Pouch-type secondary battery

Abstract

A pouch-type secondary battery, according to the present invention, comprises: an electrode assembly; a pouch-type case including an accommodation portion that accommodates the electrode assembly, and a terrace portion that is provided along the periphery of the accommodation portion and has a sealing portion in which a portion of the width thereof is sealed; an electrode lead connected to the electrode assembly and protruding from the exterior of the pouch-type case via the terrace portion; a lead film disposed between the electrode lead and the pouch-type case; and a gas guiding film disposed between the electrode lead and the lead film. In addition, the gas guiding film comprises: a permeation portion formed on the outer side of the sealing portion; and one or more gas flow paths passing through the sealing portion and formed such that the permeation portion and the interior of the pouch-type case are connected to each other, wherein a gas discharge coefficient (CR) is from 10 to 25.

Description

pouch-type secondary battery The present invention relates to a pouch-type secondary battery, and more particularly, to a pouch-type secondary battery including a gas-inducing film. Secondary batteries are used in a wide range of applications, from small products like digital cameras, DVDs, MP3 players, mobile phones, PDAs, portable game devices, power tools, and e-bikes, to larger, high-power products like electric and hybrid vehicles, as well as power storage devices that store surplus power or renewable energy, and as backup power storage devices. Types of secondary batteries include nickel-cadmium batteries, nickel-metal hydride batteries, lithium-ion batteries, and lithium-ion polymer batteries. Secondary batteries can be manufactured by housing an electrode assembly, in which a positive electrode, a negative electrode, and a separator interposed therebetween are alternately laminated, in a battery case, injecting an electrolyte, and then sealing the battery case. Secondary batteries are classified into pouch types and can types depending on the material of the case housing the electrode assembly. Among them, pouch type batteries can be manufactured by performing press processing on a flexible pouch film laminate to form a cup portion, housing the electrode assembly in the inner space of the cup portion, and sealing the seal portion. Pouch-type secondary batteries can generate gas within the pouch during high-temperature operation, overcharging, or short-circuiting. If gas pressure within the pouch increases, the pouch can vent, potentially leading to an explosion or fire. Accordingly, research is being conducted on various types of gas exhaust components to solve the above problems, and the need for gas exhaust components that simultaneously consider gas exhaust, moisture infiltration from the outside, and electrolyte leakage, gas exhaust components that can withstand high internal pressure but have low operating pressure, and gas exhaust components with excellent durability is continuously increasing. The present invention is intended to solve the above problems, and provides a pouch-type secondary battery that can operate at a low internal pressure and has a fast gas discharge rate while minimizing moisture infiltration and electrolyte leakage through the design of a gas induction film. [1] According to one embodiment, a pouch-shaped case includes an electrode assembly; a receiving portion for receiving the electrode assembly; and a terrace portion provided along a periphery of the receiving portion and having a sealing portion with a portion of the width sealed; an electrode lead connected to the electrode assembly and protruding to the outside of the pouch-shaped case via the terrace portion; a lead film disposed between the electrode lead and the pouch-shaped case; and a gas induction film disposed between the electrode lead and the lead film; wherein the gas induction film includes a permeation portion formed on the outside of the sealing portion, and at least one gas path formed via the sealing portion such that the permeation portion and the inside of the pouch-shaped case are connected to each other, and a gas emission coefficient (C) expressed by the following Equation 1 R ) is provided as a pouch-type secondary battery having a capacity of 10 to 25. [Formula 1] C R = 2(S A / W L ) + W P In the above equation 1, WP is the total width (mm) of one or more gas channels, and W L is the width of the electrode lead (mm), and S A is the area of ​​the penetration section (mm) 2 )am. [2] In the above [1], in the pouch-type secondary battery, when the internal pressure of the pouch-type case increases, the interface between the lead film and the gas induction film may be opened, so that a gas discharge path is formed along the gas path. [3] In the above [1] and / or [2], the width (W) of the electrode lead L ) for the area of ​​the permeable portion (S)A ) of the ratio (S) A / W L ) may be between 1.7 mm and 7.5 mm. [4] In at least one of the above [1] to [3], the total width of the gas path (W P ) may be between 6 mm and 20 mm. [5] In at least one of the above [1] to [4], the gas induction film may have a structure in which an adhesive resin layer and a permeable resin layer are laminated from the upper surface of the electrode lead. [6] In the above [5], the adhesive resin layer may include at least one selected from the group consisting of acid-modified polypropylene (PPa) and acid-modified polyethylene (Pea). [7] In the above [5] and / or [6], the permeable resin layer may include at least one selected from the group consisting of polyimide (PI) and polytetrafluoroethylene (PTFE). [8] In at least one of the above [5] to [7], the ratio (D1 / D2) of the thickness (D1) of the adhesive resin layer to the thickness (D2) of the permeable resin layer may be 0.4 to 2.0. [9] In at least one of the above [5] to [8], the thickness of the adhesive resin layer may be 5 ㎛ to 130 ㎛.

[0010] In at least one of the above [5] to [9], the thickness of the permeable resin layer may be 40 ㎛ to 100 ㎛.

[0011] In at least one of the above [5] to

[0010] , the adhesive resin layer of the gas induction film may have one end protruding toward the outside of the pouch-shaped case more than the end of the permeable resin layer of the gas induction film protruding toward the outside of the pouch-shaped case.

[0012] In at least one of the above [1] to

[0011] , the number of gas channels may be two or more.

[0013] In at least one of the above [1] to

[0012] , the lead film may be arranged so that one end protruding toward the outside of the pouch-shaped case protrudes further than one end of the gas induction film protruding toward the outside of the pouch-shaped case and directly contacts the electrode lead.

