Secondary battery

Abstract

The present invention relates to a secondary battery in which the total resistance of the secondary battery is reduced and the space utilization is improved, and an electrolyte can be easily injected. A secondary battery according to an embodiment of the present invention includes a cap assembly for sealing an opening of a case into which an electrode assembly has been inserted. The cap assembly includes a cap plate, an insulating plate, an upper gasket, and an electrode terminal. A through hole is formed in the cap plate. The insulating plate is disposed below the cap plate, and the upper gasket is disposed above the cap plate. The electrode terminal is inserted into the through hole. The upper end of the electrode terminal is bent to an upper portion of the upper gasket and the lower end of the electrode terminal is bent to a lower portion of the insulating plate to fix the upper gasket and the insulating plate to the cap plate.

Description

secondary battery

[0001] The present invention relates to a secondary battery.

[0002] Secondary batteries, which have high applicability according to product group and electrical characteristics such as high energy density, are widely used not only in portable devices but also in electric vehicles (EVs) and hybrid electric vehicles (HEVs) driven by electrical power sources.

[0003] These secondary batteries are attracting attention as a new energy source for environmental friendliness and energy efficiency because they not only have the primary advantage of drastically reducing the use of fossil fuels, but also have the advantage of producing no byproducts from energy use.

[0004] Commonly used secondary battery types include lithium-ion batteries, lithium polymer batteries, nickel-cadmium batteries, nickel-metal hydride batteries, and nickel-zinc batteries. The operating voltage of these unit secondary battery cells ranges from approximately 2.5 V to 4.5 V.

[0005] 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 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.

[0006] The square secondary battery has an electrode assembly housed in a metal case and a cap member attached to the open end.

[0007] The cap member of the prior art uses rivets to connect the electrode terminal and the cap plate, which increases the number of parts and thus increases the overall resistance of the secondary battery, and has the problem of reduced space utilization due to the rivets.

[0008] In addition, in the case of square batteries, an electrolyte injection port is provided, but if the electrolyte injection port is blocked by foreign substances or internal components, the electrolyte injection speed may decrease or the electrolyte may flow backward.

[0009] The present invention aims to provide a secondary battery that reduces the overall resistance of the secondary battery, improves space utilization, and allows easy injection of electrolyte.

[0010] A secondary battery according to an embodiment of the present invention includes a cap assembly that seals an opening of a case into which an electrode assembly is inserted. The cap assembly includes a cap plate, an insulating plate, an upper gasket, and an electrode terminal. A through hole is formed in the cap plate. The insulating plate is disposed below the cap plate, and the upper gasket is disposed above the cap plate. The electrode terminal is inserted into the through hole. The upper end of the electrode terminal is bent above the upper gasket, and the lower end is bent below the insulating plate, thereby fixing the upper gasket and the insulating plate to the cap plate.

[0011] A secondary battery according to an embodiment of the present invention includes a current collecting member having a current collecting plate electrically connected to an electrode assembly and a current collecting projection protruding from the current collecting plate. The current collecting projection is inserted into an insertion hole formed in an electrode terminal, and the upper ends of the current collecting projection and the electrode terminal are welded to each other.

[0012] In a secondary battery according to an embodiment of the present invention, the electrode terminal comprises a body portion, a first bend portion, and a second bend portion. The body portion is formed with an insertion hole formed in the center thereof, into which a current collector protrusion is inserted, and is inserted into a through hole. The first bend portion is bent from the upper end of the body portion to the upper end of the upper gasket. The second bend portion is bent from the lower end of the body portion to the lower end of the insulating plate.

[0013] In a secondary battery according to an embodiment of the present invention, the first bending portion may include a lower surface formed at the bottom, an outer step surface formed on the outer side of the lower surface, and an outer surface formed in a vertical direction at an end of the outer step surface.

[0014] In a secondary battery according to an embodiment of the present invention, an upper gasket may be interposed between the cap plate and the first bending portion.

[0015] In a secondary battery according to an embodiment of the present invention, the cap plate may have a mounting surface formed around a through hole and a stepped surface protruding from an outer side of the mounting surface. At this time, the upper gasket may include a first horizontal surface, a second horizontal surface, and a vertical surface. The first horizontal surface may be formed with a first thickness and may be formed to be in contact with the mounting surface of the cap plate. The second horizontal surface may be formed with a second thickness that is thicker than the first thickness and may be formed to be in contact with the mounting surface and the stepped surface. The vertical surface may be formed to extend vertically from an outer end of the second horizontal surface and surround an outer surface of the first bending portion.

[0016] In a secondary battery according to an embodiment of the present invention, a sealing gasket may be included between the through hole and the body to insulate the cap plate and the electrode terminal while preventing the electrolyte or gas inside the case from leaking to the outside.

[0017] In a secondary battery according to an embodiment of the present invention, a first alignment protrusion may be formed on the lower surface of the through hole side of the cap plate in a shape connected to the through hole, and a first alignment groove may be formed in the sealing gasket at a position corresponding to the first alignment protrusion.

[0018] In a secondary battery according to an embodiment of the present invention, a second alignment protrusion may be formed on the upper surface of the second bending portion, and a second alignment groove may be formed on the lower surface of the sealing gasket at a position corresponding to the second alignment protrusion.

[0019] In a secondary battery according to an embodiment of the present invention, an insertion groove may be formed in a slanted shape on the inner surface of the insertion hole, and an insertion projection that fits into the insertion groove may be formed on the outer surface of the current collector projection.

[0020] In a secondary battery according to an embodiment of the present invention, an undercut may be formed at the bottom of the body, and an inclined surface having a shape corresponding to the undercut may be formed at the bottom of the current collector.

[0021] In a secondary battery according to an embodiment of the present invention, a current collector projection is formed at the center of the upper surface of a current collector plate, and an adhesive layer including a heat-sealing layer may be formed on both sides of the upper surface of the current collector plate.

[0022] In a secondary battery according to an embodiment of the present invention, an insulating member may be provided between a cap plate and an electrode assembly and may include an insulating plate. The insulating member may include a guide hole positioned below an electrolyte injection port formed in the cap plate and a guide portion protruding downward from the guide hole to guide the movement of the electrolyte.

[0023] In a secondary battery according to an embodiment of the present invention, the guide portion may include a support portion positioned at the bottom of the guide hole and partially blocking the guide hole, and an internal hole formed in the support portion and configured to move a fluid.

[0024] In a secondary battery according to an embodiment of the present invention, the inner hole may face the electrolyte injection port and be located at the center of the length of the guide portion.

[0025] In a secondary battery according to an embodiment of the present invention, the guide portion may include a guide rim and a support. The guide rim surrounds the lower portion of the guide hole, the support is fixed to the guide rim, and a first opening and a second opening may be formed between a side end of the support and an inner wall of the guide rim.

[0026] In a secondary battery according to an embodiment of the present invention, a vent portion for gas discharge may be formed in the cap plate. At this time, the insulating member includes an exhaust portion protruding toward the bottom of the case and having a plurality of exhaust openings, and the exhaust portion may be located below the vent portion.

[0027] In a secondary battery according to an embodiment of the present invention, an electrode assembly includes an electrode portion and a plurality of foil tabs formed on the electrode portion, and the plurality of foil tabs can be formed in one direction of the electrode assembly.

[0028] In a secondary battery according to an embodiment of the present invention, an electrode assembly includes an electrode portion and a plurality of foil tabs formed on the electrode portion, and the plurality of foil tabs can be formed in both directions of the electrode assembly.

