Secondary battery and secondary battery manufacturing method

Abstract

The present disclosure provides a secondary battery and a secondary battery manufacturing method. The secondary battery according to the present disclosure may comprise: an electrode assembly including a first electrode, a second electrode and a separator disposed between the first electrode and the second electrode; a case which includes a bottom part facing an upper opening and a sidewall part connected to the bottom part, and which accommodates the electrode assembly; and an insulating structure disposed between the bottom part and the electrode assembly and between the sidewall part and the electrode assembly.

Description

Secondary battery and method for manufacturing a secondary battery

[0001] The present disclosure relates to a secondary battery and a method for manufacturing a secondary battery.

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

[0003] Although rechargeable batteries are used in various environments due to their excellent electrical characteristics, conventional small batteries have had limitations in terms of designable energy density. Since the amount of electrical energy that can be stored is limited relative to the size and weight of the battery, there is a gradually increasing demand for large batteries with higher energy density in applications such as electric vehicles.

[0004] 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.

[0005] The problem that the present invention aims to solve is to provide a secondary battery and a method for manufacturing a secondary battery to solve the above technical problem.

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

[0007] A secondary battery according to one embodiment of the present invention for solving the above technical problem may include an electrode assembly comprising a first electrode, a second electrode, and a separator disposed between the first electrode and the second electrode, a bottom portion facing an upper opening, and a side wall portion connected to the bottom portion, and may include an insulating structure disposed between the bottom portion and the electrode assembly and between the side wall portion and the electrode assembly.

[0008] According to one embodiment of the present disclosure, the insulating structure may comprise at least one of polypropylene (PP), polyethylene (PE), or polybutylene terephthalate (PBT).

[0009] According to one embodiment of the present disclosure, the insulating structure may include an insulating ring having a ring shape and arranged along an edge where a side wall portion is connected from a bottom portion, and at least one insulating leg portion extending in a first direction from the insulating ring and arranged between the side wall portion and the electrode assembly.

[0010] According to one embodiment of the present disclosure, the shape of at least one insulating leg portion may be triangular or square.

[0011] According to one embodiment of the present disclosure, the length of at least one insulating leg portion in a first direction may be smaller than the length of the electrode assembly in a first direction.

[0012] According to one embodiment of the present disclosure, the electrode assembly facing the bottom portion further comprises a current collector plate disposed on the lower surface and electrically connected to a first electrode, and an insulating ring may be disposed spaced apart from the current collector plate in a second direction different from the first direction.

[0013] According to one embodiment of the present disclosure, the insulating ring may overlap with the first electrode in a first direction and overlap with the current collector plate in a second direction.

[0014] According to one embodiment of the present disclosure, it may further include a rivet that penetrates the bottom portion from the outside and is coupled to a current collector plate, and an electrode terminal coupled to the rivet and electrically connected to the current collector plate.

[0015] According to one embodiment of the present disclosure, a fire extinguishing patch disposed on at least one insulating leg portion may be further included.

[0016] According to one embodiment of the present disclosure, a fire extinguishing patch comprises a plurality of microcapsules containing a fire extinguishing agent, and when a predetermined temperature is applied to an insulating structure, the fire extinguishing agent may be released from the plurality of microcapsules.

[0017] A secondary battery according to an embodiment of the present invention for solving the above technical problem comprises an electrode assembly including a first electrode, a second electrode, and a separator disposed between the first electrode and the second electrode, a bottom portion facing an upper opening, and a side wall portion connected to the bottom portion, a case in which the electrode assembly is accommodated, and an insulating structure disposed between the bottom portion and the electrode assembly and between the side wall portion and the electrode assembly, wherein the first electrode comprises a first coating portion in which an active material is applied to both sides of a first substrate including a conductive metal material, and a first non-coating portion in which the first substrate is exposed because the active material is not applied, and the first non-coating portion may be disposed on the lower surface of the electrode assembly facing the bottom portion.

[0018] According to one embodiment of the present disclosure, the insulating structure may comprise at least one of polypropylene (PP), polyethylene (PE), or polybutylene terephthalate (PBT).

[0019] According to one embodiment of the present disclosure, the insulating structure may include an insulating ring having a ring shape and disposed along an edge connecting a side wall portion to a bottom portion, and at least one insulating leg portion extending in a first direction from the insulating ring and disposed between the side wall portion and the electrode assembly.

[0020] According to one embodiment of the present disclosure, the shape of at least one insulating leg portion may be triangular or square.

[0021] According to one embodiment of the present disclosure, the length of at least one insulating leg portion in a first direction may be smaller than the length of the electrode assembly in a first direction.

[0022] According to one embodiment of the present disclosure, a first current collector plate is further included, disposed on a first non-contact portion and electrically connected to a first electrode, and an insulating ring may be disposed spaced apart from the first current collector plate in a second direction different from the first direction.

[0023] According to one embodiment of the present disclosure, the second electrode comprises a second coating portion in which an active material is applied to both sides of a second substrate comprising a conductive metal material, and a second non-coating portion in which the second substrate is exposed and the active material is not applied. The second non-coating portion is disposed on the upper surface of an electrode assembly facing an upper opening, and further comprises a second current collector plate disposed on the second non-coating portion and electrically connected to the second electrode, and the second current collector plate may be electrically connected to a side wall portion.

[0024] According to some embodiments of the present disclosure, a short circuit caused by contact between the case of a secondary battery and the positive substrate of an electrode assembly can be prevented, and the process defect rate can be reduced.

