KR102455787B1 - Flexible battery and supplementary battery including the same - Google Patents

Abstract

A flexible battery is provided. A flexible battery according to an embodiment of the present invention includes an electrode assembly; and an enclosure including a receiving part in which the electrode assembly and the electrolyte are accommodated, and a sealing part formed along the rim of the accommodating part to seal the rim of the receiving part, wherein at least a portion of the sealing part is in the longitudinal direction of the housing. And the upper surface or the lower surface of the receiving part is folded through a folding line formed parallel to at least one of the width directions, and the flexible battery is alternated along the longitudinal direction for contraction and relaxation in the longitudinal direction when bending. Including a pattern including a plurality of peaks and valleys formed as, wherein the pattern, the first pattern formed on at least one surface of the exterior material; and a second pattern formed on the electrode assembly to coincide with the first pattern.

Description

Flexible battery and supplementary battery including the same

The present invention relates to a flexible battery and an auxiliary battery including the same.

As consumer demands change due to digitalization and high performance of electronic products, the market demand is also changing to the development of a power supply device with high capacity due to thinness and weight reduction and high energy density.

In order to meet these consumer demands, power supplies such as high energy density and large capacity lithium ion secondary batteries, lithium ion polymer batteries, and supercapacitors (electric double layer capacitors and pseudo capacitors) have been developed. is being developed

Recently, the demand for mobile electronic devices such as portable telephones, notebook computers, and digital cameras is continuously increasing, and in particular, a roll-type display, a flexible e-paper, and a flexible liquid crystal display (flexible liquid crystal display, flexible-LCD) ), flexible organic light-emitting diodes (flexible-OLEDs), etc. are applied, and interest in flexible mobile electronic devices is increasing. Accordingly, a power supply device for a flexible mobile electronic device is also required to have flexible characteristics.

A flexible battery is being developed as one of the power supply devices that can reflect these characteristics.

The flexible battery may include a nickel-cadmium battery, a nickel-metal hydride battery, a nickel-metal hydride battery, and a lithium ion battery having flexible properties. In particular, the lithium-ion battery has a high energy density per unit weight compared to other batteries such as a lead-acid battery, a nickel-cadmium battery, a nickel-hydrogen battery, and a nickel-zinc battery because it can be rapidly charged.

The lithium ion battery uses a liquid electrolyte, and is mainly used in a welded form using a metal can as a container. However, a cylindrical lithium-ion battery using a metal can as a container has a fixed shape, so there is a disadvantage in limiting the design of an electric product, and there is a difficulty in reducing the volume.

In particular, as mentioned above, mobile electronic devices are developed, thinned and miniaturized as well as flexible, so that lithium-ion batteries using conventional metal cans or batteries with a prismatic structure are not easy to apply to mobile electronic devices as described above. have.

Therefore, in order to solve the structural problem as described above, recently, a pouch-type battery in which an electrolyte is placed in a pouch including two electrodes and a separator and sealed to be used has been developed.

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

That is, as shown in FIG. 1 , the pouch-type battery 1 is provided in a form in which the electrode assembly 20 is encapsulated together with the electrolyte inside the casing 10 , and the positive and negative electrodes of the electrode assembly 20 are A pair of provided electrode terminals 21 and 22 protrude to the outside of the exterior material 10 by a predetermined length.

In this case, the exterior material 10 is formed to have a sealing portion for sealing the edge to have a predetermined width in order to prevent the electrolyte sealed therein from leaking to the outside.

Accordingly, there is a limitation in that the accommodating part for accommodating the electrode assembly and the electrolyte can be formed as narrow as the area corresponding to the sealing part.

Meanwhile, the exterior material 10 has a structure in which an inner resin layer, a metal layer, and an outer resin layer are stacked. Among them, an adhesive is applied to the inner resin layer in a process of abutting the edges of the pair of exterior materials 10 to form the sealing part.

For this reason, the electrolyte contained therein leaks through the crack, and the leaked electrolyte moves through the metal layer laminated on the internal resin layer, thereby causing an electrical short.

On the other hand, as portable electronic devices have recently been miniaturized, a battery used therefor is also required to be miniaturized. However, there is a problem in that the charging capacity of the battery itself is insufficient in the process of making the battery small in response to the demand for miniaturization.

US 10-2012-0023491 A

The present invention has been devised in view of the above points, and provides a flexible battery capable of increasing the overall capacity of the battery by folding a part of the sealing part to expand the area of the accommodating part in which the electrode assembly is accommodated, and an auxiliary battery including the same but has a different purpose.

In addition, the present invention can prevent the inner resin layer constituting the exterior material from being damaged (or cracked) by curing of the adhesive in the folding process by placing a folding line for folding the sealing part on the upper side of the receiving part in order to widen the area of the accommodating part. It is another object to provide a flexible battery and an auxiliary battery including the same.

In addition, the present invention provides a flexible battery capable of preventing or minimizing deterioration of physical properties required as a battery even when repetitive bending occurs by forming patterns formed on the exterior material and the electrode assembly to match each other, and an auxiliary battery including the same but has a different purpose.

In order to solve the above problems, the present invention is an electrode assembly; and an enclosure including a receiving part in which the electrode assembly and the electrolyte are accommodated, and a sealing part formed along the rim of the accommodating part to seal the rim of the receiving part, wherein at least a portion of the sealing part is in the longitudinal direction of the housing. And the upper surface or the lower surface of the receiving part is folded through a folding line formed parallel to at least one of the width directions, and the flexible battery is alternated along the longitudinal direction for contraction and relaxation in the longitudinal direction when bending. Including a pattern including a plurality of peaks and valleys formed as, wherein the pattern, the first pattern formed on at least one surface of the exterior material; and a second pattern formed on the electrode assembly to coincide with the first pattern.

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As a preferred embodiment of the present invention, at least a portion of the fold line may be formed to be positioned on the side of the receiving unit, and the fold line is spaced apart from the boundary line dividing the receiving unit and the sealing unit by a predetermined interval to the inside of the receiving unit. can be formed.

In addition, a portion of the sealing portion that is folded toward the upper or lower surface of the accommodating portion with the fold line as a boundary may be fixed to the upper or lower surface of the accommodating portion through an adhesive layer.

