
  • Capacity retention ratio R C 2 /C 1 ⁇ 100%, where R represents rate performance, and a larger R value indicates better rate performance.
  • the lithium-ion battery was placed in a constant temperature box at 45°C and first discharged to 3.0V at a constant current of 0.2C.
  • Capacity retention at 45°C C n /C 1 ⁇ 100%, and the number of cycles n when the capacity retention at 45°C is 80% is recorded.
  • the precipitate was filtered, washed three times with deionized water, and dried in a vacuum at 80°C for 24 h to obtain a Co30.95Fe30.02Ni30.01Mn30.01Al30.01 (OH) 3 precursor.
  • the prepared positive electrode active material, conductive carbon black (Super P), and binder polyvinylidene fluoride (PVDF) were mixed in a mass ratio of 97:1.5:1.5.
  • N-methylpyrrolidone (NMP) was added as a solvent and stirred uniformly in a vacuum mixer to obtain a positive electrode slurry with a solid content of 70 wt%.
  • the positive electrode slurry was evenly coated on one surface of a 10 ⁇ m thick positive electrode current collector aluminum foil and dried at 120°C to obtain a single-sided positive electrode material layer-coated positive electrode sheet.
  • the coating weight of the positive electrode material layer was Y g/1540.25 mm2 , where Y was 0.198 g/1540.25 mm2 .
  • the above steps were repeated on the other surface of the positive electrode current collector aluminum foil to obtain a double-sided positive electrode material layer-coated positive electrode sheet. After drying at 120°C, the sheet was cold pressed, cut, slit, and the tabs were welded to obtain a 74 mm ⁇ 867 mm positive electrode sheet.
  • the thickness of the single-sided positive electrode material layer is 42 ⁇ m. Based on the mass of the positive electrode material layer, the mass percentage content m 1 % of the positive electrode binder is 1.5%, and the mass percentage content m 2 % of the positive electrode conductive agent is 1.5%.
  • the prepared negative electrode active material, binder styrene-butadiene rubber, thickener sodium carboxymethyl cellulose, and conductive carbon black (Super P) were mixed in a mass ratio of 97:1.5:0.75:0.75.
  • Deionized water was added as a solvent to form a slurry with a solid content of 45 wt%.
  • the mixture was then stirred evenly in a vacuum mixer to obtain a negative electrode slurry.
  • the negative electrode slurry was evenly coated on one surface of a 10 ⁇ m thick negative electrode current collector copper foil and dried at 120°C to obtain a negative electrode sheet coated on one side with a negative electrode material layer.
  • the coating weight of the negative electrode material layer was 6.87 mg/ cm2 .
  • the above steps were repeated on the other surface of the copper foil to obtain a negative electrode sheet coated on both sides with a negative electrode material layer. After drying at 120°C, the sheet was cold pressed, cut, slit, and tab welded to obtain a negative electrode sheet measuring 78 mm x 875 mm for later use.
  • the thickness of the negative electrode material layer on one side was 40.4 ⁇ m. Based on the mass of the negative electrode material layer, the mass percentage content m 3 % of the negative electrode binder is 1.5%, the mass percentage content m 4 % of the thickener is 0.75%, and the mass percentage content m 5 % of the negative electrode conductive agent is 0.75%.
  • ⁇ - Al2O3 particles were added to water as a solvent and mixed thoroughly.
  • Polyvinylidene fluoride (PVDF) as a binder was then added and stirred continuously to form a slurry with a solid content of 60%.
  • the mass ratio of ⁇ - Al2O3 to PVDF was 95:5.
  • the slurry was coated on one surface of a 5 ⁇ m-thick porous polyethylene (PE) substrate and dried at 90°C to produce a separator membrane coated on one side with a 2 ⁇ m-thick alumina ceramic layer.
  • the slurry was then coated on the other surface of the porous polyethylene (PE) substrate and dried at 90°C to produce a separator membrane coated on both sides with alumina ceramic layers.
  • ethylene carbonate (EC), propylene carbonate (PC), diethyl carbonate Ester (DEC) is mixed in a mass ratio of 1:1:1 to obtain an organic solvent, and then electrolyte salt LiPF 6 is added to the organic solvent and mixed evenly to obtain an electrolyte solution. Based on the mass of the electrolyte solution, the mass percentage of electrolyte salt LiPF 6 is 12.5%, and the rest is organic solvent.
  • the positive electrode sheet, separator, and negative electrode sheet prepared above are stacked in order, with the separator positioned between the positive and negative electrodes to provide insulation, and then wound to form an electrode assembly.
  • the electrode assembly is placed in an aluminum-plastic film packaging bag, dehydrated at 80°C, and then injected with the electrolyte prepared above.
  • the lithium-ion battery is produced through vacuum packaging, standing, forming, degassing, and trimming.
  • the upper limit of the formation voltage is 4.15V
  • the formation temperature is 70°C
  • the formation standing time is 2 hours.
  • the precipitate was washed three times with methanol and vacuum-dried at 90°C for 8 h to obtain lithium cobalt oxide Li 0.9495 Na 0.0005 Co 0.95 Fe 0.03 Mn 0.01 Cu 0.01 O 2 powder with a P63mc structure.
  • the precipitate was washed three times with methanol and dried in a vacuum at 90°C for 8 h to obtain lithium cobalt oxide Li 0.9495 Na 0.0005 Co 0.95 Fe 0.03 Ni 0.01 Ti 0.01 O 2 powder with a P63mc structure.
  • Example 1-1 Except that the negative electrode active material was prepared according to the above steps and the coating weight Y of the positive electrode material layer was adjusted according to Table 1 in the positive electrode sheet preparation, the rest was the same as Example 1-1.
  • Example 1-1 Except that the negative electrode active material was prepared according to the above steps and the coating weight Y of the positive electrode material layer was adjusted according to Table 1 in the positive electrode sheet preparation, the rest was the same as Example 1-1.
  • the precipitate was filtered, washed three times with deionized water, and dried in a vacuum at 80 °C for 24 h to obtain a Co30.9375Fe30.03Ni30.01Mn30.01Al30.0125 (OH) 3 precursor.
  • the precipitate was washed three times with methanol and vacuum-dried at 90°C for 8 h to obtain lithium cobalt oxide Li 0.937 Na 0.0005 Co 0.9375 Fe 0.03 Ni 0.01 Mn 0.01 Al 0.0125 O 2 powder with a P63mc structure.
  • Example 1-1 Except that the ⁇ Preparation of Positive Electrode Active Material> was prepared according to the above steps and the coating weight Y of the positive electrode material layer was adjusted according to Table 1 in the ⁇ Preparation of Positive Electrode Sheet>, the rest was the same as Example 1-1.
  • Example 1-1 Except that the ⁇ Preparation of Positive Electrode Active Material> was prepared according to the above steps and the coating weight Y of the positive electrode material layer was adjusted according to Table 1 in the ⁇ Preparation of Positive Electrode Sheet>, the rest was the same as Example 1-1.
  • the precipitate was washed three times with methanol and dried in a vacuum at 90°C for 8 h to obtain lithium cobalt oxide Li 0.9395 Na 0.0005 Co 0.94 Fe 0.02 Ni 0.01 Mn 0.01 Al 0.02 O 2 powder with a P63mc structure.
  • Example 1-1 Except that the ⁇ Preparation of Positive Electrode Active Material> was prepared according to the above steps and the coating weight Y of the positive electrode material layer was adjusted according to Table 1 in the ⁇ Preparation of Positive Electrode Sheet>, the rest was the same as Example 1-1.
  • the precipitate was washed three times with methanol and dried in a vacuum at 90°C for 8 h to obtain lithium cobalt oxide Li 0.949 Na 0.001 Co 0.95 Fe 0.02 Ni 0.01 Mn 0.01 Al 0.01 O 2 powder with a P63mc structure.
  • Example 1-11 Except that the negative electrode active material is prepared according to the above steps and the coating weight Y of the positive electrode material layer is adjusted according to Table 1 in the positive electrode sheet preparation, the rest is the same as Example 1-11.
  • the precipitate was washed three times with methanol and vacuum-dried at 90°C for 8 h to obtain lithium cobalt oxide Li 0.7795 Na 0.0005 Co 0.78 Fe 0.1 Ni 0.05 Mn 0.05 Al 0.02 O 2 powder with a P63mc structure.
  • Example 1-1 Except that the ⁇ Preparation of Positive Electrode Active Material> was prepared according to the above steps and the coating weight Y of the positive electrode material layer was adjusted according to Table 1 in the ⁇ Preparation of Positive Electrode Sheet>, the rest was the same as Example 1-1.
  • LiCoO2 , 0.16g of Al2O3 , and 0.11g of Li2CO3 were mixed evenly and transferred to a corundum crucible.
  • the mixture was sintered at 1030°C for 10h under O2 atmosphere, and then put into a jaw crusher and a roller crusher to produce powder.
  • the powder was further crushed by a jet mill and finally sieved with a 400-mesh sieve to obtain lithium cobalt oxide LiCo0.997Al0.003O2 powder with R - 3m structure.
  • the preparation of the positive electrode active material was carried out according to the above steps, the coating weight Y of the positive electrode material layer was adjusted according to Table 1, the negative electrode active material was natural graphite, and no hard carbon was added, and the rest was the same as Example 1-1.
  • LiCoO2 , 0.16g of Al2O3 and 0.11g of Li2CO3 were mixed evenly and transferred to a corundum crucible. They were sintered at 1030 °C for 10h under an O2 atmosphere. The mixture was put into a jaw crusher and a roller crusher to produce powder. The powder was further crushed by a jet mill. The powder was crushed and sieved with a 400-mesh sieve to obtain lithium cobalt oxide LiCo 0.997 Al 0.003 O 2 powder with an R-3m structure.
  • Example 1-1 Except that the ⁇ Preparation of Positive Electrode Active Material> was prepared according to the above steps and the coating weight Y of the positive electrode material layer was adjusted according to Table 1 in the ⁇ Preparation of Positive Electrode Sheet>, the rest was the same as Example 1-1.
  • the preparation method is the same as Example 1-1 except that the negative electrode active material is adjusted to natural graphite without adding hard carbon and the coating weight Y of the positive electrode material layer is adjusted according to Table 1.
  • the preparation method is the same as Example 1-1 except that the negative electrode active material is adjusted to hard carbon, natural graphite is not added, and the coating weight Y of the positive electrode material layer is adjusted according to Table 1.
  • the precipitate was filtered, washed three times with deionized water, and dried in a vacuum at 80°C for 24 h to obtain a Co30.95Fe30.02Ni30.01Mn30.01Al30.01 (OH) 3 precursor.
  • the precipitate was washed three times with methanol and vacuum-dried at 90°C for 8 h to obtain lithium cobalt oxide Li 0.9495 Na 0.0005 Co 0.95 Fe 0.02 Ni 0.01 Mn 0.01 Al 0.01 O 2 powder with a P63mc structure.
  • LiCoO2 , 1.56g of Al2O3 , and 1.13g of Li2CO3 were mixed evenly and transferred to a corundum crucible.
  • the mixture was sintered at 1030°C for 10h under O2 atmosphere, and then put into a jaw crusher and a double-roller crusher to produce powder.
  • the mixture was further crushed by a jet mill and finally sieved with a 400-mesh sieve to obtain lithium cobalt oxide LiCo0.97Al0.03O2 powder with R- 3m structure.
  • the lithium cobalt oxide powder with the R-3m structure and the lithium cobalt oxide powder with the P63mc structure prepared above were mixed at a mass ratio M of 4 to obtain a positive electrode active material.
  • the preparation of the negative electrode active material was carried out according to the above steps and the value of M in the preparation of the positive electrode active material was adjusted to 1, and the rest was the same as in Example 2-1.
  • Example 2-3 Example 2-3, Example 2-4
  • R-3m lithium cobalt oxide 100g of LiCoO2 , 1.56g of Al2O3 , 1.13g of Li2CO3 , and 0.21g of MgO were uniformly mixed and transferred to a corundum crucible. The mixture was sintered at 1030 ° C for 10h in an O2 atmosphere. The mixture was then crushed into powder using a jaw crusher and a roller mill. The powder was further crushed using a jet mill and sieved using a 400 -mesh sieve to obtain R- 3m lithium cobalt oxide LiCo36 ...
