KR20190054734A - Secondary battery - Google Patents

Abstract

The present invention relates to an electrode assembly and a secondary battery including the same, which are to prevent a cell defect caused by thermal contraction by allowing a separator to extend more than a negative electrode plate to surround at least one short side surface, and allowing a rounded short side surface to serve a role of holding the separator in case of thermal contraction. To this end, the electrode assembly comprises: a positive electrode plate having a positive electrode tab attached thereto; a negative electrode plate having a negative electrode tab attached thereto; and a separator interposed between the positive and negative electrode plates and having a binder. The electrode assembly in which a laminate of the positive electrode plate, the separator, and the negative electrode plate are wound in a jelly-roll form from a winding leading end to be thermally fused by the binder of the separator, has two long sides having a flat side surface which is a surface formed by being wound, and being in parallel with each other, and two curved short side surfaces rounded by respectively connecting two long side surfaces, and has a winding end of the negative electrode plate and a winding end of the separator to be adjacent to the different long side surfaces.

Description

[0001] The present invention relates to an electrode assembly,

The present invention relates to an electrode assembly and a secondary battery including the same.

A secondary battery is a battery that can be charged and discharged unlike a non-rechargeable primary battery. The secondary battery of low capacity is used for portable electronic devices such as smart phones, feature phones, notebook computers, digital cameras and camcorders, and the secondary battery of large capacity is used for motor driving power for electric vehicles and hybrid electric vehicles, And so on.

Such a secondary battery includes an electrode assembly composed of an anode and a cathode, a case accommodating the same, and an electrode terminal connected to the electrode assembly. The case can be classified into a circle, a square, and a pouch type according to its shape. Among them, the pouch type secondary battery can be formed into a laminate outer cover material which is easily deformed into various shapes and has a small weight.

The above-described information disclosed in the background of the present invention is only for improving the understanding of the background of the present invention, and thus may include information not constituting the prior art.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a separator that extends over at least one side surface of a negative electrode plate so that the rounded side surface serves to hold the separator during heat shrinkage, And an electrode assembly and a secondary battery including the electrode assembly, which can prevent the safety from being deteriorated by electrically separating the negative electrode plate and the positive electrode plate during heat shrinkage.

In order to accomplish the above object, an electrode assembly and a secondary battery including the same according to the present invention includes a positive electrode plate having a positive electrode tab, a negative electrode plate having a negative electrode tab, and a separator interposed between the positive electrode plate and the negative electrode plate, Wherein the laminated body of the positive electrode plate, the separator, and the negative electrode plate is wound in a jelly roll form from the winding end and thermally fused by the binder of the separator, the two side surfaces being flat and parallel to each other, And two short sides which are rounded curved surfaces, respectively, and the winding end of the negative electrode plate and the winding end of the separator may be adjacent to different long side surfaces.

The separator may have an extension portion that extends further from the winding end of the negative electrode plate and further surrounds at least one of the side surfaces of the electrode assembly, and the extension portion may be 13 mm or more.

The extension may comprise a first length extending from the winding end of the negative plate to the short side, a length enclosing the short side, and a second length extending from the short side to the winding end of the separator .

The first length and the second length may not overlap the plan viewed from the side of the positive electrode tab and the negative electrode tab.

The positive electrode tab and the negative electrode tab may be adhered to the winding front end region and positioned at the winding center portion of the electrode assembly.

Also, the electrode assembly and the secondary battery including the same according to the present invention include a positive electrode plate having a positive electrode tab, a negative electrode plate having a negative electrode tab, and a separator interposed between the positive electrode plate and the negative electrode plate, An electrode assembly having an electrode assembly and an internal space in which a laminate of the separator and the negative electrode plate is wound in a jelly roll form from the winding end and thermally fused by a binder of the separator, and the internal space, the electrode assembly and the electrolyte are accommodated in the internal space, Wherein the electrode assembly includes a positive electrode tab and a negative electrode tab drawn out to the outside, wherein the electrode assembly includes two long sides parallel to each other, the sides being flat and parallel to each other, Wherein the separator has two short side surfaces, Are extended from the end, more surrounding the at least one short side of the electrode assembly can have an extension.

