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CN-118352496-B - Nickel lithium manganate spinel positive electrode material and preparation method and application thereof

CN118352496BCN 118352496 BCN118352496 BCN 118352496BCN-118352496-B

Abstract

The invention discloses a nickel lithium manganate spinel positive electrode material, a preparation method and application thereof, and belongs to the technical field of battery materials. The lithium nickel manganese oxide spinel anode material comprises a lithium nickel manganese oxide body, wherein the molecular formula of the lithium nickel manganese oxide body is Li x Ni y Mn 2‑y O 4 , x=0.8-1.2 and y=0.4-0.6, doped elements are doped in the lithium nickel manganese oxide body, a modified layer is formed on the surface of the lithium nickel manganese oxide body, a coating layer is arranged on the surface of the modified layer, the doped elements comprise at least two of Ta, nb, la, Y, te, fe, ti, W, mo, ge and Na, the modified elements comprise at least two of Mg, al, P, zr, cl and F, and the coating layer contains a soft conductive material. The nickel lithium manganate spinel positive electrode material has higher first charge-discharge capacity and capacity retention rate, and can be further used for preparing positive electrode plates and batteries with better performance.

Inventors

  • WANG KUNYU
  • RUAN DINGSHAN
  • LI CHANGDONG
  • MAO LINLIN
  • LIU LIMING
  • TANG YAN

Assignees

  • 广东邦普循环科技有限公司
  • 湖南邦普循环科技有限公司

Dates

Publication Date
20260505
Application Date
20240416

Claims (15)

  1. 1. The lithium nickel manganese oxide spinel Dan Zheng pole material is characterized by comprising a lithium nickel manganese oxide body, wherein the molecular formula of the lithium nickel manganese oxide body is Li x Ni y Mn 2-y O 4 , x=0.8-1.2 and y=0.4-0.6; Doping elements are doped in the lithium nickel manganese oxide body, a modified layer is formed on the surface of the lithium nickel manganese oxide body, and a coating layer is arranged on the surface of the modified layer; the doping element is selected from at least two of Ta, nb, la, Y, te, fe, ti, W, mo, ge and Na, and the modifying element contained in the modifying layer consists of one of Mg, al and Zr and one of Cl and F; The preparation of the coating layer comprises the steps of directly fusing and coating the doped lithium nickel manganese oxide body with the modified layer with a coating raw material, wherein the coating raw material is soft conductive material and comprises at least one of conductive asphalt and conductive polymer; The content of each doping element in the lithium nickel manganese oxide spinel positive electrode material is 500-10000 ppm, the content of each modifying element in the lithium nickel manganese oxide spinel positive electrode material is 500-50000 ppm, and the mass of the coating layer is 0.5-5% of the lithium nickel manganese oxide spinel positive electrode material.
  2. 2. The lithium nickel manganese oxide spinel Dan Zheng pole material of claim 1, further comprising at least one of the following features: The lithium nickel manganese oxide spinel Dan Zheng electrode material is characterized in that D v10 is 1-4 mu m, D v50 is 4-8 mu m, and D v90 is 6-20 mu m; the second characteristic is that the area of the direct contact with electrolyte in the nickel lithium manganate spinel positive electrode material is less than 10% of the total surface area of the nickel lithium manganate spinel positive electrode material; and the discharge gram capacity of the nickel lithium manganate spinel anode material at 0.1C is not lower than 138mAh/g.
  3. 3. A method for preparing the lithium nickel manganese oxide spinel positive electrode material according to claim 1 or 2, comprising the steps of modifying a doped lithium nickel manganese oxide body to form the modified layer on the surface of the doped lithium nickel manganese oxide body, and preparing the coating layer on the surface of the modified layer.
  4. 4. The method according to claim 3, wherein the preparation of the doped lithium nickel manganese oxide body comprises mixing a nickel manganese precursor, a lithium source and a dopant providing the doping element to obtain a first mixture, and sintering the first mixture for the first time to obtain the doped lithium nickel manganese oxide body.
  5. 5. The method according to claim 4, wherein the temperature of the first sintering is 600 ℃ to 1000 ℃ and/or the time of the first sintering is 5h to 20h.
  6. 6. The method of claim 4, wherein modifying the doped lithium nickel manganese oxide body comprises mixing the doped lithium nickel manganese oxide body with a modifier providing the modifying element to obtain a second mixture, and sintering the second mixture a second time.
  7. 7. The method according to claim 6, wherein the temperature of the second sintering is 600 ℃ to 700 ℃ and/or the time of the second sintering is 5h to 10h.
  8. 8. The method according to claim 6, wherein the crushed material is obtained by performing double-roll rough crushing and air-flow crushing classification on the lithium nickel manganese oxide body doped with the doping element, and then performing secondary sintering on the crushed material.
  9. 9. The method according to claim 8, wherein the roll spacing is 1mm to 3mm during the rough breaking process.
  10. 10. A method of preparing according to claim 3, wherein the coating raw material is subjected to fusion coating in the form of a semi-solid liquid or a high viscosity liquid.
  11. 11. The method of claim 3, wherein the conductive polymer comprises at least one of polyaniline conductive agent, polypyrrole conductive agent, and PEDOT: PSS conductive agent.
  12. 12. The method according to claim 3, wherein the particle size of the coating material is 2 μm or less.
  13. 13. The method according to claim 3, wherein the fusion coating is performed at a temperature of 30 ℃ to 120 ℃ and/or at a rotation speed of 1000rpm to 5000 rpm.
  14. 14. A positive electrode sheet, characterized in that an active material in the positive electrode sheet comprises the lithium nickel manganese oxide spinel positive electrode material according to claim 1 or 2.
  15. 15. A battery comprising the positive electrode sheet of claim 14.