  • R-3m structured lithium cobalt oxide 100g of LiCoO2 , 1.56g of Al2O3 , 1.13g of Li2CO3 , 0.21g of MgO , and 0.41g of TiO2 were mixed uniformly and transferred to a corundum crucible. The mixture was sintered at 1030°C for 10h under an O2 atmosphere. The mixture was then crushed into powder using a jaw crusher and a roller mill. The powder was further crushed using a jet mill and sieved using a 400-mesh sieve to obtain R-3m structured lithium cobalt oxide LiCo0.96Al0.03Mg0.005Ti0.005O2 powder . The preparation was the same as in Example 2-2 , except that the R- 3m structured lithium cobalt oxide in ⁇ Preparation of Positive Electrode Active Material> was prepared as described above.
  • R-3m lithium cobalt oxide 100g of LiCoO2 , 5.21g of Al2O3 , and 3.77g of Li2CO3 were uniformly mixed and transferred to a corundum crucible. The mixture was sintered at 1030°C for 10h in an O2 atmosphere. The mixture was then crushed into powder using a jaw crusher and a roller mill. The powder was further crushed using a jet mill and sieved using a 400-mesh sieve to obtain R-3m lithium cobalt oxide LiCo0.9Al0.1O2 powder.
  • Example 2 The same method as in Example 2-2 was used, except that the R-3m lithium cobalt oxide in ⁇ Preparation of Positive Electrode Active Material> was prepared as described above, and the coating weight Y of the positive electrode material layer in ⁇ Preparation of Positive Electrode Sheet> was adjusted according to Table 2.
  • Preparation of lithium cobalt oxide with R-3m structure 100g of LiCoO2 , 1.56g of Al2O3 , 1.13g of Li2CO3 , 0.41g of MgO , 0.82g of TiO2 , 1.66g of La2O3 , 1.15g of Y2O3 and 1.26g of ZrO2 were mixed evenly and transferred to a corundum crucible . The mixture was sintered at 1030°C for 10h under O2 atmosphere and then put into a jaw crusher and a roller crusher to produce powder.
  • Example 2-2 The mixture was further crushed in a jet mill and finally sieved through a 400-mesh sieve to obtain a lithium cobalt oxide powder with an R-3m structure: LiCo 0.92 Al 0.03 Mg 0.01 Ti 0.01 La 0.01 Y 0.01 Zr 0.01 O 2.
  • the same procedures as in Example 2-2 were used, except that the R-3m lithium cobalt oxide in the "Preparation of Positive Electrode Active Material” was prepared as described above, and the coating weight Y of the positive electrode material layer in the "Preparation of Positive Electrode Sheet” was adjusted according to Table 2.
  • LiCoO2 , 1.56g of Al2O3 , and 1.13g of Li2CO3 were mixed evenly and transferred to a corundum crucible.
  • the mixture was sintered at 1030°C for 10h under O2 atmosphere, and then put into a jaw crusher and a double-roller crusher to produce powder.
  • the mixture was further crushed by a jet mill and finally sieved with a 400-mesh sieve to obtain lithium cobalt oxide LiCo0.97Al0.03O2 powder with R- 3m structure.
  • the preparation of the positive electrode active material was carried out according to the above steps, the negative electrode active material was natural graphite without adding hard carbon, and the coating weight Y of the positive electrode material layer was adjusted according to Table 2 in the preparation of the positive electrode sheet. The rest was the same as Example 2-1.
  • LiCoO2 , 1.56g of Al2O3 , and 1.13g of Li2CO3 were mixed evenly and transferred to a corundum crucible.
  • the mixture was sintered at 1030°C for 10h under O2 atmosphere, and then put into a jaw crusher and a double-roller crusher to produce powder.
  • the mixture was further crushed by a jet mill and finally sieved with a 400-mesh sieve to obtain lithium cobalt oxide LiCo0.97Al0.03O2 powder with R- 3m structure.
  • the preparation method was the same as that of Example 2-7, except that the positive electrode active material was adjusted to lithium cobalt oxide LiCo 0.9 Al 0.1 O 2 with R-3m structure and lithium cobalt oxide with P63mc structure was not included in the preparation method, and the coating weight Y of the positive electrode material layer was adjusted according to Table 2.
  • Table 1 Note: “/” in Table 1 indicates that there is no corresponding parameter or substance.
  • the positive electrode material includes lithium cobalt oxide with a P63mc structure and the characteristic peak position of the (002) crystal plane of the lithium cobalt oxide with the P63mc structure is regulated within the scope of the present application
  • the negative electrode material includes hard carbon and graphite, which can enable the lithium-ion battery to have a higher first discharge mass specific capacity, as well as a higher capacity retention rate R and a higher number of cycles at a 45°C capacity retention rate of 80%, indicating that the lithium-ion battery has a higher energy density as well as good rate performance and high-temperature cycle performance.
  • Figure 1 is Example 1-1, 1-5 to Example 1-7, Example 1-9, Comparative Example 1-1, Comparative Example 1-3, As shown in FIG1 , when the cycle capacity retention rate is 80%, the number of cycles of Example 1-1, Examples 1-5 to 1-7, and Example 1-9 is significantly greater than that of Comparative Example 1-1 and Comparative Example 1-3, indicating that the lithium-ion batteries of the embodiments of the present application have good high-temperature cycle performance.
  • Figure 2 is a graph showing the rate performance test results of Example 1-1, Examples 1-5 to 1-7, Example 1-9, Comparative Example 1-1, Comparative Example 1-3, and Comparative Example 2-1.
  • the capacity retention rates of Example 1-1, Examples 1-5 to 1-7, and Example 1-9 are all greater than those of Comparative Example 1-1 and Comparative Example 2-1, indicating that the lithium-ion batteries of the embodiments of the present application have good rate performance.
  • FIG3 is an XRD pattern of the lithium cobalt oxide with P63mc structure in the positive electrode material layer of Example 1-1.
  • the characteristic peak position of the (002) crystal plane of the lithium cobalt oxide with P63mc structure is 18.50°.
  • FIG6 is an SEM image of the negative electrode sheet of Example 1-1 of the present application.
  • the angular block-shaped particles are hard carbon
  • the lamellar particles are graphite.
  • the mass percentage of hard carbon generally affects the energy density and high-temperature cycling performance of lithium-ion batteries.
  • Examples 1-1, 1-6, 1-7, Comparative Examples 1-3, and 1-4 when hard carbon is included in the negative electrode active material and the mass percentage of the hard carbon is controlled within the range of this application, the lithium-ion battery can achieve a higher initial discharge mass specific capacity and a higher number of cycles with a 45°C capacity retention rate of 80%, demonstrating that the lithium-ion battery has both high energy density and good high-temperature cycling performance.
  • the type of element A in the P63mc-structured lithium cobalt oxide generally affects the energy density, rate capability, and high-temperature cycling performance of lithium-ion batteries. As shown in Examples 1-1 to 1-3, when the type of element A in the P63mc-structured lithium cobalt oxide falls within the scope of this application, the lithium-ion battery can exhibit a high initial discharge mass specific capacity, a high capacity retention rate R, and a high number of cycles at 45°C with a capacity retention rate of 80%. This demonstrates that the lithium-ion battery has both high energy density and good rate capability and high-temperature cycling performance.
  • the type of B element in the P63mc-structured lithium cobalt oxide generally affects the energy density, rate capability, and high-temperature cycling performance of lithium-ion batteries.
  • the lithium-ion battery can exhibit a high initial discharge mass specific capacity, a high capacity retention rate R, and a high number of cycles at 80% capacity retention at 45°C. This demonstrates that the lithium-ion battery has both high energy density and good rate capability and high-temperature cycling performance.
  • the values of x, y, a, and b in the P63mc-structured lithium cobalt oxide typically affect the energy density, rate capability, and high-temperature cycling performance of lithium-ion batteries.
  • lithium-ion batteries can exhibit a higher initial discharge mass specific capacity, a higher capacity retention rate R, and a higher number of cycles at 45°C with a capacity retention rate of 80%. This demonstrates that the lithium-ion battery has both a higher energy density and good rate capability and high-temperature cycling performance.
  • the value of the bonding force (F) between the separator and the positive electrode generally affects the energy density, rate capability, and high-temperature cycling performance of a lithium-ion battery.
  • the bonding force (F) between the separator and the positive electrode is within the range of this application, the lithium-ion battery can achieve a high initial discharge mass specific capacity, a high capacity retention rate (R), and a high number of cycles at 45°C with a capacity retention rate of 80%. This indicates that the lithium-ion battery has a high energy density while also exhibiting good rate capability and high-temperature cycling performance.
  • Table 2 Note: “/” in Table 2 indicates that there is no corresponding parameter or substance.
  • the value of I 1 /I 2 usually affects the high temperature cycle performance of lithium ion batteries. From Examples 2-1 to 2-4 and Comparative Examples 2-1 to 2-3, it can be seen that by adjusting the value of I 1 /I 2 within the scope of this application, It can make the lithium-ion battery have a higher first discharge mass specific capacity, a higher capacity retention rate R and a higher number of cycles when the capacity retention rate at 45°C is 80%, indicating that the lithium-ion battery has a higher energy density as well as good rate performance and high-temperature cycle performance.
  • Figure 4 is the XRD patterns of the lithium cobalt oxide with P63mc structure and the lithium cobalt oxide with R-3m structure in the positive electrode material layer of Example 2-2.
  • the ratio I 1 /I 2 of the characteristic peak intensity I 1 of the (003) crystal plane of the lithium cobalt oxide with R-3m structure to the characteristic peak intensity I 2 of the (002) crystal plane of the lithium cobalt oxide with P63mc structure is 0.15.
  • the position of the characteristic peak of the (003) crystal plane of R-3m lithium cobalt oxide generally affects the energy density, rate capability, and high-temperature cycling performance of lithium-ion batteries.
  • the lithium-ion battery can achieve a higher initial discharge mass specific capacity, a higher capacity retention rate R, and a higher number of cycles at 45°C with a capacity retention rate of 80%. This indicates that the lithium-ion battery has a higher energy density while also having good rate capability and high-temperature cycling performance.
  • FIG5 is an XRD pattern of the lithium cobalt oxide with R-3m structure in the positive electrode material layer of Comparative Example 2-1.
  • the characteristic peak position of the (003) crystal plane of the lithium cobalt oxide with R-3m structure is 18.93°.
  • the type of carbon element in the R-3m structured lithium cobalt oxide generally affects the energy density, rate capability, and high-temperature cycling performance of lithium-ion batteries.
  • the lithium-ion battery can have a higher initial discharge mass specific capacity, a higher capacity retention rate R, and a higher number of cycles at 45°C when the capacity retention rate is 80%. This indicates that the lithium-ion battery has a higher energy density while also having good rate capability and high-temperature cycling performance.
  • the values of m and n in the R-3m structured lithium cobalt oxide generally affect the energy density, rate capability, and high-temperature cycling performance of lithium-ion batteries.
  • Examples 2-1 to 2-8 by regulating the values of m and n in the R-3m structured lithium cobalt oxide within the ranges of this application, lithium-ion batteries can exhibit a higher initial discharge mass specific capacity, a higher capacity retention rate R, and a higher number of cycles at 45°C with a capacity retention rate of 80%. This demonstrates that the lithium-ion battery has both a higher energy density and good rate capability and high-temperature cycling performance.

