Electrode assembly, secondary battery, and method for manufacturing electrode assembly

Abstract

Disclosed are an electrode assembly, a secondary battery, and a method for manufacturing the electrode assembly. The electrode assembly includes: a first electrode including a first substrate and a first composite portion on the first substrate; a second electrode including a second substrate and a second composite portion on the second substrate; a first separator between the first electrode and the second electrode; and a winding core having a through hole, in which the second substrate extends in a longitudinal direction of the second electrode, the second substrate includes a winding direction uncoated portion exposed from the second composite portion, and in which at least a portion of the winding direction uncoated portion is at a periphery of the through hole.

Description

Technical Field

[0001] The embodiments include an electrode assembly and a secondary battery including the electrode assembly. 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 for driving 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 that houses 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 technology of this disclosure, and therefore may contain information that does not constitute related (or prior art). Summary of the Invention

[0004] An embodiment includes an electrode assembly comprising: a first electrode including a first substrate and a first composite portion on the first substrate; a second electrode including a second substrate and a second composite portion on the second substrate; a first diaphragm between the first electrode and the second electrode; and a winding core having a through-hole, wherein the second substrate extends in the longitudinal direction of the second electrode, the second substrate including a winding-direction uncoated portion exposed from the second composite portion, and wherein at least a portion of the winding-direction uncoated portion is located around the through-hole.

[0005] The uncoated portion in the winding direction and the first diaphragm may be stacked around the periphery of the through hole in the diametrical direction of the electrode assembly.

[0006] The first electrode may be on the outer surface of the first diaphragm, and the second electrode may be on the inner surface of the first diaphragm.

[0007] The electrode assembly may further include a second diaphragm between the first electrode and the second electrode, wherein the second diaphragm is on the outer surface of the first electrode.

[0008] The uncoated portion in the winding direction, the first diaphragm, and the second diaphragm may be stacked around the periphery of the through hole in the diametrical direction of the electrode assembly.

[0009] At least a portion of the second diaphragm may be located on the outer surface of the electrode assembly.

[0010] The winding tip of the first diaphragm can contact the second diaphragm, or the winding tip of the second diaphragm can contact the first diaphragm.

[0011] The winding tip of the uncoated portion in the winding direction can contact the first diaphragm, or the winding tip of the first diaphragm can contact the uncoated portion in the winding direction.

[0012] The first diaphragm and the uncoated portion in the winding direction may be located between the inner surface of the second electrode and the outer surface of the first electrode.

[0013] The second diaphragm, the first diaphragm, and the uncoated portion in the winding direction may be located between the inner surface of the second electrode and the outer surface of the first electrode, and the second diaphragm may be a double-layer structure.

[0014] The winding tip of the first diaphragm, the winding tip of the second diaphragm, and the winding tip of the uncoated portion in the winding direction can be located between the outer surface of the first electrode and the inner surface of the second electrode.

[0015] An embodiment includes a secondary battery comprising: an electrode assembly including: a first electrode including a first substrate and a first composite portion on the first substrate; a second electrode including a second substrate and a second composite portion on the second substrate; a separator between the first electrode and the second electrode; and a winding core having a through-hole; and a housing configured to house the electrode assembly, wherein the second substrate extends in the longitudinal direction of the second electrode, the second substrate including a winding-direction uncoated portion exposed from the second composite portion, and wherein at least a portion of the winding-direction uncoated portion is located around the through-hole.

[0016] The uncoated portion in the winding direction and the diaphragm may be stacked around the periphery of the through hole in the diametrical direction of the electrode assembly.

[0017] The secondary battery may further include lead terminals connected to at least a portion of the uncoated portion in the winding direction around the through hole.

[0018] The secondary battery may further include an inserted current collector, the inserted current collector including a flat portion that contacts the electrode assembly and a protrusion that protrudes from the flat portion and is inserted into the through hole, wherein the protrusion of the inserted current collector is electrically connected to the second electrode through contact with the uncoated portion in the winding direction.

[0019] The height of the protrusion may be greater than half the height of the electrode assembly, but less than the height of the electrode assembly.

[0020] The housing may include an insertion portion formed by bending a portion of a surface of the housing toward the interior of the housing to insert into the through hole, and the insertion portion of the housing may be electrically connected to the second electrode by contacting the uncoated portion in the winding direction.

[0021] The height of the insertion portion may be greater than half the height of the electrode assembly, but less than the height of the electrode assembly.

[0022] An embodiment includes a method for manufacturing an electrode assembly, the method comprising: preparing a first electrode including a first substrate and a first composite portion located on the first substrate; preparing a second electrode including a second substrate and a second composite portion located on the second substrate; disposing a separator between the first electrode and the second electrode; and winding the first electrode, the second electrode, and the separator, wherein the second substrate extends in the longitudinal direction of the second electrode, the second substrate includes a winding-direction uncoated portion exposed from the second composite portion, and wherein the winding tip of the winding-direction uncoated portion contacts the separator, or the winding tip of the separator contacts the winding-direction uncoated portion.

[0023] The method may further include inserting an insertion rod into a through hole located in the winding core of the electrode assembly.

[0024] 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 are also included. Attached Figure Description

[0025] The 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 A cross-sectional view of an example secondary battery according to an embodiment of the present disclosure is shown;

[0027] Figure 2 A diagram illustrating an example of winding a first electrode, a second electrode, a first diaphragm, and a second diaphragm according to an embodiment of the present disclosure;

[0028] Figure 3 A diagram illustrating an example of a first electrode, a second electrode, a first diaphragm, and a second diaphragm being wound according to an embodiment of the present disclosure;

[0029] Figure 4 A partial enlarged view is shown as an example of an electrode assembly according to an embodiment of the present disclosure;

[0030] Figure 5A diagram illustrating a portion of an example electrode assembly according to an embodiment of the present disclosure;

[0031] Figure 6 A diagram illustrating the process before forming the through-hole of the electrode assembly according to an embodiment of the present disclosure;

[0032] Figure 7 A diagram illustrating a through-hole forming an electrode assembly according to an embodiment of the present disclosure;

[0033] Figure 8 A cross-sectional view illustrating an example of a secondary battery including an inserted current collector according to an embodiment of the present disclosure;

[0034] Figure 9 A cross-sectional view of an example secondary battery including a casing according to an embodiment of the present disclosure is shown; and

[0035] Figure 10 The flowchart illustrates an example of a method for manufacturing an electrode assembly according to an embodiment of the present disclosure.