[0014] In at least one of the above [1] to

[0013] , one side of the electrode lead may be coated with at least one selected from the group consisting of chromium (Cr), nickel (Ni), aluminum oxide (Al2O3), zirconium (Zr)-based anhydride salt, and titanium (Ti)-based anhydride salt. The pouch-type secondary battery according to the present invention can have the advantage of low operating pressure of the gas induction film where gas discharge begins and fast gas discharge rate through the dimensional design of the gas passage and permeation portion constituting the gas induction film. Furthermore, while issues of moisture infiltration and electrolyte leakage through the gas induction film tend to be dependent on the material, they can be minimized through dimensional design, thereby significantly contributing to overcoming material limitations. Accordingly, the pouch-type secondary battery of the present invention can have excellent durability and safety by being able to immediately discharge gas to the outside as it is generated while minimizing leakage of electrolyte and infiltration of moisture. The drawings attached to the specification illustrate preferred embodiments of the present invention and, together with the contents of the invention described above, serve to further understand the technical idea of ​​the present invention. Therefore, the present invention should not be interpreted as being limited to the matters described in such drawings. Figure 1 is an exploded assembly diagram of a pouch-type secondary battery according to the present invention. Figure 2 is a cross-sectional view of a sealed pouch-type secondary battery. Figure 3 is an example of a cross-sectional view of a pouch-type secondary battery before the pouch-type case is lifted. Figure 4 is an example of a cross-sectional view of a pouch-type secondary battery when the pouch-type case is lifted. Figure 5 is another example of a cross-sectional view of a pouch-type secondary battery before the pouch-type case is lifted. Figure 6 is another example of a cross-sectional view of a pouch-type secondary battery before the pouch-type case is lifted. Figure 7 is a top perspective view of a gas induction film having one gas path according to one embodiment of the present invention. FIG. 8 is a top perspective view of a gas induction film having two gas channels according to one embodiment of the present invention. The advantages and features of the present invention, and the methods for achieving them, will become clearer with reference to the embodiments described in detail below together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below and may be implemented in various different forms. These embodiments are provided only to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention, and the present invention is defined only by the scope of the claims. Like reference numerals designate like elements throughout the specification. Unless otherwise defined, all terms (including technical and scientific terms) used herein may be used in their common sense to those of ordinary skill in the art to which the present invention pertains. Furthermore, terms defined in commonly used dictionaries are not to be interpreted ideally or excessively unless explicitly and specifically defined otherwise. The terminology used herein is for the purpose of describing embodiments and is not intended to limit the present invention. In this specification, singular forms also include plural forms, unless specifically stated otherwise. As used herein, the terms "comprises" and / or "comprising" do not exclude the presence or addition of one or more other components in addition to the components mentioned. In this specification, when it is said that a part includes a certain component, this does not mean that other components are excluded, but rather that other components may be included, unless specifically stated otherwise. In this specification, the description of “A and / or B” means A, or B, or A and B. In this specification, “%” means weight percent unless explicitly indicated otherwise. The pouch-type secondary battery described in this specification includes at least one of the technical configurations described below, and may include any combination between technically possible configurations among the technical configurations below. A pouch-type secondary battery according to the present invention comprises: an electrode assembly; a pouch-type case including a receiving portion for receiving the electrode assembly; and a terrace portion provided along the periphery of the receiving portion and having a sealing portion with a portion of the width sealed; an electrode lead connected to the electrode assembly and protruding to the outside of the pouch-type case via the terrace portion; a lead film disposed between the electrode lead and the pouch-type case; and a gas induction film disposed between the electrode lead and the lead film; wherein the gas induction film includes a permeation portion formed on the outside of the sealing portion, and at least one gas path formed via the sealing portion such that the permeation portion and the inside of the pouch-type case are connected to each other, and the pouch-type secondary battery has a gas emission coefficient (C) expressed by the following Equation 1. R ) is 10 to 25. [Formula 1] C R = 2(S A / W L ) + W P In the above equation 1, WP is the total width (mm) of one or more gas channels, and W L is the width of the electrode lead (mm), and S A is the area of ​​the penetration section (mm) 2 )am. In general, the gas discharge performance of a gas induction film is determined by the properties of the material constituting the gas induction film, and depending on the properties of the material, the moisture penetration prevention performance and electrolyte leakage prevention performance can be determined, and gas permeability is also a property that varies depending on the material, and the material constituting the gas induction film plays an important role. However, even though the material plays an important role, there are clearly areas that are not determined by the material, and considering that there are factors that can improve gas discharge performance regardless of the material, the present invention aims to define a gas induction film that can have excellent gas discharge performance while also improving moisture penetration and electrolyte leakage prevention performance by designing the area of ​​the gas-permeable portion of the gas induction film and the width of the gas path formed from the inside of the pouch-type case to the gas-permeable portion. First, each component of the pouch-type secondary battery of the present invention will be described in more detail with reference to the drawings. FIG. 1 is an exploded assembly diagram of a pouch-type secondary battery (100) according to the present invention, and FIG. 2 is a cross-sectional view of a sealed pouch-type secondary battery (100). In FIG. 2, some of the components of the pouch-type secondary battery (100) are omitted for ease of understanding. As illustrated in FIGS. 1 and 2, the pouch-type secondary battery (100) of the present invention includes a pouch-type case (110), an electrode assembly (160), an electrode lead (180), a lead film (190), and a gas induction film (200). (1) Pouch-type case According to one embodiment of the present invention, the pouch-shaped case (110) can accommodate an electrode assembly (160) inside. The pouch-shaped case (110) can be manufactured by molding a pouch film laminate. In this case, the pouch film laminate can include a substrate layer, a gas barrier layer, and a sealant layer. In the pouch film laminate, the substrate layer, the gas barrier layer, and the sealant layer can be sequentially laminated. The substrate layer is formed on the outermost layer of the pouch film laminate to protect the secondary battery from friction and collision with the outside world. The substrate layer is made of polymer and can electrically insulate the electrode assembly from the outside world. The substrate layer may be made of one or more materials selected from the group consisting of polyethylene, polypropylene, polycarbonate, polyethylene terephthalate, polyvinyl chloride, acrylic polymers, polyacrylonitrile, polyimide, polyamide, cellulose, aramid, nylon, polyester, polyparaphenylene benzobisoxazole, polyarylate, Teflon, and glass fiber. Preferably, the substrate layer may be made of polyethylene terephthalate (PET), nylon, or a combination thereof, which have wear resistance and heat resistance. The substrate layer may have a single-layer structure composed of a single material. Alternatively, the substrate layer may have a composite-layer structure composed of two or more materials, each formed as a layer. The thickness of the substrate layer may be 5 ㎛ to 50 ㎛, specifically 7 ㎛ to 40 ㎛, and more specifically 25 ㎛ to 38 ㎛. When the thickness of the substrate layer satisfies the above range, the external insulation is excellent, and the thickness of the entire pouch is not thick, so the energy density per volume of