Patent Description:
As technology development and demand for mobile devices increase, the demand for secondary batteries as an energy source is rapidly increasing. In particular, secondary batteries are of great interest as energy sources not only for mobile devices such as mobile phones, digital cameras, notebooks and wearable devices, but also for power devices such as electric bicycles, electric vehicles and hybrid electric vehicles.

Depending on the shape of a battery case, these secondary batteries are classified into a cylindrical battery and a prismatic battery in which a battery assembly is included in a cylindrical or prismatic metal can, and a pouch-type battery in which the battery assembly is included in a pouch-type case of an aluminum laminate sheet. Here, the battery assembly included in the battery case is a power element including a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode, and capable of charging and discharging, and is classified into a jelly-roll type in which long sheet-type positive and negative electrodes coated with an active material are wound with a separator being interposed therebetween, and a stack type in which a plurality of positive and negative electrodes are sequentially stacked with a separator being interposed therebetween.

Among them, in particular, a pouch-type battery in which a stack-type or stack/folding-type battery assembly is included in a pouch-type battery case made of an aluminum laminate sheet is being used more and more due to low manufacturing cost, small weight, and easy modification.

However, as the energy density of the battery cell increases in recent years, there is a problem that the amount of gas generated inside the battery cell also increases. In particular, if the gas generated inside the battery cell is not easily discharged, a venting may occur in the battery cell due to gas generation. Also, even if a separate venting portion is included in the battery cell, moisture may penetrate into the battery cell through the venting portion, which may cause deterioration of battery performance and additional gas generation due to resultant side reactions. Accordingly, there is an increasing need to develop a battery cell capable of preventing penetration of external moisture into the battery cell while having improved external emission of gas generated inside the battery cell. Document <CIT> having a priority date prior to the present application and which entered the European phase discloses a battery cell having a gas discharge element having a cone shape end protruding outside a battery case, such cone shape end being made by folding a sheet having an adhesive layer and a non-adhesive layer. Document <CIT> discloses a battery cell where a gas discharge element is made by a discharge pipe pinched between sealing surfaces of a battery case.

The present disclosure is designed to solve the problems of the related art, and therefore the present disclosure is directed to providing a battery cell capable of suppressing penetration of external moisture into the battery cell while having improved external emission of gas generated inside the battery cell, and a battery module including the same.

The object to be solved by the present disclosure is not limited to the above-mentioned object, and the objects not mentioned here may be clearly understood by those skilled in the art from this specification and the accompanying drawings.

In one aspect of the present disclosure, there is provided a battery cell According to claim <NUM>.

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

Based on a protruding direction of the gas discharge unit, the first adhesive layer may extend along a side surface of the first non-adhesive layer, and the second adhesive layer may extend along a side surface of the second non-adhesive layer.

Based on the protruding direction of the gas discharge unit, the first adhesive layer and the second adhesive layer may extend between the first non-adhesive layer and the second non-adhesive layer, respectively.

A pair of first adhesive layers and a pair of second adhesive layers may be located at both sides of the gas inlet, respectively.

The non-adhesive layer may be a film made of a non-adhesive material.

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), polyvinylidene fluoride (PVDF), polymethylpentene (TPX), fluorinated ethylene propylene (FEP), and perfluoroalkoxyalkane (PFA).

The adhesive layer may be made of an adhesive composition consisting of at least one of polyolefin-based material, epoxy, and polyvinyl chloride (PVC).

The adhesive layer may be a film made of the adhesive composition.

The adhesive layer may be formed by applying the adhesive composition on the non-adhesive layer.

The adhesive layer may have a thickness equal to or smaller than a thickness of the non-adhesive layer.

The adhesive layer may have gas permeability of <NUM> Barrer to <NUM> Barrer at <NUM>.

The non-adhesive layer may have gas permeability of <NUM> Barrer or more at <NUM>.

The adhesive layer may have a moisture penetration amount of <NUM> to <NUM> for <NUM> years at <NUM>, <NUM> %RH.

In another aspect of the present disclosure, there is also provided a battery module, comprising the battery cell described above.

According to embodiments, the present disclosure provides a battery cell having a structure including a non-adhesive layer and an adhesive layer located on the non-adhesive layer, wherein the non-adhesive layer and the adhesive layer includes a gas discharge unit bent to be opened toward the inside of the battery case, and also provides a battery module including the same, so that the external discharge of gas generated inside the battery cell is increased, and penetration of moisture flowing into the battery cell is suppressed.

