External packaging material, method for forming pattern on external packaging material, and method for manufacturing battery including external packaging material

Abstract

The outer packaging material for a battery includes at least one pattern portion formed along a transverse direction (TD) of the outer packaging material, wherein the TD of the outer packaging material is a width direction of the battery including the outer packaging material, and the longitudinal direction (MD) of the outer packaging material is a length direction of the battery including the outer packaging material.

Description

Technical Field

[0001] The present invention relates to an exterior material, a method for forming a pattern on the exterior material, and a method for manufacturing a battery including the exterior material. Background Art

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

[0003] Recently, when designing mobile devices including smartphones and various wearable devices, various designs that are different from the previous shapes are being tried, and interest in flexible devices that can be bent while maintaining functionality is increasing. Therefore, it is very important to ensure the functionality and safety of flexible electrochemical batteries that are built into such flexible devices and can be used as power sources.

[0004] When a flexible battery is repeatedly bent and unfolded, there is a risk of damaging the outer material. If the outer material is severely damaged, the internal electrolyte may leak. Moreover, even if the outer material is slightly damaged, moisture in the air penetrates into the interior of the battery, causing swelling of the battery and damaging the electrodes, thereby reducing the capacity and output of the battery.

[0005] Therefore, in order to prevent damage to the outer packaging material of the flexible battery by absorbing the compressive stress and tensile stress generated in the bent part of the battery, the outer packaging material is patterned by pressurizing the upper and lower molds. Since the initial elastic modulus (initial elastic modulus) of the patterned outer packaging material is improved, when the battery is bent, the force acting on the outer packaging material is dispersed instead of concentrated on one side. As a result, the outer packaging material and the electrode assembly housed inside will not be severely bent in a certain part.

[0006] Furthermore, the pattern of the exterior material does not need to be formed deeply, but damage to the exterior material caused by repeated bending, folding, folding, twisting, etc. of the battery needs to be minimized to improve the durability of the battery.

[0007] When external force acts on the battery, for example, when the battery is bent, folded, or twisted, the compressive force applied along the thickness direction has a greater influence on the durability of the battery than the tensile force in the length direction of the exterior material.

[0008] Furthermore, when the electrode assembly contained in the outer packaging material is deformed, a force is applied to push the outer packaging material outward. If the outer packaging material cannot withstand the force from the electrode assembly inside, the electrode assembly inside is easily bent around the weak part of the outer packaging material, and the outer packaging material at that part is damaged, resulting in pin holes, cracks, etc.

[0009] In order to further improve the durability of flexible batteries, it is necessary to adopt a pattern processing method that can increase the bending moment of the battery bending area. Specifically, in order to improve the bending durability of flexible batteries, it is necessary to form a pattern in a way 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] Problems to be solved by the invention

[0013] The present invention is used to solve the problems of the prior art as described above, and provides an outer packaging material for a battery, which includes at least one pattern portion formed along the transverse direction (TD) of the outer packaging material, the TD of the outer packaging material is the width direction of the battery including the above-mentioned outer packaging material, and the longitudinal direction (MD) of the outer packaging material is the length direction of the battery including the above-mentioned outer packaging material.

[0014] An object of the present invention is to provide a method for forming a pattern on an exterior material along a direction where the compressive stress of the exterior material is large and a method for manufacturing a battery including the exterior material, so as to prevent damage to the exterior material and improve the durability of the battery.

[0015] However, the technical problems to be solved by this embodiment are not limited to the technical problems described above, and there may be other technical problems.

[0016] Solutions for solving problems

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

[0018] In one embodiment, the outer packaging material has different tensile strength characteristics in the TD of the outer packaging material and in the MD of the outer packaging material, and the tensile strength value measured in the TD of the outer packaging material may be greater than the tensile strength value measured in the MD of the outer packaging material.

[0019] In one embodiment, the outer packaging material is folded along the MD of the outer packaging material to manufacture the battery. The outer packaging material used to manufacture the battery may be bent along the MD of the outer packaging material so that the battery is bent along the MD of the outer packaging material.

[0020] In one embodiment, the outer packaging material is folded along the TD of the outer packaging material to manufacture the battery, and the outer packaging material used to manufacture the battery may be bent along the MD of the outer packaging material, so that the battery is bent along the MD of the outer packaging material.

[0021] In one embodiment, the compressive stress of the outer packaging material may be greater than the compressive stress of another outer packaging material, and the other outer packaging material includes at least one pattern portion formed along the MD of the outer packaging material.

