Electrode assembly, rechargeable battery including the same, and method of manufacturing the same

Abstract

The invention provides an electrode assembly, a rechargeable battery including the same, and a method of manufacturing the same. The electrode assembly includes a first electrode having a first electrode uncoated portion having a convex shape, a second electrode having a second electrode uncoated portion having a convex shape, and a separator disposed between the first electrode and the second electrode, wherein the first electrode uncoated portion includes a first inner tab and a first outer tab separated by a cutting line provided inside the first electrode uncoated portion, and wherein the second electrode uncoated portion includes a second inner tab and a second outer tab separated by a cutting line provided inside the second electrode uncoated portion.

Description

Technical Field

[0001] The present disclosure relates to an electrode assembly, a rechargeable battery including the electrode assembly, and a method of manufacturing the rechargeable battery. Background Art

[0002] Unlike primary batteries, rechargeable batteries are batteries that are repeatedly charged and discharged. Small-capacity rechargeable batteries are used in small portable electronic devices such as mobile phones, laptop computers, and camcorders. Rechargeable batteries with large capacity and high density are used as power sources for driving motors in hybrid and electric vehicles, or for energy storage.

[0003] For example, a rechargeable battery can be formed by stacking multiple positive electrodes, multiple negative electrodes, and multiple separators. The separator is interposed between the positive and negative electrodes, and the positive and negative electrodes are arranged alternately with the separator interposed therebetween. To manufacture a suitable rechargeable battery, the electrodes and separators must be aligned and stacked so that they do not interfere with each other due to matching the centers of the electrodes.

[0004] In modern society where the demand for rechargeable batteries is increasing, a method for manufacturing rechargeable batteries at high speed is needed to improve the supply of rechargeable batteries. Therefore, a method for appropriately stacking electrodes at high speed is needed.

[0005] However, the separator is stacked with the electrodes through a general lamination process, and then a process of fixing the electrodes is performed separately.

[0006] If a process of fixing electrodes is added, additional facilities and additional materials may be required, thereby increasing manufacturing cost and manufacturing time.

[0007] The above information disclosed in the art serving as background of the present disclosure is only for enhancement of understanding of the background of the present disclosure and therefore may contain information that does not constitute prior art. Summary of the Invention

[0008] An embodiment includes an electrode assembly comprising: a first electrode including a first electrode uncoated portion having a convex shape; a second electrode including a second electrode uncoated portion having a convex shape; and a separator disposed between the first electrode and the second electrode, wherein the first electrode uncoated portion includes a first inner tab and a first outer tab separated by a cutting line provided inside the first electrode uncoated portion, and wherein the second electrode uncoated portion includes a second inner tab and a second outer tab separated by a cutting line provided inside the second electrode uncoated portion.

[0009] The protruding direction of the first electrode uncoated portion and the protruding direction of the second electrode uncoated portion may be opposite to each other.

[0010] The first and second external tabs may be bent in directions opposite to bending directions of the first and second inner tabs, respectively.

[0011] Each of the first and second inner tabs may have a semicircular shape.

[0012] Each of the first and second inner tabs may have a quadrilateral shape.

[0013] There may be at least two or more first and second inner tabs each.

[0014] A width of each of the first inner tab and the second inner tab may be greater than or equal to 5 mm, and a width of the first inner tab may be smaller than a width of the second outer tab.

[0015] A width difference between the first outer tab and the first inner tab and a width difference between the second outer tab and the second inner tab may both be 10 mm or less.

[0016] Each of the first electrode, the second electrode, and the separator may be provided in plurality, the first and second electrodes may be alternately stacked along the first direction with the separator interposed therebetween, and the plurality of first electrodes, the plurality of second electrodes, and the plurality of separators may be independent of each other.

[0017] An embodiment includes a rechargeable battery comprising: the electrode assembly described above; a case accommodating the electrode assembly; and a cap assembly including a first electrode terminal electrically connected to the first electrode and a second electrode terminal electrically connected to the second electrode, the cap assembly being coupled to the case to cover and seal an opening of the case, wherein the first electrode terminal may be connected to the first electrode via a first current collecting plate connected to at least one of a first inner tab and a first outer tab and the first electrode terminal, and the second electrode terminal may be connected to the second electrode via a second current collecting plate connected to at least one of a second inner tab and a second outer tab and the second electrode terminal.

[0018] An embodiment includes a method for manufacturing a rechargeable battery, the method comprising: providing the electrode assembly described above; providing a cap assembly including a first electrode terminal, a second electrode terminal, a first current collecting plate connected to the first electrode terminal, and a second current collecting plate connected to the second electrode terminal; connecting the first current collecting plate and the second current collecting plate to at least one of a first inner tab and a first outer tab and at least one of a second inner tab and a second outer tab, respectively; and inserting the electrode assembly into a case having an accommodating space, and coupling the cap assembly to the case to cover an opening of the case so that the cap assembly seals the case.

[0019] However, the effects that can be obtained by the present disclosure are not limited to the above-mentioned effects, and those skilled in the art can clearly understand other technical effects that are not mentioned from the following description of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Features will become apparent to those skilled in the art by describing in detail exemplary embodiments with reference to the accompanying drawings, in which:

[0021] Figure 1 is a perspective view showing a rechargeable battery according to one or more embodiments of the present disclosure;

[0022] Figure 2 is a partially exploded perspective view of a rechargeable battery according to one or more embodiments of the present disclosure;

[0023] Figure 3 It is along Figure 1 A cross-sectional view taken along line III-III is shown;

[0024] Figure 4 is a perspective view of an electrode assembly according to one or more embodiments of the present disclosure;

[0025] Figure 5 (a) is a partial perspective view for describing the structure of the uncoated portion of the first electrode according to one or more embodiments of the present disclosure. Figure 5 (b) is a partial perspective view showing a state in which the first inner tab of the first electrode uncoated portion is bent according to one or more embodiments of the present disclosure;

[0026] Figure 6 is a perspective view showing a state in which an inner tab and an outer tab are bent according to one or more embodiments of the present disclosure;

[0027] Figure 7 (a) is a plan view showing a case where the shape of the first inner tab according to one or more embodiments of the present disclosure is a quadrangular shape, Figure 7 (b) is a plan view showing a case where the shape of the first inner tab is a semicircular shape according to one or more embodiments of the present disclosure, Figure 7 (c) is a plan view showing a case where a plurality of first inner tabs are provided according to one or more embodiments of the present disclosure.

