Secondary battery comprising current collector

Abstract

The present invention relates to a secondary battery comprising a current collector and cap assembly coupling structure. The purpose of the present invention is to provide a secondary battery which has an improved current collector structure, eliminating the need for a separate member for connection with a terminal, and enabling a simple connection process, thereby reducing material costs and improving productivity. To this end, the present invention comprises: a case having an opening formed on at least one end thereof; an electrode assembly accommodated in the case; a current collector electrically connected to the electrode assembly; and a cap assembly which includes a terminal electrically connected to the current collector, and is installed in the opening of the case, wherein the current collector comprises a conductive boss formed going toward the terminal of the cap assembly.

Description

Secondary battery containing the entire body

[0001] The present invention relates to a secondary battery, and more particularly, to a secondary battery including a combined structure of a current collector and a cap assembly.

[0002] Secondary batteries, unlike primary batteries, which are non-rechargeable, are capable of both charging and discharging. Typically, a secondary battery comprises an electrode assembly consisting of positive and negative plates, a case housing the electrode assembly, electrode terminals connected to the electrode assembly, and a vent for degassing gases generated within the case.

[0003] The electrode assembly is housed inside a case (or can), and the electrode terminals and the vent are installed on a cap plate that is coupled to the case to form a cap assembly. The electrode assembly includes positive and negative electrode tabs, and a current collector is connected to these electrode tabs. The current collector located inside the case is electrically connected to the electrode terminals located outside the cap assembly through a predetermined connecting member.

[0004] The above-described information disclosed in the background technology of this invention is only intended to enhance understanding of the background of the present invention and may therefore include information that does not constitute prior art.

[0005] In a secondary battery structure, rivets, welding, etc. can be used as the connecting member described above to connect the electrode terminal of the cap assembly and the electrode assembly inside the case. The connection between the electrode terminal and the current collector by these connecting members itself requires a bonding process at both ends and involves the addition and management of materials called connecting members.

[0006] Therefore, the purpose of the present invention is to propose a secondary battery that reduces material costs and improves productivity by improving the structure of the current collector, eliminating a separate member for connection with a terminal, and enabling a simple connection process.

[0007] However, the technical problems to be solved by the present invention are not limited to the problems described above, and other problems not mentioned can be clearly understood by those skilled in the art from the description of the invention described below.

[0008] In order to solve the above technical problem, according to one aspect of the present invention, a secondary battery is provided, comprising: a case having an opening formed at least on one end; an electrode assembly accommodated in the case; a current collector electrically connected to the electrode assembly; and a terminal electrically connected to the current collector, the current collector including a cap assembly installed in the opening of the case, wherein the current collector includes a conductive boss formed toward the terminal of the cap assembly.

[0009] According to another aspect of the present invention, a current collector for a secondary battery is provided, comprising: a case having an opening formed at least in one end; an electrode assembly accommodated in the case; a current collector electrically connected to the electrode assembly; and a terminal electrically connected to the current collector, the current collector including a cap assembly installed in the opening of the case, wherein the current collector includes a conductive boss formed toward the terminal of the cap assembly.

[0010] In some embodiments, the conductive boss of the current collector may include a cavity formed at least in a portion of its interior. In other embodiments, the conductive boss of the current collector may include a recess formed at a distal end. In yet another embodiment, the conductive boss may include a ring groove for accommodating a ring member.

[0011] According to the present invention, the structure of a current collector connecting an electrode terminal of a cap assembly and an electrode assembly inside a case in a secondary battery structure is improved, thereby eliminating a separate member for connection to the terminal and enabling a simple connection process, thereby reducing material costs and improving productivity.

[0012] The effects that can be obtained through the present invention are not limited to the effects described above, and other technical effects not mentioned will be clearly understood by those skilled in the art from the description of the invention described below.

[0013] The following drawings attached to this specification illustrate preferred embodiments of the present invention, and together with the detailed description of the invention described below, serve to further understand the technical idea of ​​the present invention, and therefore, the present invention should not be interpreted as being limited to matters described in the drawings.

[0014] Figure 1a is a top perspective view of a secondary battery according to an example.

[0015] Figure 1b is a cross-sectional view taken along line II' of Figure 1a.

[0016] FIG. 2 is an exploded perspective view showing the coupling relationship of a collector and a cap assembly according to some embodiments of the present invention.

[0017] Figure 3 is a perspective view illustrating the configuration of some embodiments of the entire house.

[0018] Figure 4 is a cross-sectional view taken along line II-II' of Figure 3.

[0019] Figure 5 shows a state in which a ring member is fastened to a ring groove formed in a challenge boss.

[0020] Figure 6 is a cross-sectional view taken along line III-III' of Figure 5.

[0021] Figures 7a and 7b show modified examples of the challenge boss (170).

[0022] FIG. 8 is a partial cross-sectional view of a cap assembly including a cap plate in which a current collector, terminals, and related components are assembled, according to some embodiments of the present invention.

[0023] Figure 9 is a schematic diagram for explaining a riveting connection method of a challenge boss and a terminal.

[0024] FIG. 10 is a cross-sectional view of a secondary battery including a cap assembly assembled by bonding a collector to a cap plate according to some embodiments of the present invention.

