Secondary battery

Abstract

The present disclosure relates to a secondary battery. The described technical problem is to be solved by providing a cylindrical secondary battery for preventing contact shorting between a case and an electrode assembly. To this end, the present disclosure provides a secondary battery comprising: a cylindrical case having a case upper wall and a case side wall; a cylindrical electrode assembly which is accommodated in the case and which has a plurality of first tabs protruding in a first direction and a plurality of second tabs protruding in a second direction opposite to the first direction, the second tabs being electrically connected to the case; a first current collecting plate accommodated in the case and connected to the plurality of first tabs; a second current collecting plate accommodated in and connected to the case and connected to the plurality of second tabs; a rivet terminal connected to the first current collecting plate, and penetrating the case so as to be coupled thereto; and an insulating member interposed between the case and the rivet terminal, wherein the insulating member includes an insulating upper wall in contact with the upper wall of the case and an insulating side wall in contact with the side wall of the case.

Description

secondary battery

[0001] The present invention relates to an interest battery.

[0002] Secondary batteries, unlike non-rechargeable primary batteries, are rechargeable and dischargeable. Low-capacity secondary batteries are used in small, portable electronic devices such as smartphones, feature phones, laptops, digital cameras, and camcorders, while large-capacity secondary batteries are widely used as power sources for motor drives and power storage in hybrid and electric vehicles. These secondary batteries include an electrode assembly comprising a positive and negative electrode, a case housing the electrode assembly, and electrode terminals connected to the electrode assembly.

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

[0004] The present invention provides a cylindrical secondary battery that prevents contact short between a case and an electrode assembly.

[0005] However, the technical problems to be solved by the present invention are not limited to the problems described above, and other problems not mentioned can be clearly understood by those skilled in the art from the description of the invention described below.

[0006] According to one embodiment of the present invention for solving the above technical problem, a secondary battery may include a cylindrical case having a case upper wall and a case side wall; a cylindrical electrode assembly accommodated in the case and having a plurality of first tabs protruding in a first direction and a plurality of second tabs protruding in a second direction opposite to the first direction, the second tabs being electrically connected to the case; a first current collector plate accommodated in the case and connected to the plurality of first tabs; a second current collector plate accommodated and connected to the case and connected to the plurality of second tabs; a rivet terminal connected to the first current collector plate and coupled by penetrating the case; and an insulating member interposed between the case and the rivet terminal, wherein the insulating member may include an insulating upper wall contacting the case upper wall and an insulating side wall contacting the case side wall.

[0007] In one or more embodiments, the insulating top wall can be bonded to the case top wall and the insulating side wall can be bonded to the case side wall.

[0008] In one or more embodiments, the thickness of the insulating sidewall may become thinner as it proceeds in the second direction.

[0009] In one or more embodiments, the insulating sidewall may include a flat surface contacting the case sidewall and a sloped surface opposite the flat surface contacting the electrode assembly.

[0010] In one or more embodiments, the peel adhesion of the insulating upper wall to the case upper wall may be from 20 N / cm to 100 N / cm.

[0011] In one or more embodiments, the peel adhesion of the insulating sidewall to the case sidewall may be from 20 N / cm to 100 N / cm.

[0012] In one or more embodiments, a portion of the insulating upper wall may be sandwiched between the case upper wall and the rivet terminal.

[0013] In one or more embodiments, the rivet terminal may include a rivet post penetrating the case top wall, a rivet head connected to the rivet post and positioned on an upper side of the case top wall, and a rivet leg connected to the rivet post and positioned on a lower side of the case top wall, wherein a portion of the insulating top wall may be fitted between the case top wall and the rivet leg.

[0014] In one or more embodiments, the device may further include an upper insulating member interposed between the rivet head and an upper side of the case upper wall, and an insulating gasket interposed between the rivet post and the case upper wall.

[0015] In one or more embodiments, an insulating side wall may be interposed between the periphery of the first collector plate and the case side wall.

[0016] In one or more embodiments, the plurality of first tabs may be bent in one direction and welded to the first collector plate, and the first collector plate may be welded to the rivet terminal.

[0017] In one or more embodiments, the length of the insulating sidewall may be 3% to 10% of the length of the case sidewall.

[0018] In one or more embodiments, the case may further include a second collector plate that is accommodated and connected to the case and connected to the plurality of second tabs, wherein the case side wall may further include a beading portion and a crimping portion, and the second collector plate may be connected to the beading portion.

[0019] In one or more embodiments, the vent plate may further be coupled with an insulating gasket between the beading portion and the crimping portion.

[0020] In one or more embodiments, the case may further include a vent plate coupled to an area opposite the upper wall of the case.

[0021] In one or more embodiments, the insulating member may be spaced apart from the first collector plate.

[0022] In one or more embodiments, the insulating member may contact the first collector plate.

[0023] In one or more embodiments, the case top wall and the case side wall may be provided integrally.

[0024] In one or more embodiments, the case upper wall and the case side wall may be prepared separately and welded together to form an integral body.

[0025] In one or more embodiments, the case may further include a vent plate integrally provided from the case side wall as an area opposite the case upper wall, and the second tab may be electrically connected to the vent plate.

