Secondary battery cell having fire extinguishing layer formed therein

Abstract

Disclosed is a secondary battery cell having a fire extinguishing layer formed therein. The secondary battery cell having a fire extinguishing layer formed therein, according to one aspect of the present invention, may comprise: an electrode; an outer cover that forms an accommodation space in which the electrode is accommodated and protects the electrode from the outside by surrounding the electrode; and a fire extinguishing layer that is formed on at least a portion of the outer cover and is coated with a fire extinguishing material.

Description

Secondary battery cell with a digestive layer formed

[0001] The present invention relates to a secondary battery cell having a fire extinguishing layer formed therein, and more specifically, to a secondary battery cell having a fire extinguishing layer formed therein that can extinguish a battery fire at an early stage.

[0002] In recent years, environmental concerns have accelerated the development of electric vehicles to replace conventional internal combustion engines. Furthermore, the advancement of various IT devices is accelerating the development of portable electronic devices such as laptops, mobile phones, and watches.

[0003] These electric vehicles and portable electronic devices all use electricity as a power source, and a representative example of a power source of electric energy is a battery including a secondary battery.

[0004] These rechargeable secondary batteries are key components of electric vehicles and portable electronic devices.

[0005] These secondary batteries can be viewed as consisting of battery cells, battery modules in which the battery cells are assembled, and battery packs in which the battery modules are assembled. However, there is a risk of fire occurring between the battery cells and battery modules due to various reasons such as short circuits, overcharging, or overdischarging.

[0006] In general, a battery is composed of electrodes and an outer shell that surrounds the electrodes. When a fire occurs, it is reported that the electrolyte inside leaks out from the outer shell and combustion begins in the leaked electrolyte.

[0007] In particular, because secondary battery fires are difficult to extinguish due to their nature, early extinguishment is important, and it is also important to delay the spread of fire in the event of an initial fire to secure evacuation time.

[0008] In addition, in the case of electric vehicles, devices or structures for initial firefighting or delaying the spread of fire must be installed inside the vehicle structure. However, the installation of such devices may cause the vehicle interior to become narrower or the space inside the battery pack to become narrower, which may reduce battery capacity.

[0009] In the case of small portable electronic devices, there is no space to insert devices for initial fire suppression or fire spread delay in the event of a fire, so a solution is needed.

[0010] The present invention is intended to solve the above-mentioned problems, and an object of the present invention is to provide a secondary battery cell having a fire extinguishing layer formed thereon that can extinguish a fire at an early stage or delay the spread of a fire without taking up any volume.

[0011] The tasks of the present invention are not limited to the tasks mentioned above, and other tasks not mentioned will be clearly understood by those skilled in the art from the description below.

[0012] According to one aspect of the present invention, a secondary battery cell is provided, comprising: an electrode; an outer shell forming a receiving space in which the electrode is received and wrapping the electrode to protect it from the outside; a fire extinguishing layer formed on at least a portion of the outer shell and having a fire extinguishing material applied thereto; and a fire extinguishing layer formed thereon.

[0013] The above digestion layer may be formed on the entire or at least a portion of the outer surface of the receiving space of the outer shell, or may be applied to the outer surface of the joint where the outer shells are mutually joined.

[0014] The above digestion layer can be formed on the inner surface of the receiving space of the outer shell.

[0015] The above digestion layer is formed by forming a joint portion joined to the outer shell forming the receiving space, and the digestion layer can be formed in at least one of an area excluding the joint portion of the outer shell, the entire inner surface of the outer shell, or an area adjacent to the joint portion on the inner surface of the outer shell.

[0016] A fire extinguishing material protective layer may be further formed on the surface facing the inside of the storage space of the above-mentioned fire extinguishing layer to block contact between the fire extinguishing layer and the electrolyte within the storage space.

[0017] The above outer shell may be cylindrical or rectangular in shape.

[0018] The above digestion layer can be formed by any one of coating, printing, and spraying methods.

[0019] In addition, according to another aspect of the present invention, there is provided a pouch comprising: an electrode; a first outer layer forming a pocket that accommodates the electrode and an electrolyte, and protecting the electrode from the outside by surrounding the electrode and forming a first surface of the pocket; and a second outer layer forming a second surface of the pocket, wherein the first outer layer and the second outer layer form a sealing portion that are mutually joined at an outer edge of the pocket; a lead tab extending from the electrode to the outside of the pouch; and a fire extinguishing layer formed on at least a portion of the pouch and having a fire extinguishing material applied thereto; wherein the sealing portion may include a first sealing portion in which the first outer layer and the second outer layer are joined, and a second sealing portion in which the lead tab and the first outer layer, and the lead tab and the second outer layer are joined.

[0020] The above digestive layer can be applied to the entire outer surface of the pouch or along the sealing portion.

[0021] The digestion layer may be formed in at least one of an area excluding the sealing portion where the first outer layer and the second outer layer of the inner surface of the pocket of the pouch are joined, the entire inner surface of the pocket of the pouch, an area adjacent to the first sealing portion of the inner surface of the pocket, or an area adjacent to the second sealing portion where the lead tab and the pouch of the inner surface of the pocket are joined.