[0028] Figure 8 is a partial plan view for describing width and length intervals of a first outer tab and a first inner tab of an electrode assembly according to one or more embodiments of the present disclosure; and

[0029] Figure 9(a) is a flowchart for describing a method of manufacturing a rechargeable battery using a comparative example, Figure 9 (b) is a flowchart for describing a method of manufacturing a rechargeable battery according to one or more embodiments of the present disclosure. DETAILED DESCRIPTION

[0030] Example embodiments will now be described more fully hereinafter with reference to the accompanying drawings; however, they may be embodied 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 embodiments to those skilled in the art.

[0031] It will also be understood that 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 intervening layers may also be present. Additionally, it will be understood that when a layer is referred to as being “under” another layer, it can be directly under, or one or more intervening layers may also 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 the two layers, or one or more intervening layers may also be present.

[0032] Below, the embodiments of the present disclosure will be described in more detail with reference to the accompanying drawings. The terms or words used in this specification and the claims should not be interpreted as limited to their ordinary meanings or dictionary meanings, but should be interpreted as meanings and concepts that conform to the technical concepts of the present disclosure based on the principle that the inventor can appropriately define the term concepts to describe his or her disclosure in the best way. Therefore, the embodiments described in this specification and the configurations shown in the drawings are merely examples of the present disclosure and do not represent all technical concepts of the present disclosure. Therefore, it should be understood that various equivalents and modifications that can replace the embodiments and configurations at the time of filing this application may exist.

[0033] If used in this specification, the terms "comprise", "include", "comprising..." or "including..." indicate the existence of shapes, numbers, steps, operations, components, elements and / or groups thereof, but do not exclude the existence or addition of one or more other shapes, one or more other numbers, one or more other operations, one or more other components, one or more other elements and / or groups thereof.

[0034] If two objects are described as being identical, this means that the objects are "substantially identical." Thus, substantially identical objects may include objects with a deviation that is considered low in the art (e.g., within 5%). Furthermore, if a certain parameter is described as being uniform in a predetermined area, this may mean that the parameter is uniform in terms of average value.

[0035] Although the terms "first", "second", etc. are used to describe various components, the components are not limited by the terms. The terms are only used to distinguish one component from another component, and unless otherwise specified, the first component may be the second component.

[0036] Throughout the specification, unless otherwise specified, each component may be singular or plural.

[0037] Disposing any component “on (or below)” another component or “on (or below)” another component may not only mean that the component is disposed in contact with the upper surface (or lower surface) of the other component, but also mean that another component may be interposed between the other component and the component disposed on (or below) the other component.

[0038] In addition, if it is described that a component is “connected” or “coupled” to another component, the components may be directly connected or close to each other, but it should be understood that another component may be “interposed” between the components or the components may be “connected” or “coupled” through another component.

[0039] As used in this specification, the term "and / or" includes any and all combinations of one or more of the associated listed items. Additionally, the use of "may" when describing embodiments of the present disclosure refers to "one or more embodiments of the present disclosure." Expressions such as "one or more" preceding a list of components modify the entire list of components, not the individual components in the list.

[0040] Throughout the specification, reference to "A and / or B" means A, B, or A and B unless specifically stated otherwise, and reference to "C to D" means greater than or equal to C and less than or equal to D unless otherwise stated.

[0041] If a phrase 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" is used to specify a list of elements that are A, B, and C, the phrase may refer to all suitable combinations.

[0042] The term "use" may be considered synonymous with the term "utilize." The terms "substantially," "about," and similar terms used in this specification are used as terms of approximation rather than terms of degree, and are intended to take into account the inherent variations in measured or calculated values ​​that those skilled in the art will recognize.

[0043] Although the terms "first," "second," "third," etc. may be used in this specification to describe various elements, components, regions, layers, and / or parts, the elements, components, regions, layers, and / or parts should not be limited by the terms. The terms are only used to distinguish one element, component, region, layer, or part from another element, component, region, layer, or part. Therefore, without departing from the teachings of the embodiments, the "first" element, "first" component, "first" region, "first" layer, or "first" part discussed below may be referred to as the "second" element, "second" component, "second" region, "second" layer, or "second" part.

[0044] For ease of description, spatial relational terms such as "under," "beneath," "below," "above," and "upper" may be used herein to describe the relationship between one element or feature and another element or feature as shown in the figures. It will be understood that the spatial relational terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device shown in the figures is turned over, an element described as "under" or "beneath" another element may be understood to be "above" the other element. Thus, the term "under" may encompass both an above and a below orientation.

[0045] The terms used in this specification are intended to describe the embodiments of the present disclosure but are not intended to limit the present disclosure.

[0046] Figure 1 is a perspective view showing a rechargeable battery according to one or more embodiments of the present disclosure. Figure 2 is a partially exploded perspective view of a rechargeable battery according to one or more embodiments of the present disclosure. Figure 3 It is along Figure 1 A cross-sectional view taken along line III-III is shown.

[0047] Reference Figures 1 to 3 , a rechargeable battery 1000 according to an embodiment of the present disclosure may include an electrode assembly 110 , a first current collecting plate 120 , a second current collecting plate 130 , a case 150 , and a cap assembly 160 .

