KR101750085B1 - Apparatus for Manufacturing Battery Cell and Method for Preparation of Battery Cell Using The Same - Google Patents

Abstract

The present invention relates to an apparatus for adding an insulating material to a sealing portion of a battery case which is bent to face an outer surface of an electrode assembly receiving portion, the jig having a depressed portion having a size corresponding to the battery cell; A sensing unit for sensing the shape of the sealing part in a state where the battery cell is mounted on the jig; An injecting portion including an end portion of the sealing portion for injecting an insulating material between the outer surface of the electrode assembly receiving portion and the inner wall of the indented portion of the jig; And a control unit for collecting information sensed by the sensing unit and controlling an injection position of the injection unit.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery cell processing apparatus and a battery cell manufacturing method using the same,

The present invention relates to a battery cell processing apparatus and a method of manufacturing a battery cell using the same.

The secondary battery, which has recently been used in an increasing amount, has a high demand for a prismatic secondary battery and a pouch-type secondary battery that can be applied to products such as mobile phones with a thin thickness in terms of the shape of the battery. , Lithium secondary batteries, lithium ion batteries, and the like, which have advantages such as high output stability and output stability.

Also, the secondary battery is classified according to how the electrode assembly having the anode / separator / cathode structure is formed. Typically, the long battery-shaped anodes and cathodes are jelly- A stacked (stacked) electrode assembly in which a plurality of positive electrodes and negative electrodes cut in units of a predetermined size are sequentially stacked with a separator interposed therebetween, a stacked (stacked) electrode assembly in which a predetermined unit of positive and negative electrodes are stacked, A stack / folding type electrode assembly in which a Bi-cell or a full cell stacked in a single state is wound up as a separation film can be given.

Recently, a pouch-shaped battery having a structure in which a stacked or stacked / folded electrode assembly is embedded in a pouch-shaped battery case of an aluminum laminate sheet is attracting much attention due to low manufacturing cost, small weight, Its usage is also gradually increasing.

FIG. 1 schematically shows a general structure of a typical conventional pouch-type secondary battery as an exploded perspective view.

1, the pouch type secondary battery 10 includes an electrode assembly 30, electrode taps 40 and 50 extending from the electrode assembly 30, electrodes 40 and 50 welded to the electrode taps 40 and 50, Leads 60 and 70, and a battery case 20 for accommodating the electrode assembly 30. [

The electrode assembly 30 is a power generation element in which an anode and a cathode are sequentially stacked with a separation membrane interposed therebetween. The electrode assembly 30 has a stacked or stacked / folded structure. The electrode tabs 40 and 50 extend from each electrode plate 30 of the electrode assembly 30 and the electrode leads 60 and 70 are connected to a plurality of electrode tabs 40 and 50 extending from each electrode plate, Respectively, and a part of the battery case 20 is exposed to the outside. An insulating film 80 is attached to the upper and lower surfaces of the electrode leads 60 and 70 in order to increase the degree of sealing with the battery case 20 and at the same time to ensure an electrically insulated state.

The battery case 20 is made of an aluminum laminate sheet, provides a space for accommodating the electrode assembly 30, and has a pouch shape as a whole. 1, a plurality of positive electrode tabs 40 and a plurality of negative electrode tabs 50 may be coupled to the electrode leads 60 and 70. In the stacked electrode assembly 30, The inner top is spaced from the electrode assembly 30.

In such a pouch-shaped battery, the electrode assembly is housed in a laminate sheet, and an electrolyte is injected to seal the electrode assembly by thermal fusion or the like. In the step of sealing the electrode assembly, There is a problem in that it is difficult to maintain a complete sealing state even after the heat fusion is performed due to excessive melting phenomenon and / or protrusion of the inner resin layer due to the pressurization, so that penetration of moisture is easy and there is a possibility of leakage of the electrolytic solution.

In addition, the pouch-shaped battery has a possibility that insulation breakdown may occur due to the metal layer being exposed at the end of the laminate sheet, which is a battery case, and moisture or the like may be infiltrated through the heat-sealed portion at the end.

In this regard, the prior art discloses a battery that attempts to insulate using a PET label and tape on the exterior of the sealing portion. However, when the outer surface of the sealing portion is insulated by using a PET label or a tape, peeling of the label or tape may occur, and defects such as bubbles or wrinkles may occur.