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Abstract

本申请提供了一种电化学装置及电子装置，电化学装置包括正极极片、负极极片和隔离膜，其中，正极极片包括正极集流体以及设置于正极集流体至少一个表面的正极材料层，正极材料层包括正极材料，正极材料包括P63mc结构的锂钴氧化物，在正极材料层的XRD图谱中，P63mc结构的锂钴氧化物的(002)晶面的特征峰位于17°至19°之间；负极极片包括负极集流体以及设置于负极集流体至少一个表面的负极材料层，负极材料层包括负极材料，负极材料包括硬碳和石墨。通过上述设置，可使电化学装置具有较高的能量密度的同时，还具有良好的倍率性能和高温循环性能。

Description

一种电化学装置及电子装置 技术领域
本申请涉及电化学技术领域，特别是涉及一种电化学装置及电子装置。
背景技术
电化学装置，如锂离子电池，因其具有工作电压高、能量密度高、环境友好、循环稳定等优点，被广泛应用于穿戴设备、智能手机、无人机、笔记本电脑、电动汽车等领域。
近年来，随着电动汽车和可移动电子设备的高速发展，市场对锂离子电池的能量密度、使用寿命及充电速度等提出了更高的要求。通常，为使锂离子电池具有更高的能量密度，可以提高锂离子电池的充电电压，但当提高锂离子电池的充电电压时，正极材料的结构稳定性会降低，从而影响锂离子电池高温循环性能和倍率性能。
发明内容
本申请的目的在于提供一种电化学装置及电子装置，以提高电化学装置的能量密度、高温循环性能及倍率性能。具体技术方案如下：
本申请的第一方面提供了一种电化学装置，其包括正极极片、负极极片和隔离膜，其中，正极极片包括正极集流体以及设置于正极集流体至少一个表面的正极材料层，正极材料层包括正极材料，正极材料包括P63mc结构的锂钴氧化物，在正极材料层的XRD图谱中，P63mc结构的锂钴氧化物的(002)晶面的特征峰位于17°至19°之间；负极极片包括负极集流体以及设置于负极集流体至少一个表面的负极材料层，负极材料层包括负极材料，负极材料包括硬碳和石墨。正极材料包括P63mc结构的锂钴氧化物，并调控P63mc结构的锂钴氧化物的(002)晶面的特征峰位于17°至19°之间，P63mc结构的锂钴氧化物Li-O八面体与两侧的Co-O八面体分别为共棱、共面连接，Co极难迁移至Li位点，可在较高的充电电压下维持稳定的结构，可使电化学装置具有较高的能量密度的同时，还保持良好的高温循环性能；此外，P63mc结构的锂钴氧化物Co-O八面体层的层间距较大，有利于Li+的嵌入和脱出，可改善电化学装置的倍率性能。本申请的负极材料包括硬碳和石墨，硬碳可满足Na+的嵌入和脱出，并且可以使首周充电时形成合适厚度的SEI膜，减少活性锂的消耗。通过正极材料和负极材料的匹配，可进一步改善电化学装置的高温循环性能。
在本申请的一些实施方案中，P63mc结构的锂钴氧化物的(002)晶面的特征峰位于18.3°至18.7°之间。通过调控P63mc结构的锂钴氧化物的(002)晶面特征峰的位置在本申请的范围内，可提高正极材料的结构稳定性，可使电化学装置具有较高的能量密度的同 时，进一步提高电化学装置的高温循环性能。
在本申请的一些实施方案中，基于负极材料的质量，硬碳的质量百分含量为w％，1≤w≤10。通过调控硬碳的质量百分含量w％在本申请的范围内，硬碳可满足Na+的嵌入和脱出，并且可以使首周充电时形成合适厚度的SEI膜，减少活性锂的消耗，可使电化学装置具有较高的能量密度的同时，进一步改善电化学装置的高温循环性能。
在本申请的一些实施方案中，P63mc结构的锂钴氧化物包括LixNayCo1-a-bAaBbO2，其中，A包括Mn、Fe或Ni中的至少一种，B包括Al、Mg、Ti、La、Y、Zr、Zn、Cu、Cr、Ca、Ce或Lu中的至少一种，0.779≤x≤0.95，0＜y≤0.001，0＜a≤0.2，0≤b≤0.02。通过上述设置，可进一步提高正极材料的结构稳定性，可使电化学装置具有较高的能量密度和倍率性能的同时，进一步提高电化学装置的高温循环性能。
在本申请的一些实施方案中，正极材料还包括R-3m结构的锂钴氧化物，在正极材料层的XRD图谱中，R-3m结构的锂钴氧化物的(003)晶面特征峰位于18°至20°之间；R-3m结构的锂钴氧化物(003)晶面特征峰强度为I1，P63mc结构的锂钴氧化物(002)晶面特征峰强度为I2，0≤I1/I2≤20。正极材料包括R-3m结构的锂钴氧化物，并调控R-3m结构的锂钴氧化物的(003)晶面特征峰和I1/I2的值在本申请的范围内，可提高电化学装置的能量密度的同时，兼顾电化学装置的高温循环性能。
在本申请的一些实施方案中，R-3m结构的锂钴氧化物包括LiCo1-m-nAlmCnO2，其中，C包括Mg、Ti、La、Y、Zr或Lu中的至少一种，0＜m≤0.1，0≤n≤0.05。通过上述设置，可进一步提高电化学装置的高温循环性能。
在本申请的一些实施方案中，正极材料层还包括正极粘结剂和正极导电剂，基于正极材料层的质量，正极粘结剂的质量百分含量为m1％，正极导电剂的质量百分含量为m2％，满足0＜m1≤10，0＜m2≤10。通过调控正极粘结剂和正极导电剂的质量百分含量在本申请的范围内，可使正极极片具有合适的导电率和良好的稳定性。
在本申请的一些实施方案中，所述负极材料层还包括负极粘结剂、增稠剂和负极导电剂，基于所述负极材料层的质量，负极粘结剂的质量百分含量为m3％，增稠剂的质量百分含量为m4％，负极导电剂的质量百分含量为m5％，满足0＜m3≤5，0＜m4≤5，0＜m5≤5。通过调控负极材料层中负极粘结剂、增稠剂和负极导电剂的质量百分含量在本申请的范围内，可使负极极片具有合适的导电率和良好的稳定性。
在本申请的一些实施方案中，正极极片以金属锂作为对电极在3.0V至4.6V的电位区间内的容量为d，所述负极极片以金属锂作为对电极在0.005V至0.8V的电位区间内的容量为c，1.00＜c/d≤1.05。通过调控c/d的值在本申请的范围内，负极容量略大于正极容量， 可使电化学装置具有较高的能量密度和良好的高温循环性能的同时，还具有良好的安全性能。
在本申请的一些实施方案中，隔离膜与正极极片之间的粘结力为F N/m，1≤F≤50。隔离膜与正极极片之间的粘结力在本申请的范围内，说明隔离膜与正极极片之间具有高的粘结力，有利于改善电化学装置的安全性能。
在本申请的一些实施方案中，电化学装置的充电上限电压为4.5V至4.75V。说明本申请的电化学装置的充电上限电压高，应用场景广泛。
本申请的第二方面提供了一种电子装置，其包括上述任一实施方案中的电化学装置。从而，本申请提供的电化学装置具有良好的使用性能。
本申请的有益效果：
本申请提供了一种电化学装置及电子装置，电化学装置包括正极极片、负极极片和隔离膜，其中，正极极片包括正极集流体以及设置于正极集流体至少一个表面的正极材料层，正极材料层包括正极材料，正极材料包括P63mc结构的锂钴氧化物，在正极材料层的XRD图谱中，P63mc结构的锂钴氧化物的(002)晶面的特征峰位于17°至19°之间；负极极片包括负极集流体以及设置于负极集流体至少一个表面的负极材料层，负极材料层包括负极材料，负极材料包括硬碳和石墨。通过上述设置，可使电化学装置具有较高的能量密度的同时，还具有良好的倍率性能和高温循环性能。
附图说明
此处所说明的附图用来提供对本申请的进一步理解，构成本申请的一部分，本申请的示意性实施例及其说明用于解释本申请，并不构成对本申请的不当限定。
图1为本申请实施例与对比例的高温循环性能测试结果图；
图2为本申请实施例和对比例的倍率性能测试结果图；
图3为本申请实施例1-1正极的X射线衍射图谱；
图4为本申请实施例2-2正极的X射线衍射图谱；
图5为本申请对比例2-1正极的X射线衍射图谱；
图6为本申请实施例1-1负极的扫描电子显微镜图像。
具体实施方式
为使本申请的目的、技术方案、及优点更加清楚明白，以下参照附图并举实施例，对本申请进一步详细说明。显然，所描述的实施例仅仅是本申请一部分实施例，而不是全部的实施例。本领域技术人员基于本申请所获得的所有其他实施例，都属于本申请保护的范围。
需要说明的是，本申请的具体实施方式中，以锂离子电池作为电化学装置的例子来解释本申请，但是本申请的电化学装置并不仅限于锂离子电池。
本申请的第一方面提供了一种电化学装置，其包括正极极片、负极极片和隔离膜，其中，正极极片包括正极集流体以及设置于正极集流体至少一个表面的正极材料层，正极材料层包括正极材料，正极材料包括P63mc结构的锂钴氧化物，在正极材料层的XRD图谱中，P63mc结构的锂钴氧化物的(002)晶面的特征峰位于17°至19°之间。例如，P63mc结构的锂钴氧化物的(002)晶面的特征峰的位置可以为17°、17.3°、17.5°、17.8°、18°、18.3°、18.5°、18.8°、19°或为其中任意两个数值组成的范围。图3为本申请一种实施方案中P63mc结构的锂钴氧化物的XRD图谱，其(002)晶面特征峰的位置为18.5°。负极极片包括负极集流体以及设置于负极集流体至少一个表面的负极材料层，负极材料层包括负极材料，负极材料包括硬碳和石墨。石墨包括天然石墨或人造石墨中的至少一种。
发明人研究发现，P63mc结构的锂钴氧化物Li-O八面体与两侧的Co-O八面体分别为共棱、共面连接，Co极难迁移至Li位点，将其应用于电化学装置正极材料，在高充电电压条件下，P63mc结构的锂钴氧化物依旧能保持良好的结构稳定性，可使电化学装置具有较高的能量密度的同时，还保持良好的高温循环性能；此外，P63mc结构的锂钴氧化物Co-O八面体层的层间距较大，有利于Li+的嵌入和脱出，可改善电化学装置的倍率性能。但是，P63mc结构的锂钴氧化物层间含有少量Na+，掺杂在Li层，在电化学装置循环过程中，有少部分Na+会随着充放电的进行由Li位点脱出，与Li+一起迁移至负极，若采用石墨作为负极材料，由于Na+的半径远大于Li+ 迁移至负极的Na+无法嵌入石墨层间，而是沉积在负极极片表面，堵塞Li+迁移通道，影响电化学装置的高温循环性能。本申请的负极材料包括硬碳和石墨，硬碳可满足Na+的嵌入和脱出，并且可以使首周充电时形成合适厚度的SEI膜，减少活性锂的消耗。通过正极材料和负极材料的匹配，可进一步改善电化学装置的高温循环性能。本申请中，“高充电电压”是指充电上限电压大于或等于4.5V。
在本申请的一些实施方案中，P63mc结构的锂钴氧化物的(002)晶面的特征峰位于18.3°至18.7°之间。例如，P63mc结构的锂钴氧化物的(002)晶面的特征峰的位置可以为18.3°、18.4°、18.5°、18.6°、18.7°或为其中任意两个数值组成的范围。通过调控P63mc结构的锂钴氧化物的(002)晶面的特征峰位置在本申请的范围内，可提高正极材料的结构稳定性，可使电化学装置具有较高的能量密度的同时，进一步提高电化学装置的高温循环性能。
在本申请的一些实施方案中，基于负极材料的质量，硬碳的质量百分含量为w％， 1≤w≤10。例如硬碳的质量百分含量可以为1％、2％、3％、4％、5％、6％、7％、8％、9％、10％或为其中任意两个数值组成的范围。负极材料中包括硬碳，硬碳可满足Na+的嵌入和脱出，并且可以使首周充电时形成合适厚度的SEI膜，减少活性锂的消耗。通过调控硬碳的质量百分含量w％在本申请的范围内，可使电化学装置具有较高的能量密度的同时，进一步改善电化学装置的高温循环性能。