the secondary battery can be excellent. The gas barrier layer is laminated between the substrate layer and the sealant layer to secure the mechanical strength of the pouch, block the ingress of gas or moisture from outside the secondary battery, and prevent electrolyte leakage from inside the pouch-type case. The gas barrier layer may be formed of a metal, and specifically, may be formed of an aluminum alloy thin film. When the gas barrier layer is formed using an aluminum alloy thin film, a mechanical strength higher than a predetermined level can be secured, while being light in weight and ensuring complementary electrochemical properties and heat dissipation properties due to the electrode assembly and electrolyte. The aluminum alloy thin film may include at least one selected from the group consisting of metal elements other than aluminum (Al), for example, iron (Fe), copper (Cu), chromium (Cr), manganese (Mn), nickel (Ni), magnesium (Mg), silicon (Si), and zinc (Zn). The thickness of the gas barrier layer may be 40 ㎛ to 100 ㎛, specifically 50 ㎛ to 90 ㎛, and more specifically 55 ㎛ to 85 ㎛. When the thickness of the gas barrier layer satisfies the above range, the formability and gas barrier performance are excellent when forming the cup portion. The sealant layer is intended to completely seal the interior of the pouch-shaped case, which houses the electrode assembly inside, by mutually thermally bonding at the sealing portion when the pouch-shaped case is sealed. To this end, the sealant layer may be formed of a material having excellent thermal bonding strength. The sealant layer may be formed of a material having insulating, corrosion-resistant, and sealing properties. Specifically, since the sealant layer is in direct contact with the electrode assembly and / or electrolyte inside the pouch-shaped case, it may be formed of a material having insulating and corrosion-resistant properties. In addition, since the sealant layer must completely seal the inside of the pouch-shaped case to prevent material movement between the inside and the outside, it may be formed of a material having high sealing properties (e.g., excellent thermal bonding strength). To secure such insulating, corrosion-resistant, and sealing properties, the sealant layer may be formed of a polymer material. The sealant layer may be made of one or more materials selected from the group consisting of polyethylene, polypropylene, polycarbonate, polyethylene terephthalate, polyvinyl chloride, acrylic polymers, polyacrylonitrile, polyimide, polyamide, cellulose, aramid, nylon, polyester, polyparaphenylenebenzobisoxazole, polyarylate, Teflon, and glass fiber, and preferably may be made of a polyolefin resin such as polypropylene (PP) and / or polyethylene (PE). In this case, the polypropylene may be composed of cast polypropylene (CPP), acid modified polypropylene (Acid Modified Polypropylene, PPa), polypropylene-ethylene copolymer, and / or polypropylene-butylene-ethylene terpolymer. The thickness of the sealant layer may be 30 ㎛ to 130 ㎛, specifically 50 ㎛ to 120 ㎛, and more specifically 70 ㎛ to 100 ㎛. When the thickness of the sealant layer satisfies the above range, there is an effect of securing the sealing strength of the sealing portion while also securing the formability of the pouch film laminate. Meanwhile, the pouch film laminate may be drawn and stretched by a punch or the like to manufacture a pouch-shaped case (110). As a result, the pouch-shaped case (110) may include a cup portion (122) and a receiving portion (124). The receiving portion (124) is a place for receiving the electrode assembly, and may refer to a receiving space formed in the shape of a pocket on the inside of the cup portion (122) as the cup portion (122) is formed. According to one embodiment of the present invention, the pouch-type case (110) may include a first case (120) and a second case (130) as illustrated in FIG. 1. The first case (120) includes a receiving portion (124) capable of receiving an electrode assembly (160), and the second case (130) may cover the receiving portion (124) from above to prevent the electrode assembly (160) from being separated from the outside of the battery case (110). The first case (120) and the second case (130) may be manufactured such that one side thereof is connected to each other as illustrated in FIG. 1, but are not limited thereto and may be manufactured in various ways, such as being manufactured separately and separated from each other. According to another embodiment of the present invention, when forming a cup portion on a pouch film laminate, two symmetrical cup portions (122, 132) can be drawn and formed adjacent to each other on one pouch film laminate. In this case, cup portions (122, 132) can be formed on the first case (120) and the second case (130) respectively, as shown in FIG. 1. After the electrode assembly (160) is accommodated in the receiving portion (124) provided in the cup portion (122) of the first case (120), the bridge portion (140) formed between the two cup portions (122, 132) can be folded so that the two cup portions (122, 132) face each other. In this case, the cup portion (132) of the second case (130) can accommodate the electrode assembly (160) from above. Accordingly, since two cup portions (122, 132) accommodate one electrode assembly (160), an electrode assembly (160) having a thicker thickness can be accommodated than when there is only one cup portion (122). In addition, since one corner of the secondary battery (100) is formed by folding the pouch-type case (110), the number of corners to be sealed can be reduced when performing the sealing process later. Accordingly, the process speed of the pouch-type secondary battery (100) can be improved, and the number of sealing processes can be reduced. The pouch-type case (110) can be sealed while housing the electrode assembly (160) so that a portion of the electrode lead (180) described later, i.e., a terminal portion, is exposed. Specifically, when the electrode lead (180) is connected to the electrode tab (170) of the electrode assembly (160) and a lead film (190) is formed on a portion of the electrode lead (180), the electrode assembly (160) can be housed in a receiving portion (124) provided in a cup portion (122) of the first case (120), and the second case (130) can cover the receiving portion (124) from above. Subsequently, an electrolyte can be injected into the receiving portion (124), and a portion of the terrace portion (150) formed along the perimeter of the first case (120) and the second case (130) can be sealed to form a sealing portion (not shown). The sealing portion can serve to seal the receiving portion (124). Specifically, the sealing portion can seal the receiving portion (124) by being formed on the terrace portion (150) formed along the perimeter of the receiving portion (124). The temperature at which the sealing portion is sealed may be 180°C to 250°C, specifically 200°C to 250°C, and more specifically 210°C to 240°C. When the sealing temperature satisfies the above numerical range, the pouch-type case (110) can secure sufficient sealing strength through thermal bonding. (2) Electrode assembly According to one embodiment of the present invention, the electrode assembly (160) may be inserted into a pouch-shaped case (110) and sealed by the pouch-shaped case (110) after electrolyte injection. The electrode assembly (160) may be formed by sequentially stacking an anode, a separator, and a cathode. Specifically, the electrode assembly (160) may include two types of electrodes, an anode and a cathode, and a separator interposed between the electrodes to mutually insulate the electrodes. The positive and negative electrodes may each have a structure in which an active material slurry is applied to an electrode current collector in the form of a metal foil or metal mesh containing aluminum and copper, respectively. The slurry is typically formed by stirring granular active materials, auxiliary conductors, binders, and conductive agents with the addition of a solvent. The solvent can be removed in a subsequent process. A slurry containing an electrode active material, a binder, and / or a conductive material is applied to a positive electrode current collector and a negative electrode current collector to manufacture a positive electrode and a negative electrode, and these are laminated on both sides of a separator, thereby manufacturing an electrode assembly (160) in a predetermined shape. The types of electrode assembly (160) may include, but are not limited to, a stack type, a jelly roll type, a stack and folding type, etc. The electrode assembly (160) may include an electrode tab (170). The electrode tabs (170) are respectively connected to the positive and negative electrodes of the electrode assembly (160), and may protrude outward from the electrode assembly (160) to serve as a path for electrons to move between the inside and the outside of the electrode assembly (160). The electrode current collector included in the electrode assembly (160) may be composed of a portion where an electrode active material is applied