Secondary battery

Abstract

Provided is a secondary battery including: an electrode assembly including a first electrode plate, a second electrode plate, and a separator interposed therebetween; a can accommodating the electrode assembly; and a terminal portion including a crimp terminal coupled to one side of the can in the longitudinal direction and electrically connected to the first electrode plate, and an insulator between the can and the crimp terminal to insulate the can from the crimp terminal and having a stepped structure in a region contacting the crimp terminal. By reducing or minimizing a height difference between the positive electrode terminal and the insulator, shape deformation of the electrode assembly can be reduced or prevented during a manufacturing process. By reducing the thickness and weight of the insulator, the size of the electrode assembly can be increased, thereby increasing the capacity of the secondary battery.

Description

[0001] This application claims priority to and the benefit of Korean Patent Application No. 10-2023-0074062 filed in the Korean Intellectual Property Office on June 9, 2023, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0002] Embodiments of the present disclosure relate to a secondary battery having an improved terminal structure. Background Art

[0003] Generally, a cylindrical secondary battery includes a cylindrical electrode assembly, a cylindrical can accommodating the electrode assembly and an electrolyte, and a cap assembly sealing the can. The cap assembly is electrically connected to the electrode assembly and the outside of the secondary battery.

[0004] In a battery module that uses a plurality of cylindrical secondary batteries by modularizing them, bus bars are connected to the upper and lower terminals of the secondary batteries, respectively. Therefore, there is a problem that the battery module may have a complex structure and the process time may be extended. In order to solve these problems, a secondary battery having a structure in which a positive electrode terminal in a riveted form is provided on the side of the can facing the cover assembly may be used. When a riveted terminal is applied, the insulator is adapted to be insulated from the can. In order to increase the battery capacity and improve the battery efficiency in a secondary battery of the same size, it is suitable to accurately design the shape and thickness of the riveted terminal and the insulator.

[0005] The above information disclosed in this Background section is only for enhancement of understanding of the background of the present disclosure and therefore it may contain information that does not constitute prior art. Summary of the invention

[0006] Embodiments of the present disclosure provide a secondary battery having an improved terminal structure.

[0007] A secondary battery according to one or more embodiments of the present disclosure may include: an electrode assembly, including a first electrode plate, a second electrode plate, and a separator disposed between the first electrode plate and the second electrode plate; a can, accommodating the electrode assembly; and a terminal portion, including a riveted terminal coupled to one side of the can in a longitudinal direction and electrically connected to the first electrode plate, and an insulator between the can and the riveted terminal to insulate the can from the riveted terminal and having a step structure in a region contacting the riveted terminal.

[0008] In the insulator, a height of the step structure may be equal to or less than a height of the riveted terminal protruding toward the electrode assembly.

[0009] The can may include an upper surface portion defining a terminal hole, and a side portion extending downward from the upper surface portion, wherein the riveted terminal is in the terminal hole, and wherein the insulator insulates the riveted terminal from the upper surface portion.

[0010] The secondary battery may further include a first electrode collector plate between the riveted terminal and the electrode assembly and electrically connected to the first electrode plate, and a second electrode collector plate facing the first electrode collector plate and electrically connected to the second electrode plate and the side.

[0011] The insulator may include a first insulator insulating the upper surface portion from an outer end of the riveted terminal exposed outside the upper surface portion, a second insulator insulating the terminal hole from the riveted terminal, and a third insulator insulating the first electrode collector plate from an inner end of the riveted terminal located inside the can.

[0012] The third insulator may include a terminal contact portion contacting an inner end of the riveted terminal and a collector plate contact portion contacting the first electrode collector plate.

[0013] The step structure may include a step between the terminal contact portion and the current collector plate contact portion.

[0014] The secondary battery may further include a protrusion protruding on one of the first insulator and the riveted terminal, wherein the other of the first insulator and the riveted terminal defines a receiving groove for receiving the protrusion.

[0015] The secondary battery may further include a cap assembly insulated from the can and coupled to the side.

[0016] A secondary battery according to an embodiment of the present disclosure may include: an electrode assembly including a first electrode plate, a second electrode plate, and a separator between the first electrode plate and the second electrode plate; a can accommodating the electrode assembly and including an upper surface portion defining a terminal hole and a side portion extending downward from the upper surface portion; and a terminal portion including a riveted terminal in the terminal hole and electrically connected to the first electrode plate, and an insulator for insulating the riveted terminal and the upper surface portion, wherein one of the insulators is inside the can and includes a step between a surface facing the electrode assembly and a surface contacting the riveted terminal.

[0017] The secondary battery may further include a first electrode collector plate between the electrode assemblies and electrically connected to the first electrode plate, and a second electrode collector plate adjacent to an end of the side portion and electrically connected to the second electrode plate and the side portion.

[0018] The insulator may include a first insulator insulating an outer end of the riveted terminal exposed to the outside of the upper surface portion from the upper surface portion, a second insulator insulating the terminal hole from the riveted terminal, and a third insulator insulating an inner end of the riveted terminal located inside the can from the first electrode collector plate.

[0019] The third insulator may include a terminal contact portion contacting an inner end of the riveted terminal, a collector plate contact portion contacting the first electrode collector plate, and a first inclined portion connecting the terminal contact portion and the collector plate contact portion.