[0025] According to some embodiments of the present disclosure, internal damage caused by vibration or shock can be reduced by suppressing the movement of the electrode assembly inside the case.

[0026] According to some embodiments of the present disclosure, a fire extinguishing patch is included inside the secondary battery, thereby allowing a fire that may occur due to internal damage to the secondary battery to be suppressed at an early stage.

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

[0028] 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.

[0029] FIG. 1 is a drawing showing a secondary battery according to some embodiments of the present disclosure.

[0030] FIG. 2 is a drawing showing an insulating structure according to one embodiment of the present disclosure.

[0031] FIG. 3 is a drawing showing an insulating structure according to one embodiment of the present disclosure.

[0032] FIG. 4 is a drawing showing an insulating structure and a fire extinguishing patch according to one embodiment of the present disclosure.

[0033] FIG. 5 is a drawing showing an electrode assembly combined with an insulating structure according to some embodiments of the present disclosure.

[0034] FIG. 6 is a drawing showing an enlarged cross-section of a secondary battery including an electrode assembly combined with an insulating structure according to FIG. 5.

[0035] FIG. 7 is a drawing showing a secondary battery according to some embodiments of the present disclosure.

[0036] FIG. 8 is a flowchart illustrating an example of a method for manufacturing a secondary battery according to some embodiments of the present disclosure.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] Throughout the specification, unless specifically stated otherwise, each component may be singular or plural.

[0043] The statement that any component is positioned on the "upper (or lower) side" or the "upper (or lower) side" of a component implies not only that any component is positioned in contact with the upper (or lower) surface of said component, but also that another component may be interposed between said component and any component positioned on (or below) said component. Additionally, the area between the upper and lower parts of a component depicted in the drawings, or the remaining part excluding the upper and lower parts, may be referred to as a "side" or "lateral side." Furthermore, the direction facing the internal space of the component may be referred to as the "inner side," and the direction protruding into the open external space may be referred to as the "outer side." Such relative terms, such as "upper" and "upper side," may be used to describe the relationship between components depicted in the drawings, and the present disclosure is not limited by such terms.

[0044] 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.

[0045] 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.

[0046] 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” preceding a list of elements modify the entire list of elements and do not modify individual elements of the list.

[0047] 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.

[0048] 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.

[0049] The terms used in this specification are intended to describe embodiments of the present disclosure and are not intended to limit the present disclosure.

[0050] In this specification, the sizes and relative sizes of the layers and regions depicted in the drawings may be exaggerated for clarity of description. That is, the sizes depicted in the drawings are for convenience of understanding only and are not limited thereto. Additionally, throughout this specification, the same reference numerals refer to the same components.

[0051] FIG. 1 is a drawing showing a secondary battery (100) according to some embodiments of the present disclosure. Referring to FIG. 1, a secondary battery (100) according to one embodiment of the present disclosure includes an electrode assembly (110) comprising a first electrode (111), a second electrode (112), and a separator (113) disposed between the first electrode (111) and the second electrode (112). Additionally, the secondary battery (100) may include a bottom portion (120a) facing an upper opening (122) and a side wall portion (120b) connected to the bottom portion (120a), a case (120) in which the electrode assembly (110) is accommodated, and an insulating structure (170) disposed between the bottom portion (120a) and the electrode assembly (110) and between the side wall portion (120b) and the electrode assembly (110). Although not shown, the opening (122) may be combined with a configuration such as a vent cap plate so that the inside of the case (120) can be sealed.

[0052] In one embodiment, the electrode assembly (110) may be formed into a cylindrical jelly roll state with an empty core by winding the first electrode (111), the separator (113), and the second electrode (112). The first electrode (111) may include a first coating portion (111a) in which an active material is applied to both sides of a substrate containing a conductive metal material, and a first uncoated portion (111b) in which the substrate is exposed because no active material is applied to both sides of the substrate. The second electrode (112a, 112b) may include a second coating portion (112a) in which an active material is applied to both sides of a substrate containing a conductive metal material, and a second uncoated portion (112b) in which the substrate is exposed because no active material is applied to both sides of the substrate.

[0053] The first electrode (111) may be an electrode corresponding to the positive or negative electrode in a secondary battery. The second electrode (112) may be an electrode corresponding to the opposite electrode to the first electrode (111). For example, if the first electrode (111) is a positive electrode, the second electrode (112) may be a negative electrode. Conversely, if the first electrode (111) is a negative electrode, the second electrode (112) may be a positive electrode.

[0054] The first electrode (111) may form a positive electrode by coating a positive active material onto an aluminum (Al) or aluminum alloy substrate, and the second electrode (112) may form a negative electrode by coating a negative active material onto a copper (Cu), nickel, or nickel alloy substrate. The first uncoated portion (111b) and the second uncoated portion (112b) are respectively provided at both ends in the winding axis direction of the electrode assembly (110), but electrode terminals (141) and cases (120) having different polarities may be provided together in the same direction. A secondary battery (100) according to some embodiments of the present invention may form a tabless structure through the first uncoated portion (111b) and the second uncoated portion (112b).

[0055] The separator (113) functions to prevent a short circuit between the first electrode (111) and the second electrode (112) while allowing the movement of lithium ions. The separator (113) may be composed of, for example, a polyethylene film, a polypropylene film, a polyethylene-polypropylene film, etc.

