Secondary battery and method for manufacturing secondary battery

Abstract

A secondary battery and a method for manufacturing a secondary battery are provided. The secondary battery includes an electrode assembly, a case body accommodating the electrode assembly, a cover plate sealing an opening of the case body, and a positive electrode terminal and a negative electrode terminal each electrically connected to the electrode assembly, bonded to the cover plate, and protruding in a first direction from an upper surface of the cover plate. The cover plate includes an exhaust portion located between the positive electrode terminal and the negative electrode terminal. A first length of the case body in the first direction is longer than a second length of the case body in a second direction perpendicular to the first direction, and the second length is longer than a third length of the case body in a third direction perpendicular to each of the first direction and the second direction.

Description

Technical Field

[0001] The embodiments of this disclosure relate to secondary batteries and methods for manufacturing secondary batteries. Background Technology

[0002] Unlike primary batteries, which are not designed for (re)charging, secondary (or rechargeable) batteries are designed to be discharged and recharged. Low-capacity secondary batteries are used in portable small electronic devices such as smartphones, feature phones, laptops, digital cameras, and camcorders, while high-capacity secondary batteries are widely used as power sources for motors in hybrid and electric vehicles, as well as for storing electricity (e.g., household and / or utility-scale power storage). A secondary battery typically includes an electrode assembly containing positive and negative electrodes, a housing that houses the electrode assembly, and electrode terminals connected to the electrode assembly.

[0003] As a secondary battery is charged and / or discharged, gas may be generated inside it. In this case, the internal gas may cause deformation of the electrode components, potentially leading to a short circuit within the electrode components. Therefore, the safety of the secondary battery may be reduced.

[0004] The information disclosed in this background section is intended to enhance the understanding of the background of this disclosure, and therefore may contain information that does not constitute related (or prior art). Summary of the Invention

[0005] The embodiments disclosed herein can be directed to secondary batteries with improved safety and methods for manufacturing secondary batteries.

[0006] These and other aspects and features of this disclosure will be described in or will become apparent from the following description of embodiments of this disclosure.

[0007] According to one or more embodiments of this disclosure, a secondary battery includes: an electrode assembly including a positive electrode, a negative electrode, and a separator disposed between the positive and negative electrodes; a housing body housing the electrode assembly; a cover sealing an opening in the housing body; and positive and negative electrode terminals, each of which is electrically connected to the electrode assembly, coupled to the cover, and protruding from the upper surface of the cover in a first direction. The cover includes a venting portion located between the positive and negative electrode terminals. A first length of the housing body in the first direction is longer than a second length of the housing body in a second direction perpendicular to the first direction, and the second length is longer than a third length of the housing body in a third direction perpendicular to each of the first and second directions.

[0008] In an implementation, the ratio of the first length to the second length can be greater than 1 and less than 3.

[0009] In an implementation, the length of the cover plate in the first direction can be from 0.5 mm to 3.0 mm.

[0010] In an embodiment, the area of ​​the upper surface of the positive electrode terminal and the negative electrode terminal can be 20% to 50% of the area of ​​the upper surface of the cover plate.

[0011] In this embodiment, the area of ​​the upper surface of the exhaust portion can be 10% to 50% of the area of ​​the upper surface of the cover plate.

[0012] In an implementation, the exhaust portion may be spaced apart from each of the positive and negative electrode terminals.

[0013] In an implementation, the exhaust portion may include: a first region extending in a second direction; and a second region extending upward in a third direction.

[0014] In the implementation, at least a portion of the first region and at least a portion of the second region may overlap with each other.

[0015] In an implementation, the length of the first region in the second direction may be equal to or longer than the length of the second region in the third direction.

[0016] In one embodiment, the exhaust portion may include: a first notch extending in a second direction in a first region; and a second notch extending in a third direction in the second region. The first and second notches may intersect each other.

[0017] In an implementation, the edge of the exhaust portion may have a rounded shape.

[0018] In this implementation, the exhaust portion can be circular in shape.

[0019] In an embodiment, the length of the exhaust portion in the second direction may be equal to or shorter than the length of at least one of the positive electrode terminal or the negative electrode terminal in the second direction.

[0020] In an implementation, the exhaust portion may include: a first exhaust portion extending in a second direction; and a second exhaust portion extending in the second direction and spaced apart from the first exhaust portion in a third direction.

[0021] In an embodiment, the exhaust portion may include a notch corresponding to the shape of the exhaust portion.

[0022] According to one or more embodiments of this disclosure, a method for manufacturing a secondary battery includes: preparing an electrode assembly including a positive electrode, a negative electrode, and a separator inserted between the positive and negative electrodes; housing the electrode assembly in a housing body; attaching positive and negative electrode terminals to a cover plate, the positive and negative electrode terminals being electrically connected to the electrode assembly and protruding from the upper surface of the cover plate in a first direction; and attaching the cover plate to the housing body to seal an opening in the housing body. The cover plate includes a venting portion between the positive and negative electrode terminals. A first length of the housing body in the first direction is longer than a second length of the housing body in a second direction perpendicular to the first direction, and the second length is longer than a third length of the housing body in a third direction perpendicular to each of the first and second directions.

[0023] In an implementation, the exhaust portion may include: a first region extending in a second direction; and a second region extending upward in a third direction.

[0024] In the implementation, at least a portion of the first region and at least a portion of the second region may overlap with each other.

[0025] In an implementation, the length of the first region in the second direction may be equal to or longer than the length of the second region in the third direction.

[0026] In an embodiment, the exhaust portion may include a notch corresponding to the shape of the exhaust portion.

[0027] According to some embodiments of this disclosure, the positive electrode terminal, negative electrode terminal, and venting portion can be disposed on the upper surface of a secondary battery having a relatively narrow width compared to its height. Therefore, if the internal pressure of the secondary battery increases, the venting portion can rupture, allowing the internal gas to be easily released. Furthermore, even if the internal gas is released, the secondary battery will not pop upwards. Therefore, secondary damage due to an increase in the internal pressure of the secondary battery can be prevented or substantially prevented.

