WO2024000405A1 - 正极材料、电化学装置和用电装置 - Google Patents

正极材料、电化学装置和用电装置 Download PDF

Info

Publication number
WO2024000405A1
WO2024000405A1 PCT/CN2022/102822 CN2022102822W WO2024000405A1 WO 2024000405 A1 WO2024000405 A1 WO 2024000405A1 CN 2022102822 W CN2022102822 W CN 2022102822W WO 2024000405 A1 WO2024000405 A1 WO 2024000405A1
Authority
WO
WIPO (PCT)
Prior art keywords
cathode material
lithium
positive electrode
characteristic peak
coating layer
Prior art date
Application number
PCT/CN2022/102822
Other languages
English (en)
French (fr)
Inventor
郎野
袁国霞
周娟
徐磊敏
Original Assignee
宁德新能源科技有限公司
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 宁德新能源科技有限公司 filed Critical 宁德新能源科技有限公司
Priority to PCT/CN2022/102822 priority Critical patent/WO2024000405A1/zh
Priority to CN202280010316.1A priority patent/CN116802840A/zh
Publication of WO2024000405A1 publication Critical patent/WO2024000405A1/zh

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
    • H01M4/50—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
    • 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 battery technology, specifically to a cathode material, an electrochemical device and an electrical device.
  • LiMn 2 O 4 and olivine LiFePO 4 are widely used as cathode materials in lithium-ion batteries due to their low cost and good safety and reliability.
  • LiMn 2 O 4 and LiFePO 4 materials also have the problem of low charge and discharge capacity, which results in low energy density of lithium-ion batteries.
  • high-energy-density cathode materials such as increasing the Li/Mn ratio of spinel LiMn 2 O 4 materials, doping high-valence cations, or mixing ternary materials are often used in the existing technology. plan.
  • increasing the Li/Mn ratio of the material or doping high-valence cations will seriously deteriorate the high-temperature cycle performance of lithium-ion batteries
  • mixing high-energy-density cathode materials such as ternary materials will increase the cost of lithium-ion batteries.
  • the present application provides a cathode material and an electrochemical device including the cathode material.
  • the cathode material of the present application has high charging capacity and excellent structural stability, thereby greatly improving the electrochemical performance of the battery.
  • the cycle and storage performance of electrochemical devices can be improved.
  • the present application provides a cathode material, which includes lithium manganese oxide, wherein the Raman spectrum of the cathode material has a characteristic peak 1 in the range of 401 cm -1 to 410 cm -1 and 598 cm -1 to 611 cm - There is characteristic peak 2 in the range of 1 .
  • characteristic peak 1 is the characteristic peak of the orthorhombic phase in lithium manganese oxide
  • characteristic peak 2 is the characteristic peak of the monoclinic phase in lithium manganese oxide.
  • the orthorhombic phase and monoclinic phase in lithium manganese oxide have a high lithium storage capacity and can provide a high charging capacity, thus greatly increasing the energy density of electrochemical devices;
  • the monoclinic phase Coexist with the orthorhombic phase to form a solid solution, which can improve the structural stability of lithium manganese oxide in the charging state of the electrochemical device.
  • the solid solution formed by the coexistence of the two phases has oxygen vacancies, which can promote the extraction of lithium ions, thereby further improving the lithium manganese oxide.
  • the charging capacity of the oxide at the same time, the existence of the orthorhombic phase and monoclinic phase composite phase structure in the lithium manganese oxide can stabilize the structure of Mn and reduce the lattice distortion of the octahedron, improving the performance of the lithium manganese oxide in the highly delithiated state.
  • the stability of the crystal structure can inhibit the dissolution of Mn element and improve the cycle and storage performance of electrochemical devices.
  • the half-peak width of characteristic peak 1 is H1
  • the half-peak width of characteristic peak 2 is H2, which satisfy: H1 ⁇ 25cm -1 and H2 ⁇ 30cm -1 .
  • the half-peak width H1 of characteristic peak 1 and the half-peak width H2 of characteristic peak 2 are within the above range.
  • Both the orthorhombic phase and the monoclinic phase in lithium manganese oxide have high crystal regularity, which can inhibit circulation and storage. Structural phase change, thereby improving the cycle and storage performance of electrochemical devices.
  • the peak area of characteristic peak 1 is S1
  • the peak area of characteristic peak 2 is S2, satisfying: 1 ⁇ S2/S1 ⁇ 5.
  • S2/S1 is in the above range, there is a large difference in the content of the orthorhombic phase and the monoclinic phase in the lithium manganese oxide, which can synergistically form a solid solution and promote the removal of Li ions from the lithium manganese oxide, thereby further improving the oxidation of lithium manganese.
  • the charging capacity of the object is a large difference in the content of the orthorhombic phase and the monoclinic phase in the lithium manganese oxide, which can synergistically form a solid solution and promote the removal of Li ions from the lithium manganese oxide, thereby further improving the oxidation of lithium manganese.
  • the Raman spectrum of the cathode material has characteristic peak 3 in the range of 270 cm ⁇ 1 to 279 cm ⁇ 1 .
  • the presence of characteristic peak 3 in the Raman spectrum of the cathode material indicates that the monoclinic phase in lithium manganese oxide has a higher crystallographic order, which facilitates the extraction of lithium ions during charging, thereby increasing the charging capacity of the electrochemical device.
  • the half-peak width of characteristic peak 3 is H3, which satisfies: H3 ⁇ 35cm -1 .
  • the half-peak width H3 of characteristic peak 3 is within this range.
  • its degree of crystallization is relatively complete and can provide a higher delithiation capacity; on the other hand, the particle size of a single crystal is small, and lithium ions are immobilized in the material.
  • the phase diffusion path is short, which can effectively improve the kinetic performance of lithium deintercalation in the cathode material.
  • the cathode material also includes the M1 element. Based on the molar amount of the Mn element in the cathode material, the molar percentage of the M1 element in the cathode material is a1, which satisfies: 0.1% ⁇ a1 ⁇ 10%, where the M1 element Including Al, Nb, Mg, Ti, W, Ga, Zr, Y, V, Sr, Mo, Ru, Ag, Sn, Au, La, Ce, Pr, Nd, Sm, Gd, Cu, Na, Zn, Fe , at least one of Co, Ni, Cr or Ca.
  • the cathode material further includes Al element. Based on the molar amount of Mn element in the cathode material, the molar percentage content of the Al element in the cathode material is b1, which satisfies: 0.1% ⁇ b1 ⁇ 10%. The content of the element Al will cause the phase ratio to change. If the content is too high or too low, the intermediate phase of the material will increase, which will increase the grain boundary barriers and reduce the capacity.
  • the molar ratio of Li element and Mn element is c1, which satisfies: 0.9 ⁇ c1 ⁇ 1.2.
  • the Li/Mn molar ratio is within the above range, orthorhombic and monoclinic mixed phases can be stably generated and the energy density of the electrochemical device can be improved.
  • the lithium manganese oxide has a lamellar structure.
  • the lamellar structure is conducive to the extraction of Li ions from lithium manganese oxide, thereby increasing the charging capacity of lithium manganese oxide.
  • the lithium manganese oxide includes Li x Mny M1 z O 2 , where 0.9 ⁇ x ⁇ 1.2, 0.9 ⁇ y ⁇ 1, 0 ⁇ z ⁇ 0.1, and M1 includes Al, Nb, Mg, Ti, W, Ga, Zr, W, Y, V, Sr, Mo, Ru, Ag, Sn, Au, La, Ce, Pr, Nd, Sm, Gd, Cu, Na, Zn, Fe, Co, Ni, At least one of Cr or Ca. In some embodiments, 0.9 ⁇ x ⁇ 1.2, 0.9 ⁇ y ⁇ 1, 0.001 ⁇ z ⁇ 0.1.
  • the cathode material further includes a coating layer located on the surface of the cathode material.
  • the coating layer includes the M2 element. Based on the molar amount of the Mn element in the coating layer, the molar percentage of the M2 element in the coating layer is 0.05% to 2%, wherein the M2 element includes at least one of S, C, B or F.
  • the coating layer on the surface of the cathode material can further inhibit Mn dissolution, thereby improving the cycle and storage performance of the electrochemical device.
  • the cathode material also includes Al element.
  • the cathode material includes a matrix and a coating layer. Based on the molar amount of the Mn element in the matrix, the molar percentage of the Al element in the matrix is d1. Based on the Mn element in the coating layer The molar amount of Al element in the coating layer is d2, which satisfies: d2/d1 ⁇ 1.3.
  • the residual lithium amount of the cathode material is less than or equal to 0.05% based on the mass of the cathode material.
  • the pH value of the cathode material is 11 to 12.
