Pouch-type battery case, pouch-type secondary battery including the same, manufacturing method for pouch-type battery case, and molding jig for manufacturing pouch-type battery case

Abstract

A pouch-type battery case according to an embodiment of the present invention may include a storage section having a recessed shape, a folding section located on one side of the storage section, and a terrace section extending from a periphery of the storage section. The folding section may form a predetermined step with the terrace section on the outside in a direction perpendicular to a longitudinal direction of the folding section. The periphery of the storage section may include a first periphery to which the terrace section is connected, and a second periphery connecting both ends of the folding section to the terrace section, and the thickness of the second periphery may be thinner than the thickness of the first periphery.

Description

[Technical Field]

[0001] [CROSS-REFERENCE TO RELATED APPLICATIONS] This application claims the benefit of priority based on Korean Patent Application No. 10-2022-0053852 filed on April 29, 2022 and Korean Patent Application No. 10-2023-0056299 filed on April 28, 2023, and all contents disclosed in the documents of said Korean patent applications are incorporated herein by reference.

[0002] The present invention relates to a pouch-type battery case, a secondary battery including the same, a method for manufacturing the pouch-type battery case, and a molding jig for manufacturing the pouch-type battery case. [Background technology]

[0003] Common types of secondary batteries include nickel-cadmium batteries, nickel-metal hydride batteries, lithium-ion batteries, lithium-ion polymer batteries, etc. These secondary batteries are used not only in small products such as digital cameras, DVD players, MP3 players, mobile phones, PDAs (registered trademarks), portable game devices, power tools, and electric bicycles (E-bikes), but also in large products requiring high output such as electric vehicles and hybrid vehicles, as well as in power storage devices and backup power storage devices that store surplus generated power and renewable energy.

[0004] To manufacture an electrode assembly, a cathode, a separator, and an anode are fabricated and then stacked. Specifically, a cathode active material slurry is applied to a cathode current collector, and an anode active material slurry is applied to a cathode current collector to fabricate the cathode and anode. The fabricated cathode and anode are then stacked with a separator interposed between them to form a unit cell, and the unit cells are stacked together to form an electrode assembly. The electrode assembly is then housed in a specific case and filled with an electrolyte to fabricate a secondary battery.

[0005] These secondary batteries are classified into pouch types and can types depending on the material of the battery case that houses the electrode assembly. The pouch type houses the electrode assembly in a pouch made of a flexible polymer material with no fixed shape, while the can type houses the electrode assembly in a case made of a fixed material such as metal or plastic.

[0006] FIG. 1 is a front view of a conventional pouch-type secondary battery.

[0007] A conventional pouch-type secondary battery includes an electrode assembly and a pouch-type battery case 1 that houses the electrode assembly. The pouch-type battery case 1 is manufactured by drawing a flexible pouch film to form a housing portion 2. This drawing is performed by inserting the pouch film into a press and applying pressure to the pouch film with a punch to stretch the pouch film. Once the housing portion 2 is formed, an electrode assembly is placed in the housing space of the housing portion 2, and the pouch-type battery case 1 is folded and the terrace portion 4 is sealed to manufacture a secondary battery.

[0008] Furthermore, when the battery case 1 is folded, a folding portion 3 formed on one side of the storage portion 2 forms one corner of the secondary battery, and there is no need to seal the folding portion 3. Therefore, since there is no need to seal all four corners of the secondary battery, the speed of the sealing process can be improved and the number of trimming processes can be reduced.

[0009] However, in the case of a conventional secondary battery, the folded portion of the terrace portion 4 protrudes outward beyond the folded portion 3, and this may be named a bat ear 5.

[0010] Such bud ears 5 occupy unnecessary volume, which makes it difficult to assemble the secondary battery 1a into a battery module, etc., and reduces the energy density relative to the volume of the secondary battery.In addition, this also reduces the appearance quality of the pouch-type battery case 1. Summary of the Invention [Problem to be solved by the invention]

[0011] An object of the present invention is to provide a pouch-type battery case having improved appearance quality and free from bud ears, and a pouch-type secondary battery including the same.