Accordingly, some prior arts disclose a pouch-type battery in which an insulating material such as an ultraviolet hardening agent is applied as a sealing adjuvant to the outside of the sealing portion and cured to improve the sealing property. However, since it is not easy to apply an insulating material such as an ultraviolet curing agent having a predetermined viscosity and fluidity to the outside of the sealing section on the thin vertical section, defects are likely to occur.

In particular, in the case of a battery case in which a sealing portion is vertically bent to form an outer appearance of the battery case, the vertical end portion of the sealing portion is uniformly formed in a straight line There is a problem in that the insulating material is difficult to be stably applied along the vertical end in the process of coating and that the effect of improving the sealing property of the battery is reduced by flowing down to the lower end. As a result, the technique is not suitable for actual mass production processes.

Accordingly, there is a high need for a technique that can fundamentally solve the problem of using an insulating material in order to improve the sealing property of a sealing portion in a pouch-type battery and to prevent an insulation breakdown phenomenon.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems of the prior art and the technical problems required from the past.

That is, an object of the present invention is to provide an apparatus for adding an insulating material to a sealing portion of a battery case, which is bent so as to face an outer surface of an electrode assembly receiving portion, and a sensing portion for sensing the shape of the sealing portion, And a controller for controlling the injecting position of the injected part by collecting the insulating material, thereby stably adding the insulating material along the shape of the unsealed sealing part, thereby causing moisture to penetrate into the sealing part or electrolyte leakage in the battery case And an object of the present invention is to provide a device capable of solving the problem of an insulation breakdown phenomenon caused by exposure of a metal layer of a battery case.

It is a further object of the present invention to provide a method for processing a battery cell which can solve the problems such as simplification of the process compared with the existing process and defective appearance and improve the yield and the high yield rate while facilitating the manufacturing process.

According to an aspect of the present invention,

An apparatus for adding an insulating material to a sealing portion of a battery case bent so as to face an outer surface of an electrode assembly receiving portion,

A jig having a depressed portion of a size corresponding to the battery cell;

A sensing unit for sensing the shape of the sealing part in a state where the battery cell is mounted on the jig;

An injecting portion including an end portion of the sealing portion for injecting an insulating material between the outer surface of the electrode assembly receiving portion and the inner wall of the indented portion of the jig; And

A control unit for collecting information sensed by the sensing unit and controlling an injection position of the injection unit;

As shown in FIG.

Therefore, as described above, in order to form the outer appearance of the battery cell, such a battery cell is vertically bent so that the sealing portion of the battery case faces the outer surface of the electrode assembly receiving portion, and the vertical end portion of the sealing portion is uniformly straight So that it is difficult for the insulating material to be stably applied along the vertical end portion in the process of coating, so that there is a high possibility that defects will occur.

According to another aspect of the present invention, there is provided an apparatus for inserting an insulating material into a sealing portion of a battery case which is bent so as to face an outer surface of an electrode assembly receiving portion, comprising a sensing portion for sensing the shape of the sealing portion, And a control unit for controlling the injection position of the injection unit by collecting information, thereby stably adding an insulating material along the shape of the unsealed sealing unit, thereby allowing moisture to penetrate into the sealing unit or electrolyte leakage in the battery case And the problem of the insulation breakdown phenomenon caused by the metal layer of the battery case being exposed is solved.

The apparatus according to the present invention can be suitably applied to a pouch-shaped battery cell in which a laminate sheet including a metal layer and a resin layer, for example, an aluminum laminate sheet pouch-shaped case,

In one specific example, the sensing unit may be configured to sense a position of the bent end of the sealing part in a state of being spaced apart by a predetermined distance so as not to be disturbed by the movement of the injection part.

Therefore, the injection unit may be constructed by injecting an insulating material while moving along the position of the end of the sealing unit by the signal of the control unit based on the information collected by the sensing unit. With this structure, the end of the sealing unit is uniformly The insulating material can be stably injected according to the shape of the sealing portion through the movement of the injection portion.

