Secondary battery

Abstract

The present disclosure relates to a secondary battery and addresses the technical problem of providing a secondary battery having the same or similar current path length. The secondary battery according to an embodiment disclosed herein may comprise: an electrode assembly that includes a first electrode having a first base material and a second electrode having a second base material, and is wound around a winding core part; and a case for accommodating the electrode assembly, wherein the first base material extends toward one side and is bent in a first direction, and the second base material extends toward the one side and is bent in a second direction.

Description

secondary battery

[0001] The present disclosure relates to a secondary battery with improved space efficiency.

[0002]

[0003] In general, the demand for high-energy-density, high-capacity rechargeable batteries is rapidly increasing in line with the recent rapid proliferation of electronic devices using batteries, such as mobile phones, laptop computers, and electric vehicles. Accordingly, research and development to improve the performance of lithium-ion batteries is actively underway.

[0004] A lithium secondary battery is a battery comprising a positive electrode and a negative electrode containing an active material capable of lithium ion intercalation and deintercalation, and an electrolyte, and produces electrical energy through oxidation and reduction reactions when lithium ions are intercalated / deintercalated from the positive electrode and the negative electrode.

[0005] The information described above disclosed in the background technology of this invention is intended only to enhance understanding of the background of the present invention and may therefore include information that does not constitute prior art.

[0006]

[0007] One embodiment of the present invention aims to provide a secondary battery with the same or similar current path length.

[0008] For example, one embodiment of the present invention may provide a secondary battery in which the positive and negative electrode substrates extend in the same direction.

[0009] For example, one embodiment of the present invention may provide a secondary battery in which the substrates of the positive and negative electrodes are folded in different directions.

[0010] One embodiment of the present invention aims to provide a secondary battery that can omit a current collector plate.

[0011] For example, one embodiment of the present invention may provide a secondary battery comprising a cap that can be simultaneously connected to a positive electrode and a negative electrode.

[0012] One embodiment of the present invention aims to provide a secondary battery capable of simplifying the substrate cutting process.

[0013] However, the technical problems that the present disclosure aims to solve are not limited to those described above, and other unmentioned problems can be clearly understood by those skilled in the art from the description of the invention below.

[0014]

[0015] A secondary battery according to one embodiment of the present disclosure for solving the above technical problem comprises a first electrode including a first substrate and a second electrode including a second substrate, an electrode assembly formed by winding around a winding core, and a case for housing the electrode assembly, wherein the first substrate may be extended to one side and bent in a first direction, and the second substrate may be extended to one side and bent in a second direction.

[0016] According to one aspect of the above embodiment, the first direction and the second direction may be opposite directions to each other.

[0017] According to another aspect of the above embodiment, the first direction may be directed from the core portion toward the outer portion of the electrode assembly, and the second direction may be directed from the outer portion toward the core portion.

[0018] According to another aspect of the above embodiment, the first direction may be directed obliquely from the core portion to the outer portion of the electrode assembly, and the second direction may be directed obliquely from the outer portion to the center of the electrode assembly.

[0019] According to another aspect of the above embodiment, the electrode assembly may include a first region in which the first substrate is extended, a second region in which the second substrate is extended, and a third region located between the first region and the second region.

[0020] According to another aspect of the above embodiment, the first region may be a region formed within a first distance from the core, and the second region may be a region formed within a second distance greater than the first distance from the core.

[0021] According to another aspect of the above embodiment, the first substrate may include a first extension area located in the first area and a first cutting area located in the second area or the third area, and the second substrate may include a second extension area located in the second area and a second cutting area located in the first area or the third area.

[0022] According to another aspect of the above embodiment, the second extended region may be formed to be the same length as the first extended region or longer than the first extended region.

[0023] According to another aspect of the above embodiment, at least one of the first extension region and the second extension region may be formed in a streamlined shape.

[0024] According to another aspect of the above embodiment, at least one of the first extension region and the second extension region may be formed discontinuously.

[0025] According to another aspect of the above embodiment, at least one of the first extension region and the second extension region may be formed at a constant height.

[0026] According to another aspect of the above embodiment, at least one of the first extension region and the second extension region may have its height reduced in a direction toward the third region.

[0027] According to another aspect of the above embodiment, at least one of the first extension region and the second extension region may have a continuously decreasing height.

[0028] According to another aspect of the above embodiment, at least one of the first extension region and the second extension region may be lowered with a height difference.

[0029] According to another aspect of the above embodiment, the first substrate and the second substrate may be formed with at least a portion having the same height in the second region.

[0030] According to another aspect of the above embodiment, the secondary battery may further include a separator located between the first electrode and the second electrode.

[0031] According to another aspect of the above embodiment, at least one of the first substrate and the second substrate may be formed with a portion having a height less than or equal to the height of the separator.

[0032] According to another aspect of the above embodiment, the separator may be formed to a constant height.

[0033] According to another aspect of the above embodiment, the secondary battery may further include a first terminal electrically connected to the first electrode, a second terminal electrically connected to the second electrode, and a cap coupled to the opening of the case.

[0034] According to another aspect of the above embodiment, the cap may include an insulating member located between the first terminal and the second terminal.

[0035] However, the effects obtainable through the present disclosure are not limited to those described above, and other unmentioned technical effects will be clearly understood by those skilled in the art from the description of the invention below.

[0036]

[0037] The following drawings attached to this specification illustrate preferred embodiments of the present invention and serve to further enhance understanding of the technical concept of the present invention together with the detailed description of the invention provided below; therefore, the present invention should not be interpreted as being limited only to the matters described in such drawings.

[0038] FIG. 1 is a perspective view schematically showing the configuration of a battery pack according to one embodiment of the present invention.

[0039] FIG. 2 is a perspective view schematically showing a secondary battery according to one embodiment of the present invention.

[0040] FIG. 3 is a perspective view schematically showing the upper part of an electrode assembly according to one embodiment of the present invention.

[0041] FIG. 4 is a top view schematically showing the upper part of an electrode assembly according to one embodiment of the present invention.

[0042] FIG. 5 is a schematic diagram showing the unfolded state of the first electrode according to one embodiment of the present invention.

[0043] FIG. 6 is a schematic diagram showing the unfolded state of the second electrode according to one embodiment of the present invention.

[0044] FIG. 7 is a schematic diagram showing the unfolded state of an electrode assembly according to one embodiment of the present invention.

[0045] FIG. 8 is a schematic diagram showing the unfolded state of an electrode assembly according to one embodiment of the present invention.

[0046] FIG. 9 is a schematic diagram showing the unfolded state of an electrode assembly according to one embodiment of the present invention.

[0047] FIG. 10 is a top view schematically showing the upper part of an electrode assembly according to one embodiment of the present invention.

[0048] FIG. 11 is a cross-sectional view illustrating an electrode assembly according to one embodiment of the present invention.

[0049] FIG. 12 is a perspective view illustrating a cap according to one embodiment of the present invention.

[0050] FIG. 13 is a drawing showing a cap and an electrode assembly together to explain a cap according to an embodiment of the present invention.

[0051] FIG. 14 is a drawing for explaining a secondary battery including an electrode assembly and a case according to one embodiment of the present invention.

[0052]

[0053] Preferred embodiments of the present invention will be described in detail below with reference to the attached drawings. Prior to this, terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings. Instead, based on the principle that the inventor can appropriately define the concepts of terms to best describe their invention, they should be interpreted in a meaning and concept consistent with the technical spirit of the present invention. Therefore, the embodiments described in this specification and the configurations illustrated in the drawings are merely some of the most preferred embodiments of the present invention and do not represent all of the technical spirit of the present invention. It should be understood that various equivalents and modifications capable of replacing them may exist at the time of filing this application.