[0022] A fire extinguishing protective layer may be further formed on the surface of the fire extinguishing layer facing the inside of the pocket to prevent contact between the fire extinguishing layer and the electrolyte in the pocket.

[0023] The above digestion layer can be formed by any one of coating, printing, and spraying methods.

[0024] According to the above configuration, the secondary battery cell having the fire extinguishing layer formed according to the present invention has the effect of extinguishing the fire early or delaying the spread of the fire without a complex configuration when a fire occurs in the cell.

[0025] The effects of the present invention are not limited to the effects described above, and should be understood to include all effects that can be inferred from the detailed description of the present invention or the composition of the invention described in the claims.

[0026] FIG. 1 is a drawing illustrating a secondary battery cell having a pouch-shaped digestion layer formed according to a first embodiment of the present invention.

[0027] FIG. 2 is a drawing showing an opened pouch of a secondary battery cell having a pouch-shaped digestive layer formed thereon according to the first embodiment of the present invention.

[0028] FIG. 3 is a plan view and a cross-sectional view of a secondary battery cell having a pouch-shaped digestion layer formed according to the first embodiment of the present invention.

[0029] Figure 4 is a plan view and a cross-sectional view of a secondary battery cell having a pouch-shaped digestion layer formed according to a second embodiment of the present invention.

[0030] FIG. 5 is a plan view and a cross-sectional view of a secondary battery cell having a pouch-shaped digestion layer formed according to a third embodiment of the present invention.

[0031] Figure 6 is a plan view and a cross-sectional view of a secondary battery cell having a pouch-shaped digestion layer formed according to a fourth embodiment of the present invention.

[0032] FIG. 7 is a plan view and a cross-sectional view of a secondary battery cell having a pouch-shaped digestion layer formed according to a fifth embodiment of the present invention.

[0033] FIG. 8 is a plan view and a cross-sectional view of a secondary battery cell having a pouch-shaped digestion layer formed according to the sixth embodiment of the present invention.

[0034] Figure 9 is a drawing showing various patterns of the applied digestive layer of part I of Figure 3.

[0035] FIG. 10 is a drawing showing a secondary battery cell having a digestion layer formed according to the seventh embodiment of the present invention applied to a cylindrical secondary battery.

[0036] FIG. 11 is a drawing showing a secondary battery cell having a digestion layer formed according to the eighth embodiment of the present invention applied to a square secondary battery.

[0037] Hereinafter, with reference to the attached drawings, embodiments of the present invention will be described in detail so that those skilled in the art can easily practice the present invention. The present invention may be implemented in various different forms and is not limited to the embodiments described herein. To clearly explain the present invention, parts irrelevant to the description are omitted in the drawings, and the same reference numerals designate identical or similar components throughout the specification.

[0038] The words and terms used in this specification and claims should not be construed as limited to their ordinary or dictionary meanings, but should be interpreted in a way that is consistent with the technical idea of ​​the present invention, in accordance with the principles by which the inventor can define terms and concepts in order to best explain his or her invention.

[0039] Therefore, the embodiments described in this specification and the configurations illustrated in the drawings correspond to a preferred embodiment of the present invention, and do not represent all of the technical ideas of the present invention, so there may be various equivalents and modified examples that can replace the configuration at the time of filing of the present invention.

[0040] In this specification, terms such as “include” or “have” are intended to describe the presence of a feature, number, step, operation, component, part or combination thereof described in the specification, but should be understood not to exclude in advance the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts or combinations thereof.

[0041] When a component is said to be "in front of," "behind," "above," or "below" another component, this includes not only being placed "in front of," "behind," "above," or "below" the other component in direct contact with it, but also if there is another component intervening therebetween. Furthermore, when a component is said to be "connected" to another component, this includes not only being directly connected to one another, but also being indirectly connected to one another, unless there are special circumstances.

[0042] Hereinafter, a secondary battery cell having a digestion layer formed according to one embodiment of the present invention will be described with reference to the drawings.

[0043] A secondary battery cell having a digestion layer formed according to an embodiment of the present invention will be described as an example of a pouch-shaped secondary battery cell (100) as shown in FIGS. 1 and 2.

[0044] As shown in FIGS. 1 and 2, the secondary battery cell (100) in which the above digestion layer is formed may include an electrode (110), a pouch (121), a lead tab (140), and a digestion layer (151).

[0045] The above electrode (110) may have a positive electrode and a negative electrode laminated in a rectangular shape.

[0046] In addition, the pouch (121) can serve as an outer shell that wraps the electrode (110). That is, the pouch (121) forms a space in which the electrode (110) is accommodated, and can serve as an outer shell that wraps the electrode (110) and protects it from the outside.

[0047] The above pouch (121) may be made of a film or the like coated with a synthetic resin such as polyethylene terephthalate (PET) on the surface of a metal material such as aluminum.

