Electrode assembly and secondary battery using the same

Abstract

Disclosed are an electrode assembly and a secondary battery using the same. The secondary battery includes: an electrode assembly including a first electrode, a second electrode, and a winding of a separator between the first electrode and the second electrode; a case accommodating the electrode assembly; and a first protective tape attached to the first electrode of the electrode assembly, in which the first protective tape is wound around an interior of the electrode assembly by at least one turn in a winding direction of the electrode assembly.

Description

Technical Field

[0001] Embodiments of this disclosure relate to electrode assemblies and secondary batteries using electrode assemblies. Background Technology

[0002] Unlike primary batteries, which are designed not to be (re)charged, 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 portable camcorders, while high-capacity secondary batteries are widely used as power sources for 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 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 (prior) art. Summary of the Invention

[0004] The embodiment includes a secondary battery comprising: an electrode assembly including a first electrode, a second electrode, and a winding of a separator between the first and second electrodes; a housing for housing the electrode assembly; and a first protective strip attached to the first electrode of the electrode assembly, wherein the first protective strip is wound at least one turn around the interior of the electrode assembly along the winding direction of the electrode assembly.

[0005] The first protective strip can be a first distance away from the winding core of the electrode assembly in the direction of the winding diameter of the electrode assembly.

[0006] The first distance can be at least half the diameter of the electrode assembly.

[0007] The first protective strip can be located at a second distance from the front end of the first electrode along the winding direction of the electrode assembly.

[0008] The second distance can be at least one-third of the length of the first electrode.

[0009] The elastic modulus of the first protective strip in the first direction can be greater than the elastic modulus of the first protective strip in the second direction perpendicular to the first direction.

[0010] The first direction of the first protective strip can be parallel to the winding direction of the electrode assembly.

[0011] The first protective band may include an aromatic polyamide material.

[0012] The first electrode may include a substrate having a coated portion coated with an active material, the substrate further including an uncoated portion exposing the substrate, the uncoated portion having no active material, and substrate tabs connected to the uncoated portion.

[0013] The secondary battery may further include: a substrate terminal protection strip attached to the substrate terminal, wherein the first protection strip may be located above the substrate terminal protection strip and the first protection strip may cover the uncoated portion of the first electrode.

[0014] The first protective strip can be attached to the substrate connector and can cover the uncoated portion of the first electrode.

[0015] In the winding axis direction of the electrode assembly, the width of the first protective strip can be equal to or greater than the width of the first electrode.

[0016] The secondary battery may further include: a second protective strip at the outermost periphery of the electrode assembly, wherein the second protective strip is wound around the outermost periphery of the electrode assembly at least once along the winding direction of the electrode assembly.

[0017] The embodiment includes an electrode assembly comprising a first electrode, a second electrode, and a winding of a diaphragm between the first and second electrodes. The electrode assembly includes a protective strip attached to the first electrode, wherein the protective strip is wound at least one turn around the interior of the electrode assembly along the winding direction of the electrode assembly.

[0018] The protective strip may be located at a first distance from the winding core of the electrode assembly in the direction of the winding diameter of the electrode assembly. This first distance may be at least half the diameter of the electrode assembly.

[0019] The protective strip can be positioned at a second distance from the front end of the first electrode along the winding direction of the electrode assembly. This second distance can be at least one-third of the length of the first electrode.

[0020] The elastic modulus of the protective belt in the first direction can be greater than the elastic modulus of the protective belt in the second direction perpendicular to the first direction.

[0021] The first direction of the protective tape can be parallel to the winding direction of the electrode assembly.

[0022] These and other aspects and features of this disclosure will be described in the following description of embodiments of this disclosure, or will become apparent from the following description of embodiments of this disclosure.

[0023] However, the aspects and features of this disclosure are not limited to those described above, and those skilled in the art will clearly understand from the detailed description below that other aspects and features not mentioned will be apparent. Attached Figure Description

[0024] The accompanying drawings illustrate embodiments of the present disclosure and further describe aspects and features of the disclosure together with its detailed description. Therefore, this 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 The illustration shows a perspective view of an example battery according to one or more embodiments of the present disclosure;

[0027] Figure 2 The illustration shows a plan view of an example electrode assembly according to one or more embodiments of the present disclosure;

[0028] Figure 3 The figure shows a plan view of an example of an electrode assembly according to another embodiment of the present disclosure;

[0029] Figure 4 The illustration shows an example of a protective strip attached to a first electrode according to one or more embodiments of the present disclosure;

[0030] Figure 5 The figure shows a plan view of an example of an electrode assembly having a protective strip attached thereto, according to one or more embodiments of the present disclosure.

[0031] Figure 6 The figure shows a plan view of an example of an electrode assembly having a protective strip attached thereto, according to another embodiment of the present disclosure.

[0032] Figure 7 The illustration shows an example of a protective strip attached to a first electrode according to one or more embodiments of the present disclosure;

[0033] Figure 8 The illustration shows a cross-sectional view of an example of a protective strip attached to a first electrode according to one or more embodiments of the present disclosure;

[0034] Figure 9 The illustration shows an example of a first electrode having a protective strip attached thereto, according to another embodiment of the present disclosure;

[0035] Figure 10 The figure shows a cross-sectional view of an example of a first electrode having a protective strip attached thereto, according to another embodiment of the present disclosure.

