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. 10-2019-0148935 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 of manufacturing the same, and more particularly, an electrode current collector is formed in a multi-layer structure including an electrode insulating layer, and only one electrode lead is connected to an uncoated region to discharge all of the electricity generated therein. It relates to an electrode assembly capable of sufficiently externally supplied 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 small products such as digital cameras, P-DVDs, MP3Ps, mobile phones, PDAs, Portable Game Devices, Power Tools and E-bikes, but also 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 prepared 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. In addition, when the electrode assembly is accommodated in a specific case and an electrolyte is injected, a secondary battery is manufactured.
[7]
However, in the prior art, the electrodes of the anode and the cathode were formed in a single-layer structure, so that electricity could 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 multilayer structure including an electrode insulating layer, and only one electrode lead is connected to the uncoated region to sufficiently supply all of the electricity generated inside to the outside. and to provide a method for producing the same.
[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, an electrode active material is applied to at least a portion of an electrode current collector formed by sequentially stacking a first electrode foil, an electrode insulating layer, and a second electrode foil. preparing a; stacking the electrode and the separator; and connecting an electrode lead to an uncoated portion on which the electrode active material is not applied in the electrode current collector, wherein the connecting of the electrode lead includes connecting a fastening portion through the electrode current collector and the electrode lead together. .
[11]
In addition, in the step of connecting the electrode lead, the electrode current collector and the electrode lead may be connected by a rivet coupling.
[12]
In addition, in the step of connecting the electrode lead, the electrode current collector and the electrode lead may be connected by screw coupling.
[13]
In addition, in the step of connecting the electrode leads, the fastening part may be made of a conductive material.
[14]
In addition, in the step of connecting the electrode leads, the fastening portion may pass through all of the first electrode foil, the electrode insulating layer, and the second electrode foil of the electrode current collector.
[15]
An electrode assembly according to an embodiment of the present invention for solving the above problems includes an electrode coated with an electrode active material on at least a portion of an electrode current collector; a separator laminated between the electrodes; an electrode lead connected to an uncoated region to which the electrode active material is not applied in the electrode current collector; and a fastening part for penetrating and connecting the electrode current collector and the electrode lead together, wherein the electrode current collector is formed by sequentially stacking a first electrode foil, an electrode insulating layer, and a second electrode foil.
[16]
In addition, the fastening part may be a rivet.
[17]
In addition, the fastening part may be a screw.
[18]
In addition, the fastening part may be made of a conductive material.
[19]
In addition, the fastening part may pass through all of the first electrode foil, the electrode insulating layer, and the second electrode foil of the electrode current collector.
[20]
Other specific details of the invention are included in the detailed description and drawings.
Effects of the Invention
[21]
According to the embodiments of the present invention, there are at least the following effects.
[22]
The electrode current collector is formed in a multi-layered structure including an electrode insulating layer, and the conductive fastening part penetrates and connects the uncoated region and the electrode lead of the electrode current collector together, so that electricity generated inside the electrode assembly with only one electrode lead is transferred. All of them can be sufficiently supplied externally.
[23]
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
[24]
1 is an enlarged cross-sectional view of a cylindrical secondary battery according to an embodiment of the present invention.
[25]
2 is a schematic view showing a side surface of an electrode current collector according to an embodiment of the present invention.
[26]
3 is a schematic diagram illustrating a state in which a plurality of electrode leads are respectively connected to uncoated portions of a positive electrode foil and a negative electrode foil from the side;
[27]
4 is a schematic diagram illustrating a state in which a plurality of electrode leads are connected to an uncoated region from an upper surface.
[28]
5 is a schematic diagram illustrating a state in which a plurality of electrode leads are connected to an uncoated region from the bottom side.
[29]
6 is a schematic diagram illustrating a state in which electrode leads are respectively connected to the uncoated portions of the positive electrode foil and the negative electrode foil according to an embodiment of the present invention.
[30]
7 is a schematic diagram illustrating a state in which an electrode lead is connected to an uncoated region from an upper surface.
[31]
8 is a schematic view showing a state in which an electrode lead is connected to an uncoated region from the bottom side.
[32]
9 is a schematic diagram illustrating a state in which electrode leads are respectively connected to the uncoated portions of the positive electrode foil and the negative electrode foil according to another embodiment of the present invention.
Modes for carrying out the invention
[33]
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 may 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 technical field 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.
[34]
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 defined in particular.
[35]
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.
[36]
Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.
[37]
1 is an enlarged cross-sectional view of a cylindrical secondary battery 1 according to an embodiment of the present invention.
