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CN-122000419-A - Solid-state battery, positive electrode sheet, positive electrode active material, preparation method, power utilization device and application

CN122000419ACN 122000419 ACN122000419 ACN 122000419ACN-122000419-A

Abstract

The application relates to a solid-state battery, a positive electrode plate, a positive electrode active material, a preparation method, an electric device and application, wherein the solid-state battery comprises a positive electrode plate, the positive electrode plate comprises a positive electrode active material layer, the positive electrode active material layer comprises a positive electrode active material and sulfide electrolyte, the positive electrode active material comprises positive electrode coating particles, the positive electrode coating particles comprise a core and a coating layer coated on at least part of the surface of the core, the core comprises a lithium-rich manganese-based positive electrode material, the coating layer comprises lithium ruthenium-based oxide, and the lithium ruthenium-based oxide is lithium composite metal oxide containing lithium elements and ruthenium elements. The lithium ruthenium-based oxide is coated on at least part of the surface of the lithium-rich manganese-based positive electrode material to form a coating layer, so that the capacity and the cycle performance of the lithium-rich manganese-based positive electrode material are improved, and the capacity and the cycle performance of the solid-state battery are improved.

Inventors

  • WU KAI
  • Shao Qinong
  • Zheng Chuanzuo
  • ZHANG HONGTU
  • HUANG JINFENG
  • FANG YUNHAO
  • HU BOBING
  • NING ZIYANG

Assignees

  • 宁德时代新能源科技股份有限公司

Dates

Publication Date
20260508
Application Date
20241108

Claims (20)

  1. 1. A solid-state battery comprising a positive electrode layer, the positive electrode layer comprising a positive electrode active material and a sulfide electrolyte, the positive electrode active material comprising positive electrode coated particles, the positive electrode coated particles comprising: a core comprising a lithium-rich manganese-based positive electrode material, and And the coating layer is coated on at least part of the surface of the inner core, and comprises lithium ruthenium-based oxide, wherein the lithium ruthenium-based oxide is lithium composite metal oxide containing lithium element and ruthenium element.
  2. 2. The solid-state battery according to claim 1, wherein in the lithium ruthenium-based oxide, an atomic molar ratio of lithium element to ruthenium element is 2:y, and 0.5≤y≤1.
  3. 3. The solid state battery of any of claims 1 to 2, wherein the lithium ruthenium-based oxide further comprises a doping element Q, the doping element Q comprising one or more of Cr, ir, sn, ti and Zr.
  4. 4. A solid state battery according to any one of claims 1 to 3, wherein the lithium ruthenium-based oxide has a chemical formula of Li 2 Ru y Q 1-y O 3 , 0.5≤y≤1, q including one or more elements of Cr, ir, sn, ti and Zr.
  5. 5. The solid-state battery according to any one of claims 1 to 4, wherein the lithium ruthenium-based oxide contained in the coating layer accounts for 0.1 to 5% by mass in the positive electrode coated particles.
  6. 6. The solid-state battery according to any one of claims 1 to 5, wherein the lithium ruthenium-based oxide contained in the coating layer accounts for 0.1 to 3% by mass in the positive electrode coated particles.
  7. 7. The solid-state battery according to any one of claims 1 to 6, wherein the thickness of the coating layer is 0.1nm to 50nm.
  8. 8. The solid-state battery according to any one of claims 1 to 7, wherein the thickness of the coating layer is 0.1nm to 10nm.
  9. 9. The solid state battery of any of claims 1 to 8, wherein the lithium-rich manganese-based positive electrode material is a layered lithium-rich manganese-based positive electrode material.
  10. 10. The solid-state battery according to any one of claims 1 to 9, wherein the chemical formula of the lithium-rich manganese-based positive electrode material satisfies xLi 2 MnO 3 ·(1-x)LiMO 2 , and the M element includes one or several elements of Ni, co, mn, cr, fe, al, nb, zr, mo and Ta, 0< x <1.
  11. 11. The solid-state battery according to any one of claims 1 to 10, wherein the Dv50 of the positive electrode coated particles is 0.5 μm-15 μm.
  12. 12. The solid-state battery according to any one of claims 1 to 9, wherein Dv50 of the positive electrode coated particles is 1 μm-10 μm.
  13. 13. The solid state battery according to any one of claims 1 to 12, wherein the sulfide electrolyte has a Dv50 of 1nm-20 μm.
  14. 14. The solid state battery according to any one of claims 1 to 13, wherein the sulfide electrolyte has a Dv50 of 50nm-1 μm.
  15. 15. The solid state battery of any of claims 1 to 14, wherein the sulfide electrolyte comprises one or more of a sulfur silver germanium ore type sulfide electrolyte, a lithium germanium phosphorus sulfur type sulfide electrolyte, and a lithium phosphorus sulfide pentasulfide complex type sulfide electrolyte.
  16. 16. The solid state battery of claim 15, wherein the sulfide electrolyte satisfies one or more of the following features (1) - (3): (1) The chemical formula of the sulfur silver germanium ore type sulfide electrolyte meets Li 6±s P 1-j A j S 5±s-t B t X 1±s , j is more than or equal to 0 and less than or equal to 1, t is more than or equal to 0 and less than or equal to 1, s is more than or equal to 0 and less than or equal to 1, A element comprises one or more elements of Ge, si, sn and Sb, B element comprises one or more elements of O, se and Te, and X element is one or more elements of Cl, br, I and F; (2) The chemical formula of the lithium germanium phosphorus sulfur sulfide electrolyte meets the requirement that Li 10±δ Ge 1-g G g P 2-q Q q S 12-w W w ,0≤δ<1,0≤g≤1,0≤q≤2,0≤w<1,G elements comprise one or more elements of Si and Sn, Q elements comprise Sb, and W elements are one or more elements selected from O, se, te, cl, br, I and F; (3) The chemical formula of the lithium-phosphorus sulfide pentasulfide compound sulfide electrolyte meets the requirement that (100-u-v)Li 2 S·uP 2 S 5 ·vM m N n ,0<u<100,0≤v<100,0≤u+v<100,0≤m<4,0≤n<6,M elements are one or more elements selected from Li, B, ge, si, sn and Sb, and N elements are one or more elements selected from S, se, te, O, cl, br, I and F.
  17. 17. The solid state battery according to any one of claims 1 to 16, wherein the positive electrode layer satisfies one or more of the following features (1) - (2): (1) The mass ratio of the positive electrode active material in the positive electrode active material layer is 50% -99%; (2) The sulfide electrolyte accounts for 0.1-50% of the positive electrode active material layer by mass.
  18. 18. The solid state lithium ion battery of claim 17, wherein the positive electrode layer satisfies one or more of the following features (1) - (2): (1) The mass ratio of the positive electrode active material in the positive electrode active material layer is 70% -95%; (2) The sulfide electrolyte accounts for 5-30% of the positive electrode active material layer by mass.
  19. 19. The solid state battery according to any one of claims 1 to 18, wherein the solid state battery is an all-solid state lithium ion battery, further comprising a solid electrolyte layer and a negative electrode layer, the solid electrolyte layer being located between the positive electrode layer and the negative electrode layer, the solid electrolyte layer containing the sulfide electrolyte according to any one of claims 13 to 16.
  20. 20. A positive electrode sheet comprising a positive electrode active material layer containing a positive electrode active material and a sulfide electrolyte, the positive electrode active material comprising positive electrode coated particles comprising: a core comprising a lithium-rich manganese-based positive electrode material, and And the coating layer is coated on at least part of the surface of the inner core, and comprises lithium ruthenium-based oxide, wherein the lithium ruthenium-based oxide is lithium composite metal oxide containing lithium element and ruthenium element.