According to the present disclosure, since the gas generated inside the battery cell is easily discharged to the outside through the gas discharge unit, it is possible to prevent a venting phenomenon from occurring in the battery cell, thereby increasing the lifespan of the battery cell.

According to the present disclosure, since the gas is discharged through the gas discharge unit and moisture does not penetrate into the battery cell, it is possible to prevent the battery performance of the battery cell from deteriorating due to a side reaction caused by the penetration of moisture and prevent the generation of additional gas.

The effect of the present disclosure is not limited to the above effects, and the effects not mentioned here will be clearly understood by those skilled in the art from this specification and the accompanying drawings.

Hereinafter, with reference to the accompanying drawings, various embodiments of the present disclosure will be described in detail so as to be easily implemented by those skilled in the art. The present disclosure may be implemented in various different forms and is not limited to the embodiments described herein.

In order to clearly explain the present disclosure, parts irrelevant to the description are omitted, and identical or similar components are endowed with the same reference signs throughout the specification.

In addition, since the size and thickness of each component shown in the drawings are arbitrarily expressed for convenience of description, the present disclosure is not necessarily limited to the drawings. In order to clearly express various layers and regions in the drawings, the thicknesses are enlarged. Also, in the drawings, for convenience of explanation, the thickness of some layers and regions is exaggerated.

In addition, throughout the specification, when a part "includes" a certain component, it means that other components may be further included, rather than excluding other components, unless otherwise stated.

In addition, throughout the specification, when referring to "top view", it means that the target part is viewed from above, and when referring to "cross-sectional view", it means that a vertically-cut section of the target part is viewed from a side.

<FIG> is a diagram showing a battery cell according to an embodiment of the present disclosure.

Referring to <FIG>, the battery cell <NUM> according to an embodiment of the present disclosure includes a battery case <NUM> having an accommodation portion <NUM> in which an electrode assembly <NUM> is mounted, and a sealing portion <NUM> formed by sealing an outer periphery thereof; and a gas discharge unit <NUM> inserted into the sealing portion <NUM>.

The battery case <NUM> may be a laminate sheet including a resin layer and a metal layer. More specifically, the battery case <NUM> may be made of a laminate sheet, and may include an outer resin layer forming the outermost layer, a barrier metal layer preventing penetration of materials, and an inner resin layer for sealing.

The electrode assembly <NUM> may have a structure of a jelly-roll type (winding type), a stack type (lamination type), or a composite type (stack/folding type). More specifically, the electrode assembly <NUM> may include a positive electrode, a negative electrode, and a separator disposed therebetween.

The electrode lead <NUM> is electrically connected to an electrode tab <NUM> included in the electrode assembly <NUM>, and protrudes out of the battery case <NUM> via the sealing portion <NUM>. In addition, the lead film <NUM> is located at a portion corresponding to the sealing portion <NUM> in at least one of an upper portion and a lower portion of the electrode lead <NUM>. Accordingly, the lead film <NUM> may improve the sealing properties of the sealing portion <NUM> and the electrode lead <NUM> while preventing a short circuit from occurring in the electrode lead <NUM> during laminating.

The lead film <NUM> may have a wider width than the electrode lead <NUM>. Here, the width of the lead film <NUM> means a maximum value of the distance between one end and the other end of the lead film <NUM> in a direction orthogonal to the protruding direction of the electrode lead <NUM>, and the width of the electrode lead <NUM> means a maximum value of the distance between one end and the other end of the electrode lead <NUM> in a direction orthogonal to the protruding direction of the electrode lead <NUM>. The lead film <NUM> may have a greater length than the sealing portion <NUM>, but may have a smaller length than the electrode lead <NUM>. Here, the length of the lead film <NUM> means a maximum value of the distance between one end and the other end of the lead film in the protruding direction of the electrode lead <NUM>, and the length of the sealing portion <NUM> means a maximum value of the distance between one end and the other end of the sealing portion <NUM> in the protruding direction of the electrode lead <NUM>. The length of the electrode lead <NUM> means a maximum value of the distance between one end and the other end of the electrode lead <NUM> in the protruding direction of the electrode lead <NUM>. Accordingly, the lead film <NUM> may prevent the side surface of the electrode lead <NUM> from being exposed to the outside without interfering with the electrical connection of the electrode lead <NUM>.