[0029] In a secondary battery according to an embodiment of the present invention, after the electrode assembly and the current collector plate are combined, a first insulating tape may be attached to the current collector plate. Then, the outer surface of the electrode assembly may be wrapped with a second insulating tape, and then the electrode assembly may be inserted into a case. Then, the outer surface of the case into which the electrode assembly is inserted may be wrapped with a third insulating tape.

[0030] According to the present invention, the number of components is reduced by providing a rivet-structured electrode terminal, thereby reducing the overall resistance of the secondary battery, improving space utilization, and enhancing the sealing function to prevent electrolyte leakage. In addition, a guide portion for electrolyte injection is formed in the electrolyte injection port, facilitating easy electrolyte injection.

[0031] FIG. 1 is a perspective view illustrating a secondary battery according to one embodiment of the present invention.

[0032] Figure 2 is a cross-sectional view taken along line AA in Figure 1.

[0033] Figure 3 is an exploded perspective view of a secondary battery according to one embodiment of the present invention.

[0034] FIG. 4 is a perspective view illustrating an electrode assembly in which a plurality of first and second foil tabs are formed on an electrode portion in a secondary battery according to one embodiment of the present invention.

[0035] FIG. 5a and FIG. 5b are drawings showing a first electrode plate and a second electrode plate in a secondary battery according to one embodiment of the present invention.

[0036] Figure 6 is an exploded perspective view of a secondary battery according to another embodiment of the present invention.

[0037] FIG. 7 is a perspective view illustrating an electrode assembly in which a plurality of first and second foil tabs are formed on an electrode portion in a secondary battery according to another embodiment of the present invention.

[0038] FIGS. 8a, 8b, 9a, and 9b are drawings illustrating a first electrode plate and a second electrode plate in a secondary battery according to one embodiment of the present invention.

[0039] FIG. 10 is a perspective view illustrating a cap assembly according to a first embodiment of the present invention.

[0040] Fig. 11 is a cross-sectional view illustrating a cap assembly according to a first embodiment of the present invention.

[0041] Fig. 12 is a cross-sectional view illustrating a cap assembly according to a second embodiment of the present invention.

[0042] Fig. 13 is a cross-sectional view illustrating a cap assembly according to a third embodiment of the present invention.

[0043] Fig. 14 is a cross-sectional view illustrating a cap assembly according to a fourth embodiment of the present invention.

[0044] FIG. 15 is a drawing illustrating a process of forming an electrode terminal in a cap assembly according to embodiments of the present invention.

[0045] Fig. 16 is a perspective view from above of an insulating member of a secondary battery according to embodiments of the present invention.

[0046] Figure 17 is a perspective view from below of an insulating member of a secondary battery according to embodiments of the present invention.

[0047] Figure 18 is a bottom view of an insulating member of a secondary battery according to embodiments of the present invention.

[0048] Fig. 19 is a partial cross-sectional view showing a cap plate and an insulating member.

[0049] Fig. 20 is a cutaway perspective view showing a guide portion of an insulating member.

[0050] Fig. 21 is a cross-sectional view showing the exhaust part of the insulating member.

[0051] FIG. 22 is a drawing illustrating a process of combining a foil tab and a current collector member in a secondary battery according to one embodiment of the present invention.

[0052] FIG. 23 is a drawing illustrating a process of combining a cap member and a current collector member in a secondary battery according to one embodiment of the present invention.

[0053] FIG. 24 is a drawing illustrating a process of combining a current collector and a foil tab when the foil tab is formed in both directions in a secondary battery according to one embodiment of the present invention.

[0054] Figure 25 is a drawing showing the process of combining a cap member with a current collector member.

[0055] FIG. 26 is a drawing illustrating a process of combining a foil tab and a current collector member in a secondary battery according to another embodiment of the present invention.

[0056] FIG. 27 is a drawing illustrating a process of combining a cap member and a current collector member in a secondary battery according to another embodiment of the present invention.

[0057] FIG. 28 is a drawing illustrating a process of combining a current collector and a foil tab when the foil tab is formed in both directions in a secondary battery according to another embodiment of the present invention.

[0058] Figure 29 is a drawing illustrating the process of combining a cap member with a current collector member.

[0059] Figure 30 is a drawing showing the process of attaching insulating tape while the electrode assembly and the current collector are combined.

[0060] FIG. 31 is a drawing showing a secondary battery including two electrode parts according to another embodiment of the present invention.

[0061] FIG. 32 is a drawing showing a foil tab formed on two electrode portions according to another embodiment of the present invention being joined to a current collecting member.

[0062] 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.

[0063] The terminology used in the present invention is only 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.

[0064] 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.

[0065]

[0066] FIG. 1 is a perspective view illustrating a secondary battery according to an embodiment of the present invention, FIG. 2 is a cross-sectional view taken along line AA in FIG. 1, FIG. 3 is an exploded perspective view illustrating a secondary battery according to an embodiment of the present invention, FIG. 4 is a perspective view illustrating an electrode assembly in which a plurality of first and second foil tabs are formed on an electrode portion in a secondary battery according to an embodiment of the present invention, and FIGS. 5A and 5B are views illustrating a first electrode plate and a second electrode plate in a secondary battery according to an embodiment of the present invention.

[0067] As illustrated in FIGS. 1 to 5b, a secondary battery (1000) according to one embodiment of the present invention includes a case (1100), an electrode assembly (1200), a current collecting member (1300), a cap member (1400), and an insulating member (1500).

[0068] The case (1100) forms the exterior of the 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. 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.

[0069] 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.

[0070] The electrode assembly (1200) is accommodated inside the case (1100). As illustrated in FIG. 4, the electrode assembly (1200) includes an electrode portion (1210), a plurality of first foil tabs (1220), and a plurality of second foil tabs (1230). The plurality of first and second foil tabs (1220, 1230) are arranged at one end of the electrode portion (1210). In another embodiment, the first foil tab (1220) may be arranged on one side of the electrode portion (1210), and the second foil tab (1230) may be arranged on the other side of the electrode portion (1210). The plurality of first foil tabs (1220) are aligned with the first foil tabs (1220), and the plurality of second foil tabs (1230) are aligned with the second foil tabs (1230).

[0071] The electrode unit (1210) includes a plurality of first electrode plates (1211), a plurality of second electrode plates (1212), and a separator (1213).

[0072] An active material may be applied to a plurality of first electrode plates (1211) and a plurality of second electrode plates (1212). An active material such as a transition metal oxide may be applied to a metal plate such as aluminum on the plurality of first electrode plates (1211). The plurality of first electrode plates (1211) may be positive electrode plates. The plurality of second electrode plates (1212) may be negative electrode plates, wherein an active material such as graphite or carbon may be applied to a metal plate such as copper or nickel. The plurality of second electrode plates (1212) may be negative electrode plates.

[0073] A separator (1213) is positioned between a plurality of first and second electrode plates (1211, 1212) to prevent short circuits between the plurality of first and second electrode plates (1211, 1212). The material of the separator may be polyethylene, polypropylene, or a composite thereof.

[0074] The electrode portion (1210) can be formed by positioning a separator (1213) between the first electrode plate (1211) and the second electrode plate (1212) that are sequentially arranged. That is, in one embodiment, the electrode portion (1210) can be formed by stacking the first electrode plate (1211), the separator (1213), the second electrode plate (1212), and the separator (1213) in that order tens to hundreds of times.

[0075] 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.

[0076] Foil tabs (1220, 1230) on which no active material is applied are formed on one end of a plurality of first and second electrode plates (1211, 1212). In one embodiment, the electrode plates (1211, 1212) and the foil 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 plates (1211, 1212) and the foil tabs (1220, 1230). The plurality of foil tabs (1220, 1230) may be formed in a direction toward the cap member (1400).

