Secondary battery

Abstract

An embodiment of the present invention relates to a secondary battery. An embodiment of the present invention may provide a secondary battery in which a first tab and a second tab of an electrode assembly are provided in the same direction and electrically connected to a terminal and a can, so that the secondary battery has low electrical resistance and a short current path. In addition, according to an embodiment of the present invention, a first current collecting plate and a second current collecting plate are three-dimensionally coupled and provided in the same region and thus occupy a small volume in an inner space of a can. Therefore, a secondary battery, in which a relatively large electrode assembly is accommodated inside a can, can be provided. In addition, according to an embodiment of the present invention, the first current collecting plate and the second current collecting plate are spaced apart from each other to form an opening. Therefore, gas can be quickly discharged when the internal pressure rises.

Description

secondary battery

[0001] An embodiment of the present invention relates to a secondary battery.

[0002] Unlike primary batteries, which cannot be recharged, secondary batteries are batteries capable of both charging and discharging. Low-capacity secondary batteries are used in small portable electronic devices such as smartphones, feature phones, laptop computers, digital cameras, and camcorders, while high-capacity secondary batteries are widely used as power sources for motor drive systems and energy storage batteries in hybrid and electric vehicles. Such secondary batteries include an electrode assembly consisting of a positive electrode and a negative electrode, a can housing the assembly, and electrode terminals connected to the electrode assembly.

[0003] The information described above disclosed in the background technology of this invention is intended only to enhance understanding of the background of the present invention and may therefore include information that does not constitute prior art.

[0004] The present disclosure is intended to provide a secondary battery having low electrical resistance and a short current path, wherein a first tab (e.g., positive tab) and a second tab (e.g., negative tab) of an electrode assembly are provided in the same direction and electrically connected to a first terminal (e.g., rivet terminal) and a second terminal (e.g., can).

[0005] The present disclosure is intended to provide a secondary battery in which a relatively large electrode assembly is accommodated inside a can by having a first current collector plate (e.g., a positive current collector plate) and a second current collector plate (e.g., a negative current collector plate) three-dimensionally combined and provided in the same area so as to occupy a small volume in the internal space of the can.

[0006] However, the technical problems that the present invention aims to solve are not limited to those described above, and other unmentioned problems can be clearly understood by those skilled in the art from the description of the invention below.

[0007] A secondary battery according to an embodiment of the present invention may include: a cylindrical can having one end closed and the other end open; an electrode assembly having a first tab protruding in a first direction and disposed adjacent to a winding end and disposed adjacent to a winding end and protruding in the first direction, and a second tab protruding in the first direction and disposed spaced apart from the first tab; a first current collector plate disposed in the can and electrically connected to the first tab; a second current collector plate electrically connected to the second tab and the can and spaced apart from the first current collector plate; a pair of insulating plates disposed between the first current collector plate and the second current collector plate and spaced apart from each other; and a terminal electrically connected to the first current collector plate and insulatedly coupled to the closed end of the can.

[0008] A circular ring-shaped opening (G2) may be provided between the pair of the above insulating plates.

[0009] It may include a plurality of bridges provided between a pair of the above insulating plates and connecting the pair of the above insulating plates.

[0010] The first tab above may be in the shape of a circular ring with a center in the shape of a plane.

[0011] The second tab above may be in the shape of a circular ring with a center in the shape of a plane.

[0012] The diameter of the first tab may be smaller than the diameter of the second tab.

[0013] A separator may be interposed between the first tab and the second tab.

[0014] The first current collector plate may include a first connection area connected to the first tap, a connection area extending from one side of the inner circumference of the first connection area, and a second connection area extending from the connection area and connected to the terminal.

[0015] The second connection area may be in a form that does not come into contact with the first connection area facing the connection area.

[0016] The first connection area above has a planar shape in the form of a circular ring with a center, and the second connection area above may have a planar shape in the form of a circle or a polygon.

[0017] The above-mentioned second collector plate may have a planar shape in the form of a circular ring with a center.

[0018] A pair of the above insulating plates may include a first insulating plate provided on the outer surface of the first connection area and a second insulating plate provided on the inner surface of the second current collector plate.

[0019] The outer surface of the second collector plate can come into contact with the inner surface of the can.

[0020] The second current collector plate may include a can connecting portion provided at the end of the outer surface and in contact with the inner surface of the can.

[0021] The above can connection may be in a shape where the thickness increases as it faces the can.

[0022] The above can connection may be in a shape that is bent from the end of the outer surface of the second current collector plate toward the electrode assembly.

[0023] The above can connection may be in a shape that wraps around a portion of the upper part of the electrode assembly.

[0024] The electrode assembly may include a first electrode plate which is an anode having the first tab, a second electrode plate which is a cathode having the second tab, and a separator interposed between the first electrode plate and the second electrode plate.

[0025] The second electrode plate may be disposed at the outermost part of the electrode assembly.

[0026] The above can may include a rivet plate through which the terminal is joined, a side wall welded to the rivet plate and extending in a second direction opposite to the first direction, and a finishing plate integrally formed from or joined to the side wall.

[0027] It may further include an insulating member disposed between the rivet plate and the electrode assembly, and between the finishing plate and the electrode assembly.

[0028] According to an embodiment of the present invention, a first tab and a second tab of an electrode assembly are provided in the same direction and electrically connected to a terminal and a can, thereby providing a secondary battery with low electrical resistance and a short current path.

[0029] In addition, according to an embodiment of the present invention, a first current collector plate and a second current collector plate are three-dimensionally combined and provided in the same area, thereby occupying a small volume in the internal space of the can, so as to provide a secondary battery in which a relatively large electrode assembly is accommodated inside the can.

[0030] In addition, according to an embodiment of the present invention, since the first collector plate and the second collector plate are spaced apart from each other to form an opening, gas can be rapidly discharged when the internal pressure rises.

[0031] However, the effects obtainable through the present invention are not limited to those described above, and other unmentioned technical effects will be clearly understood by those skilled in the art from the description of the invention below.

[0032] The following drawings attached to this specification illustrate preferred embodiments of the present invention and serve to further enhance understanding of the technical concept of the present invention together with the detailed description of the invention provided below; therefore, the present invention should not be interpreted as being limited only to the matters described in such drawings.

[0033] FIG. 1 is a perspective view of a secondary battery according to one embodiment of the present invention.

[0034] Figure 2 is a cross-sectional view of a secondary battery according to Figure 1.