[0036] [Explanation of Labels in the Attached Image]

[0037] 100: Secondary battery

[0038] 110: Electrode assembly

[0039] 112: First electrode

[0040] 113: Second electrode

[0041] 113a: Uncoated portion in the winding direction

[0042] 114: Diaphragm

[0043] 115: First lead connector

[0044] 116: Through hole

[0045] 160: Second lead connector

[0046] 120: Shell

[0047] 122: Bottom

[0048] 124: Sidewall

[0049] 126: Coiling section

[0050] 128: Crimping section

[0051] 130: Cover component

[0052] 140: Padding

[0053] 150: Insulation board Detailed Implementation

[0054] Example embodiments will now be described more fully below with reference to the accompanying drawings; however, they may be implemented in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey exemplary implementation methods to those skilled in the art.

[0055] In the accompanying drawings, for clarity of illustration, the dimensions of layers and regions may be enlarged. It should also be understood that when a layer or element is referred to as "on" another layer or substrate, it may be directly on the other layer or substrate, or an intervening layer may be present. Furthermore, it will be understood that when a layer is referred to as "below" another layer, it may be directly below the other layer, or one or more intervening layers may be present. Additionally, it will be understood that when a layer is referred to as "between two layers," it may be the only layer between the two layers, or one or more intervening layers may be present. The same reference numerals always refer to the same elements.

[0056] The terms or words used in this specification and claims should not be construed as limited to their conventional or dictionary meanings, and should be interpreted as meanings and concepts consistent with the technical spirit of this disclosure, based on the principle that the inventor can, for his / her own lexicographer, appropriately define the concepts of the terms in order to best illustrate his / her embodiments.

[0057] The embodiments described in this specification and the structures shown in the figures are merely some 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 may exist at the time of filing this application.

[0058] 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 can 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 can be directly linked to or connected to the second element, or the first element can be indirectly linked to or connected to the second element via one or more intermediary elements.

[0059] As used herein, the term “and / or” includes any and all combinations of one or more of the associated listed items. Furthermore, when describing embodiments of this disclosure, the use of “may” refers to “one or more embodiments of this disclosure.” Expressions such as “at least one of” and “any one of” modify the entire column of elements, not individual elements of the column, when following a column 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 column 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 term “use” may be considered synonymous with the term “utilize.” As used herein, the terms “substantially,” “about,” and similar terms are used as approximate terms rather than terms of degree and are intended to take into account the inherent variations in measurements or calculations that would be recognized by one of ordinary skill in the art.

[0060] It will be understood that while the terms “first,” “second,” “third,” etc., may be used herein to describe various elements, components, regions, layers, and / or segments, these elements, components, regions, layers, and / or segments should not be limited by these terms. These terms are used to distinguish one element, component, region, layer, or segment from another. Therefore, without departing from the teachings of the exemplary embodiments, the first element, component, region, layer, or segment discussed below may be referred to as the second element, component, region, layer, or segment.

[0061] For ease of description, spatial relative terms such as “below,” “under,” “down,” “above,” and “above” may be used herein to describe the relationship between one element or feature illustrated in the figures and another element or feature. It will be understood that spatial relative terms are intended to encompass different orientations of the device in use or operation, other than those depicted in the figures. For example, if the device in the figures is flipped, an element described as “below” or “under” other elements or features would then be oriented as “above” or “above” other elements or features. Therefore, the term “below” can encompass 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.

[0062] 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 form “a” is also intended to include the plural form. It will be further understood that the terms “comprising” and / or “including” as used in this specification specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0063] Furthermore, any numerical ranges disclosed and / or enumerated herein are intended to include all subranges with the same numerical precision contained within the enumerated ranges. For example, the range “1.0 to 10.0” is intended to include all subranges between (and including) the enumerated minimum value of 1.0 and the enumerated 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 2.4 to 7.6. Any maximum numerical limit enumerated herein is intended to include all lower numerical limits contained therein, and any minimum numerical limit enumerated herein is intended to include all higher numerical limits contained therein. Accordingly, the applicant reserves the right to amend this specification, including the claims, to expressly enumerate any subranges contained within the scope expressly enumerated herein.

[0064] Referring to two compared elements, features, etc., as “identical” can mean that they are “substantially the same.” Therefore, the phrase “substantially the same” can include cases with a deviation considered low in the art, such as 5% or less. Furthermore, when a parameter is said to be consistent in a given region, this can mean that it is consistent in terms of average value.

[0065] Throughout this specification, unless otherwise stated, each element may be a single element or a plurality of elements.

[0066] Placing any element "above (or below)" or "on (below)" another element means that the element can be positioned to contact the upper (or lower) surface of the element, and the other element can be positioned between the element and any element positioned on (or below) the element.

[0067] Additionally, it will be understood that when a component is referred to as a “link,” “connect,” or “attached” to another component, these components may be directly “connected,” “linked,” or “attached” to each other, or another component may be “placed” between these components.

[0068] Throughout this specification, unless otherwise stated, the phrase "A and / or B" means A, B, or A and B. That is, "and / or" includes any or all combinations of the listed items. Unless otherwise stated, the phrase "C to D" means C and above and D and below.