[0036] Figure 11 The illustration shows examples of outer diameter measurements of electrode assemblies according to one or more embodiments of the present disclosure; and

[0037] Figure 12The illustration shows an example of an outer diameter measurement of an electrode assembly according to one or more embodiments of the present disclosure. Detailed Implementation

[0038] Example implementations will now be described more fully below with reference to the accompanying drawings; however, example implementations may be implemented in different forms and should not be construed as limited to the implementations set forth herein. Rather, these implementations are provided so that this disclosure will be comprehensive and complete, and will fully convey exemplary implementations to those skilled in the art.

[0039] When a layer or element is referred to as being "on" another layer or substrate, it can be directly on the other layer or substrate, or an intervening layer may be present. Furthermore, it should be understood that when a layer is referred to as being "below" another layer, it can be directly below it, and one or more intervening layers may be present. Additionally, it will be understood that when a layer is referred to as being "between" two layers, it can be the only layer between those two layers, or one or more intervening layers may be present.

[0040] In the following, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Based on the principle that the inventor can be his / her own lexicographer to appropriately define the concepts of terms in order to best illustrate his / her invention, 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 having meanings and concepts consistent with the technical spirit of the present disclosure.

[0041] The embodiments described in this specification and the constructions shown in the accompanying drawings are only some of the embodiments of this disclosure and do not represent all the technical ideas, aspects, and features of this disclosure. Accordingly, it should be understood that various equivalents and modifications that can replace or modify the embodiments described herein can be made at the time of filing this application.

[0042] It will be understood that when an element or layer is referred to as being "on" another element or layer, "connected to," or "attached to" another element or layer, the element or layer may be directly on, connected to, or attached 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 attached to" another element or layer, no intermediary element or layer is present. For example, when a first element is described as being "attached" or "connected" to a second element, the first element may be directly attached to or connected to the second element, or the first element may be indirectly attached to or connected to the second element via one or more intermediary elements.

[0043] In the accompanying drawings, the dimensions of various elements, layers, etc., may be exaggerated for clarity of illustration. 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 items listed. Furthermore, when describing embodiments of this disclosure, the use of "may" means "one or more embodiments of this disclosure." The expressions "at least one of" and "any one of" modify the entire list of elements without modifying individual elements in the list when placed after the 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 of A, B, and C," or "at least one selected from A, B, and C" are used to specify a list of elements A, B, and C, the phrase may refer to any and all suitable combinations or subsets of A, B, C, A and B, A and C, B and C, or A and B and C, A, B, and C. As used herein, the term "use" and its variations may be considered synonymous with the term "utilize" and its variations, respectively. As used herein, the terms “substantially,” “approximately,” and similar terms are used as approximate terms rather than terms of degree and are intended to describe the inherent biases of measurements or calculations that would be recognized by one of ordinary skill in the art.

[0044] It will be understood that although the terms "first," "second," "third," etc., can be used to describe various elements, components, areas, layers, and / or portions, these elements, components, areas, layers, and / or portions should not be limited by these terms. These terms are used to distinguish one element, component, area, layer, or portion from another element, component, area, layer, or portion. Therefore, without departing from the teachings of the exemplary embodiments, the first element, component, area, layer, or portion discussed below may be referred to as the second element, component, area, layer, or portion.

[0045] In this document, spatial relative terms such as “below,” “under,” “down,” “above,” and “above” are used to describe the relationship between one element or feature as shown in the figures and another (or several) other elements or features. It will be understood that, in addition to the orientation shown in the figures, spatial relative terms are intended to include 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 “directly above” other elements or features. Therefore, the term “below” can include both above and below orientations. The device may be oriented in other ways (rotated 90 degrees or in other orientations), and the spatial relative descriptive terms used herein should be interpreted accordingly.

[0046] The terminology used herein is for the purpose of describing embodiments of this disclosure and is not intended to limit this disclosure. As used herein, unless the context clearly indicates otherwise, the singular forms “a” and “an” are intended to include the plural forms as well. It will be further understood that, when used in this specification, the term “comprising” designates the presence of stated features, integrals, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or groups thereof.

[0047] Furthermore, any numerical range disclosed and / or enumerated herein is intended to include all subranges with the same numerical precision within the enumerated range. For example, the range “1.0 to 10.0” is intended to include, for example, 2.4 to 7.6, all subranges between the stated minimum value of 1.0 and the stated maximum value of 10.0 (inclusive), i.e., all subranges with a minimum value equal to or greater than 1.0 and a maximum value equal to or less than 10.0. Any maximum numerical limit described herein is intended to include all smaller numerical limits, and any minimum numerical limit described in this specification is intended to include all larger numerical limits. Therefore, the applicant reserves the right to amend this specification (including the claims) to explicitly detail any subranges included within the scope expressly described herein.

[0048] Referring to two compared elements, features, etc., as "identical" can mean that they are "substantially identical." Therefore, the phrase "substantially identical" can include cases with deviations considered low in the art (e.g., deviations below 5%). Additionally, when a parameter is stated to be consistent within a given region, this can mean that it is consistent in terms of average value.

[0049] Throughout this specification, unless otherwise stated, each element may be singular or plural.

[0050] Placing any element "above (or below)" or "above (below)" another element can mean that the arbitrary element can contact the upper (or lower) surface of the element, and that another element can also be located between the element and the arbitrary element disposed on (or below) the element.

