Battery and method for manufacturing battery

Abstract

The battery includes an electrode assembly including a plurality of electrodes, and an exterior material that houses the electrode assembly and has a concave-convex pattern including at least one recess and at least one protrusion, and the protrusion has a recessed portion formed in which a portion of the protrusion is recessed.

Description

[Technical Field]

[0001] The present invention relates to a battery that can be charged and discharged and can be used as a power source for mobile or flexible devices, etc. [Background technology]

[0002] A battery, or electrochemical cell, refers to an assembly that is composed of at least two electrodes and an electrolyte and can provide electrical energy. In particular, secondary batteries that can be charged and discharged are widely used in various advanced electronic devices, including smartphones.

[0003] Recently, various attempts to break away from conventional designs have been made in the design of mobile devices such as smartphones and various wearable devices, and attention has been focused on flexible devices that can be bent while maintaining functionality. Therefore, the realization of technology that can ensure the reliability and safety of the performance of flexible batteries that can be incorporated into such flexible devices and used as a power source has emerged as an issue.

[0004] In this regard, Patent Document 1 (Korean Patent Publication No. 10-2022-0015290), which is a conventional technique, discloses a technique for forming a pattern on an exterior material. However, Patent Document 1 discloses a configuration in which at least one pattern portion is formed on an exterior material in the transverse direction (TD) of the exterior material. However, when the battery is repeatedly bent with a large curvature, such a pattern changes the gap between the electrode layers stacked in the exterior material, and when a large gap is formed, this causes a problem of reduced reliability and safety of the battery.

[0005] The problem of large gaps between electrode layers in batteries fabricated by conventional techniques will now be briefly described.

[0006] Inside the exterior of a battery manufactured using conventional technology, the positive and negative electrodes are aligned in a straight line, closely packed and stacked at a constant distance, resulting in a regular layer gap between the electrodes. Between each electrode, an insulating material is included that allows lithium ions to move and prevents short circuits that can occur due to direct contact between the positive and negative electrodes.

[0007] However, in conventional batteries that have been repeatedly bent, when the battery is bent, the outermost electrode slides inward due to the curvature, and when the battery is unfolded again, the outermost electrode cannot return to its original position, resulting in deformation.This can cause the electrodes in some sections to lift up out of the regular electrode layer gap, resulting in irregular gaps.

[0008] Specifically, when a battery is deformed from a first flat state to a second bent state and then restored to a third flat state, electrodes (e.g., outermost electrodes) that are excessively deformed into bent or irregularly wavy shapes have difficulty restoring to a flat state. In particular, in a structure in which one electrode is fixed and the other is not, the outermost electrodes are relatively more susceptible to deformation than the other electrodes, and there is a problem in that the electrodes tend to lift or bend toward the pouch during the battery restoration process, resulting in irregular gaps. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Korean Patent Publication No. 10-2022-0015290 Summary of the Invention [Problem to be solved by the invention]

[0010] One object of the present invention is to provide a battery including an electrode assembly including a plurality of electrodes, and an exterior material that houses the electrode assembly and has a concave-convex pattern that includes at least one recess and at least one protrusion.

[0011] Another object of the present invention is to provide a flexible battery that can suppress irregular electrode layer gaps that may occur due to bending of the battery by forming recesses in which some areas of the protrusions are recessed.

[0012] However, the technical problems that the present embodiment aims to solve are not limited to the above-mentioned technical problems, and other technical problems may also exist. [Means for solving the problem]

[0013] As a means for achieving the above-mentioned technical object, one embodiment of the present invention can provide a battery including an electrode assembly including a plurality of electrodes, and an exterior material that houses the electrode assembly and has a concave-convex pattern that includes at least one concave portion and at least one convex portion, wherein the convex portion has a concave portion formed therein where a portion of the convex portion is sunken.

[0014] According to an embodiment, each of the at least one protrusion may have at least two recesses formed in one direction corresponding to the width of the battery.

[0015] According to one embodiment, the distance between at least two recesses formed in a first protrusion among the at least one protrusion and the distance between at least two recesses formed in a second protrusion located next to the first protrusion may be designed to be the same.

[0016] According to an embodiment, the recessed portion may be formed to have a first distance from an edge region of the exterior material.

[0017] According to one embodiment, the distance between at least two recesses formed in a first protrusion among the at least one protrusion and the distance between at least two recesses formed in a second protrusion located next to the first protrusion may be designed to be different.

[0018] According to an embodiment, the recess formed in the first protrusion may be formed to have a second distance from an edge region of the exterior material.

[0019] According to an embodiment, the recess formed in the second protrusion may be formed to have a third distance from an edge region of the exterior material.

[0020] According to an embodiment, the outer casing may include a receiving portion that receives the electrode assembly, and a sealing portion that seals the electrode assembly by joining sealing surfaces along corners of the receiving portion.

[0021] According to one embodiment, the at least one recess and the at least one protrusion may have an edge region at an end in one direction corresponding to the width of the battery, the edge region forming a boundary line that abuts the sealing portion.

[0022] According to one embodiment, the sealing portion may have a pattern having a height lower than the uneven pattern in a thickness direction of the exterior material.

[0023] According to an embodiment, a reinforcing structure for maintaining the shape of the depression of the exterior material may be formed in the depression.

[0024] Another embodiment of the present invention may provide a method for manufacturing a battery, including the steps of forming at least one convex portion in one direction in an outer casing material, forming at least one concave portion at a position adjacent to the convex portion, forming a recessed portion in the at least one convex portion, inserting an electrode assembly into the outer casing material in which the recessed portion is formed, and sealing the outer casing material with the electrode assembly inserted.

[0025] According to another embodiment, the method further includes a step of pressing the exterior material having the protrusion formed thereon, and the step of forming the depression may form a depression in the protrusion of the pressed exterior material.

[0026] According to another embodiment, the step of forming the recessed portion may be performed before or after the step of pressing the outer covering material on which the protrusions are formed.

[0027] According to another embodiment, when the recess is formed after pressing the outer covering material on which the protrusion is formed, the method may further include a step of performing additional pressing on the outer covering material. [Effects of the Invention]

[0028] According to the present invention, a battery includes an electrode assembly including a plurality of electrodes, and an exterior material that houses the electrode assembly and has a concave-convex pattern including at least one concave portion and at least one convex portion formed thereon. Since a portion of the convex portion is recessed to form a concave portion, it is possible to prevent the occurrence of irregular electrode layer gaps and large gaps when the battery is bent.

