Battery cell with insulating film capable of preventing short circuit caused by condensation and battery module including the same

Abstract

The present invention relates to a battery cell including an insulating film having a function of preventing a short circuit caused by condensation, and a battery module including the same. More specifically, the present invention relates to a battery cell including an insulating film having a function of preventing a short circuit caused by condensation, and a battery module including the same, the battery cell including the insulating film having a function of preventing a short circuit caused by condensation includes: a pouch case; an electrode assembly housed in the pouch case, the electrode assembly including a negative electrode, a positive electrode, and a separator interposed between the negative electrode and the positive electrode; 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 the pouch case sealing part and the negative electrode lead, and a positive electrode insulating film interposed between an inner surface of the pouch case sealing part and the positive electrode lead, the negative electrode insulating film and / or the positive electrode insulating film having a non-overlapping portion exposed to an outside of the pouch case sealing part, and the non-overlapping portion having a flow path through which dew moves.

Description

[Technical field]

[0001] This application claims the benefit of priority to Korean Patent Application No. 10-2022-0177032 filed on 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 with a function of preventing a short circuit caused by condensation and a battery module including the same, and more particularly, to a battery cell having an insulating film with a function of preventing a short circuit caused by condensation, which can significantly reduce the possibility of a short circuit caused by condensation by forming a flow path, a water-repellent coating layer, or a barrier in an insulating film provided between a pouch case and an electrode lead, and a battery module including the same. [Background technology]

[0003] Recently, due to air pollution and energy depletion caused by the use of fossil fuels, the demand for secondary batteries capable of storing electric energy produced by the development of alternative energy sources is increasing. Rechargeable secondary batteries are closely 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 indispensable in modern society, and the required capacity is increasing due to the increased use and complication of mobile devices and the development of electric vehicles, etc. In order to meet the needs of users, a large number of battery cells are arranged in small devices, and automobiles, etc. use battery modules in which a large number of battery cells are electrically connected, or battery packs equipped with a large number of such battery modules.

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

[0006] The condensation thus generated may act as a cause of 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 may result in a shortened life span 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, an insulating film 40 is exposed to the outside of a joint interface 11 between electrode leads 20, 30 and a pouch exterior material 10, and a groove 41 is formed on the side and top surface of the portion not overlapping with the electrode leads 20, 30 to prevent short circuits due to dew condensation.

[0008] By using an insulating film having 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 part of the edge of the insulating film, the risk of short-circuiting due to condensation remains high.

[0009] In particular, when battery cells are vertically assembled into a battery module or a battery pack, this structure allows generated condensation 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 has a function of preventing a short circuit caused by condensation by reliably blocking condensation generated outside a battery cell case from moving to an electrode lead, and a battery module including the same. [Means for solving the problem]

[0012] In order to achieve the above object, the battery cell according to the present invention includes a pouch case (100) having a storage space made of a laminate sheet, an electrode assembly (200) housed 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 an inner surface of a sealing part of the pouch case (100) and a negative electrode lead (310), and a positive electrode insulating film (420) interposed between an inner surface of a sealing part of the pouch case (100) and a 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 in that it 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) is characterized in that it has 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 first flow passage (412a) and the third flow passage (422a) have a cross section of a hemispherical, triangular or rectangular shape, and both ends are open.

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

[0016] In addition, the first flow passage (412a) and the second flow passage (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 passage (422b) spaced apart in parallel from the third flow passage (422a) at a regular interval.

[0018] In the battery cell according to the present invention, the third flow passage (422a) and the fourth flow passage (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 an edge portion perpendicular to the negative electrode lead (310), and the second water-repellent coating layer (422c) is provided along an edge portion 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 having a first cutoff band (412d) along an edge portion 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 an edge portion in a direction perpendicular to the positive electrode lead (320).

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

[0024] In addition, the method of manufacturing a battery cell according to the present invention includes a first step of preparing a pouch case (100) having an accommodation space for accommodating 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 accommodating the electrode assembly (200) in the accommodation space of the pouch case (100) and then sealing an edge 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). Effect of the Invention

[0025] As described above, according to the battery cell having an insulating film having the function of preventing short circuits due to condensation and the battery module including the same of the present invention, the non-overlapping portion of the insulating film exposed to the outside of the pouch case has a flow path through which dew can move in a direction perpendicular to the electrode lead, thereby offering the advantage of significantly reducing the possibility of short circuits due to condensation.

