Secondary battery with improved terminal structure

Abstract

The disclosed invention relates to a secondary battery, comprising: a secondary battery having a positive terminal and a negative terminal spaced apart from each other on an upper surface of a hexahedral battery case; a terminal structure including: a bent terminal body that is coupled to an upper surface and a side surface continuing from the upper surface of the battery case while enclosing the positive terminal or the negative terminal so as not to be exposed; and an extension terminal that is electrically connected to the positive terminal or the negative terminal and exposed on a side surface of the terminal body, wherein a side surface of the terminal structure is placed within a concave surface formed on a side surface of the battery case.

Description

[Technical field]

[0001] The present invention relates to a secondary battery, and more particularly to a prismatic secondary battery having an improved terminal structure that enables the arrangement of the positive electrode terminal and / or negative electrode terminal to be easily and stably changed.

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2022-0141685 dated October 28, 2022, and all contents disclosed in the documents of that Korean patent application are incorporated herein by reference. [Background technology]

[0003] Unlike primary batteries, secondary batteries can be recharged, and they have been much researched and developed in recent years due to their potential for miniaturization and large capacity. The demand for secondary batteries as an energy source is rapidly increasing due to the increasing technological development and demand for mobile devices, as well as the emergence of electric vehicles and energy storage systems in response to the modern demand for environmental protection.

[0004] Secondary batteries are classified into coin type batteries, cylindrical type batteries, square type batteries, and pouch type batteries according to the shape of the battery case. The electrode assembly installed inside the battery case of the secondary battery is a power generating element capable of charging and discharging, which is made of a laminated structure of electrodes and a separator.

[0005] Electrode assemblies can be broadly classified into a jellyroll type in which a sheet-like positive electrode and negative electrode coated with an active material are wound with a separator interposed between them; a stack type in which a number of positive electrodes and negative electrodes are sequentially stacked with a separator interposed between them; and a stack & folding type in which a stack type unit cell is wound with a long separator film.

[0006] Among the various types of secondary batteries, prismatic secondary batteries are mostly arranged with positive and negative terminals on one side or one on each of the opposing sides. The arrangement of the positive and negative terminals is determined by the design specifications of the various devices in which the prismatic secondary batteries are installed, and even if the form factor is the same, it is time-consuming to have to design the arrangement of the positive and negative terminals separately each time to match the design specifications. Summary of the Invention [Problem to be solved by the invention]

[0007] An object of the present invention is to provide a new prismatic secondary battery in which the layout structure of the positive and negative electrode terminals of the prismatic secondary battery can be easily modified without a separate design change.

[0008] Another object of the present invention is to provide a prismatic secondary battery capable of stably maintaining the changed arrangement of positive and negative electrode terminals even after the arrangement structure is changed.

[0009] However, the technical problem that the present invention aims to solve is not limited to the above-mentioned problem, and other problems not mentioned can be clearly understood by a person skilled in the art from the description of the invention described below. [Means for solving the problem]

[0010] In one example, the secondary battery according to the present invention includes a secondary battery having a positive terminal and a negative terminal spaced apart from each other on an upper surface of a hexahedral battery case; a terminal body having a bent shape and coupled to an upper surface and a side surface continuing from the upper surface of the battery case while enclosing the positive terminal or the negative terminal so as not to be exposed; and an extension terminal electrically connected to the positive terminal or the negative terminal and exposed on a side surface of the terminal body, wherein a side surface of the terminal structure is placed within a concave surface formed on a side surface of the battery case.

[0011] In one embodiment of the present invention, the terminal body is made of an insulating material, so that the positive terminal or the negative terminal is electrically isolated from the outside.

[0012] The recessed surface is formed into a shape corresponding to the side surface of the terminal structure, and the corners of the side surface of the terminal structure come into contact with and are supported by the corners of the step of the recessed surface.

[0013] Furthermore, the corners of the side surface of the terminal structure and the corners of the concave surface can be bound together by a dovetail structure.

[0014] This allows the side surface of the terminal structure to be slidably coupled to the concave surface and bonded to each other.

[0015] Meanwhile, according to another embodiment of the present invention, a concave beading portion may be formed on each of the opposing front and rear surfaces of the battery case, and a protrusion may be provided at an upper corner of the terminal structure to be inserted into the beading portion.