[0077] When a plurality of first and second electrode plates (1211, 1212) are stacked, a plurality of first foil tabs (1220) overlap each other at a first position. A plurality of second foil tabs (1230) overlap each other at a second position. That is, a plurality of first foil tabs (1220) having the same polarity are grouped at the first position, and a plurality of second foil tabs (1230) are grouped at the second position. The first position and the second position are spaced apart from each other on the electrode plates, and the plurality of first foil tabs (1220) and the plurality of second foil tabs (1230) that are grouped respectively can be spaced apart in the longitudinal direction of the electrode assembly (1200).

[0078] A plurality of foil tabs (1220, 1230) overlapping at each location can be connected to a current collector member by ultrasonic welding, laser welding, etc. to facilitate the movement of current.

[0079] The collector member (1300) has a collector plate (1310) and a collector projection (1320).

[0080] A plurality of foil tabs (1220, 1230) are bent and welded to the collector plate (1310). A collector projection (1320) is formed at the center of the collector plate (1310).

[0081] The collector protrusion (1320) protrudes upward from the upper surface of the collector plate (1310) and is coupled to the terminal hole (1421) of the electrode terminal (1420) to electrically connect the electrode assembly (1200a) and the electrode terminal (1420).

[0082] The current collector member (1300) may be made of the same material as the plurality of foil tabs (1220, 1230). An insulating material may be placed on the lower portion of the current collector member (1300). The insulating material may be an insulating film.

[0083] After welding a plurality of first foil tabs (1220) and a plurality of second foil tabs (1230), a current collector (1300) is placed on each of the first foil tabs (1220) and the second foil tabs (1230).

[0084] After bending a plurality of first foil tabs (1220) and a plurality of second foil tabs (1230), a current collector (1300) is welded on the plurality of first foil tabs (1220) and the plurality of second foil tabs (1230). Welding may be performed using a method such as ultrasonic welding or laser welding.

[0085] The cap member (1400) may include a cap plate (1410), an electrode terminal (1420), an electrolyte injection port (1430), and a vent portion (1440).

[0086] The cap plate (1410) is a plate-shaped material covering the opening of the case (1100) and has at least one through hole (1410a). 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.

[0087] An electrolyte injection port (1430) and a vent portion (1440) may be formed in the cap plate (1410).

[0088] Electrolyte can be injected into the interior of the case (1100) through the electrolyte injection port (1430). The vent part (1440) is opened when the internal pressure of the case (1100) exceeds a reference value.

[0089] The electrode terminal (1420) can be coupled to the cap plate (1410). The electrode terminal (1420) is electrically connected to the foil tabs (1220, 1230) through the current collecting member (1300). The electrode terminal (1420) can be in the shape of a plate having a circular or square shape.

[0090] An insulating member (1500) is installed between the cap member (1400) and the electrode assembly (1200) to insulate the cap member (1400) and the electrode assembly (1200).

[0091]

[0092] FIG. 6 is an exploded perspective view of a secondary battery according to another embodiment of the present invention, FIG. 7 is a perspective view of an electrode assembly in which a plurality of first and second foil tabs are formed on an electrode portion in a secondary battery according to another embodiment of the present invention, and FIGS. 8a, 8b, 9a, and 9b are views illustrating a first electrode plate and a second electrode plate in a secondary battery according to one embodiment of the present invention.

[0093] As illustrated in FIGS. 6 to 9b, a secondary battery (1000a) according to another embodiment of the present invention includes a case (1100), an electrode assembly (1200a), a current collecting member (1300a), a cap member (1400), and an insulating member (1500). Compared to the secondary battery of the aforementioned embodiment, only the structures of the electrode assembly (1200a) and the current collecting member (1300a) are different, and the remaining configurations are substantially the same, so a repeated description is omitted.

[0094] As illustrated in FIG. 7, the electrode assembly (1200a) includes an electrode portion (1210a), a plurality of first_1 foil tabs (1220a), a plurality of first_2 foil tabs (1220b), a plurality of second_1 foil tabs (1230a), and a plurality of second_2 foil tabs (1230b). The plurality of foil tabs (1220a to 1230b) are arranged at one end of the electrode portion (1210a). A plurality of first_1 foil tabs (1220a) are aligned with the first_1 foil tabs (1220a), a plurality of first_2 foil tabs (1220b) are aligned with the first_2 foil tabs (1220b), a plurality of second_1 foil tabs (1230a) are aligned with the second_1 foil tabs (1230a), and a plurality of second_2 foil tabs (1230b) are aligned with the second_2 foil tabs (1230b). The plurality of aligned foil tabs (1220a to 1230b) are arranged so as not to overlap in the width direction and the length direction of the electrode assembly (1200a).

[0095] As shown in FIGS. 8a, 8b, 9a, and 9b, the electrode portion (1210a) includes a plurality of first_1 electrode plates (1211a), a plurality of first_2 electrode plates (1211b), a plurality of second_1 electrode plates (1212a), a plurality of second_2 electrode plates (1212b), and a separator (1213).

[0096] An active material may be applied to a plurality of first_1 electrode plates (1211a), a plurality of first_2 electrode plates (1211b), a plurality of second_1 electrode plates (1212a), and a plurality of second_2 electrode plates (1212b). The plurality of first_1 electrode plates (1211a) and the plurality of first_2 electrode plates (1211b) may be formed by applying an active material such as a transition metal oxide to a metal plate such as aluminum. The plurality of first_1 electrode plates (1211a) and the plurality of first_2 electrode plates (1211b) may have the same polarity and may be positive electrode plates. The plurality of second_1 electrode plates (1212a) and the plurality of second_2 electrode plates (1212b) may be formed by applying an active material such as graphite or carbon to a metal plate such as copper or nickel. The plurality of second_1 electrode plates (1212a) and the plurality of second_2 electrode plates (1212b) may have the same polarity and may be negative electrode plates.

[0097] The separator (1213) is positioned between the plurality of electrode plates (1211a to 1212b) to prevent short circuits between the plurality of electrode plates (1211a to 1212b).

[0098] The electrode portion (1210a) can be formed by positioning a separator (1213) between the 1_1 electrode plate (1211a) and the 2_1 electrode plate (1212a), and the 1_2 electrode plate (1211b) and the 2_2 electrode plate (1212b), which are arranged sequentially.

[0099] The electrode assembly (1200a) has one electrode portion (1210a), but in other embodiments, the electrode assembly (1200a) may have multiple electrode portions (1210a). The multiple electrode portions (1210a) may be electrically connected to each other.

[0100] Foil tabs (1220a, 1220b, 1230a, 1230b) on which no active material is applied are formed at one end of a plurality of electrode plates (1211a to 1212b). In one embodiment, the electrode plates (1211a to 1212b) and the foil tabs (1220a, 1220b, 1230a, 1230b) may be formed integrally by cutting a predetermined portion from a single metal plate using a laser or the like to leave the electrode plates (1211a to 1212b) and the foil tabs (1220a, 1220b, 1230a, 1230b). The plurality of foil tabs (1220a, 1220b, 1230a, 1230b) may be formed in a direction toward the cap member (1400).

[0101] A first foil tab (1220a) is formed at a first position of the first electrode plate (1211a). A first foil tab (1220b) is formed at a second position of the first electrode plate (1211b). Similarly, a second foil tab (1230a) may be formed at a third position of the second electrode plate (1212a), and a second foil tab (1230b) may be formed at a fourth position of the second electrode plate (1212b).

