KR102566484B1 - Exterior material, method for forming pattern on exterior material and method for manufacturing battery including exterior material - Google Patents

Abstract

An exterior material used for a battery includes at least one pattern portion formed in a transverse direction (TD) of the exterior material, the TD of the exterior material is the width direction of the battery including the exterior material, and the machine direction (MD) of the exterior material is It is the longitudinal direction of the battery including the exterior material.

Description

EXTERIOR MATERIAL, METHOD FOR FORMING PATTERN ON EXTERIOR MATERIAL AND METHOD FOR MANUFACTURING BATTERY INCLUDING EXTERIOR MATERIAL}

The present invention relates to an exterior material, a method of forming a pattern on the exterior material, and a method of producing a battery including the exterior material.

An electrochemical cell means an assembly composed of at least two electrodes and an electrolyte to provide electrical energy. In particular, a lithium ion battery composed of a secondary cell capable of charging and discharging is It is widely used in various high-tech electronic devices including smart phones.

Recently, various attempts to break away from conventional shapes have been made in the design of mobile devices including smart phones and various wearable devices, and furthermore, attention to flexible devices that can be bent while maintaining functions is increasing. Therefore, it is important to secure the functionality and safety of a flexible electrochemical cell that is embedded in such a flexible device and can be used as a power source.

If the flexible battery is repeatedly bent and unfolded, there is a risk of damage to the exterior material. If the exterior material is severely damaged, leakage of the internal electrolyte may occur. In addition, even when a slight damage occurs to the exterior material, moisture in the air penetrates into the battery, causing a swelling phenomenon of the battery and damaging the electrode, which may reduce the capacity and output of the battery.

Therefore, in order to prevent damage to the exterior material of the flexible battery by absorbing compressive stress and tensile stress generated at a portion where the battery is bent, pattern processing is performed on the exterior material by pressing the upper and lower molds. Since the patterned exterior material has a high initial modulus of elasticity (initial modulus of elasticity), when the battery is bent, the force acting on the exterior material is dispersed rather than being concentrated on one side. As a result, the exterior material and the electrode assembly accommodated inside are not severely bent at any one part.

On the other hand, the pattern of the exterior material does not need to be formed deeply, but it is necessary to improve durability of the battery by minimizing damage to the exterior material due to repeated bending, bending, folding, twisting, etc. of the battery.

When an external force is applied to the battery, for example, when the battery is bent, folded, or twisted, the compressive force applied in the thickness direction of the exterior material has a greater influence on the durability of the battery than the tensile force in the longitudinal direction of the exterior material.

In addition, as the electrode assembly accommodated inside the casing is deformed, a force pushing the casing outward acts. If the exterior material cannot withstand the force acting from the electrode assembly inside, the interior electrode assembly is easily bent around a weak part of the exterior material, and the exterior material in the corresponding area is damaged, resulting in phenomena such as pinholes and cracks.

In order to further improve the durability of the flexible battery, it is necessary to adopt a pattern processing method capable of increasing a bending moment in a region where the battery is bent. Specifically, in order to increase the bending durability of the flexible battery, a method of forming a pattern to increase the compressive stress of the exterior material is required.

Korean Patent Publication No. 2005-0052069 (published on 2005.06.02) Japanese Laid-open Patent No. 2013-218991 (published on October 24, 2013)

The present invention is to solve the problems of the prior art described above, and includes at least one pattern portion formed in a TD (Transverse Direction) of an exterior material, the TD of the exterior material is the width direction of a battery including the exterior material, and the MD of the exterior material (Machine Direction) is to provide an exterior material used in a battery, which is the longitudinal direction of the battery including the exterior material.

One object of the present invention is to provide a method of forming a pattern on an exterior material in a direction in which the compressive stress of the exterior material is large to prevent damage to the exterior material and improve durability of the battery, and a method of generating a battery including the exterior material.

However, the technical problem to be achieved by the present embodiment is not limited to the technical problems described above, and other technical problems may exist.

