Exterior material, method of forming pattern in exterior material, and method of manufacturing battery including exterior material

Abstract

An outer material for a battery includes at least one pattern portion formed along a machine direction (MD) of the outer material, the MD of the outer material being a width direction of the battery including the outer material, and a transverse direction (TD) of the outer material being a length direction of the battery including the outer material.

Description

Technical Field

[0001] This invention relates to an outer casing material, a method for forming a pattern on the outer casing material, and a method for manufacturing a battery including the outer casing material. Background Technology

[0002] An electrochemical cell is a component that can provide electrical energy by consisting of at least two electrodes and an electrolyte. In particular, lithium-ion batteries, which are composed of rechargeable and dischargeable secondary cells, are widely used in various advanced electronic devices, including smartphones.

[0003] Recently, in designing mobile devices, including smartphones, and various wearable devices, there has been an increasing trend towards designs that deviate from traditional shapes. Consequently, there is growing interest in flexible devices that can bend while maintaining functionality. Therefore, ensuring the functionality and safety of flexible electrochemical batteries embedded in such flexible devices and used as power sources is of paramount importance.

[0004] Repeated bending and unfolding of flexible batteries poses a risk of damaging the outer casing. Severe damage to the casing can lead to leakage of the internal electrolyte. Furthermore, even minor damage to the casing allows moisture from the air to penetrate the battery, causing swelling and damaging the electrodes, thereby reducing the battery's capacity and output.

[0005] Therefore, in order to prevent damage to the outer casing material of a flexible battery by absorbing the compressive and tensile stresses generated during battery bending, the outer casing material is patterned using upper and lower molds under pressure. Compared to batteries using unpatterned outer casing materials, batteries using patterned outer casing materials have an increased initial modulus of elasticity (initial elastic modulus). Therefore, when the battery bends, the forces acting on the outer casing material are dispersed rather than concentrated on one side. As a result, the outer casing material and the internally housed electrode assemblies do not bend severely in any one part.

[0006] In addition, the pattern of the outer material does not need to be deep, but it needs to minimize the damage to the outer material caused by repeated bending, folding, twisting and other actions of the battery, thereby improving the battery's durability.

[0007] When external forces are applied to a battery, such as when the battery is bent, folded, or twisted, the compressive force applied along the thickness direction has a greater impact on the battery's durability than the tension in the length direction of the outer material.

[0008] Furthermore, when the electrode assembly housed inside the outer casing deforms, it exerts a force that pushes the outer casing outward. If the outer casing cannot withstand the force from the internal electrode assembly, the internal electrode assembly is prone to bending around a weak point in the outer casing, and damage to that part of the outer casing can lead to safety incidents such as reduced battery performance, swelling, and leakage.

[0009] To further improve the durability of flexible batteries, a patterning method is needed that can increase the bending moment in the battery's bending region. Specifically, to improve the bending durability of flexible batteries, a patterning method is needed that increases the compressive stress of the outer material.

[0010] Patent Document 1: Korean Patent Publication No. 2005-0052069 (published on June 2, 2005)

[0011] Patent Document 2: Japanese Patent Publication No. 2013-218991 (published on October 24, 2013) Summary of the Invention

[0012] The problem that the invention aims to solve

[0013] The present invention addresses the problems of the prior art described above by providing an outer casing material for a battery, comprising at least one patterned portion formed along the machine direction (MD) of the outer casing material, wherein the MD of the outer casing material is the width direction of the battery including the outer casing material, and the transverse direction (TD) of the outer casing material is the length direction of the battery including the outer casing material.

[0014] One object of the present invention is to provide a method for forming a pattern on an outer material along the direction of the longest fatigue life of the outer material, and a method for manufacturing a battery including the outer material, so as to prevent damage to the outer material and improve the durability of the battery.

[0015] However, the technical problem to be solved in this embodiment is not limited to the technical problem described above, and other technical problems may also exist.

[0016] Solution for solving the problem

[0017] As a solution to the technical problem described above, in one embodiment of the present invention, the outer casing material for the battery includes at least one patterned portion formed along the MD of the outer casing material, wherein the MD of the outer casing material can be the width direction of the battery including the outer casing material, and the TD of the outer casing material can be the length direction of the battery including the outer casing material.

[0018] In one embodiment, the outer casing material is folded along the TD of the outer casing material to manufacture the battery, and the outer casing material used to manufacture the battery can be bent along the TD of the outer casing material, so that the battery is bent along the TD of the outer casing material.

