Battery cell with insulating film preventing short circuit due to condensation and battery module including the same

Abstract

To provide a battery cell with an insulating film that prevents a short circuit due to condensation, and a battery module including the same.SOLUTION: A battery cell includes a pouch case, an electrode assembly housed in the pouch case and including a negative electrode, a positive electrode, and a separator interposed between the negative and positive electrodes, a pair of electrode leads including a negative electrode lead and a positive electrode lead, and a pair of insulating films including a negative electrode insulating film interposed between an inner surface of a pouch case sealing portion and the negative electrode lead, and a positive electrode insulating film interposed between the inner surface of the pouch case sealing portion and the positive electrode lead. The negative electrode insulating film and / or the positive electrode insulating film includes a non-overlapping portion exposed to the outside of the pouch case sealing portion, and the non-overlapping portion has a flow path through which dew moves. The present invention relates to the battery cell having the insulating film capable of preventing short circuits due to dew condensation, and a battery module including the same.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] This application claims the benefit of priority based on Korean Patent Application No. 10-2022-0177032, filed December 16, 2022, and all contents disclosed in the Korean Patent Application are incorporated herein by reference.

[0002] The present invention relates to a battery cell having an insulating film capable of preventing short circuits caused by condensation, and a battery module including the same. More specifically, the present invention relates to a battery cell having an insulating film capable of preventing short circuits caused by condensation, and a battery module including the same, which can significantly reduce the possibility of short circuits caused by condensation by forming a flow path, a water-repellent coating layer, or a barrier in the insulating film provided between a pouch case and an electrode lead. [Background technology]

[0003] Recently, due to air pollution and energy depletion caused by the use of fossil fuels, there has been an increasing demand for secondary batteries that can store electrical energy produced by the development of alternative energy sources. Rechargeable secondary batteries are widely used in daily life, such as in mobile devices, electric vehicles, and hybrid electric vehicles.

[0004] Secondary batteries are used as energy sources for various electronic devices that are essential in modern society, and the required capacity is increasing due to the increasing use and complexity of mobile devices and the development of electric vehicles, etc. To meet user demands, small devices are equipped with multiple battery cells, while automobiles and the like use battery modules in which multiple battery cells are electrically connected, or battery packs equipped with multiple such battery modules.

[0005] Meanwhile, condensation can occur inside battery modules and battery packs due to temperature differences with the outside during use. Condensation occurs when the temperature of moist air drops below the dew point, causing the moisture contained in the air to form droplets on the surface of an object. This phenomenon primarily occurs when the internal temperature of a secondary battery becomes lower than the surrounding area.

[0006] The condensation formed in this way can cause abnormal operation of the secondary battery. For example, when condensation occurs in a pouch-type battery cell, an electrical short circuit occurs due to capillary action between the pouch case including the metal layer and the electrode lead, which can result in a shortened lifespan of the battery cell or lead to a fire.

[0007] In this regard, Patent Document 1 discloses a secondary battery equipped with an insulating film for preventing dew flow. As shown in Fig. 1, which is a plan view of a battery cell equipped with an insulating film for preventing dew flow, insulating film 40 is exposed to the outside of bonding interface 11 between electrode leads 20, 30 and pouch outer casing 10, and grooves 41 are formed on the side and top surfaces of the portions that do not overlap with electrode leads 20, 30 to prevent short circuits due to dew condensation.

[0008] By using an insulating film with grooves formed therein, as in Patent Document 1, a certain level of short-circuit prevention can be expected, but since the grooves are formed only on a portion of the edge of the insulating film, there is still a high risk of short-circuits due to condensation.

[0009] In particular, when battery cells are vertically assembled into a battery module or a battery pack, the structure allows condensation that occurs to easily move to the electrode leads. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] Korean Patent Publication No. 10-2013-0036991 Summary of the Invention [Problem to be solved by the invention]

[0011] In order to solve the above problems, an object of the present invention is to provide a battery cell having an insulating film that functions to prevent short circuits caused by condensation by reliably blocking condensation generated outside a battery cell case from moving to electrode leads, and a battery module including the same. [Means for solving the problem]

