Secondary battery and method for manufacturing secondary battery

Abstract

A secondary battery and a method of manufacturing the same are provided. The secondary battery includes: an electrode assembly; a case accommodating the electrode assembly; a daughter board assembly coupled to a first side of the electrode assembly; and a cover assembly coupled to the daughter board assembly. The daughter board assembly includes a daughter board connected to the electrode assembly and a current collector bonded to the daughter board, and the case includes a bottom portion, a side portion connected to the bottom portion, and a cover facing the bottom portion. The cover is welded to a side portion of the housing.

Description

Technical Field

[0001] Aspects of embodiments of the present disclosure relate to a secondary battery and a method of manufacturing the secondary battery. Background Art

[0002] Secondary batteries are rechargeable batteries that can be charged and discharged multiple times. These batteries are primarily used in a variety of applications, including electronic products (e.g., smartphones, laptops, and tablets), electric vehicles, solar power generation, and emergency power supplies. For example, lithium (Li)-ion batteries are used in various electronic products and electric vehicles due to their high energy density and high charge and discharge efficiency.

[0003] Secondary batteries can be categorized into cylindrical, prismatic, and pouch-shaped batteries based on the shape of their housings. Prismatic secondary batteries have an electrode assembly embedded in a prismatic metal can. The electrode assembly is inserted into the can, and a cover plate is welded to seal the can. A poor or loose fit between the current collector and the terminal plate can degrade the battery's electrical properties.

[0004] The above information disclosed in this Background section is for enhancement of understanding of the background of the present disclosure and therefore it may contain information that does not constitute related (or prior) art. Summary of the Invention

[0005] An aspect of the present disclosure is to provide a secondary battery and a method of manufacturing the secondary battery, which may be configured to solve at least one of the above-mentioned problems.

[0006] These and other aspects and features of the present disclosure will be described in or will be apparent from the following description of embodiments of the present disclosure.

[0007] According to some embodiments of the present disclosure, a secondary battery includes: an electrode assembly; a shell in which the electrode assembly is accommodated; a sub-plate assembly coupled to a first side of the electrode assembly; and a cover assembly coupled to the sub-plate assembly, wherein the sub-plate assembly includes a sub-plate connected to the electrode assembly and a current collector coupled to the sub-plate, and the shell includes a bottom portion, a side portion connected to the bottom portion, and a cover facing the bottom portion, wherein the cover is welded to the side portion.

[0008] In some embodiments, the current collector includes a planar portion and a protruding portion, and the planar portion and the protruding portion are integral.

[0009] In some embodiments, the housing further includes a first open area and a second open area facing the first open area, and the cover assembly includes: a cover plate covering at least one of the first open area and the second open area; a terminal plate coupled to the cover plate; and a sealing member disposed between the cover plate and the terminal plate.

[0010] In some embodiments, the secondary battery further includes a vent provided in the cover.

[0011] In some embodiments, the secondary battery further includes a vent provided in the bottom portion.

[0012] In some embodiments, the cover includes a first bent portion, and the welding area is defined as an area where the first bent portion and the side portion overlap.

[0013] In some embodiments, the side portion includes a second bend, and the cover and the side portion are welded in a region where the second bend and the cover overlap.

[0014] In some embodiments, the cover includes a step portion overlapping a portion of the side portion, and the step portion is welded to the side portion.

[0015] In some embodiments, the area of the bottom portion is smaller than the area of the side portions.

[0016] According to some embodiments of the present disclosure, a secondary battery includes: an electrode assembly; a shell in which the electrode assembly is accommodated; a sub-plate assembly coupled to a first side of the electrode assembly; and a cover assembly coupled to the sub-plate assembly, wherein the cover assembly includes a terminal plate welded to the sub-plate assembly, and the shell includes a bottom portion, a side portion connected to the bottom portion, and a cover facing the bottom portion, wherein the cover is welded to the side portion.

[0017] In some embodiments, the side portion includes a step portion overlapping a portion of the cover, and the step portion is welded to the cover.

[0018] In some embodiments, the terminal plate includes an upper terminal plate and a lower terminal plate, wherein the upper terminal plate and the lower terminal plate are formed of different materials.

[0019] According to some embodiments of the present disclosure, a method for manufacturing a secondary battery includes the following steps: combining a first sub-plate assembly and a second sub-plate assembly to opposite sides of an electrode assembly; forming a cover-sub-plate electrode assembly by combining a first cover assembly to the first sub-plate assembly and combining the second cover assembly to the second sub-plate assembly; inserting the cover-sub-plate electrode assembly into a shell, wherein the shell includes a first open area, a second open area facing the first open area in a first direction, and a third open area open in a second direction orthogonal to the first direction; and welding the cover positioned in the third open area to the shell.

[0020] In some embodiments, the method further includes welding a first cover assembly positioned in the first open area to the housing and welding a second cover assembly positioned in the second open area to the housing before welding the cover to the housing.

[0021] In some embodiments, the method further includes welding the cover to the first cover assembly and welding the cover to the second cover assembly.

[0022] In some embodiments, the method further includes: welding a first cover assembly positioned in the first open area to the housing; and welding a second cover assembly positioned in the second open area to the housing.

[0023] In some embodiments, the first sub-plate assembly includes a current collector including a protruding portion, and the first cap assembly includes a terminal plate, the method further comprising welding the protruding portion to the terminal plate.

[0024] In some embodiments, the cover includes a vent.

[0025] In some embodiments, the cover includes a first bend, and the step of welding the cover to the housing includes welding overlapping portions of the first bend and a side portion of the housing.