[0019] In one embodiment, the outer casing material is folded along the MD of the outer casing material to manufacture the battery, and the outer casing material used to manufacture the battery can be bent along the TD of the outer casing material, so that the battery is bent along the TD of the outer casing material.

[0020] In one embodiment, the outer material further includes a sealing portion surrounding the patterned portion, such that a portion of the two surfaces are joined together in such a way that a sealed space is formed between the two surfaces of the outer material, and the edge portion of the patterned portion may be adjacent to the sealing portion.

[0021] In one embodiment, the radius of curvature of the edge portion of the patterned portion may be smaller than the radius of curvature of the center portion of the patterned portion.

[0022] In one embodiment, the radius of curvature gradually decreases from the center portion of the pattern portion toward the edge portion of the pattern portion.

[0023] In one embodiment, considering the possibility of damage to the edge portion of the patterned portion, the patterned portion may be formed along the MD of the outer material.

[0024] In one embodiment, the fatigue life of the edge portion of the patterned portion formed along the MD of the outer casing material can be determined based on the deformation of the edge portion of the patterned portion.

[0025] In one embodiment, the fatigue life of the deformation of the edge portion of the patterned portion may be longer than the fatigue life of the deformation of the edge portion of the patterned portion of another outer material, wherein the other outer material includes at least one patterned portion formed along the TD of the outer material.

[0026] In one embodiment, the aforementioned outer material may be formed from a multilayer structure of laminating one or more materials.

[0027] In another embodiment of the present invention, the method of forming a pattern on an outer casing material may include the following steps: placing the outer casing material between an upper mold and a lower mold; and stamping the outer casing material using the upper mold and the lower mold to form at least one patterned portion along the MD of the outer casing material, wherein the MD of the outer casing material may be the width direction of a battery including the outer casing material, and the TD of the outer casing material may be the length direction of a battery including the outer casing material.

[0028] In another embodiment of the present invention, a method for manufacturing a battery including an outer casing material may include the following steps: forming at least one patterned portion on the outer casing material along the MD of the outer casing material; folding the outer casing material; inserting an electrode assembly into the folded outer casing material; and sealing the outer casing material to which the electrode assembly is inserted. The MD of the outer casing material may be the width direction of the battery including the outer casing material, and the TD of the outer casing material may be the length direction of the battery including the outer casing material.

[0029] Invention Effects

[0030] According to one of the solutions to the problem described above, the present invention can provide an outer casing material for a battery, comprising at least one patterned portion formed along the MD of the outer casing material, wherein the MD of the outer casing material is the width direction of the battery including the outer casing material, and the TD of the outer casing material is the length direction of the battery including the outer casing material.

[0031] Furthermore, the present invention provides a method for forming a pattern on an outer casing material along the direction of the material's longest fatigue life, and a method for manufacturing a battery including the outer casing material. This reduces damage to the edge portions of the pattern with small radii of curvature and improves the battery's bending durability.

[0032] Furthermore, it prevents damage to the edges of the outer packaging material and electrolyte leakage, thereby improving battery safety. Attached Figure Description

[0033] Figure 1 A diagram illustrating the exterior materials is provided.

[0034] Figure 2 The diagram illustrates the outer material and pattern portion of an embodiment of the present invention.

[0035] Figure 3 To show along with Figure 2 The diagram shows the outer material of the patterned portion formed by different directions of the patterned portion.

[0036] Figure 4a A perspective view of a battery including an outer casing material according to an embodiment of the present invention is provided.

[0037] Figure 4b To show Figure 4a The diagram shows the cross-sectional shape of the battery.

[0038] Figure 5a This is a diagram illustrating the cross-sectional shape of the patterned portion and the radius of curvature of the patterned portion according to an embodiment of the present invention.

[0039] Figure 5b This is a diagram illustrating the radius of curvature of the patterned portion in an embodiment of the present invention.

[0040] Figure 5c This is a diagram illustrating the shape of the patterned portion when viewed from above according to an embodiment of the present invention.

[0041] Figure 6 The stress-deformation rate curve is shown.

[0042] Figure 7a This is a diagram illustrating a method for evaluating the flexural durability of a battery, including its outer casing.

[0043] Figure 7b This diagram illustrates the forces acting on the outer casing when evaluating the flexural durability of a battery, including the casing material.

