Secondary battery and method for manufacturing secondary battery

Abstract

The secondary battery according to the invention includes: an electrode assembly; and a battery housing comprising a receiving portion for housing the electrode assembly and an electrolyte, and a side portion extending from the receiving portion. The side portion includes: a cut portion formed adjacent to an end of the side portion to discharge gas from inside the receiving portion; and a plurality of sealing portions arranged between the cut portion and the receiving portion to prevent electrolyte movement toward the cut portion while gas is discharged through the cut portion. The plurality of sealing portions have gas discharge passages formed between the respective sealing portions to discharge gas, and include inflow prevention portions positioned adjacent to the inlet of the gas discharge passages and extending toward the receiving portion to prevent electrolyte from flowing into the gas discharge passages.

Description

Technical Field

[0001] Cross-references to related applications

[0002] This application is based on and claims priority to Korean Patent Application No. 10-2024-0031381, filed with the Korean Intellectual Property Office on March 5, 2024, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0003] This disclosure relates to a secondary battery and a method for manufacturing the secondary battery. More specifically, this disclosure relates to a secondary battery requiring gas emission and a method for manufacturing the secondary battery. Background Technology

[0004] With technological advancements and increasing demand for electric vehicles and mobile devices, the demand for secondary batteries as an energy source is also rising. Unlike primary batteries, secondary batteries are rechargeable batteries that can be charged after a single use. A secondary battery consists of a positive electrode and a negative electrode. When the metal positive electrode is oxidized, electricity is generated through the movement of electrons released from the metal.

[0005] To manufacture this type of secondary battery, an electrode active material slurry is first applied to a positive electrode current collector and a negative electrode current collector to create the positive and negative electrodes. Then, the positive and negative electrodes are stacked on both sides of a separator to form an electrode assembly. The electrode assembly is then housed in a battery casing, and electrolyte is injected and then sealed.

[0006] Depending on the material of the casing housing the electrode components, secondary batteries are classified into pouch-type, can-type, etc. Pouch-type secondary batteries are formed by housing the electrode components in a pouch made of a flexible polymer material. Can-type secondary batteries are formed by housing the electrode components in a casing made of a material such as metal or plastic.

[0007] The pouch, which serves as the battery casing for a pouch-type secondary battery, is manufactured by pressing a flexible pouch film to form a housing section. Once the housing section is formed, the electrode assembly is housed within the electrode housing space of the housing section, and the sides extending from the housing section are fused together to seal the pouch.

[0008] Before fusing the sides, an activation process involving test charging and / or discharging of the secondary battery can be performed. During activation, the electrode components within the housing may react with the electrolyte to generate gas. To allow the gas generated during activation to escape to the outside of the battery casing, a portion of the side can be cut or stamped to form a cut section. However, in this case, it is necessary to prevent electrolyte from being released through the cut section as gas is released towards it. This is because a reduction in electrolyte can decrease the capacity of the secondary battery. Summary of the Invention

[0009] Technical issues

[0010] This disclosure aims to solve the above-mentioned problems, and therefore aims to provide a secondary battery configured to prevent the discharge of electrolyte during degassing.

[0011] The technical problems to be solved by this disclosure are not limited to those described above, and those skilled in the art can clearly understand other problems not mentioned herein through the following description of this disclosure.

[0012] Technical solution

[0013] A secondary battery according to an embodiment of the present disclosure includes: an electrode assembly; and a battery housing including a receiving portion that together houses the electrode assembly and an electrolyte, and a side portion extending from the receiving portion, wherein the side portion includes: a cutting portion formed adjacent to an end of the side portion to discharge gas within the receiving portion; and a plurality of sealing portions located between the cutting portion and the receiving portion to prevent the electrolyte from moving into the cutting portion while gas is being discharged into the cutting portion, wherein the plurality of sealing portions includes: a gas discharge path formed between each of the plurality of sealing portions to allow gas discharge; and an inflow prevention portion positioned adjacent to the inlet of the gas discharge path and extending toward the receiving portion to prevent the electrolyte from flowing into the gas discharge path.

[0014] Each of the plurality of sealing portions may include a sealing portion body that supports the inflow prevention portion and forms a concave guiding space in a direction away from the receiving portion to guide the electrolyte together with the inflow prevention portion.

[0015] The plurality of sealing portions can be arranged in a direction parallel to the long side of the storage portion.

[0016] The inflow prevention section may have an inclined surface that is inclined in a direction away from the receiving section relative to the direction away from the gas discharge flow path.

[0017] The plurality of sealing portions can be formed by fusing the sides together.

[0018] The gas emission path can extend from the inlet to the outlet in a manner that changes direction at least once in different directions.

[0019] The gas emission path may include: an inlet path extending from an inlet near the receiving portion along a first extending direction; and a curved path extending from the inlet path along a second extending direction different from the first extending direction to prevent the electrolyte from moving.

[0020] The inlet flow path can extend perpendicular to the arrangement direction of the plurality of sealing parts.

[0021] The gas emission path may further include an outlet path that extends from an outlet located on the opposite side of the inlet along a third extension direction different from the second extension direction.

[0022] The outlet flow path can be connected to the curved flow path.

[0023] The cross-sectional area of ​​the outlet flow path can be smaller than the cross-sectional area of ​​the flow path formed in the cutting section and used for gas discharge.

[0024] The outlet may be adjacent to the cutting section.

[0025] The cutting section can be configured as a plurality of parts, and the gas discharge path can be configured as a plurality of parts corresponding to each of the plurality of cutting sections.

[0026] The portion of the gas emission path adjacent to the outlet can have a larger cross-sectional area as the portion moves toward the outlet.

