Cap assembly and secondary battery comprising same

Abstract

The present disclosure provides a cap assembly and a secondary battery comprising same. The cap assembly may comprise: a base plate having a through-hole; a terminal part having a diameter smaller than that of the through-hole and disposed in the through-hole; and an insulating part disposed between the outer circumferential surface of the terminal part and the inner circumferential surface of the through-hole and coupling the terminal part and the base plate.

Description

Cap assembly and secondary battery including the same

[0001] The present disclosure relates to a cap assembly and a secondary battery comprising the same.

[0002]

[0003] Unlike primary batteries, which cannot be recharged, secondary batteries are batteries capable of both charging and discharging. Low-capacity secondary batteries are used in small portable electronic devices such as smartphones, feature phones, laptop computers, digital cameras, and camcorders, while high-capacity secondary batteries are widely used as power sources for motor drive systems and power storage batteries in hybrid and electric vehicles. Such secondary batteries include an electrode assembly consisting of a positive electrode and a negative electrode, a case housing the assembly, and electrode terminals connected to the electrode assembly.

[0004] In the case of a secondary battery in which an electrode assembly is housed in a case and the case and cap assembly are assembled, the cap assembly may consist of a cap plate, electrode terminals, a current interruption device, etc., stacked and combined. The thickness of a cap assembly having such a configuration can account for a relatively high proportion of the total height of the secondary battery. Furthermore, the thickness of the cap assembly reduces the internal space of the case, which presents a disadvantage in terms of increasing battery capacity.

[0005] The information described above disclosed in the background technology of this invention is intended only to enhance understanding of the background of the present invention and may therefore include information that does not constitute prior art.

[0006]

[0007] The present disclosure provides a cap assembly for solving the above-mentioned problems and a secondary battery including the same.

[0008] However, the technical problems that the present invention aims to solve are not limited to those described above, and other unmentioned problems can be clearly understood by those skilled in the art from the description of the invention below.

[0009]

[0010] A cap assembly according to one embodiment of the present invention for solving the above technical problem may include a base plate having a through hole formed therein; a terminal portion having a diameter smaller than the through hole and disposed in the through hole; and an insulating portion disposed between the outer surface of the terminal portion and the inner surface of the through hole and connecting the terminal portion and the base plate.

[0011] According to one embodiment of the present invention, the insulating portion may be formed by filling an insulating material between the base plate and the terminal portion.

[0012] According to one embodiment of the present invention, the base plate, the terminal portion, and the insulating portion may have the same thickness.

[0013] According to one embodiment of the present invention, the insulating member may include an insulating member body disposed between the outer surface of the terminal member and the inner surface of the through hole, and a first extension member extending from one end of the insulating member body to both sides and covering at least a portion of one surface of the terminal member and the base plate.

[0014] According to one embodiment of the present invention, the insulating member may include a second extension member that extends from the other end of the insulating member body to both sides and surrounds at least a portion of the other surface of the terminal member and the base plate.

[0015] According to one embodiment of the present invention, the thickness of the terminal portion may be greater than the thickness of the base plate.

[0016] According to one embodiment of the present invention, a terminal portion may be positioned such that one surface is placed on the same plane as one surface of a base plate, and the other surface protrudes outwardly from the other surface of the base plate.

[0017] According to one embodiment of the present invention, the insulating member may include an insulating member body disposed between the outer surface of the terminal member and the inner surface of the through hole, and an extension portion that extends radially outward from the other end of the insulating member body and surrounds at least a portion of the other surface of the base plate.

[0018] According to one embodiment of the present invention, the height of the extension portion may be located on the same plane as the other surface of the terminal portion.

[0019] According to one embodiment of the present invention, the terminal portion may protrude from both sides of the base plate.

[0020] According to one embodiment of the present invention, the insulating member may include an insulating member body disposed between the outer surface of the terminal member and the inner surface of the through hole, and an extension portion that extends radially outward from the other end of the insulating member body and surrounds at least a portion of the other surface of the base plate.

[0021] According to one embodiment of the present invention, the height of the extension portion may be located on the same plane as the other surface of the terminal portion.

[0022] According to one embodiment of the present invention, the through hole includes a first through hole and a second through hole, the terminal part includes a first terminal part disposed in the first through hole and a second terminal part disposed in the second through hole, and the insulating part may include a first insulating part disposed between the outer surface of the first terminal part and the inner surface of the first through hole and a second insulating part disposed between the outer surface of the second terminal part and the inner surface of the second through hole.

[0023] A secondary battery according to one embodiment of the present invention for solving a technical problem comprises: an electrode assembly including a first electrode, a separator, and a second electrode; a case having one side open, accommodating the electrode assembly, and electrically connected to the second electrode; a cap assembly coupled to one side of the case and electrically connected to the first electrode, wherein the cap assembly may include a base plate having a through hole formed therein; a terminal portion having a diameter smaller than the through hole, disposed in the through hole, and electrically connected to the first electrode; and an insulating portion disposed between the outer surface of the terminal portion and the inner surface of the through hole, insulating the terminal portion and the base plate.