The extending portion may include a first length extending from the winding end to the short side of the negative plate, a length surrounding the short side, and a second length extending from the short side to the winding end of the separator , The extension may be 13 mm or more.

The first length and the second length may not overlap the plan viewed from the side of the positive electrode tab and the negative electrode tab.

The positive electrode plate further extends from the winding end of the separator and may be located at the outermost side of the electrode assembly.

The electrode assembly and the secondary battery including the separator according to the present invention are characterized in that the separator extends so as to surround at least one side surface of the negative electrode plate so that the rounded side surface serves to hold the separator during heat shrinking, So that the safety can be prevented from deteriorating.

1A is an exploded perspective view, a plan view, and a partial perspective view of a secondary battery according to various embodiments of the present invention.
FIG. 2 is a plan view showing a state before a winding end of an electrode assembly is wound in a secondary battery according to various embodiments of the present invention. FIG.
3 is a cross-sectional view illustrating an electrode assembly after rewinding in a secondary battery according to various embodiments of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The embodiments of the present invention are described in order to more fully explain the present invention to those skilled in the art, and the following embodiments may be modified into various other forms, It is not limited to the embodiment. Rather, these embodiments are provided so that this disclosure will be more faithful and complete, and will fully convey the scope of the invention to those skilled in the art.

In the following drawings, thickness and size of each layer are exaggerated for convenience and clarity of description, and the same reference numerals denote the same elements in the drawings. As used herein, the term " and / or " includes any and all combinations of one or more of the listed items. In the present specification, the term " connected " means not only the case where the A member and the B member are directly connected but also the case where the C member is interposed between the A member and the B member and the A member and the B member are indirectly connected do.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms "a," "an," and "the" include singular forms unless the context clearly dictates otherwise. Also, " comprise " and / or " comprising " when used herein should be interpreted as specifying the presence of stated shapes, numbers, steps, operations, elements, elements, and / And does not preclude the presence or addition of one or more other features, integers, operations, elements, elements, and / or groups.

Although the terms first, second, etc. are used herein to describe various elements, components, regions, layers and / or portions, these members, components, regions, layers and / It is obvious that no. These terms are only used to distinguish one member, component, region, layer or section from another region, layer or section. Thus, a first member, component, region, layer or section described below may refer to a second member, component, region, layer or section without departing from the teachings of the present invention.

It is to be understood that the terms related to space such as "beneath," "below," "lower," "above, But is used for an easy understanding of other elements or features. Terms related to such a space are for easy understanding of the present invention depending on various process states or use conditions of the present invention, and are not intended to limit the present invention. For example, if an element or feature of the drawing is inverted, the element described as "lower" or "below" will be "upper" or "above." Thus, " below " is a concept covering " upper " or " lower ".

Referring to FIGS. 1A to 1C, an exploded perspective view, a plan view, and a partial perspective view of a secondary battery according to various embodiments of the present invention are shown.

1A through 1C, a secondary battery 100 according to various embodiments of the present invention includes an electrode assembly 110 and a laminate sheath 120.

The electrode assembly 110 includes a negative electrode plate 111 (or a first electrode plate), a positive electrode plate 112 (or a second electrode plate), and a separator 113 interposed between the negative electrode plate 111 and the positive electrode plate 112 ). The electrode assembly 110 may be formed by winding a laminate of the negative electrode plate 111, the separator 113, and the positive electrode plate 112 in the form of a jelly roll.

 The negative electrode plate 111 includes, for example, but not limited to, a negative electrode active material layer coated on both surfaces of a negative electrode current collector plate made of a conductive metal thin plate, for example, copper or nickel foil or a mesh. The negative electrode active material layer may include, for example, but not limited to, a carbon-based material, Si, Sn, a tin oxide, a tin alloy composite, a transition metal oxide, a lithium metal nitride or a metal oxide. The negative electrode uncoated portion in which the negative electrode active material layer is not formed on the negative electrode collector plate can be fixed (for example, welded) to the substantially flat negative electrode tab 114, for example, but not limited thereto. That is, one end of the negative electrode tab 114 may be electrically connected to the negative electrode uncoated portion, and the other end may protrude and extend outward. An insulating member 114a is attached to the negative electrode tab 114 to prevent the negative electrode tab 114 from being short-circuited with the laminate facing member 120.

