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 and a secondary battery including the same, a method for manufacturing the pouch-type battery case, and a forming jig for manufacturing the pouch-type battery case. [Background technology]

[0003] Generally, 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, P-DVDs, MP3Ps, mobile phones, PDAs (registered trademark), portable game devices, power tools, and electric bicycles (E-bikes), but also in large products that require 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 new renewable energy.

[0004] To manufacture an electrode assembly, a cathode, a separator, and an anode are manufactured and stacked. Specifically, a cathode active material slurry is applied to a cathode current collector, and an anode active material slurry is applied to an anode current collector to manufacture a cathode and an anode. Then, when the manufactured cathode and anode are stacked with a separator interposed between them, a unit cell is formed, and the unit cells are stacked on top of each other to form an electrode assembly. Then, the electrode assembly is housed in a specific case and an electrolyte is injected to manufacture a secondary battery.

[0005] These secondary batteries are classified into pouch type and can type 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 that has no uniform shape, while the can type houses the electrode assembly in a case made of a material such as metal or plastic that has a uniform shape.

[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 in which the electrode assembly is housed. The pouch-type battery case 1 is manufactured by drawing a flexible pouch film to form a storage section 2. Such 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 storage section 2 is formed, an electrode assembly is housed in the storage space of the storage section 2, the pouch-type battery case 1 is folded, and then the terrace section 4 is sealed to manufacture a secondary battery.

[0008] Furthermore, by folding the battery case 1, 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 causes problems such as a decrease in the energy density relative to the volume of the secondary battery, and a decrease in 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 of 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 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 the 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. The thickness of the second periphery may be thinner than the thickness of the first periphery.

[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 fully unfolded.

[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 in which the electrode assembly is stored; 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 a longitudinal direction of the folding section. The periphery of the storage section may include a first periphery section to which the terrace section is connected; and a second periphery section connecting both ends of the folding section to the terrace section. The thickness of the second periphery section may be thinner than the thickness of the first periphery section.

[0017] A manufacturing method of 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 press the fold portion outwardly such that a width or length of the storage portion is increased.

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

[0019] The method for manufacturing the pouch-type battery case may further include removing the forming 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 that is inserted into the receiving portion and presses the folding portion, and a protrusion that is connected to the jig body, protrudes outside the receiving portion, and has a thickness thinner than that of 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. Effect of the Invention

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

[0027] In addition, 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] In addition, the present invention may have other effects 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 description of the drawings]

[0029] The following drawings attached to this specification are illustrative of preferred embodiments of the present invention and, together with the detailed description of the invention described below, serve to facilitate a better understanding of the technical ideas 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. [Diagram 2] 4 is a flow chart of a method for manufacturing a pouch-type battery case according to an embodiment of the present invention. [Diagram 3]FIG. 2 is a perspective view of a pouch film in which a storage portion is formed. [Figure 4] 5A to 5C are side views illustrating a method for manufacturing a pouch-type battery case according to an embodiment of the present invention. [Diagram 5] 5A to 5C are side views illustrating a method for manufacturing a pouch-type battery case according to an embodiment of the present invention. [Figure 6] 5A to 5C are side views illustrating a method for manufacturing a pouch-type battery case according to an embodiment of the present invention. [Figure 7] 5A to 5C are side views illustrating a method for manufacturing a pouch-type battery case according to an embodiment of the present invention. [Figure 8] 5A to 5C are side views 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. [Figure 10] FIG. 4 is a front view of a pouch-type secondary battery according to another embodiment of the present invention. [Figure 11] 11 is a cross-sectional view showing the inside of the storage unit shown in FIG. 10. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0031] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. However, the present invention may be embodied in various different forms and is not limited to the following embodiments.

[0032] In order to clearly explain the present invention, detailed descriptions of parts that are not relevant to the description or 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 for the same or similar components throughout the specification.

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

[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 portion has been formed, FIGS. 4 to 8 are side views for explaining the 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 for a pouch-type battery case according to one embodiment of the present invention (hereinafter, the "manufacturing method") may include a step of forming a storage portion 110 in a pouch film 100 (S10), a step of folding a folding portion 130 of the pouch film 100 (S20), a step of inserting a forming jig 300 into the storage portion 110 (S30), and a step of the forming jig 300 pressing the folding portion 130 outward (S40).