As a means for achieving the above-described technical problem, an embodiment of the present invention includes at least one pattern portion formed in a TD (Transverse Direction) of the exterior material in an exterior material used for a battery, and the TD of the exterior material is A width direction of a battery including an exterior material, and a Machine Direction (MD) of the exterior material may be a longitudinal direction of the battery including the exterior material.

In one embodiment, the exterior material has different tensile strength characteristics in the TD of the exterior material and the MD of the exterior material, and the tensile strength measured in the TD of the exterior material has a greater value than the tensile strength measured in the MD of the exterior material. it could be

In one embodiment, the exterior material is folded into the MD of the exterior material and used in manufacturing the battery, and the exterior material used in the manufacture of the battery is bent into the MD of the exterior material, so that the battery is bent in the MD of the exterior material. It may be what makes it possible.

In one embodiment, the exterior material is folded into the TD of the exterior material and used in manufacturing the battery, and the exterior material used in manufacturing the battery is bent in the MD of the exterior material, so that the battery is bent in the MD of the exterior material. It may be what makes it possible.

In one embodiment, the compressive stress of the exterior material may be greater than the compressive stress of another exterior material including at least one pattern portion formed of MD of the exterior material.

In one embodiment, the pattern part may be formed of the TD of the exterior material in consideration of the possibility of damage to the electrode assembly inserted into the exterior material.

In one embodiment, the compressive stress of the exterior material may be measured in a state in which a load is applied to the exterior material by limiting displacement to a preset strain rate with respect to the height of the pattern portion.

In one embodiment, the exterior material may be formed of a multi-layer structure in which at least one or more materials are laminated.

Another embodiment of the present invention, in the method of forming a pattern on the exterior material, by positioning the exterior material between the upper mold and the lower mold and pressing the exterior material using the upper mold and the lower mold to form the exterior material Forming at least one pattern part in a TD (Transverse Direction), wherein the TD of the packaging material is a width direction of a battery including the packaging material, and MD (Machine Direction) of the packaging material is a battery including the packaging material. It may be longitudinal.

Another embodiment of the present invention is a method for generating a battery including an exterior material, forming at least one pattern part on the exterior material in a transverse direction (TD) of the exterior material, folding the exterior material, Inserting an electrode assembly into the folded casing and sealing the casing into which the electrode assembly is inserted, wherein the TD of the casing is a width direction of a battery including the casing, and the MD (Machine Direction) of the casing is ) may be in the longitudinal direction of the battery including the exterior material.

According to any one of the above-described problem solving means of the present invention, the present invention includes at least one pattern portion formed in a TD (Transverse Direction) of the exterior material, the TD of the exterior material is the width direction of the battery including the exterior material, and the exterior material MD (Machine Direction) of may provide an exterior material used in a battery, which is a longitudinal direction of the battery including the exterior material.

In addition, it is possible to provide a method of forming a pattern on the packaging material in a direction in which the compressive stress of the packaging material increases and a method of generating a battery including the packaging material. As a result, resistance to deformation of the battery is increased to prevent the internal electrode assembly from being broken, and durability of the battery can be improved by minimizing damage to the internal electrode and the separator.

In addition, the safety and durability of the battery can be improved by preventing damage to the exterior material and leakage of the electrolyte.

In addition, the size of the battery can be flexibly changed, and it is possible to produce a large and long battery using slim equipment.

1 is a view showing an exterior material by way of example.
2 is a view showing an exterior material and a pattern part according to an embodiment of the present invention.
FIG. 3 is a view showing an exterior material having a pattern portion formed in a direction different from the pattern portion shown in FIG. 2 .
Figure 4a is a perspective view showing a battery including an exterior material according to an embodiment of the present invention.
FIG. 4B is a diagram illustrating a cross-sectional shape of the battery shown in FIG. 4A.
5 is an exemplary diagram for explaining an effect of a battery including an exterior material according to an embodiment of the present invention.
6 is a view showing a cross-sectional shape of a pattern unit according to an embodiment of the present invention.
7 is a view for explaining a method of evaluating the compressive stress of a patterned exterior material.
8 is a view for explaining a method of evaluating bending durability of a battery including an exterior material.
9 is a flowchart of a method of forming a pattern on an exterior material according to an embodiment of the present invention.
10 is a flowchart of a method of generating a battery including an exterior material according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art can easily practice the present invention with reference to the accompanying drawings. However, the present invention may be embodied in many different forms and is not limited to the embodiments described herein. And in order to clearly explain the present invention in the drawings, parts irrelevant to the description are omitted, and similar reference numerals are attached to similar parts throughout the specification.