and a terminal portion where the electrode active material is not applied, i.e., a non-coated portion. The electrode tabs (170) may be formed by cutting the non-coated portion or by connecting a separate conductive member to the non-coated portion by ultrasonic welding, etc. As illustrated in FIG. 1, the electrode tabs (170) may protrude in different directions of the electrode assembly (160), but are not limited thereto, and may be formed to protrude in various directions, such as protruding in parallel in the same direction from one side. (3) Electrode lead According to one embodiment of the present invention, the electrode lead (180) can supply electricity to the outside of the secondary battery (100). The electrode lead (180) can be connected to the electrode tab (170) of the electrode assembly (160) by spot welding or the like. The electrode lead (180) is connected to the electrode assembly (160) and can protrude to the outside of the pouch-type case (110) via the sealing portion (150). Specifically, one end of the electrode lead (180) is connected to the electrode assembly (160), particularly to the electrode tab (170), and the other end of the electrode lead (180) can protrude to the outside of the pouch-type case (110) via the terrace portion (150). The electrode lead (180) may include a positive lead (182) having one end connected to the positive tab (172) and extending in the direction in which the positive tab (172) protrudes, and a negative lead (184) having one end connected to the negative tab (174) and extending in the direction in which the negative tab (174) protrudes. Both the positive lead (182) and the negative lead (184) may have other ends protruding outward from the battery case (110). Accordingly, electricity generated inside the electrode assembly (160) may be supplied to the outside. In addition, since the positive tab (172) and the negative tab (174) are formed to protrude in various directions, the positive lead (182) and the negative lead (184) may also extend in various directions, respectively. The positive lead (182) and the negative lead (184) may be made of different materials. That is, the positive electrode lead (182) may be made of the same aluminum (Al) material as the positive electrode collector, and the negative electrode lead (184) may be made of the same copper (Cu) material as the negative electrode collector or a nickel (Ni)-coated copper material. A portion of the electrode lead (180) protruding outside the battery case (110) may serve as a terminal portion and be electrically connected to an external terminal. One surface of the electrode lead (180) that is in direct contact with the lead film (190) and / or the gas induction film (200) may be coated with at least one selected from the group consisting of chromium (Cr), nickel (Ni), aluminum oxide (Al2O3), zirconium (Zr)-based anhydride salts, and titanium (Ti)-based anhydride salts. In this case, corrosion resistance against the electrolyte and adhesion to the lead film (190) and / or the gas induction film (200) can be secured. (4) Lead film According to one embodiment of the present invention, the lead film (190) prevents electricity generated from the electrode assembly (160) from flowing to the battery case (110) through the electrode lead (180) and can maintain the sealing of the battery case (110). To this end, the lead film (190) may be formed of a non-conductive material that does not conduct electricity well. In general, the lead film (190) is often made of an insulating tape that is easy to attach to the electrode lead (180) and / or the gas induction film (200) and has a relatively thin thickness, but is not limited thereto, and any material capable of insulating the electrode lead (180) may be used. The lead film (190) may be arranged to surround the outer circumference of the electrode lead (180) and the gas induction film (200). Specifically, the electrode lead (180) and the gas induction film (200) may be in contact with each other at one side, and at least a portion of the electrode lead (180) and the gas induction film (200) may be surrounded by the lead film (190). The lead film (190) may be positioned limited to the sealing portion (150) where the first case (120) and the second case (130) of the pouch-shaped case (110) are heat-sealed, and may adhere the electrode lead (180) and the gas induction film (200) to the battery case (110). The lead film (190) may be placed between the electrode lead (180) and / or the gas induction film (200) and the pouch-shaped case (110). For example, as illustrated in FIG. 2, the lower case (110), the lead film (190), the electrode lead (180), the gas induction film (200), the lead film (190), and the upper case (110) may be sequentially stacked in the sealing portion (150) area. Meanwhile, the lead film (190) may include one or more layers. Specifically, the lead film (190) may include a sequentially laminated metal adhesive layer, a core layer, and a pouch adhesive layer. The metal adhesive layer may be in direct contact with the electrode lead (180) and may be used to adhere the lead film (190) to the electrode lead (180). The metal adhesive layer may include any material that is easily adhered to the electrode lead (180). Specifically, the metal adhesive layer may include an acid-modified polyolefin. For example, the metal adhesive layer may include at least one of acid modified polypropylene (PPa), acid modified polyethylene (PEa), and plasma-treated polypropylene (PP), but is not limited thereto. The thickness may be 50 ㎛ to 80 ㎛, specifically 50 ㎛ to 75 ㎛, and more specifically 60 ㎛ to 75 ㎛. When the thickness of the metal adhesive layer satisfies the above numerical range, there is an effect of preventing a through-hole and leakage at the edge portion when the electrode lead and the lead film are fused. The core layer may be a layer located at the center of the lead film (190). The core layer may include, but is not limited to, additives such as polypropylene, polyolefin elastomer (POE), and / or a colorant. Among them, the polymer included in the core layer may be a homopolymer. When the core layer includes a homopolymer, the melting point of the core layer can be controlled within the above numerical range, and deformation due to heat can be minimized, which is advantageous in terms of securing insulation. The thickness of the core layer may be 40 ㎛ to 70 ㎛, specifically 50 ㎛ to 70 ㎛, and more specifically 60 ㎛ to 70 ㎛. When the thickness of the core layer satisfies the above numerical range, deformation due to heat applied during fusion and sealing is prevented, thereby providing a robust design effect in terms of securing insulation. The pouch adhesive layer may be a layer that directly contacts the battery case (110), specifically, the sealant layer of the pouch film laminate. The pouch adhesive layer may include, but is not limited to, polypropylene and polyolefin elastomer (POE). Among them, the polymer included in the pouch adhesive layer may be a copolymer. The melting point of the pouch adhesive layer including the copolymer in the pouch adhesive layer can be controlled within the above numerical range, and has a similar melting point to the polymer in the sealant layer of the pouch film laminate, which is advantageous in ensuring sealing processability. The thickness of the pouch adhesive layer may be 40 ㎛ to 100 ㎛, specifically, 40 ㎛ to 80 ㎛, and more specifically, 40 ㎛ to 60 ㎛. When the thickness of the pouch adhesive layer satisfies the above numerical range, there is an effect of ensuring a polymer (e.g., polypropylene) residual rate sufficient to secure strength when sealing between the electrode lead and the pouch film laminate. (5) Gas-induced film According to one embodiment of the present invention, the gas induction film (200) is for discharging gas from the inside of the pouch-shaped case (110) to the outside. As illustrated in FIG. 2, the gas induction film (200) of the present invention may be disposed between the electrode lead (180) and the lead film (190). In this case, in the area between the electrode lead (180) and the lead film (190), where the gas induction film (200) is disposed, the electrode lead (180) and the lead film (190) do not directly contact each other, and in the area where the gas induction film (200) is not disposed, the electrode lead (180) and the lead film (190) may directly contact each other. Hereinafter, the gas induction film (200) of the present invention will be described in more detail with reference to FIGS. 3 and 4. FIG. 3 is a cross-sectional view of a pouch-type secondary battery before the pouch-type case is lifted, and FIG. 4 is a cross-sectional view of a pouch-type secondary battery when the pouch-type case is lifted. As shown in FIGS. 3 and 4, the interface between the gas induction film (200) and the lead film (190) can be maintained in a closed state without being opened in a normal driving situation or when the amount of gas generated inside is small. However, if gas is generated for a certain reason in the internal battery reaction and the internal pressure of the pouch-shaped case (110) increases, the