[0026] According to the present invention, a secondary battery is provided in which a relatively wide insulating member is bonded to a rivet terminal and a case, thereby preventing electrolyte leakage and simultaneously preventing a contact short between the case and the electrode assembly. Furthermore, according to the present invention, a secondary battery is provided in which a relatively wide insulating member is bonded to the case by fusion, thereby improving the bonding strength between the insulating member and the case. Furthermore, according to the present invention, a secondary battery is provided in which the inlet diameter of the insulating member is formed relatively wide, thereby allowing an electrode assembly to be easily assembled to the insulating member.

[0027] However, the effects that can be obtained through the present invention are not limited to the effects described above, and other technical effects that are not mentioned can be clearly understood by those skilled in the art from the description of the invention described below.

[0028] The following drawings attached to this specification illustrate preferred embodiments of the present invention, and together with the detailed description of the invention described below, serve to further understand the technical idea of ​​the present invention, and therefore, the present invention should not be interpreted as being limited to matters described in such drawings.

[0029] FIG. 1a and FIG. 1b are a perspective view and a cross-sectional view illustrating an exemplary cylindrical secondary battery according to the present invention.

[0030] Figure 2 is an enlarged cross-sectional view showing area 2 of Figure 1b.

[0031] Figure 3 is an enlarged cross-sectional view showing a portion of an exemplary cylindrical secondary battery according to the present invention.

[0032] FIG. 4 is an enlarged cross-sectional view showing a portion of an exemplary cylindrical secondary battery according to the present invention.

[0033] FIG. 5 is a drawing illustrating a method for fusing an insulating member to a case in an exemplary cylindrical secondary battery according to the present invention.

[0034] FIG. 6 is a drawing illustrating a method for measuring the adhesive strength of an insulating member to a case in an exemplary cylindrical secondary battery according to the present invention.

[0035] FIG. 7 is an enlarged cross-sectional view illustrating a portion of an exemplary cylindrical battery according to another embodiment of the present invention.

[0036] FIG. 8 is an enlarged cross-sectional view illustrating a portion of an exemplary cylindrical secondary battery according to another embodiment of the present invention.

[0037] FIG. 9 is an enlarged cross-sectional view illustrating a portion of an exemplary cylindrical secondary battery according to another embodiment of the present invention.

[0038] FIG. 10 is a cross-sectional view illustrating an exemplary cylindrical secondary battery according to another embodiment of the present invention.

[0039] FIGS. 11A and 11B are perspective views illustrating a battery pack including an exemplary cylindrical secondary battery according to the present invention.

[0040] FIGS. 12A and 12B are perspective and side views illustrating a vehicle including an exemplary battery pack according to the present invention.

[0041] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Prior to this, terms or words used in this specification and claims should not be interpreted as limited to their typical or dictionary meanings, and should be interpreted with meanings and concepts that conform to the technical spirit of the present invention based on the principle that the inventor can appropriately define the concept of a term to best explain his or her own invention. Therefore, the embodiments described in this specification and the configurations illustrated in the drawings are only some of the most preferred embodiments of the present invention and do not represent all of the technical spirit of the present invention. Therefore, it should be understood that various equivalents and modified examples may exist as substitutes for them at the time of this application.

[0042] Additionally, when used herein, the terms "comprise", "include" and / or "comprising", "including" specify the presence of stated features, numbers, steps, operations, elements, elements and / or groups thereof, but do not preclude the presence or addition of one or more other features, numbers, operations, elements, elements and / or groups thereof.

[0043] Additionally, to facilitate understanding of the invention, the attached drawings may not be drawn to scale and some components may be exaggerated in size. Furthermore, identical components may be assigned the same reference numbers in different embodiments.

[0044] The statement that two compared objects are "identical" means "substantially identical." Therefore, "substantially identical" may include deviations considered low in the art, such as deviations of less than 5%. Furthermore, uniformity of a parameter over a given region may imply uniformity on average.

[0045] Although terms like "first" and "second" are used to describe various components, these components are not limited by these terms. These terms are used merely to distinguish one component from another, and unless otherwise specified, a "first" component may also be a "second" component.

[0046] Throughout the specification, unless otherwise specifically stated, each element may be singular or plural.

[0047] Any configuration being placed "on (or under)" or "above (or below)" a component may mean not only that any configuration is placed in contact with the upper surface (or lower surface) of said component, but also that other configurations may intervene between said component and any configuration placed on (or below) said component.

[0048] Additionally, when it is described that a component is "connected," "coupled," or "connected" to another component, it should be understood that the components may be directly connected or connected to each other, but that other components may also be "interposed" between the components, or that each component may be "connected," "coupled," or "connected" through another component. Furthermore, when it is said 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 another element in between.

[0049] When reference is made throughout the specification to "A and / or B," this means A, B, or A and B, unless otherwise stated. In other words, "and / or" includes all or any combination of the listed items. When reference is made to "C through D," this means C or more and D or less, unless otherwise stated.

[0050] The terminology used herein is for the purpose of describing embodiments of the present disclosure and is not intended to be limiting of the present disclosure.

[0051] FIGS. 1A and 1B are perspective views and cross-sectional views illustrating an exemplary cylindrical secondary battery (100) according to the present invention. As illustrated in FIGS. 1A and 1B, the exemplary secondary battery (100) according to the present invention may include a case (110), an electrode assembly (120), a first collector plate (131), a second collector plate (132), a rivet terminal (140), and an insulating member (150). In one or more embodiments, the exemplary secondary battery (100) according to the present invention may further include a vent plate (160).

