Method for manufacturing a secondary battery, gas discharge and electrolyte injection mechanism, and secondary battery including the same

Abstract

The present invention provides a simplified method for manufacturing a secondary battery, which can efficiently remove activation process gas using a gas exhaust pipe capable of both gas exhaust and electrolyte injection, and can simultaneously seal the gas exhaust pipe and the battery case. In addition, the manufacturing method of a secondary battery of the present invention relates to a method for providing a secondary battery that can reduce a sealing step by injecting an electrolyte before an activation process using a gas exhaust pipe having a double pipe structure including a gas exhaust passage and an electrolyte injection passage. The present invention also provides a gas exhaust and electrolyte injection mechanism having a structure capable of both gas exhaust and electrolyte injection, and a secondary battery equipped with the same.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a secondary battery. More specifically, the present invention relates to a method for manufacturing a secondary battery that can efficiently remove gas generated in the secondary battery in an activation process to reduce the area of a gas collection part and simplify an installation process of a gas discharge pipe for gas discharge and electrolyte injection.

[0002] The present invention also relates to a gas discharge and electrolyte injection mechanism that can effectively perform gas discharge from a secondary battery and electrolyte injection into the secondary battery, and a secondary battery including the same.

[0003] This application claims the benefit of priority based on Korean Patent Application No. 10-2022-0086972 filed on July 14, 2022, and all the contents disclosed in the literature of the Korean patent application are included as part of this specification.

Background Art

[0004] As the price of energy sources rises due to the depletion of fossil fuels and the concern about environmental pollution amplifies, the demand for environmentally friendly alternative energy sources has become an essential and indispensable factor for future life. Particularly, as the technology development and demand for mobile devices increase, the demand for secondary batteries as an energy source has been rapidly increasing.

[0005] Generally, secondary batteries are largely classified into cylindrical batteries, prismatic batteries, pouch-type batteries, etc. according to their outer shapes, and may also be classified into lithium-ion batteries, lithium-ion polymer batteries, lithium polymer batteries, etc. according to the form of the electrolyte.

[0006] Also, a secondary battery is manufactured by injecting an electrolyte, which is a liquid electrolyte, into a state where an electrode assembly is housed in a battery case and sealing the battery case.

[0007] The manufacturing method for pouch-type secondary batteries includes a primary sealing step of sealing the edges of a battery case, which includes a battery section containing an electrode assembly and a gas collection section communicating with it, except for one side; an electrolyte injection step of injecting electrolyte into the battery section through the unsealed side of the battery case; a secondary sealing step of completely sealing the side of the battery case after injection; and an activation step of performing charging and discharging to impart battery characteristics to the battery. The reason for forming a gas collection section in the battery case is to provide a space for collecting the large amount of activating gas generated during the charging and discharging process for activating the secondary battery.

[0008] However, when a large amount of gas is generated, for example when using manganese-based compounds as the active material, it was necessary to design a larger gas collection section to accommodate this gas. This increased the amount of battery case material used, leading to higher manufacturing costs.

[0009] To prevent the gas collection area from expanding, a technique was proposed to install a gas discharge pipe in the battery case to discharge the gas during the activation process. However, this technique involves pouring electrolyte into the battery case, completely sealing it, then opening the sealed battery case, inserting the gas discharge pipe, and resealing it, which makes the installation of the gas discharge pipe very cumbersome. Furthermore, the battery case may be damaged during the opening process, and when the battery case is resealed, the damaged area may not be completely sealed, posing a risk of gas leakage and electrolyte leakage.

[0010] On the other hand, during the activation process, the electrolyte in the battery may become insufficient, requiring replenishment. Alternatively, even finished secondary batteries, after all battery manufacturing processes are complete, may deplete their electrolyte during use. Therefore, it is necessary to replenish the electrolyte in semi-finished products and finished secondary batteries that undergo the activation process. Furthermore, not only in the semi-finished products during the activation stage, but also in finished secondary batteries, gas can rapidly be generated inside the battery depending on the usage environment, increasing the internal pressure of the battery case, and in severe cases, there is a risk of accidents such as explosions.

[0011] Therefore, in the intermediate stages of secondary battery activation, such as semi-finished and finished secondary batteries, it is necessary to expel the gas inside the battery case and replenish the electrolyte at the same time.

[0012] However, conventionally, there has been no technology that can effectively perform gas discharge and electrolyte injection simultaneously. For example, when gas discharge and electrolyte injection are performed simultaneously through the same passage of the gas discharge pipe, there is a risk that the electrolyte may leak through the passage during gas discharge. In addition, the inside of the gas discharge passage may become contaminated with electrolyte, reducing the gas discharge efficiency, or conversely, contamination of the gas discharge passage may contaminate the electrolyte during electrolyte injection.

[0013] Therefore, there is a need for the development of technology that can facilitate the installation of gas discharge pipes for gas discharge during the activation process.

[0014] Furthermore, there is a need for the development of technologies that can effectively and simultaneously perform gas discharge and electrolyte injection. [Prior art documents] [Patent Documents]

[0015] [Patent Document 1] Korean Published Patent Publication No. 10-2018-0093792 [Overview of the project] [Problems that the invention aims to solve]

[0016] The present invention was created to solve the above-mentioned problems, and aims to provide a method for manufacturing a secondary battery that can efficiently remove activation process gas using a gas discharge pipe capable of both gas discharge and electrolyte injection.

[0017] Another objective is to provide a method for manufacturing a secondary battery that simplifies the processes before and after the activation process by using a double-pipe gas discharge pipe equipped with a gas discharge passage and an electrolyte injection passage, thereby facilitating gas discharge and electrolyte injection.

[0018] Another objective of the present invention is to provide a gas discharge and electrolyte injection mechanism with a structure that allows for both gas discharge and electrolyte injection, and a secondary battery equipped therewith. [Means for solving the problem]

[0019] A method for manufacturing a secondary battery according to the present invention to solve the above problems includes the steps of: housing an electrode assembly in the battery portion of a battery case which includes a battery portion and a gas collection portion communicating with the battery portion, and sealing the edge of the battery case except for one side of the gas collection portion; positioning a gas discharge pipe capable of both gas discharge and electrolyte injection in an open portion of the battery case on the one side, sealing both the open portion and the gas discharge pipe to simultaneously fix the gas discharge pipe to the battery case and seal the battery case; and discharging gas generated inside the battery through the gas discharge pipe to the outside of the battery when an activation process is performed on the battery which includes the battery portion and the gas collection portion.

[0020] The above manufacturing method may further include, after the step of sealing the edge of the battery case except for one side of the gas collection section, the step of pouring electrolyte into the battery section through the battery case opening on the one side.

[0021] Another example of a method for manufacturing a secondary battery of the present invention includes the steps of: housing an electrode assembly in the battery portion of a battery case which includes a battery portion and a gas collection portion communicating with the battery portion; positioning a double-tube gas discharge pipe having a gas discharge passage and an electrolyte injection passage on at least one open side of the gas collection portion; sealing the entire edge of the battery case including the side portion to simultaneously fix the gas discharge pipe to the battery case and seal the battery case; and discharging gas generated inside the battery through the gas discharge pipe to the outside of the battery when an activation process is performed on the battery which includes the battery portion and the gas collection portion.

[0022] The above manufacturing method may further include a step of injecting electrolyte into the battery unit through the electrolyte injection passage of the gas discharge pipe after the step of simultaneously fixing the gas discharge pipe to the battery case and sealing the battery case.

[0023] Also, the manufacturing method of the secondary battery may include a degassing step of discharging residual gas in the gas collection part to the outside of the battery through at least one of the degassing holes formed in the gas collection part and the gas discharge pipe after the activation step.

[0024] Also, the manufacturing method of the secondary battery may further include a step of additionally replenishing the battery with electrolyte through the gas discharge pipe during the activation step.

[0025] The gas discharge pipe may have a double pipe structure including a gas discharge passage and an electrolyte injection passage.

[0026] The gas discharge pipe is provided with a first plug coupled to the gas discharge passage and a second plug coupled to the electrolyte injection passage, respectively. The manufacturing method of the secondary battery may perform at least one of the operations of discharging gas from the battery and injecting electrolyte into the battery by coupling and decoupling at least one of the first plug and the second plug to their corresponding passages.

[0027] The gas discharge and electrolyte injection mechanism according to the present invention includes a hollow first pipe with a gas discharge passage formed therein and open top and bottom, a hollow second pipe with an electrolyte injection passage formed therein and open top and bottom and disposed within the gas discharge passage, a gas discharge pipe including a connecting member connecting the inner peripheral surface of the first pipe and the outer peripheral surface of the second pipe, a first plug detachably coupled to the open upper portion of the first pipe to seal the gas discharge passage, and a second plug detachably coupled to the open upper portion of the second pipe to seal the electrolyte injection passage.

[0028] The connecting member may connect the inner peripheral surface of the first pipe and the outer peripheral surface of the second pipe, and a plurality of them may be provided at a predetermined interval along the edges of the first pipe and the second pipe.

[0029] The first plug described above may include at least one of a sealing portion that covers the inlet of the gas discharge passage and an insertion portion that is inserted into the inlet.

[0030] The second stopper may include at least one of the following: a sealing portion that covers the entrance to the electrolyte injection passage, and an insertion portion that is inserted into the entrance.

[0031] The first plug includes a sealing portion that covers the entrance to the gas discharge passage and an insertion portion that is inserted into the entrance, and a plurality of slots may be formed along the edge of the insertion portion at predetermined intervals into which the connecting member is inserted.

[0032] The first and second plugs described above can be detachably connected to each other. In this case, the first plug is provided with a through hole for connecting to the second plug, and the second plug can be inserted into the through hole for connecting to the second plug and connected to the first plug.

[0033] Interlocking threads may be formed on the outer surface of the second stopper and the inner surface of the through-hole for connecting the second stopper, interlocking threads may be formed on the connecting surface of the first stopper and the corresponding connecting surface of the open upper part of the first pipe, and interlocking threads may be formed on the connecting surface of the second stopper and the corresponding connecting surfaces of the open upper part of the second pipe.

[0034] An opening / closing mechanism may be installed inside the first pipe described above to allow gas to flow only in the direction of the inlet of the gas discharge passage.