[0051] Additionally, it will be understood that when a component is referred to as “connected,” “linked,” or “attached” to another component, these components can be directly “connected,” “linked,” or “attached” to each other, or another component can be “between” these components.

[0052] 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 enumerated items. Unless otherwise stated, when “C to D” is mentioned, it means C and below D.

[0053] In this disclosure, for the sake of clarity, Figures 1 to 12 The sizes (dimensions) and relative sizes (dimensionality) of the layers and regions shown may be exaggerated. That is to say, Figures 1 to 12 The sizes (dimensions) shown are for ease of understanding and are not intended to limit the scope of this disclosure. Furthermore, the same reference numerals will be given the same parts throughout the specification.

[0054] Figure 1 The illustration shows a perspective view of an example of a secondary battery 100 (hereinafter simply referred to as battery 100) according to one or more embodiments of the present disclosure. Reference Figure 1 The battery 100 may include an electrode assembly 110, a housing 120, and a cover assembly 130.

[0055] Electrode assembly 110 may include a first electrode 112, a second electrode 114, and a diaphragm 116 between the first electrode 112 and the second electrode 114. For example, electrode assembly 110 may include a winding of the first electrode 112, the second electrode 114, and the diaphragm 116 between the first electrode 112 and the second electrode 114. Specifically, electrode assembly 110 may be formed by winding the first electrode 112 and the second electrode 114 together with the diaphragm 116 between the first electrode 112 and the second electrode 114.

[0056] The first electrode 112 may include a first substrate and a first active material layer applied to the first substrate. The first substrate tab may extend outward from a first uncoated portion of the first substrate to which the first active material layer is not applied, and the first substrate tab may be electrically connected to the cover assembly 130, but this arrangement may vary.

[0057] The second electrode 114 may include a second substrate and a second active material layer applied to the second substrate. In one or more embodiments, the second substrate tab may extend outward from a second uncoated portion of the second substrate to which the second active material layer is not applied, and the second substrate tab may be electrically connected to the housing 120, but this arrangement may vary.

[0058] The first electrode 112 can serve as a positive electrode. In this case, the first substrate can be formed, for example, aluminum foil, and the first active material layer can be formed, for example, a transition metal oxide. The second electrode 114 can serve as a negative electrode. In this case, the second substrate can be formed, for example, copper foil or nickel foil, and the second active material layer can include, for example, graphite.

[0059] The separator 116 can be used to prevent short circuits between the first electrode 112 and the second electrode 114 while allowing the movement of lithium ions. The separator 116 can be formed of polyethylene film, polypropylene film, or polyethylene-polypropylene film, etc., but the material of the separator can be varied.

[0060] In one or more embodiments, the electrode assembly 110 may further include a protective strip. For example, the protective strip may be attached to a specific location on the first electrode 112 and may be located on the inner side of the wound electrode assembly 110. Furthermore, the protective strip may be located on the outermost side of the wound electrode assembly 110. The protective strip may be formed of an aramid material, but the material of the protective strip may vary. (See reference...) Figures 2 to 12 A more detailed description of an example of attaching the protective tape.

[0061] The casing 120 can form the overall external appearance of the battery 100 and can be made of a conductive metal such as aluminum, aluminum alloy, or nickel-plated steel. Figure 1 As shown, the housing 120 can be a cylindrical housing, and the battery 100 can be a cylindrical battery. However, the battery 100 can have various shapes, including prismatic, pouch, and coin shapes.

[0062] The housing 120 can accommodate the electrode assembly 110. The electrode assembly 110 can be inserted into the housing 120 through an opening formed on one side of the housing 120. Subsequently, the opening of the housing 120 can be sealed by the cover assembly 130.

[0063] In one or more embodiments, multiple batteries 100 can be stacked to form a battery pack. Such a battery pack can be used in any device that requires high capacity and high power output. For example, it can be used in devices such as laptops, smartphones, and electric vehicles.

[0064] Battery 100 can be a lithium-ion secondary battery or a sodium-ion secondary battery, etc. However, battery 100 can include any battery capable of providing power through repeated charging and discharging operations. In one or more embodiments, when battery 100 is a lithium-ion secondary battery, it can be used in electric vehicles (EVs) due to its excellent lifespan and high rate performance. For example, battery 100 can be used in hybrid vehicles such as plug-in hybrid electric vehicles (PHEVs). Furthermore, lithium-ion secondary batteries can be used in applications requiring large-scale energy storage. For example, battery 100 can be used in electric bicycles and power tools, etc.

[0065] Figure 2 The illustration shows a plan view of an example of an electrode assembly 110 according to one or more embodiments of the present disclosure, and Figure 3 The figure shows a plan view of an example of an electrode assembly 110 according to another embodiment of the present disclosure.

[0066] refer to Figure 2 The electrode assembly 110 can be applied to cylindrical batteries or coin-shaped batteries, etc. For example, the electrode assembly 110 can be formed by winding an alternately stacked first electrode, a separator, and a second electrode around a winding shaft (i.e., a winding core). The cross-section of the wound electrode assembly 110 can be circular.

