WO2023206241A1 - 正极材料及包括正极材料的电化学装置和电子装置 - Google Patents

正极材料及包括正极材料的电化学装置和电子装置 Download PDF

Info

Publication number
WO2023206241A1
WO2023206241A1 PCT/CN2022/089911 CN2022089911W WO2023206241A1 WO 2023206241 A1 WO2023206241 A1 WO 2023206241A1 CN 2022089911 W CN2022089911 W CN 2022089911W WO 2023206241 A1 WO2023206241 A1 WO 2023206241A1
Authority
WO
WIPO (PCT)
Prior art keywords
cathode material
lithium
peak
molar amount
equal
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/CN2022/089911
Other languages
English (en)
French (fr)
Inventor
程世杨
下羽淳平
郎野
徐磊敏
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Ningde Amperex Technology Ltd
Original Assignee
Ningde Amperex Technology Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Ningde Amperex Technology Ltd filed Critical Ningde Amperex Technology Ltd
Priority to PCT/CN2022/089911 priority Critical patent/WO2023206241A1/zh
Priority to EP22939093.5A priority patent/EP4394928A4/en
Priority to CN202280006511.7A priority patent/CN116325219A/zh
Publication of WO2023206241A1 publication Critical patent/WO2023206241A1/zh
Priority to US18/621,481 priority patent/US20240266530A1/en
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
    • H01M4/52—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron
    • H01M4/525—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
    • C01G53/00—Compounds of nickel
    • C01G53/40—Complex oxides containing nickel and at least one other metal element
    • C01G53/42—Complex oxides containing nickel and at least one other metal element containing alkali metals, e.g. LiNiO2
    • C01G53/44—Complex oxides containing nickel and at least one other metal element containing alkali metals, e.g. LiNiO2 containing manganese
    • C01G53/50—Complex oxides containing nickel and at least one other metal element containing alkali metals, e.g. LiNiO2 containing manganese of the type (MnO2)n-, e.g. Li(NixMn1-x)O2 or Li(MyNixMn1-x-y)O2
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
    • C01G53/00—Compounds of nickel
    • C01G53/40—Complex oxides containing nickel and at least one other metal element
    • C01G53/42—Complex oxides containing nickel and at least one other metal element containing alkali metals, e.g. LiNiO2
    • C01G53/44—Complex oxides containing nickel and at least one other metal element containing alkali metals, e.g. LiNiO2 containing manganese
    • C01G53/50—Complex oxides containing nickel and at least one other metal element containing alkali metals, e.g. LiNiO2 containing manganese of the type (MnO2)n-, e.g. Li(NixMn1-x)O2 or Li(MyNixMn1-x-y)O2
    • C01G53/502—Complex oxides containing nickel and at least one other metal element containing alkali metals, e.g. LiNiO2 containing manganese of the type (MnO2)n-, e.g. Li(NixMn1-x)O2 or Li(MyNixMn1-x-y)O2 containing lithium and cobalt
    • C01G53/504—Complex oxides containing nickel and at least one other metal element containing alkali metals, e.g. LiNiO2 containing manganese of the type (MnO2)n-, e.g. Li(NixMn1-x)O2 or Li(MyNixMn1-x-y)O2 containing lithium and cobalt with the molar ratio of nickel with respect to all the metals other than alkali metals higher than or equal to 0.5, e.g. Li(MzNixCoyMn1-x-y-z)O2 with x ≥ 0.5
    • 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
    • H01M10/04—Construction or manufacture in general
    • H01M10/0422—Cells or battery with cylindrical casing
    • H01M10/0427—Button cells
    • 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
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
    • H01M10/44—Methods for charging or discharging
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
    • H01M4/50—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese
    • H01M4/505—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2002/00—Crystal-structural characteristics
    • C01P2002/50—Solid solutions
    • C01P2002/52—Solid solutions containing elements as dopants
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2002/00—Crystal-structural characteristics
    • C01P2002/50—Solid solutions
    • C01P2002/52—Solid solutions containing elements as dopants
    • C01P2002/54—Solid solutions containing elements as dopants one element only
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2002/00—Crystal-structural characteristics
    • C01P2002/70—Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data
    • C01P2002/77—Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data by unit-cell parameters, atom positions or structure diagrams
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M2004/021—Physical characteristics, e.g. porosity, surface area
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M2004/026—Electrodes composed of, or comprising, active material characterised by the polarity
    • H01M2004/028—Positive electrodes
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Definitions

