Secondary batteries and their manufacturing methods

Abstract

According to an exemplary embodiment of the present invention, a secondary battery is provided. The secondary battery may include: an electrode assembly in which a positive electrode and a negative electrode are stacked along a first direction; a housing including a receiving portion for accommodating the electrode assembly; electrode terminals protruding from a first edge portion of the housing; and a coating located on the first edge portion, wherein the first edge portion includes a first surface and a second surface opposite to each other in the first direction, the coating is disposed on the first surface, the coating comprises a thermal resin, and the coating overlaps with the electrode assembly but does not overlap with the electrode terminals.

Description

Technical Field

[0001] This disclosure relates to secondary batteries and methods for manufacturing them. Specifically, this disclosure relates to pouch-type secondary batteries and methods for manufacturing them.

[0002] This application claims the benefit of priority to Korean Patent Application No. 10-2024-0127574, filed on September 20, 2024, the entire contents of which are incorporated herein by reference. Background Technology

[0003] Unlike primary batteries, secondary batteries can be charged and discharged multiple times. They are widely used as an energy source for various wireless devices such as mobile phones, laptops, and cordless vacuum cleaners. Recently, due to increased energy density and economies of scale, the manufacturing cost per unit capacity of secondary batteries has significantly decreased, and as the driving range of BEVs (Battery Electric Vehicles) has increased to levels comparable to fuel cell vehicles, the primary application of secondary batteries is shifting from mobile devices to mobility tools.

[0004] The technological trend in secondary batteries for mobile devices is to improve energy density and safety. The safety of secondary batteries for mobile devices is paramount, as it is directly related to passenger safety. Battery safety can be achieved through mechanical strength, reliable electrical insulation, and delaying heat transfer during thermal runaway events. Summary of the Invention

[0005] Technical issues

[0006] The technical problem to be solved by this disclosure is to provide a secondary battery with improved performance and reliability.

[0007] The technical problem to be solved by this disclosure is to provide a secondary battery with improved safety.

[0008] The technical problem to be solved by this disclosure is to provide a method for manufacturing a secondary battery with improved safety.

[0009] The technical problem to be solved by this disclosure is to provide a method for manufacturing a secondary battery with improved performance and reliability.

[0010] Technical solution

[0011] According to an exemplary embodiment of this disclosure for solving the above-mentioned problems, a secondary battery is provided. The secondary battery includes: an electrode assembly in which a positive electrode and a negative electrode are stacked along a first direction; a housing including a receiving portion for receiving the electrode assembly; electrode terminals protruding from a first edge portion of the housing; and a coating located on the first edge portion, wherein the first edge portion includes a first surface and a second surface opposite to each other in the first direction, the coating is disposed on the first surface, the coating includes a thermal resin, the coating overlaps with the electrode assembly, and the coating does not overlap with the electrode terminals.

[0012] The electrode terminals may protrude along a second direction intersecting the first direction, and the coating may not overlap with the electrode terminals in the second direction.

[0013] The box may include a first corner portion that is part of a first edge portion and overlaps with the electrode assembly in a second direction, and a coating may be applied to the first corner portion.

[0014] The highest vertical height of the coating in the first direction may be equal to or lower than the highest vertical height of the accommodating portion in the first direction.

[0015] The coating may contact a first surface of a first edge portion, the coating may be spaced apart from a second surface, wherein the first surface is located between the coating portion and the second surface, and the coating may not contact the second surface.

[0016] The box may also include a first edge portion, a second edge portion, and a third edge portion adjacent to a first side, a second side, and a third side of the receiving portion, respectively. The first and second sides may extend in a second direction intersecting the first direction. The third and fourth sides of the receiving portion may extend upward in a third direction intersecting the first and second directions. The first edge portion may include a first corner portion adjacent to the fourth side, and a coating may be provided on the first corner portion.

[0017] The second edge portion may include a second corner portion adjacent to the fourth side portion, and the coating may also be applied to the second corner portion.

