Battery cell equipped with an insulating film that prevents short circuits 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 priority under Korean Patent Application No. 10-2022-0177032 dated December 16, 2022, and all content disclosed in said Korean Patent Application is incorporated herein as part of this specification.

[0002] The present invention relates to a battery cell equipped with an insulating film having a function to prevent short circuits due to condensation, and a battery module including the same. More specifically, the present invention relates to a battery cell equipped with an insulating film having a function to prevent short circuits due to condensation, which can significantly reduce the possibility of short circuits due to condensation by forming a channel, a water-repellent coating layer, or a barrier band in the insulating film provided between the pouch case and the electrode leads. [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 rechargeable batteries that can store electrical energy produced through the development of alternative energy sources. Rechargeable batteries are closely used in daily life, such as in mobile devices, electric vehicles, and hybrid electric vehicles.

[0004] Rechargeable batteries, which are used as energy sources for various electronic devices that are indispensable in modern society, are seeing increased capacity requirements due to the growing usage and complexity of mobile devices and the development of electric vehicles. To meet user demand, small devices have a large number of battery cells, while automobiles and other large vehicles use battery modules that electrically connect a large number of battery cells, or battery packs that contain many such battery modules.

[0005] On the other hand, condensation can occur inside battery modules and battery packs during use due to temperature differences with the outside. Condensation is a phenomenon in which the temperature of moisture-containing air drops below the dew point, causing the moisture contained in the air to form water droplets on the surface of an object. It mainly occurs when the internal temperature of a secondary battery is lower than the surrounding temperature.

[0006] Condensation generated in this way can act as a cause of malfunction in secondary batteries. For example, if condensation occurs in a pouch-type battery cell, a short circuit can occur due to capillary action between the pouch case containing the metal layer and the electrode leads, which can shorten the lifespan of the battery cell or even 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 Figure 1, a plan view of a battery cell equipped with an insulating film for preventing dew flow, the insulating film 40 is exposed to the outside of the bonding interface 11 between the electrode leads 20 and 30 and the pouch outer material 10, and grooves 41 are formed on the side and top surfaces of the portion that does not overlap with the electrode leads 20 and 30 to prevent short circuits due to condensation.

[0008] As described in Patent Document 1, using an insulating film with grooves formed on it can be expected to prevent short circuits to a certain extent. However, since the grooves are formed only on a part of the edge of the insulating film, the risk of short circuits due to condensation remains high.

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

[0010] [Patent Document 1] Korean Published Patent No. 10-2013-0036991 [Overview of the project] [Problems that the invention aims to solve]

[0011] To solve the aforementioned problems, the present invention aims to provide a battery cell equipped with an insulating film that has the function of preventing short circuits due to condensation by reliably blocking dew generated outside the battery cell case from moving to the electrode leads, and a battery module including the same. [Means for solving the problem]

[0012] To achieve the above objectives, the battery cell according to the present invention comprises: a pouch case (100) having a housing 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 separation membrane (230) interposed between the negative electrode (210) and the positive electrode (220); and a pair of electrode leads (310) electrically connected to the negative electrode tab (211) and a positive electrode lead (320) electrically connected to the positive electrode tab (221). The device includes a lead (300) and a pair of insulating films (400) consisting of a negative electrode insulating film (410) interposed between the inner surface of the sealing portion 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 portion 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 non-overlapping portions exposed to the outside of the sealing portion of the pouch case (100), and the non-overlapping portions have channels through which dew moves.

[0013] Furthermore, in the battery cell according to the present invention, the negative electrode non-overlapping portion (412) of the negative electrode insulating film (410) is provided with a first channel (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 provided with a third channel (422a) through which dew moves in a direction perpendicular to the positive electrode lead (320).

[0014] Further, in the battery cell according to the present invention, the cross-sections of the first flow path (412a) and the third flow path (422a) are hemispherical, triangular or quadrangular, and both side ends are open.

[0015] Further, in the battery cell according to the present invention, the negative electrode non-overlapping portion 412 is characterized by further comprising a second flow path (412b) spaced apart in parallel from the first flow path (412a) at a constant interval.

[0016] Further, the first flow path (412a) and the second flow path (412b) have different cross-sectional areas from each other.

