Electrode assembly, method for manufacturing electrode assembly, and secondary battery comprising electrode assembly

Abstract

An electrode assembly according to an embodiment of the present disclosure may comprise: a first electrode including a first coated portion coated with an active material and a first uncoated portion that is not coated with the active material; a second electrode including a second coated portion coated with an active material and a second uncoated portion that is not coated with the active material; and a separator interposed between the first electrode and the second electrode. The first electrode, the second electrode, and the separator may be wound around a winding axis. The first uncoated portion may protrude from one side of the separator in one direction of the winding axis and be bent toward the winding axis. A plurality of first stepped patterns may be formed on the outer surface of a region in which the first uncoated portion is bent.

Description

Electrode assembly, method for manufacturing electrode assembly, and secondary battery including electrode assembly

[0001] The present disclosure relates to an electrode assembly, a method for manufacturing the electrode assembly, and a secondary battery including the electrode assembly.

[0002]

[0003] 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.

[0004] Meanwhile, conventional cylindrical secondary batteries are electrically connected between the positive electrode uncoated portion and the electrode terminal of the electrode assembly, and between the negative electrode uncoated portion and the case, via electrode tabs. In secondary batteries with this configuration, current is concentrated on the electrode tabs, which can generate heat due to the resistance of the electrode tabs, potentially leading to reduced current collection efficiency.

[0005] To address these issues, the electrode assembly of a secondary battery can be positioned so that the positive electrode and negative electrode regions are positioned at the top and bottom, and a current collector plate is welded to the region of interest to improve current collection efficiency. However, if a sufficient welding area is not secured when welding the current collector plate to the region of interest, current collection efficiency may deteriorate.

[0006] 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 may therefore include information that does not constitute prior art.

[0007]

[0008] The problem to be solved by the present disclosure is to provide an electrode assembly, a method for manufacturing the electrode assembly, and a secondary battery including the electrode assembly to solve the above-mentioned problems.

[0009] 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.

[0010]

[0011] According to one embodiment of the present invention, an electrode assembly may include a first electrode including a first coated portion coated with an active material and a first uncoated portion that is not coated, a second electrode including a second coated portion coated with an active material and a second uncoated portion that is not coated, and a separator interposed between the first electrode and the second electrode. The first electrode, the second electrode, and the separator may be wound around a winding axis. The first uncoated portion may be bent and arranged to protrude toward one side of the separator in one direction of the winding axis. A plurality of first step patterns may be formed on an outer surface of an area in which the first uncoated portion is bent and arranged.

[0012] According to one embodiment, the first non-conductive portion may include a plurality of first tabs formed by successively notching along the direction in which the first electrode is wound.

[0013] According to one embodiment, the plurality of first tabs may include a plurality of tabs having the same length protruding from the separator along the direction in which the first electrode is wound.

[0014] According to one embodiment, a plurality of first tabs may be formed in the first non-conductive region at a predetermined distance from the winding axis of the wound electrode assembly.

[0015] According to one embodiment, the plurality of first tabs may be folded and arranged so as to overlap each other toward the winding axis.

[0016] According to one embodiment, a plurality of first tabs may be formed in a region of the first non-conductive portion spaced apart from an outer diameter of the rolled electrode assembly by a predetermined distance.

[0017] According to one embodiment, the plurality of first step patterns may have at least one pattern of different depth and width.

[0018] According to one embodiment, the second non-woven portion may be arranged to protrude from the other side of the separator in the other direction of the winding axis and be folded toward the winding axis. A plurality of second step patterns may be formed on the outer surface of the area where the second non-woven portion is folded.

[0019] According to one embodiment, the second non-conductive portion may include a plurality of second tabs formed by successively notching along the direction in which the second electrode is wound.

[0020] According to one embodiment, the plurality of second tabs may include a plurality of tabs having the same length protruding from the separator along the direction in which the second electrode is wound.

[0021] According to one embodiment, a plurality of second tabs can be formed in a region of the second non-conductive portion spaced apart from the winding axis of the wound electrode assembly by a predetermined distance.

[0022] According to one embodiment, the plurality of second tabs may be folded and arranged so as to overlap each other toward the winding axis.

[0023] According to one embodiment, a plurality of second tabs can be formed in a region of the second non-conductive portion spaced apart from the outer diameter of the rolled electrode assembly by a predetermined distance.

[0024] According to one embodiment, the plurality of second step patterns may have at least one pattern of different depth and width.

[0025] According to another embodiment of the present invention, a secondary battery may include a first electrode including a first non-coated portion, a second electrode including a second non-coated portion, and a separator interposed between the first electrode and the second electrode, and may include an electrode assembly in which the first electrode, the second electrode, and the separator are wound around a winding axis, a first current collector electrically connected to the first non-coated portion, a second current collector electrically connected to the second non-coated portion, a case that accommodates the electrode assembly, the first current collector, and the second current collector through one open side surface, and a vent cap plate that covers the open side surface of the case to seal the electrode assembly from the outside. The first non-coated portion may protrude from one side of the separator in one direction of the winding axis and be bent toward the winding axis. A plurality of first step patterns may be formed on an outer surface of an area in which the first non-coated portion is bent.

[0026] According to one embodiment, the first collector plate may include a plurality of second step patterns that are interlocked and joined with the first step pattern on one surface that contacts the first non-conductive portion.

[0027] According to one embodiment, the first non-conductive portion may include a plurality of first tabs formed by successively notching along the direction in which the first electrode is wound. The plurality of first tabs may be arranged in a folded manner while overlapping toward the winding axis.

[0028] According to another embodiment of the present invention, a method for manufacturing an electrode assembly may include the steps of winding a first electrode including a first uncoated portion, a second electrode including a second uncoated portion, and a separator interposed between the first electrode and the second electrode around a winding axis, the step of bending and arranging the first uncoated portion protruding on one side of the separator in one direction of the winding axis toward the winding axis, and the step of forming a plurality of first step patterns on an outer surface of the first uncoated portion that is bent and arranged.

[0029] According to one embodiment, the method for manufacturing an electrode assembly may further include a step of forming a plurality of first tabs by continuously notching one end of the first non-coated portion along the winding direction of the first electrode. The step of bending and arranging may include a step of bending and arranging the plurality of first tabs while overlapping them toward the winding axis.

[0030] According to one embodiment, the method may further include the step of disposing a first collector plate comprising a plurality of second step patterns interlocked with a plurality of first step patterns on the first non-conductive portion. The step of forming the plurality of first step patterns may include the step of forming at least one pattern having different depths and widths.

[0031]

[0032] According to some embodiments of the present invention, the contact or welding area between the current collector plate and the non-conductive portion of the negative or positive electrode of the secondary battery can be expanded, thereby increasing the bonding strength between the current collector plate and the non-conductive portion of the electrode plate.

[0033] According to some embodiments of the present invention, by increasing the contact area between the current collector plate and the non-conductive portion of the negative or positive electrode of a secondary battery, the electrical resistance in the electrical connection path between the current collector plate and the non-conductive portion of the electrode plate can be reduced.

[0034] However, the effects that can be obtained through the present invention are not limited to the effects described above, and other technical effects not mentioned can be clearly understood by those skilled in the art from the description of the invention described below.

[0035]

[0036] 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.

[0037] Figure 1 is a cross-sectional view of a secondary battery according to one embodiment of the present invention.

[0038] Figure 2 is an enlarged view of area A shown in Figure 1.

[0039] Figure 3 is a drawing showing the first non-conductive portion and the first collector plate shown in Figure 2 separated.

[0040] Figure 4 is an enlarged view of area B shown in Figure 1.

[0041] Fig. 5 is a drawing showing the second non-conductive portion and the second collector plate shown in Fig. 4 separated.

[0042] FIG. 6 is a drawing showing the configuration of a first electrode according to one embodiment of the present invention.

