Secondary battery and method for manufacturing secondary battery

Abstract

A secondary battery and a method for manufacturing the same are disclosed. The secondary battery includes: an electrode assembly having a first electrode, a second electrode, and a separator between the first electrode and the second electrode; a case accommodating the electrode assembly; and a tape attached to an inner surface of the case, in which the tape includes a first adhesive layer and a second adhesive layer, the first adhesive layer contacting and adhering to the inner surface of the case, and the second adhesive layer facing the electrode assembly.

Description

Technical Field

[0001] Embodiments of this disclosure relate to secondary batteries and methods for manufacturing secondary batteries. Background Technology

[0002] Unlike primary batteries, which are not designed for (re)charging, secondary (or rechargeable) batteries are designed to be discharged and recharged. Low-capacity secondary batteries are used in portable small electronic devices, such as smartphones, feature phones, laptops, digital cameras, and camcorders, while high-capacity secondary batteries are widely used as power sources to drive motors in hybrid and electric vehicles and for storing electricity (e.g., household and / or utility-scale power storage). A secondary battery typically includes an electrode assembly containing positive and negative electrodes, a housing of the electrode assembly, and electrode terminals connected to the electrode assembly.

[0003] The information disclosed above in this background section is intended to enhance the understanding of the background of this disclosure, and therefore may contain information that does not constitute related (or prior art). Summary of the Invention

[0004] The embodiments relate to a secondary battery, including: an electrode assembly having a first electrode, a second electrode, and a separator between the first and second electrodes; a housing housing the electrode assembly; and a strip attached to an inner surface of the housing, wherein the strip includes a first adhesive layer and a second adhesive layer, the first adhesive layer contacting and adhering to the inner surface of the housing, and the second adhesive layer facing the electrode assembly.

[0005] The first adhesive layer can be tacky at a first temperature, and the second adhesive layer can become tacky at a second temperature higher than the first temperature.

[0006] The second temperature can be 60°C or higher.

[0007] The second adhesive layer can become sticky due to the heat applied during the formation process of the secondary battery.

[0008] An electrode tab that can be connected to one of the first and second electrodes can protrude through at least one surface of the electrode assembly, and has one or more portions that are not facing the electrode tab and can be attached to the inner surface of the housing.

[0009] The housing may include a bottom portion, a cylindrical sidewall portion extending upward from the bottom portion, and an opening opposite the bottom portion, and may be attached to the inner surface of the cylindrical sidewall portion.

[0010] The electrode assembly can be a wound electrode assembly, wherein a first electrode, a diaphragm, and a second electrode are wound together. The first electrode may include a first coated portion coated with an active material, and the width of the coated portion along the extension direction of the cylindrical sidewall portion may be equal to or greater than a first length, which may be the width of the first coated portion along the winding axis of the electrode assembly.

[0011] The second electrode may include a second coated portion coated with an active material, and the width of the coated portion along the extension direction of the cylindrical sidewall portion may be equal to or less than the second length, which may be the width of the second coated portion along the winding axis direction of the electrode assembly.

[0012] The housing may include a rectangular bottom portion, at least four sidewall portions extending upward from the bottom portion, and an opening opposite the bottom portion, and the band may be attached to the inner surface of each of the at least four sidewall portions other than one of the at least four sidewall portions.

[0013] An electrode tab that can be connected to one of the first and second electrodes protrudes through at least one surface of the electrode assembly, and the electrode tab can face the inner surface of one of the at least four sidewall portions, where the strip may not be attached.

[0014] In the direction of extension from the bottom portion of at least four sidewall portions, the width of the strip, measured from the bottom portion, can be 110% to 150% of the height of the electrode assembly, measured from the bottom portion.

[0015] The embodiments relate to a method for manufacturing a secondary battery, the method comprising: preparing an electrode assembly including a first electrode, a second electrode, and a separator between the first electrode and the second electrode; preparing a housing and attaching a strip including a first adhesive layer and a second adhesive layer to an inner surface of the housing; inserting the electrode assembly into the housing; injecting an electrolyte into the housing; and sealing the housing by attaching a cover plate to the housing, wherein the first adhesive layer of the strip is positioned to contact and adhere to the inner surface of the housing, and the second adhesive layer of the strip is positioned to face the electrode assembly.

[0016] The method may further include: after sealing the casing, charging and discharging the secondary battery at a first temperature or aging the secondary battery at a second temperature.

[0017] The first temperature and the second temperature can each be 60°C or higher, and the second adhesive layer can exhibit stickiness after heat is applied during the charging and discharging of the secondary battery or after heat is applied during the aging of the secondary battery.

[0018] The method may further include: connecting an electrode tab to one of a first electrode and a second electrode, and positioning the electrode tab to protrude through at least one surface of the electrode assembly, wherein the tab may be attached to one or more portions of the inner surface of the housing other than the portion facing the inner surface of the electrode tab.

[0019] The housing may include a bottom portion, a cylindrical sidewall portion extending upward from the bottom portion, and an opening formed opposite to the bottom portion, and a strap may be attached to the inner surface of the cylindrical sidewall portion.

[0020] The electrode assembly can be fabricated by winding a first electrode, a diaphragm, and a second electrode. The first electrode may include a first coated portion coated with an active material, and the second electrode may include a second coated portion coated with an active material. The width of the portion extending along the cylindrical sidewall can be equal to or greater than a first length and can be equal to or less than a second length. The first length can be the width of the first coated portion along the winding axis of the electrode assembly, and the second length can be the width of the second coated portion along the winding axis of the electrode assembly.

[0021] The housing may include a bottom portion, at least four sidewall portions extending upward from the bottom portion, and an opening formed opposite to the bottom portion, and the band may be attached to the inner surface of each of the at least four sidewall portions other than one of the at least four sidewall portions.

[0022] The method may further include: connecting an electrode tab to one of a first electrode and a second electrode, and positioning the electrode tab to protrude through at least one surface of the electrode assembly, wherein insertion of the electrode assembly may include inserting the electrode assembly into the housing such that at least one surface of the electrode assembly may face the inner surface of one of the at least four sidewall portions, where the strip may not be attached.

