Secondary battery

Abstract

The present invention relates to a secondary battery. The secondary battery according to the present invention includes: an electrode assembly in which electrodes and separators are alternately stacked; a battery case in which a receiving portion receiving the electrode assembly is formed, and a sealing portion is formed along an outer circumferential surface; a connection tube of which one side portion is connected with the receiving portion of the battery case and the other side portion is connected with the outside of the battery case, and which passes through the sealing portion of the battery case; and an aromatic valve connected with the other side of the connection tube and located at the outside of the battery case, wherein the aromatic valve is opened and internal gas is discharged when the internal pressure of the battery case is greater than or equal to a predetermined pressure.

Description

Technical Field

[0001] Cross-reference to related applications

[0002] This application claims the benefit of priority to Korean Patent Application No. 10-2020-0085661, filed on July 10, 2020, the entire contents of which are incorporated herein by reference. Technical Field

[0004] This invention relates to a secondary battery. Background Technology

[0005] Unlike primary batteries, secondary batteries are rechargeable and offer greater potential for miniaturization and high capacity. Therefore, much research is currently being conducted on secondary batteries. With technological advancements and increasing demand for mobile devices, the need for secondary batteries as an energy source is also rapidly growing.

[0006] Based on the shape of the battery casing, rechargeable batteries are classified into coin-type batteries, cylindrical batteries, prismatic batteries, and pouch batteries. In this type of secondary battery, the electrode assembly installed in the battery casing is a rechargeable and dischargeable power generation device with a structure in which electrodes and separators are stacked.

[0007] Electrode assemblies can be appropriately classified as: wound electrode assemblies, in which a separator is inserted between the positive and negative electrodes, and the positive and negative electrodes are each arranged in the form of sheets coated with active materials, and then the positive electrode, separator and negative electrode are wound together; stacked electrode assemblies, in which multiple positive electrodes and multiple negative electrodes with separators are stacked in sequence; and stacked / folded electrode assemblies, in which stacked cell cells are wound together with a separator membrane having a long length.

[0008] Currently, as the energy density of secondary batteries increases, the amount of gas generated inside them also increases. Furthermore, the bending of secondary batteries due to gas generation causes defects, thus requiring solutions.

[0009] In addition, as the energy density of secondary batteries increases, the defect rate due to gas generation is expected to accelerate.

[0010] The problem is that the amount of moisture diffusing from the outside must be minimized when extracting the generated gas to the outside. When moisture permeates into the secondary battery, side reactions occur, causing performance degradation and gas generation.

[0011] [Prior Art Documents] (Patent Documents) Korean Patent Publication No. 10-2014-0015647 Summary of the Invention

[0012] Technical issues

[0013] One aspect of the present invention is to provide a secondary battery that can expel internal gas while minimizing moisture seepage from the outside.

[0014] Technical solution

[0015] A secondary battery according to an embodiment of the present invention includes: an electrode assembly in which electrodes and a separator are alternately stacked; a battery casing having a receiving portion for accommodating the electrode assembly and a sealing portion formed along the outer peripheral surface of the battery casing; a connecting pipe having one side connected to the receiving portion of the battery casing and the other side connected to the outside of the battery casing, and the connecting pipe passing through the battery casing; and an aroma valve connected to the other side of the connecting pipe and disposed outside the battery casing, so as to open to release internal gas when the internal pressure of the battery casing is greater than or equal to a predetermined pressure.

[0016] The battery pack according to an embodiment of the present invention may include a secondary battery according to an embodiment of the present invention.

[0017] Beneficial effects

[0018] According to the present invention, the aroma valve can be connected via a connecting pipe passing through the sealing part of the battery casing to discharge internal gas while minimizing moisture seepage from the outside. Attached Figure Description

[0019] Figure 1 This is a plan view of a secondary battery according to a first embodiment of the present invention;

[0020] Figure 2 This is a side view of a secondary battery according to a first embodiment of the present invention;

[0021] Figure 3 It is along Figure 1 A cross-sectional view of line BB′;

[0022] Figure 4 This is a perspective view of the connecting tube and the aroma valve in a secondary battery according to a first embodiment of the present invention;