[0016] When the corners of the side surface of the terminal structure come into contact with the corners of the step of the concave surface, the protrusions of the terminal structure are inserted into the beading processed portion, thereby supporting the terminal structure against the battery case.

[0017] The protrusion of the terminal structure can be slidably coupled to the beading portion to be bound to each other.

[0018] The beading processed portion may press against a surface of the electrode assembly housed inside the battery case.

[0019] The beading processing portion may be formed at a position spaced apart from the electrode tab of the electrode assembly housed inside the battery case, for example, adjacent to a cap plate so as to press against an upper portion of the electrode assembly housed inside the battery case. Effect of the Invention

[0020] According to the secondary battery of the present invention as described above, by applying a terminal structure having a simple structure, the terminal arrangement can be easily changed from a unidirectional secondary battery to a bidirectional secondary battery, and since the support structure of the terminal structure is robust, problems such as damage to the terminal structure joined to the battery case or welding deterioration caused by vibrations during vehicle operation can be prevented.

[0021] In addition, in order to limit the degree of freedom of the terminal structure, the beading processing portion formed in a concave shape on the front and rear surfaces of the battery case can compress and support the surface of the electrode assembly housed inside, thereby improving the support structure of the electrode assembly as well, thereby significantly improving the safety of the secondary battery.

[0022] However, the technical effects that can be obtained by the present invention are not limited to the effects described above, and other effects not mentioned can be clearly understood by those of ordinary skill in the art from the description of the invention described below.

[0023] The following drawings attached to this specification illustrate preferred embodiments of the present invention and, together with the detailed description of the invention described below, serve to further understand the technical concept of the present invention. Therefore, the present invention should not be interpreted as being limited only to the matters described in such drawings. [Brief description of the drawings]

[0024] [Figure 1] 1 is a perspective view showing a secondary battery according to the present invention; [Diagram 2] 1 is a perspective view showing a connection structure between a secondary battery and a terminal structure according to the present invention; [Diagram 3] 1 is a diagram showing an embodiment in which the concave surface of the battery case and the terminal structure are joined together by a dovetail structure. [Figure 4] FIG. 4 is a cross-sectional view taken along line "AA" in FIG. [Diagram 5] FIG. 4 is a perspective view showing a secondary battery according to another embodiment of the present invention. [Figure 6]6 is a perspective view showing a connection structure between the secondary battery and the terminal structure according to the embodiment of FIG. 5. [Figure 7] FIG. 6 is a cross-sectional view taken along line "BB" in FIG. 5. [Figure 8] 6 is a diagram showing a front surface of the secondary battery of FIG. 5. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] Since the present invention can be modified in various ways and can have various embodiments, specific embodiments will be described in detail below.

[0026] However, this is not intended to limit the invention to any particular embodiment, but it should be understood to include all modifications, equivalents, or alternatives falling within the spirit and scope of the invention.

[0027] In the present invention, terms such as "comprise" and "have" are intended to specify the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, and may be understood as not precluding the presence or additional possibility of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0028] In addition, in the present invention, when a layer, film, region, plate, or other portion is described as being "on" another portion, this includes not only the case where it is "directly on" the other portion, but also the case where there is another portion in between. Conversely, when a layer, film, region, plate, or other portion is described as being "under" the other portion, this includes not only the case where it is "directly under" the other portion, but also the case where there is another portion in between. In addition, in the present application, being "on" can include not only the case where it is located at the top, but also the case where it is located at the bottom.

[0029] The secondary battery according to the present invention is a secondary battery in which a positive terminal and a negative terminal are arranged at a distance from each other on an upper surface of a battery case having a hexahedral shape, and includes a terminal structure including: a terminal body having a bent shape that is coupled to an upper surface and a side surface continuing from the upper surface of the battery case while enclosing the positive terminal or the negative terminal so as not to be exposed; and an extension terminal that is electrically connected to the positive terminal or the negative terminal and exposed to a side surface of the terminal body.

[0030] The side surface of the terminal structure is placed in a recess formed in the side surface of the battery case.

[0031] In this way, the secondary battery of the present invention including the terminal structure can freely change the positions of the positive and negative terminals arranged on the upper surface of the battery case according to the user's requirements without any additional design changes, simply by applying the terminal structure, which eliminates the need to change a unidirectional secondary battery into a bidirectional secondary battery, thereby reducing the production costs of the prismatic secondary battery.