[0023] In the direction of extension from the bottom portion of at least four sidewall portions, the width of the strip, measured from the bottom portion, can be 110% to 150% of the height of the electrode assembly, measured from the bottom portion. Attached Figure Description

[0024] The accompanying drawings illustrate embodiments of the present disclosure and, together with the detailed description of the present disclosure, further describe aspects and features of the present disclosure. Therefore, the present disclosure should not be construed as limited to the drawings.

[0025] Features will become apparent to those skilled in the art from the detailed description of exemplary embodiments with reference to the accompanying drawings, in which:

[0026] Figure 1 An exploded perspective view illustrating an example of a secondary battery according to an embodiment of the present disclosure.

[0027] Figure 2 A cross-sectional view of an example of a band according to an embodiment of the present disclosure is shown.

[0028] Figure 3 A perspective view of a housing illustrating the attachment location of a strap, according to an embodiment of the present disclosure.

[0029] Figure 4 A longitudinal cross-sectional view of a secondary battery for illustrating the attachment location of a strap, according to an embodiment of the present disclosure.

[0030] Figure 5 An enlarged cross-sectional view illustrating the attachment location of a secondary battery according to an embodiment of the present disclosure.

[0031] Figure 6 A perspective view of a housing illustrating the attachment location of a strap, according to an embodiment of the present disclosure.

[0032] Figure 7 A longitudinal cross-sectional view of a secondary battery for illustrating the attachment location of a strap, according to an embodiment of the present disclosure.

[0033] Figure 8 An enlarged cross-sectional view illustrating the attachment location of a secondary battery according to an embodiment of the present disclosure.

[0034] Figure 9 A perspective view of a housing illustrating the attachment location of a strap, according to an embodiment of the present disclosure.

[0035] Figure 10 This example illustrates the attachment position of the band based on the comparison example.

[0036] Figure 11 This example illustrates the attachment position of the band based on the comparison example.

[0037] Figure 12 This example illustrates the attachment position of the band based on the comparison example.

[0038] Figure 13 A flowchart illustrating a method for manufacturing a secondary battery according to an embodiment of the present disclosure is provided. Detailed Implementation

[0039] The embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. The terms or words used in this specification and claims should not be construed as limited to their general or dictionary meanings, and based on the principle that the inventor can be his / her own lexicographer to appropriately define terms and concepts for the best interpretation of his / her invention, they should be interpreted as meanings and concepts consistent with the technical spirit of this disclosure.

[0040] The embodiments described in this specification and the configurations shown in the accompanying drawings are merely some embodiments of this disclosure and do not represent all technical ideas, aspects, and features of this disclosure. Therefore, it should be understood that various equivalents and modifications may exist to replace or modify the embodiments described herein at the time of filing this application.

[0041] It will be understood that when an element or layer is referred to as being "on" another element or layer, "connected to," or "linked to" another element or layer, it may be directly on, connected to, or linked to the other element or layer, or one or more intermediary elements or layers may be present. When an element or layer is referred to as being "directly on" another element or layer, "directly connected to," or "directly linked to" another element or layer, no intermediary element or layer is present. For example, when a first element is described as being "linked" or "connected" to a second element, the first element may be directly linked to or connected to the second element, or the first element may be indirectly linked to or connected to the second element via one or more intermediary elements.

[0042] In the accompanying drawings, the dimensions of various elements, layers, etc., may be enlarged for clarity. The same reference numerals denote the same elements. As used herein, the term "and / or" includes any and all combinations of one or more of the associated enumerated items. Furthermore, the use of "may" in describing embodiments of this disclosure refers to "one or more embodiments of this disclosure." Expressions such as "at least one of..." and "any one of..." modify the entire list of elements, not individual elements, when preceding / following a list of elements. When phrases such as "at least one of A, B, and C," "at least one of A, B, or C," "at least one selected from the group consisting of A, B, and C," or "at least one selected from A, B, and C" are used to denote a list of elements A, B, and C, the phrase may refer to any and all suitable combinations or subsets of A, B, and C, such as A, B, C, A and B, A and C, B and C, or A and B and C. As used herein, the terms "use" and "be used" may be considered synonymous with the terms "utilize" and "be exploited," respectively. As used herein, the terms “substantially,” “about,” and similar terms are used as approximations rather than terms of degree and are intended to describe the inherent variations in measured or calculated values ​​that would be recognized by one of ordinary skill in the art.

[0043] It will be understood that although the terms first, second, third, etc., may be used herein to describe various elements, components, areas, layers, and / or segments, these elements, components, areas, layers, or segments should not be limited by these terms. These terms are used to distinguish one element, component, area, layer, or segment from another element, component, area, layer, or segment. Therefore, the first element, component, area, layer, or segment discussed below may be referred to as the second element, component, area, layer, or segment without departing from the teachings of the exemplary embodiments.

[0044] For ease of description, spatial relative terms, such as “below,” “under,” “down,” “above,” and “above,” are used herein to describe the relationship of one element or feature to another element or feature illustrated in the figures. It will be understood that, in addition to the orientations depicted in the figures, spatial relative terms are intended to cover different orientations of the device in use or operation. For example, if the device in the figures is flipped, an element described as “below” or “under” other elements or features will be oriented “above” or “above” other elements or features. Thus, the term “below” can encompass both above and below orientations. The device may be oriented in other ways (rotated 90 degrees or otherwise), and the spatial relative descriptors used herein should be interpreted accordingly.

[0045] The terminology used herein is for describing embodiments of this disclosure and is not intended to limit this disclosure. Unless the context clearly indicates otherwise, the singular form “a” as used herein is intended to include the plural form as well. It will be further understood that the term “comprising” as used in this specification indicates the presence of said features, integers, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0046] Furthermore, any numerical range disclosed and / or set forth herein is intended to include all subranges with the same numerical precision contained within the set forth range. For example, the range “1.0 to 10.0” is intended to include all subranges between the stated minimum value of 1.0 and the stated maximum value of 10.0 (and including both the stated minimum value of 1.0 and the stated maximum value of 10.0), i.e., a minimum value equal to or greater than 1.0 and a maximum value equal to or less than 10.0, such as, for example, 2.4 to 7.6. Any maximum numerical limit set forth herein is intended to include all lower numerical limits contained herein, and any minimum numerical limit set forth in this specification is intended to include all higher numerical limits contained herein. Therefore, the applicant reserves the right to amend this specification (including the claims) to expressly set forth any subranges contained within the range expressly set forth herein.