[0028] According to some embodiments of this disclosure, the area of ​​the venting portion can be increased by changing the shape and / or number of the venting portions disposed between the positive and negative electrode terminals. Therefore, the area of ​​the venting portion for rupture can be ensured. Furthermore, according to some embodiments of this disclosure, while ensuring the area of ​​the venting portion, the shape and / or number of the venting portions can be modified, thereby ensuring greater freedom in the design of the secondary battery.

[0029] However, the aspects and features of this disclosure are not limited to those described above, and those skilled in the art will clearly understand from the detailed description below that other aspects and features not mentioned will be apparent. Attached Figure Description

[0030] The accompanying drawings illustrate embodiments of the present disclosure and, together with the detailed description thereof, further describe aspects and features of the present disclosure. Therefore, the present disclosure should not be construed as limited to the drawings.

[0031] Figure 1 An example of a secondary battery according to an embodiment of the present disclosure is shown.

[0032] Figure 2 This is a cross-sectional view showing an example of a secondary battery according to an embodiment of the present disclosure.

[0033] Figure 3 This is a plan view showing an example of a cover plate with an exhaust portion according to an embodiment of the present disclosure.

[0034] Figure 4 This is a plan view showing an example of a cover plate with an exhaust portion according to an embodiment of the present disclosure.

[0035] Figure 5 This is a plan view showing an example of a cover plate with an exhaust portion according to an embodiment of the present disclosure.

[0036] Figure 6 This is a plan view showing an example of a cover plate with an exhaust portion according to an embodiment of the present disclosure.

[0037] Figure 7 This is a plan view showing an example of a cover plate with an exhaust portion according to an embodiment of the present disclosure.

[0038] Figure 8 This is a flowchart illustrating an example of a method for manufacturing a secondary battery according to an embodiment of the present disclosure.

[0039] Explanation of some figure labels

[0040] 10: Secondary batteries

[0041] 110: Main body of the shell

[0042] 120: Cover plate

[0043] 122: Exhaust section

[0044] 130_1: Positive electrode terminal

[0045] 130_2: Negative electrode terminal Detailed Implementation

[0046] In the following, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. The terms or words used in this specification and claims should not be construed as limited to their general or dictionary meanings, and should be understood based on the principle that the inventor can be his / her own lexicographer to appropriately define the concepts of the terms so as to best interpret his / her invention in a manner consistent with the technical spirit of the present disclosure.

[0047] The embodiments described in this specification and the configurations shown in the accompanying drawings are only some of the embodiments of this disclosure and do not represent all the technical spirit, aspects, and features of this disclosure. Therefore, it should be understood that various equivalents and modifications that can replace or modify the embodiments described herein may exist at the time of filing this application.

[0048] It will be understood that when a layer or element is referred to as being “between” two layers, the layer or element can be the only layer or element between the two layers, or one or more intermediate layers may exist. It will be understood that when an element or layer is referred to as being “on”, “connected to”, or “bonded to” another element or layer, it can be directly on, directly connected to, or directly bonded to the other element or layer, or one or more intermediate elements or layers may exist. When an element or layer is referred to as being “directly on”, “directly connected to”, or “directly bonded to” another element or layer, no intermediate elements or layers exist. For example, when a first element is described as being “bonded” or “connected” to a second element, the first element can be directly bonded to or connected to the second element, or the first element can be indirectly bonded to or connected to the second element via one or more intermediate elements.

[0049] In the accompanying drawings, the dimensions of various elements, layers, etc., may be exaggerated for clarity. The same reference numerals denote the same elements. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items. Furthermore, when describing embodiments of this disclosure, the use of "may" refers to "one or more embodiments of this disclosure." Expressions such as "at least one of..." and "any one of..." modify the entire list of elements when following it, and do not modify individual elements in the list. When a list of elements A, B, and C is specified using phrases such as "at least one of A, B, and C," "at least one of A, B, or C," "at least one selected from the group consisting of A, B, and C," or "at least one selected from A, B, and C," the phrase may refer to any and all suitable combinations or subsets of A, B, and C, such as A, B, C, A and B, A and C, B and C, or A and B and C. As used herein, the terms "use," "using," and "being used" may be considered synonymous with the terms "utilize," "using," and "being exploited," respectively. As used herein, the terms “substantially,” “about,” and similar terms are used as approximations rather than terms of degree and are intended to describe the inherent variations in measured or calculated values ​​that would be recognized by one of ordinary skill in the art.

[0050] It should be understood that although the terms first, second, third, etc., may be used herein to describe various elements, components, regions, layers, and / or portions, these elements, components, regions, layers, and / or portions should not be limited by these terms. These terms are used to distinguish one element, component, region, layer, or portion from another element, component, region, layer, or portion. Therefore, the first element, component, region, layer, or portion discussed below may be referred to as the second element, component, region, layer, or portion without departing from the teachings of the exemplary embodiments.

[0051] For ease of description, this document uses spatial relation terms such as “below,” “under,” “lower,” “above,” “upper,” etc., to describe the relationship between one element or feature and another element or feature as shown in the figure. It should be understood that, in addition to the orientation shown in the figure, spatial relation terms are intended to cover different orientations of the device in use or operation. For example, if the device in the figure is flipped, an element described as “below” or “under” other elements or features will be oriented “above” or “above” other elements or features. Therefore, the term “below” can encompass both above and below orientations. The device may be oriented in other ways (rotated 90 degrees or in other orientations), and the spatial relation descriptors used herein should be understood accordingly.