[0012] To achieve the above object, the battery cell according to the present invention comprises a pouch case (100) having a storage space made of a laminate sheet, an electrode assembly (200) accommodated in the pouch case (100) and including a negative electrode (210) having a negative electrode tab (211), a positive electrode (220) having a positive electrode tab (221), and a separator (230) interposed between the negative electrode (210) and the positive electrode (220), and a pair of electrode leads including a negative electrode lead (310) electrically connected to the negative electrode tab (211) and a positive electrode lead (320) electrically connected to the positive electrode tab (221). and a pair of insulating films (400) consisting of a negative electrode insulating film (410) interposed between the inner surface of the sealing part of the pouch case (100) and the negative electrode lead (310), and a positive electrode insulating film (420) interposed between the inner surface of the sealing part of the pouch case (100) and the positive electrode lead (320), wherein the negative electrode insulating film (410) and / or the positive electrode insulating film (420) have a non-overlapping portion exposed to the outside of the sealing part of the pouch case (100), and the non-overlapping portion has a flow path through which dew moves.

[0013] In addition, in the battery cell according to the present invention, the negative electrode non-overlapping portion (412) of the negative electrode insulating film (410) is characterized by having a first flow path (412a) through which dew moves in a direction perpendicular to the negative electrode lead (310), and the positive electrode non-overlapping portion (422) of the positive electrode insulating film (420) is characterized by having a third flow path (422a) through which dew moves in a direction perpendicular to the positive electrode lead (320).

[0014] In the battery cell according to the present invention, the cross sections of the first flow passage (412a) and the third flow passage (422a) are hemispherical, triangular or rectangular, and both ends thereof are open.

[0015] In the battery cell according to the present invention, the negative electrode non-overlapping portion 412 further includes a second passage (412b) spaced apart in parallel from the first passage (412a) at a predetermined interval.

[0016] The first flow path (412a) and the second flow path (412b) have different cross-sectional areas.

[0017] In the battery cell according to the present invention, the positive electrode non-overlapping portion (422) further includes a fourth flow path (422b) spaced apart in parallel from the third flow path (422a) at a predetermined interval.

[0018] In the battery cell according to the present invention, the third flow path (422a) and the fourth flow path (422b) have different cross-sectional areas.

[0019] In addition, in the battery cell according to the present invention, the negative electrode non-overlapping portion (412) is provided with a first water-repellent coating layer (412c) so as not to overlap with the first flow path (412a), and the positive electrode non-overlapping portion (422) is provided with a second water-repellent coating layer (422c) so as not to overlap with the third flow path (422a).

[0020] In addition, in the battery cell according to the present invention, the first water-repellent coating layer (412c) is provided along the edge in a direction perpendicular to the negative electrode lead (310), and the second water-repellent coating layer (422c) is provided along the edge in a direction perpendicular to the positive electrode lead (320).

[0021] In the battery cell according to the present invention, the negative electrode non-overlapping portion (412) is characterized by including a first blocking band (412d) along the edge in a direction perpendicular to the negative electrode lead (310).

[0022] In the battery cell according to the present invention, the positive electrode non-overlapping portion (422) is characterized by having a second cutoff band (422d) along the edge in a direction perpendicular to the positive electrode lead (320).

[0023] The present invention also provides a battery module including the above-described battery cell.

[0024] In addition, the method for manufacturing a battery cell according to the present invention includes a first step of preparing a pouch case (100) having a storage space for storing an electrode assembly (200); a second step of attaching a negative electrode insulating film (410) and a positive electrode insulating film (420) to a negative electrode lead (310) and a positive electrode lead (320) electrically connected to the electrode assembly (200), respectively; and a third step of storing the electrode assembly (200) in the storage space of the pouch case (100) and then sealing the edges of the pouch case (100). The negative electrode insulating film (410) and / or the positive electrode insulating film (420) have a non-overlapping portion exposed to the outside of the sealing portion of the pouch case (100), the negative electrode non-overlapping portion (412) of the negative electrode insulating film (410) has a first flow path (412a) through which dew moves in a direction perpendicular to the negative electrode lead (310), and the positive electrode non-overlapping portion (422) of the positive electrode insulating film (420) has a third flow path (422a) through which dew moves in a direction perpendicular to the positive electrode lead (320). [Effects of the Invention]

[0025] As described above, the battery cell and battery module including the insulating film of the present invention that have the function of preventing short circuits due to condensation have the advantage that the non-overlapping portion of the insulating film exposed to the outside of the pouch case has a flow path that allows condensation to move in a direction perpendicular to the electrode leads, thereby significantly reducing the possibility of short circuits due to condensation.

