Pouch type secondary battery sealing method and pouch type secondary battery produced through this

Abstract

The present invention relates to a sealing method for a pouch-type secondary battery having a first pocket portion for housing an electrode assembly and a second pocket portion for gas collection, comprising: (a) a step of pressurizing and / or heating a first sealing portion located on both sides in the electric direction of the first pocket portion; and (b) a step of pressurizing and / or heating a second sealing portion located on both sides in the electric direction of the second pocket portion.

Description

Technology Field

[0001] The present invention relates to a sealing method for a pouch-type secondary battery and a pouch-type secondary battery manufactured thereby. More specifically, it relates to a sealing method for a pouch-type secondary battery that can prevent sealing defects caused by thermal deformation of a sealing tool by dividing the sealing area into multiple sections and sealing, and a pouch-type secondary battery manufactured thereby. Background Technology

[0003] With the increasing technological development and demand for mobile devices, rechargeable secondary batteries are being used as an energy source for various mobile devices. Secondary batteries are also attracting attention as an energy source for electric vehicles and hybrid electric vehicles, which are being presented as alternatives to conventional gasoline and diesel vehicles that use fossil fuels.

[0004] Secondary batteries are classified according to the shape of the battery case into cylindrical and prismatic batteries, in which the electrode assembly is embedded in a cylindrical or prismatic metal can, and pouch-type batteries, in which the electrode assembly is embedded in a pouch-type case made of aluminum laminate sheets.

[0005] A typical pouch-type secondary battery manufacturing process involves inserting an electrode assembly into a battery case housing made of a laminate sheet, injecting an electrolyte into the battery case, and then performing a sealing process.

[0006] FIG. 1 is a drawing showing a sealing device for a pouch-type secondary battery according to the prior art sealing the secondary battery, FIG. 2 is a drawing explaining the appearance of a bending phenomenon occurring in a sealing device for a pouch-type secondary battery according to the prior art, and FIG. 3 is a drawing showing a sealing area of ​​a pouch-type secondary battery according to the prior art.

[0007] Referring to FIGS. 1 to 3, a sealing device for a conventional pouch-type secondary battery includes an upper sealing tool (1) and a lower sealing tool (2) located at the upper and lower portions, respectively, of a battery case (12) that houses an electrode assembly (11). These upper sealing tool (1) and lower sealing tool (2) move in directions opposite to each other and apply a certain pressure and temperature to seal the sealing portion (S).

[0008] The upper sealing tool (1) may be configured to include a heating block (1a) in which a heating element (1b) is embedded, and a contact part (1c) coupled to the heating block (1a) to press and heat the upper part of the sealing part (S) by heat transferred from the heating element (1b), and the lower sealing tool (2) may be configured to include a heating block (2a) in which a heating element (2b) is embedded, and a contact part (2c) coupled to the heating block (2a) to press and heat the lower part of the sealing part (S) by heat transferred from the heating element (2b).

[0009] At this time, the contact portion (1c, 2c) is heated by the heating member (1b, 2b), and a bending phenomenon occurs in which the central portion is deformed convexly toward the outside due to thermal expansion. If a bending phenomenon occurs in the contact portion (1c, 2c), the sealing portion (S) of the battery case (12) cannot be heated and pressed evenly, resulting in a sealing defect.

[0010] In particular, as the full width direction length of the second pocket portion (12a), which is located on one side of the first pocket portion (12a) that accommodates the electrode assembly (11) and is provided for gas collection, increases, the length of the contact portion (1c, 2c) also increases. When the length of the contact portion (1c, 2c) increases, the bending phenomenon in which the central part is deformed convexly toward the outside due to thermal expansion becomes severe, and this can lead to serious sealing defects.

[0011] Of course, it is possible to reduce the bending phenomenon by using any one of the alloys of beryl copper alloy, aluminum beryllium alloy, and Inconel alloy for the material of the contact part (1c, 2c), but these alloys are expensive, so the manufacturing and maintenance costs of the device are high, and it is also difficult to completely prevent deformation of the sealing tool.

[0012] Additionally, the part where the electrode lead (13) protrudes from the battery case (12) has a step formed due to the thickness of the electrode lead (13) itself, and when sealing the sealing part (S) of the battery case (12) through the upper sealing tool (1) and the lower sealing tool (2), the part where the electrode lead (12) protrudes can be heat-fused between the battery case (12) and the electrode lead (13) due to the step, but the part where the electrode lead (12) does not overlap does not adhere to the sealing tool (1, 2), so a sealing defect may occur in which incomplete heat fusion is achieved. Prior art literature

[0014] Korean Published Patent Document No. 10-2023-0026860 The problem to be solved

[0015] In order to solve the above-mentioned problems, the present invention aims to provide a sealing method for a pouch-type secondary battery capable of minimizing sealing defects in a pouch-type secondary battery, and a pouch-type secondary battery manufactured thereby. means of solving the problem

[0017] As a technical means for achieving the above-mentioned purpose, a method for sealing a pouch-type secondary battery (10) having a first pocket portion (12a) for housing an electrode assembly (11) according to one embodiment of the present invention and a second pocket portion (12b) for gas collection comprises: (a) a step of pressurizing and / or heating a first sealing portion (S1) located on both sides of the electric direction of the first pocket portion (12a); and (b) a step of pressurizing and / or heating a second sealing portion (S2) located on both sides of the electric direction of the second pocket portion (12b).

