technical field
[One]
Cross Citation with Related Applications
[2]
This application claims the benefit of priority based on Korean Patent Application No. 10-2019-0134952 dated October 28, 2019, and all contents disclosed in the literature 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 secondary battery including the same.
background
[5]
Secondary batteries, unlike primary batteries, are rechargeable, and have been widely researched and developed in recent years due to their small size and large capacity. As technology development and demand for mobile devices increase, the demand for secondary batteries as an energy source is rapidly increasing.
[6]
The secondary battery is classified into a coin-type battery, a cylindrical battery, a prismatic battery, and a pouch-type battery according to the shape of the battery case. In a secondary battery, an electrode assembly mounted inside a battery case is a charging/discharging power generating element having a stacked structure of an electrode and a separator.
[7]
The electrode assembly is a sheet-type electrode assembly coated with an active material, with a separator interposed between a positive electrode and a negative electrode, and is a jelly-roll type, and a stack type in which a plurality of positive and negative electrodes are sequentially stacked with a separator interposed therebetween. , and stacked unit cells can be roughly classified into a stack/folding type in which a long-length separation film is wound.
[8]
Among them, the jelly roll type electrode assembly is widely used because it is easy to manufacture and has the advantage of high energy density per weight.
[9]
However, the jelly roll type electrode assembly has a problem in that cells deteriorate due to heat generated in the center of the winding. At this time, the jelly roll type electrode assembly has a problem in that the separator positioned at the winding center is contracted due to the high heat generated in the winding center, resulting in a short circuit between the positive electrode and the negative electrode, resulting in ignition.
[10]
In particular, in the case of a high-output cell, heat is generated at 80° C. or more only by discharging. In addition, through an experiment, it was confirmed that ignition occurred when the electrode assembly was accommodated in a hot box and maintained at 130° C. for 60 minutes.
[11]
[Prior Art Document] (Patent Document): Korean Patent Publication No. 10-2016-0010121
DETAILED DESCRIPTION OF THE INVENTION
technical challenge
[12]
One aspect of the present invention is to provide an electrode assembly capable of dissipating heat generated from a winding center of an electrode assembly and a secondary battery including the same.
[13]
Another aspect of the present invention is to provide an electrode assembly capable of suppressing contraction of a separator positioned at a winding center in an electrode assembly and a secondary battery including the same.
means of solving the problem
[14]
An electrode assembly according to an embodiment of the present invention is an electrode assembly in which a positive electrode, a separator, and a negative electrode are alternately stacked and wound, wherein the positive electrode is a positive electrode active material part and the positive electrode which is a region formed by stacking a positive electrode active material on a positive electrode current collector It includes a positive electrode uncoated region that is an area on which an active material is not laminated, and the positive electrode uncoated region includes a first positive electrode uncoated region located in a winding center, is located in the first positive electrode uncoated region, and includes a heat dissipation tape including a heat dissipation material can
[15]
Meanwhile, the secondary battery according to the embodiment of the present invention may include the electrode assembly according to the embodiment of the present invention.
Effects of the Invention
[16]
According to the present invention, by providing a heat dissipation tape including a heat dissipation material in the winding center of the electrode assembly to dissipate the heat generated in the winding center, the secondary battery prevents the risk of ignition, etc. can be prevented
[17]
In addition, according to the present invention, it is possible to suppress the contraction of the separator by attaching a heat dissipation tape to the winding center of the electrode assembly, thereby remarkably reducing or preventing the risk that the electrode is exposed and ignited.
Brief description of the drawing
[18]
1 is a perspective view illustrating an electrode assembly and a secondary battery including the same according to an embodiment of the present invention.
[19]
2 is a plan view showing the main part of the electrode assembly according to an embodiment of the present invention in an unfolded state before being wound.
[20]
3 is a front view illustrating an unfolded state before the electrode assembly is wound according to an embodiment of the present invention.
[21]
4 is a front view illustrating an unfolded state before the electrode assembly is wound according to another embodiment of the present invention.
Modes for carrying out the invention
[22]
The objects, specific advantages and novel features of the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings and preferred embodiments. In the present specification, in adding reference numbers to the components of each drawing, it should be noted that only the same components are given the same number as possible even though they are indicated on different drawings. In addition, the present invention may be embodied in several different forms and is not limited to the embodiments described herein. And, in describing the present invention, detailed descriptions of related known technologies that may unnecessarily obscure the gist of the present invention will be omitted.
