WO2025102446A1 - 磷酸锰铁锂材料及其制备方法、正极极片及锂离子电池 - Google Patents

磷酸锰铁锂材料及其制备方法、正极极片及锂离子电池 Download PDF

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WO2025102446A1
WO2025102446A1 PCT/CN2023/136385 CN2023136385W WO2025102446A1 WO 2025102446 A1 WO2025102446 A1 WO 2025102446A1 CN 2023136385 W CN2023136385 W CN 2023136385W WO 2025102446 A1 WO2025102446 A1 WO 2025102446A1
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source
manganese
lithium
iron
phosphate material
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French (fr)
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温圣耀
吴婷婷
高建行
陈勐
刘范芬
车丽媛
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Eve Power Co Ltd
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/362—Composites
    • H01M4/366—Composites as layered products
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B25/00—Phosphorus; Compounds thereof
    • C01B25/16—Oxyacids of phosphorus; Salts thereof
    • C01B25/26—Phosphates
    • C01B25/45—Phosphates containing plural metal, or metal and ammonium
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B32/00—Carbon; Compounds thereof
    • C01B32/05—Preparation or purification of carbon not covered by groups C01B32/15, C01B32/20, C01B32/25, C01B32/30
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B32/00—Carbon; Compounds thereof
    • C01B32/20—Graphite
    • C01B32/205—Preparation
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H01M4/136—Electrodes based on inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/58—Selection of substances as active materials, active masses, active liquids of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
    • H01M4/5825—Oxygenated metallic salts or polyanionic structures, e.g. borates, phosphates, silicates, olivines
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/58—Selection of substances as active materials, active masses, active liquids of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
    • H01M4/583—Carbonaceous material, e.g. graphite-intercalation compounds or CFx
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • 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 technical field of electrode materials, and in particular to a lithium iron manganese phosphate material and a preparation method thereof, a positive electrode sheet and a lithium ion battery.
  • the positive electrode material of lithium-ion secondary batteries is mainly lithium iron phosphate (LiFePO 4 ).
  • Lithium iron manganese phosphate (LiMnFePO 4 ) is a positive electrode material obtained by adding manganese to LiFePO 4.
  • the addition of manganese can make lithium iron manganese phosphate have a higher voltage platform.
  • the redox voltage of lithium iron manganese phosphate is approximately 4.1V, and the redox voltage of lithium iron phosphate is approximately 3.4V.
  • lithium iron manganese phosphate as a positive electrode material for batteries is still in the early stages of industrialization. The main reason is that the cycle performance and specific energy of lithium iron manganese phosphate are low, which seriously affects its commercial application.
  • the present application provides a lithium iron manganese phosphate material, a preparation method of the lithium iron manganese phosphate material and a lithium ion battery, which can improve the technical problems of low specific energy and poor cycle performance of lithium iron manganese phosphate.
  • an embodiment of the present application provides a lithium iron manganese phosphate material, comprising a core and a coating layer coated on the surface of the core, the material of the core comprising a chemical formula of Li a Mn b Fe c M d PO 4 , wherein M comprises at least one element selected from magnesium, calcium, strontium, cobalt, titanium, zirconium, molybdenum, vanadium, niobium, nickel, scandium, chromium, copper, zinc, beryllium, lanthanum and aluminum, the coating layer being configured to be formed by sintering a carbon source, and the carbon coating layer comprising graphitized carbon.
  • an embodiment of the present application provides a method for preparing a lithium iron manganese phosphate material, the preparation method comprising:
  • the precursor 1 is sintered to obtain a lithium manganese iron phosphate material
  • the doped metal source includes one or more of a magnesium source, a calcium source, a strontium source, a cobalt source, a titanium source, a zirconium source, a molybdenum source, a vanadium source, a niobium source, a nickel source, a scandium source, a chromium source, a copper source, a zinc source, a beryllium source, a lanthanum source and an aluminum source.
  • a magnesium source a calcium source, a strontium source, a cobalt source, a titanium source, a zirconium source, a molybdenum source, a vanadium source, a niobium source, a nickel source, a scandium source, a chromium source, a copper source, a zinc source, a beryllium source, a lanthanum source and an aluminum source.
  • an embodiment of the present application provides a method for preparing a lithium iron manganese phosphate material, the preparation method comprising the following steps:
  • the mixed solution 1 is heated, filtered and dried to obtain a precursor 2;
  • the precursor 2 a carbon source, a lithium source, and a surfactant are mixed to obtain a precursor 3;
  • the precursor 3 is sintered to obtain a lithium manganese iron phosphate material
  • the doped metal source includes one or more of a magnesium source, a calcium source, a strontium source, a cobalt source, a titanium source, a zirconium source, a molybdenum source, a vanadium source, a niobium source, a nickel source, a scandium source, a chromium source, a copper source, a zinc source, a beryllium source, a lanthanum source and an aluminum source.
  • a magnesium source a calcium source, a strontium source, a cobalt source, a titanium source, a zirconium source, a molybdenum source, a vanadium source, a niobium source, a nickel source, a scandium source, a chromium source, a copper source, a zinc source, a beryllium source, a lanthanum source and an aluminum source.
  • the present application provides a positive electrode plate, including a positive electrode current collector and a positive electrode active material layer, wherein the positive electrode active material layer is located on the surface of the positive electrode current collector, and the material of the positive electrode active material layer includes the above-mentioned lithium manganese iron phosphate material or the lithium manganese iron phosphate material obtained by the above-mentioned preparation method.
  • the present application provides a lithium-ion battery, wherein the lithium-ion battery comprises the above-mentioned lithium iron manganese phosphate material.
  • the present application dopes a metal element M into the core material of lithium iron manganese phosphate to improve the cycle performance of the lithium iron manganese phosphate material, and coats the outer surface of the core material of lithium iron manganese phosphate with a carbon coating layer containing graphitized carbon, thereby improving the specific energy of the lithium iron manganese phosphate material through graphitized carbon;
  • the specific energy of the battery can be increased by using graphitized carbon materials in the carbon coating layer.
  • the higher the graphitized carbon content in the carbon coating the better the rate performance of the battery, the higher the gram capacity, and the higher the specific energy; however, the faster the lithium ion interface diffusion, the worse the capacity retention rate of the battery will be, which may lead to worse cycle retention rate of the battery. Therefore, the cycle performance of the battery is improved by doping the metal element M into the core material of lithium iron manganese phosphate, thereby synergistically improving the technical problems of low specific energy and poor cycle performance of lithium iron manganese phosphate by doping with metal elements and using a carbon coating containing graphitized carbon.
  • range description from 1 to 6 has specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as single numbers within the numbered ranges, such as 1, 2, 3, 4, 5 and 6, which apply regardless of the range.
  • a numerical range is indicated in this article, it is meant to include any cited numbers (fractions or integers) within the indicated range.
  • A, and/or, B, and/or, C, and/or, D includes any one of A, B, C, and D (i.e., all of them are connected by "logical OR"), and also includes any and all combinations of A, B, C, and D, i.e., any combination of any two or any three of A, B, C, and D, and also includes a combination of four of A, B, C, and D (i.e., all of them are connected by "logical AND").
  • the present application provides a lithium iron manganese phosphate material, which includes a doped lithium iron manganese phosphate core and a carbon coating layer formed on the surface of the doped lithium iron manganese phosphate core, wherein the chemical formula of the doped lithium iron manganese phosphate is Li a Mn b Fe c M d PO 4 , wherein the doped metal M includes one element, two elements or more elements selected from magnesium, calcium, strontium, cobalt, titanium, zirconium, molybdenum, vanadium, niobium, nickel, scandium, chromium, copper, zinc, beryllium, lanthanum and aluminum.
  • the carbon source used to form the above-mentioned carbon coating layer includes an organic carbon source, and a suitable organic carbon source includes at least one of glucose, xylitol, PEG (polyethylene glycol), sucrose, lactose, and citric acid polyacrylamide.
  • the above-mentioned carbon coating layer includes a certain amount of graphitized carbon.
  • the graphitization of the carbon source refers to the non-graphite carbon being heated to a temperature above its graphitization temperature in a high temperature environment, a protective medium or in an airtight state. Due to physical changes, the hexagonal carbon atom plane network layer stacking structure is improved and developed, and it is transformed into graphite carbon with a three-dimensional regular and ordered structure of graphite.
  • the graphitization of the carbon source can improve the volume density, electrical conductivity, thermal conductivity, corrosion resistance and mechanical processing performance of the material. In the present application, the organic carbon source will form a certain degree of graphitization order after high-temperature calcination and carbonization.
  • the graphitization temperature of the source is usually relatively high. Therefore, the organic carbon source in the present application can also form a certain degree of graphitization order after high-temperature sintering in a high-temperature environment lower than its graphitization temperature and in a protective medium.
  • the degree of graphitization of the organic carbon source is related to the properties of the organic carbon source itself, the provided roasting temperature and the roasting time. The closer the graphitization temperature of the organic carbon source is to the provided sintering temperature and the longer the roasting time is, the higher the graphitization degree of the organic carbon source is.
  • the graphitized carbon contained in the above-mentioned carbon coating layer of the present application is not completely graphitized carbon, but carbon that forms a certain graphitized three-dimensional regular structure.
  • the carbon source is calcined at different calcination temperatures, and the graphitized carbon formed by the carbon source The degree of graphitization will vary. Different calcination temperatures and holding times are used according to different carbon sources to control the mass percentage of graphitized carbon.
  • the content of graphitized carbon accounts for 0.48% to 1.02% by mass of the lithium manganese iron phosphate active material, wherein the calculation formula for the content of graphitized carbon is:
  • Graphitized carbon content (graphitization degree * weight of carbon source) / weight of lithium manganese iron phosphate active material
  • the content of graphitized carbon in the doped lithium manganese iron phosphate material can be any value between 0.48% and 1.02%, such as 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, or the content of graphitized carbon in the lithium manganese iron phosphate material can be any range between 0.48% and 1.02%, such as 0.48% to 0.8%, 0.48% to 0.9%, 0.6% to 0.9%, 0.6% to 1.0%.
  • the carbon coating layer of the lithium iron manganese phosphate material By adding a certain amount of graphitized carbon to the carbon coating layer of the lithium iron manganese phosphate material, it is beneficial to increase the charge and discharge specific energy of the positive electrode material. Since the carbon coating layer contains a certain amount of graphitized carbon, the graphitized carbon has a regularly ordered three-dimensional structure, which is beneficial for the diffusion of lithium ions inside it.
  • the mass percentage of the carbon coating layer ranges from 0.5% to 3%, wherein the mass percentage of the carbon coating layer can be any value between 0.5% and 3%, for example, 0.8%, 1%, 1.2%, 1.5%, 1.7%, 2%, 2.2%, 2.5%, 2.8%, or the content of the carbon coating layer can be any range between 0.5% and 3%, for example, 0.5% to 1.5%, 0.5% to 2%, 1% to 3%, 2% to 3%.