[0052] The case (110) accommodates the electrode assembly (120) and the electrolyte, and together with the vent plate (160) may form the outer shape of the secondary battery (100). The case (110) may include or be referred to as a can, a housing, or an outer material. The case (110) may include a case upper wall (111) having a generally circular shape and a case side wall (112) having a cylindrical shape extending downward from the case upper wall (111). The case upper wall (111) may include or be referred to as a rivet plate or a case upper region. In one or more embodiments, the case upper wall (111) and the case side wall (112) may be provided integrally. In one or more embodiments, the case side wall (112) may be integrally extended and bent from the case upper wall (111). In one or more embodiments, a case upper wall (111) and a case side wall (112) may be provided as an integral part by manufacturing a flat metal plate by a deep drawing method. In one or more embodiments, the case (110) may be configured in various shapes, such as a pouch shape in addition to a circular shape. In addition, the case (110) may include a metal such as steel, nickel-plated steel, a steel alloy, aluminum, an aluminum alloy, a cooling sheet for deep drawing (SPCE), or a laminate film or plastic forming the pouch. A beading portion (113) recessed toward the inside may be provided on the case side wall (112), and a crimping portion (114) bent toward the inside may be provided at a lower opening of the case side wall (112). The beading portion (113) may suppress movement of the electrode assembly (120) together with the case upper wall (111) within the case (110). The crimping portion (114) can firmly fix the vent plate (160) by pressing the edge of the vent plate (160) through the insulating gasket (173).

[0053] An electrode assembly (120) may be accommodated inside a case (110) together with an electrolyte. 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) between the first electrode plate (121) and the second electrode plate (122), and may be wound in a cylindrical shape. In one or more embodiments, a hollow core (124) may be provided longitudinally at the center of the electrode assembly (120). In one or more embodiments, a center pin (optional) may be coupled to the core (124).

[0054] The first electrode plate (121) may include a first substrate (1211) and a first active material layer (1212) positioned on the first substrate (1211). A first non-conductive portion or first tab (1213) of the first substrate (1211) where the first active material layer (1212) is not positioned may extend outward (e.g., upward), and the first tab (1213) may be electrically connected to the first current collector plate (131) (i.e., the rivet terminal (140)).

[0055] The second electrode plate (122) may include a second substrate (1221) and a second active material layer (1222) positioned on the second substrate (1221). A second non-conductive portion or second tab (1223) of the second substrate (1221) where the second active material layer (1222) is not positioned may extend outward (e.g., downward), and the second tab (1223) may be electrically connected to the second collector plate (132) (i.e., the case (110)). In one or more embodiments, the first tab (1213) and the second tab (1223) may extend in opposite directions.

[0056] The first electrode plate (121) can function as an anode. In this case, the first substrate (1211) can be composed of, for example, aluminum foil, and the first active material layer (1212) can include, for example, a transition metal oxide. The second electrode plate (122) can function as an anode. In this case, the second substrate (1221) can be composed of, for example, copper foil or nickel foil, and the second active material layer (1222) can include, for example, graphite and / or silicon.

[0057] The separator (123) can prevent short circuiting between the first electrode plate (121) and the second electrode plate (122) while allowing movement of lithium ions. In one or more embodiments, the separator (123) can be positioned on opposite sides of the first electrode plate (121), or on opposite sides of the second electrode plate (122).

[0058] In one or more embodiments, a compound capable of reversible intercalation and deintercalation of lithium (a lithiated intercalation compound) may be used as the positive electrode active material. Specifically, one or more of a composite oxide of lithium and a metal selected from cobalt, manganese, nickel, and combinations thereof may be used.

[0059] The above composite oxide may be a lithium transition metal composite oxide, and specific examples thereof include lithium nickel-based oxide, lithium cobalt-based oxide, lithium manganese-based oxide, lithium iron phosphate-based compound, cobalt-free nickel-manganese-based oxide, or a combination thereof.

[0060] As an example, a compound represented by any one of the following chemical formulas may be used: Li a A 1-b X b O 2-c D c (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05); Li a Mn 2-b X b O 4-c D c(0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05); Li a Ni 1-b-c Co b X c About 2-α D α (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.5, 0<α<2); Li a Ni 1-b-c Mn b X c About 2-α D α (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.5, 0<α<2); Li a Ni b Co c L 1 d G e O2(0.90≤a≤1.8, 0≤b≤0.9, 0≤c≤0.5, 0≤d≤0.5, 0≤e≤0.1); Li a NiG b O2(0.90≤a≤1.8, 0.001≤b≤0.1); Li a CoG b O2(0.90≤a≤1.8, 0.001≤b≤0.1); Li a Mn 1-b G b O2(0.90≤a≤1.8, 0.001≤b≤0.1); Li a Mn2G b O4(0.90≤a≤1.8, 0.001≤b≤0.1); Li a Mn 1-g G g PO4(0.90≤a≤1.8, 0≤g≤0.5); Li (3-f) Fe2(PO4)3(0≤f≤2); Li a FePO4(0.90≤a≤1.8).