[0043] FIG. 7 is a drawing showing a process of bending a first plain part and a second plain part according to one embodiment of the present invention.

[0044] FIG. 8 is a drawing showing a process of overlapping and compacting a first plain part and a second plain part according to one embodiment of the present invention.

[0045] FIGS. 9A to 9D are drawings showing a process of forming a plurality of patterns in a first unlined portion and a second unlined portion according to one embodiment of the present invention.

[0046] FIGS. 10A to 10D are drawings showing an electrode assembly having a pattern formed thereon and a first collector plate and a second collector plate according to one embodiment of the present invention.

[0047] Figure 11 is a flowchart showing a process for manufacturing an electrode assembly according to one embodiment of the present invention.

[0048]

[0049] 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 filing this application.

[0050] 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.

[0051] Additionally, to facilitate understanding of the invention, the attached drawings are not drawn to scale and some components may be exaggerated in size. Furthermore, identical components may be assigned the same reference numbers in different embodiments.

[0052] 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.

[0053] 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.

[0054] Throughout the specification, unless otherwise specifically stated, each element may be singular or plural.

[0055] 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.

[0056] 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 one another, 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.

[0057] 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.

[0058] 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.

[0059] Figure 1 is a cross-sectional view of a secondary battery according to one embodiment of the present invention.

[0060] Referring to FIG. 1, a secondary battery (1) according to one embodiment of the present invention may include an electrode assembly (100) that performs charging and discharging, a case (400) that accommodates the electrode assembly (100), a first collector plate (200) and a second collector plate (300) that are connected to the electrode assembly (100), an electrode terminal (510), a vent cap plate (610), and a sealing member (630). In FIG. 1, the vent cap plate (610) is illustrated as being disposed on the upper side of the secondary battery (1) and the electrode terminal (510) is disposed on the lower side of the secondary battery (1), but this is not limited thereto. Depending on the usage environment or requirements of the secondary battery (1), the vent cap plate (610) and the electrode terminal (510) may be changed to be disposed on the lower side and the upper side of the secondary battery (1), respectively.

[0061] According to one embodiment, the electrode assembly (100) may include a first electrode (110), a second electrode (130), and a separator (150). The first electrode (110) may be a cathode, and the second electrode (130) may be an anode. Of course, the opposite is also possible. The electrode assembly (100) may be a wound electrode assembly (100) formed by winding the first electrode (110) and the second electrode (130) around a winding axis after the separator (150) is interposed between them.

[0062] According to one embodiment, the first electrode (110) may include a first coated portion (111) in an area where an active material is applied to both sides of a substrate formed of a thin metal plate, and a first uncoated portion (113) in an area where the substrate is exposed because the active material is not applied. The first electrode (110) may form a negative electrode by coating a negative electrode active material such as graphite or carbon on a metal substrate such as copper, a copper alloy, nickel, or a nickel alloy.

[0063] According to one embodiment, the first non-coated portion (113) may be provided at one end in the winding axis direction of the electrode assembly (100). The first non-coated portion (113) may be connected to the first collector plate (200) at one end in the winding axis direction of the electrode assembly (100). The first non-coated portion (113) may be welded to the first collector plate (200). The first non-coated portion (113) may be electrically connected to the case (400) through the first collector plate (200).

[0064] According to one embodiment, the first non-coated portion (113) may include a plurality of first step patterns (115, see FIG. 3). The first non-coated portion (113) may include a plurality of first step patterns (115) formed on an outer surface of a folded area. The plurality of first step patterns (115) may be coupled by being engaged with a plurality of second step patterns (211, see FIG. 3) formed on the first collector plate (200). Additionally, the first non-coated portion (113) and the first collector plate (200) may be welded together in an area where the plurality of first step patterns (115) and the plurality of second step patterns (211) are engaged.

[0065] According to one embodiment, the second electrode (130) may include a second coated portion (131) in an area where an active material is applied to both sides of a substrate formed of a thin metal plate, and a second uncoated portion (133) in an area where the substrate is exposed because the active material is not applied. The second electrode (130) may form a positive electrode by coating a positive electrode active material, such as a transition metal oxide, on a metal substrate, such as aluminum or an aluminum alloy.

[0066] According to one embodiment, the second non-coated portion (133) may be provided at the other end in the winding axis direction of the electrode assembly (100). The second non-coated portion (133) may be connected to the second collector plate (300) at the other end in the winding axis direction of the electrode assembly (100). The second non-coated portion (133) may be welded to the second collector plate (300). The second non-coated portion (133) may be electrically connected to the electrode terminal (510) through the second collector plate (300).

[0067] According to one embodiment, the second non-coated portion (133) may include a plurality of third step patterns (135, see FIG. 5). The second non-coated portion (133) may include a plurality of third step patterns (135) formed on an outer surface of a folded area. The plurality of third step patterns (135) may be coupled by being engaged with a plurality of fourth step patterns (311, see FIG. 5) formed on the second collector plate (300). Additionally, the second non-coated portion (133) and the second collector plate (300) may be welded together in an area where the plurality of third step patterns (135) and the plurality of fourth step patterns (311) are engaged.

[0068] Meanwhile, the case (400) connected to the first unused portion (113) and the electrode terminal (510) connected to the second unused portion (133) may have different polarities. A vent cap plate (610) may be placed on one side of the case (400) opposite to the other side where the electrode terminal (510) is placed.

[0069] According to one embodiment, the first electrode (110) may be a negative electrode. The negative electrode includes a current collector and a negative electrode active material layer positioned 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.

[0070] 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.

[0071] 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 in an amorphous, plate-like, flake-like, spherical, or fibrous form, and examples of the amorphous carbon include soft carbon or hard carbon, mesophase pitch carbide, calcined coke, and the like.

[0072] As the above lithium metal alloy, an alloy of lithium and a metal selected from Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Si, Sb, Pb, In, Zn, Ba, Ra, Ge, Al, and Sn can be used.

[0073] 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-Q alloy (wherein Q is selected from alkali metals, alkaline earth metals, Group 13 elements, Group 14 elements (excluding Si), Group 15 elements, Group 16 elements, transition metals, rare earth elements, and combinations thereof), or a combination thereof. The Sn-based negative electrode active material may be Sn, SnO2, a Sn-based alloy, or a combination thereof.

[0074] 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. For example, the composite may include secondary particles (cores) in which silicon primary particles are assembled and an amorphous carbon coating layer (shell) positioned on the surface of the secondary particles. The amorphous carbon may also be positioned between the silicon primary particles, such that, for example, the silicon primary particles may be coated with amorphous carbon. The secondary particles may be dispersed and present in an amorphous carbon matrix.

[0075] 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.

[0076] The above Si-based negative electrode active material or Sn-based negative electrode active material can be used in a mixture with a carbon-based negative electrode active material.

[0077] 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.

[0078] The above binder serves to adhere the negative electrode active material particles well to each other and also to adhere the negative electrode active material well to the current collector. The binder may be a non-aqueous binder, an aqueous binder, a dry binder, or a combination thereof.

[0079] Examples of the non-aqueous binder include polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, ethylene propylene copolymer, polystyrene, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, polyamideimide, polyimide, or combinations thereof.

[0080] The above-mentioned aqueous binder may be selected from styrene-butadiene rubber, (meth)acrylated styrene-butadiene rubber, (meth)acrylonitrile-butadiene rubber, (meth)acrylic rubber, butyl rubber, fluoroelastomer, polyethylene oxide, polyvinylpyrrolidone, polyepichlorohydrin, polyphosphazene, poly(meth)acrylonitrile, ethylene propylene diene copolymer, polyvinylpyridine, chlorosulfonated polyethylene, latex, polyester resin, (meth)acrylic resin, phenol resin, epoxy resin, polyvinyl alcohol, and combinations thereof.