[0056] The case (120) may be formed in a cylindrical shape to accommodate the electrode assembly (110). The case (120) may include an opening (122) that is fully open at one end with respect to the first direction (D3) to accommodate the electrode assembly (110), a bottom portion (120a) facing the opening (122), and a side wall portion (120b) connected to the bottom portion (120a). In some embodiments of the present invention, the end where the opening (122) is open is referred to as the top, but is not limited thereto, and the other end facing the end where the bottom portion (120a) is placed may also be referred to as the top. The first non-removable portion (111b) may be placed on the lower surface of the electrode assembly (110) facing the bottom portion (120a). The second non-removable portion (112b) may be placed on the upper surface of the electrode assembly (110) facing the top opening (122). The diameter of the case (120) may be 40 mm to 50 mm.

[0057] In one embodiment, the secondary battery (100) may include a current collector plate (130) that is electrically connected to a first electrode (111) and disposed on the lower surface of an electrode assembly (110) facing a bottom portion (120a), a rivet (143) that penetrates the bottom portion (120a) from the outside of the bottom portion (120a) and is coupled to the current collector plate (130), and an electrode terminal (141) that is coupled to the rivet (143) and is electrically connected to the current collector plate (130).

[0058] The case (120) may have a through hole (121) that is partially open in the bottom portion (120a). An electrode terminal (141) may be installed in the through hole (121) by a rivet structure. To this end, the electrode terminal (141) may be connected to a rivet (143). One end of the rivet (143) is welded to the current collector plate (130) and may be positioned to pass through the through hole (121). The electrode terminal (141) may be connected to the rivet (143) and positioned outside the bottom portion (120a). The electrode terminal (141) may be formed to protrude above the outer surface of the bottom portion (120a) around the through hole (121) and used as an anode terminal.

[0059] In one embodiment, the current collector plate (130) may be electrically connected to the first unoccupied portion (111b) via a rivet (143) and electrically and mechanically connected to the electrode terminal (141). The current collector plate (130) may be electrically connected to the electrode terminal (141) in a structure that reduces resistance by contacting most of the first unoccupied portion (111b). The current collector plate (130) may be an anode current collector plate. The current collector plate (130) may be placed on the first unoccupied portion (111b) of the first electrode (111). The current collector plate (130) may be placed so as not to completely cover the first unoccupied portion (111b). The current collector plate (130) may be composed of a conductive metal, specifically a conductive metal such as nickel, aluminum, copper, silver, zinc, tin, stainless steel (e.g., SUS), or nickel-plated steel or a combination thereof (alloy).

[0060] In one embodiment, the rivet (143) included in the electrode terminal (141) may be installed in a state of electrical insulation from the case (120) while forming a hermetic structure against the electrolyte by placing an insulating member (123) in the through hole (121). The insulating member (123) may be made of a polymer including ethylene propylene rubber (EPDM), polypropylene (PP), polyimide (PI), polyethylene terephthalate (PET), polycarbonate (PC), or a combination thereof. As another example, the insulating member (123) may be made of a ceramic material including epoxy resin, alumina (Al2O3), zirconia (ZrO2), aramid fiber, Nomex, or a combination thereof. However, the material of the insulating member (123) is not limited to the materials listed above and may include various materials with excellent plasticity and insulation properties depending on the choice.

[0061] In one embodiment, the insulating structure (170) may overlap with the first electrode (111) in the first direction (D3) and overlap with the current collector plate (130) in the second direction (D1). The insulating structure (170) may have a ring shape and may include an insulating ring disposed along the edge where the side wall portion (120b) is connected from the bottom portion (120a), and at least one insulating leg portion extending from the insulating ring in the first direction (D3) and disposed between the side wall portion (120b) and the electrode assembly (110). The structure and location of the insulating structure (170) will be described in detail below in FIGS. 2 to 6.

[0062] A secondary battery (100) according to some embodiments of the present disclosure may be applied to automobiles, mobile phones, and / or various types of electric devices, etc., but the present disclosure is not limited thereto. A secondary battery (100) according to some embodiments of the present disclosure is not limited to a cylindrical secondary battery and may include a secondary battery of any shape, such as a prismatic secondary battery, a pouch secondary battery, or a coin secondary battery.

[0063] FIGS. 2 and FIGS. 3 are drawings illustrating an insulating structure (170) according to an embodiment of the present disclosure. Referring to FIG. 2, the insulating structure (170) according to an embodiment of the present disclosure may include an insulating ring (210) having a ring shape and at least one insulating leg portion (220) extending from the insulating ring (210) in a first direction (D3). At least one insulating leg portion (220) may be formed in multiple numbers at regular intervals along the edge of the insulating ring (210). For example, at least one insulating leg portion (220) may be formed in four numbers at regular intervals along the edge of the insulating ring (210).

[0064] In one embodiment, at least one insulating leg (220) may be extended along the first direction (D3) with a reduced width in the second direction (D1). That is, at least one insulating leg (220) may have a tapered shape. In FIGS. 2 and 3, the end shape of at least one insulating leg (220) is shown as a square, but it is not limited thereto and may be configured in various shapes such as a triangle or a polygon. The insulating structure (170) may include at least one of polypropylene (PP), polyethylene (PE), or polybutylene terephthalate (PBT). However, the material of the insulating structure (170) is not limited to the materials listed above and may include a synthetic resin-based material having heat resistance, chemical resistance, etc., depending on the choice.