[0023] Figure 5 This is a cross-sectional view of a secondary battery according to a first embodiment of the present invention;

[0024] Figure 6 This is a cross-sectional view of the aromatic valve in a secondary battery according to a first embodiment of the present invention;

[0025] Figure 7 This is a plan view of a secondary battery according to a second embodiment of the present invention;

[0026] Figure 8This is a cross-sectional view of the aromatic valve in a secondary battery according to a second embodiment of the present invention;

[0027] Figure 9 yes Figure 8 An enlarged cross-sectional view of region A;

[0028] Figure 10 This is a plan view of the aromatic valve in a secondary battery according to a second embodiment of the present invention;

[0029] Figure 11 It is along Figure 10 A cross-sectional view of line AA′;

[0030] Figure 12 This is a plan view of a secondary battery according to a third embodiment of the present invention;

[0031] Figure 13 This is a cross-sectional view of the aromatic valve in a secondary battery according to a third embodiment of the present invention. Detailed Implementation

[0032] The objectives, specific advantages, and novel features of this invention will become clearer from the following detailed description taken in conjunction with the accompanying drawings. It should be noted that throughout this specification, even when shown in other drawings, the same reference numerals are used as much as possible to label components of the drawings. Furthermore, the invention may be embodied in different forms and should not be construed as being limited to the embodiments set forth herein. In the following description of the invention, detailed descriptions of related techniques that would unnecessarily obscure the essence of the invention will be omitted.

[0033] The secondary battery according to the first embodiment

[0034] Figure 1 This is a plan view of a secondary battery according to a first embodiment of the present invention. Figure 2 This is a side view of a secondary battery according to a first embodiment of the present invention. Figure 3 It is along Figure 1 The cross-sectional view taken from line BB′. Figure 4 This is a perspective view of the connecting tube and the aroma valve in a secondary battery according to a first embodiment of the present invention.

[0035] Reference Figures 1 to 4 According to a first embodiment of the present invention, a secondary battery 100 includes: an electrode assembly 120 in which electrodes and a separator are alternately stacked and wound; a battery housing 110 in which a receiving portion 114 for accommodating the electrode assembly 120 is formed; a connecting tube 140, one side of which is connected to the receiving portion 114 of the battery housing 110; and an aroma valve 150 connected to the other side of the connecting tube 140.

[0036] The secondary battery according to the first embodiment of the present invention will be described in more detail below.

[0037] Figure 5 This is a cross-sectional view of a secondary battery according to a first embodiment of the present invention.

[0038] Reference Figure 5 The electrode assembly 120 can be a rechargeable and dischargeable power generation element, and has a structure in which electrodes and diaphragms are combined and stacked alternately relative to each other.

[0039] The electrodes may include a positive electrode and a negative electrode. In addition, a diaphragm separates and electrically insulates the positive and negative electrodes from each other.

[0040] The positive electrode may include: a positive electrode current collector; a positive electrode active material portion, which is a region on which the positive electrode active material is stacked on the positive electrode current collector; and a positive electrode uncoated portion, which is a region where the positive electrode active material is not stacked. In this case, the positive electrode active material portion may form a positive electrode coated portion.

[0041] For example, the positive current collector can be configured as a foil made of aluminum.

[0042] The positive electrode active material may include lithium manganese oxide, lithium cobalt oxide, lithium nickel oxide, lithium iron phosphate, or a compound or mixture containing at least one of the above materials.

[0043] The negative electrode may include: a negative electrode current collector; a negative electrode active material portion, which is a region on the negative electrode current collector where the negative electrode active material is stacked; and a negative electrode uncoated portion, which is a region where the negative electrode active material is not stacked. In this case, the negative electrode active material portion may form a negative electrode coated portion.

[0044] For example, the negative electrode current collector can be configured as a foil made of copper (Cu) or nickel (Ni) material.

[0045] The negative electrode active material may include synthetic graphite, lithium metal, lithium alloy, carbon, petroleum coke, activated carbon, graphite, silicon compounds, tin compounds, titanium compounds, or alloys thereof. Here, the negative electrode active material may also include, for example, non-graphite SiO (silicon dioxide) or SiC (silicon carbide).

