Secondary battery including unidirectional terminals and method for manufacturing secondary battery

Abstract

The present disclosure relates to a secondary battery and a method for manufacturing the secondary battery. The secondary battery according to the present disclosure comprises: an electrode assembly in which a first electrode, a separator, and a second electrode are sequentially stacked and wound together; a case in which the electrode assembly is stored; a first current collector plate electrically connected to the first electrode; a second current collector plate electrically connected to the second electrode; a first terminal electrically connected to the first current collector plate; and a second terminal electrically connected to the second current collector plate, wherein the first terminal and the second terminal may pass through one surface of the case in the same direction.

Description

Secondary battery including unidirectional terminal and method for manufacturing the secondary battery

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

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

[0003] Secondary batteries are used in a variety of environments due to their excellent electrical properties. However, existing small batteries have been limited in their design energy density. Because the amount of electrical energy they can store is limited relative to their size and weight, demand for larger batteries with higher energy densities is steadily increasing in applications such as electric vehicles.

[0004] The problem to be solved by the present invention is to provide a secondary battery and a method for manufacturing a secondary battery for solving the above technical problem.

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

[0006] According to one embodiment of the present invention for solving a technical problem, a secondary battery includes an electrode assembly in which a first electrode, a separator, and a second electrode are sequentially stacked and wound, a case in which the electrode assembly is accommodated, a first collector plate electrically connected to the first electrode, a second collector plate electrically connected to the second electrode, a first terminal electrically connected to the first collector plate, and a second terminal electrically connected to the second collector plate, wherein the first terminal and the second terminal can penetrate one surface of the case in the same direction.

[0007] A secondary battery according to one embodiment of the present invention may further include a first insulator disposed between the first terminal and the case.

[0008] A secondary battery according to one embodiment of the present invention may further include a second insulator disposed between the second terminal and the case.

[0009] A secondary battery according to one embodiment of the present invention may further include a third insulator disposed between at least one of the first collector plate or the second collector plate and the case.

[0010] According to one embodiment, the case may include a cylindrical can having an opening through which a first terminal and a second terminal pass through a first surface and into which an electrode assembly is inserted in a second surface opposite the first surface, and a lower plate sealing the opening of the cylindrical can.

[0011] According to one embodiment, the case may include a cylindrical can into which an electrode assembly is inserted through an opening formed on one surface thereof, and a top plate through which a first terminal and a second terminal pass, and which seals the opening of the cylindrical can.

[0012] In one embodiment, the first terminal and the second terminal may be spaced apart from each other by a distance of 5 mm to 40 mm.

[0013] According to one embodiment, the first collector plate may be electrically connected to a first substrate tab included in the first electrode.

[0014] In one embodiment, the second collector plate may be electrically connected to a second substrate tab included in the second electrode.

[0015] In one embodiment, the first collector plate and the second collector plate may be arranged to be connected to the same side of the electrode assembly.

[0016] According to one embodiment, at least one of the first terminal or the second terminal may have a circular cross-section.

[0017] According to one embodiment, at least one of the first terminal or the second terminal may have a cross-section that is rectangular.

[0018] In one embodiment, the diameter of the case may be 40 mm to 50 mm.

[0019] A method for manufacturing a secondary battery according to one embodiment of the present invention may include a step of manufacturing an electrode assembly by sequentially stacking and winding a first electrode, a separator, and a second electrode, a step of connecting the first electrode to a first collector plate and a step of connecting the second electrode to a second collector plate, a step of inserting the electrode assembly into a case, and a step of arranging a first terminal electrically connected to the first collector plate and a second terminal electrically connected to the second collector plate so as to penetrate one surface of the case in the same direction.

[0020] According to one embodiment, the step of connecting the first electrode to the first collector plate and the step of connecting the second electrode to the second collector plate may include the steps of connecting the first substrate tab included in the first electrode and the first collector plate and connecting the second substrate tab included in the second electrode and the second collector plate.

[0021] According to one embodiment, the method may further include a step of welding the first collector plate and the first terminal or the second collector plate and the second terminal, respectively.

[0022] According to one embodiment, the method may further include the step of placing a first insulator between the first terminal and the case, and placing a second insulator between the second terminal and the case.

[0023] According to one embodiment, the case includes a cylindrical can having an opening through which a first terminal and a second terminal pass in a first surface and into which an electrode assembly is inserted in a second surface opposite the first surface, and a lower plate sealing the opening of the cylindrical can, and the manufacturing method may further include a step of welding the cylindrical can and the lower plate.

[0024] According to one embodiment, the case includes a cylindrical can into which an electrode assembly is inserted through an opening formed on one surface thereof, and a top plate through which a first terminal and a second terminal pass and which seals the opening of the cylindrical can, and the manufacturing method may further include a step of welding the can and the top plate.