[0044] Figure 8 This is a flowchart illustrating a method for forming a pattern on an outer casing material according to an embodiment of the present invention.

[0045] Figure 9 This is a flowchart illustrating a method for manufacturing a battery including an outer casing material, according to an embodiment of the present invention. Detailed Implementation

[0046] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, enabling those skilled in the art to readily implement the embodiments of the present invention. However, the present invention can be implemented by various different methods and is not limited to the embodiments described herein. Furthermore, in the accompanying drawings, parts unrelated to the description have been omitted for clarity, and similar reference numerals have been used for similar parts throughout the specification.

[0047] Throughout the specification, when a part is referred to as "including" a component, other components may be included, rather than excluded, unless specifically stated otherwise. Furthermore, throughout the specification, when a part is referred to as "connected" to another part, this includes not only direct connections but also connections with other components in between, and electrical connections through other components. Moreover, throughout the specification, when a component is referred to as being "on" another component, this includes not only cases where the component is in contact with the other component but also cases where other components exist between the two components.

[0048] The battery of the present invention, including the outer casing, can be, for example, an electrochemical battery or a lithium-ion battery. Specifically, the battery of the present invention, including the outer casing, can be configured such that the electrode assembly and the electrolyte are contained and sealed inside the outer casing, thereby charging and discharging through the movement of lithium ions. The battery of the present invention, including the outer casing, can be a flexible battery, which can be configured to be flexible and bendable while maintaining its functional state. Hereinafter, embodiments of the present invention will be specifically described with reference to the accompanying drawings.

[0049] Figure 1 The diagram illustrates an example of an outer casing material. For instance, the outer casing material 100 can be formed in a multilayer structure by laminating more than one material. Each of the more than one material may possess a specific toughness.

[0050] For example, the multi-layer structure of the outer casing material 100 may include a sealing layer, a barrier layer, and a protection layer, distinguished according to the function of each layer. The sealing layer may be made of polypropylene (PP) film. The barrier layer may be made of aluminum foil. The protection layer may be made of nylon film or a composite layer of nylon and polyethylene terephthalate (PET).

[0051] The outer material 100 is manufactured using a roll-to-roll process, and its mechanical properties can vary depending on the axial or longitudinal direction of the roller. The machine direction (MD) can refer to the length of the roller, while the transverse direction (TD) can refer to the axial direction of the roller.

[0052] In the outer casing materials used in flexible batteries, the mechanical properties of the battery can vary depending on the direction in which the pattern is formed. That is, batteries with outer casing materials in which the pattern is formed along the MD (Medium-Density) of the outer casing material and batteries with outer casing materials in which the pattern is formed along the TD (Diverterless Transformation) of the outer casing material can have different mechanical properties. Therefore, the direction of pattern formation can affect the durability of the patterned edge portions of the flexible battery.

[0053] Figure 2 This diagram illustrates the outer casing material and patterned portion according to an embodiment of the present invention. (Refer to...) Figure 2 The outer material 100 may include at least one patterned portion 111md formed along the MD of the outer material 100.

[0054] Including the formation of Figure 2 When the battery is manufactured using the outer material 100 of the patterned portion 111md shown, the MD of the outer material can be the width direction 10A of the battery, and the TD of the outer material can be the length direction 10B of the battery.

[0055] Figure 3 Show along with Figure 2 The patterned portion 111md shown has its outer material formed in different directions. Figure 3The outer material shown has a patterned portion 111td formed along the TD of the outer material.

[0056] Including the formation of Figure 3 In the case of manufacturing a battery using the outer material of the patterned portion 111td shown, the TD of the outer material can be the width direction 10A of the battery, and the MD of the outer material can be the length direction 10B of the battery.

[0057] Figure 4a To illustrate a perspective view of a battery including an outer casing material 100 according to an embodiment of the present invention, Figure 4b To show Figure 4a The diagram shows the cross-sectional shape of the battery.

[0058] Reference Figure 4a and Figure 4b The battery 10 may include: an outer casing 100; an electrode assembly 200 housed inside the outer casing 100; and an electrode lead 300 connected to the electrode assembly 200.

[0059] The electrode assembly 200 has a plurality of electrodes and may also include a separation membrane. The electrode assembly 200 can be formed in a structure in which the plurality of electrodes and the separation membrane are stacked along the thickness direction.