在本申请的一些实施方案中，P63mc结构的锂钴氧化物包括LixNayCo1-a-bAaBbO2，其中，A包括Mn、Fe或Ni中的至少一种，B包括Al、Mg、Ti、La、Y、Zr、Zn、Cu、Cr、Ca、Ce或Lu中的至少一种，0.779≤x≤0.95，0＜y≤0.001，0＜a≤0.2，0≤b≤0.02。例如，x的值可以为0.779、0.8、0.82、0.85、0.88、0.9、0.92、0.95或为其中任意两个数值组成的范围；y的值可以为0.00001、0.0001、0.0003、0.0005、0.0008、0.001或为其中任意两个数值组成的范围；a的值可以为0.001、0.01、0.05、0.08、0.1、0.13、0.15、0.18、0.2或为其中任意两个数值组成的范围；b的值可以为0、0.001、0.01、0.013、0.015、0.018、0.02或为其中任意两个数值组成的范围。通过上述设置，可进一步提高正极材料的结构稳定性，可使电化学装置具有较高的能量密度和倍率性能的同时，进一步提高电化学装置的高温循环性能。
在本申请的一些实施方案中，P63mc结构的锂钴氧化物可以包括但不限于Li0.9495Na0.0005Co0.95Fe0.02Ni0.01Mn0.01Al0.01O2、Li0.9495Na0.0005Co0.95Fe0.04Al0.01O2、Li0.9495Na0.0005Co0.95Ni0.02Mn0.02Al0.01O2、Li0.9495Na0.0005Co0.95Fe0.03Mn0.01Cu0.01O2、Li0.9495Na0.0005Co0.95Fe0.03Ni0.01Ti0.01O2、Li0.9495Na0.0005Co0.95Fe0.02Ni0.01Mn0.01Al0.01O2、Li0.937Na0.0005Co0.9375Fe0.03Ni0.01Mn0.01Al0.0125O2、Li0.9245Na0.0005Co0.925Fe0.04Ni0.01Mn0.01Al0.015O2、Li0.8Na0.0005Co0.95Fe0.02Ni0.01Mn0.01Al0.01O2、Li0.7895Na0.0005Co0.79Fe0.1Ni0.05Mn0.05Al0.01O2、Li0.9395Na0.0005Co0.94Fe0.02Ni0.01Mn0.01Al0.02O2、Li0.949Na0.001Co0.95Fe0.02Ni0.01Mn0.01Al0.01O2、Li0.7795Na0.0005Co0.78Fe0.1Ni0.05Mn0.05Al0.02O2、Li0.9495Na0.0005Co0.96Fe0.03Al0.01O2、Li0.9495Na0.0005Co0.95Fe0.02Ni0.01Mn0.01La0.01O2、Li0.9495Na0.0005Co0.95Fe0.02Ni0.01Mn0.01Lu0.01O2、Li0.9495Na0.0005Co0.95Fe0.02Ni0.01Mn0.01Y0.01O2、Li0.9495Na0.0005Co0.95Fe0.02Ni0.01Mn0.01Mg0.005Ti0.005O2、Li0.9495Na0.0005Co0.95Fe0.02Ni0.01Mn0.01Zn0.005Ce0.005O2等。
在本申请的一些实施方案中，正极材料还包括R-3m结构的锂钴氧化物，在正极材料层的XRD图谱中，R-3m结构的锂钴氧化物的(003)晶面特征峰位于18°至20°之间；R-3m结构的锂钴氧化物(003)晶面特征峰强度为I1，P63mc结构的锂钴氧化物(002)晶面特征峰强度为I2，0≤I1/I2≤20。例如，R-3m结构的锂钴氧化物的(003)晶面特征峰的位置 可以为18°、18.1°、18.2°、18.3°、18.4°、18.5°、18.6°、18.7°、18.8°、18.9°、19°、19.1°、19.2°、19.3°、19.4°、19.5°、19.6°、19.7°、19.8°、19.9°、20°或为其中任意两个数值组成的范围。I1/I2的值可以为0、1、3、5、8、10、13、15、18、20或为其中任意两个数值组成的范围。正极材料包括R-3m结构的锂钴氧化物，并调控R-3m结构的锂钴氧化物的(003)晶面特征峰和I1/I2的值在本申请的范围内，可显著提高电化学装置首次放电质量比容量，即可提高电化学装置的能量密度的同时，兼顾电化学装置的高温循环性能。
在本申请的一些实施方案中，R-3m结构的锂钴氧化物包括LiCo1-m-nAlmCnO2，其中，C包括Mg、Ti、La、Y、Zr或Lu中的至少一种，0＜m≤0.1，0≤n≤0.05。例如，m的值可以0.001、0.01、0.03、0.05、0.08、0.1或为其中任意两个数值组成的范围；n的值可以为0、0.001、0.005、0.01、0.02、0.03、0.04、0.05或为其中任意两个数值组成的范围。通过上述设置，有利于提高正极材料的结构稳定性，可进一步提高电化学装置的高温循环性能。
在本申请的一些实施方案中，R-3m结构的锂钴氧化物可以包括但不限于LiCo0.97Al0.03O2、LiCo0.965Al0.03Mg0.005O2、LiCo0.96Al0.03Mg0.005Ti0.005O2、LiCo0.9Al0.1O2、LiCo0.92Al0.03Mg0.01Ti0.01La0.01Y0.01Zr0.01O2、LiCo0.999Al0.001O2、LiCo0.99Al0.01O2、LiCo0.95Co0.05O2、LiCo0.969Al0.03Y0.001O2、LiCo0.93Al0.03Mg0.01Ti0.01La0.01Y0.01O2、LiCo0.9Al0.08Mg0.005Ti0.005La0.005Y0.005O2等。
在本申请的一些实施方案中，正极材料层还包括正极粘结剂和正极导电剂，基于正极材料层的质量，正极粘结剂的质量百分含量为m1％，正极导电剂的质量百分含量为m2％，满足0＜m1≤10，0＜m2≤10。例如，正极粘结剂的质量百分含量m1％的值可以为0.1％、1％、2％、3％、4％、5％、6％、7％、8％、9％、10％或为其中任意两个数值组成的范围；正极导电剂的质量百分含量m2％的值可以为0.1％、1％、2％、3％、4％、5％、6％、7％、8％、9％、10％或为其中任意两个数值组成的范围。通过调控正极粘结剂和正极导电剂的质量百分含量在本申请的范围内，可使正极极片具有合适的导电率和良好的稳定性。
在本申请的一些实施方案中，所述负极材料层还包括负极粘结剂、增稠剂和负极导电剂，基于所述负极材料层的质量，负极粘结剂的质量百分含量为m3％，增稠剂的质量百分含量为m4％，导电剂的质量百分含量为m5％，满足0＜m3≤5，0＜m4≤5，0＜m5≤5。例如，负极粘结剂的质量百分含量m3％的值可以为0.1％、0.5％、1％、2％、3％、4％、5％或为其中任意两个数值组成的范围；增稠剂的质量百分含量m4％的值可以为0.1％、0.5％、1％、2％、3％、4％、5％或为其中任意两个数值组成的范围；负极导电剂的质量百分含量m5％的值可以为0.1％、0.5％、1％、2％、3％、4％、5％或为其中任意两个数值组成的范围。 通过调控负极材料层中负极粘结剂、增稠剂和负极导电剂的质量百分含量在本申请的范围内，可使负极极片具有合适的导电率和良好的稳定性。
在本申请的一些实施方案中，正极极片以金属锂作为对电极在3.0V至4.6V的电位区间内的容量为d，所述负极极片以金属锂作为对电极在0.005V至0.8V的电位区间内的容量为c，1.00＜c/d≤1.05。例如c/d的值可以为1.01、1.02、1.03、1.04、1.05或为其中任意两个数值组成的范围。通过调控c/d的值在本申请的范围内，负极容量略大于正极容量，可使电化学装置具有较高的能量密度和良好的高温循环性能的同时，还具有良好的安全性能。
在本申请的一些实施方案中，隔离膜与正极极片之间的粘结力为F N/m，1≤F≤50。例如，隔离膜与正极极片之间的粘结力F的值可以为1N/m、10N/m、20N/m、30N/m、40N/m、50N/m或为其中任意两个数值组成的范围。隔离膜与正极极片之间的粘结力在本申请的范围内，说明隔离膜与正极极片之间具有高的粘结力，有利于改善电化学装置的能量密度及安全性能。
在本申请的一些实施方案中，电化学装置的充电上限电压为4.5V至4.75V。例如，充电上限电压可以为4.5V、4.55V、4.6V、4.65V、4.7V、4.75V或为其中任意两个数值组成的范围。电化学装置的充电上限电压为4.5V至4.75V，说明本申请的电化学装置的充电上限电压高，应用场景广泛。
本申请对P63mc结构的锂钴氧化物的制备方法没有特别限制，只要能实现本申请的目的即可。例如，P63mc结构的锂钴氧化物LixNayCo1-a-bAaBbO2的制备方法可以包括但不限于以下步骤：将钴源材料、A源材料、B源材料作为原料，根据P63mc结构的锂钴氧化物LixNayCo1-a-bAaBbO2的化学计量比配料，在反应釜中，将上述原料溶于水中，在氮气气氛下搅拌，并在搅拌过程中向反应釜内加入碱源溶液，调控反应釜中溶液的pH值为10至12。持续搅拌10h至14h，过滤获得沉淀物，再用去离子水清洗3次，60℃至100℃真空干燥20h至26h，得到前驱体粉末。将前驱体与钠源材料进行球磨，混合均匀，再将球磨后的混合物置于马弗炉中，空气气氛下，700℃至900℃条件下热处理20h至24h，取出样品，破碎、研磨、过筛后，根据P63mc结构的锂钴氧化物LixNayCo1-a-bAaBbO2的化学计量比，再结合钴源材料、A源材料、B源材料的加入量，加入对应量的含溴化锂的正己醇溶液，在90℃至110℃条件下，溶剂热法反应20h至26h，之后进行抽滤，得到沉淀物，使用甲醇洗涤，80℃至100℃真空干燥6至10h，得到P63mc结构的锂钴氧化物LixNayCo1-a-bAaBbO2。
本申请对上述钴源材料、A源材料、B源材料、碱源、钠源材料没有特别限定，可以 根据实际需要进行选择，只要能实现本申请的目的即可。例如，钴源材料可以包括但不限于硫酸钴、碳酸钴、氯化钴或硝酸钴中的至少一种；A源材料可以包括但不限于硫酸锰、硝酸锰、氯化锰、氯化铁、硫酸铁、硝酸铁、氯化镍、硝酸镍或硫酸镍等中的至少一种；B源材料可以包括但不限于硝酸铝、硫酸镁、硫酸铜或二氧化钛等中的至少一种；碱源可以包括但不限于氢氧化钠或一水合氨中的至少一种；钠源可以包括但不限于碳酸钠、硝酸钠或氯化钠中的至少一种。
本申请对R-3m结构的锂钴氧化物的制备方法没有特别限制，只要能实现本申请的目的即可。例如，R-3m结构的锂钴氧化物LiCo1-m-nAlmCnO2的制备方法可以包括但不限于以下步骤：将LiCoO2(CAS号：12190-79-3)、铝源材料、C源材料混合均匀，转移至刚玉坩埚中，在氧气气氛下，950℃至1050℃烧结8h至12h，之后投入颚式破碎机、对辊机制成粉末，经过气流粉碎机进一步破碎，最后用筛网筛分后得到R-3m结构的锂钴氧化物LiCo1-m-nAlmCnO2。
本申请对上述铝源材料、C源材料没有特别限定，可以根据实际需要进行选择，只要能实现本申请的目的即可。例如，铝源材料可以包括但不限于三氧化二铝；C源材料可以包括但不限于硫酸镁、二氧化钛或三氧化镧等中的至少一种。
本申请的正极极片包括正极集流体和设置在正极集流体至少一个表面上的正极材料层。本申请对正极集流体没有特别限制，只要能够实现本申请目的即可。例如，正极集流体可以包含铝箔、铝合金箔或复合集流体(例如铝碳复合集流体)等。在本申请中，对正极集流体和正极材料层的厚度没有特别限制，只要能够实现本申请目的即可。例如，正极集流体的厚度为5μm至20μm。单面正极材料层的厚度为30μm至120μm。在本申请中，正极材料层可以设置于正极集流体厚度方向上的一个表面上，也可以设置于正极集流体厚度方向上的两个表面上。需要说明，这里的“表面”可以是正极集流体的全部区域，也可以是正极集流体的部分区域，本申请没有特别限制，只要能实现本申请目的即可。