[0020] The step may have a height between a lower surface of the terminal contact portion and a lower surface of the current collector plate contact portion.

[0021] The step may be less than or equal to a thickness from a lower surface of the terminal contact portion to a lower end of the rivet terminal.

[0022] The third insulator may further include an upper contact portion connected to an outer portion of the collector plate contact portion and contacting the upper surface portion, and a second inclined portion connected between the collector plate contact portion and the upper contact portion.

[0023] The current collector plate contact portion may define a groove.

[0024] The groove may be recessed from a surface of the current collector plate contact portion in a direction toward the electrode assembly.

[0025] The secondary battery may further include a protrusion protruding on one of the first insulator and the riveted terminal, and wherein the other of the first insulator and the riveted terminal is defined with an accommodation groove for accommodating the protrusion.

[0026] The secondary battery may further include a cap assembly coupled to the side and insulated from the can.

[0027] The side portion may include a curling portion inwardly recessed at an upper side of the cap assembly and a crimping portion including an inwardly bent lower end of the side portion, wherein the cap assembly is between the curling portion and the crimping portion.

[0028] The cover assembly may include a cover plate sealing the side portions and a gasket between the cover plate and the side portions.

[0029] An edge of the second electrode current collector plate may be between the beaded portion and the gasket, and may contact the beaded portion. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is a perspective view of a secondary battery according to one or more embodiments of the present disclosure.

[0031] Figure 2 is based on Figure 1 A cross-sectional view of a secondary battery.

[0032] Figure 3 It shows that according to Figure 2 A partial cross-sectional view of the terminal structure.

[0033] Figure 4 It shows that according to Figure 2 A partial perspective view of the terminal structure.

[0034] Figure 5 It shows that according to Figure 4 Perspective view of an insulator.

[0035] Figure 6 is a partial cross-sectional view showing a terminal structure according to one or more other embodiments of the present disclosure. DETAILED DESCRIPTION

[0036] By referring to the detailed description and drawings of the embodiments, it is easier to understand the aspects of some embodiments of the present disclosure and their implementation methods. The described embodiments are provided as examples so that the present disclosure will be thorough and complete, and the aspects of the present disclosure will be fully conveyed to those skilled in the art. Therefore, redundant, irrelevant or unrelated to the description of the embodiments, or processes, elements and techniques that are not necessary for a complete understanding of the various aspects of the present disclosure for those of ordinary skill in the art can be omitted. Unless otherwise noted, in the entire drawings and written descriptions, the same reference numerals, symbols or combinations thereof represent the same elements, and therefore, their repeated descriptions can be omitted.

[0037] The described embodiments may have various modifications and may be implemented in different forms, and should not be construed as being limited to the embodiments shown herein. The use of "may", "may" or "may not" when describing an embodiment corresponds to one or more embodiments of the present disclosure. The present disclosure encompasses all modifications, equivalents and substitutes within the scope of the ideas and techniques of the present disclosure. In addition, the various features of the various embodiments of the present disclosure may be combined with each other in part or in whole, and various interlocks and drives in technology are feasible. Each embodiment may be implemented independently of one another, or may be implemented together in association.

[0038] In the drawings, the relative sizes of elements, layers, and regions may be exaggerated for clarity and / or descriptive purposes. In addition, the use of cross-hatching and / or shading in the drawings is generally provided to clarify the boundaries between adjacent elements. Therefore, unless otherwise specified, the presence or absence of cross-hatching or shading does not convey or indicate any preference or requirement for a particular material, material property, size, ratio, commonality between the illustrated elements, and / or any other characteristic, attribute, property, etc. of an element.

[0039] Various embodiments are described herein with reference to schematically illustrated cross-sectional views as embodiments and / or intermediate structures. Therefore, variations in the shapes of the drawings due to, for example, manufacturing techniques and / or tolerances are to be expected. In addition, for the purpose of describing embodiments according to the concepts of the present disclosure, the specific structural or functional descriptions disclosed herein are merely illustrative. Therefore, the embodiments disclosed herein should not be construed as being limited to the shapes of the elements, layers, or regions shown, but will include deviations in shapes due to, for example, manufacturing.

[0040] For ease of explanation, spatial relative terms such as "under ...", "below ...", "lower", "under ...", "below ...", "above ...", "upper", "upper side", etc. may be used herein to describe the relationship between an element or feature and another (some) element or feature as shown in the figure. It will be understood that, in addition to covering the orientation depicted in the figure, spatial relative terms are also intended to cover different orientations of the device in use or operation. For example, if the device in the figure is turned over, the element described as "under" , "under" or "below" other elements or features will then be oriented to be "above" the other elements or features. Therefore, the example terms "under ..." and "under ..." can cover both upper and lower orientations. The device can be oriented in addition (for example, rotated 90 degrees or in other orientations), and the spatial relative descriptors used herein should be interpreted accordingly. Similarly, when a first part (component) is described as being arranged "on" a second part (component), this indicates that the first part (component) is arranged at the upper or lower side of the second part (component) without being limited to its upper side based on the direction of gravity.

[0041] In addition, the phrase "in a schematic cross-sectional view" means a schematic cross-section taken by vertically cutting a portion of an object when viewed from the side. The term "facing" and its variations may mean that a first object may be directly or indirectly opposite to a second object. In the case where a third object is interposed between the first object and the second object, the first object and the second object may be understood to be indirectly opposite to each other, although still facing each other.

