Pouch-type battery case and pouch-type secondary battery

Abstract

In a pouch-type battery case according to an embodiment of the present application, a cup portion in which an electrode assembly formed by stacking an electrode and a separator is accommodated is formed, wherein the cup portion includes a plurality of die edges connecting a plurality of outer walls surrounding a periphery and an edge or a degassing portion, and at least one of the die edges is rounded with a curvature radius of 1 mm or less, and a depth of the cup portion is 6.5 mm or less. The pouch-type battery case includes an electrode assembly formed by stacking an electrode and a separator, and a pouch-type battery case in which a cup portion in which the electrode assembly is accommodated is formed, the battery case including a first case and a second case in which the cup portion is formed in at least one of the first case and the second case, and a folding portion for integrally connecting the first case and the second case, wherein a width of the folding portion is 1 mm to 3.2 mm, and a depth of the cup portion is 6.5 mm or less.

Description

Technical Field

[0001] Cross-references to related applications

[0002] This application claims the benefit of priority to Korean Patent Application No. 10-2020-0104228, filed on August 19, 2020, and Korean Patent Application No. 10-2021-0074472, filed on June 8, 2021, the entire contents of which are incorporated herein by reference. Technical Field

[0004] This invention relates to a pouch-type battery casing and a pouch-type secondary battery, and more specifically, to a pouch-type battery casing and a pouch-type secondary battery, wherein the pouch-type battery casing can increase energy density relative to volume, has an attractive appearance, and improves marketability. Background Technology

[0005] Typically, rechargeable batteries include nickel-cadmium batteries, nickel-metal hydride batteries, lithium-ion batteries, and lithium-ion polymer batteries. These rechargeable batteries are suitable for small products (e.g., digital cameras, P-DVDs, MP3 players, mobile phones, PDAs, portable game consoles, power tools, electric bicycles, etc.) as well as large products requiring high power (e.g., electric vehicles and hybrid vehicles, power storage devices for storing surplus or renewable energy, and backup power storage devices).

[0006] Typically, to manufacture a secondary battery, firstly, an electrode active material slurry is coated onto the positive and negative current collectors to create the positive and negative electrodes. Then, the electrodes are stacked on both sides of a separator to form an electrode assembly. Furthermore, the electrode assembly is housed in a battery casing, and the battery casing is sealed after electrolyte is injected into it.

[0007] These secondary batteries are classified into pouch batteries and can batteries based on the material of the casing housing the electrode components. In pouch batteries, the electrode components are housed in a pouch made of a flexible polymer material. Conversely, in can batteries, the electrode components are housed in a casing made of metal or plastic.

[0008] The pouch cell, serving as the casing for a pouch-type secondary battery, is manufactured by stamping a flexible pouch film to form a cup. Furthermore, during cup formation, electrode assemblies are housed within the cup's containment space, and then the edges of the cup are sealed to manufacture the secondary battery.

[0009] In stamping, stretching is achieved by inserting a flexible film into a molding apparatus, such as a stamping machine, and stretching the film by applying pressure with a punch. Therefore, when molding the cup portion onto the flexible film, there are limitations in improving the radius of curvature and gap of the cup portion's edges. Furthermore, the small volume ratio of the electrode assembly to the cup portion limits the reduction of the bat ear size, thus decreasing the energy density of the secondary battery relative to its volume. Additionally, there are limitations in manufacturing an overall sharp shape, resulting in an unattractive appearance for the secondary battery and consequently reducing its marketability.

[0010] Japanese Patent Registration No. 6022956 exists as prior art. Summary of the Invention

[0011] Technical issues

[0012] One objective of this invention is to provide a pouch-type battery casing and a pouch-type secondary battery, wherein the pouch-type battery casing can improve energy density relative to volume, has an attractive appearance, and improves marketability.

[0013] The purpose of this invention is not limited to the above-described purposes, and other purposes not described herein will be clearly understood by those skilled in the art through the following description.

[0014] Technical solution

[0015] A pouch-type battery housing according to an embodiment of the present invention for achieving the above-mentioned objectives includes: a cup portion configured to accommodate an electrode assembly formed by stacking electrodes and a separator, wherein the cup portion is configured to connect a plurality of outer walls configured to surround its periphery with edges or degassing portions, and at least one of the plurality of stamped edges is rounded with a radius of curvature of less than 1 mm.

[0016] In addition, the radius of curvature of at least one of the mold edges can be less than 0.7 mm.

[0017] Additionally, the edge of the mold can have a radius of curvature corresponding to 1 / 20 to 1 / 6 of the depth of the cup.

[0018] Additionally, the cup portion may include: a plurality of stamped edges connecting the outer wall to the bottom, and at least one of the stamped edges being rounded with a radius of curvature of less than 1 mm; and a thickness edge configured to connect to two adjacent outer walls.

[0019] In addition, the vertical distance between the vertical line of the mold edge perpendicular to the bottom, which is the boundary point between the mold edge and the outer wall of the mold edge side, and the vertical line of the edge perpendicular to the bottom, which is the boundary point between the stamping edge of the mold edge side and the outer wall of the mold edge side, can be less than 0.5 mm.

[0020] Additionally, the thickness edge can be connected to two adjacent stamping edges to form a corner, and at least one of the corners can be rounded with a radius of curvature of 2 mm to 5 mm, wherein the radius of curvature of the corner is greater than the radius of curvature of the thickness edge.

[0021] Additionally, the corners can have radii of curvature that vary within them.

[0022] In addition, the radius of curvature of the central part of the corner can be greater than the radius of curvature of the outer part of the corner.

[0023] In addition, the radius of curvature of at least one of the stamped edges can be less than 0.7 mm.

[0024] Additionally, the stamped edge can have a radius of curvature corresponding to 1 / 20 to 1 / 6 of the depth of the cup.

[0025] In addition, the soft-pack battery casing may also include: a first casing and a second casing, wherein cup portions are formed in the first casing and the second casing respectively; and a bridge portion formed between the two cup portions, wherein the thickness of the bridge portion may be less than 2 mm.

[0026] In addition, the thickness of the bridge section can be less than 1.4 mm.

[0027] Additionally, the bridge portion may have a thickness corresponding to 1 / 200 to 1 / 30 of the width of the electrode assembly.

[0028] In addition, the bridge section can be rounded with a curvature radius of less than 1 mm.

[0029] In addition, the bridge section can be rounded with a curvature radius of less than 0.7mm.

[0030] In addition, the bridge section may have a thickness corresponding to the distance between two vertical lines of the bridge section, which pass through the boundary points between the bridge section and the outer side wall of the bridge section, and are perpendicular to the bottom.

[0031] In addition, the outer wall can be inclined from the bottom at an angle of 90° to 95°.

[0032] A pouch-type secondary battery according to an embodiment of the present invention for achieving the above-mentioned objectives includes: an electrode assembly in which electrodes and a separator are stacked; a pouch-type battery casing including a cup portion configured to receive the electrode assembly therein, wherein the battery casing includes: a first casing and a second casing, at least one of the first casing and the second casing including the cup portion; and a folding portion configured to integrally connect the first casing and the second casing, wherein the width of the folding portion is 1 mm to 3.2 mm, and

[0033] The depth of the cup is less than 6.5mm.

[0034] In addition, the surface area of ​​the electrode assembly can be 15000 mm². 2 Up to 100,000 mm 2 .

[0035] In addition, the width of the folded part can be from 1mm to 1.6mm.

[0036] Additionally, the folded portion may include an inwardly recessed groove.

[0037] Additionally, the battery casing may include a pair of outwardly protruding protrusions, and a groove between the pair of protrusions, wherein the distance between the innermost portion of the groove and the outermost portion of the protrusion may be less than 0.8 mm.

[0038] In addition, the difference in width between the cup and the electrode assembly can be less than 2.5 mm.

[0039] In addition, the difference in width between the cup and the electrode assembly can be less than 1.7 mm.

[0040] In addition, the width of the cup can be the distance between the two ends of the two outer walls of the cup.

[0041] Additionally, the cup portion may include: a plurality of stamped edges connected to a plurality of outer walls configured to surround its periphery and a bottom, and at least one of the stamped edges being rounded with a radius of curvature of less than 1 mm; a plurality of die edges connecting the outer walls to the edge or degassing portion, and at least one of the plurality of die edges being rounded with a radius of curvature of less than 1 mm; and a thickness edge configured to connect to two adjacent outer walls.

[0042] In addition, the vertical distance between the vertical line of the mold edge perpendicular to the bottom, which is the boundary point between the mold edge and the outer wall of the mold edge side, and the vertical line of the edge perpendicular to the bottom, which is the boundary point between the stamping edge of the mold edge side and the outer wall of the mold edge side, can be less than 0.5 mm.

[0043] Additionally, in the electrode assembly, one end of at least one of the electrodes can be configured such that the vertical distance between it and the edge vertical line is less than 0.75 mm.

[0044] Additionally, in the electrode assembly, one end of at least one of the electrodes can be configured such that the vertical distance between it and the edge vertical line is less than 0.5 mm.

[0045] In addition, in the diaphragm, the peripheral portion protruding outward from the electrode can be folded relative to one end of the electrode in the opposite direction to the bottom.

[0046] In addition, in the electrode assembly, each of the electrodes and the diaphragm can be configured as multiple, with the peripheral portion of the diaphragm housed in the cup portion of the first housing folded toward the second housing, and the peripheral portion of the diaphragm housed in the cup portion of the second housing folded toward the first housing.

[0047] In addition, the peripheral portion of at least one of the diaphragms may be aligned with and folded over the peripheral portion of an adjacent diaphragm.

[0048] In addition, the radius of curvature of at least one of the stamped edges can be less than 0.7 mm.

[0049] Additionally, the stamped edge can have a radius of curvature corresponding to 1 / 20 to 1 / 6 of the depth of the cup.

[0050] In addition, the radius of curvature of at least one of the mold edges can be less than 0.7 mm.

[0051] Additionally, the edge of the mold can have a radius of curvature corresponding to 1 / 20 to 1 / 6 of the depth of the cup.

[0052] In addition, the outer wall can be inclined from the bottom at an angle of 90° to 95°.

[0053] Additionally, the thickness edge can be connected to two adjacent stamping edges to form a corner, and at least one of the corners can be rounded with a radius of curvature of 2 mm to 5 mm, wherein the radius of curvature of the corner is greater than the radius of curvature of the thickness edge.

[0054] Additionally, the corners can have radii of curvature that vary within them.

[0055] In addition, the radius of curvature of the central part of the corner can be greater than the radius of curvature of the outer part of the corner.

[0056] In addition, the pouch-type secondary battery may also include bat ears that protrude outwards by 1.5 mm from a portion of both ends of the fold.

[0057] In addition, the angle between the fold and the inner edge of the bat ear can be greater than 151 degrees.

[0058] Further details of the embodiments are included in the detailed description and accompanying drawings.

[0059] Beneficial effects

[0060] According to embodiments of the present invention, at least the following effects are achieved.

[0061] The curvature radius and gap of the edge of the cup portion of the pouch battery casing and the pouch secondary battery can be made smaller, and the thickness of the bridge portion can be made thinner. Therefore, the width of the fold portion can be reduced, the volume of the electrode assembly can be increased, the size of the bat-ear can be reduced, and the high edge phenomenon can be prevented. Thus, the energy density relative to the volume can be improved.

[0062] In addition, since each of the pouch-type battery casing 13 and the pouch-type secondary battery has a sharp shape as a whole, the secondary battery can have an attractive appearance and improve its marketability.

[0063] The effects of the present invention are not limited to those described above, and therefore this specification includes many more variations of the effects. Attached Figure Description

[0064] Figure 1 This is an assembly diagram of a secondary battery 1 according to an embodiment of the present invention;

[0065] Figure 2 This is a cross-sectional view of the soft film 135 according to an embodiment of the present invention;

[0066] Figure 3 This is a schematic diagram of a molding apparatus 2 according to an embodiment of the present invention;

[0067] Figure 4 This is an enlarged schematic diagram of the cup portion 333 and the bridge portion 336 based on the prior art;

[0068] Figure 5 This is an enlarged schematic diagram of the cup portion 133 and the bridge portion 136 according to an embodiment of the present invention;

[0069] Figure 6 This is an enlarged schematic diagram of the cup portion 133 and the degassing portion 137 according to an embodiment of the present invention;

[0070] Figure 7 This is a schematic top view showing the state in which the electrode assembly 10 is housed in the cup portion 133 according to an embodiment of the present invention;

[0071] Figure 8 This is a schematic diagram of corner 364 based on existing technology;

[0072] Figure 9 This is a schematic diagram of corner 164 according to an embodiment of the present invention;

[0073] Figure 10 This is a schematic diagram showing the folded state of the battery casing 13 according to an embodiment of the present invention;

[0074] Figure 11This is a schematic diagram showing the folded state of the battery casing 13 according to an embodiment of the present invention;

[0075] Figure 12 This is an enlarged view of a groove 1391 formed in a battery casing 13 according to an embodiment of the present invention;

[0076] Figure 13 This is an enlarged schematic diagram of the cup portion 133 and the mold edge 1621 according to another embodiment of the present invention;

[0077] Figure 14 This is a schematic diagram showing the folded state of the battery casing 13a according to another embodiment of the present invention;

[0078] Figure 15 This is a schematic diagram showing the folded state of the battery casing 13a according to another embodiment of the present invention;

[0079] Figure 16 This is an enlarged view of a groove 1391a formed in the battery casing 13 according to another embodiment of the present invention;

[0080] Figure 17 This is a schematic top view showing the state of the degassing portion 337 of the battery casing 33 before it is cut off, according to the prior art;

[0081] Figure 18 This is a schematic top view showing the state of the degassing portion 137 of the battery casing 13 before it is cut, according to an embodiment of the present invention;

[0082] Figure 19 This is a block diagram of an inspection device 4 according to an embodiment of the present invention;

[0083] Figure 20 This is a schematic diagram showing the state in which the degassing portion of the battery casing 13 is cut to completely manufacture the secondary battery 1 according to an embodiment of the present invention;

[0084] Figure 21 This is a schematic side view showing the state in which edge 334 is folded according to the prior art;

[0085] Figure 22 This is a schematic top view showing the state in which edge 334 is folded according to the prior art;

[0086] Figure 23 This is a schematic side view showing the state in which edge 134 is folded according to an embodiment of the present invention;

[0087] Figure 24 This is a schematic diagram of a battery module 5 according to an embodiment of the present invention;

[0088] Figure 25 This is an enlarged front view showing the secondary battery 3 housed in the casing 51 of the battery module 5, according to the prior art;

[0089] Figure 26 This is an enlarged side view showing the secondary battery 3 housed in the housing 51 of the battery module 5, according to the prior art.

[0090] Figure 27 This is an enlarged front view showing the secondary battery 1 housed in the casing 51 of the battery module according to an embodiment of the present invention;

[0091] Figure 28 This is an enlarged side view showing the secondary battery 1 housed in the casing 51 of the battery module according to an embodiment of the present invention. Detailed Implementation

[0092] The advantages and features of the present invention, as well as its implementation methods, will be illustrated by the embodiments described below in conjunction with the accompanying drawings. However, the invention may be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Furthermore, the invention is defined only by the scope of the claims. Throughout the text, the same reference numerals refer to the same parts.

[0093] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by those skilled in the art. Furthermore, unless clearly and explicitly defined in the specification, terms defined in common dictionaries are not ideally or excessively interpreted as having a formal meaning.

[0094] In the following description, technical terms are used only to explain specific exemplary embodiments and are not intended to limit the invention. In this specification, singular terms may include plural forms unless specifically mentioned. The meanings of “comprising” and / or “including” do not exclude other components besides those mentioned.

[0095] The preferred embodiments will be described in detail below with reference to the accompanying drawings.

[0096] Figure 1 This is an assembly diagram of a secondary battery 1 according to an embodiment of the present invention.

[0097] According to one embodiment of the present invention, the radius of curvature and gap of the edges of the cup portion of the pouch battery casing and the pouch secondary battery can be made smaller, and the thickness of the bridge portion can be made thinner. Therefore, the width of the folded portion can be reduced, the volume of the electrode assembly can be increased, the size of the batwing portion can be reduced, and high edge phenomena can be prevented, thus improving the energy density relative to volume. Furthermore, since each of the pouch battery casing 13 and the pouch secondary battery has a sharp overall shape, the secondary battery can have an aesthetically pleasing appearance and improved marketability.

[0098] Therefore, according to an embodiment of the present invention, a pouch-type battery housing includes a cup portion for accommodating an electrode assembly, wherein electrodes and a separator are stacked in the electrode assembly, wherein the cup portion includes: a plurality of stamped edges connecting a plurality of outer walls surrounding its periphery to a bottom, and at least one of the stamped edges being rounded with a radius of curvature of less than 1 mm; a plurality of mold edges connecting the outer walls to an edge or degassing portion, and at least one of the mold edges being rounded with a radius of curvature of less than 1 mm; and a thickness edge configured to connect two adjacent outer walls to each other, wherein the vertical distance between a mold edge perpendicular to the bottom and a mold edge vertical line passing through the boundary point of the mold edge and the mold edge side outer wall and perpendicular to the bottom edge vertical line passing through the boundary point of the mold edge side stamped edge and the mold edge side outer wall and perpendicular to the bottom edge is less than 0.5 mm, the thickness edge connecting to two adjacent stamped edges to form a corner, wherein at least one of the corners is rounded with a radius of curvature of 2 mm to 5 mm, wherein the radius of curvature is greater than the radius of curvature of the thickness edge, and the depth of the cup portion is less than 6.5 mm.