[0026] In some embodiments, the cover includes a second bend, and the step of welding the cover to the housing includes welding the second bend and overlapping portions of the cover.

[0027] According to an embodiment of the present disclosure, the cover may include a stepped portion, and the side portion may include a stepped portion. Due to the stepped shape of the stepped portion, the cover and the side portion can be welded together in an aligned state, thereby reducing defects in the secondary battery and improving the reliability of the secondary battery.

[0028] According to an embodiment of the present disclosure, during the process of forming the cap-subplate electrode assembly, the fit and alignment of the current collector and the terminal plate are checked before performing a welding operation. Therefore, the defect rate of the secondary battery can be reduced and the reliability of the secondary battery can be improved.

[0029] According to an embodiment of the present disclosure, the cover can be manufactured separately from the housing body. Therefore, when the exhaust port is provided on the cover, the difficulty of the manufacturing process can be reduced.

[0030] However, aspects and features of the present disclosure are not limited to the above-mentioned aspects and features, and other aspects and features not mentioned will be clearly understood by those skilled in the art through the detailed description described below. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The accompanying drawings attached to this specification illustrate embodiments of the present disclosure and, together with the detailed description of the present disclosure, further describe aspects and features of the present disclosure. Therefore, the present disclosure should not be interpreted as being limited to the accompanying drawings: Figure 1 shows a perspective view illustrating a secondary battery according to some embodiments of the present disclosure; Figure 2shows a perspective view illustrating a housing according to some embodiments of the present disclosure; Figure 3 shows an exploded perspective view illustrating a housing according to some embodiments of the present disclosure; Figure 4 shows an exploded view illustrating a housing according to some embodiments of the present disclosure; Figure 5 shows an exploded perspective view illustrating a housing according to some embodiments of the present disclosure; Figure 6 shows an exploded view illustrating a housing according to some embodiments of the present disclosure; Figure 7 shows a cross-sectional view illustrating a secondary battery according to some embodiments of the present disclosure; Figure 8 Shown Shown Figure 7 Exploded view of region R1 in ; Figure 9 A first cover assembly according to some embodiments of the present disclosure is shown; Figure 10 Shown Shown Figure 7 Decomposition diagram of region R2 in ; Figure 11 shows a second cover assembly according to some embodiments of the present disclosure; Figures 12 to 14 A method of manufacturing a secondary battery according to some embodiments of the present disclosure is shown; and Figure 15 A flowchart illustrating a method of manufacturing a secondary battery according to some embodiments of the present disclosure is shown. DETAILED DESCRIPTION

[0032] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. The terms or words used in this specification and claims should not be interpreted as limited to the ordinary meaning or dictionary meaning, but should be interpreted as meanings and concepts consistent with the technical concept of the present disclosure based on the principle that the inventor can be his or her own lexicographer to appropriately define the concept of the term in order to best explain his or her invention.

[0033] The embodiments described in this specification and the configurations shown in the accompanying drawings are only some of the embodiments of the present disclosure and do not represent all technical concepts, aspects, and features of the present disclosure. Therefore, it should be understood that there may be various equivalents and modifications that can replace or modify the embodiments described herein when filing this application.

[0034] It will be understood that when an element or layer is referred to as being “on,” “connected to,” or “coupled to” another element or layer, the element or layer can be directly on, directly connected to, or directly coupled to the other element or layer, or one or more intervening elements or layers may be present. When an element or layer is referred to as being “directly on,” “directly connected to,” or “directly coupled to” another element or layer, there are no intervening elements or layers. For example, when a first element is described as being “coupled” to or “connected to” a second element, the first element can be directly coupled to or directly connected to the second element, or the first element can be indirectly coupled to or indirectly coupled to the second element via one or more intervening elements.

[0035] In the figures, the sizes of various elements, layers, etc. may be exaggerated for clarity. Identical reference numerals represent identical elements. As used herein, the term "and / or" includes any and all combinations of one or more of the relevant listed items. In addition, when describing embodiments of the present disclosure, the use of "may" refers to "one or more embodiments of the present disclosure." Phrases such as "at least one of..." and "any of...", when following a list of elements, modify the entire list of elements without modifying the individual elements in that list. 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 refer to a list of elements A, B, and C, the phrase may refer to any and all suitable combinations or subsets of A, B, and C, such as A, B, C, A and B, A and C, B and C, or A, B, and C. As used herein, the term "use" and variations thereof may be considered synonymous with the term "utilize" and variations thereof, respectively. As used herein, the terms "substantially," "approximately," and similar terms are used as terms of approximation rather than as terms of degree, and are intended to account for the inherent variations in measurements or calculations that one of ordinary skill in the art would recognize.

[0036] It will be understood that, although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and / or parts, these elements, components, regions, layers and / or parts should not be limited by these terms. These terms are used to distinguish an element, component, region, layer or part from another element, component, region, layer or part. Therefore, without departing from the teachings of the exemplary 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.

[0037] For ease of description, spatially relative terms such as “under,” “beneath,” “below,” “above,” and “upper,” etc., may be used herein to describe the relationship of one element or feature to another element or feature as shown in the figures. It will be understood that the spatially relative 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 in the figures is turned over, an element described as “under” or “beneath” other elements or features would then be oriented “above” or “above” the other elements or features. Thus, the term “under” can encompass both above and below orientations. The device may be otherwise oriented (rotated 90 degrees or in other orientations), and the spatially relative descriptors used herein should be interpreted accordingly.