[0018] The first edge portion may extend in a second direction intersecting the first direction, the box may also include a sealing portion that seals the first edge portion, and a coating may be disposed between the sealing portion and the receiving portion in a third direction intersecting the first and second directions.

[0019] According to an exemplary embodiment of this disclosure for solving the above-mentioned problems, a method for manufacturing a secondary battery is provided. The method includes: assembling an electrode assembly; housing the electrode assembly in a casing; sealing the casing; forming a coating on a first surface of an edge portion; and injecting an electrolyte, wherein the coating comprises a thermally applied resin, the edge portion includes a corner portion of the casing overlapping the electrode assembly, and the coating may be formed on the corner portion.

[0020] The coating may be formed on a first surface of the edge portion, and the coating may not be formed on a second surface opposite to the first surface in a first direction.

[0021] The electrode assemblies can be stacked along a first direction, and the corner portions can overlap with the electrode assemblies in a second direction that intersects with the first direction.

[0022] Following the electrolyte injection step, the method may also include: pre-aging; activation; and aging.

[0023] Technical effect

[0024] According to an exemplary embodiment of this disclosure, a secondary battery may include a coating on the edge portions of the casing. The coating can provide rigidity to the casing, thereby preventing impact damage during the process of supplying the secondary battery. Therefore, defects that may occur during the manufacturing process of the secondary battery can be reduced.

[0025] According to exemplary embodiments of this disclosure, a secondary battery with improved safety can be provided.

[0026] According to exemplary embodiments of this disclosure, a secondary battery with improved performance and reliability can be provided.

[0027] According to exemplary embodiments of the present disclosure, a method for manufacturing a secondary battery with improved safety can be provided.

[0028] According to exemplary embodiments of the present disclosure, a method for manufacturing a secondary battery with improved performance and reliability can be provided.

[0029] The effects that can be obtained in the exemplary embodiments of this disclosure are not limited to those described above, and those skilled in the art can deduce and understand other effects not mentioned in the following description. In other words, those skilled in the art can also deduce unintended effects of implementing the exemplary embodiments of this disclosure from the exemplary embodiments of this disclosure. Attached Figure Description

[0030] Figure 1 This is a diagram of a secondary battery according to an embodiment of the present disclosure.

[0031] Figure 2This is a diagram of a secondary battery according to an embodiment of the present disclosure.

[0032] Figure 3 This is an enlarged view of a secondary battery according to an embodiment of the present disclosure.

[0033] Figure 4 This is an enlarged view of a secondary battery according to an embodiment of the present disclosure.

[0034] Figure 5 This is a flowchart illustrating a method for manufacturing a secondary battery according to an embodiment of the present disclosure.

[0035] Figure 6 This is a flowchart illustrating a method for manufacturing a secondary battery according to an embodiment of the present disclosure.

[0036] Figure 7 This is a diagram illustrating a method for manufacturing a secondary battery according to an embodiment of the present disclosure.

[0037] Figure 8 This is a diagram illustrating a method for manufacturing a secondary battery according to an embodiment of the present disclosure.

[0038] Figure 9 This is a diagram illustrating a method for manufacturing a secondary battery according to an embodiment of the present disclosure.

[0039] Figure 10 This is a diagram illustrating a method for manufacturing a secondary battery according to an embodiment of the present disclosure. Detailed Implementation

[0040] In the following, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Prior to this, the terms or words used in this specification and claims should not be construed as limited to their ordinary or dictionary meanings, but should be interpreted as conforming to the meaning and concept of the technical concept of this disclosure, based on the principle that inventors can appropriately define the concepts of terms in order to best describe their own inventions.

[0041] Therefore, it should be understood that the embodiments described in this specification and the configurations shown in the accompanying drawings are merely one of the most preferred embodiments of this disclosure and do not represent the entirety of the technical concept of this disclosure, so that various equivalents and modifications that can replace them may exist at the time of this application.

[0042] In addition, in describing this disclosure, detailed descriptions of relevant known configurations or functions will be omitted if it is determined that such detailed descriptions may obscure the main points of this disclosure.

