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CN-121983564-A - High-performance composite positive electrode material and preparation method and application thereof

CN121983564ACN 121983564 ACN121983564 ACN 121983564ACN-121983564-A

Abstract

The invention belongs to the field of battery materials, and discloses a high-performance composite positive electrode material, a preparation method and application thereof, wherein the preparation method of the high-performance composite positive electrode material comprises the following steps: ball milling to mix the MOF material and the sheet conductive carbon material, adding the solid electrolyte material for continuous ball milling, adding the anode material for continuous ball milling, and roasting in an inert atmosphere to obtain the metal oxide semiconductor. The electron-ion-active material interpenetrating structure is formed by the MOF material, the sheet conductive carbon material and the solid electrolyte material, so that interface contact can be improved, stability of the composite anode is improved, cycle life of the battery is remarkably prolonged, and the requirement of a long-cycle-life solid lithium metal battery can be met.

Inventors

  • OU XING
  • ZHU QINGKUN
  • HE XINYOU
  • XU HUAJUN
  • MING LEI
  • LIANG XINGHUI
  • DING FENGHUA
  • LIN ZHANG

Assignees

  • 中南大学

Dates

Publication Date
20260505
Application Date
20260408

Claims (10)

  1. 1. The preparation method of the high-performance composite positive electrode material is characterized by comprising the following steps of: Step 1, ball milling and mixing an MOF material and a flaky conductive carbon material to obtain a first material; step 2, ball milling and mixing the solid electrolyte material and the first material to obtain a second material; step 3, ball milling and mixing the second material and the positive electrode material to obtain an intermediate product; and step 4, roasting the intermediate product in an inert atmosphere to obtain the high-performance composite anode material.
  2. 2. The preparation method of the high-performance composite positive electrode material according to claim 1, wherein in the step 1, the MOF material is any one or two of ZIF-8 and Zr-MOF, the flaky conductive carbon material is any one or more of flake graphite, expanded graphite sheets and graphene sheets, the ball milling speed is 200-300rpm, and the ball milling time is 2-3h.
  3. 3. The method for preparing the high-performance composite positive electrode material according to claim 1 or 2, wherein the mass ratio of the MOF material to the sheet-shaped conductive carbon material in the first material obtained in the step 1 is 7:2-4.
  4. 4. The method for preparing a high-performance composite positive electrode material according to claim 1, wherein in the step 2, the solid electrolyte material is any one or more than two of Li 6 PS 5 Cl、Li 10 GeP 2 S 12 、Li 3 InCl 3 、Li 2 ZrCl 6 , the particle size of the solid electrolyte is 100-500nm, the ball milling rotation speed is 200-300rpm, and the ball milling time is 4-5h.
  5. 5. The method for preparing a high-performance composite positive electrode material according to claim 1 or 4, wherein the mass ratio of the solid electrolyte to the first material in the second material obtained in the step 2 is (1-2) to 1.
  6. 6. The preparation method of the high-performance composite positive electrode material according to claim 1, wherein in the step 3, the positive electrode material is LiNi x Co y Mn 1-x-y O 2 , x is more than or equal to 0.8 and less than or equal to 1,0.08 and y is more than or equal to 0.12, the mass ratio of the positive electrode material to the second material is (60% -85%) to (15% -40%), the ball milling rotating speed is 150-200rpm, and the ball milling time is 30-60min.
  7. 7. The method for preparing a high-performance composite cathode material according to claim 1, wherein in the step 4, the baking temperature is 300-400 ℃ and the baking time is 1-3h.
  8. 8. A high performance composite positive electrode material prepared by the preparation method of any one of claims 1 to 7.
  9. 9. The high performance composite positive electrode material of claim 8 comprising a positive electrode material and a second material, wherein the positive electrode material and the second material are uniformly distributed, the positive electrode material has a chemical formula of LiNi x Co y Mn 1-x-y O 2 , x <1,0.08 > y < 0.12, and the second material comprises a MOF material, a sheet-like conductive carbon material, and a solid electrolyte material.
  10. 10. A battery comprising the high-performance composite positive electrode material produced by the production method according to any one of claims 1 to 7.