[0052] The terminology used herein is for the purpose of describing embodiments of this disclosure and is not intended to limit this disclosure. As used herein, the singular forms “a” and “an” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that, when used in this specification, the terms “comprising,” “including,” “including,” and / or “containing” specify the presence of the stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0053] Furthermore, any numerical range disclosed and / or enumerated herein is intended to include all subranges containing the same numerical precision within the enumerated range. For example, the range “1.0 to 10.0” is intended to include all subranges between (and including) the enumerated minimum value of 1.0 and the enumerated maximum value of 10.0, i.e., all subranges having a minimum value equal to or greater than 1.0 and a maximum value equal to or less than 10.0, such as, for example, 2.4 to 7.6. Any maximum numerical limit enumerated herein is intended to include all lower numerical limits contained therein, and any minimum numerical limit enumerated in this specification is intended to include all higher numerical limits contained therein. Therefore, the applicant reserves the right to amend this specification (including the claims) to expressly enumerate any subranges contained within the ranges expressly enumerated herein. All such ranges are intended to be inherently described in this specification such that amendments to expressly enumerate any such subranges will comply with the requirements of local patent law.

[0054] Referring to two compared elements, features, etc., as “identical” can mean that they are “substantially identical.” Therefore, the phrase “substantially identical” can include cases with deviations considered low in the art, such as 5% or less. Furthermore, when a parameter is said to be uniform in a given region, it can mean that it is uniform in terms of average value.

[0055] Throughout this specification, unless otherwise stated, each element may be singular or plural.

[0056] Placing any element "above (or below)" or "under" another element can mean that the arbitrary element can be positioned to contact the upper (or lower) surface of the element, and additional elements can be inserted between the element and the arbitrary element positioned above (or below) the element.

[0057] Additionally, it will be understood that when a component is referred to as “combined,” “linked,” or “connected” to another component, these components can be directly “combined,” “linked,” or “connected” to each other, or an intermediate component can be “inserted” between these components.

[0058] Throughout this specification, when “A and / or B” is stated, it means A, B, or A and B, unless otherwise stated. That is, “and / or” includes any or all combinations of the listed items. When “C to D” is stated, it means C or greater and D or less, unless otherwise stated.

[0059] As used herein, a secondary battery can correspond to a tall cell. A tall cell can refer to a secondary battery with a relatively narrow width compared to its height. In a taller cell, because the top surface area of ​​the cover plate may be small, the venting portion can be placed on the bottom surface of the main body of the casing, opposite to the cover plate. In this case, if the venting portion ruptures under the internal gas pressure of the secondary battery, the secondary battery may be ejected upwards under gas pressure. As a result, secondary damage may occur to surrounding components due to the explosion of the secondary battery.

[0060] Figure 1 An example of a secondary battery 10 according to an embodiment of the present disclosure is shown. Figure 2 This is a cross-sectional view showing an example of a secondary battery 10 according to an embodiment of the present disclosure.

[0061] refer to Figure 1 and Figure 2 A secondary battery 10 according to one or more embodiments of the present disclosure may include: at least one wound electrode assembly 210, with a diaphragm as an insulator inserted between the positive and negative electrodes; a housing body 110 in which the electrode assembly 210 is received (or housed); and a cover plate 120, which is coupled to an opening in the housing body 110.

[0062] Each of the positive and negative electrodes may include a current collector made of a thin metal foil having a coated portion thereon coated with an active material and an uncoated portion thereon uncoated with an active material.

[0063] After the diaphragm, which serves as an insulator, is inserted between the positive and negative electrodes, the positive and negative electrodes are wound together. However, this disclosure is not limited thereto, and the electrode assembly 210 may have a structure in which positive and negative electrodes, each made of a plurality of sheets, are stacked alternately, and the diaphragm is inserted between the positive and negative electrodes.

[0064] The housing body 110 can form the overall appearance of the secondary battery 10 and can be made of a conductive metal such as aluminum, aluminum alloy, or nickel-plated steel. In addition, the housing body 110 can provide space therein to accommodate the electrode assembly 210.

[0065] The housing body 110 and the cover plate 120 may be made of conductive material. Positive electrode terminal 130_1 and negative electrode terminal 130_2, which are electrically connected to the positive electrode and the negative electrode respectively, may be mounted to penetrate (or extend through) the cover plate 120 and protrude outward through the cover plate 120.

[0066] Additionally, the outer peripheral surfaces (e.g., perimeter surfaces) of the upper pillars of the positive electrode terminal 130_1 and the negative electrode terminal 130_2 protruding outward from the cover plate 120 may have a rivet structure and may be riveted or welded to the cover plate 120.

[0067] Additionally, the cover plate 120 may be made of a thin plate and may be incorporated into an opening in the housing body 110, into which an electrolyte injection port (not shown) may be located (e.g., formed in) the cover plate 120, and a venting portion 122 with a notch may be installed in the cover plate 120.

[0068] The positive electrode for a lithium secondary battery may include a current collector and a layer of positive electrode active material formed on the current collector. The positive electrode active material layer may include a positive electrode active material and may further include a binder and / or a conductive material.

[0069] Based on a 100 wt% positive electrode active material layer, the content of the positive electrode active material is in the range of about 90 wt% to about 99.5 wt%, and based on the 100 wt% positive electrode active material layer, the contents of the binder and the conductive material are in the range of about 0.5 wt% to about 5 wt%, respectively.

[0070] The current collector can be aluminum (Al), but is not limited to this.

[0071] As the positive electrode active material, compounds capable of reversibly inserting / deintercalating lithium (e.g., lithiation intercalation compounds) can be used. For example, at least one of lithium and a composite oxide of a metal selected from cobalt, manganese, nickel, and combinations thereof can be used.

[0072] The composite oxide can be a lithium transition metal composite oxide, and examples of it can include lithium nickel-based oxides, lithium cobalt-based oxides, lithium manganese-based oxides, lithium iron phosphate-based compounds, cobalt-free nickel manganese-based oxides, or combinations thereof.

