Battery cell manufacturing method and battery cell

Abstract

The present disclosure provides a method for manufacturing a battery cell, comprising: an edge sealing process for sealing at least a portion of the edge of a case to form an edge sealing portion for blocking an electrode accommodating portion and a gas accommodating portion from the outside; and a final sealing process of sealing a boundary portion crossing between the electrode accommodating portion and the gas accommodating portion in a first direction to form an external sealing portion, in which the external sealing portion includes a first portion formed at a center region of the boundary portion and a second portion formed at an end region of the boundary portion, the final sealing process forms an extension portion extending in a second direction toward the electrode receiving portion on the second portion of the appearance sealing portion. According to the present disclosure, in a degassing process, gas can be easily discharged from an electrode accommodating portion to a gas accommodating portion, and gas flow can be made smooth.

Description

Technical Field

[0001] This disclosure relates to a method for manufacturing a rechargeable and dischargeable battery cell and the battery cell itself. Background Technology

[0002] Unlike primary batteries, secondary batteries (cells) offer the convenience of being charged and discharged, making them a popular power source for various mobile devices, electric vehicles, energy storage devices, and more.

[0003] Secondary batteries can be manufactured as pouch-type or can-type cells. Pouch-type cells have a structure in which electrode assemblies are housed within a flexible pouch-like casing. Can-type cells have a structure in which electrode assemblies are housed within a rigid casing and can be composed of cylindrical or prismatic cells.

[0004] The housing of the pouch-type battery cell includes an electrode housing that accommodates an electrode assembly and a sealing portion disposed around the electrode housing and having a shape extending outward from the electrode housing. The sealing portion can be formed by thermally welding (extrusion) the inner layer of the housing. Summary of the Invention

[0005] Technical issues

[0006] The battery cell casing may include an electrode housing and a gas housing. Sealing portions may be formed at the edges of the electrode housing and the gas housing. A portion of the sealing portion may have a shape corresponding to the appearance of the finished battery cell. For example, a sealing portion formed at a corner of the electrode housing may include a protrusion that is thicker than other portions.

[0007] The gas generated in the electrode housing can be discharged to the outside of the electrode housing through a degassing process. Protrusions formed on the seal may obstruct gas flow as it moves from the electrode housing to the gas housing. In other words, protrusions on the seal may cause obstruction of gas discharge or flow generated in the electrode housing.

[0008] Furthermore, to reduce the size of the battery cell, the sealing section can be folded based on the fold line. After the process of folding the sealing section is completed, poor insulation or leakage may occur.

[0009] According to one aspect of the present disclosures, a method for manufacturing a battery cell and a battery cell capable of easily discharging gas from an electrode housing to a gas housing can be provided.

[0010] According to one aspect of this disclosure, a method for manufacturing a battery cell and a battery cell capable of preventing damage to the seal due to gas flow can be provided.

[0011] According to another aspect of this disclosure, a method for manufacturing a battery cell and a battery cell capable of preventing or reducing leakage of electrolyte, gas, etc. due to poor insulation of the sealing portion can be provided.

[0012] The battery cells disclosed herein can be widely used in green technology fields such as electric vehicles, battery charging stations, and other battery-based solar and wind power generation. Furthermore, the battery cells disclosed herein can be used in eco-friendly electric vehicles and hybrid vehicles to prevent climate change by suppressing air pollution and greenhouse gas emissions.

[0013] Technical solution

[0014] The method for manufacturing a battery cell according to this disclosure may include: an edge sealing process for sealing at least a portion of the edge of a housing to form an edge-sealing portion that blocks the electrode housing and the gas housing from the outside; and a final sealing process for sealing a boundary portion that traverses the boundary portion and the gas housing along a first direction to form an exterior sealing portion, wherein the exterior sealing portion includes a first portion formed in a central region of the boundary portion and a second portion formed in an end region of the boundary portion, and the final sealing process may form an extension on the second portion of the exterior sealing portion extending in a second direction toward the electrode housing.

[0015] According to one embodiment, the extension may include a diagonal line with a chamfered shape formed at the corner of the electrode receiving portion.

[0016] According to one embodiment, the edge sealing portion may include an overlapping portion that overlaps with the exterior sealing portion, the overlapping portion having a shape that does not protrude toward the central region of the boundary portion relative to the periphery of the overlapping portion.

[0017] According to one embodiment, the edge sealing process may include: a process for forming a first edge sealing portion, the first edge sealing portion being formed on the lateral side of the electrode receiving portion and the gas receiving portion and extending along the second direction; and a process for forming a second edge sealing portion, the second edge sealing portion being formed on the top side of the gas receiving portion and extending along the first direction, the overlapping portion being formed at the portion where the first edge sealing portion intersects with the outer sealing portion.

[0018] According to one embodiment, the edge sealing portion may include an overlapping portion that overlaps with the exterior sealing portion, the overlapping portion having a shape in which the boundary line opposite the central region of the boundary portion is perpendicular to the first direction.

[0019] A method for manufacturing a battery cell according to one embodiment may further include: a traverse sealing portion process, performed between the edge sealing process and the final sealing process, wherein at least a portion of the boundary portion is sealed along a first direction to form a traverse sealing portion.

[0020] According to one embodiment, the transverse sealing portion may be formed to have a constant width in the second direction.

[0021] The method for manufacturing a battery cell according to one embodiment may further include: a cutting process performed after the final sealing process, cutting the boundary portion along a cutting line to correspond to the appearance of the battery cell; and a folding process for folding the sealing portion disposed around the electrode receiving portion, wherein the folding process may include a process of folding the sealing portion with reference to a folding line located in the appearance sealing portion but disposed at a position other than the one that traverses the sealing portion.

[0022] According to one embodiment, the cutting line may be configured to have an angle relative to the exterior seal to prevent the fold line from passing through the area where the edge seal overlaps with the exterior seal at both ends of the fold line.

