Secondary battery and method for manufacturing secondary battery

Abstract

The present disclosure relates to a secondary battery and a method of manufacturing the same, and a problem to be solved is to provide a secondary battery in which an electrolyte supplied to the inside of the secondary battery can be uniformly distributed. To this end, in the present disclosure, there is provided a secondary battery comprising: an electrode assembly; and a case accommodating the electrode assembly, in which the case includes: an inlet portion receiving the electrolyte through the injection nozzle; and an outlet portion forming a passage through which some of the electrolyte flowing into the inlet portion is discharged to the outside of the case.

Description

[0001] This application claims priority to and the benefit of Korean Patent Application No. 10-2024-0045197, filed on April 3, 2024, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference. TECHNICAL FIELD

[0002] The disclosure relates to a secondary battery and a manufacturing method of a secondary battery. BACKGROUND

[0003] Unlike a primary battery that cannot be charged, a secondary battery is a battery that can be charged and discharged. A low-capacity secondary battery can be used for various portable small electronic devices such as a smart phone, a feature phone, a notebook computer, a digital camera, or a camcorder, and a high-capacity secondary battery is widely used as a power source for a motor driver such as a motor driver in a hybrid electric vehicle or an electric vehicle. A secondary battery includes an electrode assembly including a positive electrode and a negative electrode, a case that accommodates the electrode assembly, and an electrode terminal connected to the electrode assembly.

[0004] The above information disclosed in this BACKGROUND section is only for enhancing the understanding of the background of the invention, and therefore it can contain information that does not constitute prior art. SUMMARY

[0005] The disclosure relates to a secondary battery and a manufacturing method of a secondary battery in which an electrolyte supplied to the inside of the secondary battery can be uniformly distributed.

[0006] However, the technical problems to be solved in the disclosed embodiments are not limited to the above-mentioned technical problems, and other technical problems not mentioned herein will be clearly understood by those skilled in the art through the following description.

[0007] An exemplary secondary battery according to an embodiment of the disclosure to solve the technical problems can include an electrode assembly; and a case that accommodates the electrode assembly, wherein the case includes an inlet portion that receives an electrolyte through an injection nozzle, and an outlet portion that forms a passage through which some of the electrolyte flowing into the inlet portion is discharged to the outside of the case.

[0008] In some examples, the case can include a pouch.

[0009] In some examples, the outlet portion can be positioned diagonally opposite to the inlet portion.

[0010] In some examples, the case can include a first pouch directly mounted to a gas pocket of the case and having the inlet portion, and a second pouch extended from the first pouch and having the outlet portion.

[0011] In some examples, the gas pocket can be removed from the case after the operation of degassing the case is completed.

[0012] In some examples, the length of the first pocket in the width direction can be greater than the length of the second pocket in the width direction.

[0013] In some examples, the lengths of the gas pocket and the first pocket in the width direction can be equal to each other.

[0014] In some examples, the lead tab connected to the electrode assembly can protrude outward from the first pocket.

[0015] In some examples, the length of the first pocket in the length direction can be less than the length of the second pocket in the length direction.

[0016] In some examples, the length of the first pocket in the length direction can be equal to or greater than the length of the second pocket in the length direction.

[0017] In some examples, the lead tab connected to the electrode assembly can protrude outward from the second pocket.

[0018] In some examples, the inlet portion can be formed on an edge of the first pocket facing the gas pocket, and the outlet portion can be formed on an edge of the second pocket positioned diagonally to the inlet portion.

[0019] An example manufacturing method of a secondary battery according to an embodiment of the disclosure to solve the technical problem can include the steps of: forming an inlet portion and an outlet portion in a case accommodating an electrode assembly; opening the outlet portion by operating an outlet head; supplying an electrolyte to the inlet portion; and guiding the electrolyte to be discharged to the outside of the outlet portion in a state in which an outlet guide tube provided in an outlet guide portion is inserted into the inside of the outlet portion.

[0020] In some examples, the outlet head can be located on both sides of the outlet portion, and the outlet portion can be opened by suctioning the case with a suction pad in contact with the outside of the case.

[0021] In some examples, after the discharge of the electrolyte is completed, the manufacturing method can further include the steps of: separating the outlet guide portion from the outlet portion; and sealing the outlet portion with the outlet head.

[0022] In some examples, the outlet head can be located on both sides of the outlet portion, and the outlet portion can be sealed by heating the case with a heating pad in contact with the outside of the case.

[0023] In some examples, an outlet rod provided in the outlet guide portion can move inside the outlet guide tube, and can guide the electrolyte to be discharged to the outside of the outlet portion.

[0024] In some examples, the manufacturing method can further include a step of measuring the weight of the electrolyte discharged to the outside of the outlet portion while the discharge rod is lowered for the first time, and a step of lowering the discharge rod for the second time and discharging the electrolyte through the connection tube connected to the discharge guide tube.

[0025] In some examples, when the electrolyte is supplied to the inside of the case, the edges of the case other than the inlet portion and the outlet portion can be sealed.

[0026] In some examples, the outlet portion can be positioned diagonally opposite the inlet portion.

[0027] In some examples, the air bag directly mounted to the case can be in communication with the inlet portion, and the outlet portion can be positioned diagonally opposite the inlet portion.

[0028] According to the present disclosure, by forming a separate outlet portion for discharging electrolyte in the case of the secondary battery, the electrolyte supplied into the case can be uniformly distributed in a short period of time, thereby improving productivity.

[0029] However, the technical effects to be achieved in the disclosed embodiments are not limited to the above-mentioned technical effects, and the disclosure of those skilled in the art will clearly understand other technical effects not mentioned herein through the following description. BRIEF DESCRIPTION OF DRAWINGS

[0030] The following accompanying drawings attached to the present specification illustrate preferred embodiments of the present disclosure and, together with the detailed description of the present disclosure, serve to further understand the technical idea of the present disclosure, and therefore, the present disclosure should not be construed as being limited to matters described in these drawings.

[0031] Figure 1 is a perspective view of an exemplary secondary battery according to a first embodiment of the present disclosure.

[0032] Figure 2 is a planar cross-sectional view of a secondary battery according to a first embodiment of the present disclosure.

[0033] Figure 3 is a cross-sectional view illustrating a state in which an electrolyte is supplied to a secondary battery according to a first embodiment of the present disclosure.

[0034] Figure 4 and Figure 5 is a cross-sectional view illustrating the flow of an electrolyte inside a secondary battery according to a first embodiment of the present disclosure.