[0027] The portion of the gas discharge path adjacent to the inlet can have a smaller cross-sectional area as the portion moves away from the inlet.

[0028] A secondary battery according to an embodiment of the present disclosure includes: an electrode assembly; and a battery housing including a receiving portion that together houses the electrode assembly and an electrolyte, and a side portion extending from the receiving portion, wherein the side portion includes: a cutting portion formed adjacent to an end of the side portion to discharge gas within the receiving portion; and a plurality of sealing portions located between the cutting portion and the receiving portion to prevent the electrolyte from moving into the cutting portion while gas is being discharged into the cutting portion, wherein the plurality of sealing portions includes a gas discharge flow path formed between each of the plurality of sealing portions to allow gas to be discharged, and the gas discharge flow path extends from the inlet to the outlet in a manner that changes direction at least once in different directions.

[0029] The plurality of sealing portions may include inflow prevention portions positioned adjacent to the inlet of the gas discharge path and extending toward the receiving portion to prevent the electrolyte from flowing into the gas discharge path.

[0030] Each of the plurality of sealing portions may include a sealing portion body that supports the inflow prevention portion and forms a concave guiding space in a direction away from the receiving portion to guide the electrolyte together with the inflow prevention portion.

[0031] The plurality of sealing portions can be arranged along a direction parallel to the long side of the receiving portion.

[0032] A method for manufacturing a secondary battery according to an embodiment of the present disclosure includes the following steps: sealing a lead sealing portion on a side of a battery housing located outside an electrode assembly; forming a cut portion adjacent to an end of the side portion; forming a plurality of sealing portions located between the cut portion and a receiving portion of the battery housing and allowing a gas discharge path to be formed between the plurality of sealing portions; and discharging gas generated by activating the electrode assembly to the cut portion through the gas discharge path, and the method further includes forming an inflow prevention portion in the plurality of sealing portions by fusing the side portion to prevent electrolyte from flowing into the gas discharge path, the inflow prevention portion being positioned adjacent to the inlet of the gas discharge path and protruding toward the receiving portion.

[0033] Beneficial effects

[0034] The secondary battery according to this disclosure may include a plurality of sealing portions and a gas discharge path, the plurality of sealing portions being located between the cutting portion and the receiving portion, the gas discharge path being formed between each of the sealing portions to allow gas discharge, thereby preventing the discharge of electrolyte during degassing.

[0035] The secondary battery according to this disclosure may include a plurality of sealing portions, the plurality of sealing portions including an inflow prevention portion positioned adjacent to the inlet of the gas discharge flow path and extending toward the receiving portion to prevent electrolyte from flowing into the gas discharge flow path, thereby preventing electrolyte discharge.

[0036] According to this disclosure, the secondary battery can be configured to form a gas discharge path extending from the inlet to the outlet in such a manner that the direction is changed at least once in different directions, thereby preventing the discharge of electrolyte.

[0037] The effects obtained by this disclosure are not limited to those described above, and other effects not mentioned can be clearly understood by those skilled in the art through the following description of this disclosure. Attached Figure Description

[0038] Figure 1 This is a perspective view of a secondary battery according to a first embodiment of the present disclosure.

[0039] Figure 2 yes Figure 1 The image shows an assembled view of the secondary battery.

[0040] Figure 3 This shows the view from above. Figure 2 The diagram shows a plan view of a portion of the secondary battery casing after it has been fused together.

[0041] Figure 4 It is shown in Figure 3 The diagram shows a plan view of the sealing portion formed in the battery casing of a secondary battery.

[0042] Figure 5 It is shown Figure 4 A magnified view of part V.

[0043] Figure 6 It is shown Figure 4 A magnified view of part of VI.

[0044] Figure 7 It is about manufacturing Figure 1 The flowchart of the secondary battery method disclosed in the paper.

[0045] Figure 8 This is an enlarged view of a secondary battery according to the second embodiment of this disclosure.

[0046] Figure 9 This is an enlarged view of a secondary battery according to the third embodiment of this disclosure.

[0047] Figure 10 This is an enlarged view of a secondary battery according to the fourth embodiment of this disclosure.

[0048] Figure 11 This is an enlarged view of a secondary battery according to the fifth embodiment of this disclosure.

[0049] Figure 12 This is an enlarged view of a secondary battery according to the sixth embodiment of this disclosure. Detailed Implementation

[0050] In the following, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings to enable those skilled in the art to readily implement the present disclosure. However, the present disclosure may be embodied in various different forms and is not limited to or construed as described below.

[0051] For clarity in describing this disclosure, detailed descriptions of known techniques that are irrelevant to this disclosure or may unnecessarily obscure the essential points of this disclosure have been omitted. When reference numerals are assigned to components in each drawing of this specification, the same or similar reference numerals are assigned to the same or similar components throughout the specification.

[0052] Furthermore, the terms or words used in this disclosure and the appended claims should not be construed as limited to their general and dictionary meanings, but should be interpreted based on their meanings and concepts corresponding to the technical aspects of this disclosure, on the basis of the principle that inventors are allowed to properly define terms for the best interpretation.

[0053] The various implementation methods and terms used herein are not intended to limit the technical features described herein to any particular implementation, but should be understood to include various modifications, equivalents or substitutions of the corresponding implementation methods.

[0054] Similar reference numerals may be used for similar or related components in conjunction with the description in the accompanying drawings.

[0055] Unless the relevant context clearly indicates otherwise, the singular form of the noun corresponding to an item may include one or more items.

[0056] As used herein, each of the phrases such as “A or B”, “at least one of A and B”, “at least one of A or B”, “A, B or C”, “at least one of A, B and C” and “at least one of A, B or C” can include any one of the items listed together in the corresponding phrase or all possible combinations thereof.