[0069] Figure 1 A cross-sectional view of an example secondary battery 100 according to an embodiment of the present disclosure is shown. Figure 1 As shown, the secondary battery 100 may include: an electrode assembly 110, a housing 120 for accommodating the electrode assembly 110 and an electrolyte, a cover assembly 130 connected to an opening in the housing 120 to seal the housing 120, and an insulating plate 150 disposed within the housing 120 between the electrode assembly 110 and the cover assembly 130 and / or the bottom 122 of the housing 120.

[0070] The electrode assembly 110 may include a first electrode 112, a second electrode 113, and a diaphragm 114. The diaphragm 114 may be disposed between the first electrode 112 and the second electrode 113. The electrode assembly 110 may be formed by winding the first electrode 112, the second electrode 113, and the diaphragm 114 relative to the winding axis Y. In addition, the electrode assembly 110 may include a through hole 116 disposed in the winding core.

[0071] The first electrode 112 may include a first substrate and a first composite portion disposed on the first substrate. A first lead tab 115 may extend outward from a first uncoated portion of the first substrate where the first composite portion is not provided. The first lead tab 115 may be electrically connected to the cover assembly 130.

[0072] The second electrode 113 may include a second substrate and a second composite portion located on the second substrate. A second lead patch 160 may extend outward from a second uncoated portion of the second substrate where the second composite portion is not provided. In other embodiments, the second lead patch 160 may be connected to or coupled to the second uncoated portion. The second lead patch 160 may be electrically connected to the housing 120. Reference Figure 1 The first lead connector 115 and the second lead connector 160 may extend in opposite directions, but the first lead connector 115 and the second lead connector 160 may extend in the same direction.

[0073] The first electrode 112 can be used as a positive electrode. In this case, the first substrate can be formed of, for example, aluminum foil, and the first composite portion can include, for example, a transition metal oxide. The second electrode 113 can be used as a negative electrode. In this case, the second substrate can be formed of, for example, copper foil or nickel foil, and the second composite portion can include, for example, graphite.

[0074] The separator 114 allows lithium ions to move and prevents short circuits between the first electrode 112 and the second electrode 113. The separator 114 can be formed of, for example, a polyethylene membrane, a polypropylene membrane, or a polyethylene-polypropylene membrane.

[0075] According to an embodiment, the second substrate may extend in the longitudinal direction of the second electrode 113 and includes a winding-direction uncoated portion 113a exposed from the second composite portion. The winding-direction uncoated portion 113a may be an uncoated portion of the substrate where no composite portion is provided, and is located in the region where the winding of the substrate begins. The winding-direction uncoated portion may be formed in the region where the winding of the substrate begins relative to the winding direction, and then the composite portion may be formed adjacent to the winding-direction uncoated portion. The outermost end of the region where the winding of the substrate begins may be referred to as the winding tip. For example, according to an embodiment of this disclosure, the "winding tip" may be referred to as the end relative to the winding direction.

[0076] At least a portion of the uncoated portion 113a in the winding direction may be located around the through hole 116. For example, the electrode assembly 110 may be formed by winding the first electrode 112, the second electrode 113, and the diaphragm 114. The winding front end of the electrode assembly 110 may include the winding front end of the uncoated portion 113a in the winding direction.

[0077] The electrode assembly 110 can be formed by setting and winding the first electrode 112, the second electrode 113, and the diaphragm 114 in the region where winding begins. At least a portion of the uncoated portion 113a in the winding direction may be located around the periphery of the through hole 116. The structure of the uncoated portion 113a in the winding direction located around the periphery of the through hole 116 will be referred to Figures 2-5 Detailed description.

[0078] According to an embodiment, the second lead patch 160 can be connected to the inner peripheral surface of the electrode assembly 110. The uncoated portion 113a in the winding direction of the second substrate can be located around the through-hole 116 of the electrode assembly 110. Accordingly, the second lead patch 160 can be connected to the uncoated portion 113a in the winding direction, and the second lead patch 160 can be electrically connected to the second electrode 113. The electrical connection of the housing 120 is such that the bottom 122 of the second lead patch 160 can be electrically connected to the second electrode 113.

[0079] The housing 120, together with the cover assembly 130, forms the external shape of the secondary battery 100. The housing 120 may include a cylindrical sidewall 124 and a bottom 122 connected to one side of the sidewall 124 (e.g., the bottom end in the shown orientation). An inwardly deformed crimped portion 126 may be formed on the sidewall 124, and an inwardly bent crimped portion 128 may be formed at the open end of the sidewall 124.

[0080] The crimping portion 126 can suppress movement of the electrode assembly 110 within the housing 120 and easily ensure the installation of the gasket 140 and the cover assembly 130. The crimping portion 128 can press the edge of the cover assembly 130 through the gasket 140 to securely fix the cover assembly 130. For example, the housing 120 can be formed of nickel-plated iron.

[0081] The insulating plate 150 is positioned to contact the electrode assembly 110 below the coiled portion 126, and a tab opening for leading out the first lead tab 115 is provided in the insulating plate 150. The cover assembly 130, which is electrically connected to the first electrode 112 via the first lead tab 115, can face the electrode assembly 110 (with the insulating plate 150 between them) and is insulated from the electrode assembly 110 by the insulating plate 150.

[0082] The insulating plate 150 is positioned to contact the electrode assembly 110 at the bottom 122 of the housing 120, and a tab opening for leading out the second lead tab 160 is provided in the insulating plate 150. The bottom 122 of the second electrode 113, electrically connected via the second lead tab 160, faces the electrode assembly 110 (with the insulating plate 150 between them) and is insulated from the electrode assembly 110 by the insulating plate 150.