[0048] The housing 150 may be formed of a conductive metal such as aluminum, an aluminum alloy, or nickel-plated steel, and may have an approximately hexahedral shape having an opening and a housing space in which the electrode assembly 110 may be inserted and placed. For example, the housing 150 may have a hexahedral box shape with at least one side open. The cap assembly 160 may be coupled to the opening of the housing 150 to seal the housing 150. The inner surface of the housing 150 may be insulated to prevent an electrical short circuit from occurring inside the housing 150. In some embodiments, one electrode of the electrode assembly 110 may be electrically connected to the housing 150 via the cap assembly 160. Even in this case, an electrical short circuit inside the housing 150 may be prevented by insulating the interior of the housing 150.

[0049] The cap assembly 160 may be coupled to an upper portion of the housing 150 toward the opening of the housing 150. For example, the cap assembly 160 may include a cap plate 161, an electrolyte injection port 162, a safety vent 163, a first terminal 164, a second terminal 165, a gasket 166, a first terminal plate 167, a second terminal plate 168, a fastening plate 169, and a lower insulating member 170.

[0050] The cap plate 161 may be coupled to the housing 150 to cover the opening of the housing 150 and thereby seal the housing 150. For example, the cap plate 161 may be formed of the same material as the housing 150. The cap plate 161 may be coupled to the housing 150 by, for example, welding (e.g., laser welding). In some embodiments, the cap plate 161 may be electrically independent or may be electrically connected to the first current collecting plate 120 or the second current collecting plate 130.

[0051] An electrolyte injection port 162 for injecting electrolyte may be formed in the cap plate 161. Electrolyte may be injected into the housing 150 through the electrolyte injection port 162, and then the electrolyte injection port 162 may be sealed by a plug 162a (see FIG. Figure 3 ).

[0052] The safety vent 163 may be relatively thin compared to other areas and may be formed at the approximate center of the cap plate 161. If the internal pressure of the case 150 is higher than a predetermined rupture pressure, the safety vent 163 may be broken to prevent the rechargeable battery 1000 from exploding.

[0053] Each of the first terminal 164 and the second terminal 165 may penetrate the cap plate 161. The first terminal 164 may be coupled to a terminal hole formed at the terminal connection portion 125 of the first current collecting plate 120 to be electrically connected to the first current collecting plate 120. Similarly, the second terminal 165 may be coupled to a terminal hole formed at the terminal connection portion 135 of the second current collecting plate 130 to be electrically connected to the second current collecting plate 130.

[0054] The gasket 166 may be provided between the first and second terminals 164 and 165 and the cap plate 161. The gasket 166 may be formed to surround the outer side of each of the first and second terminals 164 and 165 and may be made of an insulating material. The gasket 166 may seal between each of the first and second terminals 164 and 165 and the cap plate 161. The gasket 166 may prevent external moisture from penetrating into the rechargeable battery 1000 or may prevent the electrolyte included in the rechargeable battery 1000 from flowing out.

[0055] The first terminal plate 167 may be coupled to the first terminal 164 and protrude to an upper portion of the cap plate 161. After the first terminal plate 167 is coupled to the first terminal 164, an upper portion of the first terminal 164 may be riveted, or a boundary surface between the first terminal plate 167 and the first terminal 164 may be welded so that the first terminal plate 167 is fixed to the first terminal 164.

[0056] The second terminal plate 168 may be coupled to the second terminal 165 and protrude to an upper portion of the cap plate 161. After the second terminal plate 168 is coupled to the second terminal 165, an upper portion of the second terminal 165 may be riveted, or a boundary surface between the second terminal plate 168 and the second terminal 165 may be welded, so that the second terminal plate 168 is fixed to the second terminal 165.

[0057] The fastening plate 169 may be disposed between the cover plate 161 and the first terminal plate 167 and between the cover plate 161 and the second terminal plate 168. The fastening plate 169 may be formed of a conductive material or an insulating material. For example, the fastening plate 169 disposed below the first terminal plate 167 may be made of a conductive material, and the fastening plate 169 disposed below the second terminal plate 168 may be made of an insulating material. For example, the first terminal 164 may have the same polarity as the cover plate 161. In one or more embodiments, if the fastening plate 169 is made of an insulating material, the first terminal 164 and the second terminal 165 may be electrically isolated from the cover plate 161.

[0058] The lower insulation member 170 may be disposed between the first current collecting plate 120 and the cap plate 161 and between the second current collecting plate 130 and the cap plate 161 , and may electrically insulate between the first and second current collecting plates 120 and 130 and the cap plate 161 .

[0059] The electrode assembly 110 can be formed by stacking a first electrode 111, a separator 113, and a second electrode 115. The first electrode 111 has a thin plate shape or a thin film shape. The first electrode 111 can have a first polarity and can operate as a positive electrode. The second electrode 115 can have a second polarity and can operate as a negative electrode. According to the choice of a person skilled in the art, the first electrode and the second electrode can have different polarities.

[0060] like Figure 2 As shown, a plurality of first electrodes 111, a plurality of separators 113, and a plurality of second electrodes 115 may be stacked. The first electrodes 111 and the second electrodes 115 may be alternately stacked with the separator 113 interposed therebetween, and the first electrodes 111, the second electrodes 115, and the separator 113 may be independent of each other.

[0061] For example, the electrode assembly unit may be formed of one first electrode 111, one second electrode 115, and one separator 113 interposed therebetween. In one or more embodiments, the electrode assembly 110 may be formed by stacking a plurality of electrode assembly units and interposing separators 113 therebetween.

[0062] The first electrode 111 may be formed by applying a first electrode active material such as a transition metal oxide to a first electrode current collector formed of a metal foil such as an aluminum foil, and may include a first electrode uncoated portion 11, which is an area having a convex shape (i.e., it may protrude to the outside of the electrode assembly 110) that is not coated with the first electrode active material. The first electrode uncoated portion 11 may provide a path for current flow between the first electrode 111 and the outside. For example, the first electrode uncoated portion 11 may protrude to the outside of the short side of the electrode assembly to face the length direction of the electrode assembly 110 (e.g., based on the length of the electrode assembly 110). Figure 2 left direction) setting.