[0073] As an example, a compound represented by any of the following chemical formulas can be used: Li a A 1-b X b O 2-c D c (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05); Li a Mn 2-b Xb O 4-c D c (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05); Li a Ni 1-b-c Co b X c O 2-α D α (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.5, 0<α<2); Li a Ni 1-b- c Mn b X c O 2-α D α (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.5, 0<α<2); Li a Ni b Co c L 1 d G e O2 (0.90≤a≤1.8, 0≤b≤0.9, 0≤c≤0.5, 0≤d≤0.5, 0≤e≤0.1); Li a NiG b O2 (0.90≤a≤1.8, 0.001≤b≤0.1); Li a CoG b O2 (0.90≤a≤1.8, 0.001≤b≤0.1); Li a Mn 1-b G b O2 (0.90≤a≤1.8, 0.001≤b≤0.1); Li a Mn2G b O4 (0.90≤a≤1.8, 0.001≤b≤0.1); Li a Mn 1-g G g PO4 (0.90≤a≤1.8, 0≤g≤0.5); Li (3-f) Fe2(PO4)3 (0≤f≤2); and Li a FePO4 (0.90≤a≤1.8).

[0074] In the above chemical formulas: A is Ni, Co, Mn, or a combination thereof; X is Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, rare earth elements, or a combination thereof; D is O, F, S, P, or a combination thereof; G is Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V, or a combination thereof; and L 1 It is Mn, Al, or a combination thereof.

[0075] The negative electrode for a lithium secondary battery may include a current collector and a negative electrode active material layer provided on the current collector. The negative electrode active material layer may include a negative electrode active material, and may further include a binder and / or a conductive material.

[0076] For example, the negative electrode active material layer may include from about 90 wt% to about 99 wt% of the negative electrode active material, from about 0.5 wt% to about 5 wt% of the binder, and from about 0 wt% to about 5 wt% of the conductive material.

[0077] A non-aqueous binder, an aqueous binder, a dry binder, or a combination thereof may be used as the binder. When an aqueous binder is used as the negative electrode binder, a cellulose-based compound capable of imparting viscosity may be further included.

[0078] As the negative electrode current collector, one selected from a copper foil, a nickel foil, a stainless steel foil, a titanium foil, a nickel foam, a copper foam, a polymer substrate coated with a conductive metal, and a combination thereof may be used.

[0079] The negative electrode active material may include a material capable of reversibly intercalating and deintercalating lithium ions, lithium metal, an alloy of lithium and other metals, a material capable of doping and dedoping lithium, or a transition metal oxide.

[0080] The material capable of reversibly intercalating / deintercalating lithium ions may be a carbon-based negative electrode active material, which may include, for example, crystalline carbon, amorphous carbon, or a combination thereof. Examples of crystalline carbon may include graphite such as natural graphite or artificial graphite, and examples of amorphous carbon may include soft carbon, hard carbon, pitch carbide, mesophase pitch carbide, calcined coke, etc.

[0081] A Si-based negative electrode active material or a Sn-based negative electrode active material may be used as the material capable of doping and dedoping lithium. The Si-based negative electrode active material may be silicon, a silicon-carbon composite, SiO x (0 <x <2), a Si-based alloy, or a combination thereof.

[0082] The silicon-carbon composite may be a composite of silicon and amorphous carbon. According to an embodiment, the silicon-carbon composite may be in the form of silicon particles whose surface is coated with amorphous carbon.

[0083] The silicon-carbon composite may further include crystalline carbon. For example, the silicon-carbon composite may include a core containing crystalline carbon and silicon particles and an amorphous carbon coating on the surface of the core.

[0084] The electrolyte for a lithium secondary battery may include a non-aqueous organic solvent and a lithium salt.

[0085] Non-aqueous organic solvents are used as a medium through which ions participating in the electrochemical reactions of the battery can move.

[0086] Non-aqueous organic solvents can be carbonate solvents, ester solvents, ether solvents, ketone solvents, alcohol solvents, and aprotic solvents, and can be used alone or in combination of two or more.

[0087] In addition, when using carbonate solvents, a mixture of cyclic carbonates and chain carbonates can be used.

[0088] Depending on the type of lithium secondary battery, a separator may be present between the first electrode plate (e.g., the negative electrode) and the second electrode plate (e.g., the positive electrode). As the separator, polyethylene, polypropylene, polyvinylidene fluoride, or a multilayer film of two or more layers thereof can be used.

[0089] The diaphragm may include a porous substrate and a coating on one or both surfaces of the porous substrate, comprising organic materials, inorganic materials or combinations thereof.

[0090] Organic materials may include polyvinylidene fluoride polymers or (meth)acrylamide polymers.

[0091] Inorganic materials may include, but are not limited to, inorganic particles selected from Al2O3, SiO2, TiO2, SnO2, CeO2, MgO, NiO, CaO, GaO, ZnO, ZrO2, Y2O3, SrTiO3, BaTiO3, Mg(OH)2, boehmite and combinations thereof.

[0092] Organic and inorganic materials can be mixed in a coating, or the coating containing organic materials and the coating containing inorganic materials can be layered on top of each other.

[0093] In this embodiment, the electrode assembly 210 can be electrically connected to the positive electrode terminal 130_1 and the negative electrode terminal 130_2. For example, the positive electrode terminal 212_1 connected to the positive electrode of the electrode assembly 210 can be connected to the positive electrode terminal 130_1. The negative electrode terminal 212_2 connected to the negative electrode of the electrode assembly 210 can be connected to the negative electrode terminal 130_2. As another example, the positive electrode terminal 130_1 and the negative electrode terminal 130_2 can be electrically connected to the positive electrode current collector and the negative electrode current collector, respectively, and the positive electrode current collector and the negative electrode current collector can be soldered to the uncoated portion of the positive electrode and the uncoated portion of the negative electrode, respectively.