[0017] Further, in the battery cell according to the present invention, the positive electrode non-overlapping portion (422) is characterized by further comprising a fourth flow path (422b) spaced apart in parallel from the third flow path (422a) at a constant interval.

[0018] Further, 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 from each other.

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

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

[0021] Further, in the battery cell according to the present invention, the negative electrode non-overlapping portion (412) is characterized by comprising a first blocking zone (412d) along an edge in a direction orthogonal to the negative electrode lead (310).

[0022] Further, in the battery cell according to the present invention, the positive electrode non-overlapping portion (422) is characterized by comprising a second blocking zone (422d) along an edge in a direction orthogonal to the positive electrode lead (320).

[0023] Further, the present invention is characterized by providing a battery module including the aforementioned battery cell.

[0024] Further, the method for manufacturing a battery cell according to the present invention comprises: a first step of preparing a pouch case (100) provided with an accommodation space for accommodating an electrode assembly (200); a second step of attaching a negative electrode insulation film (410) and a positive electrode insulation film (420) respectively to a negative electrode lead (310) and a positive electrode lead (320) electrically connected to the electrode assembly (200); and a third step of sealing an edge of the pouch case (100) after accommodating the electrode assembly (200) in the accommodation space of the pouch case (100), wherein the negative electrode insulation film (410) and / or the positive electrode insulation film (420) is provided with a non-overlapping portion exposed to the outside of a sealing part of the pouch case (100), the negative electrode non-overlapping portion (412) of the negative electrode insulation film (410) is provided with a first flow path (412a) through which dew moves in a direction orthogonal to the negative electrode lead (310), and the positive electrode non-overlapping portion (422) of the positive electrode insulation film (420) is provided with a third flow path (422a) through which dew moves in a direction orthogonal to the positive electrode lead (320). Effects of the Invention

[0025] As described above, according to the battery cell provided with the insulation film having a function of preventing a short circuit due to dew condensation of the present invention and the battery module including the same, the non-overlapping portion of the insulation film exposed to the outside of the pouch case is provided with a flow path through which dew can move in a direction orthogonal to the electrode lead, so that there is an advantage that the possibility of a short circuit due to dew condensation can be greatly reduced.

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

[0027] Furthermore, the battery cell equipped with the dew-preventing insulating film of the present invention and the battery module including the same have the advantage that a barrier band is provided in the non-overlapping portion of the insulating film exposed to the outside of the pouch case, thereby significantly reducing the possibility of short circuits due to condensation. [Brief explanation of the drawing]

[0028] [Figure 1] This is a plan view of a battery cell equipped with an insulating film for preventing dew flow using conventional technology. [Figure 2] This is an exploded perspective view of a battery cell according to a preferred first embodiment of the present invention. [Figure 3] Figure 2 is a plan view showing the electrode assembly with the insulating film seated on the electrode leads. [Figure 4] This is a cross-sectional view taken along line AA in Figure 3. [Figure 5] This is a plan view showing an electrode assembly according to a preferred second embodiment of the present invention, with an insulating film seated on the electrode leads. [Figure 6] This is a cross-sectional view taken along line BB in Figure 5. [Figure 7] This is a plan view showing an electrode assembly according to a preferred third embodiment of the present invention, with an insulating film seated on the electrode leads. [Figure 8] This is a cross-sectional view taken along the CC line in Figure 7. [Figure 9] This is a plan view showing an electrode assembly according to a preferred fourth embodiment of the present invention, with an insulating film seated on the electrode leads. [Figure 10] This is a cross-sectional view taken along the DD line in Figure 9. [Figure 11] This is a perspective view of a battery module housing a battery cell according to the present invention. [Figure 12] This is a flowchart illustrating the method for manufacturing a battery cell according to the present invention. [Modes for carrying out the invention]

[0029] Hereinafter, embodiments that allow a person with ordinary skill in the art to carry out the present invention will be described in detail based on the attached drawings. However, in describing the operating principle of a preferred embodiment of the present invention in detail, if it is determined that a specific description of a related known function or configuration may unnecessarily obscure the gist of the present invention, such detailed description will be omitted.

[0030] Furthermore, the same reference numerals shall be used throughout the drawings for parts that have similar functions and operations. Throughout the specification, when it is said that one part is connected to another part, this includes not only direct connections but also indirect connections through other elements in between. Also, when it is said that a component is included, unless otherwise stated, it does not mean that other components are excluded, but rather that other components may be included.