[0038] The terms used herein are for the purpose of describing the embodiments of the present disclosure and are not intended to limit the present disclosure. As used herein, unless the context clearly indicates otherwise, the singular forms "a" and "an" are also intended to include the plural forms. It will also be understood that when the terms "comprises," "comprising," and / or variations thereof are used in this specification, the existence of the stated features, wholes, steps, operations, elements, and / or components is indicated, but the existence or addition of one or more other features, wholes, steps, operations, elements, components, and / or groups thereof is not excluded.

[0039] In addition, any numerical range disclosed and / or described herein is intended to include all subranges of the same numerical precision contained within the described range. For example, a range of "1.0 to 10.0" is intended to include all subranges between (and including) the described minimum value of 1.0 and the described maximum value of 10.0, that is, having 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 described herein is intended to include all lower numerical limits contained therein, and any minimum numerical limit described in this specification is intended to include all higher numerical limits contained therein. Therefore, the applicant reserves the right to amend this specification and the claims to expressly describe any subranges contained within the ranges expressly described herein. All such ranges are intended to be inherently described in this specification so that modifications to expressly describe any such subranges will meet the requirements.

[0040] Referring to two compared elements, features, etc. as "the same" may mean that they are "substantially the same." Thus, the phrase "substantially the same" may include situations with what is considered in the art to be low variance (e.g., 5% or less). Additionally, when a parameter is referred to as being uniform in a given area, this may mean that it is uniform with respect to the average value.

[0041] Throughout the specification, unless otherwise specified, each element may be in the singular or in the plural.

[0042] Arranging an arbitrary element “on (or below)” or “on (under)” another element may mean that the arbitrary element may be disposed in contact with the upper (or lower) surface of that element, and another element may also be interposed between that element and the arbitrary element disposed on (or below) that element.

[0043] Additionally, it will be understood that when a component is referred to as being “linked,” “coupled,” or “connected” to another component, these elements may be directly “coupled,” “linked,” or “connected” to each other or another component may be “interposed” between these “components.”

[0044] Throughout this specification, unless otherwise stated, when "A and / or B" is stated, it means A, B, or A and B. That is, "and / or" includes any or all combinations of the multiple listed items. Unless otherwise stated, when "C to D" is stated, it means C or greater and D or less.

[0045] Figure 1 A perspective view illustrating a secondary battery according to some embodiments of the present disclosure is shown.

[0046] Reference Figure 1 , the secondary battery may include an electrode assembly, a first sub-plate assembly, a second sub-plate assembly, a case 200 , a first cap assembly, a second cap assembly, and the like.

[0047] The electrode assembly may be housed in the case 200. The electrode assembly may be provided by stacking (or laminating) or winding a negative electrode plate, a separator, and a positive electrode plate having a shape of a thin plate or a film.

[0048] In some embodiments, the electrolyte inlet 130 may be provided on the first cover plate 360. The electrolyte may be injected into the housing 200 through the electrolyte inlet 130. Figure 1 , the electrolyte inlet 130 is shown as being provided on the first cap plate 360, but is not limited thereto. After the injection of the electrolyte is completed, the electrolyte inlet 130 may be sealed using a sealing device such as a stopper.

[0049] In some embodiments, the cover may be provided with a vent 110. The vent 110 may prevent the secondary battery from exploding or prevent a chain exothermic reaction of adjacently arranged secondary batteries.

[0050] In an example, the vent 110 may be configured to open when the internal pressure of the secondary battery exceeds a predetermined critical pressure. The critical pressure may be set differently depending on the application, material, and purpose of the secondary battery. Alternatively or in another example, the vent 110 may be configured to open when the internal temperature exceeds a predetermined critical temperature.

[0051] exist Figure 1 In the embodiment, the exhaust port 110 is shown as being provided at the center of the cover, but is not limited thereto. Any number of exhaust ports 110 may be provided at any position on the surface of the housing 200. For example, two or more exhaust ports 110 may be provided on the cover.

[0052] The first cover assembly may be coupled to the opened first side of the housing 200. The second cover assembly may be coupled to the opened second side of the housing 200. The shape of the housing 200 will be described in detail below.

[0053] Figure 2 A perspective view illustrating a housing according to some embodiments of the present disclosure is shown. Figure 3 An exploded perspective view illustrating a housing according to some embodiments of the present disclosure is shown.

[0054] Reference Figure 2 and Figure 3 , the housing 200 may include a first open area 210 , a second open area 220 , a bottom portion 250 , a side portion 260 , and a cover 270 .

[0055] The housing 200 may be formed of a conductive metal material such as aluminum (Al), Al alloy, or nickel-plated steel.

[0056] The first direction X may refer to the X-axis direction. The second direction Y may be orthogonal to the first direction X. The second direction Y may refer to the Y-axis direction. The third direction Z may be orthogonal to both the first direction X and the second direction Y. The third direction Z may refer to the Z-axis direction.

[0057] The bottom portion 250 may extend in a first direction X. The first direction X may be a length direction of the housing 200. The bottom portion 250 may face the cover 270 in a third direction Z. The bottom portion 250 and the cover 270 may face each other while being spaced apart in the third direction Z.

[0058] The side portion 260 may be connected to the bottom portion 250. The side portion 260 may be in contact with the cover 270. The area of the bottom portion 250 may be smaller than the area of the side portion 260. The side portion 260 may include a first side portion and a second side portion. The first side portion and the second side portion may face each other. The first side portion and the second side portion may face each other while being spaced apart in the second direction Y.