[0047] Referring to two compared elements, features, etc., as "identical" can mean that they are "substantially identical." Therefore, the phrase "substantially identical" can include situations in the art where the deviation is considered low, for example, a deviation of 5% or less. Additionally, when a parameter is described as uniform in a given region, this can mean that it is uniform in terms of average value.

[0048] Throughout this specification, unless otherwise stated, each element may be singular or plural.

[0049] Placing any element "above (or below)" or "above (below)" another element means that the arbitrary element can be configured to contact the upper (or lower) surface of the element, and the other element can also be located between the element and any element disposed on (or below) the element.

[0050] Additionally, it will be understood that when a component is referred to as “connected,” “linked,” or “attached” to another component, the components can be directly “connected,” “linked,” or “attached” to each other, or another component can be “between” the components.

[0051] Throughout this specification, unless otherwise stated, when “A and / or B” is mentioned, it means A, B, or A and B. That is, “and / or” includes any or all combinations of the listed items. Unless otherwise indicated, when “C to D” is mentioned, it means C or more and D or fewer.

[0052] In this disclosure, for the purpose of clarity, Figures 1 to 13 The dimensions (dimensions) and relative dimensions (scales) of the layers and regions shown can be magnified. That is, Figures 1 to 13 The dimensions (dimensions) shown are for ease of understanding and are not intended to limit the scope of this disclosure. Furthermore, throughout the specification, the same parts will be given the same reference numerals.

[0053] Figure 1 An exploded perspective view illustrating an example of a secondary battery according to an embodiment of the present disclosure.

[0054] refer to Figure 1 The secondary battery 10 may include at least one electrode assembly 130, each of which may be configured by winding or stacking a positive electrode and a negative electrode together with a separator (which may be an insulator) between the positive and negative electrodes. The secondary battery 10 may further include a housing 100 for accommodating the electrode assemblies 130.

[0055] Each of the positive and negative electrodes may include a coated portion (e.g., a mixed portion) where an active material can be applied to a current collector formed of a thin metal foil, and an uncoated portion where the active material is not applied.

[0056] In one embodiment, the positive and negative electrodes can be stacked with an insulating membrane between them. In one embodiment, the electrode assembly 130 can have a structure in which a plurality of sheet-shaped positive and negative electrodes are stacked alternately with a membrane between them. In one embodiment, the electrode assembly 130 can be formed by winding the positive and negative electrodes and the membrane between them.

[0057] The housing 100 can form the overall appearance of the secondary battery 10. In one embodiment, the housing 100 may be or include stainless steel (Stainless steel: SUS). In one embodiment, the housing 100 may be or include a conductive metal, such as aluminum, aluminum alloy, or nickel-plated steel. In one embodiment, the housing 100 may include, for example, a body 110 that houses the electrode assembly 130 and a housing cover 120 that seals the body 110. Electrode terminals 116, 118 may be located on one surface of the body 110.

[0058] The main body 110 of the housing 100 may include an opening in a side surface that is perpendicularly in contact with the surfaces where the electrode terminals 116, 118 are located. A receiving portion 112 for accommodating the electrode assembly 130 may be located approximately in the central region of the main body 110 and formed by a pressing process or the like. In one embodiment, flanges 114a, 114b, 114c, 114d may be located at the upper edge of the receiving portion 112 in four directions.

[0059] In one embodiment, the housing 100 can be formed by joining a body 110 and a housing cover 120. In one embodiment, the housing 100 can be formed by joining the body 110 and the housing cover 120 using a metal joining method (e.g., welding, brazing, or soldering). The housing cover 120 can be coupled to flanges 114a, 114b, 114c, 114d of the body 110 to seal the opening of the body 110.

[0060] The positive electrode terminal 116, electrically connected to the positive electrode tab 132 of the electrode assembly 130, and the negative electrode terminal 118, electrically connected to the negative electrode tab 134 of the electrode assembly 130, can be coupled to the body 110. In one embodiment, the electrode terminals 116, 118 may be located on at least one surface of the housing 100. The positions of the electrode terminals 116, 118 according to this disclosure can have various positions and modifications.

[0061] The electrode terminals 116, 118 may be located on the surface of the body 110, which may additionally include, for example, an electrolyte injection port or an vent port.

[0062] In the electrode assembly 130, the positive electrode contact 132 may be located on one side of the positive electrode and electrically connected to the uncoated portion of the positive electrode, and the negative electrode contact 134 may be located on one side of the negative electrode and electrically connected to the uncoated portion of the negative electrode. The positive electrode contact 132 may be located at a specific position on one side of the positive electrode, and the negative electrode contact 134 may be located at a specific position on one side of the negative electrode.

[0063] The positive electrode terminal 132 and the negative electrode terminal 134 can be oriented in the same direction on one side of the electrode assembly 130. Furthermore, multiple positive electrode terminals 132 located on multiple positive electrodes can be joined together to form a first current collector terminal. Similarly, multiple negative electrode terminals 134 located on multiple negative electrodes can be joined together to form a second current collector terminal.

[0064] The first and second current collector terminals may be located at different positions on one side of the electrode assembly 130. In one embodiment, the first and second current collector terminals may be located on one side of the electrode assembly 130 and spaced apart from each other. In another embodiment, the first current collector terminal may be located on one side of the electrode assembly 130, and the second current collector terminal may be located on the other side (e.g., the opposite side) of the electrode assembly 130. Accordingly, the first and second current collector terminals may remain separate from each other.

[0065] In one embodiment, the positive electrode terminal 132, which can be connected to the positive electrode, or the first current collector terminal, can be electrically connected to the positive electrode terminal 116. This electrode terminal can be used as a positive electrode terminal. Further, the negative electrode terminal 134, which can be connected to the negative electrode, or the second current collector terminal, can be electrically connected to the negative electrode terminal 118.