[0035] FIG. 3 is a plan view illustrating an electrode assembly of a secondary battery according to FIG. 2.

[0036] FIG. 4 is a perspective view of an electrode assembly according to FIG. 2.

[0037] FIG. 5 is a plan view illustrating the state of the electrode assembly before winding according to FIG. 2.

[0038] FIG. 6 is a plan view illustrating a collector plate assembly according to FIG. 2.

[0039] FIG. 7 is a cross-sectional view of a secondary battery according to another embodiment of the present invention.

[0040] FIG. 8 is a plan view illustrating a collector plate assembly according to FIG. 7.

[0041] FIG. 9 is a perspective view illustrating a collector plate assembly according to FIG. 8.

[0042] FIG. 10 is a cross-sectional view of a secondary battery according to another embodiment of the present invention.

[0043] FIGS. 11 and FIGS. 12 are perspective views illustrating a battery pack including an exemplary secondary battery according to the present invention.

[0044] FIGS. 13 and FIGS. 14 are a perspective view and a side view illustrating an automobile including an exemplary battery pack according to the present invention.

[0045] Preferred embodiments of the present invention will be described in detail below with reference to the attached drawings. Prior to this, terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings. Instead, based on the principle that the inventor can appropriately define the concepts of terms to best describe their invention, they should be interpreted in a meaning and concept consistent with the technical spirit of the present invention. Therefore, the embodiments described in this specification and the configurations illustrated in the drawings are merely some of the most preferred embodiments of the present invention and do not represent all of the technical spirit of the present invention. It should be understood that various equivalents and modifications capable of replacing them may exist at the time of filing this application.

[0046] Additionally, as used herein, “comprise, include” and / or “comprising, including” specify the presence of the mentioned features, numbers, steps, actions, parts, elements, and / or groups thereof, and do not exclude the presence or addition of one or more other features, numbers, actions, parts, elements, and / or groups.

[0047] Additionally, to aid in understanding the invention, the attached drawings are not drawn to actual scale, and the dimensions of some components may be exaggerated. Furthermore, the same reference numerals may be assigned to identical components in different embodiments.

[0048] The statement that two subjects of comparison are 'identical' means that they are 'substantially identical.' Therefore, substantial identity may include deviations considered low in the industry, for example, deviations within 5%. Additionally, the statement that a parameter is uniform in a given area may mean that it is uniform from an average perspective.

[0049] Although terms such as "first," "second," etc., are used to describe various components, it goes without saying that these components are not limited by these terms. These terms are used merely to distinguish one component from another, and unless specifically stated otherwise, the first component may also be the second component.

[0050] Throughout the specification, unless specifically stated otherwise, each component may be singular or plural.

[0051] The fact that any configuration is placed on the upper (or lower) surface of a component or on the upper (or lower) surface of a component may mean not only that the any configuration is placed in contact with the upper (or lower) surface of said component, but also that another configuration may be interposed between said component and any configuration placed on (or under) said component.

[0052] Furthermore, where it is stated that one component is connected, coupled, or joined to another component, it should be understood that while said components may be directly connected or joined to each other, other components may be interposed between each component, or each component may be connected, coupled, or joined through other components. Additionally, when it is stated that a part is electrically coupled to another part, this includes not only cases where they are directly connected but also cases where they are connected with other elements in between.

[0053] Throughout the specification, "A and / or B" means A, B, or A and B unless specifically stated otherwise. That is, "and / or" includes any combination or any combination of the enumerated items. "C through D" means C or more and D or less, unless specifically stated otherwise.

[0054] The terms used in this specification are intended to describe embodiments of the present disclosure and are not intended to limit the present disclosure.

[0055] Hereinafter, a secondary battery according to embodiments of the present invention will be described in detail with reference to the attached drawings.

[0056] FIG. 1 is a perspective view of a secondary battery according to an embodiment of the present invention. FIG. 2 is a cross-sectional view of the secondary battery according to FIG. 1. FIG. 3 is a plan view illustrating an electrode assembly of the secondary battery according to FIG. 2. FIG. 4 is a perspective view of the electrode assembly according to FIG. 2. FIG. 5 is a plan view illustrating the state of the electrode assembly according to FIG. 2 before winding. FIG. 6 is a plan view illustrating a current collector assembly according to FIG. 2.

[0057] First, we will explain the structure of the secondary battery (100).

[0058] Referring to FIGS. 1 to 6, a secondary battery (100) according to one embodiment of the present invention may include a can (110), an electrode assembly (120), a current collector assembly (130), and a terminal (140).

[0059] Referring to FIGS. 1 and 2, the can (110) forms the outer shape of the secondary battery (10) and may have a cylindrical shape with one end open. For example, the can (110) may include a roughly disc-shaped rivet plate (111) having a terminal hole (1111) in the center, an extended side wall (112) extending downward from the rivet plate (111), and a sealing plate (113) that seals the lower end of the side wall (112). The can (110) may include or be referred to as a can, housing, or outer casing. The can (110) may include steel, steel alloy, nickel-plated steel, aluminum, aluminum alloy, copper, or copper alloy. The can (110) can be manufactured by a deep drawing process in which a metal plate is placed on a die having an opening and pressed with a punch to form a cylinder, an extrusion process in which molten metal is put into an extrusion die and extruded into a cylinder, or a process in which a thin metal plate is rolled into a cylinder and welded. The can (110) serves to accommodate an electrode assembly (120), a current collector assembly (130), and an electrolyte (optional), and to isolate them from the external environment.

[0060] In some examples, the side wall (112) and the finishing plate (113) may be provided as a single unit. In some examples, the rivet plate (111) and the side wall (112) may be provided separately and then joined together by laser welding. In some examples, the rivet plate (111) and the side wall (112) may be joined together by beading and crimping, curling, or seaming. In some examples, the rivet plate (111) and the side wall (112) may be provided as a single unit. In some examples, the side wall (112) and the finishing plate (113) may be provided separately and then joined together by welding. In some examples, the side wall (112) and the finishing plate (113) may be joined together by beading and crimping, curling, or seaming.

[0061] For example, the end plate (113) may be in the shape of a flat disc. The end plate (113) may include a notch (1134) on its upper surface. The notch (1134) may have a thinner thickness than other areas of the end plate (113). The notch (1134) may include or be referred to as a safety vent. The notch (1134) serves to rupture and release internal gas when the internal pressure of the secondary battery is higher than the reference pressure.