[0048] The above pouch (121) has a pocket (122) formed to accommodate the electrode (110) and the electrolyte (112), and wraps the electrode (110) to protect the electrode (110) and the electrolyte (112) from the outside, and can prevent the electrolyte (112) inside from leaking to the outside.

[0049] The above pouch (121) includes a first outer layer (125) forming a first surface of the pocket (122) and a second outer layer (126) forming a second surface of the pocket (122), and the first outer layer (125) and the second outer layer (126) can form a sealing portion (130) that is mutually joined at the outer edge of the pocket (122).

[0050] The above pocket (122) may be formed only in the first outer layer (125) or in both the first outer layer (125) and the second outer layer (126).

[0051] In addition, the lead tab (140) may be formed to extend from the electrode (110) to the outside of the pouch (121) in order to electrically connect the electrode (110) to the outside.

[0052] The above lead tab (140) may be a metal surface having electrical conductivity, coated with a synthetic resin film such as polypropylene (PP) on the surface of the metal material.

[0053] Meanwhile, the pocket (122) may be formed by being inserted into the first outer layer (125) to form a space in which the electrode (110) and electrolyte (112) are accommodated.

[0054] The above pocket (122) may be stepped from the sealing portion (130), and may include a flat portion (123) that is stepped from the sealing portion (130) and an inclined portion (124) that is connected at an angle from the flat portion (123) to the sealing portion (130).

[0055] The above sealing portion (130) can extend in a plane direction perpendicular to the direction in which the pocket (122) is stepped.

[0056] In addition, the sealing portion (130) may include a first sealing portion (132) in which the first outer layer (125) and the second outer layer (126) are fused and joined, and a second sealing portion (134) in which the lead tab (140) and the first outer layer (125) and the lead tab (140) and the second outer layer (126) are joined.

[0057] At this time, the second sealing portion (134) can be bonded by fusing the films of the first outer layer (125) and the second outer layer (126) with the synthetic resin film of the lead tab (140).

[0058] Meanwhile, the digestive layer (151) may be formed on at least a portion of the pouch (121).

[0059] The above digestion layer (151) may be a layer to which a digestive substance is applied. The above-mentioned extinguishing agent is preferably a extinguishing agent having a melting point of 100°C or higher, which generates a extinguishing agent through high-temperature decomposition to ensure the functional stability of the extinguishing agent composition at room temperature and to facilitate long-term storage, and is a brominated extinguishing agent, such as tetrabromobisphenol A, tetrabromobisphenol A ether, 1,2-bis(tribromophenoxy)ethane, 1,2-bis(tetrabromophthalamide)ethane, 4-bromophthalic acid dimethyl ester, tetrabromophthalic acid disodium, decabromodiphenyl ether, tetradecabromo-1,4-diphenoxybenzene, 1,2-bis(pentabromofenyl)ethane, bromotrimethylphenyl indane (BTMPI), pentabromobenzyl acrylate, hexabromobenzene, pentabromotoluene, hexabromocyclododecane, Ethylene-bis(5,6-dibromonobonane-2,3-dicarboximide), pentabromochlorocyclohexane, brominated styrene polymer, tetrabromobisphenol A carbonate ester oligomer, polypentabromobenzyl acrylate, polydibromophenylene ether; chlorinated fire extinguishing materials such as Dechlorane Plus, chlorenedic anhydride, perchloropentacyclodecane, tetrachlorobisphenol A, polychloroolefins, chlorinated polyvinyl chloride, vinyl chloride-vinylidene chloride copolymer, chlorinated polyethylene; Organophosphorus extinguishing agents include 1-oxo-4-hydroxymethyl-2,6,7-trioxahetero-1-phosphabicyclo[2,2,2]octane, 2,2-dimethyl-1,3-propyleneglycol-bis(neopentyl glycol)bisphosphonate, 9,10-dihydrogen-9-oxahetero-10-phosphaphenanthrene-10 oxide, bis(4-carboxyphenyl)phenyl phosphorus oxide, bis(4-hydroxyphenol)phenyl phosphorus oxide, and oligomeric phenyl(diphenyl sulfone) phosphonates;Tri(2,2-bis(bromomethyl)-3-bromopropyl) phosphate, tri(2-bromophenyl) phosphate, 3,9-bis(tribromophenyl)-2,4,8,10-tetraoxahetero-3,9-diphosphaspiro[5,5]-3,9-dioxundecane, 3,9-bis(pentabromophyll)-2,4,8,10-tetraoxahetero-3,9-diphosphaspiro[5,5]-3,9-dioxundecane, 1-oxo-4-tribromophenyl-2,6,7-trioxane-1-phosphahetero-bicyclo[2,2,2]octane, p-phenylene(2,4,6-tribromophenyl)bisphosphonate, 2,2-Bis(chloromethyl)-1,3-propyleneglycol-bis(neopentylglycol)bisphosphonate, 2,9-bis(tribromopro)-2,4,8,10-tetraoxahetero-3,9-diphosphaspiro[5,5]-3,9-deoxyundecane;Nitrogen-based and phosphorus-nitrogen-based fire extinguishing materials, melamine cyanurate, melamine orthophosphate, bismelamine orthophosphate, melamine polyphosphate, melamine borate, melamine octamolybdate, tris(hydroxyethyl)isocyanurate, 2,4-diamino-6-(3,3,3-trichloropropyl)-1,3,5-triazine, 2,4-bis(N-hydroxymethylamino)-6-(3,3,3-trichloropropyl-1,3,5-triazine), bisguanidine hydrogen phosphate, dihydrogen guanidine phosphate, guanidine carbonate, guanidine aminosulfonate, urea, dihydrogen urea phosphate, dicyandiamide, bis(2,6,7-trioxyhetero-1-phosphahetero-bicyclo[2,2,2]octane-1-oxo-4-methyl) Hydroxyl phosphate ester melamine, 3,9-dihydroxy-3,9-dioxy-2,4,8,10-tetraoxahetero-3,9-diphosphaspiro[5,5]undecane-3,9-bismelamine, 1,2-bis(2-oxo-5,5-dimethyl-1,3-dioxahetero-2-phosphaheterohexyl-2-amino)ethane, N,N'-bis(2-oxo-5,5-dimethyl-1,3-dioxyhetero-2-phosphaheterohexyl)-2,2'-meta-phenylenediamine, tri(2-oxo-5,5-dimethyl-1,3-dioxyhetero-2-heterocyclohexyl-2-methyl)amine, phenoxycyclophosphazene, inorganic fire extinguishing materials, ammonium polyphosphate, diammonium hydrogen phosphate, Ammonium dihydrogen phosphate, zinc phosphate, aluminum phosphate, boron phosphate, antimony trioxide, aluminum hydroxide, magnesium hydroxide, kaolinite, basic aluminum hydroxide, zinc borate, barium metaborate, zinc oxide, zinc sulfide, zinc sulfate heptahydrate, aluminum borate single crystal, ammonium octamolybdate, hexaammonium molybdate, zinc stannate, tin oxide, ferrocene, iron acetone, ferric oxide, ferric trioxide, sodium tungstate, potassium hexafluorotitanate, potassium hexafluorozirconate, titanium dioxide, calcium carbonate, barium sulfate.;