[0043] Embodiments of this disclosure are provided to describe the disclosure more fully to those skilled in the art; therefore, for clarity of explanation, the shapes and dimensions of components in the drawings may be exaggerated, omitted, or shown schematically. Consequently, the dimensions or ratios of each component do not perfectly reflect their actual dimensions or ratios.

[0044] (First Implementation)

[0045] Figure 1 This is a diagram of a secondary battery 100 according to an embodiment of the present disclosure.

[0046] Figure 2 This is a diagram of a secondary battery 100 according to an embodiment of the present disclosure.

[0047] Figure 3 This is an enlarged view of the secondary battery 100 according to an embodiment of the present disclosure. Specifically, Figure 3 yes Figure 1 A magnified view of region EX1.

[0048] Figure 4 This is an enlarged view of the secondary battery 100 according to an embodiment of the present disclosure. Specifically, Figure 4 yes Figure 2 A magnified view of region EX2.

[0049] Reference Figure 1 and Figure 2 The secondary battery 100 may include an electrode assembly 100EA, a housing 100C, a positive terminal 100P, and a negative terminal 100N. The secondary battery 100 may also include an electrolyte.

[0050] In some embodiments, the secondary battery 100 may include a pouch-type secondary battery. The electrode assembly of the pouch-type secondary battery may be embedded in a pouch-shaped casing comprising an aluminum laminate. Hereinafter, the technical concept of this disclosure will be described based on an example in which the secondary battery 100 is a pouch-type secondary battery.

[0051] Electrode assembly 100EA may include a positive electrode, a negative electrode, and a spacer inserted between the positive and negative electrodes. Electrode assembly 100EA may be either a wound type or a stacked type. A wound type electrode assembly 100EA may include a wound structure of a positive electrode, a negative electrode, and a spacer inserted between them. A stacked type electrode assembly 100EA may include a plurality of positive electrodes, a plurality of negative electrodes, and a plurality of spacers inserted between them, stacked sequentially.

[0052] In the stacked electrode assembly 100EA, multiple positive electrodes and multiple negative electrodes can be arranged along a first direction D1. In the stacked electrode assembly 100EA, multiple positive electrodes and multiple negative electrodes can be stacked along the first direction D1.

[0053] Each of the plurality of positive electrodes of electrode assembly 100EA may include a positive electrode contact (not shown). The positive electrode contact of each of the plurality of positive electrodes of electrode assembly 100EA may be short-circuited to the positive terminal 100P. The positive electrode contact of each of the plurality of positive electrodes of electrode assembly 100EA may be soldered to the positive terminal 100P.

[0054] Each of the plurality of negative terminals of electrode assembly 100EA may include a negative terminal tab (not shown). The negative terminal tab of each of the plurality of negative terminals of electrode assembly 100EA may be short-circuited to the negative terminal 100N. The negative terminal tab of each of the plurality of negative terminals of electrode assembly 100EA may be soldered to the negative terminal 100N.

[0055] The box 100C may include an inner resin layer, a metal layer, and an outer resin layer. Adhesive and anti-corrosion layers may be further disposed between the inner resin layer and the metal layer, and between the outer resin layer and the metal layer.

[0056] The inner resin layer may be thermally adhesive and may be referred to as a sealant layer. The inner resin layer enables the sealing of box 100C. The inner resin layer may include, for example, polyolefin-based resins, such as polypropylene (PP) and polyethylene (PE). The metal layer may include alloys of iron, carbon, chromium, and manganese; alloys of iron, chromium, and nickel; and any one of aluminum. The metal layer may be a gas barrier layer. The metal layer prevents gases from entering and leaving box 100C. The outer resin layer may be a surface protective layer. The outer resin layer may include materials with abrasion resistance and heat resistance, such as nylon resin.

[0057] The positive terminal 100P and the negative terminal 100N can protrude to the outside of the housing 100C. The positive terminal 100P and the negative terminal 100N can protrude from the housing 100C along a second direction D2. Therefore, the voltage and current obtained from the secondary battery 100 can be output through the positive terminal 100P and the negative terminal 100N. The positive terminal 100P can be a positive lead. The negative terminal 100N can be a negative lead.

