Ni-plated steel foil for nickel-hydrogen secondary battery current collector, nickel-hydrogen secondary battery current collector, and nickel-hydrogen secondary battery
A high-strength steel foil for the positive and negative electrode current collectors of nickel-hydrogen secondary batteries which uses a light weight and economical steel foil and which is thin and strong and has excellent rust resistance and resistance to metal ion leaching. Also, a high-strength steel foil for the positive and negative electrode current collectors of nickel-hydrogen secondary batteries which has excellent elongation. The Ni-plated steel foil for hydrogen secondary battery current collectors comprises, by mass %, C: 0.0001 to 0.0200%, Si: 0.0001 to 0.0200%, Mn: 0.005 to 0.300%, P: 0.001 to 0.020%, S: 0.0001 to 0.0100%, Al: 0.0005 to 0.1000%, N: 0.0001 to 0.0040%, one or both of Ti and Nb: 0.800% or less respectively, and a balance of Fe and impurities. The Ni-plated steel foil has an Ni plating layer on both surfaces. The thickness of the Ni plating layer on both surfaces of the Ni-plated steel foil is greater than or equal to 0.15 μm, the thickness of the Ni-plated steel foil is 5 to 50 μm, the tensile strength is over 400 MPa but no greater than 1200 MPa, and the surface defect area percentage is less than or equal to 5.00% for both surfaces of the Ni-plated steel foil.
1. An Ni-plated steel foil for nickel-hydrogen secondary battery current collectors comprising, by mass %,
C: 0.0001 to 0.0200%,
Si: 0.0001 to 0.0200%,
Mn: 0.005 to 0.300%,
P: 0.001 to 0.020%,
S: 0.0001 to 0.0100%,
Al: 0.0005 to 0.1000%,
N: 0.0001 to 0.0040%,
one or both of Ti and Nb: 0.800% or less respectively, and
a balance of Fe and impurities, and
having an Ni plating layer on both surfaces,
wherein, an Ni plating layer thickness of each of a first surface and second surface of the Ni-plated steel foil is greater than or equal to 0.15 μm,
a thickness of the Ni-plated steel foil is 5 to 50 μm,
a tensile strength is over 400 MPa but no greater than 1200 MPa, and
a surface defect area percentage is less than or equal to 5.00% for each of the first surface and second surface of the Ni-plated steel foil.
2. The Ni-plated steel foil for nickel-hydrogen secondary battery current collectors according to claim 1 having a breaking elongation of greater than or equal to 3%.
3. The Ni-plated steel foil for nickel-hydrogen secondary battery current collectors according to claim 1 wherein the thickness of the Ni-plated steel foil is 10 to 30 μm.
4. The Ni-plated steel foil for nickel-hydrogen secondary battery current collectors according to claim 1 wherein the thickness of the Ni plating layer on the first surface and second surface of the Ni-plated steel foil is 0.20 to 1.50 μm.
5. A nickel-hydrogen secondary battery current collector comprising the Ni-plated steel foil for nickel-hydrogen secondary battery current collectors according to claim 1 .
6. A nickel-hydrogen secondary battery comprising a positive electrode current collector on which a positive electrode active material layer, a separator, a negative electrode active material layer, and a negative electrode current collector are sequentially laid, in which nickel-hydrogen secondary battery, at least one of the positive electrode current collector and the negative electrode current collector is the nickel-hydrogen secondary battery current collector according to claim 5 .
7. The Ni-plated steel foil for nickel-hydrogen secondary battery current collectors according to claim 2 wherein the thickness of the Ni-plated steel foil is 10 to 30 μm.
8. The Ni-plated steel foil for nickel-hydrogen secondary battery current collectors according to claim 2 wherein the thickness of the Ni plating layer on the first surface and second surface of the Ni-plated steel foil is 0.20 to 1.50 μm.
9. The Ni-plated steel foil for nickel-hydrogen secondary battery current collectors according to claim 3 wherein the thickness of the Ni plating layer on the first surface and second surface of the Ni-plated steel foil is 0.20 to 1.50 μm.
10. A nickel-hydrogen secondary battery current collector comprising the Ni-plated steel foil for nickel-hydrogen secondary battery current collectors according to claim 2 .
11. A nickel-hydrogen secondary battery current collector comprising the Ni-plated steel foil for nickel-hydrogen secondary battery current collectors according to claim 3 .
12. A nickel-hydrogen secondary battery current collector comprising the Ni-plated steel foil for nickel-hydrogen secondary battery current collectors according to claim 4 .
13. A nickel-hydrogen secondary battery comprising a positive electrode current collector on which a positive electrode active material layer, a separator, a negative electrode active material layer, and a negative electrode current collector are sequentially laid, in which nickel-hydrogen secondary battery, at least one of the positive electrode current collector and the negative electrode current collector is the nickel-hydrogen secondary battery current collector according to claim 10 .
14. A nickel-hydrogen secondary battery comprising a positive electrode current collector on which a positive electrode active material layer, a separator, a negative electrode active material layer, and a negative electrode current collector are sequentially laid, in which nickel-hydrogen secondary battery, at least one of the positive electrode current collector and the negative electrode current collector is the nickel-hydrogen secondary battery current collector according to claim 11 .
15. A nickel-hydrogen secondary battery comprising a positive electrode current collector on which a positive electrode active material layer, a separator, a negative electrode active material layer, and a negative electrode current collector are sequentially laid, in which nickel-hydrogen secondary battery, at least one of the positive electrode current collector and the negative electrode current collector is the nickel-hydrogen secondary battery current collector according to claim 12 .