本申请本申请对正极导电剂和粘结剂的种类没有特别限制，只要能够实现本申请目的即可。例如，导电剂可以包括但不限于导电炭黑(Super P)、碳纳米管(CNTs)、碳纤维、鳞片石墨、石墨烯、金属材料或导电聚合物中的至少一种。上述碳纳米管可以包括但不限于单壁碳纳米管和/或多壁碳纳米管。上述碳纤维可以包括但不限于气相生长碳纤维(VGCF)和/或纳米碳纤维。上述金属材料可以包括但不限于金属粉和/或金属纤维，具体地，金属可以包括但不限于铜、镍、铝或银中的至少一种。上述导电聚合物可以包括但不限于聚亚苯基衍生物、聚苯胺、聚噻吩、聚乙炔或聚吡咯中的至少一种。例如，粘结剂可以包括但不限于聚丙烯酸、聚丙烯酸钠、聚丙烯酸钾、聚丙烯酸锂、聚酰亚胺、聚乙烯醇、 羧甲基纤维素、羧甲基纤维素钠、羧甲基纤维素锂、聚酰亚胺、聚酰胺酰亚胺、丁苯橡胶或聚偏氟乙烯中的至少一种。
本申请的负极极片包括负极集流体和设置在负极集流体至少一个表面上的负极材料层。在本申请中，负极材料层可以设置于负极集流体厚度方向上的一个表面上，也可以设置于负极集流体厚度方向上的两个表面上。需要说明，这里的“表面”可以是负极集流体的全部区域，也可以是负极集流体的部分区域，本申请没有特别限制，只要能实现本申请目的即可。本申请对负极集流体没有特别限制，只要能够实现本申请目的即可。例如，负极集流体可以包括但不限于铜箔、铜合金箔、镍箔、钛箔、泡沫镍、泡沫铜或复合集流体等。在本申请中，对负极集流体和负极材料层的厚度没有特别限制，只要能够实现本申请目的即可。例如，负极集流体的厚度为4μm至15μm，单面负极材料层的厚度为30μm至130μm。本申请对负极材料层中的负极粘结剂、增稠剂和负极导电剂的种类没有特别限制，只要能够实现本申请目的即可，例如，导电剂和粘结剂可以是上述导电剂和上述粘结剂中的至少一种。增稠剂可以包括但不限于羧甲基纤维素钠或羧甲基纤维素锂中的至少一种。
本申请对隔离膜没有特别限制，只要能够实现本申请目的即可。例如，隔离膜的材料可以包括但不限于聚乙烯(PE)、聚丙烯(PP)为主的聚烯烃(PO)类、聚酯(例如聚对苯二甲酸二乙酯(PET)膜)、纤维素、聚酰亚胺(PI)、聚酰胺(PA)、氨纶或芳纶中的至少一种。隔离膜的类型可以包括织造膜、非织造膜(无纺布)、微孔膜、复合膜、碾压膜或纺丝膜中的至少一种。本申请的隔离膜可以具有多孔结构，多孔层设置在隔离膜的至少一个表面上，多孔层包括无机颗粒和粘结剂，无机颗粒可以包括氧化铝、氧化硅、氧化镁、氧化钛、二氧化铪、氧化锡、二氧化铈、氧化镍、氧化锌、氧化钙、氧化锆、氧化钇、碳化硅、勃姆石、氢氧化铝、氢氧化镁、氢氧化钙或硫酸钡中的至少一种。粘结剂可以包括聚偏氟乙烯、偏氟乙烯-六氟丙烯的共聚物、聚酰胺、聚丙烯腈、聚丙烯酸甲酯、聚丙烯酸乙酯、聚丙烯酸丁酯、聚丙烯酸、聚丙烯酸盐、羧甲基纤维素纳、聚乙烯吡咯烷酮、聚乙烯醚、聚甲基丙烯酸甲酯、聚四氟乙烯或聚六氟丙烯中的至少一种。本申请对多孔结构的孔径的尺寸没有特别限制，只要能实现本申请的目的即可，例如，孔径的尺寸可以为0.01μm至1μm。在本申请中，隔离膜的厚度没有特别限制，只要能实现本申请的目的即可，例如厚度可以为3μm至30μm。
在本申请的电化学装置还包括电解液，电解液包括锂盐和非水溶剂。
本申请对锂盐没有特别限制，只要能实现本申请的目的即可。例如锂盐可以包括但不限于LiPF6、LiBF4、LiAsF6、LiClO4、LiB(C6H5)4、LiCH3SO3、LiCF3SO3、LiN(SO2CF3)2、LiC(SO2CF3)3、Li2SiF6、双草酸硼酸锂(LiBOB)或二氟硼酸锂中的至少一种。本申请对 锂盐在电解液中的含量没有特别限制，只要能实现本申请的目的即可。
本申请对非水溶剂没有特别限制，只要能实现本申请的目的即可，例如非水溶剂可以包括但不限于碳酸酯化合物、羧酸酯化合物、醚化合物或其它有机溶剂中的至少一种。上述碳酸酯化合物可以包括但不限于链状碳酸酯化合物、环状碳酸酯化合物或氟代碳酸酯化合物中的至少一种。上述链状碳酸酯化合物可以包括但不限于碳酸二甲酯(DMC)、碳酸二乙酯(DEC)、碳酸二丙酯(DPC)、碳酸甲丙酯(MPC)、碳酸乙丙酯(EPC)或碳酸甲乙酯(MEC)中的至少一种。上述环状碳酸酯可以包括但不限于碳酸乙烯酯(EC)、碳酸亚丙酯(PC)、碳酸亚丁酯(BC)或碳酸乙烯基亚乙酯(VEC)中的至少一种。氟代碳酸酯化合物可以包括但不限于氟代碳酸乙烯酯(FEC)、碳酸1,2-二氟亚乙酯、碳酸1,1-二氟亚乙酯、碳酸1,1,2-三氟亚乙酯、碳酸1,1,2,2-四氟亚乙酯、碳酸1-氟-2-甲基亚乙酯、碳酸1-氟-1-甲基亚乙酯、碳酸1,2-二氟-1-甲基亚乙酯、碳酸1,1,2-三氟-2-甲基亚乙酯或碳酸三氟甲基亚乙酯中的至少一种。上述羧酸酯化合物可以包括但不限于甲酸甲酯、乙酸甲酯、乙酸乙酯、乙酸正丙酯、乙酸叔丁酯、丙酸甲酯、丙酸乙酯、丙酸丙酯、γ-丁内酯、癸内酯、戊内酯或己内酯中的至少一种。上述醚化合物可以包括但不限于二丁醚、四甘醇二甲醚、二甘醇二甲醚、1,2-二甲氧基乙烷、1,2-二乙氧基乙烷、1-乙氧基-1-甲氧基乙烷、2-甲基四氢呋喃或四氢呋喃中的至少一种。上述其它有机溶剂可以包括但不限于二甲亚砜、1,2-二氧戊环、环丁砜、甲基环丁砜、1,3-二甲基-2-咪唑烷酮、N-甲基-2-吡咯烷酮、二甲基甲酰胺、乙腈、磷酸三甲酯、磷酸三乙酯或磷酸三辛酯中的至少一种。本申请对非水溶剂在电解液中的含量没有特别限制，只要能实现本申请的目的即可。
本申请的电化学装置还包括壳体，用于容纳正极极片、隔离膜、负极极片和电解液，以及电化学装置领域中已知的其它部件，本申请对上述其它部件不做限定。本申请对壳体没有特别限制，可以为本领域公知的壳体，只要能够实现本申请目的即可。例如，壳体可以为硬壳壳体或柔性壳体。硬壳壳体的材料可以为金属，本申请对金属的种类不做限定，可以采用本领域已知的金属硬壳壳体，只要能实现本申请的目的即可。柔性壳体可以为金属塑膜，例如铝塑膜、钢塑膜等。
本申请的电化学装置的制备过程为本领域技术人员所熟知的，本申请没有特别的限制，例如，可以包括但不限于以下步骤：将正极极片、隔离膜和负极极片按顺序堆叠，并根据需要将其卷绕、折叠等操作得到卷绕结构的电极组件，将电极组件放入壳体内，将电解液注入壳体并封口，得到电化学装置。或者，将正极极片、隔离膜和负极极片按顺序堆叠，然后用胶带将整个叠片结构的四个角固定好得到叠片结构的电极组件，将电极组件置入壳体内，将电解液注入壳体并封口，得到电化学装置。此外，也可以根据需要将防过电 流元件、导板等置于壳体中，从而防止电化学装置内部的压力上升、过充放电。
本申请的第二方面提供了一种电子装置，其包括上述任一实施方案中的电化学装置。从而，本申请提供的电化学装置具有良好的使用性能。
本申请对电子装置的种类没有特别限定，其可以是用于现有技术中已知的任何电子装置。在本申请的一些实施方案中，电子装置可以包括但不限于笔记本电脑、笔输入型计算机、移动电脑、电子书播放器、便携式电话、便携式传真机、便携式复印机、便携式打印机、头戴式立体声耳机、录像机、液晶电视、手提式清洁器、便携CD机、迷你光盘、收发机、电子记事本、计算器、存储卡、便携式录音机、收音机、备用电源、电机、汽车、摩托车、助力自行车、自行车、照明器具、玩具、游戏机、钟表、电动工具、闪光灯、照相机、家庭用大型蓄电池和锂离子电容器等。
实施例
以下，举出实施例及对比例来对本申请的实施方式进行更具体地说明。各种的试验及评价按照下述的方法进行。另外，只要无特别说明，“份”、“％”为质量基准。
测试方法和设备：
X射线衍射图谱测试
将锂离子电池以0.2C恒流完全放电至3.0V后，拆解得到正极极片，用碳酸乙烯酯(EC)浸泡30min后，再用碳酸乙烯酯冲洗3次，在氩气气氛下自然晾干，得到处理后的正极极片。取3cm×3cm规格的处理后的正极极片进行XRD(X射线衍射)测试，正极极片放置在XRD测试仪器(型号布鲁克，D8)样品台中，采用Cu靶Kα射线，使用10°/min的扫描速率，扫描角度范围为10°至71°，得到XRD衍射图。读取相应衍射峰，记录衍射峰的位置。
硬碳的质量百分含量测试
将锂离子电池以0.2C恒流完全放电至3.0V后，拆解得到负极极片，用碳酸乙烯酯(EC)浸泡30min后，再用碳酸乙烯酯冲洗3次，在氩气气氛下自然晾干，得到处理后的负极极片。用离子束切割处理后的负极极片，得到沿其厚度方向的截面。通过扫描电子显微镜(SEM)对截面进行观察，放大倍数限定为1000X，拍摄面积为125μm×85μm。在SEM背散射模式下，硬碳颗粒形貌为有棱角的块状颗粒，石墨颗粒为片层状颗粒。使用ImageJ图像解析软件分别计算至少50张图片中硬碳颗粒与石墨颗粒的面积，将硬碳颗粒的面积除以硬碳和石墨颗粒的面积，并取算数平均数，作为硬碳的质量百分含量。
隔离膜与正极极片之间的粘结力测试
将锂离子电池以0.2C恒流完全放电至3.0V后拆解，保留一面粘有隔离膜的正极极片。 将正极极片未粘有隔离膜的一面用双面胶粘在钢板上，使用拉力机进行180°剥离测试，将钢板固定在下夹具中，上夹具夹住隔离膜，以恒定速率50mm/min拉伸50mm，将隔离膜从正极极片上撕开至180°，得到应力与位移数据。隔离膜与正极极片之间的粘结力＝应力/位移。
正极活性材料质量的计算
对于从锂离子电池中拆出的正极极片与铝箔，分别取直径44mm的圆片，称取得到重量；
正极活性材料的质量＝(正极极片圆片重量-铝箔重量)/(π×22×22)×正极极片长度×正极极片宽度×(1-导电炭黑质量分数-粘结剂质量分数)。
负极活性材料质量的计算
对于从锂离子电池中拆出的负极极片与铜箔，分别取直径44mm的圆片，称取得到重量；
负极活性材料的质量＝(负极极片圆片重量-铜箔重量)/(π×22×22)×负极极片长度×负极极片宽度×(1-导电炭质量分数-粘结剂质量分数-分散剂质量分数)。
正极极片容量d和负极极片容量c的测试
分别从正极极片、负极极片取直径14mm的圆片，以锂片为对电极，分别制作扣式电池测试正极、负极材料的首次放电质量比容量；
正极极片容量d＝正极材料质量比容量×正极活性材料质量；
负极极片容量c＝负极材料质量比容量×负极活性材料质量；
再计算得到c/d的值。
首次质量比容量的测试
将锂离子电池置于25℃环境中，以0.2C恒定电流充电至4.55V，然后以4.55V恒压充电至电流小于0.05C，再用0.2C恒定电流放电至3.0V，记录首次放电容量。锂离子电池测试设备的型号为Land CT2001A。
实施例1-13的锂离子电池进行首次质量比容量的测试时，将上述步骤中的上限电压4.55V调整为4.75V，其余实施例和对比例均按照上限电压为4.55V进行测试。
首次质量比容量＝首次放电容量/正极活性材料的质量。以锂离子电池的首次质量比容量评价锂离子电池的能量密度，首次质量比容量越大，能量密度越高，首次质量比容量越小，能量密度越低。
倍率性能的测试
将锂离子电池置于25℃环境中，首先，以0.2C恒定电流放电至3.0V，然后以0.5C恒 定电流充电至4.55V，之后以4.55V恒压充电至电流为0.05C，再用0.2C恒定电流放电至3.0V，记录此时放电容量为C1。以0.5C恒定电流充电至4.55V，然后以4.55V恒压充电至电流为0.05C，再用0.5C恒定电流放电至3.0V。以0.5C恒定电流充电至4.55V，然后以4.55V恒压充电至电流为0.05C，再用1.0C恒定电流放电至3.0V。以0.5C恒定电流充电至4.55V，然后以4.55V恒压充电至电流为0.05C，再用2.0C恒定电流放电至3.0V，记录此时放电容量为C2。锂离子电池测试设备的型号为Land CT2001A。
实施例1-13的锂离子电池进行倍率性能测试时，将上述步骤中的上限电压4.55V均调整为4.75V，其余实施例和对比例均按照上限电压为4.55V进行测试。
