Secondary battery

Abstract

A secondary battery includes an electrode assembly including a first electrode plate including a first substrate tab arranged in a first direction and a second electrode plate including a second substrate tab arranged in a second direction opposite the first direction, and the first electrode plate and the second electrode plate are provided in a stack. A case accommodating the electrode assembly; and a cover assembly including a pair of current collector plates electrically connected to the first substrate tab and the second substrate tab, respectively, and sealing the case. A larger number of the first substrate tabs are provided on the first electrode plate at a center of the stack than on the first electrode plate at an outer portion of the stack.

Description

[0001] This application claims priority and benefit to Korean Patent Application No. 10-2024-0155984, filed on November 6, 2024, with the Korean Intellectual Property Office, the entire disclosure of which is incorporated herein by reference. Technical Field

[0002] Embodiments of this disclosure relate to secondary batteries. Background Technology

[0003] Unlike primary batteries, secondary batteries are rechargeable and dischargeable. Low-capacity secondary batteries, packaged in groups with individual cells, are widely used in small portable electronic devices such as smartphones, feature phones, laptops, digital cameras, and camcorders. High-capacity secondary batteries are widely used as power sources for motors in hybrid and electric vehicles, as well as for energy storage. A secondary battery consists of an electrode assembly with positive and negative electrodes, a housing that houses the electrode assembly, and electrode terminals connected to the electrode assembly.

[0004] The information disclosed in this background section is only intended to enhance the understanding of the background technology of this invention, and therefore may contain information that does not constitute prior art. Summary of the Invention

[0005] This disclosure provides a secondary battery that, by varying the number of terminals on different electrode plates, exhibits improved reactivity in a centrally located electrode plate, thereby allowing all electrode plates within the electrode assembly to react uniformly.

[0006] However, the technical problems to be solved in the embodiments of this disclosure are not limited to those mentioned above, and those skilled in the art to which this disclosure pertains will clearly understand from the following description other technical problems not mentioned herein.

[0007] An exemplary secondary battery according to an embodiment of the present disclosure may include: an electrode assembly including a first electrode plate and a second electrode plate, the first electrode plate including a first substrate tab disposed in a first direction, the second electrode plate including a second substrate tab disposed in a second direction opposite to the first direction, and the first electrode plate and the second electrode plate being provided as a stack; a housing housing the electrode assembly; and a cover assembly including a pair of current collectors electrically connected to the first substrate tab and the second substrate tab, respectively, and the cover assembly sealing the housing, wherein a greater number of first substrate tabs are provided on the first electrode plate at the center of the stack than on the first electrode plate at the outer portion of the stack.

[0008] In some examples, the first substrate tab may be provided at the center of the stack such that the first substrate tab is dense at the center of the stack.

[0009] In some examples, the first electrode plates may be stacked such that the first substrate terminals are arranged in a diamond shape.

[0010] In some examples, the first electrode plate in the stack includes at least one first layer on a first side of the center of the stack, at least one second layer at the center of the stack, and at least one third layer on a second side of the center of the stack opposite to the first side.

[0011] In some examples, the number of first substrate terminals provided in the second layer is greater than the number of first substrate terminals provided in the first layer, and the number of first substrate terminals provided in the second layer is greater than the number of first substrate terminals provided in the third layer.

[0012] In some examples, the number of the first substrate terminals in the first layer and the number of the first substrate terminals in the third layer may be the same.

[0013] In some examples, the first substrate tab in each of the first, second, and third layers may protrude from the stack to the same length.

[0014] In some examples, one of the pair of current collectors may be soldered to the first substrate tab, and the soldering area of ​​the one of the pair of current collectors may be diamond-shaped.

[0015] In some examples, the first substrate terminals of the first layer and the first substrate terminals of the third layer may protrude from the stack to the same length, and the first substrate terminals of the first layer and the third layer may protrude from the stack to different lengths than the first substrate terminals of the second layer.

[0016] In some examples, the length by which the first substrate tab in the second layer protrudes from the stack may be greater than the length by which the first substrate tab in each of the first and third layers protrudes from the stack.

[0017] In some examples, the first substrate tab of the second layer can be bent and soldered to one of the pair of current collectors.

[0018] In some examples, the length by which the first substrate tab in the second layer protrudes from the stack may be shorter than the length by which the first substrate tab in the first layer and the third layer protrudes from the stack.

[0019] In some examples, the first substrate tabs in the first and third layers can be bent and soldered to one of the pair of current collectors.