Throughout the specification, when a certain component is said to "include", it means that it may further include other components without excluding other components unless otherwise stated. In addition, when a part is said to be "connected" to another part throughout the specification, this is not only directly connected but also connected through another member in the middle, and electrically connected to another element in the middle. Including when connected. Furthermore, throughout the present specification, when a member is said to be located “on” another member, this includes not only a case where a member is in contact with another member, but also a case where another member exists between the two members.

A battery including the exterior material according to the present invention may be, for example, an electrochemical cell and a lithium ion battery. Specifically, the battery including the packaging material according to the present invention may be configured such that the electrode assembly is accommodated and sealed together with the electrolyte inside the packaging material, and charged and discharged by the movement of lithium ions. A battery including an exterior material according to the present invention may be a flexible battery configured to be bent with flexibility while maintaining a state in which it exhibits its function. Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

1 is a view showing an exterior material by way of example. For example, the exterior material 100 may be formed in a multilayer structure in which at least one or more materials are laminated. Each of the at least one material may have ductility.

For example, the multilayer structure of the exterior material 100 may include a sealing layer, a barrier layer, and a protection layer, which are classified according to the function of each layer. The sealing layer may be composed of a polypropylene (PP) film. The material barrier layer may be composed of aluminum foil. The protective layer may be composed of a nylon film or a composite layer of nylon and polyethylene terephthalate (PET).

The packaging material 100 is manufactured by a roll to roll process, and mechanical properties of the packaging material 100 may vary according to the axial direction or the longitudinal direction of the roll. Here, TD (Transverse Direction) may mean the axial direction of the roll, and MD (Machine Direction) may mean the longitudinal direction of the roll.

In an exterior material used for a flexible battery, mechanical characteristics of the battery may vary depending on the direction in which the pattern is formed. That is, a battery including an exterior material having a pattern formed in the TD of the exterior material and a battery including an exterior material in which the pattern is formed in the MD of the exterior material may have different mechanical properties. Accordingly, the direction in which the pattern is formed may affect durability of the flexible battery.

2 is a view showing an exterior material and a pattern part according to an embodiment of the present invention. Referring to FIG. 2 , the exterior material 100 may include at least one pattern portion 111td formed by the TD of the exterior material 100 .

When a battery is generated to include the exterior material 100 in which the pattern portion 111td shown in FIG. 2 is formed, the TD of the exterior material is the width direction (10A) of the battery, and the MD of the exterior material is the length direction (10B) of the battery. ) can be.

FIG. 3 shows an exterior material having a pattern portion 111md formed in a direction different from that of the pattern portion 111td shown in FIG. 2 . In the exterior material shown in FIG. 3, the pattern portion 111md is formed in MD (Machine Direction) of the exterior material.

When a battery is generated to include an exterior material in which the pattern portion 111md shown in FIG. 3 is formed, MD of the exterior material may be in the width direction (10A) of the battery, and TD of the exterior material may be in the longitudinal direction (10B) of the battery. there is.

Referring to Figures 2 and 3 by comparison, in the case of forming the pattern portion with the TD of the exterior material, there is an advantage in the manufacturing process of the flexible battery. As shown in FIG. 3, when the pattern part is formed with the MD of the exterior material, there is a problem in that the width of the exterior material in the longitudinal direction and the battery manufacturing facilities such as rolls and molds for forming the pattern part must increase along the length of the battery when manufacturing the battery. there is.

