KR20160042796A - Flexible battery, supplementary battery and watch strap comprising the flexible battery - Google Patents

Abstract

A flexible battery is provided. According to an embodiment of the present invention, the flexible battery comprises: an electrode assembly; and a cladding encapsulating the electrode assembly with an electrolyte, and having an insulating layer, provided in one surface exposed to the outside, for blocking a heat movement between the inside and the outside of the battery. The electrode assembly and the cladding individually have a pattern for contraction and relaxation in a lengthwise direction when bending, which is formed to have the same directivity. Accordingly, the flexible battery has excellent heat movement blocking between the inside and the outside of the flexible battery, and excellent durability while having excellent flexibility, thereby being applied to various electronic devices requiring a flexible battery such as a wearable device of a smart watch, a watch strap, etc., as well as a rollable display or the like.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a flexible battery, a secondary battery including the flexible battery,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flexible battery, and more particularly, to a flexible battery which is excellent in flexibility in blocking heat transfer between the inside and the outside of a flexible battery, has excellent flexibility and has excellent durability, .

As consumers' demands have changed due to digitization and high performance of electronic products, market demand is changing due to the development of power supply devices with high capacity due to thinness and light weight and high energy density.

In recent years, demand for mobile electronic devices such as portable telephones, notebooks, digital cameras, and the like has been continuously increasing. Especially, the demand for portable electronic devices such as rolled-up displays, flexible e-paper, flexible liquid crystal display ), Flexible organic light-emitting diodes (flexible OLEDs), and the like have been increasingly interested in flexible mobile electronic devices. Accordingly, a power supply for a flexible mobile electronic device should also be required to have flexible characteristics.

Flexible batteries are being developed as one of the power supply devices capable of reflecting such characteristics.

Flexible batteries include flexible nickel-cadmium batteries, nickel-metal hydride batteries, nickel-hydrogen batteries, and lithium-ion batteries. In particular, lithium-ion batteries have high utilization because they have a high energy density per unit weight and rapid charging as compared to lead batteries and other batteries such as nickel-cadmium batteries, nickel-hydrogen batteries and nickel-zinc batteries.

The lithium-ion battery uses a liquid electrolyte, and is mainly used as a metal can as a container. However, a cylindrical lithium ion battery using a metal can as a container has a disadvantage of restricting the design of the electric appliance because of its fixed shape, and it is difficult to reduce the volume.

Particularly, as mentioned above, mobile electronic devices are developed to be thin and miniaturized as well as being flexible. Thus, a lithium ion battery using a conventional metal can or a battery having a square structure is not easy to apply to mobile electronic devices have.

Accordingly, in order to solve the above-described structural problem, a pouch type battery in which an electrolyte is sealed in a pouch containing two electrodes and a separator has been developed.

Such a pouch-type battery is made of a flexible material and can be manufactured in various forms, and has an advantage that an energy density per mass can be realized.

That is, as shown in FIG. 1, the pouch-type battery 1 is provided with an electrode assembly 20 sealed inside the casing 10, and the casing 10 has an inner resin layer, a metal layer, Layer structure. The metal layer is an essential component of the exterior material for moisture-proofing and the like. The metal layer is densely dense to prevent moisture and electrolytic solution from passing therethrough, thereby preventing moisture from permeating into the exterior material from the exterior of the exterior material. Thereby preventing the electrolyte solution from leaking to the outside of the casing.

However, such a metal layer has a problem that cracks are caused in the flexible battery in which the outer casing is used, because it is difficult to secure a flexibility higher than a certain level due to insufficient elastic restoring force.

Further, the pouch type battery 1 may be embodied in a flexible form and applied to a product. However, since the conventional pouch-type battery 1 is implemented in a simple flexible form, if the repeated bending occurs during the use process, the casing and the electrode assembly are repeatedly damaged due to shrinkage and relaxation, or the performance is considerably higher And there is a limitation in exercising its function as a battery.

On the other hand, the flexible battery may cause a heat generation problem when the battery is used for a long time. If the flexible battery is provided inside the electronic device, the heat generated may deteriorate the function and durability of the electronic component disposed adjacent to the battery. In addition, when a flexible battery is applied to a wristband or the like, a problem of heat generation may be uncomfortable to a wearer. In addition, the flexible battery is installed in a separate member for protecting the battery, and can be applied to an electronic device or a watch band. Specifically, the flexible battery may be insert molded into a polymer such as polyurethane and embedded in the molding. The insert molding process may vary in temperature depending on the melting point of the molding material used, Therefore, there is a problem that the heat applied during the process expands the electrolyte in the flexible battery to cause leakage or damages the electrode assembly. Further, in order to solve such a problem, when a flexible battery is inserted into a separately manufactured molded body, a clearance is generated between the molded body and the outer surface of the battery, and the clearance generates noise during the bending process of the flexible battery, The wrinkles are generated on the surface of the wristwatch, which can significantly impair the aesthetics of the appearance of the wristwatch. Therefore, the adoption of the insert molding method in the housing of the flexible battery may be a process that must be adopted when considering the characteristics (flexibility) of the flexible battery itself and the application (such as a wristwatch or a rollerbing device).

As a result, the heat generated in the flexible battery is delayed and blocked from being moved to the outside, and furthermore, the heat is prevented from moving to the inside of the flexible battery even in the high temperature applied to the flexible battery in the insert molding, It is urgently required to develop a flexible battery in which flexibility is improved to enable bending while maintaining durability with frequent bending.

KR 10-2012-0023491 A

It is an object of the present invention to provide a flexible battery which can prevent the occurrence of cracks even if banding occurs through a predetermined pattern formed on the casing and the electrode assembly.

Another object of the present invention is to provide a flexible battery capable of preventing or minimizing deterioration of physical properties required for a battery even if repetitive banding occurs because the patterns formed on the casing and the electrode assembly are formed to coincide with each other.

Further, according to the present invention, the heat generated inside the flexible battery or the movement of heat applied to the flexible battery from the outside is blocked to protect the user or the electronic part outside the flexible battery, and the flexible battery Another object of the present invention is to provide a flexible battery which can prevent a decrease in durability.

In addition, since the present invention is excellent in flexibility and durability and is prevented from deterioration in durability due to heat, it can be manufactured so as to be integrated with the housing, so that noise is prevented from being generated by the banding and wrinkles and bends do not occur on the outer surface of the housing Another object of the present invention is to provide a secondary battery, a watch band and a hair band for a headphone that does not transmit heat generated from the flexible battery to the outside and does not affect the user and the electronic product.

In order to solve the above problems, the present invention provides an electrode assembly comprising: an electrode assembly; And a covering member sealing the electrode assembly together with the electrolyte and having a heat insulating layer on one side exposed to the outside to block heat transfer between the inside and the outside of the battery, And the patterns for shrinkage and relaxation are formed to have the same directionality, respectively.

The pattern may include a first pattern formed on at least one surface of the casing, And a second pattern formed on the electrode assembly in the same direction as the first pattern, and the first pattern and the second pattern may be arranged to coincide with each other.

In addition, the pattern may be formed such that the hill portions and the valleys are alternately formed along the longitudinal direction, and the hill portions and the valleys may have arc-shaped cross-sections, polygonal cross-sections, and mutually-combined cross-sections.

The pattern may be formed entirely or partially along the longitudinal direction of the electrode assembly and the casing, and each of the crests and valleys may be continuously or discontinuously formed in a direction parallel to the width direction of the electrode assembly and the casing. .

At this time, the plurality of neighboring mountains or valleys may be formed to have equal intervals or unequal intervals, or alternatively, the equal intervals and the unequal intervals may be mutually combined, and the pattern may be continuously formed along the longitudinal direction, Can be continuously formed.

The casing may include a first region for forming a housing portion for housing the electrode assembly and the electrolyte, and a second region surrounding the first region to form a sealing portion, May be formed only in the first region.

Also, the electrode assembly may include a positive electrode and a negative electrode formed by coating an active material on part or all of the current collector, and a separator disposed between the positive electrode and the negative electrode. The separator may include a porous nonwoven fabric layer having micropores, The nonwoven fabric layer may include a nanofiber web layer containing polyacrylonitrile nanofibers on one side or both sides thereof. At this time, the active material may include PTFE to prevent cracking and to prevent peeling from the current collector.

In addition, the exterior material may include a first resin layer, a metal layer, and a heat insulating layer sequentially laminated. The first resin layer may include at least one of acid-modified polypropylene (PPa), cast polyprolypene (CPP), linear low density polyethylene (LLDPE), low density polyethylene (LDPE), high density polyethylene (HDPE), polyethylene terephthalate, Acetate (EVA), an epoxy resin, and a phenol resin, or may be formed by stacking two or more kinds thereof. In addition, the metal layer may be formed of a metal such as aluminum, copper, phosphor bronze (PB), aluminum bronze, white copper, beryllium-copper, And chromium-zirconium copper alloys. At this time, the first resin layer may have an average thickness of 20 탆 to 80 탆, and the metal layer may have a thickness of 5 탆 to 100 탆.

The exterior material may further include a second resin layer interposed between the metal layer and the heat insulating layer, and the second resin layer may be formed of a material selected from the group consisting of nylon, polyethylene terephthalate (PET), cycloolefin polymer (COP), polyimide And the second resin layer may have an average thickness of 10 mu m to 50 mu m.

The first adhesive layer may include at least one selected from the group consisting of silicone, polyphthalate, acid modified polypropylene (PPa), and acid modified polyethylene (PEa). The first adhesive layer may be interposed between the metal layer and the first resin layer. can do.

In addition, a dry lamination layer interposed between the metal layer and the second resin layer and a second adhesive layer interposed between the second resin layer and the heat insulating layer may be further included.

In addition, the electrolytic solution may include a gel polymer electrolytic solution.

In addition, the region where the pattern is formed may include a region having an increased surface area ratio Sdr according to the following formula (1): 0.5 to 40.0.

[Equation 1]

In this case, the surface area of one region on which the pattern is formed means the surface area based on one area of the battery having a width Lx (mm) and a length Ly (mm).

In addition, the region in which the pattern is formed may include a region where? According to Equation (2) satisfies 5.0 deg. To 47 deg.