[0018] In addition, a pouch-type secondary battery sealing method according to one embodiment of the present invention is characterized in that, in step (a), the first sealing portion (S1) is pressurized and / or heated through a first sealing tool (100) comprising a first sealing tool (110) disposed on one side of the first sealing portion (S1) and a first sealing tool (120) disposed on the other side of the first sealing portion (S1).

[0019] In addition, a pouch-type secondary battery sealing method according to one embodiment of the present invention is characterized in that, in step (a), the first sealing tool (110) and the first sealing tool (120) are arranged to come into contact with each other with the first sealing portion (S1) in between.

[0020] In addition, a pouch-type secondary battery sealing method according to one embodiment of the present invention is characterized by further including a step of positioning the first sealing portion (S1) between the first sealing tool (110) and the first sealing tool (120) prior to step (a).

[0021] In addition, a pouch-type secondary battery sealing method according to one embodiment of the present invention is characterized in that, in step (b), the second sealing part (S2) is pressurized and / or heated through the first sealing tool (100).

[0022] In addition, a pouch-type secondary battery sealing method according to one embodiment of the present invention further comprises, after step (a), a step of positioning the second sealing portion (S2) between the first sealing tool (110) and the first sealing tool (120) so that the first sealing tool (110) and the first sealing tool (120) are arranged to come into contact with each other with the second sealing portion (S2) in between.

[0023] In addition, a pouch-type secondary battery sealing method according to one embodiment of the present invention is characterized in that, in step (b), the second sealing portion (S2) is pressurized and / or heated through a second sealing tool (200) comprising a second sealing tool (210) disposed on one side of the second sealing portion (S2) and a second sealing tool (220) disposed on the other side of the second sealing portion (S2).

[0024] In addition, a pouch-type secondary battery sealing method according to one embodiment of the present invention is characterized by further including a step of positioning the second sealing part (S2) between the seconda sealing tool (210) and the secondb sealing tool (220) prior to step (b).

[0025] In addition, in a pouch-type secondary battery sealing method according to one embodiment of the present invention, the first sealing tool (110) and the second sealing tool (210) are characterized by being driven independently of each other.

[0026] In addition, in a pouch-type secondary battery sealing method according to one embodiment of the present invention, the first sealing tool (120) and the second sealing tool (220) are characterized by being driven independently of each other.

[0027] In addition, in a pouch-type secondary battery sealing method according to one embodiment of the present invention, in step (b), the second sealing part (S2) is pressed and / or heated so that one side of the first sealing part (S1) and the other side of the second sealing part (S2) come into contact.

[0028] In addition, in a pouch-type secondary battery sealing method according to one embodiment of the present invention, in step (b), the second sealing part (S2) is pressed and / or heated so that a part of one side of the first sealing part (S1) and a part of the other side of the second sealing part (S2) overlap.

[0029] In addition, a pouch-type secondary battery according to one embodiment of the present invention comprises: an electrode assembly (11) having a pair of electrode leads (13); and a battery case (12) having a first pocket portion (12a) that accommodates the electrode assembly (11), wherein at least a portion of the first sealing portion (S1) located on both sides in the electric direction of the first pocket portion (12a) has an overlapping sealing area formed by sealing multiple times.

[0030] In addition, in a pouch-type secondary battery according to one embodiment of the present invention, the battery case (12) is characterized by having a folding portion (12c) formed by folding a third sealing portion (S3) formed along the electric field direction toward the electrode assembly (11).

[0031] In addition, in a pouch-type secondary battery according to one embodiment of the present invention, the overlapping sealing region is provided in the folding portion (12c). Effects of the invention

[0033] As described above, according to the pouch-type secondary battery sealing method of the present invention and the pouch-type secondary battery manufactured thereby, by distinguishing the sealing area of ​​the first pocket portion and the sealing area of ​​the second pocket portion and performing sealing multiple times, sealing defects caused by thermal deformation of the sealing tool can be reduced.

