WO2024021276A1 - 一种镍钴锰酸锂正极材料的包覆方法 - Google Patents

一种镍钴锰酸锂正极材料的包覆方法 Download PDF

Info

Publication number
WO2024021276A1
WO2024021276A1 PCT/CN2022/120637 CN2022120637W WO2024021276A1 WO 2024021276 A1 WO2024021276 A1 WO 2024021276A1 CN 2022120637 W CN2022120637 W CN 2022120637W WO 2024021276 A1 WO2024021276 A1 WO 2024021276A1
Authority
WO
WIPO (PCT)
Prior art keywords
nickel cobalt
lithium nickel
cathode material
coating method
potassium permanganate
Prior art date
Application number
PCT/CN2022/120637
Other languages
English (en)
French (fr)
Inventor
李爱霞
余海军
谢英豪
李长东
Original Assignee
广东邦普循环科技有限公司
湖南邦普循环科技有限公司
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 广东邦普循环科技有限公司, 湖南邦普循环科技有限公司 filed Critical 广东邦普循环科技有限公司
Priority to ES202390144A priority Critical patent/ES2965272A2/es
Priority to GBGB2309841.1A priority patent/GB202309841D0/en
Publication of WO2024021276A1 publication Critical patent/WO2024021276A1/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
    • H01M4/362—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
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H01M4/131—Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H01M4/139—Processes of manufacture
    • H01M4/1391—Processes of manufacture of electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
    • H01M4/50—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
    • 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
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • 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 invention relates to the technical field of cathode material synthesis, in particular to a coating method of lithium nickel cobalt manganate cathode material.
  • Lithium nickel cobalt manganate cathode materials are prone to residual lithium problems on the surface.
  • Surface residual lithium mainly refers to substances such as LiOH and Li 2 CO 3 on the surface of material particles.
  • the source is that unburned Li in the sintering reaction remains on the surface or high-temperature sintering causes the material to decompose to produce surface residual lithium; on the other hand, It is caused by the material being left in the air for a long time.
  • Ni content the harsher the sintering conditions, and the more difficult it is to sinter to form a material with a specific lithium metal ratio, resulting in more residual lithium on the surface of the sintered product.
  • the higher the Ni content the easier it is for Li + to react with water and CO 2 in the air to generate LiOH and Li 2 CO 3 , resulting in high residual lithium on the surface.
  • manganese is easily eluted from the lithium nickel cobalt manganate cathode material during circulation, and will precipitate to the negative electrode and destroy the negative SEI film.
  • Mn 3+ will produce a disproportionation reaction during the cycle to form Mn 4+ and Mn 2+ , causing the cathode particles to break and further affecting the cycle performance of the cathode material.
  • Some surface defects will inevitably form on the surface of the cathode material, such as dents, fractures, etc. These surface defects will promote side reactions between the cathode material and the electrolyte.
  • the conventional coating method is to randomly form some coating areas on the surface of the material. The uniformity is difficult to obtain. The coating agent is small, which may result in some areas, especially the surface defect areas, not being coated. The electrolyte can pass through these areas. Side reactions occur between the surface defect area and the cathode material; if the amount of coating agent is increased, the local coating may be too thick, reducing the specific capacity and possibly increasing the impedance.
  • the object of the present invention is to overcome the above-mentioned shortcomings of the prior art and provide a coating method for lithium nickel cobalt manganate cathode material.
  • the invention provides a coating method for lithium nickel cobalt manganate cathode material. By mixing the lithium nickel cobalt manganate cathode material and potassium permanganate solution and passing in olefin, directional coating of surface defects is achieved. There is no need to generate an excessively thick coating layer, which can effectively prevent the electrolyte from causing side reactions with the cathode material through surface defects.
  • the technical solution adopted by the present invention is: a coating method of lithium nickel cobalt manganate cathode material, which includes the following steps:
  • the number of carbon atoms in olefins is ⁇ 10, and the number of carbon-carbon double bonds in olefins is 1.
  • the lithium nickel cobalt manganate cathode material and the potassium permanganate solution are mixed and the olefin is introduced into the mixture, making it easier to adhere.