[0012] Another object of the present invention is to provide a method for manufacturing the pouch-type battery case and a molding jig used therein. [Means for solving the problem]

[0013] A pouch-type battery case according to an embodiment of the present invention may include a recessed storage compartment; a folding section located on one side of the storage compartment; and a terrace section extending from a periphery of the storage compartment. The folding section may form a predetermined step with the terrace section on the outside in a direction perpendicular to the longitudinal direction of the folding section. The periphery of the storage compartment may include a first peripheral section to which the terrace section is connected; and a second peripheral section connecting both ends of the folding section to the terrace section. The thickness of the second peripheral section may be thinner than the thickness of the first peripheral section.

[0014] Of the four corners of the storage section, one pair may be located on the first peripheral edge portion, and the other pair may be located on the second peripheral edge portion.

[0015] The folded portion can be unfolded tightly.

[0016] A pouch-type secondary battery according to an embodiment of the present invention may include an electrode assembly and a pouch-type battery case. The pouch-type battery case may include a storage section that houses the electrode assembly; a folding section located on one side of the electrode assembly; and a terrace section extending from a periphery of the storage section. The folding section may form a predetermined step with the terrace section on the outside in a direction perpendicular to the longitudinal direction of the folding section. The periphery of the storage section may include a first peripheral section to which the terrace section is connected; and a second peripheral section that connects both ends of the folding section to the terrace section. The thickness of the second peripheral section may be thinner than the thickness of the first peripheral section.

[0017] A method for manufacturing a pouch-type battery case according to an embodiment of the present invention may include the steps of: forming a storage portion in a pouch film; folding a fold portion of the pouch film; inserting a forming jig into the storage portion; and using the forming jig to pressurize the fold portion outward so that the width or length of the storage portion increases.

[0018] The step of inserting the forming jig into the storage portion may include the steps of: spreading the folding portion so that one portion of the pouch film and another portion form a predetermined angle; inserting the forming jig between the one portion of the pouch film and another portion; and folding the folding portion.

[0019] The method for manufacturing the pouch-type battery case may further include removing the molding jig from the receiving portion.

[0020] A forming jig according to an embodiment of the present invention may be used to manufacture a pouch-type battery case having a folding portion on one side of a receiving portion. The forming jig may include a jig body inserted into the receiving portion and pressing the folding portion; and a protrusion connected to the jig body, protruding outward from the receiving portion, and having a thickness thinner than the jig body.

[0021] The pressure direction of the jig body may be perpendicular to the longitudinal direction of the folding portion.

[0022] The length of the jig body may correspond to the length of the folding portion.

[0023] The thickness of the jig body may correspond to the total depth of the recess or to the sum of the total depth of the recess and the thickness of the protrusion.

[0024] The protrusion may protrude from the jig body in a direction away from the folding portion.

[0025] The protrusions may be coupled to a drive that provides linear power to the forming jig. [Effects of the Invention]

[0026] According to a preferred embodiment of the present invention, unlike conventional secondary batteries, no bat-ears are formed, so the energy density of the secondary battery can be increased and the appearance quality can be improved.

[0027] Furthermore, since no bat-ears are formed, when a battery module including a plurality of secondary batteries is manufactured, the degree of alignment between the plurality of secondary batteries can be improved.

[0028] Other effects may also be included that can be easily predicted by a person skilled in the art from the configuration according to the preferred embodiment of the present invention. [Brief explanation of the drawings]

[0029] The following drawings attached to this specification illustrate preferred embodiments of the present invention and, together with the detailed description of the invention to be given later, serve to further understand the technical concept of the present invention. Therefore, the present invention should not be interpreted as being limited solely to the matters depicted in such drawings.