[23]
[24]
Electrode assembly according to an embodiment
[25]
[26]
1 is a perspective view showing an electrode assembly according to an embodiment of the present invention and a secondary battery including the same, and FIG. 2 is a plan view showing the main part of the electrode assembly according to an embodiment of the present invention in an unfolded state before being wound, FIG. 3 is a front view illustrating an unfolded state before the electrode assembly according to an embodiment of the present invention is wound.
[27]
1 to 3 , an electrode assembly 100 according to an embodiment of the present invention includes an electrode assembly 100 in which an anode 110 , a separator 160 , and a cathode 120 are alternately stacked and wound. As such, it includes a heat dissipation tape 180 including a heat dissipation material.
[28]
Hereinafter, an electrode assembly according to an embodiment of the present invention will be described in more detail with reference to FIGS. 1 to 3 .
[29]
1 to 3 , the electrode assembly 100 is a power generating element capable of charging and discharging, and the electrode 130 and the separator 160 are assembled to form a structure in which they are alternately stacked. Here, the electrode assembly 100 may be formed in a shape in which the electrodes 130 and the separator 160 are alternately assembled and wound. At this time, the electrode stack 110 may be wound in a cylindrical shape wound around the central axis (C).
[30]
The electrode 130 may include an anode 110 and a cathode 120 . In addition, the separator 160 separates and electrically insulates the anode 110 and the cathode 120 .
[31]
[32]
The positive electrode 110 includes a positive electrode current collector 111, a positive electrode active material part 112 that is a region formed by laminating a positive electrode active material on the positive electrode current collector 111, and a positive electrode uncoated region ( 113) may be included.
[33]
The positive electrode current collector 111 may be formed of, for example, an aluminum foil.
[34]
The cathode active material may be formed of lithium manganese oxide, lithium cobalt oxide, lithium nickel oxide, lithium iron phosphate, or a compound or mixture containing at least one of them.
[35]
The positive electrode uncoated region 113 may include a first positive electrode uncoated region 113a positioned in the winding center I and a second positive electrode uncoated region 113b positioned in the central portion.
[36]
The first positive electrode uncoated region 113a may be, for example, both sides (top and bottom) of one end of the positive electrode 110 facing the winding center.
[37]
As another example, the first positive electrode uncoated region 113a may be formed on the top surface of the positive electrode 110 when referring to FIG. 3 . That is, the first positive electrode uncoated region 113a may be located on the surface of the positive electrode 110 facing the first separator 140 .
[38]
As another example, the first positive electrode uncoated region 113a may be formed on the lower surface of the positive electrode 110 when referring to FIG. 3 . That is, the first positive electrode uncoated region 113a may be located on the opposite surface of the surface of the positive electrode 110 that faces the first separator 140 .
[39]
The second positive electrode uncoated region 113b may be provided in a central portion positioned between the winding center I and the winding outer portion O of the positive electrode 110 .
[40]
[41]
The negative electrode 120 includes a negative electrode current collector 121 , a negative electrode active material portion 122 that is a region formed by laminating a negative electrode active material on the negative electrode collector 121 , and a negative electrode uncoated region that is an area on which a negative electrode active material is not stacked. (123) may be included.
[42]
The negative electrode current collector 121 may be made of, for example, a foil made of a copper (Cu) or nickel (Ni) material.
[43]
The anode active material may be made of, for example, artificial graphite, lithium metal, lithium alloy, carbon, petroleum coke, activated carbon, graphite, a silicon compound, a tin compound, a titanium compound, or an alloy thereof. In this case, the negative active material may further include, for example, non-graphite-based SiO (silica, silica) or SiC (silicon carbide, silicon carbide).
[44]
The negative electrode uncoated region 123 includes the first negative electrode uncoated region 123a positioned at the winding outer portion O of the negative electrode 120 and the second negative electrode uncoated region 123b positioned at the winding center I of the negative electrode 120 . ) may be included.
[45]
[46]
The separator 160 may be made of an insulating material to insulate between the anode 110 and the cathode 120 .