&Quot; (2) "

(H) is the average vertical distance (mm) between the highest point and the lowest point of adjacent mountains and valleys in the pattern formed on the flexible battery, and p is the average horizontal distance (mm) between the highest points of the adjacent two mountains.

The present invention also relates to an electrode assembly; And an outer casing that encapsulates the electrode assembly together with the electrolyte, wherein the electrode assembly and the casing are formed such that the shrinkage and relaxation patterns in the longitudinal direction at the time of bending have the same directionality, And a region satisfying the following expression (2): &thetas; satisfies 5.0 DEG to 47 DEG.

&Quot; (2) "

(H) is the average vertical distance (mm) between the highest point and the lowest point of adjacent mountains and valleys in the pattern formed on the flexible battery, and p is the average horizontal distance (mm) between the highest points of the adjacent two mountains.

In addition, the heat insulating layer may include at least one of a porous substrate and a heat insulating film in which a plurality of micropores capable of receiving air are formed. The porous substrate includes at least one substrate selected from the group consisting of a fibrous web, a nonwoven fabric, a fabric, and a knitted fabric, and the fibers forming the substrate may include one or more fibers of organic fibers and inorganic fibers. Also, the fibrous web is a nanofiber web formed through electrospinning, and the nanofibers forming the nanofiber web include polyacrylonitrile nanofiber, polyvinylidene fluoride nanofiber, polyacrylonitrile and polyvinylidene fluoride Rid < / RTI > composite nanofibers. In this case, the composite nanofiber may be a composite nanofiber in which polyacrylonitrile and polyvinylidene fluoride are mixed in a weight ratio of 6: 4 to 8.5: 1.5 in a mono yarn.

In addition, the nanofiber web may have a basis weight of 2 to 6 g / m 2 and a porosity of 40% or more.

The present invention also relates to a flexible battery as described above. And a soft housing that covers the surface of the casing, and the housing may be implemented as an auxiliary battery having at least one terminal for electrical connection with the charging target device.

The present invention also relates to the above-described flexible battery; And a soft housing for covering the surface of the casing.

Furthermore, the present invention can be implemented in a mobile electronic device including the above-described auxiliary battery.

According to the present invention, since the pattern for shrinking and relaxing in the longitudinal direction is formed in both the casing and the electrode assembly, it is possible to prevent the occurrence of cracks even if the banding occurs, thereby securing the required physical properties as the battery.

In addition, according to the present invention, the patterns formed on the casing and the electrode assembly are formed to coincide with each other, so that even when repetitive banding occurs, deterioration of physical properties required as a battery can be prevented or minimized.

Further, as the battery is used for a long time, heat generated inside the battery is delayed and blocked from moving to the external space of the battery, thereby minimizing the influence on the wearer or neighboring electronic parts.

In addition, even if the battery is housed through insert molding to protect the battery and improve the appearance of the external appearance, leakage caused by expansion of the electrolyte inside the battery and heat damage to the electrode assembly are prevented by heat applied during insert molding, The performance can be maintained and the flexible battery can be integrally provided in the housing through the insert molding to prevent the occurrence of noise during bending and to prevent the wrinkle or bending of the outer surface of the housing, As a result, it is possible to prevent wear and tear of the outer housing and the battery from frequent bending. Therefore, wearable devices such as smart watch, watch strap, and headphone, as well as various electronic devices It is applicable.

1 is a view showing a conventional battery, in which a) is an overall schematic view, b) is a sectional view,
2 is a general schematic view of a flexible battery in accordance with an embodiment of the present invention,
FIG. 3 is a schematic view showing a flexible battery according to another embodiment of the present invention, in which the first pattern is formed only on the receiving portion side of the casing,
FIG. 4 is a view showing various patterns applied to an electrode assembly and a casing of a flexible battery according to an embodiment of the present invention, and shows various intervals between neighboring valleys or peaks,
FIG. 5 is a view illustrating various patterns applied to an electrode assembly and a facing material in a flexible battery according to an embodiment of the present invention. FIG. 5 illustrates an example in which patterns are formed continuously or discontinuously with respect to the entire length.
6 to 9 are schematic views showing various cross-sectional shapes of a pattern applied to a flexible battery according to an embodiment of the present invention,
FIG. 10 is an enlarged view showing a detailed configuration of a flexible battery according to an embodiment of the present invention, wherein FIG. 10A shows a flexible battery having an exterior material laminated in the order of a first resin layer, a metal layer, a second resin layer, , Fig. 10B shows a case in which the heat insulating layer is provided in two layers, Fig. 10C and Fig. 10D show the exterior material in which the second resin layer is omitted in the case materials in Figs. 10A and 10B,
FIG. 11 is a graph showing the performance of a flexible battery according to an embodiment of the present invention, wherein a) is a graph showing a change in battery capacity before and after banding, and b) A graph showing a change in voltage of the battery,
FIG. 12 is a schematic view showing a mode in which a flexible battery according to an embodiment of the present invention is built in a housing and is implemented as an auxiliary battery;
FIG. 13 is a view showing a device used in a method of forming a pattern on a flexible battery according to an embodiment of the present invention, a photograph of a flexible battery being manufactured therefrom, and
14 is a cross-sectional schematic diagram of a flexible battery according to a comparative example of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings, which will be readily apparent to those skilled in the art to which the present invention pertains. The present invention may be embodied in many different forms and is not limited to the embodiments described herein. In order to clearly illustrate the present invention, parts not related to the description are omitted, and the same reference numerals are assigned to the same or similar components throughout the specification.

The flexible battery 100 according to an embodiment of the present invention includes an electrode assembly 110 and a casing 120 as shown in FIGS. 2 and 3. The electrode assembly 110 includes an electrolyte 120).

The electrode assembly 110 and the sheath 120 according to the present invention are respectively provided with patterns 119 and 124 for shrinking and relaxing in the longitudinal direction at the time of bending and the first pattern 124 And the second pattern 119 formed on the electrode assembly 110 have the same directionality.

The patterns 119 and 124 may prevent or minimize the shrinkage or relaxation of the substrate itself by canceling the length variation caused by the curvature change in the bent portion of the flexible battery 100. [

Accordingly, since the amount of deformation of the substrate itself constituting the electrode assembly 110 and the casing member 120 is prevented or minimized, the amount of deformation of the substrate itself, which may occur locally in the bent portion, is minimized even if repetitive banding occurs, 110 and the jacket 120 can be prevented from being locally broken or degraded in performance by banding.

At this time, the first pattern 124 and the second pattern 119 are arranged so that the first pattern 124 and the second pattern 119 coincide with each other, as well as the same directionality. This is because the first pattern 124 and the second pattern 119 can always have the same behavior so that the first pattern 124 and the second pattern 119 are always initialized In order to maintain the state of FIG.

This can be confirmed by the graph of FIG.

That is, when a force is applied to both ends of the flexible battery in an environment of a temperature of 25 ° C and a humidity of 65%, and the curvature at the bent portion is made to be 25 mm and the charging and discharging are performed 100 times, The capacity of the flexible battery 100 or 100 'according to the present invention showed a capacity (116 mAh) reduced by about 15% compared to the capacity without the bending (135 mAh), and the performance was maintained even after 100 times of operation (Example 1) In the case of the flexible battery having the pattern for shrinkage and relaxation only on the side of the casing, the capacity gradually dropped from the initial capacity of about 60% (52 mAh). When the number of cycles exceeded 50, In the case of a flexible battery having a simple plate shape in which no pattern is formed in both the casing and the electrode assembly, a reduction in capacity (26 mAh) of about 80% It was confirmed that charging and discharging were impossible in case of exceeding 30 times (Comparative Example 2).

On the other hand, in the environment of the temperature 25 and the humidity 65%, the middle of the length of the flexible battery was returned to its original state in the fully folded state, and the voltage in the battery was measured with time. As a result, In the case of the batteries 100 and 100 ', no change in the voltage value occurred (Example 1), a flexible battery in which a pattern for shrinkage and relaxation was formed only on the exterior material side (Comparative Example 1) It was confirmed that the voltage value of the flexible battery (Comparative Example 2) provided in the form of a simple plate not formed was deteriorated.

In other words, in the case where the external electrodes 120 and the electrode assembly 110 are formed so that the patterns 119 and 124 for shrinkage and relaxation coincide with each other, even if banding occurs, the degradation of the performance does not occur largely, Cracks are generated by bending or leakage of electrolyte occurs, and the performance of the battery deteriorates.

The flexible batteries 100 and 100 'according to the present invention are formed such that the patterns 119 and 124 for shrinking and relaxing in the longitudinal direction, which are generated when the electrode assembly 110 and the casing 120 are bent, The electrode assembly 110 and the casing member 120 can always maintain a uniform gap or contact state with respect to the entire length of the electrode assembly 110 so that the electrolyte solution sealed with the electrode assembly 110 is uniform The performance as a battery can be prevented from deteriorating.

The first pattern 124 and the second pattern 119 are formed in a direction parallel to the width direction of the casing member 120 and the electrode assembly 110, And the crests and valleys are alternately arranged along the longitudinal direction of the electrode assembly 110. The first pattern 124 and the second pattern 119 are formed such that the peak and the valley are formed at the same positions with respect to the peak and the valley, 119 are aligned with each other.

The protrusions and valleys of the first pattern 124 and the second pattern 119 are formed in a direction parallel to a straight line parallel to the width direction of the casing member 120 and the electrode assembly 110 , And the crests and valleys are repeatedly arranged along the longitudinal direction (see Figs. 2 and 3).

In this case, the patterns 119 and 124 may be continuously formed in a direction parallel to the width direction of the electrode assembly 110 and the casing 120, or may be formed discontinuously (see FIG. 4) 110 and the sheath 120 and may be partially formed for a portion of the length (see FIG. 5).

The crests and valleys may be formed to have arcuate cross-sections including semicircles, polygonal cross-sections including triangular or rectangular cross-sections, and cross-sections of various shapes in which arc-shaped cross-sections and polygonal cross-sections are mutually combined. Pitch and width, but they may be provided to have different pitches and widths (see FIGS. 6 to 9).