[0025] FIG. 11 is an exemplary diagram of a secondary battery module configured by arranging secondary batteries manufactured according to embodiments of the present invention.

[0026] FIG. 12 is an example diagram of a secondary battery pack including the secondary battery module illustrated in FIG. 11.

[0027] Figure 13 is a conceptual diagram showing the secondary battery pack illustrated in Figure 12 installed in a vehicle.

[0028] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Prior to this, it should be noted that terms and words used in this specification and claims should not be interpreted as limited to their conventional or dictionary meanings, and should be interpreted with meanings and concepts that conform to the technical spirit of the present invention, based on the principle that the inventor can appropriately define the concept of a term to best explain his or her invention. Therefore, the embodiments described in this specification and the configurations illustrated in the drawings are only some of the most preferred embodiments of the present invention and do not represent all of the technical spirit of the present invention. Therefore, it should be understood that various equivalents and modified examples may exist as of the time of this application.

[0029] Additionally, when used herein, the terms "comprise", "include" and / or "comprising", "including" specify the presence of stated features, numbers, steps, operations, elements, elements, and / or groups thereof, but do not preclude the presence or addition of one or more other features, numbers, operations, elements, elements, and / or groups thereof.

[0030] Additionally, to facilitate understanding of the invention, the attached drawings may not be drawn to scale and some components may be exaggerated in size. Furthermore, identical components may be assigned the same reference numbers in different embodiments.

[0031] The statement that two compared objects are "identical" means "substantially identical." Therefore, "substantially identical" may include deviations considered low in the art, such as deviations of less than 5%. Furthermore, uniformity of a parameter over a given range may also mean uniformity on average.

[0032] Although terms like "first" and "second" are used to describe various components, these components are not limited by these terms. These terms are used merely to distinguish one component from another, and unless otherwise specified, a "first" component may also be a "second" component.

[0033] Throughout the specification, unless otherwise specifically stated, each element may be singular or plural.

[0034] Any configuration being placed "on (or under)" or "above (or below)" a component may mean not only that any configuration is placed in contact with the upper surface (or lower surface) of said component, but also that other configurations may intervene between said component and any configuration placed on (or below) said component.

[0035] Additionally, when a component is described as being "on," "connected to," or "coupled to" another component, it should be understood that the components may be directly connected or coupled to one another, but that other components may also be "interposed" between the components, or that each component may be "connected," "coupled," or "connected" through other components.

[0036] As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items. Furthermore, the use of "may" when describing embodiments of the present invention refers to "one or more embodiments of the present invention." Expressions such as "one or more" and "one or more" preceding a list of elements modify the list as a whole and do not modify individual elements within the list.

[0037] When reference is made throughout the specification to “A and / or B,” this means A, B, or A and B, unless otherwise stated, and when reference is made to “C through D,” this means C or more and D or less, unless otherwise stated.

[0038] When phrases such as "at least one of A, B, and C," "at least one of A, B, or C," "at least one selected from the group A, B, and C," or "at least one selected from A, B, and C," are used to specify a list of elements A, B, and C, the phrases can refer to any suitable combination.

[0039] The term "use" may be considered synonymous with the term "utilize." As used herein, the terms "substantially," "about," and similar terms are used as terms of approximation rather than degrees, and are intended to take into account inherent variations in measured or calculated values ​​that would be recognized by those skilled in the art.

[0040] Although terms such as first, second, third, etc. may be used herein to describe various elements, components, regions, layers, and / or sections, these elements, components, regions, layers, and / or sections should not be limited by these terms. These terms are used to distinguish one element, component, region, layer, or cross-section from another element, component, region, layer, or cross-section. Thus, a first element, component, region, layer, or section discussed below could also be termed a second element, component, region, layer, or section without departing from the teachings of the exemplary embodiments.

[0041] For ease of description, spatially relative terms such as "beneath," "below," "lower," "above," "upper," and the like may be used in the specification to describe the relationship of one element or feature to other element(s) or features as depicted in the drawings. It will be understood that spatially relative positions encompass different orientations of the device in use or operation in addition to the orientations depicted in the figures. For example, if the device in the drawings is turned over, other elements are understood to be "beneath" or "below," and the depicted elements are understood to be "above" or "above" other elements. Thus, the term "beneath" can encompass both the above and below orientations.

[0042] The terms used herein are for the purpose of describing embodiments of the invention and are not intended to limit the invention.

[0043] FIG. 1A is a top perspective view of a secondary battery according to some embodiments to which the invention can be applied.

[0044] The case (51) forms the overall appearance of the secondary battery and may be formed of a conductive metal such as aluminum, an aluminum alloy, or nickel-plated steel. In addition, the case (51) may provide a space in which an electrode assembly is accommodated.

[0045] The cap assembly (60) may include a cap plate (61) covering the opening of the case (51), and the case (60) and the cap plate (61) may be made of a conductive material. Here, the first terminal (63) and the second terminal (62) may be installed to protrude outward by penetrating the cap plate (61) and being electrically connected to the positive or negative pole inside.