[47]
In addition, the separator 160 is a multilayer film made of, for example, microporous polyethylene, polypropylene, or a combination thereof, or polyvinylidene fluoride, polyethylene oxide, polyacrylonitrile, or polyvinylidene fluoride hexadecimal. It may be a polymer film for a solid polymer electrolyte such as a fluoropropylene copolymer or for a gel polymer electrolyte.
[48]
In addition, the separation membrane 160 may include a first separation membrane 140 and a second separation membrane 150 .
[49]
In this case, the electrode assembly 100 may be stacked in the order of the positive electrode 110 , the first separator 140 , the negative electrode 120 , and the second separator 150 .
[50]
[51]
The electrode tab 170 is attached to the electrode 130 and is electrically connected to the electrode 130 .
[52]
The electrode tab 170 may include a positive electrode tab 171 attached to the positive electrode 110 and a negative electrode tab 172 attached to the negative electrode 120 .
[53]
The positive electrode tab 171 is provided in a central portion positioned between the winding center I and the winding outer portion O in the positive electrode 110 , and the negative electrode tab 172 . The silver cathode 120 may be positioned at the winding outer portion O.
[54]
Specifically, the positive electrode tab 171 may be provided on the second positive electrode uncoated region 113b, and the negative electrode tab 172 may be provided on the first negative electrode uncoated region 123a.
[55]
In addition, electrode tabs may not be attached (provided) to the first positive electrode uncoated region 113a and the second negative electrode uncoated region 123b.
[56]
[57]
On the other hand, the positive electrode tab 171 is formed in the direction in which the cap 30 is located in the upper direction when referring to FIG. 1 , and the negative electrode tab 172 is the bottom of the receiving part 21 of the battery case 20 in the lower direction. may be positioned toward the face.
[58]
[59]
The heat dissipation tape 180 may include a heat dissipation material and be positioned on the first positive electrode uncoated region 113a. Here, the heat dissipation tape 180 may be positioned at the winding center I of the wound electrode assembly 100 . In this case, the heat dissipation tape 180 may dissipate heat generated in the winding center I of the electrode assembly 100 .
[60]
In addition, the heat dissipation tape 180 may be attached to the first positive electrode uncoated region 113a. Specifically, the heat dissipation tape 180 may be positioned on the opposite surface of the surface facing the first separator 140 in the first positive electrode uncoated region 113a. That is, the heat dissipation tape 180 may be attached to the lower surface of the first positive electrode uncoated region 113a (see FIG. 3 ).
[61]
[62]
In addition, the heat dissipation tape 180 may form a width W1 wider than the width W2 of the positive electrode 110 and the width W3 of the negative electrode 120 .
[63]
In addition, the heat dissipation tape 180 may be attached over the first positive electrode uncoated region 113a, the first separator 140 and the second separator 150 .
[64]
In addition, the heat dissipation tape 180 may include a substrate 181 and an adhesive layer 282 laminated on the substrate 181 , and the substrate 181 may include a graphite-based material.
[65]
In addition, in the heat dissipation tape 180 , the adhesive layer 282 is formed on one surface of the base material 181 , so that the heat dissipation tape 180 is connected to the end of the first positive electrode uncoated region 113a through the adhesive layer 282 , and the first separator It may be attached over 140 and the second separator 150 .
[66]
Accordingly, shrinkage of portions of the first separator 140 and the second separator 150 that are adhered to the heat radiation tape 180 through the heat radiation tape 180 may be suppressed. Accordingly, it is possible to prevent the anode 110 and the cathode 120 from contacting each other according to the contraction of the separator 160 to prevent an electrode short circuit. Accordingly, it is possible to prevent the cell from being ignited.
[67]
[68]
On the other hand, the negative electrode 120 is formed to be longer than the positive electrode 110 , so that the portion of the positive electrode 110 opposite to the negative electrode 120 is longer to prevent lithium deposition.
[69]
In addition, the first separator 140 and the second separator 150 may be formed to be longer than the length of the anode 110 and the cathode 120 to insulate the anode 110 and the cathode 120 .
[70]
In addition, the second separator 150 may be formed to be longer than the first separator 140 . Accordingly, the heat dissipation tape 180 is attached over the first positive electrode uncoated region 113a, the first separator 140 and the second separator 150, and the first separator 140 and the second separator 150 are attached. shrinkage can be easily suppressed.