[0034] In addition, according to the pouch-type secondary battery sealing method and the pouch-type secondary battery manufactured thereby, by distinguishing between the sealing area of ​​the first pocket portion where the electrode lead protrudes and the sealing area of ​​the second pocket portion and proceeding with sealing, a pressure corresponding to the sealing area of ​​the first pocket portion where the electrode lead protrudes is provided during the first sealing, and a pressure corresponding to the sealing area of ​​the second pocket portion is provided during the second sealing, thereby preventing sealing defects for each area. Brief explanation of the drawing

[0036] FIG. 1 is a drawing showing a sealing device for a pouch-type secondary battery according to the prior art sealing the secondary battery. Figure 2 is a drawing illustrating the appearance of a bending phenomenon occurring in a sealing device of a pouch-type secondary battery according to the prior art. FIG. 3 is a diagram showing the sealing area of ​​a pouch-type secondary battery according to the prior art. FIG. 4 is a drawing showing the sealing area of ​​a pouch-type secondary battery according to the first embodiment of the present invention. FIG. 5 is a drawing for explaining the primary sealing of a pouch-type secondary battery according to the first embodiment of the present invention. FIG. 6 is a drawing for explaining the secondary sealing of a pouch-type secondary battery according to the first embodiment of the present invention. FIG. 7 is a drawing showing the sealing area of ​​a pouch-type secondary battery according to a modified example of the first embodiment of the present invention. FIG. 8 is a drawing for explaining the primary sealing of a pouch-type secondary battery according to a modified example of the first embodiment of the present invention. FIG. 9 is a drawing for explaining the secondary sealing of a pouch-type secondary battery according to a modified example of the first embodiment of the present invention. FIG. 10 is a drawing illustrating the sealing of a pouch-type secondary battery according to a second embodiment of the present invention. FIG. 11 is a drawing for explaining the sealing of a pouch-type secondary battery according to a modified example of the second embodiment of the present invention. FIG. 12 is a plan view illustrating a pouch-type secondary battery manufactured by the pouch-type secondary battery sealing method according to the present invention. FIG. 13 is a perspective view illustrating a pouch-type secondary battery manufactured by the pouch-type secondary battery sealing method according to the present invention. Specific details for implementing the invention

[0037] Embodiments that enable a person skilled in the art to easily implement the present invention are described in detail below with reference to the attached drawings. However, in describing the operating principles of preferred embodiments of the present invention in detail, if it is determined that a detailed description of related known functions or configurations may unnecessarily obscure the essence of the present invention, such detailed description is omitted.

[0038] In addition, the same reference numerals are used for parts having similar functions and operations throughout the drawings. Throughout the specification, when a part is described as being connected to another part, this includes not only cases where they are directly connected, but also cases where they are indirectly connected with other elements in between. Furthermore, unless specifically stated otherwise, the inclusion of a certain component does not exclude other components but implies that additional components may be included.

[0040] Hereinafter, a pouch-type secondary battery sealing method according to the present invention and a pouch-type secondary battery manufactured thereby will be described.

[0041] FIG. 4 is a drawing showing the sealed appearance of a pouch-type secondary battery according to a first embodiment of the present invention. Referring to FIG. 1 and 4 together, the pouch-type secondary battery (10) is configured to include an electrode assembly (11) in which a pair of electrode leads (13) are positioned opposite each other, and a battery case (12) that houses the electrode assembly (11). At this time, the battery case (12) may be composed of a first pocket portion (12a) that houses the electrode assembly (11) and a second pocket portion (12b) for gas collection.

[0042] Here, the electrode assembly (11) may be a jelly-roll type electrode assembly formed by a structure in which a separator is interposed between a long sheet-type cathode and an anode and then wound, or a stack type electrode assembly composed of unit cells in which rectangular anodes and cathodes are stacked with a separator interposed between them, a stack-folding type electrode assembly in which unit cells are wound by a long separating film, or a lamination-stack type electrode assembly in which unit cells are stacked with a separator interposed between them and attached to each other, but is not limited thereto.

[0043] The positive electrode is composed of a positive current collector and a positive active material coated on the upper and lower surfaces of the positive current collector; the positive active material may be mixed with a conductive material and a binder, and a filler may be further added if necessary.

[0044] The cathode is composed of a cathode current collector and a cathode active material applied to the lower and upper surfaces of the cathode current collector, and a conductive material and a binder may be additionally mixed into the cathode active material and coated onto the cathode current collector.

[0045] The separator prevents a short circuit between the aforementioned cathode and anode and enables only the movement of lithium ions. The material of such a separator is preferably selected from polyethylene, polypropylene, a polyethylene / polypropylene double layer, a polyethylene / polypropylene / polyethylene triple layer, a polypropylene / polyethylene / polypropylene triple layer, and organic fiber filter paper, but is not limited thereto.

[0046] The battery case (12) can accommodate the electrode assembly (11) using a laminate sheet composed of an outer coating layer, a metal layer, and an inner coating layer.

[0047] Since the inner coating layer is in direct contact with the electrode assembly (11), it must have insulation and electrostatic resistance, and in order to seal it from the outside, the sealing portion where the inner layers are heat-bonded together must have excellent heat-bonding strength.