  • the lithium manganese iron phosphate material is configured as a multi-metal doped lithium manganese iron phosphate material.
  • the lithium manganese iron phosphate has the same olivine structure as lithium iron phosphate, in which PO 4 has a stable tetrahedral structure. During the full charge of the battery, the tetrahedral structure of PO 4 is used as a structural support, so that the lithium manganese iron phosphate material has excellent thermodynamic and kinetic stability.
  • Adding manganese material to lithium iron phosphate can improve the positive electrode material
  • the voltage platform of the material wherein the voltage platform of the lithium iron manganese phosphate material is 4.1V, and the voltage platform of the lithium iron phosphate positive electrode material is 3.4V, thereby effectively improving the energy density of the battery.
  • the conductivity and electrochemical activity of the lithium iron manganese phosphate material decrease.
  • the lithium iron manganese phosphate material provided in the present application includes at least one doping metal element M, wherein the doping element shown in M is introduced to replace the Fe metal site in the LiMnFePO 4 crystal, thereby improving the lithium ion diffusion channel and thus improving the conductivity of the positive electrode material, or doping the metal element M and oxygen to form a more stable lattice skeleton, thereby enhancing the stability of the structure, improving the rate performance and cycle stability of the material, and at the same time improving the energy density.
  • M includes at least one element selected from magnesium, calcium, strontium, cobalt, titanium, zirconium, molybdenum, vanadium, niobium, nickel, scandium, chromium, copper, zinc, beryllium, lanthanum and aluminum.
  • M may include one metal element, two metal elements or three metal elements, and in a preferred implementation, among the metal elements included in M, the phosphates of a part of the metal elements have an olivine structure, for example, when M is a nickel element or a cobalt element, or when M is a nickel element and a cobalt element, the phosphate of the M element and the manganese phosphate or the iron phosphate are all configured as an olivine structure, thereby constituting a multi-olivine-based positive electrode material, and the charge-discharge curve and the cycle performance curve of the multi-olivine-based positive electrode material can be regarded as the linear superposition of the charge-discharge curve and the cycle performance curve of the olivine structure formed by the phosphate of each metal element, thereby effectively improving the cycle performance of the positive electrode material.
  • the phosphates of a part of the metal elements have an olivine structure, for example, when M is a nickel element or a cobalt element, or when M is a
  • the doped lithium manganese iron phosphate material oxygen atoms form a hexagonal close-packed lattice, the tetrahedral voids in the lattice are occupied by phosphoric acid and anions, the octahedral holes in the lattice are occupied by lithium ions, iron, manganese and M elements, and the voids occupied by lithium ions form continuous channels in the entire lattice. Therefore, the ratio of the lithium content to the doping metal element M, and the ratio of the doping element M to the phosphorus content are all related to the number of holes in the lattice structure formed by the positive electrode material.
  • the effects of various elements in the doped lithium manganese iron phosphate material are comprehensively considered. Ming people found through research that when the molar ratio range of each element in Li a Mn b Fe c M d PO 4 meets the following conditions, it is beneficial to balance the specific energy and cycle performance of lithium manganese iron phosphate materials, among which, 0.98 ⁇ a ⁇ 1.10, 0.10 ⁇ b ⁇ 0.68, 0.20 ⁇ c ⁇ 0.70, 0.01 ⁇ d ⁇ 0.12, and 0.98 ⁇ a/(b+c+d) ⁇ 1.03.
  • the molar ratio of each element in Li a Mn b Fe c M d PO 4 may also be in the range of 0.98 ⁇ a ⁇ 1.05, 0.10 ⁇ b ⁇ 0.68, 0.20 ⁇ c ⁇ 0.70, 0.005 ⁇ d ⁇ 0.12, and 0.98 ⁇ a/(b+c+d) ⁇ 1.03.
  • the molar ratio range of the lithium element can be any range between 0.98 and 1.10
  • the molar ratio range of the manganese element can be any range between 0.10 and 0.68
  • the molar ratio range of the iron element can be any range between 0.20 and 0.70
  • the molar ratio range of the doped metal M can be any range between 0.005 and 0.12, which are not listed one by one in the embodiments of the present application.
  • the ratio of a/(b+c+d) can be any value between 0.98 and 1.03, such as 0.99, 1.0, 1.01, 1.02, or the ratio of a/(b+c+d) can be any range between 0.98 and 1.03, such as 0.98 to 1.02, 0.99 to 1.01.
  • the molar content of iron element is less than the molar content of manganese element, wherein appropriately increasing the molar content of manganese element relative to the molar content of iron element is beneficial to increasing the energy density of lithium manganese iron phosphate material.
  • the present application provides a preparation method for preparing the above-mentioned lithium iron manganese phosphate material, wherein the preparation method is a solid phase synthesis method, and the specific preparation method includes:
  • lithium element in the lithium source, the manganese element in the manganese source, the iron element in the iron source, the M element in the doping metal source and the phosphorus element in the phosphorus source are proportioned according to the stoichiometric ratio in Li a Mn b Fe c M d PO 4 , 0.98 ⁇ a ⁇ 1.10, 0.10 ⁇ b ⁇ 0.68, 0.20 ⁇ c ⁇ 0.70, 0.01 ⁇ d ⁇ 0.12, and 0.98 ⁇ a/(b+c+d) ⁇ 1.03, and the mass percentage of the carbon source in the formed lithium manganese iron phosphate active material is in the range of 0.5%-3%;
  • Suitable process control parameters for the sintering process include: heating to 600-950°C at a heating rate of 2min-10min°C and keeping the temperature for 5-24h.
  • the present application also provides a preparation method for preparing the above-mentioned lithium manganese iron phosphate material.
  • the second preparation method includes a mixed process of liquid phase synthesis and solid phase synthesis.
  • the specific preparation method includes:
  • suitable process control parameters of the sintering process include: heating to 600-950°C at a heating rate of 2min-10min°C, and keeping warm for 5-24h.
  • the lithium element in the lithium source, the manganese element in the manganese source, the iron element in the iron source, the M element in the doping metal source and the phosphorus element in the phosphorus source are proportioned according to the stoichiometric ratio in Li a Mn b Fe c M d PO 4 , 0.98 ⁇ a ⁇ 1.05, 0.10 ⁇ b ⁇ 0.68, 0.20 ⁇ c ⁇ 0.70, 0.005 ⁇ d ⁇ 0.12, and 0.98 ⁇ a/(b+c+d) ⁇ 1.03, and the mass percentage of the carbon source in the formed lithium manganese iron phosphate active material is in the range of 0.5%-3%.
  • the complexing agent used in the above preparation method 2 includes one or more of HEDP (hydroxyethyl diphosphonic acid), ATMP (aminotrimethylphosphonic acid), or DTPA (tetramethylenediamine diacetate).
  • the surfactant used in the above preparation method 2 includes PEG (polyethylene glycol) or ATMP (aminotrimethylphosphonic acid).
  • the doped metal source includes one or more of a magnesium source, a calcium source, a strontium source, a cobalt source, a titanium source, a zirconium source, a molybdenum source, a vanadium source, a niobium source, a nickel source, a scandium source, a chromium source, a copper source, a zinc source, a beryllium source, a lanthanum source and an aluminum source.
  • the carbonization temperature of glucose is 300°C, and the graphitization temperature of glucose is not less than 800°C. Therefore, the long-term calcination temperature of 600-950°C and the inert atmosphere protection Under these conditions, glucose will form a three-dimensional structure with a certain graphitization regular arrangement. The higher the roasting temperature and the longer the roasting holding time, the higher the graphitization degree of glucose.
  • the lithium source in the above two synthesis methods includes at least one of lithium carbonate and lithium dihydrogen phosphate.
  • the iron source in the above two synthesis methods includes at least one of ferric phosphate, ferric hydrogen phosphate, ferric dihydrogen phosphate, ferric acetate, and iron powder.
  • the manganese source in the above two synthesis methods includes at least one of manganese sulfate, manganese carbonate, manganese nitrate, manganese acetate, manganese oxalate, manganese phosphate, and manganese hydrogen phosphate.
  • the phosphorus source in the above two synthesis methods includes at least one of phosphoric acid and diammonium phosphate.
  • the M source in the above two synthesis methods includes at least one of phosphates, hydrogen phosphates, dihydrogen phosphates, carbonates, formates, acetates, glycolates, lactates, tartrates, oxalates, oxides, hydroxides, fluorides, chlorides, nitrates, sulfates, and bromides of at least one element selected from the group consisting of magnesium, calcium, strontium, cobalt, titanium, zirconium, molybdenum, vanadium, niobium, nickel, scandium, chromium, copper, zinc, beryllium, lanthanum, and aluminum.
  • the M source includes a phosphate of at least one element selected from magnesium, calcium, strontium, cobalt, titanium, zirconium, molybdenum, vanadium, niobium, nickel, scandium, chromium, copper, zinc, beryllium, lanthanum, and aluminum
  • the M source includes a phosphate of at least one element selected from magnesium, calcium, strontium, cobalt, titanium, zirconium, molybdenum, vanadium, niobium, nickel, scandium, chromium, copper, zinc, beryllium, lanthanum, and aluminum configured as an olivine structure.
  • the phosphate of the M element and the manganese phosphate or the iron phosphate are configured as an olivine structure, thereby constituting a multi-element olivine-based positive electrode material, and the charge-discharge curve and the cycle performance curve of the multi-element olivine-based positive electrode material can be regarded as the linear superposition of the charge-discharge curve and the cycle performance curve of the olivine structure composed of the phosphate of each metal element, thereby effectively improving the cycle performance of the positive electrode material.
  • the precursor of ferromanganese phosphate is synthesized by the liquid phase method, which can achieve the mixing of Mn and Fe at the atomic level to form a uniform ferromanganese phosphate precursor and reduce the segregation of Mn. and dissolution; at the same time, the solid phase method is used to synthesize Li a Mn b Fe c M d PO 4 , which can reduce the damage to the ferromanganese phosphate precursor and is easy to realize industrially.
  • the present application provides a positive electrode plate, which includes a positive electrode collector and a positive electrode active material layer, the positive electrode active material layer is located on the surface of the positive electrode collector, and the material of the positive electrode active material layer includes the above-mentioned lithium manganese iron phosphate material or the lithium manganese iron phosphate material obtained by the above-mentioned preparation method.
  • the present application provides a lithium-ion battery, which includes the above-mentioned lithium iron manganese phosphate material or the lithium iron manganese phosphate material obtained by the above-mentioned preparation method, wherein the lithium-ion battery can be an aluminum shell lithium-ion battery or a soft-pack lithium-ion battery.
  • Embodiment 1 is a diagrammatic representation of Embodiment 1:
  • This embodiment provides a lithium manganese iron phosphate material, wherein the chemical formula of the core material of the lithium manganese iron phosphate material is Li 1.03 Mn 0.65 Fe 0.35 Mg 0.1 PO 4 , the carbon source forming the coating layer of the lithium manganese iron phosphate material includes glucose and PEG, and the lithium manganese iron phosphate material is prepared by the following preparation method:
  • the precursor 1 is sintered under an inert atmosphere and cooled to room temperature to obtain a powder, wherein the inert atmosphere includes nitrogen or argon or a mixture of nitrogen and argon.
