WO2024000816A1 - 一种正极材料及其制备方法和应用 - Google Patents

一种正极材料及其制备方法和应用 Download PDF

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WO2024000816A1
WO2024000816A1 PCT/CN2022/118010 CN2022118010W WO2024000816A1 WO 2024000816 A1 WO2024000816 A1 WO 2024000816A1 CN 2022118010 W CN2022118010 W CN 2022118010W WO 2024000816 A1 WO2024000816 A1 WO 2024000816A1
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cathode material
manganese
positive electrode
present
preparation
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PCT/CN2022/118010
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English (en)
French (fr)
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李爱霞
余海军
谢英豪
李长东
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广东邦普循环科技有限公司
湖南邦普循环科技有限公司
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Priority to HU2400112A priority Critical patent/HUP2400112A1/hu
Priority to GB2310145.4A priority patent/GB2624493A/en
Priority to DE112022003304.5T priority patent/DE112022003304T5/de
Publication of WO2024000816A1 publication Critical patent/WO2024000816A1/zh

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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
    • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
    • H01M4/50—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese
    • H01M4/505—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • 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
    • 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
    • H01M4/485—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
    • H01M4/52—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron
    • H01M4/525—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/58—Selection of substances as active materials, active masses, active liquids of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
    • H01M4/5825—Oxygenated metallic salts or polyanionic structures, e.g. borates, phosphates, silicates, olivines
    • 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

  • layered cathode materials are an important category, mainly including one-element materials (lithium cobalt oxide, lithium nickel oxide, lithium manganate), binary materials (lithium nickel cobalt oxide, lithium nickel manganate). , lithium cobalt manganate) and ternary materials (lithium nickel cobalt manganate).
  • one-element materials lithium cobalt oxide, lithium nickel oxide, lithium manganate
  • binary materials lithium nickel cobalt oxide, lithium nickel manganate
  • lithium cobalt manganate lithium cobalt manganate
  • ternary materials lithium nickel cobalt manganate
  • the main source of residual alkali is Li that has not been burned in the sintering reaction, or residual alkali produced by the decomposition of materials caused by high-temperature sintering. On the other hand, it is generated when the material has been left in the air for too long. Specifically, when the humidity content in the air is high When the lithium in the crystal lattice tends to migrate to the surface of the cathode material, it reacts with moisture and carbon dioxide in the environment to generate residual alkali.
  • the higher the Ni content the more obvious the tendency of lithium to migrate from the crystal lattice to the surface. Therefore, relatively speaking, the residual alkali content of high-nickel materials is higher compared with other cathode materials.
  • Mn(III) undergoes a disproportionation reaction to form Mn(IV) and Mn(II).
  • the manganese especially Mn(II) of the layered cathode materials )
  • the crystal lattice of the layered positive electrode material is destroyed, which may cause the positive electrode particles to break, further affecting the performance of the positive electrode material. Cycle performance.
  • cathode material that can effectively inhibit manganese dissolution, improve cycle performance, and reduce residual alkali content to a certain extent.
  • Layered cathode material the chemical formula of the layered cathode material is Li x MO 2 , where x ranges from 0.95 to 1.1, and M is a transition metal, including Mn;
  • the coating material is partially provided on the surface of the layered cathode material, and is partially doped in the surface layer of the layered cathode material; the coating material includes tetravalent manganese, lithium ions and phosphate. ion.
  • the surface layer of the layered cathode material is doped with tetravalent manganese (equivalent to forming a surface layer enriched in tetravalent manganese), thereby inhibiting the formation of Mn(III) in the layered cathode material. Disproportionation, thereby inhibiting the production and dissolution of Mn(II), ultimately improving the cycle performance of the resulting cathode material.
  • Lithium ions and phosphate ions in the coating material may combine to form lithium phosphate, which, as a fast ion conductor, can effectively improve the rate performance of the resulting cathode material.