[0035] Figure 6 is a view illustrating a discharge head portion and a discharge guide portion according to a first embodiment of the present disclosure.

[0036] Figure 7is a front cross-sectional view showing a state in which the rod cap is raised according to the first embodiment of the present disclosure.

[0037] Figure 8 is a front cross-sectional view showing a state in which the rod cap is lowered and the electrolyte is lowered along the discharge guide tube according to the first embodiment of the present disclosure.

[0038] Figure 9 is a front cross-sectional view showing a state in which the electrolyte is recovered along the connection tube and the recovery tube according to the first embodiment of the present disclosure.

[0039] Figure 10 is a perspective view showing a discharge head according to the first embodiment of the present disclosure.

[0040] Figure 11 is a plan view showing the discharge head located at both sides of the case according to the first embodiment of the present disclosure.

[0041] Figure 12 is a front view showing the discharge head located at both sides of the case according to the first embodiment of the present disclosure.

[0042] Figure 13 is a plan view showing a state in which the case is moved by moving the suction pad according to the first embodiment of the present disclosure.

[0043] Figure 14 is a front view showing a state in which the case is sealed by the heating pad according to the first embodiment of the present disclosure.

[0044] Figure 15 is a cross-sectional view showing an inlet portion and an outlet portion formed in the case according to the first embodiment of the present disclosure.

[0045] Figure 16 is a cross-sectional view showing a state in which the inlet portion, the outlet portion, and the edge of the air bag are sealed according to the first embodiment of the present disclosure.

[0046] Figure 17 is a cross-sectional view showing a state in which the inlet portion and the outlet portion are formed in the case according to the second embodiment of the present disclosure.

[0047] Figure 18 is a cross-sectional view showing a state in which the inlet portion, the outlet portion, and the edge of the air bag are sealed according to the second embodiment of the present disclosure.

[0048] Figure 19 is a cross-sectional view showing a state in which the electrolyte flowing into the inlet portion moves to the outlet portion according to the third embodiment of the present disclosure.

[0049] Figure 20is a cross-sectional view showing a state in which the electrolyte flowing into the inlet portion moves to the outlet portions on both sides in the width direction according to the fourth embodiment of the present disclosure.

[0050] Figure 21A and Figure 21B is a perspective view showing a battery pack including an exemplary secondary battery according to the present disclosure.

[0051] Figure 22A is a perspective view showing a vehicle including an exemplary battery pack according to the present disclosure.

[0052] Figure 22B is a side view showing a vehicle including an exemplary battery pack according to the present disclosure. DETAILED DESCRIPTION

[0053] Hereinafter, the present disclosure will be described in detail. Before the following detailed description of the present disclosure, it should be noted that the terms and words used in the specification and claims are not to be interpreted as being limited to the conventional meanings or dictionary definitions, but are to be interpreted in a conceptually and broadly manner for the purpose of describing the present disclosure in the best possible manner. Therefore, the embodiments described in the specification and the configurations described in the accompanying drawings are merely the most preferred embodiments of the present disclosure, and do not represent all technical ideas of the present disclosure. It will be understood that, at the time of filing this application, various equivalents and modifications can exist in place of them. In addition, as used herein, the terms "include or comprise" and / or variations thereof when used in this specification, indicate the presence of the stated features, numbers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, numbers, steps, operations, elements, components, and / or groups thereof. In addition, when describing embodiments of the present disclosure, "may" and "may" can include "one or more embodiments of the present disclosure".

[0054] In addition, in order to better understand the invention, the drawings are not drawn to scale and the size of some components can be exaggerated. In addition, the same reference numerals can be assigned to the same components in different embodiments.

[0055] Referring to two objects as the same means that they are substantially the same. Accordingly, the phrase "substantially the same" can include a case where the same is considered to be a low level of deviation (e.g., a deviation within 5%) in the relevant art. In addition, when any parameter is referred to as being uniform in a given region, it can mean that the parameter is uniform from an average point of view.

[0056] It will be understood that, although the terms "first", "second", "third", and the like can be used herein to describe various elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms. These terms are used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Therefore, unless otherwise defined, a first element, component, region, layer or section described below could be termed a second element, component, region, layer or section without departing from the spirit and scope of the disclosure.

[0057] Throughout the specification, unless the context clearly indicates otherwise, each component can be singular or plural.

[0058] The arrangement of any component on the "upper (or lower) portion" or "upper (or lower) part" of a component means that the any component is placed in contact with the upper (or lower) surface of the component. In addition, it can mean that other components can be placed between the component and any components disposed on (or under) the component.

[0059] Furthermore, it will be understood that when an element is referred to as being "connected to", "coupled to" or "linked to" another element, the elements can be directly connected or coupled to each other, or there can be another intervening element between the elements, or the respective elements can be connected, coupled or linked to each other through another element.

[0060] Throughout the specification, unless otherwise defined, the expression "A and / or B" means A, B or A and B. That is, as used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items. Unless otherwise defined, the expression "C to D" means C or greater and D or less.

[0061] As used herein, the terms are used to describe embodiments of the disclosure and are not intended to limit the disclosure.

[0062] Figure 1 is a perspective view of an exemplary secondary battery 1 according to a first embodiment of the disclosure, and Figure 2 is a plan cross-sectional view of the secondary battery 1 according to the first embodiment of the disclosure. In the secondary battery 1 according to the disclosure, various modifications are possible within the technical idea of having an inlet portion 17 and an outlet portion 18 to cause the flow of the electrolyte 50. The secondary battery 1 according to the first embodiment of the disclosure includes a case 10, an electrode assembly 20, a lead tab 30, and an electrolyte 50 (see Figure 4 ). The gas bag 40 (see Figure 3connected to the case 10, the electrolyte 50 can be injected into the inside of the case 10. Also, the gas bag 40 is connected to the case 10 in a state in which the injection of the electrolyte 50 has been completed, to perform an operation of degassing the inside of the case 10. Also, after the degassing operation in the case 10 is completed, the gas bag 40 can be separated from the case 10.

[0063] The case 10 can be made of a soft member, and in a state in which the outlet portion 18 is opened by the discharge head portion 70 (see Figure 6 The electrolyte 50 can be discharged to the outlet portion 18 by means of the discharge guide portion 80 (see Figure 6

[0064] The case 10 that accommodates the electrode assembly 20 has a space formed therein, and within the technical idea of surrounding the electrode assembly 20, various modifications are feasible. The case 10 can include or be referred to as a pouch, a can, a housing, or an outer material. Also, the case 10 can include a metal such as steel, nickel-plated steel, a steel alloy, aluminum, an aluminum alloy, or a cold-rolled sheet for deep drawing (SPCE) or a laminate film constituting a pouch or plastic. When the case 10 is a pouch, it can be made of a soft film. The case 10 can be modified in various ways within the technical idea that the electrode assembly 20 and the electrolyte 50 are accommodated inside.