[0032] In addition, in the rectangular secondary battery of the present invention, the terminal structure is placed and supported within a concave surface formed in the battery case, thereby limiting the freedom of movement of the terminal structure. This prevents problems such as damage to the terminal structure joined to the battery case or deterioration of the weld due to vibrations during vehicle operation.

[0033] Hereinafter, specific embodiments of the secondary battery of the present invention will be described in detail with reference to the accompanying drawings. For reference, the directions of front and back, up and down, left and right, which specify relative positions used in the following description, are intended to facilitate understanding of the invention, and unless otherwise specified, are based on the directions shown in the drawings.

[0034] (First embodiment) FIG. 1 is a perspective view showing a secondary battery 10 according to the present invention, and FIG. 2 is a perspective view showing a coupling structure of the secondary battery 10 according to the present invention and a terminal structure 300. As shown in FIG.

[0035] 1 and 2, the present invention relates to a secondary battery 10, in particular a unidirectional prismatic secondary battery 10 in which a pair of terminals, i.e., a positive terminal 122 and a negative terminal 124, are spaced apart on the top surface of a battery case 100 having a hexahedral shape. Here, the prismatic secondary battery 10 shown in the drawings is only one example, and the ratio of width, length, and height may vary, and for convenience of explanation, the directions are referred to as front, back, up, down, left, and right based on the attached drawings. For example, one surface of the battery case 100 on which the positive terminal 122 and the negative terminal 124 are arranged is called the top surface, and the opposite surface opposite thereto is called the bottom surface.

[0036] The secondary battery 10 of the present invention includes a terminal structure 300. The terminal structure 300 is a structure bent at a right angle to be connected to at least one upper corner of the battery case 100, and includes a terminal body 310 and an extension terminal 320.

[0037] The terminal body 310 refers to a body of the terminal structure 300 that is coupled to the top surface and a side surface continuing from the top surface of the battery case 100 while enclosing the positive terminal 122 or the negative terminal 124 so that they are not exposed to the outside. Although the drawings show an example in which the terminal structure 300 is coupled to both the positive terminal 122 and the negative terminal 124, the terminal structure 300 may be selectively coupled to only one of the positive terminal 122 and the negative terminal 124 depending on the embodiment.

[0038] The extension terminal 320 is electrically connected to the positive terminal 122 or the negative terminal 124, and corresponds to a connection terminal extended to the side of the terminal body 310. That is, since the positive terminal 122 or the negative terminal 124 is enclosed in the terminal body 310 and not exposed, the extension terminal 320 functions as a new positive terminal or negative terminal that has been moved to the side of the battery case 100 rather than to the top surface of the battery case 100.

[0039] In addition, the terminal body 310 is made of an insulating material, for example, an electrically insulating resin or rubber material, so that the positive electrode terminal 122 or the negative electrode terminal 124 covered by the terminal body is in an inactive state, electrically isolated from the outside. That is, in the secondary battery 10 to which the terminal structure 300 is joined, the existing positive electrode terminal 122 or negative electrode terminal 124 no longer functions as a connection terminal, and the extension terminal 320 on the terminal structure 300 functions as a new positive electrode terminal or negative electrode terminal.

[0040] In this manner, the secondary battery 10 of the present invention can freely change the arrangement structure of the electrode terminals 120 without any additional design changes by simply applying the terminal structure 300 to the positions of the positive terminal 122 and the negative terminal 124, which are both disposed on the upper surface of the battery case 100. As a result, the present invention can easily change the positions of the positive terminal 122 and / or the negative terminal 124 by adding the terminal structure 300 to a secondary battery of the same form factor, thereby reducing the production costs of a wide variety of prismatic secondary batteries.

[0041] In one embodiment of the present invention, the positive electrode terminal 122 and / or the negative electrode terminal 124 are electrically connected to the extension terminal 320 via the extension wire 330, and the extension wire 330 connected to the extension terminal 320 forms a joint 340 with the positive electrode terminal 122 and / or the negative electrode terminal 124, and the extension wire 330 and the electrode terminal 120 are mechanically and electrically firmly connected to each other by the joint 340. For example, the joint 340 may be formed by welding.

