Battery and battery manufacturing method

Abstract

A battery includes: an electrode assembly including a plurality of electrodes; and an exterior member that accommodates the electrode assembly and has formed therein a concave-convex pattern including at least one concave portion and at least one convex portion, the convex portion having formed therein a recessed portion in which a partial region of the convex portion is recessed.

Description

Technical Field

[0001] The present invention relates to a battery that is chargeable and dischargeable and can be provided as a power source for mobile devices, flexible devices, and the like. Background Art

[0002] A battery, or electrochemical cell, is a component that consists of at least two electrodes and an electrolyte and is capable of providing electrical energy. Rechargeable secondary batteries are particularly popular in a variety of cutting-edge electronic devices, including smartphones.

[0003] In recent years, the design of mobile devices, including smartphones and various wearable devices, has been evolving beyond existing form factors. Consequently, interest in flexible devices that can bend while maintaining functionality has grown. Consequently, developing technologies that ensure the performance, reliability, and safety of flexible batteries used as power sources within these devices has become a prominent challenge.

[0004] In this regard, prior art patent document 1 (KR10-2022-0015290A) discloses a technique for forming a pattern on an exterior component. However, Patent Document 1 discloses a structure in which at least one pattern portion is formed along the transverse direction (TD) of the exterior component. However, this pattern causes the gaps between the stacked electrode layers within the exterior component to change when the battery is repeatedly bent at a large curvature. When these gaps are large, the reliability and safety of the battery are reduced.

[0005] The following briefly describes the problem of increasing the distance between the layers of electrodes in batteries manufactured using conventional technology.

[0006] Inside the exterior of a battery manufactured using conventional technology, the positive and negative electrodes are arranged in a straight line, closely fitting and stacked at a constant distance, ensuring regular interlayer spacing. An insulating material is placed between the electrodes to prevent direct contact between the positive and negative electrodes, which could cause a short circuit, while also allowing lithium ions to migrate.

[0007] However, for existing batteries that are repeatedly bent, when the battery is bent, the outermost electrode will slide inward due to the curvature. When the battery is unfolded again, if the outermost electrode is deformed and cannot return to its original position, the electrode in a part of the originally regular electrode layer gap will be lifted up, resulting in an irregular gap.

[0008] Specifically, when a battery deforms from a flat first state to a curved second state, and then deforms again to return to a flat third state, electrodes that have been bent or severely deformed into an irregular, wavy shape (e.g., the outermost electrodes) have difficulty returning to a flat state. In particular, in a structure where one side of the electrodes is fixed and the other side is loose, the outermost electrodes are more susceptible to deformation than other electrodes. Consequently, during the battery's recovery process, the electrodes are prone to warping or bending toward the package (pouch), creating irregular gaps. Summary of the Invention

[0009] Technical issues

[0010] An object of the present invention is to provide a battery comprising: an electrode assembly including a plurality of electrodes; and an exterior member housing the electrode assembly and having a concave-convex pattern including at least one concave portion and at least one convex portion.

[0011] Another object of the present invention is to provide a flexible battery that can suppress irregular electrode layer gaps that may be generated due to bending of the battery by forming a depressed portion in which a portion of a convex portion is depressed.

[0012] However, the technical issues to be solved by this embodiment are not limited to the above technical issues, and there may be other technical issues.

[0013] Technical Solution

[0014] As a means for solving the above-mentioned technical problems, one embodiment of the present invention can provide a battery, comprising: an electrode assembly, comprising a plurality of electrodes; and an outer casing, which houses the electrode assembly and is formed with a concave-convex pattern comprising at least one concave portion and at least one convex portion, wherein a depression is formed in the convex portion, wherein a part of the area of the convex portion is sunken.

[0015] According to one embodiment, the at least one convex portion is formed with at least two concave portions in a direction corresponding to a width of the battery.

[0016] According to one embodiment, the interval between the at least two depressed portions formed on a first convex portion of the at least one convex portion is designed to be the same as the interval between the at least two depressed portions formed on a second convex portion located behind the first convex portion.

[0017] According to one embodiment, the depressed portion is formed to have a first gap from an edge region of the exterior member.

[0018] According to one embodiment, the interval between the at least two depressed portions formed on a first convex portion of the at least one convex portion is designed to be different from the interval between the at least two depressed portions formed on a second convex portion located behind the first convex portion.

[0019] According to one embodiment, the depressed portion formed on the first protrusion is formed to have a second gap with an edge region of the exterior member.

[0020] According to one embodiment, the depressed portion formed on the second protrusion is formed to have a third distance from an edge region of the exterior member.

[0021] According to one embodiment, the exterior member includes: a housing portion for housing the electrode assembly; and a sealing portion for sealing the electrode assembly by being bonded to a sealing surface along a periphery of the housing portion.

[0022] According to one embodiment, the at least one concave portion and the at least one convex portion include edge regions at their ends in a direction corresponding to the width of the battery, and the edge regions form a boundary line with the sealing portion.

[0023] According to one embodiment, the sealing portion has a pattern having a height in the thickness direction of the exterior member lower than that of the concavo-convex pattern.

[0024] According to one embodiment, the depressed portion is formed with a reinforcement structure for reinforcing the exterior member.

[0025] Another embodiment of the present invention provides a battery manufacturing method, comprising: a step of forming at least one convex portion along a direction on an outer casing; a step of forming at least one concave portion at a position adjacent to the convex portion; a step of forming a depressed portion on the at least one convex portion; a step of inserting an electrode assembly into the outer casing having the depressed portion formed therein; and a step of sealing the outer casing into which the electrode assembly is inserted.

[0026] According to another embodiment, the method further includes the step of punching the exterior member having the convex portion formed thereon, and in the step of forming the concave portion, the concave portion is formed on the punched convex portion of the exterior member.

[0027] According to another embodiment, the step of forming the concave portion is performed before or after the step of punching the exterior member having the convex portion formed thereon.

[0028] According to another embodiment, the present invention further includes the step of further punching the exterior member after the exterior member having the protrusion formed thereon is punched to form the concave portion.

[0029] Effects of the Invention

[0030] According to the present invention, a battery includes: an electrode assembly including a plurality of electrodes; and an outer casing that accommodates the electrode assembly and is formed with a concave-convex pattern including at least one concave portion and at least one convex portion, wherein a depression is formed in the convex portion in which a part of the convex portion is sunken, thereby suppressing the generation of irregular electrode layer gaps (Electrode Layer Gap) and large gaps (Large Gap) when the battery is bent.