[71]
And, referring to FIG. 3 , in the unfolded state before the electrode assembly 100 is wound, the length L1 of the heat dissipation tape 180 is equal to the end of the first positive electrode uncoated region 113a and the first separator 140 . It may be formed to a length that can be attached over the end of the second separator 150 and the second separator 150 . Here, one end of the first separator 140 and one end of the negative electrode 120 may be spaced apart from one end of the heat dissipation tape 180 in the horizontal direction. At this time, the spaced distance L2 from one end of the heat dissipation tape 180 to one end of the first separator 140 in the horizontal direction is from one end of the heat dissipation tape 180 to one end of the negative electrode 120 . It may be smaller than the spaced apart distance L3. In addition, the heat dissipation tape 180 may be formed not longer than the length of the second separator 150 so as not to deviate from one end of the second separator 150 .
[72]
[73]
Electrode assembly according to another embodiment
[74]
[75]
4 is a front view illustrating an unfolded state before the electrode assembly is wound according to another embodiment of the present invention.
[76]
Hereinafter, an electrode assembly 200 according to another embodiment will be described with reference to FIG. 4 .
[77]
Referring to FIG. 4 , an electrode assembly 200 according to another embodiment of the present invention is an electrode assembly 200 in which an anode 110 , a separator 160 , and a cathode 120 are alternately stacked and wound, and heat dissipation. It includes a heat dissipation tape 280 including a material.
[78]
The electrode assembly 200 according to another embodiment of the present invention has a difference in that the adhesive layer 283 is further formed on the other surface of the substrate 281 in the heat dissipation tape 280 when compared to the electrode assembly according to the above-described embodiment. have. Accordingly, the present embodiment will omit or briefly describe the content overlapping with the embodiment, and focus on the differences.
[79]
Referring to FIG. 4 , the positive electrode 110 includes a positive electrode current collector 111 , a positive electrode active material part 112 that is a region formed by stacking a positive electrode active material on the positive electrode current collector 111 , and a positive electrode active material on which the positive electrode active material is not stacked. The positive electrode uncoated region 113 as a region may be included.
[80]
The positive electrode uncoated region 113 may include a first positive electrode uncoated region 113a positioned in the winding center I and a second positive electrode uncoated region 113b positioned in the central portion.
[81]
The second positive electrode uncoated region 113b may be provided in a central portion positioned between the winding center I and the winding outer portion O of the positive electrode 110 .
[82]
[83]
The negative electrode 120 includes a negative electrode current collector 121 , a negative electrode active material portion 122 that is a region formed by laminating a negative electrode active material on the negative electrode collector 121 , and a negative electrode uncoated region that is an area on which a negative electrode active material is not stacked. (123) may be included.
[84]
The negative electrode uncoated region 123 includes the first negative electrode uncoated region 123a positioned at the winding outer portion O of the negative electrode 120 and the second negative electrode uncoated region 123b positioned at the winding center I of the negative electrode 120 . ) may be included.
[85]
[86]
The separator 160 may be made of an insulating material to insulate between the anode 110 and the cathode 120 .
[87]
In addition, the separation membrane 160 may include a first separation membrane 140 and a second separation membrane 150 .
[88]
In this case, the electrode assembly 200 may be stacked in the order of the positive electrode 110 , the first separator 140 , the negative electrode 120 , and the second separator 150 .
[89]
Here, the negative electrode 120 is formed to be longer than the positive electrode 110, and the first separator 140 and the second separator 150 are formed to be longer than the length of the positive electrode 110 and the negative electrode 120, and the second separator ( 150 may be formed to have a length longer than that of the first separator 140 .
[90]
[91]
The electrode tab 170 is attached to the electrode 130 and is electrically connected to the electrode 130 .
[92]
The electrode tab 170 may include a positive electrode tab 171 attached to the positive electrode 110 and a negative electrode tab 172 attached to the negative electrode 120 .
[93]
The positive electrode tab 171 may be provided in, for example, the second positive electrode uncoated region 113b, and the negative electrode tab 172 may be provided in the first negative electrode uncoated region 123a.
[94]
[95]
The heat dissipation tape 280 may include a heat dissipation material and be positioned on the first positive electrode uncoated region 113a. Here, the heat dissipation tape 280 may be located in the winding center I of the wound electrode assembly 200 . In this case, the heat dissipation tape 280 may dissipate heat generated in the winding center I of the electrode assembly 200 .