[0042] It will be understood that when an element, layer, region, or component is referred to as being "formed on," "on," "connected to," or "(operably or communicatively) coupled to" another element, layer, region, or component, the element, layer, region, or component may be directly formed on, directly on, directly connected to, or directly coupled to the other element, layer, region, or component, or indirectly formed on, indirectly on, indirectly connected to, or indirectly coupled to the other element, layer, region, or component such that one or more intervening elements, layers, regions, or components may be present. Additionally, this may collectively represent direct or indirect coupling or connection, as well as integral or non-integrated coupling or connection. For example, when a layer, region, or component is referred to as being "electrically connected" or "electrically coupled" to another layer, region, or component, the layer, region, or component may be directly electrically connected or directly electrically coupled to the other layer, region, and / or component, or one or more intermediate layers, regions, or components may be present. One or more intermediate components may include switches, resistors, capacitors, etc. When describing an embodiment, unless explicitly described as being directly connected, the expression of connection includes direct connection and indirect connection, and "directly connected / directly coupled" or "directly on..." means that one component is directly connected or directly coupled to another component, or is directly on another component, without intervening components.

[0043] In addition, in this specification, when a part of a layer, film, region, plate, etc. is formed on another part, the formation direction is not limited to the upper direction, but includes forming the part on the side surface or in the lower direction. On the contrary, when a part of a layer, film, region, plate, etc. is formed "below" another part, this includes not only the case where the part is "directly below" the other part, but also the case where there is another part between the part and the other part. At the same time, other expressions such as "between...", "directly between...", "adjacent to" and "directly adjacent to" that describe the relationship between components can be similarly interpreted. It will be understood that when an element or layer is referred to as "between" two elements or layers, the element or layer can be the only element or layer between the two elements or layers, or one or more intermediate elements or layers may also be present.

[0044] For the purposes of this disclosure, expressions such as "at least one of..." or "any one of..." or "one or more of...", when preceding a list of elements, modify the entire list of elements without modifying the individual elements in the list. For example, "at least one of X, Y, and Z" and "at least one selected from the group consisting of X, Y, and Z" can be interpreted as only X, only Y, only Z, any combination of two or more of X, Y, and Z (such as XYZ, XYY, YZ, and ZZ for example), or any variation thereof. Similarly, the expression "at least one of A and B" may include A, B, or A and B. As used herein, "or" generally means "and / or", and the term "and / or" includes any and all combinations of one or more of the relevant listed items. For example, the expression "A and / or B" may include A, B, or A and B. Similarly, expressions such as "at least one of...", "a plurality of...", "one of...", and other prepositional / postpositional phrases, when preceding / following a list of elements, modify the entire list of elements without modifying the individual elements in the list.

[0045] It will be understood that, although the terms "first", "second", "third", etc. can be used here 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 do not correspond to a specific order, position or superiority, and are only used to distinguish an element, member, component, region, area, layer, section or part from another element, member, component, region, area, layer, section or part. Therefore, without departing from the spirit and scope of the present disclosure, the first element, first component, first region, first layer or first part described below can be referred to as the second element, second component, second region, second layer or second part. Describing an element as a "first" element does not require or imply the presence of a second element or other elements. It is also possible to use the terms "first", "second", etc. to distinguish different categories or sets of elements. For simplicity, the terms "first", "second", etc. can represent "first category (or first set)", "second category (or second set)", etc. respectively.

[0046] The terms used herein are only for the purpose of describing embodiments, and are not intended to limit the present disclosure. As used herein, the singular forms "one" and "an" are also intended to include plural forms, and the plural forms are also intended to include singular forms, unless the context clearly indicates otherwise. It will also be understood that when the terms "include", "have", "comprise" and their variations are used in this specification, the features, integers (entirety), steps, operations, elements and / or components stated are indicated, but the presence or addition of one or more other features, integers (entirety), steps, operations, elements, components and / or their groups are not excluded.

[0047] As used herein, the terms "substantially," "approximately," "approximately," and similar terms are used as terms of approximation rather than terms of degree, and are intended to account for the inherent deviations in measured or calculated values ​​that one of ordinary skill in the art would recognize. For example, "substantially" may include a range of + / - 5% of the corresponding value. As used herein, "approximately" or "approximately" includes the value and means: within an acceptable range of deviations of a particular value as determined by one of ordinary skill in the art, taking into account the measurement in question and the errors associated with the measurement of a particular quantity (i.e., the limitations of the measurement system). For example, "approximately" may mean within one or more standard deviations, or within ±30%, ±20%, ±10%, ±5% of the stated value. In addition, when describing embodiments of the present disclosure, the use of "may" refers to "one or more embodiments of the present disclosure."

[0048] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by those of ordinary skill in the art to which the present disclosure belongs. It will also be understood that terms (such as those defined in general dictionaries) should be interpreted as having a meaning consistent with their meaning in the context of the relevant art and / or in this specification, and should not be interpreted in an idealized or overly formal sense, unless explicitly defined as such herein.

[0049] Hereinafter, a secondary battery according to one or more embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0050] First, refer to Figure 1 and Figure 2 Describe the basic structure of a cylindrical secondary battery.