[0031] Moreover, a reinforcing structure for maintaining the shape of a sunken portion is formed in a part of the convex portion, so that when the battery is bent or deformed, the resistance generated by the rigidity and supporting force of the reinforcing structure can reduce cracks in the exterior components. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 is a schematic diagram showing a battery according to a first embodiment of the present invention.

[0033] Figure 2 It will Figure 1 A schematic diagram showing an enlarged area A of the battery.

[0034] Figure 3 is a schematic diagram showing a battery according to a second embodiment of the present invention.

[0035] Figure 4 It will Figure 3 A schematic diagram showing an enlarged area B of the battery.

[0036] Figure 5 Schematic diagram showing a comparative evaluation of a flexible battery having only a concavo-convex pattern and a flexible battery having a concavo-convex pattern and recessed portions according to an embodiment of the present invention.

[0037] Figure 6 This is a schematic diagram showing a reinforcement structure formed in a depressed portion for reinforcing an exterior member according to the present invention.

[0038] Figure 7 It is a flow chart of the battery manufacturing method of the present invention.

[0039] Figure 8 Schematic diagram showing the depth of a pattern formed in each manufacturing step of the exterior member in the present invention. DETAILED DESCRIPTION

[0040] The following describes, in detail, embodiments of the present invention with reference to the accompanying drawings in a manner that can be easily implemented by those skilled in the art. However, the present invention can be implemented in a variety of different ways and is not limited to the embodiments described herein. To clarify the present invention, portions not relevant to the description are omitted from the drawings, and similar reference numerals are used throughout the specification to denote similar portions.

[0041] Throughout this specification, when a part is described as "including" a certain component, unless otherwise stated, it means that other components may also be included, and does not mean that other components are excluded. Furthermore, throughout this specification, when a part is described as "connected" to another part, this includes not only "direct connection" but also "indirect connection" with other components interposed therebetween. Furthermore, throughout this specification, when a part is described as being "on" another part, this includes not only the case where the part is in contact with the other part but also the case where there are other components between the two parts.

[0042] The battery, or electrochemical cell, according to the present invention can be a lithium-ion battery. Specifically, the electrochemical cell according to the present invention can be configured such that the electrode assembly and electrolyte are housed together within an exterior member and sealed, and charging and discharging are performed through the movement of lithium ions. The electrochemical cell according to the present invention is configured to maintain its functional state and possess flexibility. The following describes embodiments of the present invention in detail with reference to the accompanying drawings.

[0043] Figure 1 is a schematic diagram showing a battery according to a first embodiment of the present invention, Figure 2 It will Figure 1 Schematic diagram showing an enlarged area A of the battery. According to the first embodiment, the battery 10 is designed so that the interval between the at least two recessed portions formed on the first protrusion and the interval between the at least two recessed portions formed on the second protrusion of at least one protrusion are the same.

[0044] Reference Figure 1 The battery 10 according to the first embodiment of the present invention may include an exterior member 100, an electrode assembly, and an electrode lead 102. The electrode assembly includes a plurality of electrodes and may further include active materials and a separator, with these components stacked in a thickness direction.

[0045] The electrode may include a first and a second electrode plate with different polarities, and active materials may be coated on both sides or one side of each of the first and second electrode plates. A separator may be provided between the first and second electrode plates. For example, when the first electrode plate is used as a negative electrode, the current collector may be made of copper, aluminum, stainless steel, etc., and the negative electrode active material may be made of carbon, lithium, silicon, SiO xThe first and second electrode plates may be made of a combination of one or more of silicon derivatives, silicon-graphite composites, tin, and silicon-tin composites. In addition, when the second electrode plate is used as the positive electrode, the current collector may be made of aluminum, stainless steel, or the like, and the positive electrode active material may be made of a combination of one or more 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 the following shape: the first and second electrode plates extend longer in the length direction of the two directions along the forming surface than in the width direction, and are thinner in the thickness direction of the active material and the separator stack that intersects (e.g., is perpendicular) the direction of the forming surface.

[0046] In addition, the electrode assembly may include an electrode connection tab and a lead connection tab. The electrode connection tab may be formed to protrude from one end of the length direction of the first and second electrode plates, and the electrode connection tabs protruding from electrodes of the same polarity may be coupled to each other. The electrodes may be electrically connected in parallel via the electrode connection tab. The lead connection tab is connected to the electrode lead 102 and may protrude from the positive and negative electrode plates to be coupled to the electrode lead 102.

[0047] The exterior component 100 according to the first embodiment of the present invention is formed to accommodate an electrode assembly. For example, the exterior component 100 may be composed of a film having a laminated structure including polypropylene (PP), metal, and nylon layers. In addition to nylon, other materials such as polyethylene terephthalate (PET), polyvinyl chloride (PVC), polycarbonate (PC), polyethylene (PE), and polyimide (PI) may also be used.

[0048] More specifically, the exterior member 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. Each of the at least one concave portion 122 and the at least one convex portion 121 has an edge region 130 at its end in a direction corresponding to the width of the battery, forming a boundary line with the sealing portion 140.

[0049] The edge region 130 may include a boundary line between the concavo-convex pattern 120 and the sealing portion 140. Figure 1As shown, the edge region 130 may include: two points in each concave-convex pattern 120 that connect to the sealing portion 140; and a boundary line extending between the two points. The boundary line of the edge region 130 may extend substantially straight along the flat sealing portion 140 and may connect to the boundary line of the edge region 130 of the adjacent concave-convex pattern 120 to form a straight line.

[0050] For example, the concave-convex pattern 120 is a pattern that extends in one direction and is repeatedly arranged in a direction intersecting the one direction. Specifically, the pattern alternates between protrusions and depressions in the thickness direction (i.e., protrusions alternate in opposite directions), thereby forming a concave-convex shape along the one direction. Here, the one direction may be the width direction described above, and the direction in which the concave-convex pattern 120 repeats may be the length direction. The protrusions and depressions in the concave-convex pattern 120 can form a wavy or wrinkled pattern in the length direction of the exterior member 100 forming the storage portion 110.

[0051] Next, through Figure 2 The concavo-convex pattern 120 will be described in detail.

