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CN-122000297-A - Integrated lithium metal negative electrode, preparation method thereof, lithium metal battery and power utilization device

CN122000297ACN 122000297 ACN122000297 ACN 122000297ACN-122000297-A

Abstract

The application relates to the technical field of batteries, in particular to an integrated lithium metal negative electrode and a preparation method thereof, a lithium metal battery and an electric device, wherein the integrated lithium metal negative electrode comprises a porous polymer film, a conductive polymer layer, a lithium-philic substance layer and a lithium metal layer which are sequentially laminated along the thickness direction; the material of the conductive polymer layer includes a fluoropolymer, a conductive agent, and a lithium supplementing agent. The application constructs a lithium metal battery with high stability by providing an integrated lithium metal negative electrode, physical barrier, stress buffering and multi-stage protection of induced lithium deposition.

Inventors

  • YAN JINGKUN
  • Weng Zihang
  • LI GUOJUN
  • BU SHAONING
  • WU JUNWEI
  • WENG WEIJIA

Assignees

  • 江苏英联复合集流体有限公司

Dates

Publication Date
20260508
Application Date
20260228

Claims (15)

  1. 1. An integrated lithium metal negative electrode, characterized by comprising a porous polymer film, a conductive polymer layer, a lithium-philic substance layer and a lithium metal layer which are sequentially laminated along the thickness direction; The material of the conductive polymer layer comprises fluorine-containing polymer, conductive agent and lithium supplementing agent.
  2. 2. The integrated lithium metal negative electrode of claim 1, wherein at least one of the following conditions is satisfied: (1) The fluoropolymer comprises polyvinylidene fluoride-hexafluoropropylene copolymer; (2) The conductive agent comprises at least one of carbon nanofibers, carbon nanotubes and carbon nanowires; (3) The lithium supplementing agent comprises at least one of lithium oxide, lithium nitride and lithium oxalate.
  3. 3. The integrated lithium metal negative electrode according to claim 1 or 2, wherein the material of the lithium philic substance layer comprises a lithium boron alloy and silver.
  4. 4. The integrated lithium metal negative electrode of claim 3, wherein the layer of a lithium-philic substance satisfies at least one of the following conditions: (1) The lithium boron alloy comprises at least one of LiB, li 5 B 4 and Li 7 B 6 ; (2) The atomic ratio of the lithium boron alloy to the silver is (5-9): (1-5).
  5. 5. The integrated lithium metal negative electrode of any one of claims 1, 2, 4, wherein at least one of the following conditions is satisfied: (1) The thickness of the conductive polymer layer is 1-50 mu m; (2) The thickness of the lithium-philic substance layer is 10 nm-300 nm; (3) The thickness of the lithium metal layer is 1-20 mu m.
  6. 6. The integrated lithium metal negative electrode of any one of claims 1, 2, 4, wherein the material of the conductive polymer layer satisfies at least one of the following conditions: (1) The mass ratio of the fluorine-containing polymer to the conductive agent is (60-80): 5-15; (2) The mass ratio of the fluorine-containing polymer to the lithium supplementing agent is (60-80): 10-30.
  7. 7. The integrated lithium metal negative electrode of any one of claims 1,2, 4, wherein a ceramic layer is disposed between the porous polymer film and the conductive polymer layer.
  8. 8. The preparation method of the integrated lithium metal negative electrode is characterized by comprising the following steps of: Mixing fluorine-containing polymer, conductive agent, lithium supplementing agent and solvent to prepare slurry; coating the slurry on one side surface of a porous polymer film, and drying to form a conductive polymer layer on the surface of the porous polymer film; Forming a lithium-philic substance layer on the surface of the conductive polymer layer; and depositing a lithium metal layer on the surface of the lithium-philic substance layer.
  9. 9. The method for producing an integrated lithium metal anode according to claim 8, wherein at least one of the following conditions is satisfied: (1) The mass ratio of the fluorine-containing polymer to the conductive agent is (60-80): 5-15; (2) The mass ratio of the fluorine-containing polymer to the lithium supplementing agent is (60-80): 10-30.
  10. 10. The method for producing an integrated lithium metal anode according to claim 8, wherein the solvent includes at least one of nitrogen methyl pyrrolidone, polyvinylpyrrolidone, and lithium polyacrylate.
  11. 11. The method for preparing the integrated lithium metal negative electrode according to claim 8, wherein the drying treatment is performed in a vacuum environment, the temperature of the drying treatment is 60-80 ℃, and the time is 12-24 hours.
  12. 12. The method for producing an integrated lithium metal anode according to any one of claims 8 to 11, wherein at least one of the following conditions is satisfied: (1) Depositing lithium boron alloy and silver on the surface of the conductive polymer layer in a magnetron sputtering mode to form the lithium-philic substance layer; (2) And depositing the lithium metal layer on the surface of the lithium-philic substance layer by adopting an evaporation mode.
  13. 13. The method for producing an integrated lithium metal anode according to claim 12, wherein magnetron sputtering satisfies at least one of the following conditions: (1) The magnetron sputtering target comprises a lithium boron alloy target and a silver target; (2) The power of the magnetron sputtering is 30W-80W; (3) The working pressure of the magnetron sputtering is 0.3 Pa-0.8 Pa.
  14. 14. A lithium metal battery comprising an integrated lithium metal negative electrode according to any one of claims 1 to 7 or an integrated lithium metal negative electrode prepared by the preparation method according to any one of claims 8 to 13.
  15. 15. An electrical device comprising the lithium metal battery of claim 14.