  • Suitable process control parameters of the sintering process include: heating to 800°C at a heating rate of 6 min°C and keeping warm for 18 hours; wherein glucose and PEG form a carbon coating layer on the outer surface of Li 1.03 Mn 0.65 Fe 0.35 Mg 0.1 PO 4 , and glucose and PEG are calcined at high temperature to form graphitized carbon, and the mass percentage of graphitized carbon in the lithium manganese iron phosphate material is 1.0%.
  • Embodiment 2 is a diagrammatic representation of Embodiment 1:
  • This embodiment provides a lithium manganese iron phosphate material, wherein the chemical formula of the core material of the lithium manganese iron phosphate material is Li 1.02 Mn 0.58 Fe 0.35 Nb 0.1 PO 4 , the carbon source forming the carbon coating layer of the lithium manganese iron phosphate material includes glucose and PEG, and the lithium manganese iron phosphate material is prepared by the following preparation method:
  • the precursor 1 is calcined under an inert atmosphere and cooled to room temperature to obtain a powder, wherein the inert atmosphere includes nitrogen or argon or a mixture of nitrogen and argon.
  • Suitable process control parameters of the calcination process include: heating to 800°C at a heating rate of 6 min°C and keeping warm for 18 hours; wherein glucose and PEG form a carbon coating layer on the outer surface of Li 1.02 Mn 0.58 Fe 0.35 Nb 0.1 PO 4 , and glucose and PEG are calcined at high temperature to form graphitized carbon, and the content of graphitized carbon in the lithium manganese iron phosphate material is 0.8%.
  • Embodiment 3 is a diagrammatic representation of Embodiment 3
  • This embodiment provides a lithium iron manganese phosphate material, wherein the chemical formula of the core material of the lithium iron manganese phosphate material is Li 1.01 Mn 0.58 Fe 0.35 Nb 0.08 Ti 0.02 PO 4 , the carbon source forming the carbon coating layer of the lithium iron manganese phosphate material includes glucose and PEG, and the lithium iron manganese phosphate material is prepared by the following preparation method:
  • the precursor 1 is calcined under an inert atmosphere and cooled to room temperature to obtain a powder, wherein the inert atmosphere includes nitrogen or argon or a mixture of nitrogen and argon.
  • Suitable process control parameters of the calcination process include: heating to 800°C at a heating rate of 6 min°C and keeping warm for 18 hours; wherein glucose and PEG form a carbon coating layer on the outer surface of Li 1.01 Mn 0.58 Fe 0.35 Nb 0.08 Ti 0.02 PO 4 , and glucose and PEG are calcined at high temperature to form graphitized carbon, and the content of graphitized carbon in the lithium manganese iron phosphate material is 0.5%.
  • This comparative example 1 provides a lithium iron manganese phosphate material, wherein the chemical formula of the core material of the lithium iron manganese phosphate material is Li 1.04 Mn 0.55 Fe 0.35 Mg 0.1 PO 4 , the carbon source of the carbon coating layer of the lithium iron manganese phosphate material is graphite, and the lithium iron manganese phosphate material is prepared by the following preparation method:
  • the precursor 1 is calcined under an inert atmosphere and cooled to room temperature to obtain a powder, wherein the inert atmosphere includes nitrogen or argon or a mixture of nitrogen and argon.
  • Suitable process control parameters of the calcination process include: heating to 800°C at a heating rate of 6 min°C and keeping warm for 18 hours; wherein graphite forms a carbon coating layer on the outer surface of Li 1.04 Mn 0.55 Fe 0.35 Mg 0.1 PO 4 , and the mass percentage of graphite in the lithium manganese iron phosphate material is 1.2%.
  • This comparative example 1 provides a lithium iron manganese phosphate material, wherein the chemical formula of the core material of the lithium iron manganese phosphate material is Li 1.04 Mn 0.55 Fe 0.35 Co 0.1 PO 4 , the carbon source for forming the carbon coating layer of the lithium iron manganese phosphate material is carbon black, and the lithium iron manganese phosphate material is prepared by the following preparation method:
  • the precursor 1 is calcined under an inert atmosphere and cooled to room temperature to obtain a powder, wherein the inert atmosphere includes nitrogen or argon or a mixture of nitrogen and argon.
  • Suitable process control parameters of the calcination process include: heating to 800°C at a heating rate of 6 min°C and keeping warm for 18 hours; wherein carbon black forms a carbon coating layer on the outer surface of Li 1.04 Mn 0.55 Fe 0.35 Mg 0.1 PO 4 , and the carbon black forms a certain amount of graphitized carbon after high-temperature calcination, and the mass percentage of graphitized carbon in the lithium manganese iron phosphate material is 1.05%.
  • the corresponding positive electrode active material, conductive agent acetylene black and binder polyvinylidene fluoride are mixed in a weight ratio of 96:2:2, and N-methylpyrrolidone is used as a solvent. After fully grinding, stirring and mixing, a uniform positive electrode slurry is formed; after the slurry is coated on the positive electrode current collector aluminum foil, it is dried and cold pressed to obtain a positive electrode sheet.
  • the positive electrode sheet, the isolation film (PE/PP porous polymer film), and the negative electrode sheet are stacked in order so that the isolation film is placed between the positive and negative electrode sheets to play an isolating role, and then wound to obtain a bare battery cell; the bare battery cell is placed in an outer packaging foil, and a lithium ion electrolyte composed of organic solvents such as EC (ethylene carbonate)/EMC (ethyl methyl carbonate) and LiPF6 is injected into the dried battery, and then after vacuum packaging, standing, formation, shaping and other processes, a lithium ion battery is obtained.
  • organic solvents such as EC (ethylene carbonate)/EMC (ethyl methyl carbonate) and LiPF6
  • the batteries of lithium manganese iron phosphate materials prepared in the above-mentioned Example 1, Example 2, Example 3, Comparative Example 1 and Comparative Example 2 were respectively subjected to 1C discharge specific energy (mAh/g) test;
  • the batteries of lithium manganese iron phosphate materials prepared in the above-mentioned Example 1, Example 2, Example 3, Comparative Example 1 and Comparative Example 2 were respectively subjected to 1C charging specific energy (mAh/g) test;
  • the battery adopts the lithium manganese iron phosphate positive electrode material prepared by Example 1, Example 2, Example 3, Comparative Example 1 and Comparative Example 2, and the obtained battery 1C charging specific energy (mAh/g), 1C discharge specific energy (mAh/g), battery cycle charge and discharge life test (number of times) under 1C-1C charge and discharge conditions in a constant temperature environment of 25°C, and battery cycle charge and discharge life test (number of times) under 1C-1C charge and discharge conditions in a constant temperature environment of 45°C are shown in the following Table 2:
  • the battery 1C charging specific energy of the lithium manganese iron phosphate material provided by Example 1 can reach 556 mAh/g, and the battery 1C discharge specific energy can reach 518 mAh/g, which is significantly improved compared with Comparative Example 1 and Comparative Example 2;
  • the battery of lithium manganese iron phosphate material provided by Example 3 can perform charge and discharge cycle tests up to 5000 times at a constant temperature of 25°C and a charge and discharge condition of 1C-1C; and can perform charge and discharge cycle tests up to 3000 times at a constant temperature of 45°C and a charge and discharge condition of 1C-1C, which is significantly improved compared with Comparative Examples 1 and 2.
  • the lithium-ion battery prepared using the above-mentioned lithium manganese iron phosphate material will have the problem of manganese precipitation during use, that is, the manganese ions in the positive electrode material are precipitated from the positive electrode material and deposited on the negative electrode or other components. Manganese precipitation will lead to a decrease in battery capacity, a shortened battery life and a decrease in safety performance.
  • Example 4 The three lithium iron manganese phosphate materials provided in Example 4, Example 5, and Example 6 were synthesized by adopting the second preparation method provided in the above embodiment, and the two lithium iron manganese phosphate materials provided in Comparative Example 1 and Comparative Example 2 were synthesized by a pure solid phase method, and the manganese precipitation weight of the lithium battery materials prepared in Example 4, Example 5, Example 6 and Comparative Example 1 and Comparative Example 2 was analyzed and tested.
  • Embodiment 4 is a diagrammatic representation of Embodiment 4:
  • This embodiment provides a lithium iron manganese phosphate material, wherein the chemical formula of the core material of the lithium iron manganese phosphate material is Li 1.03 Mn 0.65 Fe 0.35 Mg 0.1 PO 4 , and the lithium iron manganese phosphate material is prepared by the following preparation method:
  • the precursor 3 is sintered under an inert atmosphere and cooled to room temperature to obtain a powder, wherein the inert atmosphere includes nitrogen or argon or a mixture of nitrogen and argon.
  • Suitable process control parameters of the sintering process include: heating to 800°C at a heating rate of 6 min°C and keeping warm for 18 hours; wherein glucose and PEG form a carbon coating layer on the outer surface of Li 1.03 Mn 0.65 Fe 0.35 Mg 0.1 PO 4 , and glucose and PEG are calcined at high temperature to form graphitized carbon, and the mass percentage of graphitized carbon in the lithium manganese iron phosphate material is 1.0%.
  • Embodiment 5 is a diagrammatic representation of Embodiment 5:
  • This embodiment provides a lithium iron manganese phosphate material, wherein the chemical formula of the core material of the lithium iron manganese phosphate material is Li 1.02 Mn 0.58 Fe 0.35 Nb 0.1 PO 4 , and the lithium iron manganese phosphate material is prepared by the following preparation method:
  • the precursor 3 is sintered under an inert atmosphere and cooled to room temperature to obtain a powder, wherein the inert atmosphere includes nitrogen or argon or a mixture of nitrogen and argon.
  • Suitable process control parameters of the sintering process include: heating to 800°C at a heating rate of 6 min°C and keeping warm for 18 hours; wherein glucose and PEG form a carbon coating layer on the outer surface of Li 1.02 Mn 0.58 Fe 0.35 Nb 0.1 PO 4 , and glucose and PEG are calcined at high temperature to form graphitized carbon, and the content of graphitized carbon in the lithium manganese iron phosphate material is 0.8%.
  • Embodiment 6 is a diagrammatic representation of Embodiment 6
  • This embodiment provides a lithium iron manganese phosphate material, wherein the chemical formula of the core material of the lithium iron manganese phosphate material is Li 1.01 Mn 0.58 Fe 0.35 Nb 0.08 Ti 0.02 PO 4 , and the lithium iron manganese phosphate material is prepared by the following preparation method:
  • the precursor 3 is sintered under an inert atmosphere and cooled to room temperature to obtain a powder, wherein the inert atmosphere includes nitrogen or argon or a mixture of nitrogen and argon.