[0062] Referring to FIGS. 2 through 5, the electrode assembly (120) may include or be referred to as an electrode group, an electrode body, or a jelly roll. The electrode assembly (120) may include a first electrode plate (121), a second electrode plate (122), and a separator (123). The electrode assembly (120) may have a separator (123) interposed between the first electrode plate (121) and the second electrode plate (122), and may be wound in a cylindrical shape. In some examples, the center of the electrode assembly (120) may have a hollow cylindrical region. This central region may be referred to as a core (124). Additionally, in some examples, a center pin (optional) may be inserted into the core (124). The core (124) may serve as a passage through which pressure is discharged when the internal pressure of the secondary battery exceeds a reference pressure. In some examples, internal pressure is applied to the end plate (113) through the core (124), and eventually the notch (1134) of the end plate (113) is broken so that the internal pressure can be reduced.

[0063] The first electrode plate (121) may be either a negative plate or a positive plate. The first electrode plate (121) may include a first current collector (1212) which is a metal thin plate, a first active material layer (1213) provided on at least one surface of the first current collector (1212), and a first non-active portion where the first active material layer (1213) is not provided. The first non-active portion may be referred to as the first substrate. The first non-active portion may be positioned toward the rivet plate (111). The first non-active portion may be punched and / or notched into a certain shape to become a first tab (1211). That is, the first tab (1211) may extend and protrude in the direction of the rivet plate (111). In some examples, the first tab (1211) may be in the form of a lead tab that is separately provided and welded to the first current collector (1212). The first tap (1211) can serve as a passage for current flow between the first electrode plate (121) and the terminal (140) (e.g., a rivet terminal) by being electrically connected to the first current collector plate (131) and the terminal (140) to be described later. This will be described later.

[0064] For example, the first electrode plate (121) can function as an anode. The first current collector (1212) may include an aluminum foil, and the first active material layer (1213) may include a transition metal oxide.

[0065] In some examples, a compound capable of reversible intercalation and deintercalation of lithium (a lithated intercalation compound) may be used as the positive electrode active material. Specifically, one or more composite oxides of lithium and a metal selected from cobalt, manganese, nickel, and combinations thereof may be used.

[0066] The above composite oxide may be a lithium transition metal composite oxide, and specific examples include a lithium nickel-based oxide, a lithium cobalt-based oxide, a lithium manganese-based oxide, a lithium iron phosphate-based compound, a cobalt-free nickel-manganese-based oxide, or a combination thereof.

[0067] As an example, compounds represented by any one of the following chemical formulas may be used. LiaA1-bXbO2-cDc(0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05); LiaMn2-bXbO4-cDc(0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05); LiaNi1-b-cCobXcO2-D(0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.5, 0<<2); LiaNi1-b-cMnbXcO2-D(0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.5, 0<<2); LiaNibCocL1dGeO2(0.90≤a≤1.8, 0≤b≤0.9, 0≤c≤0.5, 0≤d≤0.5, 0≤e≤0.1); LiaNiGbO2(0.90≤a≤1.8, 0.001≤b≤0.1); LiaCoGbO2(0.90≤a≤1.8, 0.001≤b≤0.1); LiaMn1-bGbO2 (0.90≤a≤1.8, 0.001≤b≤0.1); LiaMn2GbO4 (0.90≤a≤1.8, 0.001≤b≤0.1); LiaMn1-gGgPO4 (0.90=a=1.8, 0=g=0.5); Li(3-f)Fe2(PO4)3(0=f=2); LiaFePO4(0.90=a=1.8).

[0068] In the above chemical formula, A is Ni, Co, Mn, or a combination thereof; X is Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, a rare earth element, or a combination thereof; D is O, F, S, P, or a combination thereof; G is Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V, or a combination thereof; and L1 is Mn, Al, or a combination thereof.

[0069] A positive electrode for a lithium secondary battery may include a current collector (e.g., a first substrate) and a positive electrode active material layer formed on the current collector. The positive electrode active material layer may include a positive electrode active material and may further include a binder and / or a conductive material.

[0070] The content of the positive active material is 90% to 99.5% by weight with respect to 100% by weight of the positive active material layer, and the content of the binder and the conductive material may each be 0.5% to 5% by weight with respect to 100% by weight of the positive active material layer.

[0071] Aluminum may be used as the current collector mentioned above, but is not limited thereto.

[0072] The second electrode plate (122) may be the other of a negative plate and a positive plate. The second electrode plate (122) may include a second current collector (1222) which is a metal foil, a second active material layer (1223) provided on at least one surface of the second current collector (1222), and a second non-active portion where the second active material layer (1223) is not provided. The second non-active portion may be referred to as the second substrate. The second non-active portion may also be positioned toward the rivet plate (111). The second non-active portion may be notched in a certain shape to become a second tab (1221). That is, the second tab (1221) may extend and protrude in the direction of the rivet plate (111). In some examples, the second tab (1221) may be in the form of a lead tab that is separately provided and welded to the second current collector (1222). The second tap (1221) is electrically connected to the second current collector plate (131) and the can (110), which will be described later, thereby serving as a passage for current flow between the second electrode plate (122) and the can (110). This will be described later.

[0073] For example, the second electrode plate (122) can function as a negative electrode. The second current collector (1222) may include copper or nickel foil, and the second active material layer (1223) may include a carbon-based material, Si, Sn, tin oxide, tin alloy composite, transition metal oxide, lithium metal nitrite, or metal oxide, etc.

[0074] The negative electrode active material includes a material capable of reversibly intercalating / deintercalating lithium ions, lithium metal, an alloy of lithium metal, a material capable of doping and dedoping lithium, or a transition metal oxide.

[0075] A material capable of reversibly intercalating / deintercalating the above lithium ions may be a carbon-based negative electrode active material, such as crystalline carbon, amorphous carbon, or a combination thereof. Examples of the crystalline carbon include graphite, such as natural graphite or artificial graphite, and examples of the amorphous carbon include soft carbon or hard carbon, mesophase pitch carbide, calcined coke, etc.

[0076] As a material capable of doping and undoping the above lithium, a Si-based negative electrode active material or a Sn-based negative electrode active material may be used. The above Si-based negative electrode active material may be silicon, a silicon-carbon composite, SiOx (0 < x < 2), a Si-based alloy, or a combination thereof.

[0077] The silicon-carbon composite may be a composite of silicon and amorphous carbon. According to one embodiment, the silicon-carbon composite may be in the form of silicon particles and amorphous carbon coated on the surface of the silicon particles.