[0066] Secondary batteries can be, for example, lithium-ion or sodium-ion batteries. They can include any battery capable of repeatedly providing electrical energy through charge and discharge cycles.

[0067] Figure 1 The configuration of the secondary battery shown is merely exemplary, and in some embodiments, the secondary battery may include... Figure 1 Additional components not listed herein, or some components that may be omitted. Furthermore, appropriate modifications may be made. Figure 1 The shape, positional relationship, and other aspects of the components of the secondary battery shown.

[0068] Figure 2 A cross-sectional view illustrating an example of a band according to an embodiment of the present disclosure is shown. Figure 2 As shown, the strip 200 may include, for example, a first adhesive layer 210 and a second adhesive layer 220. The first adhesive layer 210 and the second adhesive layer 220 may be in direct contact with each other.

[0069] The first adhesive layer 210 may exhibit tackiness at a first temperature. Here, the first temperature may fall within the room temperature range (e.g., 15°C to 25°C). In one embodiment, the first adhesive layer 210 may exhibit tackiness at temperatures below room temperature and may also be tackiness at room temperature or above room temperature. At least a portion of the first adhesive layer 210 may be or include, for example, polyurethane, ethylene vinyl acetate (EVA), or polyolefin.

[0070] The second adhesive layer 220 may be or include a material that exhibits tackiness (e.g., becomes sticky) when heat is applied. In one embodiment, the second adhesive layer 220 may exhibit tackiness at a second temperature exceeding, for example, a first temperature. In other words, the second adhesive layer 220 may not exhibit tackiness at room temperature, but may become sticky at a second temperature that is above room temperature. Here, the second temperature may be, for example, 60°C or higher. The second adhesive layer 220 may be or include, for example, a thermoplastic adhesive or a hot melt adhesive.

[0071] In one embodiment, the strip 200 may be attached (bonded) to the inner surface of the housing. Furthermore, the strip 200 may be attached (bonded) to an electrode assembly housed within the housing, thereby helping to prevent movement or displacement of the electrode assembly.

[0072] In one embodiment, the first adhesive layer 210 of the strip 200 may contact (e.g., directly contact) and adhere to the inner surface of the housing (e.g., the inner side surface of the housing). In one embodiment, the second adhesive layer 220 of the strip 200 may face the electrode assembly housed within the housing (e.g., the second adhesive layer 220 may be between the first adhesive layer 210 and the electrode assembly). While the electrode assembly may be arranged to contact the second adhesive layer 220 during the insertion process into the housing, this is not mandatory. In one embodiment, the electrode assembly may initially not contact the second adhesive layer 220 during the insertion process into the housing, but may contact the second adhesive layer 220 during subsequent charge and discharge processes as the electrode assembly expands. (See reference...) Figures 3 to 9 An example of the positioning of the band 200 on the inner surface of the housing is described in more detail.

[0073] In one embodiment, the second adhesive layer 220 with band 200 may exhibit tackiness during the formation process (activation phase) of the secondary battery. In one embodiment, the housing into which the electrode assembly can be inserted may be sealed after the electrolyte is injected. The secondary battery may then undergo a formation process in which it is charged and discharged or aged at high temperatures (e.g., in the range of 60°C to 90°C). During this phase, the tackiness of the second adhesive layer 220 may be exhibited. For example, as described above, the second adhesive layer 220 may have adhesive properties within these temperature ranges. That is, prior to the formation process, only the first adhesive layer 210 with band 200 may exhibit tackiness, but after the formation process, both the first adhesive layer 210 and the second adhesive layer 220 with band 200 may exhibit tackiness.

[0074] With this configuration, the electrode assembly of the secondary battery can be fixed within the housing after the formation process is completed, helping to prevent movement or displacement of the electrode assembly. Furthermore, prior to the secondary battery formation process, the second adhesive layer 220 facing the electrode assembly can be non-adhesive. This ensures that the electrode assembly has sufficient time to be fully impregnated with the electrolyte.

[0075] Figure 3 An illustrative perspective view of a housing for explaining the attachment location of a strap, according to an embodiment of the present disclosure. Figure 4 An illustrative longitudinal cross-sectional view of a secondary battery for explaining the attachment location of the strap, according to an embodiment of the present disclosure, is shown. Figure 5 An enlarged cross-sectional view illustrating the attachment location of a secondary battery according to an embodiment of the present disclosure.

[0076] refer to Figure 3 The housing 300 can be adapted for cylindrical batteries. In this configuration, the band 340 can be attached along the periphery of the inner surface (e.g., the inner circumferential surface) of the housing 300. In one embodiment, the housing 300 may include a bottom portion 310 and a cylindrical sidewall portion 320 extending from the bottom portion 310, wherein an opening is provided at one end of the sidewall portion 320 opposite to the bottom portion 310. The band 340 can be attached to the inner surface of the sidewall portion 320 of the housing 300.

[0077] refer to Figure 4 The electrode assembly 330 can be inserted into the housing 300. The electrode assembly 330 can be formed by winding the first electrode 332, the diaphragm 334, and the second electrode 333. For example, the electrode assembly 330 can be a wound electrode assembly in which the first electrode 332, the diaphragm 334, and the second electrode 333 are wound.

[0078] In one embodiment, the electrode tabs may extend outward through at least one surface of the electrode assembly 330. The electrode tabs may protrude outward from the winding section of the electrode assembly 330. In one embodiment, the electrode tab connected to the first electrode 332 of the electrode assembly 330 may protrude in a direction toward an opening opposite the bottom portion 310 of the housing 300, while the electrode tab connected to the second electrode 333 may protrude in a direction toward the bottom portion 310 of the housing 300.

[0079] In one embodiment, the band 340 may be attached to at least a portion of the inner surface of the housing 300, excluding the portion of the inner surface opposite the electrode tabs of the electrode assembly 330. In one embodiment, the band 340 may not be attached to the bottom portion 310 of the housing 300, which is opposite to the electrode tabs of the second electrode 333 connected to the electrode assembly 330, for example, facing the electrode tabs of the second electrode 333 connected to the electrode assembly 330. Instead, the band 340 may be attached to the sidewall portion 320 of the housing 300. The band 340, which may be attached to the inner surface of the sidewall portion 320 of the housing 300, may face the side surface of the electrode assembly 330 parallel to the winding axis (Y-axis) of the electrode assembly 330.