  • Suitable process control parameters of the sintering process include: heating to 800°C at a heating rate of 6 min°C and keeping warm for 18 hours; wherein glucose and PEG form a carbon coating layer on the outer surface of Li 1.01 Mn 0.58 Fe 0.35 Nb 0.08 Ti 0.02 PO 4 , and glucose and PEG are calcined at high temperature to form graphitized carbon, and the content of graphitized carbon in the lithium manganese iron phosphate material is 0.5%.
  • Comparative Example 1 and Comparative Example 2 are the same as those provided in the Performance Test 1 section.
  • each lithium ion battery sample is charged to a standard voltage to ensure that the battery is in a normal working state for 24 hours;
  • the second preparation method provided in the embodiments of the present application, that is, synthesizing the precursor by a liquid phase method and synthesizing the lithium iron manganese phosphate material by a solid phase method, can significantly reduce the manganese precipitation in the lithium ion battery and prepare a lithium ion battery with better performance.

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Abstract

提供一种磷酸锰铁锂材料及其制备方法、正极极片以及锂离子电池，所述磷酸锰铁锂材料包括内核以及包覆在内核表面的包覆层，内核材料的化学式为Li aMn bFe cM dPO 4，其中M包括镁、钙、锶、钴、钛、锆、钼、钒、铌、镍、钪、铬、铜、锌、铍、镧以及铝中的至少一种元素，包覆层通过碳源烧结后形成，并且碳包覆层中包括石墨化碳。

Description

磷酸锰铁锂材料及其制备方法、正极极片及锂离子电池
本申请要求在2023年11月15日提交中国专利局、申请号为202311520716.X的中国专利申请的优先权，以上申请的全部内容通过引用结合在本申请中。
技术领域
本申请涉及电极材料技术领域，具体涉及一种磷酸锰铁锂材料及其制备方法、正极极片及一种锂离子电池。
背景技术
锂离子二次电池的正极材料主要是磷酸铁锂(LiFePO4)，磷酸锰铁锂(LiMnFePO4)是在LiFePO4的基础上增加锰元素后获得的一种正极材料，锰的加入可使磷酸锰铁锂具有更高的电压平台，其中磷酸锰铁锂的氧化还原电压大致为4.1V，磷酸铁锂的氧化还原电压大致为3.4V，相关技术中，磷酸锰铁锂作为电池的正极材料还处于产业化初期，其主要原因是磷酸锰铁锂的循环性能及比能量低，严重影响其商业应用。
技术问题
本申请提供一种磷酸锰铁锂材料、磷酸锰铁锂材料的制备方法以及锂离子电池，可以改善磷酸锰铁锂的比能量低以及循环性能差的技术问题。
技术解决方案
第一方面，本申请实施例提供了一种磷酸锰铁锂材料，所述磷酸锰铁锂材料包括内核以及包覆在所述内核表面的包覆层，所述内核的材料包括化学式为LiaMnbFecMdPO4，其中M包括镁、钙、锶、钴、钛、锆、钼、钒、铌、镍、钪、铬、铜、锌、铍、镧以及铝中的至少一种元素，所述包覆层配置为通过碳源烧结后形成，并且所述碳包覆层中包括石墨化碳。
第二方面，本申请实施例提供了一种磷酸锰铁锂材料的制备方法，所述制备方法包括：
将锂源、锰源、铁源、磷源、掺杂金属源、碳源进行混合得到前体1；
在惰性气氛保护下，将所述前体1进行烧结处理，得到磷酸锰铁锂材料；
其中，所述掺杂金属源包括镁源、钙源、锶源、钴源、钛源、锆源、钼源、钒源、铌源、镍源、钪源、铬源、铜源、锌源、铍源、镧源以及铝源中的一种或多种。
第三方面，本申请实施例提供了一种磷酸锰铁锂材料的制备方法，所述制备方法包括以下步骤：
将锰源、铁源、磷源、掺杂金属M源、双氧水和络合剂进行混合得到混合液1；
将所述混合液1进行加热后，过滤干燥得到前体2；
将所述前体2、碳源、锂源、表面活性剂进行混合得到前体3；
将所述前体3进行烧结处理后得到磷酸锰铁锂材料；
其中，所述掺杂金属源包括镁源、钙源、锶源、钴源、钛源、锆源、钼源、钒源、铌源、镍源、钪源、铬源、铜源、锌源、铍源、镧源以及铝源中的一种或多种。
第四方面，本申请提供一种正极极片，包括正极集流体，以及正极活性物质层，所述正极活性物质层位于所述正极集流体的表面，所述正极活性物质层的材料包括上述磷酸锰铁锂材料或上述制备方法得到的磷酸锰铁锂材料。
第五方面，本申请提供一种锂离子电池，所述锂离子电池包括上述磷酸锰铁锂材料。
本申请的有益效果
本申请的有益效果为：
(1)本申请在磷酸锰铁锂的内核材料中掺杂金属元素M进而提升磷酸锰铁锂材料的循环性能，在磷酸锰铁锂的内核材料的外表面包覆含有石墨化碳的碳包覆层，通过石墨化碳来提升磷酸锰铁锂材料的比能量；
(2)通过在碳包覆层中使用石墨化碳材料可以提升电池的比能量，当在 碳包覆层中含有的石墨化碳越高，锂离子界面扩散有关，进而电池的倍率性能越好，克容量越高，进而比能量越高；但是锂离子界面扩散越快，电池的容量保持率会变差，进而可能导致电池的循环保持率会变差，因此通过在磷酸锰铁锂的内核材料中掺杂金属元素M进而提升电池的循环性能，从而通过掺杂金属元素以及使用含有石墨化碳的碳包覆层来协同改善磷酸锰铁锂的比能量低以及循环性能差的技术问题。
本发明的实施方式
除非另行定义，文中所使用的所有专业与科学用语与本领域技术人员所熟悉的意义相同，并且本申请实施例和对比例中所用的材料或试剂可商购获得。此外，任何与所记载内容相似或均等的方法及材料皆可应用于本申请中。文中所述的较佳实施方法与材料仅作示范之用，但不能限制本申请的内容。
需说明的是，以下实施例的描述顺序不作为对实施例优选顺序的限定。本申请的各个实施例可以以一个范围的型式存在；应当理解，以一范围型式的描述仅仅是因为方便及简洁，不应理解为对本申请范围的硬性限制；因此，应当认为所述的范围描述已经具体公开所有可能的子范围以及该范围内的单一数值。例如，应当认为从1到6的范围描述已经具体公开子范围，例如从1到3，从1到4，从1到5，从2到4，从2到6，从3到6等，以及所数范围内的单一数字，例如1、2、3、4、5及6，此不管范围为何皆适用。另外，每当在本文中指出数值范围，是指包括所指范围内的任何引用的数字(分数或整数)。
在本申请的描述中，术语“包括”是指“包括但不限于”。
术语“多种”、“多次”或其类似表达指的是两种(次)或两种(次)以上，例如可以是两种(次)、三种(次)、四种(次)、五种(次)、六种(次)等。
术语“和/或”的选择范围包括两个或两个以上相关所列项目中任一个项目，也包括相关所列项目的任意的和所有的组合，所述任意的和所有的组合包括任意的两个相关所列项目、任意的更多个相关所列项目、或者全部相关所列项目的组合。比如，“A和/或B”包括A、B以及A+B三种并列方案。又比 如，“A，及/或，B，及/或，C，及/或，D”的技术方案，包括A、B、C、D中任一项(也即均用“逻辑或”连接的技术方案)，也包括A、B、C、D的任意的和所有的组合，也即包括A、B、C、D中任两项或任三项的组合，还包括A、B、C、D的四项组合(也即均用“逻辑与”连接的技术方案)。。
第一方面，本申请提供一种磷酸锰铁锂材料，磷酸锰铁锂材料包括掺杂磷酸锰铁锂内核以及形成于掺杂磷酸锰铁锂内核表面的碳包覆层，掺杂磷酸锰铁锂的化学式为LiaMnbFecMdPO4，其中掺杂金属M包括镁、钙、锶、钴、钛、锆、钼、钒、铌、镍、钪、铬、铜、锌、铍、镧以及铝中的一种元素、两种元素或者多种元素。
用于形成上述碳包覆层的碳源包括有机碳源，适合的有机碳源包括葡萄糖、木糖醇、PEG(聚乙二醇)、蔗糖、乳糖、柠檬酸聚丙烯酰胺中的至少一种。
上述碳包覆层中包括一定含量的石墨化碳，碳源的石墨化是指非石墨质碳在高温环境、保护性介质中或者隔绝空气的情况下，把非石墨质碳加热到其可石墨化温度以上，因物理变化使六角碳原子平面网状层堆叠结构完善发展，转变成具有石墨三维规则有序结构的石墨质碳，碳源的石墨化可以提升材料的体积密度、导电率、导热率、抗腐蚀性能以及机械加工性能，而在本申请中有机碳源在经过高温焙烧碳化之后会形成一定程度的石墨化排序，可理解的是，由于有机碳源的石墨化温度通常比较高，因此在本申请中的有机碳源在低于其石墨化温度的高温环境中、保护性介质中经过高温烧结也能够形成一定程度的石墨化排序，其中有机碳源的石墨化程度与有机碳源本身的性质、以及所提供的焙烧温度以及焙烧时间有关，其中有机碳源的石墨化温度与所提供的烧结温度越接近以及焙烧时间越长，则有机碳源的石墨化度越高，而在本申请的上述碳包覆层中所含有的石墨化碳并非完全石墨化的碳，而是形成一定石墨化三维规则结构的碳。
进一步地，碳源在不同的焙烧温度下进行焙烧，碳源所形成的石墨化碳的 石墨化程度会有不同，根据不同的碳源而控制使用不同的焙烧温度和保温时间，进而控制石墨化碳的质量百分比含量。