[0065] Referring to FIG. 3, at least one insulating leg portion (220) according to one embodiment of the present disclosure may be formed at regular intervals in three places along the edge of the insulating ring (210). The description of the other configurations is the same as the description given above with reference to FIG. 2.

[0066] According to some embodiments, the width of at least one insulating leg (220) may vary along the first direction (D3). For example, the width of at least one insulating leg (220) may decrease as it extends upward along the first direction (D3). However, the present disclosure is not limited thereto. For example, the width of at least one insulating leg (220) may be constant along the first direction (D3) or may increase as it extends upward along the first direction (D3).

[0067] FIG. 4 is a drawing showing an insulating structure (170) and a fire extinguishing patch (410) according to one embodiment of the present disclosure. Referring to FIG. 4, the insulating structure (170) according to one embodiment of the present disclosure may further include a fire extinguishing patch (410) disposed on at least one insulating leg portion (220). According to one embodiment, the fire extinguishing patches (410) may be disposed one each at each of the inner edges of the insulating leg portion (220), spaced apart at a certain distance from the center of the insulating leg portion (220) along the first direction (D3). According to another embodiment, the fire extinguishing patches (410) may be disposed on the inner side of the insulating leg portion (220) along the first direction (D3) to have a width corresponding to the width of the insulating leg portion (220). In this case, the number of insulating leg portions (220) and the number of fire extinguishing patches (410) may be the same, but the present disclosure is not limited thereto.

[0068] In one embodiment, the extinguishing patch (410) comprises a plurality of microcapsules (412) containing a extinguishing agent (414), and when a predetermined temperature is applied to the insulating structure (170), the extinguishing agent (414) may be released from the plurality of microcapsules (412). For example, the microcapsules (412) are C, which is a polymer. 10 F 18 It is composed of such that, in the event of a fire, it can quickly melt and extinguish the fire by spraying the fire extinguishing agent (414) contained therein to the outside. For example, the fire extinguishing agent (414) can be sprayed in the direction of the inner side of the secondary battery (100), that is, in the direction where the electrode assembly (110) is placed.

[0069] The fire extinguishing agent (414) may include a fluorine compound-based ketone compound. For example, the fire extinguishing agent (414) may include 55 to 65 weight% of a fluorine compound-based ketone compound, 10 to 20 weight% of 3,5-dimethyl-N-[4-(methylsulfonyl)phenyl]-4-[2-(trifluoromethyl)phenyl]-2-thiophenecarboxamide, and 25 to 35 weight% of pentanone. The chemical formula of the fluorine compound-based ketone compound is C6F 12 It could be O.

[0070] According to some embodiments of the present disclosure, a fire extinguishing patch (410) is placed on an insulating structure (170) so that a fire that may occur due to internal damage to a secondary battery into which the insulating structure (170) can be inserted can be suppressed at an early stage.

[0071] FIG. 5 is a drawing showing an electrode assembly (110) combined with an insulating structure (170) according to some embodiments of the present disclosure. Referring to FIG. 5, an insulating ring (210) of the insulating structure (170) is arranged along the circumference of a current collector plate (130), and at least one insulating leg (220) may be arranged on the side of the electrode assembly (110). In one embodiment, the length of the at least one insulating leg (220) in the first direction (D3) may be smaller than the length of the electrode assembly (110) in the first direction (D3).

[0072] FIG. 6 is a drawing showing an enlarged cross-section of a secondary battery (100) comprising an electrode assembly (110) combined with an insulating structure (170) according to FIG. 5. Referring to FIG. 6, the insulating ring (210) may be spaced apart from the current collector plate (130) in a second direction (D1) different from the first direction (D3). According to another embodiment, the insulating ring (210) may be in contact with the current collector plate (130). According to one embodiment, the insulating ring (210) may be spaced apart from the insulating member (123) in the first direction (D3) and the second direction (D1).

[0073] According to one embodiment, the insulating ring (210) of the insulating structure (170) may be positioned between the bottom portion (120a) and the electrode assembly (110). The insulating ring (210) may be positioned so that its outer end corresponds to the corner where the bottom portion (120a) and the side wall portion (120b) meet. The insulating ring (210) may overlap with the current collector plate (130) and the insulating member (123) in the first direction (D3). The insulating ring (210) may include a portion in which the thickness (i.e., the length in the third direction (D3)) decreases as it moves inward. The portion of the insulating ring (210) having reduced thickness may overlap with the current collector plate (130) in the first direction (D3). That is, the outer portion of the insulating ring (210) may be formed to overlap the current collector plate (130) and the insulating member (123), and the inner portion may be formed to overlap only the current collector plate (130).

[0074] According to one embodiment, the portion protruding inward from the insulating ring (210) may overlap with the first electrode (111) in the D3 direction (D3). In particular, the insulating ring (210) may protrude inward to cover a specific area of ​​the first uninsulated portion (111b). Here, the specific area of ​​the first uninsulated portion (111b) may be an area not covered by the current collector plate (130). Here, the thickness of the portion of the insulating ring (210) protruding inward to cover a specific area of ​​the first uninsulated portion (111b) (i.e., the length in the third direction (D3)) may be less than or equal to the thickness of the current collector plate (130). In another embodiment, the thickness of the portion of the insulating ring (210) protruding inward to cover a specific area of ​​the first uninsulated portion (111b) (i.e., the length in the third direction (D3)) may be greater than the thickness of the current collector plate (130). In this case, the portion of the insulating ring (210) that protrudes inward to cover a specific area of ​​the first uninsulated portion (111b) may be spaced apart from the insulating member (123) in the first direction (D3) and the second direction (D1). The insulating ring (210) can prevent the first uninsulated portion (111b) from being electrically connected (e.g., short-circuited) to the bottom portion (120a) or side wall portion (120b) of the case by covering the area of ​​the first uninsulated portion (111b) that is not covered by the current collector plate (130).