[0022] In one embodiment, considering the possibility of damage to the electrode assembly inserted into the exterior material, the pattern part may be formed along the TD of the exterior material.

[0023] In one embodiment, the compressive stress of the exterior material is measured in a state where a load is applied to the exterior material in such a manner that displacement is restricted according to a preset deformation rate of a height of the pattern portion.

[0024] In one embodiment, the outer packaging material is formed of a multi-layer structure in which more than one material is laminated.

[0025] In another embodiment of the present invention, the method for forming a pattern on an outer packaging material may include the following steps: positioning the outer packaging material between an upper mold and a lower mold; and punching the outer packaging material using the upper mold and the lower mold to form at least one pattern portion along the TD of the outer packaging material, wherein the TD of the outer packaging material may be a width direction of a battery including the outer packaging material, and the MD of the outer packaging material may be a length direction of the battery including the outer packaging material.

[0026] In another embodiment of the present invention, a method for manufacturing a battery including an outer packaging material may include the following steps: forming at least one pattern portion on the outer packaging material along the TD of the outer packaging material; folding the outer packaging material; inserting an electrode assembly into the folded outer packaging material; and sealing the outer packaging material with the electrode assembly inserted therein, wherein the TD of the outer packaging material may be the width direction of the battery including the outer packaging material, and the MD of the outer packaging material may be the length direction of the battery including the outer packaging material.

[0027] Effects of the Invention

[0028] According to one of the aforementioned solutions to the problem of the present invention, the present invention can provide an outer packaging material for a battery, which includes at least one pattern portion formed along the TD of the outer packaging material, the TD of the outer packaging material is the width direction of the battery including the above-mentioned outer packaging material, and the MD of the outer packaging material is the length direction of the battery including the above-mentioned outer packaging material.

[0029] Furthermore, a method for forming a pattern on an outer packaging material along a direction in which the compressive stress of the outer packaging material increases and a method for manufacturing a battery including the outer packaging material can be provided. Thus, the deformation resistance of the battery is improved to prevent the internal electrode assembly from being bent, and the damage to the internal electrode and the separation membrane is minimized, thereby improving the durability of the battery.

[0030] Furthermore, damage to the exterior material and leakage of the electrolyte can be prevented, thereby improving the safety and durability of the battery.

[0031] Furthermore, the size of the battery can be flexibly changed, and large and long batteries can be produced using slim equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 The figure exemplarily shows the exterior material.

[0033] Figure 2 It is a figure which shows the exterior material and the pattern part which concern on one Example of this invention.

[0034] Figure 3 To show that along Figure 2 The pattern portion shown in the figure is formed in different directions of the pattern portion of the exterior material.

[0035] Figure 4a The figure is a perspective view showing a battery including an external packaging material according to an embodiment of the present invention.

[0036] Figure 4b To show Figure 4a A diagram showing the cross-sectional shape of the battery shown in FIG.

[0037] Figure 5This is an illustrative diagram for explaining the effect of a battery including an exterior material according to an embodiment of the present invention.

[0038] Figure 6 1 is a diagram showing a cross-sectional shape of a pattern portion according to an embodiment of the present invention.

[0039] Figure 7 It is a figure for demonstrating the method of evaluating the compressive stress of the patterned exterior material.

[0040] Figure 8 It is a diagram for explaining a method of evaluating the bending durability of a battery including an exterior material.

[0041] Fig. 9 The present invention is a flowchart of a method for forming a pattern on an exterior material according to an embodiment of the present invention.

[0042] Fig.10 The present invention is a flowchart of a method for manufacturing a battery including an external packaging material according to an embodiment of the present invention. DETAILED DESCRIPTION

[0043] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, so that those skilled in the art can easily implement the embodiments of the present invention. However, the present invention can be implemented by various different embodiments and is not limited to the embodiments described herein. In addition, in the accompanying drawings, parts not related to the description are omitted in order to clearly illustrate the present invention, and similar parts are given similar reference numerals throughout the specification.

[0044] Throughout the specification, when it is mentioned that a part "includes" a component, unless there is a special record to the contrary, other components may also be included, rather than excluding other components. Moreover, throughout the specification, when it is mentioned that a part is "connected" to another part, it includes not only the case of direct connection, but also the case of connection with other components in the middle and the case of electrical connection through other components. Furthermore, throughout the specification of this application, when it is mentioned that a component is "on" another component, it includes not only the case of contact between the component and the other component, but also the case of other components between the two components.