The gas discharge unit <NUM> is inserted into the sealing portion <NUM>. Here, the gas discharge unit <NUM> may be fused together with the sealing portion <NUM>, and the gas discharge unit <NUM> may be fixed via the sealing portion <NUM>. For example, the gas discharge unit <NUM> may be heat-fused and/or press-fused together with the sealing portion <NUM>.

More specifically, as shown in <FIG>, the gas discharge unit <NUM> may be located in the outer periphery of the sealing portion <NUM> where the electrode lead <NUM> is not located. In other words, the gas discharge unit <NUM> may be inserted into the sealing portion <NUM> adjacent to a side of the electrode assembly <NUM>. Accordingly, the gas discharge unit <NUM> may be manufactured very simply and sufficiently secure a gas discharge path by the gas discharge unit <NUM> without interfering with the electrical connection of the electrode lead <NUM>.

As another example, although not specifically shown in the drawings, the gas discharge unit <NUM> may be located in the outer periphery of the sealing portion <NUM> where the electrode lead <NUM> is located. In other words, the gas discharge unit <NUM> may be located in the same outer periphery as the electrode lead <NUM>, but spaced apart from the electrode lead <NUM>. Accordingly, since the gas discharge unit <NUM> protrudes in the same direction as the electrode lead <NUM>, there is an advantage in that the space efficiency of the battery cell <NUM> may be further improved.

Hereinafter, the gas discharge unit <NUM> will be described in more detail.

<FIG> is a perspective view showing a gas discharge unit of <FIG>. <FIG> is a cross-sectional view, taken along the cutting line A-A' of <FIG>. <FIG> is a cross-sectional view, taken along the cutting line B-B' of <FIG>.

Referring to <FIG>, the gas discharge unit <NUM> protrudes from the inside of the battery case <NUM> toward the outside of the battery case <NUM>. More specifically, the gas discharge unit <NUM> may protrude from the inside of the battery case <NUM> toward the outside of the battery case <NUM> via the sealing portion <NUM>.

Referring to <FIG>, the gas discharge unit <NUM> includes a non-adhesive layer <NUM> and an adhesive layer <NUM> located on the non-adhesive layer <NUM>, and the non-adhesive layer <NUM> and the adhesive layer <NUM> are bent to be opened toward the inside of the battery case <NUM>. Here, the gas discharge unit <NUM> has a structure in which the adhesive layer <NUM> surrounds an outer surface of the non-adhesive layer <NUM>. That is, an inner surface of the gas discharge unit <NUM> is formed as the non-adhesive layer <NUM>, and an outer surface of the gas discharge unit <NUM> may be formed as the adhesive layer <NUM>.

Here, the adhesive layer <NUM> may refer to an adhesive layer that can be adhered by heat-fusion and/or press-fusion. In addition, the non-adhesive layer <NUM> may refer to a non-adhesive layer that cannot be adhered by heat-fusion and/or press-fusion.

Accordingly, the sealing degree between the gas discharge unit <NUM> and the sealing portion <NUM> may be improved due to the adhesive layer <NUM> located on the outer surface of the gas discharge unit <NUM>.

Referring to <FIG>, the non-adhesive layer <NUM> includes a first non-adhesive layer <NUM> and a second non-adhesive layer <NUM> spaced apart from each other. Here, an end of the first non-adhesive layer <NUM> and an end of the second non-adhesive layer <NUM> adjacent to the outer side of the sealing portion <NUM> are connected and integrated with each other. That is, the ends of the first non-adhesive layer <NUM> and the second non-adhesive layer <NUM> opposite to the ends connected to each other are spaced apart from each other, so that one surface of the non-adhesive layer <NUM> may be opened toward the inside of the battery case <NUM>.

Referring to <FIG>, the gas discharge unit <NUM> includes a gas inlet <NUM> located between the first non-adhesive layer <NUM> and the second non-adhesive layer <NUM>. Here, the gas inlet <NUM> is opened toward the inside of the battery case <NUM>. More specifically, the gas inlet <NUM> may refer to a space spaced apart between the first non-adhesive layer <NUM> and the second non-adhesive layer <NUM>.