[0099] Additionally, according to an embodiment of the present invention, a pouch-type secondary battery includes: an electrode assembly in which electrodes and a separator are stacked; and a pouch-type battery casing including a cup portion configured to house the electrode assembly therein, wherein the battery casing includes: a first casing and a second casing, at least one of the first casing and the second casing including the cup portion; a folding portion configured to integrally connect the first casing and the second casing; and bat-ear-like protrusions from both ends of the folding portion, wherein the cup portion includes: a plurality of stamped edges connecting a plurality of outer walls surrounding its periphery to a bottom, and at least one of the stamped edges being rounded with a radius of curvature of less than 1 mm; a plurality of molded edges connecting the outer walls to edges or degassing portions, and at least one of the molded edges being rounded with a radius of curvature of less than 1 mm. The outer diameter is rounded, and the thickness edge is configured to connect two adjacent outer walls to each other, wherein the vertical distance between the boundary point of the mold edge and the outer wall of the mold edge side and the vertical line of the mold edge perpendicular to the bottom and the boundary point of the stamping edge of the mold edge side and the outer wall of the mold edge side and the vertical line of the edge perpendicular to the bottom is less than 0.5 mm, the thickness edge is connected to two adjacent stamping edges to form corners, wherein at least one of the corners is rounded with a radius of curvature of 2 mm to 5 mm, wherein the radius of curvature is greater than the radius of curvature of the thickness edge, the width of the fold is 1 mm to 3.2 mm, the length of the bat ear is less than 1 mm, the difference between the width of the cup and the width of the electrode assembly is less than 2.5 mm, and the depth of the cup is less than 6.5 mm.

[0100] Electrode assembly 10 is constructed by alternately stacking electrodes 101 (see...) Figure 5 ) and diaphragm 102 (see Figure 5 The process involves first coating a slurry containing electrode active materials, binders, and plasticizers onto a positive and negative current collector to fabricate electrodes 101 (e.g., positive and negative electrodes). Then, individual separators 102 are stacked between the electrodes 101 to form an electrode assembly 10. The electrode assembly 10 is inserted into a battery housing 13, and an electrolyte is injected to seal the battery housing 13.

[0101] The surface area of ​​electrode assembly 10 can be 15000 mm² by multiplying the total length by the total width. 2 Up to 100,000 mm 2 Specifically, the total width of the electrode assembly 10 can be 60 mm or more. Furthermore, the thickness of the electrode assembly 10 in the stacking direction can be 6 mm or more. Therefore, compared to conventional small batteries, the electrode assembly 10 according to an embodiment of the present invention can provide a larger battery capacity.

[0102] Specifically, the electrode assembly 10 includes: two types of electrodes 101 (e.g., a positive electrode and a negative electrode); and a separator 102 inserted between the electrodes 101 to insulate them from each other. The electrode assembly 10 can be stacked, wound, stacked and folded, etc. Each of the two types of electrodes 101, i.e., the positive electrode and the negative electrode, has a structure in which an active material slurry is coated onto an electrode current collector having a metal foil or metal mesh shape. The active material slurry is typically formed by stirring granular active materials, conductors, etc., in a solvent-containing state. The solvent can be removed in a subsequent process.

[0103] like Figure 1 As shown, the electrode assembly 10 includes electrode tabs 11. The electrode tabs 11 are respectively connected to the positive and negative electrodes of the electrode assembly 10 and protrude outwards from the electrode assembly 10, thereby providing a path for electrons to move through the electrode assembly 10 between its interior and exterior. The electrode current collector of the electrode assembly 10 consists of a portion coated with an electrode active material and an end without electrode active material, i.e., an uncoated portion. Furthermore, each electrode tab 11 can be formed by cutting the uncoated portion or by ultrasonically welding individual conductive components to the uncoated portion. Figure 1 As shown, the electrode tabs 11 may protrude in various directions of the electrode assembly 10, but are not limited thereto. For example, the electrode tabs may protrude in various directions, such as protruding parallel to each other from one side in the same direction.

[0104] In the electrode assembly 10, electrode leads 12 supplying power to the external secondary battery 1 are connected to electrode tabs 11 by spot welding. Furthermore, a portion of the electrode leads 12 is surrounded by an insulating portion 14. The insulating portion 14 can be configured as an edge 134 defined at the thermally fused joint of the first housing 131 and the second housing 132 of the battery housing 13, such that the electrode leads 12 are bonded to the battery housing 13. This prevents electricity generated from the electrode assembly 10 from flowing through the electrode leads 12 to the battery housing 13 and maintains the seal of the battery housing 13. Therefore, the insulating portion 14 can be made of a non-conductive, non-conductive material. While insulating tape, which easily adheres to the electrode leads 12 and has a relatively thin thickness, is typically used as the insulating portion 14, the invention is not limited to this. For example, various components can be used as the insulating portion 14, as long as these components are capable of insulating the electrode leads 12.

[0105] One end of the electrode lead 12 is connected to the electrode terminal block 11, and the other end of the electrode lead 12 protrudes to the outside of the battery casing 13. That is, the electrode lead 12 includes: a cathode lead 121, one end of which is connected to the cathode terminal block 111 and extends in the direction in which the cathode terminal block 111 protrudes; and an anode lead 122, one end of which is connected to the anode terminal block 112 and extends in the direction in which the anode terminal block 112 protrudes. On the other hand, as... Figure 1 As shown, the other ends of both the positive lead 121 and the negative lead 122 protrude to the outside of the battery housing 13. Therefore, the electricity generated in the electrode assembly 10 can be supplied to the outside. Furthermore, since each of the positive terminal piece 111 and the negative terminal piece 112 is formed to protrude in a different direction, each of the positive lead 121 and the negative lead 122 can extend in a different direction.

[0106] The positive electrode lead 121 and the negative electrode lead 122 can be made of different materials. That is, the cathode lead 121 can be made of the same material as the cathode current collector, namely aluminum (Al), and the anode lead 122 can be made of the same material as the anode current collector, namely copper (Cu) or copper coated with nickel (Ni). In addition, the portion of the electrode lead 12 that protrudes to the outside of the battery casing 13 can also be provided as an end and electrically connected to an external terminal.

[0107] The battery housing 13 is manufactured by molding a flexible material and houses the electrode assembly 10 in a pouch. The case where the battery housing 13 is a pouch will be described below. When using punch 22 (see...) Figure 6 When a flexible soft film 135 is stretched and formed, a portion of the soft film 135 is stretched to form a cup portion 133 including a soft-pack-shaped receiving space 1331, thereby manufacturing a battery casing 13.

[0108] The battery housing 13 accommodates the electrode assembly 10, exposing a portion of the electrode leads 12 before sealing. For example... Figure 1 As shown, the battery housing 13 includes a first housing 131 and a second housing 132. A cup portion 133, including a receiving space 1331 housing the electrode assembly 10, can be formed in the first housing 131, and the second housing 132 can cover the upper side of the receiving space 1331, such that the electrode assembly 10 does not separate from the outside of the battery housing 13. Figure 1 As shown, one side of the first housing 131 and one side of the second housing 132 can be connected to each other. However, the invention is not limited thereto. For example, the first housing 131 and the second housing 132 can be manufactured separately and separated from each other.

[0109] When the cup portion 133 is molded in the flexible film 135, only one cup portion 133 may be formed in one flexible film 135, but the invention is not limited thereto. For example, two cup portions may be stretched and formed adjacent to each other in one flexible film 135. Then, as Figure 1 As shown, cup portions 133 are formed in the first housing 131 and the second housing 132, respectively. Here, the cup portions 133 formed in the first housing 131 and the second housing 132 may have the same depth D, but are not limited to this, and may have different depths D.

[0110] According to one embodiment of the present invention, the depth D of the cup portion 133 can be 3 mm or more and 6.5 mm or more. Therefore, compared with conventional small batteries, the cup portion 133 according to one embodiment of the present invention can accommodate an electrode assembly 10 with a larger electrode capacity.

[0111] After the electrode assembly 10 is housed in the receiving space 1331 provided in the cup portion 133 of the first housing 131, the battery housing 13 can be folded relative to the bridge portion 136 formed between the two cup portions 133 in the battery housing 13, such that the two cup portions 133 face each other. Then, the cup portion 133 of the second housing 132 also houses the electrode assembly 10 from its upper side. Therefore, since two cup portions 133 house one electrode assembly 10, an electrode assembly 10 with a greater thickness can be accommodated compared to the case where only one cup portion 133 is provided. Furthermore, since the first housing 131 and the second housing 132 contact each other by folding the battery housing 13, the number of edges 134 that need to be sealed during the subsequent sealing process can be reduced. Therefore, the process speed can be increased, and the number of sealing processes can be reduced.

[0112] The battery housing 13 may include: a cup portion 133, in which a receiving space 1331 for accommodating the electrode assembly 10 is provided; and a degassing portion 137 formed on the side of the cup portion 133 to discharge gas generated in the cup portion 133 through a degassing hole H. When the electrode assembly 10 is accommodated in the cup portion 133 of the battery housing 13 and an electrolyte is injected, and then an activation process is performed, gas is generated inside the battery housing 13, thus a degassing process is performed to discharge the gas to the outside. A detailed description of the degassing portion 137 will be described later.

[0113] When the electrode lead 12 is connected to the electrode tab 11 of the electrode assembly 10, and an insulating portion 14 is formed on a part of the electrode lead 12, the electrode assembly 10 is housed in a receiving space 1331 provided in the cup portion 133 of the first housing 131, and the second housing 132 covers the receiving space from above. Furthermore, an electrolyte is injected into the receiving space, and the edge 134 extending to the outer side of the cup portion 133 of each of the first housing 131 and the second housing 132 is sealed. The electrolyte allows lithium ions generated by the electrochemical reaction of the electrode 101 during the charging and discharging of the secondary battery 1 to move. The electrolyte may include: a non-aqueous organic electrolyte, which is a mixture of lithium salt and high-purity organic solvent; or a polymer electrolyte. Furthermore, the electrolyte may include a sulfide-based, oxide-based, or polymer-based solid electrolyte, and the solid electrolyte may have flexibility that allows it to be easily deformed by external force. The pouch-type secondary battery 1 can be manufactured by the above method.

[0114] Figure 2 This is a cross-sectional view of the soft film 135 according to an embodiment of the present invention.

[0115] According to one embodiment of the present invention, the battery casing 13 of the pouch-type secondary battery 1 can be manufactured by stretching the pouch film 135. That is, the battery casing 13 is manufactured by stretching the pouch film 135 using a punch 22 or the like to form a cup portion 133. Figure 2 As shown, the flexible film 135 may include a sealant layer 1351, a moisture barrier layer 1352, and a surface protective layer 1353, and may also include a stretching aid layer 1354 if necessary.

[0116] The sealant layer 1351 can be made of a first polymer and formed in the innermost layer, directly contacting the electrode assembly 10. Here, the innermost layer refers to the last layer when oriented in a direction opposite to that of the electrode assembly 10 relative to the moisture barrier layer 1352. When the pouch film 135 having the stacked structure described above is stretched using a punch 22 or similar method, a portion of the pouch film 135 can be stretched to form a cup portion 133 including a receiving space 1331 with a pouch shape, while simultaneously manufacturing the battery housing 13. Furthermore, when the electrode assembly 10 is received in the receiving space 1331, an electrolyte is injected. Subsequently, when the first housing 131 and the second housing 132 contact each other to face each other, and thermal compression is applied to the edges 134, the sealant layers 1351 adhere to each other to seal the pouch. Here, since the sealant layer 1351 is in direct contact with the electrode assembly 10, the sealant layer 1351 must have insulating properties. Furthermore, since the sealant layer 1351 is in contact with the electrolyte, the sealant layer 1351 must be corrosion-resistant. Furthermore, since the interior of the battery casing 13 is completely sealed to prevent material movement between the interior and exterior of the battery casing 13, high sealing performance must be achieved. That is, the edges 134 where the sealant layers 1351 are bonded together should have excellent thermal bonding strength. Typically, the first polymer forming the sealant layer 1351 may include one or more materials selected from: polyethylene, polypropylene, polycarbonate, polyethylene terephthalate, polyvinyl chloride, acrylic polymers, polyacrylonitrile, polyimide, polyamide, cellulose, aromatic polyamide, nylon, polyester, poly(p-phenylenebenzodioxazole), polyarylate, polytetrafluoroethylene, and glass fiber. Specifically, polyolefin resins (e.g., polypropylene (PP) or polyethylene (PE)) are used for the sealant layer 1351. Polypropylene (PP) has excellent mechanical properties (e.g., tensile strength, rigidity, surface hardness, abrasion resistance, and heat resistance) and chemical properties (e.g., corrosion resistance), and is therefore primarily used in the manufacture of the sealant layer 1351. Furthermore, the sealant layer 1351 can be made of cast polypropylene, acid-modified polypropylene, or a polypropylene-butene-ethylene terpolymer. Here, the acid-treated polypropylene can be maleic anhydride polypropylene (MAH PP). Additionally, the sealant layer 1351 can have a single-layer structure made of one material, or a composite layer structure in which two or more materials are formed as layers.

[0117] A moisture barrier layer 1352 is stacked between the surface protective layer 1353 and the sealant layer 1351 to ensure the mechanical strength of the pouch, prevent the introduction and release of gas or moisture from the outside of the secondary battery 1, and prevent electrolyte leakage. The moisture barrier layer 1352 can be made of an aluminum alloy film. The aluminum alloy film can ensure mechanical strength above a predetermined level, but is lightweight. Therefore, the aluminum alloy film can complement the electrochemical performance and ensure the dissipation of heat generated by the electrode assembly 10 and the electrolyte.

[0118] More specifically, the grain size of the aluminum alloy film according to one embodiment of the present invention can be from 10 μm to 13 μm, preferably from 10.5 μm to 12.5 μm, and more preferably from 11 μm to 12 μm. When the grain size of the aluminum alloy film meets the above range, the molding depth can be increased when molding the cup portion without causing pinholes or cracks.

[0119] In addition to aluminum, aluminum alloy films may include one or more of the following: iron (Fe), copper (Cu), chromium (Cr), manganese (Mn), nickel (Ni), magnesium (Mg), and zinc (Zn).

[0120] The surface protective layer 1353 is made of a second polymer and formed on the outermost layer to protect the secondary battery 1 from external friction and impact, and also to electrically insulate the electrode assembly 10 from the outside. Here, the outermost layer refers to the last layer disposed when oriented in a direction opposite to the direction in which the electrode assembly 10 is disposed relative to the moisture barrier layer 1352. The second polymer forming the surface protective layer 1353 may include one or more materials selected from polyethylene, polypropylene, polycarbonate, polyethylene terephthalate, polyvinyl chloride, acrylic polymers, polyacrylonitrile, polyimide, polyamide, cellulose, aromatic polyamide, nylon, polyester, poly(p-phenylenebenzodioxazole), polyarylate, polytetrafluoroethylene, and glass fiber. Specifically, polymers with abrasion resistance and heat resistance, such as polyethylene terephthalate (PET), may be used primarily. Furthermore, the surface protective layer 1353 may have a single-layer structure made of one material, or a composite layer structure in which two or more materials are respectively formed as layers.

[0121] Although PET is inexpensive, has excellent durability, and excellent electrical insulation, it has poor adhesion to aluminum, which is often used in the moisture barrier layer 1352, and its performance differs when stretched under pressure. Therefore, when the surface protective layer 1353 and the moisture barrier layer 1352 are directly bonded together, the surface protective layer 1353 peels off from the moisture barrier layer 1352 during stretch molding. This results in uneven stretching of the moisture barrier layer 1352, leading to poor molding performance.

[0122] According to one embodiment of the present invention, the battery casing 13 may be made of a third polymer and further includes a stretching aid layer 1354 stacked between the surface protective layer 1353 and the moisture barrier layer 1352. The stretching aid layer 1354 is stacked between the surface protective layer 1352 and the moisture barrier layer 1352 to prevent delamination of the surface protective layer 1353 and the moisture barrier layer 1352 when stretching the surface protective layer 1352 and the moisture barrier layer 1352. The third polymer forming the stretching aid layer 1354 may include one or more materials selected from polyethylene, polypropylene, polycarbonate, polyethylene terephthalate, polyvinyl chloride, acrylic polymers, polyacrylonitrile, polyimide, polyamide, cellulose, aromatic polyamide, nylon, polyester, poly(p-phenylenebenzodioxazole), polyarylate, polytetrafluoroethylene, and glass fiber. Specifically, since nylon resin readily adheres to the polyethylene terephthalate (PET) of the surface protective layer 1352 and exhibits similar behavior to the aluminum alloy of the moisture barrier layer 1352 during stretching, it is preferable to primarily use nylon resin. Furthermore, the stretching aid layer 1354 may have a single-layer structure made of one material, or a composite layer structure in which two or more materials are each formed as a layer.

[0123] The total thickness of the flexible film 135 according to the present invention can be from 160 μm to 200 μm, preferably from 180 μm to 200 μm. When the thickness of the flexible film 135 meets the above range, the molding depth increases, while the reduction in battery housing space and the deterioration of sealing durability are minimized due to the increase in the thickness of the flexible film.

[0124] Figure 3 This is a schematic diagram of a molding apparatus 2 according to an embodiment of the present invention.

[0125] According to an embodiment of the present invention, a molding apparatus 2 for molding a flexible film 135 includes: a mold 21 on which the flexible film 135 is disposed; and a punch 22 disposed above the mold 21 to descend and press the flexible film 135. Furthermore, the mold 21 includes a molding portion 211 recessed inward from its top surface, and the punch 22 forms a cup portion 133 by inserting the flexible film 135 into the molding portion 211 to stretch and shape the flexible film 135.

[0126] According to one embodiment of the present invention, when molding the soft film 135 using the molding apparatus 2, such as Figure 3As shown, the mold 21 has two adjacent molding portions 211, and a partition wall 212 is formed between the two molding portions 211. When the soft film 135 is stretched and shaped while the punch 22 is inserted into the two molding portions 211, a cup portion can be formed in each of the first housing 131 and the second housing 132 to correspond to each of the two molding portions 211, thus forming a total of two cup portions 133. In addition, a bridge portion 136 can be formed between the two cup portions 133 to correspond to the partition wall 212.