However, as shown in FIG. 2, if the pattern portion is formed with the TD of the exterior material, the above-described problem does not occur in the battery manufacturing process even if the length of the battery is increased. Therefore, in the case of forming the pattern part with the TD of the exterior material, it is easy to change the size of the battery flexibly, and it is possible to produce a large and long battery using slim equipment without having to increase battery manufacturing facilities according to the length of the battery. there is.

Figure 4a is a perspective view showing a battery including the exterior material 100 according to an embodiment of the present invention, Figure 4b is a view showing a cross-sectional shape of the battery shown in Figure 4a.

Referring to FIGS. 4A and 4B , the battery 10 may include an exterior material 100, an electrode assembly 200 accommodated inside the exterior material 100, and an electrode lead 300 connected to the electrode assembly 200. .

The electrode assembly 200 includes a plurality of electrodes, may further include a separator, and may be formed in a structure in which they are stacked in a thickness direction.

The electrode assembly 200 may include first and second electrodes having different polarities, and a mixture containing an active material may be applied to both sides or end surfaces of each of the first and second electrodes. A separator may be interposed between the first and second electrodes. For example, the current collector used as the negative electrode of the first electrode is one of graphite, carbon, lithium, silicon, silicon derivatives such as _SiOx , silicon-graphite composites, tin, and silicon-tin composites made of copper or aluminum. It may be composed of a combination of the above negative active materials. In addition, the current collector used as the positive electrode of the second electrode is made of aluminum, stainless steel, etc., such as lithium cobalt oxide, lithium nickel oxide, lithium manganese oxide, lithium cobalt-manganese oxide, lithium cobalt-nickel oxide, lithium manganese-nickel oxide, lithium It may be made of a positive electrode active material that is one or more combinations of cobalt-nickel-manganese oxide, lithium cobalt-nickel-aluminum oxide, and lithium iron phosphate. The electrode assembly 200 is an active material that extends longer in the length direction than the width direction among the two directions in which the first and second electrodes extend to form a surface, and intersects (eg, orthogonally crosses) the direction forming the surface. And it may have a thin shape in the thickness direction in which the separator is laminated.

Also, the electrode assembly 200 may include an electrode connection tab and a lead connection tab. The electrode connection tabs may be formed to protrude from one end of the first and second electrodes in the longitudinal direction, and electrode connection tabs protruding from electrodes having the same polarity may be coupled to each other. By means of the electrode connection tab, the electrodes may be electrically connected in parallel. The lead connection tab may be connected to the electrode lead 300 and may be combined with the electrode lead 300 by protruding from the positive and negative electrodes.

Specifically, the exterior material 100 may include a receiving portion 110 and a sealing portion 120 . The accommodating part 110 may form a space for accommodating the electrode assembly 200, and the sealing part 120 may be bonded to seal the accommodated electrode assembly 200 from the outside. As shown in FIG. 4B , the accommodating portion 110 may correspond to a region where the two exterior materials 100 are spaced apart from each other and face each other. In order to form the accommodating portion 110, the exterior material 100 may be pressed in the thickness direction and processed to protrude so that a predetermined area of the exterior material 100 has a substantially rectangular bowl (or cup) shape.

More specifically, at least one pattern portion 111td may be formed extending to the TD of the exterior material 100 on the surface of the accommodating portion 110 of the present embodiment. The pattern portion 111td is a pattern that extends in one direction and is repeatedly disposed in a direction crossing the one direction, and specifically, alternately protrudes or recesses in the thickness direction (that is, alternately protrudes in opposite directions), It may have a concavo-convex shape along one direction. Here, one direction may be the width direction 10A of the battery, which is the TD of the exterior material 100, and the direction in which the pattern portion 111td is repeated may be the length direction 10B of the battery. Due to the protruding and recessed pattern portion 111td, as shown in FIG. 4B , the exterior material 100 forming the accommodating portion 110 may form a wave or wrinkle pattern in the longitudinal direction.