[0075] According to one embodiment, at least one insulating leg (220) may be disposed between the sidewall (120b) and the electrode assembly (110). At least one insulating leg (220) may be formed by extending along a third direction (D3) from the insulating ring (210). The length of the at least one insulating leg (220) along the first direction (D1) may be shorter than the length of the insulating ring (210) along the first direction (D1). At least one insulating leg (220) may have the same thickness along the third direction (D3) (i.e., the length in the first direction (D1)).

[0076] According to one embodiment, the insulating ring (210) of the insulating structure (170) is positioned between the bottom portion (120a) and the electrode assembly (110), and at least one insulating leg portion (220) of the insulating structure (170) is positioned between the side wall portion (120b) and the electrode assembly (110), thereby maintaining a separation between the case (120) of the secondary battery (100) and the first electrode (111). Accordingly, a short circuit caused by contact between the case (120) and the first electrode (111) can be prevented, and the process defect rate can be reduced. In addition, the movement of the electrode assembly (110) inside the case (120) is suppressed by the insulating structure (170), thereby preventing internal damage caused by vibration or shock.

[0077] FIG. 7 is a drawing showing a secondary battery (700) according to some embodiments of the present disclosure. Hereinafter, some components of the secondary battery (700) shown in FIG. 7 may correspond to some components of the secondary battery (100) shown in FIG. 1. Referring to FIG. 7, a secondary battery (700) according to some embodiments of the present disclosure comprises an electrode assembly (710) comprising a first electrode (711), a second electrode (712), and a separator (713) disposed between the first electrode (711) and the second electrode (712); a case (720) in which the electrode assembly (710) is accommodated, comprising a bottom portion (720a) facing an upper opening (722) and a side wall portion (720b) ​​connected to the bottom portion (720a); and an insulating structure (770) disposed between the bottom portion (720a) and the electrode assembly (710) and between the side wall portion (720b) ​​and the electrode assembly (710). The first electrode (711) comprises a first coating portion (711a) on which an active material is applied to both sides of a first substrate comprising a conductive metal material, and a first portion on which the active material is not applied and the first substrate is exposed. It includes a non-existent portion (711b), and the first non-existent portion (711a) may be disposed on the lower surface of the electrode assembly (710) facing the bottom portion (720a). Additionally, the second electrode (712) includes a second coating portion (712a) on which an active material is applied to both sides of a second substrate containing a conductive metal material, and a second non-existent portion (712b) on which the second substrate is exposed as no active material is applied, and the second non-existent portion (712a) may be disposed on the upper surface of the electrode assembly (710) facing the upper opening (122).

[0078] A secondary battery (700) according to some embodiments of the present disclosure may further include an electrode terminal (741), a rivet (743), a vent cap plate (742), and a gasket (760). In FIG. 7, the vent cap plate (742) is shown positioned on the upper part of the secondary battery (700) and the electrode terminal (741) is shown positioned on the lower part of the secondary battery (700), but this is not limited thereto. Depending on the usage environment or requirements of the secondary battery (700), the vent cap plate (742) and the electrode terminal (741) may be changed to be positioned on the lower part and the upper part of the secondary battery, respectively. These configurations will be described in detail below.

[0079] The electrode assembly (710) can be formed into a cylindrical jelly roll state with an empty core by winding the first electrode (711), the separator (713), and the second electrode (712). A secondary battery (700) according to some embodiments of the present invention can form a tabless structure through the first blank portion (711b) and the second blank portion (712b). In one embodiment, the electrode assembly (710), the first electrode (711), the separator (713), and the second electrode (712) may refer to the same configuration as the electrode assembly (110), the first electrode (111), the separator (113), and the second electrode (112) disclosed in FIG. 1.

[0080] The first electrode (711) may be an electrode corresponding to the positive or negative electrode in a secondary battery. The second electrode (712) may be an electrode corresponding to the opposite electrode to the first electrode (711). For example, if the first electrode (711) is a positive electrode, the second electrode (712) may be a negative electrode. Conversely, if the first electrode (711) is a negative electrode, the second electrode (712) may be a positive electrode.

[0081] The first electrode (711) may form a positive electrode by coating a positive active material onto an aluminum (Al) or aluminum alloy substrate, and the second electrode (712) may form a negative electrode by coating a negative active material onto a copper (Cu), nickel, or nickel alloy substrate. The first uncoated portion (711b) and the second uncoated portion (712b) are respectively provided at both ends in the winding axis direction of the electrode assembly (710), but electrode terminals (741) and cases (720) having different polarities may be provided together in the same direction. A vent cap plate (742) may be located on the opposite side of the electrode terminal (741).

[0082] The separator (713) functions to prevent a short circuit between the first electrode (711) and the second electrode (712) while allowing the movement of lithium ions. The separator (713) may be composed of, for example, a polyethylene film, a polypropylene film, a polyethylene-polypropylene film, etc.