Accordingly, in the battery cell <NUM> according to this embodiment, since the gas inlet <NUM> is formed at one surface of the gas discharge unit <NUM> located inside the battery case <NUM>, the gas generated inside the battery cell <NUM> may be easily introduced into the gas discharge unit <NUM>.

Referring to <FIG>, the adhesive layer <NUM> includes a first adhesive layer <NUM> located on the upper surface of the first non-adhesive layer <NUM> and a second adhesive layer <NUM> located on the lower surface of the second non-adhesive layer <NUM>. Here, an end of the first adhesive layer <NUM> and an end of the second adhesive layer <NUM> adjacent to the outer side of the sealing portion <NUM> may be connected and integrated with each other. That is, the adhesive layer <NUM> extends along the outer surface of the non-adhesive layer <NUM>, and one surface of the adhesive layer <NUM> may be opened toward the inside of the battery case <NUM>.

Referring to <FIG>, based on a protruding direction of the gas discharge unit <NUM>, the first adhesive layer <NUM> extends along the side surface of the first non-adhesive layer <NUM>, and the second adhesive layer <NUM> extends along the side surface of the second non-adhesive layer <NUM>. More specifically, the first adhesive layer <NUM> extends along both side surfaces of the first non-adhesive layer <NUM>, respectively, and the second adhesive layer <NUM> extends along both side surfaces of the second non-adhesive layer <NUM>, respectively.

Accordingly, in the gas discharge unit <NUM>, the side surface of the non-adhesive layer <NUM> is covered by the adhesive layer <NUM>, so that the non-adhesive layer <NUM> is not exposed to the outside. That is, it is possible to prevent moisture in the outside of the battery cell <NUM> from penetrating into the battery cell <NUM> through the non-adhesive layer <NUM>.

Referring to <FIG> and <FIG>, based on the protruding direction of the gas discharge unit <NUM>, the first adhesive layer <NUM> and the second adhesive layer <NUM> extend between the first non-adhesive layer <NUM> and the second non-adhesive layer <NUM>, respectively. In other words, the first adhesive layer <NUM> extends at both ends of the lower surface of the first non-adhesive layer <NUM>, respectively, and the second adhesive layer <NUM> extends at both ends of the upper surface of the second non-adhesive layer <NUM>, respectively.

Here, the adhesive layer <NUM> is not formed in the center portion of the lower surface of the first non-adhesive layer <NUM> and the upper surface of the second non-adhesive layer <NUM>. That is, the gas inlet <NUM> is formed in the center portion of the lower surface of the first non-adhesive layer <NUM> and the upper surface of the second non-adhesive layer <NUM>, and a pair of first adhesive layers <NUM> and a pair of second adhesive layers <NUM> are be located at both sides of the gas inlet <NUM>, respectively. In this case, in the pair of first adhesive layers <NUM> and the pair of second adhesive layers <NUM> respectively located at both sides of the gas inlet <NUM>, the pair of first adhesive layers <NUM> and the pair of second adhesive layers <NUM> may be adhered to each other when being fused with the sealing portion <NUM>.

Accordingly, since the gas discharge unit <NUM> includes the adhesive layers <NUM> formed at both sides of the gas inlet <NUM>, the height of the gas inlet <NUM> may be relatively increased while increasing the sealing strength of the gas discharge unit <NUM>, so gas may be introduced and discharged easily through the gas inlet <NUM>.

In addition, the gas discharge unit <NUM> may adjust the width of the gas inlet <NUM> by adjusting the length of the adhesive layer <NUM> formed at both sides of the gas inlet <NUM>. Here, the length of the adhesive layer <NUM> means a maximum value of the distance between one end and the other end of the adhesive layer <NUM> in a direction orthogonal to the protruding direction of the gas discharge unit <NUM>. The width of the gas inlet <NUM> means a maximum value of the distance between one end and the other end of the gas inlet <NUM> in a direction orthogonal to the protruding direction of the gas discharge unit <NUM>.

Accordingly, when the length of the adhesive layers <NUM> formed at both sides of the gas inlet <NUM> is relatively small, the width of the gas inlet <NUM> may be relatively large, so that the gas may be introduced and discharged more easily through the gas inlet <NUM>. In addition, when the length of the adhesive layers <NUM> formed at both sides of the gas inlet <NUM> is relatively long, the sealing degree of the gas discharge unit <NUM> may be further improved.