[0067] In one or more embodiments, the electrode assembly 110 may further include a protective strip attached to the first electrode (e.g., a positive electrode). While the first electrode is in a wound state, the protective strip may be disposed within a first region 200 of the electrode assembly 110. The protective strip may be attached along the winding direction of the first electrode such that it is wound around the interior of the electrode assembly 110 at least one turn (or at least one full turn) within the first region 200.

[0068] As a specific example, the protective strip can be disposed at a predetermined distance (e.g., length) or greater from the winding core of the electrode assembly 110 in the winding diameter direction D. For example, the distance R2 between the protective strip and the winding core of the electrode assembly 110 in the winding diameter direction D can be the diameter of the electrode assembly 110 (e.g., length). Figure 2 At least half (1 / 2) of R1 in the equation.

[0069] The electrode assembly 110 may include multiple protective strips. In this case, each of the multiple protective strips may be disposed within the first region 200 of the electrode assembly 110 such that each protective strip is wound around the interior of the electrode assembly 110 at least once, but the number of turns may vary.

[0070] refer to Figure 3The electrode assembly 110 can be applied to pouch cells or prismatic cells, etc. For example, after alternately stacking the first electrode, the separator, and the second electrode, the electrode assembly 110 can be wound and then compressed along the winding axis. The cross-section of the wound electrode assembly 110 can be generally elliptical. Specifically, the cross-section of the wound electrode assembly 110 can include a flat portion 110_1 and a circular portion 110_2 formed at the opposite end of the flat portion 110_1. Each of the circular portions 110_2 can be substantially in the form of a semicircle around a single center O.

[0071] In one or more embodiments, the electrode assembly 110 may further include a protective strip attached to the first electrode. While the first electrode is in a wound state, the protective strip may be disposed within a second region 300 of the electrode assembly 110. The protective strip may be attached along the winding direction of the first electrode such that it wraps around the interior of the electrode assembly 110 at least once within the second region 300.

[0072] As a specific example, the protective strip can be disposed at a predetermined distance or greater from the center O of the circular portion 110_2 in the winding diameter direction D of the circular portion 110_2. For example, the distance R2 between the protective strip and the center O of the circular portion 110_2 in the diameter direction D of the circular portion 110_2 can be the diameter of the circular portion 110_2 (e.g., Figure 3 At least half (1 / 2) of R1 in the equation.

[0073] In one or more embodiments, the protective strip may be formed of an aramid material, but other materials are also possible. (See reference...) Figure 4 Specific examples of the materials used in the protective strip are described in more detail.

[0074] In this configuration, the protective tape is wound around the inside of the electrode assembly 110 at least once to suppress expansion or twisting of the electrode assembly 110 during battery charge and discharge cycles. Furthermore, by positioning the protective tape at a distance from the winding core of the electrode assembly 110 in the winding diameter direction D, the effect of suppressing expansion of the electrode assembly 110 can be maximized.

[0075] Figure 4 The illustration shows an example of a protective strip 430 attached to a first electrode 400 according to one or more embodiments of the present disclosure.

[0076] like Figure 4As shown, the first electrode 400 can extend along its longitudinal direction (X-axis). The first electrode 400 can be wound along its longitudinal direction (X-axis) to form an electrode assembly. For example, in the longitudinal direction (X-axis) of the first electrode 400, one end of the first electrode 400 can be located at the front winding end S of the electrode assembly, while the opposite end of the first electrode 400 can be located at the rear winding end E of the electrode assembly.

[0077] The first electrode 400 may include a coated portion (mixture portion) 420 on which an active material is coated on the substrate, and an uncoated portion 410 on which the substrate is exposed when the active material is not coated. For example, the uncoated portion 410 may be located at one or both ends of the first electrode 400 in the longitudinal direction (X-axis). Furthermore, or in other embodiments, the uncoated portion 410 may be located in the middle region of the first electrode 400 in the longitudinal direction (X-axis), the middle region including the central portion.

[0078] In one or more embodiments, the protective strip 430 may be attached to the first electrode 400. The protective strip 430 may be attached along the longitudinal direction (X-axis) of the first electrode 400. As a result, when the first electrode 400 is in a wound state, the protective strip 430 may be configured to surround the interior of the electrode assembly.

[0079] The protective strip 430 may be made of an anisotropic material. In a specific example, the protective strip 430 may include an aromatic polyamide material in which the aromatic polyamide fibers are arranged in a predetermined direction. In this case, the elastic modulus of the protective strip 430 in the first direction in which the aromatic polyamide fibers are arranged may be greater than (higher than) the elastic modulus in a second direction perpendicular to the first direction.

[0080] In one or more embodiments, the protective strip 430 may be arranged such that a first direction having a higher elastic modulus is parallel to or substantially parallel to the longitudinal direction (X-axis) of the first electrode 400, and a second direction having a lower elastic modulus is parallel to or substantially parallel to the width direction (Y-axis) of the first electrode 400. As a result, the first direction of the protective strip 430 having a higher elastic modulus may be parallel to or substantially parallel to the winding direction of the electrode assembly.

[0081] The protective strip 430 can be attached to a specific location on the first electrode 400 along a first direction (X-axis) extending thereon. For example, the protective strip 430 can be attached at a location spaced apart from the winding tip S of the first electrode 400 by a first length L1. The first length L1, representing the distance between the protective strip 430 and the winding tip S of the first electrode 400, can be, for example, at least 1 / 3 of the total length L0 of the first electrode 400. Accordingly, when the first electrode 400 is in a wound state, the protective strip 430 can be set to be spaced apart from the winding core of the electrode assembly by a specific length (e.g., ...). Figure 2 The distance in the middle is R2) or greater.