[0060] And other chemicals with a decomposition temperature of 100℃ or higher that can decompose extinguishing substances, such as sodium bicarbonate, potassium bicarbonate, cobalt carbonate, zinc carbonate, basic zinc carbonate, manganese carbonate, ferrous carbonate, strontium carbonate, sodium potassium carbonate hexahydrate, calcium carbonate, dolomite, basic copper carbonate, zirconium carbonate, beryllium carbonate, sodium sesquicarbonate, cerium carbonate, lanthanum carbonate, guanidine carbonate, lithium carbonate, scandium carbonate, vanadium carbonate, chromium carbonate, nickel carbonate, yttrium carbonate, silver carbonate, preseodymium carbonate, neodymium carbonate, samarium carbonate, europium carbonate, gadolinium carbonate, terbium carbonate, dysprosium carbonate, holmium carbonate, erbium carbonate, thulium carbonate, hol ytterbium carbonate, lutetium carbonate, aluminum diacetate, calcium acetate, sodium bicarbonate, sodium tartrate, sodium acetate, potassium acetate, acetic acid Zinc, strontium acetate, nickel acetate, copper acetate, sodium oxalate, potassium oxalate, ammonium oxalate, nickel oxalate, manganese (II) oxalate dihydrate, iron nitride, sodium nitrate, magnesium nitrate, potassium nitrate, zirconium nitrate, calcium dihydrogen phosphate, sodium dihydrogen phosphate, sodium dihydrogen phosphate dihydrate, potassium dihydrogen phosphate, aluminum dihydrogen phosphate, ammonium dihydrogen phosphate, zinc dihydrogen phosphate, manganese dihydrogen phosphate, magnesium dihydrogen phosphate, disodium hydrogen phosphate, diammonium hydrogen phosphate, calcium hydrogen phosphate, magnesium hydrogen phosphate, ammonium phosphate, magnesium ammonium phosphate, ammonium polyphosphate, potassium metaphosphate, potassium tripolyphosphate, potassium trimetaphosphate, ammonium hypophosphate, ammonium orthophosphite Dihydrogen phosphate, manganese phosphate, zinc dihydrogen phosphate, dimanganese hydrogen phosphate, guanidine phosphate, melamine phosphate, urea phosphate, strontium dihydrogen phosphate metaborate, potassium dihydrogen phosphate metaborate, boric acid, ammonium borate, ammonium tetraborate octahydrate, magnesium metaborate octahydrate, ammonium borate tetrahydrate, strontium metaborate, strontium tetraborate, strontium tetraborate tetrahydrate, sodium tetraborate decahydrate, manganese borate, zinc borate, ammonium fluoroborate, ferrous ammonium sulfate, aluminum sulfate, aluminum potassium sulfate, aluminum ammonium sulfate, ammonium sulfate, magnesium sulfate, aluminum hydroxide, magnesium hydroxide, iron hydroxide,Cobalt hydroxide, bismuth hydroxide, strontium hydroxide, cerium hydroxide, lanthanum hydroxide, molybdenum hydroxide, ammonium molybdate, zinc stannate, magnesium trisilicate, telluric acid, manganese tungstate, manganese ferrocene, 5-amino-tetrazol, guanidine nitrate, azodicarbonamide, nylon powder, oxamide, biuret, pentaerythritol, decabromo diphenyl ether, tetrabromophthalic anhydride, 2,2-bis(bromomethyl)-1,3-propanediol, potassium citrate, sodium citrate, manganese citrate, magnesium citrate, copper citrate, ammonium citrate, nitro guanidine.