[0045] The battery including the outer material of the present invention may be, for example, an electrochemical battery, a lithium ion battery. Specifically, the battery including the outer material of the present invention may be configured such that the electrode assembly is contained together with the electrolyte and sealed inside the outer material, so that charging and discharging are performed by the movement of lithium ions. The battery including the outer material of the present invention may be a flexible battery, which may be configured to be flexible and bend while maintaining a state in which its function is performed. Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0046] Figure 11 is a diagram exemplarily showing an exterior material. For example, the exterior material 100 may be formed in a multilayer structure in which more than one material is laminated. The more than one material may have toughness.

[0047] For example, the multilayer structure of the outer packaging material 100 may include a sealing layer, a barrier layer, and a protection layer, which are distinguished according to the functions of each layer. The sealing layer may be composed of a polypropylene (PP) film. The barrier layer may be composed of an aluminum foil. The protection layer may be composed of a nylon film or a composite layer of nylon and polyethylene terephthalate (PET).

[0048] The outer packaging material 100 is manufactured by a roll-to-roll process, and the mechanical properties of the outer packaging material 100 may be different according to the axial direction or the length direction of the roll. Among them, the transverse direction (TD) may refer to the axial direction of the roll, and the machine direction (MD) may refer to the length direction of the roll.

[0049] In an exterior material for a flexible battery, the mechanical properties of the battery may differ according to the direction in which a pattern is formed. That is, a battery including an exterior material in which a pattern is formed along the TD of the exterior material and a battery including an exterior material in which a pattern is formed along the MD of the exterior material may have different mechanical properties from each other. Thus, the direction in which the pattern is formed may affect the durability of the flexible battery.

[0050] Figure 2 1 is a diagram showing an exterior material and a pattern portion according to an embodiment of the present invention. Figure 2 , the exterior material 100 may include at least one pattern portion 111td formed along the TD of the exterior material 100 .

[0051] In the form of Figure 2 When the battery is manufactured in the form of the exterior material 100 with the pattern portion 111td shown in FIG. 1 , the TD of the exterior material may be the width direction 10A of the battery, and the MD of the exterior material may be the length direction 10B of the battery.

[0052] Figure 3 Shown along with Figure 2 The pattern portion 111td shown in FIG. is formed with an outer covering material having a pattern portion 111md in a different direction. Figure 3 The exterior material shown in FIG. 1 is formed with a pattern portion 111md along the MD of the exterior material.

[0053] In the form of Figure 3 When the battery is manufactured in the form of an exterior material with the pattern portion 111md shown in FIG. 1 , the MD of the exterior material may be the width direction 10A of the battery, and the TD of the exterior material may be the length direction 10B of the battery.

[0054] Comparison reference Figure 2 and Figure 3 When the pattern portion is formed along the TD of the exterior material, it also has advantages in the manufacturing process of the flexible battery. Figure 3 As shown, if the pattern portion is formed along the MD of the outer packaging material, when manufacturing the battery, the width of the outer packaging material and the rollers and molds for forming the pattern portion need to be increased in the length direction according to the length of the battery.

[0055] However, if Figure 2 As shown in FIG. 1 , if the pattern portion is formed along the TD of the outer packaging material, the above-mentioned problem will not occur in the battery manufacturing process even if the length of the battery becomes longer. Therefore, when the pattern portion is formed along the TD of the outer packaging material, it is easy to flexibly change the battery size, and there is no need to enlarge the battery manufacturing equipment according to the length of the battery, and a large and long battery can be manufactured using a slim equipment.

[0056] Figure 4a 1 is a perspective view showing a battery including an exterior material 100 according to an embodiment of the present invention. Figure 4b To show Figure 4a A diagram showing the cross-sectional shape of the battery shown in FIG.

[0057] Reference Figure 4a and Figure 4b The battery 10 may include: an outer packaging material 100 ; an electrode assembly 200 housed inside the outer packaging material 100 ; and an electrode lead 300 connected to the electrode assembly 200 .

[0058] The electrode assembly 200 has a plurality of electrodes and may further include a separation membrane. The electrode assembly 200 may be formed in a structure in which the plurality of electrodes and the separation membrane are stacked in a thickness direction.