[0029] In addition, a reinforcing structure may be formed in the depression where a portion of the protrusion is depressed to maintain the shape of the depression. This can reduce cracks in the exterior material when the battery is bent or deformed due to the resistance provided by the strength and support of the reinforcing structure. [Brief explanation of the drawings]

[0030] [Figure 1] 1 is an exemplary view showing a battery according to a first embodiment of the present invention. [Figure 2] 2 is an enlarged view of an area A of the battery in FIG. 1. FIG. [Figure 3] FIG. 4 is an exemplary view showing a battery according to a second embodiment of the present invention. [Figure 4] 4 is an enlarged view of an area B of the battery in FIG. 3. FIG. [Figure 5] 10A and 10B are diagrams illustrating comparative evaluations of a flexible battery having only a concave-convex pattern according to an embodiment of the present invention and a flexible battery having a concave-convex pattern and recesses; [Figure 6a] 1 is an exemplary view showing a reinforcing structure for an exterior material formed in a recess in accordance with the present invention; [Figure 6b] 1 is an exemplary view showing a reinforcing structure for an exterior material formed in a recess in accordance with the present invention; [Figure 6c] 1 is an exemplary view showing a reinforcing structure for an exterior material formed in a recess in accordance with the present invention; [Figure 6d] 1 is an exemplary view showing a reinforcing structure for an exterior material formed in a recess in accordance with the present invention; [Figure 6e] 1 is an exemplary view showing a reinforcing structure for an exterior material formed in a recess in accordance with the present invention; [Figure 6f] 1 is an exemplary view showing a reinforcing structure for an exterior material formed in a recess in accordance with the present invention; [Figure 7] FIG. 1 is a flow chart of a method for manufacturing a battery according to the present invention. [Figure 8a] 3A to 3C are exemplary views showing the depth of a pattern formed in each manufacturing step of a packaging material in accordance with the present invention; [Figure 8b] 3A to 3C are exemplary views showing the depth of a pattern formed in each manufacturing step of a packaging material in accordance with the present invention; [Figure 8c] 3A to 3C are exemplary views showing the depth of a pattern formed in each manufacturing step of a packaging material in accordance with the present invention; [Figure 8d] 3A to 3C are exemplary views showing the depth of a pattern formed in each manufacturing step of a packaging material in accordance with the present invention; [Figure 8e] 3A to 3C are exemplary views showing the depth of a pattern formed in each manufacturing step of a packaging material in accordance with the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0031] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] The present invention will now be described in detail with reference to the accompanying drawings so that those skilled in the art can easily understand and practice the present invention. However, the present invention may be embodied in various different forms and is not limited to the embodiments described herein. In the drawings, parts that are not relevant to the description are omitted in order to clearly explain the present invention, and similar parts are designated by similar reference numerals throughout the specification.

[0032] Throughout this specification, when a part is said to "include" a certain component, this does not mean that it excludes other components, but that it may further include other components, unless otherwise specified. Furthermore, throughout this specification, when a part is said to be "connected" to another part, this includes not only direct connection, but also connection with another component sandwiched between them, and electrical connection with another element sandwiched between them. Furthermore, throughout this specification, when a component is said to be "located on" another component, this includes not only contact with the other component, but also the presence of another component between the two components.

[0033] The battery, i.e., electrochemical cell, according to the present invention may be a lithium-ion battery. Specifically, the electrochemical cell according to the present invention may be configured such that an electrode assembly is housed together with an electrolyte solution inside an exterior material and sealed, and is charged and discharged by the movement of lithium ions. The electrochemical cell according to the present invention may be configured to be flexible and bendable while maintaining its functionality. Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0034] Fig. 1 is an exemplary view showing a battery according to a first embodiment of the present invention, and Fig. 2 is an exemplary view showing an enlarged region A of the battery in Fig. 1. According to the first embodiment, the battery 10 is designed such that, among at least one protrusion, the distance between at least two recesses formed in a first protrusion is the same as the distance between at least two recesses formed in a second protrusion.

[0035] 1, a battery 10 according to a first embodiment of the present invention may include an exterior material 100, an electrode assembly, and an electrode lead 102. The electrode assembly includes a plurality of electrodes, and may further include an active material and a separator, and may be formed in a structure in which these are stacked in the thickness direction.

[0036] The electrodes may include first and second electrode plates of different polarities, and active materials may be applied to both sides or cross sections of the first and second electrode plates. A separator may be interposed between the first and second electrode plates. For example, in the first electrode plate, the current collector used as the negative electrode may be copper, aluminum, stainless steel, or the like, and the negative electrode active material may be carbon, lithium, silicon, SiO. xThe second electrode plate may be made of any one or a combination of silicon derivatives such as silicon-graphite composites, prisms, and silicon-prism composites. In addition, the current collector used as the positive electrode of the second electrode plate may be made of aluminum, stainless steel, or the like, and the positive electrode active material may be any one or a combination of lithium cobalt oxide, lithium nickel oxide, lithium manganese oxide, lithium cobalt-manganese oxide, lithium cobalt-nickel oxide, lithium manganese-nickel oxide, lithium cobalt-nickel-manganese oxide, lithium cobalt-nickel-aluminum oxide, and lithium iron phosphate. The electrode assembly may have a thickness in a thickness direction, in which the active material and separator are stacked, that intersects (e.g., perpendicular to) the direction in which the first and second electrode plates form a surface, and the length direction is longer than the width direction.

[0037] The electrode assembly may include electrode connection tabs and lead connection tabs. The electrode connection tabs may be formed to protrude from one longitudinal end of the first and second electrode plates, and electrode connection tabs protruding from electrodes of the same polarity may be connected to each other. The electrode connection tabs may electrically connect the electrodes in parallel. The lead connection tabs may be connected to the electrode leads 102, protrude from the positive and negative electrode plates, and be connected to the electrode leads 102.

[0038] The exterior material 100 according to the first embodiment of the present invention is formed to accommodate an electrode assembly. The exterior material 100 may be formed of a laminated film including, for example, PP (polypropylene), metal, and nylon layers. In addition to nylon, other combinations of materials such as PET (polyethylene terephthalate), PVC (polyvinyl chloride), PC (polycarbonate), PE (polyethylene), and PI (polyimide) are also possible.

[0039] More specifically, the exterior packaging material 100 of the first embodiment is formed with a concave-convex pattern 120 including at least one concave portion 122 and at least one convex portion 121. The at least one concave portion 122 and the at least one convex portion 121 are provided with an edge region 130 that forms a boundary line that abuts against the sealing portion 140 at an end in one direction corresponding to the width of the battery.

[0040] The edge region 130 may include a boundary line between the uneven pattern 120 and the sealing portion 140. That is, as shown in Fig. 1, the edge region 130 may include two points of each uneven pattern 120 that touch the sealing portion 140 and a boundary line extending along the two points. The boundary line of the edge region 130 may extend in a substantially straight line along the flat sealing portion 140, and may be connected to the boundary line of the edge region 130 of the adjacent uneven pattern 120 and extended into a single line.