[0058] In the following description, the technical concept of this disclosure will be based on an example in which each of the plurality of secondary batteries 100 is a bidirectional battery, in which the positive terminal 100P and the negative terminal 100N of the secondary battery 100 are formed on opposite sides of the housing 100C. Those skilled in the art will be able to readily understand, based on the description herein, the case where each of the plurality of secondary batteries 100 is a unidirectional battery. The positive terminal 100P and the negative terminal 100N may be spaced apart in a second direction D2. The second direction D2 may be substantially parallel to each of the plurality of positive terminals and each of the plurality of negative terminals of the electrode assembly 100EA.

[0059] In one embodiment, the housing 100C may include a receiving portion 100R for receiving an electrode assembly 100EA and an edge portion surrounding the receiving portion 100R. The edge portion may surround the receiving portion 100R in a U-shape.

[0060] Specifically, the positive terminal 100P and the negative terminal 100N may protrude from the edge portion. For example, the positive terminal 100P and the negative terminal 100N may protrude from the edge portion along the second direction D2. For example, the positive terminal 100P may protrude from the first edge portion 121 along the second direction D2. For example, the negative terminal 100N may protrude from the second edge portion 122 along the second direction D2.

[0061] In one embodiment, coating 130 may be disposed on the first edge portion 121. Specifically, as shown... Figure 2 As shown, the first edge portion 121 may include a first surface 121_1 and a second surface 121_2 that are opposite to each other in the first direction D1. A coating 130 may be disposed on the first surface 121_1 of the first edge portion 121. The coating 130 may be in contact with the first surface 121_1. For example, the coating 130 may be spaced apart from the second surface 121_2, wherein the first surface 121_1 of the first edge portion 121 is located between the coating 130 and the second surface 121_2. The coating 130 may not be in contact with the second surface 121_2.

[0062] The coating 130 may be disposed on a local area of ​​the first edge portion 121. For example, the coating 130 may be disposed locally on a portion of the first edge portion 121 that overlaps with the electrode assembly 100EA.

[0063] The coating 130 may include a thermal resin. For example, the coating 130 may be formed by applying a thermal resin to a local area of ​​the first surface 121_1 of the first edge portion 121 and then curing the thermal resin.

[0064] The coating 130 may overlap with the electrode assembly 100EA in the second direction D2. The coating 130 may not overlap with the electrode terminal in the second direction D2. For example, the coating 130 may not overlap with the positive terminal 100P in the second direction D2.

[0065] Box 100C may include a corner portion. Specifically, box 100C may include a first corner portion 121C that is part of a first edge portion 121. Figure 1 Of the four corner portions of the box 100C shown, the corner portion that is part of the first edge portion 121 and overlaps with the electrode assembly 100EA in the second direction D2 can be referred to as the first corner portion 121C.

[0066] Specifically, the first edge portion 121, the second edge portion 122, and the third edge portion 123 may respectively surround the first side portion 111, the second side portion 112, and the third side portion 113 of the receiving portion 100R.

[0067] For example, the first side portion 111 and the first edge portion 121 may extend along a third direction D3, and the first edge portion 121 may refer to the portion adjacent to the first side portion 111. The third direction D3 may intersect with the first direction D1 and the second direction D2. For example, the second side portion 112 and the second edge portion 122 may extend along a third direction D3, and the second edge portion 122 may refer to the portion adjacent to the second side portion 112. The first edge portion 121 and the second edge portion 122 may be spaced apart, with the receiving portion 100R located between them. For example, the third side portion 113 and the third edge portion 123 may extend along the second direction D2, and the third edge portion 123 may refer to the portion adjacent to the third side portion 113. The fourth side portion 114 of the receiving portion may not be surrounded by the edge portions. The first edge portion 121, the second edge portion 122, and the third edge portion 123 may form a U-shape.