[0059] The electrode assembly 200 may include a first electrode and a second electrode of different polarities, and a mixture containing an active material may be coated on both sides or one side of the first electrode and the second electrode, respectively. A separation membrane may be provided between the first electrode and the second electrode. For example, the first electrode is a negative electrode, and the current collector used is made of copper, aluminum, etc., which may be made of graphite, carbon, lithium, silicon, SiO xThe negative electrode active material is composed of one or more combinations of silicon derivatives, silicon-graphite composites, tin, and silicon-tin composites. In addition, the second electrode is a positive electrode, and the current collector used is made of aluminum, stainless steel, etc. It can be made of one or more combinations of positive electrode active materials in 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. In the electrode assembly 200, the length direction of the two directions extending in a manner such that the first electrode and the second electrode form a surface extends longer than the width direction, and a thin shape can be formed along the thickness direction of the stacked active material and the separation membrane that intersects (for example, orthogonal) with the direction of the formation surface.

[0060] In addition, the electrode assembly 200 may include an electrode connection sheet and a lead connection sheet. The electrode connection sheet may be formed in a manner of protruding from one end of the first electrode and the second electrode in the length direction, and the electrode connection sheets protruding from the electrodes of the same polarity may be combined. The electrodes may be electrically connected in parallel through the electrode connection sheet. The lead connection sheet is connected to the electrode lead 300, and may protrude from the positive and negative electrodes to be combined with the electrode lead 300.

[0061] Specifically, the outer packaging material 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 may be joined in a manner of sealing the received electrode assembly 200 from the outside. Figure 4b As shown, the receiving portion 110 may correspond to the area where two outer packaging materials 100 are separated and face each other. In order to form the receiving portion 110, the outer packaging material 100 may be processed in a manner of being pressed and protruded along the thickness direction, so that the predetermined area of ​​the outer packaging material 100 is roughly in the shape of a quadrilateral bowl (or cup).

[0062] More specifically, in the present embodiment, the surface of the receiving portion 110 may extend along the TD of the outer packaging material 100 to form at least one pattern portion 111td. The pattern portion 111td is a pattern that extends along one direction and is repeatedly arranged in a direction intersecting the one direction. Specifically, it may have a concave-convex shape along one direction by alternately protruding or recessing along the thickness direction (i.e., alternately protruding in opposite directions). Among them, one direction is the width direction 10A of the battery as the TD of the outer packaging material 100, and the direction in which the pattern portion 111td is repeated may be the length direction 10B of the battery. Figure 4b As shown, the exterior material 100 forming the receiving portion 110 may form a corrugated or wrinkled pattern along the length direction through the protruding and recessed pattern portions 111td.

[0063] The sealing portion 120 can be formed by joining two sealing surfaces. The sealing surface refers to the joining surface of the outer packaging material 100, and the internal space (housing portion 110) can be separated from the outside by joining two sealing surfaces overlapping along the edge of the housing portion 110. The aforementioned electrode assembly 200 and electrolyte can be accommodated in the internal space, and the electrode assembly 200 and electrolyte can be kept in a sealed state.

[0064] In addition, the sealing portion 120 may have a flat plate shape extending along the width direction 10A of the battery 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 so that the surfaces do not face each other. Alternatively, the sealing portion 120 may have a pattern different from the pattern portion 111td, for example, a pattern having a height lower than that of the pattern portion 111td along the thickness direction.

[0065] In addition, the electrode lead 300 is connected to the electrode assembly 200 inside the outer packaging material 100 and extends in a manner exposed to the outside of the outer packaging material 100. The electrode lead 300 is used as a terminal for realizing electrical connection with the electrode assembly 200 accommodated inside the outer packaging material 100, and when the sealing portion 120 is formed, it can be connected in a state of being set between the sealing surfaces and penetrating the sealing portion 120. A pair of electrode leads 300 of the positive electrode and the negative electrode can be combined with a lead connection piece having the same polarity provided in the electrode assembly 200.

[0066] Figure 5 This is an example diagram for explaining the effect of a battery including an outer packaging material according to an embodiment of the present invention. When the battery is repeatedly bent, cracks in the electrode collector, damage to the electrode, and disconnection may occur. As the electrodes inside the battery are misaligned, dendrites are generated at the negative electrode, which may cause safety problems such as internal short circuits.

[0067] Figure 5 (a) shows a battery having a structure in which the tab-lead bonding portion 1001a is welded to the electrode assembly. Figure 5 (a), when the battery is bent multiple times, there is a high probability that cracks, cuts, and other damages will occur, especially in the tab-lead bonding portion 1001a, the electrode tab 1003a, and the center portion 1005a of the electrode.