The sealing part 120 may be formed by joining two sealing surfaces. The sealing surface means a bonding surface of the exterior material 100, and the two overlapping sealing surfaces along the edge of the accommodating portion 110 are bonded to each other, thereby isolating the inner space (accommodating portion 110) from the outside. The electrode assembly 200 and the electrolyte solution described above may be accommodated in the inner space, and the electrode assembly 200 and the electrolyte solution may be maintained in a sealed state.

In addition, the sealing portion 120 may have a flat plate shape extending in the battery width direction 10A or the battery length direction 10B. For example, the flat plate shape of the sealing unit 120 may be a shape that is not curved so that surfaces face each other. Alternatively, the sealing unit 120 may have a pattern different from that of the pattern unit 111td, for example, may have a pattern having a lower height in the thickness direction than the pattern unit 111td.

Meanwhile, the electrode lead 300 is connected to the electrode assembly 200 inside the casing 100 and extends to be exposed to the outside of the casing 100 . The electrode lead 300 functions as a terminal for electrical connection with the electrode assembly 200 accommodated inside the exterior material 100, and when forming the sealing unit 120, the sealing unit 120 is interposed between the sealing surfaces. It can be bonded so that it penetrates. A pair of electrode leads 300 of positive and negative electrodes may be coupled to the same poles as lead connection tabs provided in the electrode assembly 200 .

5 is an exemplary diagram for explaining an effect of a battery including an exterior material according to an embodiment of the present invention. When the battery is repeatedly bent, cracks in the current collector, damage and disconnection of the electrodes may occur, and dendrites are generated on the negative electrode as the electrodes in the battery are misaligned, resulting in internal short circuits and the like. Safety issues may arise.

Figure 5 (a) shows a battery having a structure in which the tab-lead coupling portion 1001a is deposited on the electrode assembly. Referring to (a) of FIG. 5 , when the battery is bent multiple times, there is a high probability of damage such as cracking or cutting, especially in the tab-lead coupling part 1001a, the electrode tab 1003a, and the central part 1005a of the electrode. .

5(b) shows a battery having an insertion structure in which the tab-lead coupling part 1001b is inserted/aligned into the separator of the electrode assembly. Even in the battery of the inserted structure shown in FIG. 5 (b), when the battery is bent multiple times, cracks, cuts, etc. are damaged, especially in the tab-lead coupling part 1001b, the electrode tab 1003b, and the central part 1005b of the electrode. It is highly likely that this will happen

In the battery shown in (a) and (b) of FIG. 5 described above, by including the exterior material in which the pattern portion is formed by the TD of the exterior material according to the present invention, resistance to deformation of the exterior material due to the electrode assembly is increased, thereby increasing the battery's A bending curvature may be uniformly formed in the longitudinal direction, and bending or cutting due to concentration of force on a specific portion of the exterior material and the electrode assembly may be minimized.

That is, the pattern portion may be formed as the TD of the packaging material to reduce and disperse the force concentrated on the electrode assembly inserted into the packaging material. By forming the pattern portion with the TD of the packaging material, the value of the bending moment compressive stress increases and the probability of breakage of weak parts of the packaging material and the electrode assembly, for example, the tab-lead coupling part, the electrode tab, and the central portion of the electrode, can be greatly reduced.

Hereinafter, the exterior material 100 and the pattern portion 111td according to an embodiment of the present invention will be described. 6 is a view showing a cross-sectional shape of a pattern unit 111td according to an embodiment of the present invention. Referring to FIG. 6 , the pattern portion 111td may be formed such that a concavo-convex shape having a constant pattern height h1 and pattern pitch P is repeated.

7 is a view for explaining a method of evaluating the compressive stress of a patterned exterior material. As shown in FIG. 7 , the compressive stress of the exterior material 100 is measured in a state in which force is applied to the exterior material 100 so that the height of the pattern portion 111td is deformed within a preset ratio range. For example, 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.

That is, the compressive stress of the exterior material 100 is measured in a state in which a load is applied to the exterior material 100 by limiting the displacement to a preset strain rate with respect to the height of the pattern portion 111td. Here, the strain is defined as (h1-h2)/h1×100 (%). The preset strain may be, for example, 50%.