[96]
Also, the heat dissipation tape 280 may be formed to be wider than the width of the positive electrode 110 and the width of the negative electrode 120 .
[97]
In addition, the heat dissipation tape 280 may be attached over the first positive electrode uncoated region 113a and the first separator 140 and the second separator 150 .
[98]
Meanwhile, the heat dissipation tape 280 may include a substrate 281 and adhesive layers 282 and 283 laminated on the substrate 281 , and the substrate 281 may include a graphite-based material.
[99]
In addition, in the heat dissipation tape 280 , the adhesive layers 282 and 283 may be formed on one surface and the other surface of the substrate 281 .
[100]
In addition, the heat dissipation tape 280 may be attached over the end of the first positive electrode uncoated region 113a and the first separator 140 and the second separator 150 through the adhesive layer 282 formed on one surface.
[101]
In addition, the heat dissipation tape 280 may be adhered to a member facing it through an adhesive layer 283 formed on the other surface thereof. Here, for example, the heat dissipation tape 280 may be adhered to the second separator 150 through an adhesive layer 283 formed on the other surface.
[102]
In this case, specifically, for example, the heat dissipation tape 280 may be attached to one surface of the second separator 150 while being wound through the adhesive layer 283 formed on the other surface, and the first positive electrode through the adhesive layer 282 formed on one surface. It may be attached over the end of the uncoated region 113a and the other surfaces of the first separator 140 and the second separator 150 .
[103]
Accordingly, shrinkage of the portions of the first separator 140 and the second separator 150 that are adhered to one surface of the heat radiation tape 280 through the heat radiation tape 280 may be suppressed. In this case, the shrinkage of the portion of the second separator 150 adhered to the other surface of the heat dissipation tape 280 through the heat dissipation tape 280 may be better suppressed. As a result, the positive electrode 110 and the negative electrode 120 are exposed according to the contraction of the separator 160, and as they come into contact with each other, it is possible to better prevent an electrode short circuit and ignition.
[104]
[105]
secondary battery
[106]
[107]
Hereinafter, a secondary battery according to an embodiment will be described.
[108]
Referring to FIG. 1 , a secondary battery 10 according to an embodiment of the present invention includes an electrode assembly 100 and a battery case 20 , and the electrode assembly 100 includes a positive electrode 110 and a separator 16 . 0), the negative electrode 120 is alternately stacked and wound as an electrode assembly, and may include a heat dissipation tape 180 including a heat dissipation material.
[109]
The secondary battery 10 according to the embodiment of the present invention relates to a secondary battery including the electrode assembly according to the above-described embodiment and the electrode assembly according to another embodiment. Accordingly, the present embodiment will omit or briefly describe the contents overlapping those of the above-described embodiments, and will focus on the differences.
[110]
The secondary battery 10 according to the embodiment of the present invention includes an electrode assembly 100 and a battery case 20 in which the electrode assembly 100 is accommodated. In this case, the secondary battery 10 according to the embodiment of the present invention may further include an electrolyte accommodated in the battery case 20 .
[111]
In the battery case 20 , the receiving part 21 opened to the upper part in which the electrode assembly 100 is accommodated may be formed. In this case, the battery case 20 may be formed, for example, in a cylindrical shape.
[112]
The secondary battery 10 according to an embodiment of the present invention may further include a cap 30 that covers the opened receiving part 21 of the battery case 20 .
[113]
The electrode tab 170 is attached to the electrode 130 and is electrically connected to the electrode 130 .
[114]
The electrode tab 170 may include a positive electrode tab 171 attached to the positive electrode 110 and a negative electrode tab 172 attached to the negative electrode 120 .
[115]
On the other hand, the positive electrode tab 171 is formed in the direction in which the cap 30 is located in the upper direction when referring to FIG. 1 , and the negative electrode tab 172 is the bottom of the receiving part 21 of the battery case 20 in the lower direction. may be positioned toward the face. In this case, the cap 30 connected to the positive electrode tab 171 may form a positive terminal, and a lower portion of the battery case 20 connected to the negative electrode tab 172 may form a negative terminal. Here, the cap 30 and the battery case 20 may be insulated.