[0057] The term “and / or” includes any combination of multiple related listed components, or any one of multiple related listed components.

[0058] Terms such as “first” or “second” can be simply used to distinguish one such component from another, without limiting such components in any other way (e.g., importance or order).

[0059] When it is stated that a component (e.g., the first component) is “connected” or “linked” to another component (e.g., the second component), whether or not terms such as “functionally” or “communically” are used, it means that the component can be connected to the other component directly (e.g., wired), wirelessly, or via a third component.

[0060] The terms “comprising” or “having” are intended to specify the presence of the features, numbers, steps, actions, components, parts or combinations thereof described herein, but do not exclude the presence or addition of one or more other features, numbers, steps, actions, components, parts or combinations thereof.

[0061] When a component is described as being “connected,” “linked,” “supported,” or “in contact” with another component, this includes not only cases where the components are directly connected, linked, supported, or in contact, but also cases where the components are indirectly connected, linked, supported, or in contact through a third component.

[0062] When a component is said to be "on" another component, this includes not only cases where one component is in contact with another component, but also cases where there is another component between the two components.

[0063] Meanwhile, the terms “vertical direction,” “lower side,” and “front-back direction” used in the following description are defined based on the accompanying drawings, and the shape and position of each component are not limited by these terms.

[0064] In the following, embodiments according to this disclosure will be described in detail with reference to the accompanying drawings.

[0065] Figure 1 This is a perspective view of a secondary battery B according to the first embodiment of this disclosure. Figure 2 yes Figure 1 The assembly view of secondary battery B shown. Figure 3 This shows the view from above. Figure 2 The diagram shows a plan view of a portion of the battery casing 200 of the secondary battery B after it has been fused together.

[0066] Reference Figures 1 to 3 The secondary battery B according to the first embodiment of the present disclosure will be described.

[0067] like Figure 1 As shown, a secondary battery B configured to generate electricity can be provided. In the following description, the term "secondary battery B" may refer to a secondary battery in a completed state where the process has been completed, or to a secondary battery B in the process. Therefore, the term "secondary battery B" in this disclosure may be understood according to the context.

[0068] like Figure 2 As shown, the secondary battery B may include an electrode assembly 100. The electrode assembly 100 can be formed by alternately stacking electrodes and a separator. First, a slurry obtained by mixing electrode active materials, a binder, and a plasticizer can be applied to a positive electrode current collector and a negative electrode current collector to manufacture electrodes such as positive and negative electrodes. Then, a separator is stacked between the electrodes to form the electrode assembly 100, and the electrode assembly 100 can be inserted into a battery housing 200 and sealed after electrolyte injection. At this time, the battery housing 200 can be, for example, pouch-shaped. In the following description, as an example of the battery housing 200, a pouch or pouch-shaped battery housing 200 can be considered to refer to the battery housing 200.

[0069] Specifically, the electrode assembly 100 may include two types of electrodes, namely positive and negative electrodes, and a separator inserted between the electrodes to insulate them from each other. Depending on the method of stacking the positive, negative, and separator electrodes, the electrode assembly 100 may be configured as a stacked type, a wound type, a stacked and folded type, etc. The two types of electrodes, namely positive and negative electrodes, may have a structure in which an active material slurry is applied to the electrode current collector in the form of metal foil or metal mesh, including aluminum and copper, respectively. The slurry is typically formed by stirring granular active material, auxiliary conductors, binders, and plasticizers in a solvent-added state. The solvent can be removed from the slurry in a subsequent process.

[0070] More specifically, the positive electrode may include a positive electrode material with strong oxidizing ability that provides electrons. For example, the positive electrode material may include lithium-ion transition metal oxygen. Nickel, cobalt, manganese, etc., can be used as transition metals. The negative electrode may include a negative electrode material with strong reducing ability that accepts electrons. For example, the negative electrode material may include graphite. When the secondary battery B is charged and discharged, electrons can move according to the movement of lithium ions. In this case, lithium ions can move through the electrolyte located between the positive and negative electrodes, and electrons can move through the wires connecting the positive and negative electrodes.

[0071] Electrode connectors 130 can be connected to the positive and negative terminals of electrode assembly 100, respectively, and protrude outward from electrode assembly 100 to serve as a path allowing electrons to move between the interior and exterior of electrode assembly 100. Figure 2 As shown, multiple electrode connectors 130 may each protrude from the electrode assembly 100 in different directions, but are not limited thereto, and the multiple electrode connectors 130 may each protrude in the same direction or in parallel in different directions.

[0072] The electrode assembly 100 may include electrode leads 110 connected to the electrode connector 130 and supplying power to the outside of the secondary battery B. The electrode leads 110 may be connected to the electrode connector 130 by spot welding or the like.

[0073] The electrode assembly 100 may include an insulating portion 120 surrounding a portion of the electrode lead 110. The insulating portion 120 may be positioned corresponding to the location where the sides 220, described later, are fused together. When the sides 220 facing each other are fused together, the insulating portion 120 may be located between the sides 220 to allow the electrode lead 110 to be bonded to the bag. Furthermore, the insulating portion 120 prevents the flow of electricity generated from the electrode assembly 100 through the electrode lead 110 to the bag and maintains the bag's seal. Therefore, the insulating portion 120 may be made of a non-conductive material with poor conductivity. For example, the insulating portion 120 may be an insulating tape that is easy to attach to the electrode lead 110 and has a relatively thin thickness. However, this disclosure is not limited to this, and various components may be used, provided that the electrode lead 110 is insulated.