[0030] [Figure 1] FIG. 1 is a front view of a conventional pouch-type secondary battery. [Figure 2] 1 is a flowchart illustrating a method for manufacturing a pouch-type battery case according to an embodiment of the present invention. [Figure 3]FIG. 2 is a perspective view of a pouch film in which a storage section is formed. [Figure 4] 1 is a side view illustrating a method for manufacturing a pouch-type battery case according to an embodiment of the present invention. [Figure 5] 1 is a side view illustrating a method for manufacturing a pouch-type battery case according to an embodiment of the present invention. [Figure 6] 1 is a side view illustrating a method for manufacturing a pouch-type battery case according to an embodiment of the present invention. [Figure 7] 1 is a side view illustrating a method for manufacturing a pouch-type battery case according to an embodiment of the present invention. [Figure 8] 1 is a side view illustrating a method for manufacturing a pouch-type battery case according to an embodiment of the present invention. [Figure 9] FIG. 9 is a front view of the molding jig shown in FIGS. 4 to 8. [Figure 10] FIG. 4 is a front view of a pouch-type secondary battery according to another embodiment of the present invention. [Figure 11] FIG. 11 is a cross-sectional view showing the inside of the storage section shown in FIG. 10. DETAILED DESCRIPTION OF THE INVENTION

[0031] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] The present invention will now be described in detail with reference to the accompanying drawings, so that those skilled in the art can easily understand the preferred embodiments of the present invention. However, the present invention may be embodied in various different forms and should not be construed as being limited to the following embodiments.

[0032] In order to clearly explain the present invention, detailed descriptions of parts that are not relevant to the explanation or of related known technologies that may obscure the gist of the present invention will be omitted, and in this specification, when adding reference symbols to components in each drawing, the same or similar reference symbols will be used throughout the specification for the same or similar components.

[0033] Furthermore, the terms and words used in this specification and claims should not be interpreted in a way that is limited to their ordinary and dictionary meanings, but should be interpreted in a way that is consistent with the technical idea of ​​the present invention, in accordance with the principle that the inventor himself / herself can appropriately define the concept of a term in order to explain the invention in the best possible way.

[0034] FIG. 2 is a flow chart of a method for manufacturing a pouch-type battery case according to one embodiment of the present invention, FIG. 3 is a perspective view of a pouch film in which a storage section has been formed, FIGS. 4 to 8 are side views for explaining a method for manufacturing a pouch-type battery case according to one embodiment of the present invention, and FIG. 9 is a front view of the forming jig shown in FIGS. 4 to 8.

[0035] A manufacturing method of a pouch-type battery case according to one embodiment of the present invention (hereinafter referred to as the "manufacturing method") may include a step (S10) of forming a storage portion 110 in a pouch film 100, a step (S20) of folding a folding portion 130 of the pouch film 100, a step (S30) of inserting a forming jig 300 into the storage portion 110, and a step (S40) of the forming jig 300 pressing the folding portion 130 outward.

[0036] The step (S10) of forming the receiving portion 110 in the pouch film 100 may be performed using a press device. The press device may include a die having a forming groove formed therein and a punch facing the forming groove. With the pouch film 100 positioned between the die and the punch, the punch may pressurize and stretch a portion of the pouch film 100, and insert the stretched portion into the forming groove. Thus, the pouch film 100 may be formed with a receiving portion 110 recessed to correspond to the shape of the forming groove. The receiving portion 110 may form a receiving space for receiving an electrode assembly. The configuration and operation of such a press device are well known in the art and can be easily understood by those skilled in the art.

[0037] The pouch film 100 may be a laminate sheet including a first resin layer, a metal layer, and a second resin layer. For example, the first resin layer may include polypropylene (PP) or polyethylene (PE), the metal layer may include aluminum (AL), and the second resin layer may include polyethylene terephthalate (PET).

[0038] 3, the receiving portion 110 formed in the pouch film 100 may have a recessed shape. A pair of the receiving portions 110 may be provided, connected by a folding portion 130. The pair of receiving portions 110 may have the same depth, but is not limited thereto.