容量保持率R＝C2/C1×100％，以R表征倍率性能，R值越大表示倍率性能越好。
高温循环性能的测试
将锂离子电池置于45℃的恒温箱中，首先，以0.2C恒定电流放电至3.0V。
然后以1.0C恒定电流充电至4.25V，之后以4.25V恒压充电至电流小于0.5C，然后用0.5C恒定电流充电至4.55V，再以4.55V恒压充电至电流小于0.05C，再用0.7C恒定电流放电至3.0V，记录此时放电容量C1，以此作为一次充放电循环。
每循环上述流程49次后进行1次小电流充放电循环，即以0.2C恒定电流充电至4.55V，然后以4.55V恒压充电至电流小于0.05C，再用0.2C恒定电流放电至3.0V。进行n次循环后，记录放电容量为Cn。
实施例1-13的锂离子电池进行高温循环性能测试时，将上述步骤中的上限电压4.55V均调整为4.75V，其余实施例和对比例均按照上限电压为4.55V进行测试。
45℃容量保持率＝Cn/C1×100％，记录当45℃容量保持率为80％时的循环圈数n。
实施例1-1
<正极活性材料的制备>
(1)在反应釜中，将274.99g的CoSO4·7H2O、5.73g的FeSO4·7H2O、2.71g的NiSO4·6H2O、1.74g的MnSO4·H2O、3.86g的Al(NO3)3·9H2O溶于水，在氮气气氛下搅拌，并在搅拌过程中向反应釜内加入含2mol/L的NaOH与2mol/L的NH3·H2O的溶液，使得溶液pH＝11。持续搅拌12h，过滤得到沉淀物，再用去离子水清洗3次，80℃真空干燥24h，得到Co0.95Fe0.02Ni0.01Mn0.01Al0.01(OH)3前驱体。
(2)将112.79g的Co0.95Fe0.02Ni0.01Mn0.01Al0.01(OH)3前驱体与60.03g的Na2CO3球磨混合均匀。再将球磨后的混合物置于马弗炉中，空气气氛下，850℃热处理24h，取出样品，破碎、研磨、过筛后，加入500mL 3.09mol/L溴化锂的正己醇溶液，在100℃条件下，溶剂热法反应24h，之后进行抽滤，得到沉淀物，使用甲醇洗涤3次，90℃真空干燥8h，得 到P63mc结构的锂钴氧化物Li0.9495Na0.0005Co0.95Fe0.02Ni0.01Mn0.01Al0.01O2粉末。
<正极极片的制备>
将上述制备得到的正极活性材料、导电剂导电炭黑(Super P)、粘结剂聚偏二氟乙烯(PVDF)按照质量比为97:1.5:1.5进行混合，加入N-甲基吡咯烷酮(NMP)作为溶剂，在真空搅拌机作用下搅拌均匀，得到固含量为70wt％的正极浆料。将正极浆料均匀涂覆于厚度为10μm的正极集流体铝箔的一个表面上，120℃条件下烘干，得到单面涂覆正极材料层的正极极片，正极材料层的涂布重量为Y g/1540.25mm2，Y为0.198g/1540.25mm2。在正极集流体铝箔的另一个表面上重复以上步骤，即得到双面涂覆正极材料层的正极极片。然后在120℃的条件下烘干后，再经过冷压、裁片、分切、焊接极耳得到规格为74mm×867mm的正极极片。其中，单面正极材料层的厚度为42μm。基于正极材料层的质量，正极粘结剂的质量百分含量m1％为1.5％，正极导电剂的质量百分含量m2％为1.5％。
<负极活性材料的制备>
将190g天然石墨与10g硬碳材料在容器中进行混合，混合均匀后得到负极活性材料。
<负极极片的制备>
将上述制备得到负极活性材料、粘结剂丁苯橡胶、增稠剂羧甲基纤维素钠、导电剂导电炭黑(Super P)按照质量比97:1.5:0.75:0.75进行混合，加入去离子水作为溶剂，调配成为固含量为45wt％的浆料，真空搅拌机搅拌均匀后得到负极浆料。将负极浆料均匀涂覆于厚度为10μm的负极集流体铜箔的一个表面上，120℃条件下烘干，得到单面涂布负极材料层的负极极片，负极材料层的涂布重量为6.87mg/cm2。然后在铜箔的另一个表面上重复以上步骤，即得到双面涂布负极材料层的负极极片。120℃条件下烘干后再经过冷压、裁片、分切、焊接极耳得到规格为78mm×875mm的负极极片待用。其中，单面负极材料层的厚度为40.4μm。基于负极材料层的质量，负极粘结剂的质量百分含量m3％为1.5％，增稠剂的质量百分含量m4％为0.75％，负极导电剂的质量百分含量m5％为0.75％。
<隔离膜的制备>
首先，将α-Al2O3颗粒加入水作为溶剂，混合均匀，之后再加入粘结剂聚偏氟乙烯(PVDF)继续搅拌，调配成固含量为60％的浆料，其中α-Al2O3和聚偏氟乙烯的质量比为95:5.。将浆料涂覆在5μm厚的聚乙烯(PE)多孔基材的一个表面，90℃烘干后得到单面涂覆为2μm厚的氧化铝陶瓷层的隔离膜，然后将浆料涂覆在聚乙烯(PE)多孔基材的另一个表面上，90℃烘干，得到双面涂覆氧化铝陶瓷层的隔离膜。
<电解液的制备>
在含水量小于10ppm的环境下，将碳酸乙烯酯(EC)、碳酸丙烯酯(PC)、碳酸二乙 酯(DEC)按质量比为1:1:1混合得到有机溶剂，然后向有机溶剂中加入电解质盐LiPF6，混合均匀，得到电解液。其中，基于电解液的质量，电解质盐LiPF6的质量百分含量为12.5％，其余为有机溶剂。
<锂离子电池的制备>
将上述制备的正极极片、隔离膜、负极极片按顺序叠好，使隔离膜处于正极极片和负极极片中间起到隔离的作用，卷绕得到电极组件。将电极组件装入铝塑膜包装袋中，并在80℃下脱去水分，注入上述制备得到的电解液，经过真空封装、静置、化成、脱气、切边等工序得到锂离子电池。其中，化成上限电压为4.15V，化成温度为70℃，化成静置时间为2h。
实施例1-2
<正极活性材料的制备>
(1)在反应釜中，将275.04g的CoSO4·7H2O、11.45g的FeSO4·7H2O、3.86g的Al(NO3)3·9H2O溶于水，在氮气气氛下搅拌，并在搅拌过程中向反应釜内加入含2mol/L的NaOH与2mol/L的NH3·H2O的溶液，使得溶液pH＝11。持续搅拌12h，过滤得到沉淀物，再用去离子水清洗3次，80℃真空干燥24h，得到Co0.95Fe0.04Al0.01(OH)3前驱体。
(2)将112.79g的Co0.95Fe0.04Al0.01(OH)3前驱体与60.04g的Na2CO3球磨混合均匀。再将球磨后的混合物置于马弗炉中，空气气氛下，850℃热处理24h，取出样品，破碎、研磨、过筛后，加入500mL 3.09mol/L溴化锂的正己醇溶液，在100℃条件下，溶剂热法反应24h，之后进行抽滤，得到沉淀物，使用甲醇洗涤3次，90℃真空干燥8h，得到P63mc结构的锂钴氧化物Li0.9495Na0.0005Co0.95Fe0.04Al0.01O2粉末。
除了<正极活性材料的制备>按上述步骤制备以外，其余与实施例1-1相同。
实施例1-3
<正极活性材料的制备>
(1)在反应釜中，将274.93g的CoSO4·7H2O、5.41g的NiSO4·6H2O、3.48g的MnSO4·H2O、3.86g的Al(NO3)3·9H2O溶于水，在氮气气氛下搅拌，并在搅拌过程中向反应釜内加入含2mol/L的NaOH与2mol/L的NH3·H2O的溶液，使得溶液pH＝11。持续搅拌12h，过滤得到沉淀物，再用去离子水清洗3次，80℃真空干燥24h，得到Co0.95Ni0.02Mn0.02Al0.01(OH)3前驱体。
(2)将112.79g的Co0.95Ni0.02Mn0.02Al0.01(OH)3前驱体与60.02g的Na2CO3球磨混合均匀。再将球磨后的混合物置于马弗炉中，空气气氛下，850℃热处理24h，取出样品，破碎、研磨、过筛后，加入500mL 3.09mol/L溴化锂的正己醇溶液，在100℃条件下，溶剂热法反 应24h，之后进行抽滤，得到沉淀物，使用甲醇洗涤3次，90℃真空干燥8h，得到P63mc结构的锂钴氧化物Li0.9495Na0.0005Co0.95Ni0.02Mn0.02Al0.01O2粉末。
除了<正极活性材料的制备>按上述步骤制备以外，其余与实施例1-1相同。
实施例1-4
<正极活性材料的制备>
(1)在反应釜中，将274.04g的CoSO4·7H2O、8.56g的FeSO4·7H2O、1.73g的MnSO4·H2O、2.56g的CuSO4·5H2O溶于水，在氮气气氛下搅拌，并在搅拌过程中向反应釜内加入含2mol/L的NaOH与2mol/L的NH3·H2O的溶液，使得溶液pH＝11。持续搅拌12h，过滤得到沉淀物，再用去离子水清洗3次，80℃真空干燥24h，得到Co0.95Fe0.03Mn0.01Cu0.01(OH)3前驱体。
(2)将112.75g的Co0.95Fe0.03Mn0.01Cu0.01(OH)3前驱体与59.89g的Na2CO3球磨混合均匀。再将球磨后的混合物置于马弗炉中，空气气氛下，850℃热处理24h，取出样品，破碎、研磨、过筛后，加入500mL 3.08mol/L溴化锂的正己醇溶液，在100℃条件下，溶剂热法反应24h，之后进行抽滤，得到沉淀物，使用甲醇洗涤3次，90℃真空干燥8h，得到P63mc结构的锂钴氧化物Li0.9495Na0.0005Co0.95Fe0.03Mn0.01Cu0.01O2粉末。
除了<正极活性材料的制备>按上述步骤制备以外，其余与实施例1-1相同。
实施例1-5
<正极活性材料的制备>
(1)在反应釜中，将274.37g的CoSO4·7H2O、8.57g的FeSO4·7H2O、2.70g的NiSO4·6H2O、0.82g的TiO2溶于水，在氮气气氛下搅拌，并在搅拌过程中向反应釜内加入含2mol/L的NaOH与2mol/L的NH3·H2O的溶液，使得溶液pH＝11。持续搅拌12h，过滤得到沉淀物，再用去离子水清洗3次，80℃真空干燥24h，得到Co0.95Fe0.03Ni0.01Ti0.01(OH)3前驱体。
(2)将112.75g的Co0.95Fe0.03Ni0.01Ti0.01(OH)3前驱体与59.89g的Na2CO3球磨混合均匀。再将球磨后的混合物置于马弗炉中，空气气氛下，850℃热处理24h，取出样品，破碎、研磨、过筛后，加入500mL 3.08mol/L溴化锂的正己醇溶液，在100℃条件下，溶剂热法反应24h，之后进行抽滤，得到沉淀物，使用甲醇洗涤3次，90℃真空干燥8h，得到P63mc结构的锂钴氧化物Li0.9495Na0.0005Co0.95Fe0.03Ni0.01Ti0.01O2粉末。
除了<正极活性材料的制备>按上述步骤制备以外，其余与实施例1-1相同。
实施例1-6
<负极活性材料的制备>
将180g天然石墨与20g硬碳材料在容器中进行混合，混合均匀后得到负极活性材料。
除了<负极活性材料的制备>按上述步骤制备，<正极极片的制备>按表1调整正极材料层的涂布重量Y以外，其余与实施例1-1相同。
实施例1-7
<负极活性材料的制备>
将198g天然石墨与2g硬碳材料在容器中进行混合，混合均匀后得到负极活性材料。
除了<负极活性材料的制备>按上述步骤制备，<正极极片的制备>按表1调整正极材料层的涂布重量Y以外，其余与实施例1-1相同。
实施例1-8
<正极活性材料的制备>
(1)在反应釜中，将271.92g的CoSO4·7H2O、8.61g的FeSO4·7H2O、2.71g的NiSO4·6H2O、1.74g的MnSO4·H2O、4.84g的Al(NO3)3·9H2O溶于水，在氮气气氛下搅拌，并在搅拌过程中向反应釜内加入含2mol/L的NaOH与2mol/L的NH3·H2O的溶液，使得溶液pH＝11。持续搅拌12h，过滤得到沉淀物，再用去离子水清洗3次，80℃真空干燥24h，得到Co0.9375Fe0.03Ni0.01Mn0.01Al0.0125(OH)3前驱体。