[0068] Figure 5 (b) shows a battery having an insertion structure in which the sheet-lead bonding portion 1001b is inserted into the inner side of the separation membrane of the electrode assembly or aligned on the inner side of the separation membrane. Figure 5 In the battery with the insertion structure shown in (b), when the battery is bent multiple times, there is a high probability that cracks, cuts, and other damages will occur, especially in the sheet-lead bonding portion 1001b, the electrode sheet 1003b, and the center portion 1005b of the electrode.

[0069] For the above Figure 5 (a) and Figure 5 The battery shown in (b) includes an outer packaging material having a patterned portion formed along the TD of the outer packaging material of the present invention, thereby improving the resistance of the outer packaging material to deformation caused by the electrode assembly, thereby forming a constant bending curvature along the length direction of the battery, thereby minimizing the phenomenon of folding and cutting by concentrating the force on specific portions of the outer packaging material and the electrode assembly.

[0070] That is, the pattern portion can be formed along the TD of the outer packaging material to reduce and disperse the force concentrated on the electrode assembly (which is inserted into the outer packaging material). The pattern portion is formed along the TD of the outer packaging material, thereby increasing the compressive stress value of the bending moment and greatly reducing the probability of damage to the weak parts of the outer packaging material and the electrode assembly, such as the sheet-lead bonding part, the electrode sheet and the center of the electrode.

[0071] Hereinafter, the exterior material 100 and the pattern portion 111td according to an embodiment of the present invention will be described. Figure 6 FIG. 1 is a diagram showing a cross-sectional shape of a pattern portion 111td according to an embodiment of the present invention. Figure 6 The pattern portion 111td can be formed in a manner such that a concave-convex shape having a predetermined pattern height h1 and a pattern pitch P is repeated.

[0072] Figure 7 : is a diagram for explaining a method for evaluating the compressive stress of a patterned exterior material. Figure 7 As shown, the compressive stress of the exterior material 100 is measured in a state where a force is applied to the exterior material 100 in such a manner that the height of the pattern portion 111td is deformed within a preset ratio range. For example, a force may be applied to the exterior material 100 so that the height of the pattern portion 111td becomes a height h2 that is 50% of the pattern height h1.

[0073] That is, the compressive stress of the exterior material 100 is measured in the following state: a load is applied to the exterior material 100 in a manner that limits displacement according to a preset deformation rate of the height of the pattern portion 111td. The deformation rate is defined as (h1-h2) / h1×100(%). For example, the preset deformation rate may be 50%.

[0074] It is assumed that the portion that is deformed when a load is applied to the exterior packaging material 100 is the pattern portion 111td, and the thickness of the exterior packaging material 100 does not change.

[0075] In the same manner, for another exterior material including at least one pattern portion 111md formed along the MD of the exterior material, the compressive stress of the exterior material 100 is measured in a state where a load is applied to the exterior material 100 in such a manner as to restrict displacement according to a preset deformation rate.

[0076] Among them, as the compressive stress of the bending moment of the exterior material including the pattern portion 111td or the pattern portion 111md has a larger value, the resistance to the deformation of the exterior material caused by the electrode assembly is greater, thereby improving the durability of the battery.

[0077] Table 1 shows the thickness of each structure of the exterior material A and the exterior material B and the total thickness.

[0078] Table 1

[0079] constitute Exterior Material A Exterior material B Polyethylene terephthalate (PET) - 12μm Nylon 25μm 15μm Aluminum foil (Alfoil) 40μm 40μm Polypropylene (PP) 45μm 80μm Total thickness 113μm 153μm

[0080] For the exterior material A, Table 2 shows the case where a pattern portion is formed along the TD of the exterior material A (TD pattern) and the case where a pattern portion is formed along the MD of the exterior material A (MD pattern). Figure 7 1 and 2 show the values ​​of the compressive stress of the exterior material A measured when a load was applied so that the deformation rate of the pattern portion became 50%.

[0081] Table 2

[0082]

[0083] As shown in Table 2, the results of the two experiments are as follows: in the exterior material A, the value of the compressive stress when the TD pattern is formed is greater than the value of the compressive stress when the MD pattern is formed.

[0084] For the exterior material B having a different structure from the exterior material A, Table 3 shows the case where a pattern portion is formed along the TD of the exterior material B (TD pattern) and the case where a pattern portion is formed along the MD of the exterior material B (MD pattern). Figure 7 1 and 2 show the values ​​of compressive stress measured when a load was applied so that the deformation rate of the pattern portion became 50%.