[0048] The metal layer in contact with the inner coating layer serves as a barrier layer that prevents moisture or various gases from penetrating into the battery from the outside, and a lightweight aluminum film with excellent formability can be used as a preferred material for this metal layer.

[0049] In addition, an outer coating layer is provided on the other side of the metal layer, and this outer coating layer may use a heat-resistant polymer with excellent tensile strength, moisture resistance, and air permeability resistance to ensure heat resistance and chemical resistance while protecting the electrode assembly, and may use, for example, nylon or polyethylene terephthalate, but is not limited thereto.

[0050] Additionally, a pair of electrode leads (13) may be provided as a positive electrode lead and a negative electrode lead.

[0051] Although a pair of electrode leads are facing each other in Fig. 4, it is obvious that they can be positioned parallel to each other in the same direction.

[0053] FIG. 5 is a drawing for explaining the primary sealing of a pouch-type secondary battery according to the first embodiment of the present invention, and FIG. 6 is a drawing for explaining the secondary sealing of a pouch-type secondary battery according to the first embodiment of the present invention.

[0054] Referring to FIGS. 4 to 6, a pouch-type secondary battery sealing method for sealing a pouch-type secondary battery (10) having the above-described configuration may include: (a) a step of pressurizing and / or heating a first sealing part (S1) located on both sides of the electric direction of a first pocket part (12a); and (b) a step of pressurizing and / or heating a second sealing part (S2) located on both sides of the electric direction of a second pocket part (12b). Here, the electric direction is the 3 o'clock to 9 o'clock direction with respect to FIG. 4.

[0055] First, in step (a), the first sealing portion (S1) may be pressurized and / or heated through a first sealing tool (100) comprising a firsta sealing tool (110) and a firstb sealing tool (120).

[0056] Here, the 1a sealing tool (110) may be placed on one side of the 1st sealing part (S1) (6 o'clock direction in Fig. 5), and the 1b sealing tool (120) may be placed on the other side of the 1st sealing part (S1) (12 o'clock direction in Fig. 5).

[0057] The first sealing tool (110) is provided to press and / or heat one side of the first sealing portion (S1), and the length of the first sealing tool (110) may be provided to be greater than the full width of the first pocket portion (12a) (in the 12 o'clock to 6 o'clock direction in FIG. 4). For example, the first sealing tool (110) may be provided with a length that is further extended by a preset length (e.g., 30 mm) from the other end of the first pocket portion (12a) (in the 6 o'clock direction in FIG. 4) from the position where the electrode assembly (11) is housed.

[0058] However, the length of the 1a sealing tool (110) is not limited to this, and may be provided with an extended length that allows all areas of the sealing part (S) to be sealed in two sealing steps when the 2nd sealing part (S2) is sealed after the 1st sealing part (S1) is sealed first.

[0059] Additionally, the 1a sealing tool (110) may have a heating element (not shown) embedded inside to apply pressure and / or heat to one side of the first sealing part (S1), and since this is obvious to those skilled in the art, a more detailed explanation will be omitted.

[0060] The first sealing tool (110) may include a first driving member (111) to be driven toward one side of the first sealing portion (S1), and the first driving member (111) may provide a forward movement that moves the first sealing tool (110) toward one side of the first sealing portion (S1) and a backward movement that moves the first sealing tool (110) away from one side of the first sealing portion (S1).

[0061] This first driving member (111) may be configured to include a cylinder and a rod. In this case, the cylinder provides a moving driving force through the rod, and the rod can transmit the received moving driving force to the first sealing tool (110) to move it.

[0062] Additionally, the firsta driving member (111) can drive the firsta sealing tool (110) so that the firsta sealing tool (110) is positioned toward one side of the second sealing part (S2) in step (b) after step (a).

[0063] The first sealing tool (120) is provided to pressurize and / or heat the other side of the first sealing portion (S1), and the length of the first sealing tool (120) may be provided to be greater than the full width of the first pocket portion (12a) (in the 12 o'clock to 6 o'clock direction in FIG. 4). For example, the first sealing tool (120) may be provided with a length that is further extended by a preset length (e.g., 30 mm) from the other end of the first pocket portion (12a) (in the 6 o'clock direction in FIG. 4) to the position where the electrode assembly (11) is housed.

[0064] However, the length of the 1b sealing tool (120) is not limited thereto, and it is preferable that it be provided with an extended length so that when the 2nd sealing part (S2) is sealed twice after the 1st sealing part (S1) is sealed once, all areas of the sealing part (S) can be sealed in two sealing steps. Also, the 1b sealing tool (120) may be provided to have a length corresponding to that of the 1a sealing tool (110).

[0065] Additionally, the 1b sealing tool (120) may have a heating element (not shown) embedded inside to apply pressure and / or heat to the other side of the 1st sealing part (S1). Since this is obvious to those skilled in the art, a more detailed explanation will be omitted.