[0065] Figure 3 is a cross-sectional view showing a state in which the electrolyte 50 is supplied to the secondary battery 1 according to the first embodiment of the disclosure, and Figure 4 and Figure 5 are cross-sectional views showing the flow of the electrolyte 50 inside the secondary battery 1 according to the first embodiment of the disclosure. As Figure 3 to Figure 5 indicated in FIG. 1, the case 10 according to the first embodiment of the disclosure is a pouch, and can be installed in a state of being connected to the gas bag 40 for discharging gas. The case 10 according to the first embodiment of the disclosure communicates with the gas bag 40, and can include an inlet portion 17 that receives the electrolyte 50 through the injection nozzle 60 and an outlet portion 18 that forms a passage for discharging some of the electrolyte 50 flowing into the inlet portion 17 to the outside of the case 10. The case 10 according to the first embodiment of the disclosure can be formed of a pouch.

[0066] ​The case 10 according to the first embodiment of the present disclosure is directly mounted to the air bag 40, and can include a first pouch 12 having an inlet portion 17, and a second pouch 14 extending from the first pouch 12 and having an outlet portion 18. The first pouch 12 extends in a width direction X, and the second pouch 14 extends in a length direction Y. The length of the first pouch 12 in the width direction X can be longer than the length of the second pouch 14 in the width direction X. The first pouch 12 and the second pouch 14 can be integrally formed. The length of the first pouch 12 in the length direction Y can be shorter than the length of the second pouch 14 in the length direction Y.

[0067] The outlet portion 18 according to the first embodiment of the present disclosure can be positioned diagonally opposite to the inlet portion 17. Accordingly, the path for the electrolyte 50 supplied through the inlet portion 17 to the inside of the case 10 to reach the outlet portion 18 passing through the electrode assembly 20 located inside the case 10 increases, and thus the electrolyte 50 can be uniformly supplied to the inside of the case 10. The inlet portion 17 according to the first embodiment of the present disclosure is formed at an edge 16 of the first pouch 12 facing the air bag 40, and the outlet portion 18 is formed at an edge 16 of the second pouch 14 located in a diagonal direction of the inlet portion 17. The edge 16 of the case 10 serving as a pouch is sealed by heat fusion, and the portions in which the inlet portion 17 and the outlet portion 18 are formed are opened to become passages through which the electrolyte 50 moves. After the supply of the electrolyte 50 is completed, the outlet portion 18 can be sealed by heat fusion. The inlet portion 17 can also be modified in various ways including being sealed together with the outlet portion 18 or being sealed after the degassing operation is completed.

[0068] The air bag 40 is connected to an upper side of the first pouch 12, and the second pouch 14 can be directly mounted below the first pouch 12. In a state in which the edges 16 of the case 10 other than the inlet portion 17 and the outlet portion 18 are sealed, the injection nozzle 60 can be mounted in the inlet portion 17, and the discharge guide tube 87 described herein can be mounted in the outlet portion 18. The electrolyte 50 supplied to the inside of the case 10 through the injection nozzle 60 moves inside the case 10, and is then discharged to the outside of the case 10 through the discharge guide tube 87 connected to the outlet portion 18.

[0069] Since the inlet portion 17 and the outlet portion 18 are located in diagonally opposite directions, the movement path of the electrolyte 50 moving inside the case 10 is formed to be long, and the electrolyte 50 is uniformly distributed inside the case 10. In addition, the pressure of the inlet portion 17 through which the electrolyte 50 is supplied is higher than the pressure of the outlet portion 18 through which the electrolyte 50 is discharged. Accordingly, the electrolyte 50 flows from the inlet portion 17 toward the outlet portion 18 due to the pressure difference between the inlet portion 17 and the outlet portion 18.

[0070] The electrode assembly 20 can be accommodated inside the case 10 together with the electrolyte 50. The electrode assembly 20 can include or be referred to as an electrode group, an electrode body, or a pole core. The electrode assembly 20 can include a first electrode plate, a second electrode plate, and a separator between the first electrode plate and the second electrode plate, and can be wound in a cylindrical shape. In some examples, in the electrode assembly 20, the first electrode plate, the second electrode plate, and the separator can be stacked in a plate shape.

[0071] The first electrode plate can include a first substrate and a first active material layer on the first substrate. In the first substrate, a first uncoated portion in which the first active material layer is not positioned or a first tab can extend outward, and the first tab can be electrically connected to a positive electrode current collector. In the present disclosure, the first tab can be referred to as a first uncoated portion or a positive electrode substrate tab.

[0072] The second electrode plate can include a second substrate and a second active material layer on the second substrate. In the second substrate, a second uncoated portion in which the second active material layer is not positioned or a second tab can extend outward, and the second tab can be electrically connected to a negative electrode current collector. In some examples, the first tab and the second tab can extend in the same direction. In the present disclosure, the second tab can be referred to as a second uncoated portion or a negative electrode substrate tab.

[0073] The first electrode plate can serve as a positive electrode. In this case, the first substrate can be made of, for example, an aluminum foil, and the first active material layer can include, for example, a transition metal oxide. The second electrode plate can serve as a negative electrode. In this case, the second substrate can be made of, for example, a copper foil or a nickel foil, and the second active material layer can include, for example, graphite and / or silicon.

[0074] The separator can prevent a short circuit between the first electrode plate and the second electrode plate while allowing the movement of lithium ions. In some examples, the separator can be located on opposite sides of the first electrode plate, or can be located on opposite sides of the second electrode plate.

[0075] The lead tab 30 is electrically connected to the electrode assembly 20, and various modifications are feasible within the technical concept of protruding to the outside of the case 10. The lead tab 30 can be electrically connected to the first tab and the second tab. The lead tab 30 according to the first embodiment of the present disclosure can protrude outward from the first pouch 12.

[0076] Figure 15 is a cross-sectional view illustrating the inlet portion 17 and the outlet portion 18 formed in the case 10 according to the first embodiment of the present disclosure, and Figure 16 is a cross-sectional view illustrating a state in which the edges of the inlet portion 17, the outlet portion 18, and the gas pocket 40 are sealed according to the first embodiment of the present disclosure. As Figure 15 andFigure 16 As shown in FIG. 1, the gas bag 40 is directly mounted to the case 10 serving as a pouch. In some examples, the lengths of the gas bag 40 and the first pouch 12 in the width direction X can be equal to each other.