[0026] In addition, according to the battery cell equipped with the insulating film for preventing dew flow of the present invention and the battery module including the same, a water-repellent coating layer is formed on the non-overlapping portion of the insulating film exposed to the outside of the pouch case, which has the advantage of significantly reducing the possibility of short circuits due to dew condensation.

[0027] Furthermore, the battery cell and battery module including the insulating film for preventing dew flow of the present invention have a shielding band in the non-overlapping portion of the insulating film exposed to the outside of the pouch case, which has the advantage of significantly reducing the possibility of short circuits due to dew condensation. [Brief explanation of the drawings]

[0028] [Figure 1] 1 is a plan view of a battery cell equipped with an insulating film for preventing dew flow according to the prior art; [Figure 2] 1 is an exploded perspective view of a battery cell according to a first preferred embodiment of the present invention. [Figure 3] 3 is a plan view of the electrode assembly shown in FIG. 2 with an insulating film attached to the electrode lead. [Figure 4] FIG. 4 is a cross-sectional view taken along line AA in FIG. 3. [Figure 5] 10 is a plan view showing a state in which an insulating film is attached to an electrode lead of an electrode assembly according to a second preferred embodiment of the present invention; FIG. [Figure 6] FIG. 6 is a cross-sectional view taken along line BB in FIG. 5. [Figure 7] 10 is a plan view showing a state in which an insulating film is attached to an electrode lead of an electrode assembly according to a third preferred embodiment of the present invention. FIG. [Figure 8] FIG. 8 is a cross-sectional view taken along line CC in FIG. 7. [Figure 9] 10 is a plan view showing a state in which an insulating film is attached to an electrode lead of an electrode assembly according to a fourth preferred embodiment of the present invention. FIG. [Figure 10] FIG. 10 is a cross-sectional view taken along line DD in FIG. 9. [Figure 11] 1 is a perspective view of a battery module containing battery cells according to the present invention; [Figure 12] 3 is a flowchart illustrating a method for manufacturing a battery cell according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0029] Hereinafter, with reference to the accompanying drawings, a detailed description will be given of an embodiment of the present invention that will enable a person of ordinary skill in the art to easily carry out the present invention. However, in describing the operation principle of the preferred embodiment of the present invention in detail, detailed description of related well-known functions or configurations will be omitted if it is determined that such detailed description may unnecessarily obscure the gist of the present invention.

[0030] Furthermore, the same reference numerals are used throughout the drawings for parts having similar functions and actions. Throughout the specification, when a part is said to be connected to another part, this includes not only a direct connection but also an indirect connection via another element therebetween. Furthermore, unless otherwise specified, "including a certain element" does not mean that other elements are excluded, but that other elements may also be included.

[0031] Hereinafter, a battery cell having an insulating film capable of preventing short circuits due to condensation and a battery module including the same according to the present invention will be described with reference to the accompanying drawings.

[0032] FIG. 2 is an exploded perspective view of a battery cell according to a first preferred embodiment of the present invention, FIG. 3 is a plan view of the electrode assembly shown in FIG. 2 with insulating films attached to the electrode leads, and FIG. 4 is a cross-sectional view taken along line AA in FIG. 3.

[0033] As shown in FIGS. 2 to 4, the battery cell according to the present invention includes a pouch case 100, an electrode assembly 200, an electrode lead 300, and an insulating film 400.

[0034] First, the pouch case 100 is composed of a lower case and an upper case, and has a pocket-shaped receiving space formed therein so that the electrode assembly 200 can be received therein.

[0035] In such a pouch case 100, the storage section is formed using a laminate sheet made up of an outer resin layer 110, a metal layer 120, and an inner resin layer .

[0036] In particular, the outer resin layer 110 located at the outermost periphery of the pouch case 100 may be made of a heat-resistant polymer having excellent tensile strength, moisture-proofing, and air-proofing properties so as to protect the electrode assembly 200 while ensuring heat resistance and chemical resistance. Examples of the material include, but are not limited to, nylon or polyethylene terephthalate.

[0037] The metal layer 120 located between the outer resin layer 110 and the inner resin layer 130 corresponds to a barrier layer that prevents moisture and various gases from penetrating into the interior of the battery, and a suitable material for such metal layer 120 is an aluminum thin film, which is lightweight yet has excellent formability.