优选地，在本申请的一些实施中，石墨化碳的含量占磷酸锰铁锂活性材料的质量百分比为0.48％～1.02％，其中石墨化碳的含量的计算公式为：
石墨化碳的含量＝(石墨化度*碳源的重量)/磷酸锰铁锂活性物质的重量
可理解的是，在掺杂磷酸锰铁锂材料中石墨化碳的含量可以是0.48％～1.02％之间的任意数值，例如0.5％、0.6％、0.7％、0.8％、0.9％、1.0％，或者在磷酸锰铁锂材料中石墨化碳的含量可以是0.48％～1.02％之间的任意范围，例如0.48％～0.8％、0.48％～0.9％、0.6％～0.9％、0.6％～1.0％。
通过在磷酸锰铁锂材料的碳包覆层中加入一定含量的石墨化碳，有利于增加正极材料的充放电比能量，由于在碳包覆层的内部包含一定含量的石墨化碳，石墨化碳具有规则排序的三维结构，因为有利于锂离子在其内部进行扩散，碳包覆层中的石墨化碳的含量越高，锂离子的扩散速度越快，进而磷酸锰铁锂活性材料的倍率性能越好，克容量越高，进而比能量越高；但是磷酸锰铁锂活性材料中的锂离子的扩散速度过快会导致磷酸锰铁锂活性材料的容量的保持率降低，进而导致磷酸锰铁锂活性材料的循环性能变差。
优选地，在本申请的一些实施中，在磷酸锰铁锂材料中，碳包覆层的质量百分比范围为0.5％-3％，其中碳包覆层的质量百分比可以是0.5％-3％之间的任意数值，例如0.8％、1％、1.2％、1.5％、1.7％、2％、2.2％、2.5％、2.8％，或者碳包覆层的含量可以是0.5％～3％之间的任意范围，例如0.5％～1.5％、0.5％～2％、1％～3％、2％～3％。
磷酸锰铁锂材料配置为多元金属掺杂磷酸锰铁锂材料，磷酸锰铁锂具有和磷酸铁锂一样的橄榄石结构，其中PO4具有稳定的四面体结构，在电池充分电的过程中，PO4的四面体结构用于作为结构支撑，从而使得磷酸锰铁锂材料具有优异的热力学和动力学稳定性。在磷酸铁锂中加入锰材料，可以提高正极材 料的电压平台，其中磷酸锰铁锂材料的电压平台为4.1V，磷酸铁锂正极材料的电压平台为3.4V，进而有效提升电池的能量密度。但是随着锰元素的增加，磷酸锰铁锂材料的导电性以及电化学活性降低，在本申请提供的磷酸锰铁锂材料中包括有至少一种掺杂金属元素M，其中引入M所示掺杂元素替代LiMnFePO4晶体中Fe金属位点，改善了锂离子扩散通道进而提高正极材料的电导率，或者掺杂金属元素M和氧形成更稳定的晶格骨架，进而加强结构的稳定性，提高了材料的倍率性能和循环稳定性，同时提高了能量密度。
优选地，在本申请的一些实施中，M包括镁、钙、锶、钴、钛、锆、钼、钒、铌、镍、钪、铬、铜、锌、铍、镧以及铝中的至少一种元素。可理解的是，M可以包括一种金属元素、两种金属元素或者三种金属元素，并且在优选的实施中，M所包含的金属元素中，一部分的金属元素的磷酸盐具有橄榄石结构，例如当M为镍元素或者钴元素时，或者M为镍元素和钴元素时，M元素的磷酸盐与磷酸锰或者磷酸铁均配置为橄榄石结构，从而构成多元橄榄石系正极材料，多元橄榄石系正极材料的充放电曲线、循环性能曲线可以看作每种金属元素的磷酸盐所构成的橄榄石结构的充放电曲线、循环性能曲线的线性叠加，进而有效提升正极材料的循环性能。
在掺杂型磷酸锰铁锂材料中，氧原子形成六方密排晶格，晶格内的四面体空隙被磷酸跟阴离子占据，晶格内的八面体空穴被锂离子、铁元素、锰元素以及M元素所占据，并且锂离子占据的空隙在整个晶格中形成连续的通道，因此锂元素的含量与掺杂金属元素M的含量的比值、以及掺杂元素M的含量与磷元素的含量的比值均与正极材料所构成的晶格结构内部的空穴数量有关，锂元素的含量与掺杂金属元素的含量的比值越高，正极材料的克容量越高，但材料的碱性增强，副反应增多，掺杂金属元素M的含量与磷元素的含量的比值越高，正极材料的克容量变低，比能量变低，但是有利于提升正极材料的循环性能。
在优选的实施中，综合考虑掺杂型磷酸锰铁锂材料中各个元素的作用，发 明人经研究发现，LiaMnbFecMdPO4中各个元素的摩尔比范围满足以下条件时，有利于平衡磷酸锰铁锂材料的比能量和循环性能，其中，0.98≤a≤1.10，0.10≤b≤0.68,0.20≤c≤0.70,0.01≤d≤0.12，并且0.98≤a/(b+c+d)≤1.03。
在可供选择的其它实施例中，LiaMnbFecMdPO4中各个元素的摩尔比范围还可以是，0.98≤a≤1.05，0.10≤b≤0.68,0.20≤c≤0.70,0.005≤d≤0.12，并且0.98≤a/(b+c+d)≤1.03。
进一步地，锂元素的摩尔比范围可以是0.98～1.10中的任意范围，锰元素的摩尔比范围可以是0.10～0.68中的任意范围，铁元素的摩尔比范围可以是0.20～0.70中的任意范围，掺杂金属M的摩尔比范围可以是0.005～0.12之间的任意范围，在本申请的实施例中不一一列举。
其中a/(b+c+d)的比值可以是0.98～1.03之间的任意数值，例如0.99、1.0、1.01、1.02，或者a/(b+c+d)的比值可以是0.98～1.03之间的任意范围，例如0.98～1.02、0.99～1.01。
在进一步优选的实施中，在LiaMnbFecMdPO4中，铁元素的摩尔含量小于锰元素的摩尔含量，其中相对于铁元素的摩尔含量适当增加锰元素的摩尔含量，有利于增加磷酸锰铁锂材料的能量密度。
第二方面，本申请提供一种用于制备上述磷酸锰铁锂材料的制备方法，该制备方法一配备为固相合成法，具体的制备方法包括：
(1)准备足量的锂源、锰源、铁源、掺杂金属源、磷源以及碳源，并将锂源、锰源、铁源、M源、磷源以及碳源进行混合得到前体1；其中锂源中的锂元素、锰源中的锰元素、铁源中的铁元素、掺杂金属源中的M元素以及磷源中的磷元素按照LiaMnbFecMdPO4中的化学计量比进行配比，0.98≤a≤1.10，0.10≤b≤0.68，0.20≤c≤0.70，0.01≤d≤0.12，并且0.98≤a/(b+c+d)≤1.03，碳源在所形成的磷酸锰铁锂活性材料中的质量百分比范围为0.5％-3％；
(2)将上述前体1在惰性气氛保护下进行焙烧，并在惰性气氛下冷却至室温，得到粉料，其中惰性气氛包括氮气或者氩气或者氮气和氩气的混合气体， 适合的烧结工艺的过程控制参数包括：以2min-10min℃的升温速率，升温至600-950℃，保温5-24h。
第三方面，本申请还提供一种用于制备上述磷酸锰铁锂材料的制备方法，该制备方法二包括液相法以及固相法合成的混合工艺，具体的制备方法包括：
(1)将锰源、铁源、磷源、掺杂金属M源、双氧水和络合剂进行混合得到混合液1；
(2)将所述混合液1进行加热处理后，过滤干燥得到前体2；其中加热处理的加热温度为60℃-95℃；
(3)将所述前体2、碳源、锂源、表面活性剂进行混合得到前体3；
(4)将所述前体3进行烧结处理后得到磷酸锰铁锂材料；其中适合的烧结工艺的过程控制参数包括：以2min-10min℃的升温速率，升温至600-950℃，保温5-24h。
在上述制备方法二的步骤1至步骤3中，锂源中的锂元素、锰源中的锰元素、铁源中的铁元素、掺杂金属源中的M元素以及磷源中的磷元素按照LiaMnbFecMdPO4中的化学计量比进行配比，0.98≤a≤1.05，0.10≤b≤0.68，0.20≤c≤0.70，0.005≤d≤0.12，并且0.98≤a/(b+c+d)≤1.03，碳源在所形成的磷酸锰铁锂活性材料中的质量百分比范围为0.5％-3％。
在上述制备方法二中所使用的络合剂包括HEDP(羟乙基二膦酸)或ATMP(氨基三甲膦酸)或DTPA(二乙酸四胺)中的一种或多种。
在上述制备方法二中所使用的表面活性剂包括PEG(聚乙二醇)或ATMP(氨基三甲膦酸)。
其中，在上述两种合成方法种，掺杂金属源包括镁源、钙源、锶源、钴源、钛源、锆源、钼源、钒源、铌源、镍源、钪源、铬源、铜源、锌源、铍源、镧源以及铝源中的一种或多种。
当碳源中包含有葡萄糖时，葡萄糖的碳化温度为300℃，葡萄糖的石墨化温度不低于800℃，因此在600-950℃的长时间的焙烧温度以及惰性气氛保护 下，葡萄糖会形成一定石墨化规则排序的三维结构，其中焙烧的温度越高以及焙烧的保温时间越长，葡萄糖的石墨化度越高。
优选地，在本申请的一些实施中，上述两种合成方法中的锂源包括碳酸锂、磷酸二氢锂中的至少一种。
优选地，在本申请的一些实施中，上述两种合成方法中的铁源包括磷酸铁、磷酸氢铁、磷酸二氢铁、乙酸铁、铁粉中的至少一种。
优选地，在本申请的一些实施中，上述两种合成方法中的锰源包括硫酸锰、碳酸锰、硝酸锰、醋酸锰、草酸锰、磷酸锰、磷酸氢锰中的至少一种。
优选地，在本申请的一些实施中，上述两种合成方法中的磷源包括磷酸、磷酸二氢铵中的至少一种。
优选地，在本申请的一些实施中，上述两种合成方法中的M源包括镁、钙、锶、钴、钛、锆、钼、钒、铌、镍、钪、铬、铜、锌、铍、镧、铝中的至少一种元素的磷酸盐、磷酸氢盐、磷酸二氢盐、碳酸盐、甲酸盐、乙酸盐、羟乙酸盐、乳酸盐、酒石酸盐、草酸盐、氧化物、氢氧化物、氟化物、氯化物、硝酸盐、硫酸盐、溴化物中的至少一种。
进一步地，在一些优选的实施中，M源包括镁、钙、锶、钴、钛、锆、钼、钒、铌、镍、钪、铬、铜、锌、铍、镧、铝中的至少一种元素的磷酸盐，并且所述M源包括镁、钙、锶、钴、钛、锆、钼、钒、铌、镍、钪、铬、铜、锌、铍、镧、铝中的至少一种元素的磷酸盐配置为橄榄石结构。例如，当M为镍元素或者钴元素或者当M元素为镍元素和钴元素时，M元素的磷酸盐与磷酸锰或者磷酸铁均配置为橄榄石结构，从而构成多元橄榄石系正极材料，多元橄榄石系正极材料的充放电曲线、循环性能曲线可以看作每种金属元素的磷酸盐所构成的橄榄石结构的充放电曲线、循环性能曲线的线性叠加，进而有效提升正极材料的循环性能。
需要说明的是，在制备方法二中，通过液相法合成磷酸锰铁的前驱体，可实现Mn、Fe原子级别的混合，形成均匀的磷酸锰铁前驱体，减少Mn的偏析 及溶出；同时采用固相法合成LiaMnbFecMdPO4，可以减少对磷酸锰铁前驱体的破坏，且易于工业实现。
第四方面，本申请提供一种正极极片，该正极极片包括正极集流体以及正极活性物质层，正极活性物质层位于正极集流体的表面，正极活性物质层的材料包括上述磷酸锰铁锂材料或上述制备方法得到的磷酸锰铁锂材料。