[0102] A plurality of first_1 electrode plates (1211a) and a plurality of second_1 electrode plates (1212a) can be alternately stacked with a separator (1213) therebetween. The stack of a plurality of first_1 electrode plates (1211a) and a plurality of second_1 electrode plates (1212a) forms half of an electrode portion (1210a).

[0103] A plurality of first_second electrode plates (1211b) and a plurality of second_second electrode plates (1212b) can be alternately stacked with a separator (1213) therebetween. The stack of a plurality of first_second electrode plates (1211b) and a plurality of second_second electrode plates (1212b) forms the remaining half of the electrode portion (1210a).

[0104] A stack of a plurality of first_1 electrode plates (1211a) and a plurality of second_1 electrode plates (1212a) and a stack of a plurality of first_2 electrode plates (1211b) and a plurality of second_2 electrode plates (1212b) are connected in the width direction of the electrode portion (1210a). When forming the electrode assembly (1200a), after stacking a plurality of first_1 electrode plates (1211a) and a plurality of second_1 electrode plates (1212a), a plurality of first_2 electrode plates (1211b) and a plurality of second_2 electrode plates (1212b) can be stacked.

[0105] When a plurality of electrode plates (1211a to 1212b) are stacked, a plurality of 1_1 foil tabs (1220a) overlap each other at a first position. A plurality of 1_2 foil tabs (1220b) overlap each other at a second position. That is, among a plurality of 1_1 foil tabs (1220a) and a plurality of 1_2 foil tabs (1220b) having the same polarity, a plurality of 1_1 foil tabs (1220a) are grouped at a first position, and a plurality of 1_2 foil tabs (1220b) are grouped at a second position. The first position and the second position are spaced apart from each other on the electrode plates, and the plurality of 1_1 foil tabs (1220a) and the plurality of 1_2 foil tabs (1220b) that are grouped respectively can be spaced apart in the width direction and the length direction of the electrode assembly (1200a).

[0106] In order to stably weld a large number of foil tabs, foil tabs of the same polarity are divided into two groups spaced apart from each other, aligned, and each group is welded on a respective current collector plate. That is, one foil tab is formed on one electrode plate, but by forming the foil tabs at different positions on each electrode plate, two groups of foil tabs at different positions on the same polarity are formed after lamination of the electrode plates. In another embodiment, two or more foil tabs at different positions on the same polarity may be formed.

[0107] When a plurality of electrode plates (1211a to 1212b) are stacked, a plurality of second_1 foil tabs (1230a) overlap each other at a third position, and a plurality of second_2 foil tabs (1230b) overlap each other at a fourth position. That is, a plurality of second_1 foil tabs (1230a) are grouped at a third position, and a plurality of second_2 foil tabs (1230b) are grouped at a fourth position. The third position and the fourth position are spaced apart from each other on the electrode plates, and the plurality of second_1 foil tabs (1230a) and the plurality of second_2 foil tabs (1230b) that are grouped respectively can be spaced apart in the width direction and the length direction of the electrode assembly (1200a).

[0108] The plurality of second_1 foil tabs (1230a) and the plurality of second_2 foil tabs (1230b) are foil tabs of the same polarity.

[0109] A plurality of foil tabs (1220a, 1220b, 1230a, 1230b) overlapping at each location can be connected to the current collector plate by ultrasonic welding, laser welding, etc. to facilitate the movement of current.

[0110] The collector member (1300a) has a collector plate (1310a) and a collector projection (1320).

[0111] The collector plate (1310a) has a first collector area (1311), a second collector area (1312), and a connection area (1313).

[0112] A plurality of first-first foil tabs (1220a) are bent and welded to the first current collecting area (1311). A plurality of first-second foil tabs (1220b) are welded to the second current collecting area (1312). A connection area (1313) is interposed between the first current collecting area (1311) and the second current collecting area (1312), and a current collecting projection (1320) is formed.

[0113] The first collection area (1311) and the second collection area (1312) are spaced apart in the longitudinal direction by the connection area (1313). Since the first collection area (1311) and the second collection area (1312) are spaced apart from each other, the plurality of first_1 foil tabs (1220a) and the plurality of first_2 foil tabs (1220b) do not interfere with each other when welded to the first collection area (1311) and the second collection area (1312), respectively.

[0114] The collector protrusion (1320) protrudes upward from the upper surface of the connection area (1313) and is coupled to the terminal hole (1421) of the electrode terminal (1420) to electrically connect the electrode assembly (1200a) and the electrode terminal (1420).

[0115] After welding a plurality of first_1 foil tabs (1220a) and a plurality of first_2 foil tabs (1220b), a collector plate (1310a) may be placed in the space between the first_1 foil tabs (1220a) and the first_2 foil tabs (1220b). At this time, the collector plate (1310a) is placed on some of the first_1 foil tabs (1220a) and the first_2 foil tabs (1220b).

[0116] After the current collector plate (1310a) is placed on the upper portion of the electrode portion (1210a), the plurality of 1_1 foil tabs (1220a) are bent toward the first current collector region (1311), and the plurality of 1_2 foil tabs (1220b) are bent toward the second current collector region (1312). That is, the plurality of 1_1 foil tabs (1220a) and the plurality of 1_2 foil tabs (1220b) are bent in opposite directions.

[0117] After bending a plurality of first_1 foil tabs (1220a) and a plurality of first_2 foil tabs (1220b), welding is performed on the plurality of first_1 foil tabs (1220a) and the plurality of first_2 foil tabs (1220b). Welding may be performed using a method such as ultrasonic welding or laser welding.

[0118] During welding, in the first current collecting area (1311) of the current collecting plate (1310a), welding may be performed from a plurality of first_1 foil tabs (1220a) toward the first current collecting area (1311), and in the second current collecting area (1312) of the current collecting plate, welding may be performed from a plurality of first_2 foil tabs (1220b) toward the second current collecting area (1312). To facilitate fixing and welding of the foil tabs, a plurality of micro-grooves or micro-protrusions may be formed on the upper surface of the current collecting plate (1310a).

[0119] In the secondary battery according to the embodiments of the present invention illustrated in FIGS. 1 to 9, a current collector member (1300), a cap member (1400), and an insulating member (1500) can be combined to form a cap assembly (see symbol CA in FIG. 2).

[0120]

[0121] FIG. 10 is a perspective view illustrating a cap assembly according to a first embodiment of the present invention, and FIG. 11 is a cross-sectional view illustrating a cap assembly according to the first embodiment of the present invention.

[0122] As illustrated in FIGS. 10 and 11, the cap assembly (CA1) according to the first embodiment of the present invention may include a cap plate (1410), an electrode terminal (1420), an insulating plate (1510), a sealing gasket (1450), and an upper gasket (1460).

[0123] The cap plate (1410) is a plate-shaped material covering the opening of the case (1100) and has at least one through hole (1410a). The cap plate (1410) may have a shape corresponding to the shape of the opening of the case (1100), and the cap plate (1410) may be formed of the same material as the case (1100).

[0124] In addition, the cap plate (1410) has a mounting surface (1411) and a step surface (1412). The mounting surface (1411) is formed around the through hole (1410a), and the step surface (1412) protrudes from the outside of the mounting surface (1411) to a predetermined height. The first horizontal surface (1461) and the second horizontal surface (1462) of the upper gasket (1460) are arranged on the mounting surface (1411), and the vertical surface (1463) of the upper gasket (1460) is arranged on the step surface (1412).