  • this application provides a method for preparing the cathode material of the first aspect, which includes: S1: mixing a manganese-containing oxide, a lithium source and an optional M1 element source to obtain a first mixture; A mixture is subjected to a first heat treatment under a first atmosphere condition and a first temperature condition to obtain a first lithium manganese oxide; wherein the manganese-containing oxide and the lithium source are based on a lithium-manganese molar ratio Li/Mn of 0.9- Mix within the range of 1.2; the first atmosphere condition is an inert atmosphere.
  • the inert atmosphere includes at least one of nitrogen, argon, or helium.
  • the first temperature is 880°C to 1100°C.
  • the first heat treatment time is 5 hours to 20 hours.
  • the manganese-containing oxide includes Mn 3 O 4 .
  • the M1 element includes Al, Nb, Mg, Ti, W, Ga, Zr, Y, V, Sr, Mo, Ru, Ag, Sn, Au, La, Ce, Pr, Nd, Sm , at least one of Gd, Cu, Na, Zn, Fe, Co, Ni, Cr or Ca.
  • the M1 element source includes at least one of CrO 2 , Al 2 O 3 , MgO, TiO 2 or Y 2 O 3 .
  • the manganese-containing oxide and the M1 element source are mixed according to a molar ratio of the M1 element to the Mn element in the range of 0.001-0.1.
  • the lithium source includes at least one of lithium hydroxide, lithium carbonate, lithium acetate, lithium nitrate, or lithium sulfate.
  • step S1 is followed by step S2: mixing the first lithium manganese oxide synthesized in S1 with the M2 element source to obtain a second mixture, and heating the obtained second mixture under a second atmosphere condition and a second temperature.
  • the second heat treatment is performed under the conditions to obtain a second lithium manganese oxide with a coating layer on the surface.
  • the second atmosphere condition is an inert atmosphere.
  • the inert atmosphere includes at least one of nitrogen, argon, or helium.
  • the second heat treatment time is 2 hours to 5 hours. In some embodiments, the second temperature is 200°C to 600°C.
  • the M2 element includes at least one of S, C, B, or F.
  • the present application provides an electrochemical device, which includes a positive electrode that includes the positive electrode material of the first aspect or the positive electrode material prepared according to the preparation method of the second aspect.
  • the present application provides an electrical device, which includes the electrochemical device of the third aspect.
  • Figure 1 is a charge and discharge curve of the lithium ion button battery of Example 1.
  • any lower limit can be combined with any upper limit to form an unexpressed range; and any lower limit can be combined with other lower limits to form an unexpressed range, and likewise any upper limit can be combined with any other upper limit to form an unexpressed range.
  • each individually disclosed point or single value may itself serve as a lower or upper limit in combination with any other point or single value or with other lower or upper limits to form a range not expressly recited.
  • a list of items connected by the terms “at least one of,” “at least one of,” “at least one of,” or other similar terms may mean any combination of the listed items. For example, if items A and B are listed, the phrase “at least one of A and B” means only A; only B; or A and B. In another example, if the items A, B, and C are listed, then 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.
  • the present application provides a cathode material, which includes lithium manganese oxide, wherein the Raman spectrum of the cathode material has a characteristic peak 1 in the range of 401 cm -1 to 410 cm -1 and 598 cm -1 to 611 cm - There is characteristic peak 2 in the range of 1 .
  • characteristic peak 1 is the characteristic peak of the orthorhombic phase in lithium manganese oxide
  • characteristic peak 2 is the characteristic peak of the monoclinic phase in lithium manganese oxide.
  • the orthorhombic phase and monoclinic phase in lithium manganese oxide have a high lithium storage capacity and can provide a high charging capacity, thus greatly increasing the energy density of electrochemical devices;
  • the monoclinic phase Coexist with the orthorhombic phase to form a solid solution, which can improve the structural stability of lithium manganese oxide in the charging state of the electrochemical device.
  • the solid solution formed by the coexistence of the two phases has oxygen vacancies, which can promote the extraction of lithium ions, thereby further improving the lithium manganese oxide.
  • the charge specific capacity of the oxide at the same time, the existence of the orthorhombic phase and monoclinic phase composite phase structure in the lithium manganese oxide can stabilize the structure of Mn and reduce the lattice distortion of the octahedron, improving the performance of the lithium manganese oxide in the highly delithiated state.
  • the stability of the crystal structure can inhibit the dissolution of Mn element and improve the cycle and storage performance of electrochemical devices.
  • the half-peak width of characteristic peak 1 is H1
  • the half-peak width of characteristic peak 2 is H2, which satisfy: H1 ⁇ 25cm -1 and H2 ⁇ 30cm -1 .
  • the half-peak width H1 of characteristic peak 1 and the half-peak width H2 of characteristic peak 2 are within the above range.
  • Both the orthorhombic phase and the monoclinic phase in lithium manganese oxide have high crystal regularity, which can inhibit circulation and storage. Structural phase change, thereby improving the cycle and storage performance of electrochemical devices.
  • H1 is 13cm ⁇ 1 , 14cm ⁇ 1 , 15cm ⁇ 1 , 16cm ⁇ 1 , 17cm ⁇ 1 , 18cm ⁇ 1 , 19cm ⁇ 1 , 20cm ⁇ 1 , 21cm ⁇ 1 , 22cm ⁇ 1 , 23cm ⁇ 1 1 , 24cm -1 , 25cm -1 or a range consisting of any two of these values.
  • H2 is 20cm ⁇ 1 , 21cm ⁇ 1 , 22cm ⁇ 1 , 23cm ⁇ 1 , 24cm ⁇ 1 , 25cm ⁇ 1 , 26cm ⁇ 1 , 27cm ⁇ 1 , 28cm ⁇ 1 , 29cm ⁇ 1 or these values A range consisting of any two of them.
  • the cathode material of the present application includes lithium manganese oxide having both an orthorhombic phase structure and a monoclinic phase structure.
  • the peak area of characteristic peak 1 is S1
  • the peak area of characteristic peak 2 is S2, satisfying: 1 ⁇ S2/S1 ⁇ 5.
  • S2/S1 is 1.1, 1.3, 1.5, 1.7, 2.0, 2.3, 2.5, 2.7, 3.0, 3.3, 3.5, 3.7, 4.0, 4.3, 4.5, 4.7, or any two of these values. scope.
  • S2/S1 is within the above range, there is a large difference in the content of the orthorhombic phase and the monoclinic phase in the lithium manganese oxide, which can synergistically form a solid solution and promote the removal of Li ions from the lithium manganese oxide, thereby further improving the lithium manganese oxide.
  • Charge capacity in grams of oxide.
  • the Raman spectrum of the cathode material has characteristic peak 3 in the range of 270 cm ⁇ 1 to 279 cm ⁇ 1 .
  • the presence of characteristic peak 3 in the Raman spectrum of the cathode material indicates that the monoclinic phase in lithium manganese oxide has a higher crystallographic order, which facilitates the extraction of lithium ions during charging, thereby increasing the charging capacity of the electrochemical device.
  • the half-peak width of characteristic peak 3 is H3, which satisfies: H3 ⁇ 35cm -1 .
  • H3 is 18cm ⁇ 1 , 19cm ⁇ 1 , 20cm ⁇ 1 , 21cm ⁇ 1 , 22cm ⁇ 1 , 23cm ⁇ 1 , 24cm ⁇ 1 , 25cm ⁇ 1 , 26cm ⁇ 1 , 28cm ⁇ 1 , 29cm ⁇ 1 1 , 30cm -1 , 31cm -1 , 32cm -1 , 33cm -1 , 34cm -1 , 35cm -1 or a range consisting of any two of these values.
  • the half-peak width H3 of characteristic peak 3 is within this range.
  • its degree of crystallization is relatively complete and can provide a higher delithiation capacity; on the other hand, the particle size of a single crystal is small, and lithium ions are immobilized in the material.
  • the phase diffusion path is short, which can effectively improve the kinetic performance of lithium deintercalation in the cathode material.
  • the cathode material also includes the M1 element. Based on the molar amount of the Mn element in the cathode material, the molar percentage of the M1 element in the cathode material is a1, which satisfies: 0.1% ⁇ a1 ⁇ 10%, where the M1 element Including Al, Nb, Mg, Ti, W, Ga, Zr, Y, V, Sr, Mo, Ru, Ag, Sn, Au, La, Ce, Pr, Nd, Sm, Gd, Cu, Na, Zn, Fe , at least one of Co, Ni, Cr or Ca.
  • a1 is 0.1%, 0.5%, 1%, 15%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, A range consisting of 7%, 7.5%, 8%, 8.5%, 9%, 9.5%, 10%, or any two of these values.
  • the cathode material further includes Al element.
  • the molar percentage content of the Al element in the cathode material is b1, which satisfies: 0.1% ⁇ b1 ⁇ 10%.
  • b1 is 0.1%, 0.5%, 1%, 15%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, A range consisting of 7%, 7.5%, 8%, 8.5%, 9%, 9.5%, 10%, or any two of these values.
  • the content of the element Al will cause the phase ratio to change. If the content is too high or too low, the intermediate phase of the material will increase, which will increase the grain boundary barriers and reduce the capacity.
  • the molar ratio of Li element and Mn element is c1, which satisfies: 0.9 ⁇ c1 ⁇ 1.2.
  • c1 is a range of 0.91, 0.93, 0.95, 0.97, 0.99, 1.01, 1.03, 1.05, 1.07, 1.09, 1.11, 1.13, 1.15, 1.17, 1.19, or any two of these values.