[0023] The method for manufacturing a battery cell according to one embodiment may further include: a degassing process, performed between the edge sealing process and the final sealing process, wherein gas generated in the electrode housing is discharged from the electrode housing to the gas housing.

[0024] A battery cell according to one embodiment may include: an electrode assembly; a battery cell housing including an electrode housing portion for receiving the electrode assembly and an electrolyte and a sealing portion for sealing at least a portion around the electrode housing portion; and an electrode lead electrically connected to the electrode assembly and exposed in a first direction through a lateral side of the electrode housing portion, wherein the sealing portion includes an edge sealing portion formed on the lateral side of the electrode housing portion where the electrode lead is disposed and an outer sealing portion formed on the top side of the electrode housing portion where the electrode lead is not disposed, the outer sealing portion including a first portion formed in a central region and a second portion formed in an end region, the second portion of the outer sealing portion including an extension portion extending in a second direction toward the electrode housing portion.

[0025] According to one embodiment, the extension may include a diagonal line with a chamfered shape formed at the corner of the electrode receiving portion.

[0026] According to one embodiment, the edge seal may include an overlapping portion that overlaps with the exterior seal, the overlapping portion having a shape that does not protrude toward the central region of the exterior seal relative to the periphery of the overlapping portion.

[0027] According to one embodiment, the edge sealing portion may include an overlapping portion that overlaps with the exterior sealing portion, the overlapping portion having a shape in which the boundary line opposite to the first portion of the exterior sealing portion is perpendicular to the first direction.

[0028] According to one embodiment, the sealing portion may be formed on three of the four open surfaces surrounding the electrode receiving portion, the edge sealing portions may be formed on the lateral sides of the electrode receiving portion, and the electrode leads may be disposed on the lateral sides of the electrode receiving portion.

[0029] According to one embodiment, the exterior sealing portion can be folded to form a folded portion based on a fold line extending along the first direction, the fold line being configured not to pass through the area where the edge sealing portion overlaps with the exterior sealing portion.

[0030] Technical effect

[0031] According to one embodiment of this disclosure, in the degassing process, gas can be easily discharged from the electrode container to the gas container, and the gas flow can be smooth.

[0032] According to one embodiment of this disclosure, damage to the seal caused by gas flow during the degassing process can be prevented. Therefore, it is possible to prevent or reduce poor insulation of the seal or leakage of electrolyte, gas, etc.

[0033] According to one embodiment of this disclosure, leakage of electrolyte, gas, etc., due to poor insulation of the seal or the process of folding the seal can be prevented or reduced. Attached Figure Description

[0034] Figure 1 This is a front view of a battery cell according to one embodiment.

[0035] Figure 2 It is a three-dimensional diagram of a battery cell with folds.

[0036] Figure 3 This is a flowchart illustrating a method for manufacturing a battery cell according to one embodiment.

[0037] Figures 4a to 4e This is a schematic diagram showing a method for manufacturing a battery cell according to one embodiment.

[0038] Figure 5 (a), (b) and (c) are schematic diagrams showing an edge sealing portion formed in an edge sealing process according to an embodiment, a transverse sealing portion formed in a transverse sealing process according to an embodiment, and an appearance sealing portion formed in a final sealing process according to an embodiment.

[0039] Figure 6 This is a front view of a battery cell according to another embodiment.

[0040] Figures 7a to 7c These are schematic diagrams showing the manufacturing methods of the battery cells according to the comparative examples.

[0041] Figure 8 (a), (b) and (c) are schematic diagrams showing the edge sealing portion formed in the edge sealing process according to the comparative example, the through sealing portion formed in the through sealing process according to the comparative example, and the appearance sealing portion formed in the final sealing process according to the comparative example, respectively.

[0042] Explanation of reference numerals in the attached figures

[0043] 10: Battery cell; 20: Battery cell casing

[0044] 20a: Housing; 30: Electrode Receiving Section

[0045] 35: Electrode housing space; 40: Sealing part

[0046] 41: First sealing part; 42: Second sealing part

[0047] 45: Folding guide section; 46: First folding line

[0048] 60: Electrode assembly; 65: Electrode lead.

[0049] 70: Gas containment section; 75: Gas containment space

[0050] 80: Boundary portion; 81: Central area

[0051] 82: End area; 90: Edge portion

[0052] 91: First edge 92: Second edge

[0053] S1: Edge sealing portion

[0054] S11: First edge sealing portion; S11a: Overlapping portion

[0055] S12: Second edge sealing part

[0056] S2: Traverse sealing portion

[0057] S3: Exterior sealing portion

[0058] S31: Part 1 S32: Part 2

[0059] S33: Extension portion; CL: Cutting line Detailed Implementation

[0060] The same reference numerals or symbols used in the various figures of this specification indicate parts or components that perform substantially the same function. For ease of description and understanding, the same reference numerals or symbols may also be used in different embodiments. That is, even if components with the same reference numerals are shown in multiple figures, the multiple figures do not necessarily represent the same embodiment.

[0061] In the following description, unless the context clearly indicates otherwise, singular expressions include plural expressions. It should be understood that terms such as "comprising" or "constituting" are intended to indicate the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, without precluding the presence or additional possibility of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0062] Furthermore, in the following description, terms such as upper side, upper part, lower side, lower part, side, front, and back are based on the direction shown in the accompanying drawings. If the direction of the corresponding object changes, it can be described differently.

[0063] Furthermore, in the following description and claims, terms including ordinal numbers such as "first" and "second" may be used to distinguish components. These ordinal numbers are used to distinguish identical or similar components, and the meaning of the terms should not be interpreted restrictively due to the use of these ordinal numbers. As an example, the components associated with these ordinal numbers should not be interpreted restrictively by the number itself, such as the order of use or the order of configuration. Each ordinal number may be used interchangeably with the others as needed.