[0066] The first sealing tool (120) may include a first driving member (121) to be driven toward one side of the first sealing part (S1), and the first driving member (121) may provide a forward movement to move toward the other side of the first sealing part (S1) and a backward movement to move away from the other side of the first sealing part (S1).

[0067] This first-b driving member (121) may be configured to include a cylinder and a rod. In this case, the cylinder provides a moving driving force through the rod, and the rod can transmit the received moving driving force to the first-b sealing tool (120) to move it.

[0068] Additionally, the first a driving member (111) and the first b driving member (121) in step (a) can provide a moving driving force to the first a sealing tool (110) and the first b sealing tool (120) so as to pressurize and / or heat the first sealing part (S1) with a pressing force corresponding to the first sealing part (S1).

[0069] Additionally, the first-b driving member (121) can drive the first-b sealing tool (120) so that the first-b sealing tool (120) is positioned toward the other side of the second sealing part (S2) in step (b) after step (a).

[0070] These firsta sealing tool (110) and firstb sealing tool (120) may include a step of positioning the first sealing part (S1) between the firsta sealing tool (110) and the firstb sealing tool (120) prior to step (a) so as to pressurize and / or heat the first sealing part (S1) in step (a).

[0071] Additionally, after step (a), the method may include a step of positioning the second sealing part (S2) between the firsta sealing tool (110) and the firstb sealing tool (120) so that the second sealing part (S2) is pressurized and / or heated through the first sealing tool (100). It is preferable that this step be performed after step (a) and before step (b).

[0072] More specifically, the firsta sealing tool (110) and the firstb sealing tool (120) are arranged to be in contact with each other with the first sealing part (S1) in between to pressurize and / or heat the first sealing part (S1) in step (a), and can be arranged to be in contact with each other with the second sealing part (S2) in between to pressurize and / or heat the second sealing part (S2) in step (b).

[0073] At this time, for example, the first sealing tool (110) and the first sealing tool (120) may pressurize and / or heat the first sealing part (S1) in step (a), and then, before proceeding to step (b), be moved to the second sealing part (S2) side by the first driving member (111) and the first driving member (121), respectively, to pressurize and / or heat the second sealing part (S2).

[0074] Additionally, as another example, the pouch-type secondary battery (10) can be moved so that after the first sealing part (S1) is pressed and / or heated by the firsta sealing tool (110) and the firstb sealing tool (120), the second sealing part (S2) is pressed and / or heated by the firsta sealing tool (110) and the firstb sealing tool (120).

[0075] Additionally, the first sealing tool (100) can pressurize and / or heat the second sealing part (S2) so that one side of the first sealing part (S1) (12 o'clock direction in FIG. 4) and the other side of the second sealing part (S2) (6 o'clock direction in FIG. 4) come into contact in step (b).

[0076] Here, one side of the first sealing part (S1) and the other side of the second sealing part (S2) do not overlap each other, and the first sealing part (S1) and the second sealing part (S2) can be made to come into contact with each other without any separation distance between them.

[0077] Additionally, the firsta driving member (111) and the firstb driving member (121) in step (b) can provide a moving driving force to the firsta sealing tool (110) and the firstb sealing tool (120) so as to pressurize and / or heat the second sealing part (S2) with a pressing force corresponding to the second sealing part (S2).

[0078] At this time, in steps (a) and (b), the first driving member (111) and the first driving member (121) can provide a driving force such that the driving amount of movement differs from each other due to the difference in sealing thickness between the first sealing part (S1) and the second sealing part (S2) (e.g., the difference due to the thickness of the electrode lead (13)), but the pressing force applied to the first sealing part (S1) and the second sealing part (S2) is the same.

[0079] Meanwhile, FIG. 7 is a drawing showing a sealing area of ​​a pouch-type secondary battery according to a modified example of the first embodiment of the present invention, FIG. 8 is a drawing for explaining the primary sealing of a pouch-type secondary battery according to a modified example of the first embodiment of the present invention, and FIG. 9 is a drawing for explaining the secondary sealing of a pouch-type secondary battery according to a modified example of the first embodiment of the present invention.

[0080] Referring to FIGS. 7 to 9 together, the first sealing tool (100) can pressurize and / or heat the second sealing part (S2) in step (b) such that a portion of one side (12 o'clock direction in FIG. 7) of the first sealing part (S1) and a portion of the other side (6 o'clock direction in FIG. 7) of the second sealing part (S2) overlap.

[0081] At this time, if there is a gap between one side of the first sealing part (S1) and the other side of the second sealing part (S2), an unsealed area may occur, so it is desirable for a part of one side of the first sealing part (S1) and a part of the other side of the second sealing part (S2) to overlap. In this area where the first sealing part (S1) and the second sealing part (S2) partially overlap, the sealing force is improved compared to other sealing parts (S), so that a more stable sealing process can be performed when proceeding with main sealing after the degassing process or when proceeding with pre-sealing for the degassing process.