[0024] According to one embodiment of the present invention, the base plate, the terminal portion, and the insulating portion may have the same thickness.

[0025] According to one embodiment of the present invention, the insulating member may include an insulating member body disposed between the outer surface of the terminal member and the inner surface of the through hole, and a first extension member extending from one end of the insulating member body to both sides and covering at least a portion of one surface of the terminal member and the base plate.

[0026] According to one embodiment of the present invention, the first extension may be positioned facing the electrode assembly.

[0027] According to one embodiment of the present invention, the thickness of the terminal portion may be greater than the thickness of the base plate.

[0028] According to one embodiment of the present invention, one surface of the terminal portion may be disposed on the same plane as one surface of the base plate, and the other surface may be disposed to protrude outwardly from the other surface of the base plate and face the electrode assembly.

[0029] A secondary battery according to an embodiment of the present invention for solving a technical problem comprises: an electrode assembly including a first electrode, a separator, and a second electrode; a case having one side open and accommodating the electrode assembly; and a cap assembly coupled to one side of the case and electrically connected to the first electrode and the second electrode, wherein the cap assembly comprises: a base plate having a first through hole and a second through hole formed therein; a first terminal portion having a diameter smaller than the first through hole, disposed in the first through hole, and electrically connected to the first electrode; a first insulating portion disposed between the outer surface of the first terminal portion and the inner surface of the first through hole, insulating the first terminal portion and the base plate; a second terminal portion having a diameter smaller than the second through hole, disposed in the second through hole, and electrically connected to the second electrode, and a second insulating portion disposed between the outer surface of the second terminal portion and the inner surface of the second through hole, insulating the second terminal portion and the base plate.

[0030]

[0031] According to some embodiments of the present invention, by placing a flat electrode terminal in a through hole of a cap plate or a base plate in a cap assembly of a secondary battery, the thickness of the cap assembly can be reduced, thereby securing additional space inside the case.

[0032] According to some embodiments of the present invention, current leakage can be minimized by arranging a positive or negative terminal in only one direction on a cap assembly coupled to an open side of a secondary battery case.

[0033] According to some embodiments of the present invention, by arranging a positive or negative terminal in only one direction on a cap assembly coupled to an open side of a secondary battery case, the process for arranging electrode terminals on the bottom of the case can be omitted, and the overall height of the secondary battery can be reduced.

[0034] However, the effects obtainable through the present invention are not limited to those described above, and other unmentioned technical effects will be clearly understood by those skilled in the art from the description of the invention below.

[0035]

[0036] The following drawings attached to this specification illustrate preferred embodiments of the present invention and serve to further enhance understanding of the technical concept of the present invention together with the detailed description of the invention provided below; therefore, the present invention should not be interpreted as being limited only to the matters described in such drawings.

[0037] FIG. 1 is a plan view showing an example of a cap assembly according to one embodiment of the present disclosure.

[0038] FIG. 2 is an exploded perspective view showing an example of a cap assembly according to one embodiment of the present disclosure.

[0039] FIG. 3 is a cross-sectional view showing an example of a cap assembly according to one embodiment of the present disclosure.

[0040] FIG. 4 is a cross-sectional view showing another example of an insulating part in a cap assembly according to one embodiment of the present disclosure.

[0041] FIG. 5 is a cross-sectional view showing another example of an insulating part in a cap assembly according to one embodiment of the present disclosure.

[0042] FIG. 6 is a cross-sectional view showing another example of a terminal portion in a cap assembly according to one embodiment of the present disclosure.

[0043] FIG. 7 is a cross-sectional view showing another example of a terminal portion and an insulating portion in a cap assembly according to one embodiment of the present disclosure.

[0044] FIG. 8 is a cross-sectional view showing another example of a terminal portion in a cap assembly according to one embodiment of the present disclosure.

[0045] FIG. 9 is a cross-sectional view showing another example of a terminal portion and an insulating portion in a cap assembly according to one embodiment of the present disclosure.

[0046] FIG. 10 is a cross-sectional view showing an example of a secondary battery according to one embodiment of the present disclosure.

[0047] FIG. 11 is a cross-sectional view showing another example of an insulating part in a secondary battery according to one embodiment of the present disclosure.

[0048] FIG. 12 is a cross-sectional view showing another example of a terminal portion and an insulating portion in a secondary battery according to one embodiment of the present disclosure.

[0049] FIG. 13 is a plan view showing an example of a cap assembly according to another embodiment of the present disclosure.

[0050] FIG. 14 is an exploded perspective view showing an example of a cap assembly according to another embodiment of the present disclosure.

[0051] FIG. 15 is a cross-sectional view showing an example of a cap assembly according to another embodiment of the present disclosure.

[0052] FIG. 16 is a cross-sectional view showing an example of a secondary battery according to another embodiment of the present disclosure.