[0094] In one embodiment, the positive electrode terminal 130_1 and the negative electrode terminal 130_2 may be attached to the cover plate 120 to protrude outward from the upper surface of the cover plate 120 (e.g., in the first direction D1). For example, the positive electrode terminal 130_1 and the negative electrode terminal 130_2 may protrude from the upper surface of the cover plate 120 at the same or substantially the same height as each other.

[0095] In an embodiment, the cover plate 120 may include an exhaust portion 122 located between the positive electrode terminal 130_1 and the negative electrode terminal 130_2. A notch may be formed to cause the exhaust portion 122 to rupture. Therefore, if (e.g., when) the pressure inside the housing body 110 (e.g., internal gas pressure) increases due to thermal runaway in the secondary battery 10, the exhaust portion 122 may rupture. Thus, the gas inside the housing body 110 can be vented to the outside of the secondary battery 10. An example of the exhaust portion 122 will be referenced below. Figures 3 to 7 To describe in more detail.

[0096] In one embodiment, the first length w1 of the housing body 110 in the first direction D1 may be longer than the second length w2 of the housing body 110 in the second direction D2. The first direction D1 may be perpendicular to or substantially perpendicular to the second direction D2. Additionally, the second length w2 may be longer than the third length w3 of the housing body 110 in the third direction D3. The third direction D3 may be perpendicular to or substantially perpendicular to each of the first direction D1 and the second direction D2.

[0097] In this embodiment, the secondary battery 10 may correspond to a tall cell. A tall cell may refer to a secondary battery having a relatively narrow width compared to its height. (See reference...) Figure 1 The ratio of the first length w1 to the second length w2 can be greater than 1. More specifically, the ratio of w1 to w2 can be greater than 1 and less than 3, but this disclosure is not limited thereto. In addition, the length of the cover plate 120 in the first direction D1 can be from 0.5 mm to 3.0 mm.

[0098] The secondary battery 10 can be a lithium secondary battery, a sodium secondary battery, etc. However, this disclosure is not limited to this, and the secondary battery 10 can include any suitable type of battery capable of repeatedly supplying power through charging and discharging. In embodiments, if (e.g., when) the secondary battery 10 is a lithium secondary battery, it can be used in electric vehicles (EVs) due to its excellent lifespan and high rate capability. For example, it can be used in hybrid vehicles such as plug-in hybrid electric vehicles (PHEVs). Furthermore, lithium secondary batteries can be used in various fields requiring large amounts of electricity storage, such as electric bicycles, power tools, and energy storage systems (ESS).

[0099] As described above, the positive electrode terminal, negative electrode terminal, and venting portion can be disposed on the upper surface of the secondary battery, which has a relatively narrow width compared to its height. Therefore, as the internal pressure of the secondary battery increases and the venting portion ruptures, the internal gas can be easily released. Furthermore, even if (for example, when) the internal gas is released, the secondary battery will not pop upwards. Therefore, secondary damage due to an increase in the internal pressure of the secondary battery can be prevented or substantially prevented.

[0100] Figure 3 This is a plan view showing an example of a cover plate 310 having an exhaust portion 320 according to an embodiment of the present disclosure.

[0101] In one embodiment, positive electrode terminals 330_1 and negative electrode terminals 330_2, protruding outward from the upper surface of cover plate 310, can be coupled to cover plate 310. Additionally, cover plate 310 may include an exhaust portion 320 located between positive electrode terminals 330_1 and negative electrode terminals 330_2. The exhaust portion 320 may be configured to be spaced apart from each of the positive electrode terminals 330_1 and negative electrode terminals 330_2.

[0102] In one embodiment, the area of ​​the upper surfaces of the positive electrode terminal 330_1 and the negative electrode terminal 330_2 (e.g., the sum of the areas of the upper surfaces of the positive electrode terminal 330_1 and the negative electrode terminal 330_2) can be 20% to 50% of the area of ​​the upper surface of the cover plate 310. Furthermore, the area of ​​the upper surface of the exhaust portion 320 can be 10% to 50% of the area of ​​the upper surface of the cover plate 310. Additionally, the area of ​​the upper surfaces of the positive electrode terminal 330_1 and the negative electrode terminal 330_2 can be 40% to 500% of the area of ​​the upper surface of the exhaust portion 320.

[0103] In one embodiment, the edge of the exhaust portion 320 may be rounded. Therefore, if (e.g., when) the internal pressure increases, the pressure may not concentrate at the edge of the exhaust portion 320. Additionally, the exhaust portion 320 may include a notch 340 formed corresponding to the shape of the exhaust portion 320. For example, refer to... Figure 3 If (for example, when) the exhaust section 320 is in the lateral direction (for example, Figure 1 It has an elongated groove shape in the D2 direction, and the notch 340 can be formed to extend in the lateral direction.

[0104] In the embodiment, the exhaust portion 320 is in the lateral direction (e.g., Figure 1 The length w4 in the D2 direction can be equal to or shorter than the length w5 of the positive electrode terminal 330_1 in the transverse direction. Similarly, the length w4 of the exhaust portion 320 in the transverse direction can be equal to or shorter than the length of the negative electrode terminal 330_2 in the transverse direction.

[0105] Figure 4 This is a plan view showing an example of a cover plate 410 having an exhaust portion 420 according to an embodiment of the present disclosure.

[0106] In one embodiment, positive electrode terminals 430_1 and negative electrode terminals 430_2, protruding outward from the upper surface of cover plate 410, can be coupled to cover plate 410. Additionally, cover plate 410 may include an exhaust portion 420 located between positive electrode terminals 430_1 and negative electrode terminals 430_2. The exhaust portion 420 may be configured to be spaced apart from each of the positive electrode terminals 430_1 and negative electrode terminals 430_2.