[0061] The above-mentioned fire extinguishing layer (151) is a layer containing the fire extinguishing material, and when a fire occurs in the secondary battery cell (100), the fire extinguishing material can perform a fire extinguishing action.

[0062] A fire in a secondary battery can occur for various reasons. In many cases, it is known that leakage of electrolyte (112) occurs in the outer shell such as the pouch (121), and the leaked electrolyte (112) reacts with oxygen to initiate combustion.

[0063] Accordingly, by forming a fire extinguishing layer (151) containing a fire extinguishing agent on all or part of the outer shell of the pouch (121), etc., it is possible to extinguish a fire at an early stage or delay the spread of the fire, thereby securing time for response.

[0064] In (a) of Fig. 3, the digestive layer (151) is indicated by shading.

[0065] The above digestive layer (151) may be formed in the form of a paste or paint containing the digestive substance, and may be formed by coating, printing, or spraying.

[0066] FIG. 3 is a drawing showing a secondary battery cell (100) having a digestion layer formed according to the first embodiment of the present invention. FIG. 3 (a) is a plan view, (b) is a cross-sectional view taken along line AA, and (c) is a cross-sectional view taken along line BB.

[0067] The secondary battery cell (100) having a digestion layer formed according to the first embodiment of the present invention may have a digestion layer (151) formed on the entire outer surface of the pouch (121), as shown in FIG. 3.

[0068] That is, a digestion layer (151) can be applied to the entire outer surface of the pouch (121) that serves as the outer skin of the electrode (110).

[0069] At this time, as shown in (b) of FIG. 3, the fire extinguishing layer (151) is not applied to the lead tab (140) that must be electrically connected to the outside, and as shown in (c) of FIG. 3, the fire extinguishing layer (151) may be applied to the area where the first outer layer (125) and the second outer layer (126) of the pouch (121) are joined.

[0070] Since the above fire extinguishing layer (151) is applied to the entire outer surface of the pouch (121), it is possible to block fire occurring inside the secondary battery, and it is also expected to have the effect of responding to fire spreading from the outside.

[0071] FIG. 4 is a drawing showing a secondary battery cell (200) having a digestion layer formed according to a second embodiment of the present invention. FIG. 4 (a) is a plan view, (b) is a cross-sectional view taken along line AA, and (c) is a cross-sectional view taken along line BB.

[0072] As mentioned above, it is known that a fire in a secondary battery occurs when the electrolyte (112) leaks from the outer shell such as the pouch (121), and the leaked electrolyte (112) reacts with oxygen and starts to combust. Meanwhile, when the pressure inside the pocket (122) increases due to overcharging, overdischarging, or a rise in the temperature of the battery, causing a swelling phenomenon, a leak may first occur in the sealing portion (130) where the first outer layer (125) and the second outer layer (126) are joined.

[0073] Accordingly, in the secondary battery cell (200) having the digestion layer formed according to the present embodiment, as shown in FIG. 4, the digestion layer (152) can be formed along the sealing portion (130) on the outer surface of the pouch (121).

[0074] That is, by forming the fire extinguishing layer (152) concentrated on the sealing portion (130) of the pouch (121) where there is a high possibility of leakage of the electrolyte (112), it is expected that the effect of extinguishing the fire more effectively at a lower cost can be expected.

[0075] At this time, as shown in (b) and (c) of FIG. 4, the digestive layer (152) can be applied to the sealing portion (130) of the pocket (122) as well as the edge of the inclined portion (124) and the flat portion (123) adjacent to the inclined portion (124).

[0076] Of course, the above-mentioned digestion layer (152) may not be applied to the lead tab (140) that must make an electrical connection with the outside.

[0077]

[0078] FIG. 5 is a drawing showing a secondary battery cell (300) having a digestion layer formed according to a third embodiment of the present invention. FIG. 5 (a) is a plan view, (b) is a cross-sectional view taken along line AA, and (c) is a cross-sectional view taken along line BB.

[0079] Meanwhile, the sealing portion (130) may include a first sealing portion (132) and a second sealing portion (134).