[0127] Subsequently, when the battery casing 13 is folded, the bridge portion 136 can serve as a reference portion. When the secondary battery 1 is manufactured, the bridge portion 136 can form a folded portion 139 on one side of the secondary battery 1 (see...). Figure 11 Since the first housing 131 and the second housing 132 are integrally connected to each other via the fold 139, the number of edges 134 to be sealed can be reduced when a sealing process is subsequently performed. Therefore, the process speed can be increased, and the number of sealing processes can be reduced. Here, as the width of the fold 139 decreases, the outer wall 138 of the cup portion 133 (see...) Figure 5 The space 17 between the electrode assembly 10 and the electrode assembly 10 (see Figure 5 The volume of the secondary battery 1 will also decrease, so the energy density relative to the volume will increase due to the decrease in the overall volume of the secondary battery 1.

[0128] Because the width of the fold 139 and the thickness t of the bridge 136 (see...) Figure 5 The bridge portion 136 is formed to correspond to the partition wall 212, so the thickness t of the bridge portion 136 is proportional to the thickness of the partition wall 212. Therefore, when molding the soft film 135, the thickness t of the bridge portion 136 can be minimized, and for this purpose, the thickness of the partition wall 212 can be minimized. However, if the partition wall 212 is formed to have an excessively high height in a thin state, the partition wall 212 will be damaged during the stretch forming process. Specifically, according to the prior art, the mold has a bottom, but in this case, when the punch 22 molds the soft film 135, the gas present in the space between the soft film 135 and the molding portion 211 cannot be discharged. Therefore, recently, the bottom of the mold can be removed so that the gas present in the space between the soft film 135 and the molding portion 211 can be easily discharged, but the height of the partition wall 212 will be too high. Therefore, according to an embodiment of the present invention, as Figure 3As shown, a reinforcing portion 2121 with a thickness greater than that of the partition wall 212 can be formed at the lower part of the partition wall 212. The reinforcing portion 2121 can be formed to a depth D greater than that of the cup portion 133 to be formed in the battery casing 13, and can be formed at a location where the partition wall 212 will not be damaged. The exact location of the reinforcing portion 2121 can be experimentally determined based on the thickness of the partition wall 212, the material of the partition wall 212, the pressure of the punch 22, and the molding depth D of the cup portion 133 to be formed.

[0129] Figure 4 This is an enlarged schematic diagram of the cup portion 333 and the bridge portion 336 based on the prior art.

[0130] According to the existing technology, there are limitations in manufacturing the battery casing 33 and the secondary battery 3 as a whole into a sharp shape.

[0131] Specifically, according to the prior art, there are limitations in reducing the radius of curvature of the edge 36 of the cup portion 333.

[0132] The edge 36 of the cup portion 333 includes: a stamped edge 361, formed as an edge 221 corresponding to the punch 22 (see...). Figure 3 ); and mold edge 362 (see Figure 8 ), forming an edge 213 corresponding to the mold 21 (see Figure 3 ).

[0133] The stamping edge 361 connects each of the plurality of outer walls 338 surrounding the periphery of the cup portion 333 to the bottom 3332. However, if the edge 221 of the punch 22 is not rounded, the edge 221 of the punch 22 is sharp. Therefore, when forming the soft film, stress will concentrate at the stamping edge 361 of the cup portion 333, making it prone to cracking. Furthermore, the die edge 362 connects each of the plurality of outer walls 338 to the edge 134 or the degassing portion 137. If the extrusion edge of the die 21 is not rounded, the extrusion edge of the die 21 is sharp. Therefore, when forming the soft film, stress will concentrate at the die edge 362 of the cup portion 333, making it prone to cracking. Here, rounding of the die edge refers to forming a curved surface with curvature, and this curved surface may have only uniform curvature, but is not limited to this. For example, the curved surface may have non-uniform curvature. In this specification, the rounding of the stamping edge 161, the mold edge 162, the bridge portion 136, etc. with a specific curvature not only means that the stamping edge 161, the mold edge 162, the bridge portion 136, etc. have a specific curvature as a whole, but also means that they have a specific curvature only on at least a portion of them.

[0134] To solve the above problems, such as Figure 4As shown, the edges 221 of the punch 22 and 213 of the die 21 are rounded according to the rounded stamping edge 361 of the cup portion 333. Therefore, the stress concentrated on the stamping edge 361 and the die edge 362 of the cup portion 333 can be dispersed to a certain extent.

[0135] However, even if the stamping edge 361 and the mold edge 362 of the cup portion 333 are formed into rounded shapes, if the radius of curvature R2′ of the stamping edge 361 and the radius of curvature of the mold edge 362 are small compared to the depth D′ of the cup portion 333, cracks will occur in the stamping edge 361 and the mold edge 362 of the cup portion 333. For example, in the prior art, if the depth D′ is about 7 mm or more when molding one cup portion 333, and about 6.5 mm or more when molding two cup portions 333, cracks will appear in the soft film 135 when each of the radius of curvature R2′ of the stamping edge 361 and the radius of curvature of the mold edge 362 is less than 2 mm.

[0136] Furthermore, when forming two cup portions 133, a partition wall 212 must be present in the mold 21 to form the bridge portion 136. However, in the prior art, if the depth D′ of the cup portion 333 is formed to a greater depth (e.g., 6.5 mm or more), there are limitations in forming a thinner bridge portion 336. That is, if the partition wall 212 is also formed to have a predetermined thickness or less to form a bridge portion 336 with a predetermined thickness or less, cracks will appear in the bridge portion 336 due to the sharp formation of the partition wall 212.

[0137] To solve this problem, such as Figure 4 As shown, the bridge portion 336 is formed into a rounded shape by rounding the partition wall 212. Therefore, the stress concentrated in the bridge portion 336 can be dispersed to a certain extent. Specifically, when the radius of curvature R1′ of the bridge portion 336 is constant, the radius of curvature R1′ corresponds to half the thickness t′ of the bridge portion 336. For example, when the radius of curvature R1′ of the bridge portion 336 is formed to be approximately 1 mm, the thickness t′ of the bridge portion 336 is formed to be approximately 2 mm.

[0138] However, even if the bridge portion 336 is rounded, if the depth D′ of the cup portion 333 is formed to be relatively deep, and the thickness t′ of the bridge portion 336 is relatively small, cracks will occur in the bridge portion 336. For example, when the depth D′ of the cup portion 333 is formed to be approximately 6.5 mm or more, and the radius of curvature R1′ of the bridge portion 336 is less than 1 mm, that is, when the thickness t′ of the bridge portion 336 is less than 2 mm, cracks will occur in the bridge portion 336.

[0139] Furthermore, the relatively large size of the gap CL′ limits the ability to form the outer wall 338 of the cup portion 333 into a near-vertical state. The gap CL refers to the vertical distance between the inner wall of the molding portion 211 of the mold 21 and the outer wall of the punch 22. In reality, there is a small dimensional difference, roughly the same size as the gap CL, between the molding portion 211 of the mold 21 and the punch 22. If the gap CL is too small, the distance between the inner wall of the molding portion 211 and the outer wall of the punch 22 becomes too small. Consequently, the soft film 135 cannot be inserted into the molding portion 211, or the soft film 135 may be damaged due to excessive friction. On the other hand, if the gap CL is too large, the tilt angle of the outer wall 338 of the cup portion 333 increases, and the space 37 between the outer wall 338 of the cup portion 333 and the electrode assembly 10 increases. Therefore, when molding the soft film 135, a gap CL of appropriate size must be provided.

[0140] The bridge portion 336 is formed as a partition wall 212 corresponding to the mold 21, and the stamping edge 361 is formed as an edge 221 corresponding to the punch 22. Therefore, the gap CL′, which is the vertical distance between the inner wall of the molding portion 211 of the mold 21 and the outer wall of the punch 22, can represent the vertical distance between the bridge portion 336 and the stamping edge 361 in the battery housing 33.

[0141] Specifically, such as Figure 4 As shown, the bridge vertical line V1′ and the edge vertical line V2′ are virtually illustrated. The bridge vertical line V1′ is a virtual vertical line passing through the boundary point P1′ between the bridge portion 336 and the outer wall 338 on the side of the bridge portion 336, and perpendicular to the bottom 3332. Similarly, the edge vertical line V2′ is a virtual vertical line passing through the boundary point P2′ between the stamping edge 361 on the side of the bridge portion 336 and the outer wall 338 on the side of the bridge portion 336, and perpendicular to the bottom 3332. The bridge vertical line V1′ corresponds to the inner wall of the molding portion 211 of the mold 21 (specifically, the inner wall of the partition wall 212), and the edge vertical line V2′ corresponds to the outer wall of the punch 22. Therefore, the vertical distance between the bridge vertical line V1′ and the edge vertical line V2′ corresponds to the gap CL′ generated in the battery housing 33.

[0142] However, in the prior art, if the depth D′ of the cup portion 333 is formed to be relatively deep (e.g., 6.5 mm or more), cracks are easily generated in the soft membrane 135 when the gap CL is reduced to less than 0.5 mm. As described above, in the prior art, if the depth D′ of the cup portion 333 is formed to be relatively deep (e.g., 6.5 mm or more), there are limitations in forming a smaller gap CL′, and therefore the inclination angle between the outer wall 338 of the cup portion 333 and the bottom 3332 is greater than 95°. That is, there are limitations in forming the outer wall 338 of the cup portion 333 into a vertical state similar to having an inclination angle of less than 95°.

[0143] Furthermore, due to limitations in improving the radius of curvature R2′ of the edge of the cup portion 333, there are also problems in reducing the volume of the electrode assembly 10 housed in the cup portion 333. Specifically, as Figure 4 As shown, in the prior art, due to the large radius of curvature R2′ of the stamped edge 361 of the cup portion 333, when the electrode assembly 10 is positioned too close to the outer wall 338 of the cup portion 333, there is a problem that the electrode 101 of the electrode assembly 10 is damaged by the stamped edge 361 of the cup portion 333. That is, one end of the metal electrode 101 is positioned on the stamped edge 361 of the cup portion 333, and one end of the electrode 101 is deformed to correspond to the stamped edge 361 of the cup portion 333, thereby causing damage.

[0144] To address this issue, in the prior art, when the electrode assembly 10 is housed in the cup portion 333, the electrode assembly 10 is housed at a certain distance from the outer wall 338 of the cup portion 333. First, the vertical distance g′ between the electrode assembly 10 and the edge vertical line V2′ is 0.75 mm, specifically 0.5 mm, and a reference vertical line V3′ perpendicular to the bottom 3332 is virtually shown. Then, as... Figure 4 As shown, the electrode assembly 10 is housed such that one end of the electrode 101 is positioned outside the reference vertical line V3′. Therefore, since the electrode 101 is spaced apart from the outer wall 338 of the cup portion 333 to a certain extent, damage to the electrode 101 can be prevented. However, in this case, because the space 37 between the outer wall 338 of the cup portion 333 and the electrode assembly 10 increases, the volume ratio of the electrode assembly 10 to the cup portion 333 becomes smaller, resulting in a decrease in the energy density of the secondary battery 3 relative to its volume. Furthermore, due to the unnecessary increase in the volume of the space inside the cup portion 333, there is also the problem of the electrode assembly 10 moving within the cup portion 333 before the sealing edge.

[0145] Furthermore, in the electrode assembly 10, the electrode 101 has high rigidity and is not easily deformed by external forces, while the diaphragm 102 has high flexibility and is easily deformed by external forces. However, when adjacent electrodes 101 are in direct contact with each other, a short circuit occurs. Therefore, the diaphragm 102 is formed to be larger than the electrode 101 to prevent short circuits. Thus, when forming the electrode assembly 10, a peripheral portion 1021 in which the diaphragm 102 protrudes outward from the electrode 101 is formed together. However, in the prior art, since the electrode assembly 10 is housed at a certain distance from the outer wall 338 of the cup portion 333, all the peripheral portions 1021 of the diaphragm 102 are randomly wrinkled or folded, exposing the electrode 101 to the outside, thereby increasing the possibility of short circuits.

[0146] As described above, in the prior art, when the depth D′ of the cup portion 333 is formed to be relatively deep (e.g., 6.5 mm or more), there are limitations in improving the thickness t′ of the bridge portion 336, the radius of curvature R2′ of the edge 361 of the cup portion 333, and the gap CL′. Furthermore, since the volume ratio of the electrode assembly 10 to the cup portion 333 is small, the unnecessary volume in the secondary battery 3 is also large, and the energy density relative to the volume is reduced. Moreover, since the outer wall 338 of the cup portion 333 is not formed in a near-vertical state, and the radius of curvature R2 of the edge 361 of the cup portion 333 is also large, there are limitations in manufacturing an overall sharp shape. Therefore, the problem is that the secondary battery 3 has an unattractive appearance and reduced marketability.

[0147] Figure 5 This is an enlarged schematic diagram of the cup portion 133 and the bridge portion 136 according to an embodiment of the present invention. Figure 6 This is an enlarged schematic diagram of the cup portion 133 and the degassing portion 137 according to an embodiment of the present invention.

[0148] As described above, according to one embodiment of the present invention, the depth D of the cup portion 133 is molded to be less than 6.5 mm, while the thickness t of the bridge portion 136 is thinner, and the radius of curvature R2 of the edge 16 of the cup portion 133 and the gap CL are smaller to increase the volume of the electrode assembly 10. Therefore, since unnecessary volume in the secondary battery 1 is also reduced, the energy density relative to volume can be increased. Furthermore, since each of the pouch-type battery casing 13 and the pouch-type secondary battery 1 is manufactured with an overall sharp shape, the secondary battery 1 can have an aesthetically pleasing appearance and improved marketability.

[0149] Therefore, in a pouch-type battery casing 13 according to an embodiment of the present invention, a cup portion 133 is formed therein to accommodate an electrode assembly 10 formed by stacking electrodes 101 and separator 102, wherein the cup portion 133 includes: a plurality of stamped edges 161 connecting each of a plurality of outer walls 138 surrounding the periphery to a bottom 1332; a plurality of molded edges 162 connecting the outer walls 138 and edges 134 or degassing portions 137; and a thickness edge 163 connecting two adjacent outer walls 138 to each other.

[0150] At least one of the stamping edges 161 and at least one of the die edges 162 may be rounded and formed with a radius of curvature corresponding to 1 / 20 to 1 / 6 of the depth D of the cup portion 133. If the radius of curvature R2 of each of the edges 161 and 162 is less than 1 / 20 of the depth D of the cup portion 133, stress will be excessively concentrated in each of the edges 161 and 162, causing cracks. On the other hand, if the radius of curvature R2 of each of the edges 161 and 162 is greater than 1 / 6 of the depth D of the cup portion 133, the cup portion 133 cannot be formed sharply, thus reducing the energy density.

[0151] Specifically, at least one of the stamping edges 161 may be rounded with a radius of curvature R2 of less than 1 mm, and at least one of the die edges 162 may be rounded with a radius of curvature R2 of less than 1 mm.

[0152] The vertical distance between the mold edge vertical line V4 (which passes through the boundary points P1 and P3 of the mold edge 162 and the outer wall 138 of the mold edge 162 and is perpendicular to the bottom 1332) and the edge vertical line V2 (which passes through the boundary points P2 and P4 of the stamping edge 161 of the mold edge 162 and the outer wall 138 of the mold edge 162 and is perpendicular to the bottom 1332) is less than 0.5 mm. The thickness edge connects to two adjacent stamping edges 161 to form a corner 164, wherein at least one of the corners 164 is rounded with a radius of curvature R3 of 2 mm to 5 mm, where the radius of curvature is greater than that of the thickness edge. Furthermore, the depth D of the cup portion 133 can be less than 6.5 mm.

[0153] The cup portion 133 is formed by molding a flexible soft film 135 using a punch 22 or the like. The cup portion 133 is surrounded by a plurality of outer walls 138 and a bottom 1332, and the space formed by the outer walls 138 and the bottom 1332 serves as a receiving space 1331 for accommodating the electrode assembly 10.

[0154] The outer wall 138 of the cup portion 133 surrounds the periphery of the cup portion 133 to embody the shape of the cup portion 133. Multiple outer walls 138 are formed around the cup portion 133, and are also formed on one side of the bridge portion 136, on one side of the degassing portion 137 (described below), and on one side of the electrode lead 12. The outer wall 138 has an upper end facing the opening of the cup portion 133 and a lower end facing the bottom 1332.

[0155] As described above, the edge 16 of the cup portion 133 includes: a stamping edge 161, formed as an edge 221 corresponding to the punch 22; and a die edge 162, formed as an edge 213 corresponding to the die 21 (see...). Figure 3An edge 134 and a degassing portion 137 are formed outward from the upper end of the outer wall 138, and a die edge 162 connects the upper end of the outer wall 138 to the edge 134 or the degassing portion 137. In addition, a stamping edge 161 connects the lower end of the outer wall 138 to the bottom 1332.

[0156] Since the outer walls 138 of the cup portion 133 are formed in multiple ways, the edges 16 of the cup portion 133 are also formed in multiple ways, as many as the number of outer walls 138. That is, if the cup portion 133 is formed as a quadrilateral, then since the cup portion 133 also has four outer walls 138, it also has four stamping edges 161 and four die edges 162. Furthermore, according to one embodiment of the invention, the depth D of the cup portion 133 is molded to be 6.5 mm or less, and at least one stamping edge 161 in the cup portion 133 is rounded with a radius of curvature of 1 mm or less, in particular, 0.7 mm or less.

[0157] Specifically, according to one embodiment of the present invention, two cup portions 133 are formed on a soft film 135, and a bridge portion 136 is also formed between the two cup portions 133. Furthermore, as... Figure 5 As shown, among the plurality of stamped edges 161, the bridge portion 136-side stamped edge 1611, which connects the bridge portion 136-side outer wall 1381 facing the bridge portion 136 to the bottom 1332, can be formed with a radius of curvature of 1 / 20 to 1 / 6 corresponding to the depth D of the cup portion 133. Specifically, the bridge portion 136-side stamped edge 1611 can be formed with a radius of curvature of 1 mm or less, particularly 0.7 mm or less. Furthermore, as Figure 6 As shown, among the plurality of stamping edges 161, the die edge 162-side stamping edge 1612, which connects the die edge 162-side outer wall 1382 facing the die edge 162 formed on the degassing portion 137 or electrode lead 12 to the die edge 162-side stamping edge 1612 on the bottom 1332, can also be rounded with a radius of curvature corresponding to 1 / 20 to 1 / 6 of the depth D of the cup portion 133. Specifically, the die edge 162-side stamping edge 1612 can be formed with a radius of curvature of 1 mm or less, particularly 0.7 mm or less. Here, at the boundary points P2 and P4 between the stamping edge 161 and the outer wall 138, the slope is preferably continuous.