[0081] When using an aqueous binder as the above-mentioned negative electrode binder, a cellulose-based compound capable of imparting viscosity may be further included. The cellulose-based compound may be a mixture of one or more of carboxymethyl cellulose, hydroxypropylmethyl cellulose, methyl cellulose, or an alkali metal salt thereof. The alkali metal may be Na, K, or Li.

[0082] The above dry binder is a polymeric material capable of being fiberized, and may be, for example, polytetrafluoroethylene, polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene copolymer, polyethylene oxide, or a combination thereof.

[0083] The above conductive material is used to provide conductivity to the electrode, and any material that does not cause chemical changes and is electronically conductive can be used in the battery to be constructed. Specific examples include carbon-based materials such as natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, carbon fiber, carbon nanofiber, and carbon nanotube; metal-based materials in the form of metal powder or metal fiber, including copper, nickel, aluminum, and silver; conductive polymers such as polyphenylene derivatives; or these.

[0084] The negative electrode 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.

[0085] In one embodiment, the second electrode (130) may be a positive electrode. The positive electrode may include a current collector 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.

[0086] A compound capable of reversible intercalation and deintercalation of lithium (a lithiated intercalation compound) can be used as a cathode active material. Specifically, one or more of a composite oxide of lithium and a metal selected from cobalt, manganese, nickel, and combinations thereof can be used.

[0087] 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.

[0088] As an example, a compound represented by any one of the following chemical formulas may be used: Li a A 1-b X b O 2-c D c (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05); Li a Mn 2-b X b O 4-c D c (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05); Li a Ni 1-b-c Co b X c O 2-α D α(0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.5, 0<α<2); Li a Ni 1-b-c Mn b X c O 2-α D α (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.5, 0<α<2); Li a Ni b Co c L 1 d G e O2(0.90≤a≤1.8, 0≤b≤0.9, 0≤c≤0.5, 0≤d≤0.5, 0≤e≤0.1); 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).

[0089] 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.

[0090] For example, the positive electrode active material may be a high-nickel positive electrode active material in which the nickel content is 80 mol% or more, 85 mol% or more, 90 mol% or more, 91 mol% or more, or 94 mol% or more and 99 mol% or less, based on 100 mol% of metals excluding lithium in a lithium transition metal composite oxide. The high-nickel positive electrode active material can realize high capacity and thus can be applied to a high-capacity, high-density lithium secondary battery (1).

[0091] For example, the anode may further include an additive that can act as a sacrificial anode.

[0092] 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.

[0093] The above binder serves to adhere the positive electrode active material particles well to each other and also to adhere the positive electrode active material well to the current collector. Representative examples of the binder include, but are not limited to, polyvinyl alcohol, carboxymethyl cellulose, hydroxypropyl cellulose, diacetyl cellulose, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, polymers containing ethylene oxide, polyvinyl pyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, styrene-butadiene rubber, (meth)acrylated styrene-butadiene rubber, epoxy resin, (meth)acrylic resin, polyester resin, nylon, etc.

[0094] The conductive material is used to provide conductivity to the electrode, and any material that does not cause chemical changes and is electronically conductive can be used in the battery. Examples of the conductive material include carbon-based materials such as natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, carbon fiber, carbon nanofiber, and carbon nanotube; metal-based materials containing copper, nickel, aluminum, silver, etc. in the form of metal powder or metal fiber; conductive polymers such as polyphenylene derivatives; or mixtures thereof.

[0095] Aluminum (Al) may be used as the current collector, but is not limited thereto.

[0096] According to one embodiment, the first collector plate (200) may be disposed on the first non-coated portion (113). The first collector plate (200) may be connected to the first non-coated portion (113) by making contact with it. The first collector plate (200) may be welded to the first non-coated portion (113). The first collector plate (200) may be electrically connected to the first non-coated portion (113). The first collector plate (200) may be connected to the case (400). The case (400) may be connected to the first electrode (110) through the first collector plate (200). The first collector plate (200) may be connected to the case (400) in a structure that contacts the first non-coated portion (113) over most of its area to reduce resistance.

[0097] According to one embodiment, the first collector plate (200) may include a plurality of second step patterns (211, see FIG. 3). The first collector plate (200) may include a plurality of second step patterns (211) formed on one surface that contacts the first non-coated portion (113). The plurality of second step patterns (211) may be coupled by being interlocked with the plurality of first step patterns (115, see FIG. 3) formed on the first non-coated portion (113). Additionally, the first collector plate (200) and the first non-coated portion (113) may be welded together in an area where the plurality of second step patterns (211) and the plurality of first step patterns (115) are interlocked.

[0098] According to one embodiment, the second collector plate (300) may be disposed below the second non-coated portion (133). The second collector plate (300) may be connected to the second non-coated portion (133) by making contact with it. The second collector plate (300) may be welded to the second non-coated portion (133). The second collector plate (300) may be electrically connected to the second non-coated portion (133). The second collector plate (300) may be connected to an electrode terminal (510). The electrode terminal (510) may be connected to the second electrode (130) through the second collector plate (300). The second collector plate (300) may be electrically connected to the electrode terminal (510) in a structure that contacts most of the second non-coated portion (133) of the second electrode (130) to reduce resistance.

[0099] According to one embodiment, the second collector plate (300) may include a plurality of fourth step patterns (311, see FIG. 5). The second collector plate (300) may include a plurality of fourth step patterns (311) formed on one surface that contacts the second non-coated portion (133). The plurality of fourth step patterns (311) may be coupled by being interlocked with a plurality of third step patterns (135, see FIG. 5) formed on the second non-coated portion (133). Additionally, the second collector plate (300) and the second non-coated portion (133) may be welded together in an area where the plurality of fourth step patterns (311) and the plurality of second step patterns (135) are interlocked.

[0100] According to one embodiment, an insulating tape (570) may be attached to one side of the second collector plate (300). The insulating tape (570) may be interposed between the second collector plate (300) and the case (400) or between the second non-conductive portion (133) and the case (400), and may serve to electrically insulate each component.

[0101] According to one embodiment, the central portion of the insulating tape (570) may include a perforation (571) corresponding to the shape of the rivet portion (530) so that the rivet portion (530) may come into contact with the second collector plate (300). In addition, the insulating tape (570) may include a side wall (573) so as to surround a portion of the electrode assembly (100).

[0102] According to one embodiment, the case (400) can form the overall appearance of the secondary battery (1). The case (400) can be formed in a cylindrical shape so as to accommodate the electrode assembly (100). The case (400) can accommodate the electrode assembly (100), the first current collector (200), and the second current collector (300) through one open side. After the electrode assembly (100) is accommodated in the case (400), the vent cap plate (610) can seal the electrode assembly (100) from the outside while covering the one open side of the case (400).

[0103] According to one embodiment, the case (400) may be connected to the first collector plate (200). The case (400) may be electrically connected to the first electrode (110) through the first collector plate (200).

[0104] According to one embodiment, the case (400) may include a through hole (410), an opening (430), a beading portion (450), and a crimping portion (470).

[0105] According to one embodiment, the through hole (410) may be formed on the other side (or bottom surface) of the case (400) opposite to the side where the opening (430) is formed. The through hole (410) may be formed by partially opening the other side of the case (400). An electrode terminal (510) may be arranged in a rivet structure in the through hole (410).

[0106] According to one embodiment, an opening (430) may be formed on one side of the case (400). A vent cap plate (610) may be placed in the opening (430) to seal the electrode assembly (100) accommodated in the case (400) from the outside.