第五方面，本申请提供一种锂离子电池，锂离子电池包括上述磷酸锰铁锂材料或上述制备方法得到的磷酸锰铁锂材料，其中锂离子电池可以是铝壳锂离子电池或者软包锂离子电池。
下面通过提具体实施例和对比例的技术方案及技术效果进行详细说明，需要说明的是以下提供的实施例仅仅是本申请的部分实施例，并非对本申请作出具体限定。
性能测试1：
通过对实施例1、实施例2、实施例3提供三种磷酸锰铁锂材料与对比例1和对比例2提供的两种磷酸锰铁锂材料的比能量性能以及循环性能参数进行比对分析，从而验证本申请所提供的磷酸锰铁锂材料的比能量性能以及循环性能相对于相关技术中的磷酸锰铁锂材料的比能量性能以及循环性能有显著提升。
实施例1：
本实施例提供了一种磷酸锰铁锂材料，其中磷酸锰铁锂材料的内核材料的化学式为Li1.03Mn0.65Fe0.35Mg0.1PO4，形成磷酸锰铁锂材料的包覆层的碳源包括葡萄糖和PEG，磷酸锰铁锂材料采用如下制备方法制备得到：
(1)准备足量的碳酸锂、碳酸锰、磷酸铁、氧化镁、磷酸、葡萄糖和PEG，并将碳酸锂、碳酸锰、磷酸铁、氧化镁、磷酸、葡萄糖和PEG进行混合研磨得到前体1；其中碳酸锂中锂元素、碳酸锰中的锰元素、磷酸铁中的铁元素、氧化镁中的镁元素、磷酸中的磷元素按照化学式Li1.03Mn0.65Fe0.35Mg0.1PO4中的化学计量比进行配比，即按照摩尔比Li:Mn:Fe:Mg:P＝1.03:0.65:0.35:0.1:1；
(2)将上述前体1在惰性气氛保护下进行烧结，并在惰性气氛保护下冷却至室温，得到粉料，其中惰性气氛包括氮气或者氩气或者氮气和氩气的混合气体，适合的烧结工艺的过程控制参数包括：以6min℃的升温速率，升温至800℃，保温18h；其中葡萄糖和PEG在Li1.03Mn0.65Fe0.35Mg0.1PO4的外表面形成碳包覆层，并且葡萄糖和PEG经过高温焙烧形成石墨化碳，在磷酸锰铁锂材料中石墨化碳的质量百分比含量为1.0％。
实施例2：
本实施例提供了一种磷酸锰铁锂材料，其中磷酸锰铁锂材料的内核材料的化学式为Li1.02Mn0.58Fe0.35Nb0.1PO4，形成磷酸锰铁锂材料的碳包覆层的碳源包括葡萄糖和PEG，磷酸锰铁锂材料采用如下制备方法制备得到：
(1)准备足量的碳酸锂、碳酸锰、磷酸铁、Nb2O5、磷酸、葡萄糖和PEG，并将碳酸锂、碳酸锰、磷酸铁、Nb2O5、磷酸、葡萄糖和PEG进行混合研磨得到前体1；其中碳酸锂中的锂元素、碳酸锰中的锰元素、磷酸铁中的铁元素、Nb2O5中的Nb元素以及磷酸中的磷元素按照化学式Li1.02Mn0.58Fe0.35Nb0.1PO4中的化学计量比进行配比，即按照摩尔比Li:Mn:Fe:Nb:P＝1.02:0.58:0.35:0.1:1；
(2)将上述前体1在惰性气氛保护下进行焙烧，并在惰性气氛下冷却至室温，得到粉料，其中惰性气氛包括氮气或者氩气或者氮气和氩气的混合气体，适合的焙烧工艺的过程控制参数包括：以6min℃的升温速率，升温至800℃，保温18h；其中葡萄糖和PEG在Li1.02Mn0.58Fe0.35Nb0.1PO4的外表面形成碳包覆层，并且葡萄糖和PEG经过高温焙烧形成石墨化碳，在磷酸锰铁锂材料中石墨化碳的含量为0.8％。
实施例3：
本实施例提供了一种磷酸锰铁锂材料，其中磷酸锰铁锂材料的内核材料的化学式为Li1.01Mn0.58Fe0.35Nb0.08Ti0.02PO4，形成磷酸锰铁锂材料的碳包覆层的碳源包括葡萄糖和PEG，磷酸锰铁锂材料采用如下制备方法制备得到：
(1)准备足量的碳酸锂、碳酸锰、磷酸铁、Nb2O5、TiO2、磷酸、葡萄 糖和PEG，并将碳酸锂、碳酸锰、磷酸铁、Nb2O5、TiO2、磷酸、葡萄糖和PEG进行研磨混合得到前体1；其中碳酸锂中的锂元素、碳酸锰中的锰元素、磷酸铁中的铁元素、Nb2O5中的铌元素、TiO2中的钛元素、以及磷酸中的磷元素按照化学式Li1.01Mn0.58Fe0.35Nb0.08Ti0.02PO4中的化学计量比进行配比，即按照摩尔比为Li:Mn:Fe:Nb:Ti:P＝1.01:0.58:0.35:0.08:0.02:1；
(2)将上述前体1在惰性气氛保护下进行焙烧，并在惰性气氛下冷却至室温，得到粉料，其中惰性气氛包括氮气或者氩气或者氮气和氩气的混合气体，适合的焙烧工艺的过程控制参数包括：以6min℃的升温速率，升温至800℃，保温18h；其中葡萄糖和PEG在Li1.01Mn0.58Fe0.35Nb0.08Ti0.02PO4的外表面形成碳包覆层，并且葡萄糖和PEG经过高温焙烧形成石墨化碳，在磷酸锰铁锂材料中石墨化碳的含量为0.5％。
对比例1：
本对比例一提供了一种磷酸锰铁锂材料，其中磷酸锰铁锂材料的内核材料的化学式为Li1.04Mn0.55Fe0.35Mg0.1PO4，形成磷酸锰铁锂材料的碳包覆层的碳源为石墨，磷酸锰铁锂材料采用如下的制备方法制备得到：
(1)准备足量的碳酸锂、碳酸锰、磷酸铁、氧化镁、磷酸、以及石墨，并将碳酸锂、碳酸锰、磷酸铁、氧化镁、磷酸、以及石墨进行混合得到前体1；其中碳酸锂中的锂元素、碳酸锰中的锰元素、磷酸铁中的铁元素、氧化镁中的镁元素、以及磷酸中的磷元素按照化学式Li1.04Mn0.55Fe0.35Mg0.1PO4中的化学计量比进行配比，即按照摩尔比Li:Mn:Fe:Mg:P＝1.04:0.55:0.35:0.1:1；
(2)将上述前体1在惰性气氛保护下进行焙烧，并在惰性气氛下冷却至室温，得到粉料，其中惰性气氛包括氮气或者氩气或者氮气和氩气的混合气体，适合的焙烧工艺的过程控制参数包括：以6min℃的升温速率，升温至800℃，保温18h；其中石墨在Li1.04Mn0.55Fe0.35Mg0.1PO4的外表面形成碳包覆层，在磷酸锰铁锂材料中石墨的质量百分比含量为1.2％。
对比例2：
本对比例一提供了一种磷酸锰铁锂材料，其中磷酸锰铁锂材料的内核材料的化学式为Li1.04Mn0.55Fe0.35Co0.1PO4，形成磷酸锰铁锂材料的碳包覆层的碳源为碳黑，磷酸锰铁锂材料采用如下制备方法制备得到：
(1)准备足量的碳酸锂、碳酸锰、磷酸铁、氧化钴、磷酸、以及炭黑，并将碳酸锂、碳酸锰、磷酸铁、氧化钴、磷酸、以及炭黑进行混合得到前体1；其中碳酸锂中的锂元素、碳酸锰中的锰元素、磷酸铁中的铁元素、氧化钴中的钴元素、磷酸中的磷元素按照化学式Li1.04Mn0.55Fe0.35Co0.1PO4中的化学计量比进行配比，即按照摩尔比Li:Mn:Fe:Co:P＝1.04:0.55:0.35:0.1:1；
(2)将上述前体1在惰性气氛保护下进行焙烧，并在惰性气氛下冷却至室温，得到粉料，其中惰性气氛包括氮气或者氩气或者氮气和氩气的混合气体，适合的焙烧工艺的过程控制参数包括：以6min℃的升温速率，升温至800℃，保温18h；其中碳黑在Li1.04Mn0.55Fe0.35Mg0.1PO4的外表面形成碳包覆层，并且炭黑经过高温焙烧形成一定含量的石墨化碳，在磷酸锰铁锂材料中石墨化碳的质量百分比含量为1.05％。
实施例和对比例的锂离子电池的制备方法如下：
(1)负极极片制备
将负极活性物质石墨、导电剂乙炔黑、粘结剂丁苯橡胶和增稠剂羧甲基纤维素钠按照重量比为石墨：乙炔黑：丁苯橡胶：羧甲基纤维素钠＝95:2:2:1进行混合，加入适量去离子水充分搅拌混合，形成均匀的负极浆料；将浆料涂覆于负极集流体铜箔上后，进行烘干、冷压，得到负极极片。
(2)正极极片制备
将相应的正极活性材料、导电剂乙炔黑和粘结剂聚偏二氟乙烯按重量比96:2:2进行混合，使用N-甲基吡咯烷酮作溶剂，充分研磨搅拌混合后，形成均匀的正极浆料；将浆料涂覆于正极集流体铝箔上后，进行烘干、冷压，得到正极极片。
(3)电池的制备
将正极片、隔离膜(PE/PP多孔聚合物薄膜)、负极片按顺序叠好，使隔离膜处于正负极片之间起到隔离的作用，然后卷绕得到裸电芯；将裸电芯置于外包装箔中，将EC(碳酸乙烯酯)/EMC(碳酸甲基乙基酯)等有机溶剂和LiPF6组成的锂离子电解液注入到干燥后的电池中，然后经过真空封装、静置、化成、整形等工序，获得锂离子电池。
性能测试方法：
使用恒温箱电池测试柜，在指定的温度下以0.1C电流，循环充放电三周，得到锂离子电池实际容量Q；
分别将上述实施例1、实施例2、实施例3、对比例1以及对比例2所制备得到的磷酸锰铁锂材料的电池进行1C放电比能量(mAh/g)测试；
分别将上述实施例1、实施例2、实施例3、对比例1以及对比例2所制备得到的磷酸锰铁锂材料的电池进行1C充电比能量(mAh/g)测试；
在25℃的恒温环境中，1C-1C充放电条件下进行电池循环充放电寿命测试，测试上述实施例1、实施例2、实施例3、对比例1以及对比例2所制备得到的磷酸锰铁锂材料的电池容量下降至额定容量的20％，电池可达到的循环次数；
在45℃的恒温环境中，1C-1C充放电条件下进行电池循环充放电寿命测试，测试上述实施例1、实施例2、实施例3、对比例1以及对比例2所制备得到的磷酸锰铁锂材料的电池容量下降至额定容量的20％，电池可达到的循环次数；
经过测试，电池采用实施例1、实施例2、实施例3、对比例1以及对比例2所制备得到的磷酸锰铁锂正极材料，所得到的电池1C充电比能量(mAh/g)、1C放电比能量(mAh/g)、25℃的恒温环境中1C-1C充放电条件下电池循环充放电寿命测试(次数)，45℃恒温环境中1C-1C充放电条件下电池循环充放电寿命测试(次数)的数据如下表二所示：
表一、实施例及对比例的磷酸锰铁锂正极材料组成
表二、实施例及对比例的比能量测试数据、循环性能测试数据
由实施例1所提供的磷酸锰铁锂材料的电池1C充电比能量可达到556mAh/g、电池1C放电比能量可达到518mAh/g，相对于对比例1和对比2有显著提升；
由实施例3所提供的磷酸锰铁锂材料的电池，在25℃恒温环境中，以1C-1C充放电条件下，电池进行充放电循环测试次数可达到5000次；在45℃恒温环境中，以1C-1C充放电条件下，电池进行充放电循环测试次数可达到3000次，相对于对比例1和对比例2有显著提升；
