Secondary battery

Abstract

The present disclosure relates to a secondary battery including a cap assembly. The cap assembly of the secondary battery according to the present disclosure includes a cap plate, an electrode terminal, a base insulator, and a fixing element. The fixing element penetrates the cap plate and the electrode terminal to form the cap assembly. A current collector is inserted into the fixing element and is joined to the fixing element. The cap assembly of the secondary battery according to the present disclosure may prevent leakage of electrolyte and may be simply assembled.

Description

secondary battery

[0001] The present invention relates to a secondary battery, and more particularly, to a secondary battery in which a cap assembly is joined with a fixing member and a current collecting member is inserted into the fixing member to join the current collecting member and the fixing member.

[0002] Recently, with the rapid increase in demand for portable electronic products and the full-scale development of electric vehicles, energy storage batteries, robots, satellites, etc., research on high-performance secondary batteries capable of repeated charging and discharging is actively being conducted.

[0003] Secondary batteries can be classified into can-type secondary batteries, in which the electrode assembly is housed in a metal can, and pouch-type secondary batteries, in which the electrode assembly is housed in a pouch made of an aluminum laminate sheet, depending on the shape of the battery case. Can-type secondary batteries can be classified into cylindrical secondary batteries and square secondary batteries, depending on the shape of the metal can.

[0004] In can-type secondary batteries, the electrode assembly is housed within a metal case, and a cap assembly is attached to an opening in the case. If the seal between the components forming the cap assembly weakens, problems such as electrolyte leakage can occur. In particular, sealing between the cap plate and the electrode terminals that are joined along the through-holes in the cap plate becomes crucial. Reinforcing the seal of the cap assembly to address this issue requires the use of various sealing materials, complicating the assembly process.

[0005] Accordingly, there is a need to develop a cap assembly for a secondary battery that can be assembled simply while preventing electrolyte leakage.

[0006] An object of the present invention is to provide a secondary battery including a cap assembly that prevents leakage of electrolyte and can be easily assembled.

[0007] Another object of the present invention is to provide a secondary battery including a cap assembly having improved adhesion between components.

[0008] A secondary battery according to an embodiment of the present invention may include a case, an electrode assembly, a current collector, and a cap assembly. An opening may be formed in the case. The electrode assembly may be accommodated in the case and may include an electrode portion and a plurality of electrode tabs. The electrode tabs may be formed in the electrode portion. The current collector may include a current collector and a current collector protrusion. The current collector may be electrically connected to the plurality of electrode tabs. The current collector protrusion may protrude from the current collector. The cap assembly may be coupled to the opening of the case. The cap assembly may include a cap plate, an electrode terminal, a terminal insulating member, a base insulating member, and a fixing member. The cap plate may have an electrolyte injection port for electrolyte injection and a through hole. The electrode terminal may have a terminal hole. The electrode terminal may be coupled to the cap plate such that the through hole and the terminal hole overlap. The terminal insulating member may be positioned between the electrode terminal and the cap plate. The base insulating member may be positioned between the cap plate and the electrode assembly. A guide hole may be formed in a position corresponding to an electrolyte injection port in the base insulating member. The fixing member may include a body portion, a first fixing portion, and a second fixing portion. The body portion has a hollow structure into which a current collecting protrusion may be inserted, and may be inserted into a through hole and a terminal hole. The first fixing portion may extend in an outer lateral direction from a first end of the body portion. The second fixing portion may extend in an outer lateral direction from a second end of the body portion. The current collecting protrusion and the first fixing portion of the fixing member may be joined to each other.

[0009] In a secondary battery according to an embodiment of the present invention, the cap assembly may further include a gasket positioned between the cap plate and the fixing member.

[0010] In a secondary battery according to an embodiment of the present invention, the first fixing portion and the second fixing portion of the fixing member can be pressed in the direction of the cap plate.

[0011] In a secondary battery according to an embodiment of the present invention, the first fixing portion and the electrode terminal can be welded to each other.

[0012] In a secondary battery according to an embodiment of the present invention, an electrode terminal may have a fixing groove formed around a terminal hole in which a first fixing portion of a fixing member is positioned.

[0013] In a secondary battery according to an embodiment of the present invention, the first fixing portion of the fixing member may be positioned so as to have a height lower than the upper end of the electrode terminal in the height direction.

[0014] In a secondary battery according to an embodiment of the present invention, the current collector protrusion may be inserted into the body portion so that the upper end thereof in the height direction is at the same height as or lower than the first fixing portion of the fixing member.

[0015] In a secondary battery according to an embodiment of the present invention, a first fixing groove may be formed on the upper surface of the current collector in the height direction to accommodate and secure a second fixing portion around the current collector projection.

[0016] In a secondary battery according to an embodiment of the present invention, a second protrusion may be formed on the current collector, and a second fixing groove into which the second protrusion is inserted may be formed on the second fixing portion.

[0017] In a secondary battery according to an embodiment of the present invention, a first insulating tape may be attached to a current collector electrically connected to an electrode assembly.

[0018] In a secondary battery according to an embodiment of the present invention, a second insulating tape may be attached to an outer surface of the electrode assembly on which an electrode tab is not formed.

[0019] In a secondary battery according to an embodiment of the present invention, a third insulating tape may be attached to the outer surface of a case in which an electrode assembly is accommodated and a cap assembly is coupled.

[0020] In a secondary battery according to an embodiment of the present invention, the base insulating member may further include a guide portion protruding from the guide hole toward the electrode assembly.

[0021] In a secondary battery according to an embodiment of the present invention, an electrolyte injection port has an injection protrusion formed at the bottom, and the injection protrusion can be inserted into a guide hole.

[0022] In a secondary battery according to an embodiment of the present invention, a case may be formed with a first opening and a second opening. An electrode assembly may include a plurality of first electrode tabs formed in a first direction and a plurality of second electrode tabs formed in a second direction, and may be accommodated in the case such that the first electrode tabs face the first opening and the second electrode tabs face the second opening. A current collecting member may include a first current collecting member connected to the first electrode tab and a second current collecting member connected to the second electrode tab. A cap assembly may include a first cap assembly coupled to the first opening and a second cap assembly coupled to the second opening.

[0023] In a secondary battery according to an embodiment of the present invention, the electrode terminal of the first cap assembly may be made of the same material as the fixing member, and the electrode terminal of the second cap assembly may be made of a different material from the fixing member.

[0024] In a secondary battery according to an embodiment of the present invention, the plurality of electrode tabs may include a plurality of first electrode tabs and a plurality of second electrode tabs. The plurality of first electrode tabs may include a plurality of spaced apart electrode tabs that are bent over the current collector on both sides of the current collecting projections of the current collecting member and welded to the current collector. The plurality of second electrode tabs may include a plurality of spaced apart electrode tabs that are bent over the current collector on both sides of the current collecting projections of the current collecting member different from the current collecting portion connected to the first electrode tab and welded to the current collector.

[0025] In a secondary battery according to an embodiment of the present invention, a plurality of first electrode tabs and a plurality of second electrode tabs can be formed in different directions in the electrode assembly.

[0026] In a secondary battery according to an embodiment of the present invention, an electrode assembly may include a first electrode portion and a second electrode portion. The first electrode portion may include a first electrode tab and a second electrode tab, and the second electrode portion may include a first electrode tab and a second electrode tab. The first electrode tab of the first electrode portion and the first electrode tab of the second electrode portion may be joined to the same current collecting member. The second electrode tab of the first electrode portion and the second electrode tab of the second electrode portion may be joined to the same current collecting member.

[0027] A secondary battery according to one embodiment of the present invention may include a case, an electrode assembly, a current collector, and a cap assembly. An opening may be formed in the case. The electrode assembly may include an electrode portion accommodated in the case and a plurality of electrode tabs formed at one end of the electrode portion. The current collector may include a current collector electrically connected to the electrode tab and a current collector protrusion protruding from the current collector. The cap assembly may be coupled to the opening of the case. The cap assembly may include a cap plate, an electrode terminal, and a fixing member. A through hole may be formed in the cap plate. The electrode terminal may be formed with a terminal hole. The electrode terminal may be coupled to the cap plate such that the through hole and the terminal hole overlap. The fixing member may include a body portion, a first fixing member, and a second fixing member. The body portion has a hollow structure into which a current collector protrusion may be inserted, and may be inserted into the through hole and the terminal hole. The first fixing member may extend in an outer lateral direction from a first end of the body portion. The second fixed portion may extend in an outer lateral direction from the second end of the body portion.

[0028] In a secondary battery according to one embodiment of the present invention, the cap plate and the electrode terminal can be pressed by a fixing member.

[0029] In a secondary battery according to one embodiment of the present invention, the second fixing portion may be thicker in the height direction than the first fixing portion.