[0107] According to one embodiment, the beading portion (450) may be formed in the form of a curved groove inside the case (400) so that the first collector plate (200) and the vent cap plate (610) are seated on the upper portion of the case (400). The beading portion (450) may include a curved groove formed by pressing inward along the outer periphery of the case (400). The beading portion (450) may prevent movement of the electrode assembly (100) and the first collector plate (200) and support the vent cap plate (610). A sealing member (630) may be interposed to seat the first collector plate (200) and the vent cap plate (610) on the beading portion (450).

[0108] According to one embodiment, the crimping portion (470) may be formed by bending the upper portion of the case (400) to surround the sealing member (630). The crimping portion (470) may be formed to press the upper portion of the vent cap plate (610) while the sealing member (630) is interposed therebetween. The crimping portion (470) may enclose the vent cap plate (610) and the sealing member (630), thereby bringing the vent cap plate (610) and the sealing member (630) into close contact. The crimping portion (470) may prevent the vent cap plate (610) from detaching and prevent the electrolyte from leaking.

[0109] According to one embodiment, the electrode terminal (510) may be disposed on the other side of the case (400) opposite to the side on which the vent cap plate (610) is disposed. The electrode terminal (510) may be disposed in a rivet structure in the through hole (410). To this end, the electrode terminal (510) may be connected to the rivet portion (530). The electrode terminal (510) may be disposed on the outside of the case (400) while being connected to the rivet portion (530). The rivet portion (530) may be welded to the second collector plate (300) at one end and may be disposed to penetrate the through hole (410). The electrode terminal (510) may be connected to the second collector plate (300) through the rivet portion (530). The electrode terminal (510) can be electrically connected to the second electrode (130) through the rivet portion (530) and the second collector plate (300). The electrode terminal (510) can be formed to protrude from the outer surface of the case (400) around the through hole (410) and be used as a positive electrode terminal. In this case, the second collector plate (300) can be a positive electrode collector plate.

[0110] According to one embodiment, a gasket (550) may be interposed between the electrode terminal (510) and the rivet portion (530) and the through hole (410). The gasket (550) is formed in a hermetic structure to prevent leakage of electrolyte and electrically insulate the electrode terminal (510) and the case (400).

[0111] According to one embodiment, a vent cap plate (610) may be placed in the opening (430). The vent cap plate (610) may cover the opening (430) and seal the electrode assembly (100) from the outside. The vent cap plate (610) may be fixed by a crimping member (470). The vent cap plate (610) may be a vent plate. The vent cap plate (610) may seal the opening (430) through a sealing member (630) and may be electrically isolated from the case (400). At this time, the vent cap plate (610) may be insulated from the first collector plate (200) and the case (400) and may not have polarity. The vent cap plate (610) may be electrically isolated from the first collector plate (200) by making hermetically close contact only with the sealing member (630). Due to the connection of the first collector plate (200), the case (400) can be used as a negative terminal. In this case, the first collector plate (200) becomes a negative collector plate.

[0112] The vent cap plate (610) may have a notch (620) formed on its inner surface. The notch (620) may be cut open to release internal pressure of the secondary battery to the outside when an abnormal event occurs in the secondary battery, thereby preventing a secondary explosion. The notch (620) may be easily cut open by receiving concentrated internal pressure in the event of an abnormal event. The notch (620) may be formed over the entire circumferential area of ​​the vent cap plate (610), or may be formed in multiple pieces spaced apart at set intervals.

[0113] The sealing member (630) may be interposed between the first collector plate (200) and the vent cap plate (610) and between the first collector plate (200) and the case (400) and may be fastened by the beading portion (450) and the crimping portion (470). In addition, the sealing member (630) may form a sealing structure with respect to the electrolyte between the first collector plate (200) and the opening (430) of the case (400).

[0114] Fig. 2 is an enlarged view of area A shown in Fig. 1. Fig. 3 is a drawing showing the first non-conductive portion and the first collector plate shown in Fig. 2 separated.

[0115] Referring to FIGS. 1 to 3, according to one embodiment, the first non-coated portion (113) may be provided at one end in the direction of the winding axis (WS) along which the electrode assembly (100) is wound. The first non-coated portion (113) may protrude toward one side of the separator (150) in one direction of the winding axis (WS). The first non-coated portion (113) may protrude toward one side of the separator (150) and be bent toward the winding axis (WS).

[0116] According to one embodiment, the first non-conductive portion (113) may be connected to the first collector plate (200) on the outer surface where it is folded. The first non-conductive portion (113) may be electrically connected to the case (400) through the first collector plate (200). The first non-conductive portion (113) electrically connected to the case (400) may itself be used as an electrode tab.

[0117] According to one embodiment, the first non-conductive portion (113) may include a plurality of first tabs (113a). The first non-conductive portion (113) may include a plurality of first tabs (113a) formed by being continuously notched along the direction in which the first electrode (110) is wound.

[0118] According to one embodiment, a plurality of first tabs (113a) may not be formed on the first plain portion (113) adjacent to the winding shaft (WS). To prevent the first plain portion (113) from being bent toward the hollow formed in the winding shaft (WS), a plurality of first tabs (113a) may not be formed on the first plain portion (113) adjacent to the winding shaft (WS). For example, a welding jig may be inserted into the hollow formed in the winding shaft (WS) for welding. Accordingly, a plurality of first tabs (113a) may not be formed on the first plain portion (113) adjacent to the winding shaft (WS) so that the first plain portion (113) does not shield the hollow. As another example, when a plurality of first tabs (113a) are formed in the first uncoated portion (113) adjacent to the winding axis (WS), contact may occur between the plurality of first tabs (113a) facing each other toward the winding axis (WS) in the region adjacent to the winding axis (WS). Accordingly, in the process of compacting the plurality of first tabs (113a), a problem may occur in that the plurality of first tabs (113a) adjacent to the winding axis (WS) and in contact with each other are not compacted well. In order to solve this problem, a plurality of first tabs (113a) may be formed in the region of the first uncoated portion (113) at a predetermined distance from the winding axis (WS) of the electrode assembly (100) in a wound state.

[0119] According to one embodiment, a plurality of first tabs (113a) may not be formed in the first uncoated portion (113) in an area adjacent to the outer circumference of the electrode assembly (100). For example, a short circuit may occur between the inner wall of the case (400) and the first uncoated portion (113) in an area adjacent to the outer circumference of the electrode assembly (100). To prevent this, a plurality of first tabs (113a) may not be formed in the first uncoated portion (113) in an area adjacent to the outer circumference of the electrode assembly (100). That is, the plurality of first tabs (113a) may be formed in the area of ​​the first uncoated portion (113) at a predetermined distance from the outer diameter of the wound electrode assembly (100).

[0120] According to one embodiment, the plurality of first tabs (113a) may be arranged to overlap and bend toward the winding axis (WS). For example, the plurality of first tabs (113a) may be arranged to have a greater degree of overlap around a point half the radius of the electrode assembly (100), but this is not limited thereto.

[0121] According to one embodiment, the first uncoated portion (113) may include a plurality of first step patterns (115). The first uncoated portion (113) may include a plurality of first step patterns (115) formed on an outer surface of a folded area. The plurality of first step patterns (115) may be coupled by being interlocked with a plurality of second step patterns (211) formed on the first collector plate (200). The first uncoated portion (113) and the first collector plate (200) may be welded together in an area where the plurality of first step patterns (115) and the plurality of second step patterns (211) are interlocked. That is, since a pattern having a step and interlocking with each other is formed on each of the first uncoated portion (113) and the first collector plate (200), a contact area between the first uncoated portion (113) and the first collector plate (200) may be widened, and thus a weldable area may be increased.

[0122] According to one embodiment, the first unlined portion (113) may include a plurality of first step patterns (115) of various shapes having different widths and depths. Depending on the degree of overlap of the plurality of first tabs (113a), the first unlined portion (113) may include a plurality of first step patterns (115) of various shapes having different widths and depths, but is not limited thereto.

