Battery cell and battery module including the same

Abstract

A battery cell according to one embodiment of the present invention comprises: a battery case having a sealing portion having a structure in which an electrode assembly is mounted in a housing portion and the outer periphery is sealed; and a gas discharge portion inserted into the sealing portion, wherein the gas discharge portion protrudes from the inside of the battery case toward the outside of the battery case, and the gas discharge portion comprises a non-adhesive layer and an adhesive layer located on the non-adhesive layer, wherein the non-adhesive layer and the adhesive layer are bent in a direction that opens toward the inside of the battery case.

Description

Technology Field

[0001] The present invention relates to a battery cell and a battery module including the same, and more specifically, to a battery cell and a battery module including the same that suppresses the infiltration of moisture into the battery cell while improving the external discharge of gas generated inside the battery cell. Background Technology

[0002] With the increasing technological development and demand for mobile devices, the demand for secondary batteries as an energy source is rapidly increasing. In particular, secondary batteries are attracting significant interest as an energy source not only for mobile devices such as mobile phones, digital cameras, laptops, and wearable devices, but also for power devices such as electric bicycles, electric vehicles, and hybrid electric vehicles.

[0003] These secondary batteries are classified according to the shape of the battery case into cylindrical and prismatic batteries, in which the electrode assembly is embedded in a cylindrical or prismatic metal can, and pouch-type batteries, in which the electrode assembly is embedded in a pouch-type case made of an aluminum laminate sheet. Here, the electrode assembly embedded in the battery case is a power generation element capable of charging and discharging, consisting of a positive electrode, a negative electrode, and a separator structure interposed between the positive electrode and the negative electrode. It is classified into a jelly-roll type, which is wound with a separator interposed between long sheet-type positive and negative electrodes coated with active material, and a stack type, in which a plurality of positive and negative electrodes are sequentially stacked with a separator interposed between them.

[0004] Among these, pouch-type batteries, in particular those with a structure in which a stacked or stacked / folded electrode assembly is embedded in a pouch-type battery case made of aluminum laminate sheets, are seeing a gradual increase in usage due to reasons such as low manufacturing costs, small weight, and easy deformation.

[0005] However, as the energy density of battery cells has recently increased, there is a problem where the amount of gas generated inside the cell also increases. In particular, if the gas generated inside the battery cell is not easily vented, the cell may experience venting due to the gas generation. However, even if the battery cell includes a separate venting section for gas discharge, moisture can penetrate into the cell through said venting section. This leads to side reactions that result in a decrease in battery performance and additional gas generation. Accordingly, there is a growing need to develop a battery cell that improves the external discharge of gas generated inside the cell while preventing external moisture from penetrating into the cell. The problem to be solved

[0006] The problem to be solved by the present invention is to provide a battery cell and a battery module including the same, wherein the external discharge of gas generated inside the battery cell is improved while the infiltration of moisture into the battery cell is suppressed.

[0007] The problems that the present invention aims to solve are not limited to those described above, and problems not mentioned will be clearly understood by those skilled in the art to which the present invention belongs from this specification and the attached drawings. means of solving the problem

[0008] A battery cell according to one embodiment of the present invention comprises: a battery case having a sealing portion having a structure in which an electrode assembly is mounted in a housing portion and the outer periphery is sealed; and a gas discharge portion inserted into the sealing portion, wherein the gas discharge portion protrudes from the inside of the battery case toward the outside of the battery case, and the gas discharge portion comprises a non-adhesive layer and an adhesive layer located on the non-adhesive layer, wherein the non-adhesive layer and the adhesive layer are bent in a direction that opens toward the inside of the battery case.

[0009] The above non-adhesive layer includes a first non-adhesive layer and a second non-adhesive layer spaced apart from each other, and the end of the first non-adhesive layer and the end of the second non-adhesive layer adjacent to the outer side of the sealing portion may be connected to each other and integrated.

[0010] The above gas discharge portion includes a gas inlet portion located between the first non-adhesive layer and the second non-adhesive layer, and the gas inlet portion may be open toward the inside of the battery case.

[0011] The adhesive layer comprises a first adhesive layer located on the upper surface of the first non-adhesive layer and a second adhesive layer located on the lower surface of the second non-adhesive layer, and the end of the first adhesive layer and the end of the second adhesive layer adjacent to the outer side of the sealing portion may be connected to each other and integrated.