[0046] The diaphragm can be made of insulating material to insulate the positive and negative electrodes from each other.

[0047] Alternatively, for example, the diaphragm can be a multilayer membrane made of microporous polyethylene, polypropylene, or a combination thereof, or a polymer membrane for solid polymer electrolytes or gel-type polymer electrolytes, such as polyvinylidene fluoride, polyethylene oxide, polyacrylonitrile, or polyvinylidene fluoride hexafluoropropylene copolymer.

[0048] Reference Figure 1The secondary battery 100 according to the first embodiment of the present invention may further include: an electrode lead 130 electrically connected to the electrode assembly 120. One side of the electrode lead 130 is connected to an electrode, and the other side extends to the outside of the battery case 110. Here, the electrode lead 130 may include: a positive electrode lead connected to the positive electrode and a negative electrode lead connected to the negative electrode.

[0049] Reference Figure 1 and Figure 5 Within the battery casing 110, a receiving portion 114 is formed to accommodate the electrode assembly 120, and a sealing portion 115 is formed along the outer peripheral surface 113. Here, for example, the thickness 'a' of the sealing portion 115 can be 10 mm or less. Specifically, in this case, the thickness 'a' of the sealing portion 115 can be 1 mm or less.

[0050] Additionally, the battery casing 110 may include an upper casing 111 and a lower casing 112.

[0051] The outer peripheral surfaces 111a and 112a of the upper shell 111 and the lower shell 112, facing each other, may be made of polypropylene (PP) material. Here, the sealing part 115 may apply heat and pressure to the outer peripheral surfaces 111a and 112a of the upper shell 111 and the lower shell 112, so that the outer peripheral surfaces 111a and 112a are thermally fused together.

[0052] Reference Figures 3 to 5 One side of the connecting tube 140 can be connected to the receiving portion 114 of the battery case 110, and the other side can be connected to the outside of the battery case 110. The connecting tube 140 can pass through the sealing portion 115 of the battery case 110.

[0053] Additionally, the connecting pipe 140 can pass between the outer peripheral surfaces of the upper shell 111 and the lower shell 112 in the battery housing 110, and the outer surface of the connecting pipe 140 can be sealed together with the outer peripheral surfaces 111a and 112a of the upper shell 111 and the lower shell 112. Here, the connecting pipe 140 has a discharge passage 141 that connects the receiving portion 114 of the battery housing 110 to the aroma valve 150 therein, so that the internal gas disposed in the receiving portion 114 of the battery housing 110 moves to the aroma valve 150.

[0054] Alternatively, the outer surface of the connecting tube 140 may include polypropylene (PP) material. Here, the outer surface of the connecting tube 140 may be made of PP material.

[0055] Therefore, the outer surface of the connecting tube 140 can be made of PP material, so that when the outer peripheral surfaces 111a and 112a of the upper shell 111 and the lower shell 112 are sealed, a smooth seal can be achieved to improve sealing performance. That is, the opposing surfaces between the connecting tube 140 and the outer peripheral surface 113 of the battery casing 110 can be made of the same or similar materials, so a seal can be achieved and a very strong seal can be easily obtained.

[0056] Figure 6 This is a cross-sectional view of the aromatic valve in a secondary battery according to a first embodiment of the present invention. Figure 6 In, it is further shown that in Figure 3 and Figure 5 The mask 155 is omitted in the text.

[0057] Reference Figures 3 to 6 The aroma valve 150 can be connected to the other side of the connecting pipe 140 and disposed outside the battery housing 110, such that when the internal pressure of the battery housing 110 is greater than or equal to a predetermined pressure, the aroma valve 150 opens to release internal gas. Here, for example, the predetermined pressure can be a pressure greater than the internal pressure of a conventional pouch battery and less than the bending pressure of a conventional pouch battery. In this case, for example, the predetermined pressure can specifically be 0.01 atmospheres (atm) or more. Furthermore, for example, the predetermined pressure can more specifically be 0.05 atmospheres (atm) or more.