  • the present application relates to the field of energy storage technology, and in particular to cathode materials and electrochemical devices and electronic devices including the cathode materials.
  • batteries are not only required to be lightweight, but also have high capacity and long working life.
  • Lithium-ion batteries have occupied a mainstream position in the market due to their outstanding advantages such as high energy density, high safety, no memory effect and long working life.
  • research on lithium-ion batteries has been developing in the direction of increasing voltage and increasing the amount of lithium removal.
  • high voltage and high delithiation capacity the surface oxygen release and structural phase change problems of lithium-ion battery cathode materials are also fully exposed, which leads to problems such as cycle diving and gas production of lithium-ion batteries.
  • the problem of high-temperature storage gas production in lithium-ion batteries is mainly improved by optimizing the electrolyte and cathode, for example, using an oxidation-resistant electrolyte or coating the surface of the cathode material.
  • the surface of the cathode material is coated with nano-oxide.
  • Nano-oxide is a chemically inactive substance. Its coating on the inactive surface of the cathode material cannot provide protection, while coating on the active surface of the cathode material will hinder the migration of lithium ions and affect the capacity of the material.
  • the solvent molecular chain of the oxidation-resistant electrolyte is longer. While improving gas production, it will deteriorate the lithium ion transport kinetics, which will further deteriorate the rate performance and temperature rise of the lithium ion battery.
  • the present application provides a cathode material in an attempt to solve at least one problem existing in the related art to at least some extent.
  • This application provides a cathode material.
  • An electrode including the cathode material and lithium metal are assembled into a button battery, and the button battery is charged and discharged at a current of 0.04C in the voltage range of 2.8V to 4.5V.
  • the obtained voltage capacity differential dQ/dV curve has a first oxidation peak and a first reduction peak in the range of 4.2V to 4.5V.
  • the voltage capacity differential dQ/dV curve of the button cell has a first oxidation peak and a first reduction peak in the range of 4.2V to 4.5V, indicating that the cathode material has an internal oxygen defect in the range of 4.2V to 4.5V.
  • There is reversible charge and discharge capacity in the high voltage range which gives the cathode material a high energy density and good structural stability.
  • the peak height of the first oxidation peak is greater than or equal to 300 mAh/g/V.
  • the cathode material has a higher charging capacity in the high voltage range of 4.2V to 4.5V, resulting in a higher energy density of the cathode material.
  • the peak height of the first oxidation peak is 300 mAh/g/V to 2000 mAh/g/V.
  • the absolute value of the peak height of the first reduction peak is greater than or equal to 300 mAh/g/V.
  • the cathode material has a higher discharge capacity in the high voltage range of 4.2V to 4.5V, resulting in a higher energy density of the cathode material.
  • the absolute value of the peak height of the first reduction peak is 300 mAh/g/V to 2000 mAh/g/V.
  • the peak voltage of the first oxidation peak is Vo1
  • the peak voltage of the first reduction peak is Vr1
  • the cathode material has good reversibility of charge and discharge in the high voltage range of 4.2V to 4.5V, and has good structural stability.
  • the voltage capacity differential dQ/dV curve has a second oxidation peak and a second reduction peak in the range of 3.6V to 4.0V, the peak voltage of the second oxidation peak is Vo2, and the third The peak voltage of the second reduction peak is Vr2, and
  • the cathode material mainly undergoes a transformation process from a hexagonal phase to a monoclinic phase in the range of 3.6V to 4.0V. This process involves the transport process of lithium ions and electrons. Due to the existence of oxygen defects, the overall lithium ions and The conductivity of electrons, the dynamics of the material are significantly improved, and therefore, the polarization of this process is reduced, making the difference in peak voltage of the second oxidation peak and the second reduction peak smaller.
  • the discharge curve in the obtained voltage capacity curve exists in the range of 4.2V to 4.5V.
  • the capacity of the discharge curve in the range of 4.2V to 4.5V is Q1
  • the capacity of the discharge curve in the range of 3.0V to 4.5V is Qt, satisfying: 0.14 ⁇ Q1/Qt ⁇ 0.35.
  • the cathode material has a higher capacity in the high voltage range of 4.2V to 4.5V, resulting in a higher energy density of the cathode material.
  • the unit cell parameter a of the cathode material satisfies
  • the unit cell parameter c of the cathode material satisfies
  • the unit cell parameter c of the cathode material is within the above range, the Li-O layer spacing of the cathode material is larger, thereby improving the dynamic properties of the cathode material.
  • the X-ray diffraction pattern of the cathode material has diffraction peaks in the ranges of 16° to 20°, 34° to 38°, and 42° to 46°.
  • the cathode material includes lithium transition metal composite oxide.
  • the lithium transition metal composite oxide includes element M and element T.
  • the element M includes at least one of Na, K or Y.
  • the element T includes at least one of Ni, Co or Mn. A sort of.
  • the element M with a high ionic radius is doped into the lithium layer, which can increase the distance between the lithium and oxygen layers, thus improving the dynamic performance of the cathode material.
  • the molar percentage content of Ni is greater than or equal to 50%.
  • the molar percentage of Mn is less than or equal to 50%.
  • the molar percentage of Co is less than or equal to 50%.
  • the molar percentage content of the element M is 0.1% to 5%.
  • the lithium transition metal composite oxide further includes element Q, which includes Ca, Sr, Ba, Al, Fe, B, Mg, Si, S, Ti, Cr, Fe, Cu, At least one of Zn, Ga, Zr, Mo, W, Nb, In, Sn, Pb, Sb, Ce, La, Ta or Hf, based on the total molar amount of the element T, the molar amount of the element Q The content is 0.1% to 5%.
  • element Q can play a role in supporting the transition metal layer, thereby improving the structural stability of the cathode material.
  • the lithium transition metal composite oxide further includes element M1, which includes at least one of F, Cl, Br, I, N or P; based on the total molar amount of the element T, the The molar content of element M1 ranges from 0.1% to 20%.
  • the present application further provides a method for preparing the above-mentioned cathode material, which is characterized by including the following steps: 1) under first atmosphere conditions, combining the precursor with a lithium source, an element M source, an optional element Q source, and an optional element Q source.
  • the selected element M1 source is calcined at a first temperature for a first time; 2) cooled to a second temperature and kept under a second atmosphere for a second time; 3) finally cooled to room temperature;
  • the first atmosphere is selected from an air atmosphere , oxygen atmosphere or a mixed atmosphere of air and oxygen;
  • the precursor includes element T, and the element T includes at least one of Ni, Co or Mn;
  • the element M includes at least one of Na, K or Y;
  • the element Q includes Ca, Sr, Ba, Al, Fe, B, Mg, Si, S, Ti, Cr, Fe, Cu, Zn, Ga, Zr, Mo, W, Nb, In, Sn, Pb, Sb , at least one of Ce, La, Ta or Hf;
  • the element M1 includes at least one of F, Cl, Br, I, N or P;
  • the second atmosphere is selected from an inert atmosphere or an inert gas and H At least one of 2 mixed atmospheres.
  • the first temperature is 700°C to 1200°C; the first time is 10h to 48h.
  • the second temperature ranges from 350°C to 600°C; the second time ranges from 4h to 24 hours.
  • the inert gas is selected from at least one of N 2 , Ar or He.
  • the cooling rate in step 3) is greater than or equal to 50°C/min.
  • the volume percentage of H 2 in the inert gas and H 2 mixed atmosphere is less than or equal to 10%.
  • the precursor includes a hydroxide of element T.
  • the lithium source includes at least one of lithium carbonate or lithium hydroxide.
  • the source of element M includes at least one of carbonate or hydroxide of element M.
  • the source of element Q includes an oxide of element Q.
  • the source of element M1 includes at least one of an ammonium salt or a lithium salt of element M1.
  • the molar percentage content of Ni is greater than or equal to 50%.
  • the molar percentage of Mn is less than or equal to 50%.
  • the molar percentage of Co is less than or equal to 50%.
  • the molar percentage content of the element M is 0.1% to 5%.
  • the molar percentage content of the element Q is 0.1% to 5%.
  • the molar percentage content of the element M1 is 0.1% to 20%.
  • the present application further provides an electrochemical device, which includes any one of the above cathode materials or a cathode material prepared by any of the above preparation methods.
  • the present application further provides an electronic device, which includes any one of the above electrochemical devices.
  • Figure 1 shows the charge and discharge curves of the button batteries of Comparative Example 1, Comparative Example 2 and Example 11.
  • FIG. 2 shows the voltage capacity differential dQ/dV curves of the button batteries of Comparative Example 1 and Example 11.
  • Figure 3 shows the X-ray diffraction patterns of the cathode materials of Comparative Example 1 and Example 11.
  • a list of items connected by the term "at least one of,” “at least one of,” “at least one of,” or other similar terms may mean that the listed items any combination of.
  • the phrase “at least one of A and B” means only A; only B; or A and B.
  • the phrase “at least one of A, B, and C” means only A; or only B; only C; A and B (excluding C); A and C (excluding B); B and C (excluding A); or all of A, B and C.
  • Item A may contain a single component or multiple components.
  • Item B may contain a single component or multiple components.
  • Item C may contain a single component or multiple components.
  • Ternary materials are commonly used cathode materials. Ternary materials mainly generate capacity by changing the prices of two elements, nickel and cobalt. The capacity of the ternary material is related to the nickel content in it. The higher the nickel content, the higher the capacity of the ternary material. Manganese in ternary materials is in the +4 valence state and does not provide capacity, which limits the energy density of ternary materials. In addition, the low electrochemical activity of manganese results in poor kinetics of ternary materials. In the case of deep delithiation, the oxygen ions on the surface of the ternary material are highly active and are prone to side reactions with the electrolyte, resulting in increased interface impedance or gas production. In addition, the lithium-oxygen layer spacing in ternary materials is low, which usually hinders the diffusion of lithium ions at the end of discharge, resulting in material kinetic slag and low capacity.
  • the inventor found that introducing oxygen defects inside the cathode material can, on the one hand, activate the redox properties of the transition metal, thereby greatly increasing the energy density of the cathode material; on the other hand, the oxygen vacancies formed on the surface of the cathode material can reduce the oxygen content on the surface of the cathode material.
  • the activity stabilizes oxygen ions on the surface of the material, thereby inhibiting the positive electrode material from releasing oxygen and producing gas during high-temperature cycles.
  • doping the lithium layer with elements with high ionic radius can increase the distance between the lithium and oxygen layers, thus improving the dynamic properties of the material.
  • This application can regulate the internal oxygen defects and lithium-oxygen layer spacing of the cathode material through synthesis means and combined with lithium layer element doping, so that the cathode material of this application has higher energy density, higher kinetic properties and improved high temperature. stability.
  • This application provides a cathode material.
  • An electrode including the cathode material and lithium metal are assembled into a button battery, and the button battery is charged and discharged at a current of 0.04C in the voltage range of 2.8V to 4.5V.
  • the obtained voltage capacity differential dQ/dV curve has a first oxidation peak and a first reduction peak in the range of 4.2V to 4.5V.
  • the voltage capacity differential dQ/dV curve of the button cell has a first oxidation peak and a first reduction peak in the range of 4.2V to 4.5V, indicating that the cathode material has an internal oxygen defect in the range of 4.2V to 4.5V. There is reversible charge and discharge capacity in the high voltage range, which gives the cathode material a high energy density and good structural stability.
  • the peak height of the first oxidation peak is greater than or equal to 300 mAh/g/V.
  • the cathode material has a higher charging capacity in the high voltage range of 4.2V to 4.5V, resulting in a higher energy density of the cathode material.
  • the peak height of the first oxidation peak is 300 mAh/g/V to 2000 mAh/g/V.
  • the peak height of the first oxidation peak may be 300mAh/g/V, 400mAh/g/V, 500mAh/g/V, 600mAh/g/V, 700mAh/g/V , 800mAh/g/V, 900mAh/g/V, 1000mAh/g/V, 1100mAh/g/V, 1200mAh/g/V, 1300mAh/g/V, 1400mAh/g/V, 1500mAh/g/V, 1800mAh /g/V, 2000mAh/g/V, or a range consisting of any two of the above values, such as 300mAh/g/V to 1000mAh/g/V, 500mAh/g/V to 1500mAh/g/V, 600mAh/g/ V to 1500mAh/g/V, 700mAh/g/V to 1500mAh/g/V or 1000mAh/g/V to 1500mAh/g/V, etc.