[0012] Based on the protruding direction of the gas discharge portion, the first adhesive layer may extend along the side of the first non-adhesive layer, and the second adhesive layer may extend along the side of the second non-adhesive layer.

[0013] Based on the protruding direction of the gas discharge portion, the first adhesive layer and the second adhesive layer may each extend between the first non-adhesive layer and the second non-adhesive layer.

[0014] A pair of the first adhesive layer and the second adhesive layer may be located on each side of the gas inlet section.

[0015] The adhesive layer and the non-adhesive layer have a structure in which the adhesive layer wraps around the lower surface and both sides of the non-adhesive layer, and wraps around both ends of the upper surface of the non-adhesive layer, respectively, and the gas discharge portion may have a structure in which the adhesive layer and the non-adhesive layer are folded along a boundary line.

[0016] The above non-adhesive layer may be composed of a film made of a non-adhesive material.

[0017] The above non-adhesive material may be composed of a fluorine-based polymer material.

[0018] The above fluorine-based polymer material may be at least one of polytetrafluoroethylene (PTFE), fluorinated polyvinylidene (PVDF), polymethylpentene (TPX), fluorinated ethylenepropylene (FEP), and perfluoroalkoxyalkane (PFA).

[0019] The above adhesive layer may be composed of an adhesive composition consisting of at least one of a polyolefin-based material, epoxy, and polyvinyl chloride (PVC).

[0020] The above adhesive layer may be made of a film composed of the above adhesive composition.

[0021] The adhesive layer can be formed by applying the adhesive composition onto the non-adhesive layer.

[0022] The thickness of the adhesive layer may be the same as or smaller than the thickness of the non-adhesive layer.

[0023] The gas permeability of the adhesive layer may be 20 to 60 barrer at 60°C.

[0024] The gas permeability of the above non-adhesive layer may be 40 barrer or more at 60°C.

[0025] The moisture penetration amount of the adhesive layer above may be 0.02 to 0.2 g over 10 years at 25℃ and 50 %RH.

[0026] A battery module according to another embodiment of the present invention includes the battery cell described above. Effects of the invention

[0027] According to the embodiments, the present invention provides a battery cell and a battery module including a gas discharge portion having a structure comprising a non-adhesive layer and an adhesive layer located on the non-adhesive layer, wherein the non-adhesive layer and the adhesive layer are folded in a direction open toward the interior of the battery case, thereby improving the external discharge of gas generated inside the battery cell and suppressing the penetration of moisture into the battery cell.

[0028] According to the present invention, since the gas generated inside the battery cell is easily discharged to the outside through the gas discharge part, the venting phenomenon in the battery cell can be prevented, thereby increasing the lifespan of the battery cell.

[0029] According to the present invention, gas is discharged through the gas discharge section while moisture does not penetrate into the battery cell, thereby preventing the problem of reduced battery performance and additional gas generation caused by adverse reactions due to moisture penetration.

[0030] The effects of the present invention are not limited to the effects described above, and unmentioned effects will be clearly understood by those skilled in the art from this specification and the accompanying drawings. Brief explanation of the drawing

[0031] FIG. 1 is a drawing showing a battery cell according to one embodiment of the present invention. Figure 2 is a perspective view showing the gas discharge section of Figure 1. Figure 3 is a cross-sectional view taken along the cutting line A-A' of Figure 2. Figure 4 is a cross-sectional view taken along the cutting line B-B' of Figure 2. Figure 5 is a cross-sectional view taken along the cutting line a-a' of Figure 1. Figure 6 is a drawing showing the shape of the gas discharge part of Figure 2 before it is folded. Specific details for implementing the invention

[0032] Hereinafter, various embodiments of the present invention will be described in detail with reference to the attached drawings so that those skilled in the art can easily implement the present invention. The present invention may be embodied in various different forms and is not limited to the embodiments described herein.

[0033] To clearly explain the present invention, parts unrelated to the explanation have been omitted, and the same reference numerals are used for identical or similar components throughout the specification.

[0034] Furthermore, the size and thickness of each component shown in the drawings are depicted arbitrarily for convenience of explanation, and thus the present invention is not necessarily limited to what is illustrated. Thicknesses have been enlarged in the drawings to clearly represent various layers and regions. Additionally, for convenience of explanation, the thickness of some layers and regions has been exaggerated in the drawings.