[0060] The electrode assembly 200 may include a first electrode and a second electrode with different polarities. A mixture containing active materials may be coated on both sides or one side of the first and second electrodes, respectively. A separation membrane may be disposed between the first and second electrodes. For example, the first electrode may be a negative electrode, and the current collector used may be made of copper, aluminum, etc., or may be made of graphite, carbon, lithium, silicon, SiO2, etc. x The negative electrode active material is composed of one or more combinations of silicon derivatives, silicon-graphite composites, tin, and silicon-tin composites. Furthermore, the second electrode is the positive electrode, and the current collector used is made of materials such as aluminum or stainless steel, and it can be made of one or more combinations of positive electrode active materials such as 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.

[0061] In the electrode assembly 200, the length direction of the two directions in which the first electrode and the second electrode form surfaces extend is longer than the width direction, and the active material and the separation membrane have a thin shape along the thickness direction that intersects (e.g., orthogonally) with the direction of the forming surfaces.

[0062] Furthermore, the electrode assembly 200 may include electrode connecting tabs and lead connecting tabs. The electrode connecting tabs can be formed such that one end of the first electrode and the second electrode protrudes along their length, and electrode connecting tabs protruding in electrodes of the same polarity can be combined. The electrodes can be electrically connected in parallel via the electrode connecting tabs. The lead connecting tabs are connected to the electrode leads 300 and can protrude in the positive and negative electrodes to combine with the electrode leads 300.

[0063] Specifically, the outer casing 100 may include a receiving portion 110 and a sealing portion 120. The receiving portion 110 forms a space for receiving the electrode assembly 200, and the sealing portion 120 is capable of engaging in a manner that seals the received electrode assembly 200 from the outside. Figure 4b As shown, the receiving portion 110 can correspond to the areas of two outer materials 100 that are spaced apart from each other and facing each other. In order to form the receiving portion 110, the outer materials 100 can be processed in a way that presses and protrudes along the thickness direction, so that the predetermined area of ​​the outer materials 100 is approximately in the shape of a quadrilateral bowl (or cup).

[0064] More specifically, in this embodiment, at least one patterned portion 111md may be formed on the surface of the receiving portion 110 extending along the MD of the outer casing material 100. The patterned portion 111md is a pattern that is repeated along a direction extending and intersecting another direction. Specifically, it may alternately protrude or recess along the thickness direction (i.e., alternately protrude along opposite directions) to have a raised / lower shape along a direction. One direction is the width direction 10A of the battery, which is the MD of the outer casing material 100, and the direction in which the patterned portion 111md is repeated may be the length direction 10B of the battery, which is the TD of the outer casing material 100. Figure 4b As shown, the outer material 100 forming the receiving portion 110 can form a corrugated or pleated pattern along the length direction through the protruding and recessed pattern portion 111md.

[0065] The sealing portion 120 can be formed by joining two sealing surfaces. The sealing surface refers to the joint surface of the outer material 100, and the internal space (receiving portion 110) can be separated from the outside by joining two sealing surfaces that overlap along the edge of the receiving portion 110. The aforementioned electrode assembly 200 and electrolyte can be housed in the internal space, and the electrode assembly 200 and electrolyte can be kept in a sealed state.

[0066] That is, the sealing part 120 surrounds the pattern part 111md, which can form a sealed space between the two surfaces of the outer material 100.

[0067] Furthermore, the sealing portion 120 may have a flat plate shape extending along the width direction 10A or the length direction 10B of the battery. For example, the flat plate shape of the sealing portion 120 may be a non-bent shape, such that the surfaces do not face each other. Alternatively, the sealing portion 120 may have a pattern different from the patterned portion 111md, for example, it may have a pattern whose height along the thickness direction is lower than that of the patterned portion 111md.

[0068] The edge portion 110e of the patterned portion can be a portion adjacent to the sealing portion 120. For example, the edge portion 110e of the patterned portion can include a region adjacent to a portion of the sealing portion 120 that extends along the length direction 10B of the battery.

[0069] Furthermore, the electrode leads 300 are connected to the electrode assembly 200 inside the outer casing 100 and extend to the outside of the outer casing 100. The electrode leads 300 serve as terminals for electrical connection with the electrode assembly 200 housed inside the outer casing 100, and when the sealing portion 120 is formed, they can penetrate the sealing portion 120 in a manner disposed between sealing surfaces through engagement. A pair of positive and negative electrode leads 300 can be combined with lead connectors of the same polarity disposed on the electrode assembly 200.