[0041] For example, the uneven pattern 120 may be a pattern that extends in one direction and is repeatedly arranged in a direction intersecting the one direction, and more specifically, may be alternately protruded or recessed in the thickness direction (i.e., alternately protruded in opposite directions) to have an uneven shape along one direction. Here, the one direction may be the width direction described above, and the direction in which the uneven pattern 120 is repeated may be the longitudinal direction. Due to the protruding and recessed uneven pattern 120, the exterior material 100 that forms the receiving portion 110 may form a wave or wrinkle pattern in the longitudinal direction.

[0042] The concave-convex pattern 120 will be described in more detail below with reference to FIG.

[0043] The protrusion 121 has a depression 123 formed by depressing a portion of the protrusion 121. For example, the protrusion 121 may have a depression 123 formed in a dot shape in the center region of the protrusion 121. Here, at least two depressions 123 are formed in one direction corresponding to the width of the battery in each of at least one protrusion 121.

[0044] In this case, the central region of the protrusion 121 may be a region set based on the center point of the major axis (longitudinal axis) and the shortening axis (widthwise axis) of the protrusion 121.

[0045] For example, when the central region is set based on the long axis of the convex portion 121, which has a length L in the longitudinal direction, and the center point based on the shortening of the convex portion 121, which has a width W in the width direction, the central region may refer to a region including positions spaced apart by 0.01L to 0.45L, 0.05L to 0.4L, and 0.1L to 0.3L in the longitudinal direction from the center point, and positions spaced apart by 0.01W to 0.45W, 0.05W to 0.4W, and 0.1W to 0.3W in the width direction from the center point, but the present invention is not limited thereto.

[0046] It is needless to say that the depression 123 may have not only the dot shape but also any one or more shapes selected from a prism, a cylinder, and modified shapes thereof.

[0047] For example, the shape of the depression 123 may include a tapered structure in which the area of ​​the bottom of the depression 123 is narrower than that of the top of the depression 123 in the thickness direction of the protrusion 121. In other words, the shape may include a shape in which the cross-sectional area narrows from the surface of the protrusion 121 in the thickness direction.

[0048] The shape of the recess 123 includes a tapered structure, which is advantageous in that it can prevent irregular electrode layer gaps and large gaps from occurring when the battery is bent.

[0049] For example, the size of the outer diameter of the depression 123 can be freely adjusted within the range of the width of the protrusion 121 based on the width of the protrusion 121.

[0050] For example, when the width of the protrusion 121 is W, the outer diameter of the depression 123 may be, but is not limited to, 0.1W to 0.9W, 0.2W to 0.9W, 0.3W to 0.9W, 0.3W to 0.85W, or 0.3W to 0.8W. Here, the outer diameter refers to the largest diameter of the depression 123 formed at the top end of the protrusion 121.

[0051] Furthermore, the depth of the depression 123 can be freely adjusted within the height range based on the height of the protrusion 121 .

[0052] For example, when the height of the convex portion 121 is H, the depth of the concave portion 123 can be, but is not limited to, 0.05H to 0.9H, 0.1H to 0.9H, 0.1H to 0.8H, 0.2H to 0.8H, 0.3H to 0.8H, 0.4H to 0.8H, or 0.5H to 0.8H.

[0053] However, as mentioned above, in order to effectively prevent the occurrence of irregular electrode layer gaps and large gaps when bending the battery, it may be advantageous to satisfy the size of the outer diameter of the recessed portion 123 and the size of the shape of the recessed portion 123 based on the depth of the recessed portion 123 within the above-mentioned range.

[0054] For example, the widths of the convex portion 121 and the concave portion 122 may be the same or different, and regardless of the widths of the convex portion 121 and the concave portion 122, the same effect can be achieved by forming the concave portion 123 in which a portion of the convex portion 121 is depressed, as described above.

[0055] As shown in FIG. 2, for example, among at least one protrusion 121, the distance 150 between at least two depressions 123a formed in a first protrusion 121a and the distance 150 between at least two depressions 123b formed in a second protrusion 121b located next to the first protrusion 121a are designed to be the same.

[0056] Here, the depression 123 formed in the first protrusion 121a is formed to have first distances 135a, 135b from the edge region 130. To this end, the at least two depressions 123a, 123b may be formed at points that are 0.1K to 0.4K, preferably 0.15K to 0.35K, more preferably 0.2K to 0.35K, and even more preferably 0.25K (¼K) away from each of the edge regions 130 located at both ends of the exterior packaging 100, based on the separation distance K between the edge regions 130 at both ends.

[0057] For example, one of the at least two recesses 123a formed in the first protrusion 121a may be formed to have a first distance 135a from an edge region 130a located at one end of the exterior packaging material 100, and the other of the at least two recesses 123a formed in the first protrusion 121a may be formed to have a first distance 135b from an edge region 130b located at the other end of the exterior packaging material 100. This design is intended to prevent the internal electrodes from being deformed by floating in the space between the uneven pattern of the exterior packaging material 100 and the electrode assembly, or to prevent the electrodes from breaking, when the battery 10 is deformed. For example, the first distances 135a and 135b refer to the case where the distances between the recesses located in the protrusions and adjacent protrusions are the same, and specifically may refer to points spaced from any one edge region by ¼ of the length between the edge regions at both ends.

[0058] Specifically, the depression 123 formed in the first protrusion 121a is formed to have a first gap 135a, 135b with the edge region 130. Therefore, according to the bending evaluation results of the battery 10, if the distance between the positive and negative electrodes, i.e., the electrode layers, inside the exterior material 100 is 0.02 mm before bending the battery 10, the distance between the electrode layers of 0.02 mm is maintained both when the battery 10 is bent 100 times and when it is bent 3,000 times. This prevents a decrease in battery performance and a decrease in durability of the exterior material 100 due to the occurrence of irregular electrode layer gaps and large gaps, and also prevents lithium plating, which occurs due to larger gaps between the electrode layers, thereby eliminating safety risks.

[0059] FIG. 3 is an exemplary view showing a battery according to a second embodiment of the present invention, and FIG. 4 is an exemplary view showing an enlarged region B of the battery in FIG.

[0060] In the second embodiment, the battery 20 is designed such that, among at least one protrusion, the spacing between at least two recesses formed in a first protrusion is different from the spacing between at least two recesses formed in a second protrusion.

