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WO-2026092244-A1 - COMPOSITE POSITIVE ELECTRODE MATERIAL AND PREPARATION METHOD THEREFOR, POSITIVE ELECTRODE SHEET, BATTERY, AND ELECTRIC DEVICE

WO2026092244A1WO 2026092244 A1WO2026092244 A1WO 2026092244A1WO-2026092244-A1

Abstract

The present disclosure relates to the technical field of batteries. The present disclosure provides a composite positive electrode material and a preparation method therefor, and a positive electrode sheet, a battery, and an electric device. The composite positive electrode material comprises a first component and a second component; the first component comprises at least one of LiFePO 4 , LiCoPO 4 , LiMnPO 4 , LiNiPO 4 , and LiMn x Fe 1-x PO 4 , wherein 0.2≤x≤0.8; the second component comprises LiNi y M 1 z M 2 1-y-z O 2 , wherein M 1 comprises at least one of Co, Al, and Mn, M 2 comprises at least one of Co, Al, and Mn, 0<y<1, and 0<z<1; the mass ratio of the first component to the second component is (9-5):(1-5).

Inventors

  • WU, Fangze
  • XIE, JING
  • WU, Xuan
  • WANG, XIN
  • GUO, ZIZHU

Assignees

  • 比亚迪股份有限公司

Dates

Publication Date
20260507
Application Date
20251021
Priority Date
20241031

Claims (13)

  1. A composite cathode material, comprising a first component and a second component; The first component includes at least one of LiFePO4 , LiCoPO4 , LiMnPO4 , LiNiPO4 , and LiMnxFe1 -xPO4 ; wherein 0.2 ≤ x ≤ 0.8; The second component comprises LiNi y M 1 z M 2 1-yz O 2 ; wherein M 1 comprises at least one of Co, Al and Mn, M 2 comprises at least one of Co, Al and Mn, 0<y<1, 0<z<1; The mass ratio of the first component to the second component is (9-5):(1-5).
  2. According to claim 1, the composite cathode material is wherein the mass ratio of the first component to the second component is (7-5):(3-5).
  3. According to claim 1 or 2, the composite cathode material, wherein the LiNi y M 1 z M 2 1-yz O 2 , wherein M 1 is one of Co, Al and Mn, M 2 is one of Co, Al and Mn, and M 1 and M 2 are not the same.
  4. The composite cathode material according to any one of claims 1 to 3, wherein the first component is LiMn x Fe 1-x PO 4 .
  5. The composite cathode material according to any one of claims 1 to 4, wherein the particle size of the first component is smaller than the particle size of the second component.
  6. A positive electrode sheet comprising the composite positive electrode material as described in any one of claims 1 to 5.
  7. The positive electrode sheet according to claim 6 includes a positive current collector and an active material layer, wherein the active material layer includes the composite positive electrode material according to any one of claims 1 to 5.
  8. According to claim 7, the positive electrode sheet, wherein the composite positive electrode material has a mass percentage content of 90wt% to 95wt% in the active material layer.
  9. A battery comprising the positive electrode sheet as described in any one of claims 6 to 8.
  10. The battery according to claim 9 further includes a negative electrode sheet, wherein the negative electrode sheet includes a negative current collector.
  11. The battery according to claim 9 or 10, wherein the negative electrode current collector comprises at least one of copper foil, porous copper foil, and brass foil.
  12. The battery according to any one of claims 9 to 11, wherein the battery is a negative electrode-free lithium battery.
  13. An electrical device comprising the battery as described in any one of claims 9 to 12.

Description

Composite cathode materials and their preparation methods, cathode sheets, batteries and electrical devices Priority information This disclosure claims priority and benefits to patent application No. 2024115521185, filed with the China National Intellectual Property Administration on October 31, 2024, the entire contents of which are incorporated herein by reference. Technical Field This disclosure belongs to the field of battery technology, specifically relating to a composite cathode material and its preparation method, as well as cathode sheets, batteries, and electrical devices. Background Technology Electrodeless lithium batteries are a new battery technology that may not directly use traditional negative electrode materials, but they still require a structure or region capable of receiving and releasing lithium ions. By avoiding the direct use of lithium metal, electrodeless lithium batteries greatly simplify the production process and reduce production costs, thus attracting widespread attention as a novel type of battery. However, the relevant technologies are limited to research on lithium deposition behavior, improving cycle life and capacity, while there are few reports on how to improve the safety of electrodeless lithium batteries. Public content This disclosure aims to address, at least to some extent, the safety issues of electrodeless lithium batteries. To this end, one objective of this disclosure is to provide a composite cathode material and its preparation method, as well as a cathode sheet, battery, and electrical device. This composite cathode material exhibits good thermal stability, enabling electrodeless lithium batteries to demonstrate excellent safety performance. The first aspect of this disclosure provides a composite cathode material. According to embodiments of this disclosure, the composite cathode material includes a first component and a second component; the first component includes at least one selected from LiFePO4 (lithium iron phosphate), LiCoPO4 (lithium cobalt phosphate), LiMnPO4 (lithium manganese phosphate), LiNiPO4 (lithium nickel phosphate), and LiMnxFe1 -xPO4 ( lithium manganese iron phosphate); wherein 0.2≤x≤0.8; the second component includes LiNiyM1zM21 -yzO2 ; wherein M1 includes at least one selected from Co, Al, and Mn, and M2 includes at least one selected from Co, Al, and Mn, 0<y<1, 0<z<1; the mass ratio of the first component and the second component is (9-5):(1-5). The composite cathode material provided by this disclosure improves battery safety. By mixing the first component with the second component, which is the main cathode active material, this disclosure reduces the chance of direct contact between the electrolyte and the main cathode active material (i.e., the second component), improving the structural stability of the main cathode active material. Furthermore, the first component, being entirely olivine, has high thermal stability, which helps to prevent chain reactions during thermal runaway of the main cathode active material, thereby improving battery safety. The composite cathode material provided by this disclosure exhibits good electrochemical performance. In the composite cathode material of this disclosure, the first and second components have similar voltage plateaus; therefore, the composite cathode material obtained by combining these two components can still maintain a high capacity. According to embodiments of this disclosure, the above-mentioned composite cathode material may further include at least one of the following additional technical features: In some embodiments, the mass ratio of the first component to the second component is (7-5):(3-5). In some embodiments, LiNi y M 1 z M 2 1-yz O 2 , wherein M 1 is one of Co, Al and Mn, M 2 is one of Co, Al and Mn, and M 1 and M 2 are not the same. In some embodiments, the first component is LiMn x Fe 1-x PO 4 . In some embodiments, the particle size of the first component is smaller than that of the second component. A second aspect of this disclosure provides a positive electrode sheet comprising the aforementioned composite positive electrode material. The positive electrode sheet disclosed herein contains the aforementioned composite positive electrode material and exhibits good electrochemical and safety performance. In some embodiments, the positive electrode includes a positive current collector and an active material layer, wherein the active material layer includes the aforementioned composite positive electrode material. In some embodiments, the composite cathode material has a mass percentage content of 90wt% to 95wt% in the active material layer. A third aspect of this disclosure provides a battery including the aforementioned positive electrode. The battery disclosed herein exhibits good safety and high electrochemical performance. In some embodiments, the battery further includes a negative electrode plate, which includes a negative current collector. In some embodiment