[38]
In order to manufacture the cylindrical 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, and the By laminating on both sides of a separator, an electrode assembly 11 having a predetermined shape is formed. And the beading portion 14 is formed by stretching the battery can 12 by applying pressure from the outside to the inside on the upper portion of the battery can 12 . Then, the electrode assembly 11 is inserted into the battery can 12 and the electrolyte is injected. Next, after the crimping gasket 136 is seated on the beading portion 14 , the upper opening of the battery can 12 is sealed with the cap assembly 13 . The cylindrical secondary battery 1 may be used as a power source for a mobile phone, a notebook computer, or an electric vehicle that stably provides a constant output.
[39]
As shown in FIG. 1 , the cylindrical secondary battery 1 includes an electrode assembly 11 in a jelly-roll form, a cylindrical battery can 12 accommodating the electrode assembly 11 therein, and an upper portion of the battery can 12 . A cap assembly 13 coupled to and sealing the top opening of the battery can 12 , a beading portion 14 recessed from the outside to the inside on the top of the battery can 12 for mounting the cap assembly 13 , and the battery Includes a crimping portion 15 for sealing the.
[40]
The electrode assembly 11 is formed by stacking an electrode and a separator. Specifically, the electrode assembly 11 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 11 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. Electrode current collector according to an embodiment of the present invention (101 and 102 are formed in 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. Hereinafter, the electrode assembly 11 according to an embodiment of the present invention will be described as a jelly roll type, but this is for convenience of description and is not intended to limit the scope of rights.
[41]
In order to manufacture the jelly roll type electrode assembly 11, a pair of long positive and negative electrodes and a separator are stacked and wound from one side to the other. The electrode of the electrode assembly 11 includes a portion to which the electrode active material is applied to the electrode current collectors 101 and 102 and an end portion to which the electrode active material is not applied, that is, uncoated portions 111 and 112 . In addition, uncoated regions 111 and 112 (shown in FIG. 3 ) may be present at the start and end in the direction in which the electrode is wound. A pair of electrode leads 113 corresponding to each electrode are connected to the uncoated regions 111 and 112 . The positive lead 1131 having one end connected to the positive uncoated region 111 is drawn out from the upper end of the electrode assembly 11 , the other end is electrically connected to the cap assembly 13 , and one end is connected to the negative electrode uncoated region 112 . The negative lead 1132 is drawn out from the lower end of the electrode assembly 11 and the other end is connected to the bottom of the battery can 12 . However, the present invention is not limited thereto, and both the positive electrode lead 1131 and the negative electrode lead 1132 may be drawn out in various directions, such as being drawn out toward the cap assembly 13 .
[42]
An insulating plate 16 for insulating the electrode assembly 11 is disposed on the upper end and the lower end of the electrode assembly 11 , respectively. The upper insulating plate 16 disposed at the top is disposed between the electrode assembly 11 and the cap assembly 13 to insulate the electrode assembly 11 , and the lower insulating plate (not shown) disposed at the bottom is the electrode assembly 11 . and the bottom of the battery can 12 to insulate the electrode assembly 11 .
[43]
The battery can 12 is a can made of a rigid material that accommodates the electrode assembly 11 therein. The battery can 12 may be formed in a cylindrical shape, but may be formed in various shapes such as a prismatic shape depending on the shape of the electrode assembly 11 , so that the electrode assembly 11 can be easily accommodated therein.
[44]
The battery can 12 is made of a lightweight conductive metal material such as aluminum, nickel, stainless steel, or an alloy thereof, and may have an open portion with an open top and a closed bottom portion facing the battery can 12 . In the center of the battery can 12, a center pin (not shown) that prevents the electrode assembly 11 wound in a jelly roll form from being unwound and serves as a passage for gas inside the secondary battery 1 is inserted. may be
[45]
The cap assembly 13 is coupled to the opening formed at the top of the battery can 12 to seal the opening of the battery can 12 . The cap assembly 13 may be formed in various shapes, such as a circular shape or a square shape, depending on the shape of the battery can 12 . If the battery can 12 is formed in a cylindrical shape, it is preferable that the cap assembly 13 is also formed in a disk shape corresponding to the shape.
[46]
The cap assembly 13 includes a top cap 131 that seals the opening of the battery can 12 and forms a positive terminal, a PTC element 132 that blocks current by increasing resistance when the temperature inside the battery rises, and an abnormal current. Due to the safety vent 133 that cuts off the current when the pressure inside the battery rises and exhausts the gas inside, the CID gasket 134 that electrically separates the safety vent 133 from the CID filter 135 except for a specific part; The positive electrode lead 1131 connected to the positive electrode is connected, and the CID filter 135 that blocks the current when a high voltage in the battery is generated has a structure in which the CID filter 135 is sequentially stacked.