[0080] In this configuration, interference between the strip 340 and the electrode tabs can be prevented by attaching the strip 340 to at least a portion of the inner surface of the housing 300, excluding the portion of the inner surface opposite the electrode tabs protruding from the electrode assembly 330.

[0081] Figure 5 Example Figure 4 An enlarged cross-sectional view of region A shown in the image. (Reference) Figure 5 The electrode assembly 330 may include, for example, a first electrode 332, a second electrode 333, and a separator 334. The first electrode 332 may include, for example, a substrate 332_1 and a first coating portion (first mixing portion) 332_2, each formed by coating an active material onto the substrate 332_1. Similarly, the second electrode 333 may include, for example, a substrate 333_1 and a second coating portion 333_2, each formed by coating an active material onto the substrate 333_1. In one embodiment, the width h1 of the first coating portion 332_2 along the winding axis (Y-axis) of the electrode assembly 330 may be smaller than the width h2 of the second coating portion 333_2. Here, the first electrode 332 may be a positive electrode.

[0082] In one embodiment, the strip 340 may be attached (bonded) to a sidewall portion 320 of the housing. The strip 340 may include, for example, a first adhesive layer 340_1 and a second adhesive layer 340_2. The first adhesive layer 340_1 may contact and bond to the inner surface of the sidewall portion 320 of the housing, and the second adhesive layer 340_2 may face the electrode assembly 330.

[0083] In one embodiment, the width h3 of the strip 340 extending along the sidewall portion 320 can be determined based on the widths of the first coated portion 332_2 of the first electrode 332 and the second coated portion 333_2 of the second electrode 333. In one embodiment, the width h3 of the strip 340 extending along the sidewall portion 320 can be equal to or greater than a first length, which is the width h1 of the first coated portion 332_2 along the winding axis direction (Y-axis) of the electrode assembly 330. Furthermore, the width h3 of the strip 340 extending along the sidewall portion 320 can be equal to or less than a second length, which is the width h2 of the second coated portion 333_2 along the winding axis direction (Y-axis) of the electrode assembly 330.

[0084] In this configuration, the width h3 of the strip 340 extending along the direction of the sidewall portion 320 can be at least equal to the width h1 of the first coated portion 332_2, and can not exceed the width h2 of the second coated portion 333_2 along the winding axis direction (Y-axis). This allows the strip 340 to completely cover the area where the first coated portion 332_2 and the second coated portion 333_2 overlap. Therefore, the strip 340 can comprehensively, for example, completely cover the overlapping area of ​​the first coated portion 332_2 and the second coated portion 333_2, in which the winding diameter of the electrode assembly 330 reaches its maximum value during the expansion of the electrode assembly 330.

[0085] Figure 6 A perspective view of a housing illustrating the attachment location of a strap, according to an embodiment of the present disclosure. Figure 7 A longitudinal cross-sectional view of a secondary battery for illustrating the attachment location of a strap, according to an embodiment of the present disclosure. Figure 8 An enlarged cross-sectional view illustrating an embodiment of the present disclosure for explaining a secondary battery according to the attachment position of the strip.

[0086] refer to Figure 6 The housing 600 can be adapted to a prismatic battery. For example, the housing 600 may include a rectangular base portion 610 and first to fourth sidewall portions 620_1 to 620_4 extending upward from the base portion 610. An opening may be formed in the space opposite to the base portion 610 and surrounded by the ends (e.g., the upper edges) of the first to fourth sidewall portions 620_1 to 620_4.

[0087] In one embodiment, at least one of the first to fourth sidewall portions 620_1 to 620_4 of the housing 600 may include an electrode terminal 622. In one embodiment, the first sidewall portion 620_1 may include an electrode terminal 622 that can be electrically connected to an electrode assembly. Figure 6 In the illustrated example, electrode terminal 622 is located only at the first sidewall portion 620_1. In one embodiment, electrode terminal 622 may be formed at one or more of the first to fourth sidewall portions 620_1 to 620_4.

[0088] In one embodiment, the band 640 may be attached to at least a portion of the periphery of the inner surface of the housing 600. In one embodiment, among the first to fourth sidewall portions 620_1 to 620_4, the band 640 may be attached to the inner surfaces of the second to fourth wall portions 620_2 to 620_4, excluding the first sidewall portion 620_1 where the electrode terminal 622 is formed. For example, the band 640 may be attached to the inner surfaces of the second to fourth sidewall portions 620_2 to 620_4, and may not be attached to the inner surface of the first sidewall portion 620_1. In one embodiment, the band 640 may be attached to the inner surface of the bottom portion 610 of the housing 600.

[0089] refer to Figure 7 The electrode assembly 630 can be inserted into the housing 600. The electrode assembly 630 can be a stacked electrode assembly in which a sheet-type first electrode, a sheet-type diaphragm, and a sheet-type second electrode are laminated. In one embodiment, the electrode assembly 630 can be a wound electrode assembly in which the first electrode, the diaphragm, and the second electrode are wound together.

[0090] In one embodiment, electrode tabs may extend outward through at least one surface of the electrode assembly 630. In another embodiment, electrode tabs connected to the first and second electrodes may protrude through at least one surface of the electrode assembly 630.

[0091] In one embodiment, with the electrode assembly 630 housed within the housing 600, the strip 640 may not be attached to the sidewall portion of the housing 600 where the facing electrode tabs extend through the surface of the electrode assembly 630 (e.g., the first sidewall portion 620_1 where the electrode terminals are located). In another embodiment, the strip 640 may be attached to the remaining sidewall portions of the housing 600 other than the sidewall portions where the facing electrode tabs extend through the surface of the electrode assembly 630 (e.g., the second to fourth sidewall portions 620_2 to 620_4). In this case, the strip 640 may be arranged to contact at least three surfaces of the electrode assembly 630.

[0092] In this configuration, the band 640 can be attached to one or more inner surfaces of the housing 600, excluding the surface facing the electrode tabs that protrude through the electrode assembly 630. This helps prevent the band 640 from interfering with the electrode tabs.