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

In the same way, the exterior material 100 in a state in which a load is applied to the exterior material 100 by limiting the displacement to a preset strain rate for another exterior material including at least one pattern portion 111md formed in the MD (Machine Direction) of the exterior material. ) to measure the compressive stress.

Here, as the bending moment compressive stress of the exterior material including the pattern portion 111td or 111md has a larger value, it means that the resistance to deformation of the exterior material due to the electrode assembly is greater, so the durability of the battery is excellent.

Table 1 shows the thickness and total thickness of each component of exterior material A and exterior material B.

Table 2 shows the case in which the pattern portion is formed with the TD of the packaging material A (TD pattern) and the case where the pattern portion is formed with the MD of the packaging material A (MD pattern) for the packaging material A, as shown in FIG. 7 in each case. Similarly, the value of compressive stress measured under the condition that the strain of the pattern part is 50% is displayed.

As shown in Table 2, as a result of the two experiments, the exterior material A was found to have a higher compressive stress when the TD pattern was formed than when the MD pattern was formed.

Table 3 shows the cases in which the pattern portion is formed with the TD of the exterior material B (TD pattern) and the case in which the pattern portion is formed with the MD of the exterior material B (MD pattern) for the exterior material B having a different configuration from that of the exterior material A, respectively. As shown in FIG. 7, the value of compressive stress measured in a state in which force is applied so that the strain of the pattern portion is 50% is displayed.

As shown in Table 3, as a result of the two experiments, it was found that the compressive stress when the TD pattern was formed also had a larger value than the compressive stress when the MD pattern was formed.

According to Tables 2 and 3, it was confirmed that the compressive stress in the case where the pattern portion was formed in the TD of the exterior material had a greater value than the compressive stress in the case where the pattern portion was formed in the MD of the exterior material for both the exterior material A and the exterior material B.

As the bending moment compressive stress of the packaging material has a larger value, the resistance to the compressive force of the electrode assembly caused by deformation of the battery by an external force may increase.

Accordingly, by forming the pattern portion in the TD on the packaging material, resistance to deformation of the packaging material due to the electrode assembly may be increased and durability of the battery may be improved.

The cladding material may have different tensile strength characteristics in the TD of the cladding material and the MD of the cladding material. For example, the tensile strength measured in the TD of the exterior material may have a greater value than the tensile strength measured in the MD of the exterior material.

When the tensile strength measured in the TD of the exterior material has a value greater than the tensile strength measured in the MD of the exterior material, the compressive stress when the pattern portion is formed in the TD of the exterior material is greater than the compressive stress in the case where the pattern portion is formed in the MD of the exterior material. has a value

The packaging material according to the present invention can be used, for example, in manufacturing a battery by being folded into an MD of the packaging material. When manufacturing a battery, the packaging material used after being folded into the MD of the packaging material may be bent into the MD of the packaging material so that the battery can be bent with the MD of the packaging material.

For another example, the packaging material may be folded into the TD of the packaging material and used in manufacturing a battery. During manufacture of the battery, the battery may be bent by the MD of the exterior material by being folded in the TD of the exterior material and the exterior material is bent in the MD of the exterior material.

8 is a view for explaining a method of evaluating bending durability of a battery including an exterior material. Referring to FIG. 8 , bending evaluation may be performed by bending the battery 10 including the exterior material 100 multiple times in one direction.

For the battery 10 including the exterior material 100 including the pattern portion 111td, bending evaluation may be performed with the MD of the exterior material. In other words, bending evaluation may be performed by bending the battery including the exterior material 100 in the longitudinal direction 10B of the battery.

Alternatively, the battery including the exterior material including the pattern portion 111md may be subjected to bending evaluation by bending the battery including the exterior material in the TD of the exterior material, that is, in the width direction 10A of the battery.

In one embodiment, the bending evaluation may be performed by bending the battery under R15, 25 rpm conditions.