In addition, the electrode assembly includes a pair of electrode terminals electrically connected to the anode and the cathode respectively and exposed to the outside of the casing, and the sealing part folded to the upper or lower surface of the receiving part includes the pair of electrode terminals. It may be a sealing part that does not do it.

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In addition, the ridges and valleys may be provided to have any one of arc-shaped cross-sections, polygonal cross-sections, and cross-sections in which they are combined.

In addition, the pattern may be formed entirely or partially along the longitudinal direction of the electrode assembly and the casing, and each of the peaks and valleys is continuously or discontinuously formed in a direction parallel to the width direction of the electrode assembly and the casing. can be

At this time, the intervals between a plurality of adjacent peaks or valleys may be formed to have equal or unequal intervals, or may be provided in a form in which equal intervals and unequal intervals are combined with each other, and the pattern may be formed continuously along the longitudinal direction or not It can be formed continuously.

In addition, the exterior material includes a first area for forming a accommodating portion for accommodating the electrode assembly and the electrolyte, and a second area disposed to surround the first area to form a sealing portion, and is formed on the exterior material of the pattern The pattern to be used may be formed only in the first region.

In addition, the electrode assembly includes a positive electrode and a negative electrode comprising a part or all of the current collector coated with an active material, and a separator disposed between the positive electrode and the negative electrode, wherein the separator includes a porous nonwoven layer having micropores; A nanofiber web layer containing polyacrylonitrile nanofibers may be included on one or both surfaces of the nonwoven layer. In this case, the active material may include PTFE to prevent cracks and to prevent peeling from the current collector.

In addition, in the exterior material, a first resin layer, a metal layer, and a second resin layer may be sequentially stacked, and the second resin layer may be exposed to the outside.

In addition, the first resin layer is PPa (acid modified polypropylene), CPP (casting polyprolypene), LLDPE (Linear Low Density Polyethylene), LDPE (Low Density Polyethylene), HDPE (High Density Polyethylene), polyethylene terephthalate, polypropylene, It may be formed of a single layer selected from ethylene vinyl acetate (EVA), an epoxy resin, and a phenol resin, or may be configured by stacking two or more types.

In addition, the metal layer is aluminum, copper, phosphorbronze (PB), aluminum bronze (aluminium bronze), cupronickel, beryllium-copper (Berylium-copper), chromium-copper, titanium-copper, iron-copper, Corson alloy and It may include at least one selected from among chromium-zirconium copper alloys.

In addition, the second resin layer may include at least one selected from nylon, polyethylene terephthalate (PET), cyclo olefin polymer (COP), polyimide (PI), and a fluorine-based compound.

In addition, the fluorine-based compound is PTFE (polytetra fluoroethylene), PFA (perfluorinated acid), FEP (fluorinated ethelene propylene copolymer), ETFE (polyethylene tetrafluoro ethylene), PVDF (polyvinylidene fluoride), ECTFE (Ethylene Chlorotrifluoroethylene) and PCTFE (polychlorotrifluoroethylene) It may include one or more selected.

In addition, an adhesive layer is disposed between the metal layer and the first resin layer, and the adhesive layer may contain at least one selected from silicone, polyphthalate, PPa (acid modified polypropylene) or PEa (acid modified polyethylene).

In addition, a dry lamination layer may be disposed between the metal layer and the second resin layer, and the dry lamination layer may have an average thickness of 1 μm to 7 μm.

In addition, the electrolyte may include a gel polymer electrolyte.

On the other hand, the present invention is the above-described flexible battery; a housing covering the surface of the exterior material; and at least one terminal unit for electrical connection with a charging target device; may be implemented as an auxiliary battery comprising a.

According to the present invention, it is possible to increase the overall capacity of the battery by folding a part of the sealing part to expand the area of the receiving part in which the electrode assembly is accommodated.

In addition, the present invention can prevent the inner resin layer constituting the exterior material from being damaged (or cracked) by curing of the adhesive in the folding process by placing a folding line for folding the sealing part on the upper side of the receiving part in order to widen the area of the accommodating part. have.

In addition, since the patterns respectively formed on the exterior material and the electrode assembly are formed to match each other, it is possible to prevent or minimize the deterioration of physical properties required as a battery even when repetitive bending occurs.

1 is a view showing a conventional battery, a) is an overall schematic view, b) is a cross-sectional view,
2 is an overall schematic diagram showing a flexible battery according to an embodiment of the present invention;
3 is a schematic diagram showing a state before folding the sealing part in the flexible battery according to an embodiment of the present invention;
4A and 4B are cross-sectional views of a flexible battery according to an embodiment of the present invention, FIG. 4A is a state before the sealing part is folded, and FIG. 4B is a view showing a state in which the sealing part is folded;
5 is a view showing various forms in which a part including a sealing part is folded in a flexible battery according to an embodiment of the present invention;
6 is a view showing a case in which a pattern is formed only on the receiving part side in the flexible battery according to an embodiment of the present invention;
7 is an exemplary view showing various patterns applied to the electrode assembly and the exterior material in the flexible battery according to an embodiment of the present invention, and is a view showing various intervals between adjacent valleys or ridges;
8 is an exemplary view illustrating various patterns applied to an electrode assembly and a casing in a flexible battery according to an embodiment of the present invention, and is an exemplary view showing a case in which the pattern is formed continuously or discontinuously over the entire length;
9 to 12 are schematic views showing various cross-sectional shapes of patterns applied to a flexible battery according to an embodiment of the present invention;
13 is a schematic diagram showing a case in which a pattern is formed in a prism pattern in a flexible battery according to an embodiment of the present invention;
14 is an enlarged view showing a detailed configuration of a flexible battery according to an embodiment of the present invention;
15A and 15B are graphs showing the performance of a flexible battery according to an embodiment of the present invention. FIG. 15A is a graph showing a change in battery capacity before and after bending, and FIG. 15B is a time when an instantaneous external force is applied to the folded part. A graph showing the voltage change of the battery according to
16 is a schematic diagram illustrating a form in which a flexible battery is embedded in a housing and implemented as an auxiliary battery according to an embodiment of the present invention.