[0077] As shown in FIG. 1, the gas bag 40 is directly mounted to the case 10 serving as a pouch. In some examples, the lengths of the gas bag 40 and the first pouch 12 in the width direction X can be equal to each other. Figure 15 As shown in FIG. 1, the gas bag 40 is directly mounted to the case 10 serving as a pouch. In some examples, the lengths of the gas bag 40 and the first pouch 12 in the width direction X can be equal to each other. As shown in FIG. 1, the gas bag 40 is directly mounted to the case 10 serving as a pouch. In some examples, the lengths of the gas bag 40 and the first pouch 12 in the width direction X can be equal to each other.

[0078] The electrode assembly 20 can be accommodated inside the pouch together with the electrolyte 50. Here, the electrolyte 50 can include a lithium salt (such as LiPF6 or LiBF4) dissolved in an organic solvent such as ethylene carbonate (EC), propylene carbonate (PC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), or dimethyl carbonate (DMC).

[0079] The injection nozzle 60 can be mounted through the gas bag 40 and toward the inside of the case 10 through the inlet portion 17. The electrolyte 50 can be supplied to the inside of the case 10 through the injection nozzle 60, which can be a funnel-shaped pipe.

[0080] Figure 10 FIG. 2 is a perspective view showing the discharge head 70 according to the first embodiment of the present disclosure, Figure 11 FIG. 3 is a plan view showing the discharge head 70 located at both sides of the case 10 according to the first embodiment of the present disclosure, and Figure 12 FIG. 4 is a front view showing the discharge head 70 located at both sides of the case 10 according to the first embodiment of the present disclosure. The discharge head 70 is located at both sides of the width direction X of the case 10 and can move in a direction toward the case 10 or in a direction away from the case 10. The discharge head 70 can be used to open the outlet portion 18 of the case 10 serving as a pouch. In addition, the discharge head 70 heats and seals the outlet portion 18 or the case 10 surrounding the outlet portion 18, thereby preventing the electrolyte 50 from being discharged.

[0081] The discharge head 70 according to the first embodiment of the present disclosure includes a head body 72 , a suction pad 74 , a support rod 76 , and a heating pad 78 .

[0082] The head body 72 is installed in a shape facing the housing 10. The head body 72 can be modified in various ways within the technical concept of supporting the suction pad 74 and the heating pad 78. The head body 72 can have various shapes including a rectangular parallelepiped.

[0083] The suction pad 74 is installed in a plurality of positions along the length direction Y of the head body 72. Since the suction pad 74 includes a plurality of holes, the bag-shaped housing 10 can be moved by vacuum pressure. The suction pad 74 can be located on the underside of the head body 72, and the heating pad 78 can be located above the suction pad 74. The suction pad 74 can be attached to the underside of the bag by sucking air.

[0084] The support rods 76 are provided in the same number as the suction pads 74, and the support rods 76 are respectively connected to the suction pads 74. An air movement channel is provided inside each of the support rods 76. The support rods 76 are individually connected to the linear drive unit and thus move in a linear direction together with the suction pads 74.

[0085] The heating pad 78 is heated by supplying electricity and the bag is sealed by heat fusion. The heating pad 78 may have a rectangular shape or a cuboid shape.

[0086] Figure 13 1 is a plan view showing a state in which the housing 10 is moved by moving the suction pad 74 according to the first embodiment of the present disclosure. Figure 13 As shown in FIG, the housing 10 as a bag is attached to the suction pad 74 due to the vacuum pressure of the suction pad 74. In addition, the bag moves together with the suction pad 74 by the independent movement of the support rod 76. Pressure is generated due to air suction, and after the suction pad 74 is attached to the bag, the respective suction pads 74 retract differently to open the bag outlet portion 18. The suction pad 74 positioned in the center moves the most backward.

[0087] Figure 14 1 is a front view showing a state in which the housing 10 is sealed by the heating pad 78 according to the first embodiment of the present disclosure. Figure 14 As shown in FIG, after the electrolyte 50 is discharged, the bag is sealed by heat fusion in a state where the heating pad 78 is advanced toward the bag together with the head body 72 to contact the bag. The sealing of the bag is achieved by the heat of the heating pad 78.

[0088] Figure 6 is a diagram showing a discharge head 70 and a discharge guide 80 according to a first embodiment of the present disclosure, and Figure 7 1 is a front sectional view showing a state in which the rod cap 86 of the discharge guide 80 according to the first embodiment of the present disclosure is raised.Figure 6 and Figure 7 As shown in FIG, the discharge guide portion 80 can be modified in various ways within the technical concept of guiding the electrolyte 50 to be discharged through the outlet portion 18. In a state where the outlet portion 18 is opened by the operation of the discharge head 70, the discharge guide pipe 87 of the discharge guide portion 80 moves upward and moves inside the outlet portion 18. The discharge guide portion 80 according to the first embodiment of the present disclosure includes a discharge body 81, a discharge driver unit 82, a discharge guide pipe 87, a connecting pipe 88, and a recovery pipe 89.

[0089] The discharge body 81 is located below the housing 10 and can be moved up and down by a separate driving device. As the discharge body 81 moves upward, the discharge guide pipe 87 also moves in the vertical direction Z.

[0090] The discharge actuator unit 82 is mounted inside the discharge body 81 and can move the discharge rod 85 toward the outlet portion 18. The discharge actuator unit 82 according to the first embodiment of the present disclosure includes a cylinder 83, a piston 84, a discharge rod 85, and a rod cap 86. The cylinder 83 is located inside the discharge body 81, and the piston 84 is located inside the cylinder 83 and moves linearly in the vertical direction Z. The piston 84 can be moved by supplying hydraulic pressure. The discharge rod 85, connected to the piston 84, extends upward and moves in the vertical direction Z together with the piston 84. The rod cap 86 is mounted on the upper side of the discharge rod 85. A cylindrical discharge guide pipe 87 is located outside the discharge rod 85 and the rod cap 86. The discharge guide pipe 87 extends in the vertical direction Z. The discharge guide pipe 87 can be fixedly mounted on the discharge body 81. Therefore, the discharge guide pipe 87 and the discharge body 81 can be moved in the vertical direction Z by operation of a drive device (such as a cylinder). The inner diameter of the discharge guide pipe 87 can be equal to or larger than the outer diameter of the rod cap 86. Since a sensor for measuring weight is mounted on the rod cap 86, it is possible to measure the weight of the electrolyte 50 placed on the upper side of the rod cap 86. In a state where the outlet portion 18 is opened, the discharge guide pipe 87 is inserted into the outlet portion 18. The piston 84 and the rod cap 86 are also in a raised state.