[116]
[117]
Although the present invention has been described in detail through specific examples, it is intended to describe the present invention in detail, and the electrode assembly and the secondary battery including the same according to the present invention are not limited thereto. It will be said that various implementations are possible by those of ordinary skill in the art within the technical spirit of the present invention.
[118]
In addition, the specific protection scope of the invention will be made clear by the appended claims.
[119]
[120]
[Explanation of code]
[121]
10: secondary battery
[122]
20: battery case
[123]
21: receptacle
[124]
30: cap
[125]
100,200: electrode assembly
[126]
110: positive electrode
[127]
111: positive electrode current collector
[128]
112: positive electrode active material part
[129]
113: positive uncoated region
[130]
113a: first positive electrode uncoated region
[131]
113b: second positive electrode uncoated region
[132]
120: cathode
[133]
121: negative electrode current collector
[134]
122: negative active material part
[135]
123: negative electrode uncoated region
[136]
123a: first negative electrode uncoated region
[137]
123b: second negative electrode uncoated region
[138]
130: electrode
[139]
140: first separator
[140]
150: second separator
[141]
160: separator
[142]
170: electrode tab
[143]
171: positive tab
[144]
172: negative electrode tab
[145]
180,280: heat dissipation tape
[146]
181,281: description
[147]
182,282,283: adhesive layer
[148]
C: central axis
[149]
I: Winding center
[150]
O: winding outer part

Claims

[Claim 1]
An electrode assembly in which a positive electrode, a separator, and a negative electrode are alternately stacked and wound, wherein the positive electrode includes a positive electrode active material part that is an area formed by stacking a positive electrode active material on a positive electrode current collector, and a positive electrode uncoated part that is an area where the positive electrode active material is not stacked and a heat dissipation tape including a heat dissipation material, wherein the positive electrode uncoated portion includes a first positive electrode uncoated portion positioned at a winding center portion, the first positive uncoated portion is positioned on the first positive uncoated portion.
[Claim 2]
The electrode assembly of claim 1, wherein the heat dissipation tape dissipates heat generated in a winding center of the electrode assembly.
[Claim 3]
The electrode assembly of claim 2 , wherein the heat dissipation tape is located on a surface opposite to a surface facing the separator in the first positive electrode uncoated region.
[Claim 4]
The electrode assembly of claim 1 , wherein the heat dissipation tape is wider than widths of the positive electrode and the negative electrode.
[Claim 5]
The method according to claim 1, wherein the separator includes a first separator and a second separator, and is stacked in this order: the anode, the first separator, the cathode, and the second separator, the cathode being longer than the anode; The first separator and the second separator are formed to be longer than the positive electrode and the negative electrode, the second separator is formed to have a longer length than the first separator, and the heat dissipation tape includes the first positive electrode uncoated region; An electrode assembly attached over the first separator and the second separator.
[Claim 6]
The electrode assembly of claim 5 , wherein the positive electrode, the first separator, the negative electrode, and the second separator are assembled and wound.
[Claim 7]
The electrode assembly of claim 6 , wherein the heat dissipation tape is located at a winding center of the wound electrode assembly.
[Claim 8]
The electrode assembly of claim 5 , wherein the heat dissipation tape includes a substrate and an adhesive layer laminated on the substrate, and the substrate includes a graphite-based material.
[Claim 9]
The method according to claim 8, wherein in the heat dissipation tape, the adhesive layer is formed on one surface of the substrate, so that the heat dissipation tape is attached to the end of the first positive electrode uncoated part and the first separator and the second separator through the adhesive layer. electrode assembly.
[Claim 10]
The electrode assembly of claim 9 , wherein in the heat dissipation tape, the adhesive layer is further formed on the other surface of the substrate.
[Claim 11]
The method according to claim 1, wherein the positive electrode uncoated portion further comprises a second positive electrode uncoated portion located in the center of the positive electrode, wherein the negative electrode is a negative active material portion and the negative electrode active material is a region formed by stacking a negative active material on a negative electrode current collector a positive electrode tab including a negative electrode uncoated region that is an unstacked region, wherein the negative electrode uncoated region includes a first negative electrode uncoated region positioned at an outer winding portion of the negative electrode, and is provided in the second positive electrode uncoated region; and a negative electrode tab provided in the first negative electrode uncoated region.
[Claim 12]
A secondary battery comprising the electrode assembly according to any one of claims 1 to 11.