Hereinafter, with reference to the accompanying drawings, embodiments of the present invention will be described in detail so that those of ordinary skill in the art to which the present invention pertains can easily implement them. The present invention may be embodied in many different forms and is not limited to the embodiments described herein. In order to clearly explain the present invention in the drawings, parts irrelevant to the description are omitted, and the same reference numerals are added 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 is sealed together with the electrolyte inside the casing 120 , and includes an anode 112 , a cathode 116 , and a separator 114 as shown in FIGS. 3 and 14 .

The positive electrode 112 includes a positive electrode current collector 112a and a positive electrode active material 112b, the negative electrode 116 includes a negative electrode current collector 116a and a negative electrode active material 116b, and the positive electrode current collector 112a ) and the negative electrode current collector 116a may be implemented in the form of a plate-shaped sheet having a predetermined area.

That is, the positive electrode 112 and the negative electrode 116 may be compressed, deposited, or coated with active materials 112b and 116b on one or both surfaces of the respective current collectors 112a and 116a. In this case, the active materials 112b and 116b may be provided over the entire area of the current collectors 112a and 116a, or may be provided partially over a partial area of the current collectors 112a and 116a.

Here, the negative electrode current collector 116a and the positive electrode current collector 112a may be made of thin metal foil, and may include copper, aluminum, stainless steel, nickel, titanium, chromium, manganese, iron, cobalt, zinc, molybdenum, tungsten, It may be made of silver, gold, or a mixture thereof.

In addition, the positive electrode current collector 112a and the negative electrode current collector 116a may have a negative electrode terminal 118a and a positive electrode terminal 118b for electrical connection with an external device from each body (FIG. 2). Reference). Here, the positive terminal 118b and the negative terminal 118a may extend from the positive electrode current collector 112a and the negative electrode current collector 116a to protrude from one side of the exterior material 120, and the exterior material ( It may be provided so as to be exposed on the surface of the 120 , for example, on the sealing part 126 .

Meanwhile, the positive active material 112b includes a positive active material capable of reversibly intercalating and deintercalating lithium ions, and representative examples of such positive active materials include LiCoO ₂ , LiNiO ₂ , LiNiCoO ₂ , LiMnO ₂ , LiMn ₂ O ₄ , V ₂ O ₅ , V ₆ O ₁₃ , LiNi _1-xy Co _x M _y O ₂ (0 ≤ x≤ 1, 0 ≤y ≤ 1, 0 ≤ x+y ≤ 1, M is Al, One of lithium-transition metal oxides and NCM (Lithium Nickel Cobalt Manganese)-based active materials such as Sr, Mg, and La (metals such as Sr, Mg, La) may be used, and a mixture of one or more thereof may be used.

In addition, the negative active material 116b includes an anode active material capable of reversibly intercalating and deintercalating lithium ions, and the negative active material includes crystalline or amorphous carbon, carbon fiber, or carbon of a carbon composite. It may be selected from the group consisting of a negative electrode active material, tin oxide, lithiated ones thereof, lithium, lithium alloys, and mixtures of one or more thereof. 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 should be noted that both the positive electrode active material and the negative electrode active material commonly used may be used.

In this case, in the present invention, the positive active material 112b and the negative active material 116b may contain a polytetrafluoroethylene (PTFE) component. This is to prevent the positive active material 112b and the negative active material 116b from peeling off or cracking from the respective current collectors 112a and 116a during bending.

The PTFE component may be 0.5 to 20 wt%, preferably 5 wt% or less, based on the total weight of each of the positive active material 112b and the negative active material 116b.

On the other hand, the separator 114 disposed between the anode 112 and the cathode 116 may include a nonwoven fabric layer 114a and a nanofiber web layer 114b formed on one or both surfaces of the nonwoven fabric layer 114a. can

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

Preferably, the nanofiber web layer 114b may be composed of only polyacrylnitrile nanofibers so as to have high heat resistance while ensuring radioactivity. Here, the polyacrylonitrile nanofiber may have an average diameter of 0.1 to 2 μm, preferably 0.1 to 1.0 μm.

If the average diameter of the polyacrylonitrile nanofibers is less than 0.1 μm, there may be a problem in that the separator cannot secure sufficient heat resistance, and when it exceeds 2 μm, the mechanical strength of the separator is excellent, but the elasticity of the separator is rather reduced. because it can

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

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

Here, the porous nonwoven fabric consists of a PP nonwoven fabric, a PE nonwoven fabric, a nonwoven fabric consisting of a double structure PP/PE fiber coated with PE on the outer periphery of the PP fiber as a core, and a three-layer structure of PP/PE/PP, and has a relatively melting point. Any one of a nonwoven fabric having a shutdown function by this low PE, a PET nonwoven fabric made of polyethyleneterephthalate (PET) fibers, or a nonwoven fabric made of cellulose fibers can be used. And, 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.

In this case, the porous nonwoven fabric has a thickness of 10 to 40 μm, a porosity of 5 to 55%, and a Gurley value of 1 to 1000 sec/100c.

On the other hand, the porous nanofiber web may use either a swellable polymer that swells in an electrolyte solution alone or a mixed polymer in which a heat-resistant polymer capable of enhancing heat resistance is mixed with the swellable polymer.

The porous nanofiber web is formed by dissolving a single or mixed polymer in a solvent to form a spinning solution, and then spinning the spinning solution using an electrospinning device, the spun nanofibers are accumulated in the collector and have a three-dimensional pore structure. A porous nanofiber web is formed.

Here, as long as the porous nanofiber web is dissolved in a solvent to form a spinning solution and then spun by an electrospinning method, any polymer capable of forming nanofibers can be used. As an example, the polymer may be a single polymer or a mixed polymer, and a swellable polymer, a non-swellable polymer, a heat-resistant polymer, a mixed polymer of a swellable polymer and a non-swellable polymer, a mixed polymer of a swellable polymer and a heat-resistant polymer, etc. may be used. can

At this time, 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, preferably 8: It may be mixed in a weight ratio ranging from 2 to 5:5.

In general, in the case of a non-swellable polymer, it is generally a heat-resistant polymer, and as compared with a swellable polymer, the melting point is relatively high because of its large molecular weight. Accordingly, the non-swellable polymer is preferably a heat-resistant polymer having a melting point of 180° C. or higher, and the swellable polymer is preferably a resin having a melting point of 150° C. or less, preferably within the range of 100 to 150° C.