[0061] 3, a battery 20 according to the second embodiment of the present invention may include a housing 200, an electrode assembly, and an electrode lead 202. The electrode assembly includes a plurality of electrodes, and may further include an active material and a separator, and may be formed in a structure in which these are stacked in the thickness direction.

[0062] The electrode assembly may include electrode connection tabs and lead connection tabs. The electrode connection tabs may be formed to protrude from one longitudinal end of the first and second electrode plates, and electrode connection tabs protruding from electrodes of the same polarity may be connected to each other. The electrodes may be electrically connected in parallel by the electrode connection tabs. The lead connection tabs may be connected to the electrode leads 202, protrude from the positive and negative electrode plates, and be connected to the electrode leads 202.

[0063] An outer casing 200 according to the second embodiment of the present invention is formed to house an electrode assembly.

[0064] Specifically, the outer casing 200 includes a receiving portion 210 and a sealing portion 240. The receiving portion 210 forms a space for receiving the electrode assembly, and the sealing portion 240 may be joined to seal the received electrode assembly from the outside. For example, the receiving portion 210 may correspond to regions of two outer casings 200 that are spaced apart and face each other. To form the receiving portion 210, the outer casing 200 may be pressed and protruded in the thickness direction so that a predetermined region of the outer casing 200 has a roughly rectangular vessel (or cup) shape.

[0065] More specifically, the exterior packaging material 200 of the second embodiment is formed with a concave-convex pattern 220 including at least one concave portion 222 and at least one convex portion 221. The at least one concave portion 222 and the at least one convex portion 221 are provided with an edge region 230 that forms a boundary line that abuts against the sealing portion 240 at an end in one direction corresponding to the width of the battery.

[0066] For example, the uneven pattern 220 may be a pattern that extends in one direction and is repeatedly arranged in a direction intersecting the one direction, and specifically, may be alternately protruded or recessed in the thickness direction (i.e., alternately protruded in opposite directions) to have an uneven shape along one direction. Here, the one direction may be the width direction described above, and the direction in which the uneven pattern 120 is repeated may be the longitudinal direction. Due to the protruding and recessed uneven pattern 120, the exterior material 100 forming the receiving portion 110 may form a wave or wrinkle pattern in the longitudinal direction.

[0067] The concave-convex pattern 220 will be described below with reference to FIG.

[0068] The protrusion 221 has a depression 223 formed by depressing a portion of the protrusion 221. The shape of the depression 223 and its size are as described above, and a detailed description thereof will be omitted.

[0069] For example, if a dot-shaped recess 223 is formed in the central region of a protrusion 221, another protrusion 221 may have a dot-shaped recess 223 formed in the outer region. Here, at least two recesses 223 are formed in one direction corresponding to the width of the battery in each of at least one protrusion 221. For example, the widths of the protrusion 221 and the recess 222 may be the same or different, and the same effect can be achieved regardless of the width.

[0070] As shown in FIG. 4, for example, among at least one protrusion 221, the spacing 250 between at least two depressions 223a formed in a first protrusion 221a and the spacing 251 between at least two depressions 223b formed in a second protrusion 221b located next to the first protrusion 221a are designed to be different.

[0071] Here, the depression 223a formed in the first protrusion 221a is formed to have a second gap 250a with the edge region 230a, and the depression 223b formed in the second protrusion 221b is formed to have a third gap 250b with the edge region 230b.

[0072] For this purpose, the at least two depressions 223a formed in the first protrusion 221a may be formed at points 0.1K to 0.25K, preferably 0.15K to 0.25K, and more preferably 0.2K (1 / 5K) away from each of the edge regions 230a located at both ends of the exterior material 100, based on the separation distance K between the edge regions 230a at both ends.

[0073] In addition, the at least two depressions 223b formed in the second protrusion 221b may be formed at points 0.25K' to 0.4K', preferably 0.25K' to 0.35K', and more preferably 0.33K' (1 / 3K') away from each of the edge regions 230b located at both ends of the exterior material 100, based on the separation distance K' between the edge regions 230b at both ends.

[0074] Specifically, the at least two recesses 223a formed in the first protrusion 221a are formed at points 1 / 5 of the length K between the edge regions 230a at both ends of the exterior packaging material 100, respectively, so that the at least two recesses 223a have a second gap 250a, and the at least two recesses 223b formed in the second protrusion 221b are formed at points 1 / 3 of the length K' between the edge regions 230b at both ends of the exterior packaging material 100, respectively, so that the at least two recesses 223b have a third gap 250b. In this case, if the recesses are formed so as to deviate from points 1 / 5 of the length between the edge regions at both ends from the edge regions, the recesses may not be able to prevent the internal electrodes from lifting up in the cell width direction (large gap).

[0075] Furthermore, if the depressions are formed so that they extend away from the edge region at a point 1 / 3 of the length between the edge regions at both ends, and two depressions are concentrated in the center of the exterior material (i.e., if the distance between the depressions is the same as or smaller than the outer diameter of the depressions), interference will occur between the depressions, which will deform the shape of the exterior material and will not be effective in preventing the large gap between the electrodes.

[0076] For example, of the at least two depressions 223a formed in the first protrusion 221a, one depression is formed to have a second gap 250a with the edge region 230a located at one end of the exterior packaging material 100, and the at least two depressions 223b formed in the second protrusion 221b are formed to have a third gap 250b with the edge region 230b located at one end of the exterior packaging material 100.

[0077] In the same manner, one of the at least two depressions 223b formed in the first protrusion 221a may be formed to have a second distance from the edge region (not shown) located at the other end of the outer casing 100, and one of the at least two depressions 223b formed in the second protrusion 221b may be formed to have a third distance from the edge region (not shown) located at the other end of the outer casing 100.

[0078] This design is intended to prevent the internal electrodes from being deformed when the battery 10 is deformed by the at least two recesses, which support the internal electrodes so that they do not rise into the empty space between the uneven pattern of the exterior material 100 and the electrode assembly, causing deformation or even bending of the electrodes.

[0079] Specifically, at least two recesses 223a formed in first protrusion 221a are formed to have a second gap 250a from edge region 230, and at least two recesses 223b formed in second protrusion 221b are formed to have a third gap 250b from edge region 230. As a result, according to the bending evaluation results of battery 20, when the distance between the positive and negative electrodes, i.e., the electrode layers, inside packaging material 200 before bending battery 20 is 0.02 mm, the distance between the electrode layers of 0.02 mm is maintained both when battery 20 is bent 100 times and when battery 20 is bent 3,000 times. This prevents a decrease in battery performance and a decrease in durability of packaging material 100 due to the occurrence of irregular electrode layer gaps and large gaps, and also prevents lithium plating, which occurs due to larger gaps between the electrode layers, thereby eliminating safety hazards.