  • the Li/Mn molar ratio is within the above range, orthorhombic and monoclinic mixed phases can be stably generated and the energy density of the electrochemical device can be improved.
  • the lithium manganese oxide has a lamellar structure.
  • the lamellar structure is conducive to the extraction of Li ions from lithium manganese oxide, thereby increasing the charging capacity of lithium manganese oxide.
  • the lithium manganese oxide includes Li x Mny M1 z O 2 , where 0.9 ⁇ x ⁇ 1.2, 0.9 ⁇ y ⁇ 1, 0 ⁇ z ⁇ 0.1, and M1 includes Al, Nb, Mg, Ti, W, Ga, Zr, W, Y, V, Sr, Mo, Ru, Ag, Sn, Au, La, Ce, Pr, Nd, Sm, Gd, Cu, Na, Zn, Fe, Co, Ni, At least one of Cr or Ca. In some embodiments, 0.9 ⁇ x ⁇ 1.2, 0.9 ⁇ y ⁇ 1, 0.001 ⁇ z ⁇ 0.1.
  • the cathode material further includes a coating layer located on the surface of the cathode material.
  • the coating layer includes the M2 element. Based on the molar amount of the Mn element in the coating layer, the molar percentage of the M2 element in the coating layer is 0.05% to 2%, wherein the M2 element includes at least one of S, C, B or F. In some embodiments, the molar percentage of the M2 element is 0.05%, 0.1%, 0.3%, 0.5%, 0.7%, 0.9%, 1%, 1.3%, 1.5%, 1.7%, 1.9%, 2% or A range consisting of any two of these values.
  • the coating layer on the surface of the cathode material can further inhibit Mn dissolution, thereby improving the cycle and storage performance of the electrochemical device.
  • the cathode material also includes Al element.
  • the cathode material includes a matrix and a coating layer. Based on the molar amount of Mn element in the matrix, the molar percentage content of the Al element in the matrix is d1. Based on the Mn element in the coating layer The molar amount of Al element in the coating layer is d2, which satisfies: d2/d1 ⁇ 1.3.
  • the residual lithium amount of the cathode material is less than or equal to 0.05% based on the mass of the cathode material. In some embodiments, the residual lithium amount of the cathode material is 0.0005%, 0.001%, 0.005%, 0.01%, 0.015%, 0.02%, 0.025%, 0.03%, 0.035%, 0.04%, 0.045%, or any of these values The range composed of both.
  • the cathode material has a pH value of 11 to 12, such as 11.3, 11.5, 11.7, or 11.9.
  • this application provides a method for preparing the cathode material of the first aspect, which includes: S1: mixing a manganese-containing oxide, a lithium source and an optional M1 element source to obtain a first mixture; A mixture is subjected to a first heat treatment under a first atmosphere condition and a first temperature condition to obtain a first lithium manganese oxide; wherein the manganese-containing oxide and the lithium source are based on a lithium-manganese molar ratio Li/Mn of 0.9- Mix within the range of 1.2; the first atmosphere condition is an inert atmosphere.
  • the inert atmosphere includes at least one of nitrogen, argon, or helium.
  • the first temperature is 880°C to 1100°C.
  • the first heat treatment time is 5 hours to 20 hours.
  • the manganese-containing oxide includes Mn 3 O 4 .
  • the M1 element includes Al, Nb, Mg, Ti, W, Ga, Zr, Y, V, Sr, Mo, Ru, Ag, Sn, Au, La, Ce, Pr, Nd, Sm , at least one of Gd, Cu, Na, Zn, Fe, Co, Ni, Cr or Ca.
  • the M1 element source includes at least one of CrO 2 , Al 2 O 3 , MgO, TiO 2 or Y 2 O 3 .
  • the manganese-containing oxide and the M1 element source are mixed according to a molar ratio of the M1 element to the Mn element in the range of 0.001-0.1.
  • the lithium source includes at least one of lithium hydroxide, lithium carbonate, lithium acetate, lithium nitrate, or lithium sulfate.
  • step S1 is followed by step S2: mixing the first lithium manganese oxide synthesized in S1 with the M2 element source to obtain a second mixture, and heating the obtained second mixture under a second atmosphere condition and a second temperature.
  • the second heat treatment is performed under the conditions to obtain a second lithium manganese oxide with a coating layer on the surface.
  • the second atmosphere condition is an inert atmosphere.
  • the inert atmosphere includes at least one of nitrogen, argon, or helium.
  • the second heat treatment time is 2 hours to 5 hours. In some embodiments, the second temperature is 200°C to 600°C.
  • the M2 element includes at least one of S, C, B, or F.
  • the present application provides an electrochemical device, which includes a positive electrode, the positive electrode including a positive electrode active material layer, the positive electrode active material layer including the positive electrode material of the first aspect or the positive electrode prepared according to the preparation method of the second aspect. Material.
  • the positive active material layer further includes a conductive agent and a binder.
  • binders include, but are not limited to: polyvinyl alcohol, hydroxypropyl cellulose, diacetyl cellulose, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinylpyrrolidone, polyurethane, polytetraethylene Vinyl fluoride, polyvinylidene fluoride, styrene-butadiene rubber or acrylic (ester) styrene-butadiene rubber, etc.
  • conductive agents include, but are not limited to, carbon-based materials, metal-based materials, conductive polymers, and mixtures thereof.
  • the carbon-based material is selected from graphite, carbon black, acetylene black, Ketjen black, carbon nanotubes, carbon fibers, graphene, or any combination thereof.
  • the metal-based material is selected from metal powders, metal fibers, copper, nickel, aluminum, or silver.
  • the conductive polymer is a polyphenylene derivative.
  • the positive electrode further includes a positive current collector
  • the positive current collector can be a metal foil or a composite current collector.
  • aluminum foil can be used.
  • the composite current collector can be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, silver alloy, etc.) on a polymer substrate.
  • the electrochemical device of the present application also includes a negative electrode, which includes a negative active material layer and a negative current collector.
  • the negative active material layer includes a negative active material, a conductive agent, and a binder.
  • the negative active material may include a material that reversibly intercalates/deintercalates lithium ions, lithium metal, lithium metal alloy, or transition metal oxide.
  • the negative active material includes at least one of carbon material or silicon material, the carbon material includes at least one of graphite and hard carbon, and the silicon material includes silicon, silicon oxy compound, silicon carbon compound or silicon alloy. of at least one.
  • the adhesive can include various adhesive polymers.
  • the binder includes polyvinylidene fluoride, copolymer of vinylidene fluoride-hexafluoropropylene, polyamide, polyacrylonitrile, polyacrylate, polyacrylic acid, polyacrylate, sodium carboxymethylcellulose , at least one of polyvinylpyrrolidone, polyvinyl ether, polytetrafluoroethylene, polyhexafluoropropylene or styrene-butadiene rubber.
  • the conductive agent can use any conductive material as long as it does not cause chemical changes.
  • the conductive agent includes at least one of conductive carbon black, acetylene black, carbon nanotubes, Ketjen black, carbon fiber, or graphene.
  • the negative electrode current collector may be copper foil, nickel foil, stainless steel foil, titanium foil, nickel foam, copper foam, a polymer substrate coated with conductive metal, or a combination thereof.
  • the electrochemical device of the present application also includes an electrolyte solution, which includes a lithium salt and a non-aqueous solvent.
  • the lithium salt is selected from 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 , LiSiF 6 , LiBOB and lithium difluoroborate can be LiPF 6 .
  • the non-aqueous solvent may be a carbonate compound, a carboxylate compound, an ether compound, other organic solvents, or a combination thereof.
  • the above-mentioned carbonate compound may be a chain carbonate compound, a cyclic carbonate compound, a fluorocarbonate compound, or a combination thereof.
  • Examples of the above chain carbonate compounds are dimethyl carbonate (DMC), diethyl carbonate (DEC), dipropyl carbonate (DPC), methylpropyl carbonate (MPC), ethylpropyl carbonate (EPC), carbonic acid Methyl ethyl ester (MEC) and its combinations.
  • Examples of cyclic carbonate compounds are ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate (BC), vinylethylene carbonate (VEC) and combinations thereof.
  • Examples of fluorocarbonate compounds are fluoroethylene carbonate (FEC), 1,2-difluoroethylene carbonate, 1,1-difluoroethylene carbonate, 1,1,2-trifluoroethylene carbonate.
  • Ethyl ester 1,1,2,2-tetrafluoroethylene carbonate, 1-fluoro-2-methylethylene carbonate, 1-fluoro-1-methylethylene carbonate, 1,2-dicarbonate Fluoro-1-methylethylene carbonate, 1,1,2-trifluoro-2-methylethylene carbonate, trifluoromethylethylene carbonate and combinations thereof.
  • carboxylic acid ester compounds are methyl formate, methyl acetate, ethyl acetate, n-propyl acetate, tert-butyl acetate, methyl propionate, ethyl propionate, propyl propionate, ⁇ -butyrolactone , decanolide, valerolactone, mevalonolactone, caprolactone and combinations thereof.