[0078] The silicon-carbon composite may further include crystalline carbon. For example, the silicon-carbon composite may include a core comprising crystalline carbon and silicon particles and an amorphous carbon coating layer located on the surface of the core.

[0079] A negative electrode for a lithium secondary battery may include a current collector (e.g., a second substrate) and a negative electrode active material layer formed on the current collector. The negative electrode active material layer may include a negative electrode active material and may further include a binder and / or a conductive material.

[0080] For example, the negative electrode active material layer may comprise 90% to 99% by weight of negative electrode active material, 0.5% to 5% by weight of binder, and 0% to 5% by weight of conductive material.

[0081] As the binder, a non-aqueous binder, an aqueous binder, a dry binder, or a combination thereof may be used. When an aqueous binder is used as the cathode binder, a cellulose-based compound capable of imparting viscosity may be further included.

[0082] As the current collector mentioned above, a material selected from copper foil, nickel foil, stainless steel foil, titanium foil, nickel foam, copper foam, a polymer substrate coated with a conductive metal, and combinations thereof may be used.

[0083] The separator (123) is interposed between the first electrode plate (121) and the second electrode plate (122) to prevent a short circuit between the first electrode plate (121) and the second electrode plate (122) and to enable the movement of lithium ions. The separator (123) may be larger than the size of the first electrode plate (121) and the second electrode plate (122). Therefore, the separator (123) may protrude further in the up, down, left, and right directions than the first electrode plate (121) and the second electrode plate (122), respectively. Thus, the separator (123) can prevent the first electrode plate (121) and the second electrode plate (122) from coming into direct contact with the can (110) in the up, down, and / or left and right directions of the electrode assembly (120). In some examples, the separator (123) may protrude and extend a certain length in the upper and lower directions of the electrode assembly (120) without the first tab (1211) and the second tab (1221).

[0084] For example, the separator may comprise a porous substrate and a coating layer comprising an organic material, an inorganic material, or a combination thereof located on one or both sides of the porous substrate. The organic material may comprise a polyvinylidene fluoride-based polymer or a (meth)acrylic-based polymer. The inorganic material may be Al2O3, SiO2, TiO2, SnO2, CeO2, MgO, NiO, CaO, GaO, ZnO, ZrO2, Y2O3, It may include, but is not limited to, inorganic particles selected from SrTiO3, BaTiO3, Mg(OH)2, boehmite, and combinations thereof. The organic and inorganic materials may exist mixed in a single coating layer, or may exist in a stacked form in which a coating layer containing organic materials and a coating layer containing inorganic materials are stacked.

[0085] In some examples, the electrode assembly (120) may be contained in a can (110) together with the electrolyte. The electrolyte for a lithium secondary battery may include a non-aqueous organic solvent and a lithium salt. The non-aqueous organic solvent serves as a medium through which ions involved in the electrochemical reaction of the battery can move. The non-aqueous organic solvent may be a carbonate-based, ester-based, ether-based, ketone-based, or alcohol-based solvent, a non-protic solvent, or a combination thereof, and may be used alone or in a mixture of two or more types. Additionally, when using a carbonate-based solvent, a cyclic carbonate and a chain carbonate may be used in combination.

[0086] The current collector assembly (130) may include a first current collector (131), a second current collector (132), a first insulating plate (133), and a second insulating plate (134). The first current collector (131) and the second current collector (132) may be provided separately and arranged to be spaced apart from each other. Alternatively, the first current collector (131) and the second current collector (132) may be provided separately and connected to each other or provided as a single unit. In this case as well, the first current collector (131) and the second current collector (132) may be arranged to be spaced apart from each other. The spacing between the first current collector (131) and the second current collector (132) is indicated as G2 in FIGS. 2 and FIGS. 6.

[0087] The first current collector plate (131) can electrically connect the first electrode plate (121) of the electrode assembly (120) and the terminal (140). Thus, the first current collector plate (131) can serve as a current flow path between the electrode assembly (120) and the terminal (140). The first current collector plate (131) may include or be referred to as a current collector, a conductor, or a conductive lead. The first current collector plate (131) may be manufactured from aluminum or an aluminum alloy. The first current collector plate (131) may be manufactured by a process of punching a metal plate with a die and a punch, or by a process of casting molten metal, etc.

[0088] The second current collector plate (132) can electrically connect the second electrode plate (122) of the electrode assembly (120) and the can (110) (e.g., rivet plate (111)). Thus, the second current collector plate (132) can serve as a current flow path between the electrode assembly (120) and the can (110). The second current collector plate (132) may include or be referred to as a current collector, a conductor, or a conductive lead. The second current collector plate (132) may be made of copper, a copper alloy, nickel, or a nickel alloy. The second current collector plate (132) may be manufactured by a process of punching a metal plate with a die and a punch, or by a process of casting molten metal, etc.

[0089] The terminal (140) may be connected to the can (110) by passing through it. In some examples, the terminal (140) may be connected by passing through a terminal hole (1111) provided in a rivet plate (111). In some examples, an insulating gasket (1431) may be interposed between the terminal (140) and the terminal hole (1111). In some examples, the terminal (140) may be a rivet terminal connected by a rivet method. The terminal (140) may include a relatively wide head portion (141) and a relatively narrow body portion (142) extending downward from the head portion (141) and passing through the terminal hole (1111). In some examples, the terminal (140) may further include a recess (1411) provided at a certain depth from the head portion (141) toward the body portion (142). The thickness between the bottom surface of the body portion (142) and the corresponding bottom surface is reduced relatively by the recess (1411). Accordingly, the energy of the laser beam during laser welding is well transferred to the first collector plate (131) (i.e., the second connection area (1313)), so that the terminal (140) and the first collector plate (131) can be connected to each other. In some examples, an upper insulator (1432) may be further interposed between the head portion (141) and the rivet plate (111). In some examples, an insulating member (1323) may be further interposed around the body portion (142) penetrating the rivet plate (111). In some examples, the insulating member (1323) may be interposed between the collector plate assembly (130) and the rivet plate (111). In some examples, the recess (1411) may be finished with a generally flat member (e.g., metal) after the welding process. In some examples, after the welding process, a metal member may be joined to the recess (1411) or the top of the recess (1411) may be closed.

[0090] In a secondary battery (100) according to one embodiment of the present invention described above, the first tab (1211) and the second tab (1221) of the electrode assembly (120) are provided in the same direction and are electrically connected to the terminal (140) and the can (110). Accordingly, a secondary battery (100) with low electrical resistance and a short current path can be provided. In addition, the present disclosure provides a first current collector plate (131) and a second current collector plate (132) that are three-dimensionally combined and provided in the same direction, occupying a small volume in the internal space of the can (110). Thus, a secondary battery (100) can be provided in which a relatively large electrode assembly (120) is accommodated inside the can (110).