[0035] Furthermore, throughout the specification, when a part is described as “comprising” a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but may include additional components.

[0036] Additionally, throughout the specification, "planar" means when the subject part is viewed from above, and "cross-sectional" means when the cross-section obtained by vertically cutting the subject part is viewed from the side.

[0037] FIG. 1 is a drawing showing a battery cell according to one embodiment of the present invention.

[0038] Referring to FIG. 1, a battery cell (100) according to one embodiment of the present invention includes: a battery case (200) in which an electrode assembly (110) is mounted in a storage portion (210) and a sealing portion (250) having a sealed outer periphery; and a gas discharge portion (500) inserted into the sealing portion (250).

[0039] The battery case (200) may be a laminate sheet comprising a resin layer and a metal layer. More specifically, the battery case (200) may be made of a laminate sheet and may be composed of an outer resin layer forming the outermost layer, a barrier metal layer that prevents the penetration of material, and an inner resin layer for sealing.

[0040] The electrode assembly (110) may be formed in a jelly-roll type (wound type), stack type (laminated type), or composite type (stacked / folded type) structure. More specifically, the electrode assembly (110) may be composed of an anode, a cathode, and a separator placed between them.

[0041] The electrode lead (300) is electrically connected to the electrode tab (115) included in the electrode assembly (110) and protrudes outwardly from the battery case (200) via the sealing portion (250). Additionally, the lead film (400) is located at a portion corresponding to the sealing portion (250) in at least one of the upper and lower parts of the electrode lead (300). Accordingly, the lead film (400) can prevent a short circuit from occurring in the electrode lead (300) during lamination while improving the sealing performance between the sealing portion (250) and the electrode lead (300).

[0042] The lead film (400) may have a wider width than the electrode lead (300). Here, the width of the lead film (400) refers to the maximum value of the distance between one end and the other end of the lead film (400) in a direction perpendicular to the protrusion direction of the electrode lead (300), and the width of the electrode lead (300) refers to the maximum value of the distance between one end and the other end of the electrode lead (300) in a direction perpendicular to the protrusion direction of the electrode lead (300). The lead film (400) may have a length greater than the length of the sealing portion (250) but a length smaller than the length of the electrode lead (300). Here, the length of the lead film (400) refers to the maximum value of the distance between one end and the other end of the lead film in the protrusion direction of the electrode lead (300). The length of the sealing portion (250) refers to the maximum value of the distance between one end and the other end of the sealing portion (250) in the protrusion direction of the electrode lead (300). The length of the electrode lead (300) refers to the maximum value of the distance between one end and the other end of the electrode lead (300) in the protruding direction of the electrode lead (300). Accordingly, the lead film (400) can prevent the side of the electrode lead (300) from being exposed to the outside while not interfering with the electrical connection of the electrode lead (300).

[0043] The gas discharge portion (500) may be inserted into at least a portion of the sealing portion (250). Here, the gas discharge portion (500) may be fused together with the sealing portion (250) and the gas discharge portion (500) may be fixed through the sealing portion (250). For example, the gas discharge portion (500) may be heat-fused and / or press-fused together with the sealing portion (250).

[0044] More specifically, as shown in FIG. 1, the gas exhaust portion (500) may be located in the outer periphery of the sealing portion (250) where the electrode lead (300) is not located. In other words, the gas exhaust portion (500) may be inserted into the sealing portion (250) adjacent to the side of the electrode assembly (110). Accordingly, the manufacturing process is very simple, and the gas exhaust portion (500) can sufficiently secure a gas exhaust path by the gas exhaust portion (500) without interfering with the electrical connection of the electrode lead (300).

[0045] As another example, although not specifically illustrated in the drawing, the gas exhaust portion (500) may be located at the outer periphery where the sealing portion (250) is located and the electrode lead (300) is located. In other words, the gas exhaust portion (500) may be located at the same outer periphery as the electrode lead (300) but spaced apart from each other. Accordingly, the gas exhaust portion (500) protrudes in the same direction as the electrode lead (300), which has the advantage of increasing the space efficiency of the battery cell (100).

[0046] Below, the gas discharge section (500) will be described in more detail.

[0047] FIG. 2 is a perspective view showing the gas discharge section of FIG. 1. FIG. 3 is a cross-sectional view taken along the cutting line A-A' of FIG. 2. FIG. 4 is a cross-sectional view taken along the cutting line B-B' of FIG. 2.