[0046] An electrolyte injection port (64) into which a sealing plug can be installed can be formed in the cap plate (61), and a vent (66) having a notch (65) formed therein can be installed. The vent (66) is for degassing gas generated inside the battery.

[0047] Fig. 1b is a cross-sectional view taken along line II' of Fig. 1a. Referring to Fig. 1b, the internal structure of one type of secondary battery according to this embodiment and the coupling structure with the cap assembly (60) will be described.

[0048] The secondary battery illustrated in FIG. 1b may basically include an electrode assembly (40), a first current collector (41), a first terminal (62), a second current collector (42), a second terminal (63), and a cap assembly (60).

[0049] The electrode assembly (40) may be formed by winding or stacking a laminate of a first electrode plate, a separator, and a second electrode plate formed in a plate shape or a film shape. When the electrode assembly (40) is a rolled laminate (so-called jelly roll), the winding axis may be parallel to the longitudinal direction of the case. In addition, the electrode assembly (40) may be a stack type rather than a rolled type, but the shape of the electrode assembly (40) is not limited in the present invention. In addition, the electrode assembly (40) may be a Z-stack electrode assembly in which the first electrode plate and the second electrode plate are inserted on both sides of a separator folded in a Z-stack shape. In addition, the electrode assembly (40) may be housed inside the case by stacking one or more electrode assemblies so that their long sides are adjacent to each other, and the number of electrode assemblies is not limited in the present invention. The first electrode plate of the electrode assembly (40) may function as a cathode, and the second electrode plate may function as an anode, or vice versa.

[0050] The first electrode plate is formed by applying a first electrode active material such as graphite or carbon to a first electrode current collector plate formed of a metal foil such as copper, copper alloy, nickel or nickel alloy, and may include a first electrode tab (or first uncoated region) which is a region where the first electrode active material is not applied. The first electrode tab (43) may be a passage for current flow between the first electrode plate and the first current collector (41). In some examples, the first electrode tab (43) may be formed by cutting the first electrode plate in advance so as to protrude from one side when manufacturing the first electrode plate, and may protrude further from one side than the separator without separate cutting.

[0051] The second electrode plate is formed by applying a second electrode active material such as a transition metal oxide to a substrate formed of a metal foil such as aluminum or an aluminum alloy, and may include a second electrode tab (or second non-coated portion) (44) which is a region where the second electrode active material is not applied. The second electrode tab (44) may be a passage for current flow between the second electrode plate and the second current collector (42). In some examples, the second electrode tab (44) may be formed by cutting the second electrode plate in advance so as to protrude to the other side when manufacturing the second electrode plate, and may protrude further to the other side than the separator without separate cutting.

[0052] In some embodiments, the first electrode tab (43) may be positioned on the right side of the electrode assembly (40), and the second electrode tab (44) may be positioned on the left side of the electrode assembly (40), or may be positioned on one side in the same direction. Also, in some embodiments, the first electrode tab (43) and the second electrode tab (44) may be positioned on the upper side of the electrode assembly (40). Here, left, right, and upper are for convenience of explanation based on the secondary battery illustrated in FIG. 1B, and the positions may change when the secondary battery rotates left and right or up and down.

[0053] The separator functions to prevent short circuiting between the first and second electrode plates while allowing the movement of lithium ions. The separator may be composed of, for example, a polyethylene film, a polypropylene film, a polyethylene-polypropylene film, or the like.

[0054] A first electrode tab (43) of the first electrode plate and a second electrode tab (44) of the second electrode plate extend from both ends of the electrode assembly (40) as described above. In some embodiments, the electrode assembly (40) may be accommodated in a case (51) together with an electrolyte.

[0055] In the electrode assembly (40), the first electrode tabs (43) and the second electrode tabs (44) extending from the first electrode plate and the second electrode plate to both sides can be connected to the first current collector (41) and the second current collector (42) by welding, respectively. In some embodiments where the first electrode tabs (43) and the second electrode tabs (44) are positioned on the upper portion of the electrode assembly (40) as mentioned above, the first current collector and the second current collector are positioned on the upper portion of the electrode assembly (40).

[0056] The first current collector (41) and the second current collector (42) are electrically connected to the first terminal (62) and the second terminal (63) described in Fig. 1a, respectively, through a connecting member (67). In some embodiments, the outer circumferential surface of the connecting member (67) may be threaded and may be fastened to the first terminal (62) and the second terminal (63) through a screw connection. However, the present invention is not limited thereto, and the connecting member (67) may be fastened to the first terminal (62) and the second terminal (63) by riveting or welding, respectively.

[0057] FIG. 2 is an exploded perspective view showing the coupling relationship of a collector and a cap assembly according to some embodiments of the present invention.

[0058] Roughly speaking, the current collectors (130, 140) located at the bottom of the cap plate (110) are connected to the positive and negative electrode tabs (43, 44 in FIG. 1B, 210, 220 in FIG. 10) of the electrode assembly (40 in FIG. 1B or 200 in FIG. 10) within the case, respectively, and can be connected to the terminals (150, 160) located at the top of the cap plate (110), respectively. A vent portion (112) and an electrolyte injection port (114) can be formed in the cap plate (110).