  • the coating material provided on the surface of the layered cathode material blocks the contact between the layered cathode material and the outside world to a certain extent, thereby reducing the generation of residual alkali and improving the overall performance of the resulting cathode material.
  • M further includes Ni.
  • the molar percentage of Ni in M in Li x MO 2 is ⁇ 75%.
  • the molar percentage of Ni to M in Li x MO 2 is 80 to 99%.
  • the molar percentage of Ni to M in Li x MO 2 is 90 to 95%.
  • the cathode material provided by traditional technology usually contains high residual alkali and further has poor cycle performance; the present invention can effectively improve the cycle performance of the resulting cathode material through the design of the structure and material.
  • M further includes Co.
  • M is Ni, Co and Mn.
  • M is Ni, Co and Mn, and the molar ratio of the three is 1 to 19:1:1.
  • the presence form of tetravalent manganese includes manganese dioxide.
  • a preparation method of the cathode material including:
  • the mechanism of the preparation method is as follows:
  • the phosphoric acid aqueous solution reacts with the residual alkali, reducing the residual alkali content; on the other hand, the lithium in the residual alkali can react with the phosphate radicals The reaction occurs to produce precipitated lithium phosphate, which is deposited on the surface of the layered cathode material; on the other hand, the acidity of phosphoric acid will also destroy the surface structure of the layered cathode material to a certain extent, leaving defects on it and increasing the damage of the layered cathode material. Specific surface area.
  • Alkaline potassium permanganate reacts with divalent manganese precursor to generate manganese dioxide precipitate that adheres to the surface of the layered cathode material;
  • the layered cathode material is superficially doped with manganese dioxide and lithium phosphate.
  • the defective locations formed by phosphoric acid etching on the surface of the layered cathode material are more likely to deposit manganese dioxide, and are also more likely to serve as a path for superficial doping of coating materials such as tetravalent manganese; thus, Each step of the present invention cooperates with each other to make it easier for the coating material to enter the crystal lattice and form shallow doping, thereby exerting its effect to improve the comprehensive performance of the obtained cathode material.
  • the use of phosphoric acid aqueous solution to treat the cathode layered material can convert the lithium in the residual alkali into lithium phosphate, which avoids the loss of lithium caused by traditional acid washing and alkali washing, thereby avoiding the capacity loss of the cathode material and certain The capacity of the cathode material is increased to a certain extent.
  • the divalent manganese precursor is added first and then alkaline potassium permanganate is added, the divalent manganese tends to form manganese phosphate precipitation with phosphate radicals, and the probability of forming tetravalent manganese is reduced.
  • the invention limits the order in which materials are added, further ensuring the consistency and high quality of the obtained cathode material performance.
  • the surface layer is doped with the coating material, which is equivalent to forming a manganese-rich surface layer, inhibiting the dissolution of manganese in the cathode material, and improving the performance of the resulting cathode. Cycling performance of materials.
  • the concentration of the phosphoric acid aqueous solution is 1 to 5 wt%.
  • the solid-liquid ratio of the layered cathode material and the phosphoric acid aqueous solution is 0.5-1g/mL.
  • the mixing time is 5-30 minutes.
  • the mass ratio of the solute potassium permanganate in the alkaline potassium permanganate and the layered cathode material is 4-16g:500g.
  • the mass ratio of the solute potassium permanganate in the alkaline potassium permanganate and the layered cathode material is 7.8-8.1g:500g.
  • the pH of the alkaline potassium permanganate solution is 7-13.
  • the pH of the alkaline potassium permanganate solution is approximately 12.
  • the concentration of the alkaline potassium permanganate solution is 0.1-2 mol/L.
  • the concentration of the alkaline potassium permanganate solution is approximately 1 mol/L.
  • the molar ratio of the alkaline potassium permanganate and the divalent manganese precursor is 0.8-1.2:1.
  • the divalent manganese precursor includes at least one of manganese hydroxide, manganese sulfate and manganese chloride.