[0048] Referring to FIG. 1, the gas discharge portion (500) may protrude from inside the battery case (200) toward the outside of the battery case (200). More specifically, the gas discharge portion (500) may protrude from inside the battery case (200) toward the outside of the battery case (200) via the sealing portion (250).

[0049] Referring to FIGS. 1 to 4, the gas discharge section (500) comprises a non-adhesive layer (530) and an adhesive layer (510) located on the non-adhesive layer (530), wherein the non-adhesive layer (530) and the adhesive layer (510) are folded in a direction that opens toward the interior of the battery case (200). Here, the gas discharge section (500) may have a structure in which the adhesive layer (510) surrounds the outer surface of the non-adhesive layer (530). That is, the inner surface of the gas discharge section (500) may be made of the non-adhesive layer (530), and the outer surface of the gas discharge section (500) may be made of the adhesive layer (510).

[0050] Here, the adhesive layer (510) may refer to a temporary adhesive layer that can be bonded by heat fusion and / or press fusion. Additionally, the non-adhesive layer (53) may refer to a non-adhesive layer that cannot be bonded by heat fusion and / or press fusion.

[0051] Accordingly, the degree of sealing between the gas discharge section (500) and the sealing section (250) can be improved due to the adhesive layer (510) located on the outer surface of the gas discharge section (500).

[0052] Referring to FIGS. 1 to 4, the non-adhesive layer (530) includes a first non-adhesive layer (531) and a second non-adhesive layer (535) that are spaced apart from each other. Here, the end of the first non-adhesive layer (531) and the end of the second non-adhesive layer (535) adjacent to the outside of the sealing portion (250) may be connected to each other and integrated. That is, the opposite ends of the ends of the first non-adhesive layer (531) and the second non-adhesive layer (535) that are connected to each other are spaced apart from each other, so that one side of the non-adhesive layer (530) may be open toward the inside of the battery case (200).

[0053] Referring to FIGS. 2 and 3, the gas discharge portion (500) may include a gas inlet portion (550) located between the first non-adhesive layer (531) and the second non-adhesive layer (535). Here, the gas inlet portion (550) may be open toward the inside of the battery case (200). More specifically, the gas inlet portion (550) may refer to a spaced-apart space between the first non-adhesive layer (531) and the second non-adhesive layer (535).

[0054] Accordingly, in the battery cell (100) according to the present embodiment, a gas inlet (550) is formed on one side of a gas discharge part (500) located inside a battery case (200), so that gas generated inside the battery cell (100) can be easily introduced into the gas discharge part (500).

[0055] Referring to FIGS. 1 to 3, the adhesive layer (510) includes a first adhesive layer (511) located on the upper surface of the first non-adhesive layer (531) and a second adhesive layer (515) located on the lower surface of the second non-adhesive layer (535). Here, the end of the first adhesive layer (511) and the end of the second adhesive layer (515) adjacent to the outside of the sealing portion (250) may be connected to each other and integrated. That is, the adhesive layer (510) extends along the outer surface of the non-adhesive layer (530), and one side of the adhesive layer (510) may be open toward the inside of the battery case (200).

[0056] Referring to FIG. 2, with respect to the protruding direction of the gas discharge portion (500), the first adhesive layer (511) may be extended along the side of the first non-adhesive layer (531), and the second adhesive layer (515) may be extended along the side of the second non-adhesive layer (535). More specifically, the first adhesive layer (511) may be extended along each side of the first non-adhesive layer (531), and the second adhesive layer (515) may be extended along each side of the second non-adhesive layer (535).

[0057] Accordingly, in the gas discharge section (500), the side of the non-adhesive layer (530) may be covered by the adhesive layer (510), so that the non-adhesive layer (530) is not exposed to the outside. That is, moisture from outside the battery cell (100) can be prevented from penetrating into the battery cell (100) through the non-adhesive layer (530).

[0058] Referring to FIGS. 2 and FIGS. 4, based on the protruding direction of the gas discharge portion (500), the first adhesive layer (511) and the second adhesive layer (515) may each extend between the first non-adhesive layer (531) and the second non-adhesive layer (535). In other words, the first adhesive layer (511) may each extend to both ends of the lower surface of the first non-adhesive layer (531), and the second adhesive layer (515) may each extend to both ends of the upper surface of the second non-adhesive layer (535).