[0091] Figure 8 8 is a front sectional view showing a state in which the rod cap 86 is lowered and the electrolyte 50 is lowered along the discharge guide tube 87 according to the first embodiment of the present disclosure. Figure 8 As shown in FIG, when the piston 84 is first lowered, the discharge rod 85 and the rod cap 86 are also lowered accordingly. The rod cap 86 stops at the upper side of the portion where the connecting pipe 88 is connected to the discharge guide pipe 87. The sensor provided in the rod cap 86 measures the weight of the electrolyte 50 contained in the discharge guide pipe 87 and transmits the measured value to the control unit.

[0092] Figure 9is a front cross-sectional view showing a state in which the electrolyte 50 is recovered along the connection tube 88 and the recovery duct 89 according to the first embodiment of the present disclosure. As shown in Figure 9 As shown in the middle, when the piston 84 is lowered for the second time, the discharge rod 85 and the rod cap 86 are also lowered for the second time. The rod cap 86 stops at the lower side of the portion in which the connection tube 88 is connected to the discharge guide tube 87. Thus, the electrolyte 50 that has been lowered along the rod cap 86 moves along the connection tube 88 connected to the discharge guide tube 87, and then moves to the outside of the discharge body 81 along the recovery duct 89 located below the connection tube 88.

[0093] The connection tube 88 communicates with the discharge guide tube 87, forming a passage through which the discharge of the electrolyte 50 is guided. The lower side of the connection tube 88 is connected to the recovery duct 89, which forms a conduit that causes the electrolyte 50 to be guided to the outside of the discharge body 81.

[0094] The manufacturing method of the secondary battery 1 according to the first embodiment of the present disclosure includes a step of forming the inlet portion 17 and the outlet portion 18 in the case 10 that accommodates the electrode assembly 20. The inlet portion 17 can be formed at the upper side of the case 10 that can be a pouch, and the outlet portion 18 can be formed at the lower side of the case 10.

[0095] In the present disclosure, a step of opening the outlet portion 18 by operating the discharge head 70 is included. Since the discharge head 70 opens the outlet portion 18 by opening the pouch, a passage through which the electrolyte 50 can be discharged is ensured. The discharge passage is ensured by inserting the discharge guide tube 87 into the opened outlet portion 18. The discharge head 70 is located at both sides of the outlet portion 18, and the outlet portion 18 can be opened by suctioning the case 10 with the suction pad 74 that is in contact with the outside of the case 10.

[0096] In the present disclosure, a step of supplying the electrolyte 50 to the inlet portion 17 and guiding the electrolyte 50 to be discharged to the outside of the outlet portion 18 in a state in which the discharge guide tube 87 provided in the discharge guide 80 is inserted into the inside of the outlet portion 18 is included. When the electrolyte 50 is supplied to the inside of the case 10, the edges of the case 10 other than the inlet portion 17 and the outlet portion 18 can be sealed. The outlet portion 18 can be positioned diagonally opposite to the inlet portion 17. In some examples, the air bag 40 directly mounted to the case 10 communicates with the inlet portion 17 to each other, and the outlet portion 18 can be positioned diagonally opposite to the inlet portion 17.

[0097] With the operation of injecting the electrolyte 50 into the inside of the case 10 consisting of the pouch through the inlet portion 17, the piston 84 moves backward to lower the rod cap 86. The discharge rod 85 provided in the discharge guide 80 moves inside the discharge guide tube 87 and guides the electrolyte 50 to be discharged to the outside of the outlet portion 18. Due to the lowering of the rod cap 86, the pressure inside the case 10 in which the outlet portion 18 is positioned is lowered, and thus the electrolyte 50 supplied to the inlet portion 17 is rapidly moved to the outlet portion 18. In a state in which the rod cap 86 stops above the connection portion between the connection tube 88 and the discharge guide tube 87, the weight of the discharged electrolyte 50 is measured. Since the weight of the discharged electrolyte 50 is detected, the additional amount of the electrolyte 50 supplied to the case 10 can be more accurately set.

[0098] After the discharge of the electrolyte 50 is completed, the manufacturing method can include a step of separating the discharge guide 80 from the outlet portion 18 and a step of sealing the outlet portion 18 by the discharge head 70. The discharge head 70 is positioned at both sides of the outlet portion 18, and the outlet portion 18 can be sealed by heating the case 10 by the heating pad 78 in contact with the outside of the case 10. After the supply of the electrolyte 50 is completed, the discharge head 70 moves forward to seal the case 10. The lower portion of the case 10, which can be the pouch, is sealed, and the supply of the electrolyte 50 is terminated.

[0099] With the piston 84 lowered again, the inlet of the connection tube 88 connected to the discharge guide tube 87 is opened, and thus the electrolyte 50 moves to the recovery pipe 89 through the connection tube 88. The discharged electrolyte 50 can be recovered.

[0100] As described above, in the present disclosure, by separately providing the outlet for the discharge of the electrolyte 50, the imbalance and partial accumulation of the electrolyte 50 inside the case 10 can be solved, and the electrolyte 50 can be guided to be rapidly and uniformly distributed inside the electrode assembly 20.

[0101] In addition, in the present disclosure, the inlet portion 17, which is the injection inlet of the electrolyte 50, is narrow so that the injection process is started at a specific position of the secondary battery 1. In addition, the outlet portion 18, which is the outlet for discharging the electrolyte 50, is formed at the opposite side of the inlet portion 17, so that the electrolyte 50 can be discharged.

[0102] Then, after the electrolyte 50 is injected, the discharge is performed so that the electrolyte 50 accumulated in the case 10 moves toward the outlet portion 18, and thus the electrolyte 50 can be uniformly impregnated in the electrode assembly 20. The discharge guide 80 is installed in the outlet portion 18 to guide the discharged electrolyte 50 to be discharged and to measure the weight of the discharged electrolyte 50.

[0103] In general, the electrolyte 50 accumulates at a specific location of the pouch, and the impregnation of the electrolyte 50 by diffusion is limited. However, in the present disclosure, a movement path of the electrolyte 50 leading to the inlet portion 17 and the outlet portion 18 is formed, and thus the impregnation of the electrolyte 50 can be performed uniformly and rapidly.