[0083] FIG. 10 is a drawing illustrating the sealing of a pouch-type secondary battery according to a second embodiment of the present invention.

[0084] Referring to FIG. 4 and FIG. 10, a pouch-type secondary battery sealing method according to a second embodiment of the present invention comprises, in the same manner as a pouch-type secondary battery sealing method according to a first embodiment of the present invention, (a) a step of pressurizing and / or heating a first sealing part (S1) located on both sides in the electric direction of a first pocket part (12a), and (b) a step of pressurizing and / or heating a second sealing part (S2) located on both sides in the electric direction of a second pocket part (12b).

[0085] However, unlike the first embodiment, in the second embodiment, the second sealing part (S2) in step (b) can be pressurized and / or heated through a second sealing tool (200) including a second sealing tool (210) and a second sealing tool (220).

[0086] Here, the 2a sealing tool (210) may be placed on one side of the 2nd sealing part (S2) (6 o'clock direction in Fig. 10), and the 2b sealing tool (220) may be placed on the other side of the 2nd sealing part (S2) (12 o'clock direction in Fig. 10).

[0087] The second sealing tool (210) is provided to press and / or heat one side of the second sealing portion (S2), and the length of the second sealing tool (210) may be provided to be greater than the full width of the second pocket portion (12b) (in the 12 o'clock to 6 o'clock direction in FIG. 4). For example, the second sealing tool (210) may be provided with an extended length that allows the first sealing tool (100) to seal the first sealing portion (S1) and seal all areas of the second sealing portion (S2).

[0088] Additionally, the 2a sealing tool (210) may have a heating element (not shown) embedded inside to apply pressure and / or heat to one side of the second sealing part (S2), and since this is obvious to those skilled in the art, a more detailed explanation will be omitted.

[0089] The second sealing tool (210) may include a second driving member (211) to be driven toward one side of the second sealing part (S2), and the second driving member (211) may provide a forward movement that moves the second sealing tool (210) toward one side of the second sealing part (S2) and a backward movement that moves the second sealing tool (210) away from one side of the second sealing part (S2).

[0090] This seconda driving member (211) may be configured to include a cylinder and a rod. In this case, the cylinder provides a moving driving force through the rod, and the rod can transmit the received moving driving force to the seconda sealing tool (210) to move it.

[0091] Additionally, the 2a sealing tool (210) can be driven independently of the 1a sealing tool (110). That is, the 2a driving member (211) of the 2a sealing tool (210) is driven independently of the 1a driving member (111) of the 1a sealing tool (110).

[0092] Accordingly, the 2a sealing tool (210) can seal the 2nd sealing part (S2) by the 2a driving member (211) in step (b) after the 1a sealing tool (110) seals the 1st sealing part (S1) by the 1a driving member (111) in step (a).

[0093] The second sealing tool (220) is provided to pressurize and / or heat the other side of the second sealing portion (S2), and the length of the second sealing tool (220) may be provided to be greater than the full width of the second pocket portion (12b) (in the 12 o'clock to 6 o'clock direction according to FIG. 4). For example, it is preferable that the second sealing tool (220) be provided with an extended length that allows the first sealing tool (100) to seal the first sealing portion (S1) and seal all areas of the second sealing portion (S2). In addition, it is preferable that the second sealing tool (220) be provided to have a length corresponding to that of the second sealing tool (210).

[0094] Additionally, the 2b sealing tool (220) may have a heating element (not shown) embedded inside to apply pressure and / or heat to the other side of the 2nd sealing part (S2). Since this is obvious to those skilled in the art, a more detailed explanation will be omitted.

[0095] The second sealing tool (220) may include a second driving member (221) to be driven toward the other side of the second sealing part (S2), and the second driving member (221) may provide a forward movement that moves the second sealing tool (220) toward the other side of the second sealing part (S2) and a backward movement that moves the second sealing tool (220) away from the other side of the second sealing part (S2).

[0096] This secondb driving member (221) may be configured to include a cylinder and a rod. In this case, the cylinder provides a moving driving force through the rod, and the rod can transmit the received moving driving force to the secondb sealing tool (220) to move it.

[0097] Additionally, the 2b sealing tool (220) can be driven independently of the 1b sealing tool (120). That is, the 2b driving member (221) of the 2b sealing tool (220) is driven independently of the 1b driving member (121) of the 1b sealing tool (120).

[0098] Accordingly, the second sealing tool (220) can seal the second sealing part (S2) by the second sealing member (221) in step (b) after the first sealing tool (120) seals the first sealing part (S1) by the first sealing member (121) in step (a).