The positive electrode plate 112 includes, for example, but not limited to, a positive electrode active material layer coated on both surfaces of a metal thin plate having excellent conductivity, for example, a positive electrode current collector plate made of aluminum foil or mesh. Here, the cathode active material layer may include, for example, but not limited to, chalcogenide compounds. For example, composite metal oxides such as LiCoO2, LiMn2O4, LiNiO2, and LiNiMnO2 may be used. The positive electrode tab 115 may be fixed (for example, welded) to the positive electrode uncoated portion where the positive electrode collector plate is not provided with the positive electrode active material layer, for example, but not limited thereto. An insulating member 115a is attached to the positive electrode tab 115 to prevent the positive electrode tab 115 from being short-circuited with the laminate facing member 120.

The separator 113 is interposed between the negative electrode plate 111 and the positive electrode plate 112 to prevent electrical shorting of the negative electrode plate 111 and the positive electrode plate 112. A pair of the separators 113 is substantially provided, and the anode plate 111 is sandwiched between the pair of separators 113. The separator 113 may be made of any one selected from the group consisting of, for example, polyethylene, polypropylene, and a porous copolymer of polyethylene and polypropylene. The separator 113 may be wider than the negative electrode plate 111 and the positive electrode plate 112 to prevent electrical shorting between the negative electrode plate 111 and the positive electrode plate 112. The separator 113 will be described below again.

The laminate sheathing member 120 receives the electrode assembly 110 and is formed by sealing the outer periphery of the electrode assembly 110. The laminate sheathing 120 has a first outer sheath 121 and a second outer sheath 121 having one end connected to the first outer sheath 121 and having a recess 123 having a predetermined depth to receive the electrode assembly 110, And an enclosure 122.

In addition, the peripheries 124 of the first and second external parts 121 and 122 corresponding to the outer periphery of the electrode assembly 110 are mutually thermally fused to each other so that the electrode assembly (not shown) 110 are accommodated.

That is, the laminate facing member 120 is formed by integrally forming a rectangular plate-like laminate facing member 120 in the middle with respect to the longitudinal direction of one side so as to form the first exterior member 121 and the second exterior member 122 do. The second external portion 122 is formed with a recess 123 having a predetermined depth at which the electrode assembly 110 can be received through a press or a drawing process, And a sealing portion 124 for sealing with the first enclosure 121 is formed at the periphery. The sealing portion 124 may be formed along one side and the other side where the first exterior portion 121 and the second exterior portion 122 are in contact with each other.

The second enclosure 122 also includes four extended areas 125 and 126 that are spaced apart from the first enclosure 121 and a second uncovered area 125 that is connected to these four extended areas 125 and 126, Area 128. The < / RTI > Here, a relatively long region may be defined as a long side extended region 125, and a relatively short region may be defined as a short side extended region 126, among the four extended regions 125 and 126. [

The negative electrode tab 114 and the positive electrode tab 115 of the electrode assembly 110 are drawn out to the outside through the sealing portion 124 to which the first external portion 121 and the second external portion 122 are fused. At this time, the insulating members 114a and 115b formed on the negative electrode tab 114 and the positive electrode tab 115 are sealed together with the sealing portion 124. [ That is, the insulating members 114a and 115b are interposed between the negative electrode tab 114 and the portion where the positive electrode tab 115 and the sealing portion 124 are in contact with each other so that the negative electrode tab 114 and the positive electrode tab 115 are connected to the laminate outer member 120 To be electrically short-circuited.

The laminate sheathing 120 may be formed in a multilayer structure including, but not limited to, a first insulating layer 120a, a metal layer 120b, and a second insulating layer 120c. Of course, a variety of adhesive layers and functional layers may be further added, but a description thereof will be omitted so as not to obscure the gist of the present invention.