[0035] The opening and closing mechanism includes an upward movement restricting portion and a downward movement restricting portion that are formed to protrude vertically and at intervals along the inner circumferential surface of the first pipe, and an opening and closing member located between the upward movement restricting portion and the downward movement restricting portion, wherein the opening and closing member can move between a shut-off position that contacts the downward movement restricting portion to block the downward movement of the gas and an allowable position that separates from the downward movement restricting portion due to the upward pressure of the gas and allows the upward movement of the gas.

[0036] The opening and closing member described above may be a ring-shaped member having an outer surface that contacts the inner surface of the first pipe and an inner surface that contacts the outer surface of the second pipe.

[0037] The secondary battery of the present invention includes an electrode assembly comprising a positive electrode, a negative electrode, and a separation membrane disposed between the positive electrode and the negative electrode; a battery case comprising a battery section housing the electrode assembly and a gas collection section communicating with the battery section; and a gas discharge and electrolyte injection mechanism according to any one of claims 7 to 18, which is installed on at least one side of the battery case, wherein a portion of the first tube and the second tube is inserted into the battery case, and the gas discharge and electrolyte injection mechanism can be installed in the battery case such that the inlet of the gas discharge passage and the inlet of the electrolyte injection passage protrude to the outside from one side of the battery case.

[0038] Another secondary battery of the present invention includes an electrode assembly comprising a positive electrode, a negative electrode, and a separator membrane disposed between the positive electrode and the negative electrode; a battery case housing the electrode assembly; and a gas discharge and electrolyte injection mechanism installed on at least one side of the battery case, wherein a portion of the first and second tubes are inserted into the battery case, and the gas discharge and electrolyte injection mechanism is installed in the battery case such that the inlet of the gas discharge passage and the inlet of the electrolyte injection passage protrude outward from one side of the battery case. [Effects of the Invention]

[0039] With this invention, even if a large amount of activated gas is generated, the gas can be easily discharged to the outside of the battery without needing to increase the area of ​​the gas collection section.

[0040] Furthermore, according to the present invention, an electrolyte injection system and a gas discharge pipe for gas discharge can be easily installed inside the battery case.

[0041] Furthermore, by using a double-walled gas discharge pipe equipped with a gas discharge passage and an electrolyte injection passage, the number of sealing steps before the activation process can be reduced.

[0042] Furthermore, the gas discharge and electrolyte injection mechanism, which includes the double-pipe structured gas discharge pipe and plugs that can open and close each pipe, allows for easy replenishment of the electrolyte when it becomes depleted, and simultaneously allows for the discharge of gas generated within the battery to the outside.

[0043] Furthermore, the structure, which provides separate gas discharge passages and electrolyte injection passages, allows the gas discharge process and the electrolyte injection process to proceed independently without interference, preventing contamination of these passages by gas or electrolyte. [Brief explanation of the drawing]

[0044] [Figure 1] This is an exploded perspective view showing the process of manufacturing a secondary battery according to one embodiment of the present invention. [Figure 2] This is a flowchart of a method for manufacturing a secondary battery according to one embodiment of the present invention. [Figure 3] This is a cross-sectional view showing a sealed secondary battery according to one embodiment of the present invention. [Figure 4] This is a schematic diagram showing a secondary battery according to one embodiment of the present invention. [Figure 5] This is a schematic diagram showing the degassing process of a secondary battery according to one embodiment of the present invention. [Figure 6] This is a flowchart of a method for manufacturing a secondary battery according to another embodiment of the present invention. [Figure 7] This is an exploded view of a gas discharge and electrolyte injection mechanism according to one embodiment of the present invention. [Figure 8] This is a cross-sectional view of a gas discharge and electrolyte injection mechanism according to one embodiment of the present invention. [Figure 9] This is a schematic diagram showing the gas discharge process by a gas discharge and electrolyte injection mechanism according to one embodiment. [Figure 10] This is a cross-sectional view of a gas discharge and electrolyte injection mechanism according to another embodiment of the present invention. [Figure 11] This is an exploded view of a gas discharge and electrolyte injection mechanism according to another embodiment of the present invention. [Figure 12]This is a cross-sectional view of a gas discharge and electrolyte injection mechanism according to another embodiment of the present invention. [Figure 13] This is a schematic diagram showing the electrolyte injection process by a gas discharge and electrolyte injection mechanism according to another embodiment. [Figure 14] This is a cross-sectional view of a gas discharge and electrolyte injection mechanism according to another embodiment of the present invention. [Figure 15] This is a perspective view showing the opening and closing members of the gas discharge and electrolyte injection mechanism. [Figure 16] This is a cross-sectional view showing the operation process of a gas discharge and electrolyte injection mechanism according to another embodiment of the present invention. [Figure 17] This is a schematic diagram of a secondary battery according to another embodiment of the present invention. [Modes for carrying out the invention]

[0045] The details of the present invention will be described in detail below with reference to the attached drawings and various embodiments. The embodiments described below are illustrative to aid in understanding the present invention, and the attached drawings are not illustrated to actual scale, and the dimensions of some components may be exaggerated to aid in understanding the present invention.

[0046] The present invention is subject to various modifications and may take many forms; therefore, specific embodiments are illustrated in the drawings and described in detail in the text. However, this is not intended to limit the present invention to any particular disclosure, but should be understood to include all modifications, equivalents, or substitutions that fall within the spirit and technical scope of the present invention.

[0047] A method for manufacturing a secondary battery according to one embodiment of the present invention includes the steps of: housing an electrode assembly in the battery portion of a battery case which includes a battery portion and a gas collection portion communicating with the battery portion, and sealing the edges of the battery case except for one side of the gas collection portion; positioning a gas discharge pipe capable of both gas discharge and electrolyte injection in an opening in the battery case on the one side, sealing both the opening and the gas discharge pipe to simultaneously fix the gas discharge pipe to the battery case and seal the battery case; and discharging gas generated inside the battery through the gas discharge pipe to the outside of the battery when an activation process is performed on the battery which includes the battery portion and the gas collection portion.

[0048] Another example of a method for manufacturing a secondary battery of the present invention includes the steps of: housing an electrode assembly in the battery portion of a battery case which includes a battery portion and a gas collection portion communicating with the battery portion; positioning a double-tube gas discharge pipe having a gas discharge passage and an electrolyte injection passage on at least one open side of the gas collection portion; sealing the entire edge of the battery case including the side portion to simultaneously fix the gas discharge pipe to the battery case and seal the battery case; and discharging gas generated inside the battery through the gas discharge pipe to the outside of the battery when an activation process is performed on the battery which includes the battery portion and the gas collection portion.

[0049] A gas discharge and electrolyte injection mechanism according to one embodiment of the present invention includes a hollow first pipe having a gas discharge passage and open at the top and bottom, a hollow second pipe having an electrolyte injection passage and open at the top and bottom and positioned within the gas discharge passage, a gas discharge pipe including a connecting member that connects the pipe wall of the first pipe and the pipe wall of the second pipe, a first stopper detachably coupled to the open upper part of the first pipe to seal the gas discharge passage, and a second stopper detachably coupled to the open upper part of the second pipe to seal the electrolyte injection passage.

[0050] An example of a secondary battery according to the present invention includes an electrode assembly comprising a positive electrode, a negative electrode, and a separation membrane disposed between the positive electrode and the negative electrode; a battery case comprising a battery section housing the electrode assembly and a gas collection section communicating with the battery section; and a gas discharge and electrolyte injection mechanism installed on at least one side of the battery case, wherein a portion of the first and second tubes are inserted into the battery case, and the gas discharge and electrolyte injection mechanism can be installed in the battery case such that the inlet of the gas discharge passage and the inlet of the electrolyte injection passage protrude to the outside from one side of the battery case.

[0051] Another example of the present invention is a secondary battery comprising an electrode assembly including a positive electrode, a negative electrode, and a separator membrane disposed between the positive electrode and the negative electrode; a battery case housing the electrode assembly; and a gas discharge and electrolyte injection mechanism installed on at least one side of the battery case, wherein a portion of the first and second tubes are inserted into the battery case, and the gas discharge and electrolyte injection mechanism is installed in the battery case such that the inlet of the gas discharge passage and the inlet of the electrolyte injection passage protrude outward from one side of the battery case.

[0052] <Manufacturing method for secondary batteries> (First Embodiment) Figure 1 is an exploded perspective view showing the process of manufacturing a secondary battery according to one embodiment of the present invention, Figure 2 is a flowchart of the method for manufacturing a secondary battery according to one embodiment of the present invention, Figure 3 is a cross-sectional view showing a sealed secondary battery according to one embodiment of the present invention, and Figure 4 is a schematic diagram showing a secondary battery according to one embodiment of the present invention.

[0053] A method for manufacturing a secondary battery according to one embodiment of the present invention includes a primary sealing step of housing an electrode assembly 200 in a battery case 100 and sealing a portion of the edge of the battery case 100, a secondary sealing step of sealing both the gas discharge pipe and the battery case 100, and an activation and gas discharge step.

[0054] The electrode assembly 200 is a concept that encompasses all electrode stacks including at least one positive electrode, at least one negative electrode, and at least one separator membrane, and its form is not particularly limited. For example, the electrode assembly 200 may be a jelly-roll type in which a strip-shaped positive electrode and a negative electrode are arranged with a separator membrane in between and are wound up, but it is not limited to this, and other forms of electrode assemblies 200 can also be applied to the present invention.

[0055] The materials of the positive electrode, negative electrode, and separation membrane included in the electrode assembly 200 are not particularly limited, and materials known in the art can be used without any particular restriction.

[0056] As shown in Figure 1, the electrode assembly 200 includes electrode tabs (positive electrode tab: 221, negative electrode tab: 231) protruding from a jelly roll-shaped electrode assembly 210. The electrode tabs are connected to the positive and negative electrodes of the electrode assembly 200, respectively, and protrude to the outside of the electrode assembly 200. Electrode leads (positive electrode lead: 222, negative electrode lead: 232) are connected to the electrode tabs by welding or other means. Then, insulating parts 223 and 233 enclose and connect a portion of the electrode leads. The insulating parts prevent electricity generated in the electrode assembly 200 from flowing through the electrode leads to the battery case 100 and maintain the sealing of the battery case 100.