[0091] Below, the electrical connection structure of the electrode assembly (120) and the current collector assembly (130) is described in more detail.

[0092] Referring to FIGS. 3 through 5, the first tab (1211) may extend and protrude upward from the approximately central region of the electrode assembly (120). The second tab (1221) may extend and protrude upward from the approximately periphery region of the electrode assembly (120). In some examples, the first tab (1211) and the second tab (1221) may have different diameters around the central core (124).

[0093] For example, the first tab (1211) may have a planar shape that is approximately circular ring-shaped. The center of the first tab (1211) may be the same as the winding center of the electrode assembly (120). In some examples, the second tab (1221) may have a planar shape that is approximately circular ring-shaped with a diameter that is relatively larger than the diameter of the first tab (1211). In some examples, the separator (123) is positioned between the first tab (1211) and the second tab (1221), and may have a planar shape that is approximately circular ring-shaped. In some examples, a portion of the separator (123) may be extended and protruded in the area where the first tab (1211) and the second tab (1221) are not extended and protruded. In some examples, the upper side of the first tap (1211), the upper side of the second tap (1221), and the upper side of the separator (123) may generally form the same plane. As will be explained again below, the planar shape of the first tap (1211) may be the same or similar to the planar shape of the area connected to the first collector plate (131). The planar shape of the second tap (1221) may also be the same or similar to the planar shape of the area connected to the second collector plate (132).

[0094] Referring to FIG. 5, the left end of the first electrode plate (121) and the second electrode plate (122) is the winding end (the part where winding begins). The right end is the winding end (the part where winding is completed). For convenience of explanation, the separator is not shown.

[0095] The first tab (1211) is provided close to the winding end, and the horizontal width of the first tab (1211) may be larger than the vertical width. In the winding process, by winding one first tab (1211) multiple times from the winding end, the planar shape of the first tab (1211) may become approximately a circular ring shape.

[0096] The second tab (1221) is provided near the end of the winding, and the horizontal width of the second tab (1221) may be greater than the vertical width. In the winding process, one second tab (1221) is wound multiple times at the end of the winding, so that the planar shape of the second tab (1221) may become approximately a circular ring shape. The center of the second tab (1221) may be the same as the center of the first tab (1211). In some examples, the first and second tabs (1211, 1221) may each be provided in such a way that notching is added after the material is punched.

[0097] A first current collector plate (131) may be electrically connected to the first tap (1211), and a second current collector plate (132) may be electrically connected to the second tap (1221).

[0098] Referring to FIGS. 2 and FIGS. 6, the first collector plate (131) may include a first connection area (1311), a connection area (1312), and a second connection area (1313).

[0099] The first connection area (1311) may have a planar shape that is approximately circular in the shape of a ring. The shape of the first connection area (1311) may correspond to the shape of the first tap (1211). That is, the first connection area (1311) may be a ring shape having a diameter and width corresponding to the diameter and width of the first tap (1211). A connection area (1312) may extend from one side of the inner circumference of the first connection area (1311). A first insulating plate (133) may be provided on the outer circumference of the first connection area (1311).

[0100] The connecting area (1312) may extend toward the center from one side of the inner circumference of the first connecting area (1311). The connecting area (1312) may have a rectangular shape with a predetermined size. In some examples, the connecting area (1312) may be bent upward from the first connecting area (1311) and extended. Alternatively, the connecting area (1312) may be extended without being bent. In this case, the first connecting area (1311), the connecting area (1312), and the second connecting area (1313) may be provided on the same plane. The second connecting area (1313) may be provided integrally at the end of the connecting area (1312).

[0101] The second connection area (1313) may be extended for a certain length from the end of the connection area (1312). However, the second connection area (1313) does not come into contact with the first connection area (1311) on the opposite side facing the connection area (1312). That is, the second connection area (1313) can be connected to the first connection area (1311) only by the connection area (1312). Therefore, when viewing the first current collector plate (131) from above, the second connection area (1313) and the first connection area (1311) may be spaced apart as shown in FIG. 6. The space between them is indicated as G1 in FIG. 6. The second connection area (1313) is a part that is electrically connected to the terminal (140). The second connection area (1313) may be welded to the lower part of the terminal (140), which will be described later. The second connection area (1313) may have various planar shapes, such as a circle, triangle, or square. In this embodiment, for convenience, only an example where the second connection area (1313) is circular is shown in the drawing.

[0102] For example, welding may be performed in the form of a radial straight line or a circular ring in the first connection area (1311). Accordingly, the first tap (1211) and the first connection area (1311) may be electrically connected to each other. In some examples, the first tap (1211) may be compacted or bent in an inward or outward direction and welded to the first connection area (1311). Additionally, in some examples, welding may be performed in the form of a circular ring in the second connection area (1313). Accordingly, the second connection area (1313) and the terminal (140) may be electrically connected to each other.

[0103] The first insulating plate (133) may be in the shape of a roughly circular ring. The first insulating plate (133) may be integrally provided along the outer surface of the first connection area (1311). Alternatively, the first insulating plate (133) may be provided separately and joined along the outer surface of the first connection area (1311). For example, the first insulating plate (133) may be manufactured by double injection molding with the first current collector plate (131) using an insulating material that does not react with the electrolyte. The first insulating plate (133) may be manufactured from polypropylene, polyethylene, polyethylene propylene-based synthetic rubber (EPDM), nylon, or a composite thereof. The first insulating plate (133) may be provided on a plane generally similar to that of the first current collector plate (131). Additionally, the first insulating plate (133) may include or be referred to as an insulator, an insulating block, or an insulating pacer. A second current collector plate (132) and a second insulation plate (134) may be arranged spaced apart from the first insulation plate (133).

[0104] The second current collector plate (132) may have a planar shape that is approximately circular in the shape of a ring. The shape of the second current collector plate (132) may correspond to the shape of the second tab (1221). That is, the second current collector plate (132) may have a ring shape with a diameter and width corresponding to the diameter and width of the second tab (1221). In addition, since the second tab (1221) is positioned at the winding end of the electrode assembly (120) and has a larger diameter than the first tab (1211), the second current collector plate (132) may also have a larger diameter than the first current collector plate (131). A can connection part (1321) may be provided at the outer circumferential end of the second current collector plate (132), and a second insulating plate (134) may be provided on the inner circumferential end.