  • the absolute value of the peak height of the first reduction peak is greater than or equal to 300 mAh/g/V.
  • the cathode material has a higher discharge capacity in the high voltage range of 4.2V to 4.5V, resulting in a higher energy density of the cathode material.
  • the absolute value of the peak height of the first reduction peak is 300 mAh/g/V to 2000 mAh/g/V.
  • the absolute value of the peak height of the first reduction peak may be 300mAh/g/V, 400mAh/g/V, 500mAh/g/V, 600mAh/g/V, 700mAh/ g/V, 800mAh/g/V, 900mAh/g/V, 1000mAh/g/V, 1100mAh/g/V, 1200mAh/g/V, 1300mAh/g/V, 1400mAh/g/V, 1500mAh/g/ V, 1800mAh/g/V, 2000mAh/g/V, or a range consisting of any two of the above values, such as 300mAh/g/V to 1000mAh/g/V, 500mAh/g/V to 1500mAh/g/V, 600mAh /g/V to 1500mAh/g/V, 700mAh/g/V to 1500mAh/g/V or 1000mAh/g/V to 1500mAh/g/V, etc.
  • the peak voltage of the first oxidation peak is Vo1
  • the peak voltage of the first reduction peak is Vr1
  • can be 0.3V, 0.27V, 0.25V, 0.23V, 0.20V, 0.17V, 0.16V, 0.15V, 0.14V, 0.13V, 0.12V, 0.11V, 0.10 V, 0.09V, 0.08V, 0.07V, 0.06V, 0.05V, 0.04V, 0.03V, 0.02V or 0.01V, etc.; or it can be any of the above values, such as 0.3V, 0.27V, 0.25V, 0.23V, 0.20V, 0.17V, 0.16V, 0.15V, 0.14V, 0.13V, 0.12V, 0.10V, 0.09V, 0.08V, 0.07V, 0.06V, 0.05V, 0.04V or 0.03V, etc.; or it can be above A range consisting of any two values, such as 0.03V to 0.27V, 0.05V to 0.27V or 0.01V to 0.3V, etc.
  • the voltage capacity differential dQ/dV curve has a second oxidation peak and a second reduction peak in the range of 3.6V to 4.0V.
  • the peak voltage of the second oxidation peak is Vo2 and the peak voltage of the second reduction peak is Vr2.
  • the cathode material mainly undergoes a transformation process from a hexagonal phase to a monoclinic phase in the range of 3.6V to 4.0V. This process involves the transport process of lithium ions and electrons.
  • can be 0.20V, 0.19V, 0.17V, 0.16V, 0.15V, 0.14V, 0.13V, 0.12V, 0.11V, 0.10V, 0.09V, 0.08V, 0.07 V, 0.06V, 0.05V, 0.04V, 0.03V, 0.02V, 0.01V, or a range consisting of any two of the above values, such as 0.02V to 0.19V, 0.02V to 0.12V or 0.1V to 0.20V, etc. .
  • the above-mentioned button battery is charged and discharged at a current of 0.04C in the voltage range of 2.8V to 4.5V, and the discharge curve in the obtained voltage capacity curve has a platform in the range of 4.2V to 4.5V, and the discharge
  • the capacity of the curve in the range of 4.2V to 4.5V is Q1
  • the capacity of the discharge curve in the range of 3.0V to 4.5V is Qt, which satisfies: 0.14 ⁇ Q1/Qt ⁇ 0.35.
  • the cathode material has a higher capacity in the high voltage range of 4.2V to 4.5V, resulting in a higher energy density of the cathode material.
  • Q1/Qt can be 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, 0.30, 0.31, 0.32, 0.33 , 0.34, 0.35, or a range consisting of any two of the above values, such as 0.14 to 0.28, 0.16 to 0.28, or 0.20 to 0.35, etc.
  • the unit cell parameter a of the cathode material satisfies In some embodiments, the unit cell parameter c of the cathode material satisfies In some embodiments, 4.93 ⁇ c/a ⁇ 5.10.
  • the a-axis unit cell parameters of the hexagonal crystal system are related to the valence state of the transition metal
  • the c-axis unit cell parameters are related to the distance between the lithium layer and the transition metal layer. In the presence of oxygen defects, the binding between Li-O layers is reduced, the distance between Li-O layers becomes larger, the distance between transition metal layers decreases, and the reaction on the c-axis increases correspondingly, which improves the dynamics of the cathode material.
  • the a-axis is mainly related to the valence state of the transition metal. The existence of oxygen defects will promote the transition metal to change to a low valence state, and the a-axis will increase to a certain extent.
  • a can be Or it can be a range consisting of any two values above, for example to to to or to wait.
  • c can be Or it can be a range consisting of any two values above, for example to to to or to wait.
  • c/a may be 4.93, 4.94, 4.95, 4.96, 4.97, 4.98, 4.99, 5.00, 5.01, 5.02, 5.03, 5.04, 5.05, 5.06, 5.07, 5.08, 5.09, 5.10, or may be above A range consisting of any two values, such as 4.96 to 5.00, 4.96 to 5.05, 4.96 to 5.09, or 4.98 to 5.09, etc.
  • the X-ray diffraction pattern of the cathode material has diffraction peaks in the ranges of 16° to 20°, 34° to 38°, and 42° to 46°.
  • the cathode material includes lithium transition metal complex oxide.
  • the lithium transition metal composite oxide includes element M and element T, where element M includes at least one of Na, K, or Y, and element T includes at least one of Ni, Co, or Mn.
  • element M with a high ionic radius is doped in the lithium layer, which can increase the distance between the lithium and oxygen layers, thereby improving the dynamic properties of the material.
  • the molar percentage of Ni is greater than or equal to 50% based on the total molar amount of element T.
  • the molar percentage of Mn is less than or equal to 50% based on the total molar amount of element T. In some embodiments, the molar percentage of Mn is greater than or equal to 30%.
  • the molar percentage of Co is less than or equal to 50% based on the total molar amount of element T. In some embodiments, the molar percentage of Co is greater than or equal to 10%.
  • the molar percentage of element M is 0.1% to 5% based on the total molar amount of element T.
  • the cathode material may be a composite oxide containing Li element and T element doped with M element, the element M includes at least one of Na, K or Y, and the element T includes Ni, Co or Mn. At least one.
  • the cathode material can be LiNi 0.5 Mn 0.5 O 2 doped with element M (hereinafter represented by LiMNi 0.5 Mn 0.5 O 2 ), where the element M can be Na, K, Y or Na+Y, based on the elements Ni and Mn
  • the total molar amount, the doping concentration of element M can be 0.10%, 0.20%, 0.50%, 1.00%, 2.00%, 3.00%, 4.00% or 5.00%, etc.
  • the lithium transition metal composite oxide may further include element Q, including Ca, Sr, Ba, Al, Fe, B, Mg, Si, S, Ti, Cr, Fe, Cu, Zn, Ga , at least one of Zr, Mo, W, Nb, In, Sn, Pb, Sb, Ce, La, Ta or Hf.
  • element Q including Ca, Sr, Ba, Al, Fe, B, Mg, Si, S, Ti, Cr, Fe, Cu, Zn, Ga , at least one of Zr, Mo, W, Nb, In, Sn, Pb, Sb, Ce, La, Ta or Hf.
  • the molar percentage of element Q is 0.1% to 5% based on the total molar amount of element T.
  • Element Q can play a role in supporting the transition metal layer, thereby improving the structural stability of the cathode material.
  • the cathode material may be a composite oxide containing Li element and T element doped with elements M and Q, the element M includes at least one of Na, K or Y, and the element T includes Ni, Co or Mn At least one of the elements Q includes Ca, Sr, Ba, Al, Fe, B, Mg, Si, S, Ti, Cr, Fe, Cu, Zn, Ga, Zr, Mo, W, Nb, In, Sn , at least one of Pb, Sb, Ce, La, Ta or Hf.
  • the cathode material can be LiNi 0.5 Mn 0.5 O 2 doped with elements M and Q (hereinafter represented by LiMQNi 0.5 Mn 0.5 O 2 ), where the M element is Na and the Q element is Zr, Ti, W, Ta or Sn, Based on the total molar amount of elements Ni and Mn, the doping concentrations of elements M and Q can be independently given as 0.10%, 0.20%, 0.50%, 1.00%, 2.00%, 3.00%, 4.00% or 5.00%, etc.
  • the lithium transition metal composite oxide may also include element M1, which is at least one of F, Cl, Br, I, N or P; based on the total molar amount of the element T, the element The molar percentage of M1 ranges from 0.1% to 20%.
  • the cathode material may be LiTO 1.9 M1 0.1 doped with M element, the element M includes at least one of Na, K or Y, the element T includes at least one of Ni, Co or Mn, the element M1 It is at least one of F, Cl, Br, I, N or P.
  • the cathode material may be element M-doped LiNi 0.5 Mn 0.5 O 1.9 F 0.1 (hereinafter referred to as LiMNi 0.5 Mn 0.5 O 1.9 F 0.1 ) or element M-doped LiNi 0.5 Mn 0.5 O 1.9 Cl 0.1 (hereinafter referred to as LiMNi 0.5 Mn 0.5 O 2 Cl 0.1 represents), the element M is Na, K or Y.
  • the cathode material satisfies the general formula Li x My (Ni a Co b Mn c Q d )O e M1 f , 0 ⁇ x+y ⁇ 2, 0 ⁇ a, b, c, d ⁇ 1, And a, b, c and d are not 0 at the same time, 0 ⁇ e ⁇ 3, 0 ⁇ f ⁇ 1, where the element M is at least one of Na, K or Y, and the element Q is Ca, Sr, Ba, Al , Fe, B, Mg, Si, S, Ti, Cr, Fe, Cu, Zn, Ga, Zr, Mo, W, Nb, In, Sn, Pb, Sb, Ce, La, Ta or Hf at least one species, and M1 is at least one of F, Cl, Br, I, N or P.
  • the cathode material includes element Li, and the mass fraction of element Li is greater than 5% based on the mass of the cathode material.
  • the cathode material includes element Li and other metal elements.
  • the other metal elements may include at least one of element M, element T, or element Q.
  • the ratio of the molar amount of element Li to the total molar amount of other metal elements is greater than 0.5 and less than 2.
  • the preparation method of the cathode material includes the following steps: 1) under a first atmosphere condition, combining the precursor with a lithium source, an element M source, an optional element Q source, and an optional element M1 source in a first atmosphere. Calcining at one temperature for a first time; 2) cooling to a second temperature and maintaining it under a second atmosphere for a second time; 3) finally cooling to room temperature.
  • the first atmosphere is selected from an air atmosphere, an oxygen atmosphere or a mixed atmosphere of air and oxygen;
  • the precursor includes element T, and the element T includes at least one of Ni, Co or Mn;
  • the element M includes Na, At least one of K or Y;
  • the element Q includes Ca, Sr, Ba, Al, Fe, B, Mg, Si, S, Ti, Cr, Fe, Cu, Zn, Ga, Zr, Mo, W, At least one of Nb, In, Sn, Pb, Sb, Ce, La, Ta or Hf;
  • the element M1 includes at least one of F, Cl, Br, I, N or P;
  • the second atmosphere At least one selected from an inert atmosphere or a mixed atmosphere of inert gas and H2 .
  • This application introduces oxygen defects inside the cathode material by introducing inert gas or a mixture of inert gas and H2 during the cooling process after calcination and keeping it warm for a period of time, so that the redox properties of the transition metal in the cathode material can be activated, This greatly increases the energy density of the cathode material.
  • the first temperature is 700°C to 1200°C; the first time is 10h to 48h.
  • the first temperature may be 700°C, 800°C, 900°C, 1000°C, 1100°C, 1200°C, or a range consisting of any two of the above values.
  • the first time may be 10h, 12h, 16h, 18h, 24h, 36h, 48h or may be a range consisting of any two of the above values.
  • the second temperature is 350°C to 600°C; the second time is 4h to 24h.
  • the second temperature may be 350°C, 400°C, 450°C, 500°C, 550°C, 600°C, or a range consisting of any two of the above values.
  • the second time may be 4h, 6h, 8h, 10h, 12h, 16h, 18h, 24h or may be a range consisting of any two of the above values.
  • the inert gas is selected from at least one of N 2 , Ar or He.
  • the cooling rate in step 3) is greater than or equal to 50°C/min.
  • the volume percentage of H 2 in the mixed atmosphere of the inert gas and H 2 is less than or equal to 10% based on the total volume of the mixed atmosphere of the inert gas and H 2 .
  • the volume percentage of H 2 in the inert gas and H 2 mixed atmosphere may be 1%, 2%, 3%, 4% %, 5%, 6%, 7%, 8%, 9%, 10% or a range consisting of any two of the above values, such as 1% to 3%, 5% to 10%, etc.
  • the precursor includes a hydroxide of element T.
  • the lithium source includes at least one of lithium carbonate or lithium hydroxide.
  • the source of element M includes at least one of a carbonate or hydroxide of element M.
  • the source of element Q includes an oxide of element Q.
  • the source of element M1 includes at least one of an ammonium salt or a lithium salt of element M1.
  • the molar percentage of Ni is greater than or equal to 50% based on the total molar amount of element T.
  • the molar percentage of Mn is less than or equal to 50% based on the total molar amount of element T.
  • the molar percentage of Co is less than or equal to 50% based on the total molar amount of element T.
  • the molar percentage of element M is 0.1% to 5%.
  • the molar percentage of element Q is 0.1% to 5% based on the total molar amount of element T.
  • the molar percentage of the element M1 is 0.1% to 20%.
  • the present application provides an electrochemical device, which includes a positive electrode, a negative electrode, a separator and an electrolyte, wherein the positive electrode includes a positive electrode material layer, and the positive electrode material layer includes the positive electrode material described above.
  • the cathode material layer further includes a binder.
  • the binder improves the binding of the positive electrode material particles to each other and also improves the binding of the positive electrode material to the positive electrode current collector.
  • the adhesive includes styrene-butadiene rubber (SBR), water-based acrylic resin, carboxymethylcellulose (CMC), polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), polyvinyl alcohol At least one of butyral (PVB), ethylene-vinyl acetate copolymer (EVA) or polyvinyl alcohol (PVA), but is not limited to this, and the adhesive can be selected according to actual needs.
  • the weight percentage of the binder is less than or equal to 5.0% based on the total weight of the cathode material layer. In some embodiments, based on the total weight of the cathode material layer, the weight percentage of the binder is 5.0%, 4.0%, 3.0%, 2.0%, 1.5%, 1.0%, 0.5%, 0.3%, 0.1% or may be The range composed of any two values above is, for example, 0.1% to 2.0%, 0.5% to 2.0%, 0.1% to 1.0% or 1.0% to 2.0%.
  • the cathode material layer further includes a conductive agent.