[0054] Additionally, as used herein, “comprise, include” and / or “comprising, including” specify the presence of the mentioned features, numbers, steps, actions, parts, elements, and / or groups thereof, and do not exclude the presence or addition of one or more other features, numbers, actions, parts, elements, and / or groups.

[0055] Additionally, to aid in understanding the invention, the attached drawings are not drawn to actual scale, and the dimensions of some components may be exaggerated. Furthermore, the same reference numerals may be assigned to identical components in different embodiments.

[0056] The statement that two subjects of comparison are 'identical' means that they are 'substantially identical.' Therefore, substantial identity may include deviations considered low in the industry, for example, deviations within 5%. Additionally, the statement that a parameter is uniform in a given area may mean that it is uniform from an average perspective.

[0057] Although terms such as "first," "second," etc., are used to describe various components, it goes without saying that these components are not limited by these terms. These terms are used merely to distinguish one component from another, and unless specifically stated otherwise, the first component may also be the second component.

[0058] Throughout the specification, unless specifically stated otherwise, each component may be singular or plural.

[0059] The fact that any configuration is placed on the "upper (or lower)" of a component or on the "upper (or lower)" of a component may mean not only that any configuration is placed in contact with the upper (or lower) surface of said component, but also that another configuration may be interposed between said component and any configuration placed on (or below) said component.

[0060] Furthermore, where one component is described as being "on," "connected to," or "coupled to" another component, it should be understood that while the components may be directly connected or coupled to each other, another component may be "interposed" between each component, or that each component may be "connected," "coupled," or "coupled" through another component.

[0061] As used herein, the term “and / or” includes any and all combinations of one or more of the associated listed items. Additionally, the use of “may” when describing embodiments of the present disclosure relates to “one or more embodiments of the present disclosure.” Expressions such as “one or more” and “one or more” preceding a list of elements modify the entire list of elements and do not modify individual elements of the list.

[0062] Throughout the specification, "A and / or B" means A, B, or A and B unless specifically stated otherwise, and "C to D" means C or more and D or less, unless specifically stated otherwise.

[0063] When syntax such as "at least one of A, B, and C", "at least one of A, B, or C", "at least one selected from the group of A, B, and C", or "at least one selected from A, B, and C" is used to specify a list of elements A, B, and C, the syntax can refer to any suitable combination.

[0064] The term "use" may be considered synonymous with the term "utilize." As used herein, "substantially," "about," and similar terms are used as terms of approximation rather than degree, and are intended to account for the inherent variation of measured or calculated values ​​that a person skilled in the art would recognize.

[0065] In this specification, terms such as first, second, third, etc. may be used to describe various elements, components, regions, layers, and / or sections, but these elements, components, regions, layers, and / or sections should not be limited by these terms. These terms are used to distinguish one element, component, region, layer, or section from another element, component, region, layer, or section. Accordingly, the first element, component, region, layer, or section discussed below may be named the second element, component, region, layer, or section without departing from the teachings of the exemplary embodiments.

[0066] Spatial relative terms such as "beneath," "below," "lower," "above," and "upper" may be used herein for ease of explanation to describe the relationship between one element or feature and another element(s) or feature(s) as illustrated in the drawings. Spatially relative positions are to be understood as encompassing different orientations of the device in use or operation, in addition to the orientations depicted in the figures. For example, if the device in the drawing is inverted, an element described as "below" or "below" is understood as "above" or "upper" of another element. Thus, the term "below" may encompass both the up and down directions.

[0067] The terms used in this specification are intended to describe embodiments of the present disclosure and are not intended to limit the present disclosure.

[0068]

[0069] FIG. 1 is a perspective view schematically showing the configuration of a battery pack according to one embodiment of the present invention.

[0070] FIG. 2 is a perspective view schematically showing a secondary battery according to one embodiment of the present invention.

[0071] A battery pack (1000) according to one embodiment of the present invention may include a housing (1100) and a secondary battery (100).

[0072] The housing (1100) forms the general outline of the battery pack (1000) and can provide a space in which the secondary battery (100) can be accommodated.

[0073] The housing (1100) may include a housing body (1110) and a cover (1120).

[0074] The housing body (1110) can be formed to have a box shape with an empty interior and one side open. The cross-sectional shape of the housing body (1110) is not limited to the square shape shown in FIG. 1, but can be designed to have various shapes such as polygons, circles, and ellipses.

[0075] The cover (1120) is coupled to the housing body (1110) and can close the internal space of the housing body (1110). For example, the cover (1120) may be formed to have a shape roughly like a plate and may be positioned to face the open side of the housing body (1110). The cover (1120) may be fixed to the housing body (1110) by various types of coupling methods, such as bolting, welding, or snap-fitting.

[0076] The secondary battery (100) can function as a unit structure that stores and supplies power in a battery pack.

[0077] Multiple secondary batteries (100) may be provided. Multiple secondary batteries (100) may be arranged inside the housing (1100) to form various patterns, such as a grid or a zigzag pattern. Multiple secondary batteries (100) may be arranged side by side. The number of secondary batteries (100) can be varied in design depending on the size, shape, etc. of the housing (1100).

[0078] The secondary battery (100) includes an electrode assembly (10) and a case (20) that houses the electrode assembly (10). Additionally, the secondary battery (100) may further include a cap (50) that is coupled to an opening of the case (20).

[0079] The components of the secondary battery (100) are not limited to the components shown in FIG. 2, and the secondary battery (100) may include only some of the components shown in FIG. 2 and / or include additional components other than those shown in FIG. 2.

[0080] In the following description, the secondary battery (100) is described as a cylindrical battery as a lithium-ion secondary battery. However, the present invention is not limited thereto, and the secondary battery may be a lithium polymer battery or a prismatic battery.

[0081] The case (20) is sealed after housing the electrode assembly (10) and the electrolyte. For example, the case (20) can be sealed by a cap (50).

[0082] Specifically, the case (20) forms the general outline of the secondary battery (100). The case (20) includes a lower surface forming a cylindrical lower portion and a side surface connected to the outer surface of the lower surface and extending vertically from the lower surface to form a side portion.

[0083] At this time, the case (20) may have an open cylindrical top. The case (20) can seal the inside by closing the opening with a cap (50). Accordingly, the case (20) can prevent the electrolyte from leaking out and protect the electrode assembly (10).

[0084] Meanwhile, the case (20) can be manufactured from, for example, steel, stainless steel, aluminum, aluminum alloy, a combination thereof, or an equivalent thereof.

[0085] The cap plate (60) covers the opening of the case (20) and seals the case (20).

[0086] Below, the secondary battery (100) is described in detail.

[0087]

[0088] FIG. 3 is a perspective view schematically showing the upper part of an electrode assembly according to one embodiment of the present invention.

[0089] FIG. 4 is a top view schematically showing the upper part of an electrode assembly according to one embodiment of the present invention.

[0090] An electrode assembly (10) according to one embodiment of the present invention can function as a unit structure that performs charging and discharging operations of power in a secondary battery (100).

[0091] The electrode assembly (10) includes a first electrode (11, see FIG. 5) and a second electrode (12, see FIG. 5). The first electrode (11) is either a positive or a negative electrode. The second electrode (12) is either a negative or a positive electrode and has a polarity different from that of the first electrode (11). Below, an example can be described where the first electrode (11) is a positive electrode and the second electrode (12) is a negative electrode.

[0092] Additionally, the electrode assembly (10) may further include a separator (13) located between the first electrode (11) and the second electrode (12). The separator (13) prevents the first electrode (11) and the second electrode (12) from coming into contact with each other. The separator (13) can prevent a short circuit from occurring between the first electrode (11) and the second electrode (12). That is, the electrode assembly (10) may be formed by stacking the first electrode (11), the second electrode (12), and the separator (13) provided between the first electrode (11) and the second electrode (12).