[0026] In addition, according to the battery cell having the insulating film for preventing dew flow and the battery module including the same of the present invention, 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 a short circuit due to dew condensation.

[0027] Furthermore, according to the battery cell having the insulating film for preventing dew flow of the present invention and the battery module including the same, a barrier band is provided 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 a short circuit due to dew condensation. [Brief description of the drawings]

[0028] [Figure 1] FIG. 1 is a plan view of a battery cell having an insulating film for preventing dew flow according to the prior art. [Diagram 2] 1 is an exploded perspective view of a battery cell according to a first preferred embodiment of the present invention; [Diagram 3] 3 is a plan view of a state in which an insulating film is seated on an electrode lead of the electrode assembly shown in FIG. 2. [Figure 4] FIG. 4 is a cross-sectional view taken along line AA in FIG. [Diagram 5] 11 is a plan view showing a state in which an insulating film is seated on 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] 13 is a plan view showing a state in which an insulating film is seated on 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. [Figure 9] 13 is a plan view showing a state in which an insulating film is seated on 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. [Figure 11] FIG. 2 is a perspective view of a battery module housing battery cells according to the present invention. [Figure 12] 4 is a flowchart illustrating a method for manufacturing a battery cell according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] Hereinafter, the present invention will be described in detail with reference to the accompanying drawings, in which a person having ordinary skill in the art to which the present invention pertains can easily carry out the present invention. However, when 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] In addition, 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 the case where the part is directly connected to another part, but also the case where the part is indirectly connected via another element between the two parts. In addition, when a part includes a certain component, it does not mean that the other component is excluded, but that the part may further include the other component, unless otherwise specified.

[0031] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a battery cell having an insulating film capable of preventing a short circuit caused by condensation according to the present invention and a battery module including the same 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 an insulating film seated on the electrode lead of the electrode assembly shown in FIG. 2, 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 to receive the electrode assembly 200 therein.

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

[0036] In particular, the external resin layer 110 located at the outermost portion of the pouch case 100 may be made of a heat-resistant polymer having excellent tensile strength, moisture permeability, and air permeability so as to ensure heat resistance and chemical resistance while protecting the electrode assembly 200. As an example, nylon or polyethylene terephthalate may be used, but is not limited thereto.

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

[0038] In addition, the internal resin layer 130 located at the innermost part of the pouch case 100 is in direct contact with the electrode assembly 200, and therefore must have insulating properties and electrolysis resistance. In addition, the internal resin layer 130 must have excellent sealing properties to seal against the outside, i.e., the sealing parts where the internal layers are thermally bonded together must have excellent thermal adhesion 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 preferable because it has excellent mechanical properties such as tensile strength, rigidity, surface hardness, and impact strength, as well as chemical resistance.

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

[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 having a structure in which a separator 230 is interposed between a long sheet-like negative electrode 210 and a positive electrode 220 and then wound up, a stack type electrode assembly composed of unit cells having a structure in which a rectangular negative electrode 210 and a positive electrode 220 are stacked with a separator 230 interposed therebetween, a stack folding type electrode assembly in which a unit cell is wound up by a long separator film, or a lamination stack type electrode assembly in which unit cells are stacked with a separator interposed therebetween and attached to each other, etc.

[0042] Specifically, the negative electrode 210 is manufactured by applying a slurry in which a negative electrode active material and a binder are mixed onto 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 zMetal composite oxides such as (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); 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 such as Si, SiO, SiO2 alone or mixtures thereof can be used, but are not limited thereto.

[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) nickel-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 part of the Li in the chemical formula is substituted with alkaline earth metal ions; disulfide compounds; Fe2(MoO4)3 and the like can be mentioned, but are not limited thereto.