[0074] The electrode connector 130 configured with positive polarity can be referred to as a positive connector, and the electrode connector 130 configured with negative polarity can be referred to as a negative connector. Similarly, the electrode lead 110 configured with positive polarity can be referred to as a positive lead, and the electrode lead 110 configured with negative polarity can be referred to as a negative lead. The electrode lead 110 may have one end connected to the electrode connector 130 and another end protruding outward from the bag. That is, the electrode lead 110 may include a positive lead with one end connected to the positive connector and extending in the direction of the positive connector protrusion, and a negative lead with one end connected to the negative connector and extending in the direction of the negative connector protrusion. Both the positive and negative leads may have another end protruding outward from the bag. Therefore, the positive and negative leads can supply the power generated inside the electrode assembly 100 to the outside. Furthermore, the positive and negative connectors may each extend in various directions.

[0075] The positive and negative leads can be made of different materials. The positive lead can be made of the same aluminum material as the positive current collector, and the negative lead can be made of the same copper material as the negative current collector or nickel-plated copper material. Furthermore, the portion of the electrode lead 110 protruding outward from the bag can be a terminal portion and can be electrically connected to an external terminal.

[0076] The bag film forming the bag, as an example of the battery casing 200, may include multiple layers. The bag film may include a sealant layer and a barrier layer located outside the sealant layer. The bag film may include a surface protective layer located outside the barrier layer. Here, the sealant layer may have a polymer material such as polypropylene, the barrier layer may have a metallic material such as aluminum, and the surface protective layer may have a polymer material such as nylon. Here, fusion, which will be described later, may refer to the bag films facing each other being joined when the sealant layers facing each other are fused together.

[0077] The bag can be made of a highly flexible material to house the electrode assembly 100. When a flexible bag film is drawn and molded using a punch (not shown), a portion of the flexible bag film can be stretched to form a receiving portion 210 having an electrode receiving space 210S in the form of a pocket, thereby manufacturing the bag. The bag can house and seal the electrode assembly 100, leaving a portion of the electrode leads 110 exposed.

[0078] When the receiving portion 210 is molded in the bag film, only one receiving portion 210 can be formed in one bag film, but this disclosure is not limited to this, and two receiving portions 210 can be drawn and molded adjacent to each other in one bag film. Then, two adjacent receiving portions 210 can be formed. Each of the receiving portions 210 can have the same depth, but this disclosure is not limited to this, and each of the receiving portions 210 can have different depths. After the electrode assembly 100 is housed in one receiving portion 210, the bag can be folded about an axis such that the other receiving portion 210 faces the receiving portion 210. Therefore, the other receiving portion 210 can accommodate the electrode assembly 100 from above. Since two receiving portions 210 accommodate one electrode assembly 100, a thicker electrode assembly 100 can be accommodated than when there is only one receiving portion 210. Furthermore, since the bag is folded, each of the sides 220 is integrally connected to form a fold 223, thus reducing the number of sides to be sealed when the sealing process is performed later. Therefore, the process speed can be increased, and the number of sealing processes can be reduced. For ease of description, it is assumed that two receiving portions 210 are formed in a single bag film to describe the battery housing 200 described later.

[0079] Side portion 220 may include a lead sealing portion 221 configured to be positioned corresponding to electrode lead 110 and a degassing portion 222 connected to the lead sealing portion 221. Lead sealing portion 221 may be a portion of side portion 220 formed adjacent to the electrode lead 110 side. Lead sealing portion 221 may extend in the width direction of electrode lead 110. Lead sealing portion 221 may be sealed by fusion. Thereafter, electrolyte can be injected into electrode housing space 210S through the unsealed degassing portion 222, and the degassing portion 222 can be sealed by fusion. An activation process can then be performed, and a degassing process for removing residual gas can be performed when gas generated by the activation process moves into the degassing portion 222. After resealing the degassing portion 222, a trimming process can be performed to cut off unnecessary portions, so that the degassing portion 222 has a predetermined width. Then, as... Figure 1 As shown, the degassing section 222 can be folded to form a folded section 223, thereby reducing the width.

[0080] at this time, Figure 3An electrode assembly 100 according to an embodiment of the present disclosure is shown housed within a battery housing 200, and the battery housing 200 is based on... Figure 3 The upper and lower ends are fused together to form a lead seal 221. This can be used for... Figure 3 The secondary battery B shown undergoes an activation process.

[0081] The following will refer to Figures 4 to 6 Describe the subsequent processes.

[0082] Figure 4 It is shown in Figure 3 A plan view of the secondary battery B shown, in which a sealing portion 230 is formed in the battery casing 200. Figure 5 It is shown Figure 4 A magnified view of part V. Figure 6 It is shown Figure 4 A magnified view of part of VI.

[0083] Reference Figures 4 to 6 The sealing portion 230 according to an embodiment of the present disclosure will be described.

[0084] As described above, the battery housing 200 may include a receiving portion 210 that together houses the electrode assembly 100 and the electrolyte and / or a side portion 220 extending from the receiving portion 210.

[0085] At this time, the side portion 220 may include a cut portion 250 formed adjacent to the end of the side portion 220 to discharge gas within the receiving portion 210. During the activation process of the secondary battery B, gas may be generated through the reaction between the electrode assembly 100 and the electrolyte. Since the gas may adversely affect the electrical characteristics of the secondary battery B, it may be necessary to remove it. At this time, based on... Figure 4 In the activation process, the left side of the battery casing 200 can be covered by the fold 223, and the upper and lower sides of the battery casing 200 can be sealed by the lead sealing portion 221. The right side of the battery casing 200 can also be sealed. In other words, with Figure 4 As shown, the end of the degassing section 222 can be fused to prevent gas generated in the receiving section 210 from being discharged through the end of the degassing section 222. As will be described later, the fusion of the end of the degassing section 222 can prevent electrolyte leakage. At this time, the aforementioned cutting section 250 can be formed to facilitate gas discharge. As shown, the cutting section 250 can be formed by cutting a portion of the degassing section 222 in one direction with a knife or the like, but the cutting section 250 can also be formed as a hole, allowing gas to be discharged through the cutting section 250 defined as a hole. Furthermore, Figure 4The arrows shown indicate the direction of gas movement. Gas may escape towards the unsealed right side. In other words, gas may be discharged from the interior of the housing 210 to the exterior of the secondary battery B through the degassing section 222.