[0063] In one or more embodiments, when stacking the first electrodes 111, the first electrode uncoated portions 11 may overlap at the same location, so that the first electrode uncoated portions 11 form a multi-current collecting tab structure. In this embodiment, the first electrode uncoated portion 11 may be formed integrally with the first electrode current collector, or may be provided separately from the first electrode current collector and welded thereto, so that the first electrode uncoated portion 11 forms a current collecting tab. The first electrode uncoated portion 11 may be aligned with and protrude from one side of the electrode assembly 110.

[0064] The second electrode 115 may be formed by applying a second electrode active material such as graphite, carbon, or the like to a second electrode current collector formed of a metal foil such as copper foil or nickel foil, and may include a second electrode uncoated portion 15, which is an area to which the second electrode active material is not applied and may protrude to the outside of the electrode assembly 110.

[0065] When the second electrodes 115 are stacked, the second electrode uncoated portions 15 may overlap at the same position so that the second electrode uncoated portions 15 form a multi-collecting tab structure. The second electrode uncoated portions 15 may protrude outside the short side of the electrode assembly to face the other direction of the length direction of the electrode assembly 110 (e.g., based on the length of the electrode assembly 110). Figure 2 In this embodiment, the second electrode uncoated portion 15 may be formed integrally with the second electrode current collector, or may be provided separately from the second electrode current collector to be welded thereto, so that the second electrode uncoated portion 15 forms a current collecting tab.

[0066] The separator 113 may be provided between the first electrode 111 and the second electrode 115 to prevent short circuits and enable lithium ions to move. The separator 113 may be made of polyethylene, polypropylene, or a composite film of polyethylene and polypropylene. The material of the separator 113 is not limited in the present disclosure.

[0067] For example, after the electrodes 111 and 115 are stacked together with the plurality of separators 113, the electrode assembly 110 may be maintained in the stacked state by a separate insulating tape (not shown) attached to some areas thereof. For example, the insulating tape may maintain the shape of the electrode assembly 110 so that the electrode assembly 110 can be welded to the first and second current collecting plates 120 and 130 at the correct position, and the structure of the electrode assembly 110 may be maintained within the case 150 in the final rechargeable battery.

[0068] The electrode assembly 110 may be substantially housed in the housing 150 together with the electrolyte. The electrolyte may be formed of a lithium salt such as LiPF6 or LiBF4 in an organic solvent such as ethylene carbonate (EC), propylene carbonate (PC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), or dimethyl carbonate (DMC). For example, the electrolyte may have a liquid phase, a solid phase, or a gel phase.

[0069] Collecting plates 120, 130 (see Figure 3 ) may include a first current collecting plate 120 electrically connected to the first electrode non-coating portion 11 and a second current collecting plate 130 electrically connected to the second electrode non-coating portion 15 .

[0070] The first current collecting plate 120 may be made of a conductive material such as aluminum, and may be electrically connected to the first electrode 111 by being coupled to the first electrode uncoated portion 11 protruding from one end of the electrode assembly 110 .

[0071] For example, the first current collecting plate 120 may include an electrode connection portion 121 and a terminal connection portion 125. In one or more embodiments, the electrode connection portion 121 and the terminal connection portion 125 may be coupled to each other by, for example, welding.

[0072] The electrode connection portion 121 may be provided in a vertical direction along one side surface of the electrode assembly 110. The electrode connection portion 121 may be welded in a state where the electrode connection portion 121 contacts the first electrode uncoated portion 11 of the electrode assembly 110 to have the same first polarity as that of the first electrode uncoated portion 11.

[0073] The terminal connection portion 125 may be disposed on an upper portion of the electrode assembly 110 and may be disposed parallel to the cap plate 161. For example, the terminal connection portion 125 may have a substantially flat plate shape and may be disposed between the electrode assembly 110 and the cap plate 161. The terminal connection portion 125 may include a terminal hole, to which the first terminal 164 may be fastened, for example, by riveting. The terminal connection portion 125 may be welded to the electrode connection portion 121 to form a first current collecting plate 120.

[0074] The second current collecting plate 130 may be formed of a conductive material such as nickel, and may be electrically connected to the second electrode 115 by contacting the second electrode uncoated portion 15 protruding from the other end of the electrode assembly 110. The second current collecting plate 130 may include an electrode connecting portion 131 and a terminal connecting portion 135. Since the shape of the second current collecting plate 130 is the same as that of the first current collecting plate 120, redundant description thereof will be omitted for ease of description.

[0075] Figure 4 is a perspective view of an electrode assembly 110 according to one or more embodiments of the present disclosure. Figure 4 The electrode assembly 110 and Figures 1 to 3 The electrode assembly 110 is the same as that of FIG. 1 , so redundant description thereof will be omitted.

[0076] exist Figure 4 and Figure 5In the illustrated xyz coordinate axes (hereinafter, the xyz coordinate axes also apply in other figures), the x-axis may be the length direction of the electrode assembly 110 (e.g., the left direction based on the drawing is the −x-axis direction, and the right direction based on the drawing is the +x-axis direction) or the length direction of the electrode uncoated portions 11 and 15. The y-axis may be a direction perpendicular to the x-axis direction and may be the width direction of the electrode assembly 110 (e.g., the front direction based on the drawing is the y-axis direction, and the rear direction based on the drawing is the −y-axis direction) or the width direction of the electrode uncoated portions 11 and 15. The z-axis may be a direction perpendicular to both the x-axis and y-axis directions and may be the thickness direction of the electrode assembly 110 (e.g., the upper direction based on the drawing is the +z-axis direction, and the lower direction based on the drawing is the −z-axis direction) or the thickness direction of the electrode uncoated portions 11 and 15.

[0077] Reference Figure 4 The first electrode uncoated portion 11 may include a first inner tab 10 disposed inside the first electrode uncoated portion 11 and a first outer tab 20 disposed to surround the first inner tab 10. The width of the first inner tab 10 may be smaller than that of the first electrode uncoated portion 11.