[0059] More specifically, a bottom insulator (120) may be positioned at the bottom of the cap plate (110), and a first current collector (130) and a second current collector (140) may be positioned below the bottom insulator (120). A first terminal (150) and a second terminal (160) may be positioned at the top of the cap plate (110), and these may be electrically connected to the first current collector (130) and the second current collector (140), respectively.

[0060] In FIG. 2, the first current collector (130) and the second current collector (140) are illustrated in a form that can be used in a so-called Top-tab or Multi-tab structure, in which the electrode tabs (e.g., 210 and 220 of FIG. 10) of the electrode assembly (e.g., 200 of FIG. 10) are positioned on the upper portion of the electrode assembly (200), as previously mentioned through FIG. 1b. However, in the present invention, the first current collector (130) and the second current collector (140) are not limited to this Top-tab structure, and can also be applied to a battery having a Side-tab structure, for example, as shown in FIG. 1b.

[0061] According to some embodiments of the present invention, conductive bosses (170, 180) are provided on the first current collector (130) and the second current collector (140), respectively, for electrical connection between the first terminal (150) and the second terminal (160) located on the upper portion of the cap plate (110) and the first current collector (130) and the second current collector (140). By riveting with the conductive bosses (170, 180), the first terminal (150) and the second terminal (160) can be electrically connected to the first current collector (130) and the second current collector (140), respectively.

[0062] In FIG. 2, an insulator (105) may be interposed between the first terminal (150) and / or the second terminal (160) and the surface of the cap plate (110) underneath. The reason why this insulator is necessary is, for example, to prevent short-circuiting with the positive terminal when the case has a negative polarity (and vice versa). In addition, a seal gasket (190) for sealing the battery case may be mounted on each of the conductive bosses (170, 180) of the first current collector (130) and the second current collector (140). Since an electrolyte is injected into the case, the case is sealed by the seal gasket (190).

[0063] Components of the cap assembly, for example, the lower insulating plate (120), the cap plate (110), the insulator (105), the first terminal (150), and the second terminal (160), may have through-holes (121, 115, 107) formed therein through which conductive bosses (170, 180) of the first current collector (130) and the second current collector (140) at the lowest may pass. The conductive bosses (170, 180) passing through these through-holes may be coupled to the through-holes (152) of the first terminal (150) and the second terminal (160) at the highest may be electrically connected.

[0064] FIG. 3 is a perspective view for explaining the configuration of some embodiments of the first current collector (130) and the second current collector (140), and FIG. 4 is a cross-sectional view taken along line II-II' of FIG. 3. For simplicity of explanation, the first and second current collectors (130, 140) will hereinafter be collectively referred to as current collector (130), and the first terminal (150) and the second terminal (160) will be collectively referred to as terminal (150).

[0065] In FIG. 3, the current collector (130) may include a tab connection portion (132) which is located on a first portion of the current collector substrate (131) and is connected to an electrode tab (e.g., 43, 44 of FIG. 1b or 210, 220 of FIG. 10, the same applies hereinafter) of an electrode assembly (e.g., 40 of FIG. 1b or 200 of FIG. 10, the same applies hereinafter), and a conductive boss (170) which is located on a second portion of the current collector substrate (131) and is for connection to a terminal (150). A through hole (133) formed adjacent to the tab connection portion (132) may be utilized for bonding with an electrode tab of an electrode assembly located below the tab connection portion (132).

[0066] The current collector substrate (131) may be in the form of a flat plate as illustrated, but is not limited thereto. The tab connection portion (132) is illustrated as having a bifurcated shape, but this may be modified depending on the properties of the electrode assembly and electrode tabs located below the tab connection portion (132).

[0067] Referring to FIG. 4, which is a longitudinal cross-sectional view of FIG. 3, the conductive boss (170) may be formed by a boundary wall (171) having an approximately "∩" shape formed by continuously extending the current collector substrate (131). The conductive boss (170) may include a cavity (172), which is an empty space, therein, and may include an opening (173) at the bottom thereof that is open toward an electrode assembly positioned thereunder. The upper surface of the conductive boss (170) may be sunken downward to form a recessed portion (174). The recessed portion (174) may be used to perform a riveting connection to the terminal (150).

[0068] The conductive boss (170) can be formed integrally with the current collector substrate (131). By being formed integrally, the lower portion of the conductive boss (170) can be continuously connected to the current collector substrate (131). The connection portion may be a curved connection portion (175) having a curved shape, but is not limited thereto (see FIGS. 7a and 7b).

[0069] A ring groove (176) may be formed around the circumference of the conductive boss (170). A ring member (177 in FIG. 5), such as a snap ring, an O-ring, an E-ring, or a spring ring, may be fastened to the ring groove (176). The ring member (177) may serve the purpose of positioning surrounding assembled members and reinforcing fastening strength when assembling a cap assembly for secondary battery production (described in detail later). The height of the ring groove (176), i.e., the distance from the upper surface of the current collector substrate (131), may vary depending on the quantity, shape, etc. of related members around the conductive boss (170).

[0070] In some embodiments, a press mold may be used to form the conductive boss (170) integrally with the current collector (130) while simultaneously forming the conductive boss (170) during the production of the current collector substrate (131). After forming the conductive boss (170) by pressing, the ring groove (176) may be formed by mechanical cutting or laser etching, etc.