[0053]

[0054] Preferred embodiments of the present invention will be described in detail below with reference to the attached drawings. Prior to this, terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings. Instead, based on the principle that the inventor can appropriately define the concepts of terms to best describe their invention, they should be interpreted in a meaning and concept consistent with the technical spirit of the present invention. Therefore, the embodiments described in this specification and the configurations illustrated in the drawings are merely some of the most preferred embodiments of the present invention and do not represent all of the technical spirit of the present invention. It should be understood that various equivalents and modifications capable of replacing them may exist at the time of filing this application.

[0055] Additionally, as used herein, “comprise, include” and / or “comprising, including” specify the presence of the mentioned features, numbers, steps, actions, parts, elements, and / or groups thereof, and do not exclude the presence or addition of one or more other features, numbers, actions, parts, elements, and / or groups.

[0056] Additionally, to aid in understanding the invention, the attached drawings are not drawn to actual scale, and the dimensions of some components may be exaggerated. Furthermore, the same reference numerals may be assigned to identical components in different embodiments.

[0057] The statement that two subjects of comparison are 'identical' means that they are 'substantially identical.' Therefore, substantial identity may include deviations considered low in the industry, for example, deviations within 5%. Additionally, the statement that a parameter is uniform in a given area may mean that it is uniform from an average perspective.

[0058] Although terms such as "first," "second," etc., are used to describe various components, it goes without saying that these components are not limited by these terms. These terms are used merely to distinguish one component from another, and unless specifically stated otherwise, the first component may also be the second component.

[0059] Throughout the specification, unless specifically stated otherwise, each component may be singular or plural.

[0060] The fact that any configuration is placed on the "upper (or lower)" of a component or on the "upper (or lower)" of a component may mean not only that any configuration is placed in contact with the upper (or lower) surface of said component, but also that another configuration may be interposed between said component and any configuration placed on (or below) said component.

[0061] Furthermore, where it is stated that one component is "connected," "coupled," or "connected" to another component, it should be understood that while said components may be directly connected or connected to each other, another component may be "interposed" between each component, or that each component may be "connected," "coupled," or "connected" through another component. Additionally, when it is stated that a part is electrically coupled with another part, this includes not only cases where they are directly connected but also cases where they are connected with an intermediate element in between.

[0062] Throughout the specification, "A and / or B" means A, B, or A and B unless specifically stated otherwise. That is, "and / or" includes any combination or any combination of the enumerated items. "C to D" means C or more and D or less, unless specifically stated otherwise.

[0063] The terms used in this specification are intended to describe embodiments of the present disclosure and are not intended to limit the present disclosure.

[0064] FIG. 1 is a plan view showing an example of a cap assembly according to one embodiment of the present disclosure, FIG. 2 is an exploded perspective view showing an example of a cap assembly according to one embodiment of the present disclosure, and FIG. 3 is a cross-sectional view showing an example of a cap assembly according to one embodiment of the present disclosure.

[0065] Referring to FIGS. 1 to 3, a cap assembly (100) according to one embodiment of the present disclosure may include a base plate (110) having a through hole (111) formed therein, a terminal portion (120) disposed in the through hole (111) having a diameter smaller than that of the through hole (111), and an insulating portion (130) disposed between the outer surface of the terminal portion (120) and the inner surface of the through hole (111) and connecting the terminal portion (120) and the base plate (110).

[0066] The base plate (110) and the terminal portion (120) may be made of a metal material, and the insulating portion (130) may be made of an insulating material. The insulating portion (130) may electrically insulate the base plate (110) and the terminal portion (120).

[0067] In one embodiment, a base plate (110) having a through hole (111) formed in the center is placed in a mold, and a terminal portion (120) is placed at the center of the through hole (111). Then, an insulating material is filled between the base plate (110) and the terminal portion (120) to integrally form an insulating portion (130). That is, a cap assembly (100) can be manufactured by combining the base plate (110), the terminal portion (120), and the insulating portion (130) through insert injection molding.

[0068] In another embodiment, a cap assembly (100) may be manufactured by placing a terminal portion (120) at the center of a through hole (111), fitting a ring-shaped insulating portion (130) between a base plate (110) and a terminal portion (120), and then combining the base plate (110), the terminal portion (120), and the insulating portion (130) by heat pressing. Of course, this is not limited thereto, and various known methods may be applied as long as the base plate (110), the terminal portion (120), and the insulating portion (130) can be manufactured as a single integrated structure.

[0069] The base plate (110), the terminal portion (120), and the insulating portion (130) can be formed with approximately the same thickness. Through this, the overall thickness of the cap assembly (100) can be slimmed down. In one embodiment, the thickness of each of the base plate (110), the terminal portion (120), and the insulating portion (130) can be configured to be 0.4 to 0.6 mm.

[0070] As a comparative example, a cap assembly (not shown) may be configured such that a terminal portion in the form of a rivet terminal is coupled to a cap plate, and a gasket is provided between the rivet terminal and the cap plate to insulate the cap plate from the terminal portion. The cap assembly composed of the rivet terminal is formed with a thick thickness, which may reduce the space inside the case and decrease the capacity of the secondary battery.

