Steel foil for power storage device container, power storage device container, power storage device, and manufacturing method of steel foil for power storage device container

Patent metadata

Field	Value
Publication number	US-10205135-B2
Application number	US-201515327590-A
Country	US
Kind code	B2
Filing date	Jul 22, 2015
Priority date	Jul 22, 2014
Publication date	Feb 12, 2019
Grant date	Feb 12, 2019

Abstract

A steel foil for a power storage device container includes a rolled steel foil, a nickel layer formed on a surface of the rolled steel foil, and a chromium-based surface treatment layer formed on a surface of the nickel layer. The nickel layer includes an upper layer portion which is in contact with the chromium-based surface treatment layer and contains Ni of 90 mass % or more among metal elements, and a lower layer portion which is in contact with the rolled steel foil and contains Ni of less than 90 mass % among the metal elements and Fe. <111> polar density in a reverse pole figure of the nickel layer in a rolling direction is 3.0 to 6.0. The nickel layer has a sub-boundary which is a boundary between two crystals having a relative orientation difference of 2° to 5°, and a large angle boundary which is a boundary between two crystals having the relative orientation difference of equal to or more than 15°. The average value of a ratio L 5 /L 15 between a boundary length L 5 which is the length of the sub-boundary, and a boundary length L 15 which is the length of the large angle boundary, is equal to or more than 1.0.

First claim

What is claimed is:

1. A steel foil for a power storage device container comprising:
a rolled steel foil;
a nickel layer which is formed on a surface of the rolled steel foil; and
a chromium-based surface treatment layer which is formed on a surface of the nickel layer,
wherein the nickel layer includes an upper layer portion which is in contact with the chromium-based surface treatment layer and contains Ni of 90 mass % or more among metal elements, and a lower layer portion which is in contact with the rolled steel foil and contains Ni of less than 90 mass % among the metal elements and Fe,
a <111> polar density in a reverse pole figure of the nickel layer in a rolling direction is 3.0 to 6.0,
the nickel layer has a sub-boundary which is a grain boundary between two crystals having a relative orientation difference of 2° to 5°, and a large angle boundary which is a grain boundary between two crystals having the relative orientation difference of equal to or more than 15°, and
an average value of a ratio L 5 /L 15 between a boundary length L 5 which is a length of the sub-boundary, and a boundary length L 15 which is a length of the large angle boundary, is equal to or more than 1.0.

2. The steel foil for a power storage device container according to claim 1 , wherein
an adhered amount of the nickel layer is equal to or more than 0.3 g/m 2 .

3. The steel foil for a power storage device container according to claim 2 , further comprising:
a polyolefin-based resin layer which is formed on a surface of the chromium-based surface treatment layer.

4. The steel foil for a power storage device container according to claim 1 , further comprising:
a polyolefin-based resin layer which is formed on a surface of the chromium-based surface treatment layer.

5. A power storage device container which includes the steel foil for a power storage device container according to claim 4 .

6. A power storage device comprising:
the power storage device container according to claim 5 .

7. A manufacturing method of a steel foil for a power storage device container, the method comprising:
a nickel-plating process of performing a nickel plating on a steel sheet so as to form a nickel-plated layer on the steel sheet, and obtaining a nickel-plated steel sheet;
a recrystallization annealing process of performing an annealing on the nickel-plated steel sheet so that the nickel-plated layer recrystallizes;
a cold-rolling process of performing a cold rolling on the nickel-plated steel sheet so as to obtain a steel foil; and
a chromium-based surface treatment process of performing a chromium-based surface treatment on the steel foil,
wherein in the cold-rolling process, the number of rolling passes is set to be equal to or more than seven passes, a reduction on a first rolling pass is set to be equal to or less than 30%, a cumulative rolling reduction until a fourth rolling pass is set to be equal to or less than 70%, a difference between a cumulative rolling reduction until a rolling pass before two passes from a final pass, and a cumulative rolling reduction until the final pass is set to be equal to or less than 5%, and the cumulative rolling reduction until the final pass is set to be equal to or more than 70%.

8. The manufacturing method of a steel foil for a power storage device container, according to claim 7 , wherein
in the nickel-plating process, an adhered amount of the nickel-plated layer is set to be equal to or more than 1 g/m 2 .

9. The manufacturing method of a steel foil for a power storage device container, according to claim 8 , further comprising:
a polyolefin resin layer forming process of forming a polyolefin resin layer on the surface of the steel foil after the chromium-based surface treatment process.

10. The manufacturing method of a steel foil for a power storage device container, according to claim 7 , further comprising:
a polyolefin resin layer forming process of forming a polyolefin resin layer on the surface of the steel foil after the chromium-based surface treatment process.

Assignees

• Nippon Steel & Sumitomo Metal Corp
• Nippon Steel & Sumikin Mat Co

Inventors

• Ibaragi Masaharu
• Nose Koichi
• Ishizuka Kiyokazu
• Goto Yasuto
• Nagasaki Shuji
• Unno Hiroto

Classifications

• C21D9/46 Primary

  for sheet metals · CPC title

• H01M50/178

  for pouch or flexible bag cells · CPC title

• H01M50/134

  Hardness · CPC title

• H01M50/553

  Terminals adapted for prismatic, pouch or rectangular cells · CPC title

• H01M50/55

  on the same side of the cell · CPC title