[0125] In addition, a first alignment protrusion (1413) is formed on the lower surface of the through hole (1410a) of the cap plate (1410) in a shape connected to the through hole (1410a). The first alignment protrusion (1413) is fitted into a first alignment groove (1451) formed in the sealing gasket (1450) to assist in the alignment of the cap plate (1410) and the sealing gasket (1450).

[0126] The electrode terminal (1420) can be inserted into and coupled to the through hole (1410a) of the cap plate (1410). The electrode terminal (1420) is electrically connected to the foil tabs (1220, 1230) through the current collecting member (1300). The electrode terminal (1420) can be in the shape of a plate having a circular or square shape.

[0127] An insertion hole (1420a) is formed in the center of the electrode terminal (1420), and the upper end of the electrode terminal (1420) is bent above the upper gasket (1460) and the lower end is bent below the insulating plate (1510), thereby performing a rivet function to fix the upper gasket (1460), the cap plate (1410), and the insulating plate (1510).

[0128] Specifically, the electrode terminal (1420) includes a body portion (1421), a first bending portion (1422), and a second bending portion (1423).

[0129] The body part (1421) is formed in the height direction (z direction) as a part inserted into the through hole (1410a), and an insertion hole (1420a) is formed in the center. A collector protrusion (1320) is inserted into the insertion hole (1420a).

[0130] The first bending portion (1422) is bent horizontally (xy direction) from the upper end of the body portion (1421) to the upper end of the upper gasket (1460). The first bending portion (1422) includes a lower surface (1422a) formed at the lower end, an outer stepped surface (1422b) formed on the outer side of the lower surface (1422a), and an outer surface (1422c) formed in a vertical direction at an end of the outer stepped surface (1422b). The lower surface (1422a) is in contact with the first horizontal surface (1461) of the upper gasket (1460), the outer stepped surface (1422b) is in contact with the second horizontal surface (1462), and the outer surface (1422c) is wrapped by the vertical surface (1462).

[0131] The second bending portion (1423) is bent horizontally (xy direction) from the lower end of the body portion (1421) to the lower end of the insulating plate (1510). A second alignment protrusion (1423a) is formed on the upper surface of the second bending portion (1423). The second alignment protrusion (1423a) is fitted into a second alignment groove (1452) formed on the lower surface of the sealing gasket (1450) to assist in the alignment of the second bending portion (1423) and the sealing gasket (1450).

[0132] The first bending portion (1422) has a larger length direction (y direction) and height direction (z direction) size than the second bending portion (1423).

[0133] An insulating plate (1510) is placed below the cap plate (1410) and above the second bending portion (1423) to insulate the cap plate (1410) and the electrode terminal (1420).

[0134] The sealing gasket (1450) is interposed between the through hole (1410a) and the body portion (1421), thereby insulating the cap plate (1410) and the electrode terminal (1420), thereby preventing electrolyte or gas inside the case (1100) from leaking to the outside and preventing moisture or air from penetrating into the case (1100) from the outside. At this time, the upper portion of the sealing gasket (1450) extends to contact the first horizontal surface (1461) of the upper gasket (1460), and the lower portion extends in the horizontal direction while contacting the upper surface of the first bending portion (1423). And, a first alignment groove (1451) is formed at a position corresponding to the first alignment protrusion (1413) in the sealing gasket (1450), and a second alignment groove (1452) is formed at a position corresponding to the second alignment protrusion (1423a) on the lower surface of the sealing gasket (1450).

[0135] The upper gasket (1460) is interposed between the cap plate (1410) and the first bending portion (1422) to prevent electrolyte or gas inside the case (1100) from leaking to the outside and prevent moisture or air from penetrating into the case (1100) from the outside.

[0136] The upper gasket (1460) includes a first horizontal surface (1461), a second horizontal surface (1462), and a vertical surface (1463). The first horizontal surface (1461) is formed with a first thickness and is formed to contact the seating surface (1411) of the cap plate (1410) and the upper end of the sealing gasket (1450). The second horizontal surface (1462) is formed with a second thickness that is thicker than the first thickness and is formed to contact the seating surface (1411) and the step surface (1412). The vertical surface (1463) extends vertically from the outer end of the second horizontal surface (1462) to surround the outer surface of the first bending portion (1422).

[0137] Meanwhile, the upper surface of the collector protrusion (1320) inserted into the insertion hole (1420a) and the upper surface of the electrode terminal (1420) can be joined by welding.

[0138] The cap assembly (CA1) according to the first embodiment of the present invention configured as described above has an electrode terminal (1420) of a rivet structure, thereby reducing the number of parts, thereby reducing the overall resistance of the secondary battery, improving space utilization, and preventing leakage of the electrolyte by reinforcing the sealing function.

[0139]

[0140] Fig. 12 is a cross-sectional view illustrating a cap assembly according to a second embodiment of the present invention.

[0141] As illustrated in FIG. 12, a cap assembly (CA2) according to a second embodiment of the present invention may include a cap plate (1410), an electrode terminal (1420), an insulating plate (1510), a sealing gasket (1450), and an upper gasket (1460). The only difference is that the shape of the body portion (1421) of the electrode terminal and the current collector protrusion (1320) are different, and the rest is substantially the same as the first embodiment described above, so a repeated description is omitted.

[0142] In the second embodiment, an insertion groove (1421a) may be formed on the inner surface of an insertion hole (1420a) formed in the center of a body portion (1421), and an insertion projection (1321) that fits into the insertion groove (1421a) may be formed on the outer surface of a current collector projection (1320).

[0143] The fitting groove (1421a) may be formed in a slanted shape with a width that decreases from the bottom to the top of the body portion (1421). In addition, the fitting projection (1321) may be formed in a shape corresponding to the fitting groove (1421a).

[0144] After inserting the collector protrusion (1320) of the collector member (1300) into the insertion hole (1420a), the electrode terminal (1420) and the collector protrusion (1320) can be combined by performing a connection on the upper surface of the electrode terminal (1420).

[0145] At this time, since the welding is performed in a state where the fitting projection (1321) of the collector projection (1320) is fitted into the fitting groove (1421a) of the body portion (1421), the bonding strength between the collector plate (1300) and the electrode terminal (1420) can be improved.

[0146] In addition, since the insertion projection (1321) and the insertion groove (1421a) are formed in the form of an inclined shape of the upper and lower light, when inserting the collector projection (1320) into the insertion hole (1420a), friction between the insertion projection (1321) and the insertion hole (1420a) can be minimized, and the insertion work can be facilitated.

[0147]

[0148] Fig. 13 is a cross-sectional view illustrating a cap assembly according to a third embodiment of the present invention.

[0149] As illustrated in FIG. 13, a cap assembly (CA3) according to a third embodiment of the present invention may include a cap plate (1410), an electrode terminal (1420), an insulating plate (1510), a sealing gasket (1450), and an upper gasket (1460). The only difference is that the shape of the body portion (1421) of the electrode terminal and the current collector protrusion (1320) are different, and the rest is substantially the same as the first embodiment described above, so a repeated description is omitted.

[0150] In the third embodiment, an undercut (1421b) having a triangular cross-section may be formed at the lower end of the body portion (1421), and an inclined surface (1322) having a shape corresponding to the undercut (1421b) may be formed at the lower end of the collector projection (1320).

[0151] When manufacturing a secondary battery, when inserting a current collector (1320) into an insertion hole (1420a), the insertion margin can be sufficiently secured due to the undercut (1421b) at the bottom of the body (1421), making the insertion process easy to perform.

[0152] And, while the undercut (1421b) and the inclined surface (1322) are kept in close contact after insertion, welding can be performed on the upper surface of the electrode terminal (1420) to connect the electrode terminal (1420) and the current collector protrusion (1320).