[0042] The extension wiring 330 is not exposed to the outside of the terminal body 310. For example, the extension wiring 330 may be embedded in the terminal body 310 made of an electrically insulating resin material by a manufacturing technique such as insert molding. The joint 340 is also insulated from the outside. The external insulation of the joint 340 may be achieved by at least one of an insulating cover, an insulating tape, and a hardening insulating layer.

[0043] The curable insulating layer herein refers to an insulating layer that is formed by applying a fluid insulating resin to the joint 340 and then curing it. Figures 1 and 2 show a configuration in which a film-like insulating tape 350 with an adhesive layer 352 insulates the joint 340.

[0044] Basically, the terminal structure 300 is fixed to the positive electrode terminal 122 and the negative electrode terminal 124 by the joint 340 formed by welding, but since the terminal structure 300 fixed by the joint 340 has a large degree of structural freedom, problems may occur in the terminal structure 300 if the secondary battery 10 of the present invention is subjected to continuous vibration. For example, if the secondary battery 10 of the present invention is applied to an electric vehicle and placed in an environment where it is subjected to continuous vibration, problems may occur such as damage to the terminal structure 300 joined to the battery case 100 or weld wear at the joint 340.

[0045] In the secondary battery 10 of the present invention, in order to improve the support structure for the terminal structure 300 , a concave surface 130 is formed on the side surface of the battery case 100 , and the side surface of the terminal structure 300 is placed within the concave surface 130 .

[0046] 1 and 2, the concave surface 130 formed on the side surface of the battery case 100 has a shape corresponding to the side surface of the terminal structure 300. As a result, when the side surface of the terminal structure 300 is placed in the concave surface 130, the corners of the side surface of the terminal structure 300 come into contact with the corners of the step of the concave surface 130 and are supported.

[0047] The additional support structure of the terminal structure 300 due to the concave surface 130 limits the degree of freedom in the front-rear direction of the terminal structure 300 when viewed from the drawing. If the concave surface 130 were not present, the joint 340 would have to bear the swinging motion acting on the terminal structure 300 in all directions, but the restriction of the degree of freedom due to the concave surface 130 reduces the degree of freedom of the terminal structure 300 that the joint 340 must bear. This significantly reduces the possibility of problems such as welding failure occurring in the joint 340, and improves the vibration resistance of the terminal structure 300 attached to the battery case 100.

[0048] 3 and 4 show modified embodiments of the support structure between the concave surface 130 of the battery case 100 and the terminal structure 300. Referring to the drawings, the corners of the side surface of the terminal structure 300 and the corners of the concave surface 130 are bound to each other by a dovetail 400 structure. The dovetail 400 structure refers to a structure in which the trapezoidal corners of two members engage with each other and are tightly bound so as not to come loose in a specific direction.

[0049] 3 and 4, the concave surface 130 on the side of the battery case 100 forms an inclined surface with a larger width at the bottom side on a vertical cross section of the concave surface 130, and correspondingly, the side of the terminal structure 300 forms a complementary shape (a shape of a surface inclined in the opposite direction to the inclination direction of the concave surface). As a result, the side of the terminal structure 300 is slidably coupled to the concave surface 130 along the height direction of the battery case 100, and the two are bound to each other.

[0050] When the corners of the side surface of the terminal structure 300 and the corners of the concave surface 130 are bound to each other by the dovetail 400 structure, the degree of freedom of the terminal structure 300 is further restricted. That is, the degree of freedom of the terminal structure 300 is restricted to only one direction, the height direction, relative to the battery case 100. This further reduces the load that the joint portion 340 must bear, and the support structure of the terminal structure 300 is further improved.

[0051] Second embodiment 5 is a diagram showing a secondary battery 10 according to a second embodiment of the present invention, and as can be seen from the diagram, a concave beading processed portion 140 is formed on each of the opposing front and rear surfaces of a battery case 100. In addition, corresponding to the beading processed portions 140 formed on the front and rear surfaces of the battery case 100, protrusions 312 to be inserted into the beading processed portions 140 are provided on the upper corners of the terminal structure 300.

[0052] According to the second embodiment, the corners of the side surface of the terminal structure 300 come into contact with the corners of the steps of the concave surface 130, and at the same time, the protrusions 312 at the corners of the upper surface of the terminal structure 300 are inserted into the beading processing portion 140. This allows the terminal structure 300 to be doubly supported by the battery case 100.