[0071] In comparison, the cap assembly (100) of the present embodiment can form an integral structure in which an insulating part (130) is combined between a base plate (110) and a terminal part (120) through a manufacturing process such as insert injection or fitting, thereby making the overall thickness of the cap assembly (100) slimmer. Through this, the space inside the case can be expanded to increase the capacity of the secondary battery. In addition, by arranging positive or negative terminals only in one direction on the cap assembly, current leakage can be minimized, and the process for arranging electrode terminals on the bottom of the case can be omitted.

[0072] FIG. 4 is a cross-sectional view showing another example of an insulating part in a cap assembly according to one embodiment of the present disclosure, and FIG. 5 is a cross-sectional view showing yet another example of an insulating part in a cap assembly according to one embodiment of the present disclosure.

[0073] Referring to FIG. 4, the insulating portion (130a) may include an insulating portion body (131a) positioned between the outer surface of the terminal portion (120) and the inner surface of the through hole, and a first extension portion (132a) that extends from one end of the insulating portion body (131a) to both sides and covers a portion of one surface of the terminal portion (120) and the base plate (110). The thickness of the insulating portion body (131a) may be formed to be substantially the same as the thickness of the terminal portion (120) and the base plate (110). The first extension portion (132a) may be formed to extend radially from one end of the insulating portion body (131a) to both sides and cover a portion of one surface of the terminal portion (120) and the base plate (110). Through the first extension portion (132a), the contact area of ​​the insulating portion (130a) with respect to the terminal portion (120) and the base plate (110) is expanded, thereby increasing the bonding strength of the base plate (110), the terminal portion (120), and the insulating portion (130a).

[0074] In another embodiment, referring to FIG. 5, the insulating part (130b) may include an insulating part body (131b) disposed between the outer surface of the terminal part (120) and the inner surface of the through hole, a first extension part (132b) extending from one end of the insulating part body (131b) to both sides and covering a portion of one side of the terminal part (120) and the base plate (110), and a second extension part (133b) extending from the other end of the insulating part body (131b) to both sides and covering a portion of the other side of the terminal part (120) and the base plate (110). The thickness of the insulating part body (131b) may be formed to be substantially the same as the thickness of the terminal part (120) and the base plate (110). The first extension (132b) and the second extension (133b) may be formed to extend radially from both ends of the insulating body (131b) to surround a portion of both sides of the terminal part (120) and the base plate (110). Through the first extension (132b) and the second extension (133b), the contact area of ​​the insulating part (130b) with respect to the terminal part (120) and the base plate (110) is expanded, thereby increasing the bonding strength between the base plate (110), the terminal part (120), and the insulating part (130b).

[0075] FIG. 6 is a cross-sectional view showing another example of a terminal portion in a cap assembly according to one embodiment of the present disclosure, and FIG. 7 is a cross-sectional view showing another example of a terminal portion and an insulating portion in a cap assembly according to one embodiment of the present disclosure. FIG. 8 is a cross-sectional view showing yet another example of a terminal portion in a cap assembly according to one embodiment of the present disclosure, and FIG. 9 is a cross-sectional view showing yet another example of a terminal portion and an insulating portion in a cap assembly according to one embodiment of the present disclosure.

[0076] Referring to FIGS. 6 and 7, the thickness of the terminal portion (120a) may be greater than the thickness of the base plate (110). Additionally, one side of the terminal portion (120a) may be positioned on the same plane as one side of the base plate (110), and the other side may be positioned to protrude outwardly from the other side of the base plate (110). That is, the terminal portion (120a) may be positioned to protrude only in one direction from the base plate (110). The terminal portion (120a) may be configured to be coupled with an electrode of an electrode assembly or an external electrode. Since the terminal portion (120a) protrudes outwardly from the base plate (110), coupling may be easier.

[0077] Referring to FIG. 7, the insulating portion (130c) may include an insulating portion body (131c) disposed between the outer surface of the terminal portion (120a) and the inner surface of the through hole, and an extension portion (132c) that extends radially outward from the other end of the insulating portion body (131c) and surrounds a part of the other surface of the base plate (110). The thickness of the insulating portion body (131c) may be formed to be substantially the same thickness as the terminal portion (120a) and the base plate (110). The extension portion (132c) may be formed in the same direction as the protruding direction of the terminal portion (120a), and the height of the extension portion (132c) may be formed to be a height located on the same plane as the other surface of the terminal portion (120a). The extension portion (132c) is formed to cover a portion of one side of the base plate (110) so as to electrically insulate the base plate (110) from the terminal portion (120a). Additionally, through the extension portion (132c), the contact area of ​​the insulation portion (130c) with respect to the terminal portion (120a) and the base plate (110) is expanded, thereby increasing the bonding strength between the base plate (110), the terminal portion (120a), and the insulation portion (130c).

[0078] In another embodiment, referring to FIGS. 8 and 9, the thickness of the terminal portion (120b) may be greater than the thickness of the base plate (110). The terminal portion (120b) may be positioned to protrude from both sides of the base plate (110). That is, the terminal portion (120b) may be positioned to protrude in both directions of the base plate (110). The terminal portion (120b) may be configured to be coupled with an electrode of an electrode assembly or an external electrode. Since the terminal portion (120b) protrudes outward from the base plate (110), coupling may be easier.