[0082] When the first electrode 400 is in a wound state, the protective tape 430 can be configured to wrap around the inside of the electrode assembly at least once. The length of the protective tape 430 can be appropriately adjusted based on factors such as: a first length L1 of the protective tape 430 from the winding tip S of the first electrode 400; the thickness of each of the first electrode, the second electrode, and the diaphragm; and the diameter of the electrode assembly.

[0083] In this configuration, the protective strip 430, with a high elastic modulus, is aligned parallel to the longitudinal direction (X-axis) of the first electrode 400 in a first direction, thereby effectively suppressing the expansion and twisting of the electrode assembly. (See later...) Figure 11 and Figure 12 Provide a detailed description of specific examples.

[0084] exist Figure 4 In the illustrated example, the protective tape 430 is attached to the coated portion (mixture portion) 420 of the first electrode 400. However, for example, the protective tape 430 may be attached to the uncoated portion 410 of the first electrode 400. Furthermore, the protective tape 430 may be attached to the second electrode and / or the diaphragm. Additionally, in cases where the electrode assembly includes multiple protective tapes, all protective tapes may be attached to different locations on the first electrode, or the protective tapes may be attached to the first electrode, the second electrode, or the diaphragm separately.

[0085] Figure 5 The illustration shows a plan view of an example of an electrode assembly 500 having a protective strip 510_1 attached thereto, according to one or more embodiments of the present disclosure. Reference Figure 5 The protective strip 510_1 can be disposed inside the electrode assembly 500. The protective strip 510_1 can be configured to wrap around the inside of the electrode assembly 500 at least once.

[0086] In one or more embodiments, the protective strip 510_1 may be formed of an aramid material. The protective strip 510_1 can primarily secure the shape of the electrode assembly 500 within the electrode assembly 500, thereby dispersing the pressure transmitted to the outermost periphery of the electrode assembly 500 due to its expansion. Accordingly, the formation of cracks at the outermost periphery of the electrode assembly 500 can be effectively prevented.

[0087] The battery according to an embodiment of this disclosure may further include a second protective band. Figure 6 The figure shows a plan view of an example of an electrode assembly 500 having protective strips 510_1 and 510_2 attached thereto, according to another embodiment of the present disclosure. (See reference...) Figure 6 The first protective strip 510_1 can be configured to wrap around the inside of the electrode assembly 500 at least once. Furthermore, the second protective strip 510_2 can be configured to wrap around the outermost periphery of the electrode assembly 500 at least once along the winding direction of the electrode assembly.

[0088] In some embodiments, the first protective strip 510_1 may be omitted, and only the second protective strip 510_2 may be provided to wrap around the outermost periphery of the electrode assembly 500 at least once. That is, the number and placement of the protective strips attached to the electrode assembly 500 may be appropriately varied depending on the expansion rate of the electrode assembly 500.

[0089] Figure 7 The illustration shows an example of a protective strip 750 attached to a first electrode 700 according to one or more embodiments of the present disclosure, and Figure 8 The figure shows a cross-sectional view of an example of a protective strip 750 attached to a first electrode 700 according to one or more embodiments of the present disclosure.

[0090] refer to Figure 7 The first electrode 700 may include a coated portion (mixture portion) 720 on which an active material is coated on the substrate, and uncoated portions 710 and 710_1 on which the substrate is exposed when the active material is not coated. The uncoated portion 710 may be located at one or both ends of the first electrode 700 along its longitudinal direction (X-axis). In some embodiments, the uncoated portion 710_1 may be located in a specific portion of the middle region of the first electrode 700.

[0091] The first electrode 700 can be connected to the substrate terminal block 730. The substrate terminal block 730 can be disposed on the uncoated portion 710_1 of the first electrode 700, and the substrate terminal block 730 can protrude in a direction (Y-axis) perpendicular to the longitudinal direction (X-axis) of the first electrode 700.

[0092] The substrate connector protection strip 740 can be attached to the substrate connector 730. The substrate connector protection strip 740 can cover the substrate connector 730 disposed on the uncoated portion 710_1. In addition, the substrate connector protection strip 740 can be attached to extend a predetermined length in the direction (Y-axis) in which the substrate connector 730 protrudes, thereby preventing the substrate connector 730 from contacting the second electrode.

[0093] In one or more embodiments, the substrate terminal protection strip 740 may be formed of a material such as polyethylene terephthalate (PET), polyimide (PI), polypropylene (PP), or oriented polystyrene (OPS), but the material may vary.

[0094] exist Figure 7 In the illustrated example, the substrate connector protection strip 740 is configured to cover only the overlapping area of ​​the substrate connector 730 and the uncoated portion 710_1. However, for example, the substrate connector protection strip 740 may be configured to cover the entire uncoated portion 710_1 of the first electrode 700.

[0095] A protective strip 750 can be attached to the first electrode 700. The protective strip 750 can be attached to the first electrode 700 along its longitudinal direction (X-axis). Accordingly, when the first electrode 700 is in a wound state, the protective strip 750 can be configured to wrap around the inside of the electrode assembly. In the width direction (Y-axis) of the first electrode 700, the width of the protective strip 750 can correspond to (e.g., be the same as or greater than) the width of the first electrode 700, but this width can vary.