[0039] The pair of storage units 110 may be located on both sides of the folding unit 130. Hereinafter, as shown in Fig. 3, a case where the folding unit 130 extends parallel to the length of the storage unit 110 will be described as an example. However, this is not limited thereto, and the folding unit 130 may extend parallel to the width of the storage unit 110.

[0040] In the pouch film 100, the region where the storage section 110 is not formed may form a terrace section 120. The terrace section 120 may be connected to the periphery of the storage section 110 and have a shape that extends from the periphery of the storage section 110.

[0041] The pouch film 100 may be divided into a first section 101 and a second section 102 based on a line parallel to the folding section 130. The first section 101 may be a part of the pouch film 100, and the second section 102 may be another part of the pouch film 100. The first section 101 and the second section 102 may each include a storage section 110 and a terrace section 120.

[0042] However, this is not limited to this, and only one storage section 110 may be formed in the pouch film 110. In this case, either the first section 101 or the second section 102 may include the storage section 110 and the terrace section 120, and the other may be formed flat.

[0043] Thereafter, the folding portion 130 of the pouch film 100 may be folded (S20). More specifically, the folding portion 130 may be folded so that the first portion 101 and the second portion 102 are close to each other. The step of folding the folding portion 130 (S20) may be performed by a folding device, and the configuration and operation of the folding device are well known in the art, so a detailed description thereof will be omitted.

[0044] When the folding section 130 is fully folded, the storage section 110 of the first section 101 and the storage section 110 of the second section 102 can face each other, and the terrace section 120 of the first section 101 and the terrace section 120 of the second section 102 can abut each other.

[0045] If only a single storage section 110 is formed in the pouch film 110, when the folding section 130 is fully folded, one of the first section 101 and the second section 102 that does not include the storage section 110 may cover the storage section 110 and terrace section 120 of the other of the first section 101 and the second section 102.

[0046] Before describing the step (S30) of inserting the forming jig 300 into the storage section 110 and the step (S40) of the forming jig 300 pressing the folding section 130 outward, the forming jig 300 according to an embodiment of the present invention will be described with reference to Figures 4 to 9.

[0047] The forming jig 300 according to an embodiment of the present invention may include a jig body 310 that is inserted into the storage portion 110 and presses the folding portion 130, and a protrusion 320 that is connected to the jig body 310 and protrudes outside the storage portion 110.

[0048] The jig body 310 may press the folding unit 130 and its surrounding area outward inside the storage unit 110. The surrounding area may be a portion of the inner periphery of the storage unit 110 that is connected to the folding unit 130. That is, the jig body 310 may press the portion of the inner periphery of the storage unit 110 that is connected to the folding unit 130 together with the folding unit 130.

[0049] The pressure direction of the jig body 310 may be perpendicular to the longitudinal direction of the folding unit 130. That is, the jig body 310 may pressurize the folding unit 130 and its surrounding area in the direction opposite to the z-axis shown in the drawings. For example, the pressure direction of the jig body 310 may be parallel to the width direction of the storage unit 110.

[0050] The jig body 310 may extend parallel to the folding portion 130. The length of the jig body 310 may be parallel to the y-axis shown in the drawings.

[0051] The length (L1) of the jig body 310 (see FIG. 9) may correspond to the length (L) of the folding unit 130 (see FIG. 3). The length (L1) of the jig body 310 may be the same as or slightly shorter than the length (L) of the folding unit 130. Therefore, the jig body 310 can apply uniform pressure to the entire folding unit 130 and its surrounding area.

[0052] When the folding unit 130 is folded, the jig body 310 may have a predetermined thickness in the depth direction of the storage unit 110. That is, the thickness of the jig body 310 may be parallel to the x-axis shown in the drawing.

[0053] Thickness of jig body 310 ( t1 ) (see FIG. 4) may correspond to the total depth of the storage section 110. That is, the thickness ( t1 ) may be the same as or similar to the overall depth of the receptacle 110. For example, the thickness ( t1 ) may correspond to the sum of the depth (d1) of the storage portion 110 of the first portion 101 and the depth (d2) of the storage portion 110 of the second portion 102. t1) may be the same as or similar to the total depth of the receptacle 110.