[0030] In a secondary battery according to one embodiment of the present invention, the maximum length extending in the outer side direction of the second fixing portion may be longer than the maximum length extending in the outer side direction of the first fixing portion.

[0031] The second fixing portion of the secondary battery according to one embodiment of the present invention may be divided into a plurality of segments extending in the outer side direction.

[0032] According to one embodiment of the present invention, an electrode terminal of a secondary battery may have a mounting groove formed along the circumference of the terminal hole on the upper surface in the height direction, in which a first fixing part is mounted.

[0033] In a secondary battery according to one embodiment of the present invention, the first fixing portion may be mounted so as to have a height lower than the upper end of the electrode terminal in the height direction.

[0034] In a secondary battery according to one embodiment of the present invention, the cap assembly may further include a terminal insulating member positioned between the electrode terminal and the cap plate.

[0035] In a secondary battery according to one embodiment of the present invention, a receiving groove may be formed along the circumference of a through hole on an upper surface of a cap plate in the height direction, and an insulating protrusion may be formed on a terminal insulating member to protrude in the direction of the cap plate and be received in the receiving groove.

[0036] In a secondary battery according to one embodiment of the present invention, the cap plate and the insulating protrusion may be spaced apart from each other so that a space is formed in the lateral direction.

[0037] In a secondary battery according to one embodiment of the present invention, a terminal groove may be formed on an upper surface of a terminal insulating member in the height direction, and a terminal protrusion may be formed on an electrode terminal to protrude in the direction of the terminal insulating member and be accommodated in the terminal groove.

[0038] In a secondary battery according to one embodiment of the present invention, the terminal hole has a smaller radius than the through hole, and the first fixing portion of the fixing member can extend further outward than the through hole past the terminal hole in the outer side direction.

[0039] In a secondary battery according to one embodiment of the present invention, the cap assembly may further include a base insulating member positioned between the cap plate and the electrode assembly.

[0040] In a secondary battery according to one embodiment of the present invention, the cap assembly may further include a gasket positioned between the cap plate and the fixing member.

[0041] In a secondary battery according to one embodiment of the present invention, the gasket may include an insertion portion and a support portion. The insertion portion may be inserted into a through hole. The support portion may be bent in an outer lateral direction from one end of the insertion portion and positioned between the cap plate and the second fixing portion.

[0042] In a secondary battery according to one embodiment of the present invention, the terminal hole has a smaller radius than the through hole, and the upper end of the insertion portion of the gasket can contact the lower surface of the electrode terminal in the height direction.

[0043] In a secondary battery according to one embodiment of the present invention, the cap assembly further includes a base insulating member positioned between the cap plate and the electrode assembly, and the support member can be positioned laterally parallel to the base insulating member.

[0044] In a secondary battery according to one embodiment of the present invention, the support member and the base insulating member may be spaced apart from each other so that a space is formed in the lateral direction.

[0045] In a secondary battery according to one embodiment of the present invention, the support portion of the gasket may have the same thickness in the height direction as the base insulating member.

[0046] In a secondary battery according to one embodiment of the present invention, the second fixing portion may extend past the support portion and cover at least a portion of the base insulating member while a portion thereof is in contact with the support portion.

[0047] In a secondary battery according to one embodiment of the present invention, at least one first protrusion may be formed in the second fixing portion in a direction toward the cap plate, and a fastening groove into which the first protrusion is inserted may be formed in at least one of the base insulating member or the gasket.

[0048] In a secondary battery according to one embodiment of the present invention, a gasket may have a groove formed at a portion where an insertion portion and a support portion come into contact, and a cap plate may have a gasket protrusion formed around a through hole to be inserted into the groove of the gasket.

[0049] In a secondary battery according to one embodiment of the present invention, the current collector and the second fixing part of the current collector member can be combined in an interlocking manner.

[0050] The secondary battery according to the embodiment of the present invention can prevent leakage of electrolyte and simplify the assembly process by having a fixing member.

[0051] A secondary battery according to an embodiment of the present invention can enhance sealing performance by improving the adhesion between components of a cap assembly.

[0052] A secondary battery according to an embodiment of the present invention can reduce the thickness of a cap assembly.

[0053] FIG. 1 is a perspective view illustrating a secondary battery according to an embodiment of the present invention.

[0054] FIG. 2 is a perspective view showing an exploded view of a cap assembly in a secondary battery according to an embodiment of the present invention.

[0055] FIG. 3 is a perspective view illustrating an electrode assembly in which a plurality of first and second electrode tabs are formed on an electrode portion in a secondary battery according to an embodiment of the present invention.

[0056] FIG. 4a and FIG. 4b are drawings illustrating a first electrode member and a second electrode member of a secondary battery according to an embodiment of the present invention.

[0057] Figure 5 is an exploded view showing a cap assembly according to an embodiment of the present invention.

[0058] FIG. 6 is a conceptual drawing showing an electrode terminal and a terminal insulating member being mounted on a cap plate according to an embodiment of the present invention.

[0059] FIG. 7 is a drawing showing the lower surface of an electrode terminal and a terminal insulating member according to an embodiment of the present invention.

[0060] FIGS. 8a and 8b are conceptual drawings illustrating the formation of a first fixing portion of a fixing member according to an embodiment of the present invention.

[0061] FIG. 9 is a drawing showing various modified embodiments of a fixing member according to an embodiment of the present invention.

[0062] FIGS. 10A and 10B are cross-sectional views showing a cap assembly according to an embodiment of the present invention.

[0063] FIGS. 11a and 11b are cross-sectional views of a cap assembly having a groove formed therein according to another embodiment of the present invention.

[0064] FIG. 12 is a drawing showing an electrode terminal inserted into a cap assembly according to an embodiment of the present invention.

[0065] FIG. 13a is a drawing showing a current collector member having a first fixing groove formed therein according to an embodiment of the present invention, and FIG. 13b is a drawing showing a second fixing portion of the fixing member being secured to a current collector having a first fixing groove formed therein.

[0066] FIG. 14 is a drawing showing the second fixing part of the fixing member and the entire body being combined according to an embodiment of the present invention.

[0067] FIG. 15a is a drawing showing a cap plate and a base insulating member according to an embodiment of the present invention, and FIG. 15b is a drawing showing a lower surface of the base insulating member.

[0068] Fig. 16 is a cross-sectional view showing an electrolyte injection port of a cap plate and a guide hole of a base insulating member according to one embodiment of the present invention.

[0069] FIG. 17 is a drawing conceptually illustrating a process of combining an electrode tab and a current collector member in a secondary battery according to one embodiment of the present invention.

[0070] FIG. 18 is a drawing conceptually illustrating a process of combining a cap assembly and a current collector member in a secondary battery according to one embodiment of the present invention.

[0071] FIG. 19 is a drawing conceptually illustrating a process of combining a current collector and an electrode tab when the electrode tab is formed in both directions of an electrode assembly in a secondary battery according to another embodiment of the present invention.

[0072] FIG. 20 is a drawing conceptually illustrating a process in which a cap assembly is coupled to a current collector in a secondary battery according to another embodiment of the present invention.

[0073] FIG. 21 is a conceptual drawing showing that an insulating tape is attached while the electrode assembly and the current collector are combined according to one embodiment of the present invention.

[0074] FIG. 22 is a conceptual diagram illustrating two electrode tabs having the same polarity being joined to one current collector member according to another embodiment of the present invention.

[0075] FIG. 23 is a drawing conceptually illustrating a process in which a cap assembly is coupled to a current collector in a secondary battery according to another embodiment of the present invention.

[0076] FIG. 24 is a conceptual drawing showing that in a secondary battery according to another embodiment of the present invention, electrode tabs of different polarities are formed in both directions of an electrode assembly and two electrode tabs of the same polarity are joined to one current collecting member.

[0077] FIG. 25 is a drawing conceptually illustrating a process in which a cap assembly is coupled to a current collector in a secondary battery according to another embodiment of the present invention.

[0078] FIG. 26 is a drawing showing a secondary battery including two electrode parts according to another embodiment of the present invention.

[0079] Figure 27 is a drawing showing electrode tabs formed on two electrode portions according to another embodiment of the present invention being joined to an electrode member.

[0080] The present invention is susceptible to various modifications and embodiments. Specific embodiments are illustrated and described in detail in the detailed description. However, this is not intended to limit the present invention to specific embodiments, but rather to encompass all modifications, equivalents, and alternatives falling within the spirit and technical scope of the present invention.

[0081] The terminology used herein is merely used to describe specific embodiments and is not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. In the present invention, it should be understood that the terms "comprise" or "have" are intended to specify the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, but do not exclude in advance the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0082] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Please note that, where possible, identical components are represented by identical reference numerals throughout the drawings. Furthermore, detailed descriptions of well-known functions and configurations that may obscure the gist of the present invention will be omitted. For the same reason, some components in the attached drawings are exaggerated, omitted, or schematically depicted.