[0068] Also refer to Figure 3 The first corner portion 121C may be adjacent to the fourth side portion 114. The first edge portion 121 may extend in a direction intersecting with the fourth side portion 114, and the portion of the first edge portion 121 adjacent to the fourth side portion 114 may be referred to as the first corner portion 121C. Specifically, the portion of the first edge portion 121 adjacent to the fourth side portion 114 and not overlapping with the positive terminal 100P may be referred to as the first corner portion 121C. For example, in the corner portion of the box 100C, the corner portion that is part of the first edge portion 121 and adjacent to the fourth side portion 114 may be referred to as the first corner portion 121C.

[0069] The coating 130 may be provided on the first corner portion 121C. For example, the coating 130 may be provided on one surface of the first corner portion 121C.

[0070] Refer again Figure 1The second corner portion 122C may be adjacent to the fourth side portion 114. The second edge portion 122 may extend in the direction intersecting with the fourth side portion 114, and the portion of the second edge portion 122 adjacent to the fourth side portion 114 may be referred to as the first corner portion 121C. Specifically, the portion of the second edge portion 122 adjacent to the fourth side portion 114 and not overlapping with the negative terminal 100N may be referred to as the second corner portion 122C. For example, in the corner portion of the box 100C, the corner portion that is part of the second edge portion 122 and adjacent to the fourth side portion 114 may be referred to as the second corner portion 122C.

[0071] The coating 130 may also be provided on the second corner portion 122C. For example, the coating 130 may also be provided on one surface of the second corner portion 122C.

[0072] Also refer to Figure 4 The maximum vertical height of coating 130 may be equal to or lower than the maximum vertical height of the receiving portion 100R. In this specification, vertical height may refer to the height in the +D1 direction. In this specification, a higher vertical height may mean a location at a higher height in the +D1 direction. In this specification, the maximum vertical height of a component may refer to the vertical height at the point where the component's vertical height is highest.

[0073] Specifically, the highest vertical height of the coating 130 can be a first height LV1. For example, the highest vertical height of the coating 130 can be the first height LV1. For example, the vertical height of the uppermost part of the coating 130 can be the first height LV1.

[0074] Specifically, the highest vertical height of the receiving portion 100R can be a second height LV2. For example, the highest vertical height of the receiving portion 100R can be the second height LV2. For example, the vertical height of the upper surface of the receiving portion 100R can be the second height LV2. The second height LV2 can be higher than the first height LV1.

[0075] Refer again Figure 1 and Figure 2 Box 100C may also include a sealing portion for sealing the edge portion.

[0076] Specifically, the first sealing portion 121S can seal the first edge portion 121. The first sealing portion 121S can extend along a third direction D3. The first sealing portion 121S can seal a portion of the first edge portion 121 to seal the box 100C. The first sealing portion 121S can be spaced apart from the receiving portion 100R, wherein the remaining portion of the first edge portion 121 is located between them.

[0077] Similarly, the second sealing portion 122S can seal the second edge portion 122. The second sealing portion 122S can extend along a third direction D3. The second sealing portion 122S can seal a portion of the second edge portion 122 to seal the box 100C. The second sealing portion 122S can be spaced apart from the receiving portion 100R, wherein the remainder of the second edge portion 122 is located between them.

[0078] The third sealing portion 123S can seal the third edge portion 123. The third sealing portion 123S can extend along the second direction D2. The third sealing portion 123S can seal a portion of the third edge portion 123 to seal the box 100C. The third sealing portion 123S can be spaced apart from the receiving portion 100R, wherein the remaining portion of the third edge portion 123 is located between them.

[0079] In one embodiment, coating 130 may be disposed on the first edge portion 121, located in the area where the first sealing portion 121S is not formed. Coating 130 may be disposed between the receiving portion 100R and the first sealing portion 121S. Coating 130 may be disposed between the first side portion 111 of the receiving portion 100R and the first sealing portion 121S. Coating 130 may be disposed between the receiving portion 100R and the first sealing portion 121S in the second direction D2. Coating 130 may not overlap with the first sealing portion 121S in the first direction D1.