[0080] The first sealing portion (132) is a portion where the first outer layer (125) and the second outer layer (126) are joined, and the second sealing portion (134) is a portion where the first outer layer (125) and the second outer layer (126) are joined to the lead tab (140).

[0081] To be more precise, the lead tab (140) is a synthetic resin such as PP film coated on the surface of an electrically conductive metal piece, and the film layers of the first outer layer (125) and the second outer layer (126) forming the pouch (121) can be thermally bonded to the film layer of the lead tab (140) to form a second sealing portion (134).

[0082] In general, the bonding strength of the second sealing portion (134) in which different materials are fused may be lower than that of the first sealing portion (132) in which the same materials are fused.

[0083] This means that when the pressure inside the pocket (122) of the pouch (121) increases, it is more likely that a leak will occur in the second sealing portion (134) than in other parts, and therefore it is more likely that a fire will occur in the second sealing portion (134) than in other parts.

[0084] Accordingly, in the secondary battery cell (300) having a digestion layer formed according to the third embodiment of the present invention, as illustrated in FIG. 5, the digestion layer (153) can be formed on the outer surface of the second sealing portion (134) among the sealing portions (130).

[0085] Alternatively, in this embodiment, the digestion layer (153) may be applied to the side of the sealing portion (130) where the second sealing portion (134) is formed.

[0086] At this time, as shown in (b) of FIG. 5, the digestion layer (153) can be applied not only to the sealing portion (130) of the side where the second sealing portion (134) of the pocket (122) is formed, but also to the inclined portion (124) of the pocket (122) of the side where the second sealing portion (134) is formed and the edge of the flat portion (123) adjacent to the inclined portion (124).

[0087]

[0088] The secondary battery cells (100, 200, 300) having a digestion layer formed according to the first to third embodiments described above were all explained as examples in which the digestion layer (151, 152, 153) is formed on the outer surface of the pouch (121) that serves as an outer shell.

[0089] However, in the present invention, the digestive layer is not limited to being formed on the outer surface of the pouch (121), and may also be formed on the inner surface of the pouch (121).

[0090] Hereinafter, examples in which the digestive layer is formed on the inner surface of the pouch (121) will be described.

[0091] FIG. 6 is a drawing illustrating a secondary battery cell (400) having a digestion layer formed according to a fourth embodiment of the present invention. FIG. 6 (a) is a drawing illustrating a cross-section along line AA of FIG. 1, and (b) is a drawing illustrating a cross-section along line BB.

[0092] A secondary battery cell (400) having a digestion layer formed according to the fourth embodiment of the present invention may include an electrode (110), a pouch (121), a lead tab (140), and a digestion layer (154).

[0093] The electrode (110), pouch (121), and lead tab (140) are the same as those in the above-described embodiment, so a detailed description thereof will be omitted. In addition, for the convenience of explanation in FIG. 6, the electrode (110) is omitted from the illustration.

[0094] In this embodiment, the digestive layer (154) may be formed on the inner surface of the pocket (122) of the pouch (121).

[0095] At this time, the digestion layer (154) can be formed in an area excluding the sealing portion (130) where the first outer layer (125) and the second outer layer (126) of the inner surface of the pocket (122) are joined.

[0096] This is because the sealing portion (130) is formed by thermally fusion bonding the first outer layer (125) and the second outer layer (126), and if a fire extinguishing layer (154) is formed at the bonding portion, bonding may be hindered. Therefore, the fire extinguishing layer (154) is formed by avoiding the sealing portion (130).

[0097] Since the above-mentioned fire extinguishing layer (154) is formed on the inner surface of the pouch (121) and a sealed state is maintained, deterioration of the fire extinguishing layer (154) due to external environmental factors is prevented, thereby ensuring the lifespan of the fire extinguishing layer (151). In addition, if a fire starts from the inside of the pouch (121) rather than the outside, it can be extinguished more effectively.

[0098] In addition, since the inside of the pocket (122) is filled with an electrolyte (112), in order to block the reaction between the extinguishing agent of the extinguishing layer (154) and the electrolyte (112), a extinguishing agent protection layer (164) that blocks the extinguishing agent (154) and the electrolyte (112) in the pocket (122) from contacting each other may be further formed on the surface of the extinguishing layer (154) facing the inside of the pocket (122).

[0099] The above-mentioned fire extinguishing protective layer (164) may be formed of a polyphthalamide (PPA) material that does not allow lithium hexafluorophosphate (LiPF6), a component of the electrolyte, to penetrate and does not react with lithium hexafluorophosphate (LiPF6). Of course, the above-mentioned fire extinguishing protective layer (164) may be formed of other known materials in addition to the above-mentioned polyphthalamide.

[0100] Accordingly, since the above-mentioned fire extinguishing agent protection layer (164) is formed, the reaction between the fire extinguishing agent of the fire extinguishing layer (154) and the electrolyte is blocked, so that the function of the fire extinguishing layer (154) is maintained, and when a fire occurs, the fire extinguishing agent protection layer (164) melts due to the heat of the fire, so that the fire extinguishing function of the fire extinguishing layer (154) can be exerted.