  • the divalent manganese precursor is selected from manganese hydroxide. Impurity components introduced via the divalent manganese precursor can thus be avoided as much as possible.
  • the duration of the reaction is 0.5 to 2 h; preferably, the reaction method is a standing reaction.
  • the drying temperature is 80-200°C.
  • the calcination temperature is 450 ⁇ 550°C.
  • the duration of the calcination is 6 to 8 hours.
  • the calcining atmosphere is an oxygen atmosphere.
  • a secondary battery is provided, and the raw materials for preparing the secondary battery include the cathode material.
  • Figure 1 is a scanning electron microscope image of the cathode material obtained in Example 1 of the present invention.
  • Figure 2 is a scanning electron microscope image of the cathode material obtained in Example 1 of the present invention.
  • a cathode material is prepared.
  • the specific process is:
  • step S4 Transfer the product obtained in step S3 to a muffle furnace and calcine it in an oxygen atmosphere.
  • the sintering temperature is 450°C and the time is 8 hours.
  • This embodiment prepares a cathode material.
  • the specific differences from Example 1 are:
  • step S1 the mass concentration of the phosphoric acid aqueous solution is 1%.
  • This embodiment prepares a cathode material.
  • the specific differences from Example 1 are:
  • step S4 the sintering temperature is 550°C and the sintering time is 6 hours.
  • a cathode material is prepared in this comparative example.
  • the specific differences from Example 1 are:
  • step S1 the phosphoric acid aqueous solution is replaced with an oxalic acid aqueous solution of equal concentration.
  • a cathode material is prepared in this comparative example.
  • the specific differences from Example 1 are:
  • step S1 replace the phosphoric acid aqueous solution with an equal volume of water
  • Step S2 is not included.
  • step S1 the phosphoric acid aqueous solution is replaced with an equal volume of water.
  • a cathode material is prepared in this comparative example.
  • the specific differences from Example 1 are:
  • Step S2 is not included.
  • the positive electrode material obtained in Examples 1 to 3 and Comparative Examples 1 to 4 was used as the positive active material, a button battery was prepared, and the electrochemical performance of the button battery was tested. Specifically:
  • N-methylpyrrolidone as the solvent, mix the cathode material, acetylene black and PVDF in a mass ratio of 9.2:0.5:0.3 to form a slurry. Then apply the slurry on the aluminum foil and air-dry at 80°C for 8 hours. Afterwards, it was vacuum dried at 120°C for 12 hours to obtain the positive electrode.
  • the cathode is a lithium metal sheet
  • the separator is a polypropylene film
  • the electrolyte is 1M LiPF 6 -EC/DMC (1:1, v/v)
  • a 2032 button battery case is used.
  • the obtained button cell was tested for electrochemical performance at 25°C, current 0.1C, and voltage ranging from 3.0 to 4.5V.
  • Example 2 Comparing Example 1 and Example 2, it can be seen that if the concentration of phosphoric acid is reduced, the surface defects formed on the surface of LiNi 0.9 Co 0.05 Mn 0.05 O 2 are reduced, and the corresponding loss of lithium is reduced, so it has a slightly higher gram capacity; however, The effect of superficial doping of the coating is reduced, the manganese content of the formed manganese-rich layer is reduced, and the cycle performance becomes worse.
  • Example 1 Comparing Example 1 and Example 3, it can be seen that a higher calcination temperature may lose cycle performance to a certain extent; the surface defects formed by phosphoric acid in the present invention can significantly reduce the temperature required to form shallow doping, thereby achieving a certain The cycle performance of the resulting cathode material is improved to a certain extent.