[0080] Similarly, coating 130 can be disposed on the second edge portion 122, located in the area where the second sealing portion 122S is not formed. Coating 130 can be disposed between the receiving portion 100R and the second sealing portion 122S. Coating 130 can be disposed between the second side portion 112 of the receiving portion 100R and the second sealing portion 122S. Coating 130 can be disposed between the receiving portion 100R and the second sealing portion 122S in the second direction D2. Coating 130 can be non-overlapping with the second sealing portion 122S in the first direction D1.

[0081] Reference Figures 1 to 4 The described secondary battery 100 may include a coating 130 located on the edge portion of the casing 100C. The coating 130 provides rigidity to the casing 100C. Therefore, it can prevent the casing 100C from being damaged by impact during the manufacturing process of the secondary battery 100. That is, it can reduce defects that may occur during the manufacturing process of the secondary battery 100. Therefore, the performance and reliability of the secondary battery 100 can be improved, and its safety can be enhanced.

[0082] According to embodiments of this disclosure, a secondary battery 100 with improved performance and reliability can be provided.

[0083] According to embodiments of this disclosure, a secondary battery 100 with improved safety can be provided.

[0084] (Second Implementation)

[0085] Figure 5 This is a flowchart illustrating a method S100 for manufacturing a secondary battery according to an embodiment of the present disclosure.

[0086] Figure 6 This is a flowchart illustrating a method S110 for manufacturing a secondary battery according to an embodiment of the present disclosure.

[0087] Figure 7 This is a diagram illustrating a method S110 for manufacturing a secondary battery according to an embodiment of the present disclosure.

[0088] Figure 8 This is a diagram illustrating a method S110 for manufacturing a secondary battery according to an embodiment of the present disclosure.

[0089] Figure 9 This is a diagram illustrating a method S110 for manufacturing a secondary battery according to an embodiment of the present disclosure.

[0090] Figure 10 This is a diagram illustrating a method S110 for manufacturing a secondary battery according to an embodiment of the present disclosure.

[0091] Reference Figure 5 A method for manufacturing secondary batteries, S100, can be provided.

[0092] First, step S110 of assembling the battery cells can be performed.

[0093] Specifically, a battery cell may include electrode assemblies and electrode terminals. Electrode terminals may include, for example, a positive terminal and / or a negative terminal.

[0094] In the battery cell assembly step, electrode processes including mixing, coating, rolling, selective cutting, and slit processes can be performed. Subsequently, a process of embedding the electrode assembly into the cell can be performed.

[0095] Subsequently, step S120, which involves injecting electrolytes, can be performed. The electrolytes can be injected into the box.

[0096] Subsequently, a pre-aging step S130 can be performed to allow the electrolyte to permeate into the battery cell. Pre-aging can be performed before the battery cell is charged or discharged during the activation process.

[0097] The key to the pre-aging step S130 is to uniformly distribute the electrolyte within the pouch cell, ensuring even penetration of the electrolyte into both the positive and negative electrodes. The pre-aging step S130 can improve lithium-ion mobility. The pre-aging step S130 completes the electrical connection between the positive and negative electrodes before proceeding to the subsequent activation step S140.

[0098] Subsequently, activation step S140, which involves charging or discharging the battery cell, can be performed.

[0099] When the battery cell is charging or discharging, it can be pressurized by a pressurizing fixture. Pressurization of the battery cell can prevent gas trapping and lithium plating, and can improve the uniformity of the SEI (solid electrolyte interface) film. Battery cells with a uniform SEI film can have relatively short charging or discharging times.

[0100] An SEI film can be formed on the surface of the negative electrode during the initial charge. The SEI is a thin film formed on the surface of the negative electrode material during the first charge after the battery cell is manufactured. When the battery cell is charged, lithium ions move to the negative electrode, and during this process, an SEI film can be formed on the surface of the negative electrode material through a chemical reaction that occurs during the initial electrolysis of the materials in the electrolyte. The SEI can be of the separator type. The SEI prevents additional decomposition reactions of the electrolyte during the process of lithium ions moving from the positive electrode to the negative electrode for battery charging.