Accordingly, even if the shrinkage and relaxation of the outer casing 120 and the electrode assembly 110 repeatedly occur in the longitudinal direction due to repetitive banding, the variation amounts of the shrinkage and relaxation are canceled through the patterns 119 and 124, Thereby reducing fatigue.

As shown in FIG. 4, the first pattern 124 and the second pattern 119 may be spaced apart from each other by a predetermined distance or spaced apart from each other, And may be provided in the form of a combination of equal intervals and different intervals.

For example, when the flexible battery 100 or 100 'according to the present invention is applied to a product such as a wristwatch, the intervals between the hill and valleys constituting the patterns 119 and 124 with respect to the entire length may be formed at equal intervals, By reducing the distance between the peak and the valley formed on the side of the bonding site where the banding occurs relatively frequently during the process of worn a line or releasing the wear, the change amount of contraction and relaxation canceled by the patterns 119 and 124 It may be relatively large.

In addition, the first pattern 124 formed on the exterior material 120 may be formed on the entire surface of the exterior material 120, but may be partially formed.

3, the flexible battery 100 'according to the present invention includes a first region 124 in which the first pattern 124 forms a receiving portion for receiving the electrode assembly 110 and an electrolyte, As shown in Fig.

This is because the first pattern 124 is not formed on the side of the second region S2 constituting the sealing portion in order to prevent the electrolyte from leaking to the outside, And to increase the bonding force between the first casing member 121 and the second casing member 122 to increase airtightness.

Here, when the first pattern 124 is formed only in the first region S1, the first pattern 124 may be formed over the entire area of the first region S1, It may be formed only in the area corresponding to the area corresponding to the area.

The area where the patterns 119 and 124 provided in the electrode assembly 110 and the casing 120 included in the embodiment of the present invention are formed has an increased surface area ratio Sdr of 0.5 to 40.0 , Which can prevent frequent bending, twisting, and cracking of the facer and / or electrode assembly that may occur during their restoration and can provide more enhanced flexibility, Or the noise caused by the collision of the bone and the bone can be prevented, and the user can be prevented from being uncomfortable due to the noise.

[Equation 1]

Lx and Ly in Equation (1) represent the width and length of one region in which a pattern is formed as shown in FIGS. 2 and 3, and one region is a region of a flexible battery in which a pattern is formed And may correspond to the entire area of the flexible battery in which the pattern is formed as shown in FIG.

Also, the surface area of one region of the flexible battery in which the pattern is formed means the surface area of the region when the width and the length are Lx and Ly in one region where the pattern is formed. That is, if the flexible battery is flat without forming a pattern, the increased surface area ratio of Equation (1) becomes 0, the increased surface area ratio value can be increased as the height of the pattern is higher and the pitch of the pattern is shorter, The increased surface area ratio can be used to gauge the height and / or pitch of the pattern contained in the area.

The flexible battery according to an embodiment of the present invention may include a pattern area where the increased surface area ratio (Sdr) parameter value as described above satisfies 0.5 to 40.0, more preferably 1.8 to 30.0, Contains an area that satisfies 3.0 to 23.0, so that it is easier to realize the desired physical properties. If the increased surface area ratio is less than 0.5, the flexibility of the battery is considerably reduced, so that it is not bent at the time of bending, so that it may not be suitable for use in a flexible battery, and the bending / Or cracks may occur in the electrode assembly, which may lead to a significant degradation of the durability of the battery or a fatal problem that may cause the performance of the battery itself to be lost. In addition, if the increased surface area ratio exceeds 40.0, noise may occur during bending, which may cause an uncomfortable feeling to the user. Therefore, it is difficult to actually sell the product as a product, and a feeling of tearing of the outer packaging material and / A crack may be generated in the metal layer and / or the electrode assembly of the exterior material, resulting in a problem that the durability of the flexible battery may significantly decrease or the function may be lost.

On the other hand, even if the flexible battery has a pattern partially or entirely, a pattern region that does not satisfy the enlarged surface area ratio according to the present invention may be included in some regions of the patterned portion. This is because a different compressive force / tensile force may be applied depending on the position of the battery when the battery is bent, and the portion having a high compressive force / tensile strength must satisfy the increased surface area ratio value according to the present invention, Since the metal layer of the facer or the electrode assembly has a relatively small external force to be applied to the portion having low compressive force / tensile force, the increased surface area ratio of the portion satisfies the value of Equation 1 according to the present invention .

In the region where the patterns 119 and 124 provided in the electrode assembly 110 and the case 120 included in the embodiment of the present invention are formed,? Satisfies? Region, and may preferably satisfy 5.0 to 31 DEG. Accordingly, the flexible battery according to an embodiment of the present invention can prevent cracks of the casing and / electrode assembly that may occur during frequent bending, twisting, and restoration thereof, and can exhibit improved flexibility. It is possible to prevent the noise caused by the collision of the mountain or the bone with the bone, thereby preventing the user from feeling uncomfortable due to the noise.

&Quot; (2) "

Referring to FIG. 7B and FIG. 8A, h represents the average height of the pattern formed on the flexible battery. The average vertical distance between the highest point and the lowest point of adjacent mountains and bones Distance (mm). In addition, p represents the average horizontal distance (mm) between the peaks of each of two adjacent mountains. The height and / or the pitch of a pattern included in a certain region can be estimated through the value of? In Equation (2).

The flexible battery according to an exemplary embodiment of the present invention may include a pattern area having a θ value of 5 to 47 degrees according to Equation (2) as described above, more preferably a region having a 5 to 31 degree May be easier to implement to achieve the desired physical properties. If the angle? Is less than 5 degrees, the flexibility of the battery may be considerably reduced, causing bending, twisting, and cracking of the metal layer or the electrode assembly of the casing in the process of restoration thereof. Or may fail to implement the desired physical properties of the battery such as the loss of battery function. Also, if the angle? Exceeds 47, cracks may occur in the battery in the process of forming a pattern having a height and a pitch in the battery, an interval between the adjacent mountains and mountains in the pattern is narrowed, As the pattern is embodied, when the battery is bent, there may be a problem that the desired properties of the flexible battery can not be realized, for example, the adjacent acid and the acid or the adjacent bone and the bone come into contact with each other to interfere with bending, have.

On the other hand, even if the flexible battery has a pattern partially or entirely, a pattern area which does not satisfy the? Value of the formula (2) according to the present invention may be included in a part of the area where the pattern is formed. This is because a different compressive force / tensile force may be applied depending on the position of the battery when the battery is bent, and the portion having a high compressive force / tensile strength must satisfy the increased surface area ratio value according to the present invention, Since the metal layer of the outer casing or the electrode assembly has a small external force to withstand the compressive force / tensile force, the θ value of the formula (2) of the present invention is 5.0 to 47 ° You can escape.

Also, the height (h) of the pattern included in one embodiment of the present invention is 0.072 to 1.5 mm, and the average horizontal distance (p) between the peaks of the adjacent two mountains is 0.569 to 1.524 mm, But may be changed depending on the specific shape of the pattern to be formed.

The electrode assembly 110 is encapsulated with an electrolytic solution in the casing 120 and includes an anode 112, a cathode 116 and a separator 114 as shown in FIG.

The anode 112 includes a cathode current collector 112a and a cathode active material 112b and the cathode 116 includes a cathode current collector 116a and a cathode active material 116b. The cathode current collector 112a And the anode current collector 116a may be realized in the form of a sheet having a predetermined area.

That is, the positive electrode 112 and the negative electrode 116 can be pressed, deposited, or coated with the active material 112b or 116b on one or both surfaces of the current collectors 112a and 116a. At this time, the active materials 112b and 116b may be provided for the entire area of the current collectors 112a and 116a, or may be partially provided for some areas.

The negative electrode current collector 116a and the positive electrode current collector 112a may be made of a thin metal foil and may be made of a metal such as copper, aluminum, stainless steel, nickel, titanium, chromium, manganese, iron, cobalt, zinc, molybdenum, tungsten, Silver, gold, and a mixture thereof.

The cathode current collector 112a and the anode current collector 116a may be formed with an anode terminal 118a and a cathode terminal 118b for electrical connection with an external device from each body. The positive electrode terminal 118b and the negative electrode terminal 118a may extend from the positive electrode current collector 112a and the negative electrode current collector 116a and may protrude from one side of the case member 120, 120, respectively.

On the other hand, the positive electrode active material (112b) is and reversibly including a positive electrode active material capable of migration intercalation and de-intercalation of lithium ions, and a typical example of such a positive electrode active material is LiCoO _2, LiNiO _2, LiNiCoO _2, LiMnO _2, LiMn ₂ O ₄ , V ₂ O ₅ , V ₆ O ₁₃ , LiNi _{1 -x- y} Co _x M _y O ₂ (0 ≤ x ≤ 1, 0 ≤y ≤ 1, 0 ≤ x + y ≤ 1, M is Transition metal oxides such as Al, Sr, Mg, La and the like, or lithium nickel cobalt manganese (NCM) -based active materials, and mixtures of at least one of them may be used.

In addition, the negative electrode active material 116b may include a negative electrode active material capable of reversibly intercalating and deintercalating lithium ions. Examples of the negative electrode active material include carbon, carbon fiber, carbon composite of crystalline or amorphous carbon, Based anode active material, tin oxide, lithiated lithium, lithium, lithium alloy, and mixtures of at least one of these. Here, the carbon may be at least one selected from the group consisting of carbon nanotubes, carbon nanowires, carbon nanofibers, graphite, activated carbon, graphene and graphite.

However, the positive electrode active material and the negative electrode active material used in the present invention are not limited thereto, and it is to be noted that the commonly used positive electrode active material and negative electrode active material may all be used.

At this time, in the present invention, the cathode active material 112b and the anode active material 116b may contain a PTFE (Polytetrafluoroethylene) component. This is to prevent peeling or cracking of the positive electrode active material 112b and the negative electrode active material 116b from the current collectors 112a and 116a during bending.

The PTFE component may be 0.5 to 20 wt%, preferably 5 wt% or less, of the total weight of the cathode active material 112b and the anode active material 116b.