(2)将112.91g的Co0.9375Fe0.03Ni0.01Mn0.01Al0.0125(OH)3前驱体与60.15g的Na2CO3球磨混合均匀。再将球磨后的混合物置于马弗炉中，空气气氛下，850℃热处理24h，取出样品，破碎、研磨、过筛后，加入500mL 3.10mol/L溴化锂的正己醇溶液，在100℃条件下，溶剂热法反应24h，之后进行抽滤，得到沉淀物，使用甲醇洗涤3次，90℃真空干燥8h，得到P63mc结构的锂钴氧化物Li0.937Na0.0005Co0.9375Fe0.03Ni0.01Mn0.01Al0.0125O2粉末。
除了<正极活性材料的制备>按上述步骤制备，<正极极片的制备>按表1调整正极材料层的涂布重量Y以外，其余与实施例1-1相同。
实施例1-9
<正极活性材料的制备>
(1)在反应釜中，将268.85g的CoSO4·7H2O、11.50g的FeSO4·7H2O、2.72g的NiSO4·6H2O、1.75g的MnSO4·H2O、5.82g的Al(NO3)3·9H2O溶于水，在氮气气氛下搅拌，并在搅拌过程中向反应釜内加入含2mol/L的NaOH与2mol/L的NH3·H2O的溶液，使得溶液pH＝11。持续搅拌12h，过滤得到沉淀物，再用去离子水清洗3次，80℃真空干燥24h，得到Co0.925Fe0.04Ni0.01Mn0.01Al0.015(OH)3前驱体。
(2)将113.02g的Co0.925Fe0.04Ni0.01Mn0.01Al0.015(OH)3前驱体与60.27g的Na2CO3球磨混合均匀。再将球磨后的混合物置于马弗炉中，空气气氛下，850℃热处理24h，取出样品， 破碎、研磨、过筛后，加入500mL 3.10mol/L溴化锂的正己醇溶液，在100℃条件下，溶剂热法反应24h，之后进行抽滤，得到沉淀物，使用甲醇洗涤3次，90℃真空干燥8h，得到P63mc结构的锂钴氧化物Li0.9245Na0.0005Co0.925Fe0.04Ni0.01Mn0.01Al0.015O2粉末。
除了<正极活性材料的制备>按上述步骤制备，<正极极片的制备>按表1调整正极材料层的涂布重量Y以外，其余与实施例1-1相同。
实施例1-10
<正极活性材料的制备>
(1)在反应釜中，将271.49g的CoSO4·7H2O、5.71g的FeSO4·7H2O、2.70g的NiSO4·6H2O、1.74g的MnSO4·H2O、7.71g的Al(NO3)3·9H2O溶于水，在氮气气氛下搅拌，并在搅拌过程中向反应釜内加入含2mol/L的NaOH与2mol/L的NH3·H2O的溶液，使得溶液pH＝11。持续搅拌12h，过滤得到沉淀物，再用去离子水清洗3次，80℃真空干燥24h，得到Co0.94Fe0.02Ni0.01Mn0.01Al0.02(OH)3前驱体。
(2)将112.91g的Co0.94Fe0.02Ni0.01Mn0.01Al0.02(OH)3前驱体与60.27g的Na2CO3球磨混合均匀。再将球磨后的混合物置于马弗炉中，空气气氛下，850℃热处理24h，取出样品，破碎、研磨、过筛后，加入500mL 3.10mol/L溴化锂的正己醇溶液，在100℃条件下，溶剂热法反应24h，之后进行抽滤，得到沉淀物，使用甲醇洗涤3次，90℃真空干燥8h，得到P63mc结构的锂钴氧化物Li0.9395Na0.0005Co0.94Fe0.02Ni0.01Mn0.01Al0.02O2粉末。
除了<正极活性材料的制备>按上述步骤制备，<正极极片的制备>按表1调整正极材料层的涂布重量Y以外，其余与实施例1-1相同。
实施例1-11
<正极活性材料的制备>
(1)在反应釜中，将274.37g的CoSO4·7H2O、5.71g的FeSO4·7H2O、2.70g的NiSO4·6H2O、1.74g的MnSO4·H2O、7.71g的Al(NO3)3·9H2O溶于水，在氮气气氛下搅拌，并在搅拌过程中向反应釜内加入含2mol/L的NaOH与2mol/L的NH3·H2O的溶液，使得溶液pH＝11。持续搅拌12h，过滤得到沉淀物，再用去离子水清洗3次，80℃真空干燥24h，得到Co0.95Fe0.02Ni0.01Mn0.01Al0.01(OH)3前驱体。
(2)将112.79g的Co0.94Fe0.02Ni0.01Mn0.01Al0.02(OH)3前驱体与60.03g的Na2CO3球磨混合均匀。再将球磨后的混合物置于马弗炉中，空气气氛下，850℃热处理24h，取出样品，破碎、研磨、过筛后，加入500mL 3.08mol/L溴化锂的正己醇溶液，在100℃条件下，溶剂热法反应12h，之后进行抽滤，得到沉淀物，使用甲醇洗涤3次，90℃真空干燥8h，得到P63mc结构的锂钴氧化物Li0.949Na0.001Co0.95Fe0.02Ni0.01Mn0.01Al0.01O2粉末。
除了<正极活性材料的制备>按上述步骤制备以外，其余与实施例1-1相同。
实施例1-12
<负极活性材料的制备>
将180g天然石墨与20g硬碳材料在容器中进行混合，混合均匀后得到负极活性材料。
除了<负极活性材料的制备>按上述步骤制备，<正极极片的制备>按表1调整正极材料层的涂布重量Y以外，其余与实施例1-11相同。
实施例1-13
<正极活性材料的制备>
(1)在反应釜中，将271.49g的CoSO4·7H2O、5.71g的FeSO4·7H2O、2.70g的NiSO4·6H2O、1.74g的MnSO4·H2O、7.71g的Al(NO3)3·9H2O溶于水，在氮气气氛下搅拌，并在搅拌过程中向反应釜内加入含2mol/L的NaOH与2mol/L的NH3·H2O的溶液，使得溶液pH＝11。持续搅拌12h，过滤得到沉淀物，再用去离子水清洗3次，80℃真空干燥24h，得到Co0.78Fe0.1Ni0.05Mn0.05Al0.02(OH)3前驱体。
(2)将114.29g的Co0.94Fe0.02Ni0.01Mn0.01Al0.02(OH)3前驱体与61.24g的Na2CO3球磨混合均匀。再将球磨后的混合物置于马弗炉中，空气气氛下，850℃热处理24h，取出样品，破碎、研磨、过筛后，加入500mL 3.15mol/L溴化锂的正己醇溶液，在100℃条件下，溶剂热法反应24h，之后进行抽滤，得到沉淀物，使用甲醇洗涤3次，90℃真空干燥8h，得到P63mc结构的锂钴氧化物Li0.7795Na0.0005Co0.78Fe0.1Ni0.05Mn0.05Al0.02O2粉末。
除了<正极活性材料的制备>按上述步骤制备，<正极极片的制备>按表1调整正极材料层的涂布重量Y以外，其余与实施例1-1相同。
对比例1-1
<正极活性材料的制备>
将100g的LiCoO2、0.16g的Al2O3、0.11g的Li2CO3混合均匀后转移至刚玉坩埚中，在O2气氛下1030℃烧结10h，投入颚式破碎机、对辊机制成粉末，经过气流粉碎机进一步破碎，最后用400目筛网筛分后得到R-3m结构的锂钴氧化物LiCo0.997Al0.003O2粉末。
除了<正极活性材料的制备>按上述步骤制备，<正极极片的制备>按表1调整正极材料层的涂布重量Y，负极活性材料为天然石墨，不添加硬碳以外，其余与实施例1-1相同。
对比例1-2
<正极活性材料的制备>
将100g的LiCoO2、0.16g的Al2O3、0.11g的Li2CO3混合均匀后转移至刚玉坩埚中，在O2气氛下1030℃烧结10h，投入颚式破碎机、对辊机制成粉末，经过气流粉碎机进一步 破碎，最后用400目筛网筛分后得到R-3m结构的锂钴氧化物LiCo0.997Al0.003O2粉末。
除了<正极活性材料的制备>按上述步骤制备，<正极极片的制备>按表1调整正极材料层的涂布重量Y以外，其余与实施例1-1相同。
对比例1-3
除了将负极活性材料调整为天然石墨，不添加硬碳，<正极极片的制备>按表1调整正极材料层的涂布重量Y以外，其余与实施例1-1相同。
对比例1-4
除了将负极活性材料调整为硬碳，不添加天然石墨，<正极极片的制备>按表1调整正极材料层的涂布重量Y以外，其余与实施例1-1相同。
实施例2-1
<正极活性材料的制备>
P63mc结构的锂钴氧化物的制备：
(1)在反应釜中，将274.99g的CoSO4·7H2O、5.73g的FeSO4·7H2O、2.71g的NiSO4·6H2O、1.74g的MnSO4·H2O、3.86g的Al(NO3)3·9H2O溶于水，在氮气气氛下搅拌，并在搅拌过程中向反应釜内加入含2mol/L的NaOH与2mol/L的NH3·H2O的溶液，使得溶液pH＝11。持续搅拌12h，过滤得到沉淀物，再用去离子水清洗3次，80℃真空干燥24h，得到Co0.95Fe0.02Ni0.01Mn0.01Al0.01(OH)3前驱体。
(2)将112.79g的Co0.95Fe0.02Ni0.01Mn0.01Al0.01(OH)3前驱体与60.03g的Na2CO3球磨混合均匀。再将球磨后的混合物置于马弗炉中，空气气氛下，850℃热处理24h，取出样品，破碎、研磨、过筛后，加入500mL 3.09mol/L溴化锂的正己醇溶液，在100℃条件下，溶剂热法反应24h，之后进行抽滤，得到沉淀物，使用甲醇洗涤3次，90℃真空干燥8h，得到P63mc结构的锂钴氧化物Li0.9495Na0.0005Co0.95Fe0.02Ni0.01Mn0.01Al0.01O2粉末。
R-3m结构的锂钴氧化物的制备：
将100g的LiCoO2、1.56g的Al2O3、1.13g的Li2CO3混合均匀后转移至刚玉坩埚中，在O2气氛下1030℃烧结10h，投入颚式破碎机、对辊机制成粉末，经过气流粉碎机进一步破碎，最后用400目筛网筛分后得到R-3m结构的锂钴氧化物LiCo0.97Al0.03O2粉末。
将上述制备得到的R-3m结构的锂钴氧化物粉末和P63mc结构的锂钴氧化物粉末以质量比M为4进行混合，得到正极活性材料。
<负极活性材料的制备>
将198g天然石墨与2g硬碳材料在容器中进行混合，混合均匀后得到负极活性材料。
除了<正极活性材料的制备>和<负极活性材料的制备>按上述步骤制备，<正极极片的 制备>按表2调整正极材料层的涂布重量Y以外，其余与实施例1-1相同。
实施例2-2
<负极活性材料的制备>
将195g天然石墨与5g硬碳材料在容器中进行混合，混合均匀后得到负极活性材料。
除了<负极活性材料的制备>按上述步骤制备，<正极活性材料的制备>中M的值调整为1以外，其余与实施例2-1相同。
实施例2-3、实施例2-4
除了<正极活性材料的制备>中按表2调整M的值以外，其余与实施例2-1相同。
实施例2-5
R-3m结构的锂钴氧化物的制备：将100g的LiCoO2、1.56g的Al2O3、1.13g的Li2CO3、0.21g的MgO混合均匀后转移至刚玉坩埚中，在O2气氛下1030℃烧结10h，投入颚式破碎机、对辊机制成粉末，经过气流粉碎机进一步破碎，最后用400目筛网筛分后得到R-3m结构的锂钴氧化物LiCo0.965Al0.03Mg0.005O2粉末。除了<正极活性材料的制备>中，R-3m结构的锂钴氧化物按上述方法制备以外，其余与实施例2-2相同。
实施例2-6
R-3m结构的锂钴氧化物的制备：将100g的LiCoO2、1.56g的Al2O3、1.13g的Li2CO3、0.21g的MgO、0.41g的TiO2混合均匀后转移至刚玉坩埚中，在O2气氛下1030℃烧结10h，投入颚式破碎机、对辊机制成粉末，经过气流粉碎机进一步破碎，最后用400目筛网筛分后得到R-3m结构的锂钴氧化物LiCo0.96Al0.03Mg0.005Ti0.005O2粉末。除了<正极活性材料的制备>中，R-3m结构的锂钴氧化物按上述方法制备以外，其余与实施例2-2相同。
实施例2-7
R-3m结构的锂钴氧化物的制备：将100g的LiCoO2、5.21g的Al2O3、3.77g的Li2CO3混合均匀后转移至刚玉坩埚中，在O2气氛下1030℃烧结10h，投入颚式破碎机、对辊机制成粉末，经过气流粉碎机进一步破碎，最后用400目筛网筛分后得到R-3m结构的锂钴氧化物LiCo0.9Al0.1O2粉末。除了<正极活性材料的制备>中，R-3m结构的锂钴氧化物按上述方法制备，<正极极片的制备>按表2调整正极材料层的涂布重量Y以外，其余与实施例2-2相同。