  • ether compounds examples include dibutyl ether, tetraglyme, diglyme, 1,2-dimethoxyethane, 1,2-diethoxyethane, ethoxymethane Oxyethane, 2-methyltetrahydrofuran, tetrahydrofuran and combinations thereof.
  • organic solvents mentioned above are dimethyl sulfoxide, 1,2-dioxolane, sulfolane, methylsulfolane, 1,3-dimethyl-2-imidazolidinone, N-methyl-2-pyrrolidone, Formamide, dimethylformamide, acetonitrile, trimethyl phosphate, triethyl phosphate, trioctyl phosphate and phosphate esters and combinations thereof.
  • an isolation film is provided between the positive electrode and the negative electrode to prevent short circuit.
  • the material and shape of the isolation film used in the embodiments of the present application are not particularly limited, and it can be any technology disclosed in the prior art.
  • the isolation membrane includes polymers or inorganic substances formed of materials that are stable to the electrolyte of the present application.
  • the isolation film may include a base material layer and a surface treatment layer.
  • the base material layer is a non-woven fabric, film or composite film with a porous structure, and the material of the base material layer includes at least one of polyethylene, polypropylene, polyethylene terephthalate or polyimide.
  • polypropylene porous membrane, polyethylene porous membrane, polypropylene non-woven fabric, polyethylene non-woven fabric or polypropylene-polyethylene-polypropylene porous composite membrane can be used.
  • a surface treatment layer is provided on at least one surface of the base layer.
  • the surface treatment layer may be a polymer layer or an inorganic layer, or may be a layer formed by mixing a polymer and an inorganic layer.
  • the inorganic layer includes inorganic particles and binders.
  • the inorganic particles include aluminum oxide, silicon oxide, magnesium oxide, titanium oxide, hafnium dioxide, tin oxide, ceria, nickel oxide, zinc oxide, calcium oxide, zirconium oxide, oxide At least one of yttrium, silicon carbide, boehmite, aluminum hydroxide, magnesium hydroxide, calcium hydroxide or barium sulfate.
  • Binders include polyvinylidene fluoride, vinylidene fluoride-hexafluoropropylene copolymer, polyamide, polyacrylonitrile, polyacrylate, polyacrylic acid, polyacrylate, polyvinylpyrrolidone, polyvinyl ether, poly At least one of methyl methacrylate, polytetrafluoroethylene or polyhexafluoropropylene.
  • the polymer layer contains a polymer, and the polymer material includes polyamide, polyacrylonitrile, acrylate polymer, polyacrylic acid, polyacrylate, polyvinylpyrrolidone, polyvinyl ether, polyvinylidene fluoride or poly( At least one of vinylidene fluoride-hexafluoropropylene).
  • electrochemical devices of the present application include, but are not limited to: all kinds of primary or secondary batteries.
  • the electrochemical device is a lithium secondary battery.
  • lithium secondary batteries include, but are not limited to: lithium metal secondary batteries, lithium ion secondary batteries, lithium polymer secondary batteries, or lithium ion polymer secondary batteries.
  • the electrical device of the present application can be any device using the electrochemical device of the third aspect of the present application.
  • the electrical devices include, but are not limited to: notebook computers, pen-input computers, mobile computers, e-book players, portable telephones, portable fax machines, portable copiers, portable printers, head-mounted stereos Headphones, video recorders, LCD TVs, portable cleaners, portable CD players, mini discs, transceivers, electronic notepads, calculators, memory cards, portable recorders, radios, backup power supplies, motors, cars, motorcycles, power-assisted bicycles, Bicycles, lighting equipment, toys, game consoles, clocks, power tools, flashlights, cameras, large household batteries or lithium-ion capacitors, etc.
  • Step 1 Place Mn (OOH) in a crucible, raise the temperature to 500°C at a heating rate of 5°C/min in an air atmosphere, and maintain the constant temperature for 4 hours to obtain anhydrous Mn 3 O 4 .
  • Step 2 Weigh anhydrous Mn 3 O 4 and LiOH according to the molar ratio of Li/Mn (see Table 1 for specific ratios), and add additives containing M1 elements at the same time (see Table 1 for the type and amount of additives).
  • Example 20 to 22 The difference between Examples 20 to 22 and Example 1 is that the material surface of Example 1 is further coated with a modified layer.
  • the specific steps are: combining the lithium manganese oxide of Example 1 with nanometer NH 4 F (NH 4 The content of F (the molar ratio of F to Mn is 0.001, 0.03, 0.1 respectively) is mixed in a high-speed mixer for 0.5h, then in a nitrogen atmosphere, the temperature is raised to 450°C at a heating rate of 5°C/min, and the temperature is kept constant. Process for 2h.
  • Example 23 The difference between Example 23 and Example 21 is that the nano NH 4 F was replaced with H 3 BO 3 and mixed in a high-speed mixer for 0.5 h. Then, in a nitrogen atmosphere, the temperature was raised to 280°C at a heating rate of 5°C/min. Treat at constant temperature for 2 hours.
  • Example 24 The difference between Examples 24 to 26 and Example 20 is that the nano NH 4 F is replaced by Al 2 O 3 (the content of Al 2 O 3 , based on the molar ratio of Al to Mn, is 0.03, 0.001, 0.1 respectively)
  • conductive carbon black Super-P
  • binder polyvinylidene fluoride PVDF
  • NMP N-methylpyrrolidone
  • the cathode material powder was placed on the stage and characterized using Horibr hr revolution equipment.
  • the specific parameters are as follows: resolution: ⁇ 2cm -1 ; excitation wavelength: 532nm.
  • Mn element, M1 element and Li element content Use a mixed solvent to dissolve the positive electrode material (for example, 0.4g of positive electrode material uses a mixed solvent of 10ml (nitric acid and hydrochloric acid mixed at a ratio of 1:1) aqua regia and 2ml HF), and adjust the volume to 100mL. Then use ICP-OES (Inductively Coupled Plasma-Optical Emission Spectrometer, equipment model: ICAP6300) to test and determine the content of Mn element, M1 element and Li element in the cathode material.
  • ICP-OES Inductively Coupled Plasma-Optical Emission Spectrometer, equipment model: ICAP6300
  • Content of M2 element and Mn element in the coating layer Use XPS test to obtain the content of M2 element and Mn element in the coating layer on the surface of the cathode material.
  • the lithium-ion button battery is charged with a constant current of 0.1C, up to 4.3V, and then charged with a constant voltage of 4.3V until the current is 0.05C.
  • the first charging capacity of the lithium-ion button battery is recorded, and then charged with 0.1C. Discharge at constant current to 3.0V, and record the first discharge capacity of the lithium-ion button battery.
  • Charging capacity in grams first charging capacity/mass of positive electrode material.
  • First efficiency first discharge capacity/first charge capacity ⁇ 100%.
  • Example 1 and Comparative Examples 1 to 2 From the data of Example 1 and Comparative Examples 1 to 2, it can be seen that when the characteristic peak 1 and the characteristic peak 2 exist simultaneously in the cathode material, it has a high charging capacity, mainly because of the orthogonal lithium manganese oxide.
  • the phase and monoclinic phase are rich in lithium ions.
  • the solid solution formed by the coexistence of the two phases has oxygen vacancies, which can promote the removal of lithium ions, thereby greatly increasing the charging capacity of lithium manganese oxide.
  • the existence of orthorhombic and monoclinic composite phase structures in lithium manganese oxide can stabilize the Mn structure and reduce octahedral lattice distortion, improving the stability of the crystal structure of lithium manganese oxide in the highly delithiated state. This inhibits the dissolution of Mn element and improves its service life under high temperature applications.
  • Example 6 The only difference between Examples 6 to 8 and Example 1 is the Li/Mn molar ratio, and the rest are the same as Example 1.
  • the Li/Mn molar ratio affects the capacity of the cathode material.
  • the Li/Mn molar ratio is in the range of 0.9-1.2, orthorhombic and monoclinic mixed phases can be stably generated and the energy density of the electrochemical device can be improved.
  • Example 9 the only difference between Examples 9 to 12 and Example 1 is the Al content, the rest is the same as Example 1
  • Example 12 From the data of Example 1 to Example 12, it can be seen that when 1 ⁇ S2/S1 ⁇ 1.3, or 2.2 ⁇ S2/S1 ⁇ 5, the lithium ion button battery can have a higher charge specific capacity, and it is possible The reason is that there is a large difference in the content of the orthorhombic phase and the monoclinic phase in lithium manganese oxide, which can synergistically form a solid solution and promote the removal of Li ions from lithium manganese oxide, thereby further increasing the charging capacity of lithium manganese oxide. .