[0053] Compared with the dovetail 400 structure of the first embodiment described above, there is a common point in that the degree of freedom of the terminal structure 300 is limited in two directions, but the difference is that the direction in which the degree of freedom of the terminal structure 300 is limited is different from that of the dovetail 400 structure. That is, in the second embodiment, as shown in FIG. 6, the protrusion 312 of the terminal structure 300 is slidably coupled to the beading processing portion 140 along the width direction of the battery case 100 and bound to each other. As a result, the degree of freedom of the terminal structure 300 to move along the height direction of the battery case 100 is limited by the coupling of the beading processing portion 140 and the protrusion 312. As a result, the load that the joint portion 340 must bear is further reduced in the second embodiment, and thus the support structure of the terminal structure 300 is made stronger, similarly.

[0054] Here, the beading processing portion 140 formed on each of the front and rear surfaces of the battery case 100 not only serves to support the terminal structure 300, but also functions as a means for pressing the surface of the electrode assembly 200 housed inside the battery case 100, as shown in FIG. 7.

[0055] The beading processing portion 140 forms a thin linear concave surface, and the beading processing portion 140, which is concave toward the inside of the battery case 100, has a depth that presses against the surface of the electrode assembly 200 housed inside the battery case 100.

[0056] Because the beading processed portion 140 has a thin line shape, even if a concave surface is formed on the inside of the battery case 100, the effect on the capacity of the prismatic secondary battery 10 is very small. In other words, the beading processed portion 140 has a very limited effect on the capacity or size of the essential components of the prismatic secondary battery 10 housed inside the battery case 100, such as the electrode assembly 200 and the electrolyte.

[0057] 7, the beading processed parts 140 formed along the front and rear edges of the battery case 100 press against the surface of the electrode assembly 200 from both sides. That is, the electrode assembly 200 having a gap with respect to the battery case 100 is pressed against the surface of the electrode assembly 200 from both sides by a pair of opposing beading processed parts 140 to be fixed, thereby improving the support structure of the electrode assembly 200 and suppressing the slip phenomenon in which the electrode assembly 200 moves during use.

[0058] As a result, the fluidity of the electrode assembly 200 is restricted by the beading processing portion 140, thereby preventing various problems such as short circuits due to electrical contact induced by the slip phenomenon and broken tabs, thereby significantly improving the safety of the prismatic secondary battery 10.

[0059] The beading processing part 140 may press the surface of the negative electrode 210 of the electrode assembly 200 housed inside the battery case 100. In the electrode assembly 200, the negative electrode 210 is formed to be larger than the positive electrode 214, and the surface of the negative electrode 210 covers the surface of the positive electrode 214. That is, the surface of the negative electrode 210 covers the surface of the positive electrode 214, and the positive electrode 214 is not exposed.

[0060] In the electrode assembly 200, forming the negative electrode 210 larger than the positive electrode 214 is advantageous in terms of safety. This is in consideration of the N / P ratio, which is the capacity ratio of the negative electrode 210 to the positive electrode 214. In a lithium ion secondary battery using a graphite negative electrode 210, if the capacity of the negative electrode 210 is not larger than that of the positive electrode 214, lithium deposition in the negative electrode 210 during overcharge cannot be prevented.

[0061] In this regard, it is preferable to maintain the N / P ratio at a level of about 1.12 in consideration of the safety of the secondary battery 10. As a result, the electrode assembly 200 may be formed such that the anode 210 is larger than the cathode 214. Another reason is that the anode active material has higher structural stability than the cathode active material, so it is preferable that the surface directly pressed by the beading processed portion 140 with the separator 212 in between is the anode 210.

[0062] 8 is a diagram showing the front side of the prismatic secondary battery 10, and the electrode assembly 200 housed inside the battery case 100 is shown by hidden lines. The beading processed portion 140 presses against the surface of the negative electrode 210, and here, the beading processed portion 140 is formed at a position spaced apart from the electrode tabs 220 (negative electrode tab 222, positive electrode tab 224) of the electrode assembly 200.