[0105] The can connection part (1321) is a part intended to increase the welding area when welding with the can (110). The can connection part (1321) may be provided in a certain area on the outer surface of the second collector plate (132) that is in close contact with the inner surface of the can (110). The can connection part (1321) may have a greater thickness than other areas of the second collector plate (132). The thickness of the can connection part (1321) may increase as it approaches the can (110). In some examples, referring to FIG. 2, the cross-section of the can connection part (1321) may be trapezoidal when viewed from the side. Although not shown in the drawings, the cross-section of the can connection part (1321) may be provided in a triangular, square, or the like. That is, any shape may be provided as long as the can connection part (1321) can increase the contact area with the can (110). However, the can connection (1321) is not an essential component and may be provided or omitted as needed (optional). Since the area of ​​the welded region is increased by the can connection (1321), the weld strength and current flowability can be improved.

[0106] The second insulating plate (134) may be in the shape of a roughly circular ring. The second insulating plate (134) may be integrally provided along the inner surface of the second current collector plate (132). Alternatively, the second insulating plate (134) may be provided separately and coupled along the inner surface of the second current collector plate (132). Accordingly, the second insulating plate (134) may be spaced apart from and positioned to face the first insulating plate (133). For example, the second insulating plate (134) may be manufactured by double injection molding with the second current collector plate (132) using an insulating material that does not react with the electrolyte. The second insulating plate (134) may be manufactured from polypropylene, polyethylene, polyethylene propylene-based synthetic rubber (EPDM), nylon, or a composite thereof. The second insulating plate (134) may be provided on a plane generally similar to that of the second current collector plate (132). Additionally, the second insulating plate (134) may include or be referred to as an insulator, an insulating block, or an insulating facer.

[0107] As described above, since the first collector plate (131) and the second collector plate (132) are spaced apart from each other to form an opening, gas can be quickly discharged when the internal pressure rises.

[0108] Meanwhile, the aforementioned secondary battery may include a different type of current collector plate.

[0109] FIG. 7 is a cross-sectional view of a secondary battery according to another embodiment of the present invention. FIG. 8 is a plan view illustrating a current collector assembly according to FIG. 7. FIG. 9 is a perspective view illustrating a current collector assembly according to FIG. 8.

[0110] Referring to FIGS. 7 to 9, a secondary battery (100) according to another embodiment of the present invention may have the same structure as the embodiment according to FIGS. 1 to 6 described above, except for some configurations. Hereinafter, only configurations different from the embodiment described above will be described in detail.

[0111] A secondary battery (100) according to another embodiment of the present invention may include a can (110), an electrode assembly (120), a current collector assembly (230), and a terminal (140). Here, the structure and features of the can (110), the electrode assembly (120), and the terminal (140) may be the same or similar as those of the previously described embodiment.

[0112] Referring to FIGS. 7 to 9, the current collector assembly (230) may include a first current collector (231), a second current collector (232), a first insulating plate (233), and a second insulating plate (234). The first current collector (231) and the second current collector (232) are provided separately and may be connected to each other by the first insulating plate (233) and the second insulating plate (234).

[0113] The first current collector plate (231) can electrically connect the first electrode plate (121) of the electrode assembly (120) and the terminal (140). The material and manufacturing method of the first current collector plate (231) may be the same or similar as that of the first current collector plate (131) of the previously described embodiment. The first current collector plate (231) may include a first connection area (2311), a connection area (2312), and a second connection area (2313).

[0114] The first connection area (2311) may have a planar shape that is approximately circular in the shape of a ring. The shape of the first connection area (2311) may correspond to the shape of the first tap (1211). That is, the first connection area (2311) may be a ring shape having a diameter and width corresponding to the diameter and width of the first tap (1211). A connection area (2312) may be extended from one side of the inner circumference of the first connection area (2311). A first insulating plate (233) may be provided on the outer circumference of the first connection area (2311).

[0115] The connecting area (2312) may extend toward the center from one side of the inner circumference of the first connecting area (2311). The connecting area (2312) may have a rectangular shape with a predetermined size. In some examples, the connecting area (2312) may be bent upward from the first connecting area (2311) and extended. However, if the connecting area (2312) does not come into contact with the first tab (1211), it may be extended without being bent. In this case, the first connecting area (2311), the connecting area (2312), and the second connecting area (2313) may be provided on the same plane. The second connecting area (2313) may be provided integrally at the end of the connecting area (2312).

[0116] The second connection area (2313) is a part that is electrically connected to the terminal (140). The second connection area (2313) can be welded to the lower part of the terminal (140). The second connection area (2313) can have various shapes, such as a circular, triangular, or square planar shape. In this embodiment, for convenience, only an example where the second connection area (2313) is circular is shown in the drawing.

[0117] For example, welding may be performed in the form of a radial straight line or a circular ring in the first connection area (2311). Accordingly, the first tap (1211) and the first connection area (2311) may be electrically connected to each other. In some examples, the first tap (1211) may be compacted or bent in an inward or outward direction and welded to the first connection area (2311). Additionally, in some examples, welding may be performed in the form of a circular ring in the second connection area (2313). Accordingly, the second connection area (2313) and the terminal (140) may be electrically connected to each other.

[0118] The first insulating plate (233) may be in the shape of a roughly circular ring. The first insulating plate (233) may be integrally provided along the outer surface of the first connection area (2311). Alternatively, the first insulating plate (233) may be provided separately and joined along the outer surface of the first connection area (2311). The material, manufacturing method, and shape of the first insulating plate (233) may be the same or similar as the first insulating plate (133) of the previously described embodiment. The first insulating plate (233) may be provided on a plane generally in the same plane as the first current collector plate (232). The second current collector plate (232) and the second insulating plate (234) may be arranged spaced apart from the first insulating plate (233).

[0119] The second current collector plate (232) can electrically connect the second electrode plate (122) of the electrode assembly (120) and the can (110) (e.g., rivet plate (111)). The material and manufacturing method of the second current collector plate (232) may be the same or similar as that of the first current collector plate (131) of the above-described embodiment. The second current collector plate (232) may have a planar shape that is approximately a circular ring shape. The shape of the second current collector plate (232) may correspond to the shape of the second tab (1221). That is, the second current collector plate (232) may have a ring shape having a diameter and width corresponding to the diameter and width of the second tab (1221). Additionally, since the second tab (1221) is positioned at the winding end of the electrode assembly (120) and has a larger diameter than the first tab (1211), the second current collector plate (232) may also have a larger diameter than the first current collector plate (231). A can connection part (2321) may be provided at the outer circumferential end of the second current collector plate (232), and a second insulating plate (234) may be provided on the inner circumferential end.