  • the attached gas can react with potassium permanganate in the solution in the defect area to form MnO 2 precipitation to make up for the defects, thereby achieving directional packaging of surface defects. Covering does not require the formation of an overly thick coating layer, which can well prevent side reactions between the electrolyte and the cathode material through surface defects.
  • the olefin gas reacts with the potassium permanganate solution to form a precipitate.
  • Coating MnO 2 at surface defects can form a MnO 2- rich layer inside and outside the surface of the cathode material, which can inhibit the dissolution of MnO 2 and the disproportionation reaction of Mn 3+ in the cathode material.
  • the by-products (such as alcohols) produced by the reaction can be dissolved in the solution and removed.
  • the unreacted gas is removed during the drying stage, so that it will not react with the material and cause the positive electrode material to be reduced.
  • the present invention can also adopt the method of immersing the positive electrode material in reducing gas, placing the positive electrode material in a high-pressure olefin environment, so that the olefins enter the interior of the positive electrode material through surface defects, and combine the positive electrode material with potassium permanganate.
  • the solution is mixed, and the olefin gas gradually overflows in the solution.
  • the olefin and potassium permanganate undergo an oxidation-reduction reaction to generate manganese dioxide and precipitate at the surface defects.
  • the olefin is at least one of ethylene and propylene; further preferably, the olefin is ethylene.
  • the mass concentration of the potassium permanganate solution is 0.5%-5%
  • the pH value of the potassium permanganate solution is 7-12
  • the temperature of the mixing reaction is 10-50°C
  • the mass concentration of the potassium permanganate solution is 0.5%-2%
  • the temperature of the mixing reaction is 10-25°C.
  • the method of introducing olefins is: introducing olefins in batches.
  • an air pump is used, and the air pipe of the air pump is equipped with a filter element.
  • the pressure of the air pump is 0.013-0.020MPa, and the pore size of the filter element is 0.2-0.5 ⁇ m.
  • the pore size of the filter element is the main factor affecting the size of the bubbles that pass into the gas.
  • the pore size of the filter element is 0.2-0.5 ⁇ m, the size of the bubbles that pass into the gas is appropriate and the coating effect is better.
  • the drying temperature is 60-80°C and the drying time is 8-12h; the calcining temperature is 450-550°C and the calcining time is 6-8h.
  • the present invention provides a lithium nickel cobalt manganate cathode material obtained by using the above-mentioned coating method of the lithium nickel cobalt manganate cathode material.
  • the present invention provides the application of the lithium nickel cobalt manganate cathode material in the preparation of lithium ion batteries.
  • the beneficial effects of the present invention are: the present invention mixes the lithium nickel cobalt manganate cathode material and the potassium permanganate solution and introduces olefins.
  • olefin When olefin is passed into the mixture of potassium acid solution, it is easier to adhere to the surface defect areas (pits, cracks, etc.) of the cathode material.
  • the attached gas can react with potassium permanganate in the solution in the defect areas to form MnO 2 precipitation.
  • Figure 1 is a diagram of the manganese dioxide-coated lithium nickel cobalt manganate cathode material prepared in Example 1.
  • the experimental methods used are conventional methods unless otherwise specified, and the materials and reagents used can be obtained from commercial sources unless otherwise specified.
  • This embodiment provides a coating method for lithium nickel cobalt manganate cathode material.
  • the olefin used in the present invention is ethylene, which includes the following steps:
  • the mass concentration of the potassium permanganate solution is 0.5%, the pH is 8, and the temperature of the mixing reaction is 20°C; the number of times of feeding ethylene is 5 times, and the volume of olefins fed each time is 100cm 3 , and the amount of ethylene fed is
  • the total volume of ethylene used is 500cm 3 and the volume of the potassium permanganate solution is 1L; the air pump The pressure is 0.018MPa, and the pore size of the filter element is 0.45 ⁇ m;
  • the drying temperature is 70°C and the drying time is 10h; the calcination temperature is 450°C and the calcination time is 8h.
  • This embodiment provides a coating method for lithium nickel cobalt manganate cathode material.
  • the olefin used in the present invention is propylene; wherein, high manganese
  • the mass concentration of the potassium acid solution is 0.5%, the pH is 8, the temperature of the mixing reaction is 20°C; the number of times propylene is introduced is 5 times, the volume of olefin introduced each time is 100cm 3 , the total volume of propylene introduced and the height