Here, the non-adhesive layer <NUM> may a film made of a non-adhesive material. For example, the non-adhesive material may be formed of a fluorine-based polymer material. The fluorine-based polymer material may be at least one of polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), polymethylpentene (TPX), fluorinated ethylene propylene (FEP), and perfluoroalkoxyalkane (PFA). However, it is not limited thereto, and any material having a relatively high melting point and thus is not dissolved during fusion with the sealing portion <NUM> may be included in this embodiment. The fluorine-based polymer material is advantageous for moisture sealing and has the property of easily permeating gas. In addition, it is a material that is stable in the environment within the battery cell <NUM>. For example, it is a material that does not react with the electrolyte contained in battery cell <NUM>.

In one embodiment of the present disclosure, the gas permeability of the non-adhesive layer <NUM> may be <NUM> Barrer or more at <NUM>. For example, the carbon dioxide permeability of the non-adhesive layer <NUM> may satisfy the above range.

In one embodiment of the present disclosure, the non-adhesive layer <NUM> may be made of a fluorine-based polymer material. The fluorine-based polymer material may be at least one of polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), polymethylpentene (TPX), fluorinated ethylenepropylene (FEP), and perfluoroalkoxyalkane (PFA), as mentioned above. For example, the fluorine-based polymer material may be at least one of polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), polymethylpentene (TPX), fluorinated ethylenepropylene (FEP), and perfluoroalkoxyalkane (PFA), which satisfy the gas permeability and/or the moisture penetration amount mentioned above.

Here, the adhesive layer <NUM> may be made of an adhesive composition including at least one of a polyolefin-based material, an epoxy, and polyvinyl chloride (PVC). For example, the polyolefin-based material may be polyethylene (PE), polypropylene (PP), or the like. However, the present invention is not limited thereto, and any material that is fused and adhered together with the sealing portion <NUM> may be included in this embodiment.

The adhesive layer <NUM> may have a lower melting point than the non-adhesive layer <NUM>. Accordingly, the sealing property may be further improved.

In an embodiment of the present disclosure, the gas permeability of the adhesive layer <NUM> may be <NUM> Barrer to <NUM> Barrer, or <NUM> Barrer to <NUM> Barrer at <NUM>. For example, the carbon dioxide permeability of the adhesive layer <NUM> may satisfy the above range. In addition, the gas permeability may satisfy the above range at <NUM> based on a thickness of <NUM> of the adhesive layer <NUM>. When the gas permeability of the adhesive layer <NUM> satisfies the above range, the gas generated inside the secondary battery may be more effectively discharged.

In this specification, the gas permeability may be measured by ASTM F2476-<NUM>.

In one embodiment of the present disclosure, the moisture penetration amount of the adhesive layer <NUM> may be <NUM> to <NUM>, or <NUM> to <NUM>, or <NUM> or <NUM> for <NUM> years at <NUM>, <NUM> %RH. If the moisture penetration amount of the adhesive layer <NUM> satisfies the above range, it may be more effective to prevent penetration of moisture introduced from the adhesive layer <NUM>.

In one embodiment of the present disclosure, the adhesive layer <NUM> may have a gas permeability of <NUM> Barrer to <NUM> Barrer at <NUM> and a moisture penetration amount of <NUM> to <NUM> at <NUM>, <NUM>% RH for <NUM> years. If the gas permeability and the moisture penetration amount of the adhesive layer <NUM> satisfy the above ranges, it may be more effective to prevent moisture penetration from the outside while discharging the gas generated inside the secondary battery.

The moisture penetration amount of the adhesive layer <NUM> may be measured by adopting the ASTM F <NUM> method. At this time, the moisture penetration amount may be measured using equipment officially certified by MCOON.

In an embodiment of the present disclosure, the adhesive layer <NUM> may be made of an adhesive composition consisting of at least one of a polyolefin-based material, an epoxy, and polyvinyl chloride (PVC), and the polyolefin-based material may be polyethylene (PE), polypropylene (PP) or the like, as mentioned above. For example, the adhesive layer <NUM> may be polyethylene (PE), polypropylene (PP), or the like, which satisfy the gas permeability and/or the moisture penetration amount mentioned above.

In addition, since the adhesive layer <NUM> is made of the above material, it is possible to maintain airtightness of the battery cell <NUM> and prevent the internal electrolyte from leaking.