实施例2-8
R-3m结构的锂钴氧化物的制备：将100g的LiCoO2、1.56g的Al2O3、1.13g的Li2CO3、0.41g的MgO、0.82g的TiO2、1.66g的La2O3、1.15g的Y2O3、1.26g的ZrO2混合均匀后转移至刚玉坩埚中，在O2气氛下1030℃烧结10h，投入颚式破碎机、对辊机制成粉末，经 过气流粉碎机进一步破碎，最后用400目筛网筛分后得到R-3m结构的锂钴氧化物LiCo0.92Al0.03Mg0.01Ti0.01La0.01Y0.01Zr0.01O2粉末。除了<正极活性材料的制备>中，R-3m结构的锂钴氧化物按上述方法制备，<正极极片的制备>按表2调整正极材料层的涂布重量Y以外，其余与实施例2-2相同。
对比例2-1
<正极活性材料的制备>
将100g的LiCoO2、1.56g的Al2O3、1.13g的Li2CO3混合均匀后转移至刚玉坩埚中，在O2气氛下1030℃烧结10h，投入颚式破碎机、对辊机制成粉末，经过气流粉碎机进一步破碎，最后用400目筛网筛分后得到R-3m结构的锂钴氧化物LiCo0.97Al0.03O2粉末。
除了<正极活性材料的制备>按上述步骤制备，负极活性材料为天然石墨，不添加硬碳，<正极极片的制备>按表2调整正极材料层的涂布重量Y以外，其余与实施例2-1相同。
对比例2-2
<正极活性材料的制备>
将100g的LiCoO2、1.56g的Al2O3、1.13g的Li2CO3混合均匀后转移至刚玉坩埚中，在O2气氛下1030℃烧结10h，投入颚式破碎机、对辊机制成粉末，经过气流粉碎机进一步破碎，最后用400目筛网筛分后得到R-3m结构的锂钴氧化物LiCo0.97Al0.03O2粉末。
<负极活性材料的制备>
将195g天然石墨与5g硬碳材料在容器中进行混合，混合均匀后得到负极活性材料。
除了<正极活性材料的制备>和<负极活性材料的制备>按上述步骤制备，<正极极片的制备>按表2调整正极材料层的涂布重量Y以外，其余与实施例2-1相同。
对比例2-3
除了在<正极极片的制备>中将正极活性材料调整为R-3m结构的锂钴氧化物LiCo0.9Al0.1O2，不包括P63mc结构的锂钴氧化物，<正极极片的制备>按表2调整正极材料层的涂布重量Y以外，其余与实施例2-7相同。
表1


注：表1中“/”表示不存在对应参数或物质。
从实施例1-1至实施例13、对比例1-1至对比例1-4可以看出，正极材料包括P63mc结构的锂钴氧化物并调控P63mc结构的锂钴氧化物的(002)晶面的特征峰位置在本申请的范围内，负极材料包括包括硬碳和石墨，可使锂离子电池具有较高的首次放电质量比容量，同时还具有较高的容量保持率R和较高的45℃容量保持率80％时的循环圈数，说明锂离子电池具有较高的能量密度，同时还具有良好的倍率性能和高温循环性能。
图1为实施例1-1、实施了1-5至实施例1-7、实施例1-9、对比例1-1、对比例1-3、 对比例2-1的高温循环性能测试结果图，从图1中可以看出，循环容量保持率为80％时，实施例1-1、实施了1-5至实施例1-7、实施例1-9的循环圈数明显大于对比例1-1、对比例1-3的循环圈数，说明本申请实施例的锂离子电池具有良好的高温循环性能。
图2为实施例1-1、实施了1-5至实施例1-7、实施例1-9、对比例1-1、对比例1-3、对比例2-1的倍率性能测试结果图，从图2中可以看出，在0.5C、1C、2C放电倍率下，实施例1-1、实施例1-5至实施例1-7、实施例1-9的容量保持率均大于对比例1-1、对比例2-1，说明本申请实施例的锂离子电池具有良好的倍率性能。
图3为实施例1-1正极材料层中P63mc结构的锂钴氧化物的XRD图谱，P63mc结构的锂钴氧化物(002)晶面特征峰位置为18.50°。
图6为本申请实施例1-1负极极片的SEM图片，图中形貌为有棱角的块状颗粒为硬碳，形貌为片层状的颗粒为石墨。
硬碳的质量百分含量通常会影响锂离子电池的能量密度和高温循环性能。从实施例1-1、实施例1-6、实施例1-7、对比例1-3和对比例1-4可以看出，当负极活性材材料中包括硬碳，并调控硬碳的质量百分含量在本申请的范围内，可使锂离子电池具有较高的较高的首次放电质量比容量，同时还具有较高的较高的45℃容量保持率80％时的循环圈数，说明锂离子电池具有较高的能量密度和良好的高温循环性能。
P63mc结构的锂钴氧化物中A元素种类通常会影响锂离子电池的能量密度、倍率性能和高温循环性能。从实施例1-1至实施例1-3可以看出，P63mc结构的锂钴氧化物中A元素种类在本申请的范围内，可使锂离子电池具有较高的首次放电质量比容量、较高的容量保持率R和较高的45℃容量保持率80％时的循环圈数，说明锂离子电池具有较高的能量密度，同时还具有良好的倍率性能和高温循环性能。
P63mc结构的锂钴氧化物中B元素种类通常会影响锂离子电池的能量密度、倍率性能和高温循环性能。从实施例1-1、实施例1-4、实施例1-5可以看出，P63mc结构的锂钴氧化物中B元素种类在本申请的范围内，可使锂离子电池具有较高的首次放电质量比容量、较高的容量保持率R和较高的45℃容量保持率80％时的循环圈数，说明锂离子电池具有较高的能量密度，同时还具有良好的倍率性能和高温循环性能。
P63mc结构的锂钴氧化物中x、y、a、b的值通常会影响锂离子电池的能量密度、倍率性能和高温循环性能。从实施例1-1至实施例1-12可以看出，通过调控P63mc结构的锂钴氧化物中x、y、a、b的值在本申请的范围内，可使锂离子电池具有较高的首次放电质量比容量、较高的容量保持率R和较高的45℃容量保持率80％时的循环圈数，说明锂离子电池具有较高的能量密度，同时还具有良好的倍率性能和高温循环性能。
隔离膜与正极极片之间的粘结力为F的值通常会影响锂离子电池的能量密度、倍率性能和高温循环性能。从实施例1-1至实施例1-13可以看出，隔离膜与正极极片之间的粘结力为F的值在本申请的范围内，可使锂离子电池具有较高的首次放电质量比容量、较高的容量保持率R和较高的45℃容量保持率80％时的循环圈数，说明锂离子电池具有较高的能量密度，同时还具有良好的倍率性能和高温循环性能。
表2

注：表2中“/”表示不存在对应参数或物质。
I1/I2的值通常会影响锂离子电池的会影响锂离子电池的高温循环性能。从实施例2-1至实施例2-4、对比例2-1至对比例2-3可以看出，通过调控I1/I2的值在本申请的范围内， 可使锂离子电池具有较高的首次放电质量比容量、较高的容量保持率R和较高的45℃容量保持率80％时的循环圈数，说明锂离子电池具有较高的能量密度，同时还具有良好的倍率性能和高温循环性能。
图4为实施例2-2正极材料层中P63mc结构的锂钴氧化物和R-3m结构的锂钴氧化物的XRD图谱，R-3m结构的锂钴氧化物(003)晶面特征峰强度I1和P63mc结构的锂钴氧化物(002)晶面特征峰强度I2的比值I1/I2为0.15。
R-3m结构的锂钴氧化物(003)晶面特征峰位置通常会影响锂离子电池的能量密度、倍率性能和高温循环性能。从实施例2-1至实施例2-8可以看出，R-3m结构的锂钴氧化物(003)晶面特征峰位置在申请的范围内，可使锂离子电池具有较高的首次放电质量比容量、较高的容量保持率R和较高的45℃容量保持率80％时的循环圈数，说明锂离子电池具有较高的能量密度，同时还具有良好的倍率性能和高温循环性能。
图5为对比例2-1正极材料层中R-3m结构的锂钴氧化物的XRD图谱，R-3m结构的锂钴氧化物(003)晶面特征峰位置为18.93°。
R-3m结构的锂钴氧化物中C元素的种类通常会影响锂离子电池的能量密度、倍率性能和高温循环性能。从实施例2-5至实施例2-6可以看出，R-3m结构的锂钴氧化物中C元素的种类本申请的范围内，可使锂离子电池具有较高的首次放电质量比容量、较高的容量保持率R和较高的45℃容量保持率80％时的循环圈数，说明锂离子电池具有较高的能量密度，同时还具有良好的倍率性能和高温循环性能。
R-3m结构的锂钴氧化物中m、n的值通常会影响锂离子电池的能量密度、倍率性能和高温循环性能。从实施例2-1至实施例2-8可以看出，通过调控R-3m结构的锂钴氧化物中m、n的值在本申请的范围内，可使锂离子电池具有较高的首次放电质量比容量、较高的容量保持率R和较高的45℃容量保持率80％时的循环圈数，说明锂离子电池具有较高的能量密度，同时还具有良好的倍率性能和高温循环性能。
以上所述仅为本申请的较佳实施例，并不用以限制本申请，凡在本申请的精神和原则之内，所做的任何修改、等同替换、改进等，均应包含在本申请保护的范围之内。

Claims (10)

  1. 一种电化学装置，其包括正极极片、负极极片和隔离膜，其中，
    所述正极极片包括正极集流体以及设置于正极集流体至少一个表面的正极材料层，所述正极材料层包括正极材料，所述正极材料包括P63mc结构的锂钴氧化物，在所述正极材料层的XRD图谱中，所述P63mc结构的锂钴氧化物的(002)晶面的特征峰位于17°至19°之间；
    所述负极极片包括负极集流体以及设置于负极集流体至少一个表面的负极材料层，所述负极材料层包括负极材料，所述负极材料包括硬碳和石墨。
  2. 根据权利要求1所述的电化学装置，其中，所述P63mc结构的锂钴氧化物的(002)晶面的特征峰位于18.3°至18.7°之间。
  3. 根据权利要求1所述的电化学装置，其中，基于所述负极材料的质量，所述硬碳的质量百分含量为w％，1≤w≤10。
  4. 根据权利要求1所述的电化学装置，其中，所述P63mc结构的锂钴氧化物包括LixNayCo1-a-bAaBbO2，其中，A包括Mn、Fe或Ni中的至少一种，B包括Al、Mg、Ti、La、Y、Zr、Zn、Cu、Cr、Ca、Ce或Lu中的至少一种，0.779≤x≤0.95，0＜y≤0.001，0＜a≤0.2，0≤b≤0.02。
  5. 根据权利要求1所述的电化学装置，所述正极材料还包括R-3m结构的锂钴氧化物，在所述正极材料层的XRD图谱中，所述R-3m结构的锂钴氧化物的(003)晶面特征峰位于18°至20°之间；所述R-3m结构的锂钴氧化物(003)晶面特征峰强度为I1，所述P63mc结构的锂钴氧化物(002)晶面特征峰强度为I2，0≤I1/I2≤20。
  6. 根据权利要求5所述的电化学装置，其中，所述R-3m结构的锂钴氧化物包括LiCo1-m-nAlmCnO2，其中，C包括Mg、Ti、La、Y、Zr或Lu中的至少一种，0＜m≤0.1，0≤n≤0.05。
  7. 根据权利要求1至6中任一项所述的电化学装置，其中，所述正极极片以金属锂作为对电极在3.0V至4.6V的电位区间内的容量为d，所述负极极片以金属锂作为对电极在0.005V至0.8V的电位区间内的容量为c，1.00＜c/d≤1.05。
  8. 根据权利要求1至6中任一项所述的电化学装置，其中，所述隔离膜与所述正极极片之间的粘结力为F N/m，1≤F≤50。
  9. 根据权利要求1至6中任一项所述的电化学装置，其充电上限电压为4.5V至4.75V。
  10. 一种电子装置，其包括权利要求1至9中任一项所述的电化学装置。
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CN113299903A (zh) * 2021-05-24 2021-08-24 宁德新能源科技有限公司 电化学装置和电子装置
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