通过对比实施例1、实施例2以及实施例3所提供的磷酸锰铁锂材料的电池1C充电比能量以及1C放电比能量测试数据，当磷酸锰铁锂材料中的石墨化碳的含量处于0.48％～1.02％，随着石墨化碳的含量的增加，正极材料的充放 电比能量增加，而在25℃恒温环境中，以1C-1C充放电条件下，电池进行充放电循环测试次数减少，同时在45℃恒温环境中，以1C-1C充放电条件下，电池进行充放电循环测试次数也减少；
通过对比实施例1、实施例2、实施例3、对比例1以及对比例2所提供的磷酸锰铁锂材料的电池1C充电比能量以及1C放电比能量测试数据，当磷酸锰铁锂材料中的石墨化碳的含量大于1.02％，正极材料的充放电比能量显著减少；
通过对比实施例1、实施例2以及实施例3所提供的磷酸锰铁锂材料的电池在25℃恒温环境中，以1C-1C充放电条件下，电池进行充放电循环测试次数，当正极材料LiaMnbFecMdPO4中的a/(b+c+d)的比值处于0.98～1.03，随着a/(b+c+d)比值的增加，电池的循环寿命增加；通过对比实施例1、实施例2以及实施例3所提供的磷酸锰铁锂材料的电池在45℃恒温环境中，以1C-1C充放电条件下，电池进行充放电循环测试次数，当正极材料LiaMnbFecMdPO4中的a/(b+c+d)的比值处于0.98～1.03，随着a/(b+c+d)比值的增加，电池的循环寿命增加；
通过对比实施例1、实施例2、实施例3、对比例1以及对比例2所提供的磷酸锰铁锂材料的电池在25℃恒温环境中，以1C-1C充放电条件下，电池进行充放电循环测试次数，当正极材料LiaMnbFecMdPO4中的a/(b+c+d)的比值大于1.03时，电池的循环寿命显著减少；通过对比实施例1、实施例2、实施例3、对比例1以及对比例2所提供的磷酸锰铁锂材料的电池在45℃恒温环境中，以1C-1C充放电条件下，电池进行充放电循环测试次数，当正极材料LiaMnbFecMdPO4中的a/(b+c+d)的比值大于1.03时，电池的循环寿命显著减少。
采用上述磷酸锰铁锂材料制备形成的锂离子电池，在使用的过程中会出现锰析出的问题，即正极材料中的锰离子从正极材料中析出并沉积在负极或者其他部件上，锰析出会导致电池容量的降低，电池寿命的缩短以及安全性能的下降。
通过采用本申请实施例提供的第二种制备方法，即采用液相法合成磷酸锰铁的前体2，采用固相法合成磷酸锰铁锂材料，通过采用液相法合成磷酸锰铁的前体2，可实现Mn、Fe原子级别的混合，形成均匀的磷酸锰铁的前驱体，减少锰的析出。
性能测试2：
通过采用上述实施例所提供的第二种制备方法合成实施例4、实施例5、实施例6所提供三种磷酸锰铁锂材料，以及采用纯固相法合成对比例1和对比例2提供的两种磷酸锰铁锂材料，并通过对实施例4、实施例5、实施例6以及对比例1和对比例2所制备的锂电池材料的锰的析出重量进行分析测试。
实施例4：
本实施例提供了一种磷酸锰铁锂材料，其中磷酸锰铁锂材料的内核材料的化学式为Li1.03Mn0.65Fe0.35Mg0.1PO4，磷酸锰铁锂材料采用如下制备方法制备得到：
(1)准备足量的硫酸锰、磷酸铁、氧化镁、磷酸进行混合，缓慢加入双氧水、HEDP得到混合液1，将混合液1加热至90℃，过滤干燥后得到前体2；
(2)将前体2、葡萄糖、PEG和碳酸锂进行混合研磨得到前体3；其中碳酸锂中锂元素、硫酸锰中的锰元素、磷酸铁中的铁元素、氧化镁中的镁元素、磷酸中的磷元素按照化学式Li1.03Mn0.65Fe0.35Mg0.1PO4中的化学计量比进行配比，即按照摩尔比Li:Mn:Fe:Mg:P＝1.03:0.65:0.35:0.1:1；
(3)将上述前体3在惰性气氛保护下进行烧结，并在惰性气氛保护下冷却至室温，得到粉料，其中惰性气氛包括氮气或者氩气或者氮气和氩气的混合气体，适合的烧结工艺的过程控制参数包括：以6min℃的升温速率，升温至800℃，保温18h；其中葡萄糖和PEG在Li1.03Mn0.65Fe0.35Mg0.1PO4的外表面形成碳包覆层，并且葡萄糖和PEG经过高温焙烧形成石墨化碳，在磷酸锰铁锂材料中石墨化碳的质量百分比含量为1.0％。
实施例5：
本实施例提供了一种磷酸锰铁锂材料，其中磷酸锰铁锂材料的内核材料的化学式为Li1.02Mn0.58Fe0.35Nb0.1PO4，磷酸锰铁锂材料采用如下制备方法制备得到：
(1)准备足量的硫酸锰、磷酸铁、Nb2O5、磷酸进行混合，缓慢加入双氧水、HEDP得到混合液1，将混合液1加热至90℃，过滤干燥后得到前体2；
(2)将前体2、葡萄糖、PEG和碳酸锂进行混合研磨得到前体3；其中碳酸锂中锂元素、硫酸锰中的锰元素、磷酸铁中的铁元素、氧化铌中的铌元素、磷酸中的磷元素按照化学式Li1.02Mn0.58Fe0.35Nb0.1PO4中的化学计量比进行配比，即按照摩尔比Li:Mn:Fe:Nb:P＝1.02:0.58:0.35:0.1:1；
(3)将上述前体3在惰性气氛保护下进行烧结，并在惰性气氛保护下冷却至室温，得到粉料，其中惰性气氛包括氮气或者氩气或者氮气和氩气的混合气体，适合的烧结工艺的过程控制参数包括：以6min℃的升温速率，升温至800℃，保温18h；其中葡萄糖和PEG在Li1.02Mn0.58Fe0.35Nb0.1PO4的外表面形成碳包覆层，并且葡萄糖和PEG经过高温焙烧形成石墨化碳，在磷酸锰铁锂材料中石墨化碳的含量为0.8％。
实施例6：
本实施例提供了一种磷酸锰铁锂材料，其中磷酸锰铁锂材料的内核材料的化学式为Li1.01Mn0.58Fe0.35Nb0.08Ti0.02PO4，磷酸锰铁锂材料采用如下制备方法制备得到：
(1)准备足量的硫酸锰、磷酸铁、Nb2O5、TiO2、磷酸进行混合，缓慢加入双氧水、HEDP得到混合液1，将混合液1加热至90℃，过滤干燥后得到前体2；
(2)将前体2、葡萄糖、PEG和碳酸锂进行混合研磨得到前体3；其中碳酸锂中锂元素、硫酸锰中的锰元素、磷酸铁中的铁元素、氧化铌中的铌元素、氧化钛中的钛元素、磷酸中的磷元素按照化学式Li1.01Mn0.58Fe0.35Nb0.08Ti0.02PO4中的化学计量比进行配比，即按照摩尔比Li:Mn:Fe:Nb:Ti:P＝1.01:0.58:0.35: 0.08:0.02:1；
(3)将上述前体3在惰性气氛保护下进行烧结，并在惰性气氛保护下冷却至室温，得到粉料，其中惰性气氛包括氮气或者氩气或者氮气和氩气的混合气体，适合的烧结工艺的过程控制参数包括：以6min℃的升温速率，升温至800℃，保温18h；其中葡萄糖和PEG在Li1.01Mn0.58Fe0.35Nb0.08Ti0.02PO4的外表面形成碳包覆层，并且葡萄糖和PEG经过高温焙烧形成石墨化碳，在磷酸锰铁锂材料中石墨化碳的含量为0.5％。
对比例1和对比例2同性能测试1部分所提供。
实施例4-6和对比例1-2的锂离子电池的制备方法同上。
锰离子析出重量测试测试方法：
(1)采用上述实施例4-6以及对比例1-2的锂离子电池样品，将各个锂离子电池样品充电至一标准电压，确保电池处于正常工作状态24h；
(2)取出上述实施例4-6以及对比例1-2的锂离子电池样品，并将上述实施例4-6以及对比例1-2的锂离子电池样品进行分解，分解方法是将电池进行溶剂萃取，并使用适当的溶剂将电池中的锰离子溶解出来；
(3)分别测定上述实施例4-6以及对比例1-2的锂离子电池样品中的锰离子的重量，在重量测量方法中，用溶剂将锰离子从溶液中沉淀出来，经过干燥和称重后，计算析出的锰离子的重量。
经过测试上述实施例4-6以及对比例1-2所制备的锂离子电池的锰的析出重量结果如下：
表三、实施例4-6及对比例1-2的锰析出分析数据

通过将实施例4-6与对比例1-2的锰析出重量进行比对分析，可得出采用本申请实施例提供第二种制备方法，即采用液相法合成前驱体，并采用固相法合成磷酸锰铁锂材料，可明显减少锂离子电池中的锰析出，制备出性能更好的锂离子电池。

Claims (23)

  1. 一种磷酸锰铁锂材料，所述磷酸锰铁锂材料包括内核以及包覆在所述内核表面的包覆层，所述内核的材料包括化学式为LiaMnbFecMdPO4，其中M包括镁、钙、锶、钴、钛、锆、钼、钒、铌、镍、钪、铬、铜、锌、铍、镧以及铝中的至少一种元素，所述碳包覆层中包括石墨化碳。
  2. 根据权利要求1所述的磷酸锰铁锂材料，其中，在所述磷酸锰铁锂材料中所述石墨化碳的质量百分含量为0.48％～1.02％。
  3. 根据权利要求1所述的磷酸锰铁锂材料，其中，所述包覆层配置为通过碳源烧结后形成，并且形成所述包覆层的碳源包括葡萄糖、木糖醇、聚乙二醇、蔗糖、乳糖、柠檬酸聚丙烯酰胺中的至少一种。
  4. 根据权利要求1-3任一项所述的磷酸锰铁锂材料，其中，在所述磷酸锰铁锂材料中所述碳包覆层的质量百分含量为0.5％-3％。
  5. 根据权利要求1-3任一项所述的磷酸锰铁锂材料，其中，在所述LiaMnbFecMdPO4中，0.98≤a≤1.10，0.10≤b≤0.68，0.20≤c≤0.70，0.01≤d≤0.12，0.98≤a/(b+c+d)≤1.03；或者，在所述LiaMnbFecMdPO4中，0.98≤a≤1.05，0.10≤b≤0.68，0.20≤c≤0.70，0.005≤d≤0.12，0.98≤a/(b+c+d)≤1.03。
  6. 根据权利要求5所述的磷酸锰铁锂材料，其中，在所述LiaMnbFecMdPO4中，锰元素的摩尔含量大于铁元素的摩尔含量。
  7. 一种磷酸锰铁锂材料的制备方法，所述制备方法包括以下步骤：
    将锂源、锰源、铁源、磷源、掺杂金属M源、碳源进行混合得到 前体1；
    在惰性气氛保护下，将所述前体1进行烧结处理，得到磷酸锰铁锂材料；
    其中，所述掺杂金属M源包括镁源、钙源、锶源、钴源、钛源、锆源、钼源、钒源、铌源、镍源、钪源、铬源、铜源、锌源、铍源、镧源以及铝源中的一种或多种。
  8. 根据权利要求7所述的磷酸锰铁锂材料的制备方法，其中，将锂源、锰源、铁源、磷源、掺杂金属M源、碳源进行混合得到前体1的步骤中，所述锂源中的锂元素、所述锰源中的锰元素、所述铁源的铁元素以及所述掺杂金属源中的掺杂金属元素的摩尔比为(0.98～1.10)：(0.10～0.68)：(0.20～0.70)：(0.01～0.12)。