[0058] Alternatively, for example, the aroma valve 150 may include a body 151 in which an exhaust port 151a is formed; a cap 152 disposed on the outer surface of the body 151 to cover the exhaust port 151a; and an adhesive 154 disposed between the cap 152 and the body 151 to allow the cap 152 and the body 151 to adhere to each other. Furthermore, as another example, the aroma valve 150 may also include a cover 155 outside the cap 152 to prevent the cap 152 from separating. In this case, a cover hole 155a may be formed in the cover 155 to facilitate the release of gas.

[0059] Therefore, when the internal pressure of the battery case 110 increases to exceed the adhesive force of the adhesive 154 that allows the body 151 and the cover 152 to adhere to each other, the space between the body 151 and the cover 152 will open to allow the internal gas to be discharged to the outside.

[0060] Furthermore, the aroma valve 150 can be arranged perpendicularly to the connecting pipe 140. Here, the vent 151a of the aroma valve 150 can extend perpendicularly to the internal discharge channel 141 of the connecting pipe 140 formed in the longitudinal direction of the connecting pipe 140. Thus, the aroma valve 150 can be arranged perpendicularly to the connecting pipe 140 to maximize the air permeation area of ​​the aroma valve 150. That is, when the aroma valve 150 is installed in a direction parallel to the sealing portion 115, which has a narrow width and a long length, the limitation of deterioration of gas permeation characteristics can be overcome.

[0061] In this case, for example, the width d of the vent 151a of the aroma valve 150 can be greater than the width c of the discharge channel 141 of the connecting pipe 140.

[0062] The width b of the aroma valve 150 can be formed to be 10mm or more.

[0063] Adhesive 154 may include silicone oil.

[0064] The secondary battery 100 according to the first embodiment of the present invention, configured as described above, may include an aroma valve 150 through which fluid flows in only one direction through a connecting pipe 140 passing through a sealing portion 115 of the battery casing 110, so as to discharge internal gas to the outside while minimizing the amount of moisture seeping in from the outside.

[0065] Additionally, the connecting pipe 140 can be sealed together with the sealing portion 115 provided on the outer peripheral surface 113 of the battery case 110, which is sealed by applying heat, and the aroma valve 150 can be connected to the connecting pipe 140. Thus, when the aroma valve 150 is installed to pass directly through the receiving portion 114, the portion of the battery case 110 surrounding the receiving portion 114 can be prevented from being damaged by heat.

[0066] The secondary battery according to the second embodiment

[0067] The secondary battery according to the second embodiment will be described below.

[0068] Figure 7 This is a plan view of a secondary battery according to a second embodiment of the present invention. Figure 8 This is a cross-sectional view of the aromatic valve in a secondary battery according to a second embodiment of the present invention. Figure 9 yes Figure 8 An enlarged cross-sectional view of region A.

[0069] Reference Figures 7 to 8According to a second embodiment of the present invention, a secondary battery 200 includes: an electrode assembly in which electrodes and a separator are alternately stacked and wound; a battery housing 110 in which a receiving portion for accommodating the electrode assembly is formed; a connecting tube 140, one side of which is connected to the receiving portion of the battery housing 110; and an aroma valve 250 connected to the other side of the connecting tube 140.

[0070] The secondary battery 200 according to the second embodiment of the present invention differs from the electrode assembly according to the first embodiment in the construction of the aroma valve 250. Therefore, the content of this embodiment that is repeated with the content according to the first embodiment will be omitted or briefly described, and the differences between them will be mainly described.

[0071] One side of the connecting tube 140 can be connected to the receiving part of the battery case 110, and the other side can be connected to the outside of the battery case 110. The connecting tube 140 can pass through the sealing part 115 of the battery case 110.

[0072] The connecting tube 140 may comprise polypropylene (PP) material. Here, the outer surface of the connecting tube 140 may be made of PP material. In this case, the surface of the outer peripheral surface 113 of the battery casing 110 facing the connecting tube 140 may comprise polypropylene (PP) material.

[0073] Figure 10 This is a plan view of the aromatic valve in a secondary battery according to a second embodiment of the present invention. Figure 11 It is along Figure 10 The cross-sectional view taken by line AA′. Here, Figure 11 An example is shown with the aroma valve open. Furthermore, Figure 10 Is Figure 11 The diagram is a plan view taken from above, and for convenience, a portion of the adhesive 253a is shown after the elastic element 253 has been removed.