[0059] Here, an adhesive layer (510) may not be formed in the center of the lower surface of the first non-adhesive layer (531) and the upper surface of the second non-adhesive layer (535). That is, a gas inlet (550) may be formed in the center of the lower surface of the first non-adhesive layer (531) and the upper surface of the second non-adhesive layer (535), and a pair of first adhesive layers (511) and second adhesive layers (515) may be located on each side of the gas inlet (550). At this time, in the pair of first adhesive layers (511) and second adhesive layers (515) located on each side of the gas inlet (550), the pair of first adhesive layers (511) and second adhesive layers (515) may be bonded to each other when fused with the sealing portion (250).

[0060] Accordingly, the gas discharge section (500) has an adhesive layer (510) formed on both sides of the gas inlet section (550), so that the sealing strength of the gas discharge section (500) is increased, and the height of the gas inlet section (550) can be relatively increased, making it easier to inflow and outflow of gas through the gas inlet section (550).

[0061] Additionally, the gas discharge section (500) can adjust the width of the gas inlet section (550) by adjusting the length of the adhesive layer (510) formed on both sides of the gas inlet section (550). Here, the length of the adhesive layer (510) refers to the maximum value of the distance between one end and the other end of the adhesive layer (510) in a direction perpendicular to the protrusion direction of the gas discharge section (500). The width of the gas inlet section (550) refers to the maximum value of the distance between one end and the other end of the gas inlet section (550) in a direction perpendicular to the protrusion direction of the gas discharge section (500).

[0062] Accordingly, if the length of the adhesive layer (510) formed on both sides of the gas inlet (550) is relatively small, the width of the gas inlet (550) can be relatively large, making it easier to inflow and outflow of gas through the gas inlet (550). Additionally, if the length of the adhesive layer (510) formed on both sides of the gas inlet (550) is relatively long, the sealing degree of the gas outlet (500) can be further improved.

[0063] Here, the non-adhesive layer (530) may be made of a film made of a non-adhesive material. For example, the non-adhesive material may be made of a fluorine-based polymer material. The fluorine-based polymer material may be at least one of polytetrafluoroethylene (PTFE), fluorinated polyvinylidene (PVDF), polymethylpentene (TPX), fluorinated ethylenepropylene (FEP), and perfluoroalkoxyalkane (PFA). However, it is not limited thereto, and any material that does not melt when fused together with the sealing portion (250) due to a relatively high melting point may be included in this embodiment. The above-mentioned fluorine-based polymer material is a material that is advantageous for moisture sealing and has the characteristic of being able to permeate gas well. In addition, it is a material that is stable in the environment inside the battery cell (100). For example, it is a material that does not react with the electrolyte contained in the battery cell (100).

[0064] In one embodiment of the present invention, the gas permeability of the non-adhesive layer (530) may be 40 barrer or more at 60°C. For example, the carbon dioxide permeability of the non-adhesive layer (530) may satisfy the aforementioned range.

[0065] In one embodiment of the present invention, the non-adhesive layer (530) may be made of a fluorine-based polymer material. It was previously mentioned that the fluorine-based polymer material may be at least one of polytetrafluoroethylene (PTFE), fluorinated polyvinylidene (PVDF), polymethylpentene (TPX), fluorinated ethylenepropylene (FEP), and perfluoroalkoxyalkane (PFA). For example, the non-adhesive layer (530) may be at least one of polytetrafluoroethylene (PTFE), fluorinated polyvinylidene (PVDF), polymethylpentene (TPX), fluorinated ethylenepropylene (FEP), and perfluoroalkoxyalkane (PFA) that satisfies the aforementioned gas permeability and / or moisture penetration values.

[0066] Here, the adhesive layer (510) may be composed of an adhesive composition consisting of at least one of a polyolefin-based material, epoxy, and polyvinyl chloride (PVC). As an example, the polyolefin-based material may be polyethylene (PE), polypropylene (PP), etc. However, it is not limited thereto, and any material that is fused and bonded together with the sealing portion (250) may be included in this embodiment.

[0067] The adhesive layer (510) may have a lower melting point than the non-adhesive layer (530). Accordingly, the sealing performance may be further enhanced.