[0083]

[0084] FIG. 1 is a perspective view illustrating a secondary battery according to an embodiment of the present invention, FIG. 2 is an exploded perspective view illustrating a cap assembly in a secondary battery according to an embodiment of the present invention, FIG. 3 is a perspective view illustrating an electrode assembly having a plurality of first and second electrode tabs formed on an electrode portion in a secondary battery according to an embodiment of the present invention, FIGS. 4A and 4B are views illustrating a first electrode member and a second electrode member of a secondary battery according to an embodiment of the present invention, FIG. 5 is an exploded view illustrating a cap assembly according to an embodiment of the present invention, FIG. 6 is a view conceptually illustrating an electrode terminal and a terminal insulating member being seated on a cap plate according to an embodiment of the present invention, FIG. 7 is a view illustrating a lower surface of an electrode terminal and a terminal insulating member according to an embodiment of the present invention, FIGS. 8A and 8B are views conceptually illustrating forming a first fixing portion of a fixing member according to an embodiment of the present invention, FIG. 9 is a view illustrating various modified embodiments of a fixing member according to an embodiment of the present invention, and FIGS. 10A and 10B are views illustrating cross-sections of a cap assembly according to an embodiment of the present invention.

[0085] In this embodiment, the height direction can be defined as the z-axis direction (+Z or -Z direction), and the side direction can be defined as the x-axis or y-axis direction (+X, +Y, -X or -Y direction). The height direction and the side direction can be perpendicular directions.

[0086] As illustrated in FIGS. 1 to 10, a secondary battery (1000) according to one embodiment of the present invention may include a case (1100), an electrode assembly (1200), a current collector member (1300), and a cap assembly (1400).

[0087] Referring to FIGS. 1 and 2, a case (1100) may form the exterior of a secondary battery (1000). The case (1100) may have a space formed therein to accommodate an electrode assembly (1200), and an opening formed on one side thereof. In the present embodiment, the case (1100) has a rectangular parallelepiped shape, but is not limited thereto and may be modified in various ways. The case (1100) may be made of a sturdy material capable of protecting the electrode assembly (1200) accommodated therein. For example, the case (1100) may be made of a metal such as aluminum or stainless steel.

[0088] An electrolyte may be accommodated inside the case (1100) together with an electrode assembly (1200). The electrolyte may be composed of a lithium salt such as LiPF6 or LiBF4 in an organic solvent such as EC, PC, DEC, EMC, or DMC. The electrolyte may be liquid, solid, or gel-like.

[0089] The electrode assembly (1200) is housed inside the case (1100). Referring to FIG. 3, the electrode assembly (1200) may include an electrode portion (1210) and a plurality of electrode tabs (1220, 1230).

[0090] Referring to FIGS. 3 to 4B, the electrode portion (1210) includes a plurality of first electrode members (1211), a plurality of second electrode members (1212), and a separator (1213). An active material may be applied to the plurality of first electrode members (1211) and the plurality of second electrode members (1212). The first electrode member (1211) may be formed by applying an active material such as a transition metal oxide to a metal body such as aluminum. The second electrode member (1212) may be formed by applying an active material such as graphite or carbon to a metal body such as copper or nickel. The first electrode member (1211) and the second electrode member (1212) may have a metal plate shape, but are not limited thereto. The first electrode member (1211) may be a positive electrode plate, and the second electrode member (1212) may be a negative electrode plate.

[0091] A separator (1213) is positioned between a plurality of first and second electrode members (1211, 1212) to prevent short circuits between the plurality of first and second electrode members (1211, 1212). The material of the separator may be polyethylene, polypropylene, or a composite thereof.

[0092] The electrode part (1210) can be formed by positioning a separator (1213) between a first electrode member (1211) and a second electrode member (1212) that are sequentially arranged. That is, in one embodiment, the electrode part (1210) can be formed by sequentially stacking a first electrode member (1211), a separator (1213), a second electrode member (1212), and a separator (1213). In another embodiment, the electrode part (1210) can be formed by sequentially arranging a first electrode member (1211), a separator (1213), and a second electrode member (1212) and then winding them.

[0093] In this embodiment, the electrode assembly (1200) has one electrode portion (1210), but in other embodiments, the electrode assembly (1200) may have a plurality of electrode portions (1210). The plurality of electrode portions (1210) may be electrically connected to each other.

[0094] Electrode tabs (1220, 1230) on which no active material is applied may be formed on one end of a plurality of first and second electrode members (1211, 1212). A first electrode tab (1220) may be formed on the first electrode member (1211), and a second electrode tab (1230) may be formed on the second electrode member (1212). In one embodiment, the electrode members (1211, 1212) and the electrode tabs (1220, 1230) may be formed integrally by cutting a predetermined portion from a single metal plate using a laser or the like to leave the electrode members (1211, 1212) and the electrode tabs (1220, 1230). The plurality of electrode tabs (1220, 1230) may be formed in a direction toward the cap assembly (1400). In another embodiment, a separately formed electrode tab (1220, 1230) may be attached to the electrode member (1211, 1212).

[0095] Referring to FIG. 3, when a plurality of first and second electrode members (1211, 1212) are stacked, a plurality of first electrode tabs (1220) can overlap each other at a first position, and a plurality of second electrode tabs (1230) can overlap each other at a second position. That is, a plurality of first electrode tabs (1220) having the same polarity can be grouped at the first position, and a plurality of second electrode tabs (1230) can be grouped at the second position. The first position and the second position are spaced apart from each other on the electrode member, and the plurality of first electrode tabs (1220) and the plurality of second electrode tabs (1230) that are grouped respectively can be spaced apart in the longitudinal direction of the electrode assembly (1200).

[0096] A plurality of electrode tabs (1220, 1230) overlapped at each location can be joined to each other by ultrasonic welding, laser welding, or the like to facilitate the movement of current. The joined electrode tabs (1220, 1230) can be connected to a current collecting member (1300).

[0097] In this embodiment, the first and second electrode tabs (1220, 1230) may be arranged on one end of the electrode portion (1210). In another embodiment, the first electrode tab (1220) may be arranged on one side of the electrode portion (1210), and the second electrode tab (1230) may be arranged on the other side of the electrode portion (1210).

[0098] The current collector (1300) may include a current collector (1310) and a current collector protrusion (1320). The current collector plate (1310) may be joined to a plurality of electrode tabs (1220, 1230). The current collector (1310) may be made of the same material as the plurality of electrode tabs (1220, 1230). The current collector protrusion (1320) may be formed to protrude from one surface of the current collector (1310). An insulating material may be disposed at the bottom of the current collector (1300). The insulating material may be an insulating plate or an insulating film.

[0099] Referring to FIG. 2, in the present embodiment, the current collecting member (1300) may include a first current collecting member (1300a) and a second current collecting member (1300b). The first current collecting member (1300a) may be joined to the first electrode tab (1220), and the second current collecting member (1300b) may be joined to the second electrode tab (1230). In order to join the current collecting member (1300) and the electrode tab (1220, 1230), the electrode tab (1220, 1230) may be bent, the current collecting member (1300) may be placed on the upper portion of the electrode tab (1220, 1230), and the current collector (1310) and the electrode tab (1220, 1230) may be welded on the upper portion of the current collector (1310). The welding may be performed using a method such as ultrasonic welding or laser welding.

[0100] Referring to FIGS. 1 and 2, the cap assembly (1400) can be coupled to an opening of the case (1100) to seal the opening of the case (1100) in which the electrode assembly (1200) is accommodated. The cap assembly (1400) includes a cap plate (1410), an electrode terminal (1420), a base insulating member (1430), and a fixing member (1440), as illustrated in FIG. 5.

[0101] The cap plate (1410) may be a plate shape that covers the opening of the case (1100), but is not limited thereto and may have various shapes that can seal the opening of the case (1100). The cap plate (1410) may have a shape corresponding to the shape of the opening of the case (1100). The cap plate (1410) may be formed of the same material as the case (1100), and the cap plate (1410) may be fixed to the case (1100) by a method such as laser welding.

[0102] Referring to FIGS. 5 and 6, a cap plate (1410) may have a through hole (1411) formed therein. A main body (1441) of a fixing member (1140) may penetrate the through hole (1411) in the height direction.

[0103] A receiving groove (1412) may be formed on the upper surface in the height direction of the cap plate (1410). A through hole (1411) may be formed by opening in the receiving groove (1412). The cap plate (1410) may include a plate body (1414). The plate body (1414) may have a flat plate shape. The receiving groove (1412) may be formed by being recessed from one surface of the plate body (1414). The cap plate (1410) may include a plate step portion (1415). The plate step portion (1415) may connect the receiving groove (1412) and the plate body (1414). The plate step portion (1415) may be a part of the cap plate (1410) formed in the height direction (e.g., +Z direction).