The separation membrane 114 disposed between the anode 112 and the cathode 116 may include a nanofiber web layer 114b on one side or both sides of the nonwoven fabric layer 114a.

Here, the nanofiber web layer 114b may be a nanofiber containing at least one selected from the group consisting of polyacrylonitrile nanofiber and polyvinylidene fluoride nanofiber.

Preferably, the nanofiber web layer 114b may consist solely of polyacrylonitrile nanofibers to ensure radioactive and uniform pore formation. Here, the polyacrylonitrile nanofiber may have an average diameter of 0.1 to 2 탆, and preferably 0.1 to 1.0 탆.

If the average diameter of the polyacrylonitrile nanofibers is less than 0.1 mu m, the separator may not have sufficient heat resistance. If the average diameter exceeds 2 mu m, the mechanical strength of the separator is excellent, but the elasticity of the separator is reduced It is because.

In addition, when the gel polymer electrolyte is used as the electrolytic solution, the separation membrane 114 may be a composite porous separator to optimize the impregnation of the gel polymer electrolyte.

That is, the composite porous separator may include a porous nonwoven fabric having micropores used as a matrix and a porous nanofiber web formed of a spinnable polymer material and impregnated with an electrolyte solution.

Here, the porous nonwoven fabric is composed of a PP nonwoven fabric, a PE nonwoven fabric, a three-layer structure of PP / PE / nonwoven fabric made of double structure PP / PE fiber coated with PE on the outer periphery of PP fiber as a core and PP / PE / PP, A nonwoven fabric having a shutdown function by the low PE, a PET nonwoven fabric made of polyethylene terephthalate (PET) fibers, or a nonwoven fabric made of cellulose fibers can be used. The PE nonwoven fabric may have a melting point of 100 to 120 ° C. The PP nonwoven fabric may have a melting point of 130 to 150 ° C, and the PET nonwoven fabric may have a melting point of 230 to 250 ° C.

The porous nonwoven fabric preferably has a thickness in the range of 10 to 40 mu m, a porosity of 5 to 55%, and a Gurley value of 1 to 1000 sec / 100 cc.

Meanwhile, the porous nanofiber web may be a mixed polymer in which a swelling polymer swelling in an electrolytic solution is used alone or a heat-resistant polymer capable of enhancing heat resistance of a swelling polymer is mixed.

The porous nanofiber web may be prepared by dissolving a single or mixed polymer in a solvent to form a spinning solution, spinning the spinning solution using an electrospinning device, and spinning nanofibers are accumulated in the collector to form a three-dimensional pore structure Thereby forming a porous nanofiber web.

Here, the porous nanofiber web may be any polymer that is dissolved in a solvent to form a spinning solution, and then can be spinned by an electrospinning method to form nanofibers. For example, the polymer may be a single polymer or a mixed polymer, and may include a swellable polymer, a non-swellable polymer, a heat-resistant polymer, a mixed polymer in which a swellable polymer and a non-swellable polymer are mixed, a mixed polymer in which a swellable polymer and a heat- .

In this case, when the porous nanofiber web uses a mixed polymer of a swellable polymer and a non-swellable polymer (or a heat-resistant polymer), the swellable polymer and the non-swellable polymer have a weight ratio in the range of 9: 1 to 1: 9, 2 to 5: 5.

Generally, non-swelling polymers are generally heat-resistant polymers, and their melting points are relatively high because they have a larger molecular weight than swellable polymers. Accordingly, the non-swelling polymer is preferably a heat-resistant polymer having a melting point of 180 ° C or higher, and the swelling polymer is preferably a resin having a melting point of 150 ° C or lower, preferably 100-150 ° C.

On the other hand, the swellable polymer usable in the present invention may be a resin capable of swelling in an electrolytic solution and capable of being formed into ultrafine nanofibers by electrospinning.

In one example, the swellable polymer is selected from the group consisting of polyvinylidene fluoride (PVDF), poly (vinylidene fluoride-co-hexafluoropropylene), perfluoropolymers, polyvinyl chloride or polyvinylidene chloride, Polyethylene glycol derivatives including polyethylene glycol dialkyl ethers and polyethylene glycol dialkyl esters, polyoxides including poly (oxymethylene-oligo-oxyethylene), polyethylene oxide and polypropylene oxide, polyvinyl acetate, poly Polyacrylonitrile copolymers including polystyrene and polystyrene acrylonitrile copolymers, polyacrylonitrile methyl methacrylate copolymers, polymethylmethacrylate, polymethylmethacrylate copolymers and polyacrylonitrile copolymers, Mixtures of one or more of these are used .

The heat-resistant polymer or the non-swellable polymer may be dissolved in an organic solvent for electrospinning and may be swollen more slowly or swell than the swellable polymer due to the organic solvent contained in the organic electrolytic solution, and a resin having a melting point of 180 or more may be used .

For example, the heat-resistant polymer or non-swellable polymer may be selected from the group consisting of polyacrylonitrile (PAN), polyamide, polyimide, polyamideimide, poly (meta-phenylene isophthalamide), polysulfone, polyetherketone, Aromatic polyesters such as phthalate, polytrimethylene terephthalate, and polyethylene naphthalate; polyesters such as polytetrafluoroethylene, polydiphenoxaphospazene and poly {bis [2- (2-methoxyethoxy) Polyurethane copolymers including phosphazenes, polyurethanes and polyether urethanes, cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, and the like.

Meanwhile, the nonwoven fabric constituting the nonwoven fabric layer 114a may be made of a material selected from the group consisting of cellulose, cellulose acetate, polyvinyl alcohol (PVA), polysulfone, polyimide, polyetherimide, polyamide, polyethylene oxide (PEO), polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), polyurethane (PU), polymethyl methacrylate (PMMA), poly (methylmethacrylate), and polyacrylonitrile.

The nonwoven fabric layer may further include inorganic additives such as SiO, SnO, SnO ₂ , PbO ₂ , ZnO, P ₂ O ₅ , CuO, MoO, V ₂ O ₅ , B ₂ O ₃ , Si ₃ N ₄ , CeO ₂ , Mn ₃ O ₄ , Sn ₂ P ₂ O ₇ , Sn ₂ B ₂ O ₅ , Sn ₂ BPO ₆ , TiO ₂ , BaTiO ₃ , Li ₂ O, LiF, LiOH, Li ₃ N, It may include _{BaO, Na 2 O, Li 2} CO 3, CaCO 3, LiAlO 2, SiO 2, Al 2 O 3 and at least one selected from PTFE.

The inorganic particles as the inorganic additive may have an average particle size of 10 to 50 nm, preferably 10 to 30 nm, and more preferably 10 to 20 nm.

In addition, the average thickness of the separation membrane may be 10 to 100 mu m, preferably 10 to 50 mu m. If the average thickness of the separator is less than 10 mu m, the separator may be too thin to ensure long-term durability of the separator due to repeated bending and / or spreading of the battery. If the average thickness exceeds 100 mu m, It is preferable to have an average thickness within the above range.

The non-woven fabric layer may have an average thickness of 10 to 30 탆, preferably 15 to 30 탆, and the nanofiber web layer may have an average thickness of 1 to 5 탆.

Meanwhile, the outer casing 120, which is included in one embodiment of the present invention, is made of a plate-shaped member having a predetermined area, and the electrode assembly 110 is received from an external force by accommodating the electrode assembly 110 and the electrolyte therein. To protect it.

For this purpose, the casing member 120 is provided with a pair of first casing members 121 and a second casing member 122, and the electrolyte solution and the electrode assembly 110 housed therein are sealed with an adhesive along the rim, And prevents leakage to the outside.

That is, the first casing member 121 and the second casing member 122 include a first region S1 for forming an accommodating portion for accommodating the electrode assembly and the electrolyte, and a second region S1 surrounding the first region S1, And a second region S2 forming a sealing portion for preventing leakage to the outside.

In this case 120, the first casing member 121 and the second casing member 122 are made of two members, and then the side of the frame constituting the sealing member may be sealed with an adhesive, The remaining portion that is folded in half along the width or length direction and then abutted may be sealed through the adhesive. In the case of using an exterior material having a resin layer that can be thermally adhered to the surface where the first exterior material 121 and the second exterior material 122 abut each other without any additional adhesive, heat and pressure may be applied to seal the exterior material.

The exterior materials 121 and 122 included in the embodiment of the present invention are formed of insulating materials 121d and 122d for blocking heat transfer between the inside and the outside of the battery, 121 and 122, respectively. Accordingly, the heat generated by the battery for a long period of time is discharged to the outside space of the battery, thereby preventing the user from feeling uncomfortable or affecting the electronic parts disposed adjacent to the battery. In addition, the flexible battery further protects against physical shock and penetration of gas or moisture into the battery, and when applied to place a flexible battery outside the product, such as a headband of a watch or a headphone, , The touch of the user touches the skin, the insert molding with a molding member to prevent the high heat applied during insert molding to prevent the inside of the flexible battery to prevent the function of the battery to prevent malfunction or failure do.

Meanwhile, in the housing method for a flexible battery according to an embodiment of the present invention, the insert molding process is required because the outer surface of the flexible battery has a curvature due to the pattern formed to improve the flexibility of the battery, And the housing should be housed such that the inner surface of the housing and the outer surface of the battery are integrally adhered to each other. If a flexible battery having a curvature on the outer surface is inserted into a separately manufactured housing so that a receiving portion is not provided, a problem of defective or deteriorated function of the flexible battery due to heat is not caused. It may not occur at the origin. However, a flexible battery having a curved shape formed on the outer surface of the flexible battery and having a curved shape is formed on the surface of the housing part inside the housing, A clearance necessarily arises between the outer surfaces of the first and second plates. The clearance causes noise during bending of the flexible battery, and the flexible battery accommodated in the housing can not be fixed, thereby causing the battery to move inside the housing. In addition, the outer surface of the housing where the clearance is generated has a problem of crying or wrinkling when the battery is bent, which may severely impair the beauty of the appearance. Furthermore, it is very difficult to form a pattern on the outer surface of the housing inside the housing, which has a bend formed on the outer surface of the flexible battery and a shape corresponding to the opposite phase of the bend having the same shape and size, There is a problem. However, according to the embodiment of the present invention, a heat insulating layer is provided on one surface of a casing, thereby preventing a malfunction or a failure of the flexible battery even if the flexible battery is housed by the insert molding method.