  • the conductive agent includes at least one of graphite, acetylene black, carbon black, Ketjen black, carbon nanotubes, graphene and carbon nanofibers, but is not limited thereto.
  • the conductive agent can be selected according to actual needs.
  • the weight percentage of the conductive agent is greater than or equal to 0.5% based on the total weight of the cathode material layer. In some embodiments, the weight percentage of the conductive agent is greater than or equal to 1.0%, greater than or equal to 1.5%, etc. based on the total weight of the cathode material layer.
  • the positive electrode current collector may be a metal foil or a porous metal plate, such as a foil or a porous plate using metals such as aluminum, copper, nickel, titanium or silver or their alloys, such as aluminum foil, but is not limited thereto. .
  • the thickness of the positive electrode current collector is 5 ⁇ m to 20 ⁇ m, for example, 5 ⁇ m, 6 ⁇ m, 7 ⁇ m, 8 ⁇ m, 10 ⁇ m, 12 ⁇ m, 14 ⁇ m, 16 ⁇ m, 18 ⁇ m, 20 ⁇ m, or a range consisting of any two of the above values, such as 6 ⁇ m. to 18 ⁇ m or 8 ⁇ m to 16 ⁇ m.
  • the positive electrode can be prepared by preparation methods well known in the art.
  • the positive electrode can be obtained by the following method: mixing the positive electrode material, conductive agent and binder in a solvent to prepare a positive electrode slurry, coating the positive electrode slurry on the positive electrode current collector, drying, cold pressing, etc. process to obtain the positive electrode.
  • the solvent may include N-methylpyrrolidone (NMP), but is not limited thereto.
  • the negative electrode may be a metallic lithium sheet, or may include 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 optionally includes a conductive agent and a binder.
  • the anode material may include natural graphite, artificial graphite, mesophase microcarbon beads (MCMB), hard carbon, soft carbon, silicon, silicon-carbon composite, SiO, Li-Sn alloy, Li-Sn- One or more of O alloy, Li-Al alloy and metallic lithium.
  • MCMB mesophase microcarbon beads
  • the conductive agent may include one or more of acetylene black, carbon black, Ketjen black, carbon nanotubes, graphene, and carbon nanofibers.
  • the binder may be one or more of styrene-butadiene rubber, polyvinylidene fluoride, polytetrafluoroethylene, polyvinyl butyral, water-based acrylic resin, or carboxymethyl cellulose.
  • the negative electrode in the electrochemical device of the present application is not limited to the above materials.
  • the present application can also use other materials that can be used as negative electrode materials, conductive agents, binders and thickeners of lithium ion batteries.
  • the negative electrode current collector may use a metal foil or a porous metal plate, such as a foil or a porous plate made of metal such as copper, nickel, titanium or iron or their alloys, such as copper foil.
  • the negative electrode can be prepared according to conventional methods in the art. Usually, the negative electrode material and optional conductive agent and binder are dispersed in a solvent.
  • the solvent can be N-methylpyrrolidone or water to form a uniform negative electrode slurry.
  • the negative electrode slurry is coated on the negative electrode current collector. The negative electrode is obtained through drying, cold pressing and other processes.
  • the isolation membrane in the electrochemical device of the present application is not particularly limited. Any well-known porous structure isolation membrane with electrochemical stability and chemical stability can be used, such as glass fiber, non-woven fabric, polyethylene (PE), polyethylene (PE), etc. Single-layer or multi-layer films of one or more types of propylene (PP) and polyvinylidene fluoride.
  • PP propylene
  • the electrolyte in the electrochemical device of the present application may include organic solvents, electrolyte lithium salts and additives. This application does not place specific restrictions on the types of organic solvents and electrolyte lithium salts, and can be selected according to actual needs.
  • the organic solvent may be ethylene carbonate (EC), propylene carbonate (PC), ethyl methyl carbonate (EMC), diethyl carbonate (DEC), dimethyl carbonate (DMC), dicarbonate Propyl ester (DPC), methylpropyl carbonate (MPC), ethylpropyl carbonate (EPC), butylene carbonate (BC), vinylene carbonate (VC), methyl formate (MF), methyl acetate (MA) ), ethyl acetate (EA), propyl acetate (PA), methyl propionate (MP), ethyl propionate (EP), propyl propionate (PP), methyl butyrate (MB), butyric acid At least one of ethyl ester (EB), 1,4-butyrolactone (GBL), sulfolane (SF), dimethyl sulfone (MSM), methyl ethyl sulfone (EMS) and diethyl s
  • EC
  • the electrolyte lithium salt can be lithium hexafluorophosphate (LiPF 6 ), lithium tetrafluoroborate (LiBF 4 ), lithium perchlorate (LiClO 4 ), lithium hexafluoroarsenate (LiAsF 6 ), bisfluorosulfonyl Lithium amine (LiFSI), lithium bistrifluoromethanesulfonyl imide (LiTFSI), lithium trifluoromethanesulfonate (LiTFS), lithium difluoromethanesulfonate borate (LiDFOB), lithium difluoromethane borate (LiBOB), lithium difluorophosphate (LiPO 2 F 2 ), lithium difluorodioxalate phosphate (LiDFOP), and lithium tetrafluorooxalate phosphate (LiTFOP).
  • LiPF 6 lithium hexafluorophosphate
  • LiBF 4 lithium perchlorate
  • additives in the electrolyte may include nitrile compounds, including one or more of the following compounds: succinonitrile, glutaronitrile, adiponitrile or 1,3,6 -One or more types of hexanetrinitriles.
  • the solution may optionally include other additives.
  • the other additives may be any additives that can be used as lithium-ion batteries. There are no specific limitations here and may be selected according to actual needs.
  • the electrochemical device of the present application can be prepared according to conventional methods in this field.
  • the above-mentioned positive electrode, isolation film and negative electrode are stacked in order so that the isolation film is between the positive electrode and the negative electrode to play an isolation role.
  • the electrode assembly is obtained; the electrode assembly is placed in the packaging shell and the electrolyte is injected and sealing to obtain an electrochemical device.
  • the electrochemical device described by this application is applicable to electronic devices in various fields.
  • the electrochemical device of the present application is not particularly limited, and it can be used for any purpose known in the art.
  • the electrochemical device of the present application can be used in, but is not limited to, notebook computers, pen-input computers, mobile computers, e-book players, portable telephones, portable fax machines, portable copiers, portable printers, headsets, etc.
  • step 2) after calcining in an air atmosphere at 800°C for 20 hours, the temperature was lowered to 600°C at a rate of 10°C/min, N 2 was introduced according to Table 1, and after maintaining under this condition for 6 hours , quenched to room temperature at the corresponding cooling rate in Table 1; finally, the cathode material is obtained through crushing and sieving.
  • Embodiment 2 differs from Embodiment 1 in step 2), a mixture of N 2 and H 2 is introduced according to Table 1.
  • Example 3-5 The difference between Example 3-5 and Example 2 is that in step 2), the doping concentrations of Na are 0.2%, 0.5% and 1% respectively.
  • Example 5 The difference between Examples 6-7 and Example 5 is that the precursors in step 1) are Ni 0.5 Mn 0.4 Co 0.1 (OH) 2 and Ni 0.5 Mn 0.3 Co 0.2 (OH) 2 respectively.
  • step 2) NH 4 F and NH 4 Cl are further added respectively in the grinding and mixing step.
  • Example 10 The difference between Example 10 and Example 5 is that in step 2), the doping concentration of Na is 2%.
  • Example 11-12 The difference between Examples 11-12 and Example 5 is that in step 2), a mixture of N 2 and H 2 is introduced according to Table 1, and the mixture is quenched to room temperature at the corresponding cooling rate in Table 1.
  • step 2 sodium carbonate is replaced by potassium carbonate, N 2 and H 2 mixed gas is passed in according to Table 1, and the temperature is quenched at the corresponding cooling rate in Table 1 to room temperature.
  • step 2) sodium carbonate is replaced by yttrium carbonate, N 2 and H 2 mixed gas is passed in according to Table 1, and the temperature is quenched at the corresponding cooling rate in Table 1. room temperature.
  • Example 20 The difference between Example 20 and Example 18 is that in step 2), yttrium carbonate is replaced by a mixture of yttrium carbonate and sodium carbonate, and the doping concentrations of Na and Y are each 0.5%.
  • step 2 the element Q source is further added in the grinding and mixing step.
  • the element Q sources are ZrO 2 , TiO 2 , WO 3 , Ta 2 O 5 , and SnO 2 respectively.
  • the doping concentration of element Q (the molar percentage of element Q and element T) is 0.5%.
  • Table 1 shows the doping elements, doping amounts, nitrogen and hydrogen volume percentages and cooling rates of Comparative Examples 1-3 and Examples 1-25.
  • Polyethylene (PE) porous polymer film is used as the isolation membrane.
  • the bare battery core is obtained by winding. Place the bare battery core in the outer packaging, inject the electrolyte, and package it. Lithium-ion batteries are obtained through processes such as formation, degassing, and trimming.
  • the lithium-ion battery Charge the lithium-ion battery to 4.35V at 85°C and store it for 12 hours. Use a micrometer to test the thickness change of the lithium-ion battery. Define the initial thickness of the lithium-ion battery before storage as H0, the thickness after storage as H1, and the thickness expansion rate. (H1-H0)/H0 ⁇ 100%.
  • the button battery is charged and discharged at a current of 0.04C in the voltage range of 2.8V to 4.5V to obtain the voltage capacity curve and voltage capacity differential dQ/dV curve.
  • X-ray powder diffractometer instrument model: Bruker D8 ADVANCE
  • the target material was Cu K ⁇ ; the voltage and current were 40KV/40mA, and the scanning angle range was from 10° to 70°.
  • the voltage capacity differential dQ/dV curve of the button battery prepared from the cathode material of Examples 1-25 of the present application has a first oxidation peak and a first reduction peak in the range of 4.2V to 4.5V, indicating that the Due to the existence of internal oxygen defects in the above-mentioned cathode material, the lithium ion diffusion and electron diffusion capabilities of the material are improved, and there is a reversible charge and discharge capacity in the high voltage range of 4.2V to 4.5V, so that the cathode material has a high energy density and Good structural stability.
  • the interfacial reaction activity between surface oxygen and the electrolyte is reduced, so the lithium-ion batteries of Examples 1-25 have improved high-temperature storage gas production and excellent high-temperature cycle performance.
  • the cathode material when the discharge curve of the button battery satisfies 0.14 ⁇ Q1/Qt ⁇ 0.35, at this time, the cathode material has a higher capacity in the high voltage range of 4.2V to 4.5V, which makes the cathode material have a higher Energy Density. And the cathode material of Examples 1-25 of the present application satisfies:
  • the positive electrode material mainly undergoes a transformation process from hexagonal phase to monoclinic phase in the range of 3.6V to 4.0V. This process involves the transport process of lithium ions and electrons. Due to the existence of oxygen defects, the overall lithium ion content of the material is improved. And the conductivity of electrons, the kinetics of the material are significantly improved, therefore, the polarization of this process is reduced, making the difference in peak voltage of the second oxidation peak and the second reduction peak smaller.
  • Figure 1 shows the charge and discharge curves of the button batteries of Comparative Example 1, Comparative Example 2 and Example 11. It can be seen from Figure 1 that the discharge curve of the button battery of Embodiment 11 has a plateau in the range of 4.2V to 4.5V.
  • FIG. 2 shows the voltage capacity differential dQ/dV curves of the button batteries of Comparative Example 1 and Example 11. It can be seen from Figure 2 that the voltage capacity differential dQ/dV curve of the button battery of Example 11 has a first oxidation peak and a first reduction peak in the range of 4.2V to 4.5V, while the voltage capacity of the button battery of Comparative Example 1 There are no oxidation peaks and reduction peaks in the differential dQ/dV curve between 4.2V and 4.5V.
  • Figure 3 shows the X-ray diffraction patterns of the cathode materials of Comparative Example 1 and Example 11.
  • the X-ray diffraction pattern of the cathode material has diffraction peaks in the ranges of 16° to 20°, 34° to 38°, and 42° to 46°.
  • references throughout this specification to “some embodiments,” “partial embodiments,” “one embodiment,” “another example,” “example,” “specific example,” or “partial example” mean the following: At least one embodiment or example in this application includes a specific feature, structure, material or characteristic described in the embodiment or example. Accordingly, phrases such as “in some embodiments,” “in an embodiment,” “in one embodiment,” “in another example,” “in one example,” etc. may appear in various places throughout this specification. "in”, “in a particular example” or “for example” do not necessarily refer to the same embodiment or example in this application. Furthermore, the specific features, structures, materials, or characteristics herein may be combined in any suitable manner in one or more embodiments or examples.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Inorganic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Organic Chemistry (AREA)
  • Materials Engineering (AREA)
  • Battery Electrode And Active Subsutance (AREA)