[0064] The present disclosure will now be described in detail with reference to the accompanying drawings. However, this is merely exemplary and the present disclosure is not limited to the specific embodiments described herein.

[0065] Figure 1 This is a front view of a battery cell according to one embodiment.

[0066] Reference Figure 1 The battery cell 10 may include a battery cell housing 20 and an electrode assembly 60 housed inside the battery cell housing 20. Electrode leads 65 connected to the electrode assembly 60 may be exposed to the outside of the battery cell housing 20. The electrode assembly 60 may include a positive electrode plate, a negative electrode plate, and a separator. The separator may be disposed between the positive and negative electrode plates.

[0067] The cell housing 20 may include an electrode receiving portion 30 forming an electrode receiving space 35 for accommodating an electrode assembly 60, and a sealing portion 40 disposed around the electrode receiving portion 30 and extending outward from the electrode receiving portion 30. The sealing portion 40 may be heat-fused to protect the electrode assembly 60 from external influences.

[0068] The electrode leads 65 may include positive leads electrically connected to multiple positive plates and negative leads electrically connected to multiple negative plates. The electrode leads 65 may be disposed on both sides of the electrode assembly 60. For example, the positive leads may be disposed on one side of the electrode assembly 60, and the negative leads may be disposed on the other side. However, the arrangement and number of the electrode leads 65 can be varied. For example, it is also possible to simultaneously arrange both positive and negative leads on one side of the electrode assembly 60.

[0069] The sealing portion 40 may include a first sealing portion 41 without electrode leads 65 and a second sealing portion 42 with electrode leads 65. The first sealing portion 41 may be located on the upper side of the electrode assembly 60, and the second sealing portion 42 may be located on the lateral side of the electrode assembly 60.

[0070] When the electrode receiving portion 30 is formed by folding a cell housing 20, the cell housing 20 can have a shape in which three of the four sides of the electrode receiving portion 30 are open and one side 31 is closed. The sealing portion 40 can be formed on the three open sides of the electrode receiving portion 30.

[0071] According to one embodiment, the battery cell 10 is not limited to a structure where the sealing portion 40 is formed on three sides of the electrode receiving portion 30. For example, the battery cell 10 may also have a structure in which the electrode receiving portion 30 is formed by overlapping two battery cell housings 20. In this case, the sealing portion 40 can be formed on all four sides of the electrode receiving portion 30.

[0072] The sealing portion 40 can be folded to improve the engagement reliability of the sealing portion and minimize the volume occupied by the sealing portion 40. The sealing portion 40 can be folded with reference to the fold line 45. The fold line 45 can be provided in the first sealing portion 41 without electrode lead 65. The sealing portion 40 can be folded with reference to the first fold line 46.

[0073] Figure 2 It is a three-dimensional diagram of a battery cell with folds. Figure 2 It shows that Figure 1 The sealing portion 40 of the battery cell 10 shown is in a folded state.

[0074] Reference Figure 2 The sealing portion 40 may include a first sealing portion 41 without electrode leads 65 and a second sealing portion 42 with electrode leads 65.

[0075] The first sealing portion 41 can be folded along the fold line 45 to form the folded portion 50. The folded portion 50 can be further folded along the second fold line 47 after being folded along the first fold line 46. Although Figure 2The diagram shows the folding portion 50 with a 270-degree fold, but the folding portion 50 can also be folded at an angle greater than 270 degrees. The folding portion 50 can be attached to the electrode receiving portion 30 with tape to prevent the folding portion 50 from easily unfolding due to springback.

[0076] Figure 3 This is a flowchart illustrating a method (S100) for manufacturing a battery cell according to one embodiment. Figures 4a to 4e This is a schematic diagram showing a method for manufacturing a battery cell (S100) according to one embodiment. Figure 5 (a), (b) and (c) are schematic diagrams showing the edge sealing portion S1 formed in the edge sealing process (S120) according to one embodiment, the through sealing portion S2 formed in the through sealing process (S150) according to one embodiment, and the appearance sealing portion S3 formed in the final sealing process (S160) according to one embodiment. Figure 5 (a), (b), and (c) show each sealing part separately to clearly show the shape of the edge sealing part S1, the transverse sealing part S2, and the exterior sealing part S3, respectively.

[0077] The method for manufacturing a battery cell 10 according to one embodiment (S100) may include a preparation process (S110), an edge sealing process (S120), and a final sealing process (S160). Furthermore, the method for manufacturing a battery cell according to one embodiment (S100) may further include at least a portion of the following processes: an initial charging process (S130), a degassing process (S140), a transverse portion sealing process (S150), and subsequent processes (S170).

[0078] The battery cell 10 disclosed herein is described in relation to a pouch cell, but is not limited thereto.

[0079] [Preparation Process]

[0080] Reference Figure 3 and Figure 4a The preparation process (S110) is a process of preparing a housing 20a that includes an electrode housing 30 for accommodating an electrode assembly 60 and a gas housing 70 for accommodating gas generated in the electrode housing 30.

[0081] The housing 20a may include an electrode receiving portion 30 and a gas receiving portion 70. On the other hand, Figure 1 and Figure 2 The battery cell housing 20 shown has a state in which the electrode housing 30 is removed and the gas housing 70 is excluded. In order to... Figure 1 and Figure 2Distinguished from the shown cell housing 20, the structure of the outer material including the gas containment portion 70 is named "housing 20a". Furthermore, for the cell 10a including the housing 20a with the gas containment portion 70, in order to... Figure 1 and Figure 2 The battery cell 10 shown is distinguished and is indicated by the reference numeral "10a" in the attached diagram.