[0123] According to one embodiment, the first collector plate (200) may be disposed on the first non-conductive portion (113). The first collector plate (200) may be connected to the folded outer surface of the first non-conductive portion (113). The first collector plate (200) may be connected to the first non-conductive portion (113) by welding.

[0124] According to one embodiment, as described above, the first collector plate (200) may include a plurality of second step patterns (211). The first collector plate (200) may include a plurality of second step patterns (211) formed on one surface that contacts the first non-conductive portion (113). The first collector plate (200) may include a plurality of second step patterns (211) formed with different shapes, such as widths and depths, according to shapes, such as widths and depths, of the plurality of first step patterns (115).

[0125] According to one embodiment, the first collector plate (200) may be connected to the case (400). The first collector plate (200) may be connected to the case (400) by being seated on the beading portion (450) of the case (400). The case (400) may be electrically connected to the first non-conductive portion (113) through the first collector plate (200).

[0126] According to one embodiment, the first collector plate (200) may include a bottom portion (210) welded to the first non-conductive portion (113) of the first electrode (110), a collector plate wing portion (220) formed adjacent to the bottom portion (210) and welded to the beading portion (450), and a through hole (230) provided in the center.

[0127] According to one embodiment, the bottom portion (210) may include a plurality of second step patterns (211) on one surface that comes into contact with the first non-woven portion (113). The bottom portion (210) may include a plurality of second step patterns (211) that are formed to have different shapes, such as width and depth, depending on the shapes, such as width and depth, of the plurality of first step patterns (115). After the plurality of second step patterns (211) and the plurality of first step patterns (115) are connected to be interlocked, the bottom portion (210) and the first non-woven portion (113) may be welded.

[0128] According to one embodiment, the first collector plate (200) may be formed by cutting and bending a circular plate. In this case, a plurality of bottom portions (210) and collector plate wing portions (220) are provided along the circumferential direction of the circular plate, and may be arranged alternately along the circumferential direction. The collector plate wing portions (220) may be formed by bending a portion of the circular plate in the axial direction (upward) and repeatedly performing bending along the radial outer side of the circular plate.

[0129] Accordingly, the bottom portion (210) is connected approximately evenly along the circumferential direction in the area of ​​the first non-conductive portion (113), and the collector plate wing portion (220) is connected approximately evenly along the circumferential direction in the area of ​​the beading portion (450). This configuration enables a uniform current flow along the circumferential direction in the entire area of ​​the beading portion (450) of the case (400) from the first electrode (110).

[0130] In addition, since the first collector plate (200) has a through hole (230) in the center, it can absorb and alleviate deformation caused by welding of the bottom portion (210) and the first non-conductive portion (113) and vibration and shock that may be transmitted between the collector plate wing portion (220) and the bottom portion (210). The through hole (230) may have a size within a range capable of absorbing vibration and shock without increasing current resistance between the collector plate wing portion (220) and the bottom portion (210). Although an embodiment in which the through hole (230) is formed in the first collector plate (200) has been described, the present invention is not limited thereto, and the through hole (230) may not be formed in the first collector plate (200) as needed.

[0131] Hereinafter, other configurations of the secondary battery (1) according to one embodiment of the present invention are substantially the same or similar to the configuration described with reference to FIG. 1, and thus a detailed description thereof is omitted.

[0132] Fig. 4 is an enlarged view of area B shown in Fig. 1. Fig. 5 is a drawing showing the second non-conductive portion and the second collector plate shown in Fig. 4 separated.

[0133] Referring to FIGS. 1, 4, and 5, according to one embodiment, the second non-coated portion (133) may be provided at the other end in the direction of the winding axis (WS) along which the electrode assembly (100) is wound. The second non-coated portion (133) may protrude toward the other side of the separator (150) in one direction of the winding axis (WS). The second non-coated portion (133) may protrude toward the other side of the separator (150) and be bent toward the winding axis (WS).

[0134] According to one embodiment, the second non-conductive portion (133) may be connected to the second collector plate (300) at the outer surface where it is folded. The second non-conductive portion (133) may be electrically connected to the electrode terminal (510) through the second collector plate (300). The second non-conductive portion (133) electrically connected to the electrode terminal (510) may itself be used as an electrode tab.

[0135] According to one embodiment, the second non-conductive portion (133) may include a plurality of second tabs (133a). The second non-conductive portion (133) may include a plurality of second tabs (133a) formed by being continuously notched along the direction in which the second electrode (130) is wound.

[0136] According to one embodiment, a plurality of second tabs (133a) may not be formed on the second plain portion (133) adjacent to the winding shaft (WS). To prevent the second plain portion (133) from being bent toward the hollow formed in the winding shaft (WS), a plurality of second tabs (133a) may not be formed on the second plain portion (133) adjacent to the winding shaft (WS). For example, a welding jig may be inserted into the hollow formed in the winding shaft (WS) for welding. Accordingly, a plurality of second tabs (133a) may not be formed on the second plain portion (133) adjacent to the winding shaft (WS) so that the second plain portion (133) does not shield the hollow. As another example, when a plurality of second tabs (133a) are formed in the second non-coated portion (133) adjacent to the winding axis (WS), the plurality of second tabs (133a) facing each other toward the winding axis (WS) in the area adjacent to the winding axis (WS) may be in contact with each other. Accordingly, in the process of compacting the plurality of second tabs (133a), a problem may occur in which the plurality of second tabs (133a) that are adjacent to the winding axis (WS) and in contact with each other are not compacted well. In order to solve this problem, a plurality of second tabs (133a) may be formed in the area of ​​the second non-coated portion (133) at a predetermined distance from the winding axis (WS) of the electrode assembly (100) in a wound state.

[0137] According to one embodiment, a plurality of second tabs (133a) may not be formed on the second uncoated portion (133) in an area adjacent to the outer circumference of the electrode assembly (100). For example, a short circuit may occur between the inner wall of the case (400) and the second uncoated portion (133) in an area adjacent to the outer circumference of the electrode assembly (100). To prevent this, a plurality of second tabs (133a) may not be formed on the second uncoated portion (133) in an area adjacent to the outer circumference of the electrode assembly (100). That is, the plurality of second tabs (133a) may be formed in an area of ​​the first uncoated portion (113) spaced apart from the outer diameter of the wound electrode assembly (100) by a certain distance.

[0138] According to one embodiment, the plurality of second tabs (133a) may be arranged to overlap and bend toward the winding axis (WS). For example, the plurality of second tabs (133a) may be arranged to have a greater degree of overlap around a point half the radius of the electrode assembly (100), but this is not limited thereto.

[0139] According to one embodiment, the second uncoated portion (133) may include a plurality of third step patterns (135). The second uncoated portion (133) may include a plurality of third step patterns (135) formed on the outer surface of the folded area. The plurality of third step patterns (135) may be coupled by being interlocked with a plurality of fourth step patterns (311) formed on the second collector plate (300). The second uncoated portion (133) and the second collector plate (300) may be welded together in an area where the plurality of third step patterns (135) and the plurality of fourth step patterns (311) are interlocked. That is, since a pattern having a step and interlocking with each other is formed on each of the second uncoated portion (133) and the second collector plate (300), a contact area between the second uncoated portion (133) and the second collector plate (300) may be widened, and thus a weldable area may be increased.

[0140] According to one embodiment, the second non-woven portion (133) may include a plurality of third step patterns (135) of various shapes having different widths and depths. Depending on the degree of overlap of the plurality of second tabs (133a), the second non-woven portion (133) may include a plurality of third step patterns (135) of various shapes having different widths and depths, but is not limited thereto.

[0141] According to one embodiment, the second collector plate (300) may be disposed below the second non-conductive portion (133). The second collector plate (300) may be connected to the folded outer surface of the second non-conductive portion (133). The second collector plate (300) may be connected to the second non-conductive portion (133) by welding.