[0086] Furthermore, the concept of this disclosure is not limited thereto, and the right end of the degassing section 222 may be open and not sealed. However, for ease of description, it is assumed that the end of the degassing section 222 is fused together during the activation and degassing processes to describe the battery casing 200 described later.

[0087] However, when the gas generated by the activation process is moving, the electrolyte located in the housing 210 can also move towards the cutting section 250 along with the gas. Since the amount of electrolyte in the housing 210 contained in the secondary battery B corresponds to its capacity, it is necessary to prevent electrolyte leakage. For this purpose, the secondary battery B may include a sealing section 230 located between the cutting section 250 and the housing 210 to prevent the electrolyte from moving to the cutting section 250 while the gas is being discharged into the cutting section 250.

[0088] At this time, when the sealing portion 230 is connected to the lead sealing portions 221 located on the upper and lower sides, the gas generated by the electrode assembly 100 may be difficult to discharge to the outside. To prevent the electrolyte from moving towards the cutting portion 250 while the gas moves through it, multiple sealing portions 230 can be provided, and a gas discharge path 240 can be formed between the multiple sealing portions 230 to allow gas discharge. The gas discharge path 240 may have a cross-sectional area that allows gas to pass through while making it difficult for the electrolyte to move.

[0089] like Figure 4 As shown, multiple sealing portions 230 can be arranged along a direction parallel to the long side of the receiving portion 210. If multiple gas discharge paths 240 are provided, the multiple gas discharge paths 240 can also be arranged along a direction parallel to the long side of the receiving portion 210. Since the gas discharge paths 240 extend in a direction similar to the direction in which the gas moves in the receiving portion 210, gas can be easily discharged.

[0090] Multiple sealing portions 230 can be formed by fusing the sides 220. As described above, the bag film may have a sealant layer on its inner side, and the sealant layer can melt when heat is applied. When the sealant layers on the inner sides of the bag films facing each other are heated and pressurized, the sealant layers can fuse together to form multiple sealing portions 230. Therefore, gas movement through the multiple sealing portions 230 can be prevented. Of course, the multiple sealing portions 230 can be formed by providing individual blocks instead of fusing the sides 220. However, for ease of description, this disclosure assumes and describes that the multiple sealing portions 230 are formed by fusing the sides 220.

[0091] For reference, with Figure 5 Unlike the diagram, the multiple sealing portions 230 may not all have the same length and may not be connected to the lead sealing portion 221. Therefore, the gas discharge path 240 can be formed between the lead sealing portion 221 and the adjacent sealing portion 230. However, for ease of description, it is assumed and described that the sealing portion 230 adjacent to the lead sealing portion 221 is connected to the lead sealing portion 211.

[0092] However, the electrolyte can be a fluid, and therefore can move to the cutting section 250 through the gas discharge path 240. To prevent this, as... Figure 6 As shown, the sealing portion 230 may include an inflow prevention portion 231, which is positioned adjacent to the inlet 241A of the gas discharge flow path 240 and extends toward the receiving portion 210 to prevent electrolyte from flowing into the gas discharge flow path 240. The inflow prevention portion 231 can prevent the electrolyte from moving into the gas discharge flow path 240. In particular, if as another embodiment, such as Figure 8 or Figure 9 As shown, if a portion of the gas discharge path 240 is blocked, the electrolyte may have difficulty flowing into the gas discharge path 240 from directions other than those entering from the front or rear of the gas discharge path 240. Even if... Figure 5 As shown, even when the inflow prevention section 231 is smoothly connected to the adjacent section, it may still be difficult to achieve the desired effect. Figure 8 and Figure 9 While the illustrated embodiment significantly prevents electrolyte from flowing into the gas discharge path 240, the inflow prevention section 231 may still make it difficult for the electrolyte to be guided toward the gas discharge path 240. Specifically, the fact that the inflow prevention section 231 extends toward the receiving section 210 may mean that it extends in the opposite direction to the movement direction of the electrolyte moving within the receiving section 210. Therefore, the extension direction of the sealing section 230 is a direction that hinders the movement of the electrolyte, and thus may impede its movement. Furthermore, the fact that the inflow prevention section 231 extends toward the receiving section 210 may mean that it extends toward the receiving section 210 compared to its adjacent portion. Electrolyte facing the inflow prevention section 231 can be induced to move to a portion of the receiving section 210 that is positioned adjacent to and in contact with the inflow prevention section 231 and is no closer to the receiving section 210 than the inflow prevention section 231. If the electrolyte moves in the inflow prevention section 231 in a direction away from the gas discharge flow path 240, it may form a flow in that direction, thereby increasing the possibility that subsequent electrolytes will also flow in a similar direction to the previous electrolyte.

[0093] In addition, such as Figure 6As shown, each of the plurality of sealing portions 230 may include a sealing portion body 232 that supports the inflow prevention portion 231 and forms a concave guiding space 232S in a direction away from the receiving portion 210 to guide the electrolyte together with the inflow prevention portion 231. Therefore, the electrolyte in contact with the inflow prevention portion 231 can move into the guiding space 232S. The guiding space 232S may include a smooth curved surface or a straight plane to facilitate the movement of the electrolyte.