[0104] A vent portion (1418) and an electrolyte injection port (1419) may be formed in the cap plate (1410). The vent portion (1418) may be opened when the internal pressure of the case (1100) exceeds a reference value. In the present embodiment, the vent portion (1418) is formed in the cap plate (1410), but in other embodiments, the vent portion (1418) may be formed in the case (1100). An electrolyte may be injected into the interior of the case (1100) through the electrolyte injection port (1419).

[0105] Referring to FIGS. 5 and 6, the electrode terminal (1420) may be mounted on the upper portion of the cap plate (1410). The electrode terminal (1420) may include a first electrode terminal (1420a) and a second electrode terminal (1420b). In the present embodiment, the electrode terminal (1420) may have a rectangular plate shape, but is not limited thereto and may have various shapes.

[0106] A terminal hole (1421) may be formed in the electrode terminal (1420). When the electrode terminal (1420) is mounted on the upper portion of the cap plate, the through hole (1411) and the terminal hole (1421) may overlap and communicate with each other. The through hole (1411) and the terminal hole (1421) may have the same central axis. The radius of the through hole (1411) may be larger than the radius of the terminal hole (1421).

[0107] An electrode terminal (1420) may have a mounting groove (1422) formed around a terminal hole (1421). The terminal hole (1421) may be formed to be open on the inside of the mounting groove (1422). The first fixing portion (1442) of the fixing member (1440) may be mounted in the mounting groove (1422).

[0108] The electrode terminal (1420) may include a terminal protrusion (1423). The electrode terminal (1420) may include a terminal body (1424). The terminal protrusion (1423) may protrude from the terminal body (1424) toward the cap plate (1410). The terminal protrusion (1423) may contact a terminal insulating member (1450). The electrode terminal (1420) may include a first peripheral wall (1425) and a second peripheral wall (1426). The diameter of the first peripheral wall (1425) may be larger than the diameter of the second peripheral wall (1426). The terminal hole (1422) may mean a space surrounded by the first peripheral wall (1425) and the second peripheral wall (1426). At least a portion of the fixing member (1440) may be surrounded by a first peripheral wall (1425) and a second peripheral wall (1426). For example, a first fixing portion (1442) of the fixing member (1440) may be surrounded by a first peripheral wall (1425), and a body portion (1441) of the fixing member (1440) may be surrounded by a second peripheral wall (1426). The electrode terminal (1420) may include a terminal edge (1427). The terminal edge (1427) may be a portion of the terminal body (1424) that forms a side surface of the terminal body (1424). The terminal edge (1427) may protrude further in a lateral direction (e.g., in the +X direction) than the terminal protrusion (1423). The electrode terminal (1420) may include a terminal step portion (1428). The terminal step portion (1428) can connect the terminal protrusion (1423) and the terminal edge (1427). The terminal step portion (1428) can be a part of the electrode terminal (1420) formed in the height direction (e.g., +Z direction).

[0109] Referring to FIG. 5, a base insulating member (1430) may be positioned between a cap plate (1410) and an electrode assembly (1200). The base insulating member (1430) may have a plate shape having the same length and width as the cap plate (1410). The base insulating member (1430) may insulate the cap plate (1410) and the electrode assembly (1200). The base insulating member (1430) may insulate the current collector (1310) and the fixing member (1440). A base hole (1431) may be formed in the base insulating member (1430) at a position corresponding to a through hole (1411) of the cap plate (1410). The radius of the base hole (1431) may be larger than the radius of the through hole (1411). Additionally, an exhaust hole may be formed in the base insulating member (1430) at a position corresponding to the vent portion (1418) of the cap plate (1410), and a guide hole may be formed at a position corresponding to the electrolyte injection port (1419).

[0110] The fixing member (1440) may include a body portion (1441), a first fixing member (1442), and a second fixing member (1443). The body portion (1441) has a hollow structure, and a current collecting projection (1320) of a current collecting member (1300) may be inserted into the hollow structure. The body portion (1441) may be inserted into and penetrate a through hole (1411) and a terminal hole (1421) in the height direction.

[0111] The first fixing portion (1442) may be extended by being bent in the outer side direction from the first end of the body portion (1441). The first fixing portion (1442) may be fixed in the fixing groove (1422) of the electrode terminal (1420). The first fixing portion (1442) fixed in the fixing groove (1422) may be surrounded by a peripheral wall (1425) of the fixing groove (1422). The first fixing portion (1442) fixed in the fixing groove (1422) may be welded to the electrode terminal (1420) along the outer periphery. In the present embodiment, the depth of the fixing groove (1422) in the height direction may be greater than the thickness of the first fixing portion (1442). Therefore, the first fixing portion (1442) is fixed so as to have a height lower than the upper end of the electrode terminal (1420) in the height direction. For example, the upper end of the first fixing member (1442) in the height direction may be positioned 0.05 to 10 mm lower than the upper end of the electrode terminal (1420).

[0112] In this embodiment, the fixing groove (1422) may be formed further outward than the through hole (1411) in the outer lateral direction from the center of the terminal hole (1421). Accordingly, the first fixing portion (1442) may also extend further outward than the through hole (1411) in the outer lateral direction. For example, the first fixing portion (1442) may be formed to be 10 to 50% larger than the through hole (1411) in the lateral direction. Through this structure, the first fixing portion (1442) can stably press the electrode terminal (1420).

[0113] The second fixing portion (1443) can be bent and extended in the outer side direction from the second end of the body portion (1441). The second fixing portion (1443) can be in contact with the base insulating member (1430) at the lower portion of the base insulating member (1430).

[0114] Referring to FIG. 8A, the fixing member (1440) is inserted into the through hole (1411) and the terminal hole (1421) in a state where a second fixing portion (1443) is formed at the second end of the body portion (1441). Thereafter, referring to FIG. 8B, one side of the body portion (1441) is pressurized and bent to form a first fixing portion (1442). When the first fixing portion (1442) is pressurized and bent in this manner, the second fixing portion (1443) may be formed to be thicker in the height direction than the first fixing portion (1442). For example, the thickness of the second fixing portion (1443) may be 1.1 to 3 times thicker than the thickness of the first fixing portion (1442). The thickness of the second fixing member (1443) must be thicker than the thickness of the first fixing member (1442), so that the fixing member (1440) can be formed stably, and the fixing member (1440) can strongly press the cap plate (1410) and the electrode terminal (1420).

[0115] Additionally, the maximum lateral length of the second fixing member (1443) may be formed to be longer than the maximum lateral length of the first fixing member (1442). For example, the maximum lateral length of the second fixing member (1443) may be 1.5 to 2 times longer than that of the first fixing member (1442). This allows the fixing member (1440) to increase the adhesion between the components of the cap assembly (1400).

[0116] The fixing member (1440) can have various shapes, as shown in FIGS. 9A to 9C . The main body (1441) of the fixing member (1440) can have various shapes, such as a cylinder or a square pillar. In this case, the cross-sections of the through hole (1411) and the terminal hole (1421) can have the same shape as the cross-section of the main body (1441). Depending on the shape of the main body (1441), the shapes of the first fixing member (1442) and the second fixing member (1443) can also change. The second fixing member (1443) can be divided into a plurality of parts to facilitate bending. That is, the second fixing member (1443) can be divided into a plurality of segments extending in the outer side direction. The first fixing member (1442) can also be divided into a plurality of parts, but the first fixing member (1442) can be formed integrally for sealing.

[0117] After the fixing member (1440) is mounted on the cap assembly (1400), the first fixing portion (1442) and the second fixing portion (1443) can be pressed toward the cap plate (1410). This means that at least one of the cap plate (1410), the electrode terminal (1420), and the base insulating member (1430) of the cap assembly (1400) can be pressed by the fixing member (1443). Accordingly, the elements constituting the cap assembly (1400) are closely coupled, thereby increasing the airtightness of the cap assembly (1400).

[0118] Referring to FIGS. 5 to 7, the cap assembly (1400) may include a terminal insulating member (1450). The terminal insulating member (1450) may be positioned between the electrode terminal (1420) and the cap plate (1410). The terminal insulating member (1450) may insulate the cap plate (1410) and the electrode terminal (1420). The terminal insulating member (1450) may have a shape that completely surrounds the height-wise side surface of the electrode terminal (1420). In another embodiment, the terminal insulating member (1450) may have a shape that only partially surrounds the height-wise side surface of the electrode terminal (1420). An insulating member hole (1451) may be formed in the terminal insulating member (1450) at a position corresponding to a through hole (1411) of the cap plate (1410). The size of the insulating member hole (1451) may be the same as or smaller than the through hole (1411).