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Abstract

本发明公开了一种正极材料及其制备方法和应用，本发明提供的正极材料，包括：化学式为Li xMO 2的层状正极材料和包覆物质，其中x的范围为0.95～1.1，M为过渡金属，包括Mn；包覆物质设于层状正极材料表面，并部分掺杂于层状正极材料的表层中；包覆物质中包括四价锰、锂离子和磷酸根离子。本发明提供的正极材料能够有效抑制含锰正极材料中锰的溶出，提升循环性能。本发明还提供了上述正极材料的制备方法和应用。

Description

一种正极材料及其制备方法和应用 技术领域
本发明涉及二次电池技术领域，尤其是涉及一种正极材料及其制备方法和应用。
背景技术
锂离子二次电池正极材料中，层状正极材料是重要的一类，主要包括一元材料(钴酸锂、镍酸锂、锰酸锂)、二元材料(镍钴酸锂、镍锰酸锂、钴锰酸锂)和三元材料(镍钴锰酸锂)。但是当上述层状正极材料中Ni含量超过90％时(占过渡金属总量的摩尔百分比)，正极材料表面容易产生残碱。表面残碱主要指的是正极材料颗粒表面的LiOH、Li 2CO 3之类的物质。残碱的来源主要是烧结反应未烧进去的Li，或者高温烧结导致材料分解产生的残碱，另一方面就是材料在空气中放置太久产生的，具体的是，当空气中湿度含量较高时，晶格中的锂倾向于向正极材料表面迁移，并和环境中的水分和二氧化碳反应生成残碱。
正极材料中Ni含量越高，烧结条件越苛刻，越难以烧结形成特定锂金属比的材料，造成烧结产物的残碱多。同时，Ni含量越高，锂从晶格向表面的迁移倾向更明显，因此相对而言，高镍材料的残碱含量与其他正极材料相比更高。
含锰正极材料在循环过程中，Mn(III)产生歧化反应，形成Mn(IV)和Mn(II)，此外，随着Ni含量的升高，层状正极材料的锰(特别是Mn(II))容易在循环过程中溶出，迁移并在负极处沉淀，破坏负极SEI膜；同时，随着锰的溶出层状正极材料的晶格被破坏，可能会导致正极颗粒破碎，进一步影响正极材料的循环性能。
综上，提供一种可有效抑制锰溶出，提升循环性能，并在一定程度上降低残碱含量的正极材料非常重要。
发明内容
本发明旨在至少解决现有技术中存在的技术问题之一。为此，本发明提出一种正极材料，能够有效抑制含锰正极材料中锰的溶出，并在一定程度上降低残碱含量。
本发明还提供了一种上述正极材料的制备方法。
本发明还提供了上述正极材料的应用。
根据本发明的第一方面实施例，提供了一种正极材料，所述正极材料包括：
层状正极材料，所述层状正极材料的化学式为Li xMO 2，其中x的范围为0.95～1.1，M为 过渡金属，包括Mn；
包覆物质，所述包覆物质部分设于所述层状正极材料表面，部分掺杂于所述层状正极材料的表层中；所述包覆物质中包括四价锰、锂离子和磷酸根离子。
根据本发明实施例提供的正极材料，至少具有如下有益效果：
(1)含锰层状正极材料在充放电时，内部的Mn(III)(三价锰)容易发生歧化反应生成Mn(II)和Mn(IV)，前者容易脱离层状正极材料的晶格溶出。
本发明提供的正极材料中，层状正极材料表层中掺杂有四价锰(相当于形成了四价锰富集的表层)，由此可抑制所述层状正极材料中Mn(III)的歧化，进而抑制了Mn(II)的产生和溶出，最终提升了所得正极材料的循环性能。
(2)包覆物质中的锂离子和磷酸根离子可能复合形成磷酸锂，作为一种快离子导体，可有效提升所得正极材料的倍率性能。
(3)包覆物质中，磷酸根还可以固定和保护二氧化锰中的四价锰，抑制包覆物质中锰的溶出。
(4)设于所述层状正极材料表面的包覆物质，在一定程度上阻隔了所述层状正极材料与外界的接触，因此可减少残碱的产生，提升所得正极材料的综合性能。
根据本发明的一些实施例，Li xMO 2中，M还包括Ni。
根据本发明的一些实施例，Li xMO 2中Ni占M的摩尔百分比≥75％。
根据本发明的一些优选的实施例，Li xMO 2中Ni占M的摩尔百分比为80～99％。