[0057] The electrode leads may be extended in the same direction depending on the formation positions of the positive electrode tab 221 and the negative electrode tab 231, or they may be extended in opposite directions, as in the example in Figure 1.

[0058] The battery case 100 forms the overall appearance of the secondary battery and may be a pouch made of a flexible material. The battery case 100 includes a gas barrier layer, a surface protection layer, and a sealant layer. The gas barrier layer is for blocking the entry and exit of gases and may contain metal, such as aluminum foil. The surface protection layer is located on the outermost layer of the battery case 100 and may be made of a polymer such as nylon resin or PET, which has abrasion resistance and heat resistance. The sealant layer is located on the innermost layer and may be made of a polymer such as polypropylene (PP).

[0059] The pouch-type battery case 100 is manufactured by processing a film with the above-described layers into a bag shape. Specifically, the upper pouch 100B and the lower pouch 100A are brought into contact with each other, and the edges are heat-pressed to bond the sealant layers together, thereby sealing the battery case 100. Alternatively, sealing can be performed using ultrasound or a laser.

[0060] The upper pouch 100B and lower pouch 100A are each provided with a housing space C for housing the electrode assembly 200. Referring to Figure 1, cup-shaped housing spaces C are formed on opposing parts of the upper and lower pouches. When the electrode assembly 200 is housed in either the housing space C1 of the upper pouch 100B or the housing space C2 of the lower pouch 100A, and the other housing space is placed over the electrode assembly 200, the electrode assembly 200 is housed in the battery case 100, surrounded by the housing spaces C of the upper pouch 100B and the lower pouch 100A, as shown in Figure 3. The part of the battery case 100 in which the electrode assembly 200 is housed is referred to as the battery section 110. In other words, the battery section 110 is made by combining a battery part 110B in which a housing space C1 of the upper pouch 100B is formed, and a battery part 110A in which a housing space C2 of the lower pouch 100A is formed. In this embodiment, a so-called double-cup shaped battery case is shown, in which the upper pouch 100B and the lower pouch 100A are processed to each have a concave housing space. However, a single-cup shaped battery case 100 in which only one of the upper pouch 100B and the lower pouch 100A has a cup-shaped housing space C, and the other pouch covers the housing space, is also applicable.

[0061] Furthermore, although Figure 1 shows that the upper pouch 100B and the lower pouch 100A are provided separately, the upper pouch 100B and the lower pouch 100A are connected to each other at one end, and the battery case 100 can be manufactured by folding the upper pouch 100B and the lower pouch 100A together using the aforementioned one end as a reference.

[0062] Furthermore, the battery case 100 shown in Figure 4 is not the battery case 100 of a finished secondary battery, but rather a form of a battery case for an intermediate-stage semi-finished secondary battery provided for the activation process. Initial secondary battery cells are in a discharged state and are not activated, so they do not function as batteries. The activation process is a process in which these discharged cells are charged and discharged several times to activate them so that they can function as batteries. Since such a charge-discharge process is carried out by electrochemical reactions, gas is generated as a side reaction. Because this gas can cause increased cell resistance, decreased capacity and lifespan, and cosmetic defects, a degassing process is performed after the charge-discharge process to remove the gas.

[0063] A gas collection section 120 is provided in the battery case to collect the gas generated during the activation process. Specifically, as shown in Figure 1, the upper pouch 100B and the lower pouch 100A are equipped with gas collection section parts 120B and 120A on one side of the battery parts 110B and 110A, respectively, and the gas collection section 120 is formed by joining the gas collection section parts 120B and 120A of the upper pouch 100B and the lower pouch 100A. Referring to Figure 3, it is shown that a gas collection section 120 communicating with the battery part 110 is provided in the battery case 100 on one side of the battery part 110.

[0064] However, depending on the active material or manufacturing conditions, a large amount of gas may be generated during the activation process. When a large amount of gas is generated, the internal pressure of the gas collection section 120 increases, posing a risk of rupture. Therefore, in the case of batteries that generate a large amount of gas, methods are used to either design the gas collection section 120 to be larger or to increase the volume of the gas collection section 120 by molding it. However, increasing the size of the gas collection section 120 increases the amount of battery case material used, which increases manufacturing costs. Also, molding the gas collection section 120 increases the number of steps in the manufacturing process, which also contributes to increased manufacturing costs. Furthermore, even if the size of the gas collection section 120 is increased, there are limits to how much gas can be collected that is continuously generated during the activation process.

[0065] To solve these problems, the present invention provides a gas discharge pipe 500 that can discharge gas from the gas collection section 120. Furthermore, by positioning the gas discharge pipe 500 in the battery case 100 before secondary sealing of the battery case 100, and sealing the gas discharge pipe 500 together with the secondary sealing, the fixing and sealing work of the gas discharge pipe 500 can be performed in one simple step.

[0066] A method for manufacturing a secondary battery of the present invention, as disclosed in Figure 2, involves housing an electrode assembly 200 in the battery section 110 of a battery case 100, which includes a battery section 110 and a gas collection section 120 communicating with the battery section 110, and then performing a step (S10) of sealing the edges of the battery case 100, excluding one side of the gas collection section 120. That is, as shown in Figure 1, the electrode assembly 200 is housed in the electrode assembly 200 housing space of the upper pouch 100B and the lower pouch 100A, and after the upper pouch 100B and the lower pouch 100A are tightly sealed, the edges of the battery case 100 are sealed. That is, as shown in Figure 4, for example, primary sealing is performed by sealing the remaining edges of the battery case 100 with a sealing tool, excluding only one side above the gas collection section 120. Reference numeral S1 denotes the primary sealing section. It is preferable to remove the air from inside the battery case 100 before sealing and then seal the edges.

[0067] A gas discharge pipe 500 capable of both gas discharge and electrolyte injection is positioned in the opening of the battery case on one side, and by sealing both the opening and the gas discharge pipe 500, the gas discharge pipe 500 can be fixed to the battery case 100 and the battery case 100 can be sealed at the same time (S12).

[0068] The gas discharge pipe 500 is installed in the gas collection section 120 and is a pipe for discharging the activation process gas to the outside of the battery. The diameter of the gas discharge pipe 500 is not particularly limited, but can be selected from a suitable range considering the size of the battery, the flow rate of the generated gas, the gas discharge rate, etc. Furthermore, the gas discharge pipe 500 may be made of a highly corrosion-resistant material, such as Teflon®, but is not limited thereto.

[0069] A gas exhaust pipe 500 capable of both gas discharge and electrolyte injection may be used. For example, a gas exhaust pipe 500 having a single hollow passage can be used, and gas can be discharged through the hollow passage. In addition, electrolyte can be injected into the battery from outside through the hollow passage when necessary.

[0070] Alternatively, a double-walled gas discharge pipe 500 can be used, which has both a gas discharge passage and an electrolyte injection passage. By providing separate passages for gas discharge and electrolyte injection in this way, inter-process interference and passage contamination that may occur when gas discharge and electrolyte injection are performed simultaneously in a single passage can be prevented. As such a double-walled gas discharge pipe 500, a gas discharge pipe 500 in the form shown in Figures 7 to 16 can be used, as will be described later.

[0071] In this stage (S12), as shown in Figure 3, the gas exhaust pipe 500 is positioned in the battery case opening between the opposing inner surfaces of the upper and lower pouches, and both the opening and the gas exhaust pipe 500 are sealed.

[0072] For gas discharge, at least the inlet portion of the gas discharge pipe 500 is positioned on the open portion so as to protrude outside the battery. Furthermore, a portion of the gas discharge pipe 500 is positioned inside the gas pocket portion from the sealing portion so that the gas from the gas collection portion 120 can be easily introduced into the gas discharge pipe 500. The gas discharge pipe 500 may be placed in the open portion on the upper side of the gas collection portion 120 as shown in the figures, but it may also be placed on at least one side of the gas pocket portion corresponding to the side on which the electrode leads protrude. However, considering the properties of the gas that tend to flow upward and the direction of injection, it is preferable to install the gas discharge pipe 500 on the upper side of the gas collection portion 120 as shown in Figures 3 and 4.

[0073] The gas exhaust pipe 500 described above may be a pipe with a circular cross-section, but is not limited to this. For example, a pipe with an elliptical cross-section, or a polygonal cross-section with curved R-shaped sections at the corners, may also be used.

[0074] After positioning the gas discharge pipe 500 in the opening of the battery case, both the gas collection section 120 and the gas discharge pipe 500 are sealed (secondary sealing). Reference numeral S2 denotes the secondary sealing section. In this case, a vacuum sealing method can be applied to seal the gas discharge pipe 500 and the upper and lower pouches in a vacuum atmosphere so that there is no gap between them. The vacuum sealing method can also be applied to the primary sealing and to the tertiary sealing after trimming of the battery case, which will be described later. The sealing can be performed by thermal fusion and / or by fusion methods using ultrasound or lasers. Vacuum sealing causes the inner surfaces of the opposing upper and lower pouches in the opening to be tightly joined, and at the same time, the upper pouch 100B and lower pouch 100A surrounding the gas discharge pipe 500 are tightly joined. This securely fixes the gas discharge pipe 500 to the battery case and simultaneously achieves sealing of the battery case 100. Thus, according to the manufacturing method of the present invention, the gas exhaust pipe 500 is positioned in the open portion of the battery case 100 before completely sealing the battery case 100, and the fixing of the gas exhaust pipe 500 and the sealing of the battery case 100 are performed simultaneously. Therefore, no separate installation work such as inserting the gas exhaust pipe 500 into the battery case 100 is required. This simplifies the process and allows the gas exhaust pipe 500 to be securely fixed to the battery case 100 without any gaps. Therefore, it is possible to prevent gas or electrolyte leakage through the gap between the gas exhaust pipe 500 and the battery case 100.

[0075] Figure 4 illustrates a secondary battery in a state where such secondary sealing has been performed.

[0076] The battery, which includes the battery section 110 and the gas collection section 120, is charged and discharged to perform an activation process. During the activation process, gas is generated in the battery section 110 due to chemical reactions and side reactions associated with charging and discharging, and this gas moves to and accumulates in the gas collection section 120.