The insulating material may be an ultraviolet ray-curable material. Specifically, the ultraviolet ray-curable material may exhibit a high intermolecular bonding force when crosslinked by a chemical reaction upon irradiation of ultraviolet rays. For example, the material may be an unsaturated polyester- , And polyacrylate-based materials such as polyester acrylate, epoxy acrylate, and urethane acrylate, but are not limited thereto.

In one specific example, the ultraviolet ray-curable material may be a material having a hydrophilic functional group. By using an ultraviolet ray-curable material having a hydrophilic group, moisture contained in the battery is captured and the sealability is enhanced. At the same time, the penetration of moisture can be suppressed.

The UV curable material is injected between the outer surface of the electrode assembly receiving part and the inner wall of the indented part of the jig, and then cured by irradiating ultraviolet rays for a certain period of time. Therefore, the apparatus according to the present invention may be a structure further including an ultraviolet irradiation device for irradiating ultraviolet rays. The inner wall of the jig indent may be formed of Teflon coating, for example, to prevent the jig from adhering to the battery cell by the ultraviolet ray hardening material.

The battery cell according to the present invention is preferably a lithium ion secondary battery in which a lithium-containing electrolyte is impregnated in an electrode assembly, a lithium secondary battery such as a so-called lithium ion polymer battery in which an electrode assembly is impregnated with a lithium- Lt; / RTI >

Generally, a lithium secondary battery is composed of a positive electrode, a negative electrode, a separator, and a non-aqueous electrolyte containing a lithium salt.

The positive electrode is prepared, for example, by coating a mixture of a positive electrode active material, a conductive material and a binder on a positive electrode current collector, and then drying the mixture. Optionally, a filler may be further added to the mixture.

The cathode active material may be a layered compound such as lithium cobalt oxide (LiCoO ₂ ), lithium nickel oxide (LiNiO ₂ ), or a compound substituted with one or more transition metals; Lithium manganese oxides such as Li _{1 + x} Mn _{2 -x} O ₄ (where x is 0 to 0.33), LiMnO ₃ , LiMn ₂ O ₃ , LiMnO ₂ and the like; Lithium copper oxide (Li ₂ CuO ₂ ); Vanadium oxides such as LiV ₃ O ₈ , LiFe ₃ O ₄ , V ₂ O ₅ and Cu ₂ V ₂ O ₇ ; A Ni-site type lithium nickel oxide expressed by the formula LiNi _1-x M _x O ₂ (where M = Co, Mn, Al, Cu, Fe, Mg, B or Ga and x = 0.01 to 0.3); Formula _{LiMn 2-x M x O 2} ( where, M = Co, Ni, Fe , Cr, and Zn, or Ta, x = 0.01 ~ 0.1 Im) or Li ₂ Mn ₃ MO ₈ (where, M = Fe, Co, Ni, Cu, or Zn); LiMn ₂ O _{4 in} which a part of Li in the formula is substituted with an alkaline earth metal ion; Disulfide compounds; Fe ₂ (MoO ₄ ) ₃ , and the like. However, the present invention is not limited to these.

The conductive material is usually added in an amount of 1 to 30% by weight based on the total weight of the mixture including the cathode active material. Such a conductive material is not particularly limited as long as it has electrical conductivity without causing chemical changes in the battery, for example, graphite such as natural graphite or artificial graphite; Carbon black such as carbon black, acetylene black, ketjen black, channel black, furnace black, lamp black, and summer black; Conductive fibers such as carbon fiber and metal fiber; Metal powders such as carbon fluoride, aluminum, and nickel powder; Conductive whiskey such as zinc oxide and potassium titanate; Conductive metal oxides such as titanium oxide; Conductive materials such as polyphenylene derivatives and the like can be used.

The binder is a component which assists in bonding of the active material and the conductive material and bonding to the current collector, and is usually added in an amount of 1 to 30% by weight based on the total weight of the mixture containing the cathode active material. Examples of such binders include polyvinylidene fluoride, polyvinyl alcohol, carboxymethylcellulose (CMC), starch, hydroxypropylcellulose, regenerated cellulose, polyvinylpyrrolidone, tetrafluoroethylene, polyethylene , Polypropylene, ethylene-propylene-diene terpolymer (EPDM), sulfonated EPDM, styrene butylene rubber, fluorine rubber, various copolymers and the like.