[0096] When the first electrode 700 is in a wound state, a protective strip 750 can be attached to the first electrode 700 to be located within a specific area of ​​the electrode assembly. For example, based on the cross-section of the electrode assembly, the protective strip 750 can be positioned within a region between at least half (1 / 2) of the diameter of the electrode assembly and the diameter of the electrode assembly. In other words, the distance between the protective strip 750 and the winding core of the electrode assembly relative to the winding diameter direction of the electrode assembly can be at least half the diameter of the electrode assembly. The protective strip 750 can be configured to wrap around the interior of the electrode assembly at least once within this designated region.

[0097] The protective strip 750 may be additionally attached to the substrate contact protector 740 and cover the uncoated portion 710_1 of the first electrode 700. For example, if the substrate contact 730 is located in a designated area of ​​the electrode assembly where the protective strip 750 will be provided, the protective strip 750 may be attached to both the substrate contact 730 and the substrate contact protector 740.

[0098] Figure 8The illustration shows a cross-sectional view of an example of a protective strip 750 attached to a first electrode according to one or more embodiments of the present disclosure, above a substrate bonding pad protective strip 740. For reference, Figure 8 This is a cross-sectional view of the first electrode cut along its thickness direction (Z-axis). Figure 7 Enlarged cross-sectional view of region B in the diagram.

[0099] The first electrode includes an uncoated portion 710_1 to which the substrate tab 730 is connected, and a substrate tab protective strip 740 can be attached to the substrate tab 730. Then, a protective strip 750 can cover the top of the substrate tab protective strip 740 and be attached to the top of the substrate tab protective strip 740. Here, the protective strip 750 can be formed of an aramid material, and the protective strip 750 can be attached such that a first direction of the protective strip 750 having a high elastic modulus is aligned parallel to the longitudinal direction (X-axis) of the first electrode.

[0100] In this configuration, the substrate connector protection strip 740 and the protection strip 750 are disposed on the substrate connector 730 in a double-layer structure, thereby preventing the generation of cracks caused by the expansion of the electrode assembly at the connection between the substrate connector 730 and the first uncoated portion 710_1.

[0101] exist Figure 8 In the illustrated example, the protective strip 750 is spaced apart from and does not contact the first uncoated portion 710_1. However, this may be exaggerated regarding the positional relationship between the illustrated components. That is, the protective strip 750 can be positioned to contact the first uncoated portion 710_1 while simultaneously covering and attaching to the substrate connector protective strip 740.

[0102] Figure 9 The illustration shows an example of a first electrode 700 having a protective strip 750 attached thereto, according to another embodiment of the present disclosure. Figure 10 The illustration shows a cross-sectional view of an example of a first electrode 700 having a protective strip 750 attached thereto, according to another embodiment of the present disclosure. Figure 9 and Figure 10 In the middle, the omission is already in the middle. Figure 7 and Figure 8 The redundant description of the construction described herein. For reference, Figure 10 This is a cross-sectional view of the first electrode cut along its thickness direction (Z-axis). Figure 9 Enlarged cross-sectional view of region C in the diagram.

[0103] refer to Figure 9 and Figure 10The first electrode 700 may include a coated portion (mixture portion) 720 coated with an active material and uncoated portions 710 and 710_1 of the substrate exposed without the active material. A substrate tab 730 may be connected to the uncoated portion 710_1 of the first electrode 700. The substrate tab 730 may protrude in a direction (Y-axis) perpendicular to the longitudinal direction (X-axis) of the first electrode 700.

[0104] The protective strip 750 can be attached to the substrate connector 730. Furthermore, the protective strip 750 can be configured to completely cover the uncoated portion 710_1 to which the substrate connector 730 is connected. When the first electrode 700 is in a wound state, the protective strip 750 can be attached along the longitudinal direction (X-axis) of the first electrode 700 and is configured to surround the interior of the electrode assembly.

[0105] In one or more embodiments, the protective strip 750 may be attached to extend a predetermined length in the direction (Y-axis) in which the substrate contact patch 730 protrudes. In the width direction (Y-axis) of the first electrode 700, the width of the protective strip 750 may exceed the predetermined length of the width of the first electrode 700. Accordingly, the protective strip 750 may prevent the substrate contact patch 730 from contacting the second electrode. That is, the protective strip 750 may be provided instead of the substrate contact patch protective strip (e.g., Figure 7 The substrate connector protection strip 740 in the middle performs the function of insulating and protecting the substrate connector 730.

[0106] In this configuration, the protective strip 750 can suppress the expansion and deformation of the electrode assembly and also prevent the substrate terminal block connected to the first electrode from contacting the second electrode, thereby avoiding the risk of short circuit in the battery.

[0107] Figure 11 and Figure 12 The illustration shows an example of an outer diameter measurement of an electrode assembly according to one or more embodiments of this disclosure. During repeated charge and discharge cycles, the electrode assembly undergoes expansion and contraction, resulting in twisting or deformation. This twisting or deformation can cause surface irregularities in the electrode assembly, which may lead to crack formation inside the electrode assembly and / or along its outermost periphery. The expansion and twisting of the electrode assembly can be assessed by measuring its outer diameter.