  • the total volume of propylene used is 500cm 3 and the volume of the potassium permanganate solution is 1L; the pressure of the air pump is 0.018MPa.
  • the pore size of the filter element is 0.45 ⁇ m.
  • This embodiment provides a coating method for lithium nickel cobalt manganate cathode material.
  • the only difference between this embodiment and Example 1 is that in step (2), the calcination temperature is 550°C, and the calcination time is 6h.
  • This embodiment provides a coating method for lithium nickel cobalt manganate cathode material.
  • the only difference between this embodiment and Example 1 is that in step (1), the number of times ethylene is passed is 3 times, each time The volume of olefin introduced is 100cm 3 .
  • This embodiment provides a coating method for lithium nickel cobalt manganate cathode material.
  • the only difference between this embodiment and Example 1 is that in step (1), an air pump is used to introduce olefins in batches. , the air pipe of the air pump is not equipped with a filter element.
  • This embodiment provides a coating method for lithium nickel cobalt manganate cathode material.
  • the mass concentration of the potassium permanganate solution is 5%.
  • pH is 8
  • the temperature of the mixing reaction is 50°C
  • the number of times of passing ethylene is 5 times
  • the volume of olefins passing each time is 200cm 3
  • the total volume of ethylene passed and the volume ratio of the potassium permanganate solution is ethylene : Potassium permanganate solution 1:1, specifically, the total volume of ethylene used is 1000cm 3 and the volume of potassium permanganate solution is 1L
  • the pressure of the air pump is 0.018MPa
  • the pore size of the filter element is 0.45 ⁇ m.
  • carbon-coated lithium nickel cobalt manganate is used to prepare the potassium permanganate coating layer.
  • the preparation method is as follows: take 500g LiNi 0.9 Co 0.05 Mn 0.05 O 2 with C-coated surface layer, place it in 1L neutral, In a potassium permanganate solution with a concentration of 0.5% mass fraction and a temperature of 20°C, the potassium permanganate solution is completely immersed in the positive electrode material. After the reaction is completed, the positive electrode material is separated from the solution, and the positive electrode material is placed in the oven for 70 Dried at 450°C for 10 hours, and then calcined at 450°C for 8 hours.
  • This comparative example uses the ordinary precipitation method to prepare the manganese dioxide coating layer.
  • the preparation method is as follows: take 500g LiNi 0.9 Co 0.05 Mn 0.05 O 2 and place it in 1L neutral high temperature furnace with a concentration of 0.5% mass fraction and a temperature of 20°C.
  • the potassium manganate solution make the potassium permanganate solution completely immerse the positive electrode material, then add 5g of manganese hydroxide to the solution to dissolve it.
  • the precipitation is completed, separate the positive electrode material from the solution, place the positive electrode material in an oven, and dry it at 70°C. 10h, and then calcined at 450°C for 8h in a horse boiler.
  • Test process The positive electrode materials obtained in the examples and comparative examples were formulated into button batteries for electrochemical performance testing of lithium ion batteries.
  • the specific steps were: using N-methylpyrrolidone as the solvent, according to the mass ratio of 9.2:0.5:0.3
  • Proportion Mix the positive active material, acetylene black, and PVDF evenly, apply it on aluminum foil, air dry at 80°C for 8 hours, and then vacuum dry at 120°C for 12 hours.
  • the cathode is a lithium metal sheet
  • the separator is a polypropylene film
  • the electrolyte is 1M LiPF6-EC/DMC (1:1, v/v)
  • a 2032 button battery shell is used.
  • the coin cells were assembled in an argon-protected glove box, and then the electrochemical performance was tested at 3.0-4.5V at 25°C.
  • Figure 1 is a diagram of the manganese dioxide-coated lithium nickel cobalt manganate cathode material prepared in Example 1.
  • Table 1 shows the electrochemical performance test results.
  • the manganese dioxide-coated lithium nickel cobalt manganate cathode material prepared in the embodiment of the present invention is applied to button batteries, the 0.1C discharge capacity is more than 200mAh/g, the discharge specific capacity is 180mAh/g after 100 cycles, and the cycle retention rate Reaching more than 88%.
  • Example 5 no filter element is added, the bubbles are larger and more difficult to adhere to, the coating amount is reduced, and the cycle performance is slightly reduced.
  • the temperature of the mixing reaction and the mass concentration of the potassium permanganate solution in Example 6 were too high and the reaction was too fast. Many ethylene bubbles had reacted before reaching the particle surface, thus causing a lot of manganese dioxide to precipitate. Even if the amount of ethylene in the air is increased, the coating effect is still not as good as that of Example 1.