[0063] When the beading processing part 140 presses the surface of the negative electrode 210 of the electrode assembly 200, it may support a coated part to which a negative electrode active material is applied or a plain part to which a negative electrode active material is not applied. If the beading processing part 140 presses the negative electrode plain part, it is preferable to support a lower region at a certain distance from the negative electrode tab 222 formed by notching the negative electrode plain part. That is, if the beading processing part 140 directly presses the electrode tab 220, especially the negative electrode tab 222, and creates stress on the electrode tab 220, it may damage the electrode tab 220. In addition, the beading processing part 140 may be formed adjacent to the cap plate 110 forming the upper surface of the battery case 100 so as to press the upper part of the electrode assembly 200 housed inside the battery case 100.

[0064] And, since the beading processing part 140 is formed on the front and rear surfaces, which have the longest widthwise length among the front, rear, left and right edges of the battery case 100, the beading processing part 140 can firmly support the electrode assembly 200 through a sufficient length. Also, since the protrusions 312 of the terminal structure 300 are inserted into the beading processing part 140, the support structure of the terminal structure 300 is also improved, so that the second embodiment of the present invention significantly improves the structural stability of the prismatic secondary battery 10 by the beading processing part 140.

[0065] The present invention has been described in detail above with reference to the drawings and embodiments, etc. However, the configurations described in the drawings or embodiments, etc. in this specification are merely one embodiment of the present invention and do not represent all of the technical ideas of the present invention, and therefore there may be various equivalents and modifications that can replace them at the time of filing this application. [Explanation of symbols]

[0066] 10: Secondary battery 100: Battery case 110: Cap plate 120: Electrode terminal 122: Positive terminal 124: Negative terminal 130: Concave 140: Beading processing section 200: Electrode assembly 210: Negative electrode 212: Separation membrane 214: Positive electrode 220: Electrode tab 222: Negative electrode tab 224: Positive electrode tab 300:Terminal structure 310: Terminal body 312: Protrusion 320: Extension terminal 330: Extension wiring 340: Joint 350: Insulating tape 352: Adhesive layer 400: Dovetail

Claims

1. a secondary battery having a positive electrode terminal and a negative electrode terminal spaced apart from each other on an upper surface of a hexahedral battery case; a terminal body having a bent shape and coupled to an upper surface of the battery case and a side surface continuing from the upper surface while enclosing the positive electrode terminal or the negative electrode terminal so as not to be exposed; and an extension terminal electrically connected to the positive electrode terminal or the negative electrode terminal and exposed to a side surface of the terminal body, A secondary battery, wherein a side surface of the terminal structure is placed within a concave surface formed in a side surface of the battery case.

2. The secondary battery according to claim 1 , wherein the terminal body is made of an insulating material, whereby the positive terminal or the negative terminal is electrically isolated from the outside.

3. The concave surface is formed in a shape corresponding to a side surface of the terminal structure, The secondary battery according to claim 1 , wherein a corner of the side surface of the terminal structure is supported by being in contact with a corner of a step of the concave surface.

4. The secondary battery according to claim 3 , wherein the corners of the side surfaces of the terminal structure and the corners of the concave surface are joined together by a dovetail structure.

5. The secondary battery according to claim 4 , wherein the side surfaces of the terminal structures are slidably coupled to the concave surfaces to be bound to each other.

6. The battery case has a front surface and a rear surface facing each other, each of which is formed with a concave beading portion; The secondary battery according to claim 1 , wherein the terminal structure has a protrusion at an upper corner thereof, the protrusion being inserted into the beading portion.

7. When the corner of the side surface of the terminal structure contacts the corner of the step of the concave surface, the protrusion of the terminal structure is inserted into the beading processing portion, The secondary battery according to claim 6 , wherein the terminal structure is thereby supported relative to the battery case.

8. The secondary battery according to claim 7 , wherein the protrusions of the terminal structure are slidably coupled to the beading portions to bind them together.

9. The beading processing section includes: The secondary battery according to claim 6 , wherein the electrode assembly is pressed against a surface of the electrode assembly housed inside the battery case.

10. The beading processing section includes: The secondary battery of claim 9 , wherein the electrode tab is formed at a position spaced apart from the electrode tab of the electrode assembly housed inside the battery case.

11. The beading processing section includes: The secondary battery of claim 10 , further comprising a cap plate formed adjacent to the electrode assembly housed inside the battery case to press against an upper portion of the electrode assembly.

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