Abstract

正极材料包括锂锰氧化物。正极材料的拉曼光谱在401cm -1至410cm -1的范围内具有特征峰1，在598cm -1至611cm -1的范围内具有特征峰2。正极材料具有高的充电克容量以及优异的结构稳定性，能够在大幅度提升电化学装置的能量密度的基础上，提高电化学装置的循环性能和储存性能。

Description

正极材料、电化学装置和用电装置 技术领域
本申请涉及电池技术领域，具体涉及一种正极材料、电化学装置和用电装置。
背景技术
为了解决全球能源危机、环境污染、气候变化、低碳经济等严峻问题，电动交通工具、大型动力电源及储能领域电源的研发和应用成为必然。
尖晶石LiMn 2O 4及橄榄石型LiFePO 4因成本低，安全可靠性好，作为正极材料被广泛应用于锂离子电池中。但LiMn 2O 4和LiFePO 4材料同时也存在着充放电克容量低，进而使得锂离子电池的能量密度较低的问题。
为了提高上述材料体系锂离子电池的能量密度，现有技术中多采用提高尖晶石LiMn 2O 4材料的Li/Mn比、进行高价态阳离子掺杂或混合三元材料等高能量密度正极材料的方案。但提高材料的Li/Mn比或进行高价态阳离子掺杂会严重恶化锂离子电池的高温循环性能，而混合三元材料等高能量密度正极材料会使得锂离子电池的成本增幅较高。
发明内容
鉴于现有技术存在的上述问题，本申请提供一种正极材料及包括该正极材料的电化学装置，本申请的正极材料具有高的充电克容量以及优异的结构稳定性，进而在大幅度提升电化学装置能量密度的基础上，提高电化学装置的循环和存储性能。
在第一方面，本申请提供一种正极材料，其包括锂锰氧化物，其中，正极材料的拉曼光谱在401cm -1至410cm -1范围内具有特征峰1，在598cm -1至611cm -1范围内具有特征峰2。其中，特征峰1为锂锰氧化物中正交相的特征峰，特征峰2为锂锰氧化物中单斜相的特征峰。一方面，锂锰氧化物中的正交相和单斜相具有较高的储锂容量，能够提供较高的充电克容量，从而大幅提升电化学装置的能量密度；另一方面，单斜相与正交相共存，形成固溶体，能够提升锂锰氧化物在电化学装置充电状态下的结构稳定性，两相共存形成的固溶体存在氧空位，能够促进锂离子的脱出，从而能够进一步提升锂锰氧化物的充电克容量；同时，锂锰氧化物中正交相和单斜相复合相结构的存在能够稳定Mn的结构和减少八 面体的晶格畸变，提高锂锰氧化物在高脱锂态的晶体结构的稳定性，从而抑制Mn元素的溶出，改善电化学装置的循环和存储性能。
在一些实施方式中，特征峰1的半峰宽为H1，特征峰2的半峰宽为H2，满足：H1≤25cm -1、H2≤30cm -1。特征峰1的半峰宽H1和特征峰2的半峰宽H2在上述范围内，锂锰氧化物中的正交相和单斜相均具有较高的结晶规整度，能够抑制循环和存储时的结构相变，从而提高电化学装置的循环和存储性能。
在一些实施方式中，特征峰1的峰面积为S1，特征峰2的峰面积为S2，满足：1≤S2/S1≤5。
在一些实施方式中，1≤S2/S1≤1.3，或2.2≤S2/S1≤5。S2/S1在上述范围时，锂锰氧化物中正交相与单斜相的含量存在较大差异，能够协同作用形成固溶体，促进锂锰氧化物中Li离子的脱出，从而进一步提升锂锰氧化物的充电克容量。
在一些实施方式中，正极材料的拉曼光谱在270cm -1至279cm -1范围内具有特征峰3。正极材料的拉曼光谱存在特征峰3表明锂锰氧化物中单斜相的结晶有序性较高，从而利于充电时锂离子的脱出，进而提高电化学装置的充电容量。
在一些实施方式中，特征峰3的半峰宽为H3，满足：H3≤35cm -1。特征峰3的半峰宽H3在该范围内，一方面，其结晶程度较为完整，可以提供较高的脱锂容量；另一方面，单个晶体的粒径较小，锂离子在材料中的固相扩散路径较短，能够有效提升正极材料脱嵌锂的动力学性能。
在一些实施方式中，正极材料还包括M1元素，基于正极材料中Mn元素的摩尔量，正极材料中M1元素的摩尔百分含量为a1，满足：0.1％≤a1≤10％，其中，M1元素包括Al、Nb、Mg、Ti、W、Ga、Zr、Y、V、Sr、Mo、Ru、Ag、Sn、Au、La、Ce、Pr、Nd、Sm、Gd、Cu、Na、Zn、Fe、Co、Ni、Cr或Ca中的至少一种。
在一些实施方式中，正极材料还包括Al元素，基于正极材料中Mn元素的摩尔量，正极材料中Al元素的摩尔百分含量为b1，满足：0.1％≤b1≤10％。元素Al的含量会导致相比例发生改变，含量过高或过低都会导致材料中间相增多，进而使得晶界壁垒增多，导致容量降低。
在一些实施方式中，正极材料中，Li元素和Mn元素的摩尔比为c1，满足：0.9≤c1≤1.2。Li/Mn摩尔比在上述范围内，可以稳定的生成正交和单斜混合相，提升电化学装置的能量密度。
在一些实施方式中，所述锂锰氧化物具有片层状结构。片层状结构有利于锂锰氧化物 中Li离子的脱出，从而提升锂锰氧化物的充电克容量。
在一些实施方式中，所述锂锰氧化物包括Li xMn yM1 zO 2，其中，0.9≤x≤1.2，0.9≤y≤1，0≤z≤0.1，M1包括Al、Nb、Mg、Ti、W、Ga、Zr、W、Y、V、Sr、Mo、Ru、Ag、Sn、Au、La、Ce、Pr、Nd、Sm、Gd、Cu、Na、Zn、Fe、Co、Ni、Cr或Ca中的至少一种。在一些实施方式中，0.9≤x≤1.2，0.9≤y≤1，0.001≤z≤0.1。
在一些实施方式中，正极材料还包括位于正极材料表面的包覆层，该包覆层包括M2元素，基于包覆层中Mn元素的摩尔量，包覆层中M2元素的摩尔百分含量为0.05％至2％，其中，M2元素包括S、C、B或F中的至少一种。正极材料表面的包覆层可以进一步抑制Mn溶出，进而提高电化学装置的循环和存储性能。
在一些实施方式中，正极材料还包括Al元素，正极材料包括基体和包覆层，基于基体中Mn元素的摩尔量，基体中Al元素的摩尔百分含量为d1，基于包覆层中Mn元素的摩尔量，包覆层中Al元素的摩尔百分含量为d2，满足：d2/d1≥1.3。
在一些实施方式中，基于正极材料的质量，正极材料的残锂量小于或等于0.05％。
在一些实施方式中，正极材料的pH值为11至12。
在第二方面，本申请提供了第一方面的正极材料的制备方法，其包括：S1：将含锰氧化物、锂源和可选的M1元素源进行混合得到第一混合物；将得到的第一混合物在第一气氛条件以及第一温度条件下进行第一热处理，得到第一锂锰氧化物；其中，所述含锰氧化物和所述锂源按照锂锰摩尔比Li/Mn为0.9-1.2的范围进行混合；所述第一气氛条件为惰性气氛。
在一些实施例中，所述惰性气氛包括氮气、氩气或氦气中的至少一种。
在一些实施方式中，第一温度为880℃至1100℃。
在一些实施方式中，所述第一热处理时间为5小时至20小时。
在一些实施方式中，所述含锰氧化物包括Mn 3O 4。
在一些实施方式中，所述M1元素包括Al、Nb、Mg、Ti、W、Ga、Zr、Y、V、Sr、Mo、Ru、Ag、Sn、Au、La、Ce、Pr、Nd、Sm、Gd、Cu、Na、Zn、Fe、Co、Ni、Cr或Ca中的至少一种。
在一些实施方式中，所述M1元素源包括CrO 2、Al 2O 3、MgO、TiO 2或Y 2O 3中的至少一种。
在一些实施方式中，所述含锰氧化物和所述M1元素源按照所述M1元素与Mn元素的摩尔比为0.001-0.1的范围进行混合。
在一些实施方式中，所述锂源包括氢氧化锂、碳酸锂、乙酸锂、硝酸锂或硫酸锂中的至少一种。
在一些实施方式中，步骤S1之后还包括步骤S2：将S1合成的第一锂锰氧化物与M2元素源进行混合得到第二混合物，将得到的第二混合物在第二气氛条件以及第二温度条件下进行第二热处理，得到表面具有包覆层的第二锂锰氧化物。
在一些实施方式中，所述第二气氛条件为惰性气氛。在一些实施例中，所述惰性气氛包括氮气、氩气或氦气中的至少一种。
在一些实施方式中，所述第二热处理时间为2小时至5小时。在一些实施方式中，第二温度为200℃至600℃。
在一些实施方式中，所述M2元素包括S、C、B或F中的至少一种。
在第三方面，本申请提供一种电化学装置，其包括正极，该正极包括第一方面的正极材料或根据第二方面的制备方法所制备的正极材料。
在第四方面，本申请提供一种用电装置，其包括第三方面的电化学装置。
附图说明
图1为实施例1的锂离子扣式电池的充放电曲线图。
具体实施方式
为使本申请的目的、技术方案和优点更加清楚，下面将结合实施例对本申请的技术方案进行清楚、完整地描述，显然，所描述的实施例是本申请一部分实施例，而不是全部的实施例。在此所描述的有关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。
为了简明，本文仅具体地公开了一些数值范围。然而，任意下限可以与任何上限组合形成未明确记载的范围；以及任意下限可以与其它下限组合形成未明确记载的范围，同样任意上限可以与任意其它上限组合形成未明确记载的范围。此外，每个单独公开的点或单个数值自身可以作为下限或上限与任意其它点或单个数值组合或与其它下限或上限组合形成未明确记载的范围。
在本文的描述中，除非另有说明，“以上”、“以下”包含本数。
除非另有说明，本申请中使用的术语具有本领域技术人员通常所理解的公知含义。 除非另有说明，本申请中提到的各参数的数值可以用本领域常用的各种测量方法进行测量(例如，可以按照在本申请的实施例中给出的方法进行测试)。
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可包含单个组分或多个组分。项目B可包含单个组分或多个组分。项目C可包含单个组分或多个组分。
在第一方面，本申请提供一种正极材料，其包括锂锰氧化物，其中，正极材料的拉曼光谱在401cm -1至410cm -1范围内具有特征峰1，在598cm -1至611cm -1范围内具有特征峰2。其中，特征峰1为锂锰氧化物中正交相的特征峰，特征峰2为锂锰氧化物中单斜相的特征峰。一方面，锂锰氧化物中的正交相和单斜相具有较高的储锂容量，能够提供较高的充电克容量，从而大幅提升电化学装置的能量密度；另一方面，单斜相与正交相共存，形成固溶体，能够提升锂锰氧化物在电化学装置充电状态下的结构稳定性，两相共存形成的固溶体存在氧空位，能够促进锂离子的脱出，从而能够进一步提升锂锰氧化物的充电比容量；同时，锂锰氧化物中正交相和单斜相复合相结构的存在能够稳定Mn的结构和减少八面体的晶格畸变，提高锂锰氧化物在高脱锂态的晶体结构的稳定性，从而抑制Mn元素的溶出，改善电化学装置的循环和存储性能。