[0068] In one embodiment of the present invention, the gas permeability of the adhesive layer (510) may be 20 to 60 barrer or 30 to 40 barrer at 60°C. For example, the carbon dioxide permeability of the adhesive layer (510) may satisfy the aforementioned range. Additionally, the gas permeability may satisfy the aforementioned range at 60°C based on a thickness of 200 μm of the adhesive layer (510). When the gas permeability of the adhesive layer (510) satisfies the aforementioned range, the gas generated inside the secondary battery may be discharged more effectively.

[0069] In this specification, gas permeability can be measured according to ASTM F2476-20.

[0070] In one embodiment of the present invention, the moisture penetration amount of the adhesive layer (510) may be 0.02 to 0.2 g, or 0.02 to 0.04 g, or 0.06 g or 0.15 g over 10 years at 25°C and 50%RH. When the moisture penetration amount of the adhesive layer (510) satisfies the aforementioned range, it may be more effective in preventing moisture from penetrating from the adhesive layer (510).

[0071] In one embodiment of the present invention, the adhesive layer (510) may have a gas permeability of 20 to 60 barrer at 60°C and a moisture penetration amount of 0.02 to 0.2 g over 10 years at 25°C and 50 %RH. When the gas permeability and moisture penetration amount of the adhesive layer (510) satisfy the aforementioned ranges, it may be more effective to prevent moisture penetration from the outside while discharging gas generated inside the secondary battery.

[0072] The amount of moisture penetration of the adhesive layer (510) can be measured by adopting the ASTM F 1249 method. At this time, the measurement can be performed using equipment officially certified by MCOON.

[0073] In one embodiment of the present invention, the adhesive layer (510) may be composed of an adhesive composition consisting of at least one of a polyolefin-based material, epoxy, and polyvinyl chloride (PVC), and the polyolefin-based material may be polyethylene (PE), polypropylene (PP), etc., as previously mentioned. For example, the adhesive layer (510) may be polyethylene (PE), polypropylene (PP), etc., satisfying the aforementioned gas permeability and / or moisture penetration values.

[0074] In addition, the adhesive layer (510) is made of the above-described material, so that the airtightness of the battery cell (100) can be maintained and leakage of the internal electrolyte can also be prevented.

[0075] Additionally, the adhesive layer (510) may be made of a film composed of the adhesive composition. Additionally, the adhesive layer (510) may be formed by applying the adhesive composition onto the non-adhesive layer. However, the shape of the adhesive layer (510) is not limited thereto, and is not restricted as long as it is a shape that can easily wrap the outer surface of the non-adhesive layer (530).

[0076] Accordingly, as shown in FIGS. 2 to 4, the gas discharge section (500) has a structure in which an adhesive layer (510) made of the above-described material becomes the outer surface of the gas discharge section (500), and the adhesive layer (510) may be fused together with the sealing section (250) and bonded to each other. In addition, a non-adhesive layer (530) made of the above-described material is located inside the gas discharge section (500), and the first non-adhesive layer (531) and the second non-adhesive layer (535) facing each other are not fused together, so that the inside of the gas discharge section (500) can become a gas discharge passage. Furthermore, the non-adhesive layer (530) of the above-described material can improve the external discharge of gas generated inside the battery cell (100) while preventing moisture from outside the battery cell (100) from penetrating into the interior.

[0077] In addition, the gas discharge part (500) of the above-described structure is designed to be easily inserted during the assembly of the battery cell (100), so that a battery cell of a new structure can be assembled while maintaining the existing battery cell manufacturing process.

[0078] The thickness of the adhesive layer (510) may be equal to or smaller than the thickness of the non-adhesive layer (530). More specifically, the adhesive layer (510) may have a thickness of 0.1 μm or more to 100 μm or less. More specifically, the adhesive layer (510) may have a thickness of 0.5 μm or more to 90 μm or less. For example, the adhesive layer (510) may have a thickness of 1 μm or more to 80 μm or less. In addition, the non-adhesive layer (530) may have a thickness of 10 μm or more to 500 μm or less. More specifically, the non-adhesive layer (530) may have a thickness of 15 μm or more to 450 μm or less. For example, the non-adhesive layer (530) may have a thickness of 20 μm or more to 400 μm or less.