[0077] In the secondary battery of the present invention, since the gas discharge pipe 500 is installed in the battery case 100, the gas generated simultaneously with the activation process can be discharged to the outside through the gas discharge pipe 500. That is, the present invention includes a step (S13) in which the gas generated during the activation process and flowing into the gas collection section 120 is discharged to the outside of the battery through the gas discharge pipe 500.

[0078] On the other hand, electrolyte injection is sufficient if performed only before the activation process described above. For example, the electrolyte may be injected between steps (S10) and (S12) through an opening in one side of the battery case, or between steps (S12) and (S13) through a gas discharge pipe fixed to the battery case.

[0079] As an example of the former, step (S11) may be provided between steps (S10) and (S12). In step (S11), electrolyte can be injected into the battery section 110 through the battery case opening formed on one side. Since the upper side is not sealed, an opening is formed between the opposing inner surfaces of the upper and lower pouches. Therefore, electrolyte can be injected into the gas collection section 120 through this opening. The electrolyte injection step is a step of impregnating the electrode assembly 200 housed in the battery section 110 with electrolyte. The electrolyte seeps between the positive electrode, negative electrode and separation membrane of the electrode assembly 200 by capillary force.

[0080] In the activation process, charging proceeds while the main body of the secondary battery is pressed into a flat plate, so that gas does not accumulate locally in the battery and is uniformly moved to the gas collection section 120. In this invention, since a gas discharge pipe 500 is provided, the gas inside the battery can be easily discharged to the outside in response to the above pressurization. Furthermore, if negative pressure (vacuum) is formed outside the battery, the gas can be discharged more quickly through the gas discharge pipe 500.

[0081] Thus, according to the secondary battery manufacturing method of the present invention, the gas discharge pipe 500 can be easily and securely installed in the battery case 100. Furthermore, since the gas discharge pipe 500 can quickly discharge the gas generated in the activation process, the amount of residual gas in the battery can be reduced, thereby lowering the risk of ignition and explosion during battery manufacturing. In addition, because the gas discharge pipe 500 quickly discharges gas, the capacity and size of the gas pocket can be reduced, thereby reducing dead space in the battery and reducing the amount of material used.

[0082] Figure 5 is a schematic diagram showing the degassing process of a secondary battery according to one embodiment of the present invention.

[0083] To manufacture a finished battery by discharging the remaining gas in the gas collection section 120 after the activation process is complete, degassing holes H1 to H4 are formed in the gas collection section 120 as shown in Figure 5. The gas is released from the inside to the outside of the battery case 100 through the degassing holes H1 to H4. The gas discharge pipe 500 of the present invention can also discharge gas during this degassing stage. That is, after the activation process, the remaining gas in the gas collection section 120 can be discharged to the outside of the battery through at least one of the degassing holes H1 to H4 formed in the gas collection section 120 and the gas discharge pipe 500. For example, even if degassing holes are not formed, the remaining gas can be discharged to the outside of the battery through the gas discharge pipe 500. If degassing holes H1 to H4 are drilled in the gas collection section 120, the gas can be discharged through the degassing holes. In this case, the plug of the gas discharge pipe 500 can be opened to discharge the remaining gas more quickly along with the degassing holes.

[0084] On the other hand, during the degassing stage, a vacuum environment can be created outside the battery, such as by placing the battery in a vacuum chamber, to facilitate gas discharge through the degassing holes H1 to H4 or the gas discharge pipe 500. Furthermore, gas discharge can be accelerated by pressurizing both sides of the battery during the degassing stage. In either case, the gas discharge pipe 500 of the present invention can efficiently discharge any remaining gas in the gas collection section 120.

[0085] One advantage of the gas discharge via the gas discharge pipe 500 is that it can be repeated. That is, whenever a large amount of gas accumulates in the gas collection unit 120 during the activation process or degassing, the gas can be repeatedly discharged by opening the plug 400 of the gas discharge pipe 500, for example.

[0086] Furthermore, the method for manufacturing a secondary battery of the present invention may further include a step of replenishing the battery with electrolyte through the gas discharge pipe 500 during the activation step. As described above, the gas discharge passage of the gas discharge pipe 500 can also be used as an electrolyte injection passage. Therefore, when the electrolyte in the battery becomes insufficient during the activation step, the electrolyte in the battery can be replenished by injecting electrolyte through the gas discharge pipe 500. In this case, since the gas inside the battery is discharged through the gas discharge pipe 500 and the pressure inside the battery decreases, it is possible to replenish the electrolyte at any time during the activation step by replacing the gas.

[0087] To avoid interference between gas discharge and electrolyte injection and prevent passage contamination, the gas discharge pipe 500 can have a double-pipe structure comprising a gas discharge passage and an electrolyte injection passage. As will be described later, as shown in Figures 7 to 16, the gas discharge pipe 500 can be configured as a double pipe in which the electrolyte injection passage and the gas discharge passage are arranged concentrically. Performing gas discharge and electrolyte injection with a gas discharge pipe 500 of this structure allows for efficient operation of both processes while avoiding interference such as contamination of each passage or leakage of electrolyte during gas discharge.

[0088] Furthermore, such a double-pipe gas discharge pipe 500 may include a first plug connected to the gas discharge passage and a second plug connected to the electrolyte injection passage. In this case, at least one of the operations of gas discharge from the battery and electrolyte injection into the battery can be performed by connecting and disconnecting at least one of the first and second plugs to their respective corresponding passages. For example, if gas discharge and electrolyte injection are not required in the pre- and post-activation stages, the first plug can be connected to the gas discharge passage and the second plug to the electrolyte injection passage to close each passage. When performing either gas discharge or electrolyte injection, the operation can be performed by disconnecting either the first or second plug from the corresponding passage. Also, when both the first and second plugs are disconnected, gas discharge and electrolyte injection can be performed simultaneously.

[0089] In this case, the gas discharge pipe 500, the first stopper, and the second stopper constitute the gas discharge and electrolyte injection mechanism T. An example of such a mechanism will be described later.

[0090] Furthermore, by providing plugs corresponding to each passage as described above, the inflow of external air and moisture can be blocked. The first and second plugs may have shapes that match the shapes of the corresponding passages. For example, they may be wedge-shaped press-fit sealing plugs that fit into the gas discharge passage and the electrolyte injection passage. Alternatively, each plug can be connected to each passage by screw connection by forming screw threads on the corresponding coupling surfaces of each passage and plug.

[0091] Once the degassing stage is complete, the gas collection unit 120 is removed, and the removed portion is sealed (tertiary sealing) to manufacture the final completed secondary battery. That is, in Figure 5, the connection between the gas collection unit 120 and the battery unit 110 is cut off, and this cut-off portion is prepared and sealed for the third time. The symbol S3 represents the portion to be tertiary sealed (Figure 5) or the tertiary sealed portion (Figure 17). With the removal of the gas collection unit 120, the gas discharge pipe 500 provided in the gas collection unit 120 is also removed.

[0092] (Second Embodiment) Figure 6 is a flowchart of a method for manufacturing a secondary battery according to another embodiment of the present invention.

[0093] The manufacturing method of this embodiment employs a double-pipe structure gas discharge pipe 500 equipped with a gas discharge passage and an electrolyte injection passage as the gas discharge pipe 500, which has the effect of reducing the battery case sealing step.

[0094] Referring to Figure 6, the manufacturing method of the secondary battery of this embodiment includes the step (S20) of housing an electrode assembly 200 in the battery section 110 of a battery case 100 which includes a battery section 110 and a gas collection section 120 communicating with the battery section 110, and positioning a double-pipe structure gas discharge pipe 500 having a gas discharge passage and an electrolyte injection passage on at least one open side of the gas collection section 120. That is, similar to the first embodiment, the battery section 110 is formed by bringing battery parts 110A and 110B, which have electrode assembly housing spaces formed in upper and lower pouches, into contact, and the electrode assembly 200 is housed in the electrode assembly housing space of the battery section 110. Furthermore, the gas collection parts 120A and 120B of the upper and lower pouches, which communicate with the battery section 110, are positioned opposite each other, and the double-pipe gas discharge pipe 500 is positioned in the open section between the upper and lower gas collection parts, that is, on one open side of the gas collection section 120, as shown in Figure 1.

[0095] In the next step (S21), the entire edge of the battery case 100, including the one side, is sealed. That is, instead of primary sealing the battery case 100 excluding the one side, as in the first embodiment, and then secondary sealing the battery case 100 together with the gas exhaust pipe 500, the gas exhaust pipe 500 and the battery case 100 are sealed simultaneously in the primary sealing stage. Therefore, this sealing fixes the gas exhaust pipe 500 to the battery case 100 and seals the entire edge of the battery case 100. Specific sealing methods, such as vacuum sealing, can be the same as in the first embodiment, so a detailed explanation therein is omitted.

[0096] The battery, comprising the battery section 110 and the gas collection section 120, can be charged and discharged to perform an activation process. During the activation process, gas is generated in the battery section 110 due to chemical reactions and side reactions associated with charging and discharging, and this gas moves to and accumulates in the gas collection section 120. The gas generated during the activation process and flowing into the gas collection section 120 is discharged to the outside of the battery via the gas discharge pipe 500 (S23).

[0097] On the other hand, the process may further include a step (S22) of injecting electrolyte into the battery section 110 via the electrolyte injection passage of the gas discharge pipe 500 before the activation process. For example, the plug connected to the electrolyte injection passage of the gas discharge pipe 500 can be removed, and the electrolyte injection pipe of the electrolyte injection device can be connected to the electrolyte injection passage to inject the electrolyte. This allows the electrolyte to be impregnated into the electrode assembly 200 of the battery section 110 via the electrolyte injection passage.

[0098] With the manufacturing method of this embodiment, the gas discharge pipe 500 can be sealed together with the battery case 100, allowing for simple and secure installation of the gas discharge pipe 500 in the battery case 100. Furthermore, since the gas generated during the activation process can be quickly discharged by the gas discharge pipe 500, the amount of residual gas in the battery can be reduced, and the capacity and size of the gas pocket can be reduced.