[0082] The housing 20a can be formed by folding an outer material to create spaces corresponding to the electrode receiving space 35 and the gas receiving space 75, respectively. The electrode receiving portion 30 can be located on the lower side of the housing 20a, and the gas receiving portion 70 can be located on the upper side of the housing 20a. The gas receiving portion 70 can be located on the upper side of the electrode receiving portion 30. When the housing 20a is formed by folding an outer material, the lower surface of the electrode receiving portion 30 can correspond to the folded surface of the outer material. Furthermore, the lateral sides and the top side of the housing 20a can have an open shape. That is, when the housing 20a is formed by folding an outer material, three of the edges of the housing 20a can have an open structure, and the three open edges can be sealed by the edge sealing process (S120) described later.

[0083] However, the shape and structure of the housing 20a can be modified in various ways. For example, the housing 20a can be formed by overlapping two outer materials. In this case, four of the edges of the housing 20a can have an open shape. The four open edges can be sealed by the edge sealing process (S120) described later.

[0084] The edge portion 90 of the housing 20a may include a first edge 91 located on the lateral side of the electrode receiving portion 30 and the gas receiving portion 70, and a second edge 92 located on the top side of the gas receiving portion 70. The first edge 91 may have a shape extending along a second direction (-Z axis), and the second edge 92 may have a shape extending along a first direction Y. The first edge 91 and the second edge 92 may intersect at a portion adjacent to the upper corner of the gas receiving portion 70. The first direction (Y-axis direction, hereinafter referred to as "Y") is a direction that crosses the space between the electrode receiving portion 30 and the gas receiving portion 70, and the second direction (opposite direction of the Z-axis, hereinafter referred to as "-Z") is a direction perpendicular to the first direction Y and is a direction from the gas receiving portion 70 toward the electrode receiving portion 30.

[0085] A boundary portion 80 may be formed between the electrode receiving portion 30 and the gas receiving portion 70. The boundary portion 80 is configured to traverse the space between the electrode receiving portion 30 and the gas receiving portion 70 along a first direction Y. The boundary portion 80 may include a central region 81 and end regions 82. The end regions 82 of the boundary portion 80 are regions adjacent to the first edge 91, and the central region 81 of the boundary portion 80 is a region disposed between the two end regions 82.

[0086] The preparation process (S110) may include the process of placing the electrode assembly 60 in the electrode receiving space 35. The electrode assembly 60 may be placed in the electrode receiving space 35 with electrode leads 65 attached. The electrode leads 65 may be exposed to the outside of the housing 20a through a first edge 91. The electrode leads 65 may be attached to one side and the other side of the electrode assembly 60 respectively. In this case, the electrode leads 65 may be exposed to the outside of the housing 20a through the first edge 91 located on one side of the housing 20a and the first edge 91 located on the other side of the housing 20a. However, the arrangement position and number of the electrode leads 65 may be varied. For example, the electrode leads 65 may also be arranged only on one side of the electrode assembly 60.

[0087] [Edge sealing process (S120)]

[0088] Reference Figure 3 , Figure 4b and Figure 5 (a) The edge sealing process (S120) can form an edge-sealing portion S1 that blocks the electrode receiving portion 30 and the gas receiving portion 70 from the outside by sealing at least a portion of the edge of the housing 20a. The edge-sealing portion S1 may include a first edge-sealing portion S11 and a second edge-sealing portion S12.

[0089] The edge sealing process (S120) may include a process for forming a first edge sealing portion S11 (S121) and a process for forming a second edge sealing portion S12 (S123). The edge sealing process (S120) may further include an electrolyte injection process (S122). The electrolyte injection process (S122) may be performed between the process for forming the first edge sealing portion S11 (S121) and the process for forming the second edge sealing portion S12 (S123).

[0090] The process (S121) for forming the first edge seal S11 can be performed on the first edge 91 of the housing 20a. The first edge seal S11 can be formed on the lateral side of the electrode receiving portion 30 and the gas receiving portion 70 and extends along the second direction (-Z). The first edge seal S11 can be formed on both sides of the electrode receiving portion 30 and the gas receiving portion 70, respectively. With the first edge seal S11 formed, the second edge 92 located on the upper side of the housing 20a can be in an open state. The width of the portion of the first edge seal S11 adjacent to the lower corner of the electrode receiving portion 30 can be greater than other portions. In addition, the width of the portion of the first edge seal S11 adjacent to the upper corner of the gas receiving portion 70 can be greater than other portions. Since the portions adjacent to the lower and upper corners of the electrode receiving portion 30 are the starting points of the first edge seal S11, the width of the sealing area can be increased in order to improve the sealing force compared to other portions.

[0091] The electrolyte injection process (S122) can be performed after the process (S121) of forming the first edge seal S11. The electrolyte injection process (S122) can inject electrolyte into the electrode receiving portion 30 of the electrode assembly 60 through the open second edge 92.

[0092] The process (S123) of forming the second edge seal S12 can be performed on the second edge 92 of the housing 20a. The second edge seal S12 can be formed on the top side of the gas containment portion 70 and extends along the first direction Y. The process (S123) of forming the second edge seal S12 can be performed after the electrolyte injection process (S122). By forming the second edge seal S12 (S123), the internal space of the housing 20a can be isolated from the outside.

[0093] The edge sealing part S1 may include the outer sealing part ( Figure 4d The overlapping portion S11a overlaps with the edge sealing portion S11 (S3). The overlapping portion S11a can be disposed in the end region 82 of the boundary portion 80. The overlapping portion S11a can be provided in the first edge sealing portion S11 and corresponds to the portion where the first edge sealing portion S11 overlaps with the end region 82 of the boundary portion 80. The overlapping portion S11a can be defined as the overlap between the edge sealing portion S1 and the appearance sealing portion (described later). Figure 4d The overlapping portion S11a may be formed at the intersection of the first edge sealing portion S11 and the appearance sealing portion S3.