In addition, the adhesive layer <NUM> may be a film made of the adhesive composition. Also, the adhesive layer <NUM> may be formed by applying the adhesive composition on the non-adhesive layer. However, the shape of the adhesive layer <NUM> is not limited thereto, and any shape capable of easily surrounding the outer surface of the non-adhesive layer <NUM> may be used without limitation.

Accordingly, as shown in <FIG>, since the gas discharge unit <NUM> has a structure in which the adhesive layer <NUM> made of the above material becomes the outer surface of the gas discharge unit <NUM>, the adhesive layer <NUM> may be fused and adhered together with the sealing portion <NUM>. In addition, the non-adhesive layer <NUM> made of the above material is located inside the gas discharge unit <NUM>, and the first non-adhesive layer <NUM> and the second non-adhesive layer <NUM> facing each other are not fused with each other, so the inside of the gas discharge unit <NUM> serves as a gas discharge passage. Moreover, the non-adhesive layer <NUM> of the above material may prevent moisture in the outside of the battery cell <NUM> from penetrating into the battery cell <NUM> while improving the external discharge of the gas generated inside the battery cell <NUM>.

In addition, the gas discharge unit <NUM> having the above structure is designed to be simply inserted when assembling the battery cell <NUM>, so it is possible to assemble a battery cell having a new structure while maintaining the existing battery cell manufacturing process.

The thickness of the adhesive layer <NUM> may be equal to or smaller than the thickness of the non-adhesive layer <NUM>. More specifically, the adhesive layer <NUM> may have a thickness of <NUM> or more and <NUM> or less. More specifically, the adhesive layer <NUM> may have a thickness of <NUM> or more and <NUM> or less. For example, the adhesive layer <NUM> may have a thickness of <NUM> or more and <NUM> or less. In addition, the non-adhesive layer <NUM> may have a thickness of <NUM> or more and <NUM> or less. More specifically, the non-adhesive layer <NUM> may have a thickness of <NUM> or more and <NUM> or less. For example, the non-adhesive layer <NUM> may have a thickness of <NUM> or more and <NUM> or less.

Accordingly, since the adhesive layer <NUM> may have a thickness in the above range, it is possible to minimize the effect of the non-adhesive layer <NUM> on the gas discharge of the gas discharge unit <NUM> while maintaining the sealing strength between the gas discharge unit <NUM> and the sealing portion <NUM>. In addition, since the non-adhesive layer <NUM> may have a thickness in the above range, the gas introduced through the gas inlet <NUM> may be easily discharged through the non-adhesive layer <NUM> while suppressing the penetration of moisture flowing into the battery cell <NUM>.

However, if the thickness of the adhesive layer <NUM> is less than <NUM> or more than <NUM>, the sealing strength between the gas discharge unit <NUM> and the sealing portion <NUM> is too weak, or the adhesive layer <NUM> prevents the gas discharge of the gas discharge unit <NUM>. In addition, when the thickness of the non-adhesive layer <NUM> is less than <NUM> or more than <NUM>, the area of the non-adhesive layer <NUM> may be reduced to excessively reduce the discharge amount of gas or to excessively increase the thickness of the gas discharge unit <NUM>.

<FIG> is a cross-sectional view, taken along the cutting line a-a' of <FIG>.

Referring to <FIG> and <FIG>, in the battery cell <NUM> according to an embodiment of the present disclosure, one surface of the gas discharge unit <NUM> is opened toward the inside of the battery case <NUM>, and the adhesive layer <NUM> becomes the outer surface of the gas discharge unit <NUM>, so the adhesive layer <NUM> and the sealing portion <NUM> are in contact with each other. In addition, the non-adhesive layer <NUM> become the inner surface of the gas discharge unit <NUM>, and a gas inlet <NUM> is formed between the first non-adhesive layer <NUM> and the second non-adhesive layer <NUM>.

Accordingly, in this embodiment, in the gas discharge unit <NUM>, the gas inside the battery cell <NUM> may be introduced into the gas inlet <NUM> formed between the non-adhesive layer <NUM>. In addition, the gas introduced into the gas inlet <NUM> may pass through the adhesive layer <NUM> and the non-adhesive layer <NUM> according to the pressure difference with the outside of the battery case <NUM>, and the gas introduced into the gas inlet <NUM> may be discharged to the outside.

<FIG> is a diagram showing a shape of the gas discharge unit of <FIG> before being folded.