根据本发明的一些优选的实施例，Li xMO 2中Ni占M的摩尔百分比为90～95％。
在该镍含量下，传统技术提供的正极材料，通常会包括较高的残碱，进一步的循环性能较差；本发明通过结构和材质的设计，可有效提升所得正极材料的循环性能。
根据本发明的一些实施例，Li xMO 2中，M还包括Co。
根据本发明的一些实施例，Li xMO 2中，M为Ni、Co和Mn。
根据本发明的一些实施例，Li xMO 2中，M为Ni、Co和Mn，且三者的摩尔比为1～19:1:1。
根据本发明的一些实施例，所述包覆物质中，四价锰的存在形式包括二氧化锰。
根据本发明的第二方面实施例，提出了所述正极材料的制备方法，包括：
将所述层状正极材料和磷酸水溶液混合，并向所得混合体系中依次添加碱性高锰酸钾溶液和二价锰前体；反应后将固体产物干燥、煅烧。
所述制备方法的机理如下：
层状正极材料表面都存在一定量的残碱，在与磷酸水溶液混合的过程中，一方面磷酸水溶液与残碱发生反应，降低残碱含量；另一方面，残碱中的锂可以与磷酸根发生反应产生沉 淀磷酸锂，沉积在层状正极材料表面；再一方面，磷酸的酸性也会一定程度上破坏层状正极材料的表面结构，在其上留下缺陷，增大层状正极材料的比表面积。
碱性高锰酸钾与二价锰前体发生反应，生成二氧化锰沉淀附着在层状正极材料表面；
煅烧过程中，二氧化锰和磷酸锂对层状正极材料进行浅表掺杂。
根据本发明实施例提供的制备方法，至少具有如下有益效果：
(1)在煅烧过程中，磷酸刻蚀层状正极材料表面形成的缺陷位置，更容易沉积二氧化锰，也更容易作为四价锰等包覆物质形成浅表掺杂的途径；由此，本发明各步骤之间相互配合，使包覆物质更容易进入晶格，形成浅表掺杂，进而发挥其作用提升所得正极材料的综合性能。
(2)采用磷酸水溶液处理正极层状材料，可将残碱中的锂转变为磷酸锂，即避免了传统酸洗、碱洗带来的锂流失，由此避免了正极材料的容量损失，一定程度上提升了正极材料的容量。
(3)制备方法中，若先添加二价锰前体，再添加碱性高锰酸钾，则二价锰倾向于与磷酸根形成磷酸锰沉淀，而形成四价锰的几率下降。本发明限定了物料的添加顺序，进一步确保了所得正极材料性能的一致性和高质量。
(4)所述制备方法制得的正极材料中，表层中掺杂了所述包覆物质，由此相当于形成了一层富锰表层，抑制了正极材料中锰的溶出，提升了所得正极材料的循环性能。
根据本发明的一些实施例，所述磷酸水溶液的浓度为1～5wt％。
根据本发明的一些实施例，所述层状正极材料和磷酸水溶液的固液比为0.5-1g/mL。
根据本发明的一些实施例，所述混合的时长为5-30min。
根据本发明的一些实施例，所述碱性高锰酸钾中的溶质高锰酸钾和所述层状正极材料的质量比为4～16g：500g。
根据本发明的一些优选的实施例，所述碱性高锰酸钾中的溶质高锰酸钾和所述层状正极材料的质量比为7.8～8.1g：500g。
根据本发明的一些实施例，所述碱性高锰酸钾溶液的pH为7-13。
根据本发明的一些优选的实施例，所述碱性高锰酸钾溶液的pH约为12。
根据本发明的一些实施例，所述碱性高锰酸钾溶液的浓度为0.1-2mol/L。
根据本发明的一些实施例，所述碱性高锰酸钾溶液的浓度约为1mol/L。
根据本发明的一些实施例，所述碱性高锰酸钾和二价锰前体的摩尔比为0.8～1.2:1。
根据本发明的一些实施例，所述二价锰前体包括氢氧化锰、硫酸锰和氯化锰中的至少一种。
根据本发明的一些优选的实施例，所述二价锰前体选自氢氧化锰。由此可尽可能避免经 由二价锰前体引入的杂质成分。
根据本发明的一些实施例，所述反应的时长为0.5～2h；优选地，所述反应的方法为静置反应。
根据本发明的一些实施例，所述干燥的温度为80-200℃。
根据本发明的一些实施例，所述干燥的时长为4-20h。
根据本发明的一些实施例，所述干燥的时长为8～10h。
根据本发明的一些实施例，所述煅烧的温度为450～550℃。
根据本发明的一些实施例，所述煅烧的时长为6～8h。
根据本发明的一些实施例，所述煅烧的气氛为氧气气氛。
根据本发明的第三方面实施例，提出了一种二次电池，所述二次电池的制备原料包括所述的正极材料。