The heat insulating layers 121d and 122d may be formed as a thin film and may be a known heat insulating member having heat resistance capable of maintaining the shape at a high temperature applied at the time of insert molding, for example, at 150 ° C or higher, preferably 180 ° C or higher Can be used without restrictions. For example, the heat insulating layers 121d and 122d may include a porous substrate and / or a heat insulating film having a plurality of micropores capable of receiving air.

The porous substrate may include at least one substrate selected from the group consisting of a fibrous web, a nonwoven fabric, a fabric, and a knitted fabric. The genital fabric and the knitted fabric mean conventional fabrics in which the fibers are arranged with directional and / or regularity. Further, the fibrous web and the nonwoven fabric means a substrate formed by gathering fibers without having directionality, and the fibrous web forms a three-dimensional network structure by fusion between the fibers at the same time as the spinning, And the nonwoven fabric means a conventional nonwoven fabric prepared by adhering short fibers through a separate adhesive or heat. The fibers forming the porous substrate may be selected from the group consisting of cellulose, protein, polyester (PET, PBT), polyamide (nylon 6, nylon 66, etc.), acrylic (polyacrylonitrile, Inorganic fibers such as known organic fibers and / or glass fibers, rock wool fibers, including vinyl (polyvinyl alcohol, polyvinyl chloride) and fluorine (PVDF, PCTFE, PTFE, etc.) Fiber.

The heat insulating layers 121d and 122d included in an embodiment of the present invention may be a fibrous web, for example, a nanofiber web formed through electrospinning. The nanofibers forming the nanofiber web may include polyacrylonitrile nanofibers to provide heat resistance to withstand the high heat applied during insert molding. In addition, the nanofiber itself forming the nanofiber web may include polyvinylidene fluoride nanofibers in order to exhibit adhesiveness to improve durability and mechanical strength. Alternatively, the nanofibers may be composite nanofibers of polyacrylonitrile and polyvinylidene fluoride, through which heat resistance, durability through adhesiveness, and mechanical strength can be simultaneously exhibited. In this case, the composite nanofiber may be a composite nanofiber in which polyacrylonitrile and polyvinylidene fluoride are mixed in a weight ratio of 6: 4 to 8.5: 1.5 in a mono yarn. If the PAN and PVDF are contained in a ratio of less than 6: 4, the heat resistance is lowered and the pores of the nanofiber web are significantly decreased due to the melting of the nanofiber web during the adiabatic effect, This can be. In addition, if PAN and PVDF are contained in excess of the ratio of 8.5: 1.5, it is difficult to exhibit mechanical strength and durability, and since the proportion of PAN is high, the productivity may be poor due to remarkable radioactivity during electrospinning, It is difficult to fabricate a nanofiber web that exhibits sufficient adiabatic effect because it is difficult to realize pores and pores. Further, there is a problem that the adhesion of the outer housing and the flexible battery made of the nanofiber web and the insert molding may be reduced.

 The average diameter of the nanofibers forming the nanofiber web may be 0.1 to 2 μm, preferably 0.1 to 1.0 μm. If the average diameter of the nanofibers is less than 0.1 μm, sufficient porosity is secured There may be a problem that the heat insulating property is deteriorated. If it exceeds 2 탆, there may be a problem that the void formed by the nanofiber is too large and the heat insulating property is deteriorated.

In addition, the nanofiber web may have a basis weight of 2 to 6 g / m 2, a porosity of 40% or more, more preferably 40 to 80%, and an average pore size of 300 to 400 μm , Whereby the desired adiabatic effect can be expressed to be further improved. If the porosity exceeds 80% and / or the average pore size exceeds 400 탆, the mechanical strength of the nanofibrous web may be weak and it may not be able to function properly as a heat insulating layer

The heat insulating film may be a known heat insulating film, a film having an air bag inside the film, or a known heat insulating film exhibiting an adiabatic effect in a state in which air is not contained in the film, It is not particularly limited to a specific kind. However, it may preferably be an insulating film formed from a material having a melting point of 130 캜, preferably 150 캜, more preferably 180 캜, and still more preferably 200 캜 or more in consideration of the temperature of the insert molding.

On the other hand, when a fiber web, specifically a nanofiber web, is used as a heat insulating layer, the adhesion between the housing and the flexible battery through the insert molding is further remarkably improved in addition to the effect of adiabatic effect. That is, as the molding material is embedded in the bent portion of the pattern formed on the flexible battery, the adhesion between the molding material and the flexible battery is good. However, the frequent bending of the flexible battery after the insert molding results in the weakening of adhesion between the molding material and the flexible battery There may be problems such as noise, noise, and noise. However, when the nanofiber web is used as a heat insulating layer, there is an advantage that adhesion between the outer housing and the flexible battery can be improved, and the housing can be prevented from being lifted or dislodged even with frequent bending.

It is preferable that the heat insulating layers 121d and 122d have an average thickness of 10 占 퐉 to 50 占 퐉, preferably an average thickness of 15 占 퐉 to 40 占 퐉, and more preferably 15 占 퐉 to 35 占 퐉. At this time, if the average thickness of the heat insulating layer is less than 10 mu m, there is a problem that the desired heat insulating effect can not be exhibited. If the heat insulating layer is more than 50 mu m, it is not economical and it may be undesirable for manufacturing a slimmed flexible battery.

In addition, the heat insulating layer 123d included in the embodiment of the present invention may have a structure in which the first heat insulating layer 123d ₁ and the second heat insulating layer 123d ₂ are laminated as shown in FIG. 10B, The heat insulating layer 123d ₁ may be the above-described nanofiber web, and the second heat insulating layer 123d ₂ may be a nonwoven fabric. At this time, the thickness of the nanofiber web may be 3 to 10 mu m, and the thickness of the nonwoven fabric may be 10 to 40 mu m. At this time, the nonwoven fabric may function as a heat insulating layer, and at the same time, it may serve to improve the durability of the heat insulating layer by supplementing the mechanical strength of the laminated nanofiber web.

The exterior material included in the embodiment of the present invention includes the second resin layers 121c, 122c, and 123c, the metal layers 121b, 122b, and 123b, and the second resin layers 121b, 122b, and 123b sequentially below the heat insulating layers 121d, The first resin layers 121a, 122a and 123a are disposed inside the first and second resin layers 121 and 122a and 123a so as to be in contact with the electrolyte solution The heat insulating layers 121d, 122d, and 123d are exposed to the outside.

At this time, the first resin layers 121a and 122a seal the outer sheathing materials 121 and 122 to each other to serve as a bonding member capable of sealing the electrolyte contained in the battery so as not to leak to the outside. The first resin layers 121a and 122a may be formed of a material such as an acid modified polypropylene (PPa), a cast polyprolypene (CPP), a linear low density polyethylene (LLDPE) , A single layer structure of one of LDPE (Low Density Polyethylene), HDPE (High Density Polyethylene), polyethylene, polyethylene terephthalate, polypropylene, ethylene vinyl acetate (EVA), epoxy resin and phenol resin or a laminated structure thereof And may be composed of a single layer of one selected from the group consisting of acid modified polypropylene (PPa), cast polyprolypene (CPP), linear low density polyethylene (LLDPE), low density polyethylene (LDPE) and high density polyethylene Or two or more of them may be laminated.

The first resin layers 121a and 122a may have an average thickness of 20 to 80 占 퐉, and preferably an average thickness of 20 to 60 占 퐉.

If the average thickness of the first resin layers 121a and 122a is less than 20 占 퐉, the first resin layer 121a and the second resin layer 122, which are in contact with each other in the process of sealing the edge sides of the first and second casing materials 121 and 122, And 122a, or to secure airtightness to prevent leakage of the electrolyte. If the average thickness exceeds 80 m, it is uneconomical and disadvantageous to thinning.

The metal layers 121b, 122b and 123b are for preventing moisture from permeating from the outside into the electrode assembly and the receiving portion side of the electrolyte solution, and preventing the electrolyte solution from leaking to the outside from the accommodating portion.

For this, the metal layers 121b, 122b, and 123b may be formed of a dense metal layer so that moisture and an electrolyte can not pass therethrough. The metal layer is formed on a foil-like metal thin plate or a second resin layer 121c, 122c, or 123c to be described later by a commonly known method such as sputtering or chemical vapor deposition And it may be formed of a thin metal plate. Through this, cracks of the metal layer can be prevented during pattern formation, and the electrolyte can be leaked to the outside, and moisture permeation from the outside can be prevented.

For example, the metal layers 121b, 122b, and 123b may be formed of a metal such as aluminum, copper, phosphor bronze (PB), aluminum bronze, white copper, beryllium- Iron-copper, corson alloy, and chromium-zirconium copper alloy.

The metal layers 121b, 122b and 123b may have a linear expansion coefficient of 1.0 × 10 ^-7 to 1.7 × 10 ^-7 / ° C, preferably 1.2 × 10 ^-7 to 1.5 × 10 ^-7 / have. This is because the linear expansion coefficient, and can result in 1.0 × 10 ^-7 / ℃ than when not possible to ensure sufficient flexibility cracks (crack) by an external force generated during bending, coefficient of linear expansion exceeds the 1.7 × 10 ^-7 / ℃ The rigidity is reduced and the deformation of the shape may be severely caused.

The average thickness of the metal layers 121b, 122b and 123b may be 5 占 퐉 or more, preferably 5 占 퐉 to 100 占 퐉, and more preferably 30 占 퐉 to 50 占 퐉.

This is because if the average thickness of the metal layer is less than 5 占 퐉, moisture may permeate into the inside of the housing or the electrolyte inside the housing may leak outside.

The second resin layers 121c, 122c and 123c are positioned on the exposed surface side of the casing materials 120 and 123 to reinforce the strength of the casing material and damage such as scratches to the casing material due to physical contact externally applied .

The second resin layers 121c, 122c and 123c may include at least one selected from the group consisting of nylon, polyethylene terephthalate (PET), cycloolefin polymer (COP), polyimide (PI) Nylon or a fluorine-based compound.