[0052] The convex portion 121 is formed with a depression 123 in which a portion of the convex portion 121 is depressed. For example, the convex portion 121 is formed with a depression 123 that is depressed in a dot shape in the center of the convex portion 121. Here, at least one convex portion 121 is formed with at least two depressions 123 in a direction corresponding to the width of the battery.

[0053] In this case, the central area of the convex portion 121 may refer to an area set based on the center point of the major axis (longitudinal axis) and the minor axis (widthwise axis) of the convex portion 121 .

[0054] For example, when the center area is set based on the center point with the long axis of the protrusion 121 having a length L in the longitudinal direction and the short axis of the protrusion 121 having a length W in the width direction, the above-mentioned center area can represent an area including positions spaced 0.01L to 0.45L, 0.05L to 0.4L, 0.1L to 0.3L in the longitudinal direction and positions spaced 0.01W to 0.45W, 0.05W to 0.4W, 0.1W to 0.3W in the width direction based on the center point as a reference, but the present invention is not limited to this.

[0055] Furthermore, the depressed portion 123 may have any one or more shapes of a prism, a cylinder, and their deformations, in addition to the aforementioned dot shape.

[0056] For example, the depressed portion 123 may have a tapered structure in which the lower area of the depressed portion 123 is narrower than the upper area in the thickness direction of the protrusion 121. In other words, the depressed portion 123 may have a tapered structure in which the cross-sectional area narrows from the surface of the protrusion 121 in the thickness direction.

[0057] Since the shape of the depressed portion 123 includes a tapered structure, it is beneficial to suppress the generation of irregular electrode layer gaps and large gaps when the battery is bent.

[0058] As an example, the outer diameter of the depressed portion 123 can be freely adjusted within the aforementioned widthwise length range, based on the widthwise length of the convex portion 121 .

[0059] For example, when the width direction length of the convex portion 121 is W, the outer diameter of the concave portion 123 may be 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, but is not limited thereto. Here, the outer diameter may refer to the maximum diameter of the concave portion 123 formed at the uppermost end of the convex portion 121.

[0060] In addition, the depth of the depressed portion 123 can be freely adjusted within the height range based on the height of the convex portion 121 .

[0061] As an example, when the height of the protrusion 121 is H, the depth of the recess 123 can be 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, but is not limited thereto.

[0062] However, as described above, in order to effectively suppress the generation of irregular electrode layer gaps (Electrode Layer Gap) and large gaps (Large Gap) when the battery is bent, it is preferred that the shape and size of the depression 123 based on the outer diameter size of the depression 123 and the depth of the depression 123 satisfy the above-mentioned range.

[0063] For example, the widthwise lengths of the convex portion 121 and the concave portion 122 may be the same or different, and the same effect can be produced by forming a depressed portion 123 in which a portion of the convex portion 121 is depressed as described above, regardless of the widthwise lengths of the convex portion 121 and the concave portion 122.

[0064] Reference Figure 2 For example, the interval 150 between at least two recessed portions 123a formed on the first convex portion 121a of at least one convex portion 121 is designed to be the same as the interval 150 between at least two recessed portions 123b formed on the second convex portion 121b located behind the first convex portion 121a.

[0065] Here, the recessed portion 123 formed on the first protrusion 121a is formed to have first intervals 135a and 135b from the edge region 130. To this end, at least two recessed portions 123a and 123b may be formed at positions 0.1K to 0.4K, preferably 0.15K to 0.35K, more preferably 0.2K to 0.35K, and even more preferably 0.25K (1 / 4K) away from each edge region 130 located at both ends of the exterior member 100, based on the separation distance K between the edge regions 130 at both ends.

[0066] For example, one of the at least two recessed portions 123a formed on the first protrusion 121a is formed to have a first spacing 135a from an edge region 130a at one end of the exterior member 100, while the other of the at least two recessed portions 123a formed on the first protrusion 121a is formed to have a first spacing 135b from an edge region 130b at the other end of the exterior member 100. This design is intended to provide support through the at least two recessed portions when the battery 10 deforms, preventing the internal electrodes from warping into the space between the concave-convex pattern of the exterior member 100 and the electrode assembly, causing deformation and even bending. For example, the first spacings 135a and 135b can represent the situation where the distance between the recessed portions provided on the protrusion and adjacent protrusion is the same, specifically, at a distance from one edge region that is ¼ of the length between the edge regions at both ends.

[0067] Specifically, since the recessed portion 123 formed on the first protrusion 121a is formed to have a first gap 135a, 135b with the edge area 130, according to the bending evaluation results of the battery 10, before the battery 10 is bent, the distance between the positive and negative poles, that is, the electrode layers, inside the outer component 100 is 0.02 mm. When the battery 10 is bent 100 times or 3000 times, the distance between the electrode layers is maintained at 0.02 mm. This can suppress the degradation of battery performance and the reduction of durability of the outer component 100 caused by the generation of irregular electrode layer gaps (Electrode Layer Gap) and large gaps (Large Gap), and at the same time, can suppress lithium plating (Li-plating) that may be caused by the increase in the electrode layer gap, thereby eliminating safety risks.

[0068] Figure 3 is a schematic diagram showing a battery according to a second embodiment of the present invention, Figure 4 It will Figure 3 A schematic diagram showing an enlarged area B of the battery.

[0069] According to the second embodiment, the battery 20 is designed such that the interval between the at least two depressed portions formed on the first convex portion and the interval between the at least two depressed portions formed on the second convex portion of the at least one convex portion are different.

[0070] Reference Figure 3 The battery 20 according to the second embodiment of the present invention may include an exterior member 200, an electrode assembly, and an electrode lead 202. The electrode assembly includes a plurality of electrodes and may further include active materials and a separator, with these components stacked in a thickness direction.

[0071] In addition, the electrode assembly may include an electrode connection tab and a lead connection tab. The electrode connection tab may be formed to protrude from one end of the length direction of the first and second electrode plates, and the electrode connection tabs protruding from electrodes of the same polarity may be coupled to each other. The electrodes may be electrically connected in parallel via the electrode connection tab. The lead connection tab is connected to the electrode lead 202 and may protrude from the positive and negative electrode plates and be coupled to the electrode lead 202.

[0072] The exterior member 200 according to the second embodiment of the present invention is formed to accommodate the electrode assembly.