[0108] The first to fourth graphs 1110_1, 1110_2, 1120_1 and 1120_2 provide examples of data obtained by measuring the outer diameter of the electrode assembly at multiple points X1 to X8 set along the outermost periphery of the electrode assembly after repeatedly performing charge and discharge cycles of the electrode assembly.

[0109] In the first graph 1110_1, the horizontal axis indicates the positions of multiple points X1 to X8 on the outermost periphery of the electrode assembly, and the vertical axis indicates the outer diameter of the electrode assembly measured at each of the multiple points X1 to X8. Here, the outer diameter of the electrode assembly can represent the distance (measured in millimeters) from the winding core passing through each of the multiple points X1 to X8 to the opposite side of the electrode assembly. Furthermore, the second graph 1110_2 illustrates the same data from the first graph 1110_1 in the form of a pie chart (polar graph).

[0110] The third graph 1120_1 illustrates a graph in which the vertical axis scale of the first graph 1110_1 is transformed (e.g., the range from 0 to 21.10 is transformed to the range from 21.05 to 21.10). Furthermore, the fourth graph 1120_2 illustrates the same data from the third graph 1120_1 in the form of a pie chart (polar graph). By referring to the fourth graph 1120_2, it is confirmed that expansion and distortion in the electrode assembly are possible.

[0111] For example, Figure 12 The diagram illustrates different implementation methods to be compatible with... Figure 11 The data for the outer diameter of the electrode assembly with the protective strip attached thereto, measured in the same manner as the fourth curve 1120_2, are curves 1200_1 to 1200_3.

[0112] The first embodiment, illustrated in graph 1200_1, shows an example of a protective strip formed of PI material attached to the interior of an electrode assembly. The protective strip can be positioned along the diameter of the electrode assembly at a location halfway from the center of the electrode assembly, corresponding to half the diameter of the electrode assembly.

[0113] Referring to graph 1200_1 according to the first embodiment, it can be observed that the diameter of the electrode assembly is relatively large at certain points (approximately X1 and X5). On the other hand, it can be observed that the diameter of the electrode assembly is relatively small at points (approximately X3 and X7) located in directions intersecting with the aforementioned points (e.g., X1 and X5). In this case, due to the displacement difference between the points with larger diameters and the points with smaller diameters, distortion of the electrode assembly may occur.

[0114] The second embodiment, illustrated in graph 1200_2, shows an example of a protective strip made of aramid material attached to the interior of an electrode assembly. Here, the elastic modulus of the protective strip in the first direction can be greater than its elastic modulus in a second direction perpendicular to the first direction. In the second embodiment, the protective strip can be positioned such that the second direction, having a lower elastic modulus, is aligned parallel to the winding direction of the electrode assembly. Furthermore, the protective strip can be positioned along the diameter of the electrode assembly at a position halfway from the center of the electrode assembly, corresponding to half the diameter of the electrode assembly.

[0115] Referring to graph 1200_2 according to the second embodiment, it can be observed that, similar to graph 1200_1 according to the first embodiment, the diameter of the electrode assembly is relatively large at certain points (approximately X1, X2, X5, and X6). On the other hand, it can be observed that the diameter of the electrode assembly is relatively small at points (approximately X3 and X7) where the direction intersects with the direction of the aforementioned points. In the case of the second embodiment, the displacement difference between points with large diameters and points with small diameters is relatively smaller than the displacement difference in the first embodiment, but the possibility of twisting occurring in the electrode assembly still exists.

[0116] The diagram 1200_3 of the third embodiment illustrates an example in which a protective strip formed of an aramid material is attached to the interior of an electrode assembly. In the third embodiment, the protective strip can be positioned such that a first direction having a high elastic modulus is aligned parallel to the winding direction of the electrode assembly. Furthermore, the protective strip can be positioned along the diameter of the electrode assembly at a position halfway from the center of the electrode assembly, corresponding to half the diameter of the electrode assembly.

[0117] The shape of the curve 1200_3 according to the third embodiment is approximately circular. Compared with the first and second embodiments, it can be observed that the displacement difference between points with large diameters and points with small diameters is minimized. As a result, in the third embodiment, the electrode assembly experiences minimal distortion.

[0118] Referring to graphs 1200_1 to 1200_3 according to the first to third embodiments, it was observed that when an aramid tape was attached instead of a PI tape, the twisting of the electrode assembly was significantly reduced. Furthermore, when the first direction of the protective tape, having a higher elastic modulus, was aligned parallel to the winding direction of the electrode assembly, deformation of the electrode assembly's shape (e.g., expansion or twisting) was minimized.

[0119] Electrode assemblies can have various configurations, including stacked electrode assemblies in which positive electrodes, separators, and negative electrodes are sequentially stacked, and wound electrode assemblies in which positive electrodes, separators, and negative electrodes are sequentially stacked and wound. In the case of wound electrode assemblies, during the charge and discharge cycles of the secondary battery, the electrode assembly undergoes repeated expansion and contraction, which may lead to distortion of the electrode assembly. This distortion may cause surface unevenness of the electrode assembly, resulting in crack formation.

[0120] According to some embodiments of this disclosure, the protective strip is positioned to wrap around the inside of the electrode assembly at least once, thereby effectively suppressing the expansion or twisting of the electrode assembly during battery charge and discharge cycles.