[0074] For more details, see [link to relevant documentation]. Figures 7 to 11 The aroma valve 250 can be connected to the other side of the connecting pipe 140 and is located outside the battery housing 110, so that when the internal pressure of the battery housing 110 is greater than or equal to a predetermined pressure, the aroma valve 150 opens to discharge the internal gas.

[0075] Additionally, the aroma valve 250 may include: a body 251 in which an exhaust port 251a is formed; a cover 252 disposed on the outer surface of the body 251 to cover the exhaust port 251a; and an elastic member 253 surrounding the cover 252 and fixed at one end to the body 251 to fix the cover 252 to the body 251 by the elastic force of the elastic member.

[0076] When the internal pressure of the battery case 110 is greater than the elastic force of the elastic member 253, the cover 252 and the body 251 can be spaced apart from each other, and the vent 251a can be opened to release the internal gas. Then, when the internal gas pressure of the battery case 110 decreases after the internal gas is released, the cover 252 and the body 251 can be brought into close contact with each other by the restoring force of the elastic member 253, so that the vent 251a is sealed.

[0077] The elastic element 253 may be made of at least one or more of the following materials: natural rubber, polyisoprene, polyvinylidene fluoride (PVDF) (polypropylene), polyvinyl fluoride (PVF), poly-3-hydroxybutyrate (PHB), polyvinyl acetate (PVA), polychlorotrifluoroethylene (PCTFE), polyamide, polylactic acid, polyethylene terephthalate, polyvinyl chloride, polyvinyl alcohol, polystyrene, polymethyl methacrylate (PMMA), polytetrafluoroethylene (PTFE), polycarbonate, polysulfone, and polynorborneol.

[0078] The elastic element 253 can be adhered to the outer surface of the cover 252. Here, a portion of the elastic element 253 may not be adhered to form a channel for the discharge of internal gas. Here, the elastic element 253 may include an adhesive portion 253a adhered to the outer surface of the cover 252 and a non-adhesive portion 253b not adhered to the outer surface of the cover 252. In this case, the non-adhesive portion 253b may be formed along the side and top surfaces of the cover 252 to form a channel for gas discharge.

[0079] Furthermore, in the elastic member 253, one end of the adhesive portion 253a can be fixed to the main body 251, while one end of the non-adhesive portion 253b can be left unfixed to the main body 251. That is, for example, the end of the adhesive portion 253a can be adhered to the main body 251, while the end of the non-adhesive portion 253b can be left unattached to the main body 251.

[0080] Therefore, when the internal pressure is greater than the elastic force of the elastic element 253, the cover 252 can move upward, thereby separating the body 251 and the cover 252 from each other, so that the internal gas is discharged to the outside through the vent 251a along the non-adhesive part 253b.

[0081] The aroma valve 250 may also include an O-ring 255 disposed between the cover 252 and the body 251. Therefore, the sealing performance between the cover 252 and the body 251 can be significantly improved by the O-ring 255.

[0082] The aroma valve 250 can be arranged perpendicularly to the connecting pipe 140. Here, the vent 251a of the aroma valve 250 can extend perpendicularly to the internal discharge channel 141 of the connecting pipe 140 formed in the longitudinal direction of the connecting pipe 140.

[0083] The secondary battery according to the third embodiment

[0084] The secondary battery according to the third embodiment will be described below.

[0085] Figure 12 This is a plan view of a secondary battery according to a third embodiment of the present invention. Figure 13 This is a cross-sectional view of the aromatic valve in a secondary battery according to a third embodiment of the present invention.

[0086] Reference Figures 12 to 13 According to a third embodiment of the present invention, a secondary battery 300 includes: an electrode assembly in which electrodes and a separator are alternately stacked and wound; a battery housing 110 in which a receiving portion for accommodating the electrode assembly is formed; a connecting tube 140, one side of which is connected to the receiving portion of the battery housing 110; and an aroma valve 350 connected to the other side of the connecting tube 140.