[0036] The step (S10) of forming the receiving portion 110 in the pouch film 100 may be performed by 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 portion into the forming groove. Thus, the pouch film 100 may be formed with a receiving portion 110 that is recessed to correspond to the shape of the forming groove. The receiving portion 110 may form an accommodating space for accommodating 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 a polypropylene (PP) or polyethylene (PE) material, the metal layer may include an aluminum (AL) material, and the second resin layer may include a polyethylene terephthalate (PET) material.

[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 direction 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 direction of the storage unit 110.

[0040] In the pouch film 100, an area 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 may have a shape extending from the periphery of the storage section 110.

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

[0042] However, this is not limited thereto, and only one storage section 110 may be formed in the pouch film 110. In this case, either one of the first part 101 and the second part 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 since the configuration and operation of the folding device are well-known technologies, detailed description will be omitted.

[0044] When the folding section 130 is completely 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 portion 130 is fully folded, one of the first part 101 and the second part 102 that does not include the storage section 110 may cover the storage section 110 and terrace portion 120 of the other of the first part 101 and the second part 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 applying outward pressure to the folding section 130, 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 to pressurize 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 pressurize the folded portion 130 and its surrounding area outwardly 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 folded portion 130. That is, the jig body 310 may pressurize the portion of the inner periphery of the storage unit 110 that is connected to the folded portion 130 together with the folded portion 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 peripheral portion in the opposite direction to the z-axis shown in the drawing. 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 fold 130. The length of the jig body 310 may be parallel to the y-axis shown in the drawing.

[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. Thus, the jig body 310 can apply uniform pressure to the folding unit 130 and its surroundings as a whole.

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

[0053] The thickness (W1) of the jig body 310 (see FIG. 4) may correspond to the total depth of the storage section 110. That is, the thickness (W1) of the jig body 310 may be the same as or similar to the total depth of the storage section 110. For example, the thickness (W1) of the jig body 310 may correspond to the sum of the depth (d1) of the storage section 110 of the first section 101 and the depth (d2) of the storage section 110 of the second section 102. The thickness (W1) of the jig body 310 may be the same as or similar to the total depth of the storage section 110.

[0054] Preferably, the thickness (W1) of the jig body 310 may correspond to a value obtained by adding the total depth of the storage section 110 to a thickness (W2) of the protruding section 320 described below. That is, the thickness (W1) of the jig body 310 may be the same as or similar to a value obtained by adding the total depth of the storage section 110 to a thickness (W2) of the protruding section 320 described below. For example, the thickness (W1) of the jig body 310 may correspond to the sum of the depth (d1) of the storage section 110 of the first part 101, the depth (d2) of the storage section 110 of the second part 102, and the thickness (W2) of the protruding section 320.

[0055] This is because, 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 not completely adhered to each other due to the thickness (W2) of the protruding part 320.

[0056] Therefore, the jig body 310 can apply pressure to the folded portion 130 and its surroundings 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 section 110, the protruding section 320 may extend outward through between the first section 101 and the second section 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 provide a pressure force to the jig body 310 via the protrusions 320.

[0061] The thickness (W2) of the protruding portion 320 may be thinner than the thickness (W1) of the jig body 310. 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 of inserting the forming jig 300 into the storage section 110 (S30) 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 pre-set 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 such that the first portion 101 and the second portion 102 form a preset 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 accommodated in the storage portion 110. At this time, the protrusion 320 of the forming jig 300 may extend outwardly through 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 toward the folding unit 130 by a preset distance, thereby pressing the folding unit 130 outward.

[0067] More specifically, the jig body 310 may apply pressure to the folded portion 130 and its periphery outwardly. The jig body 310 may apply pressure to the folded portion 130 and its periphery 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 surroundings in a direction parallel to the width direction of the storage portion 110. In this case, the pouch film 100 may be stretched by the pressure of the forming jig 300, and the width of the storage portion 110 may increase. More specifically, the storage portion 110 before the pressure of the forming jig 300 may have a first width (W1), and the storage portion 110 after the pressure of the forming jig 300 may have a second width (W2) larger than the first width (W1). In other words, the forming jig 300 may form the pouch film 100 such that the width of the storage portion (310) increases.