[0071] In another embodiment, the entire body substrate (131), the challenge boss (170), and the ring groove (176) can be manufactured simultaneously by casting.

[0072] In another embodiment, the ring groove (176) can be formed after the entire body substrate (131) and the conductive boss (170) are simultaneously manufactured by casting.

[0073] Figure 5 shows a state in which a ring member (177) is fastened to a ring groove (176) formed around the circumference of a challenge boss (170). The ring member (177) may be a known ring such as a snap ring, O-ring, E-ring, or spring ring as mentioned above, but is not limited thereto, and may also be a ring custom-made with a special shape.

[0074] The thickness or diameter of the ring member (177) may vary depending on the quantity, shape, etc. of related members around the challenge boss (170).

[0075] Fig. 6 is a cross-sectional view taken along the longitudinal axis III-III' of Fig. 5. The cross-sectional view shows a ring member (177) fastened to the ring groove (176) shown in the cross-sectional view of Fig. 5. The function of the ring member (177) will be described in detail later with reference to Fig. 8.

[0076] Figures 7a and 7b show modified examples of the challenge boss (170).

[0077] Fig. 7a shows that, unlike Fig. 4 and Fig. 6 introduced above, the connection between the current collector substrate (131) and the conductive boss (170) is an angular connection (175') rather than a curved surface. The cavity (172) can be formed entirely within the conductive boss (170).

[0078] Fig. 7b shows a form in which a cavity formed inside the conductive boss (170) is formed only in a portion. The conductive boss (170) shown in Fig. 7b may include a first cavity (172') located in a portion required for riveting at the distal end, and a second cavity (172") located in a portion where a riveting jig (described later) is to be positioned at the bottom. This allows the rigidity of the conductive boss (170) to be further reinforced.

[0079] Fig. 8 is a partial cross-sectional view of a cap assembly including a cap plate (110) in which the current collector (130) of the present invention described above, a terminal (150), and related components are assembled. Fig. 8 is similar to the assembled state of the components shown in the exploded view of Fig. 2 above. Among the first terminal (150) and the second terminal (160) included in the secondary battery, only the first terminal (150) and the related components are shown.

[0080] In Fig. 8, a lower insulating plate (120) is positioned at the bottom of the cap plate (110), and a current collector (130) and a terminal (150) can be connected with the lower insulating plate (130) therebetween. A conductive boss (170) formed on a substrate (131) of the current collector (130) protrudes upward through a through-hole (121) formed in the lower insulating plate (120), and a terminal (150) can be coupled to the protruding conductive boss (170). For coupling with the current collector (130), a through-hole (152) through which the conductive boss (170) passes is formed in the terminal (150) (see Fig. 2).

[0081] A seal gasket (190) for sealing the case is covered on the conductive boss (170), so as to seal the space between the current collector (130) and the terminal (150) and between adjacent members. The recessed portion (174) formed on the upper surface of the conductive boss (170) can be riveted to the terminal (150) using a riveting machine (if necessary, welding can be performed on the relevant area after riveting). In order to strengthen the bonding property when the terminal recessed portion (174) of the conductive boss (170) is pressed during riveting and joined to the terminal (150), a riveting receiving groove (151) can be formed around the insertion hole (152) of the conductive boss (170) of the terminal (150) to accommodate the spreading of the flesh during rivet joining.

[0082] By means of the ring member (177) fastened to the ring groove (176) of the conductive boss (170), the seal gasket (190) and adjacent members can be kept in the correct position. In addition, the ring member (177) can control the amount of elongation (amount of flesh spreading) of the end portion of the conductive boss (170) when riveting the recessed portion (174) by restricting the conductive boss (170) of the current collector (130) from being excessively inserted into the through hole (152) of the terminal (150). As a result, the fastening force between the current collector (130) and the terminal (150) can be strengthened.

[0083] As mentioned above, an insulator (105) may be interposed between the cap plate (110) and the terminal (150). In addition, a step (113) may be formed on the cap plate (110) so that the surface (111) on which the insulator (105) and the terminal (150) are mounted is positioned lower than the upper surface of the cap plate (110). However, this configuration is not limited, and the insulator (105) and the terminal (150) may be placed directly on the surface of the cap plate (110).

[0084] In FIG. 8, the mounting surface (111) of the cap plate (110) and the seal gasket (190) are shown to be positioned below the ring member (177) fastened to the conductive boss (170), the insulator (105) is at the same position as the ring member (177), and the terminal (150) is shown to be positioned above the ring member (177), but the present invention is not limited to this structure.

[0085] Figure 9 is a schematic diagram for explaining a riveting connection method of a challenge boss (170) and a terminal (150).

[0086] As shown in Fig. 9, the related parts are first assembled, and after installing the riveting support jig (300) under the current collector (130), the terminal recessed portion (174) of the conductive boss (170) is impacted with a riveting machine (310) to rivet the terminal through-hole (152 of Fig. 2 and Fig. 8) of the terminal (150). The terminal recessed portion (174) of the conductive boss (170) is stretched by the impact of the riveting machine (310), and as the flesh spreads, it is received into the riveting receiving groove (151) formed in the terminal (150) and firmly joined.