[0099] The method may include a step of positioning the second sealing part (S2) between the seconda sealing tool (210) and the secondb sealing tool (220) prior to step (b) so that the second sealing part (S2) is pressurized and / or heated through the seconda sealing tool (210) and the secondb sealing tool (220). For example, when the first sealing part (S1) is positioned between the firsta sealing tool (110) and the firstb sealing tool (120) prior to step (a), the second sealing part (S2) may be positioned between the seconda sealing tool (210) and the secondb sealing tool (220).

[0100] Accordingly, in step (a), the first sealing tool (110) and the first sealing tool (120) are arranged to be in contact with each other with the first sealing part (S1) in between so as to pressurize and / or heat the first sealing part (S1), and in step (b), the second sealing tool (210) and the second sealing tool (220) are arranged to be in contact with each other with the second sealing part (S2) in between so as to pressurize and / or heat the second sealing part (S2).

[0101] Additionally, in step (b), the second sealing tool (200) can pressurize and / or heat the second sealing part (S2) so that one side of the first sealing part (S1) (12 o'clock direction in FIG. 4) and the other side of the second sealing part (S2) (6 o'clock direction in FIG. 4) come into contact, and the second sealing tool (200) can be positioned so that its other side comes into contact with one side of the first sealing tool (100).

[0102] Additionally, the seconda driving member (211) and the secondb driving member (221) in step (b) can provide a moving driving force to the seconda sealing tool (210) and the secondb sealing tool (220) so as to pressurize and / or heat the second sealing part (S2) with a pressing force corresponding to the second sealing part (S2).

[0103] At this time, in steps (a) and (b), the first sealing tool (100) and the second sealing tool (200) may pressurize and / or heat the first sealing part (S1) and the second sealing part (S2) such that the amount of movement driven by the difference in sealing thickness between the first sealing part (S1) and the second sealing part (S2) (e.g., difference due to the thickness of the electrode lead (13)) is different from each other, but the pressure applied to the first sealing part (S1) and the second sealing part (S2) is the same.

[0105] FIG. 11 is a drawing for explaining the sealing of a pouch-type secondary battery according to a modified example of the second embodiment of the present invention.

[0106] Referring to FIG. 7 and FIG. 11 together, the second sealing tool (200) can pressurize and / or heat the second sealing part (S2) in step (b) such that a portion of one side (12 o'clock direction in FIG. 7) of the first sealing part (S1) and a portion of the other side (6 o'clock direction in FIG. 7) of the second sealing part (S2) overlap each other.

[0107] At this time, the other side of the second sealing tool (200) and one side of the first sealing tool (100) may be arranged in an overlapping state. In this case, the second sealing tool (200) may be arranged in a state avoided from the driving area of ​​the first sealing tool (100) so as not to interfere with the driving of the first sealing tool (100) when the first sealing tool (100) moves forward toward the first sealing part (S1) to pressurize and / or heat the first sealing part (S1) in step (a). Additionally, the first sealing tool (100) may be arranged in a state avoided from the driving area of ​​the second sealing tool (200) so as not to interfere with the driving of the second sealing tool (200) when the second sealing tool (200) moves forward toward the second sealing part (S2) to pressurize and / or heat the second sealing part (S2) in step (b).

[0108] These first sealing tool (100) and second sealing tool (200) can be driven by avoiding each other through a firsta driving member (111), a firstb driving member (121), a seconda driving member (211), and a secondb driving member (221) so as not to interfere with each other's driving.

[0110] A pouch-type secondary battery manufactured by the pouch-type secondary battery sealing method according to the present invention will be described.

[0111] FIG. 12 is a plan view for explaining a pouch-type secondary battery manufactured by the pouch-type secondary battery sealing method according to the present invention, and FIG. 13 is a perspective view for explaining a pouch-type secondary battery manufactured by the pouch-type secondary battery sealing method according to the present invention.

[0112] Referring to FIGS. 7 to 9 and FIGS. 11 to 13, the pouch-type secondary battery (10) comprises an electrode assembly (11) in which a pair of electrode leads (13) are positioned opposite each other, and a battery case (12) having a first pocket portion (12a) for housing the electrode assembly (11). Additionally, the pouch-type secondary battery (10) may further be provided with a first sealing portion (S1) located on both sides of the first pocket portion (12a) in the electric direction, and a third sealing portion (S3) formed by sealing along the electric direction of the pouch-type secondary battery (10) while the second pocket portion (12b) is partially removed by a degassing process.

[0113] At least a portion of the first sealing portion (S1) located on both sides in the full-length direction of the first pocket portion (12a) may have an overlapping sealing area formed by sealing multiple times.

[0114] The overlapping sealing area is formed by overlapping one side of the first sealing part (S1) (12 o'clock direction in FIG. 7) and the other side of the second sealing part (S2) (6 o'clock direction in FIG. 7) located on both sides of the full length direction of the second pocket part (12b) for gas collection, and this overlapping sealing area can be formed at one end of the first sealing part (S1).