[0094] The overlapping portion S11a may have a shape that does not protrude towards the central region 81 of the boundary portion 80 relative to its periphery. The overlapping portion S11a may have a flat shape along the second direction (-Z). For example, the overlapping portion S11a may have a shape in which the boundary line opposite to the central region 81 of the boundary portion 80 [or the boundary line opposite to the first portion S31 of the appearance sealing portion S3 described later] is perpendicular to the first direction Y. Therefore, in the degassing process (S140) described later, the gas can flow smoothly from the electrode receiving portion 30 to the gas receiving portion 70 at a position adjacent to the first edge sealing portion S11. Furthermore, according to the embodiment, in the degassing process (S140), the first edge sealing portion S11 can be prevented or restricted from being damaged by the flowing gas.

[0095] [Initial charging process (S130)]

[0096] The initial charging process (S130) can be performed after the edge sealing process (S120). The initial charging process (S130) can charge the battery cell 10a containing electrolyte to a constant capacity (e.g., 20-30% of the total capacity). The initial charging process (S130) can include a press-pre-charge (PPC) process in which the battery cell 10a is charged while a preset pressure is applied.

[0097] [Degassing process (S140)]

[0098] The degassing process (S140) is a process that discharges the gas generated in the electrode housing 30 of the battery cell 10a to the outside of the electrode housing 30. The degassing process (S140) can be performed after the initial charging process (S130). The degassing process (S140) can be performed between the edge sealing process (S120) and the final sealing process (S160) described later. The degassing process (S140) can be configured to discharge the gas generated in the electrode housing 30 from the electrode housing 30 to the gas housing 70. In the degassing process (S140), the gas generated in the electrode housing 30 can flow into the gas housing 70. The gas generated in the electrode housing 30 can... Figure 4b The gas flows in the direction indicated by the arrow (GF). The overlapping portion S11a of the first edge seal S11 has a shape that does not protrude towards the center region 81 of the boundary portion 80 relative to the periphery of the overlapping portion S11a, so the gas flow is not obstructed by the overlapping portion S11a of the first edge seal S11. Therefore, according to one embodiment, smooth gas flow (GF) can be achieved in the portion adjacent to the first edge seal S11. Furthermore, damage to the first edge seal S11 due to gas flow (GF) can be prevented or limited.

[0099] [Sealing process for the transverse section (S150)]

[0100] Reference Figure 3 , Figure 4c and Figure 5 (b) The traverse sealing process (S150) can be performed between the edge sealing process (S120) and the final sealing process (S160). The traverse sealing process (S150) can form a traverse sealing portion S2 on the boundary portion 80 located between the electrode receiving portion 30 and the gas receiving portion 70. The traverse sealing portion S2 can have a constant width (or thickness) in the second direction (-Z). Both ends of the traverse sealing portion S2 can overlap with the first edge sealing portion S11, respectively. The traverse sealing portion S2 can overlap with the overlapping portion S11a of the first edge sealing portion S11.

[0101] The transverse sealing portion S2 can be formed by sealing at least a portion of the boundary portion 80 along the first direction Y. Figure 4c Although the diagram shows the transverse sealing portion S2 continuously formed along the boundary portion 80, the transverse sealing portion S2 can have a partially discontinuous shape, i.e., a discontinuous or intermittent shape. When the transverse sealing portion S2 has an intermittent shape, the gas generated in the electrode receiving portion 30 during the subsequent aging process can move to the gas receiving portion 70. As an example, the aging process can be performed between the process of forming the transverse sealing portion S2 and the process of forming the appearance sealing portion S3. However, the transverse sealing process (S150) is not mandatory, and the aging process or the process of forming the appearance sealing portion S3 can be performed without performing the process of forming the transverse sealing portion S2.

[0102] [Final sealing process (S160)]

[0103] Reference Figure 3 , Figure 4d and Figure 5 (c) The final sealing process (S160) can form an exterior sealing portion S3. The exterior sealing portion S3 can be formed by sealing the boundary portion 80 between the electrode receiving portion 30 and the gas receiving portion 70 along the first direction Y. A portion of the exterior sealing portion S3 can overlap with the transverse sealing portion S2. The exterior sealing portion S3 can be formed closer to the electrode receiving portion 30 than the transverse sealing portion S2.

[0104] The exterior sealing portion S3 may include a first portion S31 formed in the central region 81 of the boundary portion 80 and a second portion S32 formed in the end region 82 of the boundary portion 80.

[0105] The final sealing process (S160) may include a process of forming an extension S33 on the second portion S32 of the outer sealing portion S3. The extension S33 may extend from the second portion S32 of the outer sealing portion S3 along a second direction (lower direction) (-Z) toward the electrode receiving portion 30.

[0106] The extension S33 may include a chamfered diagonal line formed at the corner where the edge sealing portion S1 and the outer sealing portion S3 intersect. That is, assuming a chamfer is formed at the corner where the edge sealing portion S1 and the outer sealing portion S3 intersect, the inner boundary line of the extension S33 may correspond to the chamfered diagonal line. As an example, the outer boundary line of the extension S33 in the first direction Y may have a shape perpendicular to the first direction Y, and the inner boundary line in the first direction Y may have a slope that increases in elevation as it moves downwards away from the electrode receiving portion 30.

[0107] Since the inner boundary line of the extension S33 is configured to be adjacent to the electrode receiving portion 30, the extension S33 can form a wider sealing area in the portion adjacent to the upper corner of the electrode receiving portion 30, thereby improving the sealing force of the electrode receiving portion 30.

[0108] [Subsequent Process (S170)]

[0109] Subsequent processes (S170) can be performed after the process of forming the external sealing part S3. Subsequent processes (S170) may include cutting processes and folding processes.