[0051] Figure 1 is a perspective view of a secondary battery according to one or more embodiments of the present disclosure. Figure 2 is based on Figure 1 A cross-sectional view of a cylindrical secondary battery.

[0052] like Figure 1 and Figure 2 As shown in the figure, a secondary battery 10, which may be a cylindrical secondary battery according to one or more embodiments of the present disclosure, may include a can 100, which may be cylindrical, an electrode assembly 200 accommodated inside the can 100, a first electrode collector plate 300, a second electrode collector plate 400, a terminal portion 500 disposed on one side of the can 100, and a cover assembly 600 disposed on the other side of the can 100.

[0053] like Figure 1As shown in FIG. 1 , the can 100 may include an upper surface portion 110 which may be circular and a side portion 130 which may be cylindrical and extends downward from the upper surface portion 110. Since the lower side of the side portion 130 is open, the can 100 is shaped like a cylinder having an open lower end.

[0054] A terminal hole may be formed through the center of the upper surface part 110. A portion of the terminal part 500 may be exposed to the outside of the secondary battery 10 through the terminal hole.

[0055] The upper end of the side portion 130 is connected to the upper surface portion 110, and therefore, the upper surface portion 110 and the side portion 130 are integrally formed. The lower end of the side portion 130 is open, and the cap assembly 600 is disposed at the open end. The curling portion 132 may be formed adjacent to the bottom of the side portion 130. The curling portion 132 may be formed concavely inwardly from the side portion 130. The end of the side portion 130 spaced apart from the curling portion 132 may be bent toward the inside of the can 100 to form a crimping portion 134. By means of the curling portion 132, the possibility of separation of the electrode assembly 200 may be reduced or prevented. The cap assembly 600 may be located between the curling portion 132 and the crimping portion 134. The crimping portion 134 may seal the can 100 by fixing the cap assembly 600.

[0056] The can 100 having the above structure may be made of steel, steel alloy, aluminum, aluminum alloy or equivalents thereof, but the material is not limited thereto. The electrode assembly 200, the first electrode collector plate 300, and the second electrode collector plate 400 are accommodated in the can 100 together with the electrolyte.

[0057] like Figure 2 As shown in , the electrode assembly 200 may be configured such that the first electrode plate 210, the second electrode plate 220, and the separator 230 disposed between the first electrode plate 210 and the second electrode plate 220 are wound into a cylindrical shape. In one or more embodiments, the first electrode plate 210 may be a positive electrode plate, and the second electrode plate 220 may be a negative electrode plate. In one or more embodiments, the opposite is also possible.

[0058] In the first electrode plate 210, the positive active material layer may be formed on at least one surface of the aluminum (Al) foil by coating or the like. As an example, the positive active material layer may be formed of a transition metal oxide (LiCoO2, LiNiO2, LiMn2O4, etc.). The first electrode uncoated portion on which the positive active material layer is not formed may be disposed at the upper portion of the first electrode plate 210. A plurality of first electrode substrate tabs may be formed by cutting the first electrode uncoated portion into corresponding shapes by notching or the like. In one or more embodiments, the first electrode substrate tab may be positioned toward the upper surface portion 110 of the can 100. In one or more embodiments, the first electrode substrate tab may be electrically connected to the first electrode collector plate 300. As an example, the first electrode substrate tab may be bent in one direction and then may be bonded to the first electrode collector plate 300 by welding, which will be described in detail later.

[0059] In the second electrode plate 220, a negative electrode active material layer may be formed by coating at least one surface of a copper (Cu) or nickel (Ni) foil. As an example, the negative electrode active material layer may be formed of graphite, carbon, etc. The second electrode uncoated portion on which the negative electrode active material layer is not formed may be disposed at the lower portion of the second electrode plate 220. A plurality of second electrode substrate tabs may be formed by cutting the second electrode uncoated portion into corresponding shapes by slotting, etc. In one or more embodiments, the second electrode substrate tab may be positioned toward the lower side of the can 100. In one or more embodiments, the second electrode substrate tab may protrude downward from the separator 230 and may be electrically connected to the second electrode collector plate 400. Some portions of the second electrode substrate tab may be electrically connected to the curling portion 132 of the can 100. As an example, the second electrode substrate tab may be bent in one direction and then may be bonded to the second electrode collector plate 400 by welding.

[0060] The separator 230 may be polyethylene (PE) or polypropylene (PP), but is not limited thereto. The separator 230 may reduce or prevent the possibility of an electrical short circuit between the first electrode plate 210 and the second electrode plate 220, and may allow only lithium ions to move. The separator 230 may have a length sufficient to contact the second electrode collector plate 400 based on the longitudinal direction of the electrode assembly 200, which will be described in detail later.

[0061] The electrode assembly 200 having the above-described structure is electrically connected to the first electrode collector plate 300 and the second electrode collector plate 400 , and is electrically connected to the terminal part 500 and the can 100 , respectively.