[0025] According to some embodiments of the present disclosure, the positive and negative terminals of a secondary battery can be arranged in the same direction to reduce the path of current emitted from a current collector and concentrate the flow of current at each terminal.

[0026] According to some embodiments of the present disclosure, the positive and negative terminals of a secondary battery can be arranged in the same direction to reduce the internal resistance of the secondary battery, minimize energy loss, and maximize the efficiency of power management.

[0027] According to some embodiments of the present disclosure, the positive terminal and negative terminal of a secondary battery can be arranged in the same direction to reduce the number of plates requiring welding to one, and minimize unnecessary current leakage or welding defects.

[0028] However, the effects that can be obtained through the present invention are not limited to the effects described above, and other technical effects not mentioned can be clearly understood by those skilled in the art from the description of the invention described below.

[0029] The following drawings attached to this specification illustrate preferred embodiments of the present invention, and together with the detailed description of the invention described below, serve to further understand the technical idea of ​​the present invention, and therefore, the present invention should not be interpreted as being limited to matters described in such drawings.

[0030] FIG. 1 is a plan view showing a secondary battery according to one embodiment of the present disclosure.

[0031] FIG. 2 is a schematic drawing illustrating a cross-section of an upper portion of a secondary battery according to one embodiment of the present disclosure.

[0032] FIG. 3 is a cross-sectional view showing the appearance of a secondary battery before and after electrode rivets are joined according to one embodiment of the present disclosure.

[0033] FIG. 4 is a schematic drawing illustrating a cross-section of a secondary battery according to one embodiment of the present disclosure.

[0034] FIG. 5 is a schematic drawing illustrating a cross-section of a secondary battery according to one embodiment of the present disclosure.

[0035] FIG. 6 is a plan view showing a secondary battery according to one embodiment of the present disclosure.

[0036] Figure 7 is a cross-sectional view of a secondary battery according to one embodiment of the present disclosure.

[0037] Figure 8 is a flowchart showing an example of a method for manufacturing a secondary battery according to the present disclosure.

[0038] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Prior to this, terms or words used in this specification and claims should not be interpreted as limited to their typical or dictionary meanings, and should be interpreted with meanings and concepts that conform to the technical spirit of the present invention based on the principle that the inventor can appropriately define the concept of a term to best explain his or her own invention. Therefore, the embodiments described in this specification and the configurations illustrated in the drawings are only some of the most preferred embodiments of the present invention and do not represent all of the technical spirit of the present invention. Therefore, it should be understood that various equivalents and modified examples may exist as substitutes for them at the time of filing this application.

[0039] Additionally, when used herein, the terms "comprise", "include" and / or "comprising", "including" specify the presence of stated features, numbers, steps, operations, elements, elements and / or groups thereof, but do not preclude the presence or addition of one or more other features, numbers, operations, elements, elements and / or groups thereof.

[0040] Additionally, to facilitate understanding of the invention, the attached drawings may not be drawn to scale and some components may be exaggerated in size. Furthermore, identical components may be assigned the same reference numbers in different embodiments.

[0041] The statement that two compared objects are "identical" means "substantially identical." Therefore, "substantially identical" may include deviations considered low in the art, such as deviations of less than 5%. Furthermore, uniformity of a parameter over a given region may also mean uniformity on average.

[0042] Although terms like "first" and "second" are used to describe various components, these components are not limited by these terms. These terms are used merely to distinguish one component from another, and unless otherwise specified, a "first" component may also be a "second" component.

[0043] Throughout the specification, unless otherwise specifically stated, each element may be singular or plural.

[0044] Any configuration being arranged "on the top (or bottom)" of a component or "on the upper (or lower) side" of a component may mean not only that any configuration is arranged in contact with the upper surface (or lower surface) of the component, but also that another configuration may be interposed between the component and any configuration arranged on (or under) the component. In addition, in the drawings, the portion between the upper and lower portions of the components depicted or the remaining portion excluding the upper and lower portions may be referred to as a "side" or a "side surface." Additionally, the direction toward the internal space of the component may be referred to as "inner," and the direction protruding into the open external space may be referred to as "outer." Relative terms such as "upper," "top," etc. may be used to describe the relationship between the configurations depicted in the drawings, and the present disclosure is not limited by such terms.

[0045] For ease of description, spatially relative terms such as "beneath," "below," "lower," "above," "upper," and the like may be used herein to describe the relationship of one element or feature to another element(s) or feature(s) as depicted in the drawings. It will be understood that spatially relative positions encompass 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 drawings is turned over, an element described as "beneath" or "lower" another element would be understood to be "above" or "upper" the other element. Thus, the term "beneath" can encompass both the above and below orientations.