[47]
In addition, the cap assembly 13 is installed on the beading portion 14 of the battery can 12 in a state of being mounted on the crimping gasket 136 . Therefore, under normal operating conditions, the anode of the electrode assembly 11 is connected to the top cap 131 via the anode lead 1131 , the CID filter 135 , the safety vent 133 and the PTC element 132 to conduct electricity. accomplish
[48]
The top cap 131 is disposed on the top of the cap assembly 13 to protrude upward to form a positive terminal. Accordingly, the top cap 131 may be electrically connected to an external device such as a load or a charging device. A gas hole 1311 through which gas generated inside the secondary battery 1 is discharged may be formed in the top cap 131 . Therefore, when gas is generated from the electrode assembly 11 due to a cause such as overcharging and the internal pressure increases, the CID filter 135 and the safety vent 133 of the current blocking member are ruptured, and the gas inside the ruptured It may be discharged to the outside through the portion and gas hole 1311 . Accordingly, the safety of the secondary battery 1 can be secured without further charging and discharging. The top cap 131 may be made of a metal material such as stainless steel or aluminum.
[49]
The thickness of the portion of the top cap 131 in contact with the PTC element 132 is not particularly limited as long as it can protect various components of the cap assembly 13 from external pressure, for example, , may be 0.3 to 0.5 mm. If the thickness of the top cap 131 is too thin, it is difficult to exhibit mechanical rigidity. On the contrary, if it is too thick, the capacity of the battery may be reduced compared to the same standard due to an increase in size and weight.
[50]
The PTC element (Positive Temperature Coefficient element, 132) blocks the current by increasing the battery resistance when the temperature inside the battery rises. That is, the PTC element 132 electrically connects the top cap 131 and the safety vent 133 in a normal state. However, in an abnormal state, for example, when the temperature rises abnormally, the PTC element 132 cuts off the electrical connection between the top cap 131 and the safety vent 133 . The thickness of the PTC element 132 may also vary depending on the material and structure, and may be, for example, 0.2 to 0.4 mm. If the thickness of the PTC element 132 is thicker than 0.4 mm, internal resistance may increase, and the size of the battery may be increased to reduce battery capacity compared to the same standard. Conversely, if the thickness of the PTC element 132 is thinner than 0.2 mm, it is difficult to exert a current blocking effect at a high temperature and may be destroyed even by a weak external impact. Accordingly, the thickness of the PTC element 132 may be appropriately determined within the thickness range by considering these points in combination.

Claims
[Claim 1]
manufacturing an electrode by applying an electrode active material to at least a portion of an electrode current collector formed by sequentially stacking the first electrode foil, the electrode insulating layer, and the second electrode foil; stacking the electrode and the separator; Connecting an electrode lead to an uncoated portion on which the electrode active material is not applied in the electrode current collector, wherein the connecting of the electrode lead includes connecting a fastening portion through the electrode current collector and the electrode lead together. A method for manufacturing an electrode assembly.
[Claim 2]
The method of claim 1 , wherein in the connecting of the electrode leads, the electrode current collector and the electrode lead are connected by riveting.
[Claim 3]
The method of claim 1 , wherein in the connecting of the electrode leads, the electrode current collector and the electrode lead are connected by screw coupling.
[Claim 4]
The method of claim 1 , wherein in the connecting of the electrode leads, the fastening part is made of a conductive material.
[Claim 5]
The method of claim 1 , wherein in the connecting of the electrode leads, the fastening part penetrates all of the first electrode foil, the electrode insulating layer, and the second electrode foil of the electrode current collector.
[Claim 6]
an electrode in which an electrode active material is applied to at least a portion of an electrode current collector; a separator laminated between the electrodes; an electrode lead connected to an uncoated region to which the electrode active material is not applied in the electrode current collector; and a fastening part for passing through and connecting the electrode current collector and the electrode lead together, wherein the electrode current collector is formed by sequentially stacking a first electrode foil, an electrode insulating layer, and a second electrode foil.
[Claim 7]
The electrode assembly of claim 6 , wherein the fastening part is a rivet.
[Claim 8]
The electrode assembly of claim 6 , wherein the fastening part is a screw.
[Claim 9]
The electrode assembly of claim 6 , wherein the fastening part is made of a conductive material.
[Claim 10]
The electrode assembly of claim 6 , wherein the fastening part penetrates all of the first electrode foil, the electrode insulating layer, and the second electrode foil of the electrode current collector.