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KR-102961537-B1 - Low-resistance multi-layered Fe-Ni alloy current collector and secondary battery comprising the same

KR102961537B1KR 102961537 B1KR102961537 B1KR 102961537B1KR-102961537-B1

Abstract

The present invention relates to a current collector having both cathodic and anode characteristics by laminating an Fe-Ni alloy on at least both sides of a core portion made of copper foil (Cu foil) and forming a material layer with anode or cathodic characteristics on the Fe-Ni alloy layer.

Inventors

  • 정관호
  • 김기수
  • 심영섭
  • 홍대명
  • 김지원
  • 위유정

Assignees

  • 주식회사 프렘투

Dates

Publication Date
20260507
Application Date
20231114

Claims (15)

  1. As the battery's current collector, Copper foil and, Fe-Ni alloy layers containing iron (Fe) and nickel (Ni) formed on both sides of the copper foil (Cu foil) above, and It includes an anode characteristic material layer formed on one surface of the above Fe-Ni alloy layer and containing aluminum (Al), and It includes a cathodic characteristic material layer formed on the other side of the above Fe-Ni alloy layer and comprising titanium (Ti), and The above current collector has a resistivity value of 5× 10⁻⁸ Ωm or less, and Low-resistance multilayer Fe-Ni alloy current collector for lithium metal batteries or sulfide-based all-solid-state batteries.
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  4. In Article 1, A low-resistance multilayer Fe-Ni alloy current collector having a thickness of 4㎛ to 20㎛.
  5. In Article 1 or Article 4, A low-resistance multilayer Fe-Ni alloy current collector having a copper foil (Cu foil) thickness of 3㎛ to 14㎛.
  6. In Article 1 or Article 4, A low-resistance multilayer Fe-Ni alloy current collector having a combined thickness of Fe-Ni alloy layers formed on both sides of the copper foil (Cu foil) of 1 to 6 μm.
  7. In Article 1 or Article 4, The above Fe-Ni alloy layer is a low-resistance multilayer Fe-Ni alloy current collector composed of 10 to 90 weight percent nickel (Ni) and the remainder being iron (Fe) and unavoidable impurities.
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  9. In Article 1, A low-resistance multilayer Fe-Ni alloy current collector having a cathodic characteristic material layer thickness of 10 nm to 1 µm.
  10. In Article 1, A low-resistance multilayer Fe-Ni alloy current collector having a thickness of 0.09 to 2 μm of the anode characteristic material layer.
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  12. In Article 1 or Article 4, The average grain size of the above Fe-Ni alloy layer is greater than 0 nm and less than or equal to 15 nm, and A low-resistance multilayer Fe-Ni alloy current collector having a tensile strength of 600 MPa or more and an elongation of 3% or more.
  13. A positive electrode comprising a first current collector having a stacked structure as described in claim 1, and a positive active material layer formed on a positive characteristic material layer of the first current collector, and A cathode comprising a second current collector disposed opposite to the anode and having a stacked structure as described in claim 1, and a cathode active material layer formed on a cathode characteristic material layer of the second current collector, A secondary battery comprising an electrolyte layer formed between the positive active material layer of the positive electrode and the negative active material layer of the negative electrode.
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  15. In Article 13, The above electrolyte layer comprises a solid electrolyte, in a secondary battery.

Description

Low-resistance multi-layered Fe-Ni alloy current collector and secondary battery comprising the same The present invention relates to an Fe-Ni alloy current collector having a low-resistance multilayer structure and a secondary battery including 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 low-resistance multilayer Fe-Ni alloy current collector according to a first embodiment of the present invention. FIG. 2 shows the cross-sectional structure of a low-resistance multilayer Fe-Ni alloy current collector according to a second embodiment of the present invention. FIG. 3 shows the cross-sectional structure of a solid electrolyte battery with a low-resistance multilayer Fe-Ni alloy current collector according to the third embodiment of the present invention. FIG. 4 shows the cross-sectional structure of a solid electrolyte battery with a low-resistance multilayer Fe-Ni alloy current collector according to the fourth embodiment of the present invention. Figure 5 is a schematic diagram of a process and apparatus for manufacturing a low-resistance multilayer Fe-Ni alloy current collector. 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