[0054] Preferably, the thickness of the jig body 310 ( t1 ) is the total depth of the storage section 110 plus the thickness ( t2 ) may correspond to the combined value of the thickness of the jig body 310 ( t1 ) is the total depth of the storage section 110 plus the thickness ( t2 ) may be the same as or similar to the combined thickness of the jig body 310. t1 ) is the depth (d1) of the storage section 110 of the first section 101, the depth (d2) of the storage section 110 of the second section 102, and the thickness ( t2 ) can be considered as the sum of

[0055] As shown in FIG. 6, when the jig body 310 is pressed, the first part 101 and the second part 102 of the pouch film 100 are formed to the thickness ( t2 ) and does not adhere completely.

[0056] Therefore, the jig body 310 can apply pressure to the folded portion 130 and its surrounding area more uniformly overall.

[0057] The protrusion 320 may protrude from the jig body 310. More specifically, the protrusion 320 may protrude from the jig body 310 in a direction away from the folding portion 130.

[0058] When the jig body 310 is housed in the housing portion 110, the protruding portion 320 may extend outward through between the first portion 101 and the second portion 102 of the pouch film 100.

[0059] The protrusion 320 may be formed integrally with the jig body 310, but is not limited to this.

[0060] The protrusions 320 may be connected to a drive unit (not shown) that provides linear power to the forming jig 300. For example, the drive unit may include a linear actuator. Thus, the drive unit can move the forming jig 300 and apply pressure to the jig body 310 via the protrusions 320.

[0061] The thickness of the protrusion 320 ( t2 ) is the thickness of the jig body 310 ( t1 ) Therefore, when the folding portion 130 of the pouch film 100 is folded, the protruding portion 320 can smoothly extend into the narrow gap between the first portion 101 and the second portion 102.

[0062] Based on the description of the forming jig 300, the step of inserting the forming jig 300 into the receiving part 110 (S30) and the step of the forming jig 300 pressing the folding part 130 outward (S40) will be described below.

[0063] The step (S30) of inserting the forming jig 300 into the storage section 110 may include a process of spreading the folding section 130 so that the first part 101 and the second part 102 of the pouch film 100 form a predetermined angle (FIG. 4), a process of inserting the forming jig 300 between the first part 101 and the second part 102 of the pouch film 100 (FIG. 5), and a process of folding the folding section 130 (FIG. 6).

[0064] 4 and 5, the folding portion 130 of the pouch film 100 may be expanded so that the first portion 101 and the second portion 102 form a predetermined angle, and the forming jig 300 may be moved toward the folding portion 130 and inserted between the first portion 101 and the second portion 102 of the pouch film 100. Thus, the jig body 310 of the forming jig 300 may be smoothly inserted into the receiving portion 110 without interfering with the pouch film 100.

[0065] 6, the folding portion 130 may be folded so that the jig body 310 is housed in the housing portion 110. At this time, the protrusion 320 of the forming jig 300 may extend outwardly between the first part 101 and the second part 102 of the pouch film 100. More specifically, the protrusion 320 may extend between the terrace portion 120 of the first part 101 and the terrace portion 120 of the second part 102.

[0066] 7, the forming jig 300 may press the folding unit 130 outward (S40). With the pouch film 100 fixed, the forming jig 300 may move a predetermined distance toward the folding unit 130, thereby pressing the folding unit 130 outward.

[0067] More specifically, the jig body 310 may apply pressure to the folded portion 130 and its surrounding area outward in a direction perpendicular to the longitudinal direction of the folded portion 130.