[0070] The outer casing material 100 of the present invention is folded along the TD or MD of the outer casing material 100 for manufacturing the battery 10. In this case, the outer casing material 100 for manufacturing the battery 10 can be bent along the TD of the outer casing material 100, so that the battery can be bent along the TD of the outer casing material 100. That is, by having a patterned portion with a corrugated or pleated pattern along the MD of the outer casing material 100, the outer casing material 100 can be movable along the TD of the outer casing material 100, and therefore, the battery using this outer casing material 100 can also be movable along the TD of the outer casing material 100.

[0071] Hereinafter, the outer material 100 and the patterned portion 111md of an embodiment of the present invention will be described. Figure 5a This diagram illustrates the cross-sectional shape and radius of curvature of the patterned portion 111md according to an embodiment of the present invention. (Refer to...) Figure 5a The pattern section 111md can be formed by repeating concave and convex shapes having a specified pattern height h1 and pattern spacing P. For example... Figure 5a When its shape is wavy, curvature indicates the degree of curvature of the curve or surface, and the radius of curvature R refers to the radius of the arc.

[0072] Figure 5b This diagram illustrates the radius of curvature of the pattern portion 111md according to an embodiment of the present invention. The radius of curvature of the pattern portion 111md gradually decreases from the center portion of the pattern portion toward the edge portion of the pattern portion.

[0073] Figure 5cThis diagram shows the shape of the patterned portion of an embodiment of the present invention when viewed from above. When the patterned portion 111md is viewed from above, the width of the pattern along TD gradually decreases from the center portion of the patterned portion toward the edge portion 110e. (Refer to...) Figure 5b and Figure 5c The radius of curvature R2 of the edge portion 110e of the pattern portion can be smaller than the radius of curvature R1 of the center portion of the pattern portion.

[0074] When a flexible battery is repeatedly deformed, the edge portion of the patterned part with a relatively small radius of curvature is more likely to develop damage such as pin holes and cracks compared to the center portion of the patterned part with a large radius of curvature.

[0075] Table 1 shows the thickness and total thickness of each structure of outer casing material A, outer casing material B, outer casing material C, and outer casing material D. For example, outer casing material A, outer casing material B, and outer casing material C can be manufactured roll to roll using the A lamination process, and outer casing material D can be manufactured roll to roll using the B lamination process.

[0076] Table 1

[0077]

[0078] Previous batteries did not require bending or deformation, so the mechanical properties of the outer casing material as revealed by repeated folding were not taken into account.

[0079] However, for the outer casing material using flexible batteries, the difference in mechanical properties when the outer casing material is repeatedly folded is more significant compared to the mechanical properties of the outer casing material when it is never folded. The direction of forming the patterned portion can be determined based on the mechanical properties of the outer casing material when it is repeatedly folded, including the patterned portion formed along the direction of the patterned portion (i.e., the MD of the outer casing material) and the outer casing material when it is repeatedly folded, including the patterned portion formed along the TD of the outer casing material.

[0080] In flexible batteries, the patterned edges of the outer material with the smallest radius of curvature are frequently damaged. The state with the smallest radius of curvature is the folded state, and the bending durability of the flexible battery can be easily assessed (accelerated testing) by repeatedly folding the outer material.

[0081] The following describes a method for evaluating the durability of the outer materials included in a battery, namely, a tensile test after repeated folding.

[0082] For outer casing materials with different orientations (MD, TD) in their composition and patterned areas, stamped samples are made with specified widths and lengths. For example, an outer casing material can be stamped in the shape of a dumbbell with a width of 10 mm and a length of 100 mm.

[0083] Next, press and fold the center portion of each outer material along its length using the same pressure and time. For example, it is possible to press and fold the outer material with a pressure of 0.2 MPa for 2 seconds. It is possible to repeatedly fold and unfold each outer material in the same manner.

[0084] A tensile testing machine is used to fix and limit displacement along the length of the specimen, allowing it to be stretched at a specified deformation rate. For example, the length of the outer material sample before stretching can be 100 mm, and the length of the outer material sample after stretching can be 105 mm. The limited displacement can be 5 mm, and the deformation rate can be 5%.