[0094] like Figure 5 As shown, the inflow prevention section 231 may have an inclined surface 231A that is inclined in the direction away from the receiving section 210 relative to the direction away from the gas discharge flow path 240. Therefore, the electrolyte in contact with the inflow prevention section 231 can move smoothly away from the gas discharge flow path 240 along the inclined surface 231A. By providing the inclined surface 231A, the inflow prevention section 231 can be formed longer along the extending direction of the sealing section 230 than when the inclined surface 231A is not provided. In particular, when compared with another embodiment... Figure 8 Compared to the inflow prevention unit 231 shown, Figure 5 The shown inflow prevention section 231 can be arranged more smoothly and can come into contact with more electrolyte. Enabling smooth movement of the electrolyte can mean preventing turbulence during electrolyte movement, or minimizing forces hindering movement. Enabling contact with more electrolyte means that more electrolyte can move into the guide space 232S of the sealing section 230.

[0095] exist Figure 5 In this context, the inclined surface 231A is depicted as a straight line, but this inclined surface can also be implemented as a curved surface whose slope becomes steeper as it moves away from the receiving part 210, a curved surface whose slope becomes narrower as it moves away from the receiving part 210, or a surface with inflection points and various curvature changes. However, for ease of description, this disclosure assumes and describes the inclined surface as follows: Figure 5 The straight line shown.

[0096] Furthermore, the inflow prevention section 231 can be located at both ends of a sealing section 230. Since the gas discharge path 240 can be formed between the two ends of a sealing section 230 and an adjacent sealing section 230, a pair of inflow prevention sections 231 can be provided at both ends of a sealing section 230 to prevent electrolyte from flowing into the gas discharge path 240. Furthermore, as... Figure 5 As shown, the sealing part 230 that contacts the lead sealing part 221 forms a gas discharge path 240 with the adjacent sealing part 230. Therefore, in this case, the inflow prevention part 231 can be formed only at one end.

[0097] The gas discharge path 240 can extend from inlet 241A to outlet 243A, switching at least once in different directions. If the gas discharge path 240 extends in only one direction, the electrolyte may move more easily through it. However, if the gas discharge path 240 changes direction while moving along its extension direction, friction may occur as the electrolyte moves at the point where the direction changes, or gas may be retained in that section, increasing pressure and thus preventing the electrolyte from flowing into the gas discharge path 240. Therefore, it may be more difficult for the electrolyte to enter the gas discharge path 240.

[0098] More specifically, the gas discharge path 240 may include an inlet path 241 extending from the inlet 241A near the receiving portion 210 along a first extending direction. In this case, the inlet path 241 may extend perpendicular to the arrangement direction of the plurality of sealing portions 230. Based on Figure 5 The inlet flow path 241 can extend parallel to each other in the left-right direction. The extension direction of the inlet flow path 241 can be similar to the movement direction of the gas discharged from the receiving section 210. Therefore, the generated gas can be easily introduced into the inlet flow path 241.

[0099] The gas discharge path 240 may include a curved path 242 that extends from the inlet path 241 in a second extending direction different from the first extending direction to prevent electrolyte movement. Figure 5 As shown, the second extending direction can be towards the upper right end. However, this disclosure is not limited to this; the second extending direction can be perpendicular to the first extending direction, or it can be towards the upper right end. Furthermore, as... Figure 10 As shown, the curved flow path 242 can be directly connected to the outlet 243A of the gas discharge flow path 240. In this case, the number of bends in the gas discharge flow path 240 can be one. However, for ease of description, the first embodiment will be described assuming that the curved flow path 242 is not connected to the outlet 243A.

[0100] The gas discharge path 240 may further include an outlet path 243, which extends from an outlet 243A located on the opposite side of the inlet 241A along a third extension direction different from the second extension direction. For example... Figure 5 As shown, the third extending direction can be parallel to the first extending direction. This may be to facilitate the movement of gas towards the cutting section 250. Furthermore, the third extending direction can be different from the cutting direction of the cutting section 250. This is because when the cutting direction of the cutting section 250 is parallel to the third extending direction, gas may have difficulty escaping through the gaps in the cutting section 250.

[0101] At this point, the outlet flow path 243 can be connected to the curved flow path 242. Therefore, the gas discharge flow path 240 can have two bends. Of course, as in Figure 11 In another embodiment shown, the bending may be performed more than twice.

[0102] The cross-sectional area of ​​the outlet flow path 243 can be smaller than the cross-sectional area of ​​the flow path formed in the cutting section 250 for discharging gas. In other words, the cross-sectional area of ​​the flow path formed in the cutting section 250 can be larger than the cross-sectional area of ​​the outlet flow path 243. This is because when the cross-sectional area in a flow path increases, the velocity of the fluid flowing through the flow path increases, thereby reducing the fluid pressure. Therefore, subsequent fluid can move better toward the corresponding flow path. At this time, when the cutting section 250 is an orifice, the cross-sectional area of ​​the flow path in the cutting section 250 is defined as the cross-sectional area of ​​the orifice, and when... Figure 5 As shown, when formed by cutting, it can be the cross-sectional area of ​​a flow path formed such that the cutting line forms a semicircle. This is likely because a pair of lines facing each other that are cut can each form half of the flow path as they unfold, and ideally, because the cross-sectional area of ​​the flow path can be circular.

[0103] The outlet 243A can be adjacent to the cutting section 250. This is because the gas leaving the outlet 243A should move directly through the cutting section 250 to minimize the loss of flow energy due to friction during the movement.