[0078] In one or more embodiments, the first inner tab 10 may be formed by cutting an inner region of the first electrode uncoated portion 11. For example, the first inner tab 10 may be separated from the first outer tab 20 by a cutting line CL provided inside the first electrode uncoated portion 11. A method of cutting the first inner tab 10 inside the first electrode uncoated portion 11 may be a method using laser forming or molding, but the present disclosure is not limited thereto.

[0079] Likewise, the second electrode uncoated portion 15 may include a second inner tab 30 disposed inside the second electrode uncoated portion 15 and a second outer tab 40 disposed to surround the second inner tab 30. The width of the second inner tab 30 may be smaller than that of the second electrode uncoated portion 15.

[0080] Like the first inner tab 10, the second inner tab 30 may be formed by cutting the inner region of the second electrode uncoated portion 15. For example, the second inner tab 30 may be separated from the second outer tab 40 by a cutting line CL provided inside the second electrode uncoated portion 15. The method of forming the second inner tab 30 may be using a laser forming or molding method, but the present disclosure is not limited thereto.

[0081] Figure 5 (a) is a partial perspective view for describing the structure of the first electrode uncoated portion 11 according to one or more embodiments of the present disclosure. Figure 5(b) is a partial perspective view showing a state in which the first inner tab 10 of the first electrode non-coating portion 11 is bent according to one or more embodiments of the present disclosure.

[0082] Reference Figure 5 In (a) and (b), each of the first inner tab 10 and the first outer tab 20 can be bent. For example, the first inner tab 10 can be bent in a clockwise direction (CW) or in a counterclockwise direction (CCW). The first outer tab 20 can be bent in a clockwise direction (CW) or in a counterclockwise direction (CCW).

[0083] However, the bending direction of the first inner tab 10 is different from the bending direction of the first outer tab 20. For example, if the first inner tab 10 is bent in the clockwise direction (CW), the first outer tab 20 may be bent in the counterclockwise direction (CCW); and if the first inner tab 10 is bent in the counterclockwise direction (CCW), the first outer tab 20 may be bent in the clockwise direction (CW).

[0084] The first inner tabs 10 and the first outer tabs 20 of the first electrode uncoated portions 11 of the plurality of first electrodes 111 stacked in this manner may be bent. Any one of the first inner tabs 10 may be bent to overlap with the already bent first inner tab 10. Similarly, any one of the first outer tabs 20 may be bent to overlap with the already bent first outer tab 20.

[0085] For example, as described above, the first inner tabs 10 and the first outer tabs 20 may be bent in opposite directions such that the first inner tabs 10 support each other and the first outer tabs 20 support each other in a state in which all of the first inner tabs 10 and the first outer tabs 20 constituting the plurality of first electrodes of the electrode assembly 110 are finally bent.

[0086] Therefore, the first inner tab 10 and the first outer tab 20 can be made of a bundle-type fixing body without a separate fixing device (or separate fixing means), so that the first electrode 111 or the second electrode 115 can be stacked by matching their centers. For example, the first electrode 111 or the second electrode 115 can be stacked while preventing misalignment of the first electrode 111 or the second electrode 115. A detailed description will be given later.

[0087] Figure 6 1 is a perspective view showing a state in which the first and second inner tabs 10 and 30 and the first and second outer tabs 20 and 40 are bent according to one or more embodiments of the present disclosure. Figure 6, the first inner tab 10 of the first electrode uncoated portion 11 may be bent in the counterclockwise direction CCW, and the first outer tab 20 may be bent in the clockwise direction CW. In one or more embodiments, the second inner tab 30 of the second electrode uncoated portion 15 (at Figure 6 The first inner tab 10 and the second inner tab 30 may be bent in a clockwise direction (CW), and the second outer tab 40 may be bent in a counterclockwise direction (CCW). For example, the bending direction of each of the first inner tab 10 and the second inner tab 30 may be opposite to the bending direction of each of the first outer tab 20 and the second outer tab 40.

[0088] In one or more embodiments, if the first and second inner tabs 10 and 30, as well as the first and second outer tabs 20 and 40, are bent uniformly in one direction without distinguishing between directions, the electrode assembly 110 can be prevented from moving in the lengthwise directions (+x and -x directions). However, in this case, it is difficult to completely prevent the electrode assembly 110 from moving in the widthwise directions (+y and -y directions). For example, the first and second electrodes 111 and 115 may be misaligned in the widthwise direction of the electrode assembly, making it likely that the first and second electrodes 111 and 115 are stacked while being disturbed in the +y or -y directions.

[0089] In one or more embodiments, if the first inner tab 10 and the first outer tab 20 are divided and the two tabs 10 and 20 are as shown in FIG. Figure 6 If the electrode assembly 110 is bent in opposite directions as in the illustrated embodiment, movement of the electrode assembly 110 in the length direction (+x-axis direction and -x-axis direction) can be suppressed, and movement of the electrode assembly 110 in the width direction (+y-axis direction and -y-axis direction) can be prevented because the bundle stack (or bundle laminate) of the first outer tab 20 prevents movement of the bundle stack (or bundle laminate) of the first inner tab 10. Therefore, when the electrode assembly 100 is formed by stacking a plurality of first electrodes 111, a plurality of separators 113, and a plurality of second electrodes 115, the first electrodes 111 and the second electrodes 115 can be stacked so that the centers of the first electrodes 111 and the second electrodes 115 coincide.

[0090] Similarly, the second inner tab 30 of the second electrode uncoated portion 15 can be bent in a direction opposite to the bending direction of the second outer tab 40. For example, the second inner tab 30 can be bent in a clockwise direction (CW), and the second outer tab 40 can be bent in a counterclockwise direction (CCW). The second inner tab 30 and the second outer tab 40 can prevent the electrode assembly 100 from moving in the width direction (+y-axis direction and -y-axis direction) and can also prevent the electrode assembly 100 from moving in the length direction (+x-axis direction and -x-axis direction).