Landscapes

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

Abstract

本发明公开了一种镍钴锰酸锂正极材料的包覆方法，涉及正极材料合成技术领域。本发明提供了一种镍钴锰酸锂正极材料的包覆方法，包括如下步骤：(1)将镍钴锰酸锂正极材料和高锰酸钾溶液混合，通入烯烃；(2)反应完成后干燥、煅烧，得到包覆二氧化锰的镍钴锰酸锂正极材料；其中，烯烃中碳原子数≤10，烯烃中碳碳双键数＝1。本发明提供了一种镍钴锰酸锂正极材料的包覆方法，通过将镍钴锰酸锂正极材料和高锰酸钾溶液混合，通入烯烃的方式，实现对表面缺陷的定向包覆，不需要生成过厚的包覆层，即可很好的防止电解液通过表面缺陷与正极材料产生副反应。

Description

一种镍钴锰酸锂正极材料的包覆方法 技术领域
本发明涉及正极材料合成技术领域，尤其是一种镍钴锰酸锂正极材料的包覆方法。
背景技术
镍钴锰酸锂正极材料，特别是Ni含量超过90％的超高镍正极材料，表面容易产生残锂问题。表面残锂主要指的是材料颗粒表面的LiOH、Li 2CO 3之类的物质，来源一方面是烧结反应未烧进去的Li残留于表面或者高温烧结导致材料分解产生表面残锂；另一方面是材料在空气中长时间放置产生。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，造成烧结产物的表面残锂多。另外，Ni含量越高Li +越容易跟空气中的水和CO 2反应，生成LiOH和Li 2CO 3，造成表面残锂高。随着Ni含量的升高，镍钴锰酸锂正极材料在循环过程中锰容易溶出，会沉淀到负极处破坏负极SEI膜。Mn 3+在循环过程中会产生歧化反应，形成Mn 4+和Mn 2+，导致正极颗粒破碎，进一步影响正极材料的循环性能。正极材料表面难免形成一些表面缺陷，比如凹陷、断裂等，这些表面缺陷会促进正极材料与电解液发生副反应。
通过在正极材料表面形成包覆层的方式可以修复部分表面缺陷，缓解正极材料与电解液的副反应，但是常规的包覆方法存在一些问题。常规的包覆方式是随机在材料表面形成一些包覆区域，其均匀性很难得到，包覆剂较少，可能导致部分区域，特别是表面缺陷区域得不到包覆，电解液可以通过这些表面缺陷区域与正极材料发生副反应；若增加包覆剂的使用量，则可能导致局部包覆过厚，降低比容量的同时还可能增加阻抗。
发明内容
基于此，本发明的目的在于克服上述现有技术的不足之处而提供一种镍钴锰酸锂正极材料的包覆方法。本发明提供了一种镍钴锰酸锂正极材料的包覆方法，通过将镍钴锰酸锂正极材料和高锰酸钾溶液混合，通入烯烃的方式，实现对表面缺陷的定向包覆，不需要生成过厚的包覆层，即可很好的防止电解液通过表面缺陷与正极材料产生副反应。
为实现上述目的，本发明所采取的技术方案为：一种镍钴锰酸锂正极材料的包覆方法，包括如下步骤：
(1)将镍钴锰酸锂正极材料和高锰酸钾溶液混合，通入烯烃；
(2)反应完成后干燥、煅烧，得到包覆二氧化锰的镍钴锰酸锂正极材料；
其中，烯烃中碳原子数≤10，烯烃中碳碳双键数＝1。
本发明通过将镍钴锰酸锂正极材料和高锰酸钾溶液混合，通入烯烃的方式，通过向镍 钴锰酸锂正极材料和高锰酸钾溶液的混合物中通入烯烃，更容易附着于正极材料表面的表面缺陷区域(凹坑、裂痕等)，附着的气体可以在缺陷区域与溶液中的高锰酸钾发生反应形成MnO 2沉淀从而弥补缺陷，从而可以实现对表面缺陷的定向包覆，不需要生成过厚的包覆层，即可很好的防止电解液通过表面缺陷与正极材料产生副反应。同时，烯烃气体与高锰酸钾溶液反应生成沉淀，沉淀颗粒较小，包覆更为均匀。在表面缺陷处包覆MnO 2，可以在正极材料表面内外形成富MnO 2层，可以抑制正极材料内MnO 2的溶出和Mn 3+的歧化反应。反应产生的副产物(如醇类)可以溶解于溶液中去除，未反应的气体在烘干阶段即清除干净，如此不会与材料发生反应，导致正极材料被还原。