[0099] Furthermore, electrolyte injection can be performed in the electrolyte injection passage of the gas discharge pipe 500. This has the additional advantage of reducing the number of steps, as the sealing process required before the activation process only needs to be performed once. In other words, in this embodiment, a secondary battery 1000 in the form shown in Figure 4 can be obtained by performing only steps (S20) and (S21).

[0100] The method for manufacturing a secondary battery according to this embodiment may also include a degassing step in which, after the activation step, the remaining gas in the gas collection section 120 is discharged to the outside of the battery through at least one of the degassing holes H1 to H4 formed in the gas collection section 120 and the gas discharge pipe 500.

[0101] Furthermore, the electrolyte can be additionally replenished to the battery via the gas discharge pipe 500 during the activation process. In other words, with the gas discharge pipe 500 of this embodiment, not only can the electrolyte be injected for impregnation of the electrode assembly before the activation process, but the electrolyte can also be replenished during the activation process.

[0102] In this embodiment as well, the battery may be equipped with a first plug connected to the gas discharge passage and a second plug connected to the electrolyte injection passage, and by connecting and disconnecting at least one of the first and second plugs to their respective corresponding passages, at least one of the operations of gas discharge from the battery and electrolyte injection into the battery can be performed.

[0103] Once the degassing stage is complete, the gas collection unit 120 is removed, and the removed portion is sealed (secondary sealing) to manufacture the final completed secondary battery. Specifically, in Figure 5, the connection between the gas collection unit 120 and the battery unit 110 is cut off, and this cut-off portion is prepared and sealed a second time. With the removal of the gas collection unit 120, the gas discharge pipe 500 provided in the gas collection unit 120 is also removed.

[0104] According to this embodiment, the work before and after the activation process can be performed by a total of two sealing steps, thereby enabling the production of a finished secondary battery while reducing the number of manufacturing steps.

[0105] <Gas discharge and electrolyte injection mechanism> (First Embodiment) Figure 7 is an exploded view of a gas discharge and electrolyte injection mechanism according to one embodiment of the present invention, Figure 8 is a cross-sectional view of a gas discharge and electrolyte injection mechanism according to one embodiment of the present invention, and Figure 9 is a schematic diagram showing the gas discharge process by a gas discharge and electrolyte injection mechanism according to one embodiment.

[0106] The present invention also includes a gas discharge and electrolyte injection mechanism applicable to the above-described method for manufacturing secondary batteries. This allows for effective gas discharge and electrolyte injection into intermediate-stage secondary battery semi-finished products or finished secondary batteries equipped with a gas pocket.

[0107] The gas discharge and electrolyte injection mechanism T1 of this embodiment includes a gas discharge pipe 500, a first stopper 410, and a second stopper 420.

[0108] The gas discharge pipe 500 includes a hollow first pipe 510 with a gas discharge passage 511 formed therein and open at the top and bottom, a hollow second pipe 520 with an electrolyte injection passage 521 formed therein and open at the top and bottom and positioned within the gas discharge passage 511, and a connecting member 530 that connects the pipe wall of the first pipe 510 and the pipe wall of the second pipe 520. The gas discharge pipe 500 has a double-pipe structure in which two pipes are formed in a hollow space. The upper and lower parts of the gas discharge pipe 500 are open. The open upper part of the gas discharge pipe 500 can be closed by connecting it with a plug 400. The open lower part of the gas discharge pipe 500 is inserted into the secondary battery, and gas from inside the battery can be introduced into the open part of the lower part of the gas discharge pipe. Alternatively, electrolyte injected from the outside can be injected into the battery through the open part at the bottom.

[0109] The first pipe 510 and the second pipe 520 may be arranged concentrically, but are not limited to this, and the second pipe 520 may be eccentrically arranged inside the first pipe 510 as needed. Also, although the cross-sections of the first pipe 510 and the second pipe 520 are circular, are not limited to this, and pipes with elliptical or polygonal cross-sections with curved R-shaped sections are also possible. As mentioned above, the gas discharge pipe 500 may be made of a highly corrosion-resistant material that can withstand the electrolyte or the gas produced when the electrolyte vaporizes. It is also possible to use the same material for the first pipe 510 and the second pipe 520, or to use different materials.

[0110] The length of the gas exhaust pipe 500 can be determined considering the size of the secondary battery, the installation space for the external device in which the secondary battery is installed, etc., and is not particularly limited.

[0111] The first pipe 510 and the second pipe 520 are connected by connecting members 530. That is, the pipe wall of the first pipe 510 and the pipe wall of the second pipe 520 can be connected by connecting members 530. Referring to Figure 7, multiple connecting members 530 (three in this embodiment) are provided at predetermined intervals along the edges of the first pipe 510 and the second pipe 520, connecting the inner circumferential surface of the first pipe 510 and the outer circumferential surface of the second pipe 520. In the first pipe 510, the space between the connecting members 530 becomes the gas discharge passage 511. The number and shape of the connecting members 530 can be determined considering the rigidity of the connection between the first pipe and the second pipe, the efficiency of gas discharge, etc.

[0112] The connecting member 530 may be installed near the inlet of the first pipe 510. However, if the first plug 410 has an insertion portion that fits into and is inserted into the inlet of the gas discharge passage 511, the connecting member 530 may obstruct the insertion of the insertion portion. Therefore, it is preferable that the connecting member 530 be located between the pipe walls of the first pipe and the second pipe below the inlet of the first pipe 510. However, as shown in the embodiment of Figure 11 described later, if a slot A for fitting the connecting member 530 is formed in the insertion portion, it is also possible to install the connecting member 530 near the inlet of the gas discharge passage 511.

[0113] A first plug 410, which seals the gas discharge passage 511, is detachably connected to the open upper part of the first pipe 510.

[0114] When the first valve 410 is connected to the first pipe 510, no gas is discharged. When the first valve 410 is disconnected from the first pipe 510, the gas discharge passage 511 is opened, allowing gas from inside the battery to be discharged to the outside.

[0115] The first stopper 410 described above may include at least one of a sealing portion that covers the inlet of the gas discharge passage 511 and an insertion portion that is inserted into the inlet.

[0116] In other words, as shown in Figure 8, the first stopper 410 may be a stopper having a sealing portion that completely covers and seals the inlet of the gas discharge passage 511. The inner circumferential surface of the first stopper 410 is fitted and connected to the outer circumferential surface of the first pipe 510 (gas discharge passage 511). In this case, the inner circumferential diameter of the first stopper 410 is made smaller than the outer circumferential diameter of the first pipe 510, and the sealing portion of the first stopper 410 is forcibly fitted to the inlet of the first pipe 510, thereby ensuring that the first stopper 410 reliably seals the gas discharge passage 511.

[0117] Alternatively, the first stopper 410 may be a stopper having an insertion portion that fits and connects to the inlet of the gas discharge passage 511. In this case, the outer circumferential surface of the insertion portion of the first stopper 410 fits and connects to the inner circumferential surface of the first pipe 510 (gas discharge passage 511). By making the outer circumferential diameter of the insertion portion of the first stopper 410 larger than the inner circumferential diameter of the first pipe 510, and forcibly fitting the insertion portion of the first stopper 410 to the inlet of the first pipe 510, the first stopper 410 can be made to reliably seal the gas discharge passage 511.

[0118] Furthermore, the first stopper 410 may have both a sealing portion and an insertion portion. In this case, the sealing portion covers the outer circumferential surface of the first pipe 510 or fits onto the outer circumferential surface, and the insertion portion fits onto the inner circumferential surface of the first pipe 510. A first stopper 410 of this form is illustrated in Figure 12, as will be described later.

[0119] Furthermore, as will be described later, threads can be formed on the coupling surface of the first stopper 410 and the corresponding coupling surface of the first pipe 510, thereby screw-connecting the gas discharge passage 511 of the first stopper 410 and the first pipe 510.

[0120] A second stopper 420, which seals the electrolyte injection passage 521, is detachably attached to the open upper part of the second tube 520.

[0121] When the second stopper 420 is connected to the second tube 520, electrolyte is not injected. When the second stopper 420 is disconnected from the second tube 520, the electrolyte injection passage 521 is opened, allowing electrolyte to be injected into the battery from an external electrolyte injection device.

[0122] The second stopper 420 described above may include at least one of a sealing portion that covers the entrance to the electrolyte injection passage 521 and an insertion portion that is inserted into the entrance.

[0123] That is, as shown in Figures 7 and 8, the second stopper 420 may be a stopper having a sealing portion that completely covers and seals the entrance to the electrolyte injection passage 521. The inner circumferential surface of the second stopper 420 is fitted and connected to the outer circumferential surface of the second tube 520 (electrolyte injection passage 521). In this case, the inner circumferential diameter of the second stopper 420 is made smaller than the outer circumferential diameter of the second tube 520, and the sealing portion of the second stopper 420 is forcibly fitted to the entrance of the second tube 520, thereby ensuring that the second stopper 420 reliably seals the electrolyte injection passage 521.

[0124] Alternatively, the second stopper 420 may be a stopper having an insertion portion that fits and connects to the inlet of the electrolyte injection passage 521. In this case, the outer circumferential surface of the insertion portion of the second stopper 420 fits and connects to the inner circumferential surface of the second tube 520 (electrolyte injection passage 521). By making the outer circumferential diameter of the insertion portion of the second stopper 420 larger than the inner circumferential diameter of the second tube 520, and forcibly fitting the insertion portion of the second stopper 420 to the inlet of the second tube 520, the second stopper 420 can be made to reliably seal the electrolyte injection passage 521.

[0125] Furthermore, the second stopper 420 may have both a sealing portion and an insertion portion. In this case, the sealing portion covers the outer circumferential surface of the second pipe 520 or fits onto its outer circumferential surface, while the insertion portion fits onto the inner circumferential surface of the second pipe 520.

[0126] Furthermore, as will be described later, threads can be formed on the coupling surface of the second stopper 420 and the corresponding coupling surface of the second tube 520, thereby screw-connecting the electrolyte injection passage 521 of the second stopper 420 and the second tube 520.