[0080] The outer packaging material 100 of the first embodiment and the outer packaging material 200 of the second embodiment include the receiving portions 110, 210 and the sealing portions 140, 240.

[0081] The receiving portions 110, 210 form a space for receiving the electrode assembly, and the sealing portions 140, 240 may be joined to seal the received electrode assembly from the outside. In order to form the receiving portions 110, 210 into the exterior materials, the exterior materials 100, 200 may be processed by applying pressure to the sealing portions 140, 240 in the thickness direction so that the predetermined area of ​​the exterior materials 100, 200 has a roughly rectangular vessel (or cup) shape.

[0082] The sealing portions 140 and 240 seal the electrode assembly by joining sealing surfaces along the corners of the receiving portions 110 and 210. For example, the sealing surface refers to the surface of the exterior materials 100 and 200, and two overlapping sealing surfaces along the corners of the receiving portions 110 and 210 are joined together to isolate the internal space (the receiving portions 110 and 210) from the outside. Here, the internal space can accommodate the electrode assembly and electrolyte, and the electrode assembly and electrolyte can be kept sealed.

[0083] Additionally, the sealing portions 140, 240 may have a flat plate shape extending in the width direction or the length direction. For example, the flat plate shape of the sealing portions 140, 240 may be a shape that is not curved so that the surfaces face each other. Alternatively, the sealing portions 140, 240 may have a pattern that is different from the uneven patterns 120, 220. For example, the sealing portions 140, 240 may have a pattern that is lower in height than the uneven patterns 120, 220 in the thickness direction of the exterior packaging materials 100, 200.

[0084] In the exterior packaging 100, 200 according to an embodiment of the present invention, the concave-convex patterns 120, 220 of the receiving portion 110, 210 are formed in close contact with the sealing portion 140, 240. As a result, a space between the concave-convex patterns 120, 220 and the sealing portion 140, 240, where stress can be concentrated, is not formed in this embodiment. By eliminating structurally weak parts, the possibility of damage to the edge of the concave-convex pattern in one direction or the sealing portion 140, 240 in an environment where repeated bending is applied is significantly reduced. Therefore, the batteries 10, 20 and the exterior packaging 100, 200 corresponding to the electrochemical cell according to the present invention can have improved durability without further reinforcement or addition of materials, and can have improved safety by reducing the possibility of breakage and leakage.

[0085] Meanwhile, the electrode leads 102, 202 are connected to the electrode assembly inside the exterior coverings 100, 200 and extend to be exposed to the outside of the exterior coverings 100, 200. The electrode leads 102, 202 function as terminals for electrical connection with the electrode assembly housed inside the exterior coverings 100, 200, and may be joined to penetrate the sealing portions 140, 240 while being interposed between the sealing surfaces when the sealing portions 140, 240 are formed. The pair of positive and negative electrode leads 102, 202 may be connected to lead connection taps provided on the electrode assemblies so that the same poles are connected to each other.

[0086] 5 shows the results of torsion and twist evaluations of a flexible battery fabricated using a comparative example of an outer casing having only a concave-convex pattern and a flexible battery fabricated using an outer casing having a concave-convex pattern and recesses according to an embodiment of the present invention. As shown in FIG. 5, the present invention forms dot-pattern recesses 123, 223 (without a reinforcing structure) on the protrusions 121, 221 of outer casings 100, 200, thereby preventing irregular electrode layer gaps and large gaps that occur when the battery is subjected to deformations such as bending, twisting, and torsion.

[0087] Below, a comparison will be made between a first flexible battery employing a casing material having only a concave-convex pattern including protrusions 121, 221 and recesses 122, 222 according to a conventional comparative example, and a second flexible battery employing a casing material having a concave-convex pattern including protrusions 121, 221 and recesses 122, 222 and recesses 123, 223 formed on the protrusions 121, 221 according to the first and second embodiments of the present invention. For example, an experiment can be performed by applying a torsion deformation of ±15° to the first flexible battery and a twist of ±22.5° and a torsion of ±40° to the second flexible battery based on a predetermined cycle.

[0088] For example, with each flexible battery 100% charged, the initial battery OCV (Open Circuit Voltage) and AC impedance (1,000Hz) values ​​are recorded, and then PI (Polyimide) tape is applied to the terminals of each flexible battery to insulate them, and each flexible battery is then fixed to the clamps of the test equipment.

[0089] The clamps on both ends of the flexible battery can be evaluated for torsion, where one clamp is repeatedly twisted at a fixed angle, and twist, where two clamps are twisted while rotating at positive and negative angles in opposite phases.

[0090] After that, the OCV and AC impedance (1,000Hz) values ​​of the flexible battery will be measured according to the evaluation method, and deformation, cracks, leakage, fire, explosion, etc. of the flexible battery's exterior material will be checked before and after the evaluation.

[0091] Specifically, in the case of the comparative example (first flexible battery), deformation of the external shape of the battery pouch was observed, and furthermore, after the twist evaluation, 14 irregular electrode layer gaps were found inside the first flexible battery.

[0092] However, when the OCV and AC impedance values ​​of the second flexible battery according to the first and second embodiments of the present invention were measured after torsion or twist evaluation (the bit was rotated 3,000 times at a maximum angle of + / - 45°), it was confirmed that the OCV and AC impedance values ​​(1000) did not significantly decrease or increase from their initial values, and the external shape of the battery pouch did not change significantly. Furthermore, when dot-shaped depressions were formed on the convex portions formed in the width direction of the battery to prevent irregular electrode layer gaps (increases in the distance between the positive and negative electrodes) inside the exterior material due to repeated deformation, no internal irregular electrode layer gaps or large gaps were found in the second flexible battery according to the first embodiment (linear dot pattern) and the second embodiment (dispersed dot pattern), and no deformation, cracks, or leakage of the external pouch of the battery occurred.

[0093] These experimental results confirmed that a flexible battery with a concave-convex pattern and dot-patterned recesses formed on the convex portions can perform stable electrochemical operation even under excessive torsion or twist, and that pouch cracking and mechanical durability are significantly improved.

[0094] 6 is an exemplary view showing a reinforcing structure further included in the exterior packaging material having a recess according to the present invention. As shown in FIGS. 1 to 6, the batteries 10 and 20 have reinforcing structures 500, 510a, and 510b formed on the exterior packaging materials 100 and 200.

[0095] 1A shows a plan view, a side view, and an internal view of an exterior packaging material 100 according to a first embodiment, in which a battery 10 has a reinforcing structure 500 formed in at least two recesses 123 formed in a protruding portion 121 of the exterior packaging material 100. For example, in the case of a battery 10 designed so that the distance between at least two recesses 123a formed in a first protruding portion 121a of at least one protruding portion 121 is the same as the distance between at least two recesses 123b formed in a second protruding portion 121b located next to the first protruding portion 121a, a reinforcing structure 500 is formed in the recesses 123 for the exterior packaging material 100.