[0061] In the above chemical formula, A is Ni, Co, Mn, or a combination thereof; X is Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, a rare earth element, or a combination thereof; D is O, F, S, P, or a combination thereof; G is Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V, or a combination thereof; L 1 is Mn, Al or a combination thereof.

[0062] 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 includes a positive electrode active material and may further include a binder and / or a conductive material.

[0063] The content of the positive electrode active material may be 90 wt% to 99.5 wt% with respect to 100 wt% of the positive electrode active material layer, and the contents of the binder and conductive material may be 0.5 wt% to 5 wt%, respectively, with respect to 100 wt% of the positive electrode active material layer.

[0064] Aluminum may be used as the current collector, but is not limited thereto.

[0065] 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.

[0066] The material capable of reversibly intercalating / deintercalating the lithium ions may include a carbon-based negative electrode active material, for example, crystalline carbon, amorphous carbon, or a combination thereof. Examples of the crystalline carbon include graphite such as natural graphite or artificial graphite, and examples of the amorphous carbon include soft carbon or hard carbon, mesophase pitch carbide, calcined coke, and the like.

[0067] As the material capable of doping and dedoping the lithium, a Si-based negative electrode active material or a Sn-based negative electrode active material may be used. The 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.

[0068] The above silicon-carbon composite may be a composite of silicon and amorphous carbon. According to one embodiment, the silicon-carbon composite may be in the form of silicon particles and amorphous carbon coated on the surface of the silicon particles.

[0069] The silicon-carbon composite may further comprise crystalline carbon. For example, the silicon-carbon composite may comprise a core comprising crystalline carbon and silicon particles and an amorphous carbon coating layer positioned on the surface of the core.

[0070] 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 includes a negative electrode active material and may further include a binder and / or a conductive material.

[0071] For example, the negative electrode active material layer may include 90 to 99 wt% of the negative electrode active material, 0.5 to 5 wt% of the binder, and 0 to 5 wt% of the conductive material.

[0072] The above binder may be a non-aqueous binder, an aqueous binder, a dry binder, or a combination thereof. When an aqueous binder is used as the negative electrode binder, a cellulose-based compound capable of imparting viscosity may be further included.

[0073] The current collector may be selected from copper foil, nickel foil, stainless steel foil, titanium foil, nickel foam, copper foam, a polymer substrate coated with a conductive metal, and a combination thereof.

[0074] An electrolyte for a lithium secondary battery may include a non-aqueous organic solvent and a lithium salt.

[0075] The above non-aqueous organic solvent acts as a medium through which ions involved in the electrochemical reaction of the battery can move.

[0076] The above non-aqueous organic solvent may be a carbonate-based, ester-based, ether-based, ketone-based, or alcohol-based solvent, an aprotic solvent, or a combination thereof, and may be used alone or in combination of two or more thereof.

[0077] Additionally, when using a carbonate solvent, a mixture of cyclic carbonate and chain carbonate can be used.

[0078] As described above, a lithium secondary battery may have a separator between the positive and negative electrodes. Such a separator may be a multilayer film of polyethylene, polypropylene, polyvinylidene fluoride, or two or more layers thereof.

[0079] The above separator may include a porous substrate and a coating layer comprising an organic material, an inorganic material, or a combination thereof, positioned on one or both sides of the porous substrate.

[0080] The above organic material may include a polyvinylidene fluoride-based antibody or a (meth)acrylic polymer.

[0081] The above inorganic materials are Al2O3, SiO2, TiO2, SnO2, CeO2, MgO, NiO, CaO, GaO, ZnO, ZrO2, Y2O3, It may include inorganic particles selected from, but not limited to, SrTiO3, BaTiO3, Mg(OH)2, boehmite, and combinations thereof.

[0082] The organic and inorganic substances may be mixed and present in one coating layer, or a coating layer including an organic substance and a coating layer including an inorganic substance may be present in a laminated form.

[0083] A first collector plate (131) may be connected to a first tab (1213) of an electrode assembly (110). The first collector plate (131) may include or be referred to as a first current collector, a first conductor, or a first conductive plate. In one or more embodiments, the first collector plate (131) may be provided in a generally circular disk shape. A plurality of first tabs (1213) extending / protruding from the electrode assembly (120) may be electrically connected to a lower surface of the first collector plate (131). In one or more embodiments, the first tabs (1213) may be pressed or bent inwardly toward the core (124) or outwardly away from the core (124) and laser welded to the lower surface of the first collector plate (131). The first collector plate (131) may include aluminum, an aluminum alloy, copper, a copper alloy, nickel, or a nickel alloy.

[0084] The second collector plate (132) may be connected to the second tab (1223) of the electrode assembly (110). The second collector plate (132) may include or be referred to as a second current collector, a second conductor, or a second conductive plate. In one or more embodiments, the second collector plate (132) may be provided in a generally circular disk shape. A plurality of second tabs (1223) extending / protruding from the electrode assembly (120) may be electrically connected to the upper surface of the second collector plate (132). In one or more embodiments, the second tabs (1223) may be pressed or bent inwardly toward the core (124) or outwardly away from the core (124) and laser welded to the upper surface of the second collector plate (132). The second collector plate (132) may include copper, a copper alloy, nickel, a nickel alloy, aluminum, or an aluminum alloy. In one or more embodiments, the second collector plate (132) may further include a second collector plate bend (1321) electrically connected to the case (110) by being sandwiched between the beading portion (113) and the insulating gasket (173).