[0104] Figure 17 is a cross-sectional view illustrating a state in which the inlet portion 117 and the outlet portion 118 according to the second embodiment of the present disclosure are formed in the case 110. As Figure 17 As shown in FIG. 1, the secondary battery 3 according to the second embodiment of the present disclosure includes the case 110, the electrode assembly 120, the lead tab 130, and the gas bag 140. The secondary battery 3 according to the second embodiment of the present disclosure has the same functions as those in the first embodiment, and only the shape is different.

[0105] The case 110 according to the second embodiment of the present disclosure can be installed in a state of being connected to the gas bag 140 for discharging gas. The case 110 according to the second embodiment of the present disclosure can include an inlet portion 117 communicating with the gas bag 140 and receiving the electrolyte 50 through the injection nozzle 60, and an outlet portion 118 forming a passage through which some of the electrolyte 50 introduced into the inlet portion 117 is discharged to the outside of the case 110. The case 110 according to the second embodiment of the present disclosure can be formed as a pouch.

[0106] The case 110 according to the second embodiment of the present disclosure can include a first pouch 112 directly installed to the gas bag 140 and having the inlet portion 117, and a second pouch 114 extending from the first pouch 112 and having the outlet portion 118. The first pouch 112 extends in the width direction X, and the second pouch 114 extends in the length direction Y. The length of the first pouch 112 in the width direction X is greater than the length of the second pouch 114 in the width direction X. The length of the first pouch 112 in the length direction Y is greater than or equal to the length of the second pouch 114 in the length direction Y.

[0107] The outlet portion 118 according to the second embodiment of the present disclosure is positioned diagonally opposite to the inlet portion 117.

[0108] The lead tab 130 connected to the electrode assembly 120 can protrude outward from the second pouch 114. The lead tab 130 is installed at a bottom end of the second pouch 114 extending downward from the first pouch 112. The inlet portion 117 is formed at an upper side of the first pouch 112, and the outlet portion 118 is formed at a lower side of the second pouch 114 in a diagonally opposite direction of the inlet portion 117.

[0109] When the edge of the airbag 140 is not sealed, the inlet portion 117 and the outlet portion 118 formed in the housing 110 are in an open state. By supplying the electrolyte 50 through the inlet portion 117 and discharging some of the electrolyte 50 through the outlet portion 118, the electrolyte 50 in the housing 110 can be evenly distributed.

[0110] Figure 18 1 is a cross-sectional view showing a state in which the edges of the inlet portion 117, the outlet portion 118, and the airbag 140 are sealed according to the second embodiment of the present disclosure. Figure 18 As shown in FIG, after the supply of the electrolyte 50 is completed, the edge of the air bag 140 is sealed to form a second sealed edge 142. After the supply of the electrolyte 50 is completed, the outlet portion 118 is sealed. In addition, the inlet portion 117 may be sealed, or if necessary, the inlet portion 117 may not be sealed to form a channel connected to the air bag 140. The gas generated in the housing 110 moves to the air bag 140, and when the degassing operation of the housing 110 is completed, the inlet portion 117 is sealed and the air bag 140 is separated from the housing 110.

[0111] Figure 19 6 is a cross-sectional view illustrating a state in which the electrolyte 50 flowing into the inlet portion 617 moves to the outlet portion 618 according to the third embodiment of the present disclosure.

[0112] like Figure 19 As shown in FIG, a secondary battery 5 according to a third embodiment of the present disclosure includes a case 610, an electrode assembly 620, a lead tab 630, and an air bag 640. The secondary battery 5 according to the third embodiment of the present disclosure has the same functions as those in the first embodiment, and differs only in the portion forming a single pouch.

[0113] The housing 610 according to the third embodiment of the present disclosure can be installed in a state connected to the air bag 640 for exhausting gas. The housing 610 according to the third embodiment of the present disclosure may include an inlet portion 617 and an outlet portion 618, the inlet portion 617 being in communication with the air bag 640 and receiving the electrolyte 50 through the injection nozzle 60, and the outlet portion 618 forming a passage through which some of the electrolyte 50 introduced into the inlet portion 617 is exhausted to the outside of the housing 610. The housing 610 according to the third embodiment of the present disclosure may be formed of a bag.

[0114] The housing 610 according to the third embodiment of the present disclosure may be formed with a single space. For example, the housing 610 may have a quadrangular shape. The outlet portion 618 according to the third embodiment of the present disclosure may be positioned diagonally opposite to the inlet portion 617.

[0115] The lead tab 630 connected to the electrode assembly 620 can protrude laterally from the case 610. The inlet portion 617 is formed at the upper side of the case 610, and the outlet portion 618 is formed at the lower side of the case 610 diagonally opposite the inlet portion 617.

[0116] In a state in which the edge of the gas bag 640 is not sealed, the inlet portion 617 and the outlet portion 618 formed in the case 610 are in an open state. The operation of supplying the electrolyte 50 through the inlet portion 617 and discharging some of the electrolyte 50 through the outlet portion 618 causes the electrolyte 50 to be uniformly distributed in the case 610.

[0117] Figure 20 is a cross-sectional view showing a state in which the electrolyte 50 flowing into the inlet portion 717 moves to both sides of the outlet portion 718 in the width direction X according to the fourth embodiment of the disclosure. As Figure 20 As shown in FIG. 6, the large-sized secondary battery 7 can be provided with a plurality of outlet portions 718. When the outlet portion 718 is provided as a plurality (for example, a plurality of outlet portions 718 are provided), the speed at which the electrolyte 50 moves inside the case 710 can increase, and thus the time for the electrolyte 50 to be uniformly distributed in the electrode assembly 720 can be reduced.

[0118] The secondary battery 7 according to the fourth embodiment of the disclosure includes a case 710, an electrode assembly 720, a lead tab 730, and a gas bag 740. The secondary battery 7 according to the fourth embodiment of the disclosure has the same functions as those in the first embodiment, except that the portion forming a single pouch and the portion in which the outlet portion is provided as a plurality are different.

[0119] The case 710 according to the fourth embodiment of the disclosure can be installed in a state connected to the gas bag 740 for discharging gas. The case 710 according to the fourth embodiment of the disclosure is large-sized and communicates with the gas bag 740. The case 710 can include an inlet portion 717 that receives the electrolyte 50 through the injection nozzle 60, and an outlet portion 718 that forms a passage through which some of the electrolyte 50 introduced into the inlet portion 717 is discharged to the outside of the case 710. The case 710 according to the fourth embodiment of the disclosure can be formed as a pouch.