[0059] The first open area 210 and the second open area 220 may be provided on opposite sides of the housing 200. The first open area 210 may face the second open area 220. The first open area 210 and the second open area 220 may face each other while being spaced apart in the first direction X. Each of the first open area 210 and the second open area 220 may be defined by a bottom portion 250, a side portion 260, and a cover 270.

[0060] In some embodiments, the exhaust port 110 may be provided on the cover 270 , but is not limited thereto. In some embodiments, the exhaust port 110 may be provided on the bottom portion 250 .

[0061] The cover 270 may be coupled to the side portion 260. Specifically, the cover 270 may be coupled to each of the first end of the first side portion and the first end of the second side portion.

[0062] Figure 4 1 shows an exploded view of a housing according to some embodiments of the present disclosure. Figure 4 Shown Shown Figure 2 Exploded view of the Q region in . Figure 4 , the joining operation between the cover 270 and the side portion 260 will be described in detail.

[0063] The cover 270 may include a plate, a first curved portion 275, and a first stepped portion 271. A pair of first curved portions 275 may be provided on opposite edges of the plate. The first curved portion 275 may have a shape that curves from the cover 270 toward the side portion 260. In other words, the first curved portion 275 may have a shape that is rounded from the second direction Y to the third direction Z. The first stepped portion 271 may be provided at the end of the first curved portion 275.

[0064] Each of the side portions 260 may include a second step portion 261. The second step portion 261 may be provided on an end portion of the side portion 260. In order to engage the side portion 260 and the cover 270, the first step portion 271 and the second step portion 261 may be overlapped in the second direction Y. That is, as Figure 4 As shown in , the first stepped portion 271 may have a shape corresponding to the second stepped portion 261 .

[0065] The cover 270 may be welded (and joined) to the side portion 260. Specifically, the first step portion 271 and the second step portion 261 may be welded together. As a result, a first weld region CWR1 may be formed on each of the first step portions 271. The first weld region CWR1 may include a weld bead, etc. The first weld region CWR1 may extend in the first direction X.

[0066] In a secondary battery, the electrode assembly is inserted into a case, which can be sealed by welding a cover. However, if the case and cover are misaligned, they may not engage, resulting in leakage of the electrolyte.

[0067] According to some embodiments of the present disclosure, the cover 270 may include a first stepped portion 271, and the side portion 260 may include a second stepped portion 261. Due to the stepped shapes of the first stepped portion 271 and the second stepped portion 261, the cover 270 and the side portion 260 can be welded together in an aligned state. Therefore, defects in the secondary battery can be reduced, and the reliability of the secondary battery can be improved.

[0068] Figure 5 An exploded perspective view illustrating a housing according to some embodiments of the present disclosure is shown. Figure 6 An exploded view of a housing according to some embodiments of the present disclosure is shown. For ease of description, the following description will focus on the reference Figures 2 to 4 The characteristics described are different from the characteristics.

[0069] Reference Figure 5 and Figure 6 , the cover 270 may include a plate and a third step portion 276. The third step portion 276 may be provided on opposite edges of the plate.

[0070] Each of the side portions 260 may include a second curved portion 265 and a fourth stepped portion 266 at the end. The second curved portion 265 may have a shape that curves from the side portion 260 toward the cover 270. In other words, the second curved portion 265 may have a rounded shape from the third direction Z to the second direction Y. The fourth stepped portion 266 may be provided at the end of the second curved portion 265.

[0071] In order to join the side portion 260 and the cover 270 together, the third step portion 276 and the fourth step portion 266 may be overlapped in the third direction Z. That is, as Figure 6 As shown in , the third stepped portion 276 may have a shape corresponding to the fourth stepped portion 266 .

[0072] The cover 270 may be welded to the side portion 260. Specifically, the third step portion 276 and the fourth step portion 266 may be welded together. As a result, a second weld region CWR2 may be formed on the third step portion 276. Each of the second weld regions CWR2 may include a weld bead, etc. The second weld regions CWR2 may extend in the first direction X.

[0073] In a secondary battery, an electrode assembly may be inserted into a case, and the case may be sealed by welding a cover. However, when the case and the cover are misaligned, the case and the cover may not be joined together, resulting in leakage of electrolyte.

[0074] According to some embodiments of the present disclosure, the cover 270 may include a third stepped portion 276, and the side portion 260 may include a fourth stepped portion 266. Due to the stepped shapes of the third stepped portion 276 and the fourth stepped portion 266, the cover 270 and the side portion 260 can be welded together in an aligned state. Therefore, defects in the secondary battery can be reduced, and the reliability of the secondary battery can be improved.

[0075] Figure 7 1 shows a cross-sectional view of a secondary battery according to some embodiments of the present disclosure. For reference, Figure 7 It can be intercepted on a plane defined by the first direction X and the third direction Z Figure 1 A cross-sectional view of a secondary battery.

[0076] Reference Figure 1 and Figure 7 The secondary battery may include an electrode assembly 100, a case 200 accommodating the electrode assembly 100, a first sub-plate assembly 310, a second sub-plate assembly 410, a first cap assembly 350, and a second cap assembly 450. Here, the case 200 may be the case 200 described above. Figures 2 to 6 The housing 200 is described.

