Electrode assembly having step, secondary battery, battery pack and device including electrode assembly, and method of manufacturing electrode assembly

Patent metadata

Field	Value
Publication number	US-2015288021-A1
Application number	US-201314441727-A
Country	US
Kind code	A1
Filing date	Mar 15, 2013
Priority date	Nov 9, 2012
Publication date	Oct 8, 2015
Grant date	—

Abstract

There is provided an electrode assembly including a first electrode laminate having at least one or more electrode units having a first area, stacked therein, a second electrode laminate having at least one or more electrode units having a second area smaller than the first area, stacked therein, and a step portion provided by stacking the first electrode laminate and the second electrode laminate in a direction perpendicular to a plane and having a step formed due to a difference in areas of the first and second electrode laminates, the electrode assembly being characterized in that, the electrode unit is wound by a rectangular-shaped separation film such that at least a portion of the rectangular-shaped separation film covers the step portion of the electrode assembly, and a step having a shape identical to the step portion is formed.

First claim

1 . An electrode assembly including a first electrode laminate having at least one or more electrode units having a first area, stacked therein, a second electrode laminate having at least one or more electrode units having a second area smaller than the first area, stacked therein, and a step portion provided by stacking the first electrode laminate and the second electrode laminate in a direction perpendicular to a plane and having a step formed due to a difference in areas of the first and second electrode laminates, the electrode assembly being characterized in that,
the electrode unit is wound by a rectangular-shaped separation film such that at least a portion of the rectangular-shaped separation film covers the step portion of the electrode assembly, and a step having a shape identical to the step portion is formed.

2 . The electrode assembly of claim 1 , wherein the separation film covering the step portion of the electrode assembly has a thickness equal to 90% or less of a thickness of the rectangular-shaped separation film located in the electrode laminate, by winding the electrode unit.

3 . The electrode assembly of claim 2 , wherein the separation film covering the step portion of the electrode assembly is cut.

4 . The electrode assembly of claim 1 , wherein the second electrode laminate includes an electrode laminate having at least one electrode unit having an area smaller than the second area, stacked on at least one electrode unit having the second area, in a direction perpendicular to the plane, and includes at least one step.

5 . The electrode assembly of claim 1 , wherein the electrode unit includes a single electrode; at least one unit cell including at least one anode, at least one cathode and at least one separation film; or a combination thereof.

6 . The electrode assembly of claim 5 , wherein the unit cell is selected from a group configured of a jelly-roll type unit cell, a stacked type unit cell, a laminated and stacked type unit cell and a stacked and folded type unit cell.

7 . The electrode assembly of claim 5 , wherein the unit cell includes electrodes having the same polarity and disposed on both outermost surfaces thereof in a thickness direction of the electrode assembly.

8 . The electrode assembly of claim 5 , wherein the unit cell includes electrodes having different polarities and disposed on both outermost surfaces thereof in the thickness direction of the electrode assembly.

9 . The electrode assembly of claim 1 , wherein an uppermost electrode of the first electrode laminate is a cathode.

10 . The electrode assembly of claim 1 , wherein the first electrode laminate and the second electrode laminate are formed by stacking electrodes having different polarities to face each other.

11 . The electrode assembly of claim 1 , wherein the electrode assembly is configured of two layers.

12 . The electrode assembly of claim 1 , wherein the electrode assembly is configured of three or more layers.

13 . A method of manufacturing an electrode assembly, comprising:
arraying at least one first electrode unit having a first area forming a first electrode laminate, and at least one second electrode unit having a second area forming a second electrode laminate on a rectangular-shaped separation film, and assembling the electrode assembly having a step due to a difference in areas between the electrode laminates by rolling the rectangular-shaped separation film up in a single direction to correspond to the respective electrode unit so as to allow the second electrode laminate to be stacked on the first electrode laminate; and removing tension generated on an inclined surface of the rectangular-shaped separation film formed through a passing-by thereof, by elongating or cutting the rectangular-shaped separation film on the inclined surface thereof between a distal end portion of the second electrode unit and a distal end portion of an uppermost first electrode unit of the first electrode laminate, on one side portion of the electrode assembly through which the rectangular-shaped separation film is passed and in which the step is formed.

14 . The method of claim 13 , wherein the elongating is performed by heating and compressing the rectangular-shaped separation film forming the inclined surface.

15 . The method of claim 13 , wherein the elongating is performed at a temperature ranging from 80 to 100° C.

16 . The method of claim 13 , wherein the elongating is performed by compressing the rectangular-shaped separation film forming the inclined surface using a jig having the temperature ranging from 80 to 100° C.

17 . The method of claim 16 , wherein the jig has the same shape as the step portion of the electrode assembly.

18 . The method of claim 13 , wherein the cutting is performed using a cutting blade, a laser beam or a heat ray.

19 . A secondary battery comprising the electrode assembly of claim 1 .

20 . The secondary battery of claim 19 , wherein the electrode assembly is embedded in a battery case.

21 . The secondary battery of claim 19 , wherein the battery case has a step portion having a shape identical to that of the step portion of the electrode assembly.

22 . The secondary battery of claim 19 , wherein the battery case is a pouch-type case.

23 . The secondary battery of claim 19 , wherein the secondary battery is a lithium ion secondary battery or a lithium ion polymer secondary battery.

24 . A battery pack comprising at least two secondary batteries of claim 19 .

25 . A device comprising at least one secondary battery of claim 19 .

26 . The device of claim 25 , wherein the device is a mobile phone, a portable computer, a smartphone, a smartpad, a netbook computer, a light electric vehicle, an electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, or a power storage device.

Assignees

• Lg Chemical Ltd

Inventors

• Kwon Sung-Jin
• Kim Dong-Myung
• Kim Ki-Woong
• Ahn Soon-Ho

Classifications

• H01M10/0587 Primary

  of accumulators having only wound construction elements, i.e. wound positive electrodes, wound negative electrodes and wound separators · CPC title

• H01M10/052

  Li-accumulators · CPC title

• H01M10/0585

  of accumulators having only flat construction elements, i.e. flat positive electrodes, flat negative electrodes and flat separators · CPC title

• H01M10/0525

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

• Y10T29/49108

  Electric battery cell making · CPC title