Specification
Title of Invention: Electrode assembly and manufacturing method thereof
technical field
[One]
Cross Citation with Related Applications
[2]
This application claims the benefit of priority based on Korean Patent Application No. 10-2019-0148934 dated November 19, 2019, and all contents disclosed in the documents of the Korean patent application are incorporated as a part of this specification.
[3]
technical field
[4]
The present invention relates to an electrode assembly and a method for manufacturing the same, and more particularly, an electrode current collector is formed in a multilayer structure including an electrode insulating layer, and one electrode lead is easily connected to a plurality of electrode tabs without a separate connection part. It relates to a connectable electrode assembly and a method for manufacturing the same.
background
[5]
In general, types of secondary batteries include a nickel cadmium battery, a nickel hydrogen battery, a lithium ion battery, and a lithium ion polymer battery. These secondary batteries are not only used in small products such as digital cameras, P-DVDs, MP3Ps, mobile phones, PDAs, Portable Game Devices, Power Tools and E-bikes, but also in large products requiring high output such as electric and hybrid vehicles and surplus power generation. It is also applied and used in power storage devices that store power or renewable energy and power storage devices for backup.
[6]
In order to manufacture the electrode assembly, a cathode, a separator, and a cathode are manufactured, and these are laminated. Specifically, a positive electrode active material slurry is applied to a positive electrode current collector, and a negative electrode active material slurry is applied to a negative electrode current collector to prepare a positive electrode and a negative electrode. And when a separator is interposed between the manufactured positive electrode and the negative electrode and stacked, unit cells are formed, and the unit cells are stacked on each other, thereby forming an electrode assembly. And when the electrode assembly is accommodated in a specific case and an electrolyte is injected, a secondary battery is manufactured.
[7]
However, conventionally, the electrodes of the anode and the cathode are formed in a single layer structure, so that electricity can flow between both surfaces of the electrodes. Therefore, when the electrode assembly is damaged by an impact from the outside, a short circuit occurs on one surface of the electrode and a risk of explosion or the like may occur when a short circuit occurs on the other surface of the electrode.
DETAILED DESCRIPTION OF THE INVENTION
technical challenge
[8]
The problem to be solved by the present invention is an electrode assembly in which an electrode current collector is formed in a multi-layer structure including an electrode insulating layer, and can easily connect one electrode lead to a plurality of electrode tabs without a separate connection part, and manufacturing thereof to provide a way
[9]
The problems of the present invention are not limited to the problems mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the following description.
means of solving the problem
[10]
In an electrode assembly manufacturing method according to an embodiment of the present invention for solving the above problems, a positive electrode active material is applied to at least a portion of a positive electrode current collector formed by sequentially stacking a first positive electrode foil, a positive electrode insulating layer, and a second positive electrode foil. preparing a negative electrode by applying a negative electrode active material to at least a portion of a negative electrode current collector formed by sequentially stacking the first negative electrode foil, the negative electrode insulating layer, and the second negative electrode foil; interposing a separator between the positive electrode and the negative electrode; removing the positive electrode insulating layer and the negative electrode insulating layer from at least a portion of the positive electrode tab to which the positive electrode active material is not applied in the positive electrode current collector and the negative electrode tab to which the negative active material is not applied in the negative electrode current collector, respectively; and connecting a positive electrode lead and a negative electrode lead to the positive electrode tab and the negative electrode tab, respectively.
[11]
In addition, the removing of the positive electrode insulating layer and the negative electrode insulating layer may include immersing the positive electrode tab and the negative electrode tab in an organic solvent.
[12]
In addition, the anode insulating layer and the cathode insulating layer may include PET.
[13]
In addition, the organic solvent may include acetone.
[14]
In addition, the positive electrode tab and the negative electrode tab, 20% to 80% of the total length may be immersed in the organic solvent.
[15]
In addition, the positive electrode tab and the negative electrode tab may be immersed in the organic solvent for 30 seconds to 2 minutes.