On the other hand, the swellable polymer usable in the present invention is a resin that swells in the electrolyte, and can be formed into ultrafine nanofibers by electrospinning.

In one example, the swellable polymer is polyvinylidene fluoride (PVDF), poly (vinylidene fluoride-co-hexafluoropropylene), perfluoropolymer, polyvinyl chloride or polyvinylidene chloride and copolymers thereof and Polyethylene glycol derivatives including polyethylene glycol dialkyl ethers and polyethylene glycol dialkyl esters, poly(oxymethylene-oligo-oxyethylene), polyoxides including polyethylene oxide and polypropylene oxide, polyvinyl acetate, poly(vinyl blood) Rollidone-vinyl acetate), polystyrene and polystyrene acrylonitrile copolymer, polyacrylonitrile copolymer including polyacrylonitrile methyl methacrylate copolymer, polymethyl methacrylate, polymethyl methacrylate copolymer and A mixture in which one or more of these is mixed may be used.

In addition, the heat-resistant polymer or non-swellable polymer can be dissolved in an organic solvent for electrospinning, and swelling occurs more slowly than the swellable polymer or does not swell by the organic solvent contained in the organic electrolyte, and a resin having a melting point of 180° C. or higher can be used

For example, the heat-resistant polymer or non-swellable polymer may include polyacrylonitrile (PAN), polyamide, polyimide, polyamideimide, poly(meta-phenylene isophthalamide), polysulfone, polyetherketone, polyethylene tere. Aromatic polyesters such as phthalates, polytrimethylene terephthalate, polyethylene naphthalate, etc., polytetrafluoroethylenes, polydiphenoxyphosphazenes, poly{bis[2-(2-methoxyethoxy)phosphazenes]} Phosphazenes, polyurethane copolymers including polyurethane and polyether urethane, cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, and the like can be used.

On the other hand, the nonwoven fabric constituting the nonwoven fabric layer 114a is cellulose, cellulose acetate, polyvinyl alcohol (PVA, polyvinyl alcohol), polysulfone, polyimide, polyetherimide, polyamide ( polyamide), polyethylene oxide (PEO, polyethylene oxide), polyethylene (PE, polyethylene), polypropylene (PP, polypropylene), polyethylene terephthalate (PET, polyethylene terephthalate), polyurethane (PU, polyurethane), polymethyl methacrylate At least one selected from (PMMA, poly methylmethacrylate) and polyacrylonitrile may be used.

Here, the nonwoven layer may further include an inorganic additive, and the inorganic additive is 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 at least one selected from BaO, Na ₂ O, Li ₂ CO ₃ , CaCO ₃ , LiAlO ₂ , SiO ₂ , Al ₂ O ₃ and PTFE.

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

In addition, the average thickness of the separator may be 10 ~ 100㎛, preferably 10 ~ 50㎛. This is because, if the average thickness of the separator is less than 10 μm, the separator is too thin to ensure long-term durability of the separator due to repeated bending and/or unfolding of the battery. It is preferable to have an average thickness within the above range.

And the nonwoven layer has an average thickness of 10 ~ 30㎛, preferably formed to 15 ~ 30㎛, the nanofiber web layer preferably has an average thickness of 1 ~ 5㎛.

The exterior material 120 is made of a plate-shaped member having a predetermined area, and is to protect the electrode assembly 110 from external force by accommodating the electrode assembly 110 and the electrolyte therein.

To this end, the exterior material 120 is provided with a pair of the first exterior material 121 and the second exterior material 122, and the electrolyte solution and the electrode assembly 110 accommodated therein by sealing the edge side through an adhesive is external. to prevent exposure and leakage to the outside.

That is, the first casing 121 and the second casing 122 are disposed to surround the first area forming the accommodating part 125 for accommodating the electrode assembly and the electrolyte, and the first area, so that the electrolyte is discharged from the outside. and a second region forming a sealing part 126 for blocking leakage into the ventilator (see FIG. 3 ).

In the case of the exterior material 120 , after the first exterior material 121 and the second exterior material 122 are formed of two members, all of the rim sides constituting the sealing part 126 may be sealed through an adhesive, and one It may be made of a member and folded in half along the width direction or the length direction, and then the remaining portions in contact with each other may be sealed with an adhesive.

The exterior material 120 may be provided in a form in which metal layers 121b and 122b are interposed between the first resin layers 121a and 122a and the second resin layers 121c and 122c. That is, in the exterior material 120 , first resin layers 121a and 122a, metal layers 121b and 122b and second resin layers 121c and 122c are sequentially stacked, and the first resin layers 121a and 122a are sequentially stacked. is disposed on the inside to contact the electrolyte, and the second resin layers 121c and 122c are exposed to the outside.

Through this, the rim sides of the first resin layers 121a and 122a facing each other are sealed with an adhesive, so that the receiving part 125 for accommodating the electrolyte and the electrode assembly 110 is formed in the central region, and the receiving part 125 is formed. A sealing part 126 is formed along the edge of the part 125 .

In this case, the first resin layers 121a and 122a are PPa (acid modified polypropylene), CPP (casting polyprolypene), LLDPE (Linear Low Density Polyethylene), LDPE (Low Density Polyethylene), HDPE (High Density Polyethylene), polyethylene terephthalate. It may include a single layer structure of one of phthalate, polypropylene, ethylene vinyl acetate (EVA), an epoxy resin, and a phenol resin, or a laminate structure thereof, preferably PPa (acid modified polypropylene), CPP (casting polyprolypene), It may consist of a single layer selected from Linear Low Density Polyethylene (LLDPE), Low Density Polyethylene (LDPE), and High Density Polyethylene (HDPE), and two or more of them may be stacked.

In addition, the first resin layers 121a and 122a may have an average thickness of 20 μm to 90 μm.

This is, when the average thickness of the first resin layers 121a and 122a is less than 20 μm, the first resin layer 121a abuts against each other in the process of sealing the edge side of the first exterior material 121 and the second exterior material 122 . , 122a) may decrease or it may be disadvantageous in securing airtightness to prevent leakage of electrolyte, and if the average thickness exceeds 90 μm, it is uneconomical and disadvantageous to thinning.