[0158] Therefore, the edge 221 of the punch 22 can also be rounded with a predetermined radius of curvature. Here, the radius of curvature of the edge 221 of the punch 22 can be a value obtained by subtracting the thickness of the soft film 135 itself from the radius of curvature R2 of the stamping edge 161. For example, if the thickness of the soft film 135 is 0.2 mm, then when the radius of curvature of the edge 221 of the punch 22 is 0.5 mm or less, the radius of curvature R2 of the stamping edge 161 is 0.7 mm or less.

[0159] According to one embodiment of the present invention, when the soft film 135 is stretched and formed such that the depth D of the cup portion 133 is less than 6.5 mm, a crack is generated in the stamping edge 161 of the cup portion 133.

[0160] The outer wall 138 has an upper end with an opening facing the cup portion 133, and the edge 134 and the degassing portion 137 extend to the outside of the cup portion 133. Here, as... Figure 6 As shown, the cup portion 133 may further include a plurality of mold edges 162 connecting the upper end of the outer wall 138 to the edge 134 or the degassing portion 137. Furthermore, at least one mold edge 162 may also be rounded with a radius of curvature corresponding to 1 / 20 to 1 / 6 of the depth D of the cup portion 133. Specifically, at least one mold edge 162 may be rounded with a radius of curvature of less than 1 mm, particularly less than 0.7 mm.

[0161] Therefore, the edge 213 of the mold 21 can also be rounded with a predetermined radius of curvature. Here, the radius of curvature of the edge 213 of the mold 21 can be a value obtained by subtracting the thickness of the soft film 135 itself from the radius of curvature R2 of the stamping edge 161. For example, if the thickness of the soft film 135 is 0.2 mm, then when the radius of curvature of the edge 213 of the mold 21 is 0.5 mm or less, the radius of curvature of the mold edge 162 is 0.7 mm or less.

[0162] Specifically, as described above, two cup portions 133 are formed on a soft-pack membrane 135, and a bridge portion 136 is also formed between the two cup portions 133. That is, according to an embodiment of the present invention, the soft-pack battery housing 13 includes: a first housing 131 and a second housing 132, wherein cup portions 133 are formed in the first housing and the second housing respectively, wherein electrode assemblies 10 formed by stacking electrodes 101 and separator 102 are accommodated therein; and a bridge portion 136 is formed between the two cup portions 133.

[0163] Since the bridge portion 136 is also formed as a partition wall 212 corresponding to the mold 21, the bridge portion 136 can be one of a plurality of mold edges 162.

[0164] According to one embodiment of the present invention, due to the improved molding performance of the soft film 135, the thickness of the bridge portion 136 can be 1 / 200 to 1 / 30 of the width of the electrode assembly 10. If the thickness t of the bridge portion 136 is less than 1 / 200 of the width of the electrode assembly 10, stress will be excessively concentrated in the bridge portion 136, resulting in cracks. If the thickness t of the bridge portion 136 is greater than 1 / 30 of the width of the electrode assembly 10, the bridge portion 136 cannot be formed sharply, thus reducing the energy density.

[0165] Specifically, the thickness t of the bridge portion 136 can be formed to be less than 2 mm, particularly less than 1.4 mm.

[0166] Here, as Figure 5 As shown, the thickness t of the bridge portion 136 is preferably the distance between the two boundary points P1 of the bridge portion 136 and the outer side wall 1381 of the bridge portion 136. Specifically, the thickness t of the bridge portion 136 is preferably the distance between the two perpendicular bridge lines V1 passing through the boundary points P1 of the bridge portion 136 and the outer side wall 1381 of the bridge portion 136, and the perpendicular bridge lines V1 are perpendicular to the bottom 1332. Therefore, when the bridge portion 136 has a constant radius of curvature, the radius of curvature of the bridge portion 136 can correspond to half of the thickness t. Therefore, the radius of curvature of the bridge portion 136 can be less than 1 mm, particularly less than 0.7 mm.

[0167] Therefore, the partition wall 212 of the molding section 211 can also be rounded with a predetermined radius of curvature. Here, at the boundary point P1 between the bridge section 136 and the outer side wall 1381 of the bridge section 136, the slope is preferably continuous. Here, the radius of curvature of the top surface of the partition wall 212 of the molding section 211 can be a value obtained by subtracting the thickness of the soft film 135 from the radius of curvature of the bridge section 136. For example, if the thickness of the soft film 135 is 0.2 mm, then when the radius of curvature of the top surface of the partition wall 212 is 0.5 mm or less, the radius of curvature of the bridge section 136 is 0.7 mm or less.

[0168] According to one embodiment of the invention, even if the radius of curvature of the edge 213 of the mold 21 is reduced and the thickness of the partition wall 212 is made thinner, the depth D of the cup portion 133 is also formed to be less than 6.5 mm to prevent cracks from easily forming in the mold edge 162 and the bridge portion 136. The bridge portion 136 may have a fan-shaped cross-section, and since the outer wall 138 of the cup portion 133 is formed in a near-vertical state, the cross-section may have a near-semi-circular shape.

[0169] Furthermore, due to the improved molding properties of the soft film 135, the gap CL can be reduced to below 0.5 mm, allowing all the multiple outer walls 138 to be formed in a nearly vertical state. For example, as Figure 5 As shown, the bridge portion 136 side outer wall 1381 among the plurality of outer walls 138 can be formed in a nearly vertical state. That is, the gap CL is the vertical distance between the bridge portion 136 and the bridge portion 136 side outer wall 1381 boundary point P1 and the bridge portion vertical line V1 perpendicular to the bottom 1332, and the bridge portion 136 side stamping edge 1611 and the bridge portion 136 side outer wall 1381 boundary point P2 and the bottom 1332 edge vertical line V2, which can be less than 0.5 mm, and in particular, less than 0.35 mm.

[0170] In addition, such as Figure 6As shown, the outer wall 1382 on the mold edge 162 side among the multiple outer walls 138 can also be formed in a nearly vertical state. That is, the gap CL is the vertical distance between the boundary point P3 of the mold edge 162 and the outer wall 1382 on the mold edge 162 side and the mold edge vertical line V4 perpendicular to the bottom 1332, and the boundary point P4 of the stamping edge 1612 on the mold edge 162 side and the outer wall 1382 on the mold edge 162 side and the mold edge vertical line V2 perpendicular to the bottom 1332. It can be less than 0.5 mm, and in particular, less than 0.35 mm.

[0171] Therefore, even if the depth D of the cup portion 133 is less than 6.5 mm, the inclination angle between the outer wall 138 of the cup portion 133 and the bottom 1332 can be 90° to 95°, and it can also be formed in a near-vertical state with an inclination between 90° and 93°, thus preventing cracks from appearing in the battery casing 13. Furthermore, since the space between the outer wall 138 of the cup portion 133 and the electrode assembly 10 is also reduced, the energy density of the secondary battery 1 relative to its volume can be increased.

[0172] Because the radius of curvature R2 of the stamped edge 161 of the cup portion 133 is further reduced, the electrode 101 of the electrode assembly 10 can be prevented from being damaged even when the electrode assembly 10 is positioned very close to the outer wall 138 of the cup portion 133.

[0173] Therefore, a method for manufacturing a pouch-type secondary battery 1 according to an embodiment of the present invention includes: a step of forming an electrode assembly 10 by stacking electrodes 101 and a separator 102; a step of molding a pouch film 135 to form a cup portion 133, thereby manufacturing a pouch-type battery housing 13; a step of accommodating the electrode assembly 10 in a receiving space 1331 of the cup portion 133; and a step of sealing the edge 134 extending to the outside of the cup portion 133 to manufacture the pouch-type secondary battery 1.

[0174] Specifically, in the process of accommodating the electrode assembly 10, the difference between the width CW of the cup portion 133 and the width EW of the electrode assembly 10 can be 2.5 mm or less, particularly 1.7 mm or less. Here, the width EW of the electrode assembly 10 can refer to the width of the electrode 101. That is, the peripheral portion 1021 protruding from the diaphragm 102 rather than the electrode 101 can be excluded from the calculation of the width EW.

[0175] Additionally, the electrode assembly 10 can be accommodated such that at least one end of the electrode 101 is positioned at a vertical distance g from the edge vertical line V2 of 0.75 mm, specifically less than 0.5 mm. The edge vertical line V2 passes through the boundary point P2 between the stamped edge 161 and the outer wall 138 and is perpendicular to the bottom 1332.

[0176] Specifically, such as Figure 5 and Figure 6 As shown, a perpendicular line V2, perpendicular to the bottom 1332, is virtually shown, passing through the boundary point P2 of the stamped edge 161 and the outer wall 138. Furthermore, the electrode assembly 10 is housed such that the vertical distance g between at least one end of the electrode 101 and the perpendicular line V2 is 0.75 mm or less, specifically, 0.5 mm or less. More specifically, the vertical distance g between the electrode 101 and the perpendicular line V2 is 0.75 mm, specifically, 0.5 mm, and a reference vertical line V3 perpendicular to the bottom 1332 is virtually shown. Here, since the radius of curvature R2 of the stamped edge 161 can be specifically 0.7 mm or less, the reference vertical line V3 passes through the center of curvature C of the stamped edge 161. Furthermore, the electrode assembly 10 is housed such that one end of the electrode 101 is positioned between the perpendicular line V2 and the reference vertical line V3. This can be confirmed by disassembling the secondary battery 1 itself, but is not limited to this, and can be confirmed without disassembling the secondary battery 1 by various methods such as computed tomography (CT), magnetic resonance imaging (MRI), X-ray, etc. Therefore, the volume ratio of the electrode assembly 10 to the cup portion 133 can be further increased, while preventing damage to the electrode 101, thus increasing the energy efficiency relative to volume. Furthermore, the unnecessary volume reduction inside the cup portion 133 prevents the electrode assembly 10 from moving inside the cup portion 133.

[0177] Furthermore, because the electrode assembly 10 is housed very close to the outer wall 138 of the cup portion 133, the diaphragm 102 will not wrinkle or fold messily. Figure 5 As shown, the peripheral portion 1021 of the separator 102 protruding outward from the electrode 101 is folded toward the bottom 1332 in the opposite direction to one end of the electrode 101. An electrode assembly 10 is formed by stacking the electrodes 101 and the separator 102, and multiple electrodes 101 and multiple separators 102 can be formed. The battery housing 13 includes a first housing 131 and a second housing 132. If the bridge portion 136 of the battery housing 13 is folded to accommodate the upper part of the electrode assembly 10 in the cup portion 133, the separator 102 accommodated in the cup portion 133 of the first housing 131 is provided such that the peripheral portion 1021 is folded to face the second housing, and the separator 102 accommodated in the cup portion 133 of the second housing 132 is provided such that the peripheral portion 1021 is folded to face the first housing 131. Therefore, the peripheral portions 1021 of the separator 102 are aligned and folded in an orderly manner. Furthermore, since the separator 102 covers the electrode 101 to prevent it from being exposed to the outside, short circuits can be prevented.

[0178] More specifically, before the electrode assembly 10 is housed in the cup portion 133, the width of the diaphragm 102 may be wider than the width CW of the cup portion 133. Therefore, when the electrode assembly 10 is housed in the cup portion 133, the peripheral portion 1021 of the diaphragm 102 may be folded in a predetermined direction that contacts the inner circumference of the cup portion 133.

[0179] The difference between the width CW of the cup portion 133 and the width EW of the electrode assembly 10 can be very small, such as less than 2.5 mm, and particularly less than 1.7 mm. Therefore, a process is required where the outer portion 1021 of the diaphragm 102 can be easily folded while accommodating the electrode assembly 10 in the cup portion 133.

[0180] Therefore, the process of accommodating the electrode assembly 10 in the receiving space 1331 of the cup portion 133 may include pressing the electrode assembly 10 into the cup portion 133. Thus, compared to the conventional method of placing the electrode assembly 10 on the cup portion, the diaphragm 102 can be folded in a specific direction while maintaining a small difference between the width CW of the cup portion 133 and the width EW of the electrode assembly 10, making it easy and reliable to accommodate the electrode assembly 10 in the receiving space of the cup portion 133.

[0181] Additionally, the process of accommodating the electrode assembly 10 within the receiving space 1331 of the cup portion 133 may further include folding the corners (vertices) of the plurality of diaphragms 102 in the electrode assembly 10 before pressing the electrode assembly 10 into the interior of the cup portion 133. In the above process, the corners (vertices) of the plurality of diaphragms 102 may be folded using a separate sealing tool to gather at the center portion in the stacking direction of the electrode assembly 10.

[0182] In other words, the electrode assembly 10 can be inserted into the cup portion 133 with the four corners of the diaphragm 102 pre-aligned. Therefore, the electrode assembly 10 can be smoothly inserted into the receiving space 1331 of the cup portion 133.

[0183] As described above, according to one embodiment of the present invention, due to the improved molding performance of the pouch film 135, the thickness t of the bridge portion 136 can be made thinner, the radius of curvature R2 of the edge 16 of the cup portion 133 and the gap CL can be made smaller, and the volume of the electrode assembly 10 can be increased. Therefore, since the unnecessary volume in the secondary battery 1 is also reduced, the energy density relative to volume can be increased. Furthermore, since each of the pouch battery casing 13 and the pouch secondary battery 1 is manufactured with an integrally sharp shape, the appearance of the secondary battery 1 can be excellent, and its marketability can be improved.

[0184] Figure 7 This is a schematic top view showing the state in which the electrode assembly 10 is housed in the cup portion 133 according to an embodiment of the present invention.

[0185] According to one embodiment of the present invention, as described above, since the radius of curvature R2 of the stamped edge 161 of the cup portion 133 is further reduced, the electrode assembly 10 is accommodated such that one end of the electrode 101 is disposed between the edge vertical line V2 and the reference vertical line V3. Therefore, even when the electrode assembly 10 is disposed very close to the outer wall 138 of the cup portion 133, damage to the electrode 10 of the electrode assembly 10 can be prevented.

[0186] The edge vertical line V2 and the reference vertical line V3 can also be shown on the stamping edge 1611 on the bridge 136 side and on the stamping edge 1612 on the die edge 162 side. The vertical distance g between the edge vertical line V2 and the reference vertical line V3 can be 0.75 mm, specifically 0.5 mm.

[0187] Furthermore, if two cup portions 133 are formed in the battery casing 13, since a bridge portion 136 is provided, a vertical line V1 of the bridge portion can be shown on one side of the cup portion 133, and a vertical line V4 of the mold edge can be shown on the other side of the cup portion 133. The vertical distance CL between the vertical line V1 of the bridge portion and the vertical line V2 of the edge can be 0.5 mm or less, particularly 0.35 mm or less, and the vertical distance CL between the vertical line V4 of the mold edge and the vertical line V2 of the edge can also be 0.5 mm or less, particularly 0.35 mm or less.

[0188] However, if only one cup portion 133 is formed in the battery housing 13, no bridge portion is provided. However, since mold edges 162 are formed on both sides of the cup portion 133, vertical lines V4 of the mold edges can be shown on both sides of the cup portion 133.

[0189] If two cup portions 133 are formed in the battery casing 13, the width CW of the cup portion 133 can represent the vertical distance from the bridge vertical line V1 to the mold edge vertical line V4. However, if only one cup portion 133 is formed, the width CW of the cup portion 133 can represent the vertical distance between the two mold edge vertical lines V4.

[0190] Both the vertical line V1 of the bridge portion and the vertical line V4 of the mold edge pass through the top of the outer wall 138 of the cup portion 133. Therefore, according to one embodiment of the invention, the width CW of the cup portion 133 can be the vertical distance between the upper ends of the outer walls 138 on both sides of the cup portion 133. The difference between the width CW of the cup portion 133 and the width EW of the electrode assembly 10 can be less than 2.5 mm, and in particular, less than 1.7 mm. Furthermore, as described above, the width EW of the electrode assembly 10 can be 60 mm or more.

[0191] The width CW of the cup portion 133 can be obtained by measuring the vertical distance between the upper ends of the outer walls 138 on both sides of the cup portion 133 in the battery housing 13. Furthermore, in the secondary battery 1, the position between the upper ends of the outer walls 138 on both sides can be identified from the outside of the cup portion 133 using a laser displacement sensor or the like, and then the distance between the two positions can be calculated. Here, when the laser displacement sensor moves from the edge 134 towards the mold edge 162 and the outer wall 138, and simultaneously irradiates a laser from the outside of the cup portion 133 to detect a point of sudden displacement change, the corresponding point can be identified as the upper end of the outer wall 138. The method for measuring the width CW of the cup portion described above is only an example, and is not limited to the case described above. In the sense of this invention, the width CW of the cup portion can be any width of the cup portion, as long as it falls within the scope and concept of the claims of this invention.

[0192] Figure 8 This is a schematic diagram of corner 364 based on existing technology. Figure 9 This is a schematic diagram of corner 164 according to an embodiment of the present invention.

[0193] The edge 16 of the cup portion 133 also includes: such as Figure 9 The thickness edge 163 of the two adjacent outer walls 138 of the connecting cup portion 133 is shown; as well as the stamping edge 161 and the die edge 162. The thickness edge 163 is formed in the thickness direction of the cup portion 133, and is formed when the soft film 135 is stretched between the corners of the die 21 and the corners of the punch 22. Furthermore, at least one of the thickness edges 163 may be rounded.