[0083] Figure 2 The figure illustrates an example of winding a first electrode 210, a second electrode 220, a first diaphragm 230, and a second diaphragm 240 according to an embodiment of the present disclosure. The electrode assembly can be formed by winding the first electrode 210, the second electrode 220, the first diaphragm 230, and the second diaphragm 240. The first electrode 210 may include a first substrate 212 and a first composite portion 214 disposed on the first substrate 212. The second electrode 220 may include a second substrate 222 and a second composite portion 224 disposed on the second substrate 222. The first diaphragm 230 may be disposed between the first electrode 210 and the second electrode 220. The second diaphragm 240 may be located on the outer surface of the first electrode 210. For example, the second diaphragm 240 may be located on the other surface of the first electrode 210 opposite to the surface on which the first diaphragm 230 is disposed. The second diaphragm 240 may be wound together with the first electrode 210 and the second electrode 220 to be disposed between the first electrode 210 and the second electrode 220.

[0084] According to an embodiment, the first electrode 210, the second electrode 220, the first diaphragm 230, and the second diaphragm 240 can be inserted into the winding device 250 for winding. (Reference) Figure 2The winding tips of the first diaphragm 230 and the second diaphragm 240 can be inserted first. A portion of the second substrate 222 of the second electrode 220 disposed on the first diaphragm 230 can be inserted into the winding device 250 together with the first diaphragm 230 and the second diaphragm 240. Specifically, the uncoated portion 222a of the winding direction of the second substrate 222 can be inserted into the winding device 250 together with the first diaphragm 230 and the second diaphragm 240. The winding device 250 can rotate together with the inserted first diaphragm 230, second diaphragm 240 and uncoated portion 222a. For example, the winding device 250 can rotate clockwise, but this can be varied. After the winding device 250 has rotated at a predetermined angle, the first electrode 210 can be inserted between the first diaphragm 230 and the second diaphragm 240 for rotation. As the winding device 250 rotates, the electrode assembly can be formed by winding the first electrode 210, the second electrode 220, the first diaphragm 230 and the second diaphragm 240. In this case, the first electrode 210 can be a positive electrode, and the second electrode 220 can be a negative electrode. Alternatively, the first electrode 210 can be a negative electrode, and the second electrode 220 can be a positive electrode.

[0085] The winding front end described below can refer to the front end located in the region where winding begins. For example, the winding front end 232 of the first diaphragm can be the front end of the first diaphragm 230 inserted into the winding apparatus 250. The winding front end 242 of the second diaphragm can be the front end of the second diaphragm 240 inserted into the winding apparatus 250. The winding front end 222b of the uncoated portion in the winding direction of the second substrate 222 can be the front end of the uncoated portion 222a in the winding direction inserted into the winding apparatus 250. The winding front end of the electrode assembly can include at least one of the winding front end 232 of the first diaphragm, the winding front end 242 of the second diaphragm, and the winding front end 222b of the uncoated portion 222a in the winding direction. For example, the winding front end of the electrode assembly can correspond to the structure that protrudes furthest in the winding direction among the winding front end 232 of the first diaphragm, the winding front end 242 of the second diaphragm, and the winding front end 222b of the uncoated portion 222a in the winding direction.

[0086] As described above, a portion of the first diaphragm 230, a portion of the second diaphragm 240, and at least a portion of the uncoated portion 222a in the winding direction can be disposed in the winding core of the electrode assembly. The structure for winding the first electrode 210, the second electrode 220, the first diaphragm 230, and the second diaphragm 240 can be referred to... Figure 3 and Figure 4 Detailed description.

[0087] Figure 3This diagram illustrates an example of a first electrode 210, a second electrode 220, a first diaphragm 230, and a second diaphragm 240 being wound. The winding tip of the electrode assembly can be inserted into a winding device 250, and as the winding device 250 rotates, the first electrode 210, the second electrode 220, the first diaphragm 230, and the second diaphragm 240 can be wound. A portion of the first diaphragm 230, a portion of the second diaphragm 240, and at least a portion of the uncoated portion 222a extending from the second substrate 222 in the winding direction can be located in the winding core.

[0088] According to this disclosure, the electrode assembly may include a laminated structure formed by winding an electrode and a diaphragm. The laminated structure of the electrode assembly may vary depending on the location. For example, only a portion of the diaphragm and / or substrate may be located in the winding core, and other portions of the diaphragm and / or substrate may be wound in a region outside the winding core.

[0089] According to an embodiment, the winding device 250 can be removed, and the insertion rod can be inserted into the area formed by the uncoated portion 222a in the winding direction. For example, the insertion rod can be inserted into the area surrounded by the uncoated portion 222a in the winding direction. (See reference...) Figure 2 The winding device 250 can be removed, and the insertion rod can be inserted. As the insertion rod moves in the diametrical direction, a portion of the first diaphragm 230, a portion of the second diaphragm 240, and a portion of the uncoated portion 222a in the winding direction can move in the diametrical direction (e.g., along the inner diameter of the winding device 250). As the insertion rod moves in the diametrical direction, a through-hole can be formed in the winding core of the electrode assembly. At least a portion of the uncoated portion 222a in the winding direction can be located around the periphery of the through-hole. The characteristics of the through-hole formed in the electrode assembly will be referenced. Figures 5-7 Detailed description.

[0090] According to an embodiment, the first electrode 210 may be located on the outer surface of the first diaphragm 230. The second electrode 220 may be located on the inner surface of the first diaphragm 230. At least a portion of the second diaphragm 240 may be located on the outer surface of the electrode assembly (e.g., the outer surface of the first electrode 210).

[0091] refer to Figure 3 In the region 300 of the middle electrode assembly, according to an embodiment, the wound front end of the electrode assembly may be disposed between the second diaphragm 240 and the second electrode 220 (see reference). Figure 4 (Enlarged view). At least a portion of the electrode assembly may include a structure in which the second diaphragm 240 is a double-layer structure, and the first diaphragm 230, the uncoated portion 222a in the winding direction, and the second electrode 220 are stacked in the diametrical direction of the electrode assembly. The laminated structure of the electrode assembly will be referenced. Figure 4 A detailed description of a partial enlarged view of the electrode assembly is provided.

[0092] Figure 4 Here is a partial enlarged view of an example electrode assembly according to an embodiment of the present disclosure. Figure 4 For example Figure 3 Enlarged view of region 300 of the electrode assembly.