[0038] The inner resin layer 130, located at the innermost side of the pouch case 100, is in direct contact with the electrode assembly 200 and therefore must have insulating properties and electrolysis resistance. It must also have sealing properties to seal it from the outside, i.e., the sealing areas where the inner layers are thermally bonded together must have excellent thermal adhesive strength.

[0039] The material of the inner resin layer 130 may be selected from polyolefin resins such as polypropylene, polyethylene, polyethylene acrylic acid, and polybutylene, which have excellent chemical resistance and sealing properties, polyurethane resins, and polyimide resins, but is not limited thereto. Polypropylene is most preferred because of its excellent mechanical properties such as tensile strength, rigidity, surface hardness, and impact resistance, as well as chemical resistance.

[0040] For example, although FIG. 2 shows the storage space being provided in both the upper case and the lower case, it is obvious that the storage space may be provided in only one of the upper case or the lower case.

[0041] Next, the electrode assembly 200 will be described. The electrode assembly 200 seated in the receiving space of the pouch case 100 may be, but is not limited to, a jelly-roll type electrode assembly in which a separator 230 is interposed between long sheet-shaped negative electrodes 210 and positive electrodes 220 and then wound up, a stack type electrode assembly composed of unit cells in which rectangular negative electrodes 210 and positive electrodes 220 are stacked with a separator 230 interposed therebetween, a stack folding type electrode assembly in which unit cells are wound up with a long separator film, or a lamination stack type electrode assembly in which unit cells are stacked with a separator interposed therebetween and then attached to each other.

[0042] Specifically, the negative electrode 210 is manufactured by applying a slurry containing a negative electrode active material and a binder to a negative electrode current collector.

[0043] Here, examples of the negative electrode active material include carbon such as non-graphitizable carbon and graphite-based carbon; Li x Fe2O3(0≦x≦1), Li x WO2(0≦x≦1), Sn x Me 1-x Me' y O z(Me: Mn, Fe, Pb, Ge; Me’: Al, B, P, Si, Group 1, Group 2, Group 3 elements of the periodic table, halogen; 0 < x ≤ 1; 1 ≤ y ≤ 3; 1 ≤ z ≤ 8), etc. metal composite oxides; lithium metal; lithium alloy; silicon-based alloy; tin-based alloy; metal oxides such as SnO, SnO2, PbO, PbO2, Pb2O3, Pb3O4, Sb2O3, Sb2O4, Sb2O5, GeO, GeO2, Bi2O3, Bi2O4, Bi2O5; conductive polymers such as polyacetylene; Li-Co-Ni-based materials; Si-based materials which are Si, SiO, SiO2 alone or mixtures thereof, etc. can be used, but are not limited to only these.)

[0044] The positive electrode 220 is manufactured by applying a slurry in which a positive electrode active material and a binder are mixed to a positive electrode current collector.

[0045] Here, as the positive electrode active material, layered compounds such as lithium cobalt oxide (LiCoO2), lithium nickel oxide (LiNiO2) or compounds substituted with one or more transition metals; chemical formula Li 1+x Mn 2-x O4 (where x is 0 to 0.33), lithium manganese oxides such as LiMnO3, LiMn2O3, LiMnO2; lithium copper oxide (Li2CuO2); vanadium oxides such as LiV3O8, LiV3O4, V2O5, Cu2V2O7; chemical formula LiNi 1-x MxO2 (where M = Co, Mn, Al, Cu, Fe, Mg, B or Ga and x = 0.01 to 0.3), Ni-site type lithium nickel oxides represented by; chemical formula LiMn 2-x M x O2 (where M = Co, Ni, Fe, Cr, Zn or Ta and x = 0.01 to 0.1) or lithium manganese composite oxides represented by Li2Mn3MO8 (where M = Fe, Co, Ni, Cu or Zn); LiMn2O4 in which a part of the Li in the chemical formula is substituted with an alkaline earth metal ion; disulfide compounds; Fe2(MoO4)3, etc. can be mentioned, but are not limited to only these.

[0046] Meanwhile, the negative electrode current collector and the positive electrode current collector include a portion coated with a slurry containing an active material and a plain portion where the slurry is not coated. A pair of electrode tabs, i.e., a negative electrode tab 211 and a positive electrode tab 221, are formed by cutting the plain portion or by connecting a separate conductive member to the plain portion by ultrasonic welding or the like.