Here, the fluorine-based compound may be at least one selected from the group consisting of polytetrafluoroethylene (PTFE), perfluorinated acid (PFA), fluorinated etheylene propylene copolymer (FEP), polyethylene tetrafluoroethylene (ETFE), polyvinylidene fluoride (PVDF), ethylene chlorotrifluoroethylene (ECTFE), and polychlorotrifluoroethylene And may include at least one selected.

The second resin layers 121c, 122c, and 123c may have an average thickness of 10 占 퐉 to 50 占 퐉, preferably an average thickness of 15 占 퐉 to 40 占 퐉, more preferably 15 占 퐉 to 35 占 퐉, Lt; / RTI >

If the average thickness of the second resin layers 121c, 122c, and 123c is less than 10 mu m, mechanical properties can not be secured. If the average thickness of the second resin layers 121c, 122c, and 123c is more than 50 mu m, it is advantageous in securing mechanical properties, to be.

The flexible battery 100 or 100 'according to the present invention may further include a first adhesive layer (not shown) between the metal layers 121b, 122b and 123b and the first resin layers 121a, 122a and 123a.

The first adhesive layer serves to increase the adhesive strength between the metal layers 121b, 122b and 123b and the first resin layers 121a, 122a and 123a. In addition, the electrolyte solution contained in the exterior material is applied to the metal layers 121b, 122b, The first resin layers 121a, 122a and 123a and the metal layers 121b, 122b and 123b are peeled off by the acidic electrolytic solution to prevent the metal layers 121b, 122b and 123b from corroding and / Can be prevented. In addition, when the flexible battery 100 or 100 'is in use, troubles such as abnormal overheating may occur, thereby preventing leakage of the electrolyte even when the flexible battery expands, thereby providing reliability for safety. In addition, a pattern for improving the flexibility of the battery is formed on the exterior material. When the pattern is formed on the exterior material, cracks are generated in the first resin layers 121a, 122a, and 123a to cause leakage of the electrolyte. 1 adhesive layer can prevent cracks of the first resin layers 121a, 122a, and 123a that may occur during pattern formation.

The first adhesive layer may be made of a material similar to that of the first resin layers 121a, 122a, and 123a in order to improve adhesion with the first resin layers 121a, 122a, and 123a. For example, the first adhesive layer may include at least one selected from the group consisting of silicone, polyphthalate, acid modified polypropylene (PPa), and acid modified polyethylene (PEA).

At this time, the first adhesive layer may have an average thickness of 5 탆 to 30 탆, and preferably 10 탆 to 20 탆. This is because if the average thickness of the first adhesive layer exceeds 5 mu m, it may be difficult to stably secure the adhesive strength, and if it exceeds 30 mu m, it is disadvantageous for thinning.

The flexible battery 100 or 100 'according to the present invention may further include a dry laminate layer (not shown) between the metal layers 121b, 122b and 123b and the second resin layers 121c, 122c and 123c have.

The dry laminate layer serves to bond the metal layers 121b, 122b, and 123b to the second resin layers 121c, 122c, and 123c, and drys a known aqueous and / or oily known organic solvent- .

At this time, the dry laminate layer may have an average thickness of 1 탆 to 7 탆, preferably 2 탆 to 5 탆, and more preferably 2.5 탆 to 3.5 탆.

If the average thickness of the dry laminate layer is less than 1 占 퐉, the adhesive force is too weak to cause peeling between the metal layers 121b, 122b, and 123b and the second resin layers 121c, 122c, and 123c, The thickness of the dry laminate layer becomes unnecessarily large, which may adversely affect formation of a pattern for shrinkage and relaxation.

The flexible batteries 100 and 100 'according to the present invention may further include a second adhesive layer (not shown) between the second resin layers 121c, 122c and 123c and the heat insulating layers 121d, 122d and 123d have. The second adhesive layer serves to bond the second resin layers 121c, 122c, and 123c and the heat insulating layers 121d, 122d, and 123d, and dries a known aqueous and / or oily known organic solvent- And the thickness of the second adhesive layer may be 2 to 12 占 퐉. If the thickness of the second adhesive layer is less than 2 mu m, there may be a problem that the insulating layer peels off from the casing. If the thickness of the second adhesive layer exceeds 12 mu m, if the porous substrate is used as the heat insulating layer, There is a problem that the porosity of the heat insulating layer decreases as the second adhesive layer penetrates and blocks the pores, so that the heat insulating effect of the desired level can not be exhibited.

As shown in FIG. 10C and FIG. 10D, the exterior materials 124 and 125 included in one embodiment of the present invention may include a heat insulating layer 124d and 125d sequentially from the outside of the battery to the inner layer, The metal layers 124b and 125b and the first resin layers 124a and 125a may be laminated so that the thickness of the facer material is reduced and the thickness of the insulating layer is increased by the thickness of the second resin layer There is an advantage that a more improved adiabatic effect can be exhibited. At this time, the second adhesive layer may be further formed between the heat insulating layers 124d and 125d and the metal layers 124b and 125b to adhere the heat insulating layers 124d and 125d and the metal layers 124b and 125b.

Meanwhile, a liquid electrolyte which is commonly used can be used as the electrolyte solution sealed in the accommodation portion together with the electrode assembly 110.

For example, the electrolytic solution may be an organic electrolytic solution containing a non-aqueous organic solvent and a solute of a lithium salt. Here, as the non-aqueous organic solvent, a carbonate, an ester, an ether, or a ketone may be used. Examples of the carbonate include dimethyl carbonate (DMC), diethyl carbonate (DEC), dipropyl carbonate (DPC), methyl propyl carbonate (MPC), ethyl propyl carbonate (EPC), methyl ethyl carbonate (MEC) Propylene carbonate (PC), butylene carbonate (BC) and the like can be used as the ester. Examples of the ester include butyrolactone (BL), decanolide, valerolactone, mevalonolactone Caprolactone, n-methyl acetate, n-ethyl acetate, n-propyl acetate and the like can be used. As the ether, dibutyl ether and the like can be used. As the ketone, polymethyl vinyl ketone However, the present invention is not limited to the kind of the non-aqueous organic solvent.

In addition, the electrolyte solution used in the present invention may include a lithium salt. The lithium salt acts as a source of lithium ions in the battery to enable operation of a basic lithium battery. Examples thereof include LiPF ₆ , LiBF ₄ , _{LiSbF 6, LiAsF 6, LiClO 4} , LiCF 3 SO 3, LiN (CF 3 SO 2) 2, LiN (C 2 F 5 SO 2) 2, LiAlO 4, LiAlCl 4, LiN (C x F 2x + 1 SO 2 ) (C _y F _{2x + 1} SO ₂ ) (where x and y are rational numbers), and LiSO ₃ CF ₃ .

In this case, the electrolyte used in the flexible batteries 100 and 100 'according to the present invention may be a conventional liquid electrolyte, but preferably a gel polymer electrolyte can be used, which can occur in a flexible battery having a liquid electrolyte It is possible to prevent the leakage of gas and the occurrence of leakage at the time of bending.

The gel polymer electrolyte may be formed by gelation heat treatment of an organic electrolyte solution containing a non-aqueous organic solvent and a solute of a lithium salt, a monomer for forming a gel polymer, and a polymerization initiator. However, the gel polymer electrolyte may be subjected to heat treatment alone, but heat treatment may be performed in the state where the organic electrolyte solution is impregnated in the separation membrane provided inside the flexible battery to in-situ polymerize the monomer, (114). The in-situ polymerization reaction in the flexible battery proceeds through thermal polymerization, the polymerization time takes about 20 minutes to 12 hours, and the thermal polymerization can be carried out at 40 to 90 hours.

At this time, the gel polymer forming monomer may be any monomer as long as the polymer forms a gel polymer upon polymerization reaction by a polymerization initiator. (PMA), polyacrylonitrile (PAN), polyvinylidene fluoride (PVDF), polymethacrylate (PMA), polyvinylidene fluoride (PMMA) or a polymer thereof, or a polyacrylate having two or more functional groups such as polyethylene glycol dimethacrylate and polyethylene glycol acrylate.

 Examples of the polymerization initiator include benzoyl peroxide, acetyl peroxide, dilauryl peroxide, di-tertbutylperoxide, cumyl hydroperoxide ( 2-azobis (2-cyanobutane), 2, 2-azobis (2-cyanobutane), cumene hydroperoxide, cumene hydroperoxide and hydrogen peroxide, And azo compounds such as 2-azobis (methylbutyronitrile) and the like. The polymerization initiator is decomposed by heat to form a radical, and reacts with the monomer by free radical polymerization to form a gel polymer electrolyte, that is, a gel polymer.

The gel polymer forming monomer is preferably used in an amount of 1 to 10% by weight based on the organic electrolytic solution. When the content of the monomer is less than 1, gel electrolyte is difficult to form. When the content of the monomer is more than 10% by weight, there is a problem of deterioration of life. The polymerization initiator may be contained in an amount of 0.01 to 5% by weight based on the gel polymer forming monomer.

12, the flexible battery 100 according to an exemplary embodiment of the present invention includes a housing 130 that covers the surface of the casing 120, And at least one terminal portion 132 for electrical connection of the auxiliary battery 130. [ Here, the housing 130 may be made of a rigid material such as plastic or metal, but a flexible soft material such as silicon or leather may be used, and preferably a material capable of insert molding may be used.

Here, the auxiliary battery is implemented as an accessory such as a bracelet, a bracelet, a watch band, a hair band for a headphone, etc., and is used as a fashion article when charging of the charging target device is unnecessary. The main battery of the charging object device can be charged regardless of the location by being electrically connected to the charging object device through the terminal portion 132. [

Although the terminal portions 131 are provided at the ends of the housing 130 in a pair, the present invention is not limited thereto. The terminal portions 131 may be provided at the side of the housing 130, Such as a top surface or a bottom surface of the substrate. Also, it is noted that the terminal unit 131 may be provided in a form of separating the negative terminal and the positive terminal, or may be provided in an integrated form of the positive electrode and the negative electrode, such as USB.