[0085] Table 3

[0086]

[0087] As shown in Table 3, the results of the two experiments are as follows: in the exterior material B, the value of the compressive stress when the TD pattern is formed is also greater than the value of the compressive stress when the MD pattern is formed.

[0088] According to Tables 2 and 3, it was confirmed that in the exterior materials A and B, the compressive stress value when the pattern portion was formed along the TD of the exterior materials was greater than the compressive stress value when the pattern portion was formed along the MD of the exterior materials.

[0089] As the value of the compressive stress of the bending moment of the exterior material increases, the resistance to the compressive force of the electrode assembly caused by deformation of the battery due to external force increases.

[0090] Therefore, by forming the pattern portion along the TD on the exterior material, the resistance to deformation of the exterior material caused by the electrode assembly is increased, thereby improving the durability of the battery.

[0091] The outer packaging material may have different tensile strength characteristics in the TD of the outer packaging material and in the MD of the outer packaging material. For example, the value of the tensile strength measured in the TD of the outer packaging material may be greater than the value of the tensile strength measured in the MD of the outer packaging material.

[0092] When the value of the tensile strength measured in the TD of the exterior material is greater than the value of the tensile strength measured in the MD of the exterior material, the value of the compressive stress when the pattern portion is formed along the TD of the exterior material is greater than the value of the compressive stress when the pattern portion is formed along the MD of the exterior material.

[0093] For example, the packaging material of the present invention can be folded along the MD of the packaging material and used to manufacture a battery. When manufacturing a battery, the packaging material folded along the MD of the packaging material is bent along the MD of the packaging material so that the battery is bent along the MD of the packaging material.

[0094] As another example, the outer packaging material can be folded along the TD of the outer packaging material and used to manufacture the battery. When manufacturing the battery, the outer packaging material folded along the TD of the outer packaging material is bent along the MD of the outer packaging material, so that the battery is bent along the MD of the outer packaging material.

[0095] Figure 8 : is a diagram for explaining a method for evaluating the bending durability of a battery including an exterior material. Figure 8 , the bending evaluation may be performed by bending the battery 10 including the exterior material 100 a plurality of times along one direction.

[0096] The battery 10 including the exterior material 100 including the pattern portion 111td may be subjected to bending evaluation along the MD of the exterior material. In other words, the battery 10 including the exterior material 100 may be subjected to bending evaluation by bending the battery along the length direction 10B of the battery.

[0097] Differently from this, a battery including an exterior material including the pattern portion 111md may be bent along the TD of the exterior material, that is, along the width direction 10A of the battery to perform bending evaluation.

[0098] In one embodiment, the bending evaluation may be performed by bending the battery at R15, 25 rpm.

[0099] Table 4 shows the results of bending evaluation performed in the case where a pattern portion is formed along the TD of the outer packaging material (TD pattern) or the case where a pattern portion is formed along the MD of the outer packaging material (MD pattern) for one of the outer packaging material A and the outer packaging material B shown in Table 2. For example, Battery 1 in Table 4 refers to a battery including the outer packaging material A having a pattern portion formed along the MD of the outer packaging material.

[0100] Table 4

[0101]

[0102] In Table 4, the bending durability shows how many times the battery was bent until it worked normally when the bending evaluation was performed on the battery. In the case of Battery 1 including the outer packaging material A in which the pattern portion was formed along the MD of the outer packaging material, it worked normally until it was bent 1681 times. In the case of Battery 2 including the outer packaging material A in which the pattern portion was formed along the TD of the outer packaging material, the battery also worked normally after a total of 3000 bends implemented in the bending evaluation.

[0103] Battery 3 including packaging material B having a pattern portion formed along the MD of the packaging material operated normally until bending 3228 times. Battery 4 including packaging material B having a pattern portion formed along the TD of the packaging material operated normally even after bending 5000 times in total in the bending evaluation.

[0104] Furthermore, the results of the bending evaluation of battery 1 and battery 3 showed that electrode sheet cutting, electrode displacement and damage, external material damage and electrolyte leakage occurred. In the case of batteries with damaged external materials (cracks, pin holes), excessive expansion occurred in a high temperature and high humidity environment, for example, at a temperature of 45°C and a humidity of 90% to 95%.