[0079] Referring to FIG. 9, the insulating portion (130c) may include an insulating portion body (131c) disposed between the outer surface of the terminal portion (120b) and the inner surface of the through hole, and an extension portion (132c) that extends radially outward from the other end of the insulating portion body (131c) and surrounds a part of the other surface of the base plate (110). The thickness of the insulating portion body (131c) may be formed to be substantially the same thickness as the terminal portion (120b) and the base plate (110). The extension portion (132c) may be formed in the same direction as the protruding direction of the terminal portion (120b), and the height of the extension portion (132c) may be formed to be a height located on the same plane as the other surface of the terminal portion (120b). The extension portion (132c) is formed to cover a portion of one side of the base plate (110) so as to electrically insulate the base plate (110) from the terminal portion (120b). Additionally, through the extension portion (132c), the contact area of ​​the insulation portion (130c) with respect to the terminal portion (120b) and the base plate (110) is expanded, thereby increasing the bonding strength between the base plate (110), the terminal portion (120b), and the insulation portion (130c).

[0080] FIG. 10 is a cross-sectional view showing one example of an insulating part in a secondary battery according to one embodiment of the present disclosure, FIG. 11 is a cross-sectional view showing another example of an insulating part in a secondary battery according to one embodiment of the present disclosure, and FIG. 12 is a cross-sectional view showing yet another example of a terminal part and an insulating part in a secondary battery according to one embodiment of the present disclosure.

[0081] Referring to FIG. 10, a secondary battery (10) according to one embodiment of the present disclosure may include an electrode assembly (12) comprising a first electrode (13), a separator (15), and a second electrode (14), a case (11) having one side open and accommodating the electrode assembly (12) and electrically connected to the second electrode (14), and a cap assembly (100) coupled to one side of the case (11) and electrically connected to the first electrode (13). Additionally, the secondary battery (10) may further include an insulator (16) that electrically insulates the side of the electrode assembly (12) from the inner surface of the case (11).

[0082] The case (11) may be formed with an opening on one side and a hollow interior to accommodate an electrode assembly (12). The case (11) may be formed of a conductive metal such as aluminum, an aluminum alloy, or nickel-plated steel. Alternatively, the case (11) may be formed of stainless steel (SUS).

[0083] The electrode assembly (12) may be wound in a jelly roll shape, including a first electrode (13), a separator (15), and a second electrode (14). Here, the first electrode (13) may be a positive electrode and the second electrode (14) may be a negative electrode, or vice versa. In one embodiment, the electrode assembly (12) may be wound in a jelly roll shape, with the first unwound portion (13a) of the first electrode (13) protruding to one side and the second unwound portion (14a) of the second electrode (14) protruding to the other side. For example, each of the first unwound portion (13a) and the second unwound portion (14a) may be manufactured by folding and overlapping a plurality of tabs formed to protrude from the first electrode (13) and the second electrode (14), respectively, and then pressing the overlapping plurality of tabs using a compactor jig. Of course, the shape of the electrode assembly (12) is not limited to this, and the electrode assembly may be in a form in which a plurality of first electrodes, separators, and second electrodes are sequentially stacked.

[0084] The cap assembly (100) can be coupled to the opening of the case (11) after the electrode assembly (12) is received in the case (11) so that the case (11) can be sealed. Then, the first electrode (13) or the first non-electrode portion (13a) of the electrode assembly (12) can be electrically connected to the terminal portion (120) provided in the cap assembly (100).

[0085] In one embodiment, the cap assembly (100) may include a base plate (110) having a through hole formed therein, a terminal portion (120) having a diameter smaller than the through hole and disposed in the through hole and electrically connected to a first electrode (13), and an insulating portion (130) disposed between the outer surface of the terminal portion (120) and the inner surface of the through hole and insulating the terminal portion (120) and the base plate (110). The base plate (110), the terminal portion (120), and the insulating portion (130) may be formed with substantially the same thickness. Through this, the overall thickness of the cap assembly (100) can be slimmed down. In one embodiment, the thickness of each of the base plate (110), the terminal portion (120), and the insulating portion (130) may be 0.4 to 0.6 mm. Through this, the space inside the case (11) can be expanded so that the electrode assembly (12) can be formed higher, thereby increasing the capacity of the secondary battery (10).

[0086] With the cap assembly (100) coupled to the case (11), the inner surface of the terminal portion (120) may come into contact with the first non-contact portion (13a) of the first electrode (13). The terminal portion (120) and the first non-contact portion (13a) may be joined by welding on the outer surface of the terminal portion (120). Additionally, the second non-contact portion (14a) of the first electrode (13) may come into contact with the bottom surface of the case (11). Thus, the terminal portion (120) is electrically connected to the first electrode (13), the case (11) is electrically connected to the second electrode (14), and the terminal portion (120) and the case (11) may be electrically insulated through the insulating portion (130).