[0093] When the secondary battery (100) is cylindrical, the electrode assembly (10) can form a jelly roll.

[0094] When the electrode assembly (10) forms a cylindrical shape, the laminated structure including the first electrode (11), the second electrode (12), and the separator (13) can be wound to form a jelly roll. For example, the electrode assembly (10) may have a shape wound in a clockwise or counterclockwise direction around a winding axis. The cross-sectional shape of the electrode assembly (10) can be designed to have various shapes other than a circle, such as an ellipse or a polygon. Here, the winding axis may refer to a straight line penetrating the winding core (C) of the electrode assembly (10).

[0095] A detailed description of each component of the electrode assembly (10) is as follows.

[0096]

[0097] positive electrode active material

[0098] As a positive electrode active material, a compound capable of reversible intercalation and deintercalation of lithium (a lithated intercalation compound) may be used. Specifically, one or more composite oxides of lithium and a metal selected from cobalt, manganese, nickel, and combinations thereof may be used.

[0099] The above composite oxide may be a lithium transition metal composite oxide, and specific examples include a lithium nickel-based oxide, a lithium cobalt-based oxide, a lithium manganese-based oxide, a lithium iron phosphate-based compound, a cobalt-free nickel-manganese-based oxide, or a combination thereof.

[0100] As an example, compounds represented by any one of the following chemical formulas may be used. LiaA1-bXbO2-cDc(0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05); LiaMn2-bXbO4-cDc(0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05); LiaNi1-b-cCobXcO2-αDα(0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.5, 0<α<2); LiaNi1-b-cMnbXcO2-αDα(0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.5, 0<α<2); LiaNibCocL1dGeO2(0.90≤a≤1.8, 0≤b≤0.9, 0≤c≤0.5, 0≤d≤0.5, 0≤e≤0.1); LiaNiGbO2(0.90≤a≤1.8, 0.001≤b≤0.1); LiaCoGbO2(0.90≤a≤1.8, 0.001≤b≤0.1); LiaMn1-bGbO2 (0.90≤a≤1.8, 0.001≤b≤0.1); LiaMn2GbO4 (0.90≤a≤1.8, 0.001≤b≤0.1); LiaMn1-gGgPO4(0.90≤a≤1.8, 0≤g≤0.5); Li(3-f)Fe2(PO4)3(0≤f≤2); LiaFePO4(0.90≤a≤1.8).

[0101] In the above chemical formula, A is Ni, Co, Mn, or a combination thereof; X is Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, a rare earth element, or a combination thereof; D is O, F, S, P, or a combination thereof; G is Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V, or a combination thereof; and L1 is Mn, Al, or a combination thereof.

[0102] For example, the above-mentioned positive electrode active material may be a high-nickel positive electrode active material in which the nickel content relative to 100 mol% of the metal excluding lithium in the lithium transition metal composite oxide 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. The high-nickel positive electrode active material can achieve high capacity and can be applied to high-capacity, high-density lithium batteries.

[0103] anode

[0104] A positive electrode for a secondary battery (100) may include a current collector and a positive electrode active material layer formed on the current collector. The positive electrode active material layer may include a positive electrode active material and may further include a binder and / or a conductive material.

[0105] For example, the above anode may further include an additive that can serve as a sacrificial anode.

[0106] The content of the positive active material is 90% to 99.5% by weight with respect to 100% by weight of the positive active material layer, and the content of the binder and the conductive material may each be 0.5% to 5% by weight with respect to 100% by weight of the positive active material layer.

[0107] The above binder serves to adhere the positive active material particles well to each other and also to adhere the positive active material well to the current collector. Representative examples of binders include, but are not limited to, polyvinyl alcohol, carboxymethylcellulose, hydroxypropylcellulose, diacetylcellulose, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, polymers containing ethylene oxide, polyvinylpyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, styrene-butadiene rubber, (meth)acrylated styrene-butadiene rubber, epoxy resin, (meth)acrylic resin, polyester resin, nylon, etc.

[0108] The above conductive material is used to impart conductivity to the electrode, and any electronically conductive material that does not cause chemical changes can be used in the battery being constructed. Examples of conductive materials include carbon-based materials such as natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, carbon fiber, carbon nanofiber, carbon nanotube; metal-based materials in the form of metal powder or metal fibers containing copper, nickel, aluminum, silver, etc.; conductive polymers such as polyphenylene derivatives; or mixtures thereof.

[0109] Al may be used as the current collector mentioned above, but is not limited thereto.

[0110] cathode active material

[0111] 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.

[0112] A material capable of reversibly intercalating / deintercalating the above lithium ions may be a carbon-based negative electrode active material, such as crystalline carbon, amorphous carbon, or a combination thereof. Examples of the crystalline carbon include graphite such as amorphous, plate-like, flake-like, spherical, or fibrous natural graphite or artificial graphite, and examples of the amorphous carbon include soft carbon or hard carbon, mesophase pitch carbide, calcined coke, etc.

[0113] 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 may be used.

[0114] As a material capable of doping and undoping the above lithium, a Si-based negative electrode active material or a Sn-based negative electrode active material may be used. The 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.

[0115] 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, it may include a secondary particle (core) assembled from silicon primary particles and an amorphous carbon coating layer (shell) located on the surface of the secondary particle. The amorphous carbon may also be located between the silicon primary particles, so that, for example, the silicon primary particles may be coated with amorphous carbon. The secondary particles may be dispersed in an amorphous carbon matrix.

[0116] The silicon-carbon composite may further include crystalline carbon. For example, the silicon-carbon composite may include a core comprising crystalline carbon and silicon particles and an amorphous carbon coating layer located on the surface of the core.

[0117] The above Si-based or Sn-based negative electrode active material can be used in combination with a carbon-based negative electrode active material.

[0118] cathode

[0119] The negative electrode for the secondary battery (100) includes a current collector and a negative electrode active material layer located 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.

[0120] For example, the negative electrode active material layer may comprise 90% to 99% by weight of negative electrode active material, 0.5% to 5% by weight of binder, and 0% to 5% by weight of conductive material.

[0121] The above binder serves to effectively bond the negative electrode active material particles to each other and also to effectively bond the negative electrode active material to the current collector. As the binder, a non-aqueous binder, an aqueous binder, a dry binder, or a combination thereof may be used.

[0122] Examples of the above-mentioned non-aqueous binders include polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, ethylene propylene copolymer, polystyrene, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, polyamide imide, polyimide, or combinations thereof.

[0123] The above-mentioned water-based binder may be selected from styrene-butadiene rubber, (meth)acrylated styrene-butadiene rubber, (meth)acrylonitrile-butadiene rubber, (meth)acrylic rubber, butyl rubber, fluororubber, polyethylene oxide, polyvinylpyrrolidone, polyepichlorohydrin, polyphosphazene, poly(meth)acrylonitrile, ethylenepropylenediene copolymer, polyvinylpyridine, chlorosulfonated polyethylene, latex, polyester resin, (meth)acrylic resin, phenolic resin, epoxy resin, polyvinyl alcohol, and combinations thereof.

[0124] When a water-based binder is used as the above-mentioned cathode binder, a cellulose-based compound capable of imparting viscosity may be further included. As this cellulose-based compound, one or more types such as carboxymethyl cellulose, hydroxypropylmethyl cellulose, methyl cellulose, or alkali metal salts thereof may be mixed and used. Na, K, or Li may be used as the alkali metal.

[0125] The above dry binder is a polymer material capable of fiberization, and may be, for example, polytetrafluoroethylene, polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene copolymer, polyethylene oxide, or a combination thereof.