[0073] 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 can seal the received electrode assembly relative to the outside by joining. For example, the receiving portion 210 may correspond to an area where two outer casings 200 are separated and opposite to each other. In order to form the receiving portion 210, the outer casing 200 can be processed to protrude by applying pressure in the thickness direction, so that the preset area of the outer casing 200 has a shape of a roughly rectangular groove (or cup).

[0074] More specifically, the exterior member 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 have edge regions 230 at their ends in a direction corresponding to the width of the battery, forming a boundary line with the sealing portion 240.

[0075] For example, the concave-convex pattern 220 is a pattern that extends in one direction and is repeatedly arranged in a direction intersecting the one direction. Specifically, the pattern alternates between protrusions and depressions in the thickness direction (i.e., protrusions alternate in opposite directions), thereby forming a concave-convex shape along the one direction. Here, the one direction may be the width direction described above, and the direction in which the concave-convex pattern 120 repeats may be the length direction. The protruding and recessed concave-convex pattern 120 creates a wavy or wrinkled pattern in the length direction of the exterior member 100 that forms the housing portion 110.

[0076] Next, through Figure 4 The concavo-convex pattern 220 will be described in detail.

[0077] The convex portion 221 has a depressed portion 223 formed therein, where a portion of the convex portion 221 is depressed. The shape and dimensions of the depressed portion 223 are the same as those described above, and their description is omitted here.

[0078] For example, if a depression 223 is formed on a convex portion 221, extending downward in a dotted pattern from the center of the convex portion 221, a depression 223 can be formed on the outer periphery of the next convex portion 221. Here, at least one convex portion 221 can have at least two depressions 223 formed in a direction corresponding to the width of the battery. For example, the widthwise lengths of the convex portion 221 and the concave portion 222 can be the same or different, and the same effect can be achieved regardless of the widthwise length.

[0079] Reference Figure 4 For example, it can be designed that the interval 250 between at least two recessed portions 223a formed on the first convex portion 221a of at least one convex portion 221 is different from the interval 251 between at least two recessed portions 223b formed on the second convex portion 221b located behind the first convex portion 221a.

[0080] Here, a second gap 250a is formed between the depressed portion 223a formed on the first protrusion 221a and the edge region 230a, and a third gap 250b is formed between the depressed portion 223b formed on the second protrusion 221b and the edge region 230b.

[0081] To this end, at least two recessed portions 223a formed on the first protrusion 221a can be respectively formed at positions 0.1K to 0.25K, preferably 0.15K to 0.25K, and more preferably 0.2K (1 / 5K) apart from each edge area 230a located at both ends of the exterior component 100, based on the separation distance K between the edge areas 230a at both ends.

[0082] In addition, at least two recessed portions 223b formed on the second protrusion 221b can be respectively formed at positions 0.25K' to 0.4K', preferably 0.25K' to 0.35K', and more preferably 0.33K' (1 / 3K') away from each edge area 230b located at both ends of the exterior component 100, based on the separation distance K' between the edge areas 230b at both ends.

[0083] Specifically, the at least two recessed portions 223a formed on the first protrusion 221a are formed at positions 1 / 5 of the length K between the edge regions 230a at both ends of the exterior member 100, thereby providing a second gap 250a between the at least two recessed portions 223a. The at least two recessed portions 223b formed on the second protrusion 221b are formed at positions 1 / 3 of the length K' between the edge regions 230b at both ends of the exterior member 100, thereby providing a third gap 250b between the at least two recessed portions 223b. In this case, if the recessed portions are formed at positions offset from 1 / 5 of the length between the edge regions, the recessed portions may fail to prevent the internal electrodes from warping in the width direction of the battery cell (large gap).

[0084] In addition, if the depressed portion is formed at a position that deviates from 1 / 3 of the length between the edge areas at both ends, causing the two depressed portions to gather in the central portion of the outer component (i.e., the distance between the depressed portions is less than or equal to the outer diameter of the depressed portions), interference will occur between the depressed portions, thereby causing the shape of the outer component to be deformed, and the effect of suppressing the increase in the gap between the electrodes (large gap) cannot be achieved.

[0085] For example, one of the at least two recessed portions 223a formed on the first protrusion 221a is formed to have a second gap 250a with the edge area 230a located at one end of the exterior component 100, and one of the at least two recessed portions 223b formed on the second protrusion 221b is formed to have a third gap 250b with the edge area 230b located at one end of the exterior component 100.

[0086] In the same manner, another of the at least two recessed portions 223b formed on the first protrusion 221a is formed to have a second interval from an edge area (not shown) located at the other end of the exterior component 100, and another of the at least two recessed portions 223b formed on the second protrusion 221b is formed to have a third interval from an edge area (not shown) located at the other end of the exterior component 100.

[0087] This design is to provide support through at least two recessed portions when the battery 10 is deformed, thereby preventing the internal electrodes from warping and deforming toward the space between the concave-convex pattern of the exterior component 100 and the electrode assembly, or even causing the electrodes to bend.

[0088] Specifically, at least two recessed portions 223a formed on the first protrusion 221a are formed to have a second gap 250a with the edge area 230, and at least two recessed portions 223b formed on the second protrusion 221b are formed to have a third gap 250b with the edge area 230. Therefore, according to the bending evaluation results of the battery 20, before the battery 20 is bent, the distance between the positive and negative poles, that is, the electrode layers, inside the outer component 200 is 0.02 mm. When the battery 20 is bent 100 times or 3000 times, the distance between the electrode layers is maintained at 0.02 mm. This can suppress the degradation of battery performance and the reduction of durability of the outer component 100 caused by the generation of irregular electrode layer gaps (Electrode Layer Gap) and large gaps (Large Gap), and at the same time, can suppress lithium plating (Li-plating) that may be caused by the increase in the electrode layer gap, thereby eliminating safety risks.

[0089] The exterior member 100 of the first embodiment and the exterior member 200 of the second embodiment both include a housing portion 110 , 210 and a sealing portion 140 , 240 .

[0090] The receiving portion 110, 210 forms a space for accommodating the electrode assembly, and the sealing portion 140, 240 can seal the accommodated electrode assembly from the outside by bonding. To form the receiving portion 110, 210 on the exterior component, the exterior component 100, 200 can be pressed along the thickness direction to form the sealing portion 140, 240, so that the predetermined area of the exterior component 100, 200 has a generally rectangular groove (or cup) shape.