[0031] The following description will explain, with reference to the attached drawings, a battery cell equipped with an insulating film that has the function of preventing short circuits due to condensation according to the present invention, and a battery module including the same.

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

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

[0034] First, the pouch case 100 consists of a lower case and an upper case, and a pocket-shaped storage space is formed so that the electrode assembly 200 can be accommodated.

[0035] Such a pouch case 100 has a storage compartment formed using a laminate sheet consisting of an outer resin layer 110, a metal layer 120, and an inner resin layer 130.

[0036] In detail, the outermost resin layer 110 of the pouch case 100 can be made of a heat-resistant polymer with excellent tensile strength, moisture resistance, and air resistance, so as to ensure heat resistance and chemical resistance while protecting the electrode assembly 200. For example, nylon or polyethylene terephthalate can be used, but is not limited to these.

[0037] The metal layer 120 located between the outer resin layer 110 and the inner resin layer 130 acts as a barrier layer that prevents moisture and various gases from penetrating into the battery. A suitable material for such a metal layer 120 is a thin aluminum film that is lightweight yet has excellent moldability.

[0038] Furthermore, the innermost resin layer 130 of the pouch case 100 is in direct contact with the electrode assembly 200, so it needs to have insulating and electrolytic resistance properties. In addition, it needs to have sealing properties for airtight sealing with the outside, meaning that the sealing portions where the inner layers are heat-bonded together need to have excellent heat bonding strength.

[0039] The material for such an internal resin layer 130 can be selected from polyolefin resins such as polypropylene, polyethylene, polyethylene acrylic acid, and polybutylene, polyurethane resins, and polyimide resins, which have excellent chemical resistance and good sealing properties, but are not limited to these. Polypropylene is most preferred because it has excellent mechanical properties such as tensile strength, rigidity, surface hardness, and impact strength, as well as excellent chemical resistance.

[0040] For example, Figure 2 shows that the storage space is provided in both the upper and lower cases, but it is obvious that only one of the upper or lower cases can have the storage space.

[0041] Next, the electrode assembly 200 will be described. The electrode assembly 200 that sits in the storage space of the pouch case 100 may consist of, but is not limited to, a jelly roll type electrode assembly having a structure in which a separation membrane 230 is interposed between a long sheet-like negative electrode 210 and a positive electrode 220 before being 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 separation membrane 230 interposed between them, a stack folding type electrode assembly in which the unit cells are wound up by a long separation film, or a lamination stack type electrode assembly in which the unit cells are stacked with a separation membrane interposed between them and adhere 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 the negative electrode current collector.

[0043] Here, the negative electrode active material is, for example, carbon such as non-graphitizable carbon or 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 and Group 3 elements of the periodic table, halogens; 0<x≦1; 1≦y≦3; 1≦z≦8) and other metal composite oxides; lithium metal; lithium alloys; silicon-based alloys; tin-based alloys; metal oxides such as SnO, SnO₂, PbO, PbO₂, Pb₂O₃, Pb₃O₄, Sb₂O₃, Sb₂O₄, Sb₂O₅, GeO, GeO₂, Bi₂O₃, Bi₂O₄ and Bi₂O₅; conductive polymers such as polyacenylene; Li-Co-Ni based materials; and Si-based materials that are Si, SiO, SiO₂ alone or a mixture thereof can be used, but the positive electrode active material is not limited to these.

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

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

[0046] On the other hand, 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, namely the negative electrode tab 211 and the 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, the separation membrane 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 separation membrane 230 is generally 0.01 μm to 10 μm, and the thickness is generally 5 μm to 300 μm. Such a separation membrane 230 can be, but is not limited to, sheets or nonwoven fabrics made from olefin polymers such as polypropylene with chemical resistance and hydrophobicity, glass fiber, or polyethylene.

[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. Ultrasonic welding is performed on the principle that by applying high-frequency vibrations generated by high-frequency ultrasonic waves of approximately 20 kHz, the vibration energy is rapidly converted into thermal energy through friction at the interface between the electrode tab and the electrode lead by the operation of a horn and anvil, resulting in rapid welding. Of course, the method is not limited to ultrasonic welding, as long as it allows for the welding and electrical connection of the tab bundle and the lead.