[0085] The rivet terminal (140) may be coupled to the case (110) and electrically connected to the electrode assembly (120). The rivet terminal (140) may include or be referred to as a rivet, a terminal, or a positive terminal. The rivet terminal (140) may include a rivet post (141), a rivet head (142), and a rivet leg (143). The rivet post (141) may penetrate the case upper wall (111) and be coupled to the case upper wall (111). The rivet head (142) may be connected to the upper end of the rivet post (141) and may be positioned on the upper side of the case upper wall (111). The rivet leg (142) may be connected to the lower end of the rivet post (141) and may be positioned on the lower side of the case upper wall (111). In one or more embodiments, an insulating gasket (171) may be interposed between the rivet post (141) and the case top wall (111). In one or more embodiments, an upper insulating member (172) may be interposed between the rivet head (142) and the upper side of the case top wall (111). In one or more embodiments, an insulating member (150) may be interposed between the rivet leg (143) and the lower side of the case top wall (111). In one or more embodiments, the insulating gasket (171), the upper insulating member (172), and the insulating member (150) may be provided separately. In one or more embodiments, the insulating gasket (171), the upper insulating member (172), and the insulating member (150) may not be integral. In one or more embodiments, the rivet post (141) may include a rivet recess (1411). In one or more embodiments, the rivet leg (143) may be electrically connected to the first collector plate (131). In one or more embodiments, the rivet leg (143) may be welded to the first collector plate (131) by irradiating a laser beam through the rivet recess (1411). In one or more embodiments, after the welding process, the rivet recess (1411) may be filled with metal or closed with a metal plate.The rivet terminal (140) may comprise aluminum, an aluminum alloy, copper, a copper alloy, nickel, or a nickel alloy. In this way, the rivet terminal (140) may perform a function of electrically connecting to an external device. In one or more embodiments, the case upper wall (111) may also perform a function of electrically connecting to an external device.

[0086] An insulating member (150) may be interposed between the case (110) and the rivet terminal (140). The insulating member (150) may include or be referred to as an insulator, an insulating plate, or an insulating film. The insulating member (150) may include an insulating upper wall (151) and an insulating side wall (152). The insulating upper wall (151) may be in contact with or adhered to the case upper wall (111). The insulating side wall (152) may be in contact with or adhered to the case side wall (112). Here, the fact that the insulating upper wall (151) is in contact with the case upper wall (111) means that the insulating upper wall (151) can be easily separated from the case upper wall (111). The fact that the insulating upper wall (151) is adhered to the case upper wall (111) means that the insulating upper wall (151) is not easily separated from the case upper wall (111). That the insulating side wall (152) is in contact with the case side wall (112) means that the insulating side wall (152) can be easily separated from the case side wall (112). That the insulating side wall (152) is bonded to the case side wall (112) means that the insulating side wall (152) is not easily separated from the case side wall (112). In one or more embodiments, a portion of the insulating top wall (151) may be interposed between the case top wall (111) and the rivet leg (143). In one or more embodiments, a portion of the insulating top wall (151) may be in contact with or bonded to the rivet post (141). In one or more embodiments, the insulating top wall (151) may be interposed between the case top wall (111) and the upper side of the first collector plate (131). In one or more embodiments, an insulating sidewall (152) may be interposed between the case sidewall (112) and the perimeter of the first collector plate (131). In one or more embodiments, the insulating member (151) may include polypropylene, polyethylene, or ethylene propylene diene terpolymer (EPDM) that does not react with the electrolyte.This insulating member (150) has a relatively large area and is bonded between the rivet terminal (140) and the case (110), thereby preventing leakage of the electrolyte and preventing contact short between the case (110) and the electrode assembly (120).

[0087] The vent plate (160) may be coupled between the beading portion (113) and the crimping portion (114) of the case (110) by interposing an insulating gasket (173). The vent plate (160) may include or be referred to as a cap plate, a cap assembly, a safety vent, a conductive plate, or a sealing plate. In one or more embodiments, instead of providing the beading portion and the crimping portion, the vent plate (160) may be directly welded to the case side wall (112), or the vent plates (160) may be coupled to the case side wall (112) in a curling manner or a seaming manner.

[0088] In one or more embodiments, the vent plate (160) may further include a vent notch (161) provided relatively thinly on the upper surface. In one or more embodiments, the vent plate (160) may include a peripheral region (162) sandwiched between the beading portion (113) and the crimping portion (114), an inner region (163) connected to the peripheral region (162) and lower than the peripheral region (162), and a central region (164) connected to the inner region (163) and higher than the inner region (163). The vent notch (161) may be provided on the inner region (163). In one or more embodiments, the central region (164) may be closer to the electrode assembly (120) than the peripheral region (162) and the inner region (163). This vent notch (161) is ruptured to release internal gas when the internal pressure of the secondary battery is higher than a reference pressure. The vent plate (160) may be composed of iron, nickel-plated iron, stainless steel, aluminum, or an aluminum alloy. In one or more embodiments, the case (110) and the vent plate (160) coupled thereto are collectively referred to as the case.