[0083] The case (720) may be formed in a cylindrical shape to accommodate the electrode assembly (710). The case (720) may include an opening (722) that is fully open at one end with respect to the first direction (D3) to accommodate the electrode assembly (710), a bottom portion (720a) facing the opening (722), and a side wall portion (720b) ​​connected to the bottom portion (720a). In some embodiments of the present invention, the end where the opening (722) is open is referred to as the top, but is not limited thereto, and the bottom portion (120a) may also be referred to as the top. The electrode terminal (741) and the vent cap plate (742) may be provided at the bottom portion (720a) and the opening (722), respectively, so as to face each other. In one embodiment, the diameter of the case (720) may be 40 mm to 50 mm. In one embodiment, the case (720) may refer to the same configuration as the case (120) disclosed in FIG. 1.

[0084] A secondary battery (700) according to some embodiments of the present disclosure may further include a first current collector plate (730) disposed on a first non-removable portion (711b) and electrically connected to a first electrode (711), and may further include a second current collector plate (750) disposed on a second non-removable portion (712b) and electrically connected to a second electrode (712). In one embodiment, the first current collector plate (730) may refer to the same configuration as the current collector plate (130) disclosed in FIG. 1.

[0085] In one embodiment, the electrode terminal (741) is connected to the first electrode (711) via the first current collector plate (730) through a rivet (743), and the case (720) can be connected to the second electrode (712) via the second current collector plate (750). At this time, the vent cap plate (742) may be electrically separated from the second current collector plate (750) and the case (720) and may not have polarity.

[0086] In one embodiment, an electrode terminal (741) connected to a first electrode (711) of an electrode assembly (710) inserted into a case (720) from the outside of a secondary battery (700) may be installed on the bottom portion (720a) of the case (720). The case (720) may have a through hole (721) partially open in the bottom portion (720a).

[0087] In one embodiment, the electrode terminal (741) may be installed in a through hole (721) in a rivet structure. To this end, the electrode terminal (741) may be connected to a rivet (743). One end of the rivet (743) is welded to the first current collector plate (730) and may be positioned to pass through the through hole (721). The electrode terminal (741) may be connected to the rivet (743) and positioned outside the bottom portion (720a). The electrode terminal (741) may be formed to protrude above the outer surface of the bottom portion (720a) around the through hole (721) and used as an anode terminal. At this time, the first current collector plate (730) may be an anode current collector plate. In one embodiment, the electrode terminal (741), rivet (743), and through hole (721) may refer to the same configuration as the electrode terminal (141), rivet (143), and through hole (121) disclosed in FIG. 1.

[0088] The first current collector plate (730) can be electrically connected to the first non-removable portion (711b) via a rivet (743) and electrically and mechanically connected to the electrode terminal (741). The first current collector plate (730) can be electrically connected to the electrode terminal (741) in a structure that reduces resistance by contacting most of the area of ​​the first non-removable portion (711b). The first current collector plate (730) may be an anode current collector plate. The first current collector plate (730) may be positioned so as not to completely cover the first non-removable portion (711b).

[0089] In one embodiment, the rivet (743) included in the electrode terminal (741) may be installed in a state of electrical insulation from the case (720) while forming a hermetic structure against the electrolyte by placing an insulating member (723) in the through hole (721). The insulating member (723) may be made of a polymer including ethylene propylene rubber (EPDM), polypropylene (PP), polyimide (PI), polyethylene terephthalate (PET), polycarbonate (PC), or a combination thereof. As another example, the insulating member (723) may be made of a ceramic material including epoxy resin, alumina (Al2O3), zirconia (ZrO2), aramid fiber, Nomex, or a combination thereof. However, the material of the insulating member (723) is not limited to the materials listed above and may include various materials with excellent plasticity and insulation properties depending on the choice.

[0090] In one embodiment, the first current collector plate (730) may include a metal plate (731) comprising at least one bridge (732). For example, the first current collector plate (730) may be composed of a conductive metal, specifically a conductive metal such as nickel, aluminum, copper, silver, zinc, tin, stainless steel (e.g., SUS), or nickel-plated steel or a combination thereof (alloy). Additionally, the metal plate (731) and the bridge (732) constituting the first current collector plate (730) may all be made of the same material to form a single unit.

[0091] The bridge (732) of the first collector plate (730) can be configured to break when a current exceeding a set value flows. For example, the bridge (732) normally operates as part of a circuit through which current flows, but when a current exceeding the necessary amount flows, it can act as a fuse that melts due to the heat generated to cut off the circuit.

[0092] In one embodiment, the vent cap plate (742) seals the opening (722) after inserting the electrode assembly (710) into the case (720) and can be electrically separated from the case (720). At this time, the second current collector plate (750) can be electrically connected to the second non-electrical portion (712b) and electrically connected to the side wall portion (720b) ​​of the case (720). The second current collector plate (750) can be connected to the case (720) in a structure that reduces resistance by contacting most of the area of ​​the second non-electrical portion (712b).

[0093] The second current collector plate (750) may include a flat portion (751) welded to the second non-flat portion (712b) and a wing portion (752) formed adjacent to the flat portion (751) and welded to the beading portion (729). The second current collector plate (750) is formed by cutting and bending a circular plate, and may have a plurality of flat portions (751) and wing portions (752), respectively, and may be arranged alternately along the circumferential direction. In one embodiment, the wing portion (752) may repeatedly form an axial (upward) bend and a radial (outer) bend of the electrode assembly (710).