[0091] Since the inner tabs 10 and 30 and the outer tabs 20 and 40 of the electrode uncoated portions 11 and 15 can be bent in opposite directions, the plurality of first electrodes 111 and the plurality of second electrodes 115 can be stacked so that their centers coincide. Therefore, the process of aligning the electrode assembly 110 so that the centers of the first electrodes 111 and the second electrodes 115 coincide again after stacking the first electrodes 111, the separator 113, and the second electrodes 115 can be omitted.

[0092] Since the alignment process (e.g., the fixing process or the misalignment prevention process) of the electrode assembly 110 is omitted, additional processes and materials and additional time may not be required, thereby improving the efficiency of the manufacturing process of the rechargeable battery 1000 including the electrode assembly 110. For example, the cost and time required to manufacture the rechargeable battery 1000 may be reduced.

[0093] The bending direction of each of the first inner tab 10 and the first outer tab 20 of the first electrode uncoated portion 11 and the bending direction of each of the second inner tab 30 and the second outer tab 40 of the second electrode uncoated portion 15 are not limited to the above examples, and the first inner tab 10 can be bent in the clockwise direction CW and the first outer tab 20 can be bent in the counterclockwise direction CCW, the second inner tab 30 can be bent in the counterclockwise direction CCW, and the second outer tab 40 can be bent in the clockwise direction CW.

[0094] In one or more embodiments, the bending direction of the first inner tab 10 can be independent of the bending direction of the second inner tab 30. For example, if the first inner tab 10 is bent in a clockwise direction (CW), the second inner tab 30 can be bent in a clockwise direction (CW) or a counterclockwise direction (CCW). For the first outer tab 20 and the second outer tab 40, the relationship between the bending directions is the same as for the first inner tab 10 and the second inner tab 30. That is, the bending direction of the first outer tab 20 can be independent of the bending direction of the second outer tab 40.

[0095] Figure 7 (a) to (c) are plan views for describing the shape of tabs of the electrode assembly 110 according to one or more embodiments of the present disclosure, and for convenience of description, the first inner tab of the first electrode will be described as an example.

[0096] Reference Figure 7 In (a), the shape of the first inner tab 10a of the first electrode uncoated portion 11 may be a quadrilateral. Since all sides of the first inner tab 10a are straight lines, movement of the electrode assembly 100 in the width direction (+y-axis direction and -y-axis direction) can be more reliably suppressed.

[0097] like Figure 7 As shown in (b) in FIG. 1 , the shape of the first inner terminal tab 10 b may be a semicircular shape. In this case, the bending of the first inner terminal tab 10 b may be easier. Figure 7 As shown in (c) of FIG. 1 , a plurality of first inner tabs 10c may be provided (e.g., two or more). In this case, movement of the electrode assembly 100 in the width direction (+y-axis direction and -y-axis direction) can be more reliably suppressed. While the shape of the inner tab is described as an example of the first inner tab, the shape of the inner tab is not limited to the above and may be any shape within the scope of those skilled in the art.

[0098] Figure 8 is a partial plan view for describing a width difference between a width W1 of a first inner tab 10 and a width W2 of a first outer tab 20 and a length difference between a length L1 of the first inner tab 10 and a length L2 of the first outer tab 20 of an electrode assembly 110 according to one or more embodiments of the present disclosure.

[0099] Reference Figure 8 , the widths W1 and W2 of the first inner tab 10 and the first outer tab 20 of the electrode assembly 110 according to the embodiment of the present disclosure may be set along the y-axis direction, and the lengths L1 and L2 of the first inner tab 10 and the first outer tab 20 may be set along the x-axis direction.

[0100] As the width W1 of the first inner tab 10 increases, movement caused by misalignment between the first and second electrodes in the width direction (y-axis direction) can be prevented. For example, as the width W1 of the first inner tab 10 increases, welding between the first electrode uncoated portion 11 (that is, the first inner tab 10 and / or the first outer tab 20) and the first current collecting plate 120 may become easier.

[0101] In one or more embodiments, the length L1 of the first inner tab 10 may be at least 5 mm or greater. If the length L1 of the first inner tab 10 is less than 5 mm, the misalignment prevention effect of the first and second electrodes may not be significant.

[0102] For example, the length L1 of the first inner tab 10 may be smaller than the length L2 of the first outer tab 20. In one or more embodiments, the length difference between the length L1 of the first inner tab 10 and the length L2 of the first outer tab 20 may be 5 mm to 10 mm.

[0103] If the length difference between the length L1 of the first inner tab 10 and the length L2 of the first outer tab 20 is less than 5 mm, the first inner tab 10 and the first outer tab 20 may not be well separated, and formation of the first inner tab 10 may be difficult. For example, if the length difference between the length L1 of the first inner tab 10 and the length L2 of the first outer tab 20 exceeds 10 mm, the misalignment prevention effect of the first and second electrodes may not be significant.

[0104] Although the reference is described using the first electrode uncoated portion 11 as an example Figure 7 and Figure 8 , but the above description may be equally applicable to the second electrode uncoated portion 15 .

[0105] Figure 9 (a) in FIG. 1 is a flowchart for describing a method of manufacturing a rechargeable battery using a comparative example. Figure 9 (b) is a flowchart for describing a method of manufacturing the rechargeable battery 1000 according to one or more embodiments of the present disclosure.

[0106] Reference Figure 9 In (a), in order to manufacture the rechargeable battery in the comparative example, there are required step S101 of stacking a plurality of first electrodes, a plurality of separators, and a plurality of second electrodes to form an electrode assembly, step S103 of bending an uncoated portion of each of the first electrode and the second electrode, step S105 of aligning and fixing the centers of the first electrode and the second electrode of the electrode assembly so that the centers of the first electrode and the second electrode coincide, and a final step S107 of welding the uncoated portions of the first electrode and the second electrode to the first terminal and the second terminal provided in the cap assembly.