[0079] Accordingly, the adhesive layer (510) may have a thickness within the range described above, thereby maintaining the sealing strength between the gas discharge portion (500) and the sealing portion (250), while minimizing the influence of the non-adhesive layer (530) on the gas discharge of the gas discharge portion (500). Additionally, the non-adhesive layer (530) may have a thickness within the range described above, thereby suppressing the penetration of moisture into the battery cell (100), while allowing the gas introduced through the gas inlet portion (550) to be easily discharged through the non-adhesive layer (530).

[0080] However, if the thickness of the adhesive layer (510) is less than 0.1㎛ or greater than 100㎛, there is a problem that the sealing strength between the gas discharge part (500) and the sealing part (250) is excessively weak, or that the adhesive layer (510) obstructs the gas discharge of the gas discharge part (500). Additionally, if the thickness of the non-adhesive layer (530) is less than 10㎛ or greater than 500㎛, there is a problem that the area of ​​the non-adhesive layer (530) is reduced, which may result in an excessively reduced gas discharge, or that the thickness of the gas discharge part (500) becomes excessively large.

[0081] Figure 5 is a cross-sectional view taken along the cutting line a-a' of Figure 1.

[0082] Referring to FIGS. 2 and FIGS. 5, in a battery cell (100) according to one embodiment of the present invention, one side of the gas discharge portion (500) is open toward the inside of the battery case (200), and the adhesive layer (510) is the outer surface of the gas discharge portion (500), so that the adhesive layer (510) and the sealing portion (250) can come into contact with each other. In addition, the non-adhesive layer (530) is the inner surface of the gas discharge portion (500), and a gas inlet portion (550) may be formed between the first non-adhesive layer (531) and the second non-adhesive layer (535).

[0083] Accordingly, in this embodiment, gas inside the battery cell (100) can be introduced into the gas inlet (550) formed between the non-adhesive layers (530) of the gas discharge section (500). In addition, the gas introduced into the gas inlet (550) can pass through the adhesive layer (510) and the non-adhesive layer (530) depending on the pressure difference with the outside of the battery case (200), and the gas introduced into the gas inlet (550) can be discharged toward the outside.

[0084] Figure 6 is a drawing showing the shape of the gas discharge part of Figure 2 before it is folded.

[0085] Referring to FIGS. 2 and FIGS. 6, in a battery cell (100) according to another embodiment of the present invention, the gas discharge portion (500) may have a structure in which an adhesive layer (510) and a non-adhesive layer (530) are folded. More specifically, the adhesive layer (510) and the non-adhesive layer (530) may have a structure in which the adhesive layer (510) wraps around the lower surface and both sides of the non-adhesive layer (530), and wraps around both ends of the upper surface of the non-adhesive layer (530). Here, the gas discharge portion (500) may have the adhesive layer (510) and the non-adhesive layer (530) folded along a boundary line (C-C'). For example, the boundary line (C-C') may correspond to a center line based on the longitudinal direction of the adhesive layer (510) and the non-adhesive layer (530).

[0086] In addition, on the upper surface of the non-adhesive layer (530), the shape of the portion where the adhesive layer (510) is not formed may be a rectangular shape as shown in FIG. 6, or may have various other pattern shapes such as a circle or an ellipse.

[0087] A method for manufacturing such a gas discharge section (500) involves placing a non-adhesive layer (530) approximately in the center of an adhesive layer (510), such that all sides of the non-adhesive layer (530), excluding two sides of the non-adhesive layer (530), are covered by the adhesive layer (510), and then folding both ends of the adhesive layer (510) over the non-adhesive layer (530) to create a state as shown in FIG. 6. After that, the layers are folded along a boundary line (C-C'), and the adhesive layers (510) of the folded sides are bonded together by a method such as heat fusion or press fusion. At this time, an internal space that is not bonded is formed between the folded non-adhesive layers (530), thereby providing a gas inlet section (550).

[0088] Accordingly, the gas discharge portion (500) according to the present embodiment can be formed in a structure that is folded along a predetermined boundary line, so that the manufacturing process is relatively easy and the manufacturing cost can also be simplified.

[0089] In addition, a battery module according to another embodiment of the present invention includes the battery cell described above. Meanwhile, one or more of the battery modules according to the present embodiment may be packaged within a pack case to form a battery pack.

[0090] The battery module and battery pack containing the same described above can be applied to various devices. Such devices may be applied to means of transportation such as electric bicycles, electric vehicles, and hybrid vehicles, but the present invention is not limited thereto and can be applied to various devices capable of using the battery module and battery pack containing the same, and this also falls within the scope of the rights of the present invention.