进一步的，本发明还可以采用将正极材料浸泡于还原性气体中这种方式，将正极材料置于高压的烯烃环境中，使得烯烃经由表面缺陷进入正极材料内部，将正极材料与高锰酸钾溶液混合，烯烃气体在溶液中逐渐溢出，烯烃与高锰酸钾发生氧化还原反应生成二氧化锰而沉淀于表面缺陷处。
优选地，所述烯烃为乙烯、丙烯中的至少一种；进一步优选地，所述烯烃为乙烯。
优选地，所述步骤(1)中，高锰酸钾溶液的质量浓度为0.5％-5％，高锰酸钾溶液的pH值为7-12，混合反应的温度为10-50℃；进一步优选地，所述高锰酸钾溶液的质量浓度为0.5％-2％，混合反应的温度为10-25℃。
发明人发现，在上述高锰酸钾溶液的质量浓度和反应温度范围内，反应速率较慢，可以减少气泡到达表面缺陷处之前的损失。
优选地，所述步骤(1)中，烯烃的通入方法为：分批次通入烯烃，通入烯烃时采用气泵通入，气泵的输气管装有滤芯。
优选地，所述通入烯烃的次数为3-10次，通入烯烃的总体积和高锰酸钾溶液的体积比为烯烃：高锰酸钾溶液＝(0.3-1)：1。进一步优选地，所述通入烯烃的次数为3-5次，通入烯烃的总体积和高锰酸钾溶液的体积比为烯烃：高锰酸钾溶液＝(0.3-0.5)：1。
发明人经过大量实验探究后发现，通过限定通入烯烃的次数及通入烯烃的用量，控制反应更加完全，最终包覆效果更好。
优选地，所述气泵的压力为0.013-0.020MPa，滤芯的孔径为0.2-0.5μm。
发明人经过大量实验探究后发现，滤芯的孔径是影响通入气体的气泡大小的主要因素，滤芯的孔径为0.2-0.5μm时，通入气体的气泡大小合适，包覆效果更好。
优选地，所述步骤(2)中，干燥的温度为60-80℃，干燥的时间为8-12h；煅烧的温度为450-550℃，煅烧的时间为6-8h。
此外，本发明提供了采用上述的镍钴锰酸锂正极材料的包覆方法得到的镍钴锰酸锂正极材料。
进一步地，本发明提供了所述的镍钴锰酸锂正极材料在制备锂离子电池中的应用。
相对于现有技术，本发明的有益效果为：本发明通过将镍钴锰酸锂正极材料和高锰酸钾溶液混合，通入烯烃的方式，通过向镍钴锰酸锂正极材料和高锰酸钾溶液的混合物中通入烯烃，更容易附着于正极材料的表面缺陷区域(凹坑、裂痕等)，附着的气体可以在缺陷区域与溶液中的高锰酸钾发生反应形成MnO 2沉淀从而弥补缺陷，从而可以实现对表面缺陷的定向包覆，不需要生成过厚的包覆层，即可很好的防止电解液通过表面缺陷与正极材料产生副反应。
附图说明
图1为实施例1制备得到的包覆二氧化锰的镍钴锰酸锂正极材料图。
具体实施方式
为更好的说明本发明的目的、技术方案和优点，下面将结合附图和具体实施例对本发明作进一步说明。
实施例中，所使用的实验方法如无特殊说明，均为常规方法，所用的材料、试剂等，如无特殊说明，均可从商业途径得到。
实施例1-6和对比例1-2
实施例1
本实施例提供了一种镍钴锰酸锂正极材料的包覆方法，本发明所用烯烃为乙烯，包括如下步骤：
(1)将500g镍钴锰酸锂正极材料(LiNi 0.9Co 0.05Mn 0.05O 2)和高锰酸钾溶液混合，分批次通入烯烃，通入乙烯时采用气泵通入，气泵的输气管装有滤芯(PE滤芯)；
其中，高锰酸钾溶液的质量浓度为0.5％，pH为8，混合反应的温度为20℃；通入乙烯的次数为5次，每次通入烯烃的体积为100cm 3，通入乙烯的总体积和高锰酸钾溶液的体积比为乙烯：高锰酸钾溶液＝0.5：1，具体地，所用乙烯的总体积为500cm 3，高锰酸钾溶液的体积为1L；所述气泵的压力为0.018MPa，滤芯的孔径为0.45μm；
(2)反应完成后干燥、煅烧，得到包覆二氧化锰的镍钴锰酸锂正极材料；
其中，干燥的温度为70℃，干燥的时间为10h；煅烧的温度为450℃，煅烧的时间为8h。
实施例2
本实施例提供了一种镍钴锰酸锂正极材料的包覆方法，本实施例与实施例1唯一的区别为：所述步骤(1)中，本发明所用烯烃为丙烯；其中，高锰酸钾溶液的质量浓度为0.5％，pH为8，混合反应的温度为20℃；通入丙烯的次数为5次，每次通入烯烃的体积为100cm 3， 通入丙烯的总体积和高锰酸钾溶液的体积比为丙烯：高锰酸钾溶液＝0.5：1，具体地，所用丙烯的总体积为500cm 3，高锰酸钾溶液的体积为1L；所述气泵的压力为0.018MPa，滤芯的孔径为0.45μm。