[0077] The electrode assembly 100 can be housed in the housing 200. The electrode assembly 100 can be formed by winding or stacking a laminate comprising a first electrode plate (not shown), a separator (not shown), and a second electrode plate (not shown), each formed from a thin plate or film. If the electrode assembly 100 is a wound laminate, the winding axis can be parallel to the length of the housing 200. The electrode assembly 100 can be a stacked type rather than a wound type, but the shape of the electrode assembly 100 of the present disclosure is not limited to this. The electrode assembly 100 can be a Z-stack electrode assembly in which the positive and negative electrode plates are arranged on opposite sides of a separator bent into a Z-shaped stack. One or more electrode assemblies 100 can be stacked and housed in the housing 200 so that their long sides are adjacent to each other. The present disclosure is not limited to the number of electrode assemblies 100. In the electrode assembly 100, the first electrode plate can serve as the positive electrode, and the second electrode plate can serve as the negative electrode. The reverse is also possible.

[0078] The first electrode plate can be formed by applying a first electrode active material, such as graphite or carbon, to a first electrode current collector plate formed from a metal foil, such as copper (Cu), a Cu alloy, nickel (Ni), or a Ni alloy, and can include a first electrode tab (or a first uncoated portion) as a portion not coated with the first electrode active material. The first electrode tab can be a path for current flow between the first electrode plate and the first sub-plate assembly 310. In some examples, the first electrode tab can be formed by cutting the first electrode plate during manufacture so that the first electrode tab protrudes from the first side, and the first electrode plate can protrude further from the first side than the separator without requiring additional cutting.

[0079] The second electrode plate is formed by applying a second electrode active material, such as a transition metal oxide, to a second electrode current collector plate formed from a metal foil, such as aluminum (Al) or an Al alloy, and may include a second electrode tab (or a second uncoated portion) as a portion not coated with the second electrode active material. The second electrode tab may be a path for current flow between the second electrode plate and the second sub-plate assembly 410. In some examples, the second electrode tab may be formed by cutting the second electrode plate during manufacture so that the second electrode tab protrudes from the second side, and the second electrode plate may protrude from the second side further than the separator without requiring additional cutting.

[0080] In some examples, the first electrode tab may be positioned on the right end side of the electrode assembly, and the second electrode tab may be positioned on the left end side of the electrode assembly. The terms "left" and "right" are used herein for ease of reference relative to Figure 2 The description is made with respect to the secondary battery shown in , and the position may be changed as the secondary battery is rotated left and right or up and down.

[0081] Figure 8 Shown Shown Figure 7 Exploded view of region R1 in .

[0082] Reference Figure 8 , the first sub-plate assembly 310 and the first cap assembly 350 may be coupled to the first side of the electrode assembly 100 .

[0083] The first sub-plate assembly 310 may be coupled to a first side of the electrode assembly 100 and electrically connected to a first electrode plate (eg, a positive electrode plate) of the electrode assembly 100 . The first sub-plate assembly 310 may include a first sub-plate 320 and a first current collector 330 .

[0084] The first sub-plate 320 may be coupled to the first electrode tab of the electrode assembly 100. For example, the first electrode tab may be welded to the first sub-plate 320. The first sub-plate 320 may be connected to the first electrode tab and electrically connected to the first electrode plate.

[0085] The first current collector 330 may be coupled to the first sub-plate 320. For example, the first current collector 330 and the first sub-plate 320 may be welded together. The first current collector 330 and the first sub-plate 320 may be electrically connected to each other.

[0086] The first current collector 330 may include a first planar portion 330_PL and a first protruding portion 330_PR. The first planar portion 330_PL and the first protruding portion 330_PR may be integral. The first planar portion 330_PL may be welded to the first sub-plate 320. The first protruding portion 330_PR may protrude from the first planar portion 330_PL and may have a cylindrical shape, for example.

[0087] The first insulating member 340 may be disposed between the first sub-plate assembly 310 and the first cap assembly 350. The first insulating member 340 may prevent the first sub-plate 320 and the first cap plate 360 from contacting each other.

[0088] The first cap assembly 350 may include a first cap plate 360 , a first sealing member 370 , and a first terminal plate 380 .

[0089] The first sealing member 370 may be coupled to the first cover plate 360. The first cover plate 360 may have a through hole. The first sealing member 370 may provide a seal between the first terminal plate 380 and the first cover plate 360. The first sealing member 370 may include an insulating material. The first sealing member 370 may insulate the first cover plate 360 and the first terminal plate 380 from each other.

[0090] The first terminal plate 380 may be bonded to the surface of the first sealing member 370. The top surface of the first terminal plate 380 may have a depression. For example, the depression may be formed in a portion of the top surface of the first terminal plate 380 that overlaps the first protruding portion 330_PR in the first direction X. The depression causes the thickness of the central portion of the first terminal plate 380 to be smaller than the thickness of other portions.

[0091] The first terminal plate 380 may be a positive electrode terminal of the secondary battery. For example, a bus bar may be welded to a surface of the first terminal plate 380 and electrically connected to another secondary battery.

[0092] In some embodiments, the first terminal plate 380 may have a first hole H1. The first hole H1 may be provided in a recess of the first terminal plate 380. A portion of the top surface of the first protruding portion 330_PR may be exposed through the first hole H1. However, the present disclosure is not limited thereto. For example, the first terminal plate 380 may not be provided with the first hole H1, thereby completely covering the top surface of the first protruding portion 330_PR.

[0093] The first current collector 330 may be coupled to the first terminal plate 380. Specifically, the first protrusion 330_PR may extend through the through-hole of the first sealing member 370 and contact the first terminal plate 380. The first protrusion 330_PR and the first terminal plate 380 may be welded together.

[0094] Figure 9 1 shows a first cover assembly according to some embodiments of the present disclosure. For reference, Figure 9 Can be observed in the first direction X Figure 7 A plan view of a secondary battery.