[0142] According to one embodiment, as described above, the second collector plate (300) may include a plurality of fourth step patterns (311). The second collector plate (300) may include a plurality of fourth step patterns (311) formed on one surface that contacts the second non-conductive portion (133). The second collector plate (300) may include a plurality of fourth step patterns (311) formed with different shapes, such as widths and depths, according to shapes, such as widths and depths, of the plurality of third step patterns (135).

[0143] According to one embodiment, the second collector plate (300) may be connected to an electrode terminal (510). The electrode terminal (510) may be electrically connected to the second non-conductive portion (133) through the second collector plate (300).

[0144] According to one embodiment, the second collector plate (300) may include a metal plate (310) having a hole (330) having an arc shape and at least one bridge (320) formed therein. The second collector plate (300) may be formed of a conductive metal, specifically, a conductive metal such as nickel, aluminum, copper, silver, zinc, tin, stainless steel (e.g., SUS), nickel-plated steel, or a combination (alloy) thereof. In addition, the metal plate (310) and the bridge (320) constituting the second collector plate (300) may both be integrally formed of the same material.

[0145] According to one embodiment, the metal plate (310) may include a plurality of fourth step patterns (311) on one surface that comes into contact with the second non-coated portion (133). The metal plate (310) may include a plurality of fourth step patterns (311) that are formed with different shapes, such as width and depth, depending on the shapes, such as width and depth, of the plurality of third step patterns (135). After the plurality of fourth step patterns (311) and the plurality of third step patterns (135) are connected to be interlocked, the metal plate (310) and the second non-coated portion (133) may be welded.

[0146] According to one embodiment, the bridge (320) of the second collector plate (300) may be configured to be ruptured when a current exceeding a set value flows. In one embodiment, the bridge (320) normally operates as a part of a circuit through which current flows, but when an excessive amount of current flows, it may function as a fuse that melts due to the generated heat and blocks the circuit.

[0147] Hereinafter, other configurations of the secondary battery (1) according to one embodiment of the present invention are substantially the same or similar to the configurations described with reference to FIG. 1, and thus a detailed description thereof is omitted.

[0148] FIG. 6 is a drawing showing the configuration of a first electrode according to one embodiment of the present invention.

[0149] Referring to Fig. 1, the first electrode (110) and the second electrode (130) may have a structure that is symmetrical with respect to the separator (150). Hereinafter, the description will focus on the first electrode (110) illustrated in Fig. 6, and a description of the specific configuration of the second electrode (130) will be omitted.

[0150] Referring to FIG. 6, according to one embodiment, the first electrode (110) may be wound around a winding axis (WS). The first electrode (110) may include a first coated portion (111) in an area where an active material is applied to both sides of a substrate formed of a thin metal plate, and a first uncoated portion (113) in an area where the substrate is exposed because the active material is not applied.

[0151] According to one embodiment, the first non-conductive portion (113) can be divided into a first region (10), a second region (20), and a third region (30) in the longitudinal direction (X direction). For example, when an electrode assembly (100, see FIG. 1) in which a first electrode (110), a separator (150, see FIG. 1), and a second electrode (130, see FIG. 1) are laminated is wound, the electrode assembly (100) can be divided into a first region (10) adjacent to the winding axis (WS), a second region (20) in which a plurality of first tabs (113a) are formed, and a third region (30) adjacent to the outer peripheral surface of the electrode assembly (100).

[0152] According to one embodiment, the first region (10) may be a region adjacent to the winding axis (WS) and may be a region where a plurality of first tabs (113a) are not formed in the first uncoated portion (113). The first region (10) may be a region adjacent to the inner diameter of the electrode assembly (100) when the electrode assembly (100) is wound. When the plurality of first tabs (113a) are bent in the direction of the winding axis (WS) after the electrode assembly (100) is wound, the plurality of first tabs (113a) may not be formed in the first uncoated portion (113) of the first region (10) so as not to shield the hollow formed in the winding axis (meaning the inner diameter of the wound electrode assembly (100). Since the hollow formed in the winding shaft (WS) can be inserted with a welding jig, even if the plurality of first tabs (113a) are bent, the plurality of first tabs (113a) may not be formed in the first blank portion (113) within a radius range that does not extend to the hollow formed in the winding shaft (WS).

[0153] According to one embodiment, the second region (20) may be a region in which a plurality of first tabs (113a) are formed in the first uncoated portion (113). The first uncoated portion (113) of the second region (20) may include a plurality of first tabs (113a) that are formed by being continuously notched along the direction in which the first electrode (110) is wound. The plurality of first tabs (113a) may be used as electrode tabs. The plurality of first tabs (113a) may be bent toward the winding axis (WS) and partially overlap each other.

[0154] According to one embodiment, the plurality of first tabs (113a) may be formed by partially cutting the first blank portion (113) in the height direction. For example, the plurality of first tabs (113a) may be formed by notching the first blank portion (113) with a laser. As another example, the plurality of first tabs (113a) may also be formed by a known cutting method such as ultrasonic cutting or punching, but is not limited thereto.

[0155] In one embodiment, the plurality of first tabs (113a) may be formed by notching with the same width. In another example, the plurality of first tabs (113a) may be formed by notching with different widths, but the present invention is not limited thereto.

[0156] According to one embodiment, the plurality of first tabs (113a) may be formed with the same length from the first uncoated portion (113) along the direction in which the first electrode (110) is wound. The plurality of first tabs (113a) may be formed with the same length protruding from the first uncoated portion (113) along the direction in which the first electrode (110) is wound. As another example, the plurality of first tabs (113a) may be formed with a length that protrudes from the central region of the electrode assembly (100) including the winding axis to the outer region (in the X direction), or may be formed with a length that becomes longer and then shorter, but is not limited thereto.

[0157] According to one embodiment, the plurality of first tabs (113a) may be formed from the first non-conductive portion (113) perpendicular to the longitudinal direction of the first electrode (110). As another example, the plurality of first tabs (113a) may be formed from the first non-conductive portion (113) at an angle not perpendicular to the longitudinal direction of the first electrode (110), but are not limited thereto.

[0158] According to one embodiment, the third region (30) may be a region adjacent to the winding end, and may be a region where a plurality of first tabs (113a) are not formed on the first uncoated portion (113). The third region (30) may be a region adjacent to the outer circumference (or outer diameter) of the electrode assembly (100) when the electrode assembly (100) is wound. When the electrode assembly (100) is accommodated in a case (400, see FIG. 1), a plurality of first tabs (113a) may not be formed on the first uncoated portion (113) of the third region (30) adjacent to the outer circumference of the electrode assembly (100). In order to prevent a short circuit from occurring between the inner wall of the case (400) and the first uncoated portion (113) of the third region (30) adjacent to the outer surface of the electrode assembly (100), a plurality of first tabs (113a) may not be formed on the first uncoated portion (113) of the third region (30).

[0159] Meanwhile, the configuration of the second electrode (130) is identical to that of the first electrode (110) described above in that it is symmetrical, and therefore, a detailed description of the configuration thereof is omitted.

[0160] Fig. 7 is a diagram showing a process of bending a first uncoated portion and a second uncoated portion according to an embodiment of the present invention. Fig. 8 is a diagram showing a process of overlapping and pressing a first uncoated portion and a second uncoated portion according to an embodiment of the present invention. Figs. 9a to 9d are diagrams showing a process of forming a plurality of patterns on a first uncoated portion and a second uncoated portion according to an embodiment of the present invention. Figs. 10a to 10d are diagrams showing an electrode assembly and first and second collector plates on which a pattern is formed according to an embodiment of the present invention. Fig. 11 is a flowchart showing a process of manufacturing an electrode assembly according to an embodiment of the present invention.