[0120] The can connection part (2321) is a part intended to increase the welding area when welding with the can (110). The can connection part (2321) may be in a bent shape from the outer surface of the second current collector plate (232) toward the electrode assembly (120). Thus, the can connection part (2321) may have a shape that wraps around a portion of the upper part of the electrode assembly (120). Referring to FIG. 7, a second electrode plate (122), which is a negative electrode, is placed at the outermost part of the electrode assembly (120). Thus, the can connection part (2321) may come into contact with a portion of the second electrode plate (122) and / or a portion of the second tab (1221). However, the can connection part (2321) is not an essential component and may be provided or omitted as needed (optional). Since the welding area is increased by the can connection part (2321), welding strength and current flowability may be improved. Additionally, the movement of the electrode assembly (120) can be prevented by the can connection part (2321). Generally, when the exterior of the secondary battery (100) is heated, ignition may begin at the outermost edge of the electrode assembly (120) due to the expansion and compression of the electrode assembly (120). However, in this case, a space is created between the can (110) and the electrode assembly (120) by the thickness of the can connection part (2321), so the compression strength of the electrode assembly (120) is reduced. Additionally, a passage can be secured for the gas generated during ignition to move in the vertical direction. Therefore, the ignition gas can be discharged to the outside of the secondary battery (100) through the rupture of the core (124) and the notch of the electrode assembly (120).

[0121] The second insulating plate (234) may be in the shape of a roughly circular ring. The second insulating plate (234) may be integrally provided along the inner surface of the second current collector plate (232). Alternatively, the second insulating plate (234) may be provided separately and coupled along the inner surface of the second current collector plate (232). Accordingly, the second insulating plate (234) may be spaced apart from and positioned to face the first insulating plate (233). The material, manufacturing method, and shape of the second insulating plate (234) may be the same or similar as the second insulating plate (134) of the previously described embodiment. The second insulating plate (234) may be provided on a plane generally similar to that of the second current collector plate (232). An insulating plate bridge (235) may be provided between the second insulating plate (234) and the previously described first insulating plate (231).

[0122] The insulating plate bridge (235) can connect the first insulating plate (233) and the second insulating plate (234) without blocking the opening (G2) between the first insulating plate (233) and the second insulating plate (234). The insulating plate bridge (235) may be provided in multiple numbers, at least one or more. As long as the opening (G2) between the first insulating plate (233) and the second insulating plate (234) is not blocked, the number and shape of the insulating plate bridge (235) are not limited. Since the insulating plate bridge (235) connects the first insulating plate (233) and the second insulating plate (234), the insulating plate bridge (235) can be injection molded integrally with the first insulating plate (233) and the second insulating plate (234) during the manufacturing process. Alternatively, an insulating plate bridge (235) may be separately provided and connected to the first insulating plate (233) and the second insulating plate (234).

[0123] As described above, in another embodiment of the present invention, the first collector plate (231) and the second collector plate (232) are spaced apart from each other to form an opening, so that gas can be rapidly discharged when the internal pressure rises.

[0124] The secondary battery according to the above-described embodiments has a structure having a flat-shaped finishing plate (113) that blocks the lower part of the side wall (112) of the can (110). However, the secondary battery according to another embodiment of the present invention may have a finishing plate (313) of a different shape.

[0125] FIG. 10 is a cross-sectional view of a secondary battery according to another embodiment of the present invention.

[0126] Referring to FIG. 10, a secondary battery (100) according to another embodiment of the present invention may include a can (110), an electrode assembly (120), a current collector assembly (130, 230), and a terminal (140). These may have the same or similar structure and features as the previously described embodiments. Additionally, an exemplary secondary battery (100) may include a curved, approximately circular end plate (313). Furthermore, the secondary battery (100) may further include a lower insulating member (150).

[0127] The end plate (313) may include a peripheral area (3131), a vent area (3132), and a central area (3133).

[0128] The peripheral region (3131) is a portion that is joined to the side wall (112) of the can (110). The peripheral region (3131) can be inserted into the inner side of the side wall (112) and laser welded to be joined to the side wall (112). The peripheral region (3131) may be spaced apart from the electrode assembly (120) by a predetermined distance. In some examples, the peripheral region (3131) may have a ring shape having a predetermined width.

[0129] The vent area (3132) is integrally provided with the surrounding area (3131) and may have a ring shape with a predetermined width. The vent area (3132) may be closer to the center of the secondary battery (100) than the surrounding area (3131). The vent area (3132) may protrude outward from the secondary battery (100) than the surrounding area (3131). Accordingly, the vent area (3132) is further away from the electrode assembly (120) than the surrounding area (3131). Therefore, the vent area (3132) may serve as a buffer where gas is temporarily collected when gas is generated inside the secondary battery (100). A notch (3134) may be provided in the vent area (3132). The notch (3134) may have a thinner thickness than other areas of the end plate (313). The notch (3134) may include or be referred to as a safety vent. The notch (3134) serves to rupture and release internal gas when the internal pressure of the secondary battery is higher than the reference pressure.

[0130] The central region (3133) is integrally provided with the vent region (3132) and may have a ring shape having a predetermined width. The center of the central region (3133) may be concentric with the center of the secondary battery (100). The central region (3133) may be positioned closer to the electrode assembly (120) than the vent region (3132). In some examples, the central region (3133) may be positioned in alignment with the peripheral region (3131). Alternatively, the central region (3133) may be closer to the electrode assembly (120) than the peripheral region (3131). In some examples, the central region (3133) may be in contact with the lower insulating member (150).

[0131] The lower insulating member (150) may be placed between the electrode assembly (120) and the end plate (313). The lower insulating member (150) may be made of an insulating material in the shape of a roughly disc. The lower insulating member (150) may insulate the space between the end plate (313) and the electrode assembly (120). However, if the length of the separator (123) is sufficiently long so that the lower portions of the first electrode plate (121) and the second electrode plate (122) do not come into contact with the end plate (313), the lower insulating member (150) may be omitted.