[0085] For example, an outer material with a patterned portion (MD pattern) is formed along the MD fold of the outer material, and can be stretched along the TD. An outer material with a patterned portion (TD pattern) is formed along the TD fold of the outer material, and can be stretched along the MD.

[0086] For each outer casing material, after repeated folding a single number of times, the presence or absence of damage was confirmed using an electron microscope. Table 2 shows the results of the tensile test performed on outer casing materials A to D shown in Table 1 after the aforementioned repeated folding.

[0087] Table 2

[0088]

[0089]

[0090] As shown in Table 2, after being stretched following 5 folds, no damage was found in any of the outer materials A, B, C, and D.

[0091] After repeated folding and stretching 10 times, among outer materials A, B, and C, the outer material sample with the pattern formed along the MD region of the outer material was undamaged, but the outer material sample with the pattern formed along the TD region of the outer material was damaged. In outer material D, the outer material sample with the pattern formed along the TD region of the outer material was more severely damaged than the outer material sample with the pattern formed along the MD region.

[0092] After being repeatedly folded 15 times and stretched, among outer materials A, B, and C, the outer material sample with the pattern formed along the TD part of the outer material showed greater damage than the outer material sample with the pattern formed along the MD part of the outer material.

[0093] As described above, for outer materials A, B, C, and D, the results of tensile tests after repeated folding show that the durability of outer materials A, B, C, and D when folded along MD and stretched along TD is higher than that of outer materials when folded along TD and stretched along MD. In other words, the outer materials have higher bending and folding durability.

[0094] Patterning is formed along the MD of the outer material to minimize damage to the edge portions of the patterned portions with small radii of curvature and improve the bending durability of the battery.

[0095] Figure 6 To illustrate the stress-strain curve. In Figure 6 In the graph shown, toughness represents the area under the stress-deformation rate curve.

[0096] Table 3 shows the results of evaluating the mechanical properties after performing the above-mentioned repeated folding and tensile test on the outer material B.

[0097] Table 3

[0098]

[0099] Table 4 shows the results of evaluating the mechanical properties of the outer material C after the above-mentioned repeated folding and tensile test.

[0100] Table 4

[0101]

[0102] Table 5 shows the results of evaluating the mechanical properties of the outer material D after the above-mentioned repeated folding and tensile test.

[0103] Table 5

[0104]

[0105] Typically, outer casing materials manufactured roll to roll using process A or process B exhibit significant flexibility along the MD of the outer casing material and significant rigidity along the TD of the outer casing material.

[0106] Reference Figure 6 As shown in Tables 3 to 5, with the increase of repeated folding, the toughness of the outer material with the pattern formed along the MD is higher than that with the pattern formed along the TD. Therefore, in outer materials B, C and D, it can be confirmed that the fatigue life of the outer material with the pattern formed along the MD is longer.

[0107] When the outer material D is folded 0 times, i.e., without repeated folding, the toughness shows a tendency opposite to that of the outer materials B and C without repeated folding. This is due to the difference caused by the lamination process and the internal materials. In batteries that are repeatedly bent or deformed, the mechanical properties that change through repeated deformation are more meaningful than the mechanical properties that are not repeatedly folded.

[0108] Figure 7a This is a diagram illustrating another method for evaluating the flexural durability of a battery, including its outer casing. (See reference...) Figure 7a A bending assessment is performed by bending the battery 10, including the outer casing material 100, multiple times along one direction.

[0109] Reference Figure 7b When the battery 10, including the outer casing material 100, is bent, a force 710 acts in the direction of contraction of the outer casing material 100 in the inner bending diameter, and a force 720 acts in the direction of relaxation of the outer casing material 100 in the outer bending diameter. A bending evaluation can be performed on the battery 10, including the outer casing material 100, which includes a patterned portion 111md, along the TD of the outer casing material. In other words, a bending evaluation can be performed by bending the battery including the outer casing material 100 along the length direction 10B of the battery.

[0110] In contrast, for batteries that include an outer casing material, a bending assessment can be performed by bending the battery including the outer casing material along the MD of the outer casing material, i.e., along the length direction 10B of the battery, where the outer casing material includes a patterned portion 111td.

[0111] In one embodiment, the bending assessment can be performed by bending the battery under R15, 25 rpm conditions.