[0089] FIG. 2 is an enlarged cross-sectional view illustrating area 2 of FIG. 1B. As illustrated in FIG. 2, the insulating member (150) may include an insulating upper wall (151) that contacts the case upper wall (111) and an insulating side wall (152) that contacts the case side wall (112). The insulating upper wall (151) and the insulating side wall (152) may be bent in a direction that is approximately perpendicular to each other. In one or more embodiments, a thickness (t1) of the insulating upper wall (151) may be approximately similar to a thickness (t2) of the insulating side wall (152). In one or more embodiments, t1 and t2 may be approximately 0.05 mm to approximately 0.2 mm. In one or more embodiments, the thickness of the insulating side wall (152) may gradually become thinner as it proceeds in the second direction. That is, the thickness of the insulating side wall (152) may gradually become thinner in the direction toward the vent plate (160). The insulating side wall (152) may include a flat surface (1521) that contacts the case side wall (112) and an inclined surface (1522) that contacts the electrode assembly (120) on the opposite side of the flat surface (1521). Since the surface of the insulating side wall (152) that faces the electrode assembly (120) is provided to be inclined, when the electrode assembly (120) is fitted into the case (110), the upper end of the electrode assembly (120) may be easily fitted without being damaged by the insulating member (150). In one or more embodiments, the thickness of the lower end of the insulating side wall (152) may be approximately 0.01 mm to approximately 0.02 mm. In one or more embodiments, the length of the insulating side wall (152) may be about 3% to about 10% of the total length of the case side wall (112). In this way, by wrapping the upper end of the electrode assembly (120) with the insulating member (150), an undesired electrical short with the case side wall (112) may be prevented. In one or more embodiments, the insulating upper wall (151) may be spaced apart from the first collector plate (131). In one or more embodiments, a gap or space may exist between the insulating upper wall (151) and the first collector plate (131).In one or more embodiments, the width of the gap or space may correspond to the thickness of the rivet leg (143).

[0090] FIG. 3 is an enlarged cross-sectional view illustrating a portion of an exemplary cylindrical secondary battery (100) according to the present invention. As illustrated in FIG. 3, an insulating side wall (152) of an insulating member (150) may be adhered to a case side wall (112). In one or more embodiments, the insulating side wall (152) may be thermally bonded to the case side wall (112). In one or more embodiments, a peel adhesion force of the insulating side wall (152) to the case side wall (112) may be about 20 N / cm to about 100 N / cm.

[0091] FIG. 4 is an enlarged cross-sectional view illustrating a portion of an exemplary cylindrical secondary battery (100) according to the present invention. As illustrated in FIG. 4, an insulating upper wall (151) of an insulating member (150) may be adhered to a case upper wall (111). In one or more embodiments, the insulating upper wall (151) may be heat-sealed to the case upper wall (111). In one or more embodiments, a peel adhesion force of the insulating upper wall (151) to the case upper wall (111) may be about 20 N / cm to about 100 N / cm. In one or more embodiments, the insulating upper wall (151) and the insulating side wall (152) may be heat-sealed and adhered to the case upper wall (111) and the case side wall (112), respectively.

[0092] In this way, the present invention can provide a secondary battery (100) in which leakage of electrolyte is prevented and a contact short between the case (110) and the electrode assembly (120) is prevented by bonding and adhering a relatively wide insulating member (150) between the rivet terminal (140) and the case (110). In addition, the present invention can provide a secondary battery (100) in which the bonding force between the insulating member (150) and the case (110) is improved by bonding and adhering a relatively wide insulating member (150) to the case (110). In addition, the present invention can provide a secondary battery (100) in which the electrode assembly (120) is easily assembled to the insulating member (150) by forming the inlet diameter of the insulating member (150) relatively wide.

[0093] FIG. 5 is a drawing illustrating a method of fusing an insulating member (150) to a case (110) in an exemplary cylindrical secondary battery (100) according to the present invention. As illustrated in FIG. 5, after the insulating member (150) is coupled to the case (110), a heating jig (180) may be coupled to the interior of the case (110). The heating jig (180) is pressed toward the case (110) while in close contact with the insulating upper wall (151) and the insulating side walls (152), and a temperature of about 200° C. to about 400° C. is also provided. In one or more embodiments, the pressing time may be about 10 seconds to about 60 seconds. In this way, the insulating member (150) may be melted and thus adhered to the case upper wall (111) and the case side walls (112). Thereafter, the heating jig (180) is separated from the case (110), and the insulating member (150) is cooled. Accordingly, the insulating member (150) has adhesive force to the case upper wall (111) and the case side wall (112) and maintains an adhered state.

[0094] FIG. 6 is a diagram illustrating a method for measuring the adhesive strength of an insulating member (150) to a case (110) in an exemplary cylindrical secondary battery (100) according to the present invention. As illustrated in FIG. 6, after the insulating member (150) was heat-sealed inside the case (110), the upper and lower sides of the insulating member (150) were joined through a through hole in the case (110) with a fastening member (190) (e.g., including a pair of fastening members (191) and a fastening bolt (192)). Thereafter, the fastening member (190) was pressed downward using a push-pull gauge (195), and the adhesive strength was tested when the insulating upper wall (151) was separated from the case upper wall (111). For example, when the heat-sealing time was approximately 15 seconds and the heat-sealing temperature was approximately 260°C, the adhesive strength was measured to be approximately 20 N / cm. In addition, when the thermal bonding time is approximately 20 seconds and the thermal bonding temperature is approximately 260°C, the adhesive strength was measured to be approximately 30 N / cm. When the thermal bonding time is approximately 30 seconds and the thermal bonding temperature is approximately 260°C, the adhesive strength was measured to be approximately 50 N / cm. Thus, it can be seen that the longer the thermal bonding time, the better the adhesive strength between the case (110) and the insulating member (150).