根据本发明实施例提供的二次电池，至少具有如下有益效果：
由于所述二次电池采用了上述实施例的正极材料的全部技术方案，因此至少具有上述实施例的技术方案所带来的所有有益效果。
本发明的其它特征和优点将在随后的说明书中阐述，并且，部分地从说明书中变得显而易见，或者通过实施本发明而了解。
附图说明
本发明的上述和/或附加的方面和优点从结合下面附图对实施例的描述中将变得明显和容易理解，其中：
图1是本发明实施例1所得正极材料的扫描电镜图。
图2是本发明实施例1所得正极材料的扫描电镜图。
具体实施方式
下面详细描述本发明的实施例，所述实施例的示例在附图中示出，其中自始至终相同或类似的标号表示相同或类似的元件或具有相同或类似功能的元件。下面通过参考附图描述的实施例是示例性的，仅用于解释本发明，而不能理解为对本发明的限制。
实施例1
本实施例制备了一种正极材料，具体过程为：
S1.取500g LiNi 0.9Co 0.05Mn 0.05O 2浸于质量分数为5％，体积为500ml的磷酸水溶液中，浸泡5min；
S2.依次向步骤S1所得混合物中加入50ml 1mol/L的碱性高锰酸钾(pH＝12)和5g氢氧化锰，搅拌均匀后，静置反应0.5h，反应生成的二氧化锰沉淀于LiNi 0.9Co 0.05Mn 0.05O 2表面；
S3.固液分离步骤S2所得产物，并将所得固体置于干燥箱中于80℃干燥8h；
S4.将步骤S3所得产物转移到马弗炉中，在氧气气氛下进行煅烧，烧结温度为450℃，时间为8h。
本实施例所得正极材料的SEM图如图1～2所示，结果显示，正极材料表面存在一定的凹陷，凹坑中以及表面上沉积有包覆物质。由此说明包覆物质已成功沉积在层状正极材料表面。
实施例2
本实施例制备了一种正极材料，具体与实施例1的区别在于：
步骤S1中，磷酸水溶液的质量浓度为1％。
实施例3
本实施例制备了一种正极材料，具体与实施例1的区别在于：
步骤S4中，烧结的温度为550℃，时间为6h。
对比例1
本对比例制备了一种正极材料，具体与实施例1的区别在于：
步骤S1中，将磷酸水溶液替换为等浓度的草酸水溶液。
对比例2
本对比例制备了一种正极材料，具体与实施例1的区别在于：
(1)步骤S1中，将磷酸水溶液替换为等体积的水；
(2)不包括步骤S2。
对比例3
本对比例制备了一种正极材料，具体与实施例1的区别在于：
步骤S1中，将磷酸水溶液替换为等体积的水。
对比例4
本对比例制备了一种正极材料，具体与实施例1的区别在于：
不包括步骤S2。
实验例
本试验例以实施例1～3和对比例1～4所得正极材料为正极活性材料，制备了扣式电池，并测试了扣式电池的电化学性能，具体的：
以N-甲基吡咯烷酮为溶剂，按照质量比9.2︰0.5︰0.3的比例将正极材料、乙炔黑和PVDF混合均匀形成浆料，再将浆料涂覆于铝箔上，经80℃鼓风干燥8h后，于120℃真空干燥12h， 得正极。
在氩气保护的手套箱中装配电池，负极为金属锂片，隔膜为聚丙烯膜，电解液为1M LiPF 6-EC/DMC(1︰1，v/v)，采用2032型扣式电池壳。
所得扣式电池在25℃、电流0.1C下，电压3.0～4.5V范围内进行电化学性能测试。
测试结果如表1所示。
表1 实施例1～3和对比例1～4所得正极材料对应扣式电池的电化学性能结果
Figure PCTCN2022118010-appb-000001
从表1结果可知，本发明提供的制备方法，制得的正极材料，由于包覆物质的浅表掺杂，以及包覆物质中锰和磷酸根之间的协同作用，在保证首周放电克比容量的基础上，可以维持较优异的循环性能(实施例1～3)。
其中实施例1和实施例2对比可知，若降低了磷酸的浓度，则LiNi 0.9Co 0.05Mn 0.05O 2表面形成的表面缺陷减少，相应的损失的锂减少，因此具有略高的克容量；但是包覆物进行浅表掺杂的效果降低，形成的富锰层的锰含量降低，循环性能变差。
实施例1和实施例3对比可知，较高的煅烧温度可能在一定程度上损失循环性能；本发明通过磷酸形成的表面缺陷，可显著降低形成浅表掺杂所需要的温度，由此在一定程度上提升了所得正极材料的循环性能。