Description

Integrated lithium metal negative electrode, preparation method thereof, lithium metal battery and power utilization device Technical Field The application relates to the technical field of batteries, in particular to an integrated lithium metal negative electrode, a preparation method thereof, a lithium metal battery and an electric device. Background With the development of new energy technology, the requirement on the energy surface density of the power battery is higher and higher, so that the lithium metal negative electrode becomes an ideal material for replacing the traditional graphite negative electrode. However, in practical application, the lithium metal negative electrode often has the technical problems that the lithium metal is easy to generate larger volume change in the process of deposition/stripping, the electrode structure is damaged, active materials are pulverized, the capacity of the lithium metal battery is fast attenuated, the cycle life is shortened, lithium ions are unevenly deposited on the surface of the electrode in the process of charging and discharging, lithium dendrite growth is easy to be initiated, lithium dendrite possibly pierces a diaphragm to cause internal short circuit of the lithium metal battery and even cause thermal runaway to form serious potential safety hazards, in the process of circulating, the volume change of the lithium metal causes continuous formation and consumption of an SEI film on the surface of the lithium metal, the loss of active lithium and the consumption of electrolyte are caused, the coulomb efficiency of the lithium metal battery is reduced, the internal resistance of the lithium metal battery is increased, the traditional copper foil current collector is difficult to guide lithium to be evenly deposited due to poor lithium affinity, the problem of lithium dendrite growth is solved, meanwhile, the quality of the copper foil current collector in the lithium metal negative electrode is relatively large, and the energy density of the lithium metal battery is reduced. Disclosure of Invention Based on this, it is necessary to provide a lithium metal battery and a method for manufacturing the same to improve the energy density, coulombic efficiency and cycle performance of the lithium metal battery. In a first aspect of the present application, there is provided an integrated lithium metal negative electrode comprising a porous polymer film, a conductive polymer layer, a lithium-philic substance layer and a lithium metal layer laminated in this order in a thickness direction, wherein the conductive polymer layer comprises a fluoropolymer, a conductive agent and a lithium supplementing agent. In some embodiments, at least one of the following conditions is satisfied: (1) The fluoropolymer includes polyvinylidene fluoride-hexafluoropropylene copolymer; (2) The conductive agent comprises at least one of carbon nanofibers, carbon nanotubes and carbon nanowires; (3) The lithium supplementing agent comprises at least one of lithium oxide, lithium nitride and lithium oxalate. In some embodiments, the material of the lithium-philic substance layer includes a lithium-boron alloy and silver. In some embodiments, the layer of a lithium-philic substance satisfies at least one of the following conditions: (1) The lithium boron alloy includes at least one of LiB, li 5B4, and Li 7B6; (2) The atomic ratio of the lithium boron alloy to the silver is (5-9): (1-5). In some embodiments, at least one of the following conditions is satisfied: (1) The thickness of the conductive polymer layer is 1-50 mu m; (2) The thickness of the lithium-philic substance layer is 10 nm-300 nm; (3) The thickness of the lithium metal layer is 1-20 mu m. In some embodiments, the material of the conductive polymer layer satisfies at least one of the following conditions: (1) The mass ratio of the fluorine-containing polymer to the conductive agent is (60-80): 5-15; (2) The mass ratio of the fluorine-containing polymer to the lithium supplementing agent is (60-80): 10-30. In some embodiments, a ceramic layer is disposed between the porous polymer membrane and the conductive polymer layer. In a second aspect of the present application, there is provided a method for preparing an integrated lithium metal anode, comprising the steps of: Mixing fluorine-containing polymer, conductive agent, lithium supplementing agent and solvent to prepare slurry; coating the slurry on one side surface of a porous polymer film, and drying to form a conductive polymer layer on the surface of the porous polymer film; Forming a lithium-philic substance layer on the surface of the conductive polymer layer; and depositing a lithium metal layer on the surface of the lithium-philic substance layer. In some embodiments, at least one of the following conditions is satisfied: (1) The mass ratio of the fluorine-containing polymer to the conductive agent is (60-80): 5-15; (2) The mass ratio of the fluorine-containing poly