[0121] According to some embodiments of this disclosure, the protective strip is located at a certain distance from the winding core of the electrode assembly in the winding diameter direction of the electrode assembly, thereby maximizing the effect of suppressing the expansion of the electrode assembly.

[0122] According to some embodiments of this disclosure, the first direction of the protective strip having a high elastic modulus is aligned parallel to the longitudinal direction of the first electrode, thereby effectively suppressing the expansion and twisting of the electrode assembly.

[0123] According to some embodiments of this disclosure, the substrate terminal protection strip and the protective strip are disposed on the substrate terminal in a double-layer structure above the substrate terminal, thereby effectively preventing cracks from forming at the connection between the substrate terminal and the uncoated portion, which could otherwise occur due to the expansion of the electrode assembly.

[0124] According to some embodiments of this disclosure, a protective strip is provided separately to also serve as a protective strip for the substrate connector. Therefore, expansion and twisting of the electrode assembly can be suppressed while simultaneously preventing the substrate connector connected to the first electrode from contacting the second electrode, thereby preventing short circuits in the battery.

[0125] Although this disclosure has been described above with respect to its embodiments, it is not limited thereto. Those skilled in the art will be able to make various modifications and variations thereto within the spirit of this disclosure and within the equivalents of the appended claims.

[0126] Thus far, exemplary embodiments have been disclosed. Although specific terminology has been used, it is used in a general and descriptive sense only, and is not intended to be limiting. In some cases, as would be apparent to those skilled in the art at the time of filing this application, unless specifically stated otherwise, 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. 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 appended claims.

[0127] Explanation of some figure labels

[0128] 100: Battery

[0129] 110: Electrode assembly

[0130] 112: First electrode

[0131] 114: Second electrode

[0132] 116: Diaphragm

[0133] 120: Shell

[0134] 130: Cover component

Claims

1. A secondary battery, comprising: An electrode assembly includes a first electrode, a second electrode, and a winding of a diaphragm between the first electrode and the second electrode; Housing that houses the electrode assembly; as well as A first protective strip is attached to the first electrode of the electrode assembly. The first protective strip is wound around the inside of the electrode assembly at least once along the winding direction of the electrode assembly.

2. The secondary battery according to claim 1, wherein, The first protective strip is a first distance from the winding core of the electrode assembly in the winding diameter direction of the electrode assembly.

3. The secondary battery according to claim 2, wherein, The first distance is at least half the diameter of the electrode assembly.

4. The secondary battery according to claim 1, wherein, The first protective strip is a second distance from the front end of the first electrode along the winding direction of the electrode assembly.

5. The secondary battery according to claim 4, wherein, The second distance is at least one-third of the length of the first electrode.

6. The secondary battery according to claim 1, wherein, The elastic modulus of the first protective strip in the first direction is greater than the elastic modulus of the first protective strip in the second direction perpendicular to the first direction.

7. The secondary battery according to claim 6, wherein, The first direction of the first protective strip is parallel to the winding direction of the electrode assembly.

8. The secondary battery according to any one of claims 1 to 7, wherein, The first protective strip comprises an aromatic polyamide material.

9. The secondary battery according to any one of claims 1 to 7, wherein: The first electrode includes a substrate, the substrate comprising a coated portion coated with an active material, and the substrate further comprising an uncoated portion exposing the substrate, the uncoated portion lacking the active material. The substrate connector is connected to the uncoated portion.

10. The secondary battery according to claim 9, further comprising: A substrate connector protection strip is attached to the substrate connector, wherein the first protection strip is on the substrate connector protection strip and covers the uncoated portion of the first electrode.

11. The secondary battery according to claim 9, wherein, The first protective strip is attached to the substrate tab and covers the uncoated portion of the first electrode.

12. The secondary battery according to claim 11, wherein, In the winding axis direction of the electrode assembly, the width of the first protective strip is equal to or greater than the width of the first electrode.

13. The secondary battery according to any one of claims 1 to 7, further comprising: A second protective strip is located at the outermost periphery of the electrode assembly, wherein the second protective strip is wound around the outermost periphery of the electrode assembly at least once along the winding direction of the electrode assembly.

14. An electrode assembly comprising a first electrode, a second electrode, and a winding of a diaphragm between the first electrode and the second electrode, the electrode assembly including a protective strip attached to the first electrode, wherein, The protective tape is wound around the inside of the electrode assembly at least once along the winding direction of the electrode assembly.

15. The electrode assembly of claim 14, wherein, The protective strip is a first distance from the winding core of the electrode assembly in the winding diameter direction of the electrode assembly.

16. The electrode assembly of claim 15, wherein, The first distance is at least half the diameter of the electrode assembly.

17. The electrode assembly of claim 14, wherein, The protective strip is located at a second distance from the front end of the first electrode along the winding direction of the electrode assembly.

18. The electrode assembly according to claim 17, wherein, The second distance is at least one-third of the length of the first electrode.

19. The electrode assembly according to any one of claims 14 to 18, wherein, The elastic modulus of the protective strip in the first direction is greater than the elastic modulus of the protective strip in the second direction perpendicular to the first direction.

20. The electrode assembly of claim 19, wherein, The first direction of the protective strip is parallel to the winding direction of the electrode assembly.

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