[0126] The above conductive material is used to impart conductivity to the electrode, and any electronically conductive material that does not cause chemical changes can be used in the battery being constructed. Specific examples include carbon-based materials such as natural graphite, artificial graphite, carbon black, acetylene black, Ketjenblack, carbon fiber, carbon nanofiber, carbon nanotube; metal-based materials in the form of metal powder or metal fibers including copper, nickel, aluminum, silver, etc.; conductive polymers such as polyphenylene derivatives; or mixtures thereof.

[0127] As the above-mentioned cathode current collector, a material selected from copper foil, nickel foil, stainless steel foil, titanium foil, nickel foam, copper foam, a polymer substrate coated with a conductive metal, and combinations thereof may be used.

[0128] Separator

[0129] Depending on the type of secondary battery (100), a separator may be present between the positive electrode (10) and the negative electrode (20). As such a separator, polyethylene, polypropylene, polyvinylidene fluoride, or a multilayer film of two or more layers thereof may be used, and of course, a mixed multilayer film such as a polyethylene / polypropylene two-layer separator, a polyethylene / polypropylene / polyethylene three-layer separator, or a polypropylene / polyethylene / polypropylene three-layer separator may be used.

[0130] The above separation membrane may include a porous substrate and a coating layer comprising an organic material, an inorganic material, or a combination thereof located on one or both sides of the porous substrate.

[0131] The porous substrate may be a polymer membrane formed from any one of the following: polyolefins such as polyethylene and polypropylene; polyesters such as polyethylene terephthalate and polybutylene terephthalate; polyacetal; polyamide; polyimide; polycarbonate; polyetherketone; polyaryletherketone; polyetherimide; polyamideimide; polybenzimidazole; polyethersulfone; polyphenylene oxide; cyclic olefin copolymer; polyphenylene sulfide; polyethylene naphthalate; glass fiber; Teflon; and polytetrafluoroethylene, or a copolymer or mixture of two or more of these.

[0132] The above organic material may include a polyvinylidene fluoride-based polymer or a (meth)acrylic-based polymer.

[0133] The above inorganic material may include inorganic particles selected from Al2O3, SiO2, TiO2, SnO2, CeO2, MgO, NiO, CaO, GaO, ZnO, ZrO2, Y2O3, SrTiO3, BaTiO3, Mg(OH)2, boehmite, and combinations thereof, but is not limited thereto.

[0134] The above organic and inorganic materials may exist mixed in a single coating layer, or may exist in a stacked form with a coating layer containing organic materials and a coating layer containing inorganic materials.

[0135]

[0136] electrolyte

[0137] The electrolyte for the secondary battery (100) includes a non-aqueous organic solvent and a lithium salt.

[0138] The above-mentioned non-aqueous organic solvent serves as a medium through which ions involved in the electrochemical reaction of the battery can move.

[0139] The above-mentioned 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.

[0140] The above carbonate-based solvents may include dimethyl carbonate (DMC), diethyl carbonate (DEC), dipropyl carbonate (DPC), methylpropyl carbonate (MPC), ethylpropyl carbonate (EPC), methyl ethyl carbonate (MEC), ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate (BC), etc.

[0141] Ester-based solvents such as methyl acetate, ethyl acetate, n-propyl acetate, dimethyl acetate, methylpropionate, ethylpropionate, decanolide, mevalonolactone, valerolactone, and caprolactone may be used.

[0142] As ether-based solvents, dibutyl ether, tetraglame, diglame, dimethoxyethane, 2-methyltetrahydrofuran, 2,5-dimethyltetrahydrofuran, tetrahydrofuran, etc. may be used. Additionally, as ketone-based solvents, cyclohexanone, etc. may be used. As alcohol-based solvents, ethyl alcohol, isopropyl alcohol, etc. may be used, and as aprotic solvents, nitriles such as R-CN (where R is a straight-chain, branched, or cyclic hydrocarbon group having 2 to 20 carbon atoms and may include a double bond, an aromatic ring, or an ether group); amides such as dimethylformamide; dioxolanes such as 1,3-dioxolane, 1,4-dioxolane; sulfolanes, etc. may be used.

[0143] The above-mentioned non-aqueous organic solvent can be used alone or in a mixture of two or more types.

[0144] In addition, when using a carbonate-based solvent, a mixture of cyclic carbonates and chain carbonates can be used, and the cyclic carbonates and chain carbonates can be mixed in a volume ratio of 1:1 to 1:9.

[0145] The above lithium salt is a material that is dissolved in an organic solvent and acts as a source of lithium ions within the battery, enabling the operation of a basic lithium battery and facilitating the movement of lithium ions between the positive and negative electrodes. Representative examples of lithium salts may include one or more selected from LiPF6, LiBF4, LiSbF6, LiAsF6, LiClO4, LiAlO2, LiAlCl4, LiPO2F2, LiCl, LiI, LiN(SO3C2F5)2, Li(FSO2)2N (lithium bis(fluorosulfonyl)imide (LiFSI), LiC4F9SO3, LiN(CxF2x+1SO2)(CyF2y+1SO2)(x and y are integers from 1 to 20), lithium trifluoromethanesulfonate, lithium tetrafluoroethanesulfonate, lithium difluorobis(oxalate)phosphate (LiDFOB), and lithium bis(oxalate)borate (LiBOB).

[0146]

[0147] A secondary battery (100) according to one embodiment of the present invention includes an electrode assembly (10); and a case (20) for housing the electrode assembly (10).

[0148] An electrode assembly (10) according to one embodiment of the present invention comprises a first electrode (11) including a first substrate (111); and a second electrode (12) including a second substrate (121); and is formed by winding around a core portion, wherein the first substrate (111) extends to one side and is bent in a first direction, and the second substrate (121) extends to one side and is bent in a second direction.

[0149] The electrode assembly (10) is formed by stacking a first electrode (11), a second electrode (12), and a separator (13) located between the first electrode (11) and the second electrode (12). For example, the electrode assembly (10) is formed by winding the stacked first electrode (11), second electrode (12), and separator (13). For example, the electrode assembly (10) forms a jelly roll.

[0150] The first electrode (11) includes a first substrate (111). The first electrode (11) includes the first substrate (111); and a first coating layer (112) coated on a part of the first substrate (111). Hereinafter, the area where the first coating layer (112) is coated on the first substrate (111) may be referred to as the first retaining portion, and the area where the first coating layer (112) is not coated on the first substrate (111) may be referred to as the first uncoated portion.

[0151] The first electrode (11) includes a first retaining portion and a first non-retaining portion formed by extending from the first retaining portion to one or both sides. At this time, the first substrate (111) included in the first non-retaining portion can serve as a tab that electrically connects the first electrode (11) to the outside. For example, the first substrate (111) can be connected to a current collector. For example, the first substrate (111) can be connected to various components that electrically connect the electrode assembly (10) to the outside, such as a terminal, a cap plate, a cap assembly, a sub-plate, a current collector plate, and a current collector.

[0152] Alternatively, the first electrode (11) may be configured to perform the role of the first substrate (111) described above through a separate substrate tab attached to the first non-removable portion. Below, an example is described in which the first substrate (111) is extended to perform the role of a tab.

[0153] The second electrode (12) includes a second substrate (121). The second electrode (12) includes the second substrate (121); and a second coating layer (122) coated on a portion of the second substrate (121). Hereinafter, the area where the second coating layer (122) is coated on the second substrate (121) may be referred to as the second retaining portion, and the area where the second coating layer (122) is not coated on the second substrate (121) may be referred to as the second non-retaining portion.

[0154] The second electrode (12) includes a second retaining portion and a second non-retaining portion formed by extending from the second retaining portion to one or both sides. At this time, the second substrate (121) included in the second non-retaining portion can serve as a tab that electrically connects the second electrode (12) to the outside. For example, the second substrate (121) can be connected to a current collector. For example, the second substrate (121) can be connected to various components that electrically connect the electrode assembly (10) to the outside, such as a terminal, a cap plate, a cap assembly, a sub-plate, a current collector plate, and a current collector.