[0094] In one embodiment, when the second non-removable portion (712b) and the flat portion (751) of the second current collector plate (750) are welded, the flat portion (751) can form a weld line in the diameter direction of the second current collector plate (750). Thus, the flat portion (751) can be evenly connected along the circumferential direction in the area of ​​the second non-removable portion (712b), and the wing portion (752) can be evenly connected along the circumferential direction in the area of ​​the beading portion (729). This enables a uniform current flow along the circumferential direction in the entire area of ​​the beading portion (729) of the case (720) from the second non-removable portion (712b).

[0095] The second collector plate (750) is provided with a hole (753) in the center, so it can absorb and mitigate deformation caused by welding between the flat portion (751) and the second non-flat portion (712b), as well as vibrations and shocks that may be transmitted between the wing portion (752) and the flat portion (751). The hole (753) may have a size within a range that can absorb vibrations and shocks without increasing current resistance between the wing portion (752) and the flat portion (751).

[0096] The vent cap plate (742) can be electrically separated from the second current collector plate (750) and installed in the opening (722) of the case (720) by a crimping process. Alternatively, the vent cap plate (742) can be installed in the opening (722) of the case (720) through a welding process. Due to the connection of the second current collector plate (750), the case (720) can be used as a negative terminal. Specifically, the second current collector plate (750) can be electrically connected to the side wall portion (720b) ​​of the case (720). At this time, the second current collector plate (750) may be a negative current collector plate.

[0097] The vent cap plate (742) may have a notch (744) formed on its inner surface. The notch (744) can be cut open in the event of an abnormal event in the secondary battery to release the internal pressure of the secondary battery (700) to the outside, thereby preventing a secondary explosion. Specifically, the notch (744) is designed to be easily cut open by receiving concentrated internal pressure during an abnormal event. The notch (744) may be formed over the entire area along the circumferential direction of the vent cap plate (742), or it may be formed in multiple locations spaced apart at set intervals.

[0098] The gasket (760) is interposed between the second current collector plate (750) and the vent cap plate (742) and between the second current collector plate (750) and the case (720), and can act as a seal through a beading portion (729) or a clamping process. Additionally, the gasket (760) can form an airtight structure against the electrolyte between the second current collector plate (750) and the opening (722) of the case (720). For example, the gasket (760) may include polymeric materials such as polyvinyl chloride (PVC), polytetrafluoroethylene (PTFE or Teflon), polyethylene (PE), epoxy resin, silicone, polyvinylidene fluoride (PVDF), polypropylene (PP), polyacrylonitrile (PAN), or polyethylene oxide (PEO), or ceramics, but is not limited thereto, and may be any one of the suitable compounds used as insulating materials in the industry.

[0099] In one embodiment, the insulating structure (770) may overlap with the first electrode (711) in the first direction (D3) and overlap with the first current collector plate (730) in the second direction (D1). Since the insulating structure (770) refers to the same configuration as the insulating structure (170) disclosed in FIGS. 1 to 6 described above, a detailed description thereof is omitted.

[0100] A secondary battery (700) according to some embodiments of the present disclosure may be applied to automobiles, mobile phones, and / or various types of electric devices, etc., but the present disclosure is not limited thereto. The secondary battery (700) of the present disclosure is not limited to a cylindrical secondary battery and may include a secondary battery of any shape, such as a prismatic secondary battery, a pouch secondary battery, or a coin secondary battery.

[0101] FIG. 8 is a flowchart illustrating an example of a method for manufacturing a secondary battery according to some embodiments of the present disclosure. A method for manufacturing a secondary battery (800) according to one embodiment of the present invention may be disclosed by the step (S810) of coupling a first current collector plate onto a first electrode of an electrode assembly comprising a first electrode, a second electrode, and a separator disposed between the first electrode and the second electrode, and coupling a second current collector plate onto a second electrode.

[0102] For example, referring to FIG. 7, the first current collector plate (730) may be coupled to the first non-circular portion (711b) of the first electrode (711), and the second current collector plate (750) may be coupled to the second non-circular portion (712b) of the second electrode (712).

[0103] Additionally, the step of combining an insulating structure with an electrode assembly in which a first current collector plate and a second current collector plate are combined (S820) and the step of inserting the electrode assembly in which the first current collector plate, the second current collector plate, and the insulating structure are combined into a case with one end open (S830) may be performed.

[0104] For example, referring to FIGS. 2 and FIGS. 7, the insulating structure (770) may have a ring shape and may include an insulating ring (210) disposed along the edge connecting the bottom portion (720a) to the side wall portion (720b), and at least one insulating leg portion (220) extending from the insulating ring (210) in a first direction (D3) and disposed between the side wall portion (720b) ​​and the electrode assembly (710). The insulating structure (770) may overlap with the first electrode (711) in the first direction (D3) and overlap with the first current collector plate (730) in the second direction (D1). The insulating ring (210) may be disposed spaced apart from the first current collector plate (730) in a second direction (D1) different from the first direction (D3).

[0105] After that, the step of attaching an electrode terminal to the other end opposite to one end of the case (S840) and the step of attaching a vent cap plate after beading the open end of the case (S850) can be performed.

[0106] For example, referring to FIG. 7, the open end of the case may refer to the portion where the opening (722) is formed. The electrode terminal (741) may be connected to the first current collector plate (730) via a rivet (743) and electrically connected to the first electrode (711). A beading portion (729) may be formed by beading the open end of the case.