The filler is optionally used as a component for suppressing the expansion of the anode, and is not particularly limited as long as it is a fibrous material without causing a chemical change in the battery. Examples of the filler include olefin polymers such as polyethylene and polypropylene; Fibrous materials such as glass fibers and carbon fibers are used.

The negative electrode is manufactured by applying and drying a negative electrode active material on a negative electrode collector, and if necessary, the above-described components may be selectively included.

Examples of the negative electrode active material include carbon such as non-graphitized carbon and graphite carbon; _{Li x Fe 2 O 3 (0≤x≤1} ), Li x WO 2 (0≤x≤1), Sn x Me 1-x Me 'y O z (Me: Mn, Fe, Pb, Ge; Me' : Metal complex oxides such as Al, B, P, Si, Group 1, Group 2, Group 3 elements of the periodic table, Halogen, 0 < x < Lithium metal; Lithium alloy; Silicon-based alloys; Tin alloy; _{SnO, SnO 2, PbO, PbO} 2, Pb 2 O 3, Pb 3 O 4, Sb 2 O 3, Sb 2 O 4, Sb 2 O 5, GeO, GeO 2, Bi 2 O 3, Bi 2 O 4, and Bi ₂ O ₅ ; Conductive polymers such as polyacetylene; Li-Co-Ni-based materials and the like can be used.

The separation membrane is interposed between the anode and the cathode, and an insulating thin film having high ion permeability and mechanical strength is used. The pore diameter of the separator is generally 0.01 to 10 mu m and the thickness is generally 5 to 300 mu m. Such separation membranes include, for example, olefinic polymers such as polypropylene, which are chemically resistant and hydrophobic; A sheet or nonwoven fabric made of glass fiber, polyethylene or the like is used. When a solid electrolyte such as a polymer is used as an electrolyte, the solid electrolyte may also serve as a separation membrane.

The non-aqueous electrolyte solution containing a lithium salt is composed of a polar organic electrolyte and a lithium salt. As the electrolytic solution, a non-aqueous liquid electrolytic solution, an organic solid electrolyte, an inorganic solid electrolyte and the like are used.

Examples of the nonaqueous liquid electrolytic solution include N-methyl-2-pyrrolidinone, propylene carbonate, ethylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, gamma -Butyrolactone, 1,2-dimethoxyethane, tetrahydroxyfuran, 2-methyltetrahydrofuran, dimethylsulfoxide, 1,3-dioxolane, formamide, dimethylformamide, dioxolane , Acetonitrile, nitromethane, methyl formate, methyl acetate, triester phosphate, trimethoxymethane, dioxolane derivatives, sulfolane, methylsulfolane, 1,3-dimethyl-2-imidazolidinone, propylene carbonate Nonionic organic solvents such as tetrahydrofuran derivatives, ethers, methyl pyrophosphate, ethyl propionate and the like can be used.

Examples of the organic solid electrolyte include a polymer electrolyte such as a polyethylene derivative, a polyethylene oxide derivative, a polypropylene oxide derivative, a phosphate ester polymer, an agitation lysine, a polyester sulfide, a polyvinyl alcohol, a polyvinylidene fluoride, Polymers containing ionic dissociation groups, and the like can be used.

Examples of the inorganic solid electrolyte include Li ₃ N, LiI, Li ₅ NI ₂ , Li ₃ N-LiI-LiOH, LiSiO ₄ , LiSiO ₄ -LiI-LiOH, Li ₂ SiS ₃ , Li ₄ SiO ₄ , Nitrides, halides and sulfates of Li such as Li ₄ SiO ₄ -LiI-LiOH and Li ₃ PO ₄ -Li ₂ S-SiS ₂ can be used.

The lithium salt is a material that is readily soluble in the non-aqueous electrolyte, for example, LiCl, LiBr, LiI, LiClO 4, LiBF 4, LiB 10 Cl 10, LiPF 6, LiCF 3 SO 3, LiCF 3 CO 2, LiAsF _{6, LiSbF 6, LiAlCl 4,} CH 3 SO 3 Li, CF 3 SO 3 Li, (CF 3 SO 2) 2 NLi, chloroborane lithium, lower aliphatic carboxylic acid lithium, lithium tetraphenyl borate and imide have.