[0087] At this time, although it is a repetitive explanation, the seal gasket (190) and other members underneath it can be firmly positioned between the terminal (150) and the current collector (130) without being dislodged from their original positions by the ring member (177) fastened to the challenge boss (170), and the amount by which the end of the challenge boss (170) is extended (the amount by which the flesh spreads) can be controlled to a constant level.

[0088] FIG. 10 is a cross-sectional view of a secondary battery including a cap assembly assembled by bonding the aforementioned collector (130, 140) to a cap plate (110).

[0089] Referring to FIG. 10 together with FIG. 8, the tab connection portion (132) of the current collector substrate (131) of the first current collector (130) can be connected to the first electrode tab (210) of the electrode assembly (200), and the tab connection portion (142) of the substrate (141) of the second current collector (140) can be connected to the second electrode tab (220) of the electrode assembly (200).

[0090] The coupling relationship of the lower insulating plate (120), seal gasket (190), insulator (105), first terminal (150), and second terminal (160) located at the bottom of the cap plate (110) is as shown in Fig. 8. In addition, the vent portion (112) and electrolyte injection port (114) formed in the cap plate (110) are as described in Fig. 2.

[0091] In Fig. 10, the terminal recessed portion (174) of the conductive boss (170) of the first current collector (130) is riveted and received in the riveting receiving groove (151) of the first terminal (150) described in Fig. 8, and the terminal recessed portion (184) of the conductive boss (180) of the second current collector (140) is riveted and received in the riveting receiving groove (151) of the second terminal (160). This is indicated as a riveting completion area as "178" in Fig. 10.

[0092] The secondary battery illustrated in FIG. 10 is a secondary battery having a top-tab structure, but the current collector (130) and the cap assembly assembled therewith according to the present invention are not limited to the top-tab structure and can also be applied to the side-tab structure illustrated in FIG. 1b.

[0093] Hereinafter, a method for manufacturing a secondary battery including the above-described collector and cap assembly will be described.

[0094] A method for manufacturing a secondary battery according to some embodiments of the present invention may include: a step of manufacturing a current collector substrate (131) connecting an electrode assembly (200) and a terminal (150); a step of forming a conductive boss (170) on the current collector substrate (131); a step of forming a ring groove (176) for accommodating a ring member (177) on the conductive boss (170); and a step of riveting the conductive boss (170) to the terminal (150).

[0095] The steps of manufacturing the current collector substrate (131), forming a conductive boss (170) on the current collector substrate (131), and forming a ring groove (176) on the conductive boss (170) may be steps of manufacturing the current collector (130) illustrated in FIGS. 3 and 5. In addition, the riveting step may be performed by riveting the end of the conductive boss (170) that has come out through the through hole (152) formed in the terminal (150) as illustrated in FIG. 9 to join it to the terminal (150).

[0096] A method for manufacturing a secondary battery according to some embodiments may further include, with reference to FIGS. 8 and 2, a step of mounting a seal gasket (190) on the conductive boss (170); a step of fastening a ring member (177) to the ring groove (176); and a step of assembling a cap plate (110). The ring member (177) may serve to secure the seal gasket (190) and the lower insulating plate (120) in place, as shown in FIG. 8.

[0097] Additionally, the method for manufacturing a secondary battery according to some embodiments may additionally include a step of assembling a lower insulating plate (120) between the cap plate (110) and the current collector substrate (131).

[0098] Additionally, a method for manufacturing a secondary battery according to some embodiments may additionally include a step of interposing an insulator (105) at a position where a terminal (150) is mounted on the upper surface of a cap plate (110).

[0099] A description is given of materials that can be used in a secondary battery according to the present invention.

[0100] A compound capable of reversible intercalation and deintercalation of lithium (a lithiated intercalation compound) can be used as a cathode active material. Specifically, one or more of a composite oxide of lithium and a metal selected from cobalt, manganese, nickel, and combinations thereof can be used.

[0101] The above composite oxide may be a lithium transition metal composite oxide, and specific examples thereof include lithium nickel-based oxide, lithium cobalt-based oxide, lithium manganese-based oxide, lithium iron phosphate-based compound, cobalt-free nickel-manganese-based oxide, or a combination thereof.

[0102] As an example, a compound represented by any one of the following chemical formulas may be used: Li a A 1-b X b O 2-c D c (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05); Li a Mn 2-b X b O 4-c D c (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05); Li a Ni 1-b-c Co b X c O 2-α D α (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.5, 0<α<2); Li a Ni 1-b-c Mn b X c O 2-α D α (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.5, 0<α<2); Li a Ni b Co c L 1 d G e O2(0.90≤a≤1.8, 0≤b≤0.9, 0≤c≤0.5, 0≤d≤0.5, 0≤e≤0.1); Lia NiG b O2(0.90≤a≤1.8, 0.001≤b≤0.1); Li a CoG b O2(0.90≤a≤1.8, 0.001≤b≤0.1); Li a Mn 1-b G b O2(0.90≤a≤1.8, 0.001≤b≤0.1); Li a Mn2G b O4(0.90≤a≤1.8, 0.001≤b≤0.1); Li a Mn 1-g G g PO4(0.90≤a≤1.8, 0≤g≤0.5); Li (3-f) Fe2(PO4)3(0≤f≤2); Li a FePO4(0.90≤a≤1.8).