在一些实施方式中，特征峰1的半峰宽为H1，特征峰2的半峰宽为H2，满足：H1≤25cm -1、H2≤30cm -1。特征峰1的半峰宽H1和特征峰2的半峰宽H2在上述范围内，锂锰氧化物中的正交相和单斜相均具有较高的结晶规整度，能够抑制循环和存储时的结构相变，从而提高电化学装置的循环和存储性能。在一些实施方式中，H1为13cm -1、14cm - 1、15cm -1、16cm -1、17cm -1、18cm -1、19cm -1、20cm -1、21cm -1、22cm -1、23cm -1、24cm -1、25cm -1或这些值中任意两者组成的范围。在一些实施方式中，H2为20cm -1、21cm -1、22cm - 1、23cm -1、24cm -1、25cm -1、26cm -1、27cm -1、28cm -1、29cm -1或这些值中任意两者组成的范围。
在一些实施方式中，本申请的正极材料包括同时具有正交相结构和单斜相结构的锂锰氧化物。
在一些实施方式中，特征峰1的峰面积为S1，特征峰2的峰面积为S2，满足：1≤ S2/S1≤5。在一些实施方式中，S2/S1为1.1、1.3、1.5、1.7、2.0、2.3、2.5、2.7、3.0、3.3、3.5、3.7、4.0、4.3、4.5、4.7或这些值中任意两者组成的范围。
在一些实施方式中，1≤S2/S1≤1.3，或2.2≤S2/S1≤5。S2/S1在上述范围内时，锂锰氧化物中正交相与单斜相的含量存在较大差异，能够协同作用形成固溶体，促进锂锰氧化物中Li离子的脱出，从而进一步提升锂锰氧化物的充电克容量。
在一些实施方式中，正极材料的拉曼光谱在270cm -1至279cm -1范围内具有特征峰3。正极材料的拉曼光谱存在特征峰3表明锂锰氧化物中单斜相的结晶有序性较高，从而利于充电时锂离子的脱出，进而提高电化学装置的充电容量。
在一些实施方式中，特征峰3的半峰宽为H3，满足：H3≤35cm -1。在一些实施方式中，H3为18cm -1、19cm -1、20cm -1、21cm -1、22cm -1、23cm -1、24cm -1、25cm -1、26cm -1、28cm -1、29cm -1、30cm -1、31cm -1、32cm -1、33cm -1、34cm -1、35cm -1或这些值中任意两者组成的范围。特征峰3的半峰宽H3在该范围内，一方面，其结晶程度较为完整，可以提供较高的脱锂容量；另一方面，单个晶体的粒径较小，锂离子在材料中的固相扩散路径较短，能够有效提升正极材料脱嵌锂的动力学性能。
在一些实施方式中，正极材料还包括M1元素，基于正极材料中Mn元素的摩尔量，正极材料中M1元素的摩尔百分含量为a1，满足：0.1％≤a1≤10％，其中，M1元素包括Al、Nb、Mg、Ti、W、Ga、Zr、Y、V、Sr、Mo、Ru、Ag、Sn、Au、La、Ce、Pr、Nd、Sm、Gd、Cu、Na、Zn、Fe、Co、Ni、Cr或Ca中的至少一种。在一些实施方式中，a1为0.1％、0.5％、1％、15％、2％、2.5％、3％、3.5％、4％、4.5％、5％、5.5％、6％、6.5％、7％、7.5％、8％、8.5％、9％、9.5％、10％或这些值中任意两者组成的范围。
在一些实施方式中，正极材料还包括Al元素，基于正极材料中Mn元素的摩尔量，正极材料中Al元素的摩尔百分含量为b1，满足：0.1％≤b1≤10％。在一些实施方式中，b1为0.1％、0.5％、1％、15％、2％、2.5％、3％、3.5％、4％、4.5％、5％、5.5％、6％、6.5％、7％、7.5％、8％、8.5％、9％、9.5％、10％或这些值中任意两者组成的范围。元素Al的含量会导致相比例发生改变，含量过高或过低都会导致材料中间相增多，进而使得晶界壁垒增多，导致容量降低。
在一些实施方式中，正极材料中，Li元素和Mn元素的摩尔比为c1，满足：0.9≤c1≤1.2。在一些实施方式中，c1为0.91、0.93、0.95、0.97、0.99、1.01、1.03、1.05、1.07、1.09、1.11、1.13、1.15、1.17、1.19或这些值中任意两者组成的范围。Li/Mn摩尔比在上述范围内，可以稳定的生成正交和单斜混合相，提升电化学装置的能量密度。
在一些实施方式中，所述锂锰氧化物具有片层状结构。片层状结构有利于锂锰氧化物中Li离子的脱出，从而提升锂锰氧化物的充电克容量。
在一些实施方式中，所述锂锰氧化物包括Li xMn yM1 zO 2，其中，0.9≤x≤1.2，0.9≤y≤1，0≤z≤0.1，M1包括Al、Nb、Mg、Ti、W、Ga、Zr、W、Y、V、Sr、Mo、Ru、Ag、Sn、Au、La、Ce、Pr、Nd、Sm、Gd、Cu、Na、Zn、Fe、Co、Ni、Cr或Ca中的至少一种。在一些实施方式中，0.9≤x≤1.2，0.9≤y≤1，0.001≤z≤0.1。
在一些实施方式中，正极材料还包括位于正极材料表面的包覆层，该包覆层包括M2元素，基于包覆层中Mn元素的摩尔量，包覆层中M2元素的摩尔百分含量为0.05％至2％，其中，M2元素包括S、C、B或F中的至少一种。在一些实施方式中，M2元素的摩尔百分含量为0.05％、0.1％、0.3％、0.5％、0.7％、0.9％、1％、1.3％、1.5％、1.7％、1.9％、2％或这些值中任意两者组成的范围。正极材料表面的包覆层可以进一步抑制Mn溶出，进而提高电化学装置的循环和存储性能。
在一些实施方式中，正极材料还包括Al元素，正极材料包括基体和包覆层，基于基体中Mn元素的摩尔量，基体中Al元素的摩尔百分含量为d1，基于包覆层中Mn元素的摩尔量，包覆层中Al元素的摩尔百分含量为d2，满足：d2/d1≥1.3。
在一些实施方式中，基于正极材料的质量，正极材料的残锂量小于或等于0.05％。在一些实施方式中，正极材料的残锂量为0.0005％、0.001％、0.005％、0.01％、0.015％、0.02％、0.025％、0.03％、0.035％、0.04％、0.045％或这些值中任意两者组成的范围。
在一些实施方式中，正极材料的pH值为11至12，例如11.3、11.5、11.7或11.9。
在第二方面，本申请提供了第一方面的正极材料的制备方法，其包括：S1：将含锰氧化物、锂源和可选的M1元素源进行混合得到第一混合物；将得到的第一混合物在第一气氛条件以及第一温度条件下进行第一热处理，得到第一锂锰氧化物；其中，所述含锰氧化物和所述锂源按照锂锰摩尔比Li/Mn为0.9-1.2的范围进行混合；所述第一气氛条件为惰性气氛。
在一些实施例中，所述惰性气氛包括氮气、氩气或氦气中的至少一种。
在一些实施方式中，第一温度为880℃至1100℃。
在一些实施方式中，所述第一热处理时间为5小时至20小时。
在一些实施方式中，所述含锰氧化物包括Mn 3O 4。
在一些实施方式中，所述M1元素包括Al、Nb、Mg、Ti、W、Ga、Zr、Y、V、Sr、Mo、Ru、Ag、Sn、Au、La、Ce、Pr、Nd、Sm、Gd、Cu、Na、Zn、Fe、Co、Ni、Cr或 Ca中的至少一种。
在一些实施方式中，所述M1元素源包括CrO 2、Al 2O 3、MgO、TiO 2或Y 2O 3中的至少一种。
在一些实施方式中，所述含锰氧化物和所述M1元素源按照所述M1元素与Mn元素的摩尔比为0.001-0.1的范围进行混合。
在一些实施方式中，所述锂源包括氢氧化锂、碳酸锂、乙酸锂、硝酸锂或硫酸锂中的至少一种。
在一些实施方式中，步骤S1之后还包括步骤S2：将S1合成的第一锂锰氧化物与M2元素源进行混合得到第二混合物，将得到的第二混合物在第二气氛条件以及第二温度条件下进行第二热处理，得到表面具有包覆层的第二锂锰氧化物。
在一些实施方式中，所述第二气氛条件为惰性气氛。在一些实施例中，所述惰性气氛包括氮气、氩气或氦气中的至少一种。
在一些实施方式中，所述第二热处理时间为2小时至5小时。在一些实施方式中，第二温度为200℃至600℃。
在一些实施方式中，所述M2元素包括S、C、B或F中的至少一种。
在第三方面，本申请提供一种电化学装置，其包括正极，该正极包括正极活性材料层，该正极活性材料层包括第一方面的正极材料或根据第二方面的制备方法所制备的正极材料。
在一些实施方式中，正极活性材料层还包括导电剂和粘结剂。在一些实施例中，粘合剂包括，但不限于：聚乙烯醇、羟丙基纤维素、二乙酰基纤维素、聚氯乙烯、羧化的聚氯乙烯、聚乙烯吡咯烷酮、聚氨酯、聚四氟乙烯、聚偏氟乙烯、丁苯橡胶或丙烯酸(酯)化的丁苯橡胶等。在一些实施例中，导电剂包括，但不限于：基于碳的材料、基于金属的材料、导电聚合物和它们的混合物。在一些实施例中，基于碳的材料选自石墨、碳黑、乙炔黑、科琴黑、碳纳米管、碳纤维、石墨烯或其任意组合。在一些实施例中，基于金属的材料选自金属粉、金属纤维、铜、镍、铝或银。在一些实施例中，导电聚合物为聚亚苯基衍生物。
在一些实施方式中，正极还包括正极集流体，该正极集流体可以采用金属箔片或复合集流体。例如，可以使用铝箔。复合集流体可以通过将金属材料(铜、铜合金、镍、镍合金、钛、钛合金、银及银合金等)形成在高分子基材上而形成。
本申请的电化学装置还包括负极，该负极包括负极活性材料层和负极集流体。
在一些实施方式中，负极活性材料层包括负极活性材料、导电剂和粘结剂。在一些实施方式中，负极活性材料可以包括可逆地嵌入/脱嵌锂离子的材料、锂金属、锂金属合金或过渡金属氧化物。在一些实施方式中，负极活性材料包括碳材料或硅材料中的至少一种，碳材料包括石墨、硬碳中的至少一种，硅材料包括硅、硅氧化合物、硅碳化合物或硅合金中的至少一种。在一些实施例中，该粘合剂可以包括各种粘合剂聚合物。在一些实施方式中，粘结剂包括聚偏氟乙烯、偏氟乙烯-六氟丙烯的共聚物、聚酰胺、聚丙烯腈、聚丙烯酸酯、聚丙烯酸、聚丙烯酸盐、羧甲基纤维素钠、聚乙烯吡咯烷酮、聚乙烯醚、聚四氟乙烯、聚六氟丙烯或丁苯橡胶中的至少一种。在一些实施例中，导电剂可以使用任何导电的材料，只要它不引起化学变化即可。在一些实施方式中，导电剂包括导电炭黑、乙炔黑、碳纳米管、科琴黑、碳纤维或石墨烯中的至少一种。
在一些实施方式中，负极集流体可以为铜箔、镍箔、不锈钢箔、钛箔、泡沫镍、泡沫铜、包覆有导电金属的聚合物基板或它们的组合。
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。
在本申请一些实施方案中，锂盐选自LiPF 6、LiBF 4、LiAsF 6、LiClO 4、LiB(C 6H 5) 4、LiCH 3SO 3、LiCF 3SO 3、LiN(SO 2CF 3) 2、LiC(SO 2CF 3) 3、LiSiF 6、LiBOB和二氟硼酸锂中的一种或多种。举例来说，锂盐可以选用LiPF 6。