The metal layers 121b and 122b are interposed between the first resin layers 121a and 122a and the second resin layers 121c and 122c to prevent moisture from penetrating from the outside toward the receiving part, and the electrolyte from the receiving part to the outside. This is to prevent leakage.

To this end, the metal layers 121b and 122b may be formed of a dense metal layer so that moisture and electrolyte cannot pass therethrough. Such metal layers 121b and 122b are formed on a foil-type metal thin plate or a second resin layer 121c and 122c to be described later by a known method, for example, sputtering, chemical vapor deposition, or the like. It may be formed through the formed metal deposition film, and preferably, it may be formed of a metal thin plate, which prevents cracks in the metal layer during pattern formation, thereby preventing electrolyte leakage to the outside or moisture permeation from the outside.

For example, the metal layers 121b and 122b may include aluminum, copper, phosphorbronze (PB), aluminum bronze, cupronickel, beryllium-copper, chromium-copper, titanium-copper, iron- It may include at least one selected from copper, a Corson alloy, and a chromium-zirconium copper alloy.

In this case, the metal layers 121b and 122b may have a coefficient of linear expansion of 1.0 to 1.7×10 ⁻⁷ /°C, preferably 1.2 to 1.5×10 ⁻⁷ /°C. This is, if the coefficient of linear expansion is less than 1.0 × 10 ^-7 /℃, sufficient flexibility cannot be secured, so cracks may occur due to external force generated during bending, and the coefficient of linear expansion exceeds 1.7 × 10 ^-7 /℃ This is because the rigidity is lowered and the shape deformation can occur severely.

The metal layers 121b and 122b may have an average thickness of 5 μm or more, preferably 5 μm to 100 μm, and more preferably 30 μm to 50 μm.

This is because, when the average thickness of the metal layer is less than 5 μm, moisture may penetrate into the accommodating part or the electrolyte inside the accommodating part may leak to the outside.

The second resin layers 121c and 122c are located on the exposed side of the exterior material 120 to reinforce the strength of the exterior material and prevent damage such as scratches to the exterior material by physical contact applied from the outside. will be.

The second resin layers 121c and 122c may include at least one selected from nylon, polyethylene terephthalate (PET), cyclo olefin polymer (COP), polyimide (PI), and a fluorine-based compound, preferably nylon or It may contain a fluorine-based compound.

Here, the fluorine-based compound is PTFE (polytetra fluoroethylene), PFA (perfluorinated acid), FEP (fluorinated ethelene propylene copolymer), ETFE (polyethylene tetrafluoro ethylene), PVDF (polyvinylidene fluoride), ECTFE (Ethylene Chlorotrifluoroethylene) and PCTFE (polychlorotrifluoroethylene) It may include one or more selected.

In this case, the second resin layers 121c and 122c may have an average thickness of 10 μm to 120 μm.

This is because, if the average thickness of the second resin layers 121c and 122c is less than 10 μm, mechanical properties cannot be secured, and if it exceeds 120 μm, it is advantageous to secure mechanical properties, but is uneconomical and disadvantageous in reducing the thickness.

Meanwhile, the flexible batteries 100 and 100 ′ according to the present invention may further include an adhesive layer between the metal layers 121b and 122b and the first resin layers 121a and 122a.

The adhesive layer serves to increase the adhesive force between the metal layers 121b and 122b and the first resin layers 121a and 122a, and prevents the electrolyte contained in the exterior material from reaching the metal layers 121b and 122b of the exterior material. It is possible to prevent the metal layers 121b and 122b from being corroded or the first resin layers 121a and 122a and the metal layers 121b and 122b from being peeled off by the acidic electrolyte. In addition, even when a problem such as abnormal overheating occurs during the use of the flexible batteries 100 and 100 ′ and the flexible battery expands, the electrolyte can be prevented from leaking, thereby providing reliability for safety.

The adhesive layer may be made of a material similar to that of the first resin layers 121a and 122a. For example, the adhesive layer may include at least one selected from silicone, polyphthalate, acid modified polypropylene (PPa), and acid modified polyethylene (Pea, acid modified polyethylene).

In this case, the adhesive layer may have an average thickness of 5 μm to 30 μm, preferably 10 μm to 20 μm. This is, when the average thickness of the adhesive layer exceeds 5 μm, it may be difficult to secure a stable adhesive force, and when it exceeds 30 μm, it is disadvantageous for thinning.

Meanwhile, the flexible batteries 100 and 100 ′ according to the present invention may further include a dry lamination layer between the metal layers 121b and 122b and the second resin layers 121c and 122c.

The dry laminate layer serves to bond the metal layers 121b and 122b and the second resin layers 121c and 122c, and may be formed by drying a known water-based and/or oil-based organic solvent-type adhesive.

In this case, the dry laminate layer may have an average thickness of 1 μm to 7 μm, preferably 2 μm to 5 μm, and more preferably 2.5 μm to 3.5 μm.

This is, if the average thickness of the dry laminate layer is less than 1 μm, the adhesive force is too weak, so peeling between the metal layers 121b and 122b and the second resin layers 121c and 122c may occur. This is because the thickness of the layer may become thick, which may adversely affect the formation of a pattern for contraction and relaxation.

On the other hand, as the electrolyte to be sealed in the accommodating part together with the electrode assembly 110, a liquid electrolyte that is commonly used may be used.

For example, as the electrolyte, an organic electrolyte containing a non-aqueous organic solvent and a solute of a lithium salt may be used. Here, as the non-aqueous organic solvent, carbonate, ester, ether or ketone may be used. Examples of the carbonate include dimethyl carbonate (DMC), diethyl carbonate (DEC), dipropyl carbonate (DPC), methylpropyl carbonate (MPC), ethylpropyl carbonate (EPC), methylethyl carbonate (MEC), ethylene carbonate (EC) , propylene carbonate (PC), butylene carbonate (BC), etc. may be used, and the esters include butyrolactone (BL), decanolide, valerolactone, and mevalonolactone. ), caprolactone, n-methyl acetate, n-ethyl acetate, n-propyl acetate, etc. may be used, and dibutyl ether may be used as the ether, and polymethylvinyl ketone may be used as the ketone. However, the present invention is not limited to the type of the non-aqueous organic solvent.