[0093] Figure 8 Example Figure 7 An enlarged cross-sectional view of region B shown in the figure. Figure 8 This can represent a cross-sectional view of region B taken along line I-I'.

[0094] refer to Figure 8 The strip 640 can be attached to the third sidewall portion 620_3 of the housing. The strip 640 may include a first adhesive layer 640_1 and a second adhesive layer 640_2. The first adhesive layer 640_1 can contact and adhere to the inner surface of the third sidewall portion 620_3 of the housing, while the second adhesive layer 640_2 can face the electrode assembly 630.

[0095] In one embodiment, in the direction (Z-axis) in which the third sidewall portion 620_3 of the housing extends from the bottom portion, the width h4 of the strip 640, measured from the bottom portion, can be equal to or greater than the height h5 of the electrode assembly 630, measured from the bottom portion. In one embodiment, the width h4 of the strip 640 can be 110% to 150% of the height h5 of the electrode assembly 630.

[0096] In other words, considering the increase in height h5 of electrode assembly 630 due to the expansion of electrode assembly 630, the contact area between electrode assembly 630 and strip 640 can be maximized by designing the width h4 of strip 640 to be equal to or greater than the height h5 of electrode assembly 630.

[0097] Figure 9 A perspective view of a housing illustrating the attachment location of a strap, according to one embodiment of the present disclosure. Figure 9 In the middle, will be omitted Figures 6 to 8 Redundant descriptions of the components described herein.

[0098] refer to Figure 9 The housing 900 can be adapted for a polygonal battery. In one embodiment, the housing 900 may include, for example, a polygonal base portion 910 and sidewall portions 920 including first to nth sidewall portions 920_1 to 920_n extending upward from the base portion 910, where "n" may be a natural number of 4 or greater. An opening may be formed in the space opposite to the base portion 910 and surrounded by the ends (e.g., upper edges) of the first to nth sidewall portions 920_1 to 920_n.

[0099] In one embodiment, at least one of the first to nth sidewall portions 920_1 to 920_n of the housing 900 may be provided with an electrode terminal 922. Figure 9 In the illustrated example, electrode terminal 922 is located only at the first sidewall portion 920_1. In one embodiment, electrode terminal 922 may be located at one or more of the first to nth sidewall portions 920_1 to 920_n.

[0100] In one embodiment, the band 940 may be attached to at least a portion of the periphery of the inner surface of the housing 900. In one embodiment, among the first to nth sidewall portions 920_1 to 920_n, the band 940 may be attached to the inner surfaces of the second to nth sidewall portions 920_2 to 920_n, excluding the first sidewall portion 920_1 where the electrode terminal 922 may be located. For example, the band 940 may be attached to the inner surfaces of the second to nth sidewall portions 920_2 to 920_n and may not be attached to the first sidewall portion 920_1. In one embodiment, the band 940 may be attached to the inner surface of the bottom portion 910 of the housing 900.

[0101] In this configuration, the band 940 can be attached to one or more inner surfaces of the housing 900, excluding the surface facing the electrode tabs protruding through the electrode assembly 930. This helps prevent the electrode assembly 930 from moving within the housing 900 and prevents the band 940 from interfering with the electrode tabs.

[0102] Figures 10 to 12 Each example illustrates the attachment position of the band according to the comparison example. Figures 10 to 12 Examples are illustrated in which a bonding region is formed on at least one surface of the electrode assembly or on at least one surface of the electrode assembly. For ease of explanation, the positive Y-axis direction in which the electrode tabs of the electrode assembly protrude is defined as the upward direction, and the opposite direction (negative Y-axis direction) is defined as the downward direction.

[0103] refer to Figure 10 The first example 1000_1 illustrates an example in which the strip 1040_1 can be attached to the electrode assembly 1030_1 of a wound battery. The electrode assembly 1030_1 can be formed by winding a first electrode, a separator, and a second electrode. The strip 1040_1 can be attached to the lower surface of the electrode assembly 1030_1. In this configuration, the strip 1040_1 can help prevent the separator of the electrode assembly 1030_1 from rolling inward into the electrode assembly 1030_1. However, since the strip 1040_1 is only attached to the surface of the electrode assembly 1030_1, it may not effectively limit the movement or displacement of the electrode assembly 1030_1 within the housing in the event of a battery drop.

[0104] The second example 1000_2 illustrates an example in which the strip 1040_2 can be attached to the electrode assembly 1030_2 of a stacked battery. The electrode assembly 1030_2 can be formed by sequentially stacking a sheet-like first electrode, a sheet-like separator, and a sheet-like second electrode. The strip 1040_2 can be attached to the lower surface and each of the two side surfaces of the electrode assembly 1030_2. Similar to the first example 1000_1, the strip 1040_2 can help prevent the separator of the electrode assembly 1030_2 from rolling inward. However, it may not be effective in limiting the movement or displacement of the electrode assembly 1030_2 within the housing.

[0105] refer to Figure 11 The third example 1100_1 illustrates an example in which the bonding region 1140_1 can be formed on the surface of the electrode assembly 1130_1 of the wound battery, and the fourth example 1100_2 illustrates an example in which the bonding region 1140_2 can be formed on the surface of the electrode assembly 1130_2 of the stacked battery.

[0106] Referring to the third example 1100_1, a bonding region 1140_1 can be formed on the lower surface of the electrode assembly 1130_1. The electrode assembly 1130_1 can be attached to the inner surface of the housing via the bonding region 1140_1. This configuration can help prevent movement or displacement of the electrode assembly 1130_1 within the housing. However, the electrolyte permeation path into the electrode assembly 1130_1 may be blocked by the bonding region 1140_1, resulting in reduced electrolyte impregnation. Furthermore, the bonding region 1140_1 may deform during the process of inserting the electrode assembly 1130_1 into the housing, which may degrade the quality of the battery.

[0107] Referring to the fourth example 1100_2, the bonding region 1140_2 can be formed on the lower surface and each of the two side surfaces of the electrode assembly 1130_2. Similar to the third example 1100_1, this configuration prevents movement or displacement of the electrode assembly 1130_2. However, electrolyte impregnation may be reduced, and the quality of the battery may be degraded.