[0153]

[0154] Fig. 14 is a cross-sectional view illustrating a cap assembly according to a fourth embodiment of the present invention.

[0155] As illustrated in FIG. 14, a cap assembly (CA4) according to a fourth embodiment of the present invention may include a cap plate (1410), an electrode terminal (1420), an insulating plate (1510), a sealing gasket (1450), and an upper gasket (1460). Except for the difference in the structure of the current collecting member (1300), the remainder is substantially the same as the first embodiment described above, and therefore, a repeated description thereof will be omitted.

[0156] In the fourth embodiment, the current collector member (1300) includes a current collector plate (1310), a current collector projection (1320), and an adhesive layer (1330). The current collector plate (1310) and the current collector projection (1320) are substantially the same as those in the first embodiment described above, and thus a repeated description thereof will be omitted.

[0157] The collector projection (1320) is formed in the center of the upper surface of the collector plate (1310), and the adhesive layer (1330) is formed on both sides of the upper surface of the collector plate (1310). The adhesive layer (1330) includes a conductive layer (1331) and a heat-sealing layer (1332) formed on the upper and lower surfaces of the conductive layer (1331).

[0158] The heat-sealing layer (1332) includes a thermoplastic resin that melts by heat. The heat-sealing layer (1332) is formed on the upper and lower surfaces of the conductive layer (1331) and melts and solidifies by heat, thereby allowing the collector plate (1310) and the second bending portion (1423) of the electrode terminal (1420) to be heat-sealed and joined on the upper and lower surfaces of the conductive layer (1331).

[0159] A modified polyolefin resin can be used as the heat-sealing layer (1432), and preferably, a copolymer of ethylene or propylene and a monomer having a polar group, such as an ethylene / acrylic acid copolymer, an ethylene / methacrylic acid copolymer, an ethylene / ethyl acrylate, an ethylene-butyl acrylate copolymer, an ethylene-vinyl acetate copolymer, an ethylene / itaconic acid copolymer, an ethylene / monomethyl maleate copolymer, an ethylene / maleic acid copolymer, an ethylene / acrylic acid / methyl methacrylate copolymer, an ethylene / methacrylic acid / ethyl acrylate copolymer, an ethylene / monomethyl maleate / ethyl acrylate copolymer, an ethylene / methacrylic acid / vinyl acetate copolymer, an ethylene / acrylic acid / vinyl alcohol copolymer, an ethylene / propylene / acrylic acid copolymer, an ethylene / styrene / acrylic acid copolymer, Ethylene / methacrylic acid / acrylonitrile copolymer, ethylene / fumaric acid / vinyl methyl ether copolymer, ethylene / vinyl chloride / acrylic acid copolymer, ethylene / vinylidene chloride / acrylic acid copolymer, ethylene / chlorotrifluoroethylene / methacrylic acid copolymer, ethylene / methacrylic acid sodium salt copolymer, ethylene / acrylic acid zinc salt copolymer, ethylene / styrene sulfonic acid sodium salt copolymer, styrene-ethylene-propylene copolymer, propylene / acrylic acid copolymer, propylene / methacrylic acid copolymer, propylene / ethyl acrylate, propylene-butyl acrylate copolymer, propylene-vinyl acetate copolymer, propylene / itaconic acid copolymer, propylene / monomethyl maleate copolymer, propylene / maleic acid copolymer, propylene / acrylic acid / methyl methacrylate Copolymer, propylene / methacrylic acid / ethyl acrylate copolymer, propylene / monomethyl maleate / ethyl acrylate copolymer, propylene / methacrylic acid / vinyl acetate copolymer, propylene / acrylic acid / vinyl alcohol copolymer, propylene / propylene / acrylic acid copolymer, propylene / styrene / acrylic acid copolymer, propylene / methacrylic acid / acrylonitrile copolymer, propylene / fumaric acid / vinyl methyl ether copolymer, propylene / vinyl chloride / acrylic acid copolymer, propylene / vinylidene chloride / acrylic acid copolymer,A substituted polyolefin resin, which is a propylene / chlorotrifluoroethylene / methacrylic acid copolymer, a propylene / sodium methacrylate salt copolymer, a propylene / zinc acrylic acid salt copolymer, a propylene / sodium styrene sulfonate copolymer, a styrene-propylene-propylene copolymer, a maleic anhydride-grafted polyethylene or polypropylene, which may be maleic anhydride-grafted high-density polyethylene (m-HDPE), maleic anhydride-grafted propylene (m-PP), maleic anhydride-grafted polyethylene / propylene copolymer (m-cpp), chlorinated polyethylene, polypropylene (CM), chlorosulfonated polyethylene or polypropylene (CSM).

[0160] When manufacturing a secondary battery, after inserting the current collector (1320) into the insertion hole (1420a) and before welding the electrode terminal (1420) and the current collector (1320), heat is applied to the cap assembly (CA4) so ​​that the current collector plate (1310) and the second bending portion (1423) are joined by heat fusion, thereby improving the bonding strength between the current collector member (1300) and the electrode terminal (1420).

[0161]

[0162] FIG. 15 is a drawing illustrating a process of forming an electrode terminal in a cap assembly according to embodiments of the present invention.

[0163] First, the cap plate (1410), the insulating plate (1510), the sealing gasket (1450), and the upper gasket (1460) are placed, and then a μ-shaped electrode terminal (1420b) having a hollow structure is inserted into the sealing gasket (1450). The lower horizontal portion of the electrode terminal (1420b) becomes the second bending portion (1423), and the hollow structure of the electrode terminal (1420b) becomes the insertion hole (1420a).

[0164] Next, the electrode terminal (1420b) is bent horizontally by applying pressure from above. The upper portion of the bent electrode terminal (1420b) is placed on the upper gasket (1460) to form the first bending portion (1422).

[0165]

[0166] FIG. 16 is a perspective view from above of an insulating member of a secondary battery according to embodiments of the present invention, FIG. 17 is a perspective view from below of an insulating member of a secondary battery according to embodiments of the present invention, FIG. 18 is a bottom view from below of an insulating member of a secondary battery according to embodiments of the present invention, FIG. 19 is a partial cross-sectional view illustrating a cap plate and an insulating member, and FIG. 20 is a cut-away perspective view illustrating a guide portion of the insulating member.

[0167] As illustrated in FIGS. 16 to 20, an insulating member (1500) is installed between the cap plate (1410) and the electrode assembly (1200) to insulate the cap plate (1410) and the electrode assembly (1200). The insulating member (1500) may have a shape corresponding to the cap plate (1410) and may be formed in the shape of an elongated square plate. The upper insulating member (1500) may be arranged to face the cap plate (1410) and may be arranged parallel to the cap plate (1410).

[0168] The insulating member (1500) may include a square-shaped insulating plate (1510) and two supporting protrusions (1520) protruding downward toward the case (1100) from both longitudinal edges (y-axis direction) of the insulating plate (1510).

[0169] An insertion hole (1530) into which a body portion (1421) of an electrode terminal (1420) and a sealing gasket (1450) are inserted can be formed in the insulating plate (1510).

[0170] Additionally, the insulating member (1500) may include a guide hole (1511) located at the bottom of the electrolyte injection port (1430), a guide portion (1540) protruding downward from the guide hole (1511), and an exhaust portion (1550) located at the bottom of the vent portion (1440).