实施例3
本实施例提供了一种镍钴锰酸锂正极材料的包覆方法，本实施例与实施例1唯一的区别为：所述步骤(2)中，煅烧的温度为550℃，煅烧的时间为6h。
实施例4
本实施例提供了一种镍钴锰酸锂正极材料的包覆方法，本实施例与实施例1唯一的区别为：所述步骤(1)中，通入乙烯的次数为3次，每次通入烯烃的体积为100cm 3，通入乙烯的总体积和高锰酸钾溶液的体积比为乙烯：高锰酸钾溶液＝0.3：1，具体地，所用乙烯的总体积为300cm 3，高锰酸钾溶液的体积为1L。
实施例5
本实施例提供了一种镍钴锰酸锂正极材料的包覆方法，本实施例与实施例1唯一的区别为：所述步骤(1)中，分批次通入烯烃时采用气泵通入，气泵的输气管不装有滤芯。
实施例6
本实施例提供了一种镍钴锰酸锂正极材料的包覆方法，本实施例与实施例1唯一的区别为：所述步骤(1)中，高锰酸钾溶液的质量浓度为5％，pH为8，混合反应的温度为50℃；通入乙烯的次数为5次，每次通入烯烃的体积为200cm 3，通入乙烯的总体积和高锰酸钾溶液的体积比为乙烯：高锰酸钾溶液1：1，具体地，所用乙烯的总体积为1000cm 3，高锰酸钾溶液的体积为1L；所述气泵的压力为0.018MPa，滤芯的孔径为0.45μm。
对比例1
本对比例使用碳包覆的镍钴锰酸锂制备高锰酸钾包覆层，制备方法如下：取500g表层包覆有C的LiNi 0.9Co 0.05Mn 0.05O 2，置于1L中性的、浓度为0.5％质量分数、温度为20℃的高锰酸钾溶液中，使得高锰酸钾溶液完全浸没正极材料，反应完成后，将正极材料与溶液分离，将正极材料置于烘箱中，70℃烘干10h，然后在马沸炉中450℃煅烧8h。
对比例2
本对比例使用普通沉淀法制备二氧化锰包覆层，制备方法如下：取500g LiNi 0.9Co 0.05Mn 0.05O 2，置于1L中性的、浓度为0.5％质量分数、温度为20℃的高锰酸钾溶液中，使得高锰酸钾溶液完全浸没正极材料，然后向溶液中加入5g氢氧化锰溶解，沉淀完毕后将正极材料与溶液分离，将正极材料置于烘箱中，70℃烘干10h，然后在马沸炉中450℃煅烧8h。
性能测试
测试过程：将实施例及对比例得到的正极材料配成扣式电池进行锂离子电池电化学性能测试，其具体步骤为：以N-甲基吡咯烷酮为溶剂，按照质量比9.2：0.5：0.3的比例将正极活性物质与乙炔黑、PVDF混合均匀，涂覆于铝箔上，经80℃鼓风干燥8h后，于120℃真空干燥12h。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 LiPF6-EC/DMC(1：1，v/v)，采用2032型扣式电池壳在氩气保护的手套箱中组装成扣式电池，然后在25℃下3.0-4.5V进行电化学性能测试。
测试结果：如下表1所示。
表1
Figure PCTCN2022120637-appb-000001
图1为实施例1制备得到的包覆二氧化锰的镍钴锰酸锂正极材料图，表1为电化学性能测试结果。本发明实施例制备得到的包覆二氧化锰的镍钴锰酸锂正极材料应用到扣式电池时，0.1C放电容量200mAh/g以上，100次循环后放电比容量180mAh/g，循环保持率达到88％以上。
其中，实施例5中不加滤芯，气泡较大，较难附着，包覆量降低，循环性能略有降低。实施例6中混合反应的温度和高锰酸钾溶液的质量浓度过高，反应过快，很多乙烯气泡在到达颗粒表面前就已经反应了，因此会造成很多二氧化锰沉淀。即使增加进气乙烯用量，包覆效果仍然不如实施例1。
最后所应当说明的是，以上实施例仅用以说明本发明的技术方案而非对本发明保护范围的限制，尽管参照较佳实施例对本发明作了详细说明，本领域的普通技术人员应当理解，可以对本发明的技术方案进行修改或者等同替换，而不脱离本发明技术方案的实质和范围。