[0161] Hereinafter, each step of a method for manufacturing an electrode assembly according to one embodiment of the present invention will be described in detail with reference to FIGS. 7 to 11.

[0162] In step S1100 of FIG. 11, a first electrode (110) including a first non-conductive portion (113), a second electrode (130) including a second non-conductive portion (133), and a separator (150) can be wound around a winding axis (WS) to form a wound electrode assembly (100).

[0163] According to one embodiment, a plurality of first tabs (113a) can be formed by continuously notching one end of the first non-coated portion (113) along the direction in which the first electrode (110) is wound. In addition, a plurality of second tabs (133a) can be formed by continuously notching one end of the second non-coated portion (133) along the direction in which the second electrode (130) is wound.

[0164] In step S1200 of FIG. 11, the first non-woven portion (113) protruding on one side of the separator (150) in one direction of the winding axis can be folded and arranged toward the winding axis.

[0165] Referring to FIG. 7, according to one embodiment, the electrode assembly (100) may be wound so that a plurality of first tabs (113a) of the first non-coated portion (113) protrude from one end of the separator (150). In addition, a plurality of second tabs (133a) of the second non-coated portion (133) may be disposed so as to protrude from the other end of the separator (150). The plurality of first tabs (113a) and the plurality of second tabs (133a) may be formed to have the same length from the winding axis (WS) to the outer radius of the electrode assembly (100). As another example, the plurality of first tabs (113a) and the plurality of second tabs (133a) may be formed to have a long tab length and then be formed to have a preset, constant length after a certain section, but are not limited thereto. A plurality of first tabs (113a) and a plurality of second tabs (133a) protruding from the separator (150) can be bent toward the winding axis (WS). As described in FIG. 6, in an area adjacent to the inner diameter (the hollow formed in the winding axis (WS)) of the wound electrode assembly (100) and an area adjacent to the outer diameter (the outer surface of the electrode assembly (100)) of the electrode assembly (100), a plurality of first tabs (113a) may not be formed in the first non-coated portion (113), and a plurality of second tabs (133a) may not be formed in the second non-coated portion (133).

[0166] Referring to FIG. 8, according to one embodiment, a plurality of first tabs (113a) and a plurality of second tabs (133a) of each of the first unlined portion (113) and the second unlined portion (133) may be arranged in a folded and overlapping manner. The plurality of first tabs (113a) and the plurality of second tabs (133a) may be folded and overlapped with tabs arranged around each other.

[0167] According to one embodiment, pressure can be applied to each of the plurality of overlapping first tabs (113a) and second tabs (133a) using a compactor jig (810). Pressure can be applied several times using the compactor jig (810) so that the plurality of first tabs (113a) and second tabs (133a) overlap with the tabs arranged around them and can be welded connected to the first collector plate (200) and the second collector plate (300), respectively.

[0168] In step S1300 of FIG. 11, a plurality of first step patterns (115) can be formed on the outer surface of the first non-coated portion (113) that is folded and arranged. A first collector plate (200) including a plurality of second step patterns (211) can be placed on the first non-coated portion (113). When the plurality of first step patterns (115) and the plurality of second step patterns (211) are interlocked, the first non-coated portion (113) and the first collector plate (200) can be welded and connected. A plurality of third step patterns (135) can be formed on the outer surface of the second non-coated portion (133) that is folded and arranged. A second collector plate (300) including a plurality of fourth step patterns (311) can be placed on the second non-coated portion (133). After the plurality of third step patterns (135) and the plurality of fourth step patterns (311) are connected to be interlocked, the second non-conductive portion (133) and the second collector plate (300) can be welded.

[0169] Referring to FIG. 9a, according to one embodiment, a plurality of first step patterns (115a, see FIG. 10a) and a plurality of third step patterns (135a, see FIG. 10a) may be formed on the outer surfaces of a plurality of first tabs (113a) and a plurality of second tabs (133a) that have been pressed several times to a degree that welding connection is possible, respectively.

[0170] According to one embodiment, a pattern forming jig (820) may be used to apply pressure to a plurality of first tabs (113a) and a plurality of second tabs (133a). The pattern forming jig (820) may include a first electrode pattern forming jig (821) and a second electrode pattern forming jig (822). The first electrode pattern forming jig (821) may include a first step pattern forming portion (821a) that forms a plurality of first step patterns (115a). The second electrode pattern forming jig (822) may include a third step pattern forming portion (822a) that forms a plurality of third step patterns (135a). The first electrode pattern forming jig (821) may apply pressure to the plurality of first tabs (113a) to form the plurality of first step patterns (135a). The second electrode pattern forming jig (822) can form a plurality of third step patterns (135a) by applying pressure to a plurality of second tabs (133a).

[0171] According to one embodiment, the plurality of first step patterns (115a) and the plurality of third step patterns (135a) may be formed with different patterns. This is because, as illustrated in FIG. 10a, the shapes of the first collector plate (200) connected to the first uncoated portion (113) and the second collector plate (300) connected to the second uncoated portion (133) are different. However, when the first uncoated portion (113) and the first collector plate (200) and the second uncoated portion (133) and the second collector plate (300) have the same welding range in the same behavior, the plurality of first step patterns (115a) and the plurality of third step patterns (135a) may be formed with the same pattern, but are not limited thereto.

[0172] As illustrated in FIGS. 9b to 9d, according to one embodiment, a plurality of first step patterns (115b, 115c, 115d, see FIGS. 10b to 10d) and a plurality of third step patterns (135b, 135c, 135d, see FIGS. 10b to 10d) can be formed with different recesses, widths, and shapes.

[0173] Referring to FIG. 9B compared to FIG. 9A, each of the first step pattern forming portion (821b) and the second step pattern forming portion (822b) illustrated in FIG. 9B may have a different depth from the first step pattern forming portion (821a) and the second step pattern forming portion (822a) illustrated in FIG. 9A, and may form a plurality of first step patterns (115b, see FIG. 10B) and a plurality of second step patterns (135b, see FIG. 10B). For example, the depth of the plurality of first step patterns (115b) and the plurality of second step patterns (135b) may be formed to become deeper around 1 / 2 of the radius of the wound electrode assembly (100), but is not limited thereto.

[0174] Referring to FIG. 9C in comparison with FIG. 9A, each of the first step pattern forming portion (821c) and the second step pattern forming portion (822c) illustrated in FIG. 9C has a different width from the first step pattern forming portion (821a) and the second step pattern forming portion (822a) illustrated in FIG. 9A, and may form a plurality of first step patterns (115c, see FIG. 10C) and a plurality of second step patterns (135c, see FIG. 10C). For example, the widths of the plurality of first step patterns (115c) and the plurality of second step patterns (135c) may be formed to be longer than the depths, but the present invention is not limited thereto.

[0175] Referring to FIG. 9D compared to FIG. 9A, each of the first step pattern forming portion (821d) and the second step pattern forming portion (822d) illustrated in FIG. 9D has a different shape from the first step pattern forming portion (821a) and the second step pattern forming portion (822a) illustrated in FIG. 9A, and may form a plurality of first step patterns (115d, see FIG. 10D) and a plurality of second step patterns (135d, see FIG. 10D). For example, the plurality of first step patterns (115d) and the plurality of second step patterns (135d) may be formed in a curved shape, but are not limited thereto.

[0176] Referring to FIGS. 9A and 10A, a plurality of first step patterns (115a) can be formed on the first uncoated portion (113). A first collector plate (200) including a plurality of second step patterns (211a) can be placed on the first uncoated portion (113). When the plurality of first step patterns (115a) and the plurality of second step patterns (211a) are interlocked, the first uncoated portion (113) and the first collector plate (200) can be welded together. A plurality of third step patterns (135a) can be formed on the second uncoated portion (133). A second collector plate (300) including a plurality of fourth step patterns (311a) can be placed on the second uncoated portion (133). When multiple third step patterns (135a) and multiple fourth step patterns (311a) are interlocked, the second non-conductive portion (133) and the second collector plate (300) can be welded and connected.