The first insulating layer 120a is formed on the inner surface of the laminate outer cover 120, and is made of a material having insulation and heat adhesiveness. The first insulating layer 120a is formed on one side of the metal layer 120b and forms the inner surface of the laminate facing member 120 facing the electrode assembly 110. [ The first insulating layer 120a may be formed of casted polypropylene (CPP) or its equivalent which does not react with an electrolyte or the like, but is not limited thereto. When the electrode assembly 110 is received in the recess 123 of the second enclosure 122 and covered with the first enclosure 121, the first insulation layer 120a of the laminate enclosure 120 is brought into contact with each other . Therefore, when the sealing part 124 is thermally fused, the first insulating layer 120a is adhered to each other, and the laminate facing member 120 is sealed.

The metal layer 120b is sandwiched between the first insulating layer 120a and the second insulating layer 120c to prevent moisture and oxygen from being introduced into the metal layer 120b and if the electrolyte is filled in the inside of the laminate 120, , And serves to prevent the outflow thereof. In addition, the metal layer 120b serves to maintain the mechanical strength of the laminate sheathing material 120. In general, the metal layer 120b may be formed of, but not limited to, aluminum, an aluminum alloy, an iron, and an iron alloy.

The second insulating layer 120c is an outer surface of the laminate 120, and serves to alleviate mechanical and chemical impacts with external electronic devices. The second insulating layer 120c is formed on the other surface of the metal layer 120b and forms the outer surface of the laminate facing member 120. [ The second insulating layer 120c may be formed of, but not limited to, nylon, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polybutylene naphthalate (PBN), or the like.

The second exterior portion 122 of the laminate exterior material 120 of the secondary battery 100 according to various embodiments of the present invention includes a plurality of extended regions 125, 126, and 127 extending in a direction away from the first exterior portion 121, And a flat area 128 connected to the plurality of extension areas 125, 126, 127 and approximately parallel to the first enclosure 121. [

Here, a plurality of extension regions 125, 126, and 127 and a single flat region 128 may define a recess 123 that substantially receives the electrode assembly 110. Furthermore, two of the plurality of extension regions may be defined as a relatively long extended region 125, and the remaining two extended regions may be defined as a relatively shortened short extension region 126, The corner between the extension region 125 and the short side extension region 126 may be defined as a corner extension region 127. [

Referring to FIG. 2, a plan view of the secondary battery 100 according to various embodiments of the present invention is shown before the winding end of the electrode assembly 110 is wound. Referring to FIG. 3, a cross-sectional view of the secondary battery 100 according to various embodiments of the present invention is shown after the electrode assembly 110 is wound. The electrode assembly 110 shown in FIG. 2 has a structure in which a laminate of the negative electrode plate 111, the separator 113, and the positive electrode plate 112 is wound in a jellyroll form from the winding end, Before winding. In FIG. 2, the electrode assembly 110 has a jelly roll shape 100J wound on the left side from the winding end, and the right end is the winding end. 3, the negative electrode plate 111, the separators 113a and 113b, and the positive electrode plate 112 are shown as being separated from each other. However, this is illustrated for ease of understanding of the present invention, In the wound electrode assembly 110, the negative electrode plate 111, the separators 113a and 113b, and the positive electrode plate 112 are in close contact with each other.

2 and 3, an electrode assembly 110 of a secondary battery 100 according to an embodiment of the present invention includes a negative electrode plate 111 having a negative electrode tab 114 formed at a winding end region thereof, A pair of separators 113a and 113b covering both sides of the positive electrode tab 115 and a positive electrode plate 112 having a positive electrode tab 115 formed in the winding tip region.

Here, the winding front end region refers to a region where winding begins during the winding process of the electrode assembly 110, and the winding termination region refers to a region where winding is terminated during the winding process of the electrode assembly 110. The winding end refers to the end of the area where the winding of the electrode assembly 110 is started during the winding process of the electrode assembly 110 and the winding end refers to the end of the winding area during the winding process of the electrode assembly 110. Thus, the negative electrode tab 114 and the positive electrode tab 115 in the winding front end region are positioned substantially at the winding center portion (or the inner center) in the wound electrode assembly 110. In addition, the winding termination region is generally located at the outermost portion of the electrode assembly 110.