Claims (10)

  1. 一种镍钴锰酸锂正极材料的包覆方法，其特征在于，包括如下步骤：
    (1)将镍钴锰酸锂正极材料和高锰酸钾溶液混合，通入烯烃；
    (2)反应完成后干燥、煅烧，得到包覆二氧化锰的镍钴锰酸锂正极材料；
    其中，烯烃中碳原子数≤10，烯烃中碳碳双键数＝1。
  2. 如权利要求1所述的镍钴锰酸锂正极材料的包覆方法，其特征在于，所述烯烃为乙烯、丙烯中的至少一种；优选地，所述烯烃为乙烯。
  3. 如权利要求1所述的镍钴锰酸锂正极材料的包覆方法，其特征在于，所述步骤(1)中，高锰酸钾溶液的质量浓度为0.5％-5％，混合反应的温度为10-50℃；优选地，所述高锰酸钾溶液的质量浓度为0.5％-2％，混合反应的温度为10-25℃。
  4. 如权利要求1所述的镍钴锰酸锂正极材料的包覆方法，其特征在于，所述步骤(1)中，烯烃的通入方法为：分批次通入烯烃，通入烯烃时采用气泵通入，气泵的输气管装有滤芯。
  5. 如权利要求4所述的镍钴锰酸锂正极材料的包覆方法，其特征在于，所述通入烯烃的次数为3-10次，通入烯烃的总体积和高锰酸钾溶液的体积比为烯烃：高锰酸钾溶液＝(0.3-1)：1。
  6. 如权利要求5所述的镍钴锰酸锂正极材料的包覆方法，其特征在于，所述通入烯烃的次数为3-5次，通入烯烃的总体积和高锰酸钾溶液的体积比为烯烃：高锰酸钾溶液＝(0.3-0.5)：1。
  7. 如权利要求4所述的镍钴锰酸锂正极材料的包覆方法，其特征在于，所述气泵的压力为0.013-0.020MPa，滤芯的孔径为0.2-0.5μm。
  8. 如权利要求1所述的镍钴锰酸锂正极材料的包覆方法，其特征在于，所述步骤(2)中，干燥的温度为60-80℃，干燥的时间为8-12h；煅烧的温度为450-550℃，煅烧的时间为6-8h。
  9. 一种采用如权利要求1所述的镍钴锰酸锂正极材料的包覆方法得到的镍钴锰酸锂正极材料。
  10. 一种如权利要求9所述的镍钴锰酸锂正极材料在制备锂离子电池中的应用。
PCT/CN2022/120637 2022-07-29 2022-09-22 一种镍钴锰酸锂正极材料的包覆方法 WO2024021276A1 (zh)

Priority Applications (2)

Application Number Priority Date Filing Date Title
ES202390144A ES2965272A2 (es) 2022-07-29 2022-09-22 Metodo para recubrir un material de catodo de oxido de litio-niquel-cobalto-manganeso
GBGB2309841.1A GB202309841D0 (en) 2022-09-22 2022-09-22 Iasr not published