[0171] The guide portion (1540) may include a guide rim (1541) that surrounds the lower portion of the guide hole (1511), a support member (1542) that is positioned at the lower portion of the guide hole (1511) and partially blocks the guide hole (1511), and an internal hole (1543) formed in the support member (1542) to move fluid. The guide rim (1541) may be formed in a circular ring shape, and the support member (1542) may be formed of a rod that is connected in a straight line. The support member (1542) is fixed to the lower portion of the guide rim (1541) and may extend in the diametric direction of the guide hole (1511).

[0172] The inner hole (1543) is located at the longitudinal center of the support (1542) and may be formed to face the electrolyte injection port (1430). The diameter (D3) of the inner hole (1543) is formed to be smaller than the diameter (D1) of the electrolyte injection port (1430), and the inner hole (1543) may be located inside a lower region corresponding to the electrolyte injection port (1430).

[0173] Meanwhile, the diameter (D2) of the guide hole (1511) may be formed larger than the diameter (D1) of the electrolyte injection port (1430). The width (W1) of the support (1542) may be formed to be 0.2 to 0.6 times the diameter (D2) of the guide hole (1511). However, the width (W1) of the support (1542) is formed to be larger than the diameter (D1) of the electrolyte injection port (1430), and may be formed to be 1.1 to 1.5 times the diameter (D1) of the electrolyte injection port (1430).

[0174] A first opening (1544) and a second opening (1545) are formed between the side of the support (1542) and the inner wall of the guide rim (1541), and the first opening (1544) and the second opening (1545) are open toward the bottom but can be spaced apart with the support (1542) therebetween.

[0175] The insulating member (1500) is positioned at the bottom of the cap plate (1410), and electrolyte is injected into the electrolyte injection port (1430) while the cap plate (1410) is coupled to the case (1100). When a guide portion (1540) having a guide rim (1541), a support (1542), and a guide hole (1511) is formed on the insulating member (1500), the electrolyte injection port (1430) is prevented from being blocked by the lower structure, and the electrolyte can be easily injected.

[0176] In particular, since the inner hole (1543) is located directly below the electrolyte injection port (1430), the electrolyte can be prevented from flowing backwards into the case (1100) by moving through the inner hole (1543). In addition, when the inner hole (1543) is blocked or a large amount of electrolyte is supplied, the electrolyte can be injected into the case through the first opening (1544) and the second opening (1545) formed on both sides of the support (1542).

[0177]

[0178] Fig. 21 is a cross-sectional view showing the exhaust part of the insulating member.

[0179] As illustrated in FIGS. 16 and 21, the exhaust portion (1550) is positioned at the bottom of the vent portion (1440) and has a plurality of exhaust openings. The exhaust portion (1550) may include a support frame (1512) that protrudes downward and has a ring shape, and a plurality of dividing bars (1554) that are fixed to the support frame (1512) and extend in the width direction (x-axis direction) of the insulating member (1500). A first exhaust opening (1551) is formed at the center of the exhaust portion (1550), and a second exhaust opening (1552) and a third exhaust opening (1553) may be formed on both sides of the first exhaust opening (1551). The first exhaust opening (1551) has a larger cross-sectional area than the second exhaust opening (1552) and the third exhaust opening (1553).

[0180] When the exhaust member (1550) is formed in the insulating member (1500) in this way, when the pressure inside the case (1100) increases, the vent member (1441) is broken at a preset pressure, so that the gas inside the case (1100) can be easily discharged.

[0181]

[0182] FIG. 22 is a drawing illustrating a process of combining a foil tab and a current collector in a secondary battery according to one embodiment of the present invention, and FIG. 23 is a drawing illustrating a process of combining a cap assembly and a current collector in a secondary battery according to one embodiment of the present invention.

[0183] As illustrated in FIGS. 22 and 23, the foil tabs (1220, 1230) are welded to the current collector member (1300). The foil tabs (1220, 1230) may be welded to the current collector member (1300) at the bottom of the current collector member (1300). The current collector member (1300) may be installed on each of the positive and negative electrodes. After the foil tabs (1220, 1230) and the current collector member (1300) are welded, the current collector member (1300) and the cap member (1400) may be combined.

[0184] FIG. 24 is a drawing illustrating a process of combining a current collector and a foil tab when the foil tab is formed in both directions in a secondary battery according to one embodiment of the present invention, and FIG. 25 is a drawing illustrating a process of combining a cap assembly with a current collector.

[0185] In FIGS. 22 and 23, both the positive and negative foil tabs are formed in the same direction. However, as illustrated in FIGS. 24 and 25, the electrode assembly may be formed in such a way that the positive and negative foil tabs are formed in different directions. Accordingly, the current collector (1300) may also be coupled to both sides of the electrode assembly (1200).

[0186]

[0187] FIG. 26 is a drawing illustrating a process of combining a foil tab and a current collector in a secondary battery according to another embodiment of the present invention, and FIG. 27 is a drawing illustrating a process of combining a cap member and a current collector in a secondary battery according to another embodiment of the present invention.

[0188] As illustrated in FIGS. 26 and 27, foil tabs (1220a, 1220b, 1230a, 1230b) are welded on a current collecting member (1300). In one current collecting member (1300), the foil tabs (1220a, 1220b, 1230a, 1230b) rise above the current collecting member in different directions with the current collecting projection (1320) as the center. The foil tabs (1220a, 1220b, 1230a, 1230b) can be positioned so as not to interfere with each other. The current collecting member (1300) can be installed on each of the positive and negative electrodes. At this time, an insulating material is positioned on the lower portion of the current collecting member, so that the current collecting member and the electrode assembly can be insulated.

[0189] FIG. 28 is a drawing illustrating a process of combining a current collector and a foil tab when the foil tab is formed in both directions in a secondary battery according to another embodiment of the present invention, FIG. 29 is a drawing illustrating a process of combining a cap member with a current collector, and FIG. 30 is a drawing illustrating a process of attaching an insulating member while the electrode assembly and the current collector are combined.

[0190] In FIGS. 26 and 27, both the positive and negative foil tabs are formed in the same direction. However, as illustrated in FIGS. 28 and 29, the electrode assembly may be formed in such a way that the positive and negative foil tabs are formed in different directions. Accordingly, the current collecting member (1300) may also be coupled to both sides of the electrode assembly (1200).

[0191] Meanwhile, as illustrated in FIG. 30, after the electrode assembly (1200) and the current collector member (1300) are combined, a first insulating tape (T1) may be attached to the current collector member (1300). This can prevent a short circuit between the foil tab and the cap member (1400).

[0192] After attaching the first insulating tape (T1), the outer surface of the electrode assembly (1200) can be wrapped with the second insulating tape (T2), and then the electrode assembly (1200) can be inserted into the case (1100).

[0193] Next, the outer surface of the case (1100) can be wrapped with a third insulating tape (T3) to complete the manufacture of the secondary battery.

[0194]

[0195] FIG. 31 is a drawing showing a secondary battery including two electrode parts according to another embodiment of the present invention, and FIG. 32 is a drawing showing a foil tab formed on two electrode parts according to another embodiment of the present invention joined to a current collecting member.

[0196] As illustrated in FIGS. 31 and 32, a secondary battery (1000) according to another embodiment of the present invention includes a case (1100), an electrode assembly (1200), a current collector member (1300), and a cap member (1400).

[0197] The electrode part (1210) of the electrode assembly (1200) includes a first electrode part (1210_1) and a second electrode part (1210_2). A first foil tab (1220_1) and a second foil tab (1230_1) are formed on the first electrode part (1210_1), and a first foil tab (1220_2) and a second foil tab (1230_2) are formed on the second electrode part (1210_2). The first foil tab (1220_1) and the second electrode part (1210_2) of the first electrode part (1210_1) are joined to one and the same current collecting member (1300_1). The second foil tab (1230_1) of the first electrode portion (1210_1) and the second foil tab (1230_2) of the second electrode portion (1210_2) are joined to one and the same current collecting member (1300_2).