[0096] In addition, although not shown, a reinforcing structure 500 for the exterior packaging material 100 may be formed in the recess 123, and a reinforcing structure 510b for the exterior packaging material 100 may be formed in the outer region of the exterior packaging material other than the recess 123.

[0097] 10(d), (e), and (f) show a plan view, a side view, and an internal view of an exterior material 200 according to a second embodiment, in which a battery 20 has reinforcement structures 510a, 510b formed in at least two recesses 223 formed in a protrusion 221 of the exterior material 200 and / or in other external regions of the exterior material. For example, in the case of a battery 20 designed so that the spacing between at least two recesses 223a formed in a first protrusion 221a of at least one protrusion 221 is different from the spacing between at least two recesses 223b formed in a second protrusion 221b located next to the first protrusion 221a, a reinforcement structure 510a for the exterior material 200 is formed in the recess 223, and a reinforcement structure 510b for the exterior material 200 is formed in other external regions of the exterior material.

[0098] The reinforcing structures 500, 510a, and 510b may be made of polymers. In particular, the reinforcing structures 500, 510a, and 510b may be made of an elastomer having a Shore Hardness of at least 60 among polymers. Examples of elastomers include butyl rubber, EVA (Ethylene-vinyl acetate copolymer), isoprene (IR), natural rubber (NR), neoprene (CR), polyurethane elastomers, and silicone elastomers.

[0099] If it is assumed that silicone elastomer is used for the reinforcing structures 500, 510a, and 510b, the reinforcing structures 500, 510a, and 510b can be molded at a molding temperature of 90° C., a molding time of 120 seconds, and a molding pressure of 4 MPa.

[0100] For example, if a silicone elastomer with a low hardness, such as a Shore hardness of about 30 to 50, is used, the reinforcing structures 500, 510a, 510b will not have the function of preventing deformation of the recessed portion, and therefore will be unsuitable as the reinforcing structures 500, 510a, 510b.

[0101] However, when a silicone elastomer having a minimum Shore hardness of 60 or more is used as in the present invention, the reinforcing structures 500, 510a, 510b can be easily molded and processed, deformation of the recessed portions can be prevented, and the reinforcing structures 500, 510a, 510b effectively function to prevent the battery from breaking, which is advantageous.

[0102] Furthermore, when a flexible battery is bent 3,000 times with a curvature radius of 15 mm, the reinforcing structures 500, 510a, and 510b are not destroyed or damaged, and since the reinforcing structures 500, 510a, and 510b are attached to the surface of the battery, the adhesive strength with different materials (PET, NY, and silicone) is also superior to that when using general adhesives, and the process of applying adhesive during molding can be omitted, providing the advantage of simplifying the process.

[0103] Furthermore, compared to cracks occurring in flexible batteries to which the reinforcement structures 500, 510a, and 510b are not attached, the occurrence of cracks can be suppressed.

[0104] In addition, as a result of comparing the shape and number of cracks in flexible batteries to which reinforcing structures 500, 510a, and 510b with low Shore hardness (for example, 30 to 50) were applied, it was found that the size of the cracks was small and the number of cracks was significantly less in batteries to which silicone elastomers with a Shore hardness of 60 or more were applied. Therefore, when using silicone elastomers, it is recommended to use batteries with a Shore hardness of 60 (elastic modulus of 0.16 kgf / mm 2 In this case, the upper limit of the Shore hardness of the reinforcement structures 500, 510a, and 510b is not limited as long as it is within a range that does not cause damage to the flexible battery due to hardening during the formation process of the reinforcement structures 500, 510a, and 510b, but may be a value of 100 or less.

[0105] It is possible to minimize damage to the pouches of the exterior materials 100 and 200 formed in the center of the battery in which the electrode assemblies 101 and 201 are housed due to repeated deformation (bending).

[0106] The reinforcing structures 500, 510a, 510b arranged in the concave-convex patterns 120, 220 prevent the battery from deforming beyond a standard range or limit value, thereby preventing the risk of changes in the electrode interface caused by repeated bending of the battery or deformation of the pouch due to excessive folding.This prevents the electrode layer gap between the stacked electrode layers in the pouch (exterior material) from increasing, thereby preventing the distance between the anode and cathode, which should be in close contact, from increasing, preventing a sudden increase in resistance and Li plating issues.

[0107] The manufacturing method of the exterior materials 100, 200 according to the present invention may be a method of processing the exterior materials 100, 200, and housing and sealing the electrode assemblies 101, 201 to assemble the electrochemical cell 10. The manufacturing method of the exterior materials 100, 200 according to the present invention includes the steps of forming the concave-convex patterns 120, 220 and forming the sealing portions 140, 240. The step of forming the concave-convex patterns 120, 220 may be a step of deforming the exterior materials 100, 200 by applying pressure, for example, and the step of forming the sealing portions 140, 240 may be a step of joining the exterior materials 100, 200 to house the electrode assemblies 101, 201.

[0108] Furthermore, in the step of forming the sealing portions 140, 240 of the present invention, an overlapping region, which is a portion of the uneven patterns 120, 220, may be bonded to overlap the sealing portions 140, 240. The overlapping region may be an end portion of one direction (width direction) of the uneven patterns 120, 220, and the overlapping region may overlap the sealing portions 140, 240 so that both sealing surfaces are bonded. As a result, the overlapping region is processed to form a portion of the uneven patterns 120, 220 when the uneven patterns 120, 220 are formed, and may ultimately be included in one region of the sealing portions 140, 240. As a result, edge regions 130, 230 may be formed between the overlapping region and the uneven patterns 120, 220.

[0109] FIG. 7 is a flowchart of a method for manufacturing the battery 10 described through the first embodiment and the battery 20 described through the second embodiment, and in this case, each battery can be manufactured through the same process.

[0110] In step S610, at least one protrusion 121, 221 may be formed in one direction on the exterior packaging 100, 200. For example, the at least one protrusion 121, 221 may be disposed between two recesses 122, 222 and formed to protrude in the opposite direction to the recesses 122, 222.

[0111] The outer diameter of the depressions may be designed to be 30 to 85% of the width of the protrusions, based on the width of the protrusions. If the outer diameter of the depressions is less than 30% of the width of the protrusions, irregular gaps between the electrode layers and large gaps cannot be prevented, and if the outer diameter of the depressions is more than 85%, adjacent depressions may interfere with each other, causing deformation of the shape of the depressions.