In addition, the electrolyte 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 the operation of a basic lithium battery, for example, 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 may include one or more selected from the group consisting of, or a mixture thereof.

In this case, as the electrolyte used in the flexible batteries 100 and 100' according to the present invention, a liquid electrolyte may be used, but preferably, a gel polymer electrolyte may be used. Through this, the flexible batteries 100 and 100' according to the present invention use a polymer electrolyte in a gel state as an electrolyte, so that when a liquid is used as the electrolyte of the flexible battery, leakage and leakage that may occur during bending can be prevented. .

The gel polymer electrolyte may be formed by subjecting an organic electrolyte solution including a non-aqueous organic solvent, a solute of a lithium salt, a monomer for forming a gel polymer, and a polymerization initiator to gelation heat treatment to form a gel polymer electrolyte.

Although such a gel polymer electrolyte may be heat-treated by the organic electrolyte alone, a separator provided inside the flexible battery is heat-treated in a state in which the organic electrolyte is impregnated to in-situ polymerization of monomers to form a gel polymer in a gel state as a separator It can be implemented in the form impregnated in the pores of (114). In the flexible battery, the in-situ polymerization reaction proceeds through thermal polymerization, the polymerization time is approximately 20 minutes to 12 hours, and the thermal polymerization may be performed at 40 to 90°C.

In this case, as the monomer for forming the gel polymer, any monomer may be used as long as the polymer is a monomer that forms a gel polymer while the polymerization reaction is performed by the polymerization initiator. For example, methyl methacrylate (MMA), polyethylene oxide (PEO), polypropylene oxide (PPO), polyacrylonitrile (PAN), polyvinylidene fluoride (PVDF), polymethacrylate (PMA), Polymethyl methacrylate (PMMA) or a monomer for a polymer thereof, or polyacrylate having two or more functional groups such as polyethylene glycol dimethacrylate and polyethylene glycol acrylate can be exemplified.

In addition, examples of the polymerization initiator include benzoyl peroxide, acetyl peroxide, dilauryl peroxide, di-tertbutylperoxide, cumyl hydroperoxide ( Organic peroxides or hydroperoxides such as Cumyl hydroperoxide) and hydrogen peroxide, 2,2-Azobis (2-cyanobutane) (2,2-Azobis (2-cyanobutane)), 2, and azo compounds such as 2-azobis(methylbutyronitrile) (2,2-Azobis(Methylbutyronitrile)). The polymerization initiator is decomposed by heat to form radicals, and reacts with monomers by free radical polymerization to form a gel polymer electrolyte, that is, a gel polymer.

The monomer for forming the gel polymer is preferably used in an amount of 1 to 10% by weight based on the organic electrolyte. When the content of the monomer is less than 1, it is difficult to form a gel-type electrolyte, and when it exceeds 10 wt%, there is a problem of deterioration of life. In addition, the polymerization initiator may be included in an amount of 0.01 to 5% by weight based on the monomer for forming the gel polymer.

On the other hand, in the flexible batteries 100 and 100 ′ according to the present invention, at least a portion of the sealing portion 126 is folded to at least one side of the upper surface or the lower surface of the receiving portion 125 via a folding line 127, so that the electrolyte solution and to increase the area of the accommodating part 125 for accommodating the electrode assembly 110 .

Here, the folding line 127 is disposed to be parallel to at least one of a longitudinal direction and a width direction of the exterior member 120 .

Through this, the flexible battery 100 and 100 ′ according to the present invention is the sealing portion 126 that is folded by folding the sealing portion 126 surrounding the rim of the receiving portion 125 to the upper or lower surface of the exterior material 120 . The area of the accommodating part 125 can be widened by a corresponding width. Due to this, since it is possible to reduce the dead space corresponding to the width of the sealing part 126 , the area of the accommodating part 125 is relatively reduced while maintaining the same overall width or total length of the flexible batteries 100 and 100 ′. can be expanded

That is, even if the overall sizes of the flexible batteries 100 and 100 ′ are the same, the size of the electrode assembly 110 can be increased by an area corresponding to the enlarged area of the accommodating part 125 , thereby maintaining the same size and relatively high capacity flexible. battery can be implemented.

Here, the sealing portion 126, which is folded to at least one side of the upper surface or the lower surface of the receiving portion 125, includes a pair of electrode terminals 118a and 118b electrically connected to the positive electrode 112 and the negative electrode 116, respectively. Sealing part not included.

That is, when the pair of electrode terminals 118a and 118b are disposed on the front or rear end of the casing 120 , the flexible batteries 100 and 100 ′ have both side ends that do not include the electrode terminals 118a and 118b. The side may be folded to at least one of the upper surface or the lower surface of the accommodating part 125 via a folding line 127 disposed in a direction parallel to the longitudinal direction of the exterior material 120 (FIG. 5(a) to 5(b)), the receiving part ( 125) may be folded to at least one side of the upper surface or the lower surface (refer to FIG. 5(d)), and may be folded in a combined form (see FIG. 5(e)). In addition, a partial length with respect to the entire length may be folded through a folding line disposed in a direction parallel to the width direction of the exterior material 120 (see FIGS. 5(b) and 5(c)).

In this case, the folding line 127 is disposed on the sealing part 126 so that the width of a part of the sealing part 126 may be folded, but at least a part of the folding line 127 is at a predetermined interval inward from the rim of the accommodating part 125 . It is formed to be spaced apart (see FIGS. 3 and 4A). In other words, the folding line 127 is spaced apart from the boundary line between the accommodating part 125 and the sealing part 126 to the inside of the accommodating part 125 by a predetermined interval. In more detail, it is arranged to be positioned in a region between the side end of the electrode assembly 110 accommodated in the receiving part 125 and the boundary line dividing the receiving part 125 and the sealing part 126 .

That is, at least a portion of the folding line 127 guiding the folding point of the exterior member 120 is formed to be located inside the receiving part 125 , and at least one of a longitudinal direction or a width direction of the exterior member 120 . By being arranged to be parallel to one direction, the bent part in the process of folding a part of the sealing part 126 is always positioned on the receiving part 125 side.