[0068] For example, the jig body 310 may apply pressure to the folding portion 130 and its surrounding area in a direction parallel to the width direction of the receiving portion 110. In this case, the pressure of the forming jig 300 may stretch the pouch film 100, increasing the width of the receiving portion 110. More specifically, the receiving portion 110 may have a first width (W1) before the forming jig 300 applies pressure, and the receiving portion 110 may have a second width (W2) greater than the first width (W1) after the forming jig 300 applies pressure. In other words, the forming jig 300 may form the pouch film 100 so that the width of the receiving portion 110 increases.

[0069] However, this is not a limitation. If the folding portion 130 is formed parallel to the width of the storage portion 110, the jig body 310 may apply pressure to the folding portion 130 and its surrounding area in a direction parallel to the longitudinal direction of the storage portion 110. In this case, the forming jig 300 may form the pouch film 100 so that the length of the storage portion 110 increases.

[0070] Since the folding portion 130 and its surrounding area protrude outward from the terrace portion 120, more specifically, from the folded portion of the terrace portion 120, unlike conventional secondary batteries, bad ears 5 (see FIG. 1) do not occur, and the folding portion 130 and its surrounding area can be expanded properly, eliminating wrinkles, thereby improving the appearance of the secondary battery and improving its quality.

[0071] Meanwhile, FIG. 2 shows the step of inserting the forming jig 300 into the receiving part 110 (S30) after the step of folding the folding part 130 (S20), but is not limited thereto.

[0072] For example, the folding unit 130 may be folded so that the jig body 310 of the forming jig 300 is inserted into the storage unit 110 while the jig body 310 is positioned between the first part 101 and the second part 102 of the pouch film 100. That is, the step of folding the folding unit 130 (S20) and the step of inserting the forming jig 300 into the storage unit 110 (S30) may be performed simultaneously.

[0073] In this case, there is an advantage that the manufacturing process is simplified since there is no need to unfold the folding part 130 in order to insert the molding jig 300 into the receiving part 110.

[0074] Meanwhile, the manufacturing method may further include a step of removing the molding jig 300 from the receiving part 110 (S50).

[0075] 8, the pouch film 100 may expand so that the first portion 101 and the second portion 102 form a predetermined angle, and the forming jig 300 may move in a direction away from the folding portion 130 to be separated between the first portion 101 and the second portion 102 of the pouch film 100. Thus, the forming jig 300, more specifically, the jig body 310, can be smoothly separated from the storage portion 110 without interfering with the pouch film 100.

[0076] Thus, the manufacture of the pouch-type battery case can be completed. Hereinafter, for the sake of convenience, the reference numeral for the pouch-type battery case will be denoted by the same reference numeral as the pouch film 100, "100."

[0077] Then, the electrode assembly 200 (see FIG. 11) is inserted into the storage section 110 of the pouch-type battery case 100, and the terrace sections 120 of the first section 101 and the second section 102 are sealed together to form a sealing section, thereby manufacturing the pouch-type secondary battery 10.

[0078] FIG. 10 is a front view of a pouch-type secondary battery according to another embodiment of the present invention, and FIG. 11 is a cross-sectional view showing the inside of the storage section shown in FIG.

[0079] Hereinafter, a pouch-type battery case 100 (hereinafter referred to as "battery case") manufactured by the above-described manufacturing method and a pouch-type secondary battery 10 (hereinafter referred to as "secondary battery") including the same will be described as another embodiment of the present invention.

[0080] The secondary battery 10 may include an electrode assembly 200 and a battery case 100 .

[0081] The electrode assembly 200 may include a positive electrode, a negative electrode, and a separator interposed between the positive and negative electrode plates to insulate them.

[0082] The type of the electrode assembly 200 is not limited. For example, the electrode assembly 200 may be a stack-type electrode assembly in which positive electrodes and negative electrodes are alternately stacked with a separator between them. For another example, the electrode assembly 200 may be a jelly-roll-type electrode assembly in which sheet-shaped positive electrodes and negative electrodes are wound together with a separator between them.