[0062] like Figure 2As shown in , the first electrode collector plate 300 has a circular plate shape and may be made of the same material as the first electrode plate 210. As an example, the first electrode collector plate 300 may be made of aluminum or an aluminum alloy. The diameter of the first electrode collector plate 300 may be smaller than the diameter of the can 100, which may reduce or prevent the possibility of the first electrode collector plate 300 being electrically connected to the can 100. The first electrode collector plate 300 may be welded in a state where its lower surface is in contact with the first electrode substrate tab. In one or more embodiments, the first electrode collector plate 300 and the first electrode plate 210 may be electrically connected. In one or more embodiments, the upper surface of the first electrode collector plate 300 may be welded to a riveted terminal 510 of a terminal portion 500 to be described later. In one or more embodiments, the first electrode collector plate 300 and the riveted terminal 510 may be electrically connected. The first electrode current collector plate 300 and the rivet terminal 510 may be electrically connected through the first electrode current collector plate 300 , and the first electrode current collector plate 300 may become a path for current flow between the first electrode plate 210 and the rivet terminal 510 .

[0063] like Figure 2 As shown in , the second electrode collector plate 400 may include a plate surface portion 410 having a circular plate shape and a contact portion 420 extending from the plate surface portion 410. In one or more embodiments, the contact portion 420 is an edge region of the second electrode collector plate 400. The upper surface of the plate surface portion 410 may be welded in a state of contact with the second electrode substrate tab. In one or more embodiments, the second electrode collector plate 400 and the second electrode plate 220 may be electrically connected. To this end, the second electrode collector plate 400 may be made of the same material as the second electrode plate 220. As an example, the second electrode collector plate 400 may be made of copper. In one or more embodiments, the contact portion 420 may extend downward from the edge of the plate surface portion 410. The contact portion 420 may be in close contact with the inner surface of the curling portion 132. To this end, the contact portion 420 may have a curved profile corresponding to the curved profile of the curling portion 132. As an example, the contact portion 420 may be welded to the curling portion 132 and electrically connected to the curling portion 132. In one or more embodiments, the second electrode current collector plate 400 is not electrically connected to the cap assembly 600 .

[0064] In one or more embodiments, Figure 1 and Figure 2 As shown in , the terminal part 500 may include a riveted terminal 510 and at least one insulator 520 , 530 , 540 for insulating the riveted terminal 510 .

[0065] The riveted terminal 510 is inserted into a terminal hole formed in the upper surface portion 110 of the can 100. The riveted terminal 510 is electrically connected to the first electrode plate 210 through the first electrode current collector plate 300. The riveted terminal 510 is a terminal that is coupled to the upper surface portion 110 of the can 100 by a riveting method. The riveted terminal 510 may be inserted into the terminal hole from the outside of the can 100 toward the inside. In one or more embodiments, one end of the riveted terminal 510 is located outside the can 100, and the other end is located inside the can 100. When the riveted terminal 510 is coupled, at least one of the first insulator 520 to the third insulator 540 is interposed between the riveted terminal 510 and the upper surface portion 110 of the can 100 to insulate the can 100 and the riveted terminal 510 from each other. In a state where the riveted terminal 510 is inserted into the terminal hole, the inner end of the riveted terminal 510 is compressed and deformed by a process such as pressing or screwing. In one or more embodiments, the rivet terminal 510 may be in close contact with the upper surface portion 110 of the can 100 .

[0066] As an example, the insulator may include a first insulator 520, a second insulator 530, and a third insulator 540. The first insulator 520, the second insulator 530, and the third insulator 540 may be used without limitation in type as long as they are made of an insulating material.

[0067] The first insulator 520 is located between the outer end of the rivet terminal 510 and the upper surface portion 110 . For example, the first insulator 520 may also have a hollow circular plate shape. The diameter of the first insulator 520 may be greater than the diameter of the outer end of the rivet terminal 510 .

[0068] The second insulator 530 may be shaped to surround the terminal hole formed in the upper surface part 110. In one or more embodiments, around the terminal hole, the second insulator 530 may be shaped to surround the outer and inner surfaces of the upper surface part 110 and the cross section formed with the terminal hole.

[0069] The third insulator 540 is shaped as a hollow circular plate, and is located between the inner surface of the upper surface part 110 and the inner end of the rivet terminal 510 , which will be described later.

[0070] One end of the second insulator 530 may be in close contact with the inner side of the hollow side of the first insulator 520. The other end of the second insulator 530 may be in close contact with the inner side of the hollow side of the third insulator 540. In one or more embodiments, the first insulator, the second insulator, and the third insulator may be integrally formed.

[0071] On the opposite side of the upper surface part 110 where the terminal part 500 having the above-described structure is provided, the cap assembly 600 is provided.

[0072] like Figure 2 As shown in FIG. 6 , the cap assembly 600 may include a cap plate 610 for sealing the can 100 and a gasket 620 for insulating the can 100 and the cap plate 610 from each other.

[0073] The cap plate 610 may include a planar portion 612 having a circular plate shape, an inclined surface 614 connected to the planar portion 612, and an extended surface 616 connected to the inclined surface 614. The planar portion 612 may be positioned approximately parallel to the second electrode current collector plate 400. The inclined surface 614 may extend obliquely downward from the edge of the planar portion 612. The extended surface 616 extends from the edge of the inclined surface 614 and may be parallel to the planar portion 612. The extended surface 616 may be surrounded by a gasket 620 and may be located between the crimping portion 132 and the crimping portion 134. A notch 612a may be formed on the planar portion 612. If the pressure inside the secondary battery 10 exceeds the corresponding pressure, the notch 612a may rupture. If the notch 612a ruptures, the gas inside the secondary battery 10 may be discharged. In one or more embodiments, the notch 612a may be used as a vent.