[0120] The case 710 according to the fourth embodiment of the disclosure can be formed with a single space of a large size. For example, the case 710 has a quadrangular shape. The outlet portion 718 according to the fourth embodiment of the disclosure can be positioned diagonally opposite the inlet portion 717. The inlet portion 717 can be located at the center of the upper side of the case 710, and the outlet portion 718 can be located at both sides of the lower portion of the case 710. The lead tab 730 connected to the electrode assembly 720 can protrude laterally from the case 710.

[0121] In a state in which the edge of the gas bag 740 is not sealed, the inlet portion 717 and the outlet portion 718 formed in the case 710 are in an open state. The operation of supplying the electrolyte 50 through the inlet portion 717 and discharging some of the electrolyte 50 through the outlet portion 718 causes the electrolyte 50 to be uniformly distributed in the case 710.

[0122] The electrode assembly 20, 120, 620, 720 of the present disclosure is described in more detail here.

[0123] As the positive electrode active material, a compound capable of reversibly intercalating / deintercalating lithium (e.g., a lithiated intercalation compound) can be used. For example, at least one of a composite oxide of lithium and a metal selected from cobalt, manganese, nickel, and combinations thereof can be used.

[0124] The composite oxide can be a lithium transition metal composite oxide, and examples thereof can include a lithium nickel-based oxide, a lithium cobalt-based oxide, a lithium manganese-based oxide, a lithium iron phosphate-based compound, a lithium nickel manganese-based oxide without cobalt, or combinations thereof.

[0125] As an example, a compound represented by any one of the following formulas can be used: Li a A 1-b X b O 2-c D c (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05); Li a Mn 2-b X b O 4-c D c (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05); Li a Ni 1-b-c Co b X c O 2-α D α (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.5, 0<α<2); Li a Ni 1-b- c Mn b X c O 2-α D α (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.5, 0<α<2); Li a Ni b Co c L 1 d G eO2 (0.90≤a≤1.8, 0≤b≤0.9, 0≤c≤0.5, 0≤d≤0.5, 0≤e≤0.1); Li a NiG b O2 (0.90≤a≤1.8, 0.001≤b≤0.1); Li a CoG b O2 (0.90≤a≤1.8, 0.001≤b≤0.1); Li a Mn 1-b G b O2 (0.90≤a≤1.8, 0.001≤b≤0.1); Li a Mn2G b O4 (0.90≤a≤1.8, 0.001≤b≤0.1); Li a Mn 1-g G g PO4 (0.90≤a≤1.8, 0≤g≤0.5); Li （3-f） Fe2(PO4)3 (0≤f≤2); Li a FePO4 (0.90≤a≤1.8).

[0126] In the above formula: A is Ni, Co, Mn, or a combination thereof; X is Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, a rare earth element, or a combination thereof; D is O, F, S, P, or a combination thereof; G is Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V, or a combination thereof; and L 1 is Mn, Al, or a combination thereof.

[0127] The positive electrode for a lithium secondary battery can include a current collector and a positive electrode active material layer formed on the current collector. The positive electrode active material layer can include a positive electrode active material and can further include a binder and / or a conductive material.

[0128] The content of the positive electrode active material is in the range of about 90 wt% to about 99 wt% based on 100 wt% of the positive electrode active material layer, and the content of the binder and the conductive material is in the range of about 0.5 wt% to about 5 wt% based on 100 wt% of the positive electrode active material layer, respectively.

[0129] The current collector can be aluminum (Al), but is not limited thereto.

[0130] The negative electrode active material can include a material capable of reversibly intercalating / deintercalating lithium ions, lithium metal, an alloy of lithium metal, a material capable of doping and dedoping lithium, or a transition metal oxide.

[0131] The material capable of reversibly intercalating / deintercalating lithium ions can be a carbon-based negative electrode active material, which can include, for example, crystalline carbon, amorphous carbon, or a combination thereof. Examples of the crystalline carbon can include graphite, such as natural graphite or artificial graphite, and examples of the amorphous carbon can include soft carbon, hard carbon, pitch carbide, meso-phase pitch carbide, sintered coke, etc.

[0132] A Si-based negative electrode active material or a Sn-based negative electrode active material can be used as a material capable of doping and dedoping lithium. The Si-based negative electrode active material can be silicon, a silicon-carbon composite, SiO x (0 < x < 2), a Si-based alloy, or a combination thereof.

[0133] The silicon-carbon composite can be a composite of silicon and amorphous carbon. According to an embodiment, the silicon-carbon composite can be in the form of silicon particles and amorphous carbon coated on the surface of the silicon particles.

[0134] The silicon-carbon composite can further include crystalline carbon. For example, the silicon-carbon composite can include a core including crystalline carbon and silicon particles, and an amorphous carbon coating layer on the surface of the core.

[0135] The negative electrode for a lithium secondary battery can include a current collector and a negative electrode active material layer disposed on the current collector. The negative electrode active material layer can include a negative electrode active material, and can further include a binder and / or a conductive material.

[0136] For example, the negative electrode active material layer can include about 90 wt% to about 99 wt% of the negative electrode active material, about 0.5 wt% to about 5 wt% of the binder, and about 0 wt% to about 5 wt% of the conductive material.

[0137] A non-aqueous binder, an aqueous binder, a dry binder, or a combination thereof can be used as the binder. When an aqueous binder is used as the negative electrode binder, a cellulose-based compound capable of imparting adhesiveness can be further included.

[0138] One selected from a copper foil, a nickel foil, a stainless steel foil, a titanium foil, a nickel foam, a copper foam, a conductive metal-coated polymer substrate, and a combination thereof can be used as the negative electrode current collector.

[0139] The electrolyte for a lithium secondary battery can include a non-aqueous organic solvent and a lithium salt.

[0140] The non-aqueous organic solvent serves as a medium through which ions involved in electrochemical reactions of the battery can move.

[0141] The non-aqueous organic solvent can be a carbonate-based solvent, an ester-based solvent, an ether-based solvent, a ketone-based solvent, an alcohol-based solvent, an aprotic solvent, and these can be used alone or in a combination of two or more.

[0142] In addition, when a carbonate-based solvent is used, a mixture of a cyclic carbonate and a chain carbonate can be used.

[0143] According to the type of the lithium secondary battery, a separator can be present between the first electrode plate (e.g., a negative electrode) and the second electrode plate (e.g., a positive electrode). A polyethylene, a polypropylene, a polyvinylidene fluoride, or a multi-layer film of two or more layers thereof can be used as the separator.

[0144] The separator can include a porous substrate and a coating layer including an organic material, an inorganic material, or a combination thereof on one or both surfaces of the porous substrate.