[16]
In addition, the removing of the positive electrode insulating layer and the negative electrode insulating layer may further include drying the organic solvent after immersing the positive electrode tab and the negative electrode tab in an organic solvent.
[17]
In addition, the removing of the positive electrode insulating layer and the negative electrode insulating layer may include spraying an organic solvent to the positive electrode tab and the negative electrode tab.
[18]
A positive electrode coated with a positive electrode active material on at least a portion of a positive electrode current collector according to an embodiment of the present invention for solving the above problems; a negative electrode in which an anode active material is applied to at least a portion of a negative electrode current collector; and a separator interposed between the positive electrode and the negative electrode, wherein the positive electrode current collector is formed by sequentially stacking a first positive electrode foil, a positive electrode insulating layer, and a second positive electrode foil, and the negative electrode current collector includes a first A negative electrode foil, a negative electrode insulating layer, and a second negative electrode foil are sequentially stacked and formed, and in the positive electrode tab to which the positive electrode active material is not applied in the positive electrode current collector, the positive electrode insulating layer is removed from at least some regions, and the negative electrode current collector In the negative electrode tab to which the negative electrode active material is not applied, the negative electrode insulating layer is removed in at least a partial area.
[19]
In addition, in the positive electrode tab, the positive electrode insulating layer may be removed from 20% to 80% of the total length of the positive electrode tab, and in the negative electrode tab, the negative electrode insulating layer may be removed from 20% to 80% of the total length of the negative electrode tab have.
[20]
In addition, the anode insulating layer and the cathode insulating layer may include PET.
[21]
Other specific details of the invention are included in the detailed description and drawings.
Effects of the Invention
[22]
According to the embodiments of the present invention, there are at least the following effects.
[23]
The electrode current collector is formed in a multilayer structure including an electrode insulating layer, and by etching the electrode insulating layers of the plurality of electrode tabs using an organic solvent, adjacent electrode tabs are in contact with each other to electrically connect the plurality of electrode tabs. Since they can be connected, one electrode lead can be easily connected to a plurality of electrode tabs.
[24]
The effect according to the present invention is not limited by the contents exemplified above, and more various effects are included in the present specification.
Brief description of the drawing
[25]
1 is an assembly view of a pouch-type secondary battery according to an embodiment of the present invention.
[26]
2 is a schematic diagram illustrating a side surface of an electrode current collector according to an embodiment of the present invention.
[27]
3 is a schematic diagram illustrating a state in which a connection portion is formed on a positive electrode foil and a negative electrode foil of an electrode tab, respectively, from the side.
[28]
4 is a schematic diagram illustrating a state in which an electrode lead is connected to a connection part from the top surface.
[29]
5 is a schematic diagram illustrating a state in which a plurality of positive electrode tabs and a plurality of negative electrode tabs are stacked from the front according to an embodiment of the present invention.
[30]
6 is a schematic diagram illustrating a state in which a plurality of positive electrode tabs and a plurality of negative electrode tabs are immersed in an organic solvent according to an embodiment of the present invention.
[31]
7 is a schematic diagram illustrating a state in which a positive electrode insulating layer and a negative electrode insulating layer are removed from a plurality of positive electrode tabs and a plurality of negative electrode tabs, respectively, from the front according to an embodiment of the present invention.
[32]
8 is a schematic diagram illustrating a state in which electrode leads are connected to a plurality of positive electrode tabs and a plurality of negative electrode tabs, respectively, from the front according to an embodiment of the present invention.
[33]
9 is a schematic diagram illustrating a state in which electrode leads are respectively connected to a plurality of positive electrode tabs and a plurality of negative electrode tabs according to an embodiment of the present invention from the top surface.
Modes for carrying out the invention
[34]
Advantages and features of the present invention and methods of achieving them will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but can be implemented in various different forms, and only these embodiments allow the disclosure of the present invention to be complete, and common knowledge in the art to which the present invention pertains It is provided to fully inform those who have the scope of the invention, and the present invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout.