For the purpose of improving the charge-discharge characteristics and the flame retardancy, the non-aqueous liquid electrolyte may contain, for example, pyridine, triethylphosphite, triethanolamine, cyclic ether, ethylenediamine, glyme, N, N-substituted imidazolidine, ethylene glycol dialkyl ether, ammonium salt, pyrrole, 2-methoxyethanol, aluminum trichloride, etc. are added It is possible. In some cases, a halogen-containing solvent such as carbon tetrachloride or ethylene trifluoride may be further added to impart nonflammability, or a carbon dioxide gas may be further added to improve high-temperature storage characteristics.

On the other hand, the present invention provides a method for processing a battery cell using the above apparatus,

(a) bending each of the sealing portions of the battery case so as to face the outer surface of the electrode assembly receiving portion;

(b) inserting and fixing a battery cell in which a sealing portion of the battery case is folded, in a jig having a recessed portion of a size corresponding thereto, in step (a);

(c) sensing the shape of the sealing portion and adding an insulating material in the attraction portion according to a signal from the control portion; And

(d) curing the insulating material added in the step (c);

The method of manufacturing a battery cell can be provided.

The present invention also provides a battery cell characterized by being processed by the above method.

The secondary battery may be used in a battery cell used as a power source of a small device, or as a unit cell in a battery pack including a plurality of battery cells used as a power source of the device.

Preferred examples of the device include but are not limited to a notebook, a mobile phone, a PDP, a PMP, an MP3 player, a digital still camera (DSC), a DVR, a smart phone, a GPS system and a camcorder.

As described above, the apparatus according to the present invention includes a sensing unit for sensing the shape of the sealing portion, an apparatus for adding an insulating material to the sealing portion of the battery case, which is bent to face the outer surface of the electrode assembly receiving portion, And a control unit for collecting information sensed by the sensing unit and controlling the injection position of the injection unit, thereby stably adding an insulating material along the shape of the non-uniform sealing unit to allow moisture to penetrate into the sealing unit, It is possible to provide a device capable of solving the problem of leakage of the electrolyte and the problem of the insulation breakdown phenomenon caused by exposing the metal layer of the battery case.

1 is an exploded perspective view of a general structure of a conventional pouch-shaped battery;
2 is a schematic diagram illustrating an apparatus according to one embodiment of the present invention;
3 is a cross-sectional view of a battery cell according to an embodiment of the present invention in which the sealing portion of the case is in close contact with the side wall of the receiving portion;
4 is a schematic diagram showing a method of processing a battery cell using an apparatus according to one embodiment of the present invention;
5 is a side view of the region A in Fig.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings, but the present invention is not limited by the scope of the present invention.

2 is a schematic diagram illustrating an apparatus according to one embodiment of the present invention.

2, a device 200 according to the present invention includes a jig 210 having an indentation 290 sized to correspond to a battery cell (not shown), a jig 210 having a battery cell mounted A sensing unit 220 for sensing the shape of the planned injection unit, a generation unit 230 for injecting an insulating material into the injection unit, and a sensing unit 220. The sensing unit 230 collects information sensed by the sensing unit 220, And an ultraviolet ray irradiating device 240 for irradiating ultraviolet rays to the upper end of the indentation part 290. The sensing part 220, The ultraviolet irradiating apparatus 240 is coupled to the lower support member 252 in a state where the ultraviolet irradiating apparatus 240 is mounted on the upper support member 251 which is movable separately from the jig 210. [

3 is a cross-sectional view schematically showing a structure in which a sealing portion of a case is in close contact with a side wall of a receiving portion in a battery cell according to an embodiment of the present invention.

3, the battery cell 100 includes an electrode assembly (not shown) having a positive electrode / separator / negative electrode structure mounted on the housing portion 112 of the first sheet-type case 110, 120 are thermally fused to each other through a predetermined process. The first sheet-shaped case 110 and the second sheet-shaped case 120 may be a single unit or an independent unit of two units.

The sealing portions 130 and 140 are formed in the outer circumferential direction of the housing portion 112 in the thermal fusion process and the two side sealing portions 130 and 140 are bent at the adjacent portions of the housing portion 112, (112a).