[0087] The secondary battery 300 according to the third embodiment of the present invention differs from the secondary batteries according to the first and second embodiments described above in the construction of the aroma valve 350. Therefore, the content of this embodiment that is repeated with the content of the foregoing embodiments will be omitted or briefly described, and the differences between them will be mainly described.

[0088] More specifically, one side of the connecting tube 140 can be connected to the receiving portion of the battery case 110, and the other side can be connected to the outside of the battery case 110, and the connecting tube 140 can pass through the sealing portion 115 of the battery case 110.

[0089] The connecting tube 140 may comprise polypropylene (PP) material. Here, the outer surface of the connecting tube 140 may be made of PP material. In this case, the surface of the outer peripheral surface 113 of the battery casing 110 facing the connecting tube 140 may comprise polypropylene (PP) material.

[0090] The aroma valve 350 can be connected to the other side of the connecting pipe 140 and disposed outside the battery housing 110, such that when the internal pressure of the battery housing 110 is greater than or equal to a predetermined pressure, the aroma valve 150 is opened to discharge the internal gas.

[0091] The aroma valve 350 may include: a body 351 in which an exhaust port 351a is formed; a cover 352 disposed on the outer surface of the body 351 to cover the exhaust port 351a; an elastic member 353 surrounding the cover 352 and fixed at one end to the body 351 to secure the cover 352 to the body 351; and an adhesive 354 disposed between the body 351 and the cover 352 to allow the cover 352 and the body 351 to adhere to each other.

[0092] When the internal pressure of the battery case 110 is greater than the elastic force of the elastic member 353, the space between the cover 352 and the body 351 can be opened to release the internal gas. Then, when the internal gas of the battery case 110 decreases after the gas is released, the space between the cover 352 and the body 351 can be sealed by the restoring force of the elastic member 353.

[0093] The elastic element 353 may be made of at least one or more materials selected from natural rubber, polyisoprene, vinylidene fluoride (PVDF) (polypropylene), polyvinyl fluoride (PVF), poly-3-hydroxybutyrate (PHB), polyvinyl acetate (PVA), polychlorotrifluoroethylene (PCTFE), polyamide, polylactic acid, polyethylene terephthalate, polyvinyl chloride, polyvinyl alcohol, polystyrene, polymethyl methacrylate (PMMA), polytetrafluoroethylene (PTFE), polycarbonate, polysulfone, and polynorborneol.

[0094] The elastic element 353 can be adhered to the outer surface of the cover 352. Here, a portion of the elastic element 353 may not be adhered to form a channel for the internal gas to escape.

[0095] The adhesive 354 may include silicone oil. Therefore, the sealing performance between the cap 352 and the body 351 can be further improved. That is, the space between the cap 352 and the body 351 can be double-sealed by the elastic element 353 and the adhesive 354 to significantly improve the sealing performance.

[0096] The aroma valve 350 can be arranged perpendicularly to the connecting pipe 140. Here, the vent 351a of the aroma valve 350 can extend perpendicularly to the internal discharge channel 141 of the connecting pipe 140 formed in the longitudinal direction of the connecting pipe 140.

[0097] The elastic element 353 can be adhered to the outer surface of the cover 352. Here, a portion of the elastic element 353 may not be adhered to form a channel for the internal gas to escape.

[0098] A membrane 360, which allows gas to pass through but not liquid, can be further provided on the vent 351a of the aroma valve 350. Therefore, external moisture and air can be effectively prevented from being introduced into the secondary battery 300.

[0099] Here, membrane 360 ​​can be made of a hydrophobic material. Therefore, membrane 360 ​​can have micropore size and be made of a hydrophobic material to better prevent liquid from passing through the micropores.

[0100] A battery pack may be provided, comprising any one or more secondary batteries according to the first to third embodiments of the present invention. The battery pack can be configured by electrically connecting multiple said secondary batteries and housing said secondary batteries in a casing.

[0101] While the invention has been specifically shown and described with reference to exemplary embodiments thereof, it should be understood that the scope of the invention is not limited thereto. Those skilled in the art will understand that various changes in form and detail may be made without departing from the spirit and scope of the invention.

[0102] Furthermore, the scope of protection of this invention will be defined by the appended claims.