[35]
Unless otherwise defined, all terms (including technical and scientific terms) used herein may be used with the meaning commonly understood by those of ordinary skill in the art to which the present invention belongs. In addition, terms defined in a commonly used dictionary are not to be interpreted ideally or excessively unless clearly specifically defined.
[36]
The terminology used herein is for the purpose of describing the embodiments and is not intended to limit the present invention. In this specification, the singular also includes the plural unless specifically stated otherwise in the phrase. As used herein, “comprises” and/or “comprising” does not exclude the presence or addition of one or more other components in addition to the stated components.
[37]
Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.
[38]
1 is an assembly view of a pouch-type secondary battery 1 according to an embodiment of the present invention.
[39]
In the process of manufacturing the pouch-type secondary battery 1, first, a slurry in which an electrode active material, a binder, and a plasticizer are mixed is applied to the positive electrode current collector 101 and the negative electrode current collector 102 to prepare electrodes such as a positive electrode and a negative electrode, , the electrode assembly 10 of a predetermined shape is formed by laminating it on both sides of a separator, and then the electrode assembly 10 is inserted into the battery case 13 and the electrolyte is injected and then sealed.
[40]
The electrode assembly (Electrode Assembly, 10) is formed by stacking an electrode and a separator. Specifically, the electrode assembly 10 includes two types of electrodes, such as an anode and a cathode, and a separator interposed between the electrodes to insulate the electrodes from each other. The electrode assembly 10 may be of a stack type, a jelly roll type, a stack-and-fold type, or the like. The two types of electrodes, that is, the positive electrode and the negative electrode, have a structure in which an active material slurry is applied to the electrode current collectors 101 and 102 having a multilayer structure including electrode insulating layers 1013 and 1023, respectively. The electrode current collectors 101 and 102 according to an embodiment of the present invention have a multilayer structure in which electrode insulating layers 1013 and 1023 are stacked between two electrode foils. A detailed description of the electrode current collectors 101 and 102 will be described later. In general, the slurry may be formed by stirring the granular active material, auxiliary conductor, binder, plasticizer, and the like in a state in which a solvent is added. The solvent is removed in a subsequent process.
[41]
As shown in FIG. 1 , the electrode assembly 10 includes an electrode tab 11 . The electrode tab 11 protrudes from the positive electrode and the negative electrode of the electrode assembly 10 , respectively, and serves as a path through which electrons can move between the inside and the outside of the electrode assembly 10 . The electrode current collectors 101 and 102 of the electrode assembly 10 include a portion to which the electrode active material is applied and a distal portion to which the electrode active material is not applied, that is, an uncoated portion. In addition, the electrode tab 11 may be formed by cutting the uncoated area or may be formed by connecting a separate conductive member to the uncoated area by ultrasonic welding or the like. As shown in FIG. 1 , the electrode tabs 11 may protrude side by side from one side of the electrode assembly 10 in the same direction, but are not limited thereto and may protrude in different directions.
[42]
An electrode lead 12 for supplying electricity to the outside of the secondary battery 1 is connected to the electrode tab 11 of the electrode assembly 10 by spot welding or the like. A part of the electrode lead 12 is surrounded by the insulating portion 14 . The insulating part 14 is positioned limitedly in the sealing part 134 to which the upper case 131 and the lower case 132 of the battery case 13 are thermally fused, and is attached to the battery case 13 . In addition, electricity generated from the electrode assembly 10 is prevented from flowing to the battery case 13 through the electrode lead 12 , and the sealing of the battery case 13 is maintained. Accordingly, the insulating portion 14 is made of a non-conductive material that does not conduct electricity well. In general, as the insulating part 14, an insulating tape that is easy to attach to the electrode lead 12 and has a relatively thin thickness is often used. have.