Table 4 is a case where the pattern part is formed with the TD of the exterior material (TD pattern) or the case where the pattern part is formed with the MD of the exterior material (MD pattern) for any one of the exterior material A and the exterior material B shown in Table 2, bending evaluation shows the result of performing For example, battery 1 in Table 4 means a battery including an exterior material A in which a pattern portion is formed with MD of the exterior material.

In Table 4, the bending durability indicates how many times the battery operates normally when the battery is subjected to bending evaluation. In the case of battery 1 including the exterior material A in which the pattern portion was formed by the MD of the exterior material, it operated normally until it was bent 1681 times. In the case of battery 2 including the exterior material A in which the pattern portion was formed by the TD of the exterior material, the battery operated normally even after bending a total of 3000 times in the bending evaluation.

In the case of battery 3 including the exterior material B in which the pattern portion was formed by the MD of the exterior material, it operated normally until it was bent 3228 times. In the case of battery 4 including the exterior material B in which the pattern portion was formed by the TD of the exterior material, the battery operated normally even after bending a total of 5000 times in the bending evaluation.

In addition, as a result of the bending evaluation of batteries 1 and 3, phenomena such as electrode tab cutting, electrode misalignment and damage, exterior material damage, and electrolyte leakage occurred. In the case of a battery with a damaged exterior material (crack, pinhole), excessive swelling occurred in a high-temperature and high-humidity atmosphere, for example, in an environment where the temperature was 45° C. and the humidity was 90 to 95%.

According to the bending evaluation results for batteries 1 to 4 shown in Table 4, for both the exterior material A and the exterior material B, the bending durability when the pattern portion is formed in the TD of the exterior material is superior to the case where the pattern portion is formed in the MD of the exterior material. It was confirmed.

Therefore, by forming the pattern portion in the TD on the packaging material, resistance to deformation of the packaging material due to the electrode assembly is increased, thereby delaying and improving the damage of the packaging material, thereby improving the bending durability and safety of the battery even more times.

9 is an exemplary view for explaining a method of forming a pattern on an exterior material according to an embodiment of the present invention.

In step S810, the exterior material 100 may be positioned between the upper mold and the lower mold.

In step S820, at least one pattern portion 111td may be formed in a transverse direction (TD) of the exterior material 100 by pressing the exterior material 100 using the upper and lower molds.

Here, TD of the packaging material may be a width direction of the battery including the packaging material, and MD (Machine Direction) of the packaging material may be a longitudinal direction of the battery including the packaging material.

In the foregoing description, steps S810 to S820 may be further divided into additional steps or combined into fewer steps, depending on an embodiment of the present invention. Also, some steps may be omitted as needed, and the order of steps may be switched.

10 is an exemplary diagram for explaining a method of generating a battery including an exterior material according to an embodiment of the present invention.

In step S910, at least one pattern portion 111td may be formed on the exterior material 100 in a transverse direction (TD) of the exterior material 100.

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

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

For example, in the exterior material, a pattern portion corresponding to the upper surface of the battery and a pattern portion corresponding to the lower surface of the battery are each formed by the TD of the exterior material, and the exterior material is MD of the exterior material, which can be folded based on the center line between the two pattern portions. Yes (folding operation). The exterior material folded based on the center line between the two pattern parts is positioned so that the pattern part corresponding to the upper surface of the battery and the pattern part corresponding to the lower surface of the battery overlap, and the electrode assembly may be inserted so as to overlap the position of the pattern part.

For another example, the packaging material having the pattern portion formed by the TD of the packaging material may be folded by the TD of the packaging material. The electrode assembly may be inserted into the folded exterior material.

In step S940, the exterior material 100 into which the electrode assembly 200 is inserted may be sealed. For example, the packaging material 100 may create four sealing areas by performing a sealing operation on four surfaces surrounding the packaging material, two of which are formed as TD of the packaging material 100, and the other two sealing areas. The sealing area of may be formed in the MD of the exterior material 100.