Referring to <FIG> and <FIG>, in the battery cell <NUM> according to another embodiment of the present disclosure, the gas discharge unit <NUM> have a structure in which the adhesive layer <NUM> and the non-adhesive layer <NUM> are folded. More specifically, the adhesive layer <NUM> and the non-adhesive layer <NUM> have a structure in which the adhesive layer <NUM> surrounds the lower surface and both side surfaces of the non-adhesive layer <NUM> and surrounds both ends of the upper surface of the non-adhesive layer <NUM>, respectively. Here, in the gas discharge unit <NUM>, the adhesive layer <NUM> and the non-adhesive layer <NUM> are folded based on the boundary line C-C'. As an example, the boundary line C-C' may correspond to the center line based on the longitudinal direction of the adhesive layer <NUM> and the non-adhesive layer <NUM>.

In addition, a region of the upper surface of the non-adhesive layer <NUM> where the adhesive layer <NUM> is not formed may have a rectangular shape as shown in <FIG> or may have shapes of various patterns such as a circular shape and an oval shape.

In this method of manufacturing the gas discharge unit <NUM>, the non-adhesive layer <NUM> is disposed approximately in the center of the adhesive layer <NUM>, so that all surfaces except for two surfaces of the non-adhesive layer <NUM> are covered with the adhesive layer <NUM>, and both ends of the adhesive layer <NUM> are folded on the non-adhesive layer <NUM> to make a state as shown in <FIG>. After that, it is folded based on the boundary line C-C', and the adhesive layers <NUM> on the folded sides are adhered to each other by as heat-fusion or press-fusion. At this time, a non-adhesive inner space is formed between the folded non-adhesive layers <NUM>, thereby providing the gas inlet <NUM>.

Accordingly, the gas discharge unit <NUM> according to this embodiment may be formed to be folded based on a predetermined boundary line, so the manufacturing process may be relatively easy and the manufacturing cost may also be simplified.

In addition, a battery module according to another embodiment of the present disclosure includes the battery cell described above. Meanwhile, one or more battery modules according to this embodiment may be packaged in a pack case to form a battery pack.

The battery module described above and the battery pack including the same may be applied to various devices. These devices may be transportation means such as electric bicycles, electric vehicles, hybrid electric vehicles, and the like, but the present disclosure is not limited thereto, and the present disclosure may be applied various devices that can use a battery module and a battery pack including the same, which is also within the scope of the right of the present disclosure.

Claim 1:
A battery cell (<NUM>), comprising:
a battery case (<NUM>) having an accommodation portion (<NUM>) in which an electrode assembly (<NUM>) is mounted, and a sealing portion (<NUM>) formed by sealing an outer periphery thereof; and
a gas discharge unit (<NUM>) inserted into the sealing portion (<NUM>),
wherein the gas discharge unit (<NUM>) protrudes from the inside of the battery case toward the outside of the battery case,
wherein the gas discharge unit (<NUM>) includes a non-adhesive layer (<NUM>) and an adhesive layer (<NUM>) located on the non-adhesive layer (<NUM>), and the non-adhesive layer (<NUM>) and the adhesive layer (<NUM>) are bent to be opened toward the inside of the battery case, wherein the non-adhesive layer (<NUM>) includes a first non-adhesive layer (<NUM>) and a second non-adhesive layer (<NUM>) spaced apart from each other, and
an end of the first non-adhesive layer (<NUM>) and an end of the second non-adhesive layer (<NUM>) adjacent to an outer side of the sealing portion (<NUM>) are connected and integrated with each other and wherein
the adhesive layer (<NUM>) and the non-adhesive layer (<NUM>) have a structure in which the adhesive layer (<NUM>) surrounds a lower surface and both side surfaces of the non-adhesive layer (<NUM>) and surrounds both ends of an upper surface of the non-adhesive layer (<NUM>) in continuity with said side surfaces, and
the gas discharge unit (<NUM>) has a structure in which the adhesive layer (<NUM>) and the non-adhesive layer (<NUM>) are folded based on a boundary line perpendicular to said side surfaces providing a non-adhesive inner space formed between the folded non-adhesive layers (<NUM>), thereby providing a gas inlet (<NUM>) located between the first non-adhesive layer (<NUM>) and the second non-adhesive layer (<NUM>), and opened toward the inside of the battery case (<NUM>).