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KR-102962451-B1 - Surface coated lithium electrode and lithium secondary battery containing the same

KR102962451B1KR 102962451 B1KR102962451 B1KR 102962451B1KR-102962451-B1

Abstract

One embodiment of the present invention provides a lithium electrode comprising a lithium metal and a coating layer coated on the lithium metal, wherein the coating layer comprises a combination of two or more combinations selected from lithium (Li), indium (In), and zinc (Zn) metals and the lithium (Li), indium (In), and zinc (Zn).

Inventors

  • 유승일
  • 백창근
  • 박주희

Assignees

  • 주식회사 니바 코퍼레이션

Dates

Publication Date
20260508
Application Date
20231227

Claims (9)

  1. lithium metal; and A coating layer coated on the lithium metal; comprising The above coating layer comprises single metals of lithium (Li), indium (In), and zinc (Zn), lithium (Li)-indium (In) alloy, and lithium (Li)-zinc (Zn) alloy, respectively. A lithium electrode in which the molar ratio of the zinc and the indium included in the coating layer is 1:0.1 to 1:10.
  2. In paragraph 1, A lithium electrode in which the content of the zinc and indium included in the coating layer is 0.001 wt% to 50 wt% with respect to the lithium metal.
  3. delete
  4. In paragraph 1, The above coating layer is a lithium electrode formed by immersing the lithium metal in a coating solution or applying the coating solution to the lithium metal.
  5. In paragraph 4, The above coating solution comprises a zinc compound, an indium compound, and an organic solvent, and The above zinc compound comprises one or more selected from ZnF₂ , ZnCl₂ , ZnBr₂ , ZnI₂ , and Zn(TFSI) ₂ , and The above indium compound is a lithium electrode comprising one or more selected from InF₃ , InCl₃ , InBr₃ , InI₃ , and In(TFSI) ₃ .
  6. In paragraph 5, The above zinc compound is reduced to zinc metal by the above lithium metal, and A lithium electrode in which a lithium-zinc alloy is formed in the region where the zinc metal and the lithium metal are in contact.
  7. In paragraph 5, The above indium compound is reduced to indium metal by the above lithium metal, and A lithium electrode in which a lithium-indium alloy is formed in the region where the indium metal and the lithium metal are in contact.
  8. In paragraph 1, The above coating layer is a lithium electrode further comprising oxygen (O) and carbon (C) atoms.
  9. A negative electrode comprising a lithium electrode according to any one of claims 1, 2, 4 through 8; A separator disposed on one side of the above-mentioned cathode; On the separator above, an anode disposed on a side opposite to the side where the cathode is disposed; and A lithium secondary battery comprising: the above-mentioned cathode, the above-mentioned anode, and an electrolyte surrounding the above-mentioned separator.

Description

Surface coated lithium electrode and lithium secondary battery containing the same This invention relates to a surface-coated lithium electrode and a lithium secondary battery containing the same. Lithium metal is a silvery-white alkali metal that is very light (0.534 g/mol), has a low redox voltage (-3.04 V vs. Hydrogen), and high specific capacity (3860 mAh/g), making it highly attractive as a negative electrode material for high-capacity lithium batteries. However, because lithium is highly reactive with electrolytes, attempts are continuously being made to reduce reactivity by coating a protective film on the lithium surface. Meanwhile, conventional methods for forming a protective film on the surface of lithium have mainly involved coating organic materials such as polymers, coating inorganic materials such as LiF or Al₂O₃ , or coating organic-inorganic composite films. However, while these methods can reduce the reactivity of lithium, they have the disadvantage of increasing the resistance of the lithium surface, which degrades lifespan performance during high-speed charging and discharging. Additionally, they have the disadvantage of making mass production difficult because it is difficult to ensure economic viability, such as requiring expensive raw materials or expensive equipment like vacuum deposition equipment for coating. FIG. 1 is a cross-sectional view schematically illustrating an example of a lithium electrode according to one embodiment of the present invention. FIG. 2 is a cross-sectional view schematically illustrating an example of a secondary battery to which a lithium electrode according to one embodiment of the present invention is applied. The present invention is capable of various modifications and may have various embodiments; specific embodiments are illustrated in the drawings and described in detail in the detailed description. The effects and features of the present invention, and the methods for achieving them, will become clear by referring to the embodiments described below in detail together with the drawings. However, the present invention is not limited to the embodiments disclosed below but can be implemented in various forms. In the following embodiments, terms such as first, second, etc. are used not in a limiting sense, but for the purpose of distinguishing one component from another component. In the following examples, singular expressions include plural expressions unless the context clearly indicates otherwise. In the following embodiments, terms such as "include" or "have" mean that the features or components described in the specification are present, and do not preclude the possibility that one or more other features or components may be added. In the following embodiments, when a part such as a film, region, or component is described as being on or above another part, it includes not only cases where it is directly on top of another part, but also cases where another film, region, or component is interposed in between. In the drawings, the size of components may be exaggerated or reduced for convenience of explanation. For example, the size and thickness of each component shown in the drawings are depicted arbitrarily for convenience of explanation, so the present invention is not necessarily limited to what is illustrated. Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings, and when describing with reference to the drawings, identical or corresponding components will be given the same reference numerals. FIG. 1 is a cross-sectional view schematically illustrating an example of a lithium electrode according to one embodiment of the present invention. Referring to FIG. 1, the lithium electrode (100) may include a lithium metal (10) and a coating layer (20) coated on the lithium metal. The lithium metal (10) may include a lithium foil form, and its thickness may be 300 µm or less, and as a specific example, it may be 10 µm to 300 µm, 15 µm to 250 µm, 20 µm to 200 µm, 25 µm to 150 µm, 30 µm to 100 µm, 35 µm to 80 µm, or 40 µm to 60 µm. The coating layer (20) may be a protective layer formed on the surface of the lithium metal (10). For example, the coating layer (20) may include lithium metal and an intermetallic compound, a lithium alloy, or a metal. The lithium metal and the intermetallic compound may be a lithium intermetallic compound comprising Li and one or more metals selected from Al, In, Mg, Sn, Pb, Cd, Ag, Au, Ni, Bi, Sb, Si, Ge, Pd, B, Te, Pt, As, Zn, W, Fe, Ni, Ti, Mn, Mo, Cu, Co, Ce, Ca, Zr, V, Cr, and Ru, and the lithium alloy may be a lithium alloy comprising Li and one or more metals selected from Al, In, Mg, Sn, Pb, Cd, Ag, Au, Ni, Bi, Sb, Si, Ge, Pd, B, Te, Pt, As, Zn, W, Fe, Ni, Ti, Mn, Mo, Cu, Co, Ce, Ca, Zr, V, Cr, and Ru, and the metal may be Al, In, Mg, Sn, Pb, Cd, Ag, Au, Ni, Bi, Sb, Si, Ge, Pd, B, Te, Pt, As, Zn, It may be one or more metals selected from W, Fe, Ni, Ti,