[0091] The sealing portions 140 and 240 seal the electrode assembly by joining the sealing surfaces along the periphery of the housing portions 110 and 210. For example, the sealing surfaces refer to the surfaces of the exterior components 100 and 200. The two overlapping sealing surfaces along the periphery of the housing portions 110 and 210 are joined together to isolate the interior space (housing portions 110 and 210) from the outside. The interior space can accommodate the electrode assembly and electrolyte described above, and the electrode assembly and electrolyte can be maintained in a sealed state.

[0092] Furthermore, the sealing portion 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 portion 140, 240 may be parallel to each other and uncurved. Alternatively, the sealing portion 140, 240 may have a pattern different from the concave-convex pattern 120, 220. For example, the sealing portion 140, 240 may have a pattern with a lower height than the concave-convex pattern 120, 220 in the thickness direction of the exterior member 100, 200.

[0093] The outer casing 100, 200 according to one embodiment of the present invention is formed so that the concave-convex pattern 120, 220 of the receiving portion 110, 210 is in close contact with the sealing portion 140, 240. As a result, in this embodiment, no space is formed between the concave-convex pattern 120, 220 and the sealing portion 140, 240 where stress may be concentrated. Since the weak points in the structure are eliminated, the following effect is achieved: in a use environment with repeated bending, the possibility of damage to the end of one direction of the concave-convex pattern or the sealing portion 140, 240 can be greatly reduced. Therefore, the battery 10, 20 and the outer casing 100, 200 equivalent to the electrochemical cell unit according to the present invention can improve durability, reduce the possibility of breakage and leakage, and improve safety without further reinforcement or addition of other components.

[0094] Meanwhile, electrode leads 102, 202 are connected to the electrode assembly within the exterior components 100, 200 and extend to the exterior of the exterior components 100, 200, becoming exposed. Electrode leads 102, 202 function as terminals electrically connected to the electrode assembly housed within the exterior components 100, 200. When forming the seals 140, 240, they can penetrate and bond to the seals 140, 240 while being interposed between the sealing surfaces. The pair of positive and negative electrode leads 102, 202 can be connected to the lead connection tab provided in the electrode assembly with the same polarity.

[0095] Figure 5 The figure shows the torsion and twist evaluation results of a flexible battery manufactured using an exterior member having only a concavo-convex pattern according to a comparative example and a flexible battery manufactured using an exterior member having a concavo-convex pattern and a depressed portion according to an embodiment of the present invention. Figure 5 The present invention forms dot-patterned recessed portions 123, 223 on the convex portions 121, 221 of the exterior components 100, 200 (without the need for a reinforcing structure), thereby suppressing irregular electrode layer gaps and large gaps generated when the battery is subjected to deformations such as bending, twisting, and torsion.

[0096] The following describes a first flexible battery using an exterior member having a concavo-convex pattern consisting solely of convex portions 121, 221 and concave portions 122, 222, based on a conventional comparative example, and a second flexible battery using an exterior member having a concavo-convex pattern consisting solely of convex portions 121, 221 and concave portions 122, 222, with recessed portions 123, 223 formed on the convex portions 121, 221, based on the first and second embodiments of the present invention. For example, experiments were conducted by applying a torsional 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.

[0097] For example, when each flexible battery is in a 100% charged state, the initial open circuit voltage (OCV) and AC impedance (1000Hz) values of the battery are recorded. Then, polyimide (PI) tape is attached to the terminals of each flexible battery for insulation treatment, and then each flexible battery is fixed to the fixture of the test device.

[0098] The torsion generated by repeatedly twisting one of the clamps holding both ends of the flexible battery at a certain angle, and the twist generated by twisting the two clamps while rotating at positive and negative angles in opposite phases were evaluated.

[0099] Afterwards, the OCV and AC impedance (1000 Hz) values of the flexible battery were measured based on the evaluation method, and deformation and cracking of the outer casing of the flexible battery, leakage, fire, explosion, etc. were confirmed before and after the evaluation.

[0100] Specifically, in the comparative example (first flexible battery), deformation of the battery package appearance was observed, and after twist evaluation, 14 irregular electrode layer gaps were found inside the first flexible battery.

[0101] However, according to the first and second embodiments of the present invention, after the second flexible battery was subjected to torsion or twisting (up to a maximum of + / -45 degrees, 3000 times), the OCV and AC impedance values (at 1000 Hz) were measured, showing no significant decrease or increase from their initial values. Furthermore, the battery packaging's external appearance was also confirmed to have not changed significantly. Furthermore, to prevent irregular electrode layer gaps (increase in the distance between the positive and negative electrodes) within the exterior component due to repeated deformation of the convex portions formed in the width direction of the battery to impart flexibility, dotted depressions were formed on the convex portions. In the second flexible battery using the first embodiment (straight dot pattern) and the second embodiment (dispersed dot pattern), no irregular electrode layer gaps or large gaps were observed, and no deformation, cracking, or leakage of the battery packaging occurred.

[0102] These experimental results confirm that flexible batteries with a concave-convex pattern and concave portions formed on the convex portions with a dot-shaped pattern can be stably electrochemically driven even under severe torsion or twisting evaluations, and that package cracking and mechanical durability are significantly improved.

[0103] Figure 6 Schematic diagram showing a reinforcing structure included in the exterior member having a depressed portion according to the present invention. Figures 1 to 6 The batteries 10 and 20 are formed with reinforcement structures 500 , 510 a and 510 b for reinforcing the exterior members 100 and 200 .

[0104] The figures show (a) a top view, (b) a side view, and (c) an internal view of the exterior member 100 according to the first embodiment. In a battery 10, at least two recessed portions 123 formed on a protrusion 121 of the exterior member 100 are formed with reinforcement structures 500 to reinforce the exterior member 100. For example, in a battery 10 designed so that the spacing between at least two recessed portions 123a formed on a first protrusion 121a of at least one protrusion 121 is the same as the spacing between at least two recessed portions 123b formed on a second protrusion 121b located subsequent to the first protrusion 121a, the reinforcement structures 500 to reinforce the exterior member 100 are formed on the recessed portions 123.

[0105] Although not shown in the drawings, a reinforcement structure 500 for reinforcing the exterior member 100 may be formed in the depressed portion 123 , and a reinforcement structure 510 b for reinforcing the exterior member 100 may be formed in other areas outside the exterior member.