[0074] The gasket 620 is located between the lower portion of the curling portion 132 and the crimping portion 134, and may cover the extended surface 616 of the cap plate 610. The gasket 620 may cover part or all of the extended surface 616. The side where the gasket 620 contacts the extended surface 616 may be defined as the inner side, and the side where the gasket 620 contacts the curling portion 132 may be defined as the outer side. In one or more embodiments, a portion of the contact portion 420 of the second electrode collector plate 400 may be interposed between the outer upper portion of the gasket 620 and the curling portion 132. In one or more embodiments, the contact portion 420 of the second electrode collector plate 400 and the extended surface 616 of the cap plate 610 do not contact the gasket 620. In one or more embodiments, the gasket 620 may insulate the cap plate 610 and the can 100 from each other, and may insulate the cap plate 610 and the second electrode collector plate 400 from each other.

[0075] By the above configuration, the rivet terminal 510 may have positive polarity and the can 100 may have negative polarity. In one or more embodiments, both the rivet terminal 510 of positive polarity and the upper surface portion 110 of negative polarity may be disposed on the upper side of the can 100 .

[0076] In the following, reference will be made to Figures 3 to 5 The terminal insulation structure of the present disclosure is described in more detail.

[0077] Figure 3 It shows that according to Figure 2 A partial cross-sectional view of the terminal structure. Figure 4 It shows that according to Figure 2A partial perspective view of the terminal structure. Figure 5 It shows that according to Figure 4 Perspective view of an insulator.

[0078] Figure 3 The terminal structure is shown in a state where the rivet terminal 510 faces the upper side of the secondary battery 10 . Figure 4 The terminal structure in a state where the rivet terminal 510 faces the lower side of the secondary battery 10 is shown. Figure 5 Shown based on Figure 4 The direction is the same as the direction of the shape of the third insulator 540.

[0079] Reference Figures 3 to 5 , the third insulator 540 has an approximately circular plate shape and has a certain thickness (e.g., a predetermined thickness). The third insulator 540 may include a terminal contact portion 541 in contact with the riveted terminal 510, a collector plate contact portion 543 in contact with the first electrode collector plate 300, and an upper contact portion 545 in contact with the upper surface portion 110. The terminal contact portion 541 and the collector plate contact portion 543 are connected to the first inclined portion 542. The collector plate contact portion 543 and the upper contact portion 545 are connected to the second inclined portion 544. In one or more embodiments, the terminal contact portion 541, the collector plate contact portion 543, and the upper contact portion 545 have a step or level difference relative to each other. The terminal contact portion 541, the first inclined portion 542, the collector plate contact portion 543, the second inclined portion 544, and the upper contact portion 545 are all formed integrally. A plurality of grooves 546 are formed on the collector plate contact portion 543 (see Figure 4 and 5 ).

[0080] One or more embodiments of the third insulator 540 will be described in greater detail.

[0081] The terminal contact portion 541 is a partial area of ​​the center of the third insulator 540 having a circular plate shape. For example, the terminal contact portion 541 is a circular area having a diameter larger than the inner end diameter of the rivet terminal 510. A terminal hole into which the rivet terminal 510 is inserted is formed in the center of the terminal contact portion 541. Figure 3 When viewed from above, the terminal contact portion 541 is in close contact with the inner surface of the upper surface portion 110. The riveted terminal 510 is combined in a state where the terminal contact portion 541 is in close contact with the upper surface portion 110. The inner end of the riveted terminal 510 is deformed so that the terminal contact portion 541 can be in closer contact with the upper surface portion 110. The first inclined portion 542 is connected to the terminal contact portion 541.

[0082] Since the terminal contact portion 541 is circular, the first inclined portion 542 is located outside the terminal contact portion 541. Figure 3The first inclined portion 542 extends obliquely downward from the edge of the terminal contact portion 541 toward the first electrode current collector plate 300. Figure 4 The first inclined portion 542 extends obliquely upward from the edge of the terminal contact portion 541 . The collector plate contact portion 543 is connected to the edge of the first inclined portion 542 .

[0083] The collector plate contact portion 543 is a portion occupying most of the area of ​​the third insulator 540. The collector plate contact portion 543 has a circular plate shape, and the terminal contact portion 541 is formed at the center of the collector plate contact portion 543. Figure 3 , the collector plate contact portion 543 is positioned at the lower side at a corresponding distance from the upper surface portion 110. Figure 4 , the collector plate contact portion 543 is positioned at the upper side at a distance corresponding to the upper surface portion 110. In one or more embodiments, the collector plate contact portion 543 has a step with the terminal contact portion 541. In one or more embodiments, the collector plate contact portion 543 may be parallel to the terminal contact portion 541 and the upper surface portion 110. In one or more embodiments, as Figure 4 and Figure 5 As shown in , a groove 546 having an approximately fan-shaped shape may be formed on the collector plate contact portion 543. The groove 546 may be formed concavely from the surface in the direction of the first electrode collector plate 300. The groove 546 is provided to reduce the weight of the third insulator 540, and the groove 546 may be omitted. The second inclined portion 544 is connected to the edge of the collector plate contact portion 543.