interface between the gas induction film (200) and the lead film (190) may be opened along the gas path (240) of the gas induction film (200), thereby forming a gas discharge path (300). The gas inside the pouch-shaped case (110) may move to the permeation portion (230) through the gas discharge path (300) formed along the gas path (240) and then pass through the lead film (190) to be discharged to the outside of the pouch. As a result, the internal pressure of the pouch-shaped case (110) may be lowered, thereby preventing explosion or ignition of the pouch-shaped case (110), thereby ensuring the safety of the secondary battery. Meanwhile, as shown in FIGS. 3 and 4, the gas induction film (200) of the present invention includes an adhesive resin layer (210) in contact with the electrode lead (180), and a permeable resin layer (220) disposed on the adhesive resin layer (210). The adhesive resin layer (210) is in contact with the electrode lead (180) and may be used to adhere the gas induction film (200) to the electrode lead (180). According to one embodiment of the present invention, as in FIG. 3 or 4, the adhesive resin layer (210) of the gas induction film (200) may be formed to be longer in the outward direction of the pouch-shaped case (110) than the permeable resin layer (220), and one end of the lead film (190) protruding in the outward direction of the pouch-shaped case (110) may be positioned to protrude further outward than the adhesive resin layer (210) and come into direct contact with the electrode lead (180). In this way, when the lead film (190) is formed to protrude further than one end of the gas induction film (200) toward the outside of the pouch-shaped case (110), the adhesive force between the electrode lead (180) and the gas induction film (200), and between the electrode lead (180) and the lead film (190) is strong, so that a decrease in durability due to an increase in internal pressure can be prevented, and since the area of ​​the permeable portion (230) on the permeable resin layer (220) can be easily secured, stable gas discharge can be possible. Alternatively, as in FIG. 5, the lead film (190) may be arranged so that one end protruding outwardly from the pouch-shaped case (110) protrudes further than one end of the gas induction film (200) protruding outwardly from the pouch-shaped case (110) and comes into direct contact with the electrode lead (180), and as in FIG. 6, the adhesive resin layer (210) may be arranged so that one end protruding outwardly from the pouch-shaped case (110) protrudes further than one end of the permeable resin layer (220) protruding outwardly from the pouch-shaped case (110), but the lead film (190) may not be arranged directly with the electrode lead (180) but comes into contact with the adhesive resin layer (210). In the case where the arrangement structure of the lead film (190), electrode lead (180) and gas induction film (200) is formed as in FIG. 3, FIG. 5 or FIG. 6, it may be advantageous in terms of securing durability and securing the area of ​​the permeable portion (230) compared to the case where the lead film (190) is not arranged so that one end protrudes further outward from the pouch-shaped case (110) than the gas induction film (200) but is arranged on the permeable resin layer (220) of the gas induction film (200). However, although it may be arranged as in FIG. 3 most preferably, there is no disadvantage in performance in the structure of FIG. 5 or FIG. 6, and there may be some differences in design and process. The adhesive resin layer (210) may include any material that is easily bonded to the electrode lead (180). Specifically, the adhesive resin layer (210) may include a modified polyolefin-based resin. When the adhesive resin layer (210) includes a modified polyolefin-based resin, the adhesive strength between the gas induction film (200) and the electrode lead (180) is improved, so that even when the pouch-type secondary battery is stored in a high-temperature environment, the gas induction film (200) is prevented from being detached from the electrode lead (180) and pushed out of the pouch, or the electrolyte inside the pouch is prevented from leaking. The adhesive resin layer (210) may include at least one of an acid-modified polyolefin and a silane-modified polyolefin. Acid-modified polyolefin refers to a polyolefin resin that has been graft-modified with an acid. For example, the acid-modified polyolefin may be a polyolefin resin in which a carboxyl group is introduced (graft-modified) by reacting an unsaturated carboxylic acid. In this case, the unsaturated carboxylic acid may include the concept of a carboxylic anhydride, and the carboxyl group may include the concept of a carboxylic anhydride group. The unsaturated carboxylic acid reacted with the polyolefin resin may include at least one selected from the group consisting of maleic acid, fumaric acid, itaconic acid, citraconic acid, glutaconic acid, tetrahydrophthalic acid, aconitic acid, maleic anhydride, itaconic anhydride, glutaconic anhydride, citraconic anhydride, aconitic anhydride, norbornene dicarboxylic anhydride, and tetrahydrophthalic anhydride, but is not limited thereto. Among these, it is preferable to apply maleic anhydride to improve the adhesive strength between the gas induction film (200) and the electrode lead (180). The acid-modified polyolefin may include at least one selected from the group consisting of acid-modified polypropylene (PPa) and acid-modified polyethylene (PEa), but is not limited thereto. Silane-modified polyolefin refers to a polyolefin resin that has been graft-modified with an unsaturated silane compound. The silane-modified polyolefin may have a structure in which an unsaturated silane compound is graft-copolymerized onto a polyolefin resin, which is the main chain. The silane-modified polyolefin resin may include, but is not limited to, one or more selected from the group consisting of silane-modified polypropylene resin and silane-modified ethylene-vinyl acetate copolymer. The adhesive resin layer (210) may be modified, and the modification treatment may include ion implantation treatment, plasma treatment, radiation treatment, heat treatment, etc., and a treatment that changes the bonding structure of the polymer layer is preferable. These modification treatments may be performed singly by one type, or may be performed in combination of two or more types. The modified adhesive resin layer (210) may include, but is not limited to, plasma-treated polypropylene (PP). The thickness of the adhesive resin layer (210) may be 5 µm to 130 µm, specifically 30 µm to 120 µm, and more specifically 30 µm to 80 µm. When the thickness of the adhesive resin layer (210) satisfies the above numerical range, the gas induction film (200) and the electrode lead (180) can be easily fused together by melting the adhesive resin layer (210) within a set production time (tact time). The permeable resin layer (220) may be a layer in contact with the lead film (190). The permeable resin layer (220) may include at least one of polytetrafluoroethylene (PTFE) and polyimide (PI), but is not limited thereto. Among them, when polyimide is included in the permeable resin layer (220), it is preferable in that the adhesive force between the permeable resin layer (220) and the lead film (190) is reduced, so that a gas discharge path (300) can be formed when the internal pressure of the case (110) increases. When polytetrafluoroethylene is included, the gas permeability is excellent and the liquid barrier property is also excellent, so that when the gas is not discharged, the possibility of electrolyte seeping through the gas discharge path can be reduced, and the adhesive force with the lead film (190) is also small, so that the operating pressure can be lowered and gas discharge can begin early. The thickness of the permeable resin layer (220) may be 40 ㎛ to 100 ㎛, specifically 40 ㎛ to 90 ㎛, and more specifically 45 ㎛ to 75 ㎛. When the thickness of the permeable resin layer (220) satisfies the above numerical range, the permeable resin layer (220) may not melt during the sealing process, and when the internal pressure of the case (110) increases, the interface between the permeable resin layer (220) and the lead film (190) may be lifted to form a gas discharge path (300). Meanwhile, the ratio (D1 / D2) of the thickness (D1) of the adhesive resin layer to the thickness (D2) of the permeable resin layer may be 0.4 to 2.0, specifically 0.4 to 1.5, and more specifically 0.4 to 1.0. When the ratio (D1 / D2) satisfies the above numerical range, when the internal pressure of the case (110) increases, the interface between the permeable resin layer (220) and the lead film (190) is lifted to form a gas discharge path, while improving the adhesive strength between the gas induction film (200) and the electrode lead (180). According to one embodiment of the present invention, the gas induction film (200) includes a permeable portion (230) formed on the outside of the sealing portion, and one or more gas channels (240) formed such that the permeable portion and the inside of