[0046] Additionally, when a component is described as being "on," "connected to," or "coupled to" another component, it should be understood that the components may be directly connected or coupled to one another, but that other components may also be "interposed" between the components, or that each component may be "connected," "coupled," or "connected" through other components.

[0047] As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items. Furthermore, the use of "may" when describing embodiments of the present disclosure refers to "one or more embodiments of the present disclosure." The use of phrases such as "one or more" before a list of elements modifies the list as a whole and does not modify individual elements in the list.

[0048] When reference is made throughout the specification to “A and / or B,” this means A, B, or A and B, unless otherwise stated, and when reference is made to “C through D,” this means C or more and D or less, unless otherwise stated.

[0049] Although terms such as first, second, third, etc. may be used herein to describe various elements, components, regions, layers, and / or sections, 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. Thus, a first element, component, region, layer, or section discussed below could also be termed a second element, component, region, layer, or section without departing from the teachings of the exemplary embodiments.

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

[0051] FIG. 1 is a plan view showing a secondary battery according to one embodiment of the present disclosure. FIG. 1 is a plan view showing a configuration of one side in which two electrode terminals are arranged, for example, in a cylindrical secondary battery. Referring to FIG. 1, a secondary battery (100) according to one embodiment of the present invention includes a case (110) in which an electrode assembly configured by stacking a first electrode plate, a separator, and a second electrode plate is accommodated, a first terminal (132) and a second terminal (134) electrically connected to the first electrode plate and the second electrode plate, respectively, and the first terminal (132) and the second terminal (134) can penetrate one surface of the case (110) in the same direction (e.g., in the direction from the electrode assembly accommodated inside the case (110) toward the outside of the case (110).

[0052] The second terminal (134) may be an electrode terminal corresponding to a polarity opposite to that of the first terminal (132). For example, if the first terminal (132) is a positive terminal, the second terminal (134) may be a negative terminal. Conversely, if the first terminal (132) is a negative terminal, the second terminal (134) may be a positive terminal.

[0053] In one embodiment, one side of the case (110) on which the first terminal (132) and the second terminal (134) are formed may include a can (112) (e.g., a side on which the opening of the can (112) is formed) and an upper plate (114) coupled to seal the opening of the can (112). This will be described later in FIG. 5.

[0054] The case (110) forms the overall appearance of the secondary battery and may be formed of a conductive metal such as aluminum, aluminum alloy, stainless steel (e.g., SUS), or nickel-plated steel, or a polymer. In addition, the case (110) may provide a space in which an electrode assembly including a jelly roll and a substrate tab is stored. An insulating coating material may be applied to a certain thickness on the outer or inner surface of the case (110). For the purpose of explaining the invention, the case (110) is illustrated in FIG. 1 as a cylindrical battery, but the scope of the present disclosure is not limited thereto, and includes secondary batteries of any shape, such as a square battery and a pouch battery.

[0055] The case (110) may be manufactured in a shape corresponding to the electrode assembly to accommodate it. For example, if the electrode assembly is rolled into a cylindrical shape, the case (110) may have a cylindrical shape. In this case, the case (110) may be manufactured to have a diameter corresponding to the diameter of the electrode assembly to accommodate the electrode assembly. In one embodiment, the electrode assembly is rolled into a cylindrical shape with a diameter of 40 mm to 50 mm, and similarly, the diameter of the case (110) may be 40 mm to 50 mm.

[0056] The secondary battery (100) may further include a first insulator (142) disposed between the first terminal (132) and the case (110). In addition, the secondary battery (100) may further include a second insulator (144) disposed between the second terminal (134) and the case (110). The first insulator (142) or the second insulator (144) may be made of an insulating material having high heat resistance to electrically insulate the first terminal (132) and the case (110) or the second terminal (134) and the case (110).

[0057] For example, the first insulator (142) or the second insulator (144) may be made of a polymer insulator including ethylene propylene rubber (EPDM), polypropylene (PP), polyimide (PI), polyethylene terephthalate (PET), polycarbonate (PC), or a combination thereof.

[0058] As another example, the first insulator (142) or the second insulator (144) may be made of a ceramic insulator including alumina (Al2O3), zirconia (ZrO2), aramid fiber, Nomex, epoxy resin, or a combination thereof. The first insulator (142) or the second insulator (144) is not limited to the materials listed above, and may include various materials with excellent durability and electrical insulation properties, depending on the selection of a person skilled in the art.

[0059] The shapes of the first terminal (132) and the second terminal (134) are not limited. According to one embodiment, the cross-section of at least one of the first terminal (132) or the second terminal (134) may be circular. Specifically, the upper surface of at least one of the first terminal (132) or the second terminal (134) exposed to the outside on one side of the secondary battery (100) may be circular. Various shapes of the first terminal (132) and the second terminal (134) will be described later with reference to FIG. 6.