[0084] Since the collector plate contact portion 543 is circular, the second inclined portion 544 is located outside the collector plate contact portion 543. Figure 3 The second inclined portion 544 extends upwardly and obliquely from the edge of the collector plate contact portion 543 toward the upper surface portion 110. Figure 4 The second inclined portion 544 extends from the edge of the collector plate contact portion 543 at a downward angle. The upper contact portion 545 is connected to the edge of the second inclined portion 544.

[0085] If viewed as a whole, the upper contact portion 545 is a region corresponding to the outer edge of the third insulator 540. Figure 3, the upper contact portion 545 contacts the inner surface of the upper surface portion 110. In one or more embodiments, the upper surface of the upper contact portion 545 may be positioned on the same line as the upper surface of the terminal contact portion 541. In one or more embodiments, this may mean that if the third insulator is observed alone, the upper surface of the upper contact portion is positioned on the same line as the upper surface of the terminal contact portion. In one or more embodiments, this may mean that if the third insulator is bonded to the riveted terminal, the upper surface of the upper contact portion is positioned on the same line as the upper surface of the terminal contact portion. In one or more embodiments, the upper contact portion 545 has a width smaller than the width of the terminal contact portion 541 or the collector plate contact portion 543. As an example, if the radial width of the collector plate contact portion 543 is 100 (e.g., 100 arbitrary units), the radial width of the upper contact portion 545 may be 10 (e.g., 10 arbitrary units). In one or more embodiments, the edge of the third insulator 540 may be formed with only the second inclined portion 544 without the upper contact portion 545.

[0086] The first inclined portion 542 and the second inclined portion 544 described above are structures for connecting the terminal contact portion 541, the collector plate contact portion 543, and the upper contact portion 545 to each other while making the terminal contact portion 541, the collector plate contact portion 543, and the upper contact portion 545 have steps relative to each other. In one or more embodiments, the collector plate contact portion 543 and the upper contact portion 545 may also be used to support the first electrode collector plate 300 during the manufacturing process.

[0087] In this disclosure, based on Figure 3 The step H between the terminal contact portion 541 and the collector plate contact portion 543 is the height between the lower surface of the terminal contact portion 541 and the lower surface of the collector plate contact portion 543 .

[0088] The step between the terminal contact portion 541 and the collector plate contact portion 543 is provided to ensure the installation space for the riveted terminal 510. In one or more embodiments, the step H between the terminal contact portion 541 and the collector plate contact portion 543 is effectively provided. In one or more embodiments, if the step H between the terminal contact portion 541 and the collector plate contact portion 543 is too large (for example, based on Figure 3 , if the collector plate contact portion 543 is positioned too far downward), the collector plate contact portion 543 presses the first electrode collector plate 300 toward the electrode assembly 200, and then the electrode assembly 200 is pressed, resulting in deformation. In order to reduce or prevent this possibility, the step between the terminal contact portion 541 and the collector plate contact portion 543 can be set to be equal to or less than the protruding height of the riveted terminal 510. The protruding height of the riveted terminal 510 means based on Figure 3The thickness of the range from the lower surface of the terminal contact portion 541 to the lower end (lowest part, regardless of position) of the riveted terminal 510 (i.e., the thickness of the lower inner part of the riveted terminal). Even if the step H between the terminal contact portion 541 and the collector plate contact portion 543 is less than the protruding height of the riveted terminal 510, the step H may be appropriately not greater than 0.5 mm. If the step H is too large, the possibility of the riveted terminal 510 contacting the first electrode collector plate 300 is reduced or prevented.

[0089] In one or more embodiments, the terminal structure may include a structure that reduces or prevents the riveted terminal from rotating.

[0090] Figure 6 is a partial cross-sectional view showing a terminal structure according to one or more other embodiments of the present disclosure.

[0091] like Figure 6 As shown in , the riveted terminal 510' may include a protrusion 510a contacting the upper surface of the second insulator 530 at the lower part. As an example, the protrusion 510a may protrude in a circular shape. In one or more embodiments, a plurality of protrusions having, for example, a linear shape, a hemispherical shape, an elliptical shape, or a streamlined shape may be arranged at regular intervals. The second insulator 530' may include a receiving groove 530a shaped to correspond to the above-mentioned protrusion 510a. The protrusion 510a and the receiving groove 530a may be engaged with each other to reduce or prevent the riveted terminal 510' from rotating along the plate surface direction of the upper surface portion 110 when the riveted terminal 510' is coupled to the upper surface portion 110 of the tank 100. In one or more embodiments, the above-mentioned protrusion 510a may be formed on the second insulator 530', and the receiving groove 530a may be formed on the riveted terminal 510'.

[0092] By reducing or minimizing the height difference between the positive terminal and the insulator through the insulator and the terminal structure, the shape deformation of the electrode assembly can be reduced or prevented during the manufacturing process. In one or more embodiments, by reducing the thickness and weight of the insulator, the size of the electrode assembly can be increased and the capacity of the secondary battery can be increased.

[0093] As described above, according to one or more embodiments of the present disclosure, by reducing or minimizing the height difference between the positive terminal and the insulator, shape deformation of the electrode assembly may be reduced or prevented during a manufacturing process.