[0101] Of course, if the extinguishing agent of the above-mentioned extinguishing layer (151) and the above-mentioned electrolyte (112) are substances that do not react with each other, the extinguishing agent protection layer (164) may not need to be formed.

[0102] Alternatively, if the digestive layer (151) contains a substance that interferes with the reaction between the digestive substance and the electrolyte (112) and is formed as a single liquid, the digestive protective layer (164) may not need to be formed separately.

[0103]

[0104] FIG. 7 is a drawing illustrating a secondary battery cell (500) having a digestion layer formed according to a fifth embodiment of the present invention. FIG. 7 (a) is a drawing illustrating a cross-section along line AA of FIG. 1, and (b) is a drawing illustrating a cross-section along line BB.

[0105] As described above, when the pressure inside the pocket (122) of the secondary battery increases due to overcharging, overdischarging, or a rise in the temperature of the battery, causing a swelling phenomenon, leakage may first occur in the sealing portion (130) where the first outer layer (125) and the second outer layer (126) are joined.

[0106] Accordingly, in the secondary battery cell (500) having the digestion layer formed according to the present embodiment, as shown in FIG. 7, the digestion layer (155) can be formed along the sealing portion (130) on the inner surface of the pouch (121).

[0107] That is, by concentrating the fire extinguishing layer (155) near the sealing portion (130) of the pouch (121) where there is a high possibility of leakage of the electrolyte (112), it is expected that the effect of more effectively suppressing the fire can be expected.

[0108] At this time, as shown in (b) and (c) of FIG. 7, the digestion layer (155) can also be applied to the slanted portion (124) on the inner surface of the pocket (122) and the edge of the flat portion (123) adjacent to the slanted portion (124).

[0109] Of course, it is not limited to this, and the digestive layer (155) may be applied only to the inclined portion (124) on the inner surface of the pocket (122).

[0110] Additionally, a fire extinguishing agent protection layer (165) may be further formed on the surface of the fire extinguishing layer (155) facing the inside of the pocket (122).

[0111]

[0112] FIG. 8 is a drawing illustrating a secondary battery cell (600) having a digestion layer formed according to a sixth embodiment of the present invention. FIG. 8 (a) is a drawing illustrating a cross-section along line AA of FIG. 1, and (b) is a drawing illustrating a cross-section along line BB.

[0113] As described above, the sealing portion (130) may include a first sealing portion (132) in which the first outer layer (125) and the second outer layer (126) are joined, and a second sealing portion (134) in which the first outer layer (125) and the second outer layer (126) are joined to the lead tab (140).

[0114] In addition, the bonding strength of the second sealing portion (134) in which different materials are fused may be lower than that of the first sealing portion (132) in which similar materials are fused.

[0115] Accordingly, in the secondary battery cell (600) having the digestion layer formed according to the sixth embodiment of the present invention, as illustrated in FIG. 8, the digestion layer (156) may be formed in an area adjacent to the second sealing portion (134) on the inner side of the pocket (122). Alternatively, the digestion layer (156) may be formed on the entire side of the inner side of the pocket (122) having a rectangular shape where the second sealing portion (134) is formed.

[0116] At this time, the digestive layer (156) can also be applied to the slanted portion (124) on the inner surface of the pocket (122) and the edge of the flat portion (123) adjacent to the slanted portion (124).

[0117] Of course, it is not limited to this, and the digestive layer (156) may be applied only to the inclined portion (124) on the inner side of the pocket (122).

[0118] In addition, a fire extinguishing agent protection layer (166) may be further formed on the surface of the fire extinguishing layer (156) facing the inside of the pocket (122) to prevent the fire extinguishing layer (156) and the electrolyte (112) from reacting.

[0119] In the above-described embodiments, as illustrated in (a) to (f) of FIG. 9, the digestion layer (151, 152, 153, 154, 155, 156) may be uniformly applied or painted as a paste or paint, or may be printed on the outer surface of the pouch (121) in the form of uniformly or unevenly distributed dots. Of course, in addition to the dot form, the digestion layer may also be applied, painted, or printed in a pattern such as a straight line, a grid, a diagonal line, a concentric circle, or a ring.

[0120]

[0121] As described above, the present invention has been described with respect to an embodiment in which a secondary battery cell having a digestive layer formed thereon is in a pouch shape. However, the present invention can be applied not only to a pouch-shaped secondary battery cell but also to a square or cylindrical secondary battery cell.

[0122] FIG. 10 is a drawing illustrating a secondary battery cell (700) according to the seventh embodiment of the present invention.

[0123] As illustrated in FIG. 10, a cylindrical secondary battery cell (700) may include a can (720) forming an outer shell and an electrode (710) accommodated inside the can (720).

[0124] Additionally, a cap (730) may be placed to form the upper or lower end of the can (720) to seal the inside of the can (720) and form positive and negative ends.

[0125] At this time, the digestive layer (157) can be formed on the inner surface of the cap (730) that seals the upper side of the can (720).