[0104] Multiple cutting sections 250 can be configured, and multiple gas discharge paths 240 can be configured to correspond to each of the multiple cutting sections 250. Therefore, gas moving through multiple gas discharge paths 240 can move to an adjacent cutting section 250 without having to move to another cutting section 250, thereby shortening the gas's travel distance. Consequently, flow energy loss due to gas friction can be minimized.

[0105] The farther the portion of the gas discharge path 240 adjacent to the inlet 241A is from the inlet 241A, the smaller the cross-sectional area of ​​that portion can be. Therefore, the gas flowing into the inlet 241A can be more easily introduced into the gas discharge path 240.

[0106] Figure 7 It is about manufacturing Figure 1 The flowchart of the secondary battery method disclosed in the paper.

[0107] Reference Figure 7 A method for manufacturing a secondary battery according to a first embodiment of the present disclosure is described.

[0108] In order to form the sealing part 230 that performs the above-mentioned function, the secondary battery B can be manufactured by the following method.

[0109] The method for manufacturing a secondary battery B may include step S100 of sealing a lead sealing portion 221 located outside the electrode assembly 100 on the side 220 of the battery housing 200. The method for manufacturing a secondary battery B may also include step S200 of forming a cut portion 250 adjacent to the end of the side 220. The method for manufacturing a secondary battery B may also include step S300 of forming a plurality of sealing portions 230 located between the cut portion 250 and the receiving portion 210 of the battery housing 200 and allowing a gas discharge path 240 to be formed between the plurality of sealing portions. The method for manufacturing a secondary battery B may also include step S400 of discharging gas generated by activating the electrode assembly 100 to the cut portion 250 through the gas discharge path 240. A method for manufacturing a secondary battery B may include step S500 of forming an inflow prevention portion 231 by fusing side portions 220 in a plurality of sealing portions 230 to prevent electrolyte from flowing into a gas discharge path 240, the inflow prevention portion being positioned adjacent to an inlet 241A of the gas discharge path 240 and protruding toward a receiving portion 210.

[0110] In the following sections, embodiments that differ from the first embodiment will be described. Content common to the first embodiment will be omitted wherever possible, and the differences between the other embodiments will be emphasized. That is, it is obvious that, if necessary, content not described in other embodiments can be supplemented by the content of the first embodiment.

[0111] Figure 8 This is an enlarged view of the secondary battery B according to the second embodiment of this disclosure.

[0112] Reference Figure 8 The secondary battery B according to the second embodiment of the present disclosure will be described.

[0113] The second embodiment differs from the first embodiment in that the shape of the inflow prevention part 231-1 is different.

[0114] In the second embodiment, the inflow prevention part 231-1 can protrude toward the storage part 210.

[0115] Furthermore, the gas discharge path 240 can be configured such that the portion adjacent to the outlet 243A has a larger cross-sectional area towards the outlet 243A. This facilitates the movement of gas towards the cutting section 250. This concept can also be applied to other embodiments.

[0116] Figure 9 This is an enlarged view of the secondary battery B according to the third embodiment of this disclosure.

[0117] Reference Figure 9 The secondary battery B according to the third embodiment of this disclosure will be described.

[0118] The third embodiment differs from the first embodiment in that the shape of the inflow prevention part 231-2 is different.

[0119] In the second embodiment, the inflow prevention unit 231-2 can cover at least a portion of the inlet 241A of the gas discharge flow path 240. Therefore, electrolyte can be prevented from entering the gas discharge flow path 240.

[0120] Figure 10 This is an enlarged view of the secondary battery B according to the fourth embodiment of this disclosure.

[0121] Reference Figure 10 The secondary battery B according to the fourth embodiment of this disclosure will be described.

[0122] The fourth embodiment differs from the first embodiment in that the shape of the gas discharge path 240-3 is different.

[0123] In the fourth embodiment, the gas discharge path 240-3 can bend once along the extension direction. Therefore, the gas movement can be smoother.

[0124] Figure 11 This is an enlarged view of the secondary battery B according to the fifth embodiment of this disclosure.

[0125] Reference Figure 11 The secondary battery B according to the fifth embodiment of this disclosure will be described.

[0126] The fifth embodiment differs from the first embodiment in that the shape of the gas discharge path 240 is different.

[0127] In the fifth embodiment, the gas discharge path 240-4 may have more than two bends. Therefore, it may be more difficult for electrolyte to flow into the gas discharge path 240-4.

[0128] Figure 12 This is an enlarged view of the secondary battery B according to the sixth embodiment of this disclosure.

[0129] Reference Figure 12 The secondary battery B according to the sixth embodiment of this disclosure will be described.

[0130] The sixth embodiment differs from the first embodiment in that the shape of the gas discharge path 240-5 is different.

[0131] In the sixth embodiment, the gas discharge path 240-5 can be branched. In the case of a branch, the cross-sectional area of ​​the outlet 243A may be significantly increased. Furthermore, the branched gas discharge path 240-5 may cause turbulent movement of the gas at the branch point, which may make it more difficult for the electrolyte to flow into the gas discharge path 240-5.

[0132] Unless otherwise stated, the above embodiments may be combined with other embodiments. Alternatively, combinations between embodiments should be considered possible unless the combination of one embodiment with another is explicitly limited. Any combination of embodiments with another is considered to be disclosed herein.

[0133] The present disclosure has been described above with respect to a limited number of embodiments and accompanying drawings, but the present disclosure is not limited thereto, and it will be apparent to those skilled in the art that various modifications and variations can be made to the present disclosure within the scope of the technical aspects of the present disclosure and the appended claims and their equivalents.