Abstract

本申请涉及一种正极材料及包括该正极材料的电化学装置和电子装置。将包括所述正极材料的电极与锂金属组装成扣式电池，并使所述扣式电池在2.8V至4.5V电压区间内以0.04C的电流进行充放电时，所获得的电压容量微分dQ/dV曲线在4.2V至4.5V区间存在第一氧化峰和第一还原峰。该正极材料具有较高的能量密度以及改善的动力学性能和高温稳定性。

Description

正极材料及包括正极材料的电化学装置和电子装置 技术领域
本申请涉及储能技术领域，尤其涉及正极材料以及包括所述正极材料的电化学装置和电子装置。
背景技术
随着消费电子类的产品如笔记本电脑、手机、平板电脑、移动电源和无人机等的普及，对其中电池的要求越来越严格。例如，不仅要求电池轻便，而且还要求电池拥有高容量和较长的工作寿命。锂离子电池凭借其具有能量密度高、安全性高、无记忆效应和工作寿命长等突出的优点已经在市场上占据主流地位。为了追求更高的能量密度，对锂离子电池的研究一直在朝着提高电压、提高脱锂量的方向发展。在高电压、高脱锂量下，锂离子电池正极材料的表面释氧和结构相变问题也充分暴露出来，从而带来锂离子电池的循环跳水和产气等问题。
目前主要通过优化电解液和正极来改善锂离子电池的高温存储产气问题，例如，使用耐氧化的电解液或者对正极材料表面进行包覆。通常，使用纳米氧化物对正极材料表面进行包覆。纳米氧化物为非化学活性的物质，其包覆在正极材料的非活性表面不能起到保护作用，而包覆在正极材料的活性表面则会阻碍锂离子迁移，影响材料的容量发挥。一般耐氧化电解液的溶剂分子链较长，改善产气的同时会恶化锂离子传输动力学，进而会恶化锂离子电池的倍率性能和温升。
发明内容
本申请提供一种正极材料以试图在至少某种程度上解决至少一个存在于相关领域中的问题。
本申请提供了一种正极材料，将包括所述正极材料的电极与锂金属组装成扣式电池，并使所述扣式电池在2.8V至4.5V电压区间内以0.04C的电流进行充放电时，所获得的电压容量微分dQ/dV曲线在4.2V至4.5V区间存在第一氧化峰和第一还原峰。所述扣式 电池的电压容量微分dQ/dV曲线在4.2V至4.5V区间存在第一氧化峰和第一还原峰，表明所述正极材料由于内部氧缺陷的存在，在4.2V至4.5V的高电压区间存在可逆的充放电容量，从而使得正极材料具有较高的能量密度以及良好的结构稳定性。
根据本申请的一些实施例，基于所述正极材料的质量，所述第一氧化峰的峰高大于或等于300mAh/g/V。此时，正极材料在4.2V至4.5V的高电压区间充电的容量较高，从而使得正极材料具有更高的能量密度。根据本申请的一些实施例，基于所述正极材料的质量，所述第一氧化峰的峰高为300mAh/g/V至2000mAh/g/V。
根据本申请的一些实施例，基于所述正极材料的质量，所述第一还原峰的峰高的绝对值大于或等于300mAh/g/V。此时，正极材料在4.2V至4.5V的高电压区间放电的容量较高，从而使得正极材料具有更高的能量密度。根据本申请的一些实施例，基于所述正极材料的质量，所述第一还原峰的峰高的绝对值为300mAh/g/V至2000mAh/g/V。
根据本申请的一些实施例，所述第一氧化峰的峰值电压为Vo1，所述第一还原峰的峰值电压为Vr1，且|Vo1-Vr1|≤0.3V。此时，正极材料在4.2V至4.5V的高电压区间充放电的可逆性较好，并具有良好的结构稳定性。
根据本申请的一些实施例，所述电压容量微分dQ/dV曲线在3.6V至4.0V区间存在第二氧化峰和第二还原峰，所述第二氧化峰的峰值电压为Vo2，所述第二还原峰的峰值电压为Vr2，且|Vo2-Vr2|≤0.2V。此时，正极材料在3.6V至4.0V区间主要为六方相到单斜相的转变过程，该过程涉及锂离子和电子的输运过程，由于氧缺陷的存在，提升了材料整体的锂离子和电子的电导率，材料的动力学明显改善，因此，此过程的极化降低，使得第二氧化峰和第二还原峰的峰值电压差异更小。
根据本申请的一些实施例，所述扣式电池在2.8V至4.5V电压区间内以0.04C的电流进行充放电时，所获得的电压容量曲线中的放电曲线在4.2V至4.5V区间存在平台，所述放电曲线在4.2V至4.5V区间的容量为Q1，所述放电曲线在3.0V至4.5V区间的容量为Qt，满足：0.14≤Q1/Qt≤0.35。此时，正极材料在4.2V至4.5V高电压区间的容量较高，从而使得正极材料具有更高的能量密度。
根据本申请的一些实施例，所述正极材料的晶胞参数a满足
Figure PCTCN2022089911-appb-000001
根据本申请的一些实施例，所述正极材料的晶胞参数c满足
Figure PCTCN2022089911-appb-000002
正极材料的晶胞参数c在上述范围内，正极材料的Li-O层间距较大，从而使得正极材料的动力学性能得到改善。
根据本申请的一些实施例，4.93≤c/a≤5.10。
根据本申请的一些实施例，所述正极材料的X射线衍射图谱在16°至20°、34°至38°以及42°至46°区间内均存在衍射峰。
根据本申请的一些实施例，所述正极材料包括锂过渡金属复合氧化物。
根据本申请的一些实施例，锂过渡金属复合氧化物包括元素M和元素T，所述元素M包括Na、K或Y中的至少一种，所述元素T包括Ni、Co或Mn中的至少一种。高离子半径的元素M在锂层掺杂，能够增大锂氧层间距，从而提升正极材料的动力学性能。
根据本申请的一些实施例，基于所述元素T的总摩尔量，Ni的摩尔百分含量大于或等于50％。
根据本申请的一些实施例，基于所述元素T的总摩尔量，Mn的摩尔百分含量小于或等于50％。
根据本申请的一些实施例，基于所述元素T的总摩尔量，Co的摩尔百分含量小于或等于50％。
根据本申请的一些实施例，基于所述元素T的总摩尔量，所述元素M的摩尔百分含量为0.1％至5％。
根据本申请的一些实施例，锂过渡金属复合氧化物还包括元素Q，所述元素Q包括Ca、Sr、Ba、Al、Fe、B、Mg、Si、S、Ti、Cr、Fe、Cu、Zn、Ga、Zr、Mo、W、Nb、In、Sn、Pb、Sb、Ce、La、Ta或Hf中的至少一种，基于所述元素T的总摩尔量，所述元素Q的摩尔百分含量为0.1％至5％。元素Q可起到支撑过渡金属层的作用，从而提升正极材料的结构稳定性。
根据本申请的一些实施例，锂过渡金属复合氧化物还包括元素M1，M1包括F、Cl、Br、I、N或P中的至少一种；基于所述元素T的总摩尔量，所述元素M1的摩尔百分含量为0.1％至20％。
本申请进一步提供了一种上述正极材料的制备方法，其特征在于，包括如下步骤：1)在第一气氛条件下，将前驱体与锂源、元素M源、可选的元素Q源以及可选的元素M1源在第一温度下煅烧第一时间；2)降温至第二温度，在第二气氛条件下保持第二时间；3)最后降温至室温；所述第一气氛选自空气氛、氧气氛或空气与氧气混合气氛；所述前驱体包含元素T，所述元素T包括Ni、Co或Mn中的至少一种；所述元素M包括Na、K或Y中的 至少一种；所述元素Q包括Ca、Sr、Ba、Al、Fe、B、Mg、Si、S、Ti、Cr、Fe、Cu、Zn、Ga、Zr、Mo、W、Nb、In、Sn、Pb、Sb、Ce、La、Ta或Hf中的至少一种；所述元素M1包括F、Cl、Br、I、N或P中的至少一种；所述第二气氛选自惰性气氛或惰性气体与H 2混合气氛中的至少一种。
根据本申请的一些实施例，所述第一温度为700℃至1200℃；所述第一时间为10h至48h。
根据本申请的一些实施例，所述第二温度为350℃至600℃；所述第二时间为4h至24。
根据本申请的一些实施例，所述惰性气体选自N 2、Ar或He中的至少一种。
根据本申请的一些实施例，所述步骤3)中的降温速率大于或等于50℃/min。
根据本申请的一些实施例，基于所述惰性气体与H 2混合气氛的总体积，所述惰性气体与H 2混合气氛中H 2的体积百分含量小于或等于10％。
根据本申请的一些实施例，所述前驱体包括元素T的氢氧化物。
根据本申请的一些实施例，所述锂源包括碳酸锂或氢氧化锂中的至少一种。
根据本申请的一些实施例，所述元素M源包括元素M的碳酸盐或氢氧化物中的至少一种。
根据本申请的一些实施例，所述元素Q源包括元素Q的氧化物。
根据本申请的一些实施例，所述元素M1源包括元素M1的铵盐或锂盐中的至少一种。
根据本申请的一些实施例，基于所述元素T的总摩尔量，Ni的摩尔百分含量大于或等于50％。
根据本申请的一些实施例，基于所述元素T的总摩尔量，Mn的摩尔百分含量小于或等于50％。
根据本申请的一些实施例，基于所述元素T的总摩尔量，Co的摩尔百分含量小于或等于50％。
根据本申请的一些实施例，基于所述元素T的总摩尔量，所述元素M的摩尔百分含量为0.1％至5％。
根据本申请的一些实施例，基于所述元素T的总摩尔量，所述元素Q的摩尔百分含量为0.1％至5％。
根据本申请的一些实施例，基于所述元素T的总摩尔量，所述元素M1的摩尔百分含量为0.1％至20％。
本申请进一步提供了一种电化学装置，其包括以上任一种正极材料或以上任一制备方法制备得到的正极材料。
本申请进一步提供了一种电子装置，其包括以上任一种电化学装置。
本申请的额外层面及优点将部分地在后续说明中描述、显示、或是经由本申请实施例的实施而阐释。
附图说明
在下文中将简要地说明为了描述本申请实施例或现有技术所必要的附图以便于描述本申请的实施例。显而易见地，下文描述中的附图仅只是本申请中的部分实施例。对本领域技术人员而言，依然可以根据这些附图中所例示的结构来获得其他实施例的附图。
图1示出了对比例1、对比例2和实施例11的扣式电池的充放电曲线。
图2示出了对比例1和实施例11的扣式电池的电压容量微分dQ/dV曲线。
图3示出了对比例1和实施例11的正极材料的X射线衍射图谱。
具体实施方式
本申请的实施例将会被详细的描示在下文中。在此所描述的实施例为说明性质的且用于提供对本申请的基本理解。本申请的实施例不应该被解释为对本申请的限制。
在具体实施方式及权利要求书中，由术语“中的至少一者”、“中的至少一个”、“中的至少一种”或其他相似术语所连接的项目的列表可意味着所列项目的任何组合。例如，如果列出项目A及B，那么短语“A及B中的至少一者”意味着仅A；仅B；或A及B。在另一实例中，如果列出项目A、B及C，那么短语“A、B及C中的至少一者”意味着仅A；或仅B；仅C；A及B(排除C)；A及C(排除B)；B及C(排除A)；或A、B及C的全部。项目A可包含单个元件或多个元件。项目B可包含单个元件或多个元件。项目C可包含单个元件或多个元件。
三元材料为常用的正极材料。三元材料主要是通过镍和钴两种元素变价产生容量。 三元材料的容量与其中的镍含量相关，镍含量越高，三元材料的容量越高。三元材料中的锰为+4价态，不提供容量，这限制了三元材料的能量密度。另外，锰的低电化学活性导致三元材料动力学较差。在深度脱锂的情况下，三元材料表面的氧离子活性高，容易与电解液发生副反应，导致界面阻抗增加或者产气。此外，三元材料中的锂氧层间距较低，通常在放电末端时候阻碍锂离子扩散，导致材料动力学迟滞，容量偏低。
发明人发现，在正极材料内部引入氧缺陷，一方面可以激活过渡金属的氧化还原性，从而大幅度提升正极材料的能量密度；另一方面，正极材料表面形成的氧空位可以降低正极材料表面氧的活性，稳定材料表面氧离子，从而抑制正极材料在高温循环中释氧产气。进一步地，发明人发现，在锂层掺杂高离子半径的元素，可以增大锂氧层间距，从而提升了材料的动力学性能。
本申请通过合成手段并结合锂层元素掺杂可以调控正极材料的内部氧缺陷和锂氧层间距，从而使本申请的正极材料具有较高的能量密度、较高的动力学性能以及改善的高温稳定性。
一、正极材料
本申请提供了一种正极材料，将包括所述正极材料的电极与锂金属组装成扣式电池，并使所述扣式电池在2.8V至4.5V电压区间内以0.04C的电流进行充放电时，所获得的电压容量微分dQ/dV曲线在4.2V至4.5V区间存在第一氧化峰和第一还原峰。
所述扣式电池的电压容量微分dQ/dV曲线在4.2V至4.5V区间存在第一氧化峰和第一还原峰，表明所述正极材料由于内部氧缺陷的存在，在4.2V至4.5V的高电压区间存在可逆的充放电容量，从而使得正极材料具有较高的能量密度以及良好的结构稳定性。
在一些实施例中，基于正极材料的质量，第一氧化峰的峰高大于或等于300mAh/g/V。此时，正极材料在4.2V至4.5V的高电压区间充电的容量较高，从而使得正极材料具有更高的能量密度。在一些实施例中，基于正极材料的质量，第一氧化峰的峰高为300mAh/g/V至2000mAh/g/V。在一些实施例中，基于正极材料的质量，第一氧化峰的峰高可以为300mAh/g/V、400mAh/g/V、500mAh/g/V、600mAh/g/V、700mAh/g/V、800mAh/g/V、900mAh/g/V、1000mAh/g/V、1100mAh/g/V、1200mAh/g/V、1300mAh/g/V、1400mAh/g/V、1500mAh/g/V、1800mAh/g/V、2000mAh/g/V或可以为以上任意两数值组成的范围，例如300mAh/g/V至1000mAh/g/V、500mAh/g/V至1500mAh/g/V、600mAh/g/V至1500mAh/g/V、700mAh/g/V至1500mAh/g/V或1000mAh/g/V至1500mAh/g/V等。
在一些实施例中，基于正极材料的质量，第一还原峰的峰高的绝对值大于或等于300mAh/g/V。此时，正极材料在4.2V至4.5V的高电压区间放电的容量较高，从而使得正极材料具有更高的能量密度。在一些实施例中，基于正极材料的质量，第一还原峰的峰高的绝对值为300mAh/g/V至2000mAh/g/V。在一些实施例中，基于正极材料的质量，第一还原峰的峰高的绝对值可以为300mAh/g/V、400mAh/g/V、500mAh/g/V、600mAh/g/V、700mAh/g/V、800mAh/g/V、900mAh/g/V、1000mAh/g/V、1100mAh/g/V、1200mAh/g/V、1300mAh/g/V、1400mAh/g/V、1500mAh/g/V、1800mAh/g/V、2000mAh/g/V或可以为以上任意两数值组成的范围，例如300mAh/g/V至1000mAh/g/V、500mAh/g/V至1500mAh/g/V、600mAh/g/V至1500mAh/g/V、700mAh/g/V至1500mAh/g/V或1000mAh/g/V至1500mAh/g/V等。