[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 an uncoated portion where the slurry is not coated, and a pair of electrode tabs, i.e., a negative electrode tab 211 and a positive electrode tab 221, are formed by cutting the uncoated portion or by connecting a separate conductive member to the uncoated portion by ultrasonic welding or the like.

[0047] In addition, the separator 230, which is interposed between the positive electrode 220 and the negative electrode 210 or provided 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 an olefin polymer such as polypropylene, glass fiber, or polyethylene, which is chemically resistant and hydrophobic, 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 about 20 kHz, and the vibration energy is converted into heat energy by friction at the interface between the electrode tabs and the electrode lead due to the operation of a horn and anvil, thereby rapidly welding the electrode tabs and the electrode lead. Of course, the method is not limited to ultrasonic welding, as long as it is possible to 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 the electrode leads are connected by welding, the surfaces of the electrode tabs and the electrode leads may not be smooth, which may lead to poor insulation.

[0052] In other words, if the welded surface is not smooth, and the welded portion comes into contact with the pouch case due to an impact, the inner resin layer will peel off and the metal layer will be exposed, resulting in insulation failure. Therefore, it is preferable to wrap the welded portion with a protective tape to prevent the above-mentioned insulation failure from occurring.

[0053] Here, the protective tape is made of an insulating material, for example, polypropylene, polyethylene, polyester or polyimide material, and is not limited thereto as long as it is a material that can wrap the welded part 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 hermeticity 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 positive electrode insulating film 420 may be composed of a positive electrode overlapping portion 421 located at the portion 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 to flow downward along the flow path while preventing it from moving toward the lead when the battery cell is mounted vertically.

[0059] The flow path of the present invention corresponds to a long passageway such that the generated dew flows directly into the flow path and moves, or the movement of the dew can be induced by capillary action. Therefore, as long as the direction of the dew flow can be determined, the cross-sectional shape of the first flow path 412a and the third flow path 422a is not particularly limited, and may be, for example, a hemisphere, a triangle, or a rectangle, and the width and depth may be in the range of several tens of nanometers (nm) to several micrometers (μm).

[0060] Both ends are preferably open so that the generated dew can flow into the first flow path 412a and the third flow path 422a and then be discharged or flow 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 an insulating tape that is relatively thin and can be easily attached to an electrode lead, but is not limited to this.

[0062] Specifically, the insulating film is one or more materials selected from the group consisting of polyimide (PI), polyprophylene (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 by 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, the negative electrode non-overlapping portion 412 and the positive electrode non-overlapping portion 422 each have a plurality of flow paths formed therein.

[0066] Taking the case of two flow paths as an example, the negative electrode non-overlapping portion 412 of the negative electrode insulating film 410 includes a first flow path 412a and a second flow path 412b. Here, the first flow path 412a and the second flow path 412b are preferably spaced apart in parallel at a regular interval, and the cross-sectional area of ​​the first flow path 412a located relatively inward is preferably larger than that of the second flow path 412b located at the edge, in order to minimize the movement 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 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 manner, when the first water-repellent coating layer 412c is formed on the negative electrode non-overlapping portion 412, the flow of dew onto the negative electrode lead 310 can be prevented more reliably.

[0073] Similarly, the positive electrode non-overlapping portion 422 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 manner, 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 help prevent dew from flowing onto the negative electrode lead 310 and the positive electrode lead 320.

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

[0082] Fig. 11 is a perspective view of a battery module accommodating battery cells according to the present invention. As shown in Fig. 11, a battery module 2000 accommodates a plurality of battery cells 1000 inside a module case 2100 having an accommodating space.

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

[0084] Even if condensation occurs due to temperature changes, the condensation generated by the flow path of the insulating film, the water repellent coating layer, and the barrier strip flows downward, so that a short circuit due to the condensation can be prevented. 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 the module case 2100.

[0085] 12 is a flow chart 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 a negative electrode insulating film and a positive electrode insulating film to a negative electrode lead and a positive electrode 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 attachment of the electrode lead and the insulating film, it is preferable to preliminarily form at least one of a flow path, a water-repellent coating layer, and a barrier in a non-overlapping portion of the negative electrode insulating film and the positive electrode insulating film, i.e., a portion exposed to the outside of the pouch case sealing portion, and it is more preferable that the flow path, the water-repellent coating layer, and the barrier are formed in a direction perpendicular to the electrode lead.