[0095] Reference Figure 9 , the first terminal welding region DWR1 can be provided on the top surface of the first terminal plate 380. A welding process can be performed in the first terminal welding region DWR1 to join the first terminal plate 380 and the first current collector 330. Therefore, the first current collector 330 and the first terminal plate 380 can be electrically connected. As a result of the welding process, a weld bead or the like can be provided on the first terminal welding region DWR1. The first terminal welding region DWR1 is shown as having a ring shape, but is not limited thereto. The first terminal welding region DWR1 can have any shape that allows the first terminal plate 380 and the first current collector 330 to be welded together.

[0096] Figure 10 Shown Shown Figure 7 Exploded view of region R2 in .

[0097] Reference Figure 10 , the second sub-plate assembly 410 and the second cap assembly 450 may be coupled to the second side of the electrode assembly 100 .

[0098] The second sub-plate assembly 410 may be coupled to a second side of the electrode assembly 100 and electrically connected to a second electrode plate (eg, a negative electrode plate) of the electrode assembly 100 . The second sub-plate assembly 410 may include a second sub-plate 420 and a second current collector 430 .

[0099] The second sub-plate 420 may be coupled to the second electrode tab of the electrode assembly 100. For example, the second electrode tab may be welded to the second sub-plate 420. The second sub-plate 420 may be connected to the second electrode tab and may be electrically connected to the second electrode plate.

[0100] The second current collector 430 may be coupled to the second sub-plate 420. For example, the second current collector 430 and the second sub-plate 420 may be welded together. The second current collector 430 may be electrically connected to the second sub-plate 420.

[0101] The second current collector 430 may include a second planar portion 430_PL and a second protruding portion 430_PR. The second planar portion 430_PL may be welded to the second sub-plate 420. The second protruding portion 430_PR may protrude from the second planar portion 430_PL and may have a cylindrical shape, for example.

[0102] The second insulating member 440 may be disposed between the second sub-board assembly 410 and the second cap assembly 450. The second insulating member 440 may prevent the second sub-board 420 and the second cap plate 460 from contacting each other.

[0103] The second cap assembly 450 may include a second cap plate 460 , a second sealing member 470 , and a second terminal plate 480 .

[0104] The second sealing member 470 may be coupled to the second cover plate 460. The second cover plate 460 may have a through hole. The second sealing member 470 may provide a seal between the second terminal plate 480 and the second cover plate 460. The second sealing member 470 may include an insulating material. The second sealing member 470 may insulate the second cover plate 460 and the second terminal plate 480 from each other.

[0105] The second terminal plate 480 may be coupled to the surface of the second sealing member 470. The second terminal plate 480 may be a negative electrode terminal of the secondary battery. A bus bar may be welded to the surface of the second terminal plate 480 to electrically connect to another secondary battery. For example, the bus bar may be welded to the upper terminal plate 480_UT.

[0106] The second terminal plate 480 may include an upper terminal plate 480_UT and a lower terminal plate 480_LT. The lower terminal plate 480_LT may contact the second sealing member 470. The upper terminal plate 480_UT may be disposed on top of the lower terminal plate 480_LT. That is, the lower terminal plate 480_LT may be disposed between the second sealing member 470 and the upper terminal plate 480_UT.

[0107] The top surface of the second terminal plate 480 may have a recess. The upper terminal plate 480_UT may expose a portion of the lower terminal plate 480_LT. For example, a portion of the lower terminal plate 480_LT may be exposed through the recess in the center portion of the upper terminal plate 480_UT. The recess of the upper terminal plate 480_UT may overlap with the second protruding portion 430_PR in the first direction X. The recess of the upper terminal plate 480_UT may overlap with the second protruding portion 430_PR. Figure 8 The recesses of the first terminal plate 380 have the same shape.

[0108] In some embodiments, the upper terminal plate 480_UT and the lower terminal plate 480_LT can be formed of different materials. The upper terminal plate 480_UT can include, for example, aluminum (Al). The lower terminal plate 480_LT can include, for example, copper (Cu). That is, the upper terminal plate 480_UT can be a conductive material containing Al as a main component, and the lower terminal plate 480_LT can be a conductive material containing Cu as a main component. As used herein, in the language of ordinary skill in the art, the term "main component" refers to the main content material of the alloy material.

[0109] Although the upper terminal plate 480_UT has been described as including Al and the lower terminal plate 480_LT has been described as including Cu, this should be understood as illustrative. In some embodiments, the upper terminal plate 480_UT and the lower terminal plate 480_LT may include other conductive metals.

[0110] In some embodiments, the lower terminal plate 480_LT may include a second hole H2. The second hole H2 may be formed in the lower terminal plate 480_LT and exposed through the upper terminal plate 480_UT. A portion of the top surface of the second protruding portion 430_PR may be exposed through the second hole H2. However, the present disclosure is not limited thereto. For example, the second terminal plate 480 may not be provided with the second hole H2, thereby completely covering the top surface of the second protruding portion 430_PR.

[0111] The second current collector 430 may be coupled to the second terminal plate 480. Specifically, the second protrusion 430_PR may extend through the through-hole of the second sealing member 470 to contact the lower terminal plate 480_LT. The second protrusion 430_PR and the second terminal plate 480 may be welded.

[0112] Figure 11 A second cover assembly according to some embodiments of the present disclosure is shown. For reference, Figure 11 Can be observed in the first direction X Figure 7 A plan view of a secondary battery.