非水溶剂可为碳酸酯化合物、羧酸酯化合物、醚化合物、其它有机溶剂或它们的组合。
上述碳酸酯化合物可为链状碳酸酯化合物、环状碳酸酯化合物、氟代碳酸酯化合物或其组合。
上述链状碳酸酯化合物的实例为碳酸二甲酯(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)、碳酸甲乙酯(MEC)及其组合。环状碳酸酯化合物的实例为碳酸亚乙酯(EC)、碳酸亚丙酯(PC)、碳酸亚丁酯(BC)、碳酸乙烯基亚乙酯(VEC)及其组合。氟代碳酸酯化合物的实例为碳酸氟代亚乙酯(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、碳酸三氟甲基亚乙酯及其组合。
上述羧酸酯化合物的实例为甲酸甲酯、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、甲瓦龙酸内酯、己内酯及其组合。
上述醚化合物的实例为二丁醚、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、乙氧基甲氧基乙烷、2-甲基四氢呋喃、四氢呋喃及其组合。
上述其它有机溶剂的实例为二甲亚砜、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、甲酰胺、二甲基甲酰胺、乙腈、磷酸三甲酯、磷酸三乙酯、磷酸三辛酯和磷酸酯及其组合。
在一些实施方式中，该电化学装置中，正极与负极之间设有隔离膜以防止短路。本申请的实施例中使用的隔离膜的材料和形状没有特别限制，其可为任何现有技术中公开的技术。在一些实施例中，隔离膜包括由对本申请的电解液稳定的材料形成的聚合物或无机物等。例如，隔离膜可包括基材层和表面处理层。基材层为具有多孔结构的无纺布、膜或复合膜，基材层的材料包括聚乙烯、聚丙烯、聚对苯二甲酸乙二醇酯或聚酰亚胺中的至少一种。具体地，可选用聚丙烯多孔膜、聚乙烯多孔膜、聚丙烯无纺布、聚乙烯无纺布或聚丙烯-聚乙烯-聚丙烯多孔复合膜。基材层的至少一个表面上设置有表面处理层，表面处理层可以是聚合物层或无机物层，也可以是混合聚合物与无机物所形成的层。无机物层包括无机颗粒和粘结剂，无机颗粒包括氧化铝、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、聚丙烯酸酯、聚丙烯酸、聚丙烯酸盐、聚乙烯呲咯烷酮、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。聚合物层中包含聚合物，聚合物的材料包括聚酰胺、聚丙烯腈、丙烯酸酯聚合物、聚丙烯酸、聚丙烯酸盐、聚乙烯呲咯烷酮、聚乙烯醚、聚偏氟乙烯或聚(偏氟乙烯-六氟丙烯)中的至少一种。
在一些实施方式中，本申请的电化学装置包括，但不限于：所有种类的一次电池或二次电池。在一些实施例中，所述电化学装置是锂二次电池。在一些实施例中，锂二次电池包括，但不限于：锂金属二次电池、锂离子二次电池、锂聚合物二次电池或锂离子聚合物二次电池。
第四方面，本申请的用电装置可为任何使用本申请第三方面的电化学装置的装置。
在一些实施例中，所述用电装置包括，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、家庭用大型蓄电池或锂离子电容器等。
实施例及对比例
1、正极材料的制备
对比例1
按照Li:Mn摩尔比为0.56:1的比例称取Li 2CO 3、MnO 2，按照Al:Mn摩尔比为0.03的比例加入Al 2O 3，在高速混合机中以转速300r/min混合20min得到混合物，将混合物置于空气窑炉中，以5℃/min升温至790℃，保持24h，自然冷却后取出，过300目筛后得到尖晶石型锰酸锂。
对比例2
传统方法：将Mn 2O 3与Na 2CO 3按照Na:Mn摩尔比为1.05:1混合均匀后，在N 2气氛中，以5℃/min的升温速率升温至800℃并保持恒温24h，得到NaMnO 2；按照LiBr:NaMnO 2摩尔比为10：1加入浓度为5mol/L的LiBr乙醇溶液，在空气气氛下，180℃下交换8h，完成后用乙醇洗涤，洗涤后将粉末置于120℃烘箱中干燥5h，得到传统方法的锂锰氧化物。
实施例1至实施例19
步骤1、将Mn(OOH)放置在坩埚中，在空气气氛下，以5℃/min的升温速率升温至500℃并保持恒温4h，得到无水Mn 3O 4。
步骤2、将无水Mn 3O 4与LiOH按照Li/Mn的摩尔比例(具体比例见表1)进行称取，同时加入包含M1元素的添加剂(添加剂的种类与添加量见表1)，使用机械球磨设备混合8h，得到混合物。将上述混合物放置在坩埚中，以2m 3/h的速度通入氮气，以5℃/min的升温速率升温至烧结温度恒温烧结一段时间(具体烧结温度与时间见表1)，自然冷却至室温，得到片层状锂锰氧化物LiMnO 2正极材料。
表1
Figure PCTCN2022102822-appb-000001
Figure PCTCN2022102822-appb-000002
实施例20至实施例26
实施例20至实施例22与实施例1的区别在于：在实施例1的材料表面进一步包覆改性层，具体的步骤为：将实施例1的锂锰氧化物与纳米NH 4F(NH 4F的含量，以F相对于Mn的摩尔比分别为0.001，0.03，0.1)在高速混合机中混合0.5h后，在氮气气氛下，用5℃/min的升温速率升至450℃，恒温处理2h。
实施例23与实施例21的区别在于：将纳米NH 4F更换为H 3BO 3在高速混合机中混合0.5h后，在氮气气氛下，用5℃/min的升温速率升至280℃，恒温处理2h。
实施例24至实施例26与实施例20的区别在于：将纳米NH 4F更换为Al 2O 3(Al 2O 3的含量，以Al相对于Mn的摩尔比分别为0.03，0.001，0.1)在高速混合机中混合0.5h，后在氮气气氛下，用5℃/min的升温速率升至600℃，恒温处理2h。
2、锂离子扣式电池的制备
将上述正极材料与导电炭黑(Super-P)、粘结剂聚偏氟乙烯(PVDF)按照重量比90∶5：5在N-甲基吡咯烷酮(NMP)溶剂体系中充分搅拌混合均匀后，涂覆于铝箔上，控制涂布质量为10mg/cm 2至30mg/cm 2，经105℃烘干、冷压，冲片得到正极极片。
将正极极片、隔离膜、金属锂片按顺序置于扣式电池钢壳中，滴入适量电解液(1M LiPF 6，EC：EMC：DEC体积比为1:1:1)，密封后得到扣式电池。
测试方法
1.拉曼测试
将正极材料粉末置于载物台上，采用Horibr hr revolution设备进行表征。具体参数如下：分辨率：～2cm -1；激发波长：532nm。
2.元素含量测试
Mn元素、M1元素和Li元素含量：使用混合溶剂溶解正极材料(例如，0.4g正极材料使用10ml(硝酸与盐酸按照1：1混合)王水与2ml HF的混合溶剂)，定容至100mL，然后使用ICP-OES(电感耦合等离子-发射光谱仪，设备型号：ICAP6300)测试确定正极材料中Mn元素、M1元素和Li元素的含量。
包覆层中M2元素和Mn元素含量：采用XPS测试获得正极材料表面的包覆层中M2元素和Mn元素的含量。
包覆层和基体中Al元素和Mn元素含量：采用TEM-EDS测试获得正极材料基体和包覆层中Al元素和Mn元素的含量。
3.正极材料残锂量测试
采用酸碱滴定法，用盐酸标准溶液滴定正极材料中的碳酸锂和氢氧化锂。仪器型号：905Titrando电位滴定仪；试剂：0.05mol/L HCl溶液。
4.克容量和首次库伦效率测试
在45℃的环境中，锂离子扣式电池采用0.1C恒流充电，截至4.3V，然后4.3V恒压充电至电流为0.05C，记录锂离子扣式电池的首次充电容量，再采用0.1C恒流放电至3.0V，计录锂离子扣式电池的首次放电容量。
充电克容量＝首次充电容量/正极材料质量。
首次效率＝首次放电容量/首次充电容量×100％。
5.Mn元素溶出量测试
在25℃的环境中，将锂离子扣式电池采用0.1C恒流充电至4V，然后拆解取正极极片，将正极极片浸泡于电解液(1M LiPF 6，EC：EMC：DEC体积比为1:1:1)中，60℃浸泡7天。采用ICP测试电解液中的Mn元素含量，电解液中的Mn元素含量/正极材料质量，即为Mn元素溶出量。
测试结果
Figure PCTCN2022102822-appb-000003
从实施例1与对比例1至对比例2的数据可以看出，正极材料中同时存在特征峰1和特征峰2时，具有高的充电克容量，主要是因为锂锰氧化物中的正交相和单斜相富含锂离子，同时，两相共存形成的固溶体存在氧空位，能够促进锂离子的脱出，从而能够大幅提升锂锰氧化物的充电克容量。同时，锂锰氧化物中正交相和单斜相复合相结构的存在能够稳定Mn的结构和减少八面体的晶格畸变，提高锂锰氧化物在高脱锂态的晶体结构的稳定性，从而抑制Mn元素的溶出，改善其在高温工况应用下的使用寿命。
表3
Figure PCTCN2022102822-appb-000004
注：实施例6至实施例8与实施例1的区别仅在于Li/Mn摩尔比，其余与实施例1相同
从实施例1与实施例6至实施例8的数据可以看出，Li/Mn摩尔比会影响正极材料的容量。Li/Mn摩尔比在0.9-1.2范围内，可以稳定的生成正交和单斜混合相，提升电化学装置的能量密度。
表4
Figure PCTCN2022102822-appb-000005
注：实施例9至实施例12与实施例1的区别仅在于Al含量，其余与实施例1相同
从实施例1至实施例12的数据可以看出，当满足1≤S2/S1≤1.3，或2.2≤S2/S1≤5时，锂离子扣式电池能够具有更高的充电比容量，可能的原因在于，锂锰氧化物中正交相与单斜相的含量存在较大差异，能够协同作用形成固溶体，促进锂锰氧化物中Li离子的脱出，从而进一步提升锂锰氧化物的充电克容量。
Figure PCTCN2022102822-appb-000006
Figure PCTCN2022102822-appb-000007
从实施例1与实施例20至实施例26的数据可以看出，采用包覆层包覆后，能够明显改善Mn溶出。
虽然已经说明和描述了本申请的一些示例性实施方式，然而本申请不限于所公开的实施方式。相反，本领域普通技术人员将认识到，在不脱离如所附权利要求中描述的本申请的精神和范围的情况下，可对所描述的实施方式进行一些修饰和改变。