[0110] Will Figure 3 and Figure 4e and Figure 4d When referenced together, the cutting process is performed after the final sealing process (S160), and the boundary portion 80 can be cut along the cutting line CL to correspond to the appearance of the cell 10. Through the cutting process, the portion on the housing 20a that forms the gas containment portion 70 can be separated. The cutting line CL can extend in the second direction (-Z) along the portion forming the portion traversing the sealing portion S2. The two ends of the cutting line CL can be sloped.

[0111] The folding process is a process of folding the sealing portion 40 disposed around the electrode receiving portion 30. The folding process may include folding the sealing portion based on the folding line 45. The folding process may fold the first sealing portion 41 based on the first folding line 46. The first sealing portion 41 may correspond to the outer sealing portion S3 extending along the first direction Y. When the transverse sealing portion S2 is formed, the first sealing portion 41 may correspond to both the transverse sealing portion S2 and the outer sealing portion S3. The second sealing portion 42 may correspond to the extending edge sealing portion S1. The folding line 45 may be located in the outer sealing portion S3, but disposed in a position other than the transverse sealing portion S2. However, the position of the folding line 45 is not limited to this and may be changed according to the design specifications or process conditions of the battery cell.

[0112] Additionally, the cutting line CL can be set to have an angle relative to the outer sealing portion S3 to prevent the fold line 45 from passing through the area where the edge sealing portion S1 overlaps with the outer sealing portion S3 at both ends. For example, the cutting line CL can form an angle similar to the inner boundary line of the extension portion S33 at both ends.

[0113] Thus, when the fold line 45 does not pass through the sealing area where the edge seal S1 and the outer seal S3 overlap, the phenomenon that the seal 40 becomes weak during the formation of the fold line 45 can be prevented or limited. That is, insulation failure in the folded seal 40 can be prevented or reduced. In addition, leakage of electrolyte, gas, etc., due to the decrease in sealing force of the folded seal 40 can be prevented or reduced.

[0114] However, as Figure 6 As will be described later, depending on the process conditions, the fold line 45 can also be set to partially pass through the area where the edge seal S1 overlaps with the appearance seal S3.

[0115] [Cell 10]

[0116] Will Figure 4e and Figure 1 , Figure 2 and Figure 4d When referenced together, a battery cell 10 according to one embodiment may include an electrode assembly 60, a battery cell housing 20, and electrode leads 65.

[0117] Electrode leads 65 can be electrically connected to electrode assembly 60 and are exposed in the first direction Y through the lateral side of electrode receiving portion 30.

[0118] The battery cell housing 20 may include an electrode receiving portion 30 for accommodating the electrode assembly 60 and electrolyte, and a sealing portion 40 for sealing at least a portion around the electrode receiving portion 30. The sealing portion 40 may include an edge sealing portion S1 formed on the lateral side of the electrode receiving portion 30 where the electrode leads 65 are disposed, and an outer sealing portion S3 formed on the top side of the electrode receiving portion 30 where the electrode leads 65 are not disposed. The edge sealing portion S1 may correspond to a second sealing portion 42, and the outer sealing portion S3 may correspond to a first sealing portion 41.

[0119] The appearance sealing portion S3 may include a first portion S31 formed in the central region 81 and a second portion S32 formed in the end region 82. The second portion S32 of the appearance sealing portion S3 may include an extension S33 extending in a second direction (-Z) toward the electrode receiving portion 30. The extension S33 may include a chamfered diagonal line formed at the corner of the electrode receiving portion 30.

[0120] The edge sealing portion S1 may include an overlapping portion S11a that overlaps with the outer sealing portion S3. The overlapping portion S11a may have a shape that does not protrude toward the central region 81 of the outer sealing portion S3 relative to the periphery of the overlapping portion S11a. The overlapping portion S11a may have a shape in which the boundary line opposite to the first portion S31 of the outer sealing portion S3 is perpendicular to the first direction Y.

[0121] The sealing portion can be formed on three of the four open surfaces surrounding the electrode receiving portion 30. The edge sealing portion S1 can be formed on both sides of the electrode receiving portion 30, and the electrode lead 65 can be disposed on both sides of the electrode receiving portion 30.

[0122] The exterior sealing part S3 can be folded with reference to the fold line 45 extending along the first direction Y to form a folded part. Figure 2 (50). The fold line 45 can be configured not to pass through the area where the edge seal S1 overlaps with the appearance seal S3. Fold ( Figure 2 The 50) can be formed by folding based on the first fold line 46, and the first fold line 46 can be configured not to pass through the area where the edge seal S1 and the appearance seal S3 overlap.

[0123] pass Figures 1 to 5 The content of (c) can be applied to Figure 4e The battery cell 10 shown.

[0124] Figure 6 This is a front view of a battery cell 10 according to another embodiment.

[0125] and Figure 4e compared to, Figure 6 The cell 10 shown has a difference in the position of the cutting line CL. Figure 6 The cut line CL of the cell 10 shown is compared to Figure 4e The chamfer dimension of the cut line CL of the shown cell 10 is smaller. That is, Figure 6 The cut line CL of the cell 10 shown is... Figure 4e The cut line CL of the shown cell 10 is further away from the electrode receiving portion 30. In this case, the fold line 45 can partially pass through the area where the edge seal portion S1 overlaps with the outer seal portion S3.

[0126] exist Figure 6 In this embodiment, the fold line 45 is located relatively far from the inner boundary line of the extension S33. That is, the intersection of the fold line 45 and the overlapping sealing area can be set at a position spaced apart from the inner boundary line of the sealing area. Therefore, even if the sealing force decreases at the intersection of the fold line and the overlapping sealing area, leakage can be prevented or reduced compared to the comparative example described later. Furthermore, since the dimensions of the fold line 45 and the overlapping sealing area are small, the possibility of poor insulation in the sealing area can also be reduced.