[0112] Table 6 shows the results of bending evaluations performed on any one of the outer materials A, B, C, and D shown in Table 1, with the case where the pattern is formed along the MD portion of the outer material (MD pattern) and the case where the pattern is formed along the TD portion of the outer material (TD pattern). For example, battery 1 in Table 6 refers to a battery that includes outer material A, which has the pattern formed along the MD portion of the outer material.

[0113] Table 6

[0114]

[0115]

[0116] Based on the bending evaluation results of batteries 1 to 8 shown in Table 6, it was confirmed that in the case where the patterned portion is formed along the MD of the outer casing material, the degree of damage to the edge portion of the patterned portion is significantly reduced compared to the case where the patterned portion is formed along the TD of the outer casing material.

[0117] Therefore, by forming a pattern along the MD on the outer material, damage to the edge portion of the patterned portion of the outer material is minimized, thereby reducing electrolyte leakage and swelling, and improving the battery's bending durability and safety.

[0118] Figure 8 This is an illustrative diagram illustrating a method for forming a pattern on an outer casing material according to an embodiment of the present invention.

[0119] In step S810, the outer material 100 can be positioned between the upper mold and the lower mold.

[0120] In step S820, the outer material 100 can be stamped using the upper mold and the lower mold to form at least one patterned portion 111md along the MD of the outer material 100.

[0121] Wherein, MD of the outer casing material can be the width direction of the battery including the outer casing material, and TD of the outer casing material can be the length direction of the battery including the outer casing material.

[0122] In the above description, steps S810 to S820 can be further divided into additional steps or combined into fewer steps according to the implementation of the present invention. Furthermore, some steps can be omitted as needed, and the order of the steps can be changed.

[0123] Figure 9 This is an illustrative diagram illustrating a method for manufacturing a battery including an outer casing material according to an embodiment of the present invention.

[0124] In step S910, at least one patterned portion 111md may be formed on the outer material 100 along the MD of the outer material 100.

[0125] In step S920, the outer material 100, which is foldable to form the patterned portion 111md, is folded.

[0126] In step S930, electrode assembly 200 can be inserted into folded outer material 100.

[0127] For example, the outer casing material has a patterned portion corresponding to the upper surface of the battery and a patterned portion corresponding to the lower surface of the battery formed along the MD of the outer casing material. The outer casing material can be folded (folding operation) along the TD of the outer casing material with the center line between the two patterned portions as a reference. For the outer casing material folded with the center line between the two patterned portions as a reference, the patterned portion corresponding to the upper surface of the battery and the patterned portion corresponding to the lower surface of the battery overlap, and the electrode assembly can be inserted in such an overlapping manner at the position of these patterned portions.

[0128] As another example, the outer material with a patterned portion can be folded along the MD of the outer material. Electrode assemblies can then be inserted into the folded outer material.

[0129] In step S940, the outer material 100 into which the electrode assembly 200 is inserted can be sealed. For example, the outer material 100 can be sealed by performing a sealing operation around the outer material on four sides to create four sealing regions, two of which can be formed along the MD of the outer material 100 and the remaining two sealing regions can be formed along the TD of the outer material 100.

[0130] Wherein, MD of the outer casing material can be the width direction of the battery including the outer casing material, and TD of the outer casing material can be the length direction of the battery including the outer casing material.

[0131] In the above description, steps S910 to S940 can be further divided into additional steps or combined into fewer steps according to the implementation examples of the present invention. Furthermore, some steps can be omitted as needed, and the order of the steps can be changed. In particular, the process of forming the patterned portion of the outer material can be performed before or after sealing the outer material in the present invention.

[0132] In the outer casing material of the present invention, the fatigue life of the deformation of the edge portion of the patterned portion formed along the MD of the outer casing material can be determined according to the patterned portion formed along the MD of the outer casing material. For example, the fatigue life of the deformation of the edge portion of at least one patterned portion formed along the MD of the outer casing material can be longer than the fatigue life of the deformation of the edge portion of a patterned portion of another outer casing material, which includes at least one patterned portion formed along the TD of the outer casing material.

[0133] Therefore, the outer material including the patterned portion formed along the MD of the outer material of the present invention can improve the fatigue life of the edge portion of the patterned portion of the outer material. Herein, fatigue life can refer to the fatigue life of deformation that occurs when force is applied to the edge portion of the outer material, such as folding (e.g., the operation of folding the outer material for manufacturing a battery), bending (e.g., the operation of bending a battery or the outer material), or repeated folding (e.g., the operation of repeatedly folding the outer material for battery durability testing).