[0091] Although preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements by those skilled in the art using the basic concept of the present invention as defined in the following claims also fall within the scope of the present invention. Explanation of the symbols

[0092] 100: Battery cell 110: Electrode assembly 200: Battery case 210: Storage compartment 250: Sealing part 300: Electrode lead 400: Lead film 500: Gas exhaust part

Claims

Claim 1 A battery case comprising a sealing portion having a structure in which an electrode assembly is mounted in a housing portion and the outer periphery is sealed; and a battery cell comprising a gas exhaust portion inserted in the sealing portion, wherein the gas exhaust portion protrudes from the inside of the battery case toward the outside of the battery case, and the gas exhaust portion comprises a non-adhesive layer and an adhesive layer located on the non-adhesive layer, wherein the non-adhesive layer and the adhesive layer are folded in a direction that opens toward the inside of the battery case so that the adhesive layer surrounds the outer surface of the non-adhesive layer and the non-adhesive layer is not exposed to the outside. Claim 2 In claim 1, the non-adhesive layer comprises a first non-adhesive layer and a second non-adhesive layer spaced apart from each other, and the end of the first non-adhesive layer adjacent to the outer side of the sealing portion and the end of the second non-adhesive layer are connected to each other to form an integrated battery cell. Claim 3 In paragraph 2, the gas discharge portion includes a gas inlet portion located between the first non-adhesive layer and the second non-adhesive layer, and the gas inlet portion is open toward the inside of the battery case, in a battery cell. Claim 4 In paragraph 3, the adhesive layer comprises a first adhesive layer located on the upper surface of the first non-adhesive layer and a second adhesive layer located on the lower surface of the second non-adhesive layer, and the end of the first adhesive layer and the end of the second adhesive layer adjacent to the outer side of the sealing portion are connected to each other to form an integrated battery cell. Claim 5 A battery cell according to claim 4, wherein, based on the protruding direction of the gas discharge portion, the first adhesive layer extends along the side of the first non-adhesive layer and the second adhesive layer extends along the side of the second non-adhesive layer. Claim 6 In claim 5, the battery cell wherein the first adhesive layer and the second adhesive layer are each extended between the first non-adhesive layer and the second non-adhesive layer based on the protruding direction of the gas discharge portion. Claim 7 A battery cell according to claim 6, wherein a pair of the first adhesive layer and the second adhesive layer are respectively located on both sides of the gas inlet portion. Claim 8 In claim 1, the adhesive layer and the non-adhesive layer have a structure in which the adhesive layer wraps around the lower surface and both sides of the non-adhesive layer, and each wraps around both ends of the upper surface of the non-adhesive layer, and the gas discharge portion has a structure in which the adhesive layer and the non-adhesive layer are folded along a boundary line, forming a battery cell. Claim 9 In claim 1, the non-adhesive layer is a battery cell made of a film made of a non-adhesive material. Claim 10 In paragraph 9, the above non-adhesive material is a battery cell made of a fluorine-based polymer material. Claim 11 In claim 10, the fluorine-based polymer material is a battery cell that is at least one of polytetrafluoroethylene (PTFE), fluorinated polyvinylidene (PVDF), polymethylpentene (TPX), fluorinated ethylenepropylene (FEP), and perfluoroalkoxyalkane (PFA). Claim 12 In claim 1, the battery cell is formed by an adhesive composition in which the adhesive layer is composed of at least one of a polyolefin-based material, epoxy, and polyvinyl chloride (PVC). Claim 13 In paragraph 12, the adhesive layer is a battery cell made of a film made of the adhesive composition. Claim 14 In paragraph 12, the adhesive layer is a battery cell formed by applying the adhesive composition onto the non-adhesive layer. Claim 15 In claim 1, the thickness of the adhesive layer is equal to or smaller than the thickness of the non-adhesive layer of the battery cell. Claim 16 A battery cell according to claim 1, wherein the gas permeability of the adhesive layer is 20 to 60 barrer at 60°C. Claim 17 A battery cell according to claim 1, wherein the gas permeability of the non-adhesive layer is 40 barrer or more at 60°C. Claim 18 delete Claim 19 A battery module comprising a battery cell according to claim 1.

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