[0060] According to some embodiments of the present disclosure, the first terminal (132) and the second terminal (134) of the secondary battery (100) are arranged in the same direction on one side of the case (110) of the secondary battery (100), thereby reducing the path of current emitted from the current collector and concentrating the flow of current on each terminal.

[0061] FIG. 2 is a schematic drawing illustrating a cross-section of an upper portion of a secondary battery according to one embodiment of the present disclosure.

[0062] Referring to FIG. 2, a secondary battery according to one embodiment of the present invention may include an electrode assembly (200) in which a first electrode, a separator, and a second electrode are sequentially stacked and wound, a case (210) in which the electrode assembly is housed, a first collector plate (252) electrically connected to the first electrode, a second collector plate (254) electrically connected to the second electrode, a first terminal (232) electrically connected to the first collector plate (252), and a second terminal (234) electrically connected to the second collector plate (254).

[0063] The first electrode, separator, and second electrode may be impregnated with an electrolyte (not shown). The first electrode may be an electrode corresponding to a positive or negative electrode in a secondary battery. The second electrode may be an electrode corresponding to a polarity opposite to the first electrode. For example, if the first electrode is a positive electrode, the second electrode may be a negative electrode. Conversely, if the first electrode is a negative electrode, the second electrode may be a positive electrode.

[0064] The first terminal (232) and the second terminal (234) may penetrate one side of the case (210) in the same direction. As described above in FIG. 1, in one embodiment, the case (210) may include a can and a top plate. The first terminal (232) and the second terminal (234) may penetrate one side of the top plate in the same direction. Alternatively, in one embodiment, the case (210) may include a can and a bottom plate. The first terminal (232) and the second terminal (234) may penetrate one side of the can in the same direction.

[0065] A secondary battery according to one embodiment of the present invention may further include a third insulator (260) disposed between at least one of the first current collector plate (252) or the second current collector plate (254) and the case (210). Specifically, the third insulator (260) may have a shape corresponding to the shape of the first current collector plate (252) while surrounding the lower portion of the rivet portion of the first terminal (232). Additionally or alternatively, the third insulator (260) may have a shape corresponding to the shape of the second current collector plate (254) while surrounding the lower portion of the rivet portion of the second terminal (234).

[0066] The third insulator (260) may be made of the same insulating material as the first insulator (242) or second insulator (244) described above to electrically insulate the first collector plate (252) and the case (210) or the second collector plate (254) and the case (210).

[0067] The first current collector plate (252) may be electrically connected to the first substrate tab (202) included in the first electrode. In addition, the second current collector plate (254) may be electrically connected to the second substrate tab (204) included in the second electrode. The first substrate tab (202) or the second substrate tab (204) may be an extended configuration of a non-coated portion in which the substrate is exposed because no active material is applied to both sides of the substrate formed of a thin metal plate in the first electrode or the second electrode, respectively. According to one embodiment, the first substrate tab (202) or the second substrate tab (204) may be connected to the first current collector plate (252) or the second current collector plate (254) in a state in which they are bent in different directions.

[0068] FIG. 3 is a cross-sectional view showing the appearance of a secondary battery before and after electrode rivets are joined according to one embodiment of the present disclosure. While FIG. 3 illustrates a first terminal and its surroundings as an example, the present invention is not limited thereto and the same structure can be applied to a separate terminal (e.g., a second terminal) of the present invention.

[0069] The first terminal may include a rivet portion (332) and a wing portion (335). The rivet portion (332) may have one end welded to a current collector plate (in the case of the first terminal, the first current collector plate) located inside the case (310). The wing portion (335) may be arranged on the outside of the case (310) so that the external terminal may be electrically connected to the electrode assembly. Specifically, the wing portion may be formed to protrude beyond the outer surface of the case (310) around the through hole and may be used as an external terminal for welding.

[0070] Referring to FIG. 3, the first state (301) is a state before the rivet portion (332) of the first terminal is inserted into the through-hole of the case (310), and the second state (301) is a state after the rivet portion (332) of the first terminal is inserted into the through-hole of the case (310).

[0071] In the first state (301), one side of the case (310) may include a through hole for connecting the electrode of the electrode assembly to the outside of the case (310). The size and shape of the through hole may correspond to the size and shape of the transverse cross-section of the rivet portion (332) of the first terminal. For example, when the transverse cross-section of the rivet portion (332) of the first terminal has a circular shape with a diameter of 15 mm, the through hole located on one side of the case (310) may also have a circular shape with a diameter of 15 mm.