[0112] In step S620, a depression 123, 223 may be formed in at least one of the protrusions 121, 221. For example, when the width of the protrusion 121, 221 is W, the outer diameter of the depression 123 may be, but is not limited to, 0.3W to 0.85W, or 0.35W to 0.8W.

[0113] For example, the depressions 123, 223 can be formed using a precision pneumatic press that applies pressure using a dot-shaped punch. Here, the precision pneumatic press is configured with a four-axis set in which a punch and a die are provided together with a ball bushing, and the distance between the punch and the die is physically controlled by a limit block, thereby adjusting the depth of the depressions 123, 223, and by adjusting the press drop speed, damage to the exterior materials 100, 200 can be prevented.

[0114] In step S630, at least one recess 122, 222 may be formed adjacent to the protrusion 121, 221. The recess 122, 222 may be formed to protrude toward the internal space of the receiving portion 110, i.e., toward the received electrode assembly 101, 201. In addition, the protrusion 121, 221 may be disposed between two recesses 122, 222 and formed to protrude in the opposite direction to the recesses 122, 222.

[0115] Here, the step of forming the recesses 122, 222 can be performed before or after the step of pressing the exterior materials 100, 200 on which the protrusions 121, 221 have been formed, which will be described later. If the recesses 122, 222 are formed after pressing the exterior materials 100, 200 on which the protrusions 121, 221 have been formed, additional pressing can be performed on the exterior materials 100, 200.

[0116] In step S640, the electrode assemblies 101, 201 can be inserted into the outer packaging materials 100, 200 in which the recesses 123, 223 are formed.

[0117] In step S650, the exterior materials 100, 200 into which the electrode assemblies 101, 201 are inserted can be sealed.

[0118] 7, the method may further include a step of pressing the exterior packaging materials 100, 200 on which the protrusions 121, 221 are formed. In this case, the step of forming the depressions 123, 223 may include a step of forming the depressions 123, 223 in the protrusions 121, 221 of the pressed exterior packaging materials 100, 200.

[0119] In the above description, steps S610 to S650 may be further divided into additional steps or combined into fewer steps depending on the embodiment of the present invention. In addition, some steps may be omitted as necessary, and the order between steps may be reversed.

[0120] For example, the process may be performed by first forming recesses 122, 222 in exterior packaging materials 100, 200, and then sequentially pressing the formed recesses 122, 222, forming protrusions 121, 221, and forming depressions 123, 223 in the formed protrusions 121, 221. In other words, the process may proceed in the order of forming recesses in the exterior packaging material → pressing → forming protrusions → forming depressions.

[0121] It is needless to say that the steps can be carried out in the order of forming recesses in the exterior material, pressing, forming protrusions, additional pressing, and forming recesses.

[0122] In this case, the depth of the depression formed in the convex portion can be freely adjusted within the height range based on the height of the convex portion. For example, when the height of the convex portion is H, the depth of the depression can be, but is not limited to, 0.05H to 0.9H, 0.1H to 0.9H, 0.1H to 0.8H, 0.2H to 0.8H, 0.3H to 0.8H, 0.4H to 0.8H, or 0.5H to 0.8H.

[0123] Hereinafter, the depth of the pattern in each process, including the depth of the recessed portion, will be described with reference to FIG.

[0124] 8 is an exemplary view showing the depth of a pattern formed in each process on a packaging material according to the present invention. As shown in FIG. 8, when recesses 122, 222 are formed after pressing packaging materials 100, 200 with protrusions 121, 221 formed thereon, additional pressing is performed on packaging material 100, and the depth of the pattern in each process will be described below.

[0125] 8(a), at least one protrusion 801 may be formed in one direction of the outer covering material 800. For example, at least one protrusion 801 having a pattern depth of 0.45 to 0.50 mm may be formed in the outer covering material 800.

[0126] 8(b), pressing 802 may be performed on the packaging material 800 having the convex portions 801 formed thereon. For example, pressing 802 may be performed on the packaging material 800 having the convex portions 801 formed thereon, so that the depth of the pattern becomes 0.30 to 0.35 mm through pressing 802 of the convex portions 801.

[0127] As shown in (c) of Fig. 8, a depression 803 may be formed in the protrusion 801 of the pressed exterior material. For example, at least two depressions 803 having a pattern depth of 0.40 to 0.45 mm based on the maximum height of the pressed protrusion 801 may be formed in the exterior material 800 on which the protrusion 801 is formed.

[0128] 8(d), at least one recess 804 may be formed adjacent to the protrusion 801. For example, at least one recess 804 having a pattern depth of 0.65 to 0.70 mm may be formed in the exterior material 800. In this case, the pattern depth of the recess 804 may be based on the maximum height of the pressed protrusion 801.

[0129] As shown in (e) of Figure 8, when the recesses 804 are formed after pressing the packaging material 800 on which the protrusions 801 are formed, additional pressing 805 may be performed on the packaging materials 100, 200. For example, pressing 805 may be performed on the packaging material 800 on which the recesses 804 are formed so that the pattern depth is 0.50 to 0.55 mm. In this case, the pattern depths of the finally formed protrusions 801 and recesses 804 may be the same, and the pattern depth of the depressions 803 may satisfy the depth range of the depressions described above.

[0130] As described above, when the process is performed in the order of forming convex portions on the packaging material → pressing → forming depressions → forming recesses → additional pressing, by performing pressing after the formation of the convex portions, the upper ends of the convex portions are uniformly pressed, which has the advantage of facilitating the formation of depressions at predetermined positions and with uniform depths. Thereafter, by performing additional pressing after the formation of the recesses, the overall pattern depth of the packaging material is uniformly formed at a target value, which has the advantage of improving the accuracy of the pattern process and reducing the defect rate.

[0131] At this time, by adjusting the pressing pressure, time, gap, etc., the risk of excessive deformation or pressing of the recessed portion does not occur.

[0132] Furthermore, even if two pressings are performed, if the depth of the pressed pattern is not increased to 90% or more of the depth of the convex portion, there is an advantage that cracks due to destruction of the metal layer inside the exterior material will not occur.

[0133] As a result, the pattern process is simplified, which can provide the advantages of reducing the defect rate and shortening the process time by reducing the number of process steps.

[0134] Meanwhile, apart from FIG. 8, the process of forming recesses before pressing the packaging material on which the protrusions are formed, and the depth of the pattern for each process will be described below.

[0135] At least one protrusion may be formed in one direction of the outer jacket material. For example, at least one protrusion having a pattern depth of 0.45 to 0.55 mm may be formed on the outer jacket material.