the pouch-shaped case are connected to each other via the sealing portion. In addition, the gas induction film (200) may have at least one gas path (240), preferably at least two, and there is no limitation on the number of gas paths (240) within a range that satisfies the gas emission coefficient described below. However, considering the processability and ease of manufacturing the gas induction film, it may be preferable for the gas paths (240) to be formed in two. FIGS. 7 and 8 are top perspective views of a gas induction film (200) of an electrode lead (180) and a lead film (190) according to one embodiment of the present invention, with the terrace portion (150) of the pouch-type case (110) omitted, and the sealing portion (151), which is a sealed portion, illustrated as an area. As described above, the gas induction film (200) is disposed on the electrode lead (180), and may be laminated in the order of an adhesive resin layer (210) and a permeable resin layer (220), and the lead film (190) may be disposed on the gas induction film (200), and the terrace portion (150) of the pouch-type case (110) may be disposed on the lead film (190) to form a packaging structure, and the sealing portion (151) may be formed on the terrace portion (150) through sealing. Referring to Fig. 7, the gas induction film (200) has a permeable portion (230) through which gas is transmitted, formed on the outside of the sealing portion (151), and a gas path (240) connects the inside of the pouch-shaped case (110) from the permeable portion (230) through the sealing portion (151) to form a path through which gas is discharged. The gas induction film (200) may have one gas path (240) and may have a “ㅜ” shape as in Fig. 7, or may have two gas paths (240) and may have a “ㅠ” shape as in Fig. 8. In the case where there are two or more gas paths (240) as in Fig. 6, the width (W) of the plurality of gas paths (240) P1 , W P2 , W P3 …W Pn ) is used as a factor of the gas emission coefficient in Equation 1 below. P (W P =W P1 +W P2 +W P3 +… +W Pn ) may be. Here, the permeation portion (230) and the gas path (240) can be distinguished by a horizontal dividing line in the width direction of the electrode lead (180) formed at a point where the angle of the extension line of the gas path (240) changes with respect to the longitudinal straight line of the electrode lead (180) on the upper surface perspective view of the gas induction film (200) such as FIG. 7 or FIG. 8, and the inner region of the pouch-shaped case (110) can be defined as the gas path (240), and the outer region can be defined as the permeation portion (230). The above pouch-type secondary battery has a gas emission coefficient (C) defined by the following equation 1 R ) is 10 to 25. [Formula 1] C R = 2(S A / W L ) + W P In the above equation 1, W P is the sum of the widths of one or more gas channels (mm), and W L is the width of the electrode lead (mm), and S A is the area of ​​the penetration section (mm) 2 )am. Hereinafter, in explaining the gas emission coefficient, the drawing symbols of each component are omitted. The above gas discharge coefficient is a value designed by its dimensions regardless of the material of the gas induction film, and is characterized by taking into account the area of ​​the permeation portion, the width of the gas channel, and the width of the electrode lead as factors. The gas discharge rate is advantageous when the area of ​​the permeation portion and the width of the gas channel are large, but conversely, the larger the area, the higher the possibility of problems occurring in terms of preventing moisture infiltration and electrolyte leakage. In addition, when the area of ​​the permeation portion of the gas induction film increases relative to the width of the electrode lead, the increase in gas discharge performance is not large compared to the increase in the area of ​​the permeation portion, which may result in an inappropriate design when considering the possibility of moisture infiltration and electrolyte leakage. Furthermore, when the width of the gas channel increases relative to the area of ​​the permeation portion, the gas discharge rate increases and the operating pressure decreases, forming a complex relationship in which the problem of moisture infiltration occurs. In other words, although the gas induction film has better performance as the area of ​​the permeable portion increases, under the limitations of the width of the electrode lead and the width of the gas path, the gas discharge performance, moisture infiltration prevention, and electrolyte leakage prevention effects can be improved only by expanding the area of ​​the permeable portion. Accordingly, the gas induction film according to one embodiment of the present invention has a gas discharge coefficient as expressed by Equation 1, and is characterized in that it has a fast gas discharge rate, can prevent electrolyte leakage and moisture infiltration, and can be operated at a low internal pressure. Preferably, the gas emission coefficient may be 11 or more, 12 or more, 13 or more, or 14 or more, and may also be 24 or less, 23 or less, 22 or less, or 21 or less. When the gas emission coefficient satisfies the above-mentioned range, a gas induction film that can satisfy moisture penetration prevention performance and electrolyte leakage prevention performance together with gas emission performance can be implemented. More specifically, the gas induction film according to one embodiment of the present invention has a width (W) of the electrode lead L ) for the area of ​​the permeable portion (S) A) of the ratio (S) A / W L ) may be 1.7 mm to 7.5 mm, preferably 1.9 mm or more, 2.2 mm or more, 2.5 mm or more, or 2.7 mm or more, and also preferably 7.0 mm or less, 6.5 mm or less, 6.0 mm or less, 5.5 mm or less, or 5.0 mm or less. In addition, the gas induction film according to one embodiment of the present invention has a total width of the gas path (W P ) may be 6 mm to 20 mm. Preferably, it may be 7 mm or more, 8 mm or more, 9 mm or more, or 10 mm or more, and 18 mm or less, 16 mm or less, 15 mm or less, or 14 mm or less. The gas emission coefficient of the gas induction film according to one embodiment of the present invention is “the width of the electrode lead (W L ) for the area of ​​the permeable portion (S) A ) of the ratio (S) A / W L ) and “the total width of the gas pipeline (W P )”. That is, when the sum of the permeation area and the gas path width with respect to the electrode lead width has a mutually appropriate value, that is, when it maintains an appropriate range so as to complement each other, it can be advantageous in terms of gas discharge performance, moisture penetration, and prevention of electrolyte leakage. If the permeation area and the gas path width with respect to the electrode lead width are both too small, the gas discharge coefficient can become less than 10, and accordingly, a certain level of effect can be achieved in terms of moisture penetration or electrolyte leakage, but of course, the operating pressure is too high and the gas discharge speed is slow, so the gas discharge is not smooth, and ultimately, problems due to swelling of the cell can occur. In addition, if the permeation area and the gas path width are increased simultaneously with respect to the electrode lead width, the gas emission coefficient may exceed 25, and in this case, the problems of moisture infiltration and electrolyte leakage may be so serious that it may be difficult to apply it as a gas induction film of a cell. Furthermore, even if the permeation area with respect to the electrode lead width is somewhat small, the gas induction film can be designed by utilizing the gas emission coefficient, such as designing the gas path width relatively wide, or designing the permeation area with respect to the electrode lead width wide even if the gas path width is small. Moreover, as batteries become larger and are designed in modules and packs, there may be various variables such as the battery cell itself becoming larger or multiple small battery cells being assembled, but in the case of the above gas emission coefficient, by reflecting the size of the battery cell through the width of the electrode lead, it is possible to determine an appropriate design point in the three-way trade-off relationship among the gas emission rate, moisture infiltration amount, and operating pressure depending on the amount of gas generated. Accordingly, the pouch-type secondary battery according to one embodiment of the present invention has the gas induction film as described above, so that gas can be discharged at a high rate at a low operating pressure, and also has excellent performance in preventing leakage of electrolyte and moisture infiltration, so that there is no problem of corrosion due to generated gas or corrosion due to moisture infiltration or electrolyte leakage, and thus it can contribute to an improvement in lifespan by increasing durability, and the driving performance of the cell can be maintained by continuous gas discharge, and the risk of explosion due to swelling is also