  9. 根据权利要求7所述的磷酸锰铁锂材料的制备方法，其中，将所述前体1进行烧结处理包括将所述前体1以第一升温速率升温至第一温度，保温第一时间；其中：
    所述第一升温速率为2℃/min-10℃/min；和/或
    所述第一温度为600℃-950℃；和/或
    所述第一时间为5-24h。
  10. 一种磷酸锰铁锂材料的制备方法，所述制备方法包括以下步骤：
    将锰源、铁源、磷源、掺杂金属M源、双氧水和络合剂进行混合得到混合液1；
    将所述混合液1进行加热后，过滤干燥得到前体2；
    将所述前体2、碳源、锂源、表面活性剂进行混合得到前体3；
    将所述前体3进行烧结处理后得到磷酸锰铁锂材料；
    其中，所述掺杂金属源包括镁源、钙源、锶源、钴源、钛源、锆源、钼源、钒源、铌源、镍源、钪源、铬源、铜源、锌源、铍源、镧源以 及铝源中的一种或多种。
  11. 根据权利要求10所述的磷酸锰铁锂材料的制备方法，其中，将锂源、锰源、铁源、磷源、掺杂金属M源、碳源进行混合得到前体1的步骤中，所述锂源中的锂元素、所述锰源中的锰元素、所述铁源的铁元素以及所述掺杂金属源中的掺杂金属元素的摩尔比为(0.98～1.05)：(0.10～0.68)：(0.20～0.70)：(0.005～0.12)。
  12. 根据权利要求10所述的磷酸锰铁锂材料的制备方法，其中，将所述混合液1进行加热包括将所述混合液1升温至第二温度，其中所述第二温度为60℃-95℃。
  13. 根据权利要求10所述的磷酸锰铁锂材料的制备方法，其中，将所述前体3进行烧结处理包括将所述前体3以第一升温速率升温至第一温度，保温第一时间；其中：
    所述第一升温速率为2℃/min-10℃/min；和/或
    所述第一温度为600℃-950℃；和/或
    所述第一时间为5-24h。
  14. 根据权利要求7或10所述的磷酸锰铁锂材料的制备方法，其中，所述锂源包括碳酸锂、磷酸二氢锂中的至少一种。
  15. 根据权利要求7或10所述的磷酸锰铁锂材料的制备方法，其中，所述铁源包括硫酸亚铁、磷酸铁、磷酸氢铁、磷酸二氢铁、乙酸铁、铁粉中的至少一种。
  16. 根据权利要求7或10所述的磷酸锰铁锂材料的制备方法，其中，所述锰源包括硫酸锰、碳酸锰、硝酸锰、醋酸锰、草酸锰、磷酸锰、磷酸氢锰中的至少一种。
  17. 根据权利要求7或10所述的磷酸锰铁锂材料的制备方法，其中，所述磷源包括磷酸、磷酸二氢铵中的至少一种。
  18. 根据权利要求7或10所述的磷酸锰铁锂材料的制备方法， 其特征在于，所述掺杂金属M源包括镁、钙、锶、钴、钛、锆、钼、钒、铌、镍、钪、铬、铜、锌、铍、镧、铝中的至少一种元素的磷酸盐、磷酸氢盐、磷酸二氢盐、碳酸盐、甲酸盐、乙酸盐、羟乙酸盐、乳酸盐、酒石酸盐、草酸盐、氧化物、氢氧化物、氟化物、氯化物、硝酸盐、硫酸盐、溴化物中的至少一种。
  19. 根据权利要求18所述的磷酸锰铁锂材料的制备方法，其中，所述掺杂金属源包括镁、钙、锶、钴、钛、锆、钼、钒、铌、镍、钪、铬、铜、锌、铍、镧、铝中的至少一种元素的磷酸盐，并且所述掺杂金属源包括镁、钙、锶、钴、钛、锆、钼、钒、铌、镍、钪、铬、铜、锌、铍、镧、铝中的至少一种元素的磷酸盐配置为橄榄石结构。
  20. 根据权利要求10所述的磷酸锰铁锂材料的制备方法，其中，所述络合剂包括HEDP、ATMP、DTPA中的至少一种。
  21. 根据权利要求10所述的磷酸锰铁锂材料的制备方法，其中，所述表面活性剂包括PEG和ATMP中的至少一种。
  22. 一种正极极片，包括正极集流体，以及正极活性物质层，所述正极活性物质层位于所述正极集流体的表面，所述正极活性物质层的材料包括权利要求1-6任一项所述的磷酸锰铁锂材料或权利要求7-21任一项所述的制备方法得到的磷酸锰铁锂材料。
  23. 一种锂离子电池，所述锂离子电池包括权利要求1-6任一项所述的磷酸锰铁锂材料。
PCT/CN2023/136385 2023-11-15 2023-12-05 磷酸锰铁锂材料及其制备方法、正极极片及锂离子电池 Pending WO2025102446A1 (zh)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN120527376A (zh) * 2025-07-24 2025-08-22 江苏时代新能源科技有限公司 磷酸锰铁锂材料及其制备方法、二次电池与用电装置
CN120637465A (zh) * 2025-08-11 2025-09-12 江苏时代新能源科技有限公司 一种正极活性材料、电池单体、电池装置及用电装置

Families Citing this family (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN120048843A (zh) * 2023-11-27 2025-05-27 江苏时代新能源科技有限公司 制备正极材料方法、正极材料、正极片、电池和用电装置
CN118221094A (zh) * 2024-03-26 2024-06-21 曲靖市德方纳米科技有限公司 一种磷酸锰铁锂正极材料及其制备方法和锂离子电池
CN121005384A (zh) * 2024-05-24 2025-11-25 江苏时代新能源科技有限公司 磷酸盐正极活性材料及其制备方法、正极极片、电池单体和用电装置
CN118738336A (zh) * 2024-06-28 2024-10-01 湖北亿纬动力有限公司 一种磷酸盐系正极材料及其制备方法和应用
CN118598105A (zh) * 2024-07-19 2024-09-06 广东瑞浦兰钧能源有限公司 磷酸铁锂锂离子电池正极材料、其制备方法及应用
CN118651838B (zh) * 2024-08-21 2024-11-26 四川大学 一种磷酸锰铁锂的改性方法
CN119118094B (zh) * 2024-11-14 2025-04-29 上海量孚新能源科技有限公司 磷酸锰铁锂复合材料及其制备方法、含其的锂离子电池
CN119650640A (zh) * 2024-12-10 2025-03-18 北京当升材料科技股份有限公司 正极活性材料及其制备方法、电池
CN119370823B (zh) * 2024-12-23 2025-03-28 湖南裕能新能源电池材料股份有限公司 高容量磷酸锰铁锂正极材料及其制备方法和锂电池
CN120749156A (zh) * 2025-09-03 2025-10-03 江苏时代新能源科技有限公司 电池单体、电池装置和用电装置

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20180145319A1 (en) * 2014-12-31 2018-05-24 Samsung Sdi Co., Ltd. Precursor of cathode active material for lithium secondary batteries, method of preparing same, cathode active material for lithium secondary batteries, method of preparing same, and lithium secondary battery comprising said cathode active material
CN110085839A (zh) * 2019-05-07 2019-08-02 佛山市德方纳米科技有限公司 磷酸铁锂复合正极材料及其制备方法和应用
CN115863579A (zh) * 2022-12-09 2023-03-28 宁波容百新能源科技股份有限公司 一种正极材料及其制备方法、锂离子电池
CN116216682A (zh) * 2023-02-23 2023-06-06 广东邦普循环科技有限公司 磷酸铁锰前驱体的制备方法及应用

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20180145319A1 (en) * 2014-12-31 2018-05-24 Samsung Sdi Co., Ltd. Precursor of cathode active material for lithium secondary batteries, method of preparing same, cathode active material for lithium secondary batteries, method of preparing same, and lithium secondary battery comprising said cathode active material
CN110085839A (zh) * 2019-05-07 2019-08-02 佛山市德方纳米科技有限公司 磷酸铁锂复合正极材料及其制备方法和应用
CN115863579A (zh) * 2022-12-09 2023-03-28 宁波容百新能源科技股份有限公司 一种正极材料及其制备方法、锂离子电池
CN116216682A (zh) * 2023-02-23 2023-06-06 广东邦普循环科技有限公司 磷酸铁锰前驱体的制备方法及应用

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN120527376A (zh) * 2025-07-24 2025-08-22 江苏时代新能源科技有限公司 磷酸锰铁锂材料及其制备方法、二次电池与用电装置
CN120637465A (zh) * 2025-08-11 2025-09-12 江苏时代新能源科技有限公司 一种正极活性材料、电池单体、电池装置及用电装置

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