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

[0088] Those skilled in the art will appreciate that various applications and modifications within the scope of the present invention will be possible 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 Lead 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 Barrier Zone 420 Positive electrode insulating film 421 Positive electrode overlapping part 422 Positive electrode non-overlapping part 422a 3rd Stream 422b 4th Stream 422c Second water-repellent coating layer 422d Second Blockade 2000 Battery Module 2100 Module Case

Claims

1. a pouch case having a storage space surrounded by a laminate sheet; an electrode assembly accommodated in the pouch case, the electrode assembly including a negative electrode having a negative electrode tab, a positive electrode having a positive electrode tab, and a separator interposed between the negative electrode and the positive electrode; a pair of electrode leads including a negative electrode lead electrically connected to the negative electrode tab and a positive electrode lead electrically connected to the positive electrode tab; A battery cell including a pair of insulating films, the pair including a negative electrode insulating film interposed between an inner surface of a pouch case sealing part and a negative electrode lead, and a positive electrode insulating film interposed between an inner surface of the pouch case sealing part and a positive electrode lead, The negative electrode insulating film and / or the positive electrode insulating film have a non-overlapping portion exposed to an outside of the pouch case sealing portion, and the non-overlapping portion has a flow path through which dew moves.

2. 2. The battery cell according to claim 1, wherein the negative electrode non-overlapping portion of the negative electrode insulating film has a first flow path through which dew moves in a direction perpendicular to the negative electrode lead, and the positive electrode non-overlapping portion of the positive electrode insulating film has a third flow path through which dew moves in a direction perpendicular to the positive electrode lead.

3. The battery cell according to claim 2 , wherein the first flow passage and the third flow passage have a hemispherical cross section and both ends are open.

4. The battery cell according to claim 2 , wherein the negative electrode non-overlapping portion further comprises a second flow passage spaced apart in parallel from the first flow passage at a constant interval.

5. The battery cell of claim 4 , wherein the first flow path and the second flow path have different cross-sectional areas.

6. The battery cell according to claim 2 , wherein the positive electrode non-overlapping portion further includes a fourth flow passage spaced in parallel from the third flow passage at a constant interval.

7. The battery cell of claim 6 , wherein the third flow path and the fourth flow path have different cross-sectional areas.

8. the negative electrode non-overlapping portion includes a first water-repellent coating layer so as not to overlap with the first flow path; The battery cell according to claim 2 , wherein the positive electrode non-overlapping portion is provided with a second water-repellent coating layer so as not to overlap with the third flow path.

9. The first water-repellent coating layer is provided along an edge portion in a direction perpendicular to the negative electrode lead, The battery cell according to claim 8 , wherein the second water-repellent coating layer is provided along an edge portion perpendicular to the positive electrode lead.

10. The battery cell according to claim 2 , wherein the negative electrode non-overlapping portion includes a first blocking band along an edge portion in a direction perpendicular to the negative electrode lead.

11. The battery cell according to claim 2 , wherein the positive electrode non-overlapping portion includes a second blocking band along an edge portion in a direction perpendicular to the positive electrode lead.

12. A battery module comprising the battery cell according to any one of claims 1 to 11.

13. A first step of preparing a pouch case having a storage space for storing an electrode assembly; a second step of attaching a negative electrode insulating film and a positive electrode insulating film to a negative electrode lead and a positive electrode lead electrically connected to the electrode assembly, respectively; and a third step of sealing an edge of the pouch case after accommodating an electrode assembly in the accommodating space of the pouch case, the negative electrode insulating film and / or the positive electrode insulating film have a non-overlapping portion exposed to an outside of a pouch case sealing portion, the negative electrode non-overlapping portion of the negative electrode insulating film has a first flow path through which dew moves in a direction perpendicular to the negative electrode lead, and the positive electrode non-overlapping portion of the positive electrode insulating film has a third flow path through which dew moves in a direction perpendicular to the positive electrode lead.

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