reduced, so that safety can be ensured. (6) Electrolyte The pouch-type secondary battery (100) according to the present invention may further include an electrolyte (not shown) poured into the pouch-type case (110). The electrolyte is for moving lithium ions generated by an electrochemical reaction of an electrode during charging / discharging of the secondary battery (100), and may include a non-aqueous organic electrolyte that is a mixture of a lithium salt and an organic solvent, or a polymer using a polymer electrolyte. Furthermore, the electrolyte may include a solid electrolyte of a sulfide-type, oxide-type, or polymer-type, and such a solid electrolyte may have flexibility that is easily deformed by an external force. Hereinafter, the present invention will be described in more detail through specific examples. However, the following examples are merely illustrative and serve to aid understanding of the present invention and do not limit its scope. It will be apparent to those skilled in the art that various modifications and variations are possible within the scope and technical spirit of this disclosure, and such modifications and variations are naturally within the scope of the appended claims. Examples and Comparative Examples Examples 1 to 7, Comparative Examples 1 to 6 (1) Manufacturing of pouch-type cases A polyethylene terephthalate (PET) film measuring 266 mm in width, 50 m in height, and 12 ㎛ in thickness and a nylon film measuring 266 mm in width, 50 m in height, and 25 ㎛ in thickness were laminated on one side of an aluminum alloy film measuring 266 mm in width, 50 m in height, and 60 ㎛ in thickness, and a polypropylene film measuring 266 mm in width, 50 m in height, and 80 ㎛ in thickness was laminated on the other side, thereby manufacturing a pouch film laminate having a polyethylene terephthalate / nylon / aluminum alloy film / polypropylene film structure. Here, the polyethylene terephthalate film and nylon film are the substrate layer, the aluminum alloy thin film is the gas barrier layer, and the polypropylene film is the sealant layer. A pouch-shaped case including a receiving portion and a sealing portion was manufactured by molding the above pouch film laminate. (2) Manufacturing of pouch-type secondary batteries An electrode assembly was manufactured by stacking and laminating the cathode, anode, and porous polyethylene separator. Thereafter, an electrode lead was attached to the electrode assembly. An electrolyte was prepared by dissolving LiPF6 in a solvent (EC:EMC:DMC = 3:3:4 volume ratio) to a concentration of 1.0 M. The electrode assembly was stored in the pouch-type case with the tip of the electrode lead extended outward, and the electrolyte was poured. A 40 ㎛ thick acid-modified polypropylene film (adhesive resin layer) and a 50 ㎛ thick polytetrafluoroethylene film (permeable resin layer) were sequentially laminated on the upper surface of the electrode lead to form a gas induction film. Next, a 200 μm thick lead film was laminated on the lower surface of the electrode lead and the upper surface of the gas induction film, respectively. The lead film includes a 75 μm thick metal adhesive layer containing copolymer polypropylene and acid-modified polypropylene, a 65 μm thick core layer containing homopolymer polypropylene, and a 60 μm thick pouch adhesive layer containing copolymer polypropylene. Afterwards, the sealing part of the pouch-type case was sealed for 2 seconds under the conditions of a seal bar area of ​​200 mm × 10 mm, 220°C, and 0.27 MPa, and then left at 60°C for 4 hours to manufacture a pouch-type secondary battery. At this time, the part of the terrace part where the gas induction film is formed has a structure in which a lower case / lead film / electrode lead / gas induction film / lead film / upper case are sequentially laminated. Pouch-type secondary batteries of Examples 1 to 7 and Comparative Examples 1 to 6 were manufactured using the above method so that the gas-induced film had the dimensions shown in Table 1 below. S A / W L (mm) Total width of gas path (W) L, mm)Gas emission coefficient (C R )Embodiment 13.41016.8Embodiment 23.41218.8Embodiment 33.41420.8Embodiment 43.81017.6Embodiment 52.11014.2Embodiment 62.11216.2Embodiment 72.11418.2Comparative Example 13.428.8Comparative Example 23.42026.8Comparative Example 38.01026.0Comparative Example 40.845.6Comparative Example 50.867.6Comparative Example 60.889.6 Experimental Example 1: Measurement of gas emission rate The gas emission rate was measured for each pouch-type secondary battery manufactured in Examples 1 to 7 and Comparative Examples 1 to 6. Specifically, CO2 was injected into the pouch-type secondary battery using pressure equipment from ITS Corporation to increase the pressure inside the pouch to 1.5 atm, and the amount of gas emitted for 24 hours was measured, and the results are shown in Table 2 below. Experimental Example 2: Measurement of the operating pressure of a gas-induced film The operating pressure of the gas induction film was measured for each of the pouch-type secondary batteries manufactured in Examples 1 to 7 and Comparative Examples 1 to 6. Specifically, while injecting CO2 into the interior of a pouch-type secondary battery using pressure equipment from ITS Corporation and increasing the pressure inside the pouch by 0.1 atm units, the battery was left for 24 hours at each pressure, and the pressure at which the permeation portion of the gas-inducing film was completely deformed (when the entire permeation portion was lifted) was measured, and the results are shown in Table 2 below. Experimental Example 3: Measurement of moisture penetration (HF concentration measurement) In order to evaluate the moisture penetration amount of the pouch-type secondary batteries manufactured in Examples 1 to 7 and Comparative Examples 1 to 6, the HF concentration was measured. The moisture penetration amount was evaluated by leaving the pouch-type secondary battery under conditions of 60°C and 90% relative humidity for 16 weeks, then opening the secondary battery and measuring the concentration of HF in the electrolyte. The results are shown in Table 2 below. Gas discharge rate (cc / day) Operating pressure (atm) HF concentration (ppm, wt) Example 19.9 0.5 2,000 Example 212.5 0.5 3,700 Example 313.8 0.46 500 Example 417.8 0.8 8,000 Example 54.6 1.2 1,000 Example 65.3 1.1 1,100 Example 75.8 1.0 1,200 Comparative example 12.3 1.8 800 Comparative example 215.2 0.3 11,000 Comparative example 316.8 0.3 11,000 Comparative example 43.5 2.5 170 Comparative example 53.8 2.2 360 Comparative example 64.0 2.0 450 Referring to Table 2 above, in the case of Examples 1 to 7 that satisfy the gas emission coefficient, it can be confirmed that although there are individual differences in the three types of effects, namely gas emission rate, operating pressure, and moisture penetration amount, none of the effects show a level that can be considered problematic. Specifically, it can be confirmed that Examples 1 to 4 had a very fast gas emission rate and that the HF concentration was also generated at a negligible level. In the case of Examples 5 to 7, although the operating pressure was higher than Examples 1 to 4 and the gas emission rate was relatively low, the HF concentration was almost non-existent, so it was confirmed that the moisture blocking effect was also excellent. However, in Comparative Examples 1 and 4 to 6, the gas emission coefficient was designed to be too small, so although the HF concentration was low, the operating pressure was too high and the gas emission rate was too slow in comparison, making it difficult to prevent the battery from swelling. In the case of Comparative Examples 2 and 3, it can be expected that there will be a problem in that the moisture penetration amount was too large, significantly increasing the possibility of side reactions occurring during battery operation. Meanwhile, in the case of HF concentration, although the allowable range may differ depending on the specifications of the battery, based on the specifications of the battery evaluated in this experimental example, it can be said that side reactions do not occur to an extent that would affect the cycle characteristics, although the durability of the battery may be somewhat reduced at 8,000 ppm or less, and 4,000 ppm Below this level, it can be determined that there is no effect on the battery, but above 8,000 ppm, it can be evaluated as a level where problems such as rapid deterioration of the durability of the sealing part or electrode lead due to corrosion of the battery and acceleration of capacity degradation due to side reactions can occur. [Explanation of symbols] 100: Pouch-type secondary battery 110: Pouch-type case 120: Case 1 122: Cup 124: Reception area 130: Case 2 132: Cup 140: Bridge section 150: Terrace 151: Sealing part 160: Electrode assembly 170: Electrode tab 172: Positive tab 174: Negative tab 180: Electrode lead 182: Positive lead 184: Negative lead 190: Lead Film 200: Gas-induced film 210: Adhesive resin layer 220: Permeable resin layer 230: Transmission section 240: Gas Euro 300: Gas discharge path