[0119] A terminal groove (1452) may be formed on the upper surface of the terminal insulating member (1450) in the height direction. The terminal groove (1452) is formed around the terminal insulating hole (1451). A part of the electrode terminal (1420) is accommodated in the terminal groove (1452). To this end, a terminal protrusion (1423) protruding toward the terminal insulating member (1450) is formed in the electrode terminal (1420). The terminal groove (1452) may have a shape and size capable of accommodating the terminal protrusion (1423). In one embodiment, the terminal groove (1452) may have the same shape and size as the terminal protrusion (1423). The manner in which the terminal protrusion (1423) is accommodated in the terminal groove (1452) allows the electrode terminal (1420) to be stably seated, and facilitates assembly of the electrode terminal (1420) and the terminal insulating member (1450).

[0120] An insulating protrusion (1453) protruding toward the cap plate (1410) in the height direction may be formed on the terminal insulating member (1450). The insulating protrusion (1453) may be received in a receiving groove (1412) formed on the upper surface of the cap plate (1410) in the height direction. The size of the receiving groove (1412) may be formed to be larger than the size of the insulating protrusion (1453). Accordingly, the cap plate (1410) and the insulating protrusion (1453) are spaced apart from each other in the lateral direction, and a spaced-apart space (S1) is formed between the cap plate (1410) and the insulating protrusion (1453). For example, the lateral distance of the spaced-apart space (S1) may be 0.1 to 10 mm. As the spaced-apart space (S1) is formed in this way, the assembly of the cap assembly (1400) can be facilitated.

[0121] Referring to FIGS. 10A and 10B, the cap plate (1410), the electrode terminal (1420), the base insulating member (1430), and the terminal insulating member (1450) can be stacked on each other along the height direction.

[0122] A terminal insulating member (1450) may be laminated on the upper part of the cap plate (1410) in the height direction. An insulating protrusion (1453) of the terminal insulating member (1450) may be seated in a receiving groove (1412) of the cap plate (1410). The plate step portion (1415) may face the insulating step portion (1455). The plate step portion (1415) and the insulating step portion (1455) may be aligned in the lateral direction (e.g., +X direction). For example, the plate step portion (1415) and the insulating step portion (1455) may have the same length in the height direction (e.g., +Z direction) and may be positioned at the same height in the height direction (e.g., +Z direction). The plate step portion (1415) and the insulating step portion (1455) may be spaced apart from each other in the lateral direction (+X direction). The space (S1) between the cap plate (1410) and the insulating protrusion (1453) can be formed as a space (S1) between the plate step portion (1415) and the insulating step portion (1455).

[0123] An electrode terminal (1420) may be stacked on the upper portion in the height direction of a terminal insulating member (1450). A terminal protrusion (1423) of the electrode terminal (1420) may be seated in a terminal groove (1452) of the terminal insulating member (1450). An insulating step portion (1455) may face a terminal step portion (1428). The insulating step portion (1455) and the terminal step portion (1428) may be aligned in the lateral direction. For example, the insulating step portion (1455) and the terminal step portion (1428) may have the same length in the height direction and may be positioned at the same height. A terminal edge (1427) of the electrode terminal (1420) may be seated in an insulating body (1454) of the terminal insulating member (1450). The insulating body (1454) can be placed between the terminal edge (1427) and the plate body (1414), and can be pressed by the terminal edge (1427) and the plate body (1414). Due to this structure, the thickness of the cap assembly (1400) can be reduced. For example, by settling the terminal protrusion (1423) into the terminal groove (1452) and positioning the insulating step portion (1455) and the terminal step portion (1428) at the same height, the relative position of the electrode terminal (1420) with respect to the terminal insulating member (1450) can be fixed, while at the same time reducing the thickness occupied by the terminal insulating member (1450) and the electrode terminal (1420). In addition, through this structure, the cap assembly (1400) can prevent an electrical short circuit. For example, the terminal protrusion (1423) is secured to the terminal groove (1452), and the insulating step portion (1455) supports the terminal step portion (1428) radially inward, thereby fixing the position of the electrode terminal (1420) and preventing an electrical short circuit. In addition, since the insulating body (1454) is pressed between the terminal edge (1427) and the plate body (1414), the position of the terminal insulating member (1450) is fixed, thereby preventing an electrical short circuit.

[0124] Referring to FIG. 5, the cap assembly (1400) may further include a gasket (1460). The gasket (1460) may be positioned between the cap plate (1410) and the fixing member (1440). The gasket (1460) prevents electrolyte or gas inside the case (1100) from leaking to the outside, and prevents moisture or air from penetrating from the outside of the case (1100) into the inside of the case (1100).

[0125] In this embodiment, the gasket (1460) may have an insertion portion (1461) and a support portion (1462). The insertion portion (1461) has a hollow structure and may be inserted into the through hole (1411). The insertion portion (1461) may have a cylindrical shape having a height in the height direction. The insertion portion (1461) may be located between the cap plate (1410) and the body portion (1441). The insertion portion (1461) may be located between the terminal insulating member (1450) and the body portion (1441). The hollow portion of the insertion portion (1461) may have the same central axis as the hollow portions of the through hole (1411) and the body portion (1441).

[0126] The support portion (1462) may be a flat plate shape that is bent in the outer side direction from one end of the insert portion (1461). The support portion (1462) may be positioned between the cap plate (1410) and the second fixing portion (1443). The support portion (1462) may be pressed by the second fixing portion (1443).

[0127] The support member (1462) may be positioned laterally parallel to the base insulating member (1430). Accordingly, the support member (1462) and the base insulating member (1430) may have the same height. The support member (1462) may be positioned laterally spaced apart from the base insulating member (1430) so as to form a spaced-off space (S2). For example, the lateral distance of the spaced-off space (S2) may be 0.1 to 10 mm.

[0128] As the support portion (1462) and the base insulating member (1430) are spaced apart in this way, the assembly of the cap assembly (1400) can be facilitated. For example, since a space (S2) is formed between the gasket (1460) and the base insulating member (1430), the friction between the gasket (1460) and the base insulating member (1430) can be reduced, thereby reducing the force required to assemble the gasket (1460). In addition, since the support portion (1462) and the base insulating member (1430) are pressed in the height direction by the second fixing member (1443) while being arranged at the same height, the positions of the support portion (1462) and the base insulating member (1430) can be firmly fixed. In addition, due to this structure, the thickness of the cap assembly (1400) can be reduced. For example, the support member (1462) and the base insulating member (1430) can be aligned at the same height simply by positioning them at the same height and applying pressure with the second fixing member (1443), thereby reducing the thickness occupied by the gasket (1460) and the base insulating member (1430).

[0129] In this embodiment, the second fixing portion (1443) of the fixing member (1440) may extend past the support portion (1462) of the gasket (1460) to cover at least a portion of the base insulating member (1430). Accordingly, the space (S2) between the support portion (1462) and the base insulating member (1430) may be blocked by the second fixing portion (1443), thereby enhancing the sealing effect. In this case, the thickness of the support portion (1462) and the thickness of the base insulating member (1430) may be formed to be the same in the height direction, so that the second fixing portion (1443) may be closely attached to the base insulating member (1430) and the support portion (1462) while maintaining airtightness.

[0130] The gasket (1460) may include a material that is deformed by heat. For example, the gasket (1460) may include a rubber material. By forming a space (S2) between the support portion (1462) of the gasket (1460) and the base insulating member (1430), even if the gasket (1460) expands due to heat, contact between the expanded gasket (1460) and the base insulating member (1430) is suppressed, thereby preventing damage to the gasket (1460) due to friction between the gasket (1460) and the base insulating member (1430).

[0131] The radius of the terminal hole (1421) may be smaller than the radius of the through hole (1411). For example, the radius of the terminal hole (1421) may be 75 to 95% of the radius of the through hole (1411). Accordingly, a portion of the lower surface of the electrode terminal (1420) may be exposed by the through hole (1411) around the terminal hole (1421). The upper end of the insertion portion (1461) of the gasket (1460) may contact the lower surface exposed by the through hole (1411) of the electrode terminal (1420) in the height direction. Therefore, the sealing effect of the gasket (1460) is increased.

[0132]

[0133] FIGS. 11a and 11b are cross-sectional views of a cap assembly having a groove formed therein according to another embodiment of the present invention.

[0134] Referring to FIGS. 11A and 11B, the cap assembly (1400) may include a cap plate (1410), an electrode terminal (1420), a base insulating member (1430), a fixing member (1440), a terminal insulating member (1450), and a gasket (1460). The same contents as described in FIGS. 1 to 10B are omitted for detailed description.