[0107] In this embodiment, the area of ​​the upper surfaces of the positive electrode terminal 430_1 and the negative electrode terminal 430_2 (e.g., the sum of the areas of the upper surfaces of the positive electrode terminal 430_1 and the negative electrode terminal 430_2) can be 20% to 50% of the area of ​​the upper surface of the cover plate 410. Furthermore, the area of ​​the upper surface of the exhaust portion 420 can be 10% to 50% of the area of ​​the upper surface of the cover plate 410. Additionally, the area of ​​the upper surfaces of the positive electrode terminal 430_1 and the negative electrode terminal 430_2 can be 40% to 500% of the area of ​​the upper surface of the exhaust portion 420.

[0108] In an embodiment, the exhaust portion 420 may be included in the lateral direction (e.g., Figure 1 The first region 422 extends in the D2 direction and in the vertical direction (e.g., Figure 1 The second region 424 extends in the D3 direction. At least a portion of the first region 422 and at least a portion of the second region 424 may intersect or intersect each other. For example, the central portion of the first region 422 and the central portion of the second region 424 may intersect or intersect each other. Therefore, the shape of the exhaust portion 420 may be a cross (+) shape, but this disclosure is not limited thereto.

[0109] In an embodiment, the exhaust portion 420 may include a recess 440. More specifically, the recess 440 may include a first recess 442 formed extending laterally in a first region 422 and a second recess 444 formed extending vertically in a second region 424. The recess 440 may be formed in a shape corresponding to the exhaust portion 420. For example, the first recess 442 and the second recess 444 may intersect or cross each other. Therefore, the shape of the recess 440 may be a cross (+) shape, but this disclosure is not limited thereto.

[0110] In this embodiment, the length w4 of the exhaust portion 420 in the lateral direction may be equal to or shorter than the length w5 of the positive electrode terminal 430_1 in the lateral direction. Similarly, the length w4 of the exhaust portion 420 in the lateral direction may be equal to or shorter than the length of the negative electrode terminal 430_2 in the lateral direction.

[0111] In one embodiment, the length w4 of the first region 422 in the lateral direction can be equal to or longer than the length w6 of the second region 424 in the vertical direction. Additionally, the length w6 of the second region 424 in the vertical direction can be equal to or greater than the length of the positive electrode terminal 430_1 or the negative electrode terminal 430_2 in the vertical direction. As another example, the length w6 of the second region 424 in the vertical direction can be less than the length of the positive electrode terminal 430_1 or the negative electrode terminal 430_2 in the vertical direction.

[0112] As described above, the area of ​​the venting portion disposed between the positive and negative electrode terminals can be increased by changing its shape. Therefore, the area of ​​the venting portion for rupture can be ensured. Furthermore, according to some embodiments of this disclosure, a high degree of freedom in designing the secondary battery can be ensured because various modifications to the shape of the venting portion can be made while ensuring its area.

[0113] Figure 5 This is a plan view showing an example of a cover plate 510 having an exhaust portion 520 according to an embodiment of the present disclosure.

[0114] In one embodiment, positive electrode terminals 530_1 and negative electrode terminals 530_2, protruding outward from the upper surface of cover plate 510, can be coupled to cover plate 510. Additionally, cover plate 510 may include an exhaust portion 520 located between positive electrode terminals 530_1 and negative electrode terminals 530_2. The exhaust portion 520 may be configured to be spaced apart from each of the positive electrode terminals 530_1 and negative electrode terminals 530_2.

[0115] In one embodiment, the area of ​​the upper surfaces of the positive electrode terminal 530_1 and the negative electrode terminal 530_2 (e.g., the sum of the areas of the upper surfaces of the positive electrode terminal 530_1 and the negative electrode terminal 530_2) can be 20% to 50% of the area of ​​the upper surface of the cover plate 510. Furthermore, the area of ​​the upper surface of the exhaust portion 520 can be 10% to 50% of the area of ​​the upper surface of the cover plate 510. Additionally, the area of ​​the upper surfaces of the positive electrode terminal 530_1 and the negative electrode terminal 530_2 can be 40% to 500% of the area of ​​the upper surface of the exhaust portion 520.

[0116] In an embodiment, the exhaust portion 520 may include a plurality of exhaust portions. More specifically, the exhaust portion 520 may include portions in the lateral direction (e.g., Figure 1The first exhaust portion 522 extends in the D2 direction and is disposed in the vertical direction (e.g., relative to) the first exhaust portion 522. Figure 1 The second exhaust portion 524 is located in the D3 direction. The edges of each of the first exhaust portion 522 and the second exhaust portion 524 can be formed into a rounded shape. Figure 5 In the illustration, the number of multiple exhaust sections is shown as two, but this disclosure is not limited thereto.

[0117] In an embodiment, the exhaust portion 520 may include a recess formed to correspond to the shape of the exhaust portion 520. For example, refer to Figure 5 If (for example, when) each of the first exhaust portion 522 and the second exhaust portion 524 has an elongated groove shape in the lateral direction, a first recess 542 that is elongated in the lateral direction can be formed in the first exhaust portion 522, and a second recess 544 that is elongated in the lateral direction can be formed in the second exhaust portion 524.

[0118] In one embodiment, the length w4 of the exhaust portion 520 in the lateral direction may be equal to or shorter than the length w5 of the positive electrode terminal 530_1 in the lateral direction. Similarly, the length w4 of the exhaust portion 520 in the lateral direction may be equal to or shorter than the length of the negative electrode terminal 530_2 in the lateral direction.

[0119] exist Figure 5 In the present invention, the shapes of the first exhaust portion 522 and the second exhaust portion 524 are shown to be the same or substantially the same as each other, but the present disclosure is not limited thereto, and at least one of the lateral length, vertical length or shape of the first exhaust portion 522 may be different from that of the second exhaust portion 524.

[0120] As described above, the area can be increased by changing the number of venting portions disposed between the positive and negative electrode terminals. Therefore, the area of ​​the venting portions for rupture can be ensured. Furthermore, according to some embodiments of this disclosure, a high degree of freedom in designing the secondary battery can be ensured because various modifications can be made to the number of venting portions while ensuring the area of ​​the venting portions.