[0093] According to an embodiment, the winding front end 410 of the electrode assembly may include at least one of the winding front end 232 of the first diaphragm, the winding front end 242 of the second diaphragm, and the winding front end 222b of the uncoated portion in the winding direction. (See reference...) Figure 4 The winding tip 232 of the first diaphragm, the winding tip 242 of the second diaphragm, and the winding tip 222b of the uncoated portion in the winding direction can face each other. In this case, the winding tip 410 of the electrode assembly can be formed from the winding tip 232 of the first diaphragm, the winding tip 242 of the second diaphragm, and the winding tip 222b of the uncoated portion in the winding direction. However, the winding tip 410 of the electrode assembly can correspond to the structure that protrudes furthest in the winding direction among the winding tip 232 of the first diaphragm, the winding tip 242 of the second diaphragm, and the winding tip 222b of the uncoated portion 222a in the winding direction.

[0094] refer to Figure 4 The winding tip 410 of the electrode assembly can be disposed between the outer surface of the first electrode 210 and the inner surface of the second electrode 220. Specifically, the winding tip 232 of the first diaphragm, the winding tip 242 of the second diaphragm, and the winding tip 222b of the uncoated portion 222a in the winding direction can be disposed between the outer surface of the first electrode 210 and the inner surface of the second electrode 220.

[0095] According to one embodiment, the winding tip 232 of the first diaphragm may protrude further in the winding direction than the winding tip 242 of the second diaphragm. In this case, the winding tip 242 of the second diaphragm may contact the first diaphragm 230. In other embodiments, the winding tip 242 of the second diaphragm 240 may protrude further in the winding direction than the winding tip 232 of the first diaphragm. In this case, the winding tip 232 of the first diaphragm may contact the second diaphragm 240.

[0096] The winding tip 222b of the uncoated portion 222a in the winding direction may protrude further in the winding direction than the winding tip 232 of the first diaphragm. In this case, the winding tip 232 of the first diaphragm may contact the uncoated portion 222a in the winding direction. In other embodiments, the winding tip 232 of the first diaphragm may protrude further than the winding tip 222b of the uncoated portion 222a in the winding direction. In this case, the winding tip 222b of the uncoated portion 222a in the winding direction may contact the first diaphragm 230.

[0097] According to an embodiment, the second diaphragm 240, the first diaphragm 230, and the uncoated portion 222a in the winding direction can be disposed between the inner surface of the second electrode 220 and the outer surface of the first electrode 210. The second diaphragm 240 can be located in both layers.

[0098] The outer surface of the uncoated portion 222a in the winding direction may face the second electrode 220. The inner surface of the uncoated portion 222a in the winding direction may face the first diaphragm 230. According to an embodiment, the winding tip 222b of the uncoated portion 222a in the winding direction may protrude further in the winding direction than the winding tip 232 of the first diaphragm and / or the winding tip 242 of the second diaphragm. In this case, the winding tip 222b of the uncoated portion 222a in the winding direction may be disposed between the second electrode 220 and the second diaphragm 240. As part of the second substrate, the uncoated portion in the winding direction may contact the second electrode 220 or the first diaphragm 230, but may not contact the first electrode 210, thereby preventing a short circuit due to the uncoated portion 222a in the winding direction.

[0099] Figure 5 The figure shows a portion of an example of an electrode assembly according to an embodiment of the present disclosure. According to the embodiment, the winding device 250 can be from... Figure 2 The electrode assembly is removed, and the insert rod can be inserted into the space between (e.g., in the middle) the uncoated portions 222a in the winding direction. As the insert rod moves in the diametrical direction, it can push a portion of the first diaphragm 230, a portion of the second diaphragm 240, and a portion of the uncoated portions 222a in the winding direction to form a through hole 510. At least a portion of the uncoated portions 222a in the winding direction may be located around the periphery of the through hole 510.

[0100] According to an embodiment, the electrode assembly may include a structure in which the uncoated portion 222a in the winding direction, the first diaphragm 230, and the second diaphragm 240 are stacked in the diametrical direction around the through hole 510. Specifically, the electrode assembly may include a structure in which the uncoated portion 222a in the winding direction, the first diaphragm 230, the double-layered second diaphragm 240, the first diaphragm 230, and the uncoated portion 222a in the winding direction are sequentially stacked in the diametrical direction around the through hole 510.

[0101] As described above, a portion of the second substrate may be located on the inner wall of the through-hole or around its periphery. A conductive structure (e.g., an electrode tab with the same polarity as the second electrode 220) may be inserted through the through-hole 510 to connect to the second substrate (e.g., the uncoated portion in the winding direction), thereby electrically connecting to the second electrode. By utilizing the space of the through-hole 510 of the electrode assembly and eliminating the need for a separator electrode tab outside the electrode assembly, the energy density of the secondary battery including the electrode assembly can be increased. Furthermore, a structure may be arranged in which a multilayered separator and a second electrode are stacked on the outer surface of the uncoated portion in the winding direction around the through-hole 510, such that the uncoated portion 222a in the winding direction around the through-hole 510 can be stably electrically connected to other components (e.g., electrode tabs, current collectors, etc.).

[0102] Figure 6 The diagram illustrates a process prior to the formation of a through-hole in an electrode assembly according to an embodiment of the present disclosure. Figure 7 A diagram illustrating a through-hole forming an electrode assembly according to an embodiment of the present disclosure is shown. Figure 6 For example, by winding the first electrode (e.g., Figure 2 First electrode 210), second electrode (e.g., Figure 2 The second electrode 220), the first diaphragm (e.g., Figure 2 The first diaphragm 230) and the second diaphragm (e.g., Figure 2 The figure shows the electrode assembly 600 formed by the second diaphragm 240.