[0105] The bending evaluation results of Battery 1 to Battery 4 shown in Table 4 confirmed that the bending durability of both the case where the pattern portion was formed along the TD of the outer packaging material A and the case where the pattern portion was formed along the MD of the outer packaging material was superior.

[0106] Therefore, a pattern portion is formed along the TD on the exterior material, thereby increasing the resistance to deformation of the exterior material caused by the electrode assembly, thereby delaying and improving damage to the exterior material, thereby improving the bending durability and safety of the battery even after more bending.

[0107] Fig. 9 The figure is an exemplary diagram for explaining a method of forming a pattern on an exterior material according to an embodiment of the present invention.

[0108] In step S810 , the exterior material 100 may be positioned between an upper mold and a lower mold.

[0109] In step S820 , the exterior packaging material 100 may be punched using an upper mold and a lower mold to form at least one pattern portion 111 td along the TD of the exterior packaging material 100 .

[0110] The TD of the outer packaging material may be the width direction of the battery including the outer packaging material, and the MD of the outer packaging material may be the length direction of the battery including the outer packaging material.

[0111] In the above description, step S810 to step S820 can be further divided into additional steps or combined into fewer steps according to the embodiment of the present invention. In addition, some steps can be omitted according to needs, and the order of the steps can be changed.

[0112] Fig.10 An exemplary diagram for explaining a method for manufacturing a battery including an exterior material according to an embodiment of the present invention.

[0113] In step S910 , at least one pattern portion 111 td may be formed on the exterior material 100 along the TD of the exterior material 100 .

[0114] In step S920 , the exterior material 100 on which the pattern portion 111 td is formed may be folded.

[0115] In step S930 , the electrode assembly 200 may be inserted into the folded exterior material 100 .

[0116] For example, a pattern portion corresponding to the upper surface of the battery and a pattern portion corresponding to the lower surface of the battery are formed on the outer packaging material along the TD of the outer packaging material, and the outer packaging material can be folded along the MD of the outer packaging material with the center line between the two pattern portions as a reference (folding operation). The outer packaging material folded with the center line between the two pattern portions as a reference is arranged so that the pattern portion corresponding to the upper surface of the battery and the pattern portion corresponding to the lower surface of the battery overlap, and the electrode assembly can be inserted in a manner in which the positions of such pattern portions overlap.

[0117] As another example, the exterior packaging material having the pattern portion formed along the TD of the exterior packaging material may be folded along the TD of the exterior packaging material. The electrode assembly may be inserted into the folded exterior packaging material.

[0118] In step S940, the outer packaging material 100 inserted with the electrode assembly 200 may be sealed. For example, the outer packaging material 100 may be sealed on four sides to generate four sealing areas, two of which may be formed along the TD of the outer packaging material 100, and the remaining two may be formed along the MD of the outer packaging material 100.

[0119] The TD of the outer packaging material may be the width direction of the battery including the outer packaging material, and the MD of the outer packaging material may be the length direction of the battery including the outer packaging material.

[0120] In the above description, steps S910 to S940 can be further divided into additional steps or can be combined into fewer steps according to the embodiment of the present invention. In addition, some steps can be omitted according to needs, and the order of the steps can be changed. In particular, the process of forming the pattern part on the outer packaging material can be performed before sealing the outer packaging material or after sealing the outer packaging material in the present invention.

[0121] As described above, a battery including an exterior material having a pattern portion formed along the TD of the exterior material can prevent force from being concentrated on a specific portion of the battery to damage an internal electrode assembly and the exterior material, and thus can be applied to devices requiring flexibility and rigidity.

[0122] For example, the bending radius of the battery in the device is equivalent to 35R (ankle circumference) to 150R (hip circumference), and can be applied to devices such as ankle straps, neck straps, and headphones.

[0123] The foregoing description of the present invention is for illustration, and it is understood by those skilled in the art that the present invention can be easily modified into other specific forms without changing the technical concept or essential features of the present invention. Therefore, the embodiments described above are only illustrative in all respects and should not be understood as limiting. For example, each component described in a single type can also be implemented in a dispersed manner, and similarly, the components described in a dispersed manner can also be implemented in a combined form.

[0124] The scope of the present invention is indicated by the claims rather than the detailed description, and all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts are included in the scope of the present invention.