[0101] Subsequently, step S150, which involves aging the battery cells, can be performed. In aging step S150, the battery cells can be stored at room temperature for a predetermined time to stabilize the charging or discharging battery cells.

[0102] Subsequently, degassing step S160 can be performed. For example, by removing 100g of cavitation portion (see... Figure 10 This can remove the gases generated by the side reactions of the electrolyte during the previous activation step S140.

[0103] Reference Figure 6 Method S110 for manufacturing secondary batteries can be provided. (See reference...) Figure 5 The described method S100 for manufacturing a secondary battery may include Figure 6 Method S110 for manufacturing a secondary battery. For example. Figure 5 Step S110 of assembling the battery cell may include Figure 6 Method S110 for manufacturing secondary batteries.

[0104] First, step S111 of assembling the electrode assembly can be performed. Specifically, the assembly can be performed as described in reference... Figure 1 and Figure 2The electrode assembly 100EA is described. For example, the stacked electrode assembly 100EA can be assembled by stacking multiple positive electrodes and multiple negative electrodes along a first direction D1.

[0105] Subsequently, step S112, which involves housing the electrode assembly in the housing, can be performed. Specifically, the electrode assembly 100EA can be as described in reference... Figure 1 and Figure 2 It is contained in box 100C as described.

[0106] Also refer to Figure 7 A box 100C can be manufactured. Box 100C can be provided by combining a first box 100C1 and a second box 100C2. The first box 100C1 may include a first receiving portion 100R1. The first receiving portion 100R1 is part of a bowl-shaped configuration of the first box 100C1 for receiving an electrode assembly 100EA. The second box 100C2 may include a second receiving portion 100R2. The second receiving portion 100R2 is part of a bowl-shaped configuration of the second box 100C2 for receiving an electrode assembly 100EA. The first receiving portion 100R1 and the second receiving portion 100R2 can be formed by a bag forming process. The first receiving portion 100R1 and the second receiving portion 100R2 can constitute receiving portion 100R.

[0107] The first box 100C1 and the second box 100C2 can be integrally formed. The electrode assembly 100EA can be housed in the receiving portion 100R of the box 100C. For example, the boundary lines of the first box 100C1 and the second box 100C2 can be folded so that the first receiving portion 100R1 and the second receiving portion 100R2 overlap in the first direction D1, and the first box 100C1 and the second box 100C2 can be combined.

[0108] Also refer to Figure 8 The electrode assembly 100EA can be housed in a housing 100C, which includes a receiving portion 100R and a cavitation portion 100G. The housing 100C may include a first edge portion 121 and a second edge portion 122. The first edge portion 121 and the second edge portion 122 may be located on one side of the receiving portion 100R. The first edge portion 121 and the second edge portion 122 may include portions that overlap with the receiving portion 100R in a second direction D2. The first edge portion 121 and the second edge portion 122 may extend along a third direction D3. The positive terminal 100P and the negative terminal 100N may protrude from the housing 100C.

[0109] Then, step S113 of sealing the box can be performed.

[0110] Specifically, refer to Figure 9A first sealing portion 121S and a second sealing portion 122S can be formed. For example, the first sealing portion 121S can be formed by sealing the first edge portion 121. For example, the second sealing portion 122S can be formed by sealing the second edge portion 122.

[0111] Subsequently, step S114, which involves forming a coating on the first surface of the edge portion, can be performed.

[0112] Specifically, refer to Figure 10 Coating 130 can be formed on the corner portion of box 100C. For example, as shown in reference... Figure 1 As described, coating 130 can be formed on a corner portion that overlaps with electrode assembly 100EA in the second direction D2 but does not overlap with electrode terminals in the second direction D2. For example, as referenced Figure 2 As described, coating 130 can be formed on the first surface 121_1 of the first edge portion 121. For example, coating 130 can be formed on the first surface of the second edge portion 122.