[0134] That is, the pattern portion can be formed along the MD of the outer material, taking into account the possibility of damage to the edge portion of the pattern portion in the outer material. By forming the pattern portion along the MD of the outer material, the probability of damage to the edge portion of the pattern portion in the outer material with a relatively small radius of curvature can be reduced.

[0135] As described above, the battery, which includes the MD patterned portion along the outer material, has a small bending radius, thus making it suitable for use in devices with relatively high fatigue strength.

[0136] For example, the bending radius of the battery inside the device is equivalent to 5R (finger circumference) to 35R (ankle circumference), which can be applied to wristbands, watches, ring-type smart devices, etc.

[0137] The foregoing description of the present invention is illustrative, and it will be understood by those skilled in the art that it can be easily modified into other specific forms without changing the technical concept or essential features of the invention. Therefore, the embodiments described above are merely illustrative in all respects and should not be construed as limiting. For example, components described as a single element can also be implemented separately; similarly, components described separately can also be implemented in combination.

[0138] The scope of this invention is set forth in the claims rather than in the detailed description, and the meaning and scope of the claims, as well as all variations or modifications derived therefrom, are included within the scope of this invention.

Claims

1. A battery comprising an outer casing material, characterized in that, The outer casing materials include: At least one patterned portion extending longitudinally along the outer material and having a raised or recessed shape repeatedly arranged in a direction intersecting the longitudinal direction; and A sealing portion, which surrounds the patterned portion, engages portions of the two surfaces in such a way that a sealing space is formed between the two surfaces of the outer material. The longitudinal direction of the outer casing material is the width direction of the battery including the outer casing material. The transverse direction of the outer casing material is the length direction of the battery including the outer casing material. The edge portion of the patterned part is adjacent to the sealing part. The radius of curvature of the edge portion of the pattern is smaller than the radius of curvature of the center portion of the pattern. Wherein, the transverse direction is the axial direction of the rollers of the outer material manufactured by the roll-to-roll process, and the longitudinal direction is the length direction of the rollers of the outer material.

2. The battery according to claim 1, characterized in that, The outer casing material is used to manufacture the battery by folding it laterally. The outer material used to manufacture the battery is bent laterally along the outer material, such that the battery is bent laterally along the outer material.

3. The battery according to claim 1, characterized in that, The outer casing material is folded along its longitudinal direction to manufacture the battery. The outer material used to manufacture the battery is bent laterally along the outer material, such that the battery is bent laterally along the outer material.

4. The battery according to claim 1, characterized in that, The radius of curvature gradually decreases from the center portion of the pattern towards the edge portion of the pattern.

5. The battery according to claim 1, characterized in that, Considering the possibility of damage to the edge portion of the patterned part, the patterned part is formed along the longitudinal direction of the outer material.

6. The battery according to claim 1, characterized in that, The fatigue life is determined by the deformation of the edge portion of the patterned portion formed along the longitudinal direction of the outer material.

7. The battery according to claim 6, characterized in that, The fatigue life of the deformation of the edge portion of the patterned part is longer than that of the deformation of the edge portion of the patterned part of another outer material, the other outer material including at least one patterned part formed along the transverse direction of the outer material.

8. The battery according to claim 1, characterized in that, The outer casing material is formed by a multi-layer structure of laminating one or more materials.

9. A method for manufacturing a battery including an outer casing material, characterized in that, The steps include the following: At least one patterned portion is formed in the outer material, wherein the at least one patterned portion extends along the longitudinal direction of the outer material and has a concave-convex shape that is repeatedly arranged along a direction intersecting the longitudinal direction; Fold the aforementioned outer casing material; Insert the electrode assembly into the folded outer casing material; The outer casing material into which the electrode assembly is sealed; and A portion of the two surfaces is joined together in such a way that a sealing space is formed between the two surfaces of the outer material to form a sealing portion surrounding the patterned portion. The longitudinal direction of the outer casing material is the width direction of the battery including the outer casing material. The transverse direction of the outer casing material is the length direction of the battery including the outer casing material. The edge portion of the patterned part is adjacent to the sealing part. The radius of curvature of the edge portion of the pattern is smaller than the radius of curvature of the center portion of the pattern. Wherein, the transverse direction is the axial direction of the rollers of the outer material manufactured by the roll-to-roll process, and the longitudinal direction is the length direction of the rollers of the outer material.

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