在一些实施例中，第一氧化峰的峰值电压为Vo1，第一还原峰的峰值电压为Vr1，且|Vo1-Vr1|≤0.3V。此时，由于氧缺陷的存在，锂离子在二维通道内部的束缚力明显降低，因此，锂离子的扩散得到明显改善，且由于氧缺陷的存在激活了过渡金属小极化子缺陷，提升了材料的电子电导率，从而使得正极材料在4.2V至4.5V的高电压区间充放电的可逆性较好，并具有良好的结构稳定性。在一些实施例中，|Vo1-Vr1|可以为0.3V、0.27V、0.25V、0.23V、0.20V、0.17V、0.16V、0.15V、0.14V、0.13V、0.12V、0.11V、0.10V、0.09V、0.08V、0.07V、0.06V、0.05V、0.04V、0.03V、0.02V或0.01V等；或者可以为以上任意数值，例如0.3V、0.27V、0.25V、0.23V、0.20V、0.17V、0.16V、0.15V、0.14V、0.13V、0.12V、0.10V、0.09V、0.08V、0.07V、0.06V、0.05V、0.04V或0.03V等；或者可以为以上任意两数值组成的范围，例如0.03V至0.27V、0.05V至0.27V或0.01V至0.3V等。
在一些实施例中，电压容量微分dQ/dV曲线在3.6V至4.0V区间存在第二氧化峰和第二还原峰，第二氧化峰的峰值电压为Vo2，第二还原峰的峰值电压为Vr2，且|Vo2-Vr2|≤0.2V。此时，正极材料在3.6V至4.0V区间主要为六方相到单斜相的转变过程，该过程涉及锂离子和电子的输运过程，由于氧缺陷的存在，提升了材料整体的锂离子和电子的电导率，材料的动力学明显改善，因此，此过程的极化降低，使得第二氧化峰和第二还原峰的峰值电压差异更小。在一些实施例中，|Vo2-Vr2|可以为0.20V、0.19V、0.17V、0.16V、0.15V、0.14V、0.13V、0.12V、0.11V、0.10V、0.09V、0.08V、0.07V、0.06V、0.05V、0.04V、0.03V、0.02V、0.01V，或可以为以上任意两数值组成的范围，例如0.02V至0.19V、0.02V至0.12V或0.1V至0.20V等。
在一些实施例中，上述扣式电池在2.8V至4.5V电压区间内以0.04C的电流进行充放电，所获得电压容量曲线中的放电曲线在4.2V至4.5V区间存在平台，所述放电曲线在4.2V至4.5V区间的容量为Q1，所述放电曲线在3.0V至4.5V区间的容量为Qt，满足：0.14≤Q1/Qt≤0.35。此时，正极材料在4.2V至4.5V高电压区间的容量较高，从而使得正极材料具有更高的能量密度。
在一些实施例中，Q1/Qt可以为0.14、0.15、0.16、0.17、0.18、0.19、0.20、0.21、0.22、0.23、0.24、0.25、0.26、0.27、0.28、0.29、0.30、0.31、0.32、0.33、0.34、0.35或可以为以上任意两数值组成的范围，例如0.14至0.28、0.16至0.28或0.20至0.35等。
在一些实施例中，正极材料的晶胞参数a满足
Figure PCTCN2022089911-appb-000003
在一些实施例中，正极材料的晶胞参数c满足
Figure PCTCN2022089911-appb-000004
在一些实施例中，4.93≤c/a≤5.10。一般来讲，六方晶系的a轴晶胞参数与过渡金属价态相关，c轴晶胞参数与锂层和过渡金属层间距相关。在氧缺陷存在下，降低了Li-O层间的束缚，Li-O层间距变大，过渡金属层间距降低，反应到c轴上相应增大，使得正极材料动力学改善。在a轴上主要与过渡金属价态相关，氧缺陷的存在会促使过渡金属向低价态变化，a轴会有一定程度的增大。
在一些实施例中，a可以为
Figure PCTCN2022089911-appb-000005
Figure PCTCN2022089911-appb-000006
或可以为以上任意两数值组成的范围，例如
Figure PCTCN2022089911-appb-000007
至
Figure PCTCN2022089911-appb-000008
至
Figure PCTCN2022089911-appb-000009
至
Figure PCTCN2022089911-appb-000010
或
Figure PCTCN2022089911-appb-000011
至
Figure PCTCN2022089911-appb-000012
等。
在一些实施例中，c可以为
Figure PCTCN2022089911-appb-000013
Figure PCTCN2022089911-appb-000014
或可以为以上任意两数值组成的范围，例如
Figure PCTCN2022089911-appb-000015
至
Figure PCTCN2022089911-appb-000016
至
Figure PCTCN2022089911-appb-000017
至
Figure PCTCN2022089911-appb-000018
或
Figure PCTCN2022089911-appb-000019
至
Figure PCTCN2022089911-appb-000020
等。
在一些实施例中，c/a可以为4.93、4.94、4.95、4.96、4.97、4.98、4.99、5.00、5.01、5.02、5.03、5.04、5.05、5.06、5.07、5.08、5.09、5.10或可以为以上任意两数值组成的范围，例如4.96至5.00、4.96至5.05、4.96至5.09或4.98至5.09等。
在一些实施例中，正极材料的X射线衍射图谱在16°至20°、34°至38°以及42°至46°区间内均存在衍射峰。
在一些实施例中，所述正极材料包括锂过渡金属复合氧化物。
在一些实施例中，锂过渡金属复合氧化物包括元素M和元素T，元素M包括Na、K或Y中的至少一种，元素T包括Ni、Co或Mn中的至少一种。高离子半径的元素M在 锂层掺杂，能够增大锂氧层间距，从而提升了材料的动力学性能。
在一些实施例中，基于元素T的总摩尔量，Ni的摩尔百分含量大于或等于50％。
在一些实施例中，基于所述元素T的总摩尔量，Mn的摩尔百分含量小于或等于50％。在一些实施例中，Mn的摩尔百分含量大于或等于30％。
在一些实施例中，基于所述元素T的总摩尔量，Co的摩尔百分含量小于或等于50％。在一些实施例中，Co的摩尔百分含量大于或等于10％。
在一些实施例中，基于元素T的总摩尔量，元素M的摩尔百分含量为0.1％至5％。
在一些实施例中，正极材料可以为M元素掺杂的含Li元素和T元素的复合氧化物，元素M包括Na、K或Y中的至少一种，元素T包括Ni、Co或Mn中的至少一种。例如，正极材料可以为元素M掺杂的LiNi 0.5Mn 0.5O 2(下文用LiMNi 0.5Mn 0.5O 2表示)，其中元素M可以为Na、K、Y或Na+Y，基于元素Ni和Mn的总摩尔量，元素M的掺杂浓度可以为0.10％、0.20％、0.50％、1.00％、2.00％、3.00％、4.00％或5.00％等。
在一些实施例中，锂过渡金属复合氧化物还可以包括元素Q，元素Q包括Ca、Sr、Ba、Al、Fe、B、Mg、Si、S、Ti、Cr、Fe、Cu、Zn、Ga、Zr、Mo、W、Nb、In、Sn、Pb、Sb、Ce、La、Ta或Hf中的至少一种。基于元素T的总摩尔量，元素Q的摩尔百分含量为0.1％至5％。元素Q可起到支撑过渡金属层的作用，从而提升正极材料的结构稳定性。
在一些实施例中，正极材料可以为元素M和Q掺杂的含Li元素和T元素的复合氧化物，元素M包括Na、K或Y中的至少一种，元素T包括Ni、Co或Mn中的至少一种，元素Q包括Ca、Sr、Ba、Al、Fe、B、Mg、Si、S、Ti、Cr、Fe、Cu、Zn、Ga、Zr、Mo、W、Nb、In、Sn、Pb、Sb、Ce、La、Ta或Hf中的至少一种。例如，正极材料可以为元素M和Q掺杂的LiNi 0.5Mn 0.5O 2(下文用LiMQNi 0.5Mn 0.5O 2表示)，其中M元素为Na，Q元素为Zr、Ti、W、Ta或Sn，基于元素Ni和Mn的总摩尔量，元素M和Q的掺杂浓度可以给自独立的为0.10％、0.20％、0.50％、1.00％、2.00％、3.00％、4.00％或5.00％等。
在一些实施例中，锂过渡金属复合氧化物还可以包括元素M1，M1为F、Cl、Br、I、N或P中的至少一种；基于所述元素T的总摩尔量，所述元素M1的摩尔百分含量为0.1％至20％。
在一些实施例中，正极材料可以为M元素掺杂的LiTO 1.9M1 0.1，元素M包括Na、K或Y中的至少一种，元素T包括Ni、Co或Mn中的至少一种，元素M1为F、Cl、Br、I、N或P中的至少一种。例如，正极材料可以为元素M掺杂的LiNi 0.5Mn 0.5O 1.9F 0.1(下文用LiMNi 0.5Mn 0.5O 1.9F 0.1表示)或元素M掺杂的LiNi 0.5Mn 0.5O 1.9Cl 0.1(下文用LiMNi 0.5Mn 0.5O 2Cl 0.1表示)，元素M为Na、K或Y。
在一些实施例中，正极材料满足通式Li xM y(Ni aCo bMn cQ d)O eM1 f，0＜x+y≤2，0≤a、b、c、d≤1，且a、b、c、d不同时为0，0＜e≤3，0≤f＜1，其中元素M为Na、K或Y中的至少一种，元素Q为Ca、Sr、Ba、Al、Fe、B、Mg、Si、S、Ti、Cr、Fe、Cu、Zn、Ga、Zr、Mo、W、Nb、In、Sn、Pb、Sb、Ce、La、Ta或Hf中的至少一种，且M1为F、Cl、Br、I、N或P中的至少一种。
在一些实施例中，正极材料包含元素Li，且其中基于正极材料的质量，元素Li的质量分数大于5％。
在一些实施例中，正极材料包含元素Li与其他金属元素，其他金属元素可以包含元素M、元素T或元素Q中的至少一种。元素Li的摩尔量与其他金属元素的摩尔量总和的比值大于0.5且小于2。
在一些实施例中，正极材料的制备方法包括如下步骤：1)在第一气氛条件下，将前驱体与锂源、元素M源、可选的元素Q源以及可选的元素M1源在第一温度下煅烧第一时间；2)降温至第二温度，在第二气氛条件下保持第二时间；3)最后降温至室温。所述第一气氛选自空气氛、氧气氛或空气与氧气混合气氛；所述前驱体包含元素T，所述元素T包括Ni、Co或Mn中的至少一种；所述元素M包括Na、K或Y中的至少一种；所述元素Q包括Ca、Sr、Ba、Al、Fe、B、Mg、Si、S、Ti、Cr、Fe、Cu、Zn、Ga、Zr、Mo、W、Nb、In、Sn、Pb、Sb、Ce、La、Ta或Hf中的至少一种；所述元素M1包括F、Cl、Br、I、N或P中的至少一种；所述第二气氛选自惰性气氛或惰性气体与H 2混合气氛中的至少一种。本申请通过在煅烧后的降温过程中通入惰性气体或惰性气体与H 2混合气体并保温一段时间以在正极材料内部引入氧缺陷，使得正极材料中的过渡金属的氧化还原性可以被激活，从而大幅度提升正极材料的能量密度。
在一些实施例中，所述第一温度为700℃至1200℃；所述第一时间为10h至48h。在一些实施例中，所述第一温度可以为700℃、800℃、900℃、1000℃、1100℃、1200℃或可以为以上任意两数值组成的范围。在一些实施例中，所述第一时间可以为10h、12h、16h、 18h、24h、36h、48h或可以为以上任意两数值组成的范围。
在一些实施例中，所述第二温度为350℃至600℃；所述第二时间为4h至24h。在一些实施例中，所述第二温度可以为350℃、400℃、450℃、500℃、550℃、600℃或可以为以上任意两数值组成的范围。在一些实施例中，所述第二时间可以为4h、6h、8h、10h、12h、16h、18h、24h或可以为以上任意两数值组成的范围。
在一些实施例中，所述惰性气体选自N 2、Ar或He中的至少一种。
在一些实施例中，所述步骤3)中的降温速率大于或等于50℃/min。
在一些实施例中，基于所述惰性气体与H 2混合气氛的总体积，所述惰性气体与H 2混合气氛中H 2的体积百分含量小于或等于10％。在一些实施例中，基于所述惰性气体与H 2混合气氛的总体积，所述惰性气体与H 2混合气氛中的H 2的体积百分含量可以为1％、2％、3％、4％、5％、6％、7％、8％、9％、10％或可以为以上任意两数值组成的范围，例如1％至3％、5％至10％等。
在一些实施例中，所述前驱体包括元素T的氢氧化物。
在一些实施例中，所述锂源包括碳酸锂或氢氧化锂中的至少一种。
在一些实施例中，所述元素M源包括元素M的碳酸盐或氢氧化物中的至少一种。
在一些实施例中，所述元素Q源包括元素Q的氧化物。
在一些实施例中，所述元素M1源包括元素M1的铵盐或锂盐中的至少一种。
在一些实施例中，基于所述元素T的总摩尔量，Ni的摩尔百分含量大于或等于50％。
在一些实施例中，基于所述元素T的总摩尔量，Mn的摩尔百分含量小于或等于50％。
在一些实施例中，基于所述元素T的总摩尔量，Co的摩尔百分含量小于或等于50％。
在一些实施例中，基于所述元素T的总摩尔量，所述元素M的摩尔百分含量为0.1％至5％。
在一些实施例中，基于所述元素T的总摩尔量，所述元素Q的摩尔百分含量为0.1％至5％。
在一些实施例中，基于所述元素T的总摩尔量，所述元素M1的摩尔百分含量为0.1％至20％。
二、电化学装置
本申请提供了一种电化学装置，其包括正极、负极、隔离膜和电解液，其中所述正极包含正极材料层，正极材料层包含上文所述的正极材料。
在一些实施例中，正极材料层还包括粘合剂。粘合剂提高正极材料颗粒彼此间的结合，并且还提高正极材料与正极集流体的结合。
在一些实施例中，粘合剂包括丁苯橡胶(SBR)、水性丙烯酸树脂、羧甲基纤维素(CMC)、聚偏二氟乙烯(PVDF)、聚四氟乙烯(PTFE)、聚乙烯醇缩丁醛(PVB)、乙烯-醋酸乙烯酯共聚物(EVA)或聚乙烯醇(PVA)中的至少一种，但不限于此，可以根据实际需求来选择粘合剂。
在一些实施例中，基于正极材料层的总重量，粘结剂的重量百分比小于或等于5.0％。在一些实施例中，基于正极材料层的总重量，粘结剂的重量百分比为5.0％、4.0％、3.0％、2.0％、1.5％、1.0％、0.5％、0.3％、0.1％或可以为以上任意两数值组成的范围，例如0.1％至2.0％、0.5％至2.0％、0.1％至1.0％或1.0％至2.0％。
在一些实施例中，正极材料层还包括导电剂，导电剂包括石墨、乙炔黑、炭黑、科琴黑、碳纳米管、石墨烯及碳纳米纤维中的至少一种，但不限于此，可以根据实际需求来选择导电剂。
在一些实施例中，基于正极材料层的总重量，导电剂的重量百分比大于或等于0.5％。在一些实施例中，基于正极材料层的总重量，导电剂的重量百分比大于或等于1.0％或大于或等于1.5％等。
在一些实施例中，正极集流体可以采用金属箔材或多孔金属板，例如使用铝、铜、镍、钛或银等金属或它们的合金的箔材或多孔板，例如铝箔，但不限于此。
