Method for manufacturing electrode and method for manufacturing secondary battery

Patent metadata

Field	Value
Publication number	US-10553852-B2
Application number	US-201615337220-A
Country	US
Kind code	B2
Filing date	Oct 28, 2016
Priority date	Oct 30, 2015
Publication date	Feb 4, 2020
Grant date	Feb 4, 2020

Abstract

Disclosed is a method for manufacturing a positive electrode including a positive electrode substrate made of aluminum foil and a positive electrode active material layer containing a positive electrode active material on the positive electrode substrate. This method includes the steps of stretching a first exposed region of the positive electrode substrate with a first stretching roller disposed upstream; stretching a second exposed region of the positive electrode substrate with a second stretching roller disposed downstream; and compressing the positive electrode active material layer with a pair of compression rollers.

First claim

What is claimed is:

1. A method for manufacturing an electrode comprising a strip-shaped substrate and an active material layer containing an active material on the substrate, the method comprising the steps of:
forming the active material layer on the substrate in a longitudinal direction of the substrate such that the substrate has first and second exposed regions extending in the longitudinal direction of the substrate on opposing sides of the active material layer in a lateral direction of the substrate;
a first stretching step stretching the first exposed region of the substrate after the step of forming the active material layer;
a second stretching step stretching the second exposed region of the substrate; and
compressing the active material layer after the second stretching step, wherein
the first stretching step causes the first exposed region to stretch while the second exposed regions remains substantially unstretched, and the second stretching step causes the second exposed region to stretch while the first exposed regions remains substantially unstretched, wherein the second stretching step is performed after the first stretching step.

2. The method for manufacturing the electrode according to claim 1 , wherein
the first stretching step comprises stretching the first exposed region of the substrate with a first stretching roller in abutment with the first exposed region of the substrate, and
the second stretching step comprises stretching the second exposed region of the substrate with a second stretching roller, separate and different from the first stretching roller, in abutment with the second exposed region of the substrate.

3. The method for manufacturing the electrode according to claim 2 , wherein
a guide roller is disposed between the first and second stretching rollers, and
the substrate is tensioned by the guide roller.

4. The method for manufacturing the electrode according to claim 3 , wherein a path through which the substrate passes includes, in order from upstream, the first stretching roller, the guide roller, and the second stretching roller.

5. The method for manufacturing the electrode according to claim 2 , wherein
the first stretching roller comprises a first body and a first large-diameter portion having a larger diameter than the first body,
the second stretching roller comprises a second body and a second large-diameter portion having a larger diameter than the second body,
the first large-diameter portion stretches the first exposed region of the substrate, and
the second large-diameter portion stretches the second exposed region of the substrate.

6. The method for manufacturing the electrode according to claim 1 ,
wherein the electrode further comprises a protective layer disposed on at least a portion of the first exposed region;
the protective layer includes a binder and at least one of the group consisting of alumina, zirconia, titania, and silica; and
the first stretching step includes stretching the portion of the first exposed region with the protective layer.

7. The method for manufacturing the electrode according to claim 1 ,
wherein the electrode further comprises a protective layer disposed on at least a portion of the first exposed region;
the protective layer being thinner than the active material layer; and
the first stretching step includes stretching the portion of the first exposed region with the protective layer.

8. The method for manufacturing the electrode according to claim 1 ,
wherein the electrode further comprises a protective layer disposed on at least a portion of the first exposed region, and a binder;
a mass percentage of the binder within the protective layer is greater than a mass percentage of the binder within the active material layer; and
the first stretching step includes stretching the portion of the first exposed region with the protective layer.

9. The method for manufacturing the electrode according to claim 1 ,
wherein the electrode further comprises a protective layer disposed on at least a portion of the first exposed region, and a binder;
a mass percentage of the binder in the protective layer is 10% by mass or greater; and
the first stretching step includes stretching the portion of the first exposed region with the protective layer.

10. The method for manufacturing the electrode according to claim 1 ,
wherein the electrode further comprises a third exposed region of the substrate provided between the first and second exposed regions in the lateral direction of the substrate; and
stretching the third exposed region of the substrate.

11. The method for manufacturing the electrode according to claim 10 ,
wherein the stretching of the third exposed region of the substrate is performed after the second stretching step and before the compression step.

12. A method for manufacturing a secondary battery, comprising the steps of:
fabricating an electrode assembly comprising a positive electrode, a negative electrode, and a separator, the positive electrode being manufactured by the method according to claim 1 ; and
placing the electrode assembly and a nonaqueous electrolyte in a casing.

13. A method for manufacturing an electrode comprising a strip-shaped substrate and an active material layer containing an active material on the substrate, the method comprising the steps of:
forming the active material layer on the substrate in a longitudinal direction of the substrate such that the substrate has first and second exposed regions extending in the longitudinal direction of the substrate on opposing sides of the active material layer in a lateral direction of the substrate;
a first stretching step stretching the first exposed region of the substrate after the step of forming the active material layer;
a second stretching step stretching the second exposed region of the substrate, wherein the second stretching step is performed after the first stretching step;
compressing the active material layer after the second stretching step;
and
wherein an amount by which the first exposed region is stretched in the first stretching step is greater than an amount by which the second exposed region is stretched in the first stretching step, and an amount by which the second exposed region is stretched in the second stretching step is greater than an amount by which the first exposed region is stretched in the second stretching step.

14. The method for manufacturing the electrode according to claim 13 ,
wherein the electrode further comprises a protective layer disposed on at least a portion of the first exposed region, and a binder;
a mass percentage of the binder within the protective layer is greater than a mass percentage of the binder within the active material layer; and
the first stretching step includes stretching the portion of the first exposed region with the protective layer.

15. The method for manufacturing the electrode according to claim 13 ,
wherein the electrode further comprises a protective layer disposed on at least a portion of the first exposed region;
the protective layer includes a binder and at least one of the group consisting of alumina, zirconia, titania, and silica; and
the first stretching step includes stretching the portion of the first exposed region with the protective layer.

16. The method for manufacturing the electrode according to claim 13 ,
wherein the electrode further comprises a third exposed region of the substrate provided between the first and second exposed regions in the lateral direction of the substrate; and
a third stre

Assignees

• Sanyo Electric Co

Inventors

• Fukunaga Masao
• Shirota Ryosuke
• Nishio Kazuya
• Nakai Haruya

Classifications

• H01M4/131

  Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx · CPC title

• H01M4/505

  of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy · CPC title

• H01M4/1391

  of electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx · CPC title

• H01M4/661

  Metal or alloys, e.g. alloy coatings (H01M4/669 take precedence) · CPC title

• H01M4/587

  for inserting or intercalating light metals · CPC title