[0072] A first insulator (342) may be placed around the through hole. Specifically, the first insulator (342) may be placed between the rivet portion (332) of the first terminal connected to the first electrode and the case (310) and between the wing portion (335) and the case (310) to electrically insulate the first electrode and the case (310).

[0073] In one embodiment, the first insulator (342) surrounds the top, side, and bottom surfaces of the through hole, and the transverse cross-section of the first insulator (342) disposed around the through hole may have a 'ㄷ' shape. The first insulator (342) may be formed or disposed in various ways used in the art, such as insert injection molding. For example, the first insulator (342) may be formed integrally with the third insulator (360) disposed on the inner surface of the case (310).

[0074] In the second state (302), the rivet portion (332) can be integrally formed with the wing portion (335). In one embodiment, the rivet portion (332) and the wing portion (335) can be welded using any one of ultrasonic welding, laser welding, resistance welding, Tungsten Inert Gas Welding (TIG welding), or a combination thereof. The welding method is not limited to the types of welding listed above, and various methods generally used for welding two materials can be used according to the selection of a person skilled in the art.

[0075] FIG. 4 is a schematic drawing illustrating a cross-section of a secondary battery according to one embodiment of the present disclosure.

[0076] Referring to FIG. 4, a case according to one embodiment may include a cylindrical can (410) having a first terminal (432) and a second terminal (434) penetrating a first surface thereof and an opening (401) into which an electrode assembly is inserted in a second surface opposite to the first surface, and a lower plate (490) sealing the opening (401) of the cylindrical can (410). As illustrated in FIG. 4, the first surface of the cylindrical can (410) may be positioned at the top so as to face the second surface on which the lower plate (490) is positioned.

[0077] A first insulator (442) may be placed between a first surface of the cylindrical can (410) and a first terminal (432). A second insulator (444) may be placed between a first surface of the cylindrical can (410) and a second terminal (434).

[0078] The surfaces where the opening (401) of the cylindrical can (410) and the lower plate (490) come into contact with each other can be integrally joined by welding. The welding method is not limited to that described above in FIG. 3, and various methods generally used for welding two materials can be used according to the selection of a person skilled in the art.

[0079] The surfaces where the opening (401) of the cylindrical can (410) and the lower plate (490) contact each other can be sealed by a method other than welding. In one embodiment, the opening (401) of the cylindrical can (410) can be sealed by installing the lower plate (490) through a crimping process. This will be described later in FIG. 7.

[0080] According to some embodiments of the present disclosure, when the lower plate (490) is sealed by welding rather than a crimping process, the shape of the lower plate (490) can be made simpler, which is economical in terms of process, and the space existing between the lower plate (490) and the electrode assembly can be minimized, thereby increasing the energy density of the secondary battery.

[0081] FIG. 5 is a schematic drawing illustrating a cross-section of a secondary battery according to one embodiment of the present disclosure.

[0082] Referring to FIG. 5, a case according to another embodiment may include a cylindrical can (510) into which an electrode assembly is inserted through an opening (501) formed on one side thereof, and an upper plate (590) that seals the opening (501) of the cylindrical can (510).

[0083] The upper plate (590) may include a through hole through which the first terminal (532) and the second terminal (532) pass. The first insulator (542) may be disposed between the upper plate (590) and the first terminal (532). Additionally, the second insulator (544) may be disposed between the upper plate (590) and the second terminal (534).

[0084] The surfaces where the opening (501) of the cylindrical can (510) and the upper plate (590) contact each other can be integrally joined by welding. For other unexplained configurations, the same applies to FIG. 4.

[0085] According to some embodiments of the present disclosure, when the upper plate (590) is sealed by welding, the shape of the upper plate (590) can be made simpler, which is economical in terms of process, and the space existing between the upper plate (590) and the electrode assembly can be minimized, thereby increasing the energy density of the secondary battery.

[0086] FIG. 6 is a plan view showing a terminal of a secondary battery according to one embodiment of the present disclosure.

[0087] The shapes of the first terminal (632) and the second terminal (634) according to the present invention are not limited. For example, referring to FIG. 1, the cross-section of at least one of the first terminal (632) or the second terminal (634) may be circular. According to one embodiment, as illustrated in FIG. 6, the cross-section of at least one of the first terminal (632) or the second terminal (634) may be rectangular.

[0088] The first insulator (642) may have a shape that wraps around the circumference of the first terminal (632) to effectively insulate the case (610) and the first terminal (632). For example, if the cross-section of the first terminal (632) is rectangular, the shape of the first insulator (642) may also be rectangular to wrap the wing portion of the first terminal (632) protruding outside the case (610). Similarly, the second insulator (644) may have a shape that wraps around the circumference of the second terminal (634) to effectively insulate the case (610) and the second terminal (634).