[0194] The radius of curvature of the thickness edge 163 can be the same as, but is not limited to, the radius of curvature R2 of the two adjacent stamping edges 161, namely the first stamping edge 1613 and the second stamping edge 1614. For example, the thickness edges can be formed differently. For example, as described above, although the depth D of the cup portion 133 is molded to be less than 6.5 mm, at least one of the stamping edges 161 can be rounded with a radius of curvature of less than 1 mm, particularly less than 0.7 mm, and at least one of the thickness edges 163 can be rounded with a radius of curvature of 0.5 mm to 5 mm, particularly less than 0.5 mm to 2 mm. According to the prior art, when the thickness edge 363 is formed to be rounded with a radius of curvature of less than 5 mm, particularly less than 2 mm, there is a problem that stress is also concentrated on the thickness edge 363 of the cup portion 333, causing cracks. However, according to an embodiment of the present invention, cracks in the thickness edge 163 of the cup portion 133 can be prevented. Here, one of the first stamping edge 1613 and the second stamping edge 1614 can be the stamping edge 1611 on the bridge portion 136 side, and the other can be the stamping edge on the electrode lead 12 side (not shown). Alternatively, one of the two stamping edges can be the stamping edge 1612 on the die edge 162 side, and the other can be the stamping edge on the electrode lead 12 side (not shown).

[0195] The thickness edge 163 is connected to two adjacent stamping edges 161, i.e., as shown in the figure. Figure 9 The first stamping edge 1613 and the second stamping edge 1614 shown are used to form a corner 164. In the prior art, such as Figure 8 As shown, all the plurality of edges 221 of the punch 22 are rounded with the same radius of curvature, so the corners (not shown) of the punch 22 are naturally rounded with the same radius of curvature. Therefore, when the soft film 135 is stretched by molding the soft film 135 with the punch 22, the corners 364 are naturally rounded with the same radius of curvature as the stamping edges 361.

[0196] However, when the flexible membrane 135 is stretched, there is a problem of stress concentration at the corner 364. Specifically, the corner 364 is formed by the convergence of three edges 361, so the corner 364 can be stretched more than the stamping edges 361 or the thick edges 363. Therefore, stress is concentrated more at the corner 364 than at the stamping edges 361 or the thick edges 363. As a result, the excessive stretching of the flexible membrane 135 causes whitening, in which specific portions turn white just before cracking occurs, and ultimately become prone to cracking.

[0197] Therefore, according to one embodiment of the present invention, such as Figure 12As shown, at least one of the corners 164 is also rounded, and the radius of curvature of the corner 164 is greater than or equal to the radius of curvature of at least one of the stamping edge 161 and the thickness edge 163.

[0198] Specifically, according to one embodiment of the invention, the radius of curvature inside the corner 164 can vary. That is, the radius of curvature of the central portion 1641 of the corner 164 and the radius of curvature of the peripheral portion 1642 of the corner 164 can be different from each other. Specifically, the radius of curvature of the central portion 1641 of the corner 164 can be greater than the radius of curvature of the peripheral portion 1642 of the corner 164. For example, the radius of curvature of the peripheral portion 1642 of the first corner 164 can be the same as the radius of curvature of at least one of the stamping edge 161 and the thickness edge 163 because it is adjacent to the first stamping edge 132, the second stamping edge 134 and the thickness edge 163. On the other hand, the radius of curvature of the central portion 1641 of the first corner 164 can be greater than the radius of curvature of at least one of the stamping edge 161 and the thickness edge 164 because it is spaced apart from the first stamping edge 1613, the second stamping edge 1614 and the thickness edge 163. In other words, the radius of curvature of the corner 164 may be different from the radius of curvature of at least one of the stamped edge 161 and the thickness edge 163.

[0199] Therefore, the radius of curvature of the corner 164 can gradually increase from the outer portion 1642 of the corner 164 towards the central portion 1641 of the corner 164. Furthermore, since the radius of curvature inside the corner 164 is not constant but varies, the central portion 1641 of the corner 164 can have an aspherical shape rather than a precise spherical shape.

[0200] Unlike the stamped edge 161, the corner 164 not only needs to have its radius of curvature clearly defined, but also its range within the cup portion 133. If the range of the corner 164 within the cup portion 133 is too narrow, the soft film 135 will still be overstretched, causing whitening or cracking. On the other hand, if the range of the corner 164 within the cup portion 133 is too wide, the space 17 between the outer wall 138 of the cup portion 133 and the electrode assembly 10 will be reduced, thus increasing the energy density of the secondary battery 1 relative to its volume. Therefore, according to an embodiment of the invention, as Figure 12 As shown, the corner 164 can be formed within 2 mm to 3.5 mm from the thickness edge 163 along the longitudinal direction 1c of the cup portion 133, within 2 mm to 3.5 mm from the thickness edge 163 along the width direction Wc of the cup portion 133, and within 2 mm to 3.5 mm from the stamping edge 161 along the thickness direction dc of the cup portion 133. Furthermore, the range in which the corner 164 is formed can gradually widen as the depth of the cup portion 133 increases.

[0201] As described above, the corner 164 of the cup portion 133 is formed, and the stress concentrated at the corner 164 can be dispersed to prevent whitening and cracking.

[0202] Figure 10 This is a schematic diagram showing the folded state of the battery casing 13 according to an embodiment of the present invention. Figure 11 This is a schematic diagram showing the battery casing 13 in a folded state according to an embodiment of the present invention.

[0203] When two cup portions 133 are formed in the soft film 135, the cup portions 133 are respectively formed in the first housing 131 and the second housing 132 of the battery housing 13. After the electrode assembly 10 is accommodated in the receiving space 1331 provided in the cup portion 133 of the first housing 131, as Figure 10 As shown, a bridge portion 136 formed between the two cup portions 133 is folded into the battery housing 13, such that the two cup portions 133 face each other. Because the bridge portion 136 is folded, a fold portion 139 is formed on one side of the secondary battery 1. Electrolyte can then be injected, and the edges 134 extending to the outside of the cup portions 133 of the first housing 131 and the second housing 132 can be sealed to create a structure as shown. Figure 11 The soft-pack type secondary battery shown is shown.

[0204] A pouch-type secondary battery 1 manufactured as described above according to an embodiment of the present invention may include: an electrode assembly 10, wherein electrodes 101 and a separator 102 are stacked; and a pouch-type battery housing 13 having a cup portion 133 therein for receiving the electrode assembly 10, wherein the cup portion 133 includes a plurality of stamped edges 161 respectively connecting a plurality of outer walls 138 and a bottom 1332. At least one of the stamped edges 161 may be rounded with a radius of curvature corresponding to 1 / 20 to 1 / 6 of the depth D of the cup portion 133. Specifically, at least one of the stamped edges 161 may be formed with a radius of curvature of less than 1 mm, particularly less than 0.7 mm. The difference between the width CW of the cup portion 133 and the width EW of the electrode assembly 10 may be less than 2.5 mm, particularly less than 1.7 mm. Furthermore, the electrode assembly 10 can be accommodated such that at least one end of the electrode 101 is positioned at a vertical distance g from the edge vertical line V2 of 0.75 mm, specifically less than 0.5 mm. The edge vertical line V2 passes through the boundary point P2 between the stamped edge 161 and the outer wall 138 and is perpendicular to the bottom 1332. Additionally, the battery housing 13 may include: a first housing 131 and a second housing 132, on which at least one of the first housing and the second housing is formed a cup portion 133; and a folding portion 139 integrally connecting the first housing 131 and the second housing 132.

[0205] When the battery casing 13 is folded to manufacture the secondary battery 1, the bridge portion 136 becomes the folded portion 139. In the secondary battery 1, the folded portion 139 integrally connects the first casing 131 and the second casing 132. Furthermore, the stamping edge 1611 on the side of the bridge portion 136 becomes the stamping edge 1611 on the side of the folded portion 139, and the outer wall 1381 on the side of the bridge portion 136 becomes the outer wall 1381 on the side of the folded portion 139.

[0206] Furthermore, among the plurality of stamped edges 161, the stamped edge 1611 on the folded portion 139 side, which connects the outer wall 1381 facing the folded portion 139 to the bottom 1332, can be rounded with a radius of curvature corresponding to 1 / 20 to 1 / 6 of the depth D of the cup portion 133. Specifically, the stamped edge 1611 on the folded portion 139 side can be rounded with a radius of curvature of 1 mm or less, particularly 0.7 mm or less. In addition, an electrode assembly 10 can be accommodated such that at least one end of the electrode 101 is disposed between the edge vertical line V2 and the reference vertical line V3. The edge vertical line V2 passes through the boundary point P2 between the stamped edge 161 and the outer wall 138 and is perpendicular to the bottom 1332. The vertical distance g between the reference vertical line V3 and the edge vertical line V2 is 0.75 mm, particularly 0.5 mm or less, and is perpendicular to the bottom 1332. As described above, the reference vertical line V3 can pass through the curvature center C of the stamped edge 161.

[0207] Figure 12 This is an enlarged view of a groove 1391 formed in a battery casing 13 according to an embodiment of the present invention.

[0208] According to one embodiment of the present invention, when the battery casing 13 is folded as described above to manufacture the secondary battery 1, the bridge portion 136 may be in the form of a folded portion 139. Specifically, when the battery casing 13 is folded, the rounded shape of the bridge portion 136 may also be unfolded to a certain extent, but the marks of the bridge portion 136 remain on the secondary battery 1, and these marks become the folded portions 139. Therefore, the bridge portion 136 and the folded portion 139 of the battery casing 13 may correspond to each other.

[0209] For example, when the rounded shape of the bridge portion 136 is not fully unfolded (like a flat surface), the fold portion 139 includes a groove 1391 recessed into the inner side of the secondary battery 1, such as... Figure 12 As shown in the figure. In this case, since the curvature of the fold 139 is smaller than that of the bridge 136, the fold 139 can have a larger radius of curvature.

[0210] Because the bridge portion 136 has a curved surface and the outer side wall 1381 of the bridge portion 136 has a planar shape, their deformation amounts differ. Therefore, when the battery casing 13 is folded, the outer side wall 1381 of the bridge portion 136 deforms relatively more, while the bridge portion 136 deforms relatively little, just enough to allow the rounded shape to unfold to a certain extent. Then, when the battery casing 13 is folded, as... Figure 12 As shown, the increase or decrease in the slope change changes near the boundary point P1. That is, each boundary point P1 becomes an inflection point. Therefore, the fold 139 can be formed as a curved surface between the two boundary points P1, i.e., the two inflection points.

[0211] Furthermore, when the rounded shape of the bridge portion 136 is not fully unfolded, the two boundary points P1, that is, the portions corresponding to the two inflection points, can protrude outward to form protrusions. In other words, the protrusions can be formed as a pair of outwardly protruding portions, with a fold portion 139, or more specifically, a groove 1391, inserted between them.

[0212] Alternatively, even if the rounded shape of the bridge portion 136 is fully unfolded (like a plane), the boundary point P1 between the bridge portion 136 and the outer side wall 1381 of the bridge portion 136 is connected to the secondary battery 1 through each of two lines (not shown), and the fold portion 139 is formed as a plane between the two lines.

[0213] The fold 139 can be visually identified from the appearance of the secondary battery 1. And as described above, since the thickness t of the bridge portion 136 is preferably the distance between the two boundary points P1 of the bridge portion 136 and the outer side wall 1381 of the bridge portion 136, the width FW of the fold 139 is the distance between the two boundary points P1. That is, if the rounded shape of the bridge portion 136 is not fully unfolded, the width FW of the fold 139 is the distance between the two boundary points P1, i.e., the two inflection points. Or, if the rounded shape of the bridge portion 136 is fully unfolded, the fold 139 is the distance between the two boundary points P1, i.e., the distance between the two lines.

[0214] The width FW of the folded portion 139 does not exceed the length of the bridge portion 136 and can be from 1 mm to 3.2 mm, particularly from 1 mm to 1.6 mm. As mentioned above, the width FW of the folded portion 139 can be measured directly with a ruler, but it can also be measured using a Lupe, or using a 3D camera or a laser 2D line sensor. That is to say, the width FW can be measured in various ways without limitation.

[0215] According to the prior art, the bridge portion 336 has a relatively thick thickness t′, and the folded portion 339 has a relatively large width, thus the space 37 between the outer wall 338 of the cup portion 333 and the electrode assembly 10 is also relatively large. However, according to an embodiment of the present invention, since the width FW of the folded portion 139 can be reduced, the space 17 between the outer wall 138 of the cup portion 133 and the electrode assembly 10 will also be reduced. Therefore, the energy density of the secondary battery 1 relative to its volume will increase.

[0216] Furthermore, due to the low forming performance of the soft film in the prior art, the protrusions protrude outwards significantly. However, according to an embodiment of the present invention, the protrusions can protrude relatively small, and the flatness of the fold 139 or the outer wall 1381 of the fold 139 side can be improved.

[0217] Specifically, the distance p between the innermost portion of the groove 1391 and the outermost portion of the protrusion can be defined as flatness. In the case of battery casings according to the prior art, the flatness is formed to be 1 mm or more, and even 1.5 mm. On the other hand, according to an embodiment of the present invention, the flatness p can be formed to be 0.8 mm or less, preferably 0.3 mm or less. Therefore, the energy density of the secondary battery 1 relative to its volume can be further increased.

[0218] Figure 13 This is an enlarged schematic diagram of the cup portion 133 and the mold edge 1621 according to another embodiment of the present invention.

[0219] According to one embodiment of the invention, two molding portions 211 are formed on the mold 21 adjacent to each other, and a partition wall 212 may be formed between the two molding portions 211. Therefore, when the soft film 135 is formed, two cup portions 133 are formed in one soft film 135, and a bridge portion 136 is also formed together between the two cup portions 133. That is, one cup portion 133 is formed in each of the first housing 131 and the second housing 132.

[0220] However, according to another embodiment of the invention, only one molding portion 211 is formed on the mold 21, and there are no partition walls. Therefore, when the soft film 135 is formed, a cup portion 133 is formed in the soft film 135, and there are no bridge portions. That is, the cup portion 133 is formed only in the first housing 131.

[0221] According to another embodiment of the invention, the depth D of the cup portion 133 is molded to be 6.5 mm or less, and at least one stamped edge 161a of the cup portion 133 is rounded with a radius of curvature corresponding to 1 / 20 to 1 / 6 of the depth D of the cup portion 133. Specifically, at least one of the stamped edges 161a of the cup portion 133 may be formed with a radius of curvature of 1 mm or less, particularly 0.7 mm or less. Therefore, it is possible to prevent cracks from easily forming in the stamped edges 161a of the cup portion 133.

[0222] Specifically, according to another embodiment of the present invention, such as Figure 13 As shown, among the plurality of stamped edges 161a, the second housing 132a-side stamped edge 1611, which connects the outer wall 1381a of the second housing 132a facing the second housing 132a to the bottom 1332, can be formed with a rounded radius of curvature corresponding to 1 / 20 to 1 / 6 of the depth D of the cup portion 133. Specifically, the second housing 132a-side stamped edge 1611a can be rounded and formed with a radius of curvature of 1 mm or less, particularly 0.7 mm or less.

[0223] Alternatively, the stamping edge 1612 on the die edge 162 side can also be rounded with a radius of curvature of 1 / 20 to 1 / 6 of the depth D of the cup portion 133. Specifically, the stamping edge 1612 on the die edge 162 side can be formed with a radius of curvature of 1 mm or less, particularly 0.7 mm or less. Here, at the boundary points P2 and P4 between the stamping edge 161a and the outer wall 138, the slope is preferably continuous.

[0224] In the following description of another embodiment of the invention, content that is repeated in one embodiment of the invention will be omitted. However, this is for ease of description and is not intended to limit the scope of the claims.

[0225] Figure 14 This is a schematic diagram showing the battery casing 13a in a folded state according to another embodiment of the present invention. Figure 15 This is a schematic diagram showing the battery casing 13a in a folded state according to another embodiment of the present invention.

[0226] The outer wall 138 has an upper end with an opening facing the cup portion 133, and the second housing 132a, edge 134, and degassing portion 137 extend to the outside of the cup portion 133. Here, the mold edge 162 connecting the upper end of the outer wall 138 and the second housing 132a, edge 134, or degassing portion 137 can be rounded with a radius of curvature corresponding to 1 / 20 to 1 / 6 of the depth D of the cup portion 133. Specifically, the mold edge 162 can be formed with a radius of curvature of less than 1 mm, particularly less than 0.7 mm.

[0227] That is, according to another embodiment of the present invention, such as Figure 14 As shown, there is no bridge portion in the battery casing 13a, and the mold edge 1621 connects the cup portion 133 of the first casing 131 to the second casing 132a. For this purpose, the edge 213 of the mold 21 can be rounded with a radius of curvature obtained by subtracting the thickness of the soft-film 135 from the mold edge 162. For example, if the thickness of the soft-film 135 is 0.2 mm, the edge 213 of the mold 21 can be rounded with a radius of curvature of 0.8 mm or less, particularly 0.5 mm or less.

[0228] Furthermore, by reducing the gap CL to below 0.5 mm, the outer wall 138 of the cup portion 133 can be formed into a near-vertical state. For example, as... Figure 13 As shown, the gap CL is the vertical distance between the boundary point P1 of the die edge 1621 and the outer wall 1381a of the second housing 132a side and the vertical line V4 of the die edge perpendicular to the bottom 1332, and the boundary point P2 of the stamping edge 1611a of the second housing 132a side and the outer wall 1381a of the second housing 132a side and the vertical line V2 of the edge perpendicular to the bottom 1332. It can be less than 0.5 mm, and in particular, less than 0.35 mm.

[0229] Additionally, the electrode assembly 10 is arranged such that one end of the electrode 101 is positioned between the edge vertical line V2 and the reference vertical line V3, with a vertical distance of 0.75 mm, specifically 0.5 mm, between the reference vertical line V3 and the edge vertical line V2, and perpendicular to the bottom 1332.

[0230] Therefore, according to another embodiment of the present invention, the depth D of the cup portion 133 is molded to be less than 6.5 mm, and the outer wall 138 of the cup portion 133 can be formed in a near-vertical state, such that the inclination angle with the bottom 1332 is 90° to 95°, in particular 90° to 93°. Furthermore, while preventing damage to the electrode 101, the volume ratio of the electrode assembly 10 to the volume of the cup portion 133 can be further increased, thereby increasing the energy efficiency relative to the volume.