[0126] Accordingly, in the event of a fire occurring in the electrode (710) housed inside the can (720), the fire extinguishing layer (157) applied to the inner surface of the cap (730) located directly above the location of the fire can immediately perform the fire extinguishing action.

[0127] Alternatively, the digestive layer (157) may be applied to the entire outer or inner surface of the can (720) or may be applied to the outer or inner surface of the joint between the can (720) and the cap (730), as needed.

[0128]

[0129] FIG. 11 is a drawing illustrating a secondary battery cell (800) according to the eighth embodiment of the present invention.

[0130] As illustrated in FIG. 11, a square secondary battery cell (800) may include a can (820) forming an outer casing, an electrode (810) accommodated inside the can, and a cap plate (830) sealing the can (820).

[0131] The above can (820) is formed in a rectangular parallelepiped shape and has a space therein for accommodating an electrode (810), and the upper side can be opened.

[0132] In addition, the cap plate (830) covers and seals the upper opening of the can (820), and the positive and negative electrodes of the electrode (810) accommodated inside the can (820) can be formed.

[0133] At this time, the digestion layer (157) may be formed on the inner surface of the cap plate (830) that seals the upper side of the can ().

[0134] Alternatively, the digestive layer (157) may be applied to the entire outer or inner surface of the can (820) or may be applied to the outer or inner surface of the joint between the can (820) and the cap plate (830), as needed.

[0135]

[0136] Although the embodiments of the present invention have been described, the spirit of the present invention is not limited to the embodiments presented in this specification, and those skilled in the art who understand the spirit of the present invention will be able to easily propose other embodiments by adding, changing, deleting, or adding components within the scope of the same spirit, but this will also be considered to fall within the spirit of the present invention.

Claims

1. Electrode; An outer shell that forms a space in which the electrode is accommodated and surrounds the electrode to protect it from the outside; A digestive layer formed on at least a portion of the above outer skin and coated with a digestive substance; A secondary battery cell having a digestive layer formed therein.

2. In paragraph 1, A secondary battery cell having a digestion layer formed thereon, wherein the digestion layer is formed on the entire or at least a portion of the outer surface of the receiving space of the outer shell, or is applied to the outer surface of the joint where the outer shells are mutually joined.

3. In paragraph 1, The above digestion layer is a secondary battery cell having a digestion layer formed on the inner surface of the receiving space of the outer shell.

4. In paragraph 3, A secondary battery cell having a digestion layer formed thereon, wherein the digestion layer is formed in at least one of an area excluding the joint of the outer skin, the entire inner surface of the outer skin, or an area adjacent to the joint of the inner surface of the outer skin.

5. In paragraph 3, A secondary battery cell having a fire extinguishing layer formed thereon, wherein a fire extinguishing material protective layer is further formed on a surface facing the inside of the storage space of the fire extinguishing layer to prevent contact between the fire extinguishing layer and the electrolyte within the storage space.

6. In paragraph 1, A secondary battery cell having a digestive layer formed in the shape of a cylinder or a rectangular parallelepiped.

7. In paragraph 1, A secondary battery cell having a digestive layer formed thereon, wherein the digestive layer is formed by any one of coating, printing, and spraying.

8. Electrode; A pouch that forms a pocket that accommodates the electrode and electrolyte, wraps the electrode to protect it from the outside, and includes a first outer layer forming a first surface of the pocket and a second outer layer forming a second surface of the pocket, wherein the first outer layer and the second outer layer form a sealing portion that is mutually joined at the outer edge of the pocket; A lead tab extending from the electrode to the outside of the pouch; A digestive layer formed on at least a portion of the above pouch and coated with a digestive substance; Includes, A secondary battery cell having a fire extinguishing layer formed thereon, wherein the sealing portion comprises a first sealing portion in which the first outer layer and the second outer layer are joined, and a second sealing portion in which the lead tab and the first outer layer, and the lead tab and the second outer layer are joined.

9. In paragraph 8, A secondary battery cell having a digestion layer formed thereon, wherein the digestion layer is applied along the entire outer surface or sealing portion of the pouch.

10. In paragraph 8, A secondary battery cell having a digestion layer formed thereon, wherein the digestion layer is formed in at least one of an area excluding the sealing portion where the first outer layer and the second outer layer of the inner surface of the pocket of the pouch are joined, the entire inner surface of the pocket of the pouch, an area adjacent to the first sealing portion of the inner surface of the pocket, or an area adjacent to the second sealing portion where the lead tab and the pouch of the inner surface of the pocket are joined.

11. In paragraph 8, A secondary battery cell having a fire extinguishing layer formed thereon, wherein a fire extinguishing material protective layer is further formed on a surface of the fire extinguishing layer facing inside the pocket to prevent contact between the fire extinguishing layer and the electrolyte within the pocket.

12. In paragraph 11, A secondary battery cell having a digestive layer formed thereon, wherein the digestive layer is formed by any one of coating, printing, and spraying.

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