[0103] In the above chemical formula, A is Ni, Co, Mn, or a combination thereof; X is Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, a rare earth element, or a combination thereof; D is O, F, S, P, or a combination thereof; G is Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V, or a combination thereof; L 1 is Mn, Al, or a combination thereof.

[0104] A positive electrode for a lithium secondary battery may include a positive electrode substrate and a positive electrode active material layer formed on the substrate. The positive electrode active material layer includes a positive electrode active material and may further include a binder and / or a conductive material.

[0105] The content of the positive electrode active material may be 90 wt% to 99.5 wt% with respect to 100 wt% of the positive electrode active material layer, and the contents of the binder and conductive material may be 0.5 wt% to 5 wt%, respectively, with respect to 100 wt% of the positive electrode active material layer.

[0106] Al may be used as the above anode material, but is not limited thereto.

[0107] The negative electrode active material includes a material capable of reversibly intercalating / deintercalating lithium ions, lithium metal, an alloy of lithium metal, a material capable of doping and dedoping lithium, or a transition metal oxide.

[0108] The material capable of reversibly intercalating / deintercalating the lithium ions may include a carbon-based negative electrode active material, for example, crystalline carbon, amorphous carbon, or a combination thereof. Examples of the crystalline carbon include graphite such as natural graphite or artificial graphite, and examples of the amorphous carbon include soft carbon or hard carbon, mesophase pitch carbide, calcined coke, and the like.

[0109] As the material capable of doping and dedoping the lithium, a Si-based negative electrode active material or a Sn-based negative electrode active material can be used. The Si-based negative electrode active material is silicon, a silicon-carbon composite, SiO x (0 <x<2), Si계 합금, 또는 이들의 조합일 수 있다.

[0110] The above silicon-carbon composite may be a composite of silicon and amorphous carbon. According to one embodiment, the silicon-carbon composite may be in the form of silicon particles and amorphous carbon coated on the surface of the silicon particles.

[0111] The silicon-carbon composite may further comprise crystalline carbon. For example, the silicon-carbon composite may comprise a core comprising crystalline carbon and silicon particles and an amorphous carbon coating layer positioned on the surface of the core.

[0112] A negative electrode for a lithium secondary battery includes an negative electrode substrate and a negative electrode active material layer positioned on the substrate. The negative electrode active material layer includes a negative electrode active material and may further include a binder and / or a conductive material.

[0113] For example, the negative electrode active material layer may include 90 to 99 wt% of the negative electrode active material, 0.5 to 5 wt% of the binder, and 0 to 5 wt% of the conductive material.

[0114] The above binder may be a non-aqueous binder, an aqueous binder, a dry binder, or a combination thereof. When an aqueous binder is used as the negative electrode binder, a cellulose-based compound capable of imparting viscosity may be further included.

[0115] The cathode substrate may be selected from copper foil, nickel foil, stainless steel foil, titanium foil, nickel foam, copper foam, a polymer substrate coated with a conductive metal, and a combination thereof.

[0116] An electrolyte for a lithium secondary battery contains a non-aqueous organic solvent and a lithium salt.

[0117] The above non-aqueous organic solvent acts as a medium through which ions involved in the electrochemical reaction of the battery can move.

[0118] The above non-aqueous organic solvent may be a carbonate-based, ester-based, ether-based, ketone-based, or alcohol-based solvent, an aprotic solvent, or a combination thereof, and may be used alone or in combination of two or more thereof.

[0119] Additionally, when using a carbonate solvent, a mixture of cyclic carbonate and chain carbonate can be used.

[0120] Depending on the type of lithium secondary battery, a separator may be present between the positive and negative electrodes. Such separators may be polyethylene, polypropylene, polyvinylidene fluoride, or a multilayer film comprising two or more layers of these materials.

[0121] The separator may include a porous substrate and a coating layer comprising an organic material, an inorganic material, or a combination thereof, positioned on one or both sides of the porous substrate.

[0122] The above organic material may include a polyvinylidene fluoride-based antibody or a (meth)acrylic polymer.

[0123] The above inorganic materials are Al2O3, SiO2, TiO2, SnO2, CeO2, MgO, NiO, CaO, GaO, ZnO, ZrO2, Y2O3, It may include inorganic particles selected from, but not limited to, SrTiO3, BaTiO3, Mg(OH)2, boehmite, and combinations thereof.

[0124] The organic and inorganic substances may be mixed and present in one coating layer, or a coating layer including an organic substance and a coating layer including an inorganic substance may be present in a laminated form.

[0125] Fig. 11 is an exemplary diagram of a secondary battery module in which secondary batteries are arranged according to the aforementioned embodiment of the present invention. In accordance with the need for higher capacity secondary batteries for driving electric vehicles and the like, a secondary battery module is manufactured by arranging and connecting a plurality of secondary battery cells in a transverse and / or longitudinal direction. A plurality of secondary batteries are arranged in a space formed by a pair of opposing end plates (68a, 68b) and a pair of opposing side plates (69a, 69b). The arrangement of the secondary batteries can be designed in terms of the arrangement direction and number to obtain desired voltage and current specifications.