[0113] Reference Figure 11 , the second terminal welding region DWR2 can be provided on the top surface of the lower terminal plate 480_LT. A welding process can be performed in the second terminal welding region DWR2 to join the second terminal plate 480 and the second current collector 430. Thus, the second current collector 430 and the second terminal plate 480 can be electrically connected. As a result of the welding process, a weld bead, etc., can be provided in the second terminal welding region DWR2. The second terminal welding region DWR2 is shown as having a ring shape, but is not limited thereto. The second terminal welding region DWR2 can have any shape, and the second terminal plate 480 and the second current collector 430 are welded together through the second terminal welding region DWR2.

[0114] Figures 12 to 14 A method of manufacturing a secondary battery according to some embodiments of the present disclosure is shown.

[0115] Reference Figure 12 , a cap-sub-plate electrode assembly may be formed by combining the first sub-plate assembly 310 , the second sub-plate assembly, the first cap assembly 350 , and the second cap assembly 450 on the electrode assembly 100 .

[0116] Specifically, the first sub-plate assembly 310 may be coupled to a first side of the electrode assembly 100, and the second sub-plate assembly may be coupled to a second side of the electrode assembly 100. Thereafter, the first cap assembly 350 may be coupled to a surface of the first sub-plate assembly 310, and the second cap assembly 450 may be coupled to a surface of the second sub-plate assembly, thereby forming a cap-sub-plate electrode assembly ( Figure 13 100CS in the box).

[0117] The first sub-plate assembly 310 and the first cover assembly 350 may be welded together to form a first terminal welding region ( Figure 9 Specifically, the first protruding portion ( Figure 8 330_PR) and the first terminal board ( Figure 8 380) are welded together to form a first terminal welding region (DWR1).

[0118] Reference Figure 13 , the cover-sub-plate electrode assembly 100CS can be inserted into the case body 200B.

[0119] The housing body 200B may include a first open area 210, a second open area 220, a third open area 230, a bottom portion 250, and a side portion 260. The description of the first open area 210, the second open area 220, the bottom portion 250, and the side portion 260 may be the same as that of the reference Figure 2 For ease of description, the following description will focus on features that are different from those described above.

[0120] The third open area 230 may be a portion opened in the third direction Z. The third open area 230 may be opposite to the bottom portion 250 in the third direction Z.

[0121] In some embodiments, the side portion 260 may include Figure 5 The second bend 265 in.

[0122] The cap-sub-plate electrode assembly 100CS can be inserted into the case body 200B such that the first cap assembly 350 is positioned in the second open area 220 and the second cap assembly 450 is positioned in the first open area 210. The cap-sub-plate electrode assembly 100CS can be inserted into the case body 200B by moving it in the first direction X or the third direction Z.

[0123] Reference Figure 13 and Figure 14 , the cover 270 can be joined to the surface of the housing body 200B.

[0124] Specifically, the cover 270 may be welded to the third open region 230 of the case body 200B.

[0125] In some embodiments, the cover 270 may include the exhaust port 110, but the present disclosure is not limited thereto. For example, the exhaust port 110 may be provided on the bottom portion 250. Since the cover 270 is manufactured separately from the housing body 200B, when the exhaust port 110 is provided on the cover 270, the manufacturing process may be easier.

[0126] In some embodiments, the cover 270 may include Figure 3 The first bend 275 in the embodiment of the present invention.

[0127] In some embodiments, before welding the cover 270 to the case body 200B, the case body 200B, the first cover assembly 350, and the second cover assembly 450 may be joined. Specifically, the first cover assembly 350 in the second open area 220 may be welded to the case body 200B, and the second cover assembly 450 in the first open area 210 may be welded to the case body 200B. Thereafter, the cover 270 in the third open area 230 may be welded to the case body 200B.

[0128] In some embodiments, the method of joining the cover 270 and the case body 200B in the third open area 230 by welding may include joining the side portion 260 and the cover 270 by welding the cover 270 to each of the first cover assembly 350 and the second cover assembly 450 .

[0129] By incorporating the cover 270 in the third open area 230, it is possible to manufacture Figure 1 of secondary batteries.

[0130] A secondary battery can be manufactured by combining an electrode assembly with a current collector and combining the current collector with a terminal plate. In such a secondary battery manufacturing process, the current collector and the terminal plate may not fit tightly together, which may cause defects during welding and joining operations. For example, when combining the electrode assembly with the current collector and bonding the cover plate to the surface of the housing, it may be impossible to determine whether the terminal plate and the current collector fit tightly together. When the current collector and the terminal plate are not tightly fitted or aligned, the electrical characteristics of the secondary battery may deteriorate.

[0131] Methods for manufacturing secondary batteries according to some embodiments of the present disclosure may include inserting a cover-subplate electrode assembly 100CS into a case body 200B and joining a cover 270 to the case body 200B. Therefore, during the process of forming the cover-subplate electrode assembly 100CS, after checking to ensure a tight fit and alignment between the current collectors (capacitors) 330 and 430 and the terminal plates 380 and 480, welding may be performed. Consequently, the defect rate of the secondary battery may be reduced, and the reliability of the secondary battery may be improved.

[0132] Figure 15 A flowchart illustrating a method of manufacturing a secondary battery according to some embodiments of the present disclosure is shown.

[0133] Reference Figure 15 In step 1310 , each of the first sub-plate assembly and the second sub-plate assembly may be coupled to opposite sides of the electrode assembly, respectively.

[0134] In step 1320 , the first cap assembly may be bonded to the first sub-plate assembly, and the second cap assembly may be bonded to the second sub-plate assembly to form a cap-sub-plate electrode assembly.