Claims

1. Electrode assembly; A pouch-shaped case including a receiving portion for receiving the electrode assembly and a terrace portion having a sealing portion having a portion of the width thereof sealed along the periphery of the receiving portion; An electrode lead connected to the electrode assembly and protruding to the outside of the pouch-shaped case via the terrace portion; A lead film disposed between the electrode lead and the pouch-shaped case; and A gas induction film disposed between the electrode lead and the lead film; The above gas induction film includes a permeable portion formed on the outside of the sealing portion, and one or more gas passages formed through the sealing portion so that the permeable portion and the inside of the pouch-shaped case are connected to each other. The gas emission coefficient (C) expressed by the following equation 1 R ) is 10 to 25, pouch-type secondary battery: [Formula 1] C R = 2(S A / W L ) + W P In the above equation 1, W P is the sum of the widths of one or more gas channels (mm), and W L is the width of the electrode lead (mm), and S A is the area of ​​the penetration section (mm) 2 )am.

2. In claim 1, The above pouch-type secondary battery is a pouch-type secondary battery in which, when the internal pressure of the pouch-type case increases, the interface between the lead film and the gas induction film is opened, thereby forming a gas discharge path along the gas path.

3. In claim 1, The above gas induction film has a width (W) of the electrode lead L ) for the area of ​​the permeable portion (S) A ) of the ratio (S) A / W L ) is a pouch-type secondary battery having a thickness of 1.7 mm to 7.5 mm.

4. In claim 1, The above gas induction film is the total width of the gas path (W P ) is a pouch-type secondary battery having a thickness of 6 mm to 20 mm.

5. In claim 1, The above gas induction film is a pouch-type secondary battery having a structure in which an adhesive resin layer and a permeable resin layer are laminated from the upper surface of an electrode lead.

6. In claim 5, A pouch-type secondary battery, wherein the adhesive resin layer comprises at least one selected from the group consisting of acid-modified polypropylene (PPa) and acid-modified polyethylene (Pea).

7. In claim 5, A pouch-type secondary battery, wherein the above-mentioned permeable resin layer comprises at least one selected from the group consisting of polyimide (PI) and polytetrafluoroethylene (PTFE).

8. In claim 5, A pouch-type secondary battery, wherein the ratio (D1 / D2) of the thickness (D1) of the adhesive resin layer to the thickness (D2) of the permeable resin layer is 0.4 to 2.

0.

9. In claim 5, A pouch-type secondary battery, wherein the thickness of the adhesive resin layer is 5 ㎛ to 130 ㎛.

10. In claim 5, A pouch-type secondary battery, wherein the thickness of the above-mentioned permeable resin layer is 40 ㎛ to 100 ㎛.

11. In claim 5, A pouch-type secondary battery, wherein the adhesive resin layer of the gas-inducing film has one end protruding toward the outside of the pouch-type case more than the end of the permeable resin layer of the gas-inducing film protruding toward the outside of the pouch-type case.

12. In claim 1, A pouch-type secondary battery having two or more of the above gas paths.

13. In claim 1, A pouch-type secondary battery, wherein the lead film has one end protruding outwardly from the pouch-type case more than one end of the gas-inducing film protruding outwardly from the pouch-type case.

14. In claim 1, A pouch-type secondary battery, wherein one side of the electrode lead is coated with at least one selected from the group consisting of chromium (Cr), nickel (Ni), aluminum oxide (Al2O3), zirconium (Zr)-based anhydride salt, and titanium (Ti)-based anhydride salt.

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