Folding device for manufacturing electrode assembly and method for manufacturing stack/folding type electrode assembly

Patent metadata

Field	Value
Publication number	US-10497983-B2
Application number	US-201716088556-A
Country	US
Kind code	B2
Filing date	Dec 1, 2017
Priority date	Dec 7, 2016
Publication date	Dec 3, 2019
Grant date	Dec 3, 2019

Abstract

The present disclosure provides a folding device for manufacturing an electrode assembly having a structure in which plate type unit cells are wound with a separator film, including:
a mandrel configured to rotate and wind a web in which plate type unit cells are arranged on an upper surface of the separator film at predetermined intervals so that the unit cells are sequentially stacked with the separator film interposed therebetween; and a pair of rollers configured to horizontally bend a surplus winding end portion of the separator film, which is formed by arranging a first unit cell at a winding start portion of the web in a state of being spaced apart from a winding end portion of the separator film, in a direction covering an upper surface of the first unit cell,

wherein the mandrel includes one or more grippers composed of one or more upper legs configured to fix an upper surface portion of the first unit cell and one or more lower legs configured to fix a lower surface portion of the separator film corresponding to the upper legs, and the pair of rollers operate to vertically bend the surplus winding end portion of the separator film upward and then horizontally bend the surplus winding end portion toward the upper surface of the unit cell.

First claim

The invention claimed is:

1. A folding device for manufacturing an electrode assembly having a structure in which plate type unit cells are wound with a separator film, comprising:
a mandrel configured to rotate and wind a web in which plate type unit cells are arranged on an upper surface of the separator film at predetermined intervals so that the unit cells are sequentially stacked with the separator film interposed therebetween; and
a pair of rollers configured to horizontally bend a surplus winding end portion of the separator film, which is formed by arranging a first unit cell at a winding start portion of the web in a state of being spaced apart from a winding end portion of the separator film, in a direction covering an upper surface of the first unit cell,
wherein the mandrel includes one or more grippers composed of one or more upper legs configured to fix an upper surface portion of the first unit cell and one or more lower legs configured to fix a lower surface portion of the separator film corresponding to the upper legs, and the pair of rollers operate to vertically bend the surplus winding end portion of the separator film upward and then horizontally bend the surplus winding end portion toward the upper surface of the unit cell.

2. The device of claim 1 , wherein the pair of rollers is configured to operate independently of each other, or to operate in conjunction with each other.

3. The device of claim 1 , wherein the pair of rollers includes a first roller located at a relatively upper portion and a second roller located at a relatively lower portion in a process of horizontally bending the surplus winding end portion.

4. The device of claim 3 , wherein the first roller and the second roller move upward to vertically bend the surplus winding end portion upward in a state of being positioned close to a boundary between the first unit cell and the surplus winding end portion of the separator film at a lower portion of the separator film, and move in a direction of the first unit cell to horizontally bend the vertically bent surplus winding end portion in a direction of the upper surface of the first unit cell, so that the surplus winding end portion of the separator film is folded inward in the direction of covering the upper surface of the first unit cell.

5. The device of claim 4 , wherein the first roller and the second roller allow the web to be interposed therebetween after the surplus winding end portion is horizontally bent, and then the first roller is moved downward and the second roller is moved upward, thereby performing a process of pressing the horizontally bent surplus winding end portion on the first unit cell.

6. The device of claim 1 , wherein a length of the surplus winding end portion of the separator film in the web is 5% to 100% of a width of the first unit cell.

7. The device of claim 1 , wherein the upper leg of the gripper fixes the first unit cell together with the horizontally bent surplus winding end portion of the separator film.

8. A method of manufacturing a stacked/folded type electrode assembly by using the folding device of claim 1 , comprising:
(a) manufacturing a plurality of unit cells including a positive electrode, a negative electrode, and a separator, and arranging the unit cells on a separator film in a long sheet form to manufacture a web;
(b) vertically bending a surplus winding end portion by moving upward a pair of rollers located on a boundary between the surplus winding end portion of the separator film and a first unit cell of a winding start portion, which is arranged in a state of being spaced apart from a winding end portion of the separator film in the web, and moving the pair of rollers in a direction of the first unit cell to horizontally bend the surplus winding end portion;
(c) pressing the horizontally bent surplus winding end portion of the separator film on the first unit cell after interposing the web between the pair of rollers; and
(d) winding by rotating a mandrel so that the unit cells are sequentially stacked with the separator film interposed therebetween.

9. The method of claim 8 , wherein the pair of rollers includes a first roller located at a relatively upper portion and a second roller located at a relatively lower portion in a process of horizontally bending the surplus winding end portion.

10. The method of claim 9 , wherein the pressing process of process (c) is performed by moving the first roller downward and the second roller upward.

11. The method of claim 8 , wherein the mandrel includes a gripper composed of at least one upper leg configured to fix an upper surface portion of the first unit cell and the separator film in which the surplus winding end portion is horizontally bent and at least one lower leg configured to fix a lower surface portion of the separator film corresponding to the upper leg.

12. The method of claim 8 , wherein the first unit cell and a second unit cell among the plurality of unit cells are arranged on the separator film at a separation distance corresponding to at least one unit cell, and the unit cells after the second unit cell are arranged on the separator film in a form of an array in which distances between the unit cells are gradually increased corresponding to a winding width.

13. A secondary battery including the stacked/folded electrode assembly manufactured by the method of claim 8 .

Assignees

• Lg Chemical Ltd

Inventors

• Nam Ye Jin

Classifications

• H01M10/0472

  Vertically superposed cells with vertically disposed plates · CPC title

• H01M10/0468

  Compression means for stacks of electrodes and separators · CPC title

• H01M10/0459

  Cells or batteries with folded separator between plate-like electrodes · CPC title

• H01M10/0404 Primary

  Machines for assembling batteries · CPC title

• H01M10/0583 Primary

  of accumulators with folded construction elements except wound ones, i.e. folded positive or negative electrodes or separators, e.g. with "Z"-shaped electrodes or separators · CPC title