[0135] The gasket (1460) may have a groove (1463) formed at a portion where the insertion portion (1461) and the support portion (1462) come into contact. The groove (1463) may be formed continuously along the outer circumference of the insertion portion (1461). The depth of the groove (1463) may be 0.1 to 5 mm. The cap plate (1410) may have a gasket protrusion (1413) formed at the bottom of the through hole (1411). The gasket protrusion (1413) may be inserted into the groove (1463). The shape of the gasket protrusion (1413) may be formed to correspond to the shape of the groove (1463). When the gasket protrusion (1413) is inserted into the groove (1463), the gasket (1460) and the cap plate (1410) are tightly coupled, thereby improving the sealing force of the gasket (1460).

[0136] A second fixing portion (1443) of the fixing member (1440) may be formed with a first protrusion (1444) facing the cap plate (1410). There may be a plurality of first protrusions (1444). A fastening groove (1464) may be formed in the support portion (1462) of the gasket (1460) corresponding to the first protrusion (1444). The first protrusion (1444) is inserted into the fastening groove (1464). In another embodiment, a fastening groove (1464) may be formed in at least one of the base insulating member (1430) or the gasket (1460). The fastening grooves (1464) may be formed in the same number as the first protrusions (1444). The fixing member (1440) may be stably fixed through the combination of the first protrusion (1440) and the fastening groove (1464).

[0137]

[0138] FIG. 12 is a drawing showing an electrode terminal inserted into a cap assembly according to an embodiment of the present invention, FIG. 13a is a drawing showing a current collector member having a first fixing groove formed therein according to an embodiment of the present invention, FIG. 13b is a drawing showing a second fixing portion of the fixing member being seated on a current collector having a first fixing groove formed therein, and FIG. 14 is a drawing showing a current collector and a second fixing portion of the fixing member being coupled therein according to an embodiment of the present invention.

[0139] Referring to FIG. 12, a cap assembly (1400) according to one embodiment of the present invention can be coupled with a current collector member (1300). The coupling of the cap assembly (1400) and the current collector member (1300) can be achieved by inserting a current collector protrusion (1320) into a hollow formed in a body portion (1441) of a fixing member (1440). To this end, the size of the current collector protrusion (1320) can be formed to be the same as or slightly larger than the hollow portion of the body portion (1441). When the cap assembly (1400) and the current collector member (1300) are coupled, the current collector (1310) can come into contact with the second fixing portion (1443) of the fixing member (1440).

[0140] After the cap assembly (1400) and the collector member (1300) are coupled, the collector projection (1320) and the first fixing portion (1442) of the fixing portion (1440) can be welded to each other. More specifically, the welding can be performed along the upper outer periphery of the collector projection (1320) using a method such as ultrasonic welding or laser welding. For neat and continuous welding, the outer periphery of the collector projection (1320) and the inner side of the first fixing portion (1442) can be rounded or chamfered.

[0141] When the collector projection (1320) is inserted into the hollow formed in the body portion (1441) of the fixing member (1440), the upper end of the collector projection (1320) in the height direction may be positioned at the same height as the first fixing portion (1442) of the fixing member (1440). In another embodiment, the upper end of the collector projection (1320) in the height direction may be positioned at a lower height than the first fixing portion (1442) of the fixing member (1440). Since the first fixing portion (1442) is lower than the upper end of the electrode terminal (1420), the upper end of the collector projection (1320) also becomes lower than the upper end of the electrode terminal (1420). Therefore, the welded portion (W) does not rise to the outside of the electrode terminal (1420).

[0142] The current collector (1310) of the current collector member (1300) can be joined to the electrode tabs (1220, 1230) of the electrode assembly (1200). The current collector protrusion (1320) formed by protruding from one surface of the current collector (1310) is connected to the electrode terminal (1420) through the fixing member (1440), so that the electrode assembly (1200) is electrically connected to the electrode terminal (1420).

[0143] In this embodiment, the current collector (1310) and the second fixing member (1443) of the current collector member (1300) can be combined in an interlocking manner.

[0144] As an example, referring to FIGS. 13A and 13B, the current collector member (1300) may have a first fixing groove (1330) formed on the upper surface of the current collector (1310). The first fixing groove (1330) may be formed around the current collector protrusion (1320) with the current collector protrusion (1320) as the center. When the cap assembly (1400) and the current collector member (1300) are coupled, the second fixing portion (1443) of the fixing member (1440) may be received and seated in the first fixing groove (1330). Accordingly, the current collector member (1300) and the fixing member (1440) are stably coupled.

[0145] In another embodiment, referring to FIG. 14, the current collector member (1300) may have a second protrusion (1340) formed on the upper surface of the current collector (1310). A second fixing groove (1443a) into which the second protrusion (1340) is inserted may be formed in the second fixing portion (1443) of the fixing member (1440). As the second protrusion (1340) is inserted into the second fixing groove (1443a), the current collector member (1300) and the fixing member (1440) are stably coupled.

[0146] When the current collector member (1300) and the fixing member (1440) are stably connected in the manner described in FIGS. 13a to 14, the concentricity of the hollow portion of the current collector projection (1340) and the main body portion (1441) of the fixing member (1440) can be easily matched. In addition, the height of the upper portion of the current collector projection (1340) and the first fixing portion (1442) of the fixing member (1440) can be easily matched. This can improve the assembling efficiency of the cap assembly (1400).

[0147]

[0148] FIG. 15a is a drawing showing a cap plate and a base insulating member according to an embodiment of the present invention, FIG. 15b is a drawing showing a lower surface of the base insulating member, and FIG. 16 is a cross-sectional view showing an electrolyte injection port of the cap plate and a guide hole of the base insulating member according to an embodiment of the present invention.

[0149] Referring to FIGS. 15A to 16, the cap plate (1410) and the base insulating member (1430) may have a square plate shape. The base insulating member (1430) may have two supporting protrusions (1432) formed at both ends thereof, protruding in directions opposite to the position of the cap plate (1410). A vent portion (1418) and an electrolyte injection port (1419) are formed in the cap plate (1410), and an exhaust hole (1433) and a guide hole (1434) are formed in the base insulating member (1430).

[0150] The exhaust hole (1433) is located at the bottom of the vent part (1418) and has a plurality of exhaust openings. When the exhaust hole (1433) is formed in the base insulating member (1430) in this way, when the pressure inside the case (1100) increases, the vent part (1418) is ruptured at the set reference pressure, so that the gas inside the case (1100) can be easily discharged to the outside.

[0151] The guide hole (1434) is located at the bottom of the electrolyte injection port (1419). An injection protrusion (1419a) is formed at the bottom of the electrolyte injection port (1419) and is inserted into the upper portion of the guide hole (1434). A guide portion (1435) is formed in the guide hole (1434) in a direction toward the electrode assembly. The guide portion (1435) may include a guide rim (1435a) that surrounds the lower portion of the guide hole (1434), a support (1435b) that is located at the lower portion of the guide hole (1434) and partially blocks the guide hole (1434), and an internal hole (1435c) that is formed in the support (1435b) and moves a fluid. The guide rim (1435a) may have a circular ring shape. The support (1435b) may have a rod shape that is connected in a straight line. The support (1435b) is fixed to the lower end of the guide rim (1435a) and can extend in the diametric direction of the guide hole (1434). The inner hole (1435c) is located at the longitudinal center of the support (1435b) and can be formed to face the electrolyte injection port (1419). The diameter (D3) of the inner hole (1435c) is formed to be smaller than the diameter (D1) of the electrolyte injection port (1419), and the inner hole (1435c) can be located inside a lower region corresponding to the electrolyte injection port (1419).

[0152] Meanwhile, the diameter (D2) of the guide hole (1434) may be formed larger than the diameter (D1) of the electrolyte injection port (1419). The width (W1) of the support (1435b) may be formed to be 0.2 to 0.6 times the diameter (D2) of the guide hole (1434). However, the width (W1) of the support (1435b) is formed to be larger than the diameter (D1) of the electrolyte injection port (1419), and may be formed to be 1.1 to 1.5 times the diameter (D1) of the electrolyte injection port (1419).

[0153] When a guide portion (1435) is formed in the base insulating member (1430), the electrolyte injection port (1419) is prevented from being blocked by the lower structure, and the electrolyte can be easily injected. In particular, since the inner hole (1435c) is located directly below the electrolyte injection port (1419), the electrolyte can move into the case (1100) through the inner hole (1435c), thereby preventing the electrolyte from flowing backward. In addition, when the inner hole (1435c) is blocked or a large amount of electrolyte is supplied, the electrolyte can be injected into the case (1100) through the first opening (1435d) and the second opening (1435e) formed on both sides of the support (1435b).

[0154]

[0155] FIG. 17 is a drawing conceptually illustrating a process of combining an electrode tab and a current collector in a secondary battery according to one embodiment of the present invention, and FIG. 18 is a drawing conceptually illustrating a process of combining a cap assembly and a current collector in a secondary battery according to one embodiment of the present invention.