[0089] In one embodiment, the first terminal (632) and the second terminal (634) may be spaced apart from each other by a distance of 5 mm to 40 mm. The separation distance may refer to the closest distance among the distances at which the first terminal (632) and the second terminal (634) are separated from each other.

[0090] Figure 7 is a cross-sectional view of a secondary battery according to one embodiment of the present disclosure.

[0091] Referring to FIG. 7, a secondary battery according to one embodiment of the present disclosure includes an electrode assembly (710) that performs charging and discharging, a case (720) that houses the electrode assembly (710), a first current collector (731) connected to the electrode assembly (710), a second current collector (732), a first electrode terminal (741), a second electrode terminal (742), and a gasket (750).

[0092] An electrode assembly (710) is formed into a jelly roll state by winding a first electrode (711a, 711b), a separator (713), and a second electrode (712a, 712b). The first electrode (711a, 711b) and the second electrode (712a, 712b) each include a coated portion (711a, 712a) in which an active material is applied to both sides of a substrate formed of a thin metal plate, and a non-coated portion (711b, 712b) in which the substrate is exposed because the active material is not applied.

[0093] For example, the first electrode (711a, 711b) may be formed as a positive electrode by coating a positive electrode active material on an aluminum (Al) substrate, and the second electrode (712a, 712b) may be formed as a negative electrode by coating a negative electrode active material on a copper (Cu) substrate. The uncoated portion (711b) of the first electrode and the uncoated portion (712b) of the second electrode may be provided at one or more of the opposite ends or one end in the winding axis direction of the electrode assembly (710).

[0094] The uncoated portion (711b) of the first electrode may be electrically connected to the first collector plate (731), and the uncoated portion (712b) of the second electrode may be electrically connected to the second collector plate (732). According to one embodiment, the first collector plate (731) and the second collector plate (732) may be arranged to be connected to the same side of the electrode assembly (710).

[0095] In one embodiment, a second electrode terminal (742) having a different polarity may be provided in the same direction as the first electrode terminal (741) with respect to the electrode assembly (710).

[0096] The case (720) is formed in a cylindrical shape to house the electrode assembly (710), and a first electrode terminal (741), a second electrode terminal (742), and a vent plate (752) are provided at each of the axial ends of the case (720). The first electrode terminal (741) is connected to the first electrode (711a, 711b) by the first collector plate (731), and the second electrode terminal (742) is connected to the second electrode (712a, 712b) by the second collector plate (732). At this time, the vent plate (752) is electrically separated from the first collector plate (731) and the second collector plate (732) and has no polarity.

[0097] A first electrode terminal (741) and a second electrode terminal (742) connected to the first electrode (711a, 711b) of the electrode assembly (710) inserted into the case (720) from the outside are installed on one side of the case (720). The case (720) has a partially open through hole on one side.

[0098] For example, the first electrode terminal (741) may be installed in a rivet structure in a through hole of the case (720). In addition, the second electrode terminal (742) may be installed in a rivet structure in a through hole of the case (720). To this end, the first electrode terminal (741) or the second electrode terminal (742) may include a rivet portion and a wing portion. The rivet portion is welded at one end to the first collector plate (731) or the second collector plate (732) and is positioned to penetrate the through hole. The rivet portions of the first electrode terminal (741) and the second electrode terminal (742) are connected to the wing portions positioned on the outside of the case (720). Specifically, the wing portions may be formed to protrude from the outer surface of the case (720) around the through hole and may be used as external terminals for welding.

[0099] At this time, the first collector plate (731) is electrically and mechanically connected to the uncoated portion (711b) of the first electrode through the rivet portion of the first electrode terminal (741). The first collector plate (731) is electrically connected to the first electrode terminal (741) in a structure that reduces resistance by contacting most of the uncoated portion (711b) of the first electrode. A first insulator (721) is interposed between the first electrode terminal (741) and the through hole to form a sealing structure with respect to the electrolyte, and is installed in an electrically insulated state from the case (720).

[0100] Likewise, the second collector plate (732) is electrically and mechanically connected to the uncoated portion (712b) of the second electrode through the rivet portion of the second electrode terminal (742). The second collector plate (732) is electrically connected to the second electrode terminal (742) in a structure that reduces resistance by contacting most of the uncoated portion (712b) of the second electrode. A second insulator (722) is interposed between the second electrode terminal (742) and the through hole to form a sealing structure with respect to the electrolyte, and is installed in an electrically insulated state from the case (720).

[0101] Due to the first insulator (721) and the second insulator (722), the case (720) may be electrically separated from the first collector plate (731) and the second collector plate (732) and may not have polarity.