[0127] Figures 7a to 7c This is a schematic diagram showing the manufacturing method of cell 1 according to the comparative example. Figure 8 (a), (b) and (c) are schematic diagrams showing the edge sealing part S1' formed in the edge sealing process according to the comparative example, the transverse sealing part S2' formed in the transverse sealing process according to the comparative example, and the appearance sealing part S3' formed in the final sealing process according to the comparative example. Figure 8 (a), (b) and (c) show each sealing part separately in order to clearly show the shape of the edge sealing part S1', the transverse sealing part S2' and the appearance sealing part S3' according to the comparative example.

[0128] The comparative examples are used to compare with the battery cell manufacturing method (S100) and battery cell 10 according to the embodiments of the present disclosure, and it is assumed that the shapes of the edge sealing portion S1' and the appearance sealing portion S3' are different from those of the embodiments of the present disclosure, and the remaining structures of the comparative examples have structures that are substantially similar to those of the embodiments of the present disclosure for the purpose of description.

[0129] According to the comparative example, the casing 20a of cell 1 can have the same as... Figure 4a The shell 20a shown has the same shape.

[0130] like Figure 7a and Figure 8As shown in (a), the edge sealing portion S1' can be formed according to the edge sealing process of the comparative example. The edge sealing process may include a process for forming the first edge sealing portion S11' and a process for forming the second edge sealing portion S12'.

[0131] The first edge sealing portion S11' may be formed on the first edge 91 of the housing 20a. The first edge sealing portion S11' may be formed on the lateral side of the electrode receiving portion 30 and the gas receiving portion 70 and extend along the second direction (-Z). The first edge sealing portion S11' may be formed on both lateral sides of the electrode receiving portion 30 and the gas receiving portion 70, respectively.

[0132] The second edge seal S12' can be formed on the second edge 92 of the housing 20a. The second edge seal S12' can be formed on the top side of the gas containment portion 70 and extend along the first direction Y. The process of forming the second edge seal S12' can be performed after the electrolyte injection process.

[0133] The edge sealing portion S1' may include an overlapping portion S11a' disposed on the end region 82 of the boundary portion 80. The overlapping portion S11a' may be provided in the first edge sealing portion S11' and corresponds to the portion where the first edge sealing portion S11' overlaps with the end region 82 of the boundary portion 80. The overlapping portion S11a' may include a protrusion P that protrudes toward the center region 81 of the boundary portion 80 relative to the periphery. This protrusion P can expand the sealing area to improve the sealing force at the upper corner of the electrode receiving portion 30.

[0134] However, as Figure 7a As shown, during the degassing process, when gas flows from the electrode housing 30 to the gas housing 70 at a position adjacent to the first edge seal S11', the protrusion P in the comparative example may become an obstacle hindering gas flow (GF). Therefore, in the case of the comparative example, the gas flow is not smooth during the degassing process. Furthermore, the gas may collide with the protrusion P during the degassing process, which could potentially damage the first edge seal S11'.

[0135] Conversely, in the embodiment, the overlapping portion S11a of the first edge sealing portion S11 may have a shape that does not protrude toward the central region 81 of the boundary portion 80 relative to the periphery of the overlapping portion S11a. Therefore, according to the embodiment, in the degassing process, smooth gas flow can be achieved, and damage to the first edge sealing portion S11 due to the flowing gas can be prevented or limited.

[0136] like Figure 7b and Figure 8As shown in (b), the cross-section sealing process according to the comparative example may include a process for forming the cross-section sealing section S2'.

[0137] A transverse sealing portion S2' may be formed at the boundary portion 80 located between the electrode receiving portion 30 and the gas receiving portion 70. The transverse sealing portion S2' may be formed by sealing at least a portion of the boundary portion 80. Both ends of the transverse sealing portion S2' may overlap with the overlapping portion S11a' of the first edge sealing portion S11', respectively. The transverse sealing portion S2' may be formed to have a constant width (or thickness) in the second direction (-Z). The shape of the transverse sealing portion S2' according to the comparative example is substantially similar to that of the embodiment, therefore specific description is omitted.

[0138] like Figure 7c and Figure 8 As shown in (c), the final sealing process according to the comparative example may include a process for forming an external sealing portion S3'. The external sealing portion S3' can be formed by sealing the boundary portion 80 between the electrode receiving portion 30 and the gas receiving portion 70 along the first direction Y. A portion of the external sealing portion S3' may overlap with the transverse sealing portion S2'. The external sealing portion S3' may be formed at a position closer to the electrode receiving portion 30 than the transverse sealing portion S2'.

[0139] The exterior sealing portion S3' may include a first portion S31' formed in the central region 81 of the boundary portion 80 and a second portion S32' formed in the end region 82 of the boundary portion 80. The exterior sealing portion S3' may be formed to have a constant width (or thickness) in the second direction (-Z). That is, the width of the first portion S31' and the width of the second portion S32' of the exterior sealing portion S3' may have the same value.

[0140] The outer sealing portion S3' can overlap with the overlapping portion S11a' of the first edge sealing portion S11'. At this time, the outer sealing portion S3' can intersect with the protrusion P formed on the overlapping portion S11a'.

[0141] In the comparative example, the folding line used in the folding process can be located at the outer sealing portion S3' and extend along the first direction Y. The first fold line can be configured in the area where the outer sealing portion S3' overlaps with the first edge sealing portion S11'. Specifically, the protrusion P of the first edge sealing portion S11' overlaps with the outer sealing portion S3', and the first fold line passes through the area where the protrusion P of the first edge sealing portion S11' overlaps with the outer sealing portion S3'. The intersection of the first fold line and the overlapping sealing area is located very close to the inner boundary line of the sealing area.