[0103] At least a portion of the uncoated portion 610 in the winding direction of the second substrate and a portion of the second diaphragm 620 may be located within the winding core of the electrode assembly. The portion of the uncoated portion 610 and the portion of the second diaphragm 620 may contact the winding core of the electrode assembly and may form an interface 640 passing through the center of the electrode assembly. For example, the interface 640 may be a portion of the uncoated portion 610 in the winding direction and the second diaphragm 620 inserted into the center of the winding device 250. The interface 640 may further include a first diaphragm between the uncoated portion 610 in the winding direction and the second diaphragm 620.

[0104] According to an embodiment, an insert rod can be inserted into the space 630 between the uncoated portions 610 in the winding direction. The insert rod is movable in the diametrical direction of the electrode assembly. As the insert rod moves, the interface 640 can be pushed out to the periphery of the through-hole. The interface 640 can be located at the periphery of the through-hole of the electrode assembly.

[0105] refer to Figure 7 The insertion rod moves in the diametrical direction (e.g., rotates in the diametrical direction), and the through hole 720 can be formed in the winding core of the electrode assembly. Figure 7 For example Figure 5The electrode assembly shown is a wound core. The through-hole 720 may have a circular shape. When the interface is located around the through-hole of the electrode assembly, the uncoated portion 710 in the winding direction may be located around the through-hole 720. The electrode assembly may include a structure in which the uncoated portion in the winding direction, a first diaphragm, and a second diaphragm are stacked in the diaphragm of the through-hole 720.

[0106] In electrode assemblies where only the separator is located around the through-hole, the rigidity of the wound core can be weak. Therefore, the electrode assembly may easily deform when an external impact occurs in the secondary battery including the electrode assembly. However, according to embodiments of this disclosure, because a portion of the second substrate is located around the through-hole 720 of the electrode assembly, the rigidity of the wound core of the electrode assembly can be relatively strong. Therefore, even if the secondary battery including the electrode assembly is subjected to an external impact, the electrode assembly will not easily deform.

[0107] Figure 8 A cross-sectional view is shown as an example of a secondary battery 800 including an inserted current collector 810 according to an embodiment of the present disclosure. Figure 8 The secondary battery 800 may include the same structure as the secondary battery 100 except for the second lead connection piece 160 and the insulating plate 150. Additionally, Figure 8 The secondary battery 800 may include an inserted current collector 810. Figure 8 Redundant descriptions will be omitted, and the description will focus on the inserted current collector 810.

[0108] According to an embodiment, the inserted current collector 810 may have a plate shape (e.g., an inverted "T" shape in the illustrated orientation) and may include a flat portion 812 that contacts the electrode assembly 110. The flat portion 812 may be disposed between the bottom 122 of the housing 120 and the electrode assembly 110. The flat portion 812 may include a conductive material and may be electrically connected to the protrusion 814 and the bottom 122 of the housing 120 that contacts the flat portion 812. At least a portion of the flat portion 812 may include an insulating material. For example, the area of ​​the flat portion 812 that contacts the electrode assembly 110 may include an insulating material. The inserted current collector 810 may include an insulating layer disposed between the flat portion 812 and the electrode assembly 110. Therefore, a short circuit will not occur between the flat portion 812 and the electrode assembly 110.

[0109] According to an embodiment, the inserted current collector 810 may include a protrusion 814 that protrudes from the flat portion 812 and is inserted into the through-hole 116 of the electrode assembly 110. The protrusion 814 may contact an uncoated portion 113a in the winding direction disposed around the periphery of the through-hole 116. The protrusion 814 may include a conductive material and may be electrically connected to the uncoated portion 113a in the winding direction. Accordingly, the protrusion 814 may be electrically connected to the second electrode 113.

[0110] According to an embodiment, the height T1 of the protrusion can be greater than half the height H of the electrode assembly and less than the height H of the electrode assembly. Therefore, the protrusion 814 can be sufficiently electrically connected to the second substrate including the uncoated portion 113a in the winding direction. In addition, the protrusion 814 can prevent the electrode assembly 110 from being exposed to the outside, thereby preventing short circuits from other components inside the secondary battery 800.

[0111] Figure 9 A cross-sectional view is shown as an example of a secondary battery 900 including a housing 910 according to an embodiment of the present disclosure. Figure 9 The secondary battery 900 may include, in addition to Figure 1 The secondary battery 100 has the same structure as the second lead terminal 160, insulating plate 150, and bottom 122 of housing 120. According to an embodiment, the housing 910 of the secondary battery 900 may include a bottom 912, sidewalls 914, and insertion portion 916. The secondary battery 900 may include an insulating plate 920. Figure 9 Redundant descriptions will be omitted, and the description will focus on the insertion part 916 and the insulating plate 920.

[0112] The housing 910 may include a cylindrical sidewall 914 and a bottom 912 connected to one side (e.g., one end) of the sidewall 914. According to an embodiment, the housing 910 may include an insertion portion 916, formed by bending a portion of a surface of the housing 910 toward the interior of the housing 910 to insert into a through-hole 116. The insertion portion 916 may contact an uncoated portion 113a disposed around the periphery of the through-hole 116. The insertion portion 916 may be electrically connected to the uncoated portion 113a to be electrically connected to a second electrode 113. Additionally, the bottom 912 connected to the insertion portion 916 may be electrically connected to the second electrode 113.

[0113] According to an embodiment, an insulating plate 920 may be disposed between the electrode assembly 110 and the bottom 912 of the housing 910. The insulating plate 920 may include an insertion opening through which the insertion portion 916 passes. The bottom 912, which is electrically connected to the second electrode 113, may face the electrode assembly 110 (with the insulating plate 920 between them) and may be insulated from the electrode assembly 110 by means of the insulating plate 920.

[0114] According to an embodiment, the height T2 of the insertion portion may be greater than 1 / 2 (e.g., "half") and less than the height H of the electrode assembly. The insertion portion 916 may be sufficiently electrically connected to a second substrate including the uncoated portion 113a in the winding direction. In addition, the insertion portion 916 may prevent the electrode assembly 110 from being exposed to the outside, thereby preventing short circuits caused (e.g., potentially caused) by other components inside the secondary battery 900.