Further, the flexible battery of the present invention can be used as a main battery or an auxiliary battery of an electrical and / or electronic device requiring flexibility. For example, it can be seen that the flexible battery according to the present invention can be widely used in electronic devices such as a smart wristwatch, a flexible display, and the like.

The flexible battery 100 according to the present invention includes the electrode assembly 110 and the casing 120 so that the patterns 119 and 124 for contraction and relaxation can be formed in the electrode assembly 110 and the casing 120, And simultaneously pressing the electrode assembly 110 and the casing 120 in a sealed state.

For example, the patterns 119 and 124 can be formed by passing a sheet-like flexible battery between a pair of rollers having a predetermined pattern formed on the outer peripheral surface. The pair of rollers may be formed by alternately forming a valley portion and a crest portion that constitute the patterns 119 and 124 along the outer circumferential surface, respectively, and a crest portion formed on one of the rollers at the time of engagement, So that they are engaged with each other.

Accordingly, when the plate-shaped flexible battery is passed between the pair of rollers, the electrode assembly 110 and the casing 120 are simultaneously pressed through the pair of rollers, whereby the crests and valleys are alternately formed continuously in the longitudinal direction And a pattern corresponding to each other is formed on each of the electrode assembly 110 and the casing member 120 (refer to FIG. 13).

The electrolyte solution sealed through the casing member 120 together with the electrode assembly 110 may be injected into the casing member 120 after passing through the pair of rollers to form a pattern, May be injected into the interior of the facings material 120 before passing through.

However, the manufacturing method of the flexible battery according to the present invention is not limited thereto, and the first pattern 124 and the second pattern 119 may be separately formed on the sheathing member 120 and the electrode assembly 110, 1 pattern 124 and the second pattern 119 may be made to coincide with each other.

≪ Example 1 >

First, a metal layer of aluminum having a thickness of 30 탆 is prepared, a first resin layer having a thickness of 40 탆 composed of CPP (casting polypropylene) is formed on one surface of the metal layer, and a nylon The acid-modified polypropylene layer containing 6 wt% of acrylic acid in the copolymer was interposed between the first resin layer and the metal layer at 5 mu m, and the second resin layer composed of the second A dry laminate layer of 3 μm was interposed between the resin layer and the metal layer. Thereafter, a solution prepared by electrospinning a spinning solution mixed with PAN (DOLAN, N-PAN, weight average molecular weight 85,000 g / mol) and PVDF (Solvary / Solef 5130) at a weight ratio of 8: (3M, acrylic adhesive) having a basis weight of 4.6 g / m 2, a porosity of 65% and an average pore size of 330 탆 was interposed at 5 탆 in a total thickness of 98 탆 Was prepared.

Next, in order to manufacture an electrode assembly, a cathode assembly and a cathode assembly were first prepared. The positive electrode assembly was prepared by casting a positive electrode current collector made of aluminum having a thickness of 20 탆 on both sides of a positive electrode current collector such that a final thickness of 120 탆 was formed by a negative electrode active material of NCM (Lithium Nickel Cobalt Manganese). Also, the negative electrode assembly was made by casting a graphite negative electrode active material on a copper negative electrode current collector having a thickness of 15 탆 on both sides of a negative electrode current collector so as to have a final thickness of 115 탆. Then, a 20 mu m thick PET / PEN separator was prepared, and the positive electrode assembly, the separator and the negative electrode assembly were alternately laminated to prepare an electrode assembly including three positive electrode assemblies, six separators, and four negative electrode assemblies.

Thereafter, the first resin layer of the outer casing is folded to be an inner surface, and then the first resin layer of the outer casing, which is folded up with the electrode assembly, is disposed inside the casing so as to contact the electrode assembly. Lt; 0 > C for 10 seconds. Then, an electrolyte solution for a conventional lithium ion secondary battery was charged into the above portion, and the portion into which the electrolyte solution was injected was thermally compressed for 10 seconds at a temperature of 150 ° C to produce a battery. Then, a battery was charged into the manufacturing apparatus as shown in FIG. 13 to form a pattern of a wavy pattern as shown in FIG. 8, and the increased surface area ratio Sdr according to Equation 1 was 12.524, Inch flexible battery. Specific specifications of the manufactured flexible battery are shown in Table 1 below.

Section thickness (mm) 1.1 ± 0.5 Width (mm) 26.0 ± 2.0 Length (mm, excluding the outer projecting terminal) 84.0 ± 2.0 Weight (g) 4.7 ± 0.5 Nominal capacity (mAh) 135 Nominal Voltage (V) 3.7

≪ Examples 2 to 12 >

The flexible battery was fabricated in the same manner as in Example 1 except that the increased surface area ratio of the pattern of the battery was changed as shown in Table 3 or Table 4 below.

At this time, in Example 12, 5 pieces of anode assembly, 10 pieces of separator, and 6 pieces of cathode assembly were changed. The produced flexible battery had a nominal capacity of 530 mAh and a nominal voltage of 3.7V.

≪ Comparative Example 1 &

The same procedure as in Example 1 was carried out to prepare a facade, and the facade was put into a manufacturing apparatus as shown in FIG. 13 to form a pattern (1100). Thereafter, the electrode assembly 1000 in which no pattern was formed was sealed with a casing having a pattern formed thereon to produce a flexible battery as shown in the following Table 5 having a sectional structure as shown in Fig.

≪ Comparative Example 2 &

A flexible battery as shown in Table 4 below was fabricated in the same manner as in Example 1 except that no pattern was formed on both the casing and the electrode assembly of the battery.

≪ Comparative Examples 3 and 4 &

The flexible battery was fabricated in the same manner as in Example 1 except that the increased surface area ratio of the patterns provided in the battery was changed as shown in Table 5 below.

<Experimental Example 1>

The following properties of the fabricated flexible batteries were evaluated and are shown in Tables 3 to 5.

1. Satisfying Equations 1 and 2

The following expressions (1) and (2) are satisfied, and when they are satisfied, they are marked with &amp; cir &amp;

[Equation 1]

&Quot; (2) &quot;

2. Evaluation of charging efficiency in bending state

Under the environment of temperature 25 and humidity 65%, a force was applied to both ends of a fully discharged flexible battery, and the battery was fully charged in the bending state so as to have a curvature of 25 mm at the bent portion, The recharge process was performed 100 times in total to measure the average charge capacity. However, if the charge capacity was 0 mAh before 100 runs, the average of the charge capacities measured until the first 0 mAh was measured was calculated.

The charging and discharging conditions are shown in Table 2 below.

Charging conditions Normal Current 0.2C Max. Current 0.5 C CC-CV 4.2V Cut-Off 0.05C Discharge condition
Normal Current 0.2C Max. Current 0.5 C Cut-off Voltage 2.8V

3. Durability

After 500 sets of bending and restoration of the flexible battery were performed as one set, the appearance of the battery was observed with an optical microscope, and it was evaluated whether or not appearance abnormality such as leakage of electrolyte and incidence of incontinence occurred in the casing was evaluated. Was evaluated as 0, and the evaluation result of the comparative example 1 was evaluated as 5, and it was evaluated as 1 to 4 according to the severity of the abnormality.

4. Evaluate battery performance after complete folding

In the environment of temperature 25 and humidity 65%, a fully charged flexible battery is folded 1/2 point with respect to the length of the battery, and a load of 0.8 kN / 24 cm 2 (= 26 mm × 91.5 mm) is applied to the hydraulic ram, After folding and folding, the voltage was measured for 120 seconds, and the voltage at 120 seconds after the measurement was shown in the table.

5. Noise Is Occurred

The evaluation was made as to whether creaking noise occurred during the bending and restoring process of the flexible battery. It was evaluated as 0 when no noise occurred, 1 when noise generation was severe, and / 5.

Specifically, as shown in Tables 3 to 5,

Even in the case where the increased surface area ratio of the pattern is sealed with the exterior material satisfying the range according to the present invention, the comparative example 1 in which the pattern is not provided in the electrode assembly significantly reduces the average filling capacity and durability in the bending state Therefore, it can be confirmed that it is not suitable for a flexible battery. In particular, as can be seen from FIG. 11A, it can be seen that the battery performance is lost after about 56 charge / discharge cycles, which can be expected to be lost due to the breakage of the electrode assembly.

In Comparative Example 2 in which no pattern was formed on both the casing and the electrode assembly, it was confirmed that the average charging capacity in the bending state was significantly lower than that in Example 1, and the durability was also remarkably decreased. As you can see, after 30 charge / discharge cycles, the battery function is completely lost and you can see that it is not durability.

In the case of Comparative Example 3 and Comparative Example 4 in which the pattern provided by the flexible battery does not satisfy the increased surface area ratio according to the present invention, the average charging capacity, durability, performance after complete folding and / Or in terms of prevention of noise generation. However, in the case of Comparative Example 3, since the pattern height is higher than that of Example 1 and the pattern is formed with a shorter pitch, flexibility is good, but a squeaking sound is remarkable, and excessive charging of the battery due to damage to the electrode assembly due to excessive pattern formation It can be confirmed that it is significantly reduced compared with Example 1.

On the other hand, among Examples, Examples 1 and 3 to 10, which satisfied the more preferable surface area ratio of 3.0 to 23.0 in the present invention, are superior in physical properties to Examples 2 and 11.

In addition, even in the case of Example 12 in which the thickness of the flexible battery is increased as the number of the electrode assemblies is increased by increasing the number of the electrode assemblies, the increased surface area ratio of the present invention is satisfied, thereby demonstrating excellent flexibility and durability and no noise.

&Lt; Examples 13 to 14 >

The PAN and PVDF contents of the nanofiber web used as a heat insulating layer were prepared in the same manner as in Example 1 except that the content of PAN and PVDF was changed as shown in Table 6 below to prepare a flexible battery as shown in Table 6 below.

&Lt; Comparative Example 5 &

Except that the heat insulating layer was omitted, and a flexible battery as shown in Table 6 was manufactured through the procedure.