在一些实施例中，正极集流体的厚度为5μm至20μm，例如，5μm、6μm、7μm、8μm、10μm、12μm、14μm、16μm、18μm、20μm或可以为以上任意两数值组成的范围，例如6μm至18μm或8μm至16μm。
在一些实施例中，正极可以通过本领域公知的制备方法制备。例如，正极可以通过如下方法获得：在溶剂中将正极材料、导电剂和粘合剂混合，以制备正极浆料，将该正极浆料涂覆在正极集流体上，经烘干、冷压等工序得到正极。。在一些实施例中，溶剂可以包括N-甲基吡咯烷酮(NMP)等，但不限于此。
在一些实施例中，负极可以是金属锂片，也可以是包括负极集流体及设置于负极集流体 至少一个表面上的负极材料层。
在一些实施例中，负极材料层包括负极材料，并可选地包括导电剂和粘结剂。
在一些实施例中，负极材料可以包括天然石墨、人造石墨、中间相微碳球(MCMB)、硬碳、软碳、硅、硅-碳复合物、SiO、Li-Sn合金、Li-Sn-O合金、Li-Al合金及金属锂中的一种或多种。
在一些实施例中，导电剂可以包括乙炔黑、炭黑、科琴黑、碳纳米管、石墨烯及碳纳米纤维中的一种或多种。
在一些实施例中，粘结剂可以是丁苯橡胶、聚偏二氟乙烯、聚四氟乙烯、聚乙烯醇缩丁醛、水性丙烯酸树脂或羧甲基纤维素中的一种或多种。
本申请的电化学装置中的负极不限定于以上材料，本申请还可以使用可被用作锂离子电池负极材料、导电剂、粘结剂和增稠剂的其它材料。
负极集流体可以使用金属箔材或多孔金属板等材料，例如使用铜，镍，钛或铁等金属或它们的合金的箔材或多孔板，如铜箔。
负极可以按照本领域常规方法制备。通常将负极材料及可选的导电剂和粘结剂分散于溶剂中，溶剂可以是N-甲基吡咯烷酮或水，形成均匀的负极浆料，将负极浆料涂覆在负极集流体上，经烘干、冷压等工序得到负极。
本申请的电化学装置中的隔离膜没有特别的限制，可以选用任意公知的具有电化学稳定性和化学稳定性的多孔结构隔离膜，例如玻璃纤维、无纺布、聚乙烯(PE)，聚丙烯(PP)及聚偏二氟乙烯中的一种或多种的单层或多层薄膜。
本申请的电化学装置中的电解液可以包括有机溶剂、电解质锂盐和添加剂。本申请对有机溶剂和电解质锂盐的种类不做具体限制，可以根据实际需求进行选择。
在一些实施例中，有机溶剂可以为碳酸乙烯酯(EC)、碳酸丙烯酯(PC)、碳酸甲乙酯(EMC)、碳酸二乙酯(DEC)、碳酸二甲酯(DMC)、碳酸二丙酯(DPC)、碳酸甲丙酯(MPC)、碳酸乙丙酯(EPC)、碳酸丁烯酯(BC)、碳酸亚乙烯酯(VC)、甲酸甲酯(MF)、乙酸甲酯(MA)、乙酸乙酯(EA)、乙酸丙酯(PA)、丙酸甲酯(MP)、丙酸乙酯(EP)、丙酸丙酯(PP)、丁酸甲酯(MB)、丁酸乙酯(EB)、1，4-丁内酯(GBL)、环丁砜(SF)、二甲砜(MSM)、甲乙砜(EMS)及二乙砜(ESE)中的至少一种。在一些实施例中，有机溶剂包括上述化合物中的至少两种。
在一些实施例中，电解质锂盐可以为六氟磷酸锂(LiPF 6)、四氟硼酸锂(LiBF 4)、高氯酸锂(LiClO 4)、六氟砷酸锂(LiAsF 6)、双氟磺酰亚胺锂(LiFSI)、双三氟甲磺酰亚胺锂(LiTFSI)、三氟甲磺酸锂(LiTFS)、二氟草酸硼酸锂(LiDFOB)、二草酸硼酸锂(LiBOB)、二氟磷酸锂(LiPO 2F 2)、二氟二草酸磷酸锂(LiDFOP)及四氟草酸磷酸锂(LiTFOP)中的一种或多种。
在一些实施例中，电解液中的添加剂可以包括腈类化合物，所述腈类化合物包括以下化合物中的一种或多种：丁二腈、戊二腈、己二腈或1，3，6-己烷三腈中一种或多种。
在一些实施例中，解液中还可选地包括其它添加剂，其它添加剂可以是任意可被用作锂离子电池的添加剂，在此不做具体限制，可以根据实际需求进行选择。
本申请的电化学装置可以按照本领域常规的方法制备。例如，将上述正极、隔离膜及负极按顺序堆叠好，使隔离膜处于正极与负极之间起到隔离的作用，经卷绕后得到电极组件；将电极组件置于包装外壳中，注入电解液并封口，得到电化学装置。
三、电子装置
由本申请所述的电化学装置适用于各种领域的电子装置。
本申请的电化学装置的用途没有特别限定，其可用于现有技术中已知的任何用途。在一个实施例中，本申请的电化学装置可用于，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。
四、实施例
以下，举出实施例和对比例对本申请进一步具体地进行说明，但只要不脱离其主旨，则本申请并不限定于这些实施例。
1、正极材料的制备
对比例1
1)根据元素摩尔比Ni∶Mn＝50∶50配置含有NiSO 4、MnSO 4的混合溶液，将其和沉淀剂(NaOH溶液)、络合剂(氨水)混合反应，控制氨水浓度为1mol/L、PH＝12.2得到平均粒径 Dv50为11μm的前驱体Ni 0.5Mn 0.5(OH) 2；
2)将上述步骤1)中的前驱体、碳酸锂按照Li：元素T(Ni/Mn)的摩尔比为1.02研磨混合均匀，在800℃空气氛下煅烧20h，按照10℃/min的速率降温至室温，最后经过破碎、过筛得到正极材料。
对比例2
1)前驱体Ni 0.5Mn 0.5(OH) 2的制备同对比例1；
2)将上述步骤1)中的前驱体、碳酸锂和碳酸钠按照Li：元素T(Ni/Mn)的摩尔比为1.02、Na的掺杂浓度(Na与元素T的摩尔百分比)为0.1％研磨混合均匀，在800℃空气氛下煅烧20h，按照10℃/min的速率降温至室温，最后经过破碎、过筛得到正极材料。
对比例3
1)根据元素摩尔比Ni∶Mn∶Co＝50∶30∶20配置含有NiSO 4、MnSO 4、CoSO 4的混合溶液，将其和沉淀剂(NaOH溶液)、络合剂(氨水)混合反应，控制氨水浓度为1mol/L、PH＝12.2得到平均粒径Dv50为11μm的前驱体Ni 0.5Mn 0.3Co 0.2(OH) 2；
2)将上述步骤1)中的前驱体、碳酸锂和碳酸钠按照Li：元素T(Ni/Mn/Co)的摩尔比为1.02、Na的掺杂浓度为1％研磨混合均匀，在800℃空气氛下煅烧20h，按照50℃/min的速率降温至室温，最后经过破碎、过筛得到正极材料。
实施例1
与对比例2的区别在于，步骤2)中，在800℃空气氛下煅烧20h后，按照10℃/min的速率降温至600℃，根据表1通入N 2，在该条件下保持6h后，以表1中相应的降温速率淬冷至室温；最后经过破碎、过筛得到正极材料。
实施例2与实施例1的区别在于，步骤2)中，根据表1通入N 2与H 2混合气。
实施例3-5与实施例2的区别在于，步骤2)中，Na的掺杂浓度分别为0.2％、0.5％和1％。
实施例6-7与实施例5的区别在于，步骤1)中的前驱体分别为Ni 0.5Mn 0.4Co 0.1(OH) 2、Ni 0.5Mn 0.3Co 0.2(OH) 2。
实施例8-9与实施例5的区别在于，步骤2)中，研磨混合步骤中进一步分别加入NH 4F和NH 4Cl。
实施例10与实施例5的区别在于，步骤2)中，Na的掺杂浓度为2％。
实施例11-12与实施例5的区别在于，步骤2)中，根据表1通入N 2与H 2混合气，以表1中相应的降温速率淬冷至室温。
实施例13-15与实施例5的区别在于，步骤2)中，将碳酸钠替换为碳酸钾，根据表1通入N 2与H 2混合气，以表1中相应的降温速率淬冷至室温。
实施例16-19与实施例5的区别在于，步骤2)中，将碳酸钠替换为碳酸钇，根据表1通入N 2与H 2混合气，以表1中相应的降温速率淬冷至室温。
实施例20与实施例18的区别在于，步骤2)中，将碳酸钇替换为碳酸钇与碳酸钠的混合物，Na和Y的掺杂浓度各自为0.5％。
实施例21-25与实施例12的区别在于，步骤2)中，研磨混合步骤中进一步加入元素Q源，元素Q源分别为ZrO 2、TiO 2、WO 3、Ta 2O 5、SnO 2，元素Q的掺杂浓度(元素Q与元素T的摩尔百分比)为0.5％。
表1示出了对比例1-3与实施例1-25的掺杂元素、掺杂量、氮气和氢气体积百分比和降温速率。
表1
Figure PCTCN2022089911-appb-000021
Figure PCTCN2022089911-appb-000022
2、扣式电池的制备方法：
(1)将一定重量比(90∶5∶5)的正极材料、聚偏氟乙烯(PVDF)和导电炭黑(SuperP)加入N-甲基吡咯烷酮(NMP)中制备成正极浆料；
(2)调节正极浆料的粘度为3000mPa·s至6000mPa·s，将混合好的浆料均匀涂覆在铝箔上，涂覆厚度为40μm，单面涂覆；干燥后进行辊压制成所需电极，电极加工和转运环境湿度45％。其中，涂布电极面密度为14mg/cm 2，经烘干得到正极片，并冲切为14mm的圆片；
(3)将隔离膜冲切为18mm的圆片；所使用的负极为直径18mm的锂金属片；在碳酸丙烯酯(PC)、碳酸乙烯酯(EC)、碳酸二乙酯(DEC)(重量比1∶1∶1)混合而成的溶剂中，加入LiPF 6混合均匀得到电解液，其中LiPF 6的质量浓度为12.5％；将正极片、隔离膜、负极片(锂片)及电解液、电池壳等配件移入到手套箱内(水含量需小于11ppm)；
(4)按照从下到上的叠放顺序组装电池并注入电解液，在封装机上封装，得到扣式电池。
3、锂离子电池的制备方法：
正极的制备
(1)将一定重量比(96∶2∶2)的正极材料、聚偏氟乙烯(PVDF)和导电炭黑(Super P)加入N-甲基吡咯烷酮(NMP)中制备成正极浆料；
(2)调节正极浆料的粘度为3000mPa·s至6000mPa·s，将混合好的浆料均匀涂覆在铝箔上，单面涂覆厚度为40μm，双面涂覆；干燥后进行辊压制成所需电极，电极加工和转运环境湿度45％。其中，涂布电极面密度为14mg/cm 2。
负极的制备
将人造石墨、丁苯橡胶和羧甲基纤维素钠(CMC)按照96∶2∶2的质量比与去离子水混合，搅拌均匀，得到负极浆料。将该负极浆料涂布在12μm厚的铜箔上。干燥，冷压，再经过裁片、焊接极耳，得到负极。
电解液的制备
在干燥氩气环境下，在碳酸丙烯酯(PC)、碳酸乙烯酯(EC)、碳酸二乙酯(DEC)(重量比1∶1∶1)混合而成的溶剂中，加入LiPF 6混合均匀得到电解液，其中LiPF 6的质量浓度为12.5％。
隔离膜的制备
以聚乙烯(PE)多孔聚合薄膜作为隔离膜。
锂离子电池的制备
将正极、隔离膜、负极按顺序叠好，使隔离膜处于正极和负极中间以起到隔离的作用。卷绕得到裸电芯。将裸电芯置于外包装中，注入电解液，封装。经过化成、脱气、切边等工艺流程得到锂离子电池。
4、测试方法
厚度膨胀率测试
将锂离子电池在85℃条件下充电至4.35V，存储12h，用千分尺测试锂离子电池的厚度变化，定义锂离子电池存储前的初始厚度为H0，存储后的厚度为H1，厚度膨胀率为：(H1-H0)/H0×100％。
45℃循环容量保持率测试
将锂离子电池放至45℃恒温箱中，以1.5C倍率恒流充电至4.35V，再在4.35V下恒压充电至电流为0.05C，再以4C倍率恒流放电至3.0V，此为一个充放电循环，将锂离子电池按照上述方法进行充放电循环300次，并记录锂离子电池的首次循环的放电容量以及第300次循环的放电容量，循环容量保持率＝第300次循环的放电容量/首次循环的放电容量×100％。
扣式电池充放电循环测试
25℃下，将扣式电池在2.8V至4.5V电压区间内以0.04C的电流进行充放电，以获得电压容量曲线和电压容量微分dQ/dV曲线。
X射线衍射测试
采用X射线粉末衍射仪(XRD，仪器型号：Bruker D8 ADVANCE)测试正极材料，靶材为Cu Kα；电压电流为40KV/40mA，扫描角度范围为10°至70°。
5、测试结果与分析
使用由对比例1-3以及实施例1-25的正极材料制备扣式电池和锂离子电池，对扣式电池进行充放电循环测试，并对锂离子电池进行厚度膨胀率测试和45℃循环容量保持率测试。表2示出了各对比例和实施例的扣式电池的峰值电压、容量占比率、电压差值以及各对比例和实施例的锂离子电池的厚度膨胀率和容量保持率的测试结果。
表2
Figure PCTCN2022089911-appb-000023
根据表2可知，由本申请的实施例1-25的正极材料所制备的扣式电池的电压容量微分dQ/dV曲线在4.2V至4.5V区间存在第一氧化峰和第一还原峰，表明所述正极材料由于内部氧缺陷的存在，改善了材料的锂离子扩散和电子扩散能力，在4.2V至4.5V的高电压区间存在可逆的充放电容量，从而使得正极材料具有较高的能量密度以及良好的结构稳 定性。同时，由于氧缺陷的存在，降低了表面氧与电解液的界面反应活性，因此实施例1-25的锂离子电池具有改善的高温存储产气以及优异的高温循环性能。
从表2中可知，当扣式电池的放电曲线满足0.14≤Q1/Qt≤0.35时，此时，正极材料在4.2V至4.5V高电压区间的容量较高，从而使得正极材料具有更高的能量密度。且本申请实施例1-25的正极材料满足：|Vo2-Vr2|≤0.2V。这是由于，正极材料在3.6V至4.0V区间主要为六方相到单斜相的转变过程，该过程涉及锂离子和电子的输运过程，由于氧缺陷的存在，提升了材料整体的锂离子和电子的电导率，材料的动力学明显改善，因此，此过程的极化降低，使得第二氧化峰和第二还原峰的峰值电压差异更小。
图1示出了对比例1、对比例2和实施例11的扣式电池的充放电曲线。从图1中可以看出实施例11的扣式电池的放电曲线在4.2V至4.5V区间存在平台。
图2示出了对比例1和实施例11的扣式电池的电压容量微分dQ/dV曲线。从图2可以看出实施例11的扣式电池的电压容量微分dQ/dV曲线在4.2V至4.5V区间存在第一氧化峰和第一还原峰，而对比例1的扣式电池的电压容量微分dQ/dV曲线在4.2V至4.5V区间不存在氧化峰和还原峰。
图3示出了对比例1和实施例11的正极材料的X射线衍射图谱。所述正极材料的X射线衍射图谱在16°至20°、34°至38°以及42°至46°区间内均存在衍射峰。
整个说明书中对“一些实施例”、“部分实施例”、“一个实施例”、“另一举例”、“举例”、“具体举例”或“部分举例”的引用，其所代表的意思是在本申请中的至少一个实施例或举例包含了该实施例或举例中所描述的特定特征、结构、材料或特性。因此，在整个说明书中的各处所出现的描述，例如：“在一些实施例中”、“在实施例中”、“在一个实施例中”、“在另一个举例中”，“在一个举例中”、“在特定举例中”或“举例“，其不必然是引用本申请中的相同的实施例或示例。此外，本文中的特定特征、结构、材料或特性可以以任何合适的方式在一个或多个实施例或举例中结合。
尽管已经演示和描述了说明性实施例，本领域技术人员应该理解上述实施例不能被解释为对本申请的限制，并且可以在不脱离本申请的精神、原理及范围的情况下对实施例进行改变，替代和修改。