[0115] As described above, without requiring electrode terminals connected to the second electrode 113 and a separate space for forming the electrode terminals, the second electrode 113 can be formed by using an inserted current collector (e.g., an inserted current collector 810). Figure 8 (in Chinese) and / or Figure 9 The insertion portion 916 is electrically connected to the bottom 912. Therefore, the energy density of the secondary battery 900 can be increased. In addition, without using the electrode terminals connected to the second electrode 113, the internal resistance of the secondary battery 900 can be reduced, and the output of the secondary battery 900 can be increased.

[0116] Figure 10 A flowchart illustrating an example of a method 1000 for manufacturing an electrode assembly according to an embodiment of the present disclosure is provided. The method 1000 for manufacturing an electrode assembly may be performed by an apparatus for manufacturing an electrode assembly. The apparatus for manufacturing an electrode assembly may include a winding device (e.g., Figure 2 The winding device 250 and the insertion rod.

[0117] In step S1010, the electrode assembly manufacturing method 1000 can be started by preparing a first electrode including a first substrate and a first composite portion disposed on the first substrate.

[0118] In step S1020, the electrode assembly manufacturing method 1000 can prepare a second electrode including a second substrate and a second composite portion disposed on the second substrate. The second substrate may extend in the longitudinal direction of the second electrode and includes a winding-direction uncoated portion exposed from the second composite portion.

[0119] In step S1030, the electrode assembly manufacturing method 1000 may provide (e.g., insert) a first diaphragm between the first electrode and the second electrode. The electrode assembly manufacturing method 1000 may further include providing a second diaphragm. The second diaphragm may be provided on the outer surface of the first electrode.

[0120] In step S1040, the electrode assembly manufacturing apparatus can wind the first electrode, the second electrode, and the first diaphragm. Additionally, the electrode assembly manufacturing apparatus can wind the second diaphragm. The leading edge of the uncoated portion in the winding direction can contact the first diaphragm, or the leading edge of the first diaphragm can contact the uncoated portion in the winding direction.

[0121] According to an embodiment, the electrode assembly manufacturing apparatus may insert an insertion rod into the space between uncoated portions in the winding direction. The electrode assembly manufacturing apparatus may move the insertion rod to position at least a portion of the uncoated portions in the winding direction around a through-hole disposed in the winding core of the electrode assembly. In some embodiments, the electrode assembly manufacturing method 1000 may further include: inserting the insertion rod into a through-hole located in the winding core of the electrode assembly.

[0122] According to an embodiment, in the electrode assembly, the uncoated portion in the winding direction and the first diaphragm may be stacked in the diametrical direction around the through hole.

[0123] In the electrode assembly, the first electrode may be located on the outer surface of the first diaphragm, and the second electrode may be located on the inner surface of the first diaphragm.

[0124] In the electrode assembly, the uncoated portion in the winding direction, the first diaphragm, and the second diaphragm can be stacked in the diameter direction around the through hole.

[0125] At least a portion of the second diaphragm may be located on the outer surface of the electrode assembly.

[0126] The leading edge of the first diaphragm can contact the second diaphragm, and the leading edge of the second diaphragm can contact the first diaphragm. Additionally, the leading edge of the uncoated portion in the winding direction can contact the first diaphragm, and the leading edge of the first diaphragm can contact the uncoated portion in the winding direction.

[0127] In the electrode assembly, the first diaphragm and the uncoated portion in the winding direction can be disposed between the inner surface of the second electrode and the outer surface of the first electrode.

[0128] In the electrode assembly, the second diaphragm, the first diaphragm, and the uncoated portion in the winding direction can be disposed between the inner surface of the second electrode and the outer surface of the first electrode, and the second diaphragm can be located in both layers. Alternatively, or in other embodiments, in the electrode assembly, the winding tip of the first diaphragm, the winding tip of the second diaphragm, and the winding tip of the uncoated portion in the winding direction can be disposed between the outer surface of the first electrode and the inner surface of the second electrode.

[0129] The secondary battery may include an electrode assembly and a housing for accommodating the electrode assembly. The secondary battery may further include lead terminals connected to at least a portion of the periphery of a through-hole in the uncoated portion of the winding direction.

[0130] The secondary battery may further include an inserted current collector comprising a flat portion disposed on an electrode assembly and a protrusion extending from the flat portion and inserted into a through-hole, wherein the protrusion of the inserted current collector is available to contact an uncoated portion in the winding direction for electrical connection to a second electrode. For example, the height of the protrusion of the secondary battery may be greater than half the height of the electrode assembly and less than the height of the electrode assembly.

[0131] The housing may include an insertion portion formed by bending a portion of one surface of the housing inward to insert into a through-hole, and the insertion portion of the housing may contact an uncoated portion in the winding direction for electrical connection to a second electrode. For example, the height of the insertion portion may be greater than half the height of the electrode assembly and less than the height of the electrode assembly.

[0132] Figure 10The flowcharts and descriptions above are merely illustrative, and the scope of this disclosure is not limited to... Figure 10 The flowchart and the above description are as follows. For example, one or more steps in the flowchart and the above description may be added / changed / deleted, the order of one or more steps may be changed, and multiple steps may be executed simultaneously.

[0133] The electrode assembly of a secondary battery can be formed by winding positive and negative electrodes. Typically, the area of ​​the winding core of the electrode assembly is formed by a separator, thus exhibiting weak rigidity. Therefore, the electrode assembly may deform due to external impacts to the secondary battery. Additionally, electrode terminals may be formed on the outside of the electrode assembly. However, the problem is that the energy density of the secondary battery is reduced due to the electrode terminals and the space required for them.

[0134] According to various embodiments of this disclosure, the uncoated portion in the winding direction may be part of the second substrate and contact the second electrode and / or the first diaphragm, but not the first electrode. Therefore, a short circuit caused by the uncoated portion in the winding direction will not occur.