[0142] Therefore, in the comparative example, during the folding process, the insulation of the seal is prone to failure in the overlapping sealing area, and due to the reduced sealing force, leakage of electrolyte, gas, etc. may easily occur.

[0143] On the other hand, Figure 4e In the illustrated embodiment, since the fold line 45 is configured not to pass through the overlapping sealing area, poor insulation and leakage of the seal can be prevented or reduced. Furthermore, in Figure 6 In the illustrated embodiment, since the intersection of the fold line 45 and the overlapping sealing area is located at a considerable distance from the inner boundary line of the sealing area, therefore... Figures 7a to 8 Compared to the comparative example shown in (c), it can significantly reduce the occurrence of poor insulation or leakage in the sealed area.

[0144] The above description is merely an example of applying the principles of this disclosure, and other configurations may be further included without departing from the scope of this disclosure. Furthermore, it can be implemented by deleting some components from the foregoing embodiments, and the embodiments can also be combined with each other.

Claims

1. A method of manufacturing an electrode assembly, the method comprising: an edge sealing process of sealing at least a portion of an edge of a case to form an edge seal portion that blocks the electrode accommodation portion and the gas accommodation portion from the outside; and a final sealing process of sealing a boundary portion between the electrode accommodation portion and the gas accommodation portion in a first direction to form an appearance seal portion, wherein the appearance seal portion includes a first portion formed in a central region of the boundary portion and a second portion formed in an end region of the boundary portion, the final sealing process forms an extension portion extending in a second direction toward the electrode accommodation portion on the second portion of the appearance seal portion.

2. The method of manufacturing an electrical cell according to claim 1, wherein, the extension portion includes a diagonal line that forms a chamfer shape at a corner of the electrode accommodation portion.

3. The method of manufacturing an electric chip according to claim 1 or 2, wherein the edge seal portion includes an overlapping portion overlapping the appearance seal portion, the overlapping portion has a shape that does not protrude toward the central region of the boundary portion with respect to a periphery of the overlapping portion.

4. The method of manufacturing an electrical cell according to claim 3, wherein, the edge sealing process includes: a process of forming a first edge seal portion formed in a side of the electrode accommodation portion and the gas accommodation portion and extending in the second direction; and a process of forming a second edge seal portion formed in an upper side of the gas accommodation portion and extending in the first direction, the overlapping portion is formed in a portion where the first edge seal portion intersects the appearance seal portion.

5. The method of manufacturing an electrical cell according to claim 1 or 2, wherein, the edge seal portion includes an overlapping portion overlapping the appearance seal portion, the overlapping portion has a shape in which a boundary line opposite the central region of the boundary portion is perpendicular to the first direction.

6. The method of manufacturing an electrode assembly according to claim 1 or 2, further comprising: a cross-sealing process performed between the edge sealing process and the final sealing process of sealing at least a portion of the boundary portion in a first direction to form a cross-seal portion.

7. The method of manufacturing an electrical cell according to claim 6, wherein, the cross-seal portion is formed to have a constant width in the second direction.

8. The method of manufacturing an electrode assembly according to claim 6, further comprising: a cutting process performed after the final sealing process of cutting the boundary portion along a cutting line to correspond to an appearance of an electrode assembly; and a folding process of folding a seal portion disposed around the electrode accommodation portion, wherein the folding process includes a process of folding the seal portion with a folding line as a reference, the folding line is located in the appearance seal portion but disposed at a position outside the cross-seal portion.

9. The method of manufacturing an electrical cell according to claim 8, wherein, the cutting line is disposed to have a slope with respect to the appearance seal portion to avoid the folding line passing through a region where the edge seal portion overlaps the appearance seal portion at both ends of the folding line.

10. The method of manufacturing an electrode assembly according to claim 1 or 2, further comprising: a degassing process performed between the edge sealing process and the final sealing process of discharging a gas generated in the electrode accommodation portion from the electrode accommodation portion to the gas accommodation portion.

11. An electrode assembly, comprising: an electrode assembly; an electrode assembly case including an electrode accommodation portion that accommodates the electrode assembly and an electrolyte, and a seal portion that seals at least a portion of a periphery of the electrode accommodation portion; and an electrode lead electrically connected to the electrode assembly and exposed through a side portion of the electrode accommodation portion in a first direction, wherein the sealing portion includes an edge sealing portion formed at a side portion of the electrode accommodation portion where the electrode lead is disposed and an appearance sealing portion formed at an upper side of the electrode accommodation portion where the electrode lead is not disposed, the appearance sealing portion includes a first portion formed at a central region and a second portion formed at an end region, the second portion of the appearance sealing portion includes an extension portion extending in a second direction toward the electrode accommodation portion.

12. The electric cell of claim 11, wherein, the extension portion includes a diagonal line formed in a chamfer shape at a corner of the electrode accommodation portion.

13. The electric cell of claim 11 or 12, wherein, the edge sealing portion includes an overlapping portion overlapping the appearance sealing portion, the overlapping portion has a shape that does not protrude toward a central region of the appearance sealing portion with respect to a periphery of the overlapping portion.

14. The electric cell of claim 11 or 12, wherein, the edge sealing portion includes an overlapping portion overlapping the appearance sealing portion, the overlapping portion has a shape in which a boundary line opposite the first portion of the appearance sealing portion is perpendicular to the first direction.

15. The electric cell of claim 11 or 12, wherein, the sealing portion is formed on three open faces among four faces surrounding the electrode accommodation portion, the edge sealing portions are formed at two side portions of the electrode accommodation portion, respectively, the electrode leads are disposed at the two side portions of the electrode accommodation portion, respectively.

16. The electrically core of claim 11 or 12, wherein, the appearance sealing portion is folded to form a folded portion with a folding line extending in the first direction as a reference, the folding line is configured not to pass through a region where the edge sealing portion overlaps the appearance sealing portion.

Images