The electrode assembly 110 further includes two short side surfaces 110a and 110b which are parallel to each other and two short side surfaces 110c and 110d which connect the two long side surfaces 110a and 110b, Respectively. Here, the side surface refers to a surface formed by winding the electrode assembly 110. At this time, the surface on which the negative electrode tab 114 and the positive electrode tab 115 protrude becomes the upper surface 110e, the opposite surface of the upper surface 110e becomes the lower surface 110f, and vice versa. Here, the two short side surfaces 110c and 110d are rounded surfaces formed by winding the electrode assembly 110. That is, the side surface of the electrode assembly 110 includes a flat first side surface 110a, a second long side surface 110b opposite to the first long side surface 110a, a first long side surface 110a, And a first end surface 110c and a second end surface 110d which are connected to both ends of the long side surface 110b and have curved surfaces, respectively. Here, the first end side 110c denotes a short side in a direction from the first long side 110a to the second long side 110b at the time of winding, and the second short side 110d denotes a short side Means a short side in a direction from the side surface 110b to the first long side surface 110a.

The negative electrode plate 111, the positive electrode plate 112 and the separators 113a and 113b of the electrode assembly 110 will be described in more detail. The electrode assembly 110 described below is merely an example for the understanding of the present invention, and the formation position of the tab, the active material layer (active material coating portion) and / or the non-coating portion (non-active material coating portion) It should be understood that various changes may be made.

The negative electrode plate 111 includes a negative electrode collector plate 111a, a negative electrode active material layer 111b, and the negative electrode tab 114 described above. The negative electrode current collector plate 111a has a substantially flat plate shape and includes a first side and a second side opposite to the first side. The negative electrode active material layer 111b may be coated on at least one of the first and second surfaces of the negative electrode collector plate 111a.

Here, the negative electrode plate 111 may be provided with a negative electrode uncoated portion in which the negative electrode active material layer 111b is not coated on the winding front end region and the winding end region of the negative electrode current collector plate 111a. Of the negative electrode uncoated portions of the negative electrode plate 111, the negative electrode tab 114 is fixed to the negative electrode non-coated portion provided at the winding end region by, for example, ultrasonic welding, laser welding or resistance welding have. The negative electrode plate 111 can be variously modified depending on the characteristics of the secondary battery whether or not the negative electrode active material layer 111b of the winding end region and the winding end region is coated.

The pair of separators 113 covers both sides of the negative electrode plate 111. The length and width of the pair of separators 113 may be larger than the length and width of the negative electrode plate 111. [ Here, the length means the size of the direction x in which the electrode assembly 110 is wound, and the width means the direction y in which the electrode tabs 114 and 115 perpendicular to the longitudinal direction x protrude. The pair of separators 113a and 113b are formed by a first separator 113a interposed between one surface of the negative electrode plate 111 and the positive electrode plate 112 and a second separator 113b interposed between the other surface of the negative electrode plate 111 and the positive electrode plate 112, (113b). In addition, the first separator 113a and the second separator 113b may have the same length and width.

In the electrode assembly 110 before about one turn from the winding end shown in FIG. 2, the second separator 113b is illustrated as wound on a jelly roll form 100J. This is for clearly indicating the relationship between the winding end 113y of the first separator 113a and the winding end 111y of the negative plate 111. The winding end 113y of the second separator 113b is also a winding end 113y of the second separator 113b, Extends to the same position as the winding terminating end 113y of the engaging portion 113a. The second separator 113b is wound at the same time as the negative electrode plate 111, the first separator 113a and the positive electrode plate 112 substantially.

The winding end 113y of the pair of separators 113 may extend further in the longitudinal direction x than the winding end 111y of the anode plate 111 by the extension A. For example, if the winding end 111y of the negative electrode plate 111 is positioned adjacent to the first long side surface 110a side of the electrode assembly 110, the winding end 113y of the separator 113 is positioned at the center of the electrode assembly 110, And is located adjacent to the second side surface 110b side. The opposite is also possible. That is, the winding end 111y of the negative electrode plate 111 and the winding end 113y of the separator 113 are positioned adjacent to the different long side surfaces 110a and 110b of the electrode assembly 110.

The extension A of the separator 113 surrounds at least one of the short side surfaces 110c and 110d of the electrode assembly 110 and extends the first long side surface 110a and the second long side surface 110b to a certain portion And has a length that can be covered. Preferably, the extension A may be 13 mm or more.