[0107] Reference Figure 9 In (b), the rechargeable battery 1000 according to one or more embodiments of the present disclosure may be manufactured by stacking a plurality of first electrodes 111, a plurality of separators 113, and a plurality of second electrodes 115 to form an electrode assembly 110 (S201), cutting uncoated portions 11 and 15 of the first and second electrodes 111 and 115 to form inner tabs 10 and 30 and outer tabs 20 and 40, respectively, to bend the inner tabs 10 and 30 and the outer tabs 20 and 40 (S203), and welding the electrode uncoated portions 11 and 15 (i.e., the first and second inner tabs 10 and 30 and / or the first and second outer tabs 20 and 40) to the terminals 164 and 165 (S207).

[0108] Therefore, a separate process of aligning and fixing the uncoated portion forming the tab can be omitted when manufacturing the electrode assembly 110. Therefore, the rechargeable battery 1000 can be efficiently manufactured. In addition, the cost and time required to manufacture the rechargeable battery 1000 can be reduced.

[0109] In the embodiments of the present disclosure, a compound capable of reversibly intercalating and deintercalating lithium (i.e., a lithium intercalation compound) can be used as the positive electrode active material constituting the positive electrode active material layer of the positive electrode. For example, one or more composite oxides of lithium and a metal selected from the group consisting of cobalt, manganese, nickel, and combinations thereof can be used as the positive electrode active material.

[0110] The composite oxide may be a lithium transition metal composite oxide, for example, the composite oxide may include a lithium nickel-based oxide, a lithium cobalt-based oxide, a lithium manganese-based oxide, a lithium iron phosphate-based compound, a cobalt-free nickel manganese-based oxide, or a combination thereof.

[0111] As an example, a compound represented by any one of the following chemical formulae can be used as the positive electrode active material. a A 1-b X b O 2-c D c (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05); Li a Mn 2-b X b O 4-c D c (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05); Li a Ni 1-b-c Co b X c O 2-α D α (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.5, 0<α<2); Li a Ni 1-b-c Mn b X c O 2-α D α (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.5, 0<α<2); Li a Ni b Co c L 1 d G e O2 (0.90≤a≤1.8, 0≤b≤0.9, 0≤c≤0.5, 0≤d≤0.5, 0≤e≤0.1); Li aNiG b O2 (0.90≤a≤1.8, 0.001≤b≤0.1); Li a CoG b O2 (0.90≤a≤1.8, 0.001≤b≤0.1); Li a Mn 1-b G b O2 (0.90≤a≤1.8, 0.001≤b≤0.1); Li a Mn2G b O4 (0.90≤a≤1.8, 0.001≤b≤0.1); Li a Mn 1- g G g PO4 (0.90≤a≤1.8, 0≤g≤0.5); Li (3-f) Fe2(PO4)3 (0≤f≤2); and Li a FePO4 (0.90≤a≤1.8).

[0112] In the above chemical formula, A can be Ni, Co, Mn or a combination thereof; X can be Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, a rare earth element or a combination thereof; D can be O, F, S, P or a combination thereof; G can be Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V or a combination thereof; L 1 It may be Mn, Al or a combination thereof.

[0113] The positive electrode according to the embodiment may include a positive electrode current collector, a positive electrode active material layer is provided at the positive electrode current collector, and the positive electrode active material layer may include a binder and / or a conductive material.

[0114] The positive electrode active material may be included in an amount of 90 to 99.5 wt % based on 100 wt % of the positive electrode active material layer, and each of the binder and the conductive material may be included in an amount of 0.5 to 5 wt % based on 100 wt % of the positive electrode active material layer.

[0115] Aluminum (Al) may be used as the positive electrode current collector, but the present disclosure is not limited thereto.

[0116] In one or more embodiments of the present disclosure, the negative electrode active material constituting the negative electrode active material layer of the negative electrode may include a material capable of reversibly inserting and extracting lithium ions, lithium metal, an alloy of lithium metal, a material capable of doping and dedoping lithium, or a transition metal oxide.

[0117] For example, materials capable of reversibly inserting and extracting lithium ions may include carbon-based negative electrode active materials (e.g., crystalline carbon, amorphous carbon, or a combination thereof). Examples of crystalline carbon may include graphite, such as natural graphite or artificial graphite, and examples of amorphous carbon may include soft carbon, hard carbon, mesophase pitch carbide, calcined coke, etc.

[0118] A Si-based negative electrode active material or a Sn-based negative electrode active material may be used as a material capable of doping and de-doping lithium. The Si-based negative electrode active material may be silicon, a silicon-carbon composite, SiOx (0 < x < 2), a Si-based alloy, or a combination thereof.

[0119] The silicon-carbon composite may be a composite of silicon and amorphous carbon. According to an embodiment, the silicon-carbon composite may have a form in which amorphous carbon is coated on the surface of silicon particles.

[0120] The silicon-carbon composite may further include crystalline carbon. For example, the silicon-carbon composite may include a core containing crystalline carbon and silicon particles and an amorphous carbon coating layer provided on the surface of the core.

[0121] According to an embodiment, the negative electrode may include a negative electrode current collector where a negative electrode active material layer is provided, and the negative electrode active material layer may include a binder and / or a conductive material.

[0122] For example, based on 100 wt% of the negative electrode active material, the negative electrode active material layer may contain 90 wt% to 99 wt% of the negative electrode active material, 0.5 wt% to 5 wt% of the binder, and 0 wt% to 5 wt% of the conductive material.

[0123] A non-aqueous binder, an aqueous binder, a dry binder, or a combination thereof may be used as the binder. If an aqueous binder is used as the binder, it may further include a cellulose-based compound capable of imparting viscosity.

[0124] The negative electrode current collector may be selected from copper foil, nickel foil, stainless steel foil, titanium foil, nickel foam, copper foam, a polymer substrate coated with a conductive metal, and combinations thereof.

[0125] The electrolyte for a lithium rechargeable battery may include a non-aqueous organic solvent and a lithium salt.

[0126] The non-aqueous organic solvent may serve as a medium through which ions involved in the electrochemical reaction of the battery can move.