[0155] Alternatively, the second electrode (12) may be configured to perform the role of the second substrate (121) described above through a separate substrate tab attached to the second blank portion. Below, an example is described in which the second substrate (112) is extended to perform the role of a tab.

[0156] The first substrate (111) extends to one side of the electrode assembly (10). For example, the first substrate (111) extends toward the upper side of the electrode assembly (10). For example, the first substrate (111) extends in the direction in which the opening of the case (20) is formed.

[0157] The second substrate (121) extends to one side of the electrode assembly (10). As shown in FIGS. 3 and 4, the second substrate (121) may extend in the same direction as the first substrate (111). For example, the second substrate (121) extends toward the upper side of the electrode assembly (10). For example, the second substrate (121) extends in the direction in which the opening of the case (20) is formed.

[0158] Through such a structure, the secondary battery (100) can provide a structure advantageous for packaging the battery module and / or battery pack (1000).

[0159] At this time, a short circuit must not occur between the first material (111) and the second material (121) that are extended in the same direction. To this end, the first material (111) and the second material (121) may be extended so as not to overlap each other.

[0160] For example, the electrode assembly (10) includes a first region (A) in which a first substrate (111) is extended; a second region (B) in which a second substrate (121) is extended; and a third region (C) located between the first region (A) and the second region (B).

[0161] The first region (A) is a region where the first substrate (111) extends from one side of the electrode assembly (10). For example, the first substrate (111) extends to the first region (A), which is a part of the upper surface (e.g., the xy plane of FIG. 4) of the electrode assembly (10).

[0162] The second region (B) is a region where the second substrate (121) extends from one side of the electrode assembly (10). The second region (B) is located spaced apart from the first region (A). For example, the second substrate (121) extends to the second region (B), which is another part of the upper surface of the electrode assembly (10).

[0163] The third region (C) is a region where neither the first substrate (111) nor the second substrate (121) extends from one side of the electrode assembly (10). For example, the third region (C) is another part of the upper surface of the electrode assembly (10).

[0164] The third region (C) is located between the first region (A) and the second region (B). That is, the first region (A) and the second region (B) are spaced apart from each other by the amount of the third region (C). Accordingly, as shown in FIG. 3, the upper part of the electrode assembly (10) may include a protruding region (A, B) and a concave region (C) formed by the substrate (111, 121).

[0165] The third region (C) prevents the first region (A) and the second region (B) from coming into contact. For example, the third region (C) prevents a short circuit from occurring between the extended first substrate (111) and the extended second substrate (121).

[0166] At this time, for example, the first region (A) may be a region formed within a first distance from the core of the winding. For example, the first region (A) may be located in the circumferential inner diameter of the electrode assembly (10). For example, the first region (A) is located close to the core of the electrode assembly (10).

[0167] Additionally, for example, the second region may be a region formed within a second distance from the core of the winding. In this case, the second distance is greater than the first distance. For example, the second region (B) may be located on the circumferential outer diameter of the electrode assembly (10). For example, the second region (B) is located far from the core of the electrode assembly (10).

[0168] Through such a structure, the electrode (11, 12) according to one embodiment of the present invention can provide a method for the substrate (111, 121) to be extended in the same direction without being cut into a complex shape.

[0169] Below, the electrodes (11, 12) and the electrode assembly (10) including the electrodes (11, 12) will be described in more detail.

[0170]

[0171] FIG. 5 is a schematic diagram showing the unfolded state of the first electrode according to one embodiment of the present invention.

[0172] FIG. 6 is a schematic diagram showing the unfolded state of the second electrode according to one embodiment of the present invention.

[0173] FIG. 7 is a schematic diagram showing the unfolded state of an electrode assembly according to one embodiment of the present invention.

[0174] As described in FIGS. 3 and 4, an electrode assembly (10) according to one embodiment of the present invention comprises: a first region (A) in which a first substrate (111) is extended; a second region (B) in which a second substrate (121) is extended; and a third region (C) located between the first region (A) and the second region (B).

[0175] As illustrated in FIG. 5, the first electrode (11) comprises a first substrate (111) and a first coating layer (112) coated on a portion of the first substrate (111). All or part of the area (first uncoated portion) on the first substrate (111) where the first coating layer (112) is not coated may serve as a tab.

[0176] At this time, the first substrate (111) may be formed by extending from the first region (A). For example, the first substrate (111) may be formed by extending only from the first region (A).

[0177] Additionally, the first substrate (111) may be formed by extending to one side of the first electrode (11). For example, the first substrate (111) may be formed by extending only to the upper side of the wound electrode assembly (10).

[0178] To this end, for example, the first material (111) includes a first extension region located in a first region (A) by being wound; and a first cutting region located in a second region (B) or a third region (C).

[0179] The first extension region is at least a part of the first non-retaining portion. The first extension region is an area where the first substrate (111) extends from the first retaining portion. The first extension region is an area that acts as a tap in the first electrode (11). The first extension region corresponds to or is formed within the first region (A) of the electrode assembly (10). For example, the first extension region is formed close to the winding core.

[0180] The first cutting region is formed by cutting off at least a portion of the first non-retaining portion. The first cutting region is an area where the first substrate (111) is cut off without extending from the first retaining portion, thereby forming an empty space as shown in FIG. 5. The first cutting region corresponds to the second region (B) and / or the third region (C) of the electrode assembly (10) or is formed within the second region (B) and / or the third region (C).

[0181] As shown in FIG. 5, when the first electrode (11) is unfolded without being wound, a first extension region may be formed on one side of the first electrode (11) (e.g., the side closer to the core) and a first cutting region may be formed on the other side of the first electrode (11) (e.g., the side farther from the core).

[0182] In the first electrode (11), the first extension region and the first cutting region may be located in separate regions that are divided from each other. Additionally, the cutting process of the first substrate (111) may be simplified.

[0183] As illustrated in FIG. 6, the second electrode (12) comprises a second substrate (121) and a second coating layer (122) that is coated on a portion of the second substrate (121). All or part of the area (second uncoated portion) on the second substrate (121) where the second coating layer (122) is not coated can serve as a tab.

[0184] The second material (121) may be formed by extending from the second region (B). For example, the second material (121) may be formed by extending only from the second region (B).

[0185] The second substrate (121) may be formed by extending to one side of the second electrode (12). For example, the second substrate (121) may be formed by extending only to the upper side of the wound electrode assembly (10).

[0186] To this end, the second material (121) includes a second extended area located in a second area that is wound; and a second cut area located in a first area or a third area.

[0187] The second extension region is at least a part of the second non-retaining portion. The second extension region is an area where the second substrate (121) extends from the second retaining portion. The second extension region is an area that acts as a tap in the second electrode (12). The second extension region corresponds to or is formed within the second region (B) of the electrode assembly (10). For example, the second extension region is formed far from the winding core.

[0188] The second cutting region is formed by cutting off at least a portion of the second non-retaining portion. The second cutting region is an area where the second substrate (121) is cut off without extending from the second retaining portion, thereby forming an empty space as shown in FIG. 6. The second cutting region corresponds to the first region (A) and / or the third region (C) of the electrode assembly (10) or is formed within the first region (A) and / or the third region (C).

[0189] As shown in FIG. 6, when the second electrode (12) is unfolded without being wound, a second extension region may be formed on one side of the second electrode (12) (e.g., the side closer to the core) and a second cutting region may be formed on the other side of the second electrode (12) (e.g., the side farther from the core).

[0190] In the second electrode (12), the second extension region and the second cutting region may be located in separate regions. Additionally, the cutting process of the second substrate (121) may be simplified.

[0191] The electrode assembly (10) may be formed by stacking a first electrode (11); a second electrode (12); and a separator (13). FIG. 7 shows the electrode assembly (10) in a stacked state, in an unfolded state before being wound.