[0095] FIG. 7 is an enlarged cross-sectional view illustrating a portion of an exemplary cylindrical battery according to another embodiment of the present invention. The cylindrical battery illustrated in FIG. 7 may be similar to the cylindrical battery illustrated in FIG. 2 except that the insulating member (150A) is relatively thicker. In the example illustrated in FIG. 7, the insulating member (150A) may also include an insulating upper wall (151A) and an insulating side wall (152), wherein the thickness (t2) of the insulating upper wall (151A) may be thicker than the thickness (t1) of the insulating side wall (152). In one or more embodiments, the insulating upper wall (151A) may contact the case upper wall (111) and the first collector plate (131) simultaneously. In one or more embodiments, there may be no gap or space between the insulating upper wall (151A) and the first collector plate (131). In one or more embodiments, the insulating upper wall (151A) may be wrapped around the lateral side of the rivet leg (143). That is, the insulating upper wall (151A) may be in contact with the lateral side of the rivet leg (143). In one or more embodiments, the insulating side wall (152) may be wrapped around the lateral side of the first collector plate (131). That is, the insulating side wall (152) may be in contact with the lateral side of the first collector plate (131). Therefore, the cylindrical battery according to the present invention not only improves the sealing force of the case but also reduces the internal dead space of the case.

[0096] FIG. 8 is an enlarged cross-sectional view illustrating a portion of an exemplary cylindrical secondary battery according to another embodiment of the present invention. The cylindrical battery illustrated in FIG. 8 may be similar to the cylindrical battery illustrated in FIG. 3 except that the insulating member (150A) is relatively thick. In the example illustrated in FIG. 8, the insulating upper wall (151A) may be in contact with the case upper wall (111) and the first current collector (131) simultaneously, and the insulating side wall (152) may be adhered to the case side wall (112).

[0097] FIG. 9 is an enlarged cross-sectional view illustrating a portion of an exemplary cylindrical secondary battery according to another embodiment of the present invention. The cylindrical battery illustrated in FIG. 9 may be similar to the cylindrical battery illustrated in FIG. 4 except that the insulating member (150A) is relatively thick. In the example illustrated in FIG. 9, the upper side of the insulating upper wall (151A) may be adhered to the case upper wall (111), and the lower side of the insulating upper wall (151A) may be in contact with the first collector plate (131). In addition, the insulating side wall (152) may be adhered to the case side wall (112). In this way, the cylindrical battery according to the present invention may further improve the sealing force of the case.

[0098] Fig. 10 is a cross-sectional view illustrating an exemplary cylindrical secondary battery according to another embodiment of the present invention. The cylindrical battery (100A) illustrated in Fig. 10 may be similar to the cylindrical battery (100) illustrated in Fig. 1B, except that the case upper wall (111A) is separately prepared and welded to the case side wall (112), and the vent plate (160A) is provided integrally with the case side wall (112). In the example illustrated in Fig. 10, the case upper wall (111A) in the shape of a disk is separately prepared and joined to the case side wall (112), and then, for example, a laser beam is irradiated to the joining area of ​​the case upper wall (111A) and the case side wall (112), whereby the case upper wall (111A) can be completely joined and integrated with the case side wall (112). Accordingly, the joining area of ​​the case upper wall (111A) and the case side wall (112) may be provided in an approximately right-angled shape rather than a round shape. In one or more embodiments, the boundary area of ​​the insulating upper wall (151) and the insulating side wall (152) of the insulating member (150) may also be provided in an approximately right-angled shape rather than a round shape.

[0099] A vent plate (160A) may be integrally provided from a case side wall (112) as an area opposite to the case upper wall (111A). Accordingly, a boundary area between the case side wall (112) and the vent plate (160A) may be provided in an approximately round shape. In one or more embodiments, the vent plate (160A) may further include a vent notch (161A) that is provided relatively thinly on the upper surface. In one or more embodiments, the vent plate (160A) and the case side wall (112) may be integrally provided by processing the metal plate in a deep drawing manner.

[0100] In one or more embodiments, the second tab (1223) of the electrode assembly (120) may be electrically connected to the upper side of the vent plate (160A). In one or more embodiments, the second current collector plate described above may be omitted, and the second tab (1223) may be directly welded to the vent plate (160A) by a laser or ultrasonic waves. Accordingly, the current flow path between the electrode assembly (120) and the case (110) may be shortened, thereby lowering the electrical resistance and preventing the generation of heat.