[0103] [Figure Labels]

[0104] 100, 200, 300: Secondary batteries

[0105] 110: Battery casing

[0106] 111: Upper shell

[0107] 112: Lower shell

[0108] 113: Peripheral surface

[0109] 114: Reception Department

[0110] 115: Sealing part

[0111] 120: Electrode assembly

[0112] 130: Electrode lead

[0113] 140: Connecting pipe

[0114] 141: Discharge Channel

[0115] 150, 250, 350: Aromatic valve

[0116] 151, 251, 351: Main body

[0117] 151a, 251a, 351a: Exhaust port

[0118] 152, 252, 352: Cover

[0119] 154, 354: Adhesives

[0120] 155: Cover

[0121] 155a: Cover hole

[0122] 253: Elastic element

[0123] 253a: Adhesive part

[0124] 253b: Non-adhesive portion

[0125] 255: O-ring

[0126] 360: Membrane

Claims

1. A secondary battery, comprising: An electrode assembly in which electrodes and diaphragms are stacked alternately; A battery case having a receiving portion formed therein to accommodate the electrode assembly, and a sealing portion formed along the outer peripheral surface of the battery case; A connecting tube, one side of which is connected to the receiving portion of the battery case, and the other side of which is connected to the outside of the battery case, and the connecting tube passes through the battery case; as well as An aroma valve is connected to the other side of the connecting pipe and is disposed outside the battery casing. The aroma valve includes: The main body has vent holes formed therein; A cover is disposed on the outer surface of the main body to cover the vent hole; An adhesive is disposed between the body and the cover such that the cover adheres to the body, and the space between the body and the cover opens to release internal gas when the internal pressure of the battery casing is greater than or equal to the adhesive force of the adhesive; and An elastic element is configured to surround the cover, wherein one end of the elastic element is fixed to the body, and the elastic element secures the cover to the body by its elastic force. The elastic element is adhered to the outer surface of the cover, and a portion of the elastic element is not adhered to form a channel through which the internal gas is discharged.

2. The secondary battery according to claim 1, wherein, The connecting pipe is made of polypropylene (PP) material.

3. The secondary battery according to claim 2, wherein, The battery casing includes an upper casing and a lower casing. The outer peripheral surfaces of the upper shell and the lower shell that face each other are made of polypropylene (PP) material. The connecting pipe passes between the outer peripheral surface of the upper shell and the outer peripheral surface of the lower shell, and The outer surface of the connecting tube is sealed together with the outer peripheral surfaces of the upper shell and the lower shell.

4. The secondary battery according to claim 1, wherein, When the internal pressure of the battery casing is equal to or greater than the elastic force of the elastic element, the cover separates from the body, causing the vent to open and release internal gas. When the internal pressure of the battery casing decreases after the internal gas is released, the restoring force of the elastic element causes the cover and the body to come into close contact with each other, thereby sealing the vent.

5. The secondary battery according to claim 1, wherein, The elastic element is made of at least one of the following materials: natural rubber, polyvinylidene fluoride (PVDF), polypropylene, polyvinyl fluoride (PVF), poly-3-hydroxybutyrate (PHB), polyvinyl acetate (PVA), polychlorotrifluoroethylene (PCTFE), polyamide, polylactic acid, polyethylene terephthalate, polyvinyl chloride, polyvinyl alcohol, polystyrene, polymethyl methacrylate (PMMA), polytetrafluoroethylene (PTFE), polycarbonate, polysulfone, and polynorborneol.

6. The secondary battery according to claim 1, wherein, The aroma valve also includes an O-ring disposed between the cap and the body.

7. The secondary battery according to claim 1, wherein, The adhesive includes silicone oil.

8. The secondary battery according to claim 1, wherein, The aroma valve is positioned perpendicular to the connecting pipe.

9. The secondary battery according to claim 8, wherein, The vent of the aroma valve extends perpendicularly to the internal discharge channel of the connecting pipe formed in the longitudinal direction of the connecting pipe.

10. The secondary battery according to claim 8 further includes a membrane located on the vent of the aromatic valve, wherein gas passes through the membrane while liquid does not.

11. A battery pack comprising the secondary battery as described in any one of claims 1 to 7.

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