[0020] In some examples, the side surface of the stack may have a central region and an edge region, the first substrate tab of the first electrode plate protrudes from the side surface of the stack, the first substrate tab in the second layer may be provided in the central region and the edge region, and the first substrate tab in the second layer provided in the central region and the first substrate tab in the second layer provided in the edge region may have the same protrusion length or different protrusion lengths.

[0021] In some examples, the first substrate terminal block provided in the edge region of the second layer may protrude longer than the first substrate terminal block provided in the center region of the second layer.

[0022] In some examples, the first substrate tab provided in the edge region of the second layer can be bent and soldered to one of the pair of current collectors.

[0023] In some examples, each of the first and third layers may include multiple electrode plates, and more first substrate tabs may be provided toward the center of the stack.

[0024] In some examples, the housing may include a bottom surface and a long side surface and a short side surface extending upward from the bottom surface, the cover assembly may further include a first terminal portion electrically connected to the first electrode plate, and one of the pair of current collector plates may include a first terminal connection portion connected to the first terminal portion and a first electrode connection portion extending from the first terminal connection portion, parallel to the short side surface and connected to the first electrode plate.

[0025] In some examples, each of the second electrode plates may have at least one second substrate tab, and a greater number of second substrate tabs may be provided on the second electrode plate at the center of the stack than on the second electrode plate at the outer portion of the stack.

[0026] In some examples, the outermost layer of the first electrode plate may have a first substrate terminal piece.

[0027] According to this disclosure, a secondary battery is provided that improves the reactivity of an electrode plate located at the center of a stack of electrode plates by changing the number of terminals on the electrode plates. This allows all electrode plates within the electrode assembly to react uniformly, thereby improving battery life and cycle performance.

[0028] However, the technical effects to be achieved in the embodiments of this disclosure are not limited to those mentioned above, and those skilled in the art to which this disclosure pertains will clearly understand from the following description other technical effects not mentioned herein. Attached Figure Description

[0029] The following figures, which are attached to this specification, illustrate preferred embodiments of the present disclosure and are used together with the detailed description of the present disclosure to further understand the technical ideas of the present disclosure. Therefore, the present disclosure should not be construed as being limited to the content described in these figures.

[0030] Figure 1 An exploded perspective view of a secondary battery according to an embodiment of the present disclosure is shown.

[0031] Figure 2 To show Figure 1 A cross-sectional view of a secondary battery.

[0032] Figure 3 This is a cross-sectional view of the terminal piece of an electrode assembly according to an embodiment of the present disclosure in a secondary battery from the side that protrudes from it.

[0033] Figure 4 This is a perspective view of a portion of an electrode assembly in a secondary battery according to an embodiment of the present disclosure.

[0034] Figures 5-7 This is a perspective view of a portion of an electrode assembly in a secondary battery according to various embodiments of the present disclosure.

[0035] Figure 8 A side view showing the combined state of the current collector plate and electrode assembly in a secondary battery according to an embodiment of the present disclosure.

[0036] Figure 9 A side view showing the combined state of the current collector plate and electrode assembly in a secondary battery according to another embodiment of the present disclosure.

[0037] Figure 10 A perspective view of a battery module according to an embodiment of the present disclosure is shown.

[0038] Figure 11 and Figure 12 A perspective view of a battery pack according to an embodiment of the present disclosure.

[0039] Figure 13 and Figure 14These are perspective and side views, respectively, showing the vehicle body and vehicle components according to embodiments of the present disclosure. Detailed Implementation

[0040] 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 having a general or dictionary meaning, and should be interpreted as being consistent with the technical spirit of the present disclosure, based on the principle that the inventor can best describe his / her invention in a way that appropriately defines the concepts of the terms for his / her own lexicographer. Therefore, the embodiments described in this specification and the configurations shown in the figures are merely some embodiments of the present disclosure and do not represent all the technical spirit, aspects, and features of the present disclosure. Accordingly, 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. Furthermore, it will be understood that the terms “comprising” and / or “including” as used in this specification 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. Additionally, when describing embodiments of the present disclosure, the terms “may be” or “may be” may include “one or more embodiments of the present disclosure”.

[0041] Furthermore, for a better understanding of the invention, the drawings are not drawn to scale, and the dimensions of some components may be enlarged. Additionally, in different embodiments, the same reference numerals may be assigned to the same components.

[0042] In comparisons, referring to two objects as identical means that they are substantially the same. Therefore, the phrase "substantially the same" can include situations where similarity is considered to be at a low level in the relevant domain, for example, a deviation within 5%. Additionally, when any parameter is referred to as consistent within a given region, this can mean that the parameter is consistent from an average perspective.