Description

High-performance composite positive electrode material and preparation method and application thereof Technical Field The invention belongs to the field of battery materials, and relates to a positive electrode material, in particular to a high-performance composite positive electrode material, and a preparation method and application thereof. Background Along with the rapid increase of the demands of the fields of new energy automobiles, energy storage power stations and the like for batteries with high energy density and high safety, the development requirements of the next generation energy storage technology are difficult to meet due to the problems of electrolyte leakage, thermal runaway risk and the like of the traditional liquid lithium ion battery. The solid-state lithium battery uses the solid electrolyte to replace the liquid electrolyte, and has the advantages of high energy density, high safety and the like, so that the solid-state lithium battery becomes a research hot spot of next-generation energy storage devices. The composite positive electrode is used as a core component of the solid-state battery, and the requirements of electron conduction, ion transmission, interface stability and the like are simultaneously met. At present, the traditional composite anode has the following problems that solid electrolyte (such as sulfide Li 6PS5 Cl) and an anode ternary high-nickel NCM active material are high in interface reactivity, high-impedance byproducts are easy to generate, so that the cycle performance is attenuated, an electron conductor (such as a carbon material) and an ion conductor (such as the solid electrolyte) are unevenly dispersed, an electron-ion transmission path is blocked, the mechanical strength of a composite system is low, the structure collapses due to volume expansion of the active material in the charging and discharging process, the performance is further aggravated, and the electrochemical performance of a battery is influenced. Disclosure of Invention In order to overcome the defects and shortcomings of the prior art, the invention provides a preparation method of a high-performance composite positive electrode material, a second aspect of the high-performance composite positive electrode material and a third aspect of the high-performance composite positive electrode material. In a first aspect, the present invention provides a method for preparing a high-performance composite positive electrode material, comprising the steps of: Step 1, ball milling and mixing an MOF material and a flaky conductive carbon material to obtain a first material; step 2, ball milling and mixing the solid electrolyte material and the first material to obtain a second material; step 3, ball milling and mixing the second material and the positive electrode material to obtain an intermediate product; and step 4, roasting the intermediate product in an inert atmosphere to obtain the high-performance composite anode material. Preferably, in step 1, the MOF material is any one or two of ZIF-8 and Zr-MOF. Preferably, in step 1, the sheet-shaped conductive carbon material is any one or more than two of flake graphite, expanded graphite sheet and graphene sheet. Preferably, in the first material obtained in the step 1, the mass ratio of the MOF material to the sheet-shaped conductive carbon material is 7:2-4. Preferably, in the step 1, the ball milling rotation speed is 200-300rpm, and the ball milling time is 2-3h. Preferably, in the second material obtained in the step 2, the mass ratio of the solid electrolyte to the first material is (1-2) to 1. Preferably, in the step 2, the ball milling rotation speed is 200-300rpm, and the ball milling time is 4-5h. Preferably, in step 2, the solid electrolyte material is any one or two or more of LPSC（Li6PS5Cl）、LGPS（Li10GeP2S12）、LIC（Li3InCl3）、LZC（Li2ZrCl6）. Preferably, in step 2, the solid electrolyte has a particle size of 100 to 500nm. Preferably, in the step 3, the positive electrode material is LiNi xCoyMn1-x-yO2, and x is more than or equal to 0.8 and less than or equal to 1,0.08 and y is more than or equal to 0.12. Preferably, in the step 3, the mass ratio of the positive electrode material to the second material is (60% -85%) to (15% -40%). Preferably, in the step 3, the ball milling rotation speed is 150-200rpm, and the ball milling time is 30-60min. Preferably, in step 4, the calcination temperature is 300-400 ℃ and the calcination time is 1-3h. In a second aspect, the present invention provides a high performance composite positive electrode material, prepared by the above preparation method. The cathode material is characterized by comprising a cathode material and a second material, wherein the cathode material and the second material are uniformly distributed, the chemical general formula of the cathode material is LiNi xCoyMn1-x-yO2, x is more than or equal to 0.8 and less than or equal to 1,0.08 and y is more than or equal to 0.12, and the seco