Hereinafter, when the winding end 111y of the cathode plate 111 is positioned on the first long side 110a and the winding end 113y of the separator 113 is positioned on the second long side 110b in accordance with FIG. 3 . Therefore, the extension A of the separator 113 can cover all of the first end side face 110c.

 The length of the extension A may be equal to Equation (1).

은 제1단측면(110c)을 모두 감싸는 길이 방향(x) 길이로, 전극 조립체(110)의 제1장측면(110a)과 제2장측면(110b) 사이의 수직 거리가 2r일 경우이다. 또한 a1은 음극판(111)의 권취 종단(111y)부터 제1단측면(110c)까지의 길이인 제1길이(a1)이고, a2는 세퍼레이터(113)의 권취 종단(113y)으로부터 제1단측면(110c)의 제2길이(a2)이다. 즉, a1은 음극판(111)의 권취 종단(111y)부터 제1단측면(110c)까지 제1장측면(110a)을 덮는 세퍼레이터(113)의 연장부의 길이를 의미하고, a2는 제1단측면(110c)부터 세퍼레이터(113)의 권취 종단(113y)까지 제2장측면(110b)을 덮는 세퍼레이터(113)의 연장부의 길이를 의미한다. here

And the vertical distance between the first long side 110a and the second long side 110b of the electrode assembly 110 is 2r in a longitudinal direction x that entirely covers the first short side 110c. A1 is a first length a1 that is the length from the winding end 111y to the first end side 110c of the negative electrode plate 111 and a2 is a distance from the winding end 113y of the separator 113 to the first end side (A2) of the first portion 110c. That is, a1 means the length of the extension of the separator 113 covering the first long side 110a from the winding end 111y of the negative plate 111 to the first short side 110c, Refers to the length of the extension of the separator 113 covering the second long side 110b from the first end 110c to the winding end 113y of the separator 113. [

Here, it is preferable that the positive electrode tab 115 and the negative electrode tab 114 are not located within the first length a1 and the second length a2. That is, it is preferable that the positive electrode tab 115 and the negative electrode tab 114 do not lie between the winding end 113y of the negative electrode plate 111 and the winding end 113y of the separator 113 on the plane viewed from the long side. The thickness of the negative electrode tab 114 and the positive electrode tab 115 may have a thickness of 50 to 100 탆. The second length a2 may be defined such that the winding termination 113y of the separator 113 extends to a position where the separator 113 does not overlap with the positive electrode tab 115 and the negative electrode tab 114 in plan view. This is because the separator 113 overlaps the negative electrode tab 114 and the positive electrode tab 115 which are thicker than the negative electrode plate 111, the positive electrode plate 112 and the separator 113 to increase the thickness of the electrode assembly 110 .

Since the separator 113 extends to cover at least one side surface of the negative electrode plate 111, the side surface of the separator 113 serves to hold the separator 113 at the time of heat shrinkage, and the negative electrode plate 111 and the positive electrode plate 112 Can be electrically isolated from each other to prevent the safety from being deteriorated.

The separator 113 may be made of polyethylene (PE), polypropylene (PP), or a base film. In addition, the separator 113 may be a heat-resistant insulating separator in which at least one layer of an inorganic ceramic layer such as alumina or boehmite is coated on one surface or both surfaces of the PE or PP separator. Further, the separator 113 may be a polymer-coated separator in which at least one layer of polymer is coated on one surface or both surfaces of a PE or PP separator. The separator 113 may be a multilayer coating separator having both an inorganic ceramic layer and a polymer layer. The separator 113 may be a multifunctional separator having both an inorganic ceramic layer and a binder.

The heat-resistant insulating separator, the polymer-coated separator, the multilayered coating separator, and the multifunctional separator further include a binder (adhesive component), which prevents the separator 113 from contacting the electrode assembly 110 after the electrode- And can be bonded to the positive electrode plate 112 and the negative electrode plate 111.

The thickness of the separator 113 may be 7 to 15 占 퐉.