[0087] Referring to FIG. 11, the insulating portion (130a) of the cap assembly (100) may include an insulating portion body (131a) positioned between the outer surface of the terminal portion (120) and the inner surface of the through hole, and a first extension portion (132a) that extends from one end of the insulating portion body (131a) to both sides and encloses a portion of one surface of the terminal portion (120) and the base plate (110). The thickness of the insulating portion body (131a) may be formed to be substantially the same as the thickness of the terminal portion (120) and the base plate (110). The first extension portion (132a) may be formed to extend radially from one end of the insulating portion body (131a) to both sides and enclose a portion of one surface of the terminal portion (120) and the base plate (110).

[0088] In one embodiment, the first extension (132a) may be positioned facing the electrode assembly (12). That is, the first extension (132a) may be positioned on the inside of the case (11). The first extension (132a) having this configuration can prevent the first non-removable portion (13a) from coming into contact with the base plate (110). Of course, the first extension (132a) may also be positioned on the outside of the case (11). Additionally, although not shown in the drawings, as illustrated in FIG. 5, the insulating portion (130b) may be provided with the first extension (132b) and the second extension (133b) at both ends of the insulating portion body (131b).

[0089] Referring to FIG. 12, the thickness of the terminal portion (120a) of the cap assembly (100) may be greater than the thickness of the base plate (110). Additionally, one side of the terminal portion (120a) may be positioned on the same plane as one side of the base plate (110), and the other side may be positioned to protrude outwardly from the other side of the base plate (110). That is, the terminal portion (120a) may be positioned to protrude only in one direction from the base plate (110).

[0090] In one embodiment, the terminal portion (120a) may be positioned so that a protruding part faces the electrode assembly (12). Through this, the inner surface of the terminal portion (120a) comes into contact with the first non-removable portion (13a), and the first non-removable portion (13a) may be positioned spaced apart from the base plate (110). Of course, the cap assembly (100) may be coupled to the case (11) so that the protruding part of the terminal portion (120a) is positioned on the outside of the case (11).

[0091] Additionally, the insulating portion (130c) may include an insulating portion body (131c) disposed between the outer surface of the terminal portion (120a) and the inner surface of the through hole, and an extension portion (132c) that extends radially outward from the other end of the insulating portion body (131c) to surround a portion of the other surface of the base plate (110). The thickness of the insulating portion body (131c) may be formed to be substantially the same thickness as the terminal portion (120a) and the base plate (110). The extension portion (132c) may be formed in the same direction as the protruding direction of the terminal portion (120a), and the height of the extension portion (132c) may be formed to be a height located on the same plane as the other surface of the terminal portion (120a). The extension portion (132c) may be formed to surround a portion of one surface of the base plate (110) so as to electrically insulate the base plate (110) from the first non-insulating portion (13a). Additionally, although not shown in the drawings, as illustrated in FIG. 8, the terminal portion (120b) may be positioned to protrude from both sides of the base plate (110).

[0092] FIG. 13 is a plan view showing an example of a cap assembly according to another embodiment of the present disclosure, FIG. 14 is an exploded perspective view showing an example of a cap assembly according to another embodiment of the present disclosure, and FIG. 15 is a cross-sectional view showing an example of a cap assembly according to another embodiment of the present disclosure.

[0093] Referring to FIGS. 13 to 15, a cap assembly (200) according to another embodiment of the present disclosure may include two terminals on a base plate (210).

[0094] In one embodiment, the cap assembly (200) may include a base plate (210) having a first through hole (211) and a second through hole (212), a first terminal portion (221) disposed in the first through hole (211), a second terminal portion (222) disposed in the second through hole (212), a first insulating portion (231) disposed between the outer surface of the first terminal portion (221) and the inner surface of the first through hole (211), and a second insulating portion (232) disposed between the outer surface of the second terminal portion (222) and the inner surface of the second through hole (212).

[0095] The base plate (210), the first terminal part (221), and the second terminal part (222) may be made of a metal material, and the first insulating part (231) and the second insulating part (232) may be made of an insulating material. The first insulating part (231) and the second insulating part (232) may electrically insulate the base plate (110) from the first terminal part (221) and the second terminal part (222).

[0096] The base plate (210), the first terminal portion (221), the second terminal portion (222), the first insulating portion (231), and the second insulating portion (232) can be formed with the same thickness. Through this, the overall thickness of the cap assembly (200) can be slimmed down. In one embodiment, the thickness of each of the base plate (210), the first terminal portion (221), the second terminal portion (222), the first insulating portion (231), and the second insulating portion (232) can be configured to be 0.4 to 0.6 mm.

[0097] Although not shown in the drawings, the shapes of the first terminal part (221) and the second terminal part (222), and the first insulating part (231) and the second insulating part (232) may be formed in the shape described with reference to FIGS. 4 to 9.

[0098] FIG. 16 is a cross-sectional view showing an example of a secondary battery according to another embodiment of the present disclosure.