[0102] Additionally, the case (720) has a fully open opening (702) to allow the electrode assembly (710) to be inserted into the other side. The vent plate (752) seals the opening (702) after the electrode assembly (710) is inserted into the case (720).

[0103] The vent plate (752) can be installed in the opening (702) of the case (720) through a crimping process. Specifically, a gasket (750) is placed between the vent plate (752) and the opening (702) of the case (720), and the gasket (750) and the case (720) can be folded to surround the vent plate (752) to seal the opening (702). In one embodiment, the gasket (750) is insulating, so that the vent plate (752) and the case (720) can be electrically isolated from each other.

[0104] The finishing tape (790) may be attached so as to wrap the outer surface of the jelly roll of the electrode assembly (710) at least once. In addition, the electrode assembly (710) may be inserted into the case (720) with the finishing tape (790) attached, and the finishing tape (790) may be positioned between the electrode assembly (710) and the case (720). Accordingly, in the assembled secondary battery, the electrode assembly (710) does not move in the up-and-down or front-and-back direction inside the case (720), thereby preventing separation of the terminal or damage to the element, and even in a state where the electrode assembly (710) expands due to charging and discharging, cracks in the case (720) or the electrode assembly (710) due to excessive expansion of the electrode assembly (710) may be suppressed.

[0105] A secondary battery according to one embodiment of the present invention can be applied to automobiles, mobile phones, and / or various types of electrical devices, and the present invention is not limited thereto.

[0106] According to some embodiments of the present disclosure, the positive and negative terminals of a secondary battery can be arranged in the same direction to reduce the internal resistance of the secondary battery, minimize energy loss, and maximize the efficiency of power management.

[0107] Figure 8 is a flowchart showing an example of a method for manufacturing a secondary battery according to the present disclosure.

[0108] A method for manufacturing a secondary battery according to one embodiment (800) may be initiated by sequentially stacking and winding a first electrode, a separator, and a second electrode to manufacture an electrode assembly (S810). Here, the diameter of the electrode assembly may be 40 mm to 50 mm.

[0109] Thereafter, the first electrode may be connected to the first collector plate and the second electrode may be connected to the second collector plate (S820). Specifically, the first electrode may be electrically connected to the first collector plate, and the second electrode may be electrically connected to the second collector plate. Here, the first collector plate and the second collector plate may be arranged to be connected to the same side of the electrode assembly. According to one embodiment, the step of connecting the first electrode to the first collector plate and the step of connecting the second electrode to the second collector plate may include the step of connecting a first substrate tab included in the first electrode and the first collector plate, and the step of connecting a second substrate tab included in the second electrode and the second collector plate.

[0110] Thereafter, the electrode assembly can be inserted into the case (S830). Here, the diameter of the case may be 40 mm to 50 mm. According to one embodiment, the method for manufacturing a secondary battery (800) may further include the steps of placing a first insulator between the first terminal and the case, and placing a second insulator between the second terminal and the case. Additionally, the secondary battery may further include a third insulator placed between at least one of the first current collecting plate or the second current collecting plate and the case.

[0111] In one embodiment, a first terminal electrically connected to a first collector plate and a second terminal electrically connected to a second collector plate may be arranged to penetrate one surface of the case in the same direction (S840). Here, the first terminal and the second terminal may be spaced apart from each other by a gap of 5 mm to 40 mm. In one embodiment, the cross-section of at least one of the first terminal or the second terminal may be circular. In another embodiment, the cross-section of at least one of the first terminal or the second terminal may be rectangular.

[0112] According to one embodiment, the method for manufacturing a secondary battery (800) may further include a step of welding the first current collector plate and the first terminal or the second current collector plate and the second terminal, respectively. Specifically, the first current collector plate and the first terminal or the second current collector plate and the second terminal may be welded using any one of ultrasonic welding, laser welding, resistance welding, TIG welding (Tungsten Inert Gas Welding), or a combination thereof. The welding method is not limited to the types of welding listed above, and various methods generally used for welding two materials may be used according to the selection of a person skilled in the art.

[0113] A method for manufacturing a secondary battery (800) according to one embodiment may further include a step of welding a cylindrical can and a lower plate. At this time, the case may include a cylindrical can having an opening through which a first terminal and a second terminal pass through a first surface and an electrode assembly is inserted through a second surface opposite the first surface, and a lower plate that seals the opening of the cylindrical can. Alternatively or additionally, a method for manufacturing a secondary battery (800) according to one embodiment may further include a step of welding a can and an upper plate. At this time, the case may include a cylindrical can having an opening formed through which an electrode assembly is inserted through a first terminal and a second terminal pass through a second surface, and an upper plate that seals the opening of the cylindrical can. A method for welding the lower plate or the upper plate is as described above.