[0136] At least one recess may be formed adjacent to the protrusion. For example, at least one recess having a pattern depth of 0.70 to 0.75 mm may be formed in the packaging material. In this case, the depth of the recess pattern may be based on the maximum height of the protrusion. When a recess is formed following a protrusion, the depth of the protrusion pattern may be formed to be the same as the depth of the recess pattern based on the lowest end of the recess.

[0137] When at least one recess is formed in the packaging material, pressing may be performed on the packaging material on which at least one protrusion is formed. For example, when at least one protrusion is formed in the packaging material, pressing may be performed so that the protrusion has a pattern depth of 0.50 to 0.55 mm.

[0138] A depression may be formed in the protrusion of the pressed exterior material. For example, the exterior material on which the pressed protrusion is formed may have at least two depressions that satisfy the depth range of the depressions described above based on the maximum height of the protrusion.

[0139] As described above, when the process is performed in the order of forming a convex portion on the exterior material, forming a concave portion, pressing, and forming a depressed portion, the pattern process is simplified, thereby reducing the defect rate, and the process time is reduced by shortening the process steps.

[0140] Here, when forming convex and concave portions on the exterior material before the pressing process, the pressure is not constant, and the concave portions are easily pressed even with the same load, which can cause the pattern depth to become irregularly shallow. However, by performing the pressing process as a finishing step, optimization can be carried out through the design of the upper and lower molds to prevent large deformations such as asymmetry and variations.

[0141] Furthermore, after forming the recessed portion, an additional pressing process may be included as needed.

[0142] The effects exerted by the depressions formed in the convex portions of the present invention are as follows: These effects can be obtained by performing a similar evaluation on a conventional exterior packaging material (in which only convex portions and concave portions are formed on the exterior packaging material) and on the exterior packaging material of the present invention (in which convex portions and concave portions are formed on the exterior packaging material and in which concave portions are formed on the convex portions).

[0143] Specifically, the evaluation methods used were: 1) a bending evaluation (bending radius 15 mm, repeated 100 times) followed by an evaluation to check for cracks and damage to the exterior material, and 2) CT scans to check the arrangement and degree of adhesion of the internal electrodes.

[0144] As a result of evaluating the conventional exterior material and the exterior material of the present invention, it was found that, since the conventional exterior material does not have a recess, when repeatedly bending with a large curvature, if the battery is bent or deformed beyond the standard range or limit value due to misuse, the battery may break or fold, causing cracks in the exterior material and damaging the battery, which may result in the problem of electrolyte leakage.

[0145] Meanwhile, in the exterior material of the present invention, depressions are formed in the protrusions, so that the occurrence of irregular electrode layer gaps and large gaps can be minimized.

[0146] Furthermore, it was confirmed that, during repeated bending of a flexible battery including a housing material having a recessed portion and a reinforcing structure formed in the recessed portion as proposed in the present invention, no cracks were generated in the housing material due to resistance from the strength and support force of the reinforcing structure. Specifically, when the inside of the housing material proposed in the present invention was examined, it was confirmed that the gap between each electrode layer was maintained uniform throughout the entire section during bending.

[0147] The above description of the present invention is for illustrative purposes only, and those skilled in the art will understand that the present invention may be easily modified into other specific forms without changing the technical spirit or essential features of the present invention. Therefore, it should be understood that the above-described embodiments are illustrative in all respects and not limiting. For example, each component described as a single component may be implemented in a distributed form, and similarly, each component described as a distributed component may be implemented in a combined form.

[0148] The scope of the present invention is defined by the claims below rather than the detailed description, and all modifications and variations that fall within the meaning and scope of the claims and their equivalents should be interpreted as being included in the scope of the present invention. [Explanation of symbols]

[0149] 10, 20: Batteries, electrochemical cells 100, 200: exterior materials 101, 201: Electrode assembly 102, 202: Electrode leads 110, 210: Storage section 120, 220: uneven pattern 121, 221: Convex 122, 222: recess 123, 223: Depression 130, 230: Edge area 140, 240: Sealing part

Claims

1. In batteries, an electrode assembly including a plurality of electrodes; an exterior material that accommodates the electrode assembly and has a concave-convex pattern including at least one recess and at least one protrusion; Including, The battery, wherein the protrusion has a recess formed in which a partial area of ​​the protrusion is recessed.

2. The battery according to claim 1 , wherein each of the at least one protrusions has at least two recesses formed in one direction corresponding to the width of the battery.

3. 3. The battery according to claim 2, wherein a distance between at least two recesses formed in a first protrusion among the at least one protrusion and a distance between at least two recesses formed in a second protrusion located next to the first protrusion are designed to be the same.

4. The battery according to claim 2 , wherein the recessed portion is formed to have a first gap from an edge region of the exterior material.

5. 3. The battery according to claim 2, wherein a distance between at least two recesses formed in a first protrusion among the at least one protrusion is designed to be different from a distance between at least two recesses formed in a second protrusion located next to the first protrusion.

6. The battery according to claim 5 , wherein the recess formed in the first protrusion is formed to have a second distance from an edge region of the exterior material.

7. The battery according to claim 5 , wherein the recess formed in the second protrusion is formed to have a third distance from an edge region of the exterior material.

8. The exterior material is a housing portion that houses the electrode assembly; a sealing portion that seals the electrode assembly by joining a sealing surface along a corner of the receiving portion; 10. The battery of claim 1, comprising:

9. The battery according to claim 8 , wherein the at least one recess and the at least one protrusion have an edge region that forms a boundary line that abuts the sealing portion at an end in one direction corresponding to the width of the battery.

10. The battery according to claim 8 , wherein the sealing portion has a pattern having a height lower than the concave-convex pattern in the thickness direction of the exterior material.

11. The battery according to claim 1 , wherein a reinforcing structure for the exterior material is formed in the recess.

12. 1. A method of manufacturing a battery, comprising: forming at least one protrusion in one direction on the exterior material; forming at least one recessed portion adjacent to the protruding portion; forming a depression in the at least one protrusion; inserting an electrode assembly into the outer casing having the recess; sealing the outer casing into which the electrode assembly is inserted; A method for manufacturing a battery, comprising:

13. Pressing the exterior material on which the protrusions are formed. further comprising The method for manufacturing a battery according to claim 12 , wherein the step of forming the recessed portion comprises forming the recessed portion in a protruding portion of the pressed exterior material.

14. The method for manufacturing a battery according to claim 12 , wherein the step of forming the recessed portion is performed before or after the step of pressing the exterior material on which the protrusions have been formed.

15. If the recess is formed after pressing the exterior material on which the protrusion is formed, a step of additionally pressing the exterior material. The method of manufacturing the battery of claim 14 further comprising:

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