[0113] Reference Figures 5 to 10 The described methods for manufacturing a secondary battery, S100 and S110, may include step S114 of forming a coating on a first surface of the edge portion. As described above, the coating 130 can provide rigidity to the housing 100C. Therefore, damage and defects to the housing 100C that may occur in subsequent processes can be prevented. That is, the performance and reliability of the secondary battery 100 can be improved, and safety can be enhanced.

[0114] According to embodiments of the present disclosure, methods S100 and S110 can be provided for manufacturing secondary batteries with improved performance and reliability.

[0115] According to embodiments of this disclosure, methods S100 and S110 can be provided for manufacturing secondary batteries with improved safety.

[0116] As described above, this disclosure has been described in more detail with reference to the accompanying drawings and embodiments. However, it should be understood that the configurations described in the drawings or the embodiments described in this specification are merely one embodiment of this disclosure and do not represent all the technical concepts of this disclosure. Therefore, various equivalents and modifications that can replace these embodiments may exist at the time of filing this application.

Claims

1. A secondary battery, comprising: An electrode assembly in which a positive electrode and a negative electrode are stacked along a first direction; A housing, the housing including a receiving portion for accommodating the electrode assembly; Electrode terminals protrude from a first edge portion of the housing; as well as A coating, the coating being located on the first edge portion, The first edge portion includes a first surface and a second surface that are opposite to each other in the first direction. The coating is disposed on the first surface. The coating comprises a thermoplastic resin. The coating overlaps with the electrode assembly, but does not overlap with the electrode terminals.

2. The secondary battery according to claim 1, wherein, The electrode terminal protrudes along a second direction intersecting the first direction, and Wherein, the coating does not overlap with the electrode terminal in the second direction.

3. The secondary battery according to claim 2, wherein, The box includes a first corner portion, which is part of the first edge portion and overlaps with the electrode assembly in the second direction. The coating is applied to the first corner portion.

4. The secondary battery according to claim 1, wherein, The highest vertical height of the coating in the first direction is equal to or lower than the highest vertical height of the receiving portion in the first direction.

5. The secondary battery according to claim 1, wherein, The coating is in contact with the first surface of the first edge portion, the coating is spaced apart from the second surface such that the first surface is located between the coating and the second surface, and the coating is not in contact with the second surface.

6. The secondary battery according to claim 1, wherein, The box also includes a first edge portion, a second edge portion, and a third edge portion that are respectively adjacent to the first side, the second side, and the third side of the receiving portion. The first side portion and the second side portion extend in a second direction intersecting the first direction. The third and fourth sides of the receiving portion extend upward at a third point intersecting the first and second directions. Wherein, the first edge portion includes a first corner portion adjacent to the fourth side portion, and The coating is applied to the first corner portion.

7. The secondary battery according to claim 6, wherein, The second edge portion includes a second corner portion adjacent to the fourth side portion, and The coating is also applied to the second corner portion.

8. The secondary battery according to claim 1, wherein, The first edge portion extends in a second direction intersecting the first direction. The box further includes a sealing portion that seals the first edge portion, and The coating is disposed between the sealing portion and the receiving portion in a third direction intersecting the first direction and the second direction.

9. A method for manufacturing a secondary battery, comprising: Assemble electrode assemblies; The electrode assembly is housed in a box; Seal the box; A coating is formed on the first surface of the edge portion; as well as Inject electrolytes, The coating comprises a thermoplastic resin. The edge portion includes the corner portion of the box that overlaps with the electrode assembly, and The coating is formed on the corner portion.

10. The method for manufacturing a secondary battery according to claim 9, wherein, The coating is formed on the first surface of the edge portion, and The coating is not formed on a second surface opposite to the first surface in the first direction.

11. The method for manufacturing a secondary battery according to claim 9, wherein, The electrode assemblies are stacked along a first direction, and The corner portion overlaps with the electrode assembly in a second direction that intersects with the first direction.

12. The method for manufacturing a secondary battery according to claim 9, further comprising, after the step of injecting the electrolyte: Pre-aging; activation; as well as aging.

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