In this case, when the first resin layers 121a and 122a constituting the exterior material are cured by an adhesive, the probability of occurrence of cracks is very high. Accordingly, when the fold line 127 is positioned on the sealing part 126 that is in direct contact with the adhesive during the folding process, the first resin layers 121a and 122a are cured by the adhesive to generate cracks in the foldable part. will do For this reason, the electrolyte contained in the accommodating part 125 leaks through the crack, and the leaked electrolyte moves through the metal layers 121b and 122b stacked on the first resin layers 121a and 122a, thereby causing an electrical short. will do

In the present invention, the first resin layer by folding by preventing the curing of the first resin layers 121a and 122a by the adhesive by placing the fold line 127 on the receiving part 123 where the adhesive is not disposed. It is possible to prevent the risk of cracks occurring in (121a, 122a) in advance.

In other words, when the edge including the sealing part 126 protruding in the width direction or the length direction is folded toward one side of the receiving part 125 in order to minimize the dead space, the folded part is the folding line 127 . ) is guided and folded, so that it is formed in a portion coincident with the fold line 127 .

At this time, when the folding line 127 is positioned at the boundary line of the sealing part 126 connected to the receiving part 125 or located to be biased toward the sealing part 126 , the folded part is the sealing part 126 . ) or located at the boundary line between the sealing part 126 and the receiving part 125, the first resin layers 121a and 122a come into contact with the adhesive present in the sealing part 126 area, so that curing by the adhesive is possible. occurs

Accordingly, when cracks occur in the first resin layers 121a and 122a cured by the adhesive during the folding process, the electrolyte contained in the accommodating part 125 leaks through the cracks and the first resin layers 121a and 122a ) by moving to the metal layers 121b and 122b stacked on top of each other, thereby causing an electrical short.

In the present invention, in order to solve this problem, the folding line 127 for guiding the folding position is received from the inner region of the sealing part 126 , that is, from the boundary line between the receiving part 125 and the sealing part 126 . By forming the portion 125 in a position spaced apart from each other by a predetermined distance, it prevents curing by the adhesive, thereby eliminating cracks in the folded portion, thereby preventing an electric short due to leakage of the electrolyte in advance.

At this time, the portion of the flexible battery 100 and 100 ′ that is folded toward the upper or lower surface of the accommodating part 125 may be folded on the same surface of the accommodating part 125 (see FIG. 2 ), or on opposite surfaces. Each may be folded (refer to FIG. 5(a)).

On the other hand, the flexible battery 100 according to the present invention is provided with patterns 119 and 124 for contraction and relaxation in the longitudinal direction when bending the electrode assembly 110 and the exterior material 120, respectively, and is formed on the exterior material 120. The first pattern 124 and the second pattern 119 formed on the electrode assembly 110 are provided to have the same directionality.

Such patterns 119 and 124 offset an amount of length change caused by a change in curvature in a bent portion of the flexible battery 100 during bending, thereby preventing or minimizing the shrinkage or relaxation of the substrate itself.

Through this, since the amount of deformation of the substrate itself constituting the electrode assembly 110 and the casing 120 is prevented or minimized, the amount of deformation of the substrate itself that may occur locally in the bent portion is minimized even if repeated bending occurs, thereby minimizing the electrode assembly ( 110) and the exterior material 120 can be prevented from being locally damaged by bending or from deterioration in performance.

In this case, 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 allows the first pattern 124 and the second pattern 119 to always have the same behavior, so that even if the first pattern 124 and the second pattern 119 are returned to their original state after bending occurs, the first pattern 124 and the second pattern 119 are always the first. in order to maintain the status of

This can be confirmed through the graphs of FIGS. 15A and 15B .

That is, when a force is applied to both ends of the flexible battery in an environment of 25° C. and 85% humidity to bend the bent portion so that the curvature becomes 25 mm, and 100 times of charging and discharging are performed, as shown in FIG. 15A , In the case of the flexible batteries 100 and 100' according to the present invention, the capacity (110 mAh) was reduced by approximately 15% compared to the capacity (130 mAh) when not banded, and the performance was maintained even after performing 100 times (Example), but the exterior material In the case of a flexible battery that formed a pattern for contraction and relaxation only on the side, it showed a performance that gradually decreased at a capacity (52mAh) that was reduced by approximately 60% compared to the first, and charging and discharging was impossible after 50 times (Comparative Example 1), and the exterior material And in the case of the flexible battery provided in the form of a simple plate with no pattern formed on both of the electrode assemblies, the capacity (26mAh) decreased by approximately 80% compared to the first, and it was confirmed that charging and discharging was impossible after 30 cycles. (Comparative Example 2).

On the other hand, after returning to the original state in the fully folded state in the middle of the length of the flexible battery in an environment of temperature 25 ℃ and humidity of 85%, as a result of measuring the voltage in the battery over time, as shown in Fig. 15b, according to the present invention In the case of the flexible batteries 100 and 100', the voltage value did not change (Example), but the flexible battery in which a pattern for contraction and relaxation was formed only on the side of the exterior material (Comparative Example 1), the pattern of both the exterior material and the electrode assembly It was confirmed that a voltage value decrease occurred in the flexible battery (Comparative Example 2) provided in the form of a simple plate that was not formed.

In other words, when the patterns 119 and 124 for contraction and relaxation are formed on the exterior material 120 and the electrode assembly 110 to match each other, even if banding occurs, a significant decrease in performance does not occur, whereas a pattern is formed only on the exterior material side. Alternatively, it was confirmed that, if the pattern was not formed on both the exterior material and the electrode assembly, cracks occurred due to banding or electrolyte leakage occurred, resulting in deterioration of performance as a battery.

In this way, the flexible batteries 100 and 100 ′ according to the present invention are formed so that the patterns 119 and 124 for contraction and relaxation in the longitudinal direction generated when bending the electrode assembly 110 and the exterior material 120 coincide with each other. Even when this occurs, since the electrode assembly 110 and the exterior material 120 can always maintain a uniform distance or contact state over the entire length, the electrolyte sealed together with the electrode assembly 110 is uniformly distributed over the entire length. As a result, it is possible to prevent deterioration of performance as a battery.

To this end, in the first pattern 124 and the second pattern 119, each of the peaks and valleys is formed in a direction parallel to the width direction of the exterior material 120 and the electrode assembly 110, and the exterior material 120 ) and the ridges and valleys are alternately disposed along the longitudinal direction of the electrode assembly 110 . In addition, the first pattern 124 and the second pattern 124 and the second pattern ( 119) to coincide with each other.