Here, TD of the packaging material may be a width direction of the battery including the packaging material, and MD (Machine Direction) of the packaging material may be a longitudinal direction of the battery including the packaging material.

In the above description, steps S910 to S940 may be further divided into additional steps or combined into fewer steps, depending on an embodiment of the present invention. Also, some steps may be omitted as needed, and the order of steps may be switched. In particular, the process of forming the pattern portion on the exterior material may be performed before sealing (sealing) the exterior material or after sealing (sealing) the exterior material in the present invention.

As described above, since a battery including an exterior material having a pattern portion formed by the TD of the exterior material can prevent damage to the internal electrode assembly and the exterior material due to concentration of force on a specific part of the battery, a device that requires flexibility and rigidity at the same time. can be applied to

For example, the bending radius of the battery in the device corresponds to 35R (ankle circumference) to 150R (hip circumference), and can be applied to devices such as ankle bands, neckbands, and headsets.

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

The scope of the present invention is indicated by the following claims rather than the detailed description, and all changes or modifications derived from the meaning and scope of the claims and equivalent concepts thereof should be construed as being included in the scope of the present invention.

10: battery
100: exterior material
110: pattern part
130: sealing part
200: electrode assembly
300: electrode lead

Claims (10)

In the exterior material used for the battery,
At least one pattern part formed in the Transverse Direction (TD) of the exterior material
including,
TD of the exterior material is the width direction of the battery including the exterior material,
MD (Machine Direction) of the exterior material is the longitudinal direction of the battery including the exterior material,
The exterior material has different tensile strength characteristics in the TD of the exterior material and the MD of the exterior material,
The tensile strength measured in the TD of the exterior material has a greater value than the tensile strength measured in the MD of the exterior material.
delete According to claim 1,
The exterior material is folded into the MD of the exterior material and used in manufacturing the battery,
The exterior material used in manufacturing the battery is bent in the MD of the exterior material so that the battery can be bent in the MD of the exterior material.
According to claim 1,
The exterior material is folded into the TD of the exterior material and used in manufacturing the battery,
The exterior material used in manufacturing the battery is bent in the MD of the exterior material so that the battery can be bent in the MD of the exterior material.
According to claim 1,
Wherein the compressive stress of the exterior material is greater than the compressive stress of another exterior material including at least one pattern portion formed of the MD of the exterior material.
According to claim 5,
The pattern portion is formed by the TD of the exterior material in consideration of the possibility of damage to the electrode assembly inserted into the exterior material.
According to claim 5,
The compressive stress on the exterior material is measured in a state in which a load is applied to the exterior material by limiting the displacement to a predetermined strain rate with respect to the height of the pattern portion.
According to claim 1,
The exterior material is formed of a multi-layer structure in which at least one or more materials are laminated.
In the method of forming a pattern on the exterior material,
positioning the exterior material between an upper mold and a lower mold; and
Forming at least one pattern part in a Transverse Direction (TD) of the exterior material by pressing the exterior material using the upper mold and the lower mold
including,
TD of the exterior material is the width direction of the battery including the exterior material,
MD (Machine Direction) of the exterior material is the longitudinal direction of the battery including the exterior material,
The exterior material has different tensile strength characteristics in the TD of the exterior material and the MD of the exterior material,
The tensile strength measured in the TD of the exterior material has a value greater than the tensile strength measured in the MD of the exterior material.
In the method of producing a battery comprising an exterior material,
Forming at least one pattern part on the exterior material in a Transverse Direction (TD) of the exterior material;
folding the exterior material;
inserting an electrode assembly into the folded exterior material; and
Sealing the exterior material into which the electrode assembly is inserted
including,
TD of the exterior material is the width direction of the battery including the exterior material,
MD (Machine Direction) of the exterior material is the longitudinal direction of the battery including the exterior material,
The exterior material has different tensile strength characteristics in the TD of the exterior material and the MD of the exterior material,
The tensile strength measured in the TD of the exterior material has a value greater than the tensile strength measured in the MD of the exterior material.

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