[0050] For example, although not shown in the drawing, protective tape (not shown) can be provided to cover the overlapping portion of the electrode tab and electrode lead.

[0051] Since the electrode tab and electrode lead are joined by welding, the surfaces of the electrode tab and electrode lead may not be smooth, which can lead to insulation failure.

[0052] In other words, if the welded surface is not smooth, and the welded area comes into contact with the pouch case due to impact, the internal resin layer will peel off, exposing the metal layer, resulting in insulation failure. Therefore, it is preferable to wrap the welded area with protective tape to prevent the aforementioned insulation failure from occurring.

[0053] Here, the protective tape is made of an insulating material, and is not limited to, for example, polypropylene, polyethylene, polyester, or polyimide, as long as it is a material that can wrap around the welded area 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, that is, at the position where the edge of the pouch case 100 that is sealed for airtightness and the electrode lead 300 overlap. This insulating film 400 can maintain the sealing of the pouch case 100 while preventing the electricity generated in the electrode assembly 200 from flowing to the pouch case 100 through the electrode lead 300.

[0055] In detail, to prevent the pouch case 100 and the negative electrode lead 310 from coming into direct contact, the negative electrode insulating film 410 consists of 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] Furthermore, 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, it may consist of 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, the negative electrode non-overlapping portion 412 or the positive electrode non-overlapping portion 422 is preferably provided with 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 is provided with a first flow path 412a, and the positive electrode non-overlapping portion 422 is provided with a third flow path 422a.

[0058] Here, the first channel 412a of the negative electrode non-overlapping portion 412 is formed in a direction perpendicular to the negative electrode lead 310, and the third channel 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 the dew to flow downward along the channel while suppressing its movement towards the leads when the battery cell is mounted vertically.

[0059] The flow channels of the present invention correspond to long passages that allow generated dew to flow directly into the channels and move, or to be guided to move by capillary action. Therefore, as long as the direction in which the dew flows can be determined, the cross-sectional shapes of the first flow channel 412a and the third flow channel 422a are not particularly limited and may be hemispherical, triangular, or quadrilateral, for example, and their width and depth may be in the range of tens of nanometers (nm) to several micrometers (μm).

[0060] It is preferable that both ends are open so that the generated dew flows into the first channel 412a and the third channel 422a before being discharged, or flows while in contact with the channels.

[0061] The aforementioned insulating film 400 is preferably made of a non-conductive material that does not conduct electricity well, and generally, insulating tapes that are relatively thin and easily adhere to electrode leads are often used, but are not limited to these.

[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 heat-fused to the inner resin layer of the pouch case by heat and pressure.

[0063] Figure 5 is a plan view of an electrode assembly according to a preferred second embodiment of the present invention, showing an insulating film seated on the electrode leads, and Figure 6 is a cross-sectional view taken along line BB in Figure 5.

[0064] Except for the insulating film, the rest of the process 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, there are multiple flow channels formed in the negative electrode non-overlapping portion 412 and the positive electrode non-overlapping portion 422, respectively.

[0066] Taking the case with two channels as an example, the negative electrode non-overlapping portion 412 of the negative electrode insulating film 410 comprises a first channel 412a and a second channel 412b. Here, it is preferable that the first channel 412a and the second channel 412b are spaced parallel to each other at a certain interval, and it is preferable that the cross-sectional area of ​​the first channel 412a, which is located relatively inward to the second channel 412b located at the edge, is larger in order to minimize the movement of dew to the negative electrode lead 310.

[0067] Furthermore, the positive electrode non-overlapping portion 422 of the positive electrode insulating film 420 also includes a third channel 422a and a fourth channel 422b, and their positions and cross-sectional areas are the same as those of the first channel 412a and second channel 412b of the negative electrode non-overlapping portion 412, so a redundant explanation will be omitted.

[0068] Figure 7 is a plan view of an electrode assembly according to a preferred third embodiment of the present invention, showing an insulating film seated on the electrode leads, and Figure 8 is a cross-sectional view taken along the CC line in Figure 7.

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

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

[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 channel 412a, and it is more preferable that the first water-repellent coating layer 412c is provided along the edge 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, it is possible to more reliably block dew from flowing onto the negative electrode lead 310.

