Fabrication process to make electrodes by rolling

Patent metadata

Field	Value
Publication number	US-11936030-B2
Application number	US-202117539811-A
Country	US
Kind code	B2
Filing date	Dec 1, 2021
Priority date	Dec 2, 2020
Publication date	Mar 19, 2024
Grant date	Mar 19, 2024

Abstract

A method of manufacturing an electrode for an electrochemical cell includes providing an admixture including an electroactive material, a binder, and a solvent. The method further includes rolling the admixture to form a sheet and forming a multi-layer stack from the sheet. The method further includes forming an electrode film precursor by performing a plurality of sequential rollings, each including rolling the stack through a first gap. The plurality of sequential rollings includes first and second rollings. In the first rolling, the stack is in a first orientation. In the second rolling, the stack is in a second orientation different from the first orientation. The method further includes forming an electrode film by rolling the electrode film precursor through a second gap less than or equal to the first gap. The method further includes drying the electrode film to remove at least a portion of the solvent.

First claim

What is claimed is:

1. A method of manufacturing an electrode for an electrochemical cell, the method comprising:
providing an admixture including an electroactive material, a binder, and a solvent;
rolling the admixture to form a sheet;
forming a multi-layer stack from the sheet;
forming an electrode film precursor by performing a plurality of sequential rollings, each rolling including rolling the multi-layer stack through a first gap defined in a direction transverse to a plane of the multi-layer stack, the plurality of sequential rollings including,
a first rolling in which the multi-layer stack is in a first orientation with respect to a machine direction, and
a second rolling in which the multi-layer stack is in a second orientation with respect to the machine direction, the second orientation being different from the first orientation;

forming an electrode film by rolling the electrode film precursor through a second gap defined in the direction, the second gap being less than or equal to the first gap; and
drying the electrode film to remove at least a portion of the solvent to form the electrode.

2. The method of claim 1 , wherein the second orientation is about 85-95° from the first orientation.

3. The method of claim 1 , wherein the electroactive material has a tap density of less than or equal to about 1.3 g/cm 3.

4. The method of claim 1 , wherein the plurality of sequential rollings includes 2-50 rollings.

5. The method of claim 1 , wherein the second gap is less than the first gap.

6. The method of claim 1 , wherein the second gap is 20 μm-2 mm.

7. The method of claim 1 , wherein the providing includes,
forming a pre-admixture by admixing the electroactive material and a conductive filler, and
forming the admixture by lump-mixing the pre-admixture, the binder, and the solvent.

8. The method of claim 1 , wherein the providing includes forming the admixture by kneading the electroactive material, a conductive filler, the binder, and the solvent.

9. The method of claim 1 , further comprising:
coupling the electrode to a current collector after the drying.

10. The method of claim 9 , wherein the coupling includes, p 1 disposing an electrically-conductive glue between the electrode and the current collector, and
hot laminating the electrode to the current collector.

11. The method of claim 10 , wherein the hot laminating includes passing the electrode and the current collector having the electrically-conductive glue therebetween through a third gap defined in the direction, the third gap being greater than the second gap.

12. The method of claim 10 , wherein the coupling further includes pre-heating the electrode and the current collector prior to the hot laminating.

13. The method of claim 9 , wherein
the current collector is a mesh current collector, and
the coupling includes pressing the electrode onto the mesh current collector.

14. The method of claim 1 , wherein the forming the electrode film includes applying the sheet to a film prior to the rolling.

15. The method of claim 1 , wherein the forming the electrode film includes disposing the electrode film precursor on a substrate prior to the rolling.

16. The method of claim 15 , wherein the substrate comprises polyethylene terephthalate.

17. The method of claim 1 , wherein the first gap is 150 μm-5 mm.

18. The method of claim 3 , wherein the electroactive material includes lithium manganese iron phosphate.

Assignees

• Gm Global Tech Operations Llc

Inventors

• Kong Dewen
• Que Xiaochao
• Wu Meiyuan
• Liu Haijing
• Huang Xiaosong
• Verbrugge Mark W

Classifications

• Y02E60/10

  Energy storage using batteries · CPC title

• H01M4/0435 Primary

  Rolling or calendering · CPC title

• H01M4/0404

  by coating on electrode collectors · CPC title

• H01M4/1397

  of electrodes based on inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy · CPC title

• H01M4/30

  Pressing · CPC title