[0126] Fig. 12 is an exemplary diagram of a secondary battery pack (70) configured to apply the secondary battery module illustrated in Fig. 11 to an actual product (e.g., an automobile). The secondary battery pack can be manufactured by embedding a plurality of secondary battery modules in a pack housing designed to be mounted on an actual product. The pack housing may include fasteners and electrical outlets necessary for mounting on a product. In Fig. 12, for convenience of illustration, bus bars for electrical connection of secondary batteries, a cooling unit, external terminals, and other related elements are omitted.

[0127] A secondary battery pack can be mounted on a vehicle. The vehicle may be, for example, an electric vehicle, a hybrid vehicle, or a plug-in hybrid vehicle. The vehicle includes a four-wheel drive or two-wheel drive vehicle. FIG. 13 is a drawing illustrating a vehicle including the secondary battery pack illustrated in FIG. 12. FIG. 13 illustrates a secondary battery pack (70) according to some embodiments of the present invention mounted on the lower part of a body of a vehicle (V). The vehicle (V) operates by receiving power from the secondary battery pack (70) according to some embodiments of the present invention.

[0128] Although the present invention has been described above with reference to 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 idea of ​​the present invention and the equivalent scope of the patent claims to be described below by a person having ordinary skill in the art to which the present invention pertains.

[0129] [Explanation of symbols]

[0130] 40: electrode assembly, 41: first current collector, 42: second current collector, 43: first electrode tab, 44: second electrode tab, 51: case, 60: cap assembly, 61: cap plate, 62: first terminal, 63: second terminal, 64: electrolyte injection port, 65: notch, 66: vent, 67: connecting member, 68a 68b: end plate, 69a 69b: side plate, 70: secondary battery pack, 100: case, 105: insulator, 110: cap plate, 107 115: through hole, 111: mounting surface, 112: vent part, 114: electrolyte injection port, 120: lower insulating plate, 121: through hole, 130: first current collector, 140: second Current collector, 131: current collector substrate, 132: tab connection, 133: through hole, 140: second current collector, 150: first terminal, 151: riveting receiving groove, 160: second terminal, 170 180: conductive boss, 172 172' 172": cavity, 171: boundary wall, 173: opening, 174: recessed portion, 175: curved connection, 175': angled connection, 176: ring groove, 177: ring member, 178: riveted completion area, 190: seal gasket (190), 200: electrode assembly, 210: first electrode tab, 220: second electrode tab, 300: riveting support jig, 310: riveting machine, V: automobile

Claims

1. A case where at least one opening is formed; An electrode assembly accommodated in the above case; a current collector electrically connected to the above electrode assembly; and A cap assembly including a terminal electrically connected to the above-mentioned collector and installed in an opening of the case, A secondary battery, wherein the above-mentioned collector includes a conductive boss formed toward the terminal of the cap assembly.

2. In the first paragraph, the conductive boss of the entire body A secondary battery, connected to the above-mentioned device and surface.

3. In the first paragraph, the conductive boss of the entire body A secondary battery, connected to each surface as described above.

4. In the first paragraph, the conductive boss of the entire body A secondary battery comprising a cavity formed in at least a portion of its interior.

5. In the first paragraph, the conductive boss of the entire body A secondary battery comprising a recessed portion formed at a terminal.

6. In the first paragraph, the conductive boss of the entire body A secondary battery comprising a ring groove for accommodating a ring member.

7. A secondary battery in accordance with claim 6, wherein the terminal is positioned on the upper portion of the ring member accommodated in the ring groove.

8. In paragraph 1, The above-mentioned conductive boss of the entire body is connected to the above-mentioned terminal by riveting, A secondary battery, wherein the terminal includes a riveting receiving groove that receives a terminal that is extended when the challenge boss is riveted.

9. In the 6th paragraph, the cap assembly A secondary battery further comprising a cap plate positioned between the entire body and the ring member accommodated in the ring groove.

10. A secondary battery according to claim 6, further comprising a seal gasket positioned between the entire body and the ring member accommodated in the ring groove.

11. A secondary battery according to claim 1, further comprising an insulator positioned between the current collector and the terminal.

12. A secondary battery including a case having at least one opening formed therein, an electrode assembly accommodated in the case, a terminal electrically connected to the electrode assembly, and a cap assembly installed in the opening of the case, A current collector for a secondary battery, which electrically connects the electrode assembly and the terminal and includes a conductive boss formed toward the terminal of the cap assembly.

13. In paragraph 12, the challenge boss A current collector for a secondary battery, connected to the above-described surface.

14. In paragraph 12, the challenge boss A current collector for a secondary battery, connected to each surface as described above.

15. In paragraph 12, the challenge boss A current collector for a secondary battery, comprising a cavity formed in at least a portion of the interior.

16. In paragraph 12, the challenge boss A current collector for a secondary battery, comprising a recessed portion formed at a terminal.

17. In paragraph 12, the challenge boss A current collector for a secondary battery, comprising a ring groove for accommodating a ring member.

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