FIG. 4 is a schematic view of a method of processing a battery cell using an apparatus according to an embodiment of the present invention, and FIG. 5 is a schematic view of a side view of a portion A in FIG.

Referring to FIG. 4 together with FIG. 2, the battery cell 100 is mounted and fixed to a jig 210 having a depression 290 formed therein, The shape of the cell 100 and the size thereof.

Since the vertical end 310 of the sealing portion of the battery cell 100 is formed by thermally fusing a case of a laminated sheet material having a low mechanical rigidity, it is not uniformly formed in a straight line but forms a fine bend.

Hereinafter, a method of processing a battery cell using an apparatus including a jig according to the present invention will be described.

First, the sensing unit 220 senses the shape of the vertical end 310 of the sealing unit and adds ultraviolet ray-curable material to the injection unit 230 according to a signal from the control unit. At this time, (FIG. 5: 400) through the ultraviolet ray irradiating device 240 after curing the ultraviolet ray-curable material (FIG. 5: 400) by stably moving the ultraviolet ray- ).

5, the ultraviolet ray-curable material 400 is injected to be applied along the sealing vertical end 310 of the battery cell 100, wherein the amount of the ultraviolet ray- 100). ≪ / RTI >

The apparatus 200 having such a structure is configured such that the curable material 400 is applied and coated on a part of the end of the sealing portion of the battery cell 100 and at the same time the outer side wall 150 of the battery cell 100 and the inner side wall of the jig 210, The outer side wall 150 of the battery cell 100 may be completely enclosed between the battery cells 100 and 260 and then cured. Thus, the outer cell of the battery cell 100 may be formed in a gentle shape

Accordingly, as described above, since the injection part 130 is moved according to the position of the vertical end surface 310 of the sealing part to inject the insulating material, the operation is easy and the end part 310 of the sealing part is formed in a straight line The curable material can be stably applied and then cured to gently form the outer portion of the battery cell 100, thereby significantly improving the production yield of the battery and the efficiency of the manufacturing process.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (16)

An apparatus for adding an insulating material to a sealing portion of a battery case bent so as to face an outer surface of an electrode assembly receiving portion,
A jig having a depressed portion of a size corresponding to the battery cell;
A sensing unit for sensing the shape of the sealing part in a state where the battery cell is mounted on the jig;
An injecting portion including an end portion of the sealing portion for injecting an insulating material between the outer surface of the electrode assembly receiving portion and the inner wall of the indented portion of the jig; And
A control unit for collecting information sensed by the sensing unit and controlling an injection position of the injection unit;
Lt; / RTI >
Wherein the battery case is made of a laminate sheet including a resin layer and a metal layer,
Wherein the sensing portion senses the position of the end of the folded sealing portion. delete The apparatus of claim 1, wherein the laminate sheet is an aluminum laminate sheet. The apparatus of claim 1, wherein the sensing unit is spaced apart from the sensing unit by a predetermined distance so as not to be disturbed by the movement of the stimulation unit. delete The apparatus according to claim 1, wherein the injection unit injects the insulating material along the position of the end of the sealing unit by the signal of the control unit based on the information collected by the sensing unit. The apparatus of claim 1, wherein the insulating material is an ultraviolet curable material. 8. The apparatus of claim 7, wherein the ultraviolet curable material is a material having a hydrophilic functional group. The apparatus of claim 7, wherein the ultraviolet curable material is an unsaturated polyester-based material or a polyacrylate-based material. The apparatus according to claim 1, wherein the apparatus further comprises an ultraviolet light irradiation device for irradiating ultraviolet light. The apparatus of claim 1, wherein Teflon is coated on the inner surface of the recessed portion of the jig. 11. A method of processing a battery cell using an apparatus according to any one of claims 1, 3, 4, and 6 to 11,
(a) bending each of the sealing portions of the battery case so as to face the outer surface of the electrode assembly receiving portion;
(b) inserting and fixing a battery cell in which a sealing portion of the battery case is folded, in a jig having a recessed portion of a size corresponding thereto, in step (a);
(c) sensing the shape of the sealing portion and adding an insulating material in the attraction portion according to a signal from the control portion; And
(d) curing the insulating material added in the step (c);
And a plurality of battery cells. delete delete delete delete

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