[0094] In one or more embodiments, by reducing the thickness and weight of the insulator, the size of the electrode assembly may be increased, and the capacity of the secondary battery may be increased.

[0095] Although the foregoing embodiments for carrying out the present disclosure are not particularly limited, those skilled in the art will understand that various changes in form and details may be made therein without departing from the spirit and scope of the present disclosure as defined by the appended claims (which shall include functional equivalents thereof).

Claims

1. A secondary battery, comprising: An electrode assembly, comprising a first electrode plate, a second electrode plate, and a separator disposed between the first electrode plate and the second electrode plate; a tank accommodating the electrode assembly; as well as The terminal part includes: a riveting terminal coupled to one side of the can in the longitudinal direction and electrically connected to the first electrode plate; as well as An insulator is between the can and the rivet terminal to insulate the can from the rivet terminal and has a step structure in a region contacting the rivet terminal.

2. The secondary battery according to claim 1, wherein In the insulator, a height of the step structure is equal to or less than a height of the riveted terminal protruding toward the electrode assembly.

3. The secondary battery according to claim 2, wherein: The can includes an upper surface portion defining a terminal hole and a side portion extending downward from the upper surface portion, Wherein, the riveted terminal is in the terminal hole, and The insulator insulates the rivet terminal from the upper surface portion.

4. The secondary battery according to claim 3, further comprising: a first electrode current collector plate between the riveted terminal and the electrode assembly and electrically connected to the first electrode plate; as well as A second electrode collector plate faces the first electrode collector plate and is electrically connected to the second electrode plate and the side portion.

5. The secondary battery according to claim 4, wherein The insulator comprises: a first insulator that insulates the upper surface portion from an outer end of the rivet terminal that is exposed to the outside of the upper surface portion; a second insulator, insulating the terminal hole from the riveted terminal; and A third insulator insulates the first electrode current collector plate from an inner end of the riveted terminal located inside the can.

6. The secondary battery according to claim 5, wherein The third insulator includes a terminal contact portion contacting the inner end of the rivet terminal and a collector plate contact portion contacting the first electrode collector plate.

7. The secondary battery according to claim 6, wherein The step structure includes a step between the terminal contact portion and the current collector plate contact portion.

8. The secondary battery according to claim 5, further comprising a protrusion protruding on one of the first insulator and the riveted terminal, and wherein, The other of the first insulator and the riveted terminal defines an accommodation groove for accommodating the protrusion.

9. A secondary battery, comprising: An electrode assembly, comprising a first electrode plate, a second electrode plate, and a separator between the first electrode plate and the second electrode plate; a can accommodating the electrode assembly and including an upper surface portion defining a terminal hole and a side portion extending downward from the upper surface portion; and a terminal portion including a riveted terminal in the terminal hole and electrically connected to the first electrode plate and an insulator for insulating the riveted terminal from the upper surface portion, Among them, one of the insulators is inside the can and includes a step between a surface facing the electrode assembly and a surface contacting the riveted terminal.

10. The secondary battery according to claim 9, further comprising: a first electrode current collector plate between the electrode assemblies and electrically connected to the first electrode plate; as well as A second electrode current collector plate is adjacent to an end of the side portion and is electrically connected to the second electrode plate and the side portion.

11. The secondary battery according to claim 10, wherein The insulator comprises: a first insulator that insulates an outer end of the rivet terminal exposed to the outside of the upper surface portion from the upper surface portion; a second insulator, insulating the terminal hole from the riveted terminal; and A third insulator insulates an inner end of the riveted terminal located inside the can from the first electrode collector plate.

12. The secondary battery according to claim 11, wherein The third insulator comprises: a terminal contact portion contacting the inner end of the riveted terminal; a current collector plate contact portion contacting the first electrode current collector plate; and The first inclined portion connects the terminal contact portion and the current collector plate contact portion.

13. The secondary battery according to claim 12, wherein: The step has a height between a lower surface of the terminal contact portion and a lower surface of the collector plate contact portion.

14. The secondary battery according to claim 13, wherein The step is smaller than or equal to a thickness from the lower surface of the terminal contact portion to a lower end of the rivet terminal.

15. The secondary battery according to claim 14, wherein The third insulator further comprises: an upper contact portion connected to an outer side of the collector plate contact portion and contacting the upper surface portion; and The second inclined portion is connected between the collector plate contact portion and the upper contact portion.

16. The secondary battery according to claim 15, wherein The current collector plate contact portion defines a groove.

17. The secondary battery according to claim 11, further comprising a protrusion protruding on one of the first insulator and the riveted terminal, and in, The other of the first insulator and the riveted terminal defines an accommodation groove for accommodating the protrusion.

18. The secondary battery according to claim 10, further comprising a cap assembly coupled to the side portion and insulated from the can, in, The side portion comprises: a curling portion recessed inwardly at an upper side of the cover assembly; and a crimping portion including an inwardly bent lower end of the side portion, and Wherein, the cover assembly is between the curling portion and the crimping portion.

19. The secondary battery according to claim 18, wherein The cover assembly includes a cover plate sealing the side portion and a gasket between the cover plate and the side portion.

20. The secondary battery according to claim 19, wherein An edge of the second electrode current collector plate is between the beaded portion and the gasket and contacts the beaded portion.

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