Claims (14)

  1. 一种正极材料，其包括锂锰氧化物，其中，所述正极材料的拉曼光谱在401cm -1至410cm -1范围内具有特征峰1，在598cm -1至611cm -1范围内具有特征峰2。
  2. 根据权利要求1所述的正极材料，其中，所述正极材料满足如下条件(1)至(2)中的至少一者：
    (1)所述特征峰1的半峰宽为H1，所述特征峰2的半峰宽为H2，满足：H1≤25cm - 1、H2≤30cm -1；
    (2)所述特征峰1的峰面积为S1，所述特征峰2的峰面积为S2，满足：1≤S2/S1≤5。
  3. 根据权利要求2所述的正极材料，其中，1≤S2/S1≤1.3，或2.2≤S2/S1≤5。
  4. 根据权利要求1所述的正极材料，其中，所述正极材料的拉曼光谱在270cm -1至279cm -1范围内具有特征峰3。
  5. 根据权利要求4所述的正极材料，其中，所述特征峰3的半峰宽为H3，满足：H3≤35cm -1。
  6. 根据权利要求1所述的正极材料，其中，所述正极材料满足如下条件(a)至(e)中的至少一者：
    (a)所述正极材料还包括M1元素，基于所述正极材料中Mn元素的摩尔量，所述正极材料中M1元素的摩尔百分含量为a1，满足：0.1％≤a1≤10％，其中，所述M1元素包括Al、Nb、Mg、Ti、W、Ga、Zr、W、Y、V、Sr、Mo、Ru、Ag、Sn、Au、La、Ce、Pr、Nd、Sm、Gd、Cu、Na、Zn、Fe、Co、Ni、Cr或Ca中的至少一种；
    (b)所述正极材料还包括Al元素，基于所述正极材料中Mn元素的摩尔量，所述正极材料中Al元素的摩尔百分含量为b1，满足：0.1％≤b1≤10％；
    (c)所述正极材料中，Li元素和Mn元素的摩尔比为c1，满足：0.9≤c1≤1.2；
    (d)所述锂锰氧化物具有片层状结构；
    (e)所述锂锰氧化物包括Li xMn yM1 zO 2，其中，0.9≤x≤1.2，0.9≤y≤1，0≤z≤0.1，M1包括Al、Nb、Mg、Ti、W、Ga、Zr、W、Y、V、Sr、Mo、Ru、Ag、Sn、Au、La、Ce、Pr、Nd、Sm、Gd、Cu、Na、Zn、Fe、Co、Ni、Cr或Ca中的至少一种。
  7. 根据权利要求1所述的正极材料，其中，所述正极材料还包括位于所述正极材料表面的包覆层，所述包覆层包括M2元素，基于所述包覆层中Mn元素的摩尔量，所述包覆层中M2元素的摩尔百分含量为0.05％至2％，其中，所述M2元素包括S、C、B或F 中的至少一种。
  8. 根据权利要求1所述的正极材料，其中，所述正极材料还包括Al元素，所述正极材料包括基体和包覆层，基于所述基体中Mn元素的摩尔量，所述基体中Al元素的摩尔百分含量为d1，基于所述包覆层中Mn元素的摩尔量，所述包覆层中Al元素的摩尔百分含量为d2，满足：d2/d1≥1.3。
  9. 根据权利要求1所述的正极材料，其中，基于所述正极材料的质量，所述正极材料的残锂量小于或等于0.05％；
    和/或所述正极材料的pH值为11至12。
  10. 一种正极材料的制备方法，所述方法包括：
    S1：将含锰氧化物、锂源和可选的M1元素源进行混合得到第一混合物；将所述第一混合物在第一气氛条件以及第一温度条件下进行第一热处理，得到第一锂锰氧化物；
    其中，所述含锰氧化物和所述锂源按照锂锰摩尔比Li/Mn为0.9-1.2的范围进行混合；所述第一气氛条件为惰性气氛。
  11. 根据权利要求10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)所述惰性气氛包括氮气、氩气或氦气中的至少一种；
    (2)所述第一温度为880℃-1100℃；
    (3)所述煅烧的时间为5小时至20小时；
    (4)所述含锰氧化物包括Mn 3O 4；
    (5)所述M1元素包括Al、Nb、Mg、Ti、W、Ga、Zr、Y、V、Sr、Mo、Ru、Ag、Sn、Au、La、Ce、Pr、Nd、Sm、Gd、Cu、Na、Zn、Fe、Co、Ni、Cr或Ca中的至少一种；
    (6)所述M1元素源包括CrO 2、Al 2O 3、MgO、TiO 2或Y 2O 3中的至少一种；
    (7)所述含锰氧化物和所述M1元素源按照所述M1元素与Mn元素的摩尔比为0.001-0.1的范围进行混合；
    (8)所述锂源包括氢氧化锂、碳酸锂、乙酸锂、硝酸锂或硫酸锂中的至少一种；
    (9)所述步骤S1之后还包括步骤S2：将所述第一锂锰氧化物与M2元素源进行混合得到第二混合物，将所述第二混合物在第二气氛条件以及第二温度条件下进行第二热处理，得到表面具有包覆层的第二锂锰氧化物。
  12. 根据权利要求11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)所述第二气氛条件为惰性气氛；
    (2)所述第二热处理时间为2小时至5小时；
    (3)第二温度为200℃至600℃；
    (4)所述M2元素包括S、C、B或F中的至少一种。
  13. 一种电化学装置，包括正极，所述正极包括权利要求1至9中任一项所述的正极材料或根据权利要求10至12中任一项所述的正极材料的制备方法所制备的正极材料。
  14. 一种用电装置，包括权利要求13所述的电化学装置。
PCT/CN2022/102822 2022-06-30 2022-06-30 正极材料、电化学装置和用电装置 WO2024000405A1 (zh)

Priority Applications (2)

Application Number Priority Date Filing Date Title
PCT/CN2022/102822 WO2024000405A1 (zh) 2022-06-30 2022-06-30 正极材料、电化学装置和用电装置
CN202280010316.1A CN116802840A (zh) 2022-06-30 2022-06-30 正极材料、电化学装置和用电装置

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/CN2022/102822 WO2024000405A1 (zh) 2022-06-30 2022-06-30 正极材料、电化学装置和用电装置

Publications (1)

Publication Number Publication Date
WO2024000405A1 true WO2024000405A1 (zh) 2024-01-04

Family

ID=88045291

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2022/102822 WO2024000405A1 (zh) 2022-06-30 2022-06-30 正极材料、电化学装置和用电装置

Country Status (2)

Country Link
CN (1) CN116802840A (zh)
WO (1) WO2024000405A1 (zh)

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001006676A (ja) * 1999-04-23 2001-01-12 Mitsubishi Chemicals Corp リチウム二次電池用正極材料及び正極、並びにリチウム二次電池
JP2002145619A (ja) * 2000-09-04 2002-05-22 Mitsubishi Chemicals Corp リチウムマンガン複合酸化物、リチウム二次電池用正極材料、リチウム二次電池用正極、リチウム二次電池及びリチウムマンガン複合酸化物の製造方法
CN102376948A (zh) * 2010-08-06 2012-03-14 株式会社日立制作所 锂二次电池用正极材料，锂二次电池及采用它的二次电池模块
US20220131142A1 (en) * 2020-10-23 2022-04-28 Korea Institute Of Science And Technology Cathode for all-solid-state battery

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001006676A (ja) * 1999-04-23 2001-01-12 Mitsubishi Chemicals Corp リチウム二次電池用正極材料及び正極、並びにリチウム二次電池
JP2002145619A (ja) * 2000-09-04 2002-05-22 Mitsubishi Chemicals Corp リチウムマンガン複合酸化物、リチウム二次電池用正極材料、リチウム二次電池用正極、リチウム二次電池及びリチウムマンガン複合酸化物の製造方法
CN102376948A (zh) * 2010-08-06 2012-03-14 株式会社日立制作所 锂二次电池用正极材料，锂二次电池及采用它的二次电池模块
US20220131142A1 (en) * 2020-10-23 2022-04-28 Korea Institute Of Science And Technology Cathode for all-solid-state battery

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
SAMARASINGHA PUSHPAKA B.; ANDERSEN NIELS H.; SøRBY MAGNUS H.; KUMAR SUSMIT; NILSEN OLA; FJELLVåG HELMER: "Neutron diffraction and Raman analysis of LiMn1.5Ni0.5O4 spinel type oxides for use as lithium ion battery cathode and their capacity enhancements", SOLID STATE IONICS, NORTH HOLLAND PUB. COMPANY. AMSTERDAM; NL, NL, vol. 284, 1 January 1900 (1900-01-01), NL , pages 28 - 36, XP029374580, ISSN: 0167-2738, DOI: 10.1016/j.ssi.2015.11.018 *

Also Published As

Publication number Publication date
CN116802840A (zh) 2023-09-22

Similar Documents

Publication Publication Date Title
CN103137960B (zh) 锂离子电池正极材料及其制备方法以及锂离子电池
CN109920987A (zh) 负极材料及包含所述负极材料的电化学装置及电子装置
WO2022198654A1 (zh) 一种正极补锂材料、包含该材料的正极极片和电化学装置
CN116093316B (zh) 负极活性材料及其制备方法、负极极片和二次电池
WO2022198660A1 (zh) 一种正极补锂材料、包含该材料的正极极片和电化学装置
CN109860546B (zh) 正极材料和包含所述正极材料的电化学装置
CN113812021A (zh) 一种电化学装置及电子装置
WO2023015429A1 (zh) 复合金属氧化物材料及其制备方法、正极极片、二次电池、电池模块、电池包和用电装置
CN114144919A (zh) 一种正极极片、包含该正极极片的电化学装置和电子装置
CN114497498B (zh) 电化学装置和电子装置
WO2022198662A1 (zh) 一种正极补锂材料、包含该材料的正极极片和电化学装置
EP4089766B1 (en) Positive electrode plate, electrochemical device comprising same, and electronic device
WO2021189408A1 (zh) 负极活性材料及使用其的电化学装置和电子装置
WO2021189406A1 (zh) 电化学装置和电子装置
WO2024000405A1 (zh) 正极材料、电化学装置和用电装置
CN114156472A (zh) 电化学装置和电子装置
WO2024000406A1 (zh) 电化学装置和用电装置
WO2024036437A1 (zh) 金属氢氧化物、正极材料、电化学装置及用电设备
WO2023236226A1 (zh) 正极材料、电化学装置和电子装置
CN116706076B (zh) 一种负极材料、负极极片、电化学装置及电子装置
WO2023206241A1 (zh) 正极材料及包括正极材料的电化学装置和电子装置
WO2021189407A1 (zh) 负极活性材料及使用其的电化学装置和电子装置
WO2024000513A1 (zh) 电化学装置与用电装置
WO2023097458A1 (zh) 电化学装置和电子装置
WO2022121293A1 (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: 22948510

Country of ref document: EP

Kind code of ref document: A1