实施例1和对比例1对比可知，若将磷酸替换为草酸，则由于草酸的酸性过强，对正极材料结构造成严重破坏，同时损失了容量和循环性能。
实施例1和对比例2对比可知，若仅采用普通水洗，则与磷酸洗相比，锂的损失较少，因此容量在一定程度上提升；但是由于没有包覆物质的沉积和浅表掺杂，因此所得正极材料的循环性能显著变差。
实施例1和对比例3对比可知，若将磷酸洗替换为水洗，则由于包覆物中不含磷酸根，则在制备过程中，正极材料表面不能形成缺陷，进而不能有效促进锰进入正极材料晶格，形 成浅表掺杂，由此不能抑制正极材料中锰的歧化和溶出，最终循环性能显著下降。
实施例1和对比例4对比可知，若仅采用磷酸洗，则包覆物中不含有锰，也不能抑制正极材料中锰的溶出，由此，循环性能也显著下降。
上面结合附图对本发明实施例作了详细说明，但本发明不限于上述实施例，在所属技术领域普通技术人员所具备的知识范围内，还可以在不脱离本发明宗旨的前提下作出各种变化。

Claims (10)

  1. 一种正极材料，其特征在于，所述正极材料包括：
    层状正极材料，所述层状正极材料的化学式为Li xMO 2，其中x的范围为0.95～1.1，M为过渡金属，包括Mn；
    包覆物质，所述包覆物质部分设于所述层状正极材料表面，部分掺杂于所述层状正极材料的表层中；所述包覆物质中包括四价锰、锂离子和磷酸根离子。
  2. 根据权利要求1所述的正极材料，其特征在于，Li xMO 2中，M还包括Ni；优选地，Li xMO 2中Ni占M的摩尔百分比≥75％。
  3. 根据权利要求1或2所述的正极材料，其特征在于，所述包覆物质中，四价锰的存在形式包括二氧化锰。
  4. 一种如权利要求1～3任一项所述正极材料的制备方法，其特征在于，包括：
    将所述层状正极材料和磷酸水溶液混合，并向所得混合体系中依次添加碱性高锰酸钾溶液和二价锰前体；反应后，将固体产物干燥、煅烧。
  5. 根据权利要求4所述的制备方法，其特征在于，所述磷酸水溶液的浓度为1～5wt％。
  6. 根据权利要求4所述的制备方法，其特征在于，所述层状正极材料和磷酸水溶液的固液比为0.5-1g/mL。
  7. 根据权利要求4所述的制备方法，其特征在于，所述碱性高锰酸钾和二价锰前体的摩尔比为0.8～1.2:1。
  8. 根据权利要求4所述的制备方法，其特征在于，所述煅烧的温度为450～550℃。
  9. 根据权利要求4所述的制备方法，其特征在于，所述煅烧的时长为6～8h。
  10. 一种二次电池，其特征在于，制备原料包括权利要求1～3任一项所述的正极材料。
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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2006027925A2 (en) * 2004-09-06 2006-03-16 Nissan Motor Co., Ltd. Positive electrode material for non-aqueous electrolyte lithium-ion secondary battery and method for production thereof
CN108321386A (zh) * 2018-01-10 2018-07-24 湖南邦普循环科技有限公司 一种控制层状高镍材料表面残余锂含量的方法
CN108695503A (zh) * 2018-05-24 2018-10-23 北京长城华冠汽车科技股份有限公司 在材料表面包覆二氧化锰的方法及用该方法制备的电池正极改性材料
CN108717971A (zh) * 2018-05-24 2018-10-30 北京长城华冠汽车科技股份有限公司 二氧化锰的制备方法及用二氧化锰包覆的电池正极改性材料