Description

Solid-state battery, positive electrode sheet, positive electrode active material, preparation method, power utilization device and application Technical Field The application relates to the technical field of solid-state batteries, in particular to a solid-state battery, a positive electrode plate, a positive electrode active material, a preparation method, an electric device and application. Background The statements herein merely provide background information related to the present disclosure and may not necessarily constitute prior art. The solid-state battery adopts a nonflammable solid electrolyte to replace organic electrolyte in the traditional liquid-state battery, so that the safety of the battery is greatly improved, and the battery is considered to be a new generation battery closest to industrialization. However, when a lithium-rich manganese-based positive electrode material is used for a solid-state battery, there are problems of low capacity and poor cycle performance. Disclosure of Invention The application provides a solid-state battery, a positive electrode plate, a positive electrode active material, a preparation method, an electric device and application. The solid-state battery has both higher capacity performance and good cycle performance. In order to achieve the above object, a first aspect of the present application provides a solid-state battery including a positive electrode layer including a positive electrode active material layer containing a positive electrode active material including positive electrode coated particles and a sulfide electrolyte, the positive electrode coated particles including: a core comprising a lithium-rich manganese-based positive electrode material, and And the coating layer is coated on at least part of the surface of the inner core, and comprises lithium ruthenium-based oxide, wherein the lithium ruthenium-based oxide is lithium composite metal oxide containing lithium element and ruthenium element. Thus, by providing a sulfide electrolyte having a fast ion-transport property in the positive electrode active material layer of the solid-state battery, the interface resistance of the positive electrode layer can be advantageously reduced, and the active ion transport rate in the positive electrode layer can be improved; further, the adopted positive electrode active material comprises a core containing the lithium-rich manganese-based positive electrode material and positive electrode coating particles containing a coating layer of lithium ruthenium-based oxide, and the coating layer containing the lithium ruthenium-based oxide is arranged on at least one part of the surface of the core, so that on one hand, the characteristic that the lithium ruthenium-based oxide has higher electronic conductivity can be utilized to make up the defect of very low electronic conductivity of the lithium-rich manganese-based positive electrode material, and the capacity exertion of the lithium-rich manganese-based positive electrode material with the advantages of high theoretical gram capacity, high energy density and the like in a solid-state battery can be promoted; on the other hand, oxygen can be released from the lithium-rich manganese-based positive electrode material in the process of anion oxidation reduction, for example, the sulfide electrolyte is contacted with oxygen to easily cause accelerated decomposition, the lithium-rich manganese-based positive electrode material can be isolated from direct contact with the sulfide electrolyte by utilizing the lithium-ruthenium-based oxide, so that side reactions between the lithium-rich manganese-based positive electrode material and the sulfide electrolyte can be remarkably reduced, the possible oxygen release problem can be effectively restrained from causing continuous cycle capacity attenuation and voltage attenuation, on the other hand, ruthenium (Ru) element in the lithium-ruthenium-based oxide can be doped into crystal lattices of the lithium-rich manganese-based positive electrode material to form Ru-O with stronger covalent property, thereby restraining oxygen release of the lithium-rich manganese-based positive electrode material, improving structural stability and cycle performance of the lithium-rich manganese-based positive electrode material, and in this way, the coating layer containing the lithium-ruthenium-based oxide can improve interface compatibility between the lithium-rich manganese-based positive electrode material and the sulfide electrolyte, the lithium-rich manganese-based positive electrode material has the advantages that the high electron conductivity can be provided on the surface of the lithium-rich manganese-based positive electrode material, and the structural stability of the lithium-rich manganese-based positive electrode material can be improved to inhibit oxygen release, so that the lithium-rich manganese-based positive electrode material, the lithium ruthenium-based oxide and