Claims

1. An outer packaging material for a battery, characterized in that: The outer packaging material includes a plurality of pattern portions formed along a transverse direction of the outer packaging material, wherein the transverse direction of the outer packaging material is an axial direction of a roll of the outer packaging material manufactured by a roll-to-roll process, Each of the pattern parts extends in the transverse direction of the roller of the outer packaging material, and the pattern parts are repeatedly arranged in the longitudinal direction of the outer packaging material, and the longitudinal direction of the outer packaging material is the length direction of the roller of the outer packaging material. The value of the tensile strength measured in the transverse direction of the roller of the outer packaging material is greater than the value of the tensile strength measured in the longitudinal direction of the roller of the outer packaging material, The transverse direction of the roller of the outer packaging material is the width direction of the battery, and the longitudinal direction of the roller of the outer packaging material is the length direction of the battery. The compressive stress of the exterior material for the battery is greater than the compressive stress of another exterior material including a plurality of pattern parts formed along a longitudinal direction of the roll of the exterior material.

2. The exterior material according to claim 1, characterized in that: The exterior material has different tensile strength characteristics in a transverse direction of the exterior material and in a longitudinal direction of the exterior material.

3. The exterior material according to claim 1, characterized in that: The outer packaging material is folded along the longitudinal direction of the outer packaging material to manufacture the battery, An exterior material for manufacturing the battery is bent in a longitudinal direction of the exterior material so that the battery is bent in the longitudinal direction of the exterior material.

4. The exterior material according to claim 1, characterized in that: The outer packaging material is folded in a transverse direction of the outer packaging material to manufacture the battery, An exterior material for manufacturing the battery is bent in a longitudinal direction of the exterior material so that the battery is bent in the longitudinal direction of the exterior material.

5. The exterior material according to claim 1, characterized in that: In consideration of the possibility of damage to the electrode assembly inserted into the exterior material, the pattern portion is formed along a lateral direction of the exterior material.

6. The exterior material according to claim 1, characterized in that: The compressive stress of the exterior material is measured in a state where a load is applied to the exterior material in such a manner that displacement is restricted according to a preset deformation rate of a height of the pattern portion.

7. The exterior material according to claim 1, characterized in that: The exterior material is formed of a multi-layer structure in which one or more materials are laminated.

8. A method for forming a pattern on an exterior material, characterized in that: The steps include: placing the exterior material between the upper mold and the lower mold; and The outer packaging material is punched by the upper mold and the lower mold to form a plurality of pattern portions along a transverse direction of the outer packaging material, wherein the transverse direction of the outer packaging material is an axial direction of a roll of the outer packaging material manufactured by a roll-to-roll process, Each of the pattern parts extends in the transverse direction of the roller of the outer packaging material, and the pattern parts are repeatedly arranged in the longitudinal direction of the outer packaging material, and the longitudinal direction of the outer packaging material is the length direction of the roller of the outer packaging material. The value of the tensile strength measured in the transverse direction of the roller of the outer packaging material is greater than the value of the tensile strength measured in the longitudinal direction of the roller of the outer packaging material, The transverse direction of the roll of the outer packaging material is the width direction of the battery including the outer packaging material, and the longitudinal direction of the roll of the outer packaging material is the length direction of the battery. The compressive stress of the exterior material for the battery is greater than the compressive stress of another exterior material including a plurality of pattern parts formed along a longitudinal direction of the roll of the exterior material.

9. A method for manufacturing a battery comprising an outer packaging material, characterized in that: The steps include: forming a plurality of pattern portions on the outer packaging material along a transverse direction of the outer packaging material, wherein the transverse direction of the outer packaging material is an axial direction of a roll of the outer packaging material manufactured by a roll-to-roll process; folding the outer packaging material; inserting an electrode assembly into the folded outer packaging material; as well as sealing the outer packaging material in which the electrode assembly is inserted, Each of the pattern parts extends in the transverse direction of the roller of the outer packaging material, and the pattern parts are repeatedly arranged in the longitudinal direction of the outer packaging material, and the longitudinal direction of the outer packaging material is the length direction of the roller of the outer packaging material. The value of the tensile strength measured in the transverse direction of the roller of the outer packaging material is greater than the value of the tensile strength measured in the longitudinal direction of the roller of the outer packaging material, The transverse direction of the roller of the outer packaging material is the width direction of the battery, and the longitudinal direction of the roller of the outer packaging material is the length direction of the battery. The compressive stress of the exterior material for the battery is greater than the compressive stress of another exterior material including a plurality of pattern parts formed along a longitudinal direction of the roll of the exterior material.

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