[0145] The organic material can include a polyvinylidene fluoride-based polymer or a (meth)acrylic polymer.

[0146] The inorganic material can include inorganic particles selected from the group consisting of Al2O3, SiO2, TiO2, SnO2, CeO2, MgO, NiO, CaO, GaO, ZnO, ZrO2, Y2O3, SrTiO3, BaTiO3, Mg(OH)2, boehmite, and combinations thereof, but is not limited thereto.

[0147] The organic material and the inorganic material can be mixed in one coating layer or can be in a form in which a coating layer including the organic material and a coating layer including the inorganic material are stacked on each other.

[0148] The secondary battery according to the above-described embodiments can be used to manufacture a battery pack.

[0149] Figure 21A and Figure 21B is a perspective view showing a battery pack 300 including exemplary secondary batteries according to the disclosure. Referring to Figure 21A and Figure 21B The battery pack 300 can include a plurality of battery modules 200 and a housing 310 for accommodating the plurality of battery modules 200. For example, the housing 310 can include a first housing 311 and a second housing 312 that are combined in directions facing each other, and the plurality of battery modules 200 are interposed between the first housing 311 and the second housing 312. The plurality of battery modules 200 can be electrically connected to each other using bus bars 251, and the plurality of battery modules 200 can be electrically connected in series / parallel or a mixed series-parallel manner to obtain a desired electrical output. In the drawings, components such as bus bars, cooling units, and external terminals for electrical connection of the battery cells are omitted for convenience. In some embodiments, the battery pack 300 can be installed on a vehicle. The vehicle can be, for example, an electric vehicle, a hybrid vehicle, or a plug-in hybrid vehicle. The vehicle can include both four-wheeled vehicles and two-wheeled vehicles.

[0150] Figure 22A and Figure 22B are perspective and side views, respectively, showing vehicles 400, 500 including example battery packs according to the present disclosure.

[0151] In Figure 22A , the battery pack 300 can include a battery pack cover 311, which is a part of a vehicle underbody 410 and can correspond to the first housing, and a pack frame 312, which is placed under the vehicle underbody 410 and can correspond to the second housing. The battery pack cover 311 and the pack frame 312 can be structurally integrated with a vehicle floor 420. The vehicle underbody 410 separates the inside and outside of the vehicle, and the pack frame 312 can be positioned at the outside of the vehicle.

[0152] As Figure 22B shown in the above, the vehicle 500 can be assembled with additional components such as an engine hood 510 in front of the vehicle body and fenders 520 located at the front and rear of the vehicle 500. The vehicle 500 includes the battery pack 300 including the battery pack cover 311 and the pack frame 312, and the battery pack 300 can be incorporated into the vehicle body part.

[0153] While the foregoing embodiment is merely one embodiment for implementing the present disclosure, the present disclosure is not limited to this embodiment, but it will be understood by those skilled in the art that various modifications and changes in form and details can be made therein within the equivalent scope of the technical idea of the present disclosure as defined by the appended claims.

Claims

1. A secondary battery, comprising: electrode assembly; as well as a housing accommodating the electrode assembly, The housing includes an inlet portion receiving the electrolyte through an injection nozzle, and an outlet portion forming a passage through which some of the electrolyte flowing into the inlet portion is discharged to the outside of the housing.

2. The secondary battery according to claim 1, wherein The housing includes a bag.

3. The secondary battery according to claim 1, wherein The outlet portion is positioned diagonally opposite the inlet portion.

4. The secondary battery according to claim 1, wherein The housing includes a first bag mounted directly to the airbag of the housing and having an inlet portion, and a second bag extending from the first bag and having an outlet portion, wherein the airbag is removed from the housing after the operation of degassing the housing is completed.

5. The secondary battery according to claim 4, wherein The length of the first bag in the width direction is greater than the length of the second bag in the width direction.

6. The secondary battery according to claim 4, wherein The airbag and the first bag have lengths in a width direction equal to each other.

7. The secondary battery according to claim 4, wherein Lead tabs connected to the electrode assembly protrude outward from the first pouch.

8. The secondary battery according to claim 4, wherein The length of the first bag in the longitudinal direction is smaller than the length of the second bag in the longitudinal direction.

9. The secondary battery according to claim 4, wherein The length of the first bag in the longitudinal direction is equal to or greater than the length of the second bag in the longitudinal direction.

10. The secondary battery according to claim 9, wherein Lead tabs connected to the electrode assembly protrude outward from the second pouch.

11. The secondary battery according to claim 9, wherein The inlet portion is formed on an edge of the first pocket facing the airbag, and the outlet portion is formed on an edge of the second pocket located diagonally from the inlet portion.

12. A method for manufacturing a secondary battery, comprising the following steps: forming an inlet portion and an outlet portion in a case accommodating the electrode assembly; opening the outlet portion by operating the discharge head; supplying an electrolyte to the inlet portion; as well as The electrolyte is guided to be discharged to the outside of the outlet portion in a state where a discharge guide pipe provided in the discharge guide portion is inserted into the inside of the outlet portion.

13. The manufacturing method according to claim 12, wherein: The discharge heads are located at both sides of the outlet portion, and the outlet portion is opened by adsorbing the housing by suction pads that are in contact with the outside of the housing.

14. The manufacturing method according to claim 12, further comprising: after the step of discharging the electrolyte is completed; a step of separating the discharge guide from the outlet portion; as well as The discharge head includes the step of sealing the outlet portion.

15. The manufacturing method according to claim 14, wherein: The discharge heads are located on both sides of the outlet portion, and the outlet portion is sealed by heating the housing with heating pads in contact with the exterior of the housing.

16. The manufacturing method according to claim 12, wherein: A discharge rod provided in the discharge guide portion moves inside the discharge guide pipe and guides the electrolyte to be discharged to the outside of the outlet portion.

17. The manufacturing method according to claim 16, further comprising: a step of measuring the weight of the electrolyte discharged to the outside of the outlet portion while the discharge rod is first lowered; as well as The discharge rod is lowered a second time and the electrolyte is discharged through the connection pipe connected to the discharge guide pipe.

18. The manufacturing method according to claim 12, wherein: When the electrolyte is supplied to the interior of the case, the edge of the case except for the inlet portion and the outlet portion is sealed.

19. The manufacturing method according to claim 12, wherein: The outlet portion is positioned diagonally opposite the inlet portion.

20. The manufacturing method according to claim 12, wherein: An air bag mounted directly to the housing communicates with the inlet portion, the outlet portion is positioned diagonally opposite the inlet portion, and the air bag is removed from the housing after the operation of degassing the housing is completed.

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