[0198] In this embodiment, the first electrode portion (1210_1) and the second electrode portion (1210_2) are taped together with a fourth insulating tape (T4) and a fifth insulating tape (T5). The fourth insulating tape (T4) is attached to a height-wise side surface of the electrode assembly (1200), and the fifth insulating tape (T5) is attached to a length-wise side surface of the electrode assembly (1200).

[0199] When n fourth or fifth insulating tapes (T4, T5) are attached to one side, the fourth and fifth insulating tapes (T4, T5) 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 (T4) is attached to one height-wise side as in FIG. 31, the fourth insulating tape (T4) 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 (T5) are attached to one length-wise side, the fifth insulating tapes (T5) 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 the fourth insulating tape (T4) is one and the number of the fifth insulating tapes (T5) is two, but is not limited thereto. The fourth insulating tape (T4) and the fifth insulating tape (T5) serve to bind the first electrode part (1210_1) and the second electrode part (1210_2) together and also have an insulating effect.

[0200] After the electrode assembly (1200) is taped with the fourth and fifth insulating tapes (T4, T5), a sixth insulating tape (T6) may be attached to cover all sides except for the sides where the foil 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 a cap member (1400) is coupled to the opening of the case (1100).

[0201]

[0202] Above, the embodiments of the present invention have been described, but those of 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.

[0203]

[0204] [Explanation of symbols]

[0205] 1000: Secondary battery 1100: Case

[0206] 1200: Electrode assembly 1210: Electrode section

[0207] 1220, 1230: Foil tab 1300: Current collector member

[0208] 1310: collector plate 1320: collector bump

[0209] 1400: Cap absence

[0210] 1410: Cap plate 1420: Electrode terminal

[0211] 1421: Body section 1422: First bending section

[0212] 1423: Second bending section 1430: Electrolyte injection port

[0213] 1440: Vent part 1450: Sealing gasket

[0214] 1460: Upper gasket

[0215] 1500: Insulating member 1510: Insulating plate

[0216] 1520: Support protrusion 1530: Insertion hole

[0217] 1540: Guide section 1550: Exhaust section

Claims

1. A secondary battery including a cap assembly that seals an opening of a case into which an electrode assembly is inserted, The above cap assembly A cap plate with a through hole formed therein; An upper gasket disposed on the upper portion of the cap plate; An insulating plate disposed under the cap plate; A secondary battery including an electrode terminal inserted into the above through hole, the upper end of which is bent to the upper end of the upper gasket, and the lower end of which is bent to the lower end of the insulating plate, thereby fixing the upper gasket and the insulating plate to the cap plate.

2. In paragraph 1, It includes a current collecting member having a current collecting plate electrically connected to the electrode assembly and a current collecting projection protruding from the current collecting plate, A secondary battery characterized in that the current collecting protrusion is inserted into an insertion hole formed in the electrode terminal, and the current collecting protrusion and the upper end of the electrode terminal are welded to each other.

3. In paragraph 2, The above electrode terminal is inserted into the through hole, and the body part has the insertion hole formed in the center, A first bending portion that is bent from the upper part of the body portion to the upper part of the upper gasket; A secondary battery characterized by including a second bending portion that is bent from the lower end of the body portion to the lower portion of the insulating plate.

4. In paragraph 3, A secondary battery characterized in that the first bending portion includes a lower surface, an outer stepped surface formed on the outer side of the lower surface, and an outer surface formed in a vertical direction at an end of the outer stepped surface.

5. In paragraph 3, A secondary battery characterized in that the upper gasket is interposed between the cap plate and the first bending portion.

6. In paragraph 5, The above cap plate has a mounting surface formed around the through hole and a step surface formed protruding from the outside of the mounting surface, A secondary battery characterized in that the upper gasket is formed with a first thickness and includes a first horizontal plane formed to be in contact with the seating surface of the cap plate, a second horizontal plane formed with a second thickness thicker than the first thickness and formed to be in contact with the seating surface and the step surface, and a vertical plane extending in a vertical direction from an outer end of the second horizontal plane and surrounding an outer surface of the first bending portion.

7. In paragraph 6, A secondary battery characterized by including a sealing gasket interposed between the through hole and the body portion, insulating the cap plate and the electrode terminal while preventing electrolyte or gas inside the case from leaking to the outside.

8. In paragraph 7, A first alignment protrusion is formed on the lower surface of the through hole side of the cap plate in a shape connected to the through hole, A secondary battery characterized in that the sealing gasket has a first alignment groove formed at a position corresponding to the first alignment protrusion.

9. In paragraph 7, A secondary battery characterized in that a second alignment protrusion is formed on the upper surface of the second bending portion, and a second alignment groove is formed on the lower surface of the sealing gasket at a position corresponding to the second alignment protrusion.

10. In paragraph 3, A secondary battery characterized in that an insertion groove is formed in the form of a slope of upper and lower rays on the inner surface of the insertion hole, and an insertion projection that is inserted into the insertion groove is formed on the outer surface of the current collector projection.

11. In paragraph 3, A secondary battery characterized in that an undercut is formed at the lower end of the body portion, and an inclined surface having a shape corresponding to the undercut is formed at the lower end of the current collector.

12. In paragraph 3, A secondary battery characterized in that the above-mentioned current collector protrusion is formed in the center of the upper surface of the current collector plate, and an adhesive layer including a heat-sealing layer is formed on both sides of the upper surface of the current collector plate.

13. In paragraph 1, An insulating member is disposed between the cap plate and the electrode assembly and includes the insulating plate, A secondary battery characterized in that the insulating member includes a guide hole positioned at the bottom of the electrolyte injection port formed in the cap plate and a guide portion protruding downward from the guide hole to guide the movement of the electrolyte.

14. In paragraph 13, A secondary battery characterized in that the guide portion includes a support member positioned at the lower portion of the guide hole and partially blocking the guide hole, and an internal hole formed in the support member and configured to move a fluid.

15. In paragraph 14, A secondary battery characterized in that the inner hole faces the electrolyte injection port and is located at the longitudinal center of the guide portion.

16. In paragraph 14, A secondary battery characterized in that the guide portion includes a guide rim surrounding the lower portion of the guide hole, the support is fixed to the guide rim, and a first opening and a second opening are formed between a side end of the support and an inner wall of the guide rim.

17. In paragraph 13, A vent section for gas discharge is formed in the above cap plate, The insulating member includes an exhaust portion protruding toward the bottom of the case and having a plurality of exhaust openings, A secondary battery characterized in that the exhaust part is located below the vent part.

18. In paragraph 1, The above electrode assembly includes an electrode portion and a plurality of foil tabs formed on the electrode portion, A secondary battery characterized in that the plurality of foil tabs are formed in one direction of the electrode assembly.

19. In paragraph 1, The above electrode assembly includes an electrode portion and a plurality of foil tabs formed on the electrode portion, A secondary battery characterized in that the plurality of foil tabs are formed in both directions of the electrode assembly.

20. In paragraph 1, After the electrode assembly and the collector plate are combined, a first insulating tape is attached to the collector plate, After the outer surface of the electrode assembly is wrapped with a second insulating tape, the electrode assembly is inserted into the case, A secondary battery characterized in that the outer surface of the case into which the electrode assembly is inserted is wrapped with a third insulating tape.

Images