Specifically, the ridges 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 exterior material 120 and the electrode assembly 110, , the ridges and valleys are repeatedly arranged along the longitudinal direction.

At this time, 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. 7 ), and the electrode assembly ( 110) and the exterior member 120 may be formed for the entire length or may be formed partially for a partial length (refer to FIG. 8).

Here, the peaks and valleys may be provided to have a cross section of any one of an arc-shaped cross-section including a semicircle, a polygonal cross-section including a triangle or a square, and a cross-section of various shapes in which arc-shaped cross-sections and polygonal cross-sections are combined with each other, and each The peaks and valleys may be provided to have the same pitch and width, but may also be provided to have different pitches and widths (see FIGS. 9 to 12 ). In addition, the patterns 119 and 124 may be formed in a cubic pattern such as a prism pattern or an embossing pattern (see FIG. 13 ).

Through this, even if the packaging material 120 and the electrode assembly 110 repeatedly undergo contraction and relaxation in the longitudinal direction due to repeated bending, the amount of change in contraction and relaxation is offset through the patterns 119 and 124 and applied to the substrate itself. It can reduce fatigue.

Meanwhile, as shown in FIG. 7 , the first pattern 124 and the second pattern 119 may have the same spacing between adjacent peaks or valleys, or may be provided to have different spacings. In addition, the same interval and different intervals may be provided in a combined form.

As an example, when the flexible battery 100 and 100 ′ according to the present invention is applied to a product such as a watch band, the interval between the peaks and valleys constituting the patterns 119 and 124 for the entire length may be formed at the same interval, but The amount of change in contraction and relaxation offset by the patterns 119 and 124 by making the distance between the ridge and trough formed on the side of the joint where banding occurs relatively frequently in the process of wearing or releasing the string closer is compared with other parts. It can also be made 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 or may be partially formed.

For example, as shown in FIG. 6 , in the flexible battery 100 ′ according to the present invention, the first pattern 124 forms a accommodating part 125 for accommodating the electrode assembly 110 and the electrolyte. It may be formed in only one area.

This blocks the possibility that the electrolyte may move along the first pattern 124 by not forming the first pattern 124 on the side of the second region constituting the sealing part in order to prevent the electrolyte from leaking to the outside. This is to improve airtightness by improving the bonding force between the first exterior material 121 and the second exterior material 122 .

Here, when the first pattern 124 is formed only in the first region, the first pattern 124 may be formed with respect to the entire area of the first region, or may be formed on the area coincident with the area of the electrode assembly 110 . Note that it may be formed only in the corresponding area.

On the other hand, the flexible battery 100 according to an embodiment of the present invention includes a housing 130 covering the surface of the exterior material 120 as shown in FIG. 16 , and the housing 130 is a charging target device and At least one terminal unit 132 for electrical connection of the battery may be provided in the form of an auxiliary battery. Here, the housing 130 may be made of a material having rigidity such as plastic or metal, but a flexible and soft material such as silicon or leather may be used.

Here, the auxiliary battery is implemented as accessories such as bracelets and anklets, watch straps, etc., and is used as a fashion product when charging of the charging target device is unnecessary, and when charging of the charging target device is required, the terminal unit 132 By being electrically connected to the charging target device through the , it is possible to charge the main battery of the charging target device regardless of location.

Here, although it is illustrated that the terminal part 131 is provided as a pair at the end of the housing 130 , the present invention is not limited thereto, and the position of the terminal part 131 may be provided on the side of the housing 130 , It may be formed in various positions, such as the upper surface or the lower surface of the. In addition, it should be noted that the terminal unit 131 may be provided in a form in which a negative terminal and a positive terminal are separated, or may be provided in a form in which a positive electrode and a negative electrode are integrated, such as USB.

In addition, the flexible battery of the present invention may be used as a main battery or an auxiliary battery of an electrical and/or electronic device requiring flexibility. For example, it is pointed out that the flexible battery according to the present invention can be widely used in electronic devices such as a watch strap of a smart watch and a flexible display.

Although one embodiment of the present invention has been described above, the spirit of the present invention is not limited to the embodiments presented herein, and those skilled in the art who understand the spirit of the present invention can add components within the scope of the same spirit. , changes, deletions, additions, etc. may easily suggest other embodiments, but this will also fall within the scope of the present invention.

100,100': flexible battery 110: electrode assembly
112: positive electrode 112a: positive electrode current collector
112b: positive active material 114: separator
114a: nonwoven layer 114b: nanofiber web layer
116: negative electrode 116a: negative electrode current collector
116b: negative active material 118a: negative terminal
118b: positive terminal 119: second pattern
120: exterior material 121: first exterior material
121a: first resin layer 121b: metal layer
121c: second resin layer 122: second exterior material
122a: first resin layer 122b: metal layer
123c: second resin layer 124: first pattern
125: accommodating part 126: sealing part
127: folding line 130: housing
132: terminal part

Claims (25)

electrode assembly; and
Including; and a housing part in which the electrode assembly and the electrolyte are accommodated, and a sealing part formed along the rim of the accommodating part to seal the rim of the accommodating part;
At least a portion of the sealing portion is folded to the upper or lower surface of the receiving portion via a folding line formed parallel to at least one of the longitudinal direction and the width direction of the exterior material,
Including a pattern including a plurality of peaks and valleys alternately formed along the longitudinal direction for contraction and relaxation in the longitudinal direction during bending,
The pattern is
a first pattern formed on at least one surface of the exterior material; and
A flexible battery comprising a; a second pattern formed on the electrode assembly to coincide with the first pattern. The method of claim 1,
The foldable line is formed to be spaced apart from the boundary line dividing the accommodating part and the sealing part to the inside of the accommodating part by a predetermined interval. The method of claim 1,
The packaging material is a flexible battery that is formed by sequentially stacking a first resin layer, a metal layer, and a second resin layer. delete The flexible battery according to any one of claims 1 to 3;
a housing covering the surface of the exterior material; and
Auxiliary battery including; at least one terminal for electrical connection with the charging target device. delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete

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