[0231] Figure 16 This is an enlarged view of the groove 1391a formed in the battery casing 13 according to another embodiment of the present invention.

[0232] According to another embodiment of the present invention, when the battery casing 13a is folded to manufacture the secondary battery 1a, the mold edge 1621 on the second casing 132a side becomes a folded portion 139a. Specifically, when the battery casing 13 is folded, the rounded shape of the mold edge 1621 can also be unfolded, but the mark of the mold edge 1621 remains on the secondary battery 1, and this mark becomes the folded portion 139a. Therefore, the mold edge 1621 and the folded portion 139a on the second casing 132a side of the battery casing 13a correspond to each other.

[0233] For example, when the rounded shape of the mold edge 1621 is not fully unfolded (like a flat surface), the folded portion 139a includes a groove 1391a recessed into the inner side of the secondary battery 1a, such as... Figure 19 As shown in the figure. In this case, since the curvature of the fold 139a is less than the curvature of the mold edge 1621, the fold 139a can have a larger radius of curvature.

[0234] Because the mold edge 1621 has a curved surface and the outer wall 1381a of the mold edge 1621 has a planar shape, their deformation amounts differ. Therefore, when the battery casing 13 is folded, the outer wall 1381a of the mold edge 1621 deforms relatively more, while the mold edge 1621 deforms relatively little, just enough to allow the rounded shape to unfold to a certain extent. Then, when the battery casing 13 is folded, as... Figure 19 As shown, the increase or decrease in the slope change occurs near the boundary point P1. That is, each boundary point P1 becomes an inflection point. Therefore, the fold 139a can be formed as a curved surface between the two boundary points P1, i.e., the two inflection points.

[0235] Alternatively, even if the rounded shape of the mold edge 1621 is fully unfolded, the boundary point P1 between the mold edge 1621 and the outer wall 1381 of the second housing 132a and the boundary point between the mold edge 1621 and the second housing 132a respectively form two lines (not shown) in the secondary battery 1a, and the folded portion 139a is formed as a plane between the two lines.

[0236] The width FW of the fold 139 does not exceed the length of the mold edge 1621 and can be from 1 mm to 3.2 mm, particularly from 1 mm to 1.6 mm.

[0237] Figure 17 This is a schematic top view showing the state of the degassing portion 337 of the battery casing 33 before it is cut, according to the prior art.

[0238] The bridge portion 136 of the battery casing 13 is folded to form a folded portion 139 on one side of the secondary battery 1, and the folded portion 139 integrally connects the first casing 131 and the second casing 132. However, the battery casing 13 is formed by stretching the soft film 135, in which case not only is the cup portion 133 stretched to a limited extent, but the peripheral edge 134 of the cup portion 133 is also slightly stretched overall. Therefore, when the bridge portion 136 is folded, the slightly stretched portion of the edge 134 converges as it protrudes outward from both ends of the folded portion 139 and thus becomes visually noticeable. This is referred to as bat ears 35 or 15.

[0239] The dimensions of the bat-ear 35 vary depending on the thickness t′ of the bridge portion 336, the gap CL′, the radius of curvature R2′ of the stamped edge 361 of the cup portion 333, and the depth D′ of the cup portion 333. That is, the thicker the bridge portion 336, the larger the gap CL′, and the larger the radius of curvature R2′ of the stamped edge 361 of the cup portion 333, the larger the size of the bat-ear 35. However, in the prior art, there are limitations in improving the thickness t′ of the bridge portion 336, the radius of curvature R2′ of the edge 361 of the cup portion 333, and the gap CL′. Therefore, as... Figure 17 As shown, the size of the bat ears 35 is formed to be quite large, and there are also limitations in reducing the size of the bat ears 35.

[0240] When the size of the bat-ear 35 is made too large, the unnecessary volume of the secondary battery 3 increases further, thus causing errors between the designed and actual values ​​of the shape and size of the secondary battery 3. Therefore, when the secondary battery 3 is assembled into the battery module 5 (see...), Figure 24 When assembling, it is not easy, and there is a problem that, considering the bat ears 35, the size of the secondary battery 3 must be designed to be small from the beginning. In addition, due to the increased volume of the secondary battery 3, there is also the problem of reduced energy density relative to volume.

[0241] As described above, a soft-pack battery housing 13 according to an embodiment of the present invention may include: a cup portion 133, wherein a receiving space 1331 for receiving an electrode assembly 10 is provided; and a degassing portion 137, formed on one side of the cup portion 133 to discharge gas generated in the cup portion 133 through a degassing hole H.

[0242] Additionally, in the process of sealing the edge 134, a forming process and a degassing process can be performed. Specifically, after the electrode assembly 10 is housed in the cup portion 133, the corner portion 1371 included in the degassing portion 137 in the battery housing 13 is opened, and the remaining edge 134 is sealed. When the edge of the battery housing 13 is opened to form an opening, electrolyte is injected into the battery housing 13 through the opening.

[0243] After the electrolyte is injected into the battery casing 13, the degassing section 137 is first sealed to form a temporary seal 1340. Since the seal 1341 is formed by the secondary sealing of the subsequent degassing section 137, the temporary seal 1340 is preferably formed in the degassing section 137 near the edge 1371.

[0244] Afterwards, the forming process can be performed. The forming process (activation process) is the final charging process to enable the secondary battery 1 to supply power. Since the forming process is performed after the formation of the temporary sealing part 1340, and the battery casing 13 is completely sealed, the manufacturing of the secondary battery can be completed within a predetermined process time by rapidly venting the gas with a high filling rate.

[0245] When the forming process is completed, gas is generated in the battery casing 13. Therefore, a degassing hole H is punched in the degassing portion 137 of the battery casing 13. Through the degassing hole H, the gas is discharged from the inside of the battery casing 13 to the outside. Here, the injected electrolyte may leak through the degassing hole H, while the gas can easily escape. To prevent this, it is preferable to punch the degassing hole H near the temporary sealing portion 1340. When the degassing hole H is punched, a degassing process is performed to discharge the gas to the outside of the battery casing 13.

[0246] When the degassing hole H is punched, the interior of the battery casing 13 is reopened, and the internal electrolyte leaks to the outside. Therefore, a sealing portion 1341 is formed at the boundary between the secondary sealing cup portion 133 and the degassing portion 137. Here, the sealing portion 1341 is formed between the cup portion 133 and the degassing hole H, and preferably is formed near the cup portion 133.

[0247] As described above, during the forming and degassing processes, the degassing holes H must be stamped, and primary and secondary sealing must be performed. Furthermore, when mass-producing the secondary battery 1, it is necessary to uniformly manage the specifications and quality of the secondary battery 1. For this purpose, an inspection device 4 including a vision sensor 41 (see...) can be used. Figure 19 To check the battery casing 13 or the secondary battery 1.

[0248] According to existing technology, there are limitations in manufacturing the battery casing 33 and the secondary battery 3 into an integrally sharp shape. Therefore, when the battery casing 33 is photographed using a visual sensor, the size and position of the components show significant errors.

[0249] Specifically, when the manufacturing of the secondary battery 1 is completed, the battery module 5 can be manufactured by connecting the electrode leads 12 of multiple secondary batteries 1 to each other (see...). Figure 24Therefore, the positions of all electrode leads 12 formed in the multiple secondary batteries 1 must remain unchanged. However, in the prior art, since the electrode 101 is spaced to some extent from the outer wall 338 of the cup portion 333, the electrode assembly 10 moves inside the cup portion 333 before the sealing edge 134. Therefore, when mass-producing the secondary batteries 3, even if the volume of the cup portion 333 and the volume of the electrode assembly 10 remain unchanged, the position of the electrode assembly 10 is slightly different, and therefore the position of the electrode leads 12 is also slightly different. Therefore, the position of the electrode leads 12 must be accurately measured using the inspection device 4.

[0250] Furthermore, in order to stamp the degassing hole H in the correct position and size, and to perform primary and secondary sealing in the correct position and size, the position of the degassing part 137 must be accurately measured. In addition, in order to effectively manage the overall weight of multiple secondary batteries 1, the positions of the battery casing 13 or individual components of the secondary battery 1, such as the edge 134, the fold 139, and the insulating part 14 protruding from the battery casing, must be accurately measured, and furthermore, the width between the cup parts 133 must be accurately measured.

[0251] To measure the position of a component, a specific reference line must be established and the vertical distance from the reference line to the component to be measured must be measured. For example, when the electrode assembly 10 frequently moves inside the cup portion 333, typically, based on... Figure 17 The strip shown is in the left and right directions, that is, in the direction toward the folded portion 339 and the degassing portion 337. Therefore, in order to measure the position of the electrode lead 12, the position of the left edge or the right edge of the electrode lead 12 must be measured, and in order to measure the vertical distance to the left edge or the right edge, a reference parallel to the left edge or the right edge must be established.

[0252] However, in the prior art, the outer wall 338 of the cup portion 333 is not formed in a nearly vertical state, and the radius of curvature R2′ of the stamped edge 361 of the cup portion 333 is also relatively large. Therefore, when the battery casing 33 is photographed with the vision sensor 41, the stamped edge 361 of the cup portion 333 is not sharply presented in the image, such as... Figure 17 As shown in the diagram. Therefore, the position of the component cannot be measured based on the stamped edge 361 of the cup portion 333, and the bat ear 35 near the stamped edge 361 can be set as a reference, or the user can manually set the stamped edge 361 of the cup portion 333 as a reference.

[0253] However, since the bat ears 35 are formed by folding the bridge portion 136 while the outer edge 134 of the cup portion 133 is also slightly stretched overall, the bat ears 35 of each of the multiple secondary batteries 1 are slightly different in size. Therefore, even when the position of the components is measured with a visual sensor, the deviation in the position of the components among the secondary batteries 3 increases due to the difference in the size of the bat ears 35 used as a reference, making quality control difficult.

[0254] In particular, even when the position of the electrode leads 12 is measured by photographing the battery casing 33 with a visual sensor, the position of the electrode leads 12 is slightly different. Therefore, when connecting the electrode leads 12 to manufacture the battery module 5, there is a problem that it is not easy to connect them. In addition, when multiple secondary batteries 1 are stacked or aligned in a row in order to manufacture the battery module 5, the position of the cup portion 333 is inaccurate, so there is also a problem of reduced alignment of multiple secondary batteries 1.

[0255] By housing the secondary battery 3 in a separate casing 51 (see...) Figure 24 When battery module 5 is manufactured using the same method, if the deviation of the measured value is large, the design tolerance when designing the casing 51 becomes unnecessarily large, resulting in a decrease in energy density compared to the volume of battery module 5.

[0256] Figure 18 This is a schematic top view showing the state of the degassing portion 137 of the battery casing 13 before it is cut, according to an embodiment of the present invention. Figure 19 This is a block diagram of an inspection device 4 according to an embodiment of the present invention.

[0257] According to one embodiment of the present invention, such as Figure 18 As shown, due to the improved molding performance of the soft film 135, the thickness t of the bridge portion 136 can be made thinner, the radius of curvature R2 of the edge 1611 of the cup portion 133 and the gap CL can be made smaller, and the size of the bat ears 15 can be further reduced. Therefore, the secondary battery 1 can be easily assembled into the battery module 5, and the unnecessary reduction in the volume of the secondary battery 1 can increase the energy density relative to the volume.

[0258] Furthermore, according to one embodiment of the present invention, such as Figure 18As shown, since the stamped edge 1611 of the cup portion 133 is clearly visible in the image of the battery casing 13, the inspection device 4 can automatically set the stamped edge 161 of the cup portion 133 as the baseline ST. Based on the stamped edge 161 of the cup portion 133, the distance to each component of the battery casing 13 or the secondary battery 1 can be accurately measured. Furthermore, the width CW between the cup portions 133 can be measured precisely. Therefore, the position of the components of the battery casing 13 or the secondary battery 1 can be accurately measured, reducing measurement errors and minimizing deviations between the secondary batteries 1.

[0259] Therefore, according to an embodiment of the present invention, an inspection device 4 for a battery casing 13 or a secondary battery 1 includes: a vision sensor 41 for capturing images of the battery casing 13 to obtain images of the battery casing 13 or the secondary battery 1; a contour extraction unit 421 for extracting the contours of the components of the battery casing 13 or the secondary battery 1 from the images; an image analysis unit 422 for analyzing the images to detect the contours of the stamping edge 161 corresponding to the cup portion 133, wherein a receiving space 1331 for accommodating the electrode assembly 10 in the battery casing 13 is provided in the cup portion 133; a reference line setting unit 423 for setting the contours corresponding to the stamping edge 161 as a reference line ST; and a distance calculation unit 424 for calculating the distance from the reference line ST to the component.

[0260] Furthermore, an inspection method for a battery casing 13 or a secondary battery 1 according to an embodiment of the present invention includes: a step of photographing the battery casing 13 to obtain an image of the battery casing 13 or the secondary battery 1; a step of extracting the contour of a component of the battery casing 13 or the secondary battery 1 from the image by a contour extraction unit 421; a step of analyzing the image to detect the contour of a stamping edge 161 corresponding to a cup portion 133, wherein a receiving space 1331 for accommodating an electrode assembly 10 in the battery casing 13 is provided in the cup portion 133; a step of setting the contour corresponding to the stamping edge 161 as a reference line ST; and a step of calculating the distance from the reference line ST to the component.

[0261] Specifically, such as Figure 19 As shown, the inspection device 4 includes a vision sensor 41 and a controller 42. Furthermore, the aforementioned components can be connected to each other to communicate via a bus (not shown). All components in the controller 42 can be connected to the bus via at least one interface or adapter, or can be directly connected to the bus. In addition to the aforementioned components, the bus can be connected to other subsystems. The bus includes a memory bus, a memory controller, a peripheral bus, and a local bus.

[0262] The vision sensor 41 acquires an image by photographing a specific area to receive an image signal of that specific area. For this purpose, the vision sensor 41 typically includes an imaging device, such as a charge-coupled device (CCD) or a complementary metal-oxide-semiconductor (CMOS) image sensor. Specifically, in the vision sensor 41 according to an embodiment of the invention, after the bridge portion 136 of the battery housing 13 is folded, the battery housing 13 is photographed to obtain images of the various components of the battery housing 13 or the secondary battery 1. Here, the components include the aforementioned cup portion 133, degassing portion 137, electrode leads 12, batwing portion 15, edge 134, fold portion 139, and insulating portion 14. Then, the degassing portion 137 is cut to complete the manufacturing of the secondary battery 1. Therefore, if the vision sensor 41 photographs the battery housing 13 before cutting the degassing portion 137, images of the battery housing 13 and the electrode leads 12 can be acquired; if the battery housing 13 is photographed after cutting the degassing portion 137, an image of the secondary battery 1 can be acquired.

[0263] The controller 42 receives image signals acquired by the vision sensor 41 to identify the positions of various components of the battery casing 13 or the secondary battery 1 from the image signals. The controller 42 includes a contour extraction unit 421, an image analysis unit 422, a baseline setting unit 423, and a distance calculation unit 424. Preferably, a central processing unit (CPU), a microcontroller unit (MCU), or a digital signal processor (DSP) is used as the controller 42, but it is not limited thereto. For example, various logic operation processors can be used.

[0264] The contour extraction unit 421 extracts the contours of the battery casing 13 or the secondary battery 1 from the image received by the vision sensor 41. Here, the contour extraction unit 421 can extract the contours of all components presented in the image, but is not limited to this; it can also set a region of interest (ROI) in a portion of the image, and can also extract only the contours of the components presented in the ROI. To extract the contours, information about the pixels in the image is first extracted. For this, a commonly used gradient formula can be used. The contours of the battery casing 13 and the electrode leads 12 are displayed using the extracted pixel information.

[0265] According to one embodiment of the present invention, the radius of curvature R2 and gap CL of the stamped edge 161 of the cup portion 133 can be formed to be smaller, and since the outer wall 138 of the cup portion 133 is formed to be nearly vertical, the gradient of the pixel information corresponding to the stamped edge 161 of the cup portion 133 in the image is larger. Therefore, since the boundary between the contour and the background is clear, the contour corresponding to the stamped edge 161 of the cup portion 133 can be clearly extracted.

[0266] The image analysis unit 422 analyzes the image and detects the contour corresponding to the stamped edge 161 of the cup portion 133 in the battery casing 13. To this end, the image analysis unit 422 matches pre-stored reference contour information of the stamped edge 161 of the cup portion 133 with the extracted contour information to detect the contour corresponding to the stamped edge 161 of the cup portion 133. In this case, the image analysis unit 422 can use template matching technology to match the two pieces of information.

[0267] The reference line setting unit 423 can set the contour corresponding to the stamping edge 161 as the reference line ST. Since the cup portion 133 includes multiple stamping edges 161, multiple contours corresponding to the stamping edges 161 are also extracted. Here, in order to accurately measure the position of each component of the battery casing 13 or the secondary battery 1, the reference line setting unit 423 can preferably set the contour corresponding to the stamping edge 161 closest to the component to be measured among the multiple stamping edges 161 as the reference line ST. Furthermore, as described above, since the position of the component must be measured at its perpendicular distance to the reference line ST, the reference line setting unit 423 can set the contour corresponding to the stamping edge 161 parallel to the edge of the component to be measured among the multiple stamping edges 161 as the reference line ST.

[0268] For example, in order to stamp the degassing hole H and perform primary and secondary sealing, the inspection device 4 needs to measure the position of the degassing section 137. In this case, the reference line setting unit 423 can set the contour corresponding to the die edge 1612 on the side of the stamping edge 162 that is close to the degassing section 137 and parallel to the edge 1371 included in the degassing section 137 as the reference line ST.

[0269] For example, in order to check whether the position of the electrode lead 12 remains unchanged, the inspection device 4 must measure the position of the electrode lead 12. In this case, the reference line setting unit 423 can set the electrode lead 12 side profile corresponding to the stamping edge 1611 on the side of the fold portion 139 that is close to the electrode lead 12 and parallel to the left and right edges of the electrode lead 12 among the plurality of stamping edges 161.