[0127] The non-aqueous organic solvent may be a carbonate-based solvent, an ester-based solvent, an ether-based solvent, a ketone-based solvent, an alcohol-based solvent, an aprotic solvent, or a combination thereof, and the materials may be used alone or in combination of two or more.

[0128] If a carbonate-based solvent is used, a mixture of cyclic carbonates and chain carbonates may be used.

[0129] Depending on the type of lithium rechargeable battery, a separator may be present between the positive electrode and the negative electrode. Polyethylene, polypropylene, polyvinylidene fluoride, or a multilayer film having two or more layers thereof may be used as the separator.

[0130] The separator may include a porous substrate and a coating layer including an organic material, an inorganic material, or a combination thereof provided on one surface or both surfaces of the porous substrate.

[0131] The organic material may include a polyvinylidene fluoride-based polymer or a (meth)acryl-based polymer.

[0132] The inorganic material may include inorganic particles selected from Al2O3, SiO2, TiO2, SnO2, CeO2, MgO, NiO, CaO, GaO, ZnO, ZrO2, Y2O3, SrTiO3, BaTiO3, Mg(OH)2, boehmite, and combinations thereof, but the present disclosure is not limited thereto.

[0133] The organic material and the inorganic material may be mixed in one coating layer, or a coating layer including an organic material and a coating layer including an inorganic material may be stacked.

[0134] The present disclosure provides an electrode assembly configured to not require separate electrode fixation when manufacturing an electrode assembly for a rechargeable battery.

[0135] Although the present disclosure has been described above through limited embodiments and drawings, the present disclosure is not limited thereto, and various modifications and changes may be made by those skilled in the art within the technical idea of ​​the present disclosure and the equivalent scope of the claims.

[0136] Example embodiments have been disclosed herein, and although specific terms are employed, they are used and interpreted in a general and descriptive sense only and not for purposes of limitation. In some cases, as will be apparent to one of ordinary skill in the art upon filing this application, features, characteristics, and / or elements described in conjunction with a particular embodiment may be used alone or in combination with features, characteristics, and / or elements described in conjunction with other embodiments, unless otherwise specifically stated. Therefore, it will be understood by those skilled in the art 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.

[0137] <Description of Symbols>

[0138] 10: First inner terminal piece

[0139] 11: Uncoated portion of the first electrode

[0140] 15: Uncoated portion of the second electrode

[0141] 20: First external terminal

[0142] 30: Second inner terminal piece

[0143] 40: Second external terminal

[0144] 110: Electrode assembly

[0145] 111: First electrode

[0146] 113: Diaphragm

[0147] 115: Second electrode

[0148] 120: First collector plate

[0149] 130: Second collector plate

[0150] 150: Shell

[0151] 160: Cover assembly

[0152] 1000: Rechargeable battery

[0153] W1: Width of the first inner lug

[0154] W2: Width of the first external terminal

[0155] L1: Length of the first inner lug

[0156] L2: Length of the first external terminal

Claims

1. An electrode assembly comprising: a first electrode including a first electrode uncoated portion having a convex shape; a second electrode including a second electrode uncoated portion having a convex shape; and a separator disposed between the first electrode and the second electrode, wherein the first electrode uncoated portion includes a first inner tab and a first outer tab separated by a cutting line provided inside the first electrode uncoated portion, and wherein the second electrode uncoated portion includes a second inner tab and a second outer tab separated by a cutting line provided inside the second electrode uncoated portion.

2. The electrode assembly according to claim 1, wherein A protruding direction of the first electrode uncoated portion and a protruding direction of the second electrode uncoated portion are opposite to each other.

3. The electrode assembly according to claim 1, wherein The first outer tab and the second outer tab are bent in directions opposite to bending directions of the first inner tab and the second inner tab, respectively.

4. The electrode assembly according to claim 1, wherein Each of the first inner tab and the second inner tab has a semicircular shape.

5. The electrode assembly according to claim 1, wherein Each of the first inner tab and the second inner tab has a quadrilateral shape.

6. The electrode assembly according to claim 1, wherein There are at least two or more first inner tabs and at least two or more second inner tabs.

7. The electrode assembly according to claim 1, wherein A width of each of the first inner tab and the second inner tab is greater than or equal to 5 mm, and a width of the first inner tab is smaller than a width of the second outer tab.

8. The electrode assembly according to claim 7, wherein: A width difference between the first outer tab and the first inner tab and a width difference between the second outer tab and the second inner tab are both 10 mm or less.

9. The electrode assembly according to claim 1, wherein Each of the first electrode, the second electrode, and the separator is provided in plurality, the first electrodes and the second electrodes are alternately stacked in a first direction with the separator interposed therebetween, and the plurality of first electrodes, the plurality of second electrodes, and the plurality of separators are independent of each other.

10. A rechargeable battery comprising: The electrode assembly according to claim 1; a shell for accommodating the electrode assembly; and a cap assembly including a first electrode terminal electrically connected to the first electrode and a second electrode terminal electrically connected to the second electrode, the cap assembly being coupled to the case to cover and seal an opening of the case, wherein the first electrode terminal is connected to the first electrode through a first current collecting plate, the first current collecting plate is connected to the first electrode terminal and at least one of the first inner tab and the first outer tab, and the second electrode terminal is connected to the second electrode through a second current collecting plate, the second current collecting plate is connected to at least one of the second inner tab and the second outer tab and the second electrode terminal.

11. A method for manufacturing a rechargeable battery, the method comprising: Providing the electrode assembly according to claim 1; providing a cap assembly including a first electrode terminal, a second electrode terminal, a first current collecting plate connected to the first electrode terminal, and a second current collecting plate connected to the second electrode terminal; connecting the first current collecting plate and the second current collecting plate to at least one of the first inner tab and the first outer tab and at least one of the second inner tab and the second outer tab, respectively; and The electrode assembly is inserted into a case having an accommodation space, and the cap assembly is coupled to the case to cover an opening of the case so that the cap assembly seals the case.

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