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KR-102961538-B1 - Current collector with improved corrosion resistance and secondary battery containing the same

KR102961538B1KR 102961538 B1KR102961538 B1KR 102961538B1KR-102961538-B1

Abstract

The present invention relates to a current collector with improved corrosion resistance and a secondary battery including the same. The current collector according to the present invention comprises a current collector substrate and a metal oxide layer formed on at least one side of the current collector substrate, wherein the metal oxide layer has a gradient composition in which the oxygen concentration increases continuously or intermittently from the current collector substrate side toward the surface.

Inventors

  • 정관호
  • 김기수
  • 유신
  • 심영섭

Assignees

  • 주식회사 프렘투

Dates

Publication Date
20260507
Application Date
20231114

Claims (17)

  1. A current collector substrate comprising an Fe-Ni alloy layer comprising, in weight percent, Ni: 3~32% or Ni: 40~90%, the remainder being Fe and unavoidable impurities, and A metal layer formed on at least one side of the above-mentioned current collector substrate, and It includes a metal oxide layer formed on the above metal layer, and The above metal layer is made of titanium (Ti), and The metal oxide layer has a gradient composition in which the oxygen concentration increases continuously or intermittently from the current collector substrate side toward the surface, and The metal oxide layer comprises a first oxide layer formed on the titanium (Ti) layer in a state in which titanium (Ti) and titanium oxide are mixed, and a second oxide layer formed on the first oxide layer and composed of titanium dioxide. The thickness of the metal oxide layer is 4.75 nm to 20 nm, and A current collector with improved corrosion resistance, wherein the combined thickness of the metal layer and the metal oxide layer is 9.5 nm to 1 µm.
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  6. In Article 1, A current collector with excellent corrosion resistance, wherein the thickness of the above current collector substrate is 4㎛ to 20㎛.
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  9. In Article 1, A current collector with excellent corrosion resistance, wherein the metal oxide layer has a composition represented by the following chemical formula 1 overall. [Chemical Formula 1] TiO x (0<x<2)
  10. In Article 1, A current collector with excellent corrosion resistance, wherein the resistivity of the above current collector has a value of 20× 10⁻⁸ Ωm or less.
  11. In Article 1, A current collector with excellent corrosion resistance, wherein the average grain size of the above current collector substrate is 15 nm or less (excluding 0 nm).
  12. In Article 1, A current collector having excellent corrosion resistance, wherein the tensile strength of the above current collector substrate is 800 MPa or higher.
  13. In Article 1, A current collector with excellent corrosion resistance, wherein the elongation of the above current collector substrate is 2% or more.
  14. In Article 1, The above current collector substrate is a current collector with excellent corrosion resistance manufactured by the electroforming method.
  15. In Article 1, A current collector with excellent corrosion resistance, wherein the metal oxide layer is formed by vapor deposition.
  16. An anode comprising a current collector described in claim 1 and an anode active material layer formed on a metal oxide layer of said current collector, and A cathode disposed opposite to the anode and comprising a current collector described in claim 1 and a cathode active material layer formed on the metal oxide layer, and A secondary battery comprising an electrolyte layer formed between the positive electrode active material layer and the negative electrode active material layer.
  17. In Article 16, The above electrolyte layer comprises a solid electrolyte, a secondary battery.

Description

Current collector with improved corrosion resistance and secondary battery containing the same The present invention relates to a contactor with improved corrosion resistance and a secondary battery containing the same. Lithium-ion batteries are widely commercialized due to their superior energy density and power output characteristics among various types of rechargeable batteries. Furthermore, as demand for electric vehicles and large-capacity power storage devices increases, there is a need for the development of high-energy batteries to meet these needs. In response to this, technology for applying lithium metal anodes to secondary batteries is being actively developed as a method to achieve high energy densities of over 400 Wh/kg. However, there have been recent reports that when lithium metal is applied to the anode, corrosion occurs in the copper foil used as the anode current collector, leading to a decrease in battery life. Meanwhile, carbonate-based organic solvents included in the liquid electrolytes currently widely used in lithium-ion batteries have problems such as low thermal stability and very high flammability. To address this, all-solid-state battery technology using solid electrolytes is being actively researched; however, in sulfide-based all-solid-state batteries, which are the most actively researched and developed, a problem is emerging in which sulfide-based solid electrolytes corrode the copper foil current collector. In secondary batteries, the current collector acts as a connecting medium to supply electrons or holes provided from an external wire to the electrode active material, or conversely, as a carrier that collects electrons or holes generated as a result of the electrode reaction and flows them to the external wire. In addition, the current collector functions as an important support in realizing the shape of the actual electrode plate. Furthermore, it is important that the metal constituting the current collector does not oxidize in the low potential region for the negative electrode current collector and in the high potential region for the positive electrode current collector. Generally, considering electrical conductivity, electrochemical stability, and suitability for the electrode plate manufacturing process, copper (Cu) is used for the negative electrode and aluminum (Al) or platinum (Pt) is used for the positive electrode, and active material particles are coated onto it and then dried to manufacture the electrode. However, as mentioned above, copper foil (Cu foil) has the critical problem of corrosion in lithium metal batteries and sulfide-based all-solid-state batteries, and since aluminum (Al) cannot be used as a negative electrode, it is impossible to utilize aluminum alone as a current collector possessing both negative and positive electrode characteristics. Furthermore, platinum (Pt) is excessively expensive, which increases battery costs, thus presenting limitations in terms of low economic efficiency for battery application and mass production. FIG. 1 shows the cross-sectional structure of a current collector according to a first embodiment of the present invention. FIG. 2 shows the cross-sectional structure of a current collector according to a second embodiment of the present invention. FIG. 3 shows the cross-sectional structure of a solid electrolyte secondary battery with a current collector applied according to the first embodiment of the present invention. FIG. 4 shows the cross-sectional structure of a solid electrolyte secondary battery with a current collector applied according to the second embodiment of the present invention. FIG. 5 is a schematic diagram of a process and apparatus for manufacturing a current collector according to a first or second embodiment of the present invention. Embodiments of the present invention are described below with reference to the attached drawings so that those skilled in the art can easily implement them. However, the present invention may be embodied in various different forms and is not limited to the embodiments described herein. In addition, to clearly explain the present invention in the drawings, parts unrelated to the explanation have been omitted, and similar parts throughout the specification have been given similar reference numerals. Throughout this specification, when a part is described as being "connected" to another part, this includes not only cases where they are "directly connected," but also cases where they are "electrically connected" with other elements interposed between them. Throughout the entire specification, when a component is described as being located "on," "on top," "on top," "under," "on bottom," or "on bottom" of another component, this includes not only cases where the component is in contact with the other component but also cases where another component exists between the two components. Throughout this specification, when a part is described as "comprising" a certain compone