[0047] Furthermore, a separator 230, which is disposed between the positive electrode 220 and the negative electrode 210 or on the outside of the negative electrode 210, is an insulating thin film having high ion permeability and mechanical strength. The pore diameter of the separator 230 is generally 0.01 μm to 10 μm, and the thickness is generally 5 μm to 300 μm. The separator 230 may be, for example, a sheet or nonwoven fabric made of a chemically resistant and hydrophobic olefin polymer such as polypropylene, glass fiber, or polyethylene, but is not limited thereto.

[0048] A pair of electrode leads 300 consisting of a negative electrode lead 310 and a positive electrode lead 320 are electrically connected to a negative electrode tab 211 and a positive electrode tab 221, respectively, and then exposed to the outside of the pouch case 100.

[0049] Here, the electrode lead 300 and the pair of tabs can be electrically connected by welding, for example, ultrasonic welding. Connection by ultrasonic welding is achieved by applying high-frequency vibrations generated by high-frequency ultrasonic waves of approximately 20 kHz, and the vibration energy is converted into heat energy through friction by the operation of a horn and anvil at the interface between the electrode tabs and the electrode lead, thereby rapidly welding them. Of course, the method is not limited to ultrasonic welding, as long as it can weld the tab bundle and the lead to electrically connect them.

[0050] For example, although not shown in the drawings, a protective tape (not shown) for wrapping the overlapping portion of the electrode tab and the electrode lead may be provided.

[0051] Since the electrode tabs and electrode leads are connected by welding, the surfaces of the electrode tabs and electrode leads may not be smooth, which may lead to poor insulation.

[0052] In other words, if the welded surface is not smooth, and an impact causes contact between the welded portion and the pouch case, the inner resin layer will peel off, exposing the metal layer, resulting in poor insulation. Therefore, it is preferable to wrap the welded portion with protective tape to prevent the above-mentioned poor insulation.

[0053] Here, the protective tape is made of an insulating material, for example, polypropylene, polyethylene, polyester, or polyimide material, and is not limited to these, as long as it is a material that can wrap the welded portion and maintain an insulating state when in contact with the pouch case.

[0054] Next, the insulating film 400 will be described. The insulating film 400 is provided at the sealing portion of the pouch case 100, i.e., at the position where the edge of the pouch case 100 to be sealed for hermetic sealing overlaps with the electrode lead 300. This insulating film 400 can maintain the sealing of the pouch case 100 while preventing electricity generated in the electrode assembly 200 from flowing to the pouch case 100 via the electrode lead 300.

[0055] In detail, in order to prevent the pouch case 100 and the negative electrode lead 310 from coming into direct contact with each other, the negative electrode insulating film 410 comprises a negative electrode overlapping portion 411 located where the negative electrode lead 310 and the sealing portion of the pouch case 100 overlap each other, and a negative electrode non-overlapping portion 412 exposed to the outside of the sealing portion of the pouch case 100.

[0056] In addition, in the case of the positive electrode insulating film 420, in order to prevent the pouch case 100 and the positive electrode lead 320 from coming into direct contact with each other, the film may also include a positive electrode overlapping portion 421 located where the positive electrode lead 320 and the sealing portion of the pouch case 100 overlap each other, and a positive electrode non-overlapping portion 422 exposed to the outside of the sealing portion of the pouch case 100.

[0057] Here, it is preferable that the negative electrode non-overlapping portion 412 or the positive electrode non-overlapping portion 422 has a flow path for guiding dew to flow in a desired direction, and it is more preferable that the negative electrode non-overlapping portion 412 has a first flow path 412a and the positive electrode non-overlapping portion 422 has a third flow path 422a.

[0058] Here, the first flow path 412a of the negative electrode non-overlapping portion 412 is formed in a direction perpendicular to the negative electrode lead 310, and the third flow path 422a of the positive electrode non-overlapping portion 422 is formed in a direction perpendicular to the positive electrode lead 320. This is to guide dew downward along the flow path while preventing it from moving toward the leads when the battery cell is installed vertically.

[0059] The flow paths of the present invention correspond to long passages through which generated dew can flow directly into the flow paths or can induce the movement of dew by capillary action. Therefore, as long as the direction of dew flow can be determined, the cross-sectional shapes of the first flow path 412a and the third flow path 422a are not particularly limited, and may be, for example, hemispherical, triangular, or rectangular, and the width and depth may range from several tens of nanometers (nm) to several micrometers (μm).