[0073] Similarly, the positive electrode non-overlapping portion 422 is preferably provided with a second water-repellent coating layer 422c so as not to overlap with the third flow channel 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, known water-repellent materials such as fluorine-based compounds and silane-based compounds can be used as the water-repellent coating material, and the coating layer can be formed by a dip coating method or a spray coating method.

[0075] For example, in Example 3, the case in which a water-repellent coating layer is formed in a non-overlapping section having a single channel was described, but it is obvious that a water-repellent coating layer can also be formed in a non-overlapping section having two or more channels, as in the Second Example.

[0076] Figure 9 is a plan view of an electrode assembly according to a preferred fourth embodiment of the present invention, showing an insulating film seated on the electrode leads, and Figure 10 is a cross-sectional view taken along the DD line in Figure 9.

[0077] Except for the insulating film, the rest of the process 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 barrier band is further formed in the negative electrode non-supervised portion 412 and the positive electrode non-supervised portion 422, respectively.

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

[0080] As described above, by providing a first blocking band 412d and a second blocking band 422d in the negative electrode non-overlapping portion 412 and the positive electrode non-overlapping portion 422, 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, the case in which a barrier is formed in a non-overlapping section having a single flow path was described, but it is obvious that a barrier can also be formed in a non-overlapping section having two or more flow paths, as in the second example.

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

[0083] Here, the battery cell 1000 is a battery cell having one or more of the flow channels, water-repellent coating layers, and barrier bands described in Examples 1 to 4 on an insulating film, and is housed in the module case 2100 in an upright position arranged vertically to the bottom surface.

[0084] Even if condensation occurs due to temperature changes, the dew generated by the insulating film's channel, water-repellent coating layer, and barrier band flows downwards, thus preventing short circuits caused by condensation. For example, although not shown in the drawing, the module case 2100 can be further provided with a passage for discharging the dew that has flowed downwards to the outside.

[0085] Figure 12 is a flowchart illustrating the 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 a housing space for housing an electrode assembly; a second step of attaching a negative electrode insulating film and a positive electrode insulating film to the negative electrode lead and positive electrode lead electrically connected to the electrode assembly, respectively; and a third step of housing the electrode assembly in the housing space of the pouch case and then sealing the edges of the pouch case.

[0086] On the other hand, prior to attaching the electrode leads and insulating films, it is preferable to pre-form one or more of the following 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 that these channels, water-repellent coating layers and barrier bands be formed in a direction perpendicular to the electrode leads.

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

[0088] A person with ordinary skill in the field to which this invention belongs will be able to make various applications and modifications within the scope of this invention based on the above description. [Explanation of Symbols]

[0089] 1000 battery cells 100 pouch cases 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 Tab 230 Separation membrane 300 electrode leads 310 Negative lead 320 Positive Lead 400 insulating film 410 Negative electrode insulating film 411 Negative electrode superposition section 412 Negative electrode non-superposition area 412a First channel 412b Second channel 412c First water-repellent coating layer 412d First Barrier Zone 420 Positive electrode insulating film 421 Positive electrode superposition section 422 Positive electrode non-superimposed area 422a Third channel 422b Fourth channel 422c Second water-repellent coating layer 422d Second Barrier Zone 2000 Battery Module 2100 Module Case

Claims

1. In an insulating film interposed between the case and the electrode lead, The insulating film includes an overlapping portion that overlaps with the case sealing portion and a non-overlapping portion that does not overlap with the case sealing portion and is exposed to the outside. The non-overlapping portion is an insulating film having a channel through which dew moves in a direction perpendicular to the longitudinal direction of the electrode lead within the surface on which the electrode lead extends.

2. The insulating film according to claim 1, wherein the cross-section of the channel is hemispherical.

3. The insulating film according to claim 1, wherein the aforementioned flow channels are provided in a plurality of parallel locations spaced at regular intervals.

4. The insulating film according to claim 3, wherein the cross-sectional areas of the plurality of channels are different from each other.

5. The insulating film according to claim 1, wherein the non-overlapping portion is provided with a water-repellent coating layer so as not to overlap with the flow path.

6. The insulating film according to claim 5, wherein the water-repellent coating layer is provided along the edge in a direction perpendicular to the electrode lead.

7. The insulating film according to claim 1, wherein the non-overlapping portion is provided with a barrier band along the edge in a direction perpendicular to the electrode lead.

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