[0106] (d) A top view, (e) A side view, and (f) An internal view of an exterior member 200 according to the second embodiment are shown. In a battery 20, reinforcing structures 510a and 510b are formed on at least two recessed portions 223 formed on a convex portion 221 of the exterior member 200 and / or in other regions outside the exterior member to reinforce the exterior member 200. For example, in a battery 20 designed such that the spacing between at least two recessed portions 223a formed on a first convex portion 221a of at least one convex portion 221 is different from the spacing between at least two recessed portions 223b formed on a second convex portion 221b located subsequent to the first convex portion 221a, the reinforcing structure 510a is formed on the recessed portion 223 to reinforce the exterior member 200, and the reinforcing structure 510b is formed in other regions outside the exterior member to reinforce the exterior member 200.

[0107] These reinforcement structures 500, 510a, and 510b may be polymers. In particular, the reinforcement structures 500, 510a, and 510b may be formed from an elastomer having a Shore Hardness of at least 60. Examples of elastomers include butyl rubber, ethylene-vinyl acetate copolymer (EVA), isoprene (IR), natural rubber (NR), neoprene (CR), polyurethane elastomers, and silicone elastomers.

[0108] Assuming that silicone rubber is used as 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.

[0109] For example, when using low-hardness silicone rubber with a Shore hardness of approximately 30 to 50, the reinforcing structures 500, 510a, and 510b cannot function to prevent the sunken portion from deforming, and thus are not suitable as the reinforcing structures 500, 510a, and 510b.

[0110] However, when silicone rubber with a Shore hardness of at least 60 is used as in the present invention, the following advantages are achieved: the reinforcing structures 500, 510a, 510b are easy to mold and process, deformation of the sunken portion can be prevented, and the reinforcing structures 500, 510a, 510b can properly perform their function of preventing the battery from bending.

[0111] In addition, when the flexible battery is bent 3000 times with a curvature radius of 15 mm, the reinforcing structures 500, 510a, and 510b are not destroyed or damaged. Since the reinforcing structures 500, 510a, and 510b are attached to the surface of the battery, the adhesion with dissimilar materials (PET, NY, and silicone rubber) is also better than that using general adhesives, and the process of applying the adhesive can be omitted during molding, thereby providing the advantage of simplifying the process.

[0112] In addition, compared with a flexible battery to which no reinforcing structures 500 , 510 a , 510 b are attached, the generation of cracks can be suppressed.

[0113] In addition, the results of comparing the shape and number of cracks in the flexible battery using the reinforcement structure 500, 510a, 510b with a low Shore hardness (e.g., 30-50) show that the crack size of the battery using silicone rubber with a Shore hardness of 60 or more is small and the number of cracks is significantly reduced. Therefore, when using silicone rubber, a Shore hardness of 60 (elastic modulus 0.16 kgf / mm2) is preferred. 2 In this case, the upper limit of the Shore hardness of the reinforcing structures 500, 510a, and 510b is not limited as long as it does not cause damage to the flexible battery due to hardening during the formation of the reinforcing structures 500, 510a, and 510b, and can be a value of 100 or less.

[0114] It is possible to minimize damage to the packaging of the exterior members 100 and 200 formed at the center portion of the battery housing the electrode assemblies 101 and 201 due to repeated deformation (bending).

[0115] The reinforcing structures 500, 510a, and 510b disposed on the concave-convex patterns 120 and 220 prevent the battery from deforming beyond a reference range or a limit value, thereby avoiding the risk of changes in the electrode interface caused by deformation of the package due to repeated bending or excessive bending of the battery. This prevents the gap between the stacked electrode layers within the package (external component) from increasing, preventing the distance between the negative and positive electrodes, which should be in close contact, from increasing, and also prevents a sharp increase in resistance or lithium plating.

[0116] The method for manufacturing the exterior member 100, 200 according to the present invention may be a method of processing the exterior member 100, 200, housing the electrode assembly 101, 201, and sealing it to assemble the electrochemical cell 10. The method for manufacturing the exterior member 100, 200 according to the present invention includes the steps of forming the concave-convex pattern 120, 220 and forming the sealing portion 140, 240. The step of forming the concave-convex pattern 120, 220 may be a step of deforming the exterior member 100, 200 by applying pressure or the like, and the step of forming the sealing portion 140, 240 may be a step of joining the exterior members 100, 200 to house the electrode assembly 101, 201.

[0117] In addition, during the step of forming the sealing portion 140, 240 of the present invention, the overlapping region, which is a portion of the concave-convex pattern 120, 220, can be combined in a manner that overlaps with the sealing portion 140, 240. The overlapping region can be the end of the concave-convex pattern 120, 220 in one direction (width direction), and the overlapping region can overlap with the sealing portion 140, 240, so that the two sealing surfaces are joined. As a result, the overlapping region is processed to form a portion of the concave-convex pattern 120, 220 when the concave-convex pattern 120, 220 is formed, and can ultimately be included in a region of the sealing portion 140, 240. As a result, an edge region 130, 230 can be formed between the overlapping region and the concave-convex pattern 120, 220.

[0118] Figure 7 1 is a flowchart showing a method for manufacturing the battery 10 described in the first embodiment and the battery 20 described in the second embodiment. In this case, each battery can be manufactured through the same process.

[0119] In step S610, at least one convex portion 121, 221 may be formed along a direction on the exterior member 100, 200. For example, the at least one convex portion 121, 221 may be disposed between two concave portions 122, 222 and protrude in a direction opposite to the concave portions 122, 222.

[0120] Based on the width of the convex portion, the outer diameter of the concave portion can be designed to be 30-85% of the convex portion width. If the outer diameter of the concave portion is less than 30% of the convex portion width, irregular electrode layer gaps and large gaps cannot be suppressed. If the outer diameter of the concave portion is greater than 85%, it will interfere with adjacent concave portions and cause deformation of the concave shape.

[0121] In step S620, a recessed portion 123, 223 may be formed on at least one convex portion 121, 221. For example, when the width direction length of the convex portion 121, 221 is W, the outer diameter of the recessed portion 123 may be 0.3W to 0.85W, or 0.35W to 0.8W, but is not limited thereto.