[0134] [List of reference numerals]

[0135] B: Secondary battery

[0136] 100: Electrode assembly

[0137] 110: Electrode leads

[0138] 120: Insulation section

[0139] 130: Electrode connector

[0140] 200: Battery casing

[0141] 210: Storage Department

[0142] 210S: Electrode storage space

[0143] 220: Side

[0144] 221: Lead wire sealing part

[0145] 222: Degassing section

[0146] 223: Folding section

[0147] 230: Sealing part

[0148] 231: Inflow Prevention Department

[0149] 231A: Inclined surface

[0150] 232: Sealing part body

[0151] 232S: Boot Space

[0152] 240: Gas emission path

[0153] 241A: Entrance

[0154] 243A: Export

[0155] 241: Inlet Flow Path

[0156] 242: Curved Flow Path

[0157] 243: Exit flow path

[0158] 250: Cutting section

Claims

1. A secondary battery, the secondary battery comprising: Electrode assembly; as well as A battery housing, the battery housing including a receiving portion that together houses the electrode assembly and the electrolyte, and a side portion extending from the receiving portion. The side portion includes: A cutting section, formed adjacent to the end of the side portion to discharge gas from the receiving portion; and Multiple sealing portions are located between the cutting portion and the receiving portion to prevent the electrolyte from moving into the cutting portion while gas is being discharged into it. The plurality of sealing portions include: A gas discharge path, said gas discharge path being formed between each of the plurality of seals to allow gas discharge; and An inflow prevention section is positioned adjacent to the inlet of the gas discharge path and extends toward the receiving section to prevent the electrolyte from flowing into the gas discharge path.

2. The secondary battery according to claim 1, in, Each of the plurality of sealing portions includes a sealing portion body that supports the inflow prevention portion and forms a concave guiding space in a direction away from the receiving portion to guide the electrolyte together with the inflow prevention portion.

3. The secondary battery according to claim 1, in, The plurality of sealing portions are arranged in a direction parallel to the long side of the receiving portion.

4. The secondary battery according to claim 1, in, The inflow prevention section has an inclined surface that is inclined in the direction away from the receiving section relative to the direction away from the gas discharge flow path.

5. The secondary battery according to claim 1, in, The plurality of sealing portions are formed by fusing the sides together.

6. The secondary battery according to claim 1, in, The gas emission path extends from the inlet to the outlet in such a manner that it changes direction at least once in different directions.

7. The secondary battery according to claim 1, in, The gas emission path includes: An inlet flow path, the inlet flow path extending from an inlet near the receiving section along a first extending direction; and A curved flow path extends from the inlet flow path along a second extension direction different from the first extension direction to prevent the electrolyte from moving.

8. The secondary battery according to claim 7, in, The inlet flow path extends perpendicular to the arrangement direction of the plurality of sealing parts.

9. The secondary battery according to claim 7, in, The gas emission path further includes an outlet path that extends from an outlet located on the opposite side of the inlet along a third extension direction different from the second extension direction.

10. The secondary battery according to claim 9, in, The outlet flow path is connected to the curved flow path.

11. The secondary battery according to claim 9, in, The cross-sectional area of ​​the outlet flow path is smaller than the cross-sectional area of ​​the flow path formed in the cutting section and used for gas discharge.

12. The secondary battery according to claim 9, in, The outlet is adjacent to the cutting section.

13. The secondary battery according to claim 1, in, The cutting section is configured as multiple parts, and The gas emission path is configured as a plurality of paths to correspond to each of the plurality of cutting sections.

14. The secondary battery according to claim 1, in, The portion of the gas emission path adjacent to the outlet has a larger cross-sectional area as it moves toward the outlet.

15. The secondary battery according to claim 1, in, The portion of the gas discharge path adjacent to the inlet has a smaller cross-sectional area as the portion moves further away from the inlet.

16. A secondary battery, the secondary battery comprising: Electrode assembly; as well as A battery housing, the battery housing including a receiving portion that together houses the electrode assembly and the electrolyte, and a side portion extending from the receiving portion. The side portion includes: A cutting section, formed adjacent to the end of the side portion to discharge gas from the receiving portion; and Multiple sealing portions are located between the cutting portion and the receiving portion to prevent the electrolyte from moving into the cutting portion while gas is being discharged into it. The plurality of sealing portions include gas discharge channels formed between each of the plurality of sealing portions to allow gas to be discharged. The gas emission path extends from the inlet to the outlet in a manner that changes direction at least once in different directions.

17. The secondary battery according to claim 16, in, The plurality of sealing portions include an inflow prevention portion, which is positioned adjacent to the inlet of the gas discharge path and extends toward the receiving portion to prevent the electrolyte from flowing into the gas discharge path.

18. The secondary battery according to claim 17, in, The plurality of sealing portions include a sealing portion body that supports the inflow prevention portion and forms a concave guiding space in a direction away from the receiving portion to guide the electrolyte together with the inflow prevention portion.

19. The secondary battery according to claim 16, in, The plurality of sealing portions are arranged in a direction parallel to the long side of the receiving portion.

20. A method for manufacturing a secondary battery, the method comprising the following steps: The step of sealing the lead sealing portion on the side of the battery casing, located outside the electrode assembly; The step of forming a cut portion adjacent to the end of the side portion; The step of forming the plurality of sealing portions located between the cutting portion and the receiving portion of the battery housing and allowing the formation of a gas discharge flow path between the plurality of sealing portions; as well as The step of discharging the gas generated by activating the electrode assembly to the cutting section through the gas discharge flow path. The method further includes the step of forming an inflow prevention portion in the plurality of sealing portions by fusing the sides to prevent electrolyte from flowing into the gas discharge path, the inflow prevention portion being positioned adjacent to the inlet of the gas discharge path and extending toward the receiving portion.

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