[0127] The present invention provides a first stopper 410 connected to the gas discharge passage 511 of the first pipe 510 and a second stopper 420 connected to the electrolyte injection passage 521 of the second pipe 520, thereby enabling convenient performance of at least one of gas discharge and electrolyte injection operations. That is, by connecting and disconnecting at least one of the first stopper 410 and the second stopper 420 to their respective corresponding passages, at least one of the operations of gas discharge from the battery and electrolyte injection into the battery can be performed. For example, if gas discharge and electrolyte injection are not required before or after the activation process, the first stopper 410 can be connected to the gas discharge passage 511 and the second stopper 420 to the electrolyte injection passage 521 to close the respective passages.

[0128] When performing either gas discharge or electrolyte injection, the operation can be carried out by disconnecting either the first stopper 410 or the second stopper 420 from the corresponding passage. For example, as shown in Figure 9, with the second stopper 420 connected to the second pipe 520, gas can be discharged from the battery to the outside of the battery via the gas discharge passage 511 of the first pipe 510 by disconnecting the first stopper 410 from the first pipe 510. In this case, since the electrolyte injection passage 521 is sealed by the second stopper 420, leakage of electrolyte can be prevented. Conversely, by sealing the first stopper 410 and disconnecting the second stopper 420 from the second pipe 520, electrolyte can be introduced into the battery while preventing gas discharge.

[0129] Furthermore, when both the first and second plugs are uncoupled, gas can be discharged via the gas discharge passage 511 and electrolyte can be injected via the electrolyte injection passage 521 simultaneously. In this case, the lower the internal pressure of the battery due to gas discharge, the easier it is to inject the electrolyte into the battery, which is an advantage.

[0130] The first and second plugs described above may have shapes that match the shape of the corresponding passage.

[0131] The first stopper 410 and the second stopper 420 can be detachably connected to each other. As shown in Figures 7 and 8, the first stopper 410 has a through hole 411 for connecting to the second stopper, and the second stopper 420 can be inserted into the through hole 411 and connected to the first stopper 410. That is, since the second pipe 520 is located within the gas discharge passage 511 of the first pipe 510, the second stopper 420 can also be connected to the second pipe 520 located within the gas discharge passage 511 via the through hole 411 formed in the first stopper 410. Furthermore, since the first stopper 410 and the second stopper 420 can be connected to each other, transportation of the stoppers is convenient and the risk of losing a particular stopper can be reduced. In addition, since the first and second stoppers can be connected to the gas discharge pipe 500 at once while they are connected, connection is convenient. Furthermore, since the first and second stoppers are detachably connected, for example, with one of the first or second stoppers connected to the first pipe 510 or the second pipe 520, the remaining stopper can be separated from the corresponding pipe to selectively perform gas discharge or electrolyte injection operations.

[0132] (Second Embodiment) Figure 10 is a cross-sectional view of a gas discharge and electrolyte injection mechanism T2 according to another embodiment of the present invention.

[0133] In this embodiment, threads G1, G2, and G3 are formed on the joint surfaces where the first stopper and the second stopper are joined to each other, on the joint surface where the first stopper 410 and the first pipe 510 are joined, and on the joint surface where the second stopper 420 and the second pipe 520 are joined.

[0134] Specifically, threads G3 that interlock with each other are formed on the outer surface of the second stopper 420 and on the inner surface of the through hole for connecting the second stopper 420. In addition, threads G1 that interlock with each other are formed on the connecting surface of the first stopper 410 (the inner circumferential surface of the first stopper 410 in Figure 10) and the corresponding connecting surface of the open upper part of the first pipe 510 (the outer circumferential surface of the first pipe 510 in Figure 10). Furthermore, threads G2 that interlock with each other may be formed on the connecting surface of the second stopper 420 (the inner circumferential surface of the second stopper 420 in Figure 10) and the corresponding connecting surfaces of the open upper part of the second pipe 520 (the outer circumferential surface of the second pipe 520 in Figure 10).

[0135] In this embodiment, for example, the combined body of the first and second stoppers can be brought into contact with the corresponding connecting surfaces of the first and second pipes at once, and the combined body can be rotated to firmly screw-connect the stopper combined body to the gas discharge pipe 500. Such a strong screw connection can further improve the airtightness of the gas discharge and electrolyte injection members in this embodiment.

[0136] Furthermore, in this case, the plug assembly can be separated from the first pipe 510 by rotating only the first plug 410 while it is still connected, or separated from the second pipe 520 by rotating only the second plug 420, which is convenient for selectively performing gas discharge or electrolyte injection operations.

[0137] (Third embodiment) Figure 11 is an exploded view of the gas discharge and electrolyte injection mechanism T3 according to another embodiment of the present invention, Figure 12 is a cross-sectional view of the gas discharge and electrolyte injection mechanism according to another embodiment of the present invention, and Figure 13 is a schematic diagram showing the electrolyte injection process by the gas discharge and electrolyte injection mechanism according to another embodiment.

[0138] In this embodiment, the double-pipe structure of the gas discharge pipe 500, which includes a first pipe 510 and a second pipe 520, is the same as in the first embodiment. The plug 400' in this embodiment differs from that of the first embodiment in the structure of the first plug 410 and the second plug 420.

[0139] First, the first stopper 410 of this embodiment includes both a sealing portion 410A that covers the inlet of the gas discharge passage 511 and an insertion portion 410B that is inserted into the inlet. That is, the sealing portion 410A covers the upper part of the inlet of the first pipe 510 to maintain the airtightness of the first pipe 510. It also includes an insertion portion 410B that is inserted into the gas discharge passage 511 of the first pipe 510. Therefore, the airtightness of the gas discharge passage 511 can be reliably guaranteed by the sealing portion 410A and the insertion portion 410B of the first stopper 410.

[0140] Furthermore, the insertion portion 410B is provided with a plurality of slots A along its edge at predetermined intervals into which the connecting members 530 are inserted. The connecting members 530 are installed between the first pipe 510 and the second pipe 520, that is, across the gas discharge passage 511 of the first pipe 510. Therefore, the connecting members 530 get in the way when inserting the insertion portion 410B of the first plug 410 into the gas discharge passage 511. In this embodiment, since slots into which the connecting members 530 can be inserted are formed along the edge of the insertion portion 410B, the insertion portion can be easily fitted and connected to the connecting members 530. The connection of the slots A and the connecting members 530 allows the first plug 410 to be more firmly connected to the first pipe 510.

[0141] On the other hand, the second stopper 420, like in the first embodiment, does not cover and seal the inlet of the second pipe 520, but rather is fitted and connected to the inner circumferential surface of the second pipe 520 in the form of an insertion portion. Therefore, the diameter of the second stopper 420 is smaller than the diameter of the second stopper 420 in the first embodiment.

[0142] Figure 13 shows that the first stopper 410 is coupled to the first tube 510, the second stopper 420 is uncoupled from the second tube 520, and the injection tube 600 of the electrolyte injection device is inserted into the electrolyte injection passage 521 of the second tube 520. This allows the electrolyte to be injected from outside the battery into the battery via the second tube 520, for example, when electrolyte replenishment is needed during the activation process, or when electrolyte is injected for electrode assembly impregnation before the activation process.

[0143] (Fourth Embodiment) Figure 14 is a cross-sectional view of a gas discharge and electrolyte injection mechanism T4 according to another embodiment of the present invention, Figure 15 is a perspective view showing the opening and closing member of the gas discharge and electrolyte injection mechanism, and Figure 16 is a cross-sectional view showing the operation process of the gas discharge and electrolyte injection mechanism according to another embodiment of the present invention.

[0144] This embodiment is designed to block the inflow of air and moisture from outside the battery during gas discharge, thereby preventing electrolyte leakage from inside the battery.

[0145] For this purpose, the gas discharge and electrolyte injection mechanism T4 of this embodiment is equipped with an opening / closing mechanism inside the first pipe 510 that causes gas to flow only in the direction of the inlet of the gas discharge passage 511.

[0146] For example, gas can be discharged by separating the first stopper 410 from the first pipe 510. In this case, it is assumed that the second stopper 420 is connected to the second pipe 520 and no electrolyte solution is injected.

[0147] A vacuum atmosphere can be formed outside the gas discharge pipe 500, allowing gas to be quickly discharged from inside the battery. In this case, if air or moisture enters from outside the first pipe 510, not only will gas discharge be hindered, but the inside of the battery may become contaminated, potentially causing product defects. Furthermore, not only gas from inside the battery, but also the pressure difference between the inside and outside of the battery may cause the electrolyte inside the battery to leak through the gas discharge passage 511.

[0148] The opening and closing mechanism of this embodiment is installed inside the first pipe 510 and can block the ingress of air and moisture from the outside by causing the gas to flow in only one direction (towards the inlet of the gas discharge passage 511). Furthermore, since the opening and closing mechanism opens the gas discharge passage 511 only to the extent that the gas inside the battery can be discharged, leakage of the electrolyte can also be prevented.

[0149] Specifically, the opening and closing mechanism includes an upward movement restricting portion 512 and a downward movement restricting portion 513 that are formed to protrude vertically at intervals along the inner circumferential surface of the first pipe 510, and an opening and closing member 540 located between the upward movement restricting portion 512 and the downward movement restricting portion 513.

[0150] The upward movement restricting portion 512 described above is a portion that protrudes from the inner circumferential surface of the first pipe 510 toward the center of the first pipe 510. When the opening / closing member 540 rises along the first pipe 510 due to the internal pressure of the battery, the upward movement of the opening / closing member 540 is interrupted by contact with the upward movement restricting portion 512. The upward movement restricting portion 512 may be formed in a ring shape corresponding to the shape of the opening / closing member 540. That is, the opening / closing member 540 may be a ring-shaped member installed on the first pipe 510 while surrounding the second pipe 520, as will be described later. Therefore, the upward movement restricting portion 512 may also be made to protrude in a ring shape along the inner circumferential surface of the first pipe 510 so that it can contact and restrict the upper surface of the opening / closing member 540. However, the upward movement restricting portion 512 does not need to be continuously ring-shaped along the inner circumferential surface of the first pipe 510; it may be formed to protrude intermittently, and it is sufficient if it is generally ring-shaped. Alternatively, if the opening / closing members 540 can be restricted upward at multiple locations by being installed in an appropriate number along the inner surface of the first pipe 510, the upward movement restricting section 512 does not necessarily need to be extended in a ring shape.

