Composite metal foil and production method therefor

Patent metadata

Field	Value
Publication number	US-9595719-B2
Application number	US-201213985599-A
Country	US
Kind code	B2
Filing date	Mar 23, 2012
Priority date	Apr 8, 2011
Publication date	Mar 14, 2017
Grant date	Mar 14, 2017

Abstract

A composite metal foil is provided comprising a porous metal foil comprising a two-dimensional network structure composed of a metal fiber, and a primer provided on at least a part of the interior and/or periphery of pores of the porous metal foil. According to the present invention, it is possible to obtain a composite metal foil which has a desired function imparted by a primer in addition to superior properties derived from a porous metal foil, in a highly productive and cost effective manner that is suited for continuous production.

First claim

The invention claimed is:

1. A composite metal foil consisting of:
a porous metal foil composed of a metal fiber formed from metal particles that are connected to one another via nucleation; and
a primer provided on at least a part of the interior and/or periphery of pores of the porous metal foil;
wherein the metal fiber has a metal fiber diameter D, defining a width of a basal plane of the metal fiber, and a spherical part, defining a maximum cross-sectional height H of the metal fiber, and the metal fiber is irregularly networked along the basal plane; and
wherein the porous metal foil has a thickness in a range of 3 to 40 μm corresponding to the maximum cross-sectional height H of the spherical part of the metal fiber, and a weight-based aperture ratio P of 3 to 60%, wherein the weight-based aperture ratio P is defined as:
P= 100−[( W p /W n )×100],

wherein W p /W n is a ratio of a weight W p of the porous metal foil to a theoretical weight W n of a non-porous metal foil having a composition and dimensions that are identical to those of the porous metal foil.

2. The composite metal foil according to claim 1 , wherein the metal fiber diameter D is in a range of 5 to 80 μm.

3. The composite metal foil according to claim 1 , wherein the metal fiber is a branched fiber, the branched fiber being irregularly networked.

4. The composite metal foil according to claim 1 , wherein the irregularly networked structure of the metal fiber has an irregular shape derived from a crack, which has been formed on a surface of a substrate, in which the metal particles are connected to one another via nucleation.

5. The composite metal foil according to claim 1 , wherein the metal fiber comprises at least one selected from the group consisting of copper, aluminum, gold, silver, nickel, cobalt, and tin.

6. The composite metal foil according to claim 1 , wherein the pores are filled with the primer over the whole surface of the porous metal foil.

7. The composite metal foil according to claim 1 , wherein the primer is a current collector primer.

8. The composite metal foil according to claim 7 , wherein the current collector primer comprises an electrically conductive material selected from the group consisting of electrically conductive carbon particles, an electrically conductive carbon fiber, metal particles, and an electrically conductive polymer; and a binder.

9. The composite metal foil according to claim 1 , wherein the porous metal foil has a tensile strength of 10N/10 mm or more.

10. A method for producing a composite metal foil, which comprises the steps of:
preparing an electrically conductive substrate comprising on its surface a peelable layer in which a crack is generated;
plating the peelable layer with a metal capable of depositing preferentially on the crack, to deposit the metal as metal particles along the crack, thereby forming a porous metal foil consisting of a two-dimensional network structure composed of a metal fiber formed from the metal particles, which are connected to one another via nucleation, wherein the porous metal foil has a thickness of 3 to 40 μm and has a weight-based aperture ratio P of 3 to 60%, wherein the weight-based aperture ratio P is defined as:
P= 100−[( W p /W n )×100],

wherein W p /W n is a ratio of a weight W p of the porous metal foil to a theoretical weight W n of a non-porous metal foil having a composition and dimensions that are identical to those of the porous metal foil;
peeling off the porous metal foil from the peelable layer; and
coating the porous metal foil with a primer liquid to obtain a composite metal foil.

11. The method according to claim 10 , further comprising the step of drying the primer liquid.

12. The method according to claim 10 , wherein the crack has been generated by a stress in the peelable layer.

13. The method according to claim 10 , wherein the peelable layer comprises at least one selected from the group consisting of chromium, titanium, tantalum, niobium, nickel, and tungsten, or is composed of an organic material.

14. The method according to claim 10 , wherein the peelable layer is composed of chromium, a chromium alloy, or a chromium oxide.

15. The method according to claim 10 , wherein the metal capable of depositing preferentially on the crack comprises at least one selected from the group consisting of copper, aluminum, gold, silver, nickel, cobalt, and tin.

16. The method according to claim 10 , wherein the composite metal foil has a thickness of 3 to 40 μm.

17. The method according to claim 10 , wherein the primer liquid is a current collector primer liquid.

18. The method according to claim 17 , wherein the current collector primer liquid comprises an electrically conductive material selected from the group consisting of electrically conductive carbon particles, an electrically conductive carbon fiber, metal particles, and an electrically conductive polymer; a binder; and a solvent.

Assignees

• Matsunaga Tetsuhiro
• Watanabe Hajime
• Nishikawa Joe
• Mitsui Mining & Smelting Co

Inventors

• Matsunaga Tetsuhiro
• Watanabe Hajime
• Nishikawa Joe

Classifications

• H01M4/0402

  Methods of deposition of the material · CPC title

• B05D7/50

  Multilayers · CPC title

• C25D1/04

  Wires; Strips; Foils · CPC title

• H01G9/016

  Electricity · mapped topic

• C25D7/0635

  In radial cells · CPC title