[0270] In addition, in order to measure the width between the cup portions 133, the reference line setting unit 423 can use one of the contours of two stamped edges 161 that correspond to the boundary of the width of the cup portion 133 as the reference line ST.

[0271] In other words, as long as the baseline setting unit 423 accurately measures the position of each component of the battery casing 13 or the secondary battery 1, the baseline setting unit 423 can set various contour lines as baseline ST without limitation.

[0272] The distance calculation unit 424 calculates the distance from the reference line ST to each component of the battery casing 13 or the secondary battery 1 in the image. For example, if the contour corresponding to the stamping edge 1612 on the mold edge 162 side is set as the reference line ST, the distance calculation unit 424 can calculate the distance from the reference line ST to the edge included in the degassing section 137. Alternatively, if the contour corresponding to the stamping edge 1611 on the folding section 139 side is set as the reference line ST, the distance calculation unit 424 can calculate the distance from the reference line ST to one edge of the electrode lead 12, and also calculate the distance from the reference line ST to the contour corresponding to the stamping edge 1612 on the mold edge 162 side.

[0273] The distance calculation unit 424 can utilize information about the relationship between the number of pixels in the image and the pre-stored actual distance. That is, the distance calculation unit 424 can calculate the distance from the baseline ST to each component by using the number of pixels in the image, and then calculate the actual distance corresponding to the counted number of pixels by utilizing information about the relationship between the number of pixels in the image and the actual distance.

[0274] The inspection device 4 may also include a storage unit 44. The storage unit 44 stores programs for processing and controlling the operation of the inspection device 4, as well as various data generated or received signals during the execution of each program step. Specifically, it may store reference information about the battery casing 13, enabling the image analysis unit 422 to detect the contour corresponding to the stamped edge 1611 of the cup portion 133. Here, the reference information about the battery casing 13 includes: reference contour information about the stamped edge 1611 of the cup portion 133 and reference information about the distance to the battery casing 13 or the component of the secondary battery 1. This can be directly stored in the storage unit 44 by the user, or the inspection device 4 can generate and store the reference information through repeated learning. Furthermore, the storage unit 44 may store information about the relationship between the number of pixels in the image and the actual distance, enabling the distance calculation unit 424 to calculate the actual distance from the reference line ST to each component. Additionally, it may store inspection result information of the battery casing 13 to be inspected. This storage unit 44 may be embedded in the inspection device 4, but it may also be set up as a separate storage server. The storage unit 44 includes a non-volatile storage device and a volatile storage device. The non-volatile storage device may be a small, lightweight NAND flash memory that is resistant to external shocks, and the volatile storage device may be a DDR SDRAM.

[0275] The controller 42 may further include a defect determination unit 425 for determining whether the battery casing 13 to be inspected is defective. The defect determination unit 425 can compare the reference information about the battery casing 13 stored in the storage unit 44 with the inspection result information of the battery casing 13 to be inspected. Furthermore, if the inspection result information is within the error range of the reference information, the battery casing 13 can be determined to be normal. However, if the inspection result information is outside the error range of the reference information, the battery casing 13 can be determined to be defective.

[0276] The inspection device 4 may also include a display unit 43 for receiving and displaying image signals. The display unit 43 receives image signals and displays the images to the user. Furthermore, when the contour extraction unit 421 extracts the contour of the battery casing 13, the contour can be displayed on the image so that the user can inspect the contour through the display unit 43. The display unit 43 can use various methods, such as a liquid crystal display (LCD), an organic liquid crystal display (OLED), a cathode ray tube (CRT), and a plasma display panel (PDP). In addition, the display unit 43 is connected to a bus via a video interface, and data transmission between the display unit 43 and the bus can be controlled by a graphics controller.

[0277] The inspection device 4 may also include an alarm unit 45, which generates an alarm when the defect determination unit 425 determines that the battery casing 13 is defective. When an alarm is generated, it is preferable to generate an auditory or visual alarm, such as the lighting of a light or a warning sound, so that the user is intuitively aware of the situation.

[0278] The various components of the currently described vision sensor 41, controller 42, storage unit 44, and display unit 43 can be implemented by software consisting of tasks, categories, subroutines, processes, objects, execution threads, and programs running in predetermined areas of memory, or by hardware such as field-programmable gate arrays (FPGAs) or application-specific integrated circuits (ASICs), or by a combination of software and hardware. Components may be contained in computer-readable storage media, or a portion of a component may be distributed across multiple computers.

[0279] Additionally, each block can represent a module, segment, or portion of code, including one or more executable instructions for performing a specified logical function. Furthermore, in some alternative implementations, the functions mentioned in a block may not appear in sequence. For example, two program blocks displayed consecutively may actually execute simultaneously, and sometimes these program blocks execute in reverse order according to their respective functions.

[0280] When using the detection device 4 according to an embodiment of the present invention, since the stamped edge 1611 of the cup portion 133 is sharply displayed, the detection device 4 can automatically set the stamped edge 1611 of the cup portion 133 as the reference line ST, and accurately measure the distance to each component of the battery casing 13 based on the stamped edge 1611 of the cup portion 133. For example, the size and position of the degassing portion 137 can be measured, and even after the manufacturing of the secondary battery 1 is completed, the size and position of the cup portion 133, electrode leads 12, batwing ears 15 and edges 134, folds 139 and insulation portions 14 can be accurately identified. Therefore, it is easy to determine whether the secondary battery 1 is defective, and even in mass production of the secondary battery 1, its specifications and quality can be effectively and uniformly managed.

[0281] In particular, because the position of the electrode leads 12 is precisely measured, the components can be easily connected to each other when the electrode leads 12 are connected to manufacture the battery module 5. In addition, the position of the cup portion 333 is precisely measured, so the alignment of the multiple secondary batteries 1 can be improved when multiple secondary batteries 1 are stacked sequentially or aligned in a line to manufacture the battery module 5.

[0282] Figure 20 This is a schematic diagram showing the state in which the degassing portion of the battery casing 13 is cut to completely manufacture the secondary battery 1 according to an embodiment of the present invention.

[0283] After the battery casing 13 is sealed a second time to form a sealing portion 1341, the degassing portion 137 is cut by setting a cutting line CT on the outside of the sealing portion 1341. As a result, as... Figure 20 As shown, the length of the degassing section 137 can be shortened, and the volume of the secondary battery 1 can be reduced. Through the above process, the manufacturing of the pouch-type secondary battery 1 is completed.

[0284] In the remaining edges 134 after the degassing section 137 is cut, the electrode leads 12 are not formed to protrude from the plurality of edges 134. However, if the edges 134 remain as they are after sealing, the overall volume of the secondary battery 1 increases. Therefore, in order to reduce the energy density relative to volume, it is preferable to fold the edges 134.

[0285] Edge 134 may include a sealing portion 1341 and a non-sealing portion 1342, such as Figure 20 As shown in the diagram, the sealing portion 1341 is a sealing area provided on the relatively outer side, and the non-sealing portion 1342 is a non-sealing area provided on the relatively inner side.

[0286] Specifically, when the sealing portion 1341 is formed by the secondary seal of the battery housing 13, the sealing portion 1341 is not directly connected to the cup portion 133, but can be formed to be spaced apart to a certain extent. When sealing the edge 134, a separate sealing tool (not shown) is required to apply heat and pressure to the edge 134. However, if the edge 134 is sealed while the sealing tool is in close contact with the cup portion 133, the sealant layer 1351 disposed inside the edge 134 partially melts and leaks into the electrode assembly 10, thereby contaminating the electrode assembly 10. In addition, the heat of the sealing tool is transferred to the electrode assembly 10, thereby damaging the electrode assembly 10. Therefore, it is preferable to seal the edge 134 while the sealing tool is spaced apart from the cup portion 133 to a certain extent. Then, the portion sealed by the sealing tool becomes the sealing portion 1341, and the portion not sealed due to the spaced separation between the sealing tool and the cup portion 133 becomes the unsealed portion 1342.

[0287] Figure 21 This is a schematic side view showing the state in which edge 334 is folded according to the prior art. Figure 22 This is a schematic top view showing the state in which edge 334 is folded according to the prior art.

[0288] In the prior art, when the edge 334 is folded, there is a problem that the edge 334 is not fixed and unfolds again at a predetermined angle. Specifically, as described above, the soft film 135 is formed by stacking a sealant layer 1351, a moisture barrier layer 1352, a stretching aid layer 1354, and a surface protective layer 1353. The sealant layer 1351 contains a first polymer, specifically polypropylene (PP), and therefore exhibits good flexibility and elasticity. Thus, when the edge 334 is folded, the restoring force to its initial state is relatively large. On the other hand, since the moisture barrier layer 1352 is made of metal, specifically aluminum alloy, after the edge 334 is folded, it exceeds the limit of elastic deformation, thereby maintaining a relatively large holding force in the folded state.

[0289] However, in the soft-pack film according to the prior art, the thickness of the moisture barrier layer is about 30 μm to 50 μm, and the thickness of the sealant layer is about 60 μm to 100 μm. That is, the thickness of the moisture barrier layer is significantly thinner than the thickness of the sealant layer. Therefore, the restoring force is greater than the holding force, so the edge 334 is not fixed and unfolds again at the predetermined angle. Then, there is a problem of unnecessary volume increase of the secondary battery 3 due to the edge 334.

[0290] To solve this problem, such as Figure 21 and Figure 22As shown, tape 38 is individually adhered to the edge 334. Specifically, tape 38 is adhered together to the outer surface of the edge 334 and the bottom 3332 of the cup portion 333 to secure the edge 334 to the cup portion 333, thereby preventing the edge from unfolding again. However, in this case, as... Figure 21 As shown, there is a problem that the overall thickness of the secondary battery 3 increases due to the thickness of the tape 38 itself. In addition, after the process of folding the edge 334, an additional process of adhering the tape 38 is required, which takes a lot of time, thereby increasing the number of processes and reducing the manufacturing yield of the secondary battery 3.

[0291] During the degassing process, as gas is discharged from the inside of the battery casing 13 to the outside, the internal pressure of the cup portion 133 decreases. In the prior art, the electrode assembly 10 is positioned to be spaced apart from the outer wall 338 of the cup portion 333. Therefore, in order to reduce the volume of the space 37 between the outer wall 338 of the cup portion 333 and the electrode assembly 10 while reducing the internal pressure of the cup portion 333, the outer wall 338 or the bottom 3332 of the cup portion 333 will deform. Specifically, as... Figure 21 As shown, due to the inward indentation of the outer wall 338 on the folded side of the secondary battery 3, a high-edge phenomenon occurs where the stamped edge 361 on the folded side of the cup portion 333 protrudes outward and increases in height. This high-edge phenomenon leads to an unnecessary increase in the thickness of the secondary battery 3, resulting in a decrease in energy density relative to volume. Furthermore, due to the deformation of the outer wall 338 on the folded side of the cup portion 333, the appearance of the secondary battery 3 is unattractive, thus reducing its marketability. Additionally, there is a problem of further enlargement of the size of the bat-ear 15, and its shape protrudes due to the high-edge phenomenon.

[0292] Figure 23 This is a schematic top view showing the state in which the edge 134 is folded according to an embodiment of the present invention.

[0293] According to one embodiment of the invention, in the flexible film 135, the thickness of the moisture barrier layer 1352 is thicker than in the prior art because the thickness of the moisture barrier layer 1352 is 50 μm to 70 μm and the thickness of the sealant layer 1351 is 70 μm to 100 μm. Therefore, since the holding force is further increased when the edge 134 is folded, the edge 134 can be prevented from being unfolded again without the need for separate adhesive tape 38.

[0294] Therefore, a secondary battery 1 according to an embodiment of the present invention includes: an electrode assembly 10 formed by stacking electrodes 101 and a separator 102; and a pouch-type battery housing 13 having a cup portion 133 for receiving the electrode assembly 10 therein. The pouch-type battery housing 13 includes an edge 134 extending outward from the cup portion 133, the edge 134 including a sealing portion 1344 that is sealed by being disposed on the opposite outer side and a non-sealing portion 1345 that is disposed on the opposite inner side and is not sealed. Therefore, the edge 134 does not adhere to the cup portion 133 and is folded at the non-sealing portion 1345.

[0295] In other words, such as Figure 23 As shown, after the edge 134 of the secondary battery 1 is folded toward the cup portion 133, the edge 134 does not adhere to the cup portion 133 while remaining folded, and therefore does not unfold. In this case, the edge 134 can be folded at an angle of 85° to 95°, particularly 88° to 92°. Furthermore, the edge 134 can be folded at a position adjacent to the cup portion 133, such that the edge 134 contacts the outer wall 138 of the cup portion 133. Specifically, as described above, the edge 134 may include a sealing portion 1341 disposed on the relatively outer side and thus sealed, and a non-sealing portion 1342 disposed on the relatively inner side and thus not sealed. Furthermore, when folding the edge 134, it is preferable to fold the non-sealing portion 1342 which is relatively close to the cup portion 133. Therefore, the unnecessary volume of the secondary battery 1 can be further reduced. However, even in this case, the edge 134 and the cup portion 133 do not adhere to each other, and the holding force of the edge 134 increases to maintain the folded state.

[0296] When two cup portions 133 are formed on the soft film 135, the depth D of the cup portions 133 can be shallower than when only one cup portion 133 is formed. This is because, as described above, not only are the cup portions 133 stretched strongly, but the outer edge 134 of the cup portions 133 is also stretched slightly overall. However, if the width of the edge 134 is greater than the depth D of the cup portion 133, then when the edge 134 is folded only once, the outer end 1343 of the edge 134 will protrude more outward than the bottom 1332 of the cup portion 133.

[0297] Therefore, if two cup portions 133 are formed on the soft membrane 135, then as follows: Figure 23The diagram illustrates a double-edge folding (DSF) method that folds edge 134 twice. Specifically, edge 134 may include a first fold portion 1344 and a second fold portion 1345. The first fold portion 1344 is the portion folded relatively close to the outer end 1343, and the second fold portion 1345 is the portion folded relatively close to the cup portion 133. Therefore, after the edge 134 is folded a first time based on the first fold portion 1344, the edge 134 can be folded a second time based on the second fold portion 1345. In this case, the first fold portion 1344 may be provided on the sealing portion 1341 of the edge 134, and the second fold portion 1345 may be provided on the non-sealing portion 1342 of the edge 134. Furthermore, the edge 134 may be folded at an angle of 170° to 180° in the first fold portion 1344, particularly at 180°. Furthermore, the second fold portion 1345 may be folded at an angle of 85° to 95°, particularly at 88° to 92°. Therefore, it can prevent the outer end 1343 of the edge 134 from protruding further outward than the bottom 1332 of the cup portion 133.

[0298] According to one embodiment of the present invention, since the electrode assembly 10 can be disposed very close to the outer wall 138 of the cup portion 133, unnecessary volume reduction of the cup portion 133 is achieved. Therefore, even if the internal pressure of the cup portion 133 decreases due to the degassing process, deformation of the outer wall 138 or the bottom 1332 of the cup portion 133 can be prevented. That is, as Figure 23 As shown, this prevents high-edge phenomena from occurring, so the energy density relative to volume does not decrease.

[0299] Figure 24 This is a schematic diagram of a battery module 5 according to an embodiment of the present invention.

[0300] Because medium and large electronic devices, such as those in automobiles, require significant output, they necessitate numerous secondary batteries 1. To facilitate the movement and installation of these secondary batteries 1, battery modules 5 can be manufactured. When multiple secondary batteries 1 are installed in the battery module 5, power can be stably supplied to the external environment.

[0301] In order to generate electricity in the electrode assembly 10 of the secondary battery 1, a chemical reaction occurs between the electrode 101 and the electrolyte, and heat is generated in this process. However, when the ambient temperature rises excessively due to heat, problems arise such as malfunctions in the circuitry of the electronic device on which the secondary battery 1 is installed, or a shortened lifespan of the electronic device. Therefore, the battery module 5 includes a cooling system for cooling the secondary battery 1. Cooling systems are mainly divided into water-cooled systems that use cooling water to cool the secondary battery and air-cooled systems that use air to cool the secondary battery. Among them, water-cooled cooling systems have higher cooling efficiency than air-cooled cooling systems and are therefore more widely used.

[0302] The cooling system includes a cooling plate that directly cools the secondary battery 1, and separate flow paths are formed inside the cooling plate to allow cooling water to flow. Furthermore, as the thickness and length of the channels increase, the surface area increases to improve cooling efficiency.

[0303] To manufacture the battery module 5, multiple secondary batteries 1 are first manufactured, then the secondary batteries 1 are connected to each other and housed within the casing 51. In this case, the secondary batteries 1 can be aligned and stacked in a line. Figure 24 As shown, when the secondary battery 1 is housed in the casing 51, the long side of the secondary battery 1 can face downwards, and a cooling plate (not shown) can be formed on the bottom surface of the casing 51. Therefore, cooling efficiency can be improved by cooling the cooling plate from the long side of the secondary battery 1.

[0304] The folded portion 139, formed by the folded bridge portion 136, is formed on one side of the secondary battery 1, and the edge 134, which is the area remaining after the degassing portion 137 is cut, is formed on the other side. However, if the cooling plate is cooled from the side of the secondary battery 1 where the edge 134 is formed, the distance between the cooling plate and the electrode assembly 10 increases due to the edge 134, resulting in poor cooling efficiency. Therefore, it is preferable to cool the cooling plate from the side of the secondary battery 1 where the folded portion 139 is formed on its long side. For this purpose, when the secondary battery 1 is housed in the housing 51, the folded portion 139 can be housed downwards in the direction toward the cooling plate.

[0305] Figure 25 This is an enlarged front view showing the secondary battery 3 housed in the casing 51 of the battery module 5, according to the prior art. Figure 26 This is an enlarged side view showing the secondary battery 3 housed in the casing 51 of the battery module 5, according to the prior art.

[0306] As mentioned above, there are limitations in the prior art regarding the reduction of the size of the bat ears 35.

