CPC C25D 5/627 (2020.08) [B32B 15/01 (2013.01); B32B 15/20 (2013.01); C25D 5/12 (2013.01); C25D 5/50 (2013.01); C25D 5/611 (2020.08); C25D 7/06 (2013.01); H01M 4/661 (2013.01); H01M 4/667 (2013.01); B32B 2307/732 (2013.01); H01M 2004/027 (2013.01)] | 8 Claims |
1. A nickel-coated copper foil comprising:
a copper layer made of Cu or a Cu alloy; and
an upper exposed nickel plating layer made of Ni or a Ni alloy, the upper exposed nickel plating layer covering an upper surface of the copper layer and exposing a surface opposite to a surface in contact with the copper layer in order to be welded to a portion of an other material used in batteries by YAG laser,
a bottom exposed nickel plating layer made of Ni or a Ni alloy, the bottom exposed nickel plating layer covering a bottom surface of the copper layer and exposing a surface opposite to a surface in contact with the copper layer in order to be welded to a portion of an other material used in batteries by YAG laser,
the upper exposed nickel plating layer and the bottom exposed nickel plating layer having a thickness of 0.01 μm or more and less than 0.1 μm,
surfaces of the upper exposed nickel plating layer and the bottom exposed nickel plating layer have an L* value of 70 or more and 78 or less, an a* value of 0 or more and 4 or less and a b* value of 0 or more and 14 or less in an L*a*b* color system obtained by an SCI measurement method in accordance with JIS Z 8722,
at least one of the surfaces of the upper exposed nickel plating layer and the bottom exposed nickel plating layer are welded to a portion of an other material used in batteries by YAG laser,
and wherein the nickel-coated copper foil has an overall thickness of 100 μm or more and 200 μm or less.
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