[0108] refer to Figure 12 The fifth example 1200_1 illustrates an example in which the bonding region 1240_1 can be formed on the surface of the electrode assembly 1230_1 of the wound battery, and the sixth example 1200_2 illustrates an example in which the bonding region 1240_2 can be formed on the surface of the electrode assembly 1230_2 of the stacked battery.

[0109] Referring to the fifth example 1200_1, in the Z-axis direction, the bonding region 1240_1 can be formed on each of the front and rear surfaces of the electrode assembly 1230_1. This configuration can help prevent the electrode assembly 1230_1 from moving or shifting within the housing. However, the winding cross-section of the electrode assembly 1230_1 may be exposed, causing the separator to roll inward. Furthermore, since the thickness of the electrode assembly 1230_1 along the Z-axis direction increases due to the bonding region 1240_1, this may be disadvantageous from a battery capacity perspective.

[0110] Referring to the sixth example 1200_2, the bonding region 1240_2 can be formed on each of the front and rear surfaces of the electrode assembly 1230_2. Similar to the fifth example 1200_1, this configuration prevents movement or displacement of the electrode assembly 1230_2. However, this may cause the separator to roll inward, resulting in a reduction in the energy density of the battery.

[0111] like Figures 2 to 9 As described, the strip can be attached to the inner surface of the sidewall portion of the housing, rather than the surface of the electrode assembly. Therefore, movement or displacement of the electrode assembly can be effectively controlled, and the separator can be prevented from rolling inward (curling). Furthermore, by ensuring that the adhesion of the second adhesive layer of the strip, which can face the electrode assembly, is exhibited during the battery formation process, such as activation, sufficient time for electrolyte impregnation can be ensured.

[0112] Figure 13 A flowchart illustrating a method for manufacturing a secondary battery according to an embodiment of the present disclosure is provided. Method 1300 may begin with the preparation of an electrode assembly including a first electrode, a second electrode, and a separator between the first and second electrodes (step S1310). An electrode tab that may be connected to one of the first and second electrodes may protrude through at least one surface of the electrode assembly.

[0113] Subsequently, a housing in which the strip can be attached to its inner surface can be prepared (step S1320). The strip may include, for example, a first adhesive layer and a second adhesive layer. The strip may be attached such that the first adhesive layer contacts and adheres to the inner surface of the housing.

[0114] Next, the electrode assembly can be inserted into the housing (step S1330). At this time, the second adhesive layer of the strip can face the electrode assembly inserted into the housing. The strip can be attached to one or more portions of the inner surface of the housing, excluding the portion facing the inner surface of the electrode tabs of the electrode assembly. In other words, the electrode assembly can be inserted such that the electrode tabs, through at least one of their protruding surfaces, face a sidewall portion of the housing where the strip may not be attached.

[0115] In one embodiment, the secondary battery may be a cylindrical battery. In one embodiment, the housing may include, for example, a bottom portion, a cylindrical sidewall portion extending upward from the bottom portion, and an opening formed opposite to the bottom portion. In one embodiment, the electrode assembly may be formed by winding a first electrode, a separator, and a second electrode. The first electrode may include, for example, a first coated portion coated with an active material, and the second electrode may include a second coated portion coated with an active material. In this case, a strip may be attached to the inner surface of the cylindrical sidewall portion. In one embodiment, the width of the strip in the direction of extension of the cylindrical sidewall portion may be at least equal to a first length, which may be the width of the first coated portion in the winding axis direction of the electrode assembly. In one embodiment, the width of the strip in the direction of extension of the cylindrical sidewall portion may not be greater than a second length, which may be the width of the second coated portion in the winding axis direction of the electrode assembly.

[0116] In another embodiment, the secondary battery may be a prismatic battery. In one embodiment, the housing may include, for example, a bottom portion, at least four sidewall portions extending upward from the bottom portion, and an opening formed opposite to the bottom portion. In this case, a strip may be attached to the inner surface of each of the at least four sidewall portions, except for the inner surface of one of the sidewall portions. In one embodiment, the width of the strip, measured from the bottom portion, in the direction in which the sidewall portions extend from the bottom portion may be 110% to 150% of the height of the electrode assembly, measured from the bottom portion.

[0117] Subsequently, the electrolyte can be injected into the casing (step S1340). Afterward, the casing can be sealed by attaching a cover plate to it (step S1350). Following sealing the casing, the method may further include at least one of the steps of charging and discharging the secondary battery at a first temperature and aging the secondary battery at a second temperature. Both the first and second temperatures can be 60°C or higher. In one embodiment, the second adhesive layer of the strip may exhibit viscous properties under the heat applied during the charging and discharging steps or the aging steps.

[0118] In one implementation, one or more processes described above can be added, modified, or deleted from the flowchart. The order of one or more processes can be changed, and multiple processes can be executed simultaneously.

[0119] In summary, a secondary battery can be manufactured by inserting electrode assemblies into a housing, injecting electrolyte into the housing, and then sealing the housing with a cover assembly or housing cap. However, if the electrode assemblies are not securely bonded and secured in place within the housing, they may shift or move within the housing due to external impacts or accidental drops. Such movement can lead to damage to the electrode assemblies or a deterioration in the overall quality of the battery.

[0120] Embodiments of this disclosure can provide a secondary battery and a method for manufacturing a secondary battery.

[0121] According to some embodiments of this disclosure, instead of securing the electrode assembly to the housing via a strip attached to the electrode assembly or by applying an adhesive to form a bonding area, a strip attached to the inner surface of the housing can be used to secure the electrode assembly to the housing. Accordingly, movement or displacement of the electrode assembly during a secondary battery drop event can be effectively suppressed.

[0122] According to some embodiments of this disclosure, the strip facing the electrode assembly can exhibit viscous properties after heat is applied to the secondary battery during the formation process (activation stage), thereby ensuring sufficient time for electrolyte impregnation. Therefore, the electrode assembly can be secured inside the housing, unaffected by the electrolyte impregnation process or impregnation time.

[0123] These and other aspects and features of this disclosure will be described in the foregoing description of embodiments of this disclosure, or will become apparent from the foregoing description of this disclosure.