CN112186157A (zh) * 2020-09-24 2021-01-05 惠州亿纬创能电池有限公司 一种高镍正极材料的水洗方法及其产品和用途

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2006027925A2 (en) * 2004-09-06 2006-03-16 Nissan Motor Co., Ltd. Positive electrode material for non-aqueous electrolyte lithium-ion secondary battery and method for production thereof
CN108321386A (zh) * 2018-01-10 2018-07-24 湖南邦普循环科技有限公司 一种控制层状高镍材料表面残余锂含量的方法
CN108695503A (zh) * 2018-05-24 2018-10-23 北京长城华冠汽车科技股份有限公司 在材料表面包覆二氧化锰的方法及用该方法制备的电池正极改性材料
CN108717971A (zh) * 2018-05-24 2018-10-30 北京长城华冠汽车科技股份有限公司 二氧化锰的制备方法及用二氧化锰包覆的电池正极改性材料
CN112186157A (zh) * 2020-09-24 2021-01-05 惠州亿纬创能电池有限公司 一种高镍正极材料的水洗方法及其产品和用途

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
C HANG-HEUM JO ET AL.: "An Effective Method to Reduce Residual Lithium Compounds on Ni-rich Li[Ni0.6Co0.2Mn0.2]02 Active Material Using a Phosphoric Acid Derived Li3PO4 Nanolayer", NANO RESEARC H, vol. 8, no. 5, 4 December 2014 (2014-12-04), pages 1464 - 1479, XP002739724, ISSN: 1998-0214, DOI: 10.1007/s12274-014-0631-8 *
ZAHNG, JIANDONG ET AL.: "Pretreated Precursor to Realize Dual Modification that Improves the High Voltage Electrochemical Performance of LiNi0.8Co0.1Mn0.102 Cathode Materials", J OURNAL OF ALLOYS AND COMPOUNDS, vol. 858, 15 December 2020 (2020-12-15), pages 1 - 10, XP086475358, ISSN: 0925-8388, DOI: 10.1016/j.jallcom.2020.158325 *
ZAHNG, JIANDONG ET AL.: "Pretreated Precursor to Realize Dual Modification that Improves the High Voltage Electrochemical Performance of LiNi0.8Co0.1Mn0.102 Cathode Materials", JOURNAL OF ALLOYS AND COMPOUNDS, vol. 858, 15 December 2020 (2020-12-15), pages 1 - 10, XP086475358, ISSN: 0925-8388, DOI: 10.1016/j.jallcom.2020.158325 *

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