[0101] FIGS. 11A and 11B are perspective views illustrating a battery pack (300) including an exemplary cylindrical secondary battery according to the present invention. Referring to FIGS. 11A and 11B, 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 series-parallel hybrid manner to obtain a required electrical output. In the drawings, for convenience of illustration, components such as a bus bar, a cooling unit, and an external terminal for electrically connecting battery cells are omitted. In one or more embodiments, the battery pack (300) may be mounted on a vehicle. The vehicle may be, for example, an electric vehicle, a hybrid vehicle, or a plug-in hybrid vehicle. The vehicle may include a four-wheel vehicle or a two-wheel vehicle.

[0102] Figures 12a and 12b are perspective views and side views illustrating a vehicle (400, 500) including an exemplary battery pack (300) according to the present invention. In Figure 12a, the battery pack (300) may include a battery pack cover (311) (which may correspond to the first housing) which is a part of a vehicle underbody (410) and a pack frame (312) (which may correspond to the second housing) which is disposed at a lower portion of the vehicle underbody (410). The battery pack cover (311) and the pack frame (312) may be formed integrally with the vehicle floor (420). The vehicle underbody (410) separates the interior and exterior of the vehicle, and the pack frame (312) may be disposed at the exterior of the vehicle.

[0103] As illustrated in FIG. 12b, the vehicle (500) may be formed by combining additional components, such as a hood (510) at the front of the vehicle and fenders (520) positioned at the front and rear of the vehicle, respectively, with the vehicle body (400). The vehicle (500) includes a battery pack (300) including a battery pack cover (311) and a pack frame (312), and the battery pack (300) may be combined with the vehicle body component (400).

[0104] Although the present invention has been described above with reference to limited embodiments and drawings, the present invention is not limited thereto, and it is obvious that various modifications and variations are possible within the scope of the technical idea of ​​the present invention and the equivalent scope of the patent claims to be described below by a person having ordinary skill in the art to which the present invention pertains.

Claims

1. A cylindrical case having a case top wall and case side walls; A cylindrical electrode assembly accommodated in the case and having a plurality of first tabs protruding in a first direction and a plurality of second tabs protruding in a second direction opposite to the first direction, wherein the second tabs are electrically connected to the case; A first collector plate accommodated in the case and connected to the plurality of first tabs; A rivet terminal connected to the first collector plate and coupled through the case; and Including an insulating member interposed between the case and the rivet terminal, A secondary battery, wherein the insulating member includes an insulating upper wall in contact with the upper wall of the case and an insulating side wall in contact with the side wall of the case.

2. In paragraph 1, A secondary battery, wherein the insulating upper wall is bonded to the case upper wall and the insulating side wall is bonded to the case side wall.

3. In paragraph 1, A secondary battery in which the thickness of the insulating side wall becomes thinner as it proceeds in the second direction.

4. In paragraph 1, A secondary battery, wherein the insulating side wall includes a flat surface contacting the case side wall and an inclined surface contacting the electrode assembly on the opposite side of the flat surface.

5. In paragraph 1, A secondary battery, wherein the peeling adhesion of the insulating upper wall to the upper wall of the case is 20 N / cm to 100 N / cm.

6. In paragraph 1, A secondary battery, wherein the peeling adhesion of the insulating side wall to the case side wall is 20 N / cm to 100 N / cm.

7. In paragraph 1, A secondary battery, wherein a portion of the insulating upper wall is sandwiched between the upper wall of the case and the rivet terminal.

8. In paragraph 1, The rivet terminal includes a rivet post penetrating the upper wall of the case, a rivet head connected to the rivet post and positioned on the upper side of the upper wall of the case, and a rivet leg connected to the rivet post and positioned on the lower side of the upper wall of the case. A secondary battery, wherein a portion of the insulating upper wall is sandwiched between the case upper wall and the rivet leg.

9. In paragraph 8, A secondary battery further comprising an upper insulating member interposed between the rivet head and the upper side of the case upper wall, and an insulating gasket interposed between the rivet pillar and the case upper wall.

10. In paragraph 1, A secondary battery, wherein the insulating side wall is interposed between the periphery of the first collector plate and the side wall of the case.

11. In paragraph 1, A secondary battery, wherein the plurality of first tabs are bent in one direction and welded to the first collector plate, and the first collector plate is welded to the rivet terminal.

12. In paragraph 1, A secondary battery, wherein the length of the insulating side wall is 3% to 10% of the length of the case side wall.

13. In paragraph 1, further comprising a second collector plate that is accommodated and connected to the case and connected to the plurality of second tabs; A secondary battery, wherein the case side wall further includes a beading portion and a crimping portion, and the second collector plate is connected to the beading portion.

14. In paragraph 13, A secondary battery further comprising a vent plate joined by interposing an insulating gasket between the beading portion and the crimping portion.

15. In paragraph 1, A secondary battery further comprising a vent plate coupled to an area opposite to the upper wall of the case.

16. In paragraph 1, A secondary battery, wherein the insulating member is spaced apart from the first collector plate.

17. In paragraph 1, A secondary battery in which the insulating member is in contact with the first collector plate.

18. In paragraph 1, A secondary battery in which the upper wall of the case and the side wall of the case are provided as one piece.

19. In paragraph 1, A secondary battery in which the upper wall of the case and the side wall of the case are prepared separately and welded together to become one body.

20. In paragraph 19, Further comprising a vent plate integrally provided from the case side wall as an area opposite to the case upper wall, The second tab is a secondary battery electrically connected to the vent plate.

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