[0121] Figure 6 This is a plan view showing an example of a cover plate 610 having an exhaust portion 620 according to an embodiment of the present disclosure.

[0122] In one embodiment, positive electrode terminals 630_1 and negative electrode terminals 630_2, protruding outward from the upper surface of cover plate 610, can be coupled to cover plate 610. Additionally, cover plate 610 may include an venting portion 620 located between positive electrode terminals 630_1 and negative electrode terminals 630_2. The venting portion 620 may be configured to be spaced apart from each of the positive electrode terminals 630_1 and negative electrode terminals 630_2.

[0123] In one embodiment, the area of ​​the upper surfaces of the positive electrode terminal 630_1 and the negative electrode terminal 630_2 (e.g., the sum of the areas of the upper surfaces of the positive electrode terminal 630_1 and the negative electrode terminal 630_2) can be 20% to 50% of the area of ​​the upper surface of the cover plate 610. Furthermore, the area of ​​the upper surface of the exhaust portion 620 can be 10% to 50% of the area of ​​the upper surface of the cover plate 610. Additionally, the area of ​​the upper surfaces of the positive electrode terminal 630_1 and the negative electrode terminal 630_2 can be 40% to 500% of the area of ​​the upper surface of the exhaust portion 620.

[0124] In an embodiment, the exhaust portion 620 may be circular in shape. In this case, the exhaust portion 620 may include a plurality of recesses 640. For example, the exhaust portion 620 may include recesses formed in the lateral direction (e.g., Figure 1 The first notch 642 extends in the D2 direction and is formed in the vertical direction (e.g., Figure 1 A second notch 644 extends in the D3 direction. The first notch 642 and the second notch 644 may intersect or cross each other. Figure 6 In the figure, the number of notches 640 is shown as two, but the present disclosure is not limited thereto, and additional notches may be formed in the exhaust portion 620.

[0125] In this embodiment, the length w4 of the exhaust portion 620 in the lateral direction may be equal to or shorter than the length w5 of the positive electrode terminal 630_1 in the lateral direction. Similarly, the length w4 of the exhaust portion 620 in the lateral direction may be equal to or shorter than the length of the negative electrode terminal 630_2 in the lateral direction.

[0126] Figure 7 This is a plan view showing an example of a cover plate 710 having an exhaust portion 720 according to an embodiment of the present disclosure.

[0127] In one embodiment, positive electrode terminals 730_1 and negative electrode terminals 730_2, protruding outward from the upper surface of cover plate 710, can be coupled to cover plate 710. Additionally, cover plate 710 may include an exhaust portion 720 located between positive electrode terminals 730_1 and negative electrode terminals 730_2. The exhaust portion 720 may be configured to be spaced apart from each of the positive electrode terminals 730_1 and negative electrode terminals 730_2.

[0128] In one embodiment, the area of ​​the upper surfaces of the positive electrode terminal 730_1 and the negative electrode terminal 730_2 (e.g., the sum of the areas of the upper surfaces of the positive electrode terminal 730_1 and the negative electrode terminal 730_2) can be 20% to 50% of the area of ​​the upper surface of the cover plate 710. Furthermore, the area of ​​the upper surface of the exhaust portion 720 can be 10% to 50% of the area of ​​the upper surface of the cover plate 710. Additionally, the area of ​​the upper surfaces of the positive electrode terminal 730_1 and the negative electrode terminal 730_2 can be 40% to 500% of the area of ​​the upper surface of the exhaust portion 720.

[0129] In an embodiment, the exhaust portion 720 may be elliptical in shape. In this case, the exhaust portion 720 may include a plurality of recesses 740. For example, the exhaust portion 720 may include recesses formed in the lateral direction (e.g., Figure 1 The first notch 742 extends in the D2 direction and is formed in the vertical direction (e.g., Figure 1 The second notch 744 extends in the D3 direction. The first notch 742 and the second notch 744 may intersect or cross each other.

[0130] In one embodiment, the length w4 of the exhaust portion 720 in the lateral direction may be equal to or shorter than the length w5 of the positive electrode terminal 730_1 in the lateral direction. Similarly, the length w4 of the exhaust portion 720 in the lateral direction may be equal to or shorter than the length of the negative electrode terminal 730_2 in the lateral direction.

[0131] In one embodiment, the length w4 of the exhaust portion 720 in the lateral direction may be longer than the length w6 of the exhaust portion 720 in the vertical direction. Additionally, the length w6 of the exhaust portion 720 in the vertical direction may be equal to or greater than the length of the positive electrode terminal 730_1 or the negative electrode terminal 730_2 in the vertical direction. As another example, the length w6 of the exhaust portion 720 in the vertical direction may be less than the length of the positive electrode terminal 730_1 or the negative electrode terminal 730_2 in the vertical direction.

[0132] Figure 8 This is a flowchart illustrating an example of a method 800 for manufacturing a secondary battery according to an embodiment of the present disclosure.

[0133] In one embodiment, a method 800 for manufacturing a secondary battery can be initiated, and an electrode assembly can be prepared (S810). The electrode assembly may include a positive electrode, a negative electrode, and a separator inserted between the positive and negative electrodes. The electrode assembly may be housed in a housing body (S820).

[0134] The positive and negative electrode terminals can be attached to the cover plate (S830). Each of the positive and negative electrode terminals can be electrically connected to the electrode assembly and can each protrude from the upper surface of the cover plate in a first direction. Additionally, the cover plate can be attached to the housing body (S840) to seal the opening in the housing body, and method 800 can then end.

[0135] In one embodiment, the first length of the housing body in the first direction may be longer than the second length of the housing body in the second direction perpendicular to or substantially perpendicular to the first direction. Furthermore, the second length may be longer than the third length of the housing body in a third direction perpendicular to or substantially perpendicular to each of the first and second directions. Additionally, the ratio of the first length to the second length may be greater than 1 and less than 3.