[0099] Referring to FIG. 16, a secondary battery (20) according to another embodiment of the present disclosure may include an electrode assembly (22) comprising a first electrode (23), a separator (25), and a second electrode (24), a case (21) having one side open and accommodating the electrode assembly (22), and a cap assembly (200) coupled to one side of the case (21) and electrically connected to the first electrode (23) and the second electrode (24). Additionally, the secondary battery (20) may further include an insulator (26) that electrically insulates the side of the electrode assembly (22) from the inner surface of the case (21), and an insulating sheet (27) disposed between the upper side of the electrode assembly (22) and the first electrode tab (23a) and the second electrode tab (24a) to electrically insulate the electrode assembly (22) from the first electrode tab (23a) and the second electrode tab (24a).

[0100] The electrode assembly (22) may include a separator (25), a first electrode (23) positioned between the separator (25), and a second electrode (24), and may be wound in the form of a jelly roll. Of course, the shape of the electrode assembly (22) is not limited thereto, and the electrode assembly may be in the form in which a plurality of first electrodes, separators, and second electrodes are sequentially stacked.

[0101] The first electrode (23) may include a first substrate and a first active material layer located on the first substrate. A second electrode tab (23a) may extend outwardly from a first non-active portion of the first substrate where the first active material layer is not located, and the second electrode tab (23a) may be electrically connected to a cap assembly (200).

[0102] The second electrode (24) may include a second substrate and a second active material layer located on the second substrate. A second electrode tab (24a) may extend outwardly from a second non-active portion of the second substrate where the second active material layer is not located, and the second electrode tab (24a) may be electrically connected to the case (21). The second electrode tab (23a) and the second electrode tab (24a) may extend in the same direction from each other.

[0103] The first electrode (23) can function as an anode. In this case, the first substrate may be composed of, for example, aluminum foil, and the first active material layer may include, for example, a transition metal oxide. The second electrode (24) can function as a cathode. In this case, the second substrate may be composed of, for example, copper foil or nickel foil, and the second active material layer may include, for example, graphite.

[0104] The separator (25) functions to prevent short circuits between the first electrode (23) and the second electrode (24) while allowing the movement of lithium ions. The separator (25) may be composed of, for example, a polyethylene film, a polypropylene film, a polyethylene-polypropylene film, etc.

[0105] The case (21) accommodates the electrode assembly (22) and the electrolyte, and together with the cap assembly (200), can form the external shape of the secondary battery. The case (21) may include a roughly cylindrical body portion and a bottom portion connected to one side of the body portion. The case may be made of a metal such as aluminum, aluminum alloy, or nickel-plated steel.

[0106] The cap assembly (200) can be coupled to the opening of the case (21) after the electrode assembly (22) is received in the case (21), thereby sealing the case (21). Then, the second electrode tab (23a) of the first electrode (23) can be electrically connected to the first terminal portion (221) provided in the cap assembly (200), and the second electrode tab (24a) of the second electrode (24) can be electrically connected to the second terminal portion (222).

[0107] In one embodiment, the cap assembly (200) may include a base plate (210) having a first through hole and a second through hole formed therein. Additionally, the cap assembly (200) may include a first terminal portion (221) having a diameter smaller than the first through hole, disposed in the first through hole and electrically connected to a first electrode (23), and a first insulating portion (231) disposed between the outer surface of the first terminal portion (221) and the inner surface of the first through hole and insulating the first terminal portion (221) from the base plate (210). Additionally, the cap assembly (200) may include a second terminal portion (222) having a diameter smaller than the second through hole and disposed in the second through hole and electrically connected to the second electrode (24), and a second insulating portion (232) disposed between the outer surface of the second terminal portion (222) and the inner surface of the second through hole and insulating the second terminal portion (222) and the base plate (210).

[0108] With the cap assembly (200) coupled to the case (21), the inner surface of the first terminal part (221) may come into contact with the second electrode tab (23a) of the first electrode (23), and the inner surface of the second terminal part (222) may come into contact with the second electrode tab (24a) of the second electrode (24). The first terminal part (221) and the second electrode tab (23a) may be joined by welding on the outer surface of the first terminal part (221), and the second terminal part (222) and the second electrode tab (24a) may be joined by welding on the outer surface of the second terminal part (222). Alternatively, the first terminal part (221) and the second electrode tab (23a) may be joined by welding, and the second terminal part (222) and the second electrode tab (24a) may be joined, after which the cap assembly (200) may be coupled to the case (21).

[0109] The base plate (210), the first terminal portion (221), the second terminal portion (222), the first insulating portion (231), and the second insulating portion (232) can be formed with substantially the same thickness. Through this, the overall thickness of the cap assembly (200) can be slimmed down. In one embodiment, the thickness of each of the base plate (210), the first terminal portion (221), the second terminal portion (222), the first insulating portion (231), and the second insulating portion (232) can be configured to be 0.4 to 0.6 mm. Through this, the space inside the case (21) can be expanded so that the electrode assembly (22) can be formed higher, thereby increasing the capacity of the secondary battery (20).

[0110] Although not shown in the drawings, the first terminal portion (221) and the second terminal portion (222), and the first insulating portion (231) and the second insulating portion (232) may be formed in the form described with reference to FIGS. 4 to 9.