[0083] The electrode assembly 200 may be provided with electrode tabs protruding in its entire length direction. A pair of electrode tabs may be provided, and the pair of electrode tabs may include a positive electrode tab connected to the positive electrode and a negative electrode tab connected to the negative electrode. As shown in FIGS. 10 and 11 , the positive electrode tab and the negative electrode tab may protrude in opposite directions from both ends of the electrode assembly 200. However, the present invention is not limited thereto, and the positive electrode tab and the negative electrode tab may protrude parallel to each other from one end of the electrode assembly 200.

[0084] The electrode leads 210 may be connected to the electrode tabs. For example, the electrode leads 210 may be welded to the electrode tabs. A pair of electrode leads 210 may be provided, and the pair of electrode leads 210 may include a positive electrode lead connected to the positive electrode tab and a negative electrode lead connected to the negative electrode tab.

[0085] An insulating film (not shown) may be provided around the periphery of the electrode lead 210, and a part of the sealing portion of the battery case 100 may be sealed with the insulating film.

[0086] Meanwhile, the battery case 100 may include a storage section 110, a terrace section 120, and a folding section .

[0087] The receiving portion 110 may have a recessed shape and may receive the electrode assembly 200 therein.

[0088] The folding portion 130 may be located on one side of the storage portion 110. More specifically, the folding portion 130 may be located on a portion of the periphery of the storage portion 110. The folding portion 130 may extend parallel to the length or width of the storage portion 110.

[0089] The terrace portion 120 may be connected to the periphery of the storage portion 110. The terrace portion 120 may extend from the periphery of the storage portion 110. Both ends of the terrace portion 120 may be folded. The terrace portion 120 may have a sealing portion formed thereon by sealing with heat and / or pressure. The internal space of the storage portion 110 may be sealed by the sealing portion.

[0090] As described above, in the manufacturing process of the battery case 100, the folding portion 130 and its surrounding area may be pressurized by the molding jig 300. Therefore, the folding portion 130 may form a predetermined step (S) with the terrace portion 120 on the outer side in a direction perpendicular to the longitudinal direction of the folding portion 130. More specifically, the folding portion 130 may form a predetermined step (S) with the folded portion of the terrace portion 120 on the outer side in a direction perpendicular to the longitudinal direction of the folding portion 130.

[0091] For example, the folding section 130 may extend in the longitudinal direction of the storage section 110, and may form a predetermined step (S) with the terrace section 120 on the outer side in the width direction of the storage section 110.

[0092] Therefore, unlike conventional secondary batteries, no bat-ears are formed in the secondary battery 1, and therefore the energy density of the secondary battery 1 can be increased and the appearance quality can be improved.

[0093] Furthermore, the folding portion 130 can be expanded firmly because it is pressed by the forming jig 300. This reduces wrinkles on the exterior of the secondary battery 10, further improving the appearance quality.

[0094] The periphery of the storage section 110 may include a first periphery 111 to which the terrace section 120 is connected, and a second periphery 112 that connects both ends of the folding section 130 to the terrace section 120. The second periphery 112 may be a portion that corresponds to the step (S).

[0095] The storage section 110 may have four corners (E) connecting its long and short sides. Of the four corners (E) of the storage section 110, one pair may be located on the first peripheral edge 111, and the other pair may be located on the second peripheral edge 112. Therefore, since the pair of corners (E) of the storage section 110 protrudes outward from the folded portion of the terrace section 120, there is a possibility that a bat-ear will not be formed.

[0096] The thickness of the second peripheral portion 112 ( t12 ) is the thickness of the first peripheral edge portion 111 (t11 ) because, as the folded portion 130 is pressed by the molding jig 300, the portions of the periphery of the storage portion 110 adjacent to both ends of the folded portion 130 are stretched more than the portions further away. In other words, the remaining thickness ( t12 ) is the remaining thickness ( t11 ) may be thinner than

[0097] The above description is merely an illustrative example of the technical concept of the present invention, and various modifications and variations can be made by a person having ordinary knowledge in the technical field to which the present invention pertains without departing from the essential characteristics of the present invention.