[0192] As illustrated in FIG. 7, the first material (111) and the second material (121) extend in the same direction. Also, the first material (111) and the second material (121) do not overlap. Additionally, the first material (111) and the second material (121) extend in different regions. At this time, the extended first material (111) may be positioned closer to the winding core, and the extended second material (121) may be positioned further away from the winding core.

[0193] Accordingly, even if the electrode assembly (10) is wound around the core, the first material (111) and the second material (121) do not come into contact with each other.

[0194] Meanwhile, when the electrode assembly (10) is unfolded, for example, the first extension region and the second extension region can be extended symmetrically around the third region (C).

[0195] For example, the first extension region and the second extension region are formed by extending from the first coating layer (112) and the second coating layer (122) by the same length. Alternatively, for example, the first extension region and the second extension region may be formed by the same length. Accordingly, the secondary battery (100) can propose a structure in which the electrodes (11, 12) extend in the same direction while maximizing the convenience of the manufacturing process.

[0196] Alternatively, when the electrode assembly (10) is unfolded, for example, the first extension region and the second extension region may be extended asymmetrically around the third region (C).

[0197] For example, the first extension region and the second extension region are formed by extending to different lengths. The first extension region and the second extension region should be arranged so as not to overlap each other. Alternatively, the first extension region and the second extension region may be connected to terminals at different heights. Accordingly, the first extension region and the second extension region may be formed by extending to different lengths if necessary. For example, the second extension region is formed by extending to be equal to or longer than the first extension region. Or, for example, the first extension region may be formed by extending to be equal to or longer than the second extension region.

[0198] For example, at least one of the first extension region and the second extension region may be formed by extending to a certain height. Accordingly, a separate cutting process is not required in the first region (A) and the second region (B), so the manufacturing process can be simplified. Alternatively, the cutting process can be performed in the first region (A) and the second region (B) without separate height control, making the manufacturing process easier.

[0199] Alternatively, for example, at least one of the first extension area and the second extension area may have its height reduced in a direction toward the third area. For example, the first extension area may have its height reduced as it approaches the second extension area. This prevents the first extension area from contacting the second extension area and causing a short circuit. Alternatively, for example, the second extension area may have its height reduced as it approaches the first extension area. This prevents the second extension area from contacting the first extension area and causing a short circuit.

[0200] At this time, for example, at least one of the first extension region and the second extension region may have at least a portion of its height continuously lowered. FIGS. 5 to 7 illustrate an example in which a portion of the first extension region and the second extension region has a portion of its height continuously lowered. For example, as shown in FIGS. 5 and 7, the first extension region may form a slope in a direction approaching the second extension region. Or, for example, as shown in FIGS. 6 and 7, the second extension region may form a slope in a direction approaching the first extension region. Through this, the substrate (111, 121) can maximize the area that can perform the function of a tab while a portion of it is cut to prevent short circuits.

[0201] Alternatively, for example, at least one of the first extension area and the second extension area may be lowered with a step difference in height. For example, the first extension area may be lowered in height in a stepwise manner toward the second extension area. Alternatively, for example, the second extension area may be lowered in height in a stepwise manner toward the first extension area. Through this, the substrates (111, 121) can efficiently prevent overlap within each substrate (111, 121) and overlap between the substrates (111, 121).

[0202] For example, at least one of the first extension region and the second extension region is formed with at least a portion having a certain height.

[0203] For example, as illustrated in FIGS. 5 and 7, the first extension region may be formed with a certain height in part and a slope in other parts, with the height decreasing toward the second extension region. Alternatively, for example, as illustrated in FIGS. 5 and 7, the first extension region may be formed with a certain height in part and a step in other parts, with the height decreasing toward the second extension region.

[0204] In addition, as illustrated in FIGS. 6 and 7, for example, the second extension area may be formed with a certain height in part and a slope in other parts, with the height decreasing toward the first extension area. Or, as illustrated in FIGS. 6 and 7, for example, the second extension area may be formed with a certain height in part and a step in other parts, with the height decreasing toward the first extension area.

[0205] In this way, the substrate (111, 121) can minimize the resistance of the electrode assembly (10) by having a region with a constant height. Additionally, the substrate (111, 121) can minimize the occurrence of short circuits between substrates by having a region with a reduced height.

[0206] Meanwhile, as illustrated in FIG. 7, for example, the first substrate (111) and the second substrate (121) may be formed at least partially at the same height in the second region (B). For example, the first substrate (111) forms a first cutting region in at least a part of the third region (C). For example, the second substrate (121) forms a second cutting region in at least a part of the third region (C). At this time, the first cutting region and the second cutting region may overlap at least partially. In this way, the substrates (111, 121) prevent short circuits by cutting the extended region in the third region (C).

[0207] As illustrated in FIG. 7, the electrode assembly (10) may further include a separator (13) located between the first electrode (11) and the second electrode (12).

[0208] For example, at least one of the first substrate (111) and the second substrate (121) is formed with a height equal to or lower than the height of the separator (13). For example, the first substrate (111) is formed with a height equal to or lower than the separator (13) in the second region (B) and / or the third region (C). That is, the first cutting region in the first substrate (111) may be formed with a height equal to or lower than the separator (13). Also, for example, the second substrate (121) is formed with a height equal to or lower than the separator (13) in the first region (A) and / or the third region (C). That is, the second cutting region in the second substrate (121) may be formed with a height equal to or lower than the separator (13). In addition, for example, the separator (13) is formed at a certain height. That is, the separator (13) can prevent the first substrate (111) and the second substrate (121) from coming into contact without interfering with the first extension area or the second extension area.

[0209] Through this, the electrode assembly (10) according to one embodiment of the present invention can propose a structure in which the first electrode (11) and the second electrode (12) extend to the same side, making the cutting process of the substrate (111, 121) easy.

[0210] Various examples of such electrode assemblies (10) are described below.

[0211]

[0212] FIG. 8 is a schematic diagram showing the unfolded state of an electrode assembly according to one embodiment of the present invention.

[0213] An electrode assembly (10) according to one embodiment of the present invention comprises: a first region (A) in which a first substrate (111) is extended; a second region (B) in which a second substrate (121) is extended; and a third region (C) located between the first region (A) and the second region (B).

[0214] For example, at least one of the first extension region and the second extension region is formed in a streamlined shape. For example, the first extension region may extend from the first region (A) while forming a streamlined shape. Or, for example, the second extension region may extend from the second region (B) while forming a streamlined shape.

[0215] Through this, the electrode assembly (10) can improve the area of ​​the current path of the first electrode (11) and / or the second electrode (12) while facilitating the cutting process.

[0216]

[0217] FIG. 9 is a schematic diagram showing the unfolded state of an electrode assembly according to one embodiment of the present invention.

[0218] An electrode assembly (10) according to one embodiment of the present invention comprises: a first region (A) in which a first substrate (111) is extended; a second region (B) in which a second substrate (121) is extended; and a third region (C) located between the first region (A) and the second region (B).

[0219] For example, at least one of the first extension region and the second extension region is formed discontinuously. For example, the first extension region may be formed by extending discontinuously from the first region (A). Or, for example, the second extension region may be formed by extending discontinuously from the second region (B).

[0220] Through this, the electrode assembly (10) can facilitate the bending process of the first substrate (111) and / or the second substrate (121) described below.

[0221]

[0222] Meanwhile, the unfolded shape of the electrode assembly (10) is not limited to that illustrated in FIGS. 5 to 9. For example, the electrode assembly (10) may be formed by a combination of the contents illustrated in FIGS. 7 to 9. For example, the electrode assembly (10) may be formed such that the first extension region is discontinuously extended and the second extension region is continuously extended while forming a streamlined shape. Alternatively, for example, the electrode assembly (10) may be formed such that the first extension region is formed at a constant height and the second extension region is formed such that its height gradually decreases toward the first extension region.