[0060] Both ends are preferably open so that the generated dew flows into the first flow path 412a and the third flow path 422a and then is discharged or flows in contact with the flow paths.

[0061] The insulating film 400 is preferably made of a non-conductive material that does not conduct electricity well, and is generally made of insulating tape that is easily attached to the electrode lead and has a relatively thin thickness, but is not limited to this.

[0062] Specifically, the insulating film is made of one or more materials selected from the group consisting of polyimide (PI), polypropylene (PP), polyethylene (PE), polyethylene terephthalate (PET), polyvinyl chloride (PVC), high density polyethylene (HDPE), and epoxy resin, and is thermally fused and bonded to the inner resin layer of the pouch case using heat and pressure.

[0063] FIG. 5 is a plan view showing a state in which an insulating film is attached to an electrode lead of an electrode assembly according to a second preferred embodiment of the present invention, and FIG. 6 is a cross-sectional view taken along line BB in FIG.

[0064] Except for the insulating film, the rest is the same as in Example 1, so only the insulating film will be described below.

[0065] In the second embodiment of the present invention, a plurality of flow channels are formed in each of the negative electrode non-overlapping portion 412 and the positive electrode non-overlapping portion 422.

[0066] Taking the case of two channels as an example, the negative electrode non-overlapping portion 412 of the negative electrode insulating film 410 includes a first channel 412a and a second channel 412b. The first channel 412a and the second channel 412b are preferably spaced apart in parallel at a regular interval, and the cross-sectional area of ​​the first channel 412a located relatively inward is preferably larger than that of the second channel 412b located at the edge, so as to minimize the transfer of dew to the negative electrode lead 310.

[0067] In addition, the positive electrode non-overlapping portion 422 of the positive electrode insulating film 420 also has a third flow path 422a and a fourth flow path 422b, and since their positions, cross-sectional areas, etc. are the same as those of the first flow path 412a and the second flow path 412b of the negative electrode non-overlapping portion 412, redundant explanations will be omitted.

[0068] FIG. 7 is a plan view showing a state in which an insulating film is attached to an electrode lead of an electrode assembly according to a third preferred embodiment of the present invention, and FIG. 8 is a cross-sectional view taken along line CC in FIG.

[0069] Except for the insulating film, the rest is the same as in Example 1, so only the insulating film will be described below.

[0070] In the third embodiment of the present invention, a water-repellent coating layer is further formed on each of the negative electrode non-overlapping portion 412 and the positive electrode non-overlapping portion 422.

[0071] In detail, it is preferable that the negative electrode non-overlapping portion 412 is provided with a first water-repellent coating layer 412c so as not to overlap with the first flow path 412a, and it is more preferable that the first water-repellent coating layer 412c is provided along the edge portion in a direction perpendicular to the negative electrode lead 310.

[0072] In this way, when the first water-repellent coating layer 412c is formed on the negative electrode non-overlapping portion 412, dew can be prevented from flowing onto the negative electrode lead 310 more reliably.

[0073] Similarly, the positive electrode non-overlapping portion 422 also preferably has a second water-repellent coating layer 422c so as not to overlap with the third flow path 422a, and it is more preferable that the second water-repellent coating layer 422c is provided along the edge in a direction perpendicular to the positive electrode lead 320.

[0074] Here, the water-repellent coating material may be a known water-repellent material such as a fluorine-based compound or a silane-based compound, and the coating layer may be formed by a dip coating method or a spray coating method.

[0075] For example, in Example 3, a water-repellent coating layer is formed on a non-overlapping portion having a single flow path, but it is obvious that a water-repellent coating layer can also be formed on a non-overlapping portion having two or more flow paths, as in Example 2.

[0076] FIG. 9 is a plan view showing a state in which an insulating film is attached to an electrode lead of an electrode assembly according to a fourth preferred embodiment of the present invention, and FIG. 10 is a cross-sectional view taken along line DD in FIG.

[0077] Except for the insulating film, the rest is the same as in Example 1, so only the insulating film will be described below.

[0078] In the fourth embodiment of the present invention, a blocking band is further formed in each of the negative electrode non-overlapping portion 412 and the positive electrode non-overlapping portion 422.

[0079] In detail, the negative electrode non-overlapping portion 412 has a first blocking band 412d along its edge in a direction perpendicular to the negative electrode lead 310, while the positive electrode non-overlapping portion 422 has a second blocking band 422d along its edge in a direction perpendicular to the positive electrode lead 320.