Claims (12)

  1. 一种正极材料，其特征在于，将包括所述正极材料的电极与锂金属组装成扣式电池，并使所述扣式电池在2.8V至4.5V电压区间内以0.04C的电流进行充放电时，所获得的电压容量微分dQ/dV曲线在4.2V至4.5V区间存在第一氧化峰和第一还原峰。
  2. 根据权利要求1所述的正极材料，其中，所述正极材料满足下列条件中的至少一者：
    (i)基于所述正极材料的质量，所述第一氧化峰的峰高大于或等于300mAh/g/V；
    (ii)基于所述正极材料的质量，所述第一还原峰的峰高的绝对值大于或等于300mAh/g/V。
  3. 根据权利要求1所述的正极材料，其中，所述第一氧化峰的峰值电压为Vo1，所述第一还原峰的峰值电压为Vr1，且|Vo1-Vr1|≤0.3V。
  4. 根据权利要求1所述的正极材料，其中，所述电压容量微分dQ/dV曲线在3.6V至4.0V区间存在第二氧化峰和第二还原峰，所述第二氧化峰的峰值电压为Vo2，所述第二还原峰的峰值电压为Vr2，且|Vo2-Vr2|≤0.2V。
  5. 根据权利要求1所述的正极材料，其中，所述扣式电池在2.8V至4.5V电压区间内以0.04C的电流进行充放电时，所获得的电压容量曲线中的放电曲线在4.2V至4.5V区间存在平台，所述放电曲线在4.2V至4.5V区间的容量为Q1，所述放电曲线在3.0V至4.5V区间的容量为Qt，满足：0.14≤Q1/Qt≤0.35。
  6. 根据权利要求1所述的正极材料，其中，所述正极材料的晶胞参数a和晶胞参数c满足下列条件中的至少一者：
    (a)
    Figure PCTCN2022089911-appb-100001
    (b)
    Figure PCTCN2022089911-appb-100002
    (c)4.93≤c/a≤5.10。
  7. 根据权利要求1所述的正极材料，其中，所述正极材料的X射线衍射图谱在16°至20°、34°至38°以及42°至46°区间内均存在衍射峰。
  8. 根据权利要求1所述的正极材料，其中，所述正极材料包括锂过渡金属复合氧化物，所述锂过渡金属复合氧化物包括元素M和元素T，所述元素M包括Na、K或Y中的至少一种，所述元素T包括Ni、Co或Mn中的至少一种，所述锂过渡金属复合氧化物满足下列条件中 的至少一者：
    (1)基于所述元素T的总摩尔量，Ni的摩尔百分含量大于或等于50％；
    (2)基于所述元素T的总摩尔量，Mn的摩尔百分含量小于或等于50％；
    (3)基于所述元素T的总摩尔量，Co的摩尔百分含量小于或等于50％；
    (4)基于所述元素T的总摩尔量，所述元素M的摩尔百分含量为0.1％至5％；
    (5)所述锂过渡金属复合氧化物还包括元素Q，所述元素Q包括Ca、Sr、Ba、Al、Fe、B、Mg、Si、S、Ti、Cr、Fe、Cu、Zn、Ga、Zr、Mo、W、Nb、In、Sn、Pb、Sb、Ce、La、Ta或Hf中的至少一种；基于所述元素T的总摩尔量，所述元素Q的摩尔百分含量为0.1％至5％；
    (6)所述锂过渡金属复合氧化物还包括元素M1，M1包括F、Cl、Br、I、N或P中的至少一种；基于所述元素T的总摩尔量，所述元素M1的摩尔百分含量为0.1％至20％。
  9. 一种正极材料的制备方法，其特征在于，包括如下步骤：
    1)在第一气氛条件下，将前驱体与锂源、元素M源、可选的元素Q源以及可选的元素M1源在第一温度下煅烧第一时间；
    2)降温至第二温度，在第二气氛条件下保持第二时间；
    3)最后降温至室温；
    所述第一气氛选自空气氛、氧气氛或空气与氧气混合气氛；
    所述前驱体包含元素T，所述元素T包括Ni、Co或Mn中的至少一种；
    所述元素M包括Na、K或Y中的至少一种；
    所述元素Q包括Ca、Sr、Ba、Al、Fe、B、Mg、Si、S、Ti、Cr、Fe、Cu、Zn、Ga、Zr、Mo、W、Nb、In、Sn、Pb、Sb、Ce、La、Ta或Hf中的至少一种；
    所述元素M1包括F、Cl、Br、I、N或P中的至少一种；
    所述第二气氛选自惰性气氛或惰性气体与H 2混合气氛中的至少一种。
  10. 根据权利要求9所述的正极材料的制备方法，其中，所述制备方法满足下列条件中的至少一者：
    (1)所述第一温度为700℃至1200℃；所述第一时间为10h至48h；
    (2)所述第二温度为350℃至600℃；所述第二时间为4h至24h；
    (3)所述惰性气体选自N 2、Ar或He中的至少一种；
    (4)所述步骤3)中的降温速率大于或等于50℃/min；
    (5)基于所述惰性气体与H 2混合气氛的总体积，所述惰性气体与H 2混合气氛中H 2的体积 百分含量小于或等于10％；
    (6)所述前驱体包括元素T的氢氧化物；
    (7)所述锂源包括碳酸锂或氢氧化锂中的至少一种；
    (8)所述元素M源包括元素M的碳酸盐或氢氧化物中的至少一种；
    (9)所述元素Q源包括元素Q的氧化物；
    (10)所述元素M1源包括元素M1的铵盐或锂盐中的至少一种；
    (11)基于所述元素T的总摩尔量，Ni的摩尔百分含量大于或等于50％；
    (12)基于所述元素T的总摩尔量，Mn的摩尔百分含量小于或等于50％；
    (13)基于所述元素T的总摩尔量，Co的摩尔百分含量小于或等于50％；
    (14)基于所述元素T的总摩尔量，所述元素M的摩尔百分含量为0.1％至5％；
    (15)基于所述元素T的总摩尔量，所述元素Q的摩尔百分含量为0.1％至5％；
    (16)基于所述元素T的总摩尔量，所述元素M1的摩尔百分含量为0.1％至20％。
  11. 一种电化学装置，其包括根据权利要求1至8任一项所述的正极材料或根据权利要求9至10任一项所述的制备方法制备得到的正极材料。
  12. 一种电子装置，所述电子装置包含权利要求11所述的电化学装置。
PCT/CN2022/089911 2022-04-28 2022-04-28 正极材料及包括正极材料的电化学装置和电子装置 Ceased WO2023206241A1 (zh)

Priority Applications (4)

Application Number Priority Date Filing Date Title
PCT/CN2022/089911 WO2023206241A1 (zh) 2022-04-28 2022-04-28 正极材料及包括正极材料的电化学装置和电子装置
EP22939093.5A EP4394928A4 (en) 2022-04-28 2022-04-28 POSITIVE ELECTRODE MATERIAL AND ELECTROCHEMICAL DEVICE THEREOF AND ELECTRONIC DEVICE
CN202280006511.7A CN116325219A (zh) 2022-04-28 2022-04-28 正极材料及包括正极材料的电化学装置和电子装置
US18/621,481 US20240266530A1 (en) 2022-04-28 2024-03-29 Positive electrode material and electrochemical apparatus and electronic apparatus using such positive electrode material

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/CN2022/089911 WO2023206241A1 (zh) 2022-04-28 2022-04-28 正极材料及包括正极材料的电化学装置和电子装置

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US18/621,481 Continuation US20240266530A1 (en) 2022-04-28 2024-03-29 Positive electrode material and electrochemical apparatus and electronic apparatus using such positive electrode material

Publications (1)

Publication Number Publication Date
WO2023206241A1 true WO2023206241A1 (zh) 2023-11-02

Family

ID=86824392

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2022/089911 Ceased WO2023206241A1 (zh) 2022-04-28 2022-04-28 正极材料及包括正极材料的电化学装置和电子装置

Country Status (4)

Country Link
US (1) US20240266530A1 (zh)
EP (1) EP4394928A4 (zh)
CN (1) CN116325219A (zh)
WO (1) WO2023206241A1 (zh)

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN119156720B (zh) * 2023-10-20 2025-12-26 宁德新能源科技有限公司 正极材料、电化学装置和电子装置
WO2025081485A1 (zh) * 2023-10-20 2025-04-24 宁德新能源科技有限公司 正极材料、电化学装置和电子装置
CN119213578B (zh) * 2023-10-20 2025-12-09 宁德新能源科技有限公司 电化学装置和电子装置
WO2025081487A1 (zh) * 2023-10-20 2025-04-24 宁德新能源科技有限公司 一种正极材料、电化学装置和电子装置
CN118743060A (zh) * 2023-10-20 2024-10-01 宁德新能源科技有限公司 正极材料、电化学装置和电子装置
CN119156718B (zh) * 2023-10-20 2025-11-11 宁德新能源科技有限公司 正极材料、电化学装置和电子装置
CN119325651B (zh) * 2023-10-20 2025-12-16 宁德新能源科技有限公司 电化学装置和电子装置

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20010056566A (ko) * 1999-12-15 2001-07-04 성재갑 리튬전지용 리튬 망간 복합산화물 분말의 제조방법
CN101834291A (zh) * 2010-04-09 2010-09-15 中南大学 一种亚微米级LiNi0.5Mn0.5O2正极材料的制备方法
JP2015220220A (ja) * 2014-05-21 2015-12-07 戸田工業株式会社 非水電解質二次電池用正極活物質粒子粉末及びその製造方法、並びに非水電解質二次電池
JP2018107053A (ja) * 2016-12-28 2018-07-05 日立オートモティブシステムズ株式会社 リチウムイオン二次電池
CN109716564A (zh) * 2016-09-21 2019-05-03 巴斯夫户田电池材料有限公司 正极活性物质及其制造方法、以及非水电解质二次电池
CN114361406A (zh) * 2020-10-14 2022-04-15 艾可普罗 Bm 有限公司 正极活性材料以及包括其的锂二次电池

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2004323331A (ja) * 2003-04-28 2004-11-18 Tosoh Corp リチウム−ニッケル−マンガン複合酸化物及びその製造方法並びにその用途
JP6395051B2 (ja) * 2014-09-18 2018-09-26 本田技研工業株式会社 リチウム複合酸化物、リチウム複合酸化物の製造方法、リチウム二次電池用正極活物質、及び、リチウム二次電池
KR102391115B1 (ko) * 2015-01-21 2022-04-27 삼성에스디아이 주식회사 양극 활물질 및 이를 포함한 양극을 함유한 리튬 이차 전지
CN110970616B (zh) * 2019-12-23 2022-06-24 北京理工大学重庆创新中心 一种表面高密度位错的ncm三元正极材料的制备方法
CN111697221B (zh) * 2020-07-07 2022-02-11 蜂巢能源科技有限公司 掺杂包覆的单晶正极材料及掺杂包覆单晶正极材料的方法
CN114551856B (zh) * 2020-11-25 2025-01-21 宁德新能源科技有限公司 正极材料及使用其的电化学装置和电子设备

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20010056566A (ko) * 1999-12-15 2001-07-04 성재갑 리튬전지용 리튬 망간 복합산화물 분말의 제조방법
CN101834291A (zh) * 2010-04-09 2010-09-15 中南大学 一种亚微米级LiNi0.5Mn0.5O2正极材料的制备方法
JP2015220220A (ja) * 2014-05-21 2015-12-07 戸田工業株式会社 非水電解質二次電池用正極活物質粒子粉末及びその製造方法、並びに非水電解質二次電池
CN109716564A (zh) * 2016-09-21 2019-05-03 巴斯夫户田电池材料有限公司 正极活性物质及其制造方法、以及非水电解质二次电池
JP2018107053A (ja) * 2016-12-28 2018-07-05 日立オートモティブシステムズ株式会社 リチウムイオン二次電池
CN114361406A (zh) * 2020-10-14 2022-04-15 艾可普罗 Bm 有限公司 正极活性材料以及包括其的锂二次电池

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP4394928A4 *

Also Published As

Publication number Publication date
EP4394928A1 (en) 2024-07-03
US20240266530A1 (en) 2024-08-08
CN116325219A (zh) 2023-06-23
EP4394928A4 (en) 2025-04-02

Similar Documents

Publication Publication Date Title
US20220216471A1 (en) Lithium supplementing material and positive electrode containing same
WO2023206241A1 (zh) 正极材料及包括正极材料的电化学装置和电子装置
WO2020135512A1 (zh) 正极活性物质前驱体、其制备方法、正极活性物质、锂离子二次电池及装置
CN114762151A (zh) 正极材料和包含所述正极材料的电化学装置
EP4131540A1 (en) Electrochemical device, and electronic device comprising same
WO2022121293A1 (zh) 正极材料、电化学装置和电子装置
US20200227741A1 (en) Cathode material and electrochemical device including cathode material
WO2023164794A1 (zh) 电化学装置及包含该电化学装置的电子装置
WO2023236226A1 (zh) 正极材料、电化学装置和电子装置
US20250029986A1 (en) Positive electrode material, and electrochemical apparatus and electronic apparatus containing same
WO2025081482A1 (zh) 正极材料、电化学装置和电子装置
WO2025209064A1 (zh) 正极材料、电化学装置和电子装置
CN117996076A (zh) 一种负极材料、负极极片、二次电池及电子装置
WO2024197436A1 (zh) 正极材料、包含该正极材料的电化学装置和电子装置
WO2022188181A1 (zh) 正极材料、包含其的电化学装置和电子设备
WO2021189408A1 (zh) 负极活性材料及使用其的电化学装置和电子装置
CN112599742B (zh) 电化学装置和电子装置
WO2024036437A1 (zh) 金属氢氧化物、正极材料、电化学装置及用电设备
CN116802826A (zh) 电化学装置及电子装置
CN117941104B (zh) 一种电化学装置及包含该电化学装置的电子装置
KR102957523B1 (ko) 전기화학 디바이스 및 이 전기화학 디바이스를 포함하는 전자 디바이스
WO2025081487A1 (zh) 一种正极材料、电化学装置和电子装置
WO2025081486A1 (zh) 一种正极材料、电化学装置和电子装置
WO2025081483A1 (zh) 一种正极材料、电化学装置和电子装置
WO2025081485A1 (zh) 正极材料、电化学装置和电子装置

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 22939093

Country of ref document: EP

Kind code of ref document: A1

WWE Wipo information: entry into national phase

Ref document number: 2022939093

Country of ref document: EP

ENP Entry into the national phase

Ref document number: 2022939093

Country of ref document: EP

Effective date: 20240329

NENP Non-entry into the national phase

Ref country code: DE