[0132] The secondary battery (100) having the aforementioned end plate (313) has a structure in which the end plate (313) occupies less space compared to a structure in which the end plate is fixed by a beading portion and a crimping portion. In addition, the first current collector plate (131) and the second current collector plate (132) are three-dimensionally combined and provided in the same direction, occupying a small volume in the internal space of the can (110). Thus, a secondary battery (100) can be provided in which a relatively large electrode assembly (120) is accommodated inside the can (110). Furthermore, similar to the embodiments described above, the first tab (1211) and the second tab (1221) are provided in the same direction and are electrically connected to the terminal (140) and the can (110). Accordingly, a secondary battery (100) with low electrical resistance and a short current path can be provided.

[0133] The secondary battery according to the above-described embodiment can be used to manufacture a battery pack (the reference numbers of the components described below are reference numbers applicable only to the drawings).

[0134] FIGS. 11 and 12 are perspective views illustrating a battery pack (300) including an exemplary cylindrical secondary battery according to the present invention. Referring to FIGS. 11 and 12, the battery pack (300) may include a plurality of battery modules (200) and a housing (310) for accommodating the plurality of battery modules (200). For example, the housing (310) may include first and second housings (311, 312) that are coupled in a direction facing each other with the plurality of battery modules (200) interposed therebetween. The plurality of battery modules (210) may be electrically connected to each other using a bus bar (251), and the plurality of battery modules (200) may be electrically connected to each other in a series / parallel or mixed series / parallel manner to obtain the required electrical output. In the drawings, for convenience of illustration, components such as a bus bar for electrically connecting the battery cells, a cooling unit, and external terminals are omitted. In some examples, the battery pack (300) may be mounted in a vehicle. The vehicle may be, for example, an electric vehicle, a hybrid vehicle, or a plug-in hybrid vehicle. The vehicle may include a four-wheeled vehicle or a two-wheeled vehicle.

[0135] FIGS. 13 and FIGS. 14 are a perspective view and a side view illustrating an automobile (400, 500) including an exemplary battery pack (300) according to the present invention. In FIG. 13, the battery pack (300) may include a battery pack cover (311) (which may correspond to the first housing) which is part of the vehicle under body (410) and a pack frame (312) (which may correspond to the second housing) disposed at the bottom of the vehicle under body (410). The battery pack cover (311) and the pack frame (312) may be structures formed integrally with the vehicle floor portion (420). The vehicle under body (410) separates the interior and exterior of the vehicle, and the pack frame (312) may be disposed on the exterior of the vehicle.

[0136] As illustrated in FIG. 14, the vehicle (500) may be formed by combining additional parts, such as a hood (510) at the front of the vehicle and fenders (520) located at the front and rear of the vehicle, respectively, with the vehicle body (400). The vehicle (500) includes a battery pack (300) comprising a battery pack cover (311) and a pack frame (312), and the battery pack (300) may be combined with the vehicle body part (400).

[0137] The above description is merely one embodiment for implementing the present invention, and the present invention is not limited to the above-described embodiment. The technical spirit of the present invention extends to the scope in which various modifications can be made by anyone with ordinary knowledge in the field to which the invention belongs, without departing from the essence of the invention as claimed in the following patent claims.

Claims

1. A cylindrical can with one end closed and the other end open; An electrode assembly having a first tab protruding in a first direction and positioned adjacent to the winding end and spaced apart from the first tab and positioned adjacent to the winding end and protruding in the first direction; A first current collector plate accommodated in the above can and electrically connected to the above first tab; A second current collector plate electrically connected to the second tap and the can, and spaced apart from the first current collector plate; A pair of insulating plates spaced apart from each other and disposed between the first current collector plate and the second current collector plate; and A secondary battery comprising a terminal electrically connected to the first current collector plate and insulatedly coupled to the closed end of the can.

2. In Paragraph 1, A secondary battery having a circular ring-shaped opening (G2) between a pair of insulating plates.

3. In Paragraph 2, A secondary battery comprising a plurality of bridges connected to the pair of insulating plates, provided between the pair of insulating plates.

4. In Paragraph 1, The above first tab is a secondary battery in which the shape of the flat surface is a circular ring shape having a center.

5. In Paragraph 4, The above second tab is a secondary battery in which the shape of the planar form is a circular ring having a center.

6. In Paragraph 5, A secondary battery in which the diameter of the first tab is smaller than the diameter of the second tab.

7. In Paragraph 6, A secondary battery having a separator interposed between the first tab and the second tab.

8. In Paragraph 1, A secondary battery comprising: a first current collector plate connected to the first tab; a connection area extending from one side of the inner surface of the first connection area; and a second connection area extending from the connection area and connected to the terminal.

9. In Paragraph 8, A secondary battery in which the second connection area is in a form that does not come into contact with the first connection area facing the connection area.

10. In Paragraph 9, A secondary battery in which the first connection area has a planar shape in the form of a circular ring with a center, and the second connection area has a planar shape in the form of a circle or a polygon.

11. In Paragraph 10, The above second current collector plate is a secondary battery having a planar shape in the form of a circular ring with a center.

12. In Paragraph 11, A secondary battery comprising a pair of insulating plates, the first insulating plate provided on the outer surface of the first connection area and the second insulating plate provided on the inner surface of the second current collector plate.

13. In Paragraph 12, The above second current collector plate is a secondary battery in which the outer surface contacts the inner surface of the can.

14. In Paragraph 12, A secondary battery comprising a can connecting portion provided at the end of the outer surface of the second current collector plate and in contact with the inner surface of the can.

15. In Paragraph 14, A secondary battery in which the thickness of the above-mentioned can connection increases as it faces the can.

16. In Paragraph 14, A secondary battery in which the above-mentioned can connection portion is bent toward the electrode assembly from the end of the outer surface of the second current collector plate.

17. In Paragraph 16, A secondary battery in which the above-mentioned can connection portion is shaped to wrap around a portion of the upper part of the electrode assembly.

18. In Paragraph 17, The above electrode assembly comprises a first electrode plate which is a positive electrode having the first tab, a second electrode plate which is a negative electrode having the second tab, and a separator interposed between the first electrode plate and the second electrode plate, a secondary battery.

19. In Paragraph 18, A secondary battery in which the second electrode plate is disposed on the outermost part of the electrode assembly.

20. In Paragraph 1, The above can is a secondary battery comprising a rivet plate through which the terminal is joined, a side wall welded to the rivet plate and extending in a second direction opposite to the first direction, and a finishing plate integrally provided from the side wall or joined to the side wall.

21. In Paragraph 20, A secondary battery further comprising an insulating member disposed between the rivet plate and the electrode assembly, and between the finishing plate and the electrode assembly.

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