Bipolar electrode, bipolar secondary battery using the same and method for manufacturing bipolar electrode

Patent metadata

Field	Value
Publication number	US-10283774-B2
Application number	US-201113811793-A
Country	US
Kind code	B2
Filing date	Jul 21, 2011
Priority date	Jul 28, 2010
Publication date	May 7, 2019
Grant date	May 7, 2019

Abstract

A bipolar electrode is composed of a first active material layer which is, for example, a positive electrode active material layer formed to include a first active material on one side of a collector, and a second active material layer which is, for example, a negative electrode active material layer formed to include a second active material with less compressive strength than that of the first active material on the other side of the collector. Then, a density adjusting additive which is an additive material with larger compressive strength than that of the second active material is included in the second active material layer.

First claim

The invention claimed is:

1. A bipolar electrode comprising:
a collector;
a first active material layer including a first active material formed on one side of the collector; and
a second active material layer including a second active material having a smaller compressive strength than that of the first active material formed on an other side of the collector, the first active material layer and the second active material layer being subjected to press working for density adjustment, wherein
the bipolar electrode does not include an electrolyte layer,
the press working for density adjustment is simultaneously applied to the first active material layer and the second active material layer from both sides of the bipolar electrode, and the press working for density adjustment is not applied to the electrolyte layer,
for reduction of a difference between elongation of the first active material layer and elongation of the second active material layer resulting from the press working for density adjustment, an additive material having a larger compressive strength than that of the second active material is only included in the second active material layer,
the second active material is present in a greater wt % than the additive material,
the additive material comprises alumina, titanium dioxide, magnesium oxide, solid hard carbon material, silicon, or silicon oxide, and
the additive material has a larger particle diameter than the second active material.

2. The bipolar electrode according to claim 1 , wherein the compressive strength of the additive material is equal to that of the first active material.

3. The bipolar electrode according to claim 1 , wherein the compressive strength of the additive material is larger than that of the first active material.

4. A bipolar secondary battery using the bipolar electrode according to claim 1 .

5. A method for manufacturing a bipolar electrode comprising:
applying a first slurry including a first active material on one side of a collector;
applying, on the other side of the collector, a second slurry obtained by mixing a second active material having a smaller compressive strength than that of the first active material and an additive material having a larger compressive strength than that of the second active material; and
simultaneously pressing the first slurry and the second slurry from both sides of the bipolar electrode, wherein
the bipolar electrode does not include an electrolyte layer,
the step of simultaneously pressing the first slurry and the second slurry from both sides of the bipolar electrode does not include pressing the electrolyte layer,
the additive material is only included in the second slurry,
the second active material is present in a greater wt % than the additive material,
the additive material comprises alumina, titanium dioxide, magnesium oxide, solid hard carbon material, silicon, or silicon oxide, and
the additive material has a larger particle diameter than the second active material.

6. The method for manufacturing the bipolar electrode according to claim 5 , wherein a particle diameter of the additive material having a larger compressive strength than that of the second active material is set to be equal to a design value of a thickness of the second active material layer.

7. The bipolar electrode according to claim 1 , wherein a maximum particle diameter is substantially equal to a thickness of the second active material layer after pressing.

8. The method for manufacturing the bipolar electrode according to claim 5 , wherein a maximum particle diameter is substantially equal to a thickness of the second active material layer after pressing.

9. The bipolar electrode according to claim 1 , wherein the additive material comprises alumina.

10. The bipolar electrode according to claim 1 , wherein the additive material comprises titanium dioxide.

11. The bipolar electrode according to claim 1 , wherein the additive material comprises magnesium oxide.

12. The bipolar electrode according to claim 1 , wherein the additive material comprises silicon.

13. The bipolar electrode according to claim 1 , wherein the additive material comprises silicon oxide.

Assignees

• Sato Masanobu
• Ohta Yasuo
• Horie Hideaki
• Aoyagi Masanori
• Nissan Motor

Inventors

• Sato Masanobu
• Ohta Yasuo
• Horie Hideaki
• Aoyagi Masanori

Classifications

• H01M2004/021

  Physical characteristics, e.g. porosity, surface area · CPC title

• H01M4/0435

  Rolling or calendering · CPC title

• H01M4/62 Primary

  Selection of inactive substances as ingredients for active masses, e.g. binders, fillers · CPC title

• H01M4/0409

  by a doctor blade method, slip-casting or roller coating · CPC title

• H01M4/134

  Electrodes based on metals, Si or alloys · CPC title