[0080] In this way, when the negative electrode non-overlapping portion 412 and the positive electrode non-overlapping portion 422 are provided with the first blocking band 412d and the second blocking band 422d, respectively, a step is created, which can contribute to preventing dew from flowing onto the negative electrode lead 310 and the positive electrode lead 320.

[0081] For example, in Example 4, a case where a blocking zone is formed in a non-overlapping section having a single flow path is described, but it is obvious that a blocking zone can also be formed in a non-overlapping section having two or more flow paths, as in Example 2.

[0082] Fig. 11 is a perspective view of a battery module 2000 that houses battery cells according to the present invention. As shown in Fig. 11, a battery module 2000 houses a plurality of battery cells 1000 inside a module case 2100 that has a housing space.

[0083] Here, the battery cells 1000 are battery cells having one or more of the flow paths, water-repellent coating layers, and barriers on an insulating film as described in Examples 1 to 4, and are housed in a vertically aligned state against the bottom surface of the module case 2100.

[0084] Even if condensation occurs due to temperature changes, the condensation flows downward due to the flow path of the insulating film, the water-repellent coating layer, and the barrier, thereby preventing short circuits due to condensation. For example, although not shown in the drawings, a passage for discharging the condensation that flows downward to the outside may be further provided in module case 2100.

[0085] 12 is a flowchart illustrating a method for manufacturing a battery cell according to the present invention. The method for manufacturing a battery cell according to the present invention may include a first step of preparing a pouch case having an accommodation space for accommodating an electrode assembly, a second step of attaching an anode insulating film and a cathode insulating film to an anode lead and a cathode lead electrically connected to the electrode assembly, respectively, and a third step of accommodating the electrode assembly in the accommodation space of the pouch case and then sealing an edge of the pouch case.

[0086] Meanwhile, prior to attaching the electrode leads and insulating films, it is preferable to preliminarily form one or more of a flow path, a water-repellent coating layer, and a shielding band in the non-overlapping portion of the negative electrode insulating film and the positive electrode insulating film, i.e., the portion exposed to the outside of the pouch case sealing portion, and it is more preferable to form the flow path, the water-repellent coating layer, and the shielding band in a direction perpendicular to the electrode leads.

[0087] The present invention may be a battery pack including the battery module described above.

[0088] Those skilled in the art will be able to make various applications and modifications within the scope of the present invention based on the above content. [Explanation of symbols]

[0089] 1000 battery cells 100 pouch case 110 outer resin layer 120 metal layer 130 Internal resin layer 200 electrode assembly 210 negative electrode 211 Negative electrode tab 220 Positive electrode 221 Positive electrode tab 230 Separation membrane 300 electrode leads 310 Negative lead 320 Positive lead 400 insulating film 410 Negative electrode insulating film 411 Negative electrode overlapping part 412 Negative electrode non-overlapping part 412a First flow path 412b Second flow path 412c First water-repellent coating layer 412d First Blockade Zone 420 Positive electrode insulating film 421 Positive electrode overlapping part 422 Positive electrode non-overlapping part 422a Third Channel 422b 4th channel 422c Second water-repellent coating layer 422d Second Blockade 2000 battery modules 2100 Module Case

Claims

1. Insulating film interposed between the case and the electrode lead, the insulating film includes an overlapping portion where the insulating film overlaps with the case sealing portion and a non-overlapping portion where the insulating film does not overlap with the case sealing portion and is exposed to the outside, The non-overlapping portion of the insulating film has a flow path through which dew moves.

2. The insulating film according to claim 1 , wherein the flow path is provided along a direction perpendicular to the electrode lead.

3. The insulating film of claim 2 , wherein the cross section of the flow channel is hemispherical.

4. The insulating film according to claim 2 , wherein the flow path comprises a plurality of flow paths spaced apart in parallel at regular intervals.

5. The insulating film according to claim 4 , wherein the cross-sectional areas of the plurality of flow paths are different from one another.

6. The insulating film according to claim 2 , wherein the non-overlapping portion is provided with a water-repellent coating layer so as not to overlap with the flow path.

7. The insulating film according to claim 6 , wherein the water-repellent coating layer is provided along an edge portion in a direction perpendicular to the electrode lead.

8. The insulating film according to claim 2 , wherein the non-overlapping portion has a blocking band along an edge portion in a direction perpendicular to the electrode lead.

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