[0156] Referring to FIGS. 17 and 18, in a secondary battery according to one embodiment of the present invention, electrode tabs (1220, 1230) of an electrode assembly (1200) are welded to a current collecting member (1300). To this end, first electrode tabs (1220) are welded to first electrode tabs (1220), and second electrode tabs (1230) are welded to second electrode tabs (1230).

[0157] The welded electrode tabs (1220, 1230) are bent by applying force in the bending direction, and the current collector member (1300) is positioned on the upper portion of the electrode tabs (1220, 1230), and the current collector (1310) of the current collector member (1300) is welded on the upper portion to join the electrode tabs (1220, 1230) and the current collector (1310).

[0158] When the electrode tabs (1220, 1230) and the current collector member (1300) are welded, the electrode assembly (1200) is accommodated in a case (1100). The case (1100) has an opening formed on one surface, and a current collector protrusion (1310) is exposed to the outside through the opening. A cap assembly (1400) is coupled to the case (1100). The cap assembly (1400) is coupled so that the current collector protrusion (1310) of the current collector (1300) is inserted into the hollow portion of the fixing member.

[0159]

[0160] FIG. 19 is a drawing conceptually showing a process of combining a current collector member and an electrode tab when the electrode tab is formed in both directions of an electrode assembly in a secondary battery according to another embodiment of the present invention, and FIG. 20 is a drawing conceptually showing a process of combining a cap assembly and a current collector member in a secondary battery according to another embodiment of the present invention.

[0161] Referring to FIGS. 19 and 20, in a secondary battery according to another embodiment of the present invention, a first electrode tab (1220) and a second electrode tab (1230) are disposed on different sides of an electrode assembly (1200). That is, the first electrode tab (1220) is formed in a first direction, and the second electrode tab (1230) is formed in a second direction. A first current collecting member (1300a) is positioned on the upper portion of the first electrode tab (1220), and a second current collecting member (1300b) is positioned on the upper portion of the second electrode tab (1230). Accordingly, a current collector (1310) is positioned on the upper portion of the electrode tabs (1220, 1230), and the electrode tabs (1220, 1230) and the current collector (1310) are welded to each other.

[0162] When the electrode tabs (1220, 1230) and the current collector member (1300) are welded, the electrode assembly (1200) is accommodated in the case (1100). The case (1100) has a first opening and a second opening formed on one side and the other side, respectively, and the current collector protrusions (1310) of the current collector member (1300) joined to the electrode tabs (1220, 1230) are exposed to the outside through each of the openings. The cap assembly (1400) is coupled to the opening of the case (1100) as the current collector protrusions (1310) of the current collector (1300) are inserted into the hollow portion of the fixing member. The first cap assembly (1400a) is coupled to the first opening, and the second cap assembly (1400b) is coupled to the second opening.

[0163] The electrode terminal of the first cap assembly (1400a) may be a positive terminal, and the electrode terminal of the second cap assembly (1400b) may be a negative terminal. In this case, the electrode terminal of the first cap assembly (1400a) may be made of the same material as the fixing member, and the electrode terminal of the second cap assembly (1400b) may be made of a different material from the fixing member.

[0164]

[0165] FIG. 21 is a conceptual drawing showing that an insulating tape is attached while the electrode assembly and the current collector are combined according to one embodiment of the present invention.

[0166] Referring to FIG. 21, in a secondary battery according to one embodiment of the present invention, two current collectors (1300) are joined to electrode tabs at different sides of an electrode assembly (1200). After the electrode assembly (1200) and the current collectors (1300) are joined, a first insulating tape (1510) may be attached to the current collectors (1300). The first insulating tape (1510) covers the current collectors (1310) on both sides of the current collector protrusions (1320) and may be extended and attached to the electrode assembly (1200). The current collectors (1300) are stably fixed by the first insulating tape (1300), and a short circuit between the electrode tabs and the cap assembly (1400) may be prevented.

[0167] After attaching the first insulating tape (1510), the entire outer surface of the electrode assembly (1200) where the electrode tab is not formed is wrapped with the second insulating tape (1520), and then the electrode assembly (1200) is inserted into the case (1100). The case (1100) and the electrode assembly (1200) are insulated through the second insulating tape (1520).

[0168] After inserting the electrode assembly (1200) into the case (1100), the cap assembly (1400) is attached to the opening of the case (1100). The outer surface of the case (1100) is wrapped with a third insulating tape (1530) to complete the manufacture of the secondary battery.

[0169]

[0170] FIG. 22 is a drawing conceptually illustrating two electrode tabs having the same polarity being joined to one current collecting member according to another embodiment of the present invention, and FIG. 23 is a drawing conceptually illustrating a process in which a cap assembly is coupled to a current collecting member in a secondary battery according to another embodiment of the present invention.

[0171] Referring to FIGS. 22 and 23, an electrode assembly (1200) of a secondary battery according to an embodiment of the present invention includes a plurality of 1-1 electrode tabs (1220a), a plurality of 1-2 electrode tabs (1220b), a plurality of 2-1 electrode tabs (1230a), and a plurality of 2-2 electrode tabs (1230b). The plurality of 1-1 electrode tabs (1220a) are aligned and overlapped with the 1-1 electrode tabs (1220a), the plurality of 1-2 electrode tabs (1220b) are aligned and overlapped with the 1-2 electrode tabs (1220b), the plurality of 2-1 electrode tabs (1230a) are aligned and overlapped with the 2-1 electrode tabs (1230a), and the plurality of 2-2 electrode tabs (1230b) are aligned and overlapped with the 2-2 electrode tabs (1230b). A plurality of aligned electrode tabs (1220a to 1230b) are arranged so as not to overlap in the width and length directions of the electrode assembly (1200). The overlapping electrode tabs (1220a to 1230b) at each location are welded to each other.

[0172] A current collector (1300) is positioned between the 1-1 electrode tab (1220a) and the 1-2 electrode tab (1220b). A current collector insulating member may be positioned between the current collector (1300) and the electrode assembly (1200). The 1-1 electrode tab (1220a) is bent over the current collector (1310) on one side based on the current collector protrusion (1320), and the 1-2 electrode tab (1220b) is bent over the current collector (1310) on the other side based on the current collector protrusion (1320). A current collector (1300) is also positioned between the 2-1 electrode tab (1230a) and the 2-2 electrode tab (1230b). The 2-1 electrode tab (1230a) is bent over the current collector (1310) on one side based on the current collector protrusion (1320), and the 2-2 electrode tab (1230b) is bent over the current collector (1310) on the other side based on the current collector protrusion (1320).

[0173] When a plurality of electrode tabs (1220a to 1230b) are bent over the current collector (1310), the electrode tabs (1220a to 1230b) and the current collector (1310) are joined by welding at the upper portions of the electrode tabs (1220a to 1230b). Welding may be performed using a method such as ultrasonic welding or laser welding.

[0174] When the electrode tabs (1220a to 1230b) and the current collector member (1300) are joined, the electrode assembly (1200) is accommodated in a case (1100). An opening is formed on one surface of the case (1100), and a current collector protrusion (1310) is exposed to the outside through the opening. A cap assembly (1400) is coupled to the case (1100), and the current collector protrusion (1310) of the current collector (1300) is inserted into the hollow portion of the fixing member.

[0175]

[0176] FIG. 24 is a drawing conceptually showing that electrode tabs of different polarities are formed in both directions of an electrode assembly and two electrode tabs of the same polarity are joined to one current collector in a secondary battery according to another embodiment of the present invention, and FIG. 25 is a drawing conceptually showing a process of combining a cap assembly with a current collector in a secondary battery according to another embodiment of the present invention.

[0177] Referring to FIGS. 24 and 25, an electrode assembly (1200) of a secondary battery according to one embodiment of the present invention includes a plurality of first-first electrode tabs (1220a), a plurality of first-second electrode tabs (1220b), a plurality of second-first electrode tabs (1230a), and a plurality of second-second electrode tabs (1230b). In this embodiment, the same details as those described in FIGS. 22 and 23 are omitted for detailed description.

[0178] The first-first electrode tab (1220a) and the first-second electrode tab (1220b) are positioned on one side of the electrode assembly (1200), and the second-first electrode tab (1230a) and the second-second electrode tab (1230b) are positioned on the other side of the electrode assembly (1200). A current collector (1300) is positioned between the first-first electrode tab (1220a) and the first-second electrode tab (1220b) and between the second-first electrode tab (1230a) and the second-second electrode tab (1230b). When a plurality of electrode tabs (1220a to 1230b) are bent over the current collector (1310), the electrode tabs (1220a to 1230b) and the current collector (1310) are joined by welding at the upper portions of the electrode tabs (1220a to 1230b).