[0124] Although the present disclosure has been described above with respect to embodiments thereof, the present disclosure is not limited thereto. Various modifications and variations may be made by those skilled in the art within the spirit and equivalent scope of the claims.

[0125] Example embodiments have been disclosed herein, and while specific terminology has been used, it is used and interpreted in a general and descriptive sense only and not for limiting purposes. In some cases, as will be apparent to those skilled in the art at the time of filing of this application, features, characteristics, and / or elements described in connection with particular embodiments may be used alone or in combination with features, characteristics, and / or elements described in connection with other embodiments, unless otherwise specifically indicated. Accordingly, those skilled in the art will understand that various changes in form and detail may be made without departing from the spirit and scope of the invention as set forth in the claims.

Claims

1. A secondary battery, comprising: An electrode assembly includes a first electrode, a second electrode, and a diaphragm between the first electrode and the second electrode; Housing that houses the electrode assembly; as well as A strap is attached to the inner surface of the housing. in: The strip includes a first adhesive layer and a second adhesive layer. The first adhesive layer contacts and adheres to the inner surface of the housing, and The second adhesive layer is applied to the electrode assembly.

2. The secondary battery according to claim 1, wherein: The first adhesive layer is tacky at the first temperature, and The second adhesive layer becomes sticky at a second temperature higher than the first temperature.

3. The secondary battery according to claim 2, wherein, The second temperature is 60°C or higher.

4. The secondary battery according to claim 2, wherein, The second adhesive layer becomes sticky due to the heat applied during the formation process of the secondary battery.

5. The secondary battery according to claim 1, wherein: An electrode tab connected to one of the first and second electrodes protrudes through at least one surface of the electrode assembly, and The band is attached to one or more portions of the inner surface of the housing that do not face the electrode terminals.

6. The secondary battery according to claim 1, wherein: The housing includes a bottom portion, a cylindrical sidewall portion extending upward from the bottom portion, and an opening opposite the bottom portion. The band is attached to the inner surface of the cylindrical sidewall portion.

7. The secondary battery according to claim 6, wherein: The electrode assembly is a wound electrode assembly, wherein the first electrode, the diaphragm, and the second electrode are wound together. The first electrode includes a first coating portion coated with an active material, and The width of the strip along the extension direction of the cylindrical sidewall portion is equal to or greater than a first length, the first length being the width of the first coated portion along the winding axis direction of the electrode assembly.

8. The secondary battery according to claim 7, wherein: The second electrode includes a second coating portion coated with an active material, and The width of the strip along the extension direction of the cylindrical sidewall portion is equal to or less than the second length, the second length being the width of the second coated portion along the winding axis direction of the electrode assembly.

9. The secondary battery according to claim 1, wherein: The housing includes a bottom portion, at least four side wall portions extending upward from the bottom portion, and an opening opposite the bottom portion. The band is attached to the inner surface of each of the at least four sidewall portions, excluding one of the at least four sidewall portions.

10. The secondary battery according to claim 9, wherein: An electrode tab connected to one of the first and second electrodes protrudes through at least one surface of the electrode assembly, and The electrode terminal faces the inner surface of the one sidewall portion of the at least four sidewall portions where the strip is not attached.

11. The secondary battery according to claim 9, wherein, In the direction extending from the bottom portion of the at least four sidewall portions, the width of the strip, measured from the bottom portion, is 110% to 150% of the height of the electrode assembly, measured from the bottom portion.

12. A method for manufacturing a secondary battery, the method comprising: An electrode assembly comprising a first electrode, a second electrode, and a membrane between the first electrode and the second electrode is prepared. Prepare a housing and attach a tape including a first adhesive layer and a second adhesive layer to the inner surface of the housing; Insert the electrode assembly into the housing; Electrolytes are injected into the casing; as well as The housing is sealed by attaching a cover plate to the housing. in: The first adhesive layer of the strip is positioned to contact and adhere to the inner surface of the housing, and The second adhesive layer of the strip is positioned facing the electrode assembly.

13. The method of claim 12, further comprising: After sealing the housing: The secondary battery is charged and discharged at a first temperature; or The secondary battery is aged at a second temperature.

14. The method of claim 13, wherein: The first temperature and the second temperature are each 60°C or higher, and The second adhesive layer becomes sticky after heat is applied during the charging and discharging of the secondary battery or after heat is applied during the aging of the secondary battery.

15. The method of claim 12, further comprising: Connect the electrode terminals to one of the first electrode and the second electrode, and The electrode tab is positioned to protrude through at least one surface of the electrode assembly. The band is attached to one or more portions of the inner surface of the housing, excluding the portion facing the electrode terminals.

16. The method of claim 12, wherein: The housing includes a bottom portion, cylindrical sidewall portions extending upward from the bottom portion, and an opening formed opposite to the bottom portion. The band is attached to the inner surface of the cylindrical sidewall portion.

17. The method of claim 16, wherein: The electrode assembly is fabricated by winding the first electrode, the diaphragm, and the second electrode together. The first electrode includes a first coating portion coated with an active material. The second electrode includes a second coating portion coated with an active material, and The width of the strip along the extension direction of the cylindrical sidewall portion is equal to or greater than a first length and equal to or less than a second length, the first length being the width of the first coated portion along the winding axis direction of the electrode assembly, and the second length being the width of the second coated portion along the winding axis direction of the electrode assembly.

18. The method according to claim 12, wherein: The housing includes a bottom portion, at least four sidewall portions extending upward from the bottom portion, and an opening formed opposite to the bottom portion. The band is attached to the inner surface of each of the at least four sidewall portions, excluding one of the at least four sidewall portions.

19. The method of claim 18, further comprising: Connect the electrode terminals to one of the first electrode and the second electrode, and The electrode tab is positioned to protrude through at least one surface of the electrode assembly. The insertion of the electrode assembly includes inserting the electrode assembly into the housing such that at least one surface of the electrode assembly faces the inner surface of the unattached sidewall portion of the at least four sidewall portions.

20. The method according to claim 19, wherein, In the direction extending from the bottom portion of the at least four sidewall portions, the width of the strip, measured from the bottom portion, is 110% to 150% of the height of the electrode assembly, measured from the bottom portion.

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