[0122] For example, the depressions 123 and 223 can be formed using a precision air press that applies pressure to a punch formed into a dot shape. The precision air press consists of a punch, a die, and a four-axis assembly equipped with a ball bush. Limit blocks physically limit the distance between the punch and the die to adjust the depth of the depressions 123 and 223. The speed of the punch drop is adjusted to prevent damage to the exterior components 100 and 200.

[0123] 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 into the interior of the housing 110, i.e., into the accommodated electrode assembly 101, 201. Alternatively, the protrusion 121, 221 may be disposed between two recesses 122, 222, and may be formed to protrude in the opposite direction of the recesses 122, 222.

[0124] Here, the step of forming the recesses 122, 222 can be performed before or after the subsequent step of stamping the exterior parts 100, 200 with the convex parts 121, 221. In the case where the recesses 122, 222 are formed after the exterior parts 100, 200 with the convex parts 121, 221 are stamped, the exterior parts 100, 200 can be additionally stamped.

[0125] In step S640 , the electrode assembly 101 , 201 may be inserted into the exterior member 100 , 200 having the recessed portion 123 , 223 formed therein.

[0126] In step S650 , the exterior member 100 , 200 with the electrode assembly 101 , 201 inserted therein may be sealed.

[0127] Figure 7 Although not shown, the step of stamping the exterior member 100, 200 having the convex portion 121, 221 may be further included. In this case, the step of forming the concave portion 123, 223 may include forming the concave portion 123, 223 on the convex portion 121, 221 of the exterior member 100, 200 after stamping.

[0128] In the above description, steps S610 to S650 can be further divided into more steps or combined into fewer steps according to the implementation examples of the present invention. In addition, some steps can be omitted as needed, and the order of the steps can also be interchanged.

[0129] For example, the recessed portions 122 and 222 may be formed on the exterior components 100 and 200, followed by the steps of stamping to form the recessed portions 122 and 222, forming the convex portions 121 and 221, and then forming the depressed portions 123 and 223 on the formed convex portions 121 and 221. Specifically, the steps may be performed in the following order: forming the recessed portion on the exterior component → stamping → forming the convex portion → forming the depressed portion.

[0130] Furthermore, it is also possible to carry out the following steps: forming a concave portion on the exterior member → punching → forming a convex portion → additional punching → forming a depressed portion.

[0131] At this time, the depth of the depression formed on the protrusion can be freely adjusted within the above-mentioned height range based on the height of the protrusion. As an example, when the height of the protrusion is H, the depth of the depression can be 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, but is not limited to this.

[0132] Below, refer to Figure 8 The pattern depth in each step including the depth of the depressed portion will be exemplified.

[0133] Figure 8 Schematic diagram showing the depth of the pattern formed on the exterior component according to the process in the present invention. Figure 8 , describing the process of additional stamping of the exterior member 100 and the pattern depth of each process when the recessed portions 122 and 222 are formed after the exterior members 100 and 200 having the protrusions 121 and 221 are stamped.

[0134] Reference Figure 8 In (a), at least one convex portion 801 may be formed in one direction of the exterior member 800. For example, at least one convex portion 801 having a pattern depth of 0.45 to 0.50 mm may be formed on the exterior member 800.

[0135] Reference Figure 8 In (b), the exterior member 800 having the convex portion 801 formed thereon may be subjected to punching 802. For example, the exterior member 800 having the convex portion 801 formed thereon may be subjected to punching 802 so that the pattern depth thereof is 0.30 to 0.35 mm.

[0136] Reference Figure 8(c) A recessed portion 803 may be formed on the protrusion 801 of the exterior member after stamping. For example, at least two recessed portions 803 may be formed on the exterior member 800 having the protrusion 801 formed thereon, and the at least two recessed portions 803 may have a pattern depth of 0.40 to 0.45 mm based on the maximum height of the protrusion 801 after stamping.

[0137] Reference Figure 8 In (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 on the exterior member 800. In this case, the pattern depth of the recess 804 may be based on the maximum height of the protrusion 801 after stamping.

[0138] Reference Figure 8 In (e), after the recessed portion 804 is formed by stamping the exterior member 800 having the protrusion 801, the exterior members 100 and 200 may be subjected to additional stamping 805. For example, stamping 805 may be performed so that the exterior member 800 having the recessed portion 804 has a pattern depth of 0.50 to 0.55 mm. In this case, the pattern depths of the ultimately formed protrusions 801 and recessed portion 804 can be the same, and the pattern depth of the recessed portion 803 can meet the depth range of the recessed portion described above.

[0139] As described above, when the steps of forming a convex portion, stamping, forming a recessed portion, forming a concave portion, and then additional stamping are sequentially performed on the exterior component, the stamping is performed after the convex portion is formed, so the upper end of the convex portion is uniformly pressed. This has the advantage of facilitating the formation of a uniform depth at an accurate location when forming the recessed portion. Subsequently, additional stamping is performed after the concave portion is formed, thereby uniformly forming the pattern depth of the entire exterior component to the target value. This has the advantage of improving the accuracy of the patterning process and reducing the defect rate.

[0140] At this time, the risk of severe deformation or crushing of the sunken part can be avoided by adjusting the stamping pressure, time, gap, etc.

[0141] Furthermore, even if punching is performed twice, there is an advantage that cracks will not be generated due to damage to the metal layer inside the exterior member unless the punching pattern depth is 90% or more relative to the depth of the convex portion.

[0142] In this way, the patterning process is simplified, thereby having the advantages of reducing the defect rate and shortening the process steps, thereby reducing the process time.

[0143] On the other hand, Figure 8 Regardless of this, the process steps of forming the recessed portions before the step of punching the exterior member having the protruding portions formed thereon and the pattern depths in each step will be described below.

[0144] At least one convex portion may be formed in one direction of the exterior member. For example, at least one convex portion having a pattern depth of 0.45 to 0.55 mm may be formed on the exterior member.

[0145] At least one recessed portion may be formed adjacent to a convex portion. For example, at least one recessed portion may have a pattern depth of 0.70 to 0.75 mm on the exterior component. In this case, the recessed portion pattern depth may be based on the maximum height of the convex portion. If a recessed portion is formed after a convex portion, the pattern depth of the convex portion may be the same as the pattern depth of the recessed portion, based on the lowest end of the recessed portion.

