Method of manufacturing a lithium-ion secondary battery electrode sheet based on an active material dry powder

Patent metadata

Field	Value
Publication number	US-10276855-B2
Application number	US-201515325176-A
Country	US
Kind code	B2
Filing date	Jun 29, 2015
Priority date	Jul 11, 2014
Publication date	Apr 30, 2019
Grant date	Apr 30, 2019

Abstract

In a method of manufacturing a lithium-ion secondary battery electrode sheet proposed herein, a current collector (11), a powder material (13) of granulated particles, and a binder solution (12) are prepared. The binder solution (12) is applied onto the current collector (11). Subsequently, the powder material (13) of the granulated particles is fed onto the current collector (11). (Then, the powder material (13) of the granulated particles is pressed against the current collector (11). In the basic manufacturing method, adhesive strength of the powder material (13) of the granulated particles is enhanced after the powder material (13) of the granulated particles is fed onto the current collector (11) and before or while the powder material (13) of the granulated particles is pressed against the current collector (11).

First claim

The invention claimed is:

1. A method of manufacturing a lithium-ion secondary battery electrode sheet, comprising the steps of:
(a) preparing a current collector;
(b) preparing a powder material of granulated particles containing active material particles and a binder;
(c) preparing a binder solution;
(d) applying the binder solution onto the current collector;
(e) feeding the powder material onto the current collector;
(f) pressing the powder material against the current collector; and
(g) spraying droplets of a solvent onto the powder material subsequent to the step (e) and prior to or during the step (f) in an amount from 0.01 mL 2 to 0.1 mL/cm 2.

2. The method according to claim 1 , wherein the solvent is added to the powder material of the granulated particles prior to the step (f).

3. The method according to claim 1 , wherein, in the step (f), the current collector and the granulated particles are pressed by a pair of pressure rollers.

4. The method according to claim 3 , wherein the pair of pressure rollers are rotated at different rotational speeds.

5. The method according to claim 1 , wherein
the step (f) comprises imparting shearing stress to the powder material of the granulated particles while pressing the powder material of the granulated particles against the current collector.

6. The method according to claim 5 , wherein, in the step (f), the current collector and the granulated particles are pressed by a pair of pressure rollers to impart the shearing stress.

7. The method according to claim 6 , wherein the pair of pressure rollers are rotated at different rotational speeds.

8. The method according to claim 1 , wherein a size of the droplets of the solvent is 100 nm to 1000 nm.

9. The method of claim 1 , wherein the droplets of the solvent are sprayed by an electrostatic spraying device that imparts an electrostatic charge to the droplets.

10. The method of claim 1 , wherein the binder solution is applied to the current collector in step (d) with a direct gravure roll coater having a pattern engraved on a surface thereof that contacts the current collector.

11. The method of claim 10 , wherein the pattern on the surface comprises grooves having a depth of 10 to 30 μm.

12. The method of claim 11 , wherein the grooves have a width of 50 μm, and a pitch of 200 μm, along an oblique line inclined with respect to a rotational axis of the roll coater.

13. The method of claim 5 , wherein the shear stress is imparted in step (f) by a press device having a pair of flat plates, where the plates are dislocated with respect to one another to apply the shear stress.

14. The method of claim 1 , wherein the step (g) is performed during the step (f).

15. The method of claim 1 , wherein the solvent consists of water.

16. The method of claim 1 , wherein the solvent comprises water and an organic compound selected from the group consisting of alcohols, ethers, ketones, aromatic hydrocarbons, and chlorinated hydrocarbons.

Assignees

• Toyota Motor Co Ltd
• Zeon Corp

Inventors

• Uchida Yozo
• Kitagawa Yuya
• Shibata Yuji

Classifications

• H01M4/139 Primary

  Processes of manufacture · CPC title

• B05D3/12

  by mechanical means · CPC title

• H01M10/0525

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title

• H01M4/0435

  Rolling or calendering · CPC title

• B05D5/12

  to obtain a coating with specific electrical properties · CPC title