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN202210903702.5 2022-07-29
CN202210903702.5A CN115275143A (zh) 2022-07-29 2022-07-29 一种镍钴锰酸锂正极材料的包覆方法

Publications (1)

Publication Number Publication Date
WO2024021276A1 true WO2024021276A1 (zh) 2024-02-01

Family

ID=83771781

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2022/120637 WO2024021276A1 (zh) 2022-07-29 2022-09-22 一种镍钴锰酸锂正极材料的包覆方法

Country Status (3)

Country Link
CN (1) CN115275143A (zh)
FR (1) FR3138572A1 (zh)
WO (1) WO2024021276A1 (zh)

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20150016024A1 (en) * 2013-07-12 2015-01-15 Korea Insitiute Of Science And Technology Cathode active material having core-shell structure and producing method thereof
CN110462773A (zh) * 2017-03-07 2019-11-15 挪威东南大学 具有硅纳米结构的片上超级电容器
CN111769265A (zh) * 2020-06-23 2020-10-13 合肥国轩高科动力能源有限公司 一种改性高镍三元正极材料的制备方法

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20150016024A1 (en) * 2013-07-12 2015-01-15 Korea Insitiute Of Science And Technology Cathode active material having core-shell structure and producing method thereof
CN110462773A (zh) * 2017-03-07 2019-11-15 挪威东南大学 具有硅纳米结构的片上超级电容器
CN111769265A (zh) * 2020-06-23 2020-10-13 合肥国轩高科动力能源有限公司 一种改性高镍三元正极材料的制备方法

Also Published As

Publication number Publication date
CN115275143A (zh) 2022-11-01
FR3138572A1 (fr) 2024-02-02

Similar Documents

Publication Publication Date Title
CN110931768B (zh) 一种高镍类单晶锂离子电池正极材料及制备方法
WO2021023313A1 (zh) 一种双包覆层改性锂离子电池正极材料及其制备方法
WO2019037459A1 (zh) 一种高电压镍钴锰酸锂前驱体及其制备方法和高电压镍钴锰酸锂正极材料
CN112670506B (zh) 快离子导体包覆的镍钴锰钽复合四元正极材料及其制备方法
CN103715424A (zh) 一种核壳结构正极材料及其制备方法
CN106910887B (zh) 一种富锂锰基正极材料、其制备方法及包含该正极材料的锂离子电池
WO2022022605A1 (zh) 一种预锂化处理的锂离子正极材料及其制备方法和应用
US20230268488A1 (en) Cathode active material for lithium-ion battery (lib) and preparation method thereof
CN109301189B (zh) 一种类单晶型高镍多元材料的制备方法
CN104953109B (zh) 一种提升耐高温性能的核壳结构锰酸锂及其合成方法
CN112271277A (zh) 一种含有金属元素梯度掺杂的负极材料及其应用
WO2023024446A1 (zh) 一种四元正极材料及其制备方法和应用
WO2023184996A1 (zh) 一种改性高镍三元正极材料及其制备方法
WO2023221625A1 (zh) 大粒径单晶三元正极材料及其制备方法和应用
WO2023179247A1 (zh) 一种超高镍三元前驱体及其制备方法
WO2024040903A1 (zh) 共沉淀制备磷酸锰铁的方法及其应用
CN114804235B (zh) 一种高电压镍钴锰酸锂正极材料及其制备方法和应用
CN115498171A (zh) 一种高镍三元正极材料及其制备方法和应用
WO2023207247A1 (zh) 一种多孔隙球形钴氧化物颗粒及其制备方法
CN113764638A (zh) 正极材料、其制备方法、包括其的正极和锂离子电池
WO2024060548A1 (zh) 一种铁包覆硼掺杂的高镍正极材料及其制备方法和应用
WO2024021276A1 (zh) 一种镍钴锰酸锂正极材料的包覆方法
WO2023207248A1 (zh) 核壳结构nca正极材料前驱体及其制备方法和应用
CN115411258A (zh) 一种钠离子电池正极材料及其制备方法和应用
CN113562779B (zh) 一种原位包覆锆酸铝锂的单晶ncm三元材料

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: 22952717

Country of ref document: EP

Kind code of ref document: A1