[0136] In this embodiment, the area of ​​the upper surface of the positive electrode terminal and the negative electrode terminal can be 20% to 50% of the area of ​​the upper surface of the cover plate. Additionally, the area of ​​the upper surface of the exhaust portion can be 10% to 50% of the area of ​​the upper surface of the cover plate.

[0137] In one embodiment, the cover plate may include an venting section located between the positive electrode terminal and the negative electrode terminal. The venting section may be configured to be spaced apart from each of the positive and negative electrode terminals.

[0138] In one embodiment, the exhaust portion may include a first region extending in a second direction and a second region extending in a third direction. At least a portion of the first region and at least a portion of the second region may intersect or intersect each other. Furthermore, the length of the first region in the second direction may be equal to or longer than the length of the second region in the third direction.

[0139] In one embodiment, the exhaust portion may include a first recess extending in a second direction in a first region and a second recess extending upward in a third direction in the second region. The first and second recesses may intersect or cross each other.

[0140] In one embodiment, the edge of the exhaust portion can be rounded, and the shape of the exhaust portion can be circular. As another example, the shape of the exhaust portion can be at least one of ellipse or polygon.

[0141] In an embodiment, the length of the exhaust portion in the second direction may be equal to or shorter than the length of either the positive electrode terminal and / or the negative electrode terminal in the second direction. Additionally, the exhaust portion may include a notch formed to correspond to the shape of the exhaust portion.

[0142] In this embodiment, the exhaust portion may include multiple exhaust portions. More specifically, the exhaust portion may include a first exhaust portion extending in a second direction and a second exhaust portion extending in the second direction and disposed on a third direction above the first exhaust portion.

[0143] Although embodiments of this disclosure have been described above, this disclosure is not limited thereto. Various modifications and variations can be made by those skilled in the art within the spirit of this disclosure and the equivalents of the appended claims.

Claims

1. A secondary battery, comprising: An electrode assembly includes a positive electrode, a negative electrode, and a diaphragm inserted between the positive electrode and the negative electrode; The housing body houses the electrode assembly; A cover plate that seals the opening of the housing body; as well as A positive electrode terminal and a negative electrode terminal, each of which is electrically connected to the electrode assembly, is coupled to the cover plate, and protrudes from the upper surface of the cover plate in a first direction. The cover plate includes an exhaust portion located between the positive electrode terminal and the negative electrode terminal. The first length of the housing body in the first direction is longer than the second length of the housing body in the second direction perpendicular to the first direction, and The second length is longer than the third length of the housing body in a third direction, which is perpendicular to each of the first and second directions.

2. The secondary battery according to claim 1, wherein the ratio of the first length to the second length is greater than 1 and less than 3.

3. The secondary battery according to claim 1, wherein the length of the cover plate in the first direction is 0.5 mm to 3.0 mm.

4. The secondary battery according to claim 1, wherein the area of ​​the upper surface of the positive electrode terminal and the negative electrode terminal is 20% to 50% of the area of ​​the upper surface of the cover plate.

5. The secondary battery according to claim 1, wherein the area of ​​the upper surface of the venting portion is 10% to 50% of the area of ​​the upper surface of the cover plate.

6. The secondary battery according to claim 1, wherein the venting portion is spaced apart from each of the positive electrode terminal and the negative electrode terminal.

7. The secondary battery according to claim 1, wherein the venting portion comprises: The first region extends in the second direction; as well as The second region extends upwards from the third party.

8. The secondary battery of claim 7, wherein at least a portion of the first region and at least a portion of the second region intersect each other.

9. The secondary battery according to claim 7, wherein the length of the first region in the second direction is equal to or longer than the length of the second region in the third direction.

10. The secondary battery according to claim 7, wherein the venting portion comprises: A first notch extends in the first region in the second direction; as well as The second notch extends upward in the second region from the third party, and The first notch and the second notch intersect each other.

11. The secondary battery according to claim 1, wherein the edge of the venting portion has a rounded shape.

12. The secondary battery according to claim 1, wherein the shape of the venting portion is circular.

13. The secondary battery according to claim 1, wherein the length of the venting portion in the second direction is equal to or shorter than the length of at least one of the positive electrode terminal or the negative electrode terminal in the second direction.

14. The secondary battery according to claim 1, wherein the venting portion comprises: The first exhaust portion extends in the second direction; as well as The second exhaust portion extends in the second direction and is spaced apart from the first exhaust portion in the third direction.

15. The secondary battery according to claim 1, wherein the venting portion includes a notch corresponding to the shape of the venting portion.

16. A method for manufacturing a secondary battery, the method comprising: Prepare an electrode assembly, the electrode assembly including a positive electrode, a negative electrode, and a diaphragm inserted between the positive electrode and the negative electrode; The electrode assembly is housed within the housing body; Positive and negative electrode terminals are coupled to a cover plate, the positive and negative electrode terminals being electrically connected to the electrode assembly and protruding from the upper surface of the cover plate in a first direction; as well as The cover plate is attached to the housing body to seal the opening of the housing body. The cover plate includes an exhaust portion between the positive electrode terminal and the negative electrode terminal. The first length of the housing body in the first direction is longer than the second length of the housing body in the second direction perpendicular to the first direction, and The second length is longer than the third length of the housing body in a third direction, which is perpendicular to each of the first and second directions.

17. The method of claim 16, wherein the exhaust portion comprises: The first region extends in the second direction; as well as The second region extends upwards from the third party.

18. The method of claim 17, wherein at least a portion of the first region and at least a portion of the second region intersect each other.

19. The method of claim 17, wherein the length of the first region in the second direction is equal to or longer than the length of the second region in the third direction.

20. The method of claim 16, wherein the exhaust portion includes a notch corresponding to the shape of the exhaust portion.

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