[0107] The secondary battery manufactured by the method described above may be a secondary battery having the same configuration as the secondary battery (100, 700) described with reference to FIG. 1 or FIG. 7, for example.

[0108] Although the present invention has been described above by means of 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 spirit of the present invention and the equivalent scope of the claims described below by those skilled in the art to which the present invention belongs. Since various substitutions, modifications, and changes are possible within the scope of the technical spirit of the present invention without departing from it, by those skilled in the art to which the present invention belongs, the present invention is not limited by the aforementioned embodiments and attached drawings.

Claims

1. An electrode assembly comprising a first electrode, a second electrode, and a separator disposed between the first electrode and the second electrode; A case comprising a bottom portion facing an upper opening and a side wall portion connected to said bottom portion, wherein the electrode assembly is accommodated; and An insulating structure disposed between the bottom portion and the electrode assembly and between the side wall portion and the electrode assembly A secondary battery including 2. In Paragraph 1, The above insulating structure is, A secondary battery comprising at least one of polypropylene (PP), polyethylene (PE), or polybutylene terephthalate (PBT).

3. In Paragraph 1, The above insulating structure is, An insulating ring having a ring shape and disposed along the edge connecting the side wall portion to the bottom portion; and A secondary battery comprising at least one insulating leg portion extending in a first direction from the insulating ring and disposed between the sidewall portion and the electrode assembly.

4. In Paragraph 3, The above-mentioned at least one insulating leg portion extends along the first direction with a width that decreases in a second direction different from the first direction, a secondary battery.

5. In Paragraph 3, A secondary battery in which the length of at least one insulating leg portion in the first direction is smaller than the length of the electrode assembly in the first direction.

6. In Paragraph 3, It further includes a current collector plate disposed on the lower surface of the electrode assembly facing the bottom portion and electrically connected to the first electrode, and A secondary battery in which the insulating ring is spaced apart from the current collector plate in a second direction different from the first direction.

7. In Paragraph 6, A secondary battery in which the insulating ring overlaps with the first electrode in the first direction and overlaps with the current collector plate in the second direction.

8. In Paragraph 6, A rivet penetrating the bottom portion from the outside of the bottom portion and coupled to the current collector plate; and A secondary battery further comprising an electrode terminal coupled to the above rivet and electrically connected to the above current collector plate.

9. In Paragraph 3, A secondary battery further comprising a fire extinguishing patch disposed on at least one insulating leg portion.

10. In Paragraph 9, The above digestive patch is, It includes a plurality of microcapsules containing digestive agents, and A secondary battery in which the extinguishing agent is released from the plurality of microcapsules when a predetermined temperature is applied to the insulating structure.

11. An electrode assembly comprising a first electrode, a second electrode, and a separator disposed between the first electrode and the second electrode; A case comprising a bottom portion facing an upper opening and a side wall portion connected to said bottom portion, wherein the electrode assembly is accommodated; and An insulating structure disposed between the bottom portion and the electrode assembly and between the side wall portion and the electrode assembly Includes, The first electrode above is, A first coating portion having an active material applied to both sides of a first substrate comprising a conductive metal material; and A first uncoated portion where the first substrate is exposed because the above active material is not coated. Includes, A secondary battery in which the first non-removable portion is disposed on the lower surface of the electrode assembly facing the bottom portion.

12. In Paragraph 11, The above insulating structure is, A secondary battery comprising at least one of polypropylene (PP), polyethylene (PE), or polybutylene terephthalate (PBT).

13. In Paragraph 11, The above insulating structure is, An insulating ring having a ring shape and disposed along the edge connecting the side wall portion to the bottom portion; and A secondary battery comprising at least one insulating leg portion extending in a first direction from the insulating ring and disposed between the sidewall portion and the electrode assembly.

14. In Paragraph 13, The above-mentioned at least one insulating leg portion extends along the first direction with a width that decreases in a second direction different from the first direction, a secondary battery.

15. In Paragraph 13, A secondary battery in which the length of at least one insulating leg portion in the first direction is smaller than the length of the electrode assembly in the first direction.

16. In Paragraph 13, It further includes a first current collector plate disposed on the first non-removable portion and electrically connected to the first electrode, and The above insulating ring is arranged spaced apart from the first current collector plate in a second direction different from the first direction, in a secondary battery.

17. In Paragraph 16, A secondary battery in which the insulating ring overlaps with the first electrode in the first direction and overlaps with the first current collector plate in the second direction.

18. In Paragraph 13, A secondary battery further comprising a fire extinguishing patch disposed on at least one insulating leg portion.

19. In Paragraph 18, The above digestive patch is, It includes a plurality of microcapsules containing digestive agents, and A secondary battery in which the extinguishing agent is released from the plurality of microcapsules when a predetermined temperature is applied to the insulating structure.

20. In Paragraph 11, The second electrode above is, A second coating portion having an active material applied to both sides of a second substrate comprising a conductive metal material; and A second uncoated portion where the second substrate is exposed because the above active material is not coated. Includes, The above second non-removable portion is disposed on the upper surface of the electrode assembly facing the upper opening, and It further includes a second current collector plate disposed on the second non-removable portion and electrically connected to the second electrode, and The above second current collector plate is electrically connected to the above side wall portion, a secondary battery.

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