[0115] These overlapping sealing regions may be provided in a folding portion (12c) formed by folding toward the electrode assembly (11) a third sealing portion (S3) formed along the electric direction of the pouch-type secondary battery (10).

[0116] In the sealing portion (S) formed in the width direction of the pouch-type secondary battery (10), not only is an overlapping sealing area formed by partially overlapping the first sealing portion (S1) and the second sealing portion (S2), but an overlapping sealing area formed by partially overlapping the second sealing portion (S2) and the third sealing portion (S3) may also be formed. Additionally, these two overlapping sealing areas may be folded and arranged in the folding portion (12c).

[0118] As specific parts of the present invention have been described in detail above, it is obvious to those skilled in the art that such specific descriptions are merely preferred embodiments and do not limit the scope of the invention, and that various changes and modifications are possible within the scope and spirit of the invention, and that such variations and modifications fall within the scope of the appended claims. Explanation of the symbols

[0119] 10: Pouch-type secondary battery 11: Electrode assembly 12: Battery case 12a: 1st pocket section 12b: Second pocket section 12c: Folding part 13: Electrode lead 100: 1st sealing tool 110: 1a Sealing Tool 111: 1a Driving member 120: Sealing tool 1b 121: 1b driving member 200: 2nd sealing tool 210: 2a Sealing Tool 211: 2a driving member 220: 2b Sealing Tool 221: 2b driving member S: Sealing part S1: 1st sealing part S2: Second sealing part S3: Third sealing part

Claims

Claim 1 A method for sealing a pouch-type secondary battery having a first pocket portion for housing an electrode assembly and a second pocket portion for gas collection, comprising: (a) a step of pressurizing and / or heating a first sealing portion located on both sides of the first pocket portion in the electric direction; and (b) a step of pressurizing and / or heating a second sealing portion located on both sides of the second pocket portion in the electric direction; characterized by comprising: a method for sealing a pouch-type secondary battery. Claim 2 A method for sealing a pouch-type secondary battery according to claim 1, wherein in step (a), the first sealing portion is pressurized and / or heated through a first sealing tool comprising a first sealing tool of type 1a disposed on one side of the first sealing portion and a first sealing tool of type 1b disposed on the other side of the first sealing portion. Claim 3 A pouch-type secondary battery sealing method according to claim 2, wherein in step (a), the first sealing tool of 1a and the first sealing tool of 1b are arranged to come into contact with each other with the first sealing portion in between. Claim 4 A pouch-type secondary battery sealing method according to claim 3, further comprising the step of positioning the first sealing portion between the firsta sealing tool and the firstb sealing tool prior to step (a). Claim 5 A pouch-type secondary battery sealing method according to claim 4, wherein in step (b) above, the second sealing portion is pressurized and / or heated through the first sealing tool. Claim 6 A pouch-type secondary battery sealing method according to claim 5, further comprising the step of positioning the second sealing portion between the first sealing tool a and the first sealing tool b after step (a), such that the first sealing tool a and the first sealing tool b are positioned to come into contact with each other with the second sealing portion in between. Claim 7 A method for sealing a pouch-type secondary battery according to claim 4, wherein in step (b), the second sealing portion is pressurized and / or heated through a second sealing tool comprising a second sealing tool (2a) disposed on one side of the second sealing portion and a second sealing tool (2b) disposed on the other side of the second sealing portion. Claim 8 A pouch-type secondary battery sealing method according to claim 7, further comprising the step of positioning the second sealing portion between the seconda sealing tool and the secondb sealing tool prior to step (b). Claim 9 A pouch-type secondary battery sealing method according to claim 7, characterized in that the sealing tool 1a and the sealing tool 2a are driven independently of each other. Claim 10 A pouch-type secondary battery sealing method according to claim 7, characterized in that the 1b sealing tool and the 2b sealing tool are driven independently of each other. Claim 11 A pouch-type secondary battery sealing method according to claim 2, wherein in step (b), the second sealing part is pressed and / or heated so that one side of the first sealing part and the other side of the second sealing part come into contact. Claim 12 A pouch-type secondary battery sealing method according to claim 2, wherein in step (b), the second sealing part is pressurized and / or heated so that a portion of one side of the first sealing part and a portion of the other side of the second sealing part overlap. Claim 13 A pouch-type secondary battery comprising: an electrode assembly having a pair of electrode leads; and a battery case having a first pocket portion for housing the electrode assembly, wherein at least a portion of a first sealing portion located on both sides in the electric direction of the first pocket portion has an overlapping sealing area formed by sealing multiple times. Claim 14 A pouch-type secondary battery according to claim 13, characterized in that the battery case is provided with a folding portion formed by folding a third sealing portion formed along the electric field direction toward the electrode assembly. Claim 15 A pouch-type secondary battery characterized in that, in claim 14, the overlapping sealing area is provided in the folding portion.

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