[0098] Therefore, the embodiments disclosed in the present invention are intended to explain, not to limit, the technical idea of ​​the present invention, and the scope of the technical idea of ​​the present invention is not limited by such embodiments.

[0099] The scope of protection of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent range thereof should be interpreted as being included in the scope of the present invention. [Explanation of symbols]

[0100] 10 Pouch-type secondary battery (secondary battery) 100 Pouch film (pouch-type battery case) 101 Part 1 102 Part 2 110 Storage section 111 First peripheral part 112 Second Periphery 120 Terrace 130 Folding section 200 electrode assembly 210 Electrode Lead 300 molding jig 310 Jig body 320 Protrusion

Claims

1. a storage section having a recessed shape; a folding section located on one side of the storage section; a terrace portion extending from the periphery of the storage portion, the folding portion protrudes outward from the folded portion of the terrace portion so as to form a predetermined step with the terrace portion outward in a direction perpendicular to the longitudinal direction of the folding portion, The periphery of the storage section is a first peripheral edge portion to which the terrace portions are connected; a second peripheral portion connecting both ends of the folding portion and the terrace portion and corresponding to the step; The pouch-type battery case, wherein the second peripheral portion has a thickness smaller than the thickness of the first peripheral portion.

2. The pouch-type battery case according to claim 1 , wherein one pair of the four corners of the storage section are located on the first peripheral edge portion, and the other pair are located on the second peripheral edge portion.

3. The pouch-type battery case according to claim 1 or 2, wherein the folding portion is expandable.

4. A pouch-type secondary battery including an electrode assembly and a pouch-type battery case, The pouch-type battery case includes: a receiving portion in which the electrode assembly is received; a folding portion located on one side of the electrode assembly; a terrace portion extending from the periphery of the storage portion, the folding portion protrudes outward from the folded portion of the terrace portion so as to form a predetermined step with the terrace portion outward in a direction perpendicular to the longitudinal direction of the folding portion, The periphery of the storage section is a first peripheral edge portion to which the terrace portions are connected; a second peripheral portion connecting both ends of the folding portion and the terrace portion and corresponding to the step; The pouch-type secondary battery, wherein the second peripheral portion has a thickness smaller than the thickness of the first peripheral portion.

5. forming a recessed storage portion in a pouch film; Folding the fold portion of the pouch film; inserting a molding jig into the housing; the forming jig presses the folded portion outward so that the width or length of the storage portion increases; and when the folding portion is pressed outward, the folding portion may protrude outward from a folded portion of a terrace portion extending from a periphery of the receiving portion. Manufacturing method for pouch-type battery cases.

6. The step of inserting the molding jig into the receiving portion includes: unfolding the folded portion so that one part of the pouch film and another part form a predetermined angle; inserting the forming jig between one portion of the pouch film and another portion of the pouch film; The method for manufacturing a pouch-type battery case according to claim 5 , further comprising the step of folding the foldable portion.

7. The method for manufacturing a pouch-type battery case according to claim 5 or 6, further comprising the step of removing the molding jig from the receiving portion.

8. A molding jig for manufacturing a pouch-type battery case having a folding portion on one side of a storage portion, a jig body that is inserted into the storage portion and presses the folding portion; a protrusion connected to the jig body and protruding outward from the receiving portion, the protrusion having a thickness thinner than that of the jig body.

9. The forming jig according to claim 8 , wherein the pressure direction of the jig body is perpendicular to the longitudinal direction of the folding portion.

10. The molding jig of claim 8 , wherein the length of the jig body corresponds to the length of the folding portion.

11. The molding jig according to claim 8 , wherein the thickness of the jig body corresponds to the total depth of the recess or corresponds to the sum of the total depth of the recess and the thickness of the protrusion.

12. The molding jig according to claim 8 , wherein the protrusion protrudes from the jig body in a direction away from the folding portion.

13. 13. A forming jig according to any one of claims 8 to 12, wherein the protrusions are coupled to a drive that provides linear power to the forming jig.

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