[0179] When the electrode tabs (1220a to 1230b) and the current collector member (1300) are joined, the electrode assembly (1200) is accommodated in a case (1100). The case (1100) has openings formed on one side and the other side, and the current collector protrusion (1310) is exposed to the outside through the openings. A cap assembly (1400) is coupled to the case (1100), and the current collector protrusion (1310) of the current collector (1300) is inserted into the hollow portion of the fixing member in the cap assembly (1400).

[0180]

[0181] FIG. 26 is a drawing showing a secondary battery including two electrode parts according to another embodiment of the present invention, and FIG. 27 is a drawing showing an electrode tab formed on two electrode parts according to another embodiment of the present invention being joined to an electrode member.

[0182] Referring to FIGS. 26 and 27, a secondary battery (1000) according to another embodiment of the present invention includes a case (1100), an electrode assembly (1200), a current collector (1300), and a cap assembly (1400). In this embodiment, the same details as those described in FIGS. 1 to 25 are omitted for detailed description.

[0183] The electrode part (1210) of the electrode assembly (1200) includes a first electrode part (1210a) and a second electrode part (1210b). A first electrode tab (1220-1) and a second electrode tab (1230-1) are formed in the first electrode part (1210a), and a first electrode tab (1220-2) and a second electrode tab (1230-2) are formed in the second electrode part (1210b). The first electrode tab (1220-1) of the first electrode part (1210a) and the first electrode tab (1220-2) of the second electrode part (1210b) are joined to one and the same current collecting member (1300a). The second electrode tab (1230-1) of the first electrode portion (1210a) and the second electrode tab (1230-2) of the second electrode portion (1210b) are joined to one and the same current collecting member (1300b).

[0184] In this embodiment, the first electrode portion (1210a) and the second electrode portion (1210b) are taped together with a fourth insulating tape (1540) and a fifth insulating tape (1550). The fourth insulating tape (1540) is attached to a height-wise side surface of the electrode assembly (1200), and the fifth insulating tape (1550) is attached to a length-wise side surface of the electrode assembly (1200).

[0185] When n fourth or fifth insulating tapes (1540, 1550) are attached to one side, the fourth and fifth insulating tapes (1540, 1550) can be attached to points that divide the length of the side to which they are attached into (n+1) equal parts. For example, when one fourth insulating tape (1540) is attached to one height-wise side as in FIG. 26, the fourth insulating tape (1540) is attached to a point that divides the height-wise side of the electrode assembly (1200) into two equal parts. When two fifth insulating tapes (1550) are attached to one length-wise side, the fifth insulating tapes (1550) are attached to two points that divide the length-wise side of the electrode assembly (1200) into three equal parts. In the present embodiment, the number of fourth insulating tapes (1540) is one and the number of fifth insulating tapes (1550) is two, but is not limited thereto. The fourth insulating tape (1540) and the fifth insulating tape (1550) serve to bind the first electrode part (1210a) and the second electrode part (1210b) together and also have an insulating effect.

[0186] After the electrode assembly (1200) is taped with the fourth and fifth insulating tapes (1540, 1550), a sixth insulating tape (1560) may be attached to cover all sides except for the sides where the electrode tabs (1220-1, 1220-2, 1230-1, 1230-2) are formed for insulation from the case (1100). Thereafter, the electrode assembly (1200) is inserted into the case (1100), and the cap assembly (1400) is coupled to the opening of the case (1100).

[0187]

[0188] Above, one embodiment of the present invention has been described, but a person having ordinary skill in the art will be able to modify and change the present invention in various ways by adding, changing, deleting or adding components, etc., within the scope that does not depart from the spirit of the present invention described in the claims, and this will also be considered to be included within the scope of the rights of the present invention.

Claims

1. A case with an opening formed; An electrode assembly accommodated in the case and having an electrode portion and a plurality of electrode tabs formed on the electrode portion; A current collector member having a current collector electrically connected to the plurality of electrode tabs and a current collector projection protruding from the current collector; and A cap assembly coupled to the opening of the above case; The above cap assembly A cap plate with an electrolyte injection port for electrolyte injection and a through hole formed therein, An electrode terminal is formed, and is combined with the cap plate so that the through hole and the terminal hole overlap each other; A terminal insulating member positioned between the electrode terminal and the cap plate, A base insulating member positioned between the cap plate and the electrode assembly, wherein a guide hole is formed at a position corresponding to the electrolyte injection port; A fixing member having a hollow structure into which the above-mentioned current collector protrusion can be inserted, a body part inserted into the through hole and the terminal hole, a first fixing part extending in the outer side direction from a first end of the body part, and a second fixing part extending in the outer side direction from a second end of the body part, A secondary battery, wherein the above-mentioned current collector protrusion and the first fixing portion of the above-mentioned fixing member are joined to each other.

2. In paragraph 1, A secondary battery, wherein the cap assembly further comprises a gasket positioned between the cap plate and the fixing member.

3. In paragraph 1 or 2, A secondary battery, wherein the first fixing portion and the second fixing portion of the fixing member are pressed in the direction of the cap plate.

4. In paragraph 1 or 2, A secondary battery, wherein the first fixing portion and the electrode terminal are welded to each other.

5. In paragraph 1 or 2, A secondary battery, wherein the electrode terminal has a mounting groove formed around the terminal hole in which the first fixing portion of the fixing member is positioned.

6. In paragraph 5, A secondary battery, wherein the first fixing portion of the fixing member is secured so as to have a height lower than the upper end of the electrode terminal in the height direction.

7. In paragraph 6, A secondary battery, wherein the above-mentioned current collector protrusion is inserted into the body portion so that the upper end thereof in the height direction is the same height as or lower than the first fixing portion of the above-mentioned fixing member.

8. In paragraph 1 or 2, A secondary battery, wherein a first fixing groove is formed on the upper surface in the height direction of the current collector to accommodate and secure the second fixing part around the current collector protrusion.

9. In paragraph 1 or 2, A secondary battery, wherein a second protrusion is formed on the above-mentioned collector, and a second fixing groove into which the second protrusion is inserted is formed on the second fixing portion.

10. In paragraph 1 or 2, A secondary battery, wherein a first insulating tape is attached to a current collector electrically connected to the above electrode assembly.

11. In paragraph 1 or 2, The above electrode assembly is a secondary battery in which a second insulating tape is attached to an outer surface where the electrode tab is not formed.

12. In paragraph 1 or 2, A secondary battery, wherein a third insulating tape is attached to the outer surface of a case in which the electrode assembly is accommodated and the cap assembly is combined.

13. In paragraph 1 or 2, A secondary battery, wherein the base insulating member further includes a guide portion protruding from the guide hole toward the electrode assembly.

14. In paragraph 1 or 2, A secondary battery in which the electrolyte injection port has an injection protrusion formed at the bottom, and the injection protrusion is inserted into the guide hole.

15. In paragraph 1 or 2, The above case has a first opening and a second opening formed therein, The electrode assembly has a plurality of first electrode tabs formed in a first direction and a plurality of second electrode tabs formed in a second direction, and is accommodated in the case such that the first electrode tabs face the first opening and the second electrode tabs face the second opening. The above current collector member comprises a first current collector member connected to the first electrode tab and a second current collector member connected to the second electrode tab, A secondary battery, wherein the cap assembly comprises a first cap assembly coupled to the first opening and a second cap assembly coupled to the second opening.

16. In paragraph 15, The electrode terminal of the above first cap assembly is made of the same material as the fixing member, A secondary battery in which the electrode terminal of the second cap assembly is made of a different material from the fixing member.

17. In paragraph 1 or 2, The above plurality of electrode tabs comprises a plurality of first electrode tabs and a plurality of second electrode tabs, The plurality of first electrode tabs are provided with a plurality of spaced apart electrode tabs that are bent upwards from the current collector on both sides of the current collector projection of the current collector member and welded to the current collector, A secondary battery having a plurality of second electrode tabs, each of which is spaced apart from the other and is bent upward from the current collector on both sides of the current collector protrusion of the current collector member connected to the first electrode tab and welded to the current collector.

18. In paragraph 17, A secondary battery, wherein the plurality of first electrode tabs and the plurality of second electrode tabs are formed in different directions in the electrode assembly.

19. In paragraph 1 or 2, The above electrode assembly comprises a first electrode portion and a second electrode portion, The first electrode part has a first electrode tab and a second electrode tab, and the second electrode part has a first electrode tab and a second electrode tab. The first electrode tab of the first electrode portion and the first electrode tab of the second electrode portion are joined to the same current collecting member, A secondary battery, wherein the second electrode tab of the first electrode portion and the second electrode tab of the second electrode portion are joined to the same current collecting member.