[0151] Furthermore, an upward movement restricting portion 512 may be additionally formed along the outer surface of the second pipe 520, in addition to the inner surface of the first pipe 510. In this case, the upward movement restricting portion 512 formed on the inner surface of the first pipe 510 and the upward movement restricting portion 512 formed on the outer surface of the second pipe 520 work together to more stably restrict the upward movement of the opening / closing member 540.

[0152] The downward movement restricting portion 513 is a portion that protrudes from the inner circumferential surface of the first pipe 510 toward the center of the first pipe 510, and is provided on the inner circumferential surface of the first pipe 510 at a vertical distance from the upward movement restricting portion. The distance between the upward movement restricting portion 512 and the downward movement restricting portion 513 is greater than the height of the opening / closing member. Therefore, when the opening / closing member 540 moves upward due to the internal pressure of the battery, a predetermined gap can be formed between the opening / closing member 540 and the downward movement restricting portion. The gap continues to increase until the opening / closing member comes into contact with the upward movement restricting portion 512.

[0153] On the other hand, when no internal pressure is applied to the battery, the opening / closing member 540 is secured to the downward movement restricting part 513, and the downward movement restricting part 513 restricts the opening / closing member 540 from descending any further inside the first pipe.

[0154] The downward movement restricting portion 513 described above may be formed in a ring shape corresponding to the shape of the opening / closing member 540. The downward movement restricting portion 513 may be formed to protrude in a ring shape along the inner circumferential surface of the first pipe 510 so that it can contact and restrict the lower surface of the opening / closing member 540. However, the downward movement restricting portion does not need to be continuously ring-shaped along the inner circumferential surface of the first pipe 510; it may be formed to protrude intermittently, and it is sufficient as long as it is ring-shaped overall. Alternatively, if an appropriate number of downward movement restricting portions are installed along the inner circumferential surface of the first pipe 510 and the downward movement of the opening / closing member 540 can be restricted at multiple locations, the downward movement restricting portion 513 does not necessarily need to be extended in a ring shape.

[0155] Furthermore, in addition to the inner surface of the first pipe 510, a downward movement restricting portion 513 may be additionally formed along the outer surface of the second pipe 520. In this case, the downward movement restricting portion 513 formed on the inner surface of the first pipe 510 and the downward movement restricting portion 513 formed on the outer surface of the second pipe 520 work together to more stably restrict the downward movement of the opening / closing member 540.

[0156] As shown in Figure 15, the opening / closing member 540 may be a ring-shaped member 541 having an outer surface 541 that contacts the inner surface of the first pipe 510 and an inner surface 542 that contacts the outer surface of the second pipe 520. The second pipe 520 is inserted into the opening in the center of the ring of the opening / closing member 540. Therefore, the opening / closing member 540 is located between the pipe wall of the first pipe 510 and the pipe wall of the second pipe 520 and can move up and down along the inner surface of the first pipe 510 and the outer surface of the second pipe 520. Since the height of the opening / closing member 540 is less than the distance (interval) between the upward movement restricting part 512 and the downward movement restricting part 513, the opening / closing member 540 can move between the upward and downward movement restricting parts by a stroke corresponding to the difference between the distance and the height of the opening / closing member.

[0157] The opening / closing member 540 can move between a shut-off position in which it contacts the downward movement restricting portion 513 to block the downward movement of the gas, and an allowable position in which it moves away from the downward movement restricting portion 513 due to the upward pressure of the gas, thereby allowing the upward movement of the gas.

[0158] In Figure 14, the opening / closing member 540 is in the shut-off position. That is, it is the state just before the first valve is separated from the first pipe 510 and the gas is discharged from inside the battery. In this position, the opening / closing member 540 is fixed on the downward movement restricting part 513, preventing air from entering from outside the battery, and also shutting off the discharge of gas from inside the battery.

[0159] As shown in Figure 16, when gas pressure is applied from inside the battery, the opening / closing member rises, creating a gap between the opening / closing member 540 and the downward movement restricting member 513. Gas from inside the battery can be discharged to the outside through this gap. The gap increases until the opening / closing member 540 contacts the upward movement restricting member 512. When the opening / closing member 540 is in contact with the upward movement restricting member 512, the gap is at its maximum, allowing gas from inside the battery to be rapidly discharged to the outside.

[0160] The ring-shaped opening / closing member 540 described above has an upper ring diameter that approximately matches the distance between the pipe wall of the first pipe 510 and the pipe wall of the second pipe, and its upper surface 541a is a flat surface that contacts the lower surface of the upward movement restricting portion 512. Therefore, even if there is a distance between the upward movement restricting portion 512 and the opening / closing member 540 as shown in Figure 14, no gap is created between the opening / closing member and the gas discharge passage 511. Consequently, outside air cannot enter the inside of the battery. On the other hand, the lower edge of the ring-shaped portion of the opening / closing member 540 is tapered, and the corresponding contact surface of the downward movement restricting portion 513 is also tapered. In the shut-off position, the tapered portions 541c and 541d of the opening / closing member and the tapered portion of the downward movement restricting portion 513 come into contact and shut off the gas discharge passage 511 without any gaps, thus also preventing gas from rising from the bottom of the passage.

[0161] In the permissible position shown in Figure 16, the opening / closing member 540 rises, separating the tapered portions 541c and 541d at the bottom of the opening / closing member from the tapered portion of the downward movement restricting portion 513, creating a gap X. Through this gap, gas inside the battery can move upward and be discharged to the outside. However, since this gap is very narrow, it is difficult for the electrolyte inside the battery to move upward through this gap X. Furthermore, even if the electrolyte is introduced into this gap, the body of the opening / closing member 540 occupies almost the entire volume of the gas discharge passage 511, making it extremely difficult for the electrolyte to rise any further. In other words, gas can be discharged through the minute gap between the opening / closing member 540 and the gas discharge passage 511, but the discharge of the electrolyte is prevented. Therefore, according to this embodiment, only a unidirectional flow of gas is permitted, and leakage of the electrolyte through the gas discharge passage 511 can be prevented while blocking the introduction of outside air.

[0162] In other words, in both the blocked position and the permitted position, the opening and closing member can block the introduction of air from the outside.

[0163] <Secondary battery> (First Embodiment) Figure 4 is a schematic diagram showing a secondary battery 1000 according to one embodiment of the present invention.

[0164] This embodiment relates to a secondary battery comprising a double-pipe structure gas discharge pipe 500 having both a gas discharge passage 511 and an electrolyte injection passage 521, and the gas discharge and electrolyte injection mechanism T having a first stopper 410 and a second stopper 420 that are detachably coupled to each passage.

[0165] The secondary battery 1000 of this embodiment includes an electrode assembly 200 including a positive electrode, a negative electrode, and a separation membrane disposed between the positive electrode and the negative electrode; a battery case 100 comprising a battery section 110 housing the electrode assembly 200 and a gas collection section 120 communicating with the battery section 110; and a gas discharge and electrolyte injection mechanism T installed on at least one side of the battery case 100. The detailed configurations of the electrode assembly 200 and the battery case 100 have been described in detail in relation to the manufacturing method of the secondary battery, so repeated descriptions will be omitted.

[0166] The secondary battery of this embodiment is a secondary battery used during the activation process, comprising both a battery section 110 and a gas collection section 120. In other words, it is not a finished secondary battery, but an intermediate-stage semi-finished secondary battery designed to facilitate gas discharge and electrolyte injection during the activation or degassing process. The secondary battery comprises a double-tube gas discharge pipe 500, as described with reference to Figures 7 to 16, and gas discharge and electrolyte injection mechanisms T1 to T4, each equipped with a first and second stopper. Specifically, the gas discharge and electrolyte injection mechanisms T1 to T4 are installed in the battery case 100 such that a portion of the first pipe 510 and the second pipe 520 of the gas discharge and electrolyte injection mechanisms T1 to T4 are inserted into the battery case 100, and the inlet of the gas discharge passage 511 and the inlet of the electrolyte injection passage 521 protrude to the outside from one side of the battery case 100. The gas discharge and electrolyte injection mechanisms T1 to T4 described above can be sealed together with the battery case 100 and fixed to the battery case 100, as shown in Figure 4. Furthermore, in this embodiment, since gas can be rapidly discharged in the activation and degassing processes via the gas discharge pipe 500, the size of the gas collection section 120 can be reduced. In addition, the electrolyte can be replenished via the electrolyte injection passage 521 provided in the gas discharge pipe 500. In particular, if the electrolyte is injected via the electrolyte injection passage 521 during the primary sealing stage of the battery case 100, the number of sealing processes can be reduced as described above.

[0167] (Second Embodiment) Figure 17 is a schematic diagram of a secondary battery 2000 according to another embodiment of the present invention.

[0168] This embodiment relates to a secondary battery that includes a double-walled gas discharge pipe 500 having both a gas discharge passage 511 and an electrolyte injection passage 521, and a gas discharge and electrolyte injection mechanism (T:T1~T4) having a first stopper and a second stopper detachably connected to each passage.

[0169] The secondary battery 2000 of this embodiment includes an electrode assembly 200 including a positive electrode, a negative electrode, and a separator membrane disposed between the positive electrode and the negative electrode; a battery case 100 housing the electrode assembly 200; and the gas discharge and electrolyte injection mechanisms T1 to T4 installed on at least one side of the battery case 100.

[0170] The secondary battery of this embodiment does not have a gas collection unit 120, and is a finished secondary battery in which the electrode assembly 200 is housed in a battery case 100. The finished secondary battery is manufactured by degassing, as shown in Figure 5, to remove the gas collection unit 120, then removing the gas collection unit 120, trimming the removed portion, and sealing the trimmed portion.

[0171] As mentioned above, even in finished rechargeable batteries, gas can be generated through electrochemical reactions. Furthermore, repeated charging and discharging can cause the electrolyte to vaporize, potentially leading to depletion or shortage of electrolyte inside the battery. This phenomenon is not unique to pouch-type rechargeable batteries; it occurs commonly in prismatic and cylindrical batteries as well. Therefore, finished rechargeable batteries require gas venting and electrolyte replenishment.