Description

Nickel lithium manganate spinel positive electrode material and preparation method and application thereof Technical Field The invention relates to the technical field of battery materials, in particular to a lithium nickel manganese oxide spinel positive electrode material, a preparation method and application thereof. Background The spinel-phase lithium nickel manganese oxide is a lithium battery anode with ultrahigh platform voltage, theoretical capacity and energy density, for example, the platform voltage can be 4.7V, the theoretical capacity can be 147mAh/g, and the energy density can be more than or equal to 650Wh/kg. From the energy density and cost point of view, there is a great market potential for this material. In addition, the spinel-structured lithium nickel manganese oxide has the advantages of very stable thermochemical structure and good rate performance. However, lithium nickel manganese oxide is poor in cyclic storage, mainly because Ni element in the material is oxidized to +4 valence during charging, and has extremely high lithium removal voltage and high electropositivity, which can cause electrolyte decomposition and induce a series of failure reactions. In view of this, the present invention has been made. Disclosure of Invention The invention aims to provide a nickel lithium manganate spinel positive electrode material, a preparation method and application thereof, so as to solve or improve the technical problems. The invention can be realized as follows: In a first aspect, the invention provides a lithium nickel manganese oxide spinel positive electrode material, which comprises a lithium nickel manganese oxide body, wherein the molecular formula of the lithium nickel manganese oxide body is Li xNiyMn2-yO4, x=0.8-1.2, and y=0.4-0.6; Doping elements are doped in the lithium nickel manganese oxide body, a modified layer is formed on the surface of the lithium nickel manganese oxide body, and a coating layer is arranged on the surface of the modified layer; the doping element comprises at least two of Ta, nb, la, Y, te, fe, ti, W, mo, ge and Na, and the modifying element contained in the modifying layer comprises at least two of Mg, al, P, zr, cl and F; the coating layer contains a soft conductive material. In an alternative embodiment, the lithium nickel manganese oxide spinel further includes at least one of the following features: The characteristic is that the D v10 of the lithium nickel manganese oxide spinel Dan Zheng electrode material is 1-4 mu m, the D v50 is 4-8 mu m, and the D v90 is 6-20 mu m; the second characteristic is that the content of each doping element in the nickel lithium manganate spinel positive electrode material is 500 ppm-10000 ppm; the third characteristic is that the content of each modified element in the nickel lithium manganate spinel positive electrode material is 500 ppm-50000 ppm; The quality of the coating layer is 0.5% -5% of that of the nickel lithium manganate spinel anode material; The area of direct contact with electrolyte in the lithium nickel manganese oxide spinel positive electrode material is less than 10% of the total surface area of the lithium nickel manganese oxide spinel positive electrode material; and the discharge gram capacity of the nickel lithium manganate spinel anode material at 0.1C is not lower than 138mAh/g. In a second aspect, the invention provides a preparation method of the nickel lithium manganate spinel positive electrode material, which comprises the following steps of modifying a nickel lithium manganate body doped with doping elements to form a modified layer on the surface of the nickel lithium manganate body doped with the doping elements, and preparing a coating layer on the surface of the modified layer. In an alternative embodiment, the preparation of the doped lithium nickel manganese oxide body comprises the steps of mixing a nickel manganese precursor, a lithium source and a doping agent for providing the doping element to obtain a first mixture, and performing first sintering on the first mixture to obtain the doped lithium nickel manganese oxide body. In an alternative embodiment, the temperature of the first sintering is 600 ℃ to 1000 ℃, and/or the time of the first sintering is 5h to 20h. In an alternative embodiment, modifying the doped lithium nickel manganese oxide body includes mixing the doped lithium nickel manganese oxide body with a modifier that provides a modifying element to obtain a second mixture and sintering the second mixture a second time. In an alternative embodiment, the temperature of the second sintering is 600 ℃ to 700 ℃, and/or the time of the second sintering is 5h to 10h. In an alternative embodiment, the lithium nickel manganese oxide body doped with the doping element is firstly subjected to double-roller coarse crushing and airflow crushing classification to obtain crushed materials, and then the crushed materials are subjected to secondary sintering. In an alternative emb