[0069] However, the present invention is not limited to this. When the folding portion 130 is formed parallel to the width of the storage portion 110, the jig body 310 may pressurize 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 folded portion 130 and its surroundings protrude outward from the terrace portion 120, more specifically, from the folded portion of the terrace portion 120, unlike the conventional secondary battery, bad ears 5 (see FIG. 1) do not occur, and the folded portion 130 and its surroundings can be fully expanded to remove wrinkles, thereby improving the appearance of the secondary battery and improving its quality.

[0071] Meanwhile, FIG. 2 illustrates 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 the present invention is not limited thereto.

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

[0073] In this case, since it is not necessary to unfold the folding portion 130 in order to insert the molding jig 300 into the receiving portion 110, there is an advantage that the manufacturing process is simplified.

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

[0076] Thus, the manufacture of the pouch-type battery case can be completed. Hereinafter, for convenience of explanation, 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 portion 110 of the pouch-type battery case 100, and the terrace portions 120 of the first portion 101 and the second portion 102 are sealed together to form a sealing portion, 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 receiving part 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 other embodiments 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 electrodes 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 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 and negative electrodes are rolled up together with a separator between them.

[0083] The electrode assembly 200 may be provided with electrode tabs protruding in the overall length direction thereof. A pair of electrode tabs may be provided, and the pair of electrode tabs may include a positive electrode tab connected to a positive electrode and a negative electrode tab connected to a 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 in parallel to each other from one end of the electrode assembly 200.

[0084] The electrode lead 210 may be connected to the electrode tab. For example, the electrode lead 210 may be welded to the electrode tab. A pair of electrode leads 210 may be provided, and the pair of electrode leads 210 may include a positive electrode lead connected to a positive electrode tab and a negative electrode lead connected to a 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 130.

[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 direction or width direction 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 by sealing with heat and / or pressure. The sealing portion may seal the interior space of the storage portion 110.

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

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

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

[0093] In addition, the folding portion 130 can be fully expanded because it is pressed by the forming jig 300. As a result, wrinkles in the exterior of the secondary battery 10 are reduced, and the quality of the exterior appearance can be further improved.

[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 sides and short sides. Of the four corners (E) of the storage section 110, one pair may be located on the first peripheral edge section 111, and the other pair may be located on the second peripheral edge section 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 (t2) of the second peripheral portion 112 may be thinner than the thickness (t1) of the first peripheral portion 111. This is because, while the folded portion 130 is pressed by the forming 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 farther away. In other words, the remaining thickness (t2) of the second peripheral portion 112 may be thinner than the remaining thickness (t1) of the first peripheral portion 111.

[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 those 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 the technical idea of ​​the present invention, rather than to limit it, 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 according to the following claims, and all technical ideas within the scope equivalent thereto 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 periphery 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 a periphery of the storage portion, the folding portion has a predetermined step with the terrace portion on an outer side in a direction perpendicular to a longitudinal direction of the folding portion, The periphery of the storage section is a first peripheral portion to which the terrace portions are connected; a second peripheral portion connecting both ends of the folded portion and the terrace portion; The pouch-type battery case, wherein the second peripheral portion has a thickness smaller than a thickness of the first peripheral portion.

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

3. The pouch-type battery case according to claim 1 or 2, wherein the folded portion unfolds firmly.

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 folded portion located on one side of the electrode assembly; A terrace portion extending from a periphery of the storage portion, the folding portion has a predetermined step with the terrace portion on an outer side in a direction perpendicular to a longitudinal direction of the folding portion, The periphery of the storage section is a first peripheral portion to which the terrace portions are connected; a second peripheral portion connecting both ends of the folded portion and the terrace portion; A pouch-type secondary battery, wherein the second peripheral portion has a thickness smaller than a thickness of the first peripheral portion.

5. forming a storage portion in a pouch film; folding the fold portion of the pouch film; inserting a molding jig into the recess; the forming jig presses the folded portion outwardly so that a width or a length of the storage portion increases.

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 of the pouch film form a preset 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 forming 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 folded 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 a pressure direction of the jig body is perpendicular to a longitudinal direction of the folding portion.

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

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

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

13. 13. A moulding jig as claimed in any one of claims 8 to 12, wherein the protrusions are coupled to a drive which provides linear power to the moulding jig.

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