[0135] According to various embodiments of this disclosure, the electrode assembly may not include separate electrode terminals on the outside, and the through-hole space of the electrode assembly can be used, thereby increasing the energy density of the secondary battery including the electrode assembly. Additionally, the structure can be arranged by stacking a separator comprising multiple layers and a second electrode on the outer surface of the uncoated portion in the winding direction around the through-hole. Therefore, the uncoated portion in the winding direction around the through-hole can be stably electrically connected to other components (e.g., electrode terminals, current collectors, etc.).

[0136] According to various embodiments of this disclosure, a portion of the second substrate may be disposed around the through-hole, thereby enabling the winding core of the electrode assembly to have relatively high rigidity. Therefore, even if the secondary battery including this electrode assembly is subjected to external impact, the electrode assembly will not easily deform.

[0137] According to various embodiments of this disclosure, instead of providing electrode tabs connected to the second electrode and a separate space for forming the electrode tabs, the second electrode can be electrically connected to the bottom portion using an inserted current collector and / or an insert portion. Therefore, the energy density of the secondary battery can be increased.

[0138] According to various embodiments of this disclosure, the internal resistance of the secondary battery can be reduced without using an electrode tab connected to the second electrode, thereby increasing the output of the secondary battery.

[0139] While this disclosure has been described above with respect to embodiments thereof, it is not limited thereto. Various modifications and variations may be made by those skilled in the art within the spirit of this disclosure and the equivalents of the appended claims.

[0140] Example embodiments have been disclosed herein, and while specific terminology is used, it is used and interpreted in a general and descriptive sense only and is not intended to be limiting. In some cases, 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 expressly stated otherwise. 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. An electrode assembly, comprising: The first electrode includes a first substrate and a first composite portion on the first substrate; The second electrode includes a second substrate and a second composite portion on the second substrate; A first diaphragm is located between the first electrode and the second electrode; as well as The wound core has a through hole. The second substrate extends in the longitudinal direction of the second electrode, and the second substrate includes an uncoated portion in the winding direction exposed from the second composite portion. At least a portion of the uncoated portion in the winding direction is located around the through hole.

2. The electrode assembly of claim 1, wherein the uncoated portion in the winding direction and the first diaphragm are stacked around the periphery of the through hole in the diametrical direction of the electrode assembly.

3. The electrode assembly according to claim 1, wherein: The first electrode is on the outer surface of the first diaphragm, and The second electrode is on the inner surface of the first diaphragm.

4. The electrode assembly of claim 1, further comprising a second diaphragm between the first electrode and the second electrode, wherein the second diaphragm is on the outer surface of the first electrode.

5. The electrode assembly of claim 4, wherein the uncoated portion in the winding direction, the first diaphragm, and the second diaphragm are stacked around the periphery of the through hole in the diametrical direction of the electrode assembly.

6. The electrode assembly of claim 4, wherein at least a portion of the second diaphragm is located on the outer surface of the electrode assembly.

7. The electrode assembly according to claim 4, wherein: The winding tip of the first diaphragm contacts the second diaphragm, or The front end of the second diaphragm is in contact with the first diaphragm.

8. The electrode assembly according to claim 1, wherein: The uncoated portion of the winding direction contacts the first diaphragm, or The winding tip of the first diaphragm contacts the uncoated portion in the winding direction.

9. The electrode assembly of claim 1, wherein the first diaphragm and the uncoated portion in the winding direction are located between the inner surface of the second electrode and the outer surface of the first electrode.

10. The electrode assembly according to claim 4, wherein: The second diaphragm, the first diaphragm, and the uncoated portion in the winding direction are located between the inner surface of the second electrode and the outer surface of the first electrode, and The second diaphragm has a double-layer structure.

11. The electrode assembly of claim 4, wherein the winding tip of the first diaphragm, the winding tip of the second diaphragm, and the winding tip of the uncoated portion in the winding direction are located between the outer surface of the first electrode and the inner surface of the second electrode.

12. A secondary battery, comprising: Electrode assembly according to any one of claims 1 to 11; as well as A housing configured to house the electrode assembly.

13. The secondary battery of claim 12, further comprising a lead terminal piece connected to at least a portion of the uncoated portion in the winding direction around the through hole.

14. The secondary battery of claim 12, further comprising an inserted current collector, the inserted current collector comprising a flat portion contacting the electrode assembly and a protrusion extending from the flat portion and inserted into the through-hole. The protrusion of the inserted current collector is electrically connected to the second electrode by contacting the uncoated portion in the winding direction.

15. The secondary battery of claim 14, wherein the height of the protrusion is greater than half the height of the electrode assembly and less than the height of the electrode assembly.

16. The secondary battery according to claim 12, wherein: The housing includes an insertion portion formed by bending a portion of one surface of the housing toward the interior of the housing to insert it into the through-hole. The insertion portion of the housing is electrically connected to the second electrode by contacting the uncoated portion in the winding direction.

17. The secondary battery of claim 16, wherein the height of the insertion portion is greater than half the height of the electrode assembly and less than the height of the electrode assembly.

18. A method for manufacturing an electrode assembly, the method comprising: A first electrode comprising a first substrate and a first composite portion located on the first substrate is fabricated; A second electrode comprising a second substrate and a second composite portion located on the second substrate is fabricated; A diaphragm is disposed between the first electrode and the second electrode; as well as The first electrode, the second electrode, and the diaphragm are wound together. The second substrate extends in the longitudinal direction of the second electrode, and the second substrate includes an uncoated portion in the winding direction exposed from the second composite portion. The uncoated portion in the winding direction contacts the diaphragm, or the uncoated portion in the winding direction contacts the uncoated portion in the winding direction.

19. The method of claim 18, further comprising: Insert the insertion rod into the through hole located in the winding core of the electrode assembly.

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