The positive electrode plate 112 includes a positive electrode collector plate 112a, a positive electrode active material layer 112b, and the positive electrode tab 115 described above. The positive electrode current collector plate 112a has a substantially flat plate shape and includes a first side and a second side opposite to the first side. Also, the positive electrode active material layer 112b may be coated on at least one surface of one side or the other side of the positive electrode current collector plate 112a.

Here, the positive electrode plate 112 may be provided with a positive electrode uncoated portion in which the positive electrode active material layer 112b is not coated on the winding front end region and the winding end region of the positive electrode current collector plate 112a. In addition, of the positive electrode uncoated portions of the positive electrode plate 112, the positive electrode tab 114 provided in the winding front end region can be fixed by, for example, ultrasonic welding, laser welding, or resistance welding have. In addition, the positive electrode plate 112 can be variously modified depending on the characteristics of the secondary battery whether the positive electrode active material layer 112b of the winding end region and the winding end region is coated.

The positive electrode plate 112 may be longer than the separator 113 and the width of the positive electrode plate 112 may be smaller than that of the separator 113 like the negative electrode plate 111. The winding end 112y of the positive electrode plate 112 can be extended by a certain length in the longitudinal direction as compared with the winding end 113y of the separator 113. [ The positive electrode plate 112 may be located at the outermost side of the electrode assembly 110.

Although the present invention has been described and illustrated in detail, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, It will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention.

100; A secondary battery 110; Electrode assembly
111; Cathode plate 111y; Winding end
112; A bipolar plate 113; Separator
113y; A winding termination 120; Laminate Outer Material

Claims (10)

A positive electrode plate having a positive electrode tab attached thereto;
A negative electrode plate having a negative electrode tab attached thereto; And
And a separator interposed between the positive electrode plate and the negative electrode plate and having a binder, wherein the laminate of the positive electrode plate, the separator and the negative electrode plate is wound in a jelly roll form from the winding end and thermally fused by the binder of the separator ,
Wherein the electrode assembly has two short side surfaces, which are rounded surfaces, connecting two long sides parallel to each other and a flat surface having sides formed as a result of being wound,
Wherein the winding end of the negative electrode plate and the winding end of the separator are adjacent to different longitudinal sides. The method according to claim 1,
Wherein the separator further has an extension extending further from the winding end of the negative electrode plate so as to further surround at least one of the end faces of the electrode assembly, wherein the extension is 13 mm or more. The method of claim 2,
And the extension portion is formed of a first length extending from the winding end to the short side of the negative electrode plate, a length surrounding the short side, and a second length extending from the short side to the winding end of the separator . The method of claim 3,
Wherein the first length and the second length do not overlap in plan view from the positive and negative electrode taps and the long side. The method according to claim 1,
Wherein the positive electrode tab and the negative electrode tab are adhered to the winding front end region and located at the winding center portion of the electrode assembly. A positive electrode plate with a positive electrode tab, a negative electrode plate with a negative electrode tab, and a separator interposed between the positive electrode plate and the negative electrode plate and having a binder, wherein the laminate of the positive electrode plate, the separator and the negative electrode plate is formed into a jelly roll form And the electrode assembly is thermally fused by a binder of the separator; And
And a laminate outer material having an inner space and accommodating the electrode assembly and the electrolyte in the inner space and having the cathode tab and the anode tab drawn out,
Wherein the electrode assembly has two short side surfaces, which are rounded surfaces, connecting the two long sides parallel to each other and the two short side surfaces which are flat and parallel to each other,
Wherein the separator further has a winding end further extending from the winding end of the negative electrode plate and having an extension portion that further surrounds at least one end surface of the electrode assembly. The method of claim 6,
Wherein the extending portion comprises a first length extending from the winding end to the short side of the negative electrode plate, a length surrounding the short side, and a second length extending from the short side to the winding end of the separator,
Wherein the extended portion is 13 mm or more. The method of claim 7,
Wherein the first length and the second length do not overlap the plan viewed from the side surfaces of the positive electrode tab and the negative electrode tab. The method of claim 6,
Wherein the positive electrode plate further extends from the winding end of the separator and is located at the outermost side of the electrode assembly. The method of claim 6,
Wherein the positive electrode tab and the negative electrode tab are adhered to the winding front end region and located at the winding center portion of the electrode assembly.

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