[0111] Although the present invention has been described above by limited embodiments and drawings, the present invention is not limited thereto, and it is obvious that various modifications and variations are possible within the scope of the technical spirit of the present invention and the equivalent scope of the claims described below by those skilled in the art to which the present invention belongs.

Claims

1. A base plate with a through hole formed therein; A terminal portion having a diameter smaller than the through hole and disposed in the through hole; and An insulating part disposed between the outer surface of the terminal portion and the inner surface of the through hole, and connecting the terminal portion and the base plate. A cap assembly including 2. In Paragraph 1, The above insulating part is, A cap assembly formed by filling an insulating material between the base plate and the terminal portion.

3. In Paragraph 1, A cap assembly having the same thickness as the base plate, the terminal portion, and the insulation portion.

4. In Paragraph 1, The above insulating part is, An insulating body disposed between the outer surface of the terminal portion and the inner surface of the through hole; and A first extension part extending from one end of the insulating body to both sides and surrounding at least a portion of one surface of the terminal part and the base plate. A cap assembly including 5. In Paragraph 4, The above insulating part is, A second extension part extending to both sides from the other end of the insulating body and surrounding at least a portion of the other surface of the terminal part and the base plate. A cap assembly further comprising 6. In Paragraph 1, The thickness of the above terminal portion is, A cap assembly with a thickness greater than that of the base plate.

7. In Paragraph 6, The above terminal part is, A cap assembly having one surface positioned on the same plane as one surface of the base plate, and the other surface positioned to protrude outwardly from the other surface of the base plate.

8. In Paragraph 7, The above insulating part is, An insulating body disposed between the outer surface of the terminal portion and the inner surface of the through hole; and An extension extending radially outward from the other end of the insulating body and wrapping at least a portion of the other surface of the base plate. A cap assembly including 9. In Paragraph 8, The height of the above extension is, A cap assembly located on the same plane as the other side of the above terminal portion.

10. In Paragraph 6, The above terminal part is, A cap assembly protruding from both sides of the above base plate.

11. In Paragraph 10, The above insulating part is, An insulating body disposed between the outer surface of the terminal portion and the inner surface of the through hole; and An extension extending radially outward from the other end of the insulating body and wrapping at least a portion of the other surface of the base plate. A cap assembly including 12. In Paragraph 11, The height of the above extension is, A cap assembly located on the same plane as the other side of the above terminal portion.

13. In Paragraph 1, The above through hole includes a first through hole and a second through hole, and The above terminal portion includes a first terminal portion disposed in the first through hole and a second terminal portion disposed in the second through hole, and The above insulating part comprises a first insulating part disposed between the outer surface of the first terminal part and the inner surface of the first through hole, and a second insulating part disposed between the outer surface of the second terminal part and the inner surface of the second through hole, forming a cap assembly.

14. An electrode assembly comprising a first electrode, a separator, and a second electrode; A case having one side open, accommodating the electrode assembly, and electrically connected to the second electrode; A cap assembly coupled to one side of the above case and electrically connected to the first electrode Includes, The above cap assembly is, A base plate with a through hole formed therein; A terminal portion having a diameter smaller than the through hole, disposed in the through hole, and electrically connected to the first electrode; and An insulating part disposed between the outer surface of the terminal portion and the inner surface of the through hole, and insulating the terminal portion and the base plate. A secondary battery including 15. In Paragraph 14, A secondary battery having the same thickness as the base plate, the terminal portion, and the insulating portion.

16. In Paragraph 14, The above insulating part is, An insulating body disposed between the outer surface of the terminal portion and the inner surface of the through hole; and A first extension part extending from one end of the insulating body to both sides and surrounding at least a portion of one surface of the terminal part and the base plate. A secondary battery including 17. In Paragraph 16, The above-mentioned first extension part is, A secondary battery positioned facing the above electrode assembly.

18. In Paragraph 14, The thickness of the above terminal portion is, A secondary battery with a thickness greater than that of the base plate above.

19. In Paragraph 18, The above terminal part is, A secondary battery having one surface disposed on the same plane as one surface of the base plate, and the other surface protruding outwardly from the other surface of the base plate and disposed to face the electrode assembly.

20. An electrode assembly comprising a first electrode, a separator, and a second electrode; A case having one side open and accommodating the electrode assembly; A cap assembly coupled to one side of the above case and electrically connected to the first electrode and the second electrode Includes, The above cap assembly is, A base plate having a first through hole and a second through hole formed therein; A first terminal portion having a diameter smaller than the first through hole, disposed in the first through hole, and electrically connected to the first electrode; A first insulating part disposed between the outer surface of the first terminal part and the inner surface of the first through hole, and insulating the first terminal part and the base plate; A second terminal portion having a diameter smaller than the second through hole, disposed in the second through hole, and electrically connected to the second electrode; and A second insulating part disposed between the outer surface of the second terminal part and the inner surface of the second through hole, and insulating the second terminal part and the base plate. A secondary battery including

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