[0172] When a gas discharge pipe 500 is installed in the gas collection unit 120 for gas discharge during the activation process, the gas discharge pipe 500 is also removed when the gas collection unit 120 is removed.

[0173] However, instead of immediately sealing the open side of the battery case 100 from which the gas collection section 120 has been removed, the gas discharge and electrolyte injection mechanisms T1 to T4 can be positioned in the open section of that side and then sealed. This allows the installation of the gas discharge and electrolyte injection mechanisms T1 to T4 and the sealing of the battery case 100 to be achieved simultaneously in the final sealing process for manufacturing the finished product.

[0174] At this time, the gas discharge and electrolyte injection mechanisms T1 to T4 are installed in the battery case 100 such that a portion of the first tube 510 and the second tube 520 of the gas discharge and electrolyte injection mechanisms T1 to T4 are inserted into the battery case 100, and the inlet of the gas discharge passage 511 and the inlet of the electrolyte injection passage 521 protrude to the outside from one side of the battery case 100.

[0175] Therefore, the secondary battery of this embodiment is equipped with gas discharge and electrolyte injection mechanisms T1 to T4 unique to the present invention in the finished secondary battery. As a result, the secondary battery 2000 of this embodiment can, when necessary, remove the first stopper 410 and quickly discharge gas through the gas discharge pipe 500. Also, when necessary, remove the second stopper 420 and replenish the electrolyte through the electrolyte injection passage 521 provided in the gas discharge pipe 500.

[0176] According to the secondary battery of this embodiment, in addition to pouch-type secondary batteries, gas discharge and electrolyte injection can be performed simultaneously in all types of secondary batteries that generate gas through electrochemical reactions and inject electrolyte, such as prismatic secondary batteries and cylindrical secondary batteries.

[0177] On the other hand, the gas exhaust pipe can be installed on at least one side of the battery case. That is, as shown in Figure 17, the gas exhaust pipe can be installed on one side where the electrode leads are not located, but it can also be installed on the side where the electrode leads are located. Furthermore, if necessary, the gas exhaust pipe can be installed on multiple sides.

[0178] The present invention has been described in more detail above with reference to the drawings and embodiments. However, the configurations described in the drawings or embodiments described herein are merely one embodiment of the present invention and do not represent the entire technical concept of the present invention. It should be understood that there are various equivalents and modifications that can substitute for them at the time of filing this application. [Explanation of Symbols]

[0179] 100: Battery case 100A: Bottom pouch 100B: Top pouch 110: Battery section 110A: Battery parts in the lower pouch 110B: Battery parts in the top pouch C: Containment space C1: Battery compartment in the upper pouch C2: Battery compartment in the lower pouch 120: Gas collection unit 120A: Gas collection part of the lower pouch 120B: Gas collection part of the upper pouch 200: Electrode assembly 210: Jelly roll-shaped electrode assembly 221: Positive Tab 222: Positive lead 223: Insulation 231: Negative electrode tab 232: Negative lead 233: Insulation S1: Primary sealing section S2: Secondary sealing section S3: Third sealing section H1~H4: Degassing Hall 400, 400': stopper 410: First stopper 411: Through hole for connecting the second plug 420: Second stopper 500: Gas exhaust pipe 510: 1st pipe 511: Gas discharge channel 512: Upward movement restriction section 513: Downward movement restriction section 520: 2nd tube 521: Electrolyte injection passage 540: Opening / closing member T, T1, T2, T3, T4: Gas discharge and electrolyte injection mechanism 600: Injection tube 1000, 2000: Secondary battery

Claims

1. The battery case includes a battery section and a gas collection section communicating with the battery section. The battery section contains an electrode assembly, and the edges of the battery case, excluding one side of the gas collection section, are sealed. The steps include positioning a gas discharge pipe capable of both gas discharge and electrolyte injection into the open portion of the battery case on one side, sealing both the open portion and the gas discharge pipe to simultaneously fix the gas discharge pipe to the battery case and seal the battery case, The activation process for a battery comprising the battery section and the gas collection section includes the step of discharging gas generated inside the battery to the outside of the battery via the gas discharge pipe, A method for manufacturing a secondary battery, wherein the gas collection unit is removed after the step of discharging the gas.

2. The steps include: housing an electrode assembly in the battery section of a battery case, which includes a battery section and a gas collection section communicating with the battery section; and positioning a double-pipe gas discharge pipe having a gas discharge passage and an electrolyte injection passage on at least one open side of the gas collection section; The steps include sealing the entire edge of the battery case, including the aforementioned side, to simultaneously fix the gas discharge pipe to the battery case and seal the battery case, A method for manufacturing a secondary battery, comprising the step of discharging gas generated inside the battery to the outside of the battery via the gas discharge pipe when performing an activation process on a battery comprising the battery section and the gas collection section.

3. A method for manufacturing a secondary battery according to claim 1 or 2, further comprising a degassing step after the activation step, in which the remaining gas in the gas collection section is discharged to the outside of the battery through at least one of the degassing hole formed in the gas collection section and the gas discharge pipe.

4. A method for manufacturing a secondary battery according to claim 1 or 2, further comprising the step of replenishing the battery with electrolyte via the gas discharge pipe during the activation step.

5. The method for manufacturing a secondary battery according to claim 1, wherein the gas discharge pipe has a double-pipe structure comprising a gas discharge passage and an electrolyte injection passage.

6. The gas discharge pipe comprises a first stopper connected to the gas discharge passage and a second stopper connected to the electrolyte injection passage, A method for manufacturing a secondary battery according to claim 2, wherein at least one of the operations of discharging gas from the battery and injecting electrolyte into the battery is performed by connecting and disconnecting at least one of the first plug and the second plug to their respective corresponding passages.

7. The gas discharge pipe comprises a first stopper connected to the gas discharge passage and a second stopper connected to the electrolyte injection passage, A method for manufacturing a secondary battery according to claim 5, wherein at least one of the operations of discharging gas from the battery and injecting electrolyte into the battery is performed by connecting and disconnecting at least one of the first plug and the second plug to their respective corresponding passages.

8. A gas discharge pipe comprising a first hollow pipe having a gas discharge passage and open at both ends, a second hollow pipe having an electrolyte injection passage and open at both ends and positioned within the gas discharge passage, and a connecting member connecting the pipe wall of the first pipe and the pipe wall of the second pipe, A first plug is detachably coupled to the open upper part of the first pipe to seal the gas discharge passage, The device includes a second stopper that is detachably coupled to the open upper part of the second tube and seals the electrolyte injection passage, A gas discharge and electrolyte injection mechanism installed on at least one side of the battery case.

9. The gas discharge and electrolyte injection mechanism according to claim 8, wherein the connecting members connect the inner surface of the first pipe and the outer surface of the second pipe, and a plurality of such connecting members are provided at predetermined intervals along the edges of the first pipe and the second pipe.

10. The gas discharge and electrolyte injection mechanism according to claim 8, wherein the first stopper includes at least one of a sealing portion that covers the inlet of the gas discharge passage and an insertion portion that is inserted into the inlet.

11. The gas discharge and electrolyte injection mechanism according to claim 8, wherein the second stopper includes at least one of a sealing portion that covers the entrance to the electrolyte injection passage and an insertion portion that is inserted into the entrance.

12. The first plug includes a sealing portion that covers the entrance to the gas discharge passage and an insertion portion that is inserted into the entrance. The gas discharge and electrolyte injection mechanism according to claim 9, wherein a plurality of slots are formed along the edge of the insertion portion at predetermined intervals into which the connecting member is inserted.

13. The gas discharge and electrolyte injection mechanism according to claim 8, wherein the first stopper and the second stopper are detachably coupled to each other.

14. The first plug is provided with a through hole for connecting to the second plug, The gas discharge and electrolyte injection mechanism according to claim 13, wherein the second stopper is inserted into the through-hole for connecting the second stopper and connected to the first stopper.

15. The outer surface of the second plug and the inner surface of the through-hole for connecting the second plug are formed to interlock with each other, The coupling surface of the first stopper and the corresponding coupling surface of the open upper part of the first pipe are formed to interlock with each other. The gas discharge and electrolyte injection mechanism according to claim 14, wherein the coupling surface of the second stopper and the corresponding coupling surfaces of the open upper part of the second pipe have threads that interlock with each other.

16. The gas discharge and electrolyte injection mechanism according to claim 8, wherein an opening and closing mechanism is installed inside the first pipe that causes gas to flow only in the direction of the inlet of the gas discharge passage.

17. The opening and closing mechanism is An upward movement restricting portion and a downward movement restricting portion are formed to protrude at intervals along the inner circumferential surface of the first pipe, It includes an opening / closing member located between the upward movement restricting portion and the downward movement restricting portion, The gas discharge and electrolyte injection mechanism according to claim 16, wherein the opening / closing member moves between a shut-off position that contacts the downward movement restricting portion to block the downward movement of the gas and an allowable position that moves away from the downward movement restricting portion due to the upward pressure of the gas to allow the upward movement of the gas.

18. The gas discharge and electrolyte injection mechanism according to claim 17, wherein the opening and closing member is a ring-shaped member having an outer surface that contacts the inner surface of the first pipe and an inner surface that contacts the outer surface of the second pipe.

19. An electrode assembly comprising a positive electrode, a negative electrode, and a separator membrane disposed between the positive electrode and the negative electrode, A battery case comprising a battery section for housing the electrode assembly and a gas collection section communicating with the battery section, A gas discharge and electrolyte injection mechanism according to any one of claims 8 to 18, A secondary battery in which a portion of the first tube and the second tube are inserted into the battery case, and the gas discharge and electrolyte injection mechanism is installed in the battery case such that the inlet of the gas discharge passage and the inlet of the electrolyte injection passage protrude to the outside from one side of the battery case.

20. An electrode assembly comprising a positive electrode, a negative electrode, and a separator membrane disposed between the positive electrode and the negative electrode, A battery case housing the electrode assembly, A gas discharge and electrolyte injection mechanism according to any one of claims 8 to 18, A secondary battery in which a portion of the first tube and the second tube are inserted into the battery case, and the gas discharge and electrolyte injection mechanism is installed in the battery case such that the inlet of the gas discharge passage and the inlet of the electrolyte injection passage protrude to the outside from one side of the battery case.

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