[0135] However, the manufacturing method according to the present disclosure is not limited to the above order. In some embodiments, the first sub-plate assembly and the first cap assembly can be coupled to the first side of the electrode assembly, and the second sub-plate assembly and the second cap assembly can be coupled to the second side of the electrode assembly to form a cap-sub-plate electrode assembly.

[0136] In step 1330, the cap-subplate electrode assembly can be inserted into the housing body. The housing body can include a first open area, a second open area, and a third open area. The first cap assembly can be positioned in the first open area. The second cap assembly can be positioned in the second open area.

[0137] In step 1340 , the first cover assembly in the first open area may be coupled to the case body, and the second cover assembly in the second open area may be coupled to the case body.

[0138] Thereafter, the cover and the case body in the third open region may be joined together in step 1350. Specifically, the secondary battery may be manufactured by joining the cover to the side portion of the case body, the first cover assembly, and the second cover assembly through welding.

[0139] Although the present disclosure has been described above with reference to the embodiments of the present disclosure, the present disclosure is not limited thereto, and various modifications and variations may be made by those skilled in the art within the spirit of the present disclosure and the equivalent scope of the appended claims.

[0140] <Description of Reference Signs> 100: Electrode assembly 200: Shell 200B: Housing body 210: First open area 220: Second open area 230: Third open area 250: bottom part 260: side part 265: Second curved portion 270: Cover 275: First bend 310: First sub-board assembly 350: First cover assembly 360: First cover plate 410: Second daughter board assembly 450: Second cover assembly 460: Second cover plate CWR1: First welding area CWR2: Second welding region.

Claims

1. A secondary battery, comprising: electrode assembly; a housing in which the electrode assembly is housed; a daughter plate assembly coupled to the first side of the electrode assembly; as well as a cover assembly, coupled to the daughterboard assembly, wherein the sub-plate assembly includes a sub-plate connected to the electrode assembly and a current collector coupled to the sub-plate, wherein the housing includes a bottom portion, a side portion connected to the bottom portion, and a cover facing the bottom portion, and wherein the cover is welded to the side portion.

2. The secondary battery according to claim 1, wherein The current collector includes a planar portion and a protruding portion, and the planar portion and the protruding portion are integrated.

3. The secondary battery according to claim 1, wherein The housing further includes a first open area and a second open area facing the first open area, and The cap assembly includes: a cap plate covering at least one of the first open area and the second open area; a terminal plate coupled to the cap plate; and a sealing member disposed between the cap plate and the terminal plate. 4 . The secondary battery according to claim 1 , further comprising a vent provided in the cover. 5 . The secondary battery according to claim 1 , further comprising a vent provided in the bottom portion.

6. The secondary battery according to claim 1, wherein The cover includes a first bent portion, and the cover is welded to the side portion in an area where the bent portion and the side portion overlap.

7. The secondary battery according to claim 1, in, The side portion includes a second bend, and the cover and the side portion are welded in a region where the second bend and the cover overlap.

8. The secondary battery according to claim 1, wherein The cover includes a step portion overlapping a portion of the side portion, and the step portion is welded to the side portion.

9. The secondary battery according to claim 1, wherein An area of the bottom portion is smaller than an area of the side portion.

10. A secondary battery, comprising: electrode assembly; a housing in which the electrode assembly is housed; a daughter plate assembly coupled to the first side of the electrode assembly; as well as a cover assembly, coupled to the daughterboard assembly, wherein the cover assembly includes a terminal plate, the terminal plate being welded to the sub-plate assembly, wherein the housing includes a bottom portion, a side portion connected to the bottom portion, and a cover facing the bottom portion, and wherein the cover is welded to the side portion.

11. The secondary battery according to claim 10, wherein The side portion includes a step portion overlapping a portion of the cover, and Wherein, the step portion is welded to the cover.

12. The secondary battery according to claim 10, wherein The terminal plate includes an upper terminal plate and a lower terminal plate, Wherein, the upper terminal plate and the lower terminal plate are formed of different materials.

13. A method for manufacturing a secondary battery, the method comprising the following steps: coupling a first sub-plate assembly and a second sub-plate assembly to opposite sides of the electrode assembly; forming a cap-subplate electrode assembly by bonding a first cap assembly to the first subplate assembly and bonding a second cap assembly to the second subplate assembly; Inserting the cap-subplate electrode assembly into a housing, wherein the housing comprises: a first open area; a second open area facing the first open area in a first direction; and a third open area open in a second direction orthogonal to the first direction; and A cover positioned in the third open area is welded to the housing.

14. The method according to claim 13, further comprising: Before welding the cover to the housing, welding the first cover assembly positioned in the first open area to the housing; as well as The second cover assembly positioned in the second open area is welded to the housing. 15 . The method of claim 14 , further comprising welding the cover to the first cover assembly and welding the cover to the second cover assembly.

16. The method according to claim 13, further comprising: welding the first cover assembly positioned in the first open area to the housing; as well as The second cover assembly positioned in the second open area is welded to the housing.

17. The method according to claim 13, wherein: The first sub-plate assembly includes a current collector including a protruding portion, and the first cap assembly includes a terminal plate, and Wherein, the method further comprises welding the protruding portion to the terminal plate.

18. The method according to claim 13, wherein The cover includes a vent.

19. The method according to claim 13, wherein The cover includes a first bent portion, and The step of welding the cover to the housing includes welding an overlapping portion of the first bent portion and a side portion of the housing.

20. The method according to claim 13, in, The side portion of the housing includes a second curved portion, and The step of welding the cover to the housing includes welding an overlapping portion of the second bent portion and the cover.

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