[0146] When at least one recess is formed on the exterior member, the exterior member having at least one protrusion may be punched. For example, the exterior member having at least one protrusion may be punched so that the protrusion has a pattern depth of 0.50 to 0.55 mm.

[0147] The recessed portion may be formed on the protrusion of the stamped exterior component. For example, at least two recessed portions may be formed on the stamped exterior component having the protrusion formed thereon, each of which satisfies the depth range of the recessed portion based on the maximum height of the protrusion.

[0148] As described above, when the patterning process is performed on the exterior component in the order of forming a convex portion → forming a concave portion → punching → forming a depressed portion, the patterning process is simplified, thereby having the advantages of reducing the defect rate, shortening the process steps, and reducing the process time.

[0149] Here, when the convex and concave portions are formed on the exterior component before the stamping process, the pressure is not applied at a constant level. Therefore, even under the same load, the concave portions are easily compressed, resulting in an irregular reduction in the pattern depth. However, by performing the stamping process last, the upper and lower mold designs can be optimized to avoid severe asymmetric and uneven deformation.

[0150] Furthermore, it is of course possible to further include a step of additional punching as needed after forming the depressed portion.

[0151] The effects achieved by the recessed portions formed on the convex portions of the present invention are as follows. These effects can be obtained by performing the same evaluation on a conventional exterior component (having only convex portions and concave portions) and an exterior component of the present invention (having not only convex portions and concave portions but also recessed portions formed on the convex portions).

[0152] Specifically, the evaluation method is as follows: (1) after performing a bending evaluation (bending radius 15 mm, repeated 100 times), confirm the cracks and damage of the exterior parts; (2) confirm the internal electrode arrangement and the degree of adhesion through CT imaging.

[0153] Evaluations of existing exterior components and the exterior components of the present invention revealed that existing exterior components lack a recessed portion. Consequently, when the components are repeatedly bent with a large curvature, if they are bent or deformed beyond a reference range or a limit value due to misuse and abuse of the battery, the bending and folding of the battery may cause cracks in the exterior components, potentially damaging the battery and potentially leading to electrolyte leakage.

[0154] In contrast, the exterior member of the present invention can minimize the generation of irregular electrode layer gaps and large gaps because the recessed portion is formed on the convex portion.

[0155] Furthermore, when the flexible battery, including the exterior component provided in the present invention and including a recessed portion and a reinforcing structure formed in the recessed portion, was repeatedly bent, it was confirmed that the exterior component did not crack due to the resistance generated by the rigidity and support force of the reinforcing structure. Specifically, inspection of the interior of the exterior component provided by the present invention revealed that the gaps between the electrode layers remained uniform across all sections of the exterior component during bending.

[0156] The above description of the present invention is exemplary, and those skilled in the art will appreciate that the present invention can be easily implemented in other specific forms without changing the technical concept or essential features of the present invention. Therefore, it should be understood that the above embodiments are exemplary in all respects and not restrictive. For example, each component described as a single form can be implemented in a dispersed manner, and similarly, components described as dispersed can also be implemented in a combined form.

[0157] The scope of the present invention is indicated by the following claims rather than detailed description, and it should be understood that all changes or modifications derived from the meaning, scope and equivalent concepts of the claims are included in the scope of the present invention.

[0158] Description of Reference Numerals

[0159] 10, 20: battery, electrochemical cell

[0160] 100, 200: Exterior parts

[0161] 101, 201: electrode assembly

[0162] 102, 202: Electrode leads

[0163] 110, 210: Storage department

[0164] 120, 220: Concave and convex pattern

[0165] 121, 221: convex part

[0166] 122, 222: concave part

[0167] 123, 223: sunken part

[0168] 130, 230: marginal areas

[0169] 140, 240: Sealing part.

Claims

1. A battery comprising: an electrode assembly comprising a plurality of electrodes; as well as The outer member accommodates the electrode assembly and is formed with a concave-convex pattern including at least one concave portion and at least one convex portion. The convex portion includes a depressed portion in which a portion of the convex portion is depressed.

2. The battery according to claim 1, wherein The at least one convex portion is formed with at least two depressed portions in a direction corresponding to a width of the battery.

3. The battery according to claim 2, wherein It is designed that the interval between the at least two depressed portions formed on the first convex portion of the at least one convex portion is the same as the interval between the at least two depressed portions formed on the second convex portion located behind the first convex portion.

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

5. The battery according to claim 2, wherein It is designed that the interval between the at least two depressed portions formed on a first convex portion of the at least one convex portion is different from the interval between the at least two depressed portions formed on a second convex portion located behind the first convex portion.

6. The battery according to claim 5, wherein The depressed portion formed on the first convex portion is formed to have a second gap from an edge region of the exterior member.

7. The battery according to claim 5, wherein The depressed portion formed on the second convex portion is formed to have a third gap between it and an edge region of the exterior member.

8. The battery according to claim 1, wherein The exterior component comprises: a receiving portion for receiving the electrode assembly; and The sealing portion is bonded to the sealing surface along the periphery of the housing portion to seal the electrode assembly.

9. The battery according to claim 8, wherein The at least one concave portion and the at least one convex portion include edge regions at their ends in a direction corresponding to the width of the battery, and the edge regions form a boundary line with the sealing portion.

10. The battery according to claim 8, wherein The sealing portion has a pattern whose height in the thickness direction of the exterior member is lower than that of the concavo-convex pattern.

11. The battery according to claim 1, wherein The depressed portion is formed with a reinforcement structure for reinforcing the exterior member.

12. A method for manufacturing a battery, comprising: forming at least one protrusion along a direction on the exterior member; forming at least one concave portion at a position adjacent to the convex portion; forming a depressed portion in the at least one convex portion; a step of inserting the electrode assembly into the outer casing having the recessed portion; as well as The step of sealing the exterior member into which the electrode assembly is inserted.

13. The battery manufacturing method according to claim 12, wherein: The method further includes the step of punching the outer member having the convex portion formed thereon, In the step of forming the depressed portion, the depressed portion is formed in the punched convex portion of the exterior member.

14. The battery manufacturing method according to claim 12, wherein: The step of forming the concave portion is performed before or after the step of punching the exterior member having the convex portion formed thereon.

15. The battery manufacturing method according to claim 14, wherein: The method further includes the step of further punching the exterior member after the recessed portion is formed by punching the exterior member having the protruding portion.

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