[0307] Furthermore, in the prior art, the angle θ′ formed between the fold 339 and the inner edge 35a of the bat ear 35 is formed to be less than 151 degrees.

[0308] Here, angle θ′ can refer to the angle formed by the first dashed line L1 corresponding to the fold 339 and the second dashed line L2 corresponding to the inner edge 35a of the bat ear 35. Specifically, the first line L1 and the second line L2 can be determined by image analysis. For example, the first line L1 and the second line L2 can be extracted by connecting multiple edge points identified in the region of interest (ROI) in the visual device. Therefore, even when the fold 339 or the inner edge 35a of the bat ear 35 is partially bent or kinked, the first line L1 and the second line L2 can be clearly defined. Since image analysis is a well-known technique, its detailed description will be omitted.

[0309] Therefore, as Figure 25 As shown, when the secondary battery 3 is housed in the housing 51, the housing 51 and the fold 339 are separated from each other by a large gap d′ (e.g., greater than 1.5 mm) via the batwing 35. Therefore, the gap d′ interferes with the cooling of the cooling plate, thus reducing cooling efficiency. To solve this problem, a thermally conductive material 52 is injected into the space between the cooling plate and the fold 339 of the secondary battery 1, so that the cooling plate cools the fold 139 via the thermally conductive material 52.

[0310] However, if the size of the bat ear 15 is large, the cost increases due to the need to inject a large amount of thermally conductive material 52, and the cooling efficiency remains low due to the large gap d′ between the cooling plate and the fold 139.

[0311] Additionally, when the degassing process is carried out through the degassing port H, such as Figure 26 As shown, when the internal pressure of the battery casing 33 decreases, the folded portion 339 of the battery casing 33 comes into close contact with the electrode assembly 10. However, there are limitations in the prior art in reducing the gap CL′, and the width of the folded portion 339 is also relatively large. Therefore, the space 37 between the outer wall 338 of the cup portion 333 and the electrode assembly 10 is relatively large, resulting in a decrease in the energy density of the secondary battery 3 relative to its volume. Furthermore, since the distance between the electrode assembly 10 and the thermal paste 52 also increases, there is a further decrease in cooling efficiency.

[0312] Figure 27 This is an enlarged front view showing the secondary battery 1 housed in the casing 51 of the battery module according to an embodiment of the present invention. Figure 28 This is an enlarged side view showing the secondary battery 1 housed in the casing 51 of the battery module according to an embodiment of the present invention.

[0313] According to an embodiment of the present invention, a pouch-type secondary battery 1 includes: an electrode assembly 10 in which electrodes 101 and a separator 102 are stacked; and a pouch-type battery housing 13 having a cup portion 133 therein for accommodating the electrode assembly 10, wherein the battery housing 13 includes: a first housing 131 and a second housing 132, wherein the cup portion 133 is formed in at least one of the first housing and the second housing; a folding portion 139 for integrally connecting the first housing 131 and the second housing 132; and bat ears 15 protruding outward from a portion of both ends of the folding portion 139, wherein the length d of the bat ears 15 is less than 1.5 mm.

[0314] Furthermore, the angle θ between the fold 139 and the inner edge 15a of the bat ear 15 can be greater than 151 degrees. Alternatively, the angle θ can be less than 180 degrees. Furthermore, when the angle θ is 180 degrees, it can represent a state where the bat ear 15 is not present.

[0315] Here, angle θ′ can refer to the angle formed by the first dashed line L1 corresponding to the fold 139 and the second dashed line L2 corresponding to the inner edge 15a of the bat ear 15. The descriptions of the first line L1 and the second line L2 can be obtained from the description above.

[0316] According to an embodiment of the present invention, the battery module 5 includes: a pouch-type secondary battery, wherein an electrode assembly 10, in which electrodes 101 and separator 102 are stacked, is housed in a cup portion 133 formed in a pouch-type battery housing 13; and a housing 51 therein, wherein the secondary battery 1 is housed, wherein the battery housing 13 includes: a first housing 131 and a second housing 132, in which the cup portion 133 is formed; a folding portion 139 for integrally connecting the first housing 131 and the second housing 132; and bat ears 15, which protrude outward from a portion of both ends of the folding portion 139, wherein the length d of the bat ears 15 is less than 1.5 mm.

[0317] As described above, the bat ear 15 is formed to protrude outward from a portion of both ends of the folded portion 139 via the folded bridge portion 136. According to one embodiment of the invention, the length of this bat ear 15 can be less than 1.5 mm, particularly less than 1 mm. The length of the bat ear 15 can be the length measured from the outer wall 1381 of the folded portion 139 to the outermost end of the bat ear 15. In this case, as described above, due to the gap CL, the inclination angle between the outer wall 1381 of the folded portion 139 and the bottom 1332 can be 90° to 95°. Taking this into consideration, as an example of measuring the bat ear, the length of the bat ear 15 can be the length measured from the outermost protruding portion of the outer wall 1381 of the folded portion 139 to the outermost end of the bat ear 15.

[0318] The length of the bat ear 15 can be measured using a ruler or vernier caliper in direct contact with the secondary battery 1, or it can be measured non-contactly using a laser displacement sensor or a vision sensor.

[0319] As described above, a method for measuring the length of a bat's ear has been presented as an example, and limiting the method solely to the aforementioned measurement method is not within the scope of this invention. The length of a bat's ear can be any length of bat's ear as understood in this invention, as long as it falls within the scope of the claims and concept of this invention.

[0320] According to one embodiment of the invention, the depth D of the cup portion 133 is molded to be less than 6.5 mm, the thickness t of the bridge portion 136 is formed to be thinner, and the radius of curvature R2 of the edge 1611 of the cup portion 133 and the gap CL can be formed to be smaller.

[0321] Therefore, the length d of the bat ear 15 can be further reduced to below 1.5 mm, and specifically, below 1 mm. Therefore, as... Figure 27 As shown, the gap d between the housing 51 and the fold 139 can be reduced to less than 1.5 mm. Therefore, the thickness of the thermal paste 52 inside the housing 51 can be less than 1.5 mm, thus further reducing the amount of thermal paste 52 injected, thereby reducing costs and improving cooling efficiency.

[0322] In addition, such as Figure 28 As shown, the gap CL can be made smaller, and the width FW of the fold 139 can be made smaller. Therefore, the space 17 between the outer wall 138 of the cup portion 133 and the electrode assembly 10 is reduced, thereby increasing the energy density of the secondary battery 1 relative to its volume. Furthermore, since the distance between the electrode assembly 10 and the thermal paste 52 is also reduced, the cooling efficiency can be further improved.

[0323] It will be understood by those skilled in the art to which this invention pertains that the invention can be implemented in other specific forms without altering the technical concept or essential characteristics. Therefore, the embodiments disclosed above are considered exemplary rather than restrictive. Consequently, the scope of the invention is defined by the appended claims rather than by the foregoing description and the exemplary embodiments described therein. Various modifications made within the equivalent meaning of the claims and within the scope of the claims should be considered within the scope of the invention.

[0324] [Figure Labels]

[0325] 1: Secondary battery 2: Molding device

[0326] 3: Secondary batteries based on existing technology

[0327] 4: Testing equipment

[0328] 5: Electrode Module 10: Electrode Assembly

[0329] 11: Electrode connector 12: Electrode lead

[0330] 13: Battery casing 14: Insulation part

[0331] 15: Bat ears 16: Edges

[0332] 17: Space 21: Mold

[0333] 22: Punch head; 33: Battery casing according to the prior art

[0334] 35: Bat ears according to the prior art 36: Edges according to the prior art

[0335] 37: Space according to the prior art 38: Tape according to the prior art

[0336] 41: Vision sensor 42: Controller

[0337] 43: Display Unit 44: Storage Unit

[0338] 45: Alarm unit 51: Outer casing

[0339] 52: Thermal paste; 101: Electrode

[0340] 102: Diaphragm; 111: Positive electrode terminal piece

[0341] 112: Negative terminal piece; 121: Positive terminal lead

[0342] 122: Negative lead; 131: First housing

[0343] 132: Second shell 133: Cup portion

[0344] 134: Edge; 135: Soft wrapping film

[0345] 136: Bridge section; 137: Degassing section

[0346] 138: Outer wall; 139: Folding section

[0347] 161: Stamping edge; 162: Die edge

[0348] 163: Thickness edge 164: Corner

[0349] 211: Molding section; 212: Partition wall

[0350] 213: Edge of the mold 221: Edge of the punch

[0351] 333: Cup portion according to the prior art; 334: Edge according to the prior art

[0352] 336: Bridge section according to the prior art; 337: Degassing section according to the prior art.

[0353] 338: Outer wall according to the prior art 339: Folding part according to the prior art

[0354] 361: Stamping edge according to existing technology

[0355] 362: Mold edge according to existing technology

[0356] 421: Contour extraction unit; 422: Image analysis unit

[0357] 423: Baseline setting unit; 424: Distance calculation unit

[0358] 425: Defect Determination Section 1021: Peripheral Section

[0359] 1331: Storage space 1332: Bottom

[0360] 1333: Outer wall; 1340: Temporary sealing section

[0361] 1341: Sealing part; 1342: Non-sealing part

[0362] 1343: Outer end; 1344: First fold section

[0363] 1345: Second fold; 1351: Sealant layer

[0364] 1352: Moisture barrier layer; 1353: Surface protective layer

[0365] 1354: Stretch auxiliary layer; 1371: Edge

[0366] 1381: Outer wall of the bridge section; 1382: Outer wall of the degassing section.

[0367] 1391: Groove; 1611: Stamped edge on the side of the bridge section.

[0368] 1612: Side stamping edge of the degassing section; 1613: First stamping edge

[0369] 1614: Second stamping edge

Claims

1. A pouch battery casing, the pouch battery casing including a cup portion configured to receive an electrode assembly formed by stacking electrodes and a separator. in, The cup portion includes multiple mold edges, which are connected and configured to surround a plurality of outer walls and edges or degassing portions around their periphery. At least one of the edges of the plurality of molds is rounded with a radius of curvature of less than 1 mm, and the depth of the cup portion is less than 6.5 mm. The edge of the mold has a radius of curvature corresponding to 1 / 20 to 1 / 6 of the depth of the cup portion. The pouch battery casing includes a first casing and a second casing, and a bridge portion formed between the first casing and the second casing. When the battery casing is folded, the bridge portion takes the form of a folded portion, and The width of the folded portion is 1 mm to 1.6 mm.

2. The soft-pack battery casing according to claim 1, wherein, At least one of the edges of the mold is rounded with a radius of curvature of less than 0.7 mm.

3. The soft-pack battery casing according to claim 1, wherein, The cup portion also includes: Multiple stamped edges, the multiple stamped edges connecting the outer wall and the bottom, and at least one of the multiple stamped edges being rounded with a radius of curvature of less than 1 mm; and The thickness edge is configured to connect with two adjacent outer walls.

4. The soft-pack battery casing according to claim 3, wherein, The vertical distance between the vertical line of the mold edge passing through the boundary point between the mold edge and the outer wall of the mold edge side and perpendicular to the bottom, and the vertical line of the edge passing through the boundary point between the stamping edge of the mold edge side and the outer wall of the mold edge side and perpendicular to the bottom, is less than 0.5 mm.

5. The soft-pack battery casing according to claim 3, wherein, The thickness edge connects to two adjacent stamping edges to form a corner, and at least one of the corners is rounded with a radius of curvature of 2 mm to 5 mm. The radius of curvature of the corner is greater than the radius of curvature of the thickness edge.

6. The soft-pack battery casing according to claim 5, wherein, The corner has a radius of curvature that varies therein.

7. The soft-pack battery casing according to claim 6, wherein, The radius of curvature of the central portion of the corner is greater than the radius of curvature of the outer portion of the corner.

8. The soft-pack battery casing according to claim 3, wherein, The radius of curvature of at least one of the stamped edges is less than 0.7 mm.

9. The soft-pack battery casing according to claim 3, wherein, The stamped edge has a radius of curvature corresponding to 1 / 20 to 1 / 6 of the depth of the cup portion.

10. The soft-pack battery casing according to claim 1, wherein, The thickness of the bridge section is less than 2 mm.

11. The soft-pack battery casing according to claim 10, wherein, The thickness of the bridge section is less than 1.4 mm.

12. The soft-pack battery casing according to claim 10, wherein, The bridge portion has a thickness of 1 / 200 to 1 / 30 of the width of the electrode assembly.

13. The soft-pack battery casing according to claim 10, wherein, The bridge section is rounded with a curvature radius of less than 1 mm.

14. The soft-pack battery casing according to claim 13, wherein, The bridge section is rounded with a curvature radius of less than 0.7 mm.

15. The soft-pack battery casing according to claim 10, wherein, The bridge section has a thickness corresponding to the distance between two vertical lines of the bridge section, which respectively pass through the boundary point between the bridge section and the outer side wall of the bridge section, and are perpendicular to the bottom.

16. The soft-pack battery casing according to claim 1, wherein, The outer wall is 90 o Up to 95 o The tilt angle slopes from the bottom.

17. A pouch-type secondary battery, comprising: Electrode assembly, in which electrodes and a diaphragm are stacked; A pouch battery casing includes a cup portion configured to house the electrode assembly therein. The battery casing includes: A first housing and a second housing, at least one of the first housing and the second housing including a cup portion; and The bridge portion is configured to integrally connect the first housing and the second housing. The depth of the cup portion is less than 6.5 mm. The cup portion includes multiple mold edges, which are connected and configured to surround a plurality of outer walls and edges or degassing sections around its periphery. The edge of the mold has a radius of curvature corresponding to 1 / 20 to 1 / 6 of the depth of the cup portion. When the battery casing is folded, the bridge portion takes the form of a folded portion, and The width of the folded portion is 1 mm to 1.6 mm.

18. The pouch-type secondary battery according to claim 17, wherein, The area of ​​the electrode assembly is 15000 mm². 2 Up to 100,000 mm 2 .

19. The pouch-type secondary battery according to claim 17, wherein, The fold includes an inwardly recessed groove.

20. The pouch-type secondary battery according to claim 19, wherein, The battery casing includes a pair of outwardly projecting protrusions and the groove is located between the pair of protrusions. The distance between the innermost part of the groove and the outermost part of the protrusion is less than 0.8 mm.

21. The soft-pack secondary battery according to claim 17, wherein, The difference in width between the cup portion and the electrode assembly is less than 2.5 mm.

22. The soft-pack secondary battery according to claim 21, wherein, The difference in width between the cup portion and the electrode assembly is less than 1.7 mm.

23. The soft-pack secondary battery according to claim 21, wherein, The width of the cup portion is the distance between the two ends of the two outer walls of the cup portion.

24. The pouch-type secondary battery according to claim 17, wherein, The cup portion includes: Multiple stamped edges are connected to a plurality of outer walls surrounding the periphery and the bottom, and at least one of the stamped edges is rounded with a radius of curvature of less than 1 mm; Multiple mold edges, connecting the outer wall to the edge or degassing section, and at least one of the multiple mold edges is rounded with a radius of curvature of less than 1 mm; and The thickness edge is configured to connect with the two outer walls that are adjacent to each other.

25. The pouch-type secondary battery according to claim 24, wherein, The vertical distance between the vertical line of the mold edge passing through the boundary point between the mold edge and the outer wall of the mold edge side and perpendicular to the bottom, and the vertical line of the edge passing through the boundary point between the stamping edge of the mold edge side and the outer wall of the mold edge side and perpendicular to the bottom, is less than 0.5 mm.

26. The pouch-type secondary battery according to claim 25, wherein, In the electrode assembly, one end of at least one of the electrodes is configured such that the vertical distance from the vertical line of the edge is less than 0.75 mm.

27. The soft-pack secondary battery according to claim 26, wherein, In the electrode assembly, one end of at least one of the electrodes is configured such that the vertical distance from the vertical line of the edge is less than 0.5 mm.

28. The pouch-type secondary battery according to claim 24, wherein, In the diaphragm, the peripheral portion protruding outward from the electrode is folded in the opposite direction at the bottom end relative to the electrode.

29. The pouch-type secondary battery according to claim 28, wherein, In the electrode assembly, each of the electrodes and the diaphragm is configured as a plurality of electrodes. Within the diaphragm housed in the cup portion of the first housing, the peripheral portion is folded toward the second housing, and In the diaphragm housed in the cup portion of the second housing, the peripheral portion is folded toward the first housing.

30. The soft-pack secondary battery according to claim 29, wherein, The peripheral portion of at least one of the diaphragms is aligned with the peripheral portion of the adjacent diaphragm and is folded.

31. The soft-pack secondary battery according to claim 24, wherein, The radius of curvature of at least one of the stamped edges is less than 0.7 mm.

32. The soft-pack secondary battery according to claim 24, wherein, The stamped edge has a radius of curvature corresponding to 1 / 20 to 1 / 6 of the depth of the cup portion.

33. The soft-pack secondary battery according to claim 24, wherein, The radius of curvature of at least one of the mold edges is less than 0.7 mm.

34. The pouch-type secondary battery according to claim 24, wherein, The outer wall extends from the bottom at a 90° angle. o Up to 95 o The tilt angle is tilted.

35. The soft-pack secondary battery according to claim 24, wherein, The thickness edge connects to two adjacent stamping edges to form a corner, and at least one of the corners is rounded with a radius of curvature of 2 mm to 5 mm. The radius of curvature of the corner is greater than the radius of curvature of the thickness edge.

36. The soft-pack secondary battery according to claim 35, wherein, The corner has a radius of curvature that varies therein.

37. The pouch-type secondary battery according to claim 36, wherein, The radius of curvature of the central portion of the corner is greater than the radius of curvature of the outer portion of the corner.

38. The pouch-type secondary battery according to claim 17, wherein the pouch-type secondary battery further comprises bat ears of a length of 1.5 mm protruding outward from a portion of both ends of the folded portion.

39. The pouch-type secondary battery according to claim 38, wherein, The angle between the fold and the inner edge of the bat ear is greater than 151 degrees.

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