[0177] According to one embodiment, as described above in FIG. 9a, since the shapes of the first collector plate (200) and the second collector plate (300) are different, the plurality of first step patterns (113a) and the plurality of third patterns (135a) may be different, and the plurality of second step patterns (211a) and the plurality of fourth step patterns (311a) may be different. However, when the first non-coated portion (113) and the first collector plate (200) and the second non-coated portion (133) and the second collector plate (300) have the same behavior and the same welding range, the plurality of first step patterns (115a) and the plurality of third step patterns (135a) may be formed with the same pattern, and the plurality of second step patterns (211a) and the plurality of fourth step patterns (311a) may be formed with the same pattern, but are not limited thereto.

[0178] Compared with FIG. 10a, referring to FIGS. 9b and 10b, the plurality of first to fourth step patterns (113b, 135b, 211b, 311b) illustrated in FIG. 10b may be formed with different depths from the plurality of first to fourth step patterns (113a, 135a, 211a, 311a) illustrated in FIG. 10a. For example, the plurality of first to fourth step patterns (113b, 135b, 211b, 311b) may be formed to be deeper around 1 / 2 of the radius of the wound electrode assembly (100), but is not limited thereto.

[0179] Compared to FIG. 10a, referring to FIGS. 9c and 10c, the plurality of first to fourth step patterns (113c, 135c, 211c, 311c) illustrated in FIG. 10c may be formed with different widths from the plurality of first to fourth step patterns (113a, 135a, 211a, 311a) illustrated in FIG. 10a. For example, the plurality of first to fourth step patterns (113b, 135b, 211b, 311b) may be formed with a width longer than a depth, but is not limited thereto.

[0180] Compared to FIG. 10a, referring to FIGS. 9d and 10d, the plurality of first to fourth step patterns (113d, 135d, 211d, 311d) illustrated in FIG. 10d may be formed in a different shape from the plurality of first to fourth step patterns (113a, 135a, 211a, 311a) illustrated in FIG. 10a. For example, the plurality of first to fourth step patterns (113b, 135b, 211b, 311b) may be formed in a curved shape, but is not limited thereto.

[0181] As described above, the secondary battery (1) according to one embodiment of the present invention can increase the welding area between the first non-coated portion (113) and the first collector plate (200) and the second non-coated portion (133) and the second collector plate (300), thereby increasing the bonding strength between the first non-coated portion (113) and the first collector plate (200) and the second non-coated portion (133) and the second collector plate (300). In addition, the secondary battery (1) according to one embodiment of the present invention can increase the contact area between the first non-coated portion (113) and the first collector plate (200) and the second non-coated portion (133) and the second collector plate (300), thereby reducing the electrical resistance in the electrical connection path between the first non-coated portion (113) and the first collector plate (200) and the second non-coated portion (133) and the second collector plate (300).

[0182] 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 first electrode including a first coated portion coated with an active material and a first uncoated portion not coated; A second electrode including a second coated portion coated with an active material and a second uncoated portion that is not coated; and A separator is included between the first electrode and the second electrode, The first electrode, the second electrode, and the separator are wound around the winding axis, The above first non-woven portion is arranged to protrude toward one side of the separator in one direction of the winding axis and to be bent toward the winding axis, A plurality of first step patterns are formed on the outer surface of the area where the first non-woven part is folded, Electrode assembly.

2. In paragraph 1, The above first part is, Including a plurality of first tabs formed by continuously notching along the direction in which the first electrode is wound, Electrode assembly.

3. In paragraph 2, The above plurality of first tabs are, A plurality of tabs having the same length protruding from the separator along the direction in which the first electrode is wound, Electrode assembly.

4. In paragraph 2, The above plurality of first tabs are, Formed in the region of the first non-woven portion at a certain distance from the winding axis of the wound electrode assembly, Electrode assembly.

5. In paragraph 2, The above plurality of first tabs are, Folded and arranged while overlapping toward the above-mentioned winding axis, Electrode assembly.

6. In paragraph 2, The above plurality of first tabs are, Formed in the region of the first non-conductive portion at a certain distance from the outer diameter of the wound electrode assembly, Electrode assembly.

7. In paragraph 1, The above plurality of first step patterns have at least one pattern of different depth and width. Electrode assembly.

8. In paragraph 1, The above second part is, It is protruded in the other direction of the above winding axis to the other side of the above separator and is bent toward the above winding axis, A plurality of second step patterns are formed on the outer surface of the area where the second non-woven portion is folded, Electrode assembly.

9. In paragraph 8, The above second part is, A plurality of second tabs formed by continuously notching along the direction in which the second electrode is wound, Electrode assembly.

10. In paragraph 9, The above plurality of second tabs are, The second electrode includes a plurality of tabs having the same length protruding from the separator along the direction in which the second electrode is wound. Electrode assembly.

11. In paragraph 9, The above plurality of second tabs are, Formed in the region of the second non-conductive portion at a certain distance from the winding axis of the wound electrode assembly, Electrode assembly.

12. In paragraph 9, The above plurality of second tabs are, Folded and arranged while overlapping toward the above-mentioned winding axis, Electrode assembly.

13. In paragraph 9, The above plurality of second tabs are, Formed in the area of ​​the second non-conductive portion at a certain distance from the outer diameter of the wound electrode assembly, Electrode assembly.

14. In paragraph 8, The above plurality of second step patterns have at least one pattern of different depth and width. Electrode assembly.

15. An electrode assembly comprising a first electrode including a first non-conductive portion, a second electrode including a second non-conductive portion, and a separator interposed between the first electrode and the second electrode, wherein the first electrode, the second electrode, and the separator are wound around a winding axis; A first collector plate electrically connected to the first non-conductive portion; A second collector plate electrically connected to the second non-conductive portion; A case accommodating the electrode assembly, the first collector plate and the second collector plate through an open side; and A vent cap plate is included to cover one open side of the case and seal the electrode assembly from the outside, The above first non-woven portion is protruded from one side of the separator in one direction of the winding axis and is bent toward the winding axis, A plurality of first step patterns are formed on the outer surface of the area where the first non-woven part is folded, Secondary battery.

16. In paragraph 15, The above first collector plate, Including a plurality of second step patterns that are interlocked and combined with the plurality of first step patterns on one surface that contacts the first non-woven part, Secondary battery.

17. In paragraph 16, The first non-conductive portion includes a plurality of first tabs formed by continuously notching along the direction in which the first electrode is wound, The above plurality of first tabs are arranged in a folded manner while overlapping toward the winding axis. Secondary battery.

18. A step of winding a first electrode including a first non-woven portion, a second electrode including a second non-woven portion, and a separator interposed between the first electrode and the second electrode around a winding axis; A step of bending and arranging the first non-woven portion protruding on one side of the separator in one direction of the winding axis toward the winding axis; and A step of forming a plurality of first step patterns on the outer surface of the first non-woven portion arranged in the above bending arrangement, A method for manufacturing an electrode assembly.

19. In paragraph 18, Further comprising a step of forming a plurality of first tabs by continuously notching one end of the first non-conductive portion along the direction in which the first electrode is wound, The above bending arrangement step is: Including a step of bending and arranging the plurality of first tabs while overlapping them toward the winding axis, A method for manufacturing an electrode assembly.

20. In paragraph 18, Further comprising a step of arranging a first collector plate including a plurality of second step patterns interlocked with the plurality of first step patterns on the first non-conductive portion, The step of forming the plurality of first step patterns is: Comprising the step of forming a pattern having at least one different depth and width, A method for manufacturing an electrode assembly.

Images