[0114] According to some embodiments of the present disclosure, the positive terminal and negative terminal of a secondary battery can be arranged in the same direction to reduce the number of plates requiring welding to one, and minimize unnecessary current leakage or welding defects.

[0115] Although the present invention has been described above with reference to limited embodiments and drawings, the present invention is not limited thereto, and various modifications and variations can be made by those skilled in the art within the scope of the technical idea of ​​the present invention and the equivalent scope of the claims to be described below. Those skilled in the art can make various substitutions, variations, and changes without departing from the technical idea of ​​the present invention, and therefore the present invention is not limited by the above-described embodiments and the attached drawings.

Claims

1. An electrode assembly in which a first electrode, a separator, and a second electrode are sequentially laminated and wound; A case in which the electrode assembly is stored; A first collector plate electrically connected to the first electrode; A second collector plate electrically connected to the second electrode; a first terminal electrically connected to the first collector plate; and including a second terminal electrically connected to the second collector plate, A secondary battery, wherein the first terminal and the second terminal penetrate one side of the case in the same direction.

2. In paragraph 1, A secondary battery further comprising a first insulator disposed between the first terminal and the case.

3. In paragraph 1, A secondary battery further comprising a second insulator disposed between the second terminal and the case.

4. In paragraph 1, A secondary battery further comprising a third insulator disposed between at least one of the first collector plate or the second collector plate and the case.

5. In paragraph 1, The above case is, A cylindrical can having an opening through which the first terminal and the second terminal pass on the first surface and into which the electrode assembly is inserted on the second surface opposite the first surface; and A secondary battery comprising a lower plate that seals the opening of the cylindrical can.

6. In paragraph 1, The above case is, A cylindrical can into which the electrode assembly is inserted through an opening formed on one side; and A secondary battery comprising an upper plate through which the first terminal and the second terminal pass and which seals the opening of the cylindrical can.

7. In paragraph 1, A secondary battery, wherein the first terminal and the second terminal are spaced apart from each other by a distance of 5 mm to 40 mm.

8. In paragraph 1, A secondary battery, wherein the first collector plate is electrically connected to the first substrate tab included in the first electrode.

9. In paragraph 1, A secondary battery, wherein the second collector plate is electrically connected to the second substrate tab included in the second electrode.

10. In paragraph 1, A secondary battery, wherein the first collector plate and the second collector plate are arranged to be connected to the same side of the electrode assembly.

11. In paragraph 1, A secondary battery, wherein at least one of the first terminal or the second terminal has a circular cross-section.

12. In paragraph 1, A secondary battery, wherein at least one of the first terminal or the second terminal has a rectangular cross-section.

13. In paragraph 1, A secondary battery having a case diameter of 40 mm to 50 mm.

14. A step of manufacturing an electrode assembly by sequentially stacking and winding a first electrode, a separator, and a second electrode; A step of connecting the first electrode to the first collector plate and connecting the second electrode to the second collector plate; A step of inserting the electrode assembly into the case; and A method for manufacturing a secondary battery, comprising the step of arranging a first terminal electrically connected to the first collector plate and a second terminal electrically connected to the second collector plate so as to penetrate one surface of the case in the same direction.

15. In paragraph 14, The step of connecting the first electrode to the first collector plate and connecting the second electrode to the second collector plate is: A method for manufacturing a secondary battery, comprising the steps of connecting a first substrate tab included in the first electrode and the first current collector plate, and connecting a second substrate tab included in the second electrode and the second current collector plate.

16. In paragraph 14, A method for manufacturing a secondary battery, further comprising a step of welding the first current collector plate and the first terminal or the second current collector plate and the second terminal, respectively.

17. In paragraph 14, A method for manufacturing a secondary battery, further comprising the step of placing a first insulator between the first terminal and the case, and placing a second insulator between the second terminal and the case.

18. In paragraph 14, The case comprises a cylindrical can having an opening through which the first terminal and the second terminal pass on a first surface and into which the electrode assembly is inserted on a second surface opposite to the first surface, and a lower plate sealing the opening of the cylindrical can. The above manufacturing method is, A method for manufacturing a secondary battery, further comprising the step of welding the cylindrical can and the lower plate.

19. In paragraph 14, The case includes a cylindrical can into which the electrode assembly is inserted through an opening formed on one side, and an upper plate through which the first terminal and the second terminal pass and which seals the opening of the cylindrical can. The above manufacturing method is, A method for manufacturing a secondary battery, further comprising the step of welding the can and the upper plate.

20. In paragraph 14, A method for manufacturing a secondary battery, wherein the first collector plate and the second collector plate are arranged to be connected to the same side of the electrode assembly.

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