[43]
The electrode lead 12 has one end connected to the positive electrode tab 111 , one end connected to the positive electrode lead 121 and the negative electrode tab 112 extending in the protruding direction of the positive electrode tab 111 , and the negative electrode tab 112 . ) includes a negative lead 122 extending in the protruding direction. On the other hand, as shown in FIG. 1 , the positive lead 121 and the negative lead 122 both have the other end protruding to the outside of the battery case 13 . Accordingly, electricity generated inside the electrode assembly 10 may be supplied to the outside. In addition, since the positive electrode tab 111 and the negative electrode tab 112 are formed to protrude in various directions, respectively, the positive electrode lead 121 and the negative electrode lead 122 may also extend in various directions.

Claims
[Claim 1]
A positive electrode is prepared by applying a positive electrode active material to at least a portion of a positive electrode current collector formed by sequentially stacking the first positive electrode foil, the positive electrode insulating layer, and the second positive electrode foil, and the first negative electrode foil, the negative electrode insulating layer and the second negative electrode foil are preparing a negative electrode by applying a negative electrode active material to at least a portion of a negative electrode current collector formed by being sequentially stacked; interposing a separator between the positive electrode and the negative electrode; removing the positive electrode insulating layer and the negative electrode insulating layer from at least a portion of the positive electrode tab to which the positive electrode active material is not applied in the positive electrode current collector and the negative electrode tab to which the negative active material is not applied in the negative electrode current collector, respectively; and connecting a positive electrode lead and a negative electrode lead to the positive electrode tab and the negative electrode tab, respectively.
[Claim 2]
The method of claim 1 , wherein removing the positive electrode insulating layer and the negative electrode insulating layer comprises immersing the positive electrode tab and the negative electrode tab in an organic solvent.
[Claim 3]
The method of claim 2 , wherein the anode insulating layer and the cathode insulating layer include PET.
[Claim 4]
The method of claim 3 , wherein the organic solvent comprises acetone.
[Claim 5]
The method of claim 2 , wherein the positive electrode tab and the negative electrode tab are immersed in 20% to 80% of a total length in the organic solvent.
[Claim 6]
The method of claim 2 , wherein the positive electrode tab and the negative electrode tab are immersed in the organic solvent for 30 seconds to 2 minutes.
[Claim 7]
The electrode of claim 2 , wherein the removing of the positive electrode insulating layer and the negative electrode insulating layer further comprises drying the organic solvent after immersing the positive electrode tab and the negative electrode tab in an organic solvent. A method of manufacturing an assembly.
[Claim 8]
The method of claim 1 , wherein removing the positive electrode insulating layer and the negative electrode insulating layer comprises spraying an organic solvent onto the positive electrode tab and the negative electrode tab.
[Claim 9]
a positive electrode in which a positive electrode active material is applied to at least a portion of a positive electrode current collector; a negative electrode in which an anode active material is applied to at least a portion of a negative electrode current collector; and a separator interposed between the positive electrode and the negative electrode, wherein the positive electrode current collector is formed by sequentially stacking a first positive electrode foil, a positive electrode insulating layer, and a second positive electrode foil, and the negative electrode current collector includes a first A negative electrode foil, a negative electrode insulating layer, and a second negative electrode foil are sequentially stacked and formed, and in the positive electrode tab to which the positive electrode active material is not applied in the positive electrode current collector, the positive electrode insulating layer is removed from at least some regions, and the negative electrode current collector In the negative electrode tab to which the negative electrode active material is not applied, the negative electrode insulating layer is removed from at least a partial area of ​​the electrode assembly.
[Claim 10]
10 . The method of claim 9 , wherein in the positive electrode tab, 20% to 80% of the positive electrode insulating layer is removed from the total length of the positive electrode tab, and in the negative electrode tab, the negative electrode insulating layer is 20% to 80% of the total length of the negative electrode tab % electrode assembly removed.
[Claim 11]
The electrode assembly of claim 9 , wherein the anode insulating layer and the cathode insulating layer include PET.