[0223] In this way, at least one of the extension height, forming area, and forming shape of the first extension area or the second extension area can be set in various ways by considering the shape of the electrode assembly (10), the size of the electrode assembly (10), the shape of the case (20), the size of the case (20), etc.

[0224] Below, a structure is described in detail that allows the first substrate (111) and / or the second substrate (121) in such an electrode assembly (10) to perform the role of a tab.

[0225]

[0226] FIG. 10 is a top view schematically showing the upper part of an electrode assembly according to one embodiment of the present invention.

[0227] FIG. 11 is a cross-sectional view illustrating an electrode assembly according to one embodiment of the present invention.

[0228] An electrode assembly (10) according to one embodiment of the present invention comprises a first electrode (11) including a first substrate (111); and a second electrode (12) including a second substrate (121); and is formed by winding around a core portion, wherein the first substrate (111) is extended to one side and bent in a first direction (①), and the second substrate (121) is extended to one side and bent in a second direction (②).

[0229] The first material (111) is extended to one side and bent in the first direction (①). For example, the first extended area is bent in the first direction (①). Also, the second material (121) is extended to one side and bent in the second direction (②). For example, the second extended area is bent in the second direction (②).

[0230] At this time, the first direction (①) and the second direction (②) may be different from each other. For example, the first direction (①) may be an outward folding direction in which the first substrate (111) is folded toward the outer part of the wound electrode assembly (10). Also, for example, the second direction (②) may be an inward folding direction in which the second substrate (121) is folded toward the core part of the wound electrode assembly (10).

[0231] Accordingly, as illustrated in FIG. 11, the first substrate (111) and the second substrate (121) can be folded without coming into contact with each other. Additionally, the first substrate (111) and the second substrate (121) can provide an area that can be connected to a current collector through the folding.

[0232] At this time, as described in FIGS. 5 to 9, the first extension region and the second extension region may be extended by different lengths. In this case, unlike as shown in FIG. 11, the first extension region and the second extension region may have bent portions located at different heights.

[0233] At this time, the bent first substrate (111) and second substrate (121) can form a certain height. Through this, the first substrate (111) and second substrate (121) can be connected to a current collecting member while expanding the area of ​​the current path.

[0234] Through this, the electrode assembly (10) according to one embodiment of the present invention provides a method in which the first electrode (11) and the second electrode (12) are extended to the same side, while the cutting of the substrate (111, 121) is easy and the area of ​​the current path is maximized.

[0235] In this case, for example, the first direction (①) and the second direction (②) are opposite directions. That is, the first direction (①) can be the second direction (②).

[0236] For example, as illustrated in FIG. 10, the first direction (①) is directed from the core portion toward the outer portion of the electrode assembly (10), and the second direction (②) is directed from the outer portion of the electrode assembly (10) toward the core portion. At this time, the first direction (①) may be a direction representing the shortest distance from the core portion toward the outer portion of the electrode assembly (10). Also, the second direction (②) may be a direction representing the shortest distance from the outer portion of the electrode assembly (10) toward the core portion. Through this, the substrate (111, 121) according to one embodiment of the present invention can be easily bent.

[0237] For example, the first direction (①) is directed obliquely from the core of the winding to the outer part of the electrode assembly (10), and the second direction (②) is directed obliquely from the outer part of the electrode assembly (10) to the center of the electrode assembly (10). At this time, the first direction (①) may represent a direction that is not the shortest distance from the core of the winding to the outer part of the electrode assembly (10). Also, the second direction (②) may represent a direction that is not the shortest distance from the outer part of the electrode assembly (10) to the core of the winding. Accordingly, the first substrate (111) and / or the second substrate (121) may be formed to be extended further. Through this, the current collection area of ​​the substrate (111, 121) according to one embodiment of the present invention can be maximized.

[0238]

[0239] FIG. 12 is a perspective view illustrating a cap according to one embodiment of the present invention.

[0240] FIG. 13 is a drawing showing a cap and an electrode assembly together to explain a cap according to an embodiment of the present invention.

[0241] As described in FIGS. 3 and 4, the substrate (111, 121) can be electrically connected to a current collector. Through this, the secondary battery (100) including the electrode assembly (10) can perform charging and discharging. FIGS. 12 and 13 describe a current collector electrically connected to an electrode (11, 12) including a folded substrate (111, 121).

[0242] A secondary battery (100) according to one embodiment of the present invention (e.g., including the secondary battery described in FIGS. 1 to 11) comprises: a first terminal (51) electrically connected to a first electrode (11); and a second terminal (52) electrically connected to a second electrode (12); and a cap (50) coupled to an opening of a case (20).

[0243] For example, the secondary battery (100) may include a cap (50) as one embodiment of a current collector.

[0244] The cap (50) can be coupled to an opening of the case (20). For example, the cap (50) can be coupled to an opening formed at the top of the case (20) to seal the inside of the case (20).

[0245] The cap (50) can be electrically connected to the electrode assembly (10). For example, the cap (50) can be directly connected to the electrode assembly (10) to collect current from the electrode assembly (10). In addition, the cap (50) can simultaneously perform the role of a sealing member that seals the case (20).

[0246] For example, the cap (50) is electrically connected to the first electrode (11). To this end, the cap (50) may include a first terminal (51) that can be connected to the first electrode (11). Or, for example, the cap (50) is electrically connected to the second electrode (12). To this end, the cap (50) may include a second terminal (52) that can be connected to the second electrode (12). Or, for example, the cap (50) is electrically connected to the first electrode (11) and the second electrode (12) that extend in the same direction. To this end, the cap (50) may include a first terminal (51) and a second terminal (52).

[0247] As illustrated in FIG. 12, the cap (50) includes a first terminal (51) and a second terminal (52). To prevent a short circuit, the cap (50) may further include an insulating member (54) located between the first terminal (51) and the second terminal (52).

[0248] The first terminal (51) can be electrically connected to the first electrode (11). To this end, the first terminal (51) can be positioned corresponding to the first electrode (11). For example, the first terminal (51) can be formed in a circular shape within a predetermined distance from the center of the cap (50). At this time, the predetermined distance at which the first terminal (51) is formed may be greater than the first distance described in FIGS. 3 and 4.

[0249] Additionally, the second terminal (52) can be electrically connected to the second electrode (12). To this end, the second terminal (52) can be positioned corresponding to the second electrode (12). For example, the second terminal (52) can be formed in a circular shape within a predetermined distance from the center of the cap (50). At this time, the predetermined distance at which the second terminal (52) is formed may be greater than the second distance described in FIGS. 3 and 4.

[0250] The first terminal (51) and / or the second terminal (52) comprises a conductive material. The conductive material comprises any material capable of electrical connection. The conductive material may comprise, for example, a conductive metal such as nickel (Ni), copper (Cu), aluminum (Al), iron (Fe), tungsten (W), gold (Au), silver (Ag), steel, SUS, and an alloy of two or more of these. Alternatively, the conductive material may comprise a material coated with a conductive polymer.

[0251] The insulating member (54) can insulate between the first terminal (51) and the second terminal (52). The insulating member (54) is located between the first terminal (51) and the second terminal (52). Accordingly, as shown in FIG. 12, when viewed from the top, the cap (50) may include a first terminal (51) forming a circular shape, an insulating member (54) formed in a circular shape surrounding the first terminal (51), and a second terminal (52) formed in a circular shape surrounding the insulating member (54).

[0252] Furthermore, the insulating member (54) can insulate the cap (50) and the case (20). For example, the insulating member (54) is positioned to surround the outer edge of the cap (50). Alternatively, the insulating member (54) is positioned to surround the outer edge of the lower part of the cap (50).