<Experimental Example 2>

Polyurethane was injected into a hopper of an ordinary injection molding machine as an insert molding material for the flexible battery manufactured through Examples 1, 13, 14, and 5, and then melted at 185 캜 to obtain a flexible battery The housing was integrally formed with the flexible battery so that the thickness of the housing was 0.5 mm. Table 6 shows the properties of the produced insert-molded flexible battery in order to evaluate whether or not there is a change in performance as a result of performing the insert molding process.

1. Evaluation of charging efficiency

The total charge capacity of the flexible battery was measured after charging the fully discharged flexible battery at a temperature of 25 ° C and a humidity of 65%, measuring the charge capacity, completely discharging the battery, and recharging the battery 100 times. However, if the charge capacity was 0 mAh before 100 runs, the average of the charge capacities measured until the first 0 mAh was measured was calculated. At this time, charging and discharging conditions are shown in Table 2 above.

2. Durability

The cross section of the insert-molded flexible battery was observed under an optical microscope to evaluate whether leakage of the electrolyte occurred. The evaluation results were evaluated as &quot; o &quot;, and when leakage occurred, &quot; x &quot;

3. Evaluation of adhesion between outer housing and flexible battery

After 500 sets of bending and restoring of the insert-molded flexible battery as one set, the appearance change of the housing and the section of the flexible battery were observed with an optical microscope to evaluate whether there was lifting phenomenon between the housing and the flexible battery. And the degree of abnormality was evaluated as 1 to 4. The degree of the abnormality was evaluated based on the evaluation result of Comparative Example 5 as 5.

As can be seen from Table 6, Example 1 in which a nanofiber web electrospun with a spinning solution in which PAN and PVDF were mixed in a weight ratio within the preferred range of the present invention was used as a heat insulating layer, 11A (no-bending, the average charge capacity of Example 1 is about 125 mAh), and that the difference in the average charge capacity after insert molding does not occur.

On the contrary, in Example 13 in which the PAN was more contained in the spinning solution than in Example 1, in which the insulating layer was prepared, the average charging capacity was significantly reduced as compared with Example 1, As the fibers are electrospun in the same state, the prepared nanofiber web layer is not produced with a high porosity and the average pore size is very small, which is interpreted as a result that the adiabatic effect is remarkably lowered than in Example 1. In the case of Example 13, the durability evaluation result showed no leakage, but it is expected that an abnormality occurred in the electrode assembly due to the decrease in the average charging capacity. In addition, since the adhesive force between the outer housing and the flexible battery is weakened, it can be seen that there is frequent lifting and separation between the housing and the battery after bending.

On the other hand, in Example 14 using a nanofiber web having a higher PVDF content as a heat insulating layer, the average charge capacity was significantly lower than that of Example 1 and Example 13 because the PVDF of the heat insulating layer was partially melted in the insert molding process, And it is possible to interpret it as a result of failing to perform the function of the insulating layer properly. However, even in the case of Example 14, it is expected that the leakage of the liquid does not occur, which may result in a deterioration of physical properties due to severe thermal damage to the electrode assembly.

In Comparative Example 5 in which the heat insulating layer was not provided on the exterior material, the average filling capacity of the flexible battery after the insert molding process was only 21.3 mAh. As a result of the durability evaluation, leakage occurred and the durability was remarkably poor. It is clearly shown that the function of the flexible battery is deteriorated and defective when the insert molding process is performed in a state in which the heat insulating layer is not provided.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

100, 100 ': Flexible battery 110: Electrode assembly
112: positive electrode 112a: positive electrode collector
112b: cathode active material 114: separator
114a: nonwoven fabric layer 114b: nanofiber web layer
116 cathode 116a anode collector
116b: negative electrode active material 118a: negative electrode terminal
118b: positive terminal 119: second pattern
120, 123, 124, 125: exterior material 121: first exterior material
121a, 122a, 123a, 124a, and 125a:
121b, 122b, 123b, 124b, and 125b:
121c, 122c and 123c: the second resin layer
121d, 122d, 123d, 124d, 125d:
124: first pattern 130: housing
132: terminal portion

Claims (30)

An electrode assembly; And
And a cover member sealing the electrode assembly together with the electrolyte and having a heat insulating layer on one side exposed to the outside to block heat transfer between the inside and the outside of the battery,
Wherein the electrode assembly and the casing are respectively formed such that patterns for shrinking and relaxing in the longitudinal direction at the time of bending have the same directionality. The method according to claim 1,
A first pattern formed on at least one surface of the casing; And
And a second pattern formed on the electrode assembly in the same direction as the first pattern,
Wherein the first pattern and the second pattern are arranged to coincide with each other. The method according to claim 1,
The pattern is formed by alternately forming a plurality of peak portions and valley portions along the longitudinal direction,
Wherein the hill portions and the valleys are provided so as to have arc-shaped cross-sections, polygonal cross-sections, and mutually-combined cross-sections. The method of claim 3,
Wherein each of the mountain and valley portions is formed continuously or discontinuously in a direction parallel to the width direction of the electrode assembly and the casing. The method of claim 3,
Wherein the pattern is formed entirely or partially in the electrode assembly and the casing. The method of claim 3,
Wherein the spacing between the adjacent hills or between the valleys is formed to have an equal interval or an unequal spacing, or the equal interval and the unequal spacing are combined with each other. The method according to claim 1,
Wherein the pattern is formed continuously or discontinuously along the longitudinal direction. The method according to claim 1,
Wherein the exterior member includes a first region for forming a housing portion for housing the electrode assembly and the electrolyte, and a second region disposed to surround the first region and forming a sealing portion,
Wherein a pattern formed on the casing is formed only in the first area. The method according to claim 1,
The electrode assembly includes:
A positive electrode and a negative electrode formed by coating an active material on part or all of the collector, and a separator disposed between the positive electrode and the negative electrode,
Wherein the separation membrane comprises a porous nonwoven fabric layer having micropores and a nanofiber web layer containing polyacrylonitrile nanofibers on one or both sides of the nonwoven fabric layer. 10. The method of claim 9,
Wherein the active material includes PTFE to prevent cracking and to prevent peeling from the current collector. The method according to claim 1,
Wherein the exterior material comprises a first resin layer, a metal layer, and a heat insulating layer sequentially laminated. 12. The method of claim 11,
The first resin layer may include at least one of acid-modified polypropylene (PPa), cast polyprolypene (CPP), linear low density polyethylene (LLDPE), low density polyethylene (LDPE), high density polyethylene (HDPE), polyethylene terephthalate, (EVA), an epoxy resin, and a phenol resin, or a laminate of two or more thereof. 12. The method of claim 11,
Wherein the metal layer is selected from the group consisting of aluminum, copper, phosphor bronze (PB), aluminum bronze, white copper, beryllium-copper, chromium-copper, titanium- Zirconium copper alloy, and a zirconium copper alloy. 12. The method of claim 11,
Wherein the first resin layer has an average thickness of 20 占 퐉 to 80 占 퐉 and the metal layer has a thickness of 5 占 퐉 to 100 占 퐉. 12. The method of claim 11,
Wherein the exterior material further comprises a second resin layer interposed between the metal layer and the heat insulating layer,
Wherein the second resin layer comprises at least one selected from the group consisting of nylon, polyethylene terephthalate (PET), cycloolefin polymer (COP), polyimide (PI), and a fluorine compound. 12. The method of claim 11,
Further comprising a first adhesive layer interposed between the metal layer and the first resin layer,
Wherein the first adhesive layer comprises at least one selected from the group consisting of silicone, polyphthalate, acid modified polypropylene (PPa), and acid modified polyethylene (PEa). 16. The method of claim 15,
Wherein the second resin layer has an average thickness of 20 占 퐉 to 80 占 퐉. 16. The method of claim 15,
A dry lamination layer interposed between the metal layer and the second resin layer,
And a second adhesive layer interposed between the second resin layer and the heat insulating layer. The method according to claim 1,
Wherein the electrolytic solution comprises a gel polymer electrolytic solution. The method according to claim 1,
Wherein the area where the pattern is formed includes an area having an increased surface area ratio (Sdr) according to the following formula (1): 0.5 to 40.0:
[Equation 1]

In this case, the surface area of one region on which the pattern is formed means the surface area based on one area of the battery having a width Lx (mm) and a length Ly (mm). The method according to claim 1,
Wherein the area in which the pattern is formed includes an area satisfying the following equation (2) &amp;thetas; 5.0 DEG to 47 DEG:
&Quot; (2) &quot;

(H) is the average vertical distance (mm) between the highest point and the lowest point of adjacent mountains and valleys in the pattern formed on the flexible battery, and p is the average horizontal distance (mm) between the highest points of the adjacent two mountains. The method according to claim 1,
Wherein the heat insulating layer includes at least one of a porous substrate and a heat insulating film having a plurality of micropores capable of accommodating air. 23. The method of claim 22,
Wherein the porous substrate comprises at least one substrate selected from the group consisting of a fibrous web, a nonwoven fabric, a fabric and a knitted fabric, and the fibers forming the substrate include at least one of organic fiber and inorganic fiber. 24. The method of claim 23,
The fibrous web is a nanofiber web formed through electrospinning,
Wherein the nanofiber forming the nanofiber web comprises at least one of a polyacrylonitrile nanofiber, a polyvinylidene fluoride nanofiber, and a composite nanofiber of polyacrylonitrile and polyvinylidene fluoride. 25. The method of claim 24,
Wherein the composite nanofiber is a mixture of polyacrylonitrile and polyvinylidene fluoride in a weight ratio of 6: 4 to 8.5: 1.5 in a mono yarn. 25. The method of claim 24,
Wherein the nanofiber web has a basis weight of 2 to 6 g / m &lt; 2 &gt; and a porosity of 40% or more. 26. A flexible battery according to any one of claims 1 to 26. And
And a flexible housing insert molded to cover an outer surface of the flexible battery,
Wherein the housing is provided with at least one terminal portion for electrical connection with a device to be charged. 26. A flexible battery according to any one of claims 1 to 26. And
And a flexible housing insert molded to cover the outer surface of the flexible battery. 26. A flexible battery according to any one of claims 1 to 26. And
And a flexible housing insert-molded to cover the outer surface of the flexible battery. 29. A mobile electronic device comprising an auxiliary battery according to claim 27.

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