[0253] The insulating member (54) includes an insulating material. The insulating material includes any material capable of insulating electricity. The insulating material may include, for example, at least one material selected from the group consisting of polyimide (PI), polysulfone, polyurethane (PU), polyamide (PA), 6,6-nylon (6,6nylon), polycarbonate (PC), polytetrafluoroethylene (PTFE), polymethyl methacrylate (PMMA), and polyethylene terephthalate (PET).

[0254] Meanwhile, the cap (50) may further include an electrolyte injection port (53) through which an electrolyte can be injected into the case (20). The electrolyte injection port (53) provides a path through which an electrolyte can be injected into the case (20). For example, the electrolyte injection port (53) is formed by penetrating the first terminal (51). For example, the electrolyte injection port (53) is formed in the center of the cap (50). For example, the electrolyte injection port (53) is formed corresponding to the core of the electrode assembly (10).

[0255] For example, as shown in FIG. 13, the cap (50) is connected to the electrode assembly (10).

[0256] For example, the first terminal (51) is electrically connected to the first electrode (11) located in the first region (A). For example, the first terminal (51) can be connected to the first substrate (111) which is extended and bent in the first direction (①). To this end, the position, shape and / or size of the first terminal (51) may correspond to the first region (A).

[0257] For example, the first terminal (51) can be connected to the extended and bent first substrate (111) by welding. Welding includes, for example, laser welding, ultrasonic welding, but is not limited to these methods.

[0258] Additionally, for example, the second terminal (52) is electrically connected to the second electrode (12) located in the second region (B). For example, the second terminal (52) can be connected to the second substrate (121) which is extended and bent in the second direction (②). To this end, the position, shape, and / or size of the second terminal (52) may correspond to the second region (B). Meanwhile, the insulating member (54) located between the first terminal (51) and the second terminal (52) may be formed corresponding to the third region (C).

[0259] For example, the second terminal (52) can be connected to the extended and bent second material (121) by welding. Welding includes, for example, laser welding, ultrasonic welding, but is not limited to these methods.

[0260] Through this, the cap (50) can collect current from the first electrode (11) and the second electrode (12). In addition, the cap (50) can insulate between the first electrode (11) and the second electrode (12).

[0261] In this way, a secondary battery (100) according to one embodiment of the present invention can collect current from an electrode assembly (10) through a cap (50) without a separate current collector plate. For example, the secondary battery (100) can collect current from an electrode assembly (10) by connecting to a first electrode (11) and a second electrode (12) that are extended in the same direction. Accordingly, the space efficiency inside the secondary battery (100) can be maximized.

[0262]

[0263] FIG. 14 is a drawing for explaining a secondary battery including an electrode assembly and a case according to one embodiment of the present invention.

[0264] A secondary battery (100) according to one embodiment of the present invention (e.g., including the secondary battery described in FIGS. 1 to 13) comprises an electrode assembly (10) (e.g., including the electrode assembly described in FIGS. 1 to 13); and a case (20) for housing the electrode assembly (10) (e.g., including the case described in FIGS. 1 to 13).

[0265] FIG. 14 schematically shows the lower surface of a case (20) into which an electrode assembly (10) is inserted, with the interior projected.

[0266] The case (20) can be joined to the electrode assembly (10). For example, the case (20) can be soldered to the electrode assembly (10). For example, the bottom surface of the case (20) can be soldered to the electrode assembly (10). For example, the bottom surface of the case (20) and the electrode assembly (10) can be soldered by applying heat to the bottom surface of the case (20). In this case, the heat includes ultrasonic, laser, and / or direct heating methods.

[0267] As described in FIGS. 3 to 13, the electrode assembly (10) may have a first electrode (11) and a second electrode (12) extending in the same direction. For example, the first electrode (11) and the second electrode (12) may extend toward the upper side of the case (20). The lower side of the electrode assembly (10) provides an area that can be joined to the case (20). Accordingly, the case (20) according to one embodiment of the present invention can fix the electrode assembly (10) to the case (20) without a separate beading part.

[0268]

[0269] According to the embodiments of the present invention described above, the space efficiency of a secondary battery can be improved and the resistance of the secondary battery can be reduced. Furthermore, the manufacturing process of the secondary battery can be simplified and the manufacturing cost of the secondary battery can be reduced. In addition, a secondary battery advantageous for battery module and / or battery pack packaging can be provided.

[0270]

[0271] Although the present invention has been described with reference to the embodiments illustrated in the drawings, this is merely illustrative, and those skilled in the art will understand that various modifications and equivalent alternative embodiments are possible therefrom.

[0272] Therefore, the technical scope of protection of the present invention should be determined by the following patent claims.

[0273]

[0274] It can be utilized in industries related to the manufacture of secondary batteries, particularly lithium-ion secondary batteries.

Claims

1. An electrode assembly comprising a first electrode including a first substrate and a second electrode including a second substrate, formed by winding around a core portion; and It includes a case for housing the above electrode assembly, The above-mentioned first material is extended to one side and bent in a first direction, and The above second material is a secondary battery that extends to one side and is bent in a second direction.

2. In Paragraph 1, A secondary battery in which the first direction and the second direction are opposite directions.

3. In Paragraph 1, The first direction above is directed from the core portion toward the outer portion of the electrode assembly, and The above second direction is a secondary battery directed from the outer part toward the core part.

4. In Paragraph 1, The first direction is directed obliquely from the core portion to the outer portion of the electrode assembly, and The above second direction is a secondary battery that is obliquely directed from the outer portion toward the center of the electrode assembly.

5. In claim 1, the electrode assembly is, A first region in which the above-mentioned first description is extended; A second region in which the above-mentioned second description is extended; and A secondary battery comprising a third region located between the first region and the second region.

6. In Paragraph 5, The first region is a region formed within a first distance from the core portion, and A secondary battery, wherein the second region is a region formed within a second distance greater than the first distance from the core portion.

7. In Paragraph 5, The first material comprises a first extension region located in the first region after being wound, and a first cutting region located in the second region or the third region. The second material above comprises a second extension region located in the second region and a second cutting region located in the first region or the third region, wherein the second material above is wound and comprises a second extension region located in the second region and a second cutting region located in the first region or the third region.

8. In Paragraph 7, A secondary battery, wherein the second extension region is formed to be the same length as the first extension region or to be longer than the first extension region.

9. In Paragraph 7, A secondary battery in which at least one of the first extension region and the second extension region is formed in a streamlined shape.

10. In Paragraph 7, A secondary battery in which at least one of the first extension region and the second extension region is formed discontinuously.

11. In Paragraph 7, A secondary battery in which at least one of the first extension region and the second extension region is formed at a constant height.

12. In Paragraph 7, A secondary battery in which at least one of the first extension region and the second extension region has a height that decreases in the direction toward the third region.

13. In Paragraph 12, A secondary battery in which at least one of the first extension region and the second extension region has a continuously decreasing height.

14. In Paragraph 12, A secondary battery in which at least one of the first extension region and the second extension region has a height that decreases with a step.

15. In Paragraph 5, A secondary battery in which the first and second materials are formed at least a portion of the second region at the same height.

16. In Paragraph 1, The above secondary battery further comprises a separator located between the first electrode and the second electrode.

17. In Paragraph 16, A secondary battery in which at least one of the first substrate and the second substrate is formed with a portion having a height less than or equal to the height of the separator.

18. In Paragraph 16, The above separator is a secondary battery formed to a certain height.

19. In claim 1, the secondary battery is, A first terminal electrically connected to the first electrode; A second terminal electrically connected to the second electrode; and A secondary battery further comprising a cap coupled to the opening of the above case.

20. In Paragraph 19, The above cap is a secondary battery comprising an insulating member located between the first terminal and the second terminal.

Images