[0043] It will be understood that although the terms “first,” “second,” etc., may be used herein to describe various components, these components should not be limited by these terms. These terms are used to distinguish one component from another. Therefore, unless otherwise defined, the first component described below may be referred to as the second component without departing from the spirit and scope of this disclosure.

[0044] Throughout this specification, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise.

[0045] The arrangement of any component on or above the "upper (or lower) part" of a component means that any component is placed in contact with the upper (or lower) surface of the component. Additionally, this can mean that other components may be located between the component and any other components disposed on (or below) the component.

[0046] Furthermore, it will be understood that when an element is referred to as "connected to," "linked to," or "connected to" another element, these elements may be directly connected or linked to each other, or the elements may be connected, linked, or linked to each other through other intermediary elements. Additionally, it will be understood that when an element is referred to as "electrically connected to" another element, the element may be directly connected to the other element, or there may be an intermediary element between them that allows the element and the other element to be indirectly connected to each other.

[0047] Throughout this specification, unless otherwise stated, the phrase "A and / or B" means A, B, or A and B. That is, "and / or" includes any one or all of the listed items. Unless otherwise stated, the phrase "C to D" means C and below D.

[0048] Figure 1 An exploded perspective view of a secondary battery according to an embodiment of the present disclosure is shown. Figure 2 To show Figure 1 A cross-sectional view of a secondary battery.

[0049] refer to Figure 1 and Figure 2 The secondary battery 100 may include an electrode assembly 110, a housing 160, a cover assembly, and an insulating member 180. In some examples, the cover assembly may include a first current collector 120, a second current collector 130, a first terminal portion 140, a second terminal portion 150, and a cover plate 170.

[0050] The electrode assembly 110 can be formed by overlapping a first electrode plate 111, a diaphragm 113, and a second electrode plate 112, which are formed in the shape of a sheet or a film. In some examples, the first electrode plate 111 can be used as a positive electrode, and the second electrode plate 112 can be used as a negative electrode. Of course, the reverse is also possible.

[0051] In some examples, electrode assemblies 110 can be housed inside a housing by stacking multiple electrode assemblies 110 adjacent to each other, and the number of electrode assemblies 110 is not limited in this invention.

[0052] The first electrode plate 111 can be formed by coating a first electrode active material (such as graphite or carbon) onto a first electrode current collector plate (or first electrode current collector) formed of a metal foil (such as aluminum or aluminum alloy). The first electrode plate 111 may include a first active material layer coated with the first electrode active material. The first electrode plate 111 may include a first electrode uncoated portion 111a, which is a region where the first electrode active material is not coated.

[0053] In some examples, the uncoated portion 111a of the first electrode may be a first substrate tab. The first substrate tab 111a may be formed during the fabrication of the first electrode plate 111 by cutting the first electrode plate 111 so that the tab 111a protrudes from one side of the first electrode plate 111. In other examples, the first substrate tab 111a may protrude further from one side of the first electrode plate 111 than the diaphragm 113, without requiring separate cutting. Multiple first substrate tabs 111a may be formed such that at least some of the tabs 111a overlap when the first electrode plates 111 are stacked, thereby forming a multi-tab structure. The first substrate tab 111a may also be referred to as a first current collector tab. The first substrate tab 111a is structurally integral with the first electrode plate 111 and is led out from each of the stacked first electrode plates 111, thereby increasing the current collection efficiency of the electrode assembly 110. In some examples, a plurality of first substrate tabs 111a may be provided on each electrode plate and may protrude from one side of the electrode assembly 110 in the same direction (e.g., a first direction).

[0054] As the positive electrode active material that is the first active material, a compound capable of reversibly inserting / deintercalating lithium (e.g., a lithiation intercalation compound) can be used. Specifically, at least one of a composite oxide of lithium and a metal selected from cobalt, manganese, nickel, and combinations thereof can be used.

[0055] The composite oxide can be a lithium transition metal composite oxide, and specific examples may 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.

[0056] 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 X b O 4-c D c (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05); Li a Ni 1-b-c Co b X c O 2-α D α (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.5, 0<α<2); Li a Ni 1-b- c Mnb 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).

[0057] 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.

[0058] The positive electrode for a lithium secondary battery may include a current collector (e.g., a first substrate) and a positive electrode active material layer formed on the current collector. The positive electrode active material layer may include a positive electrode active material and may further include a binder and / or a conductive material.

[0059] Based on a 100wt% positive electrode active material layer, the content of the positive electrode active material is in the range of about 90wt% to about 99.5wt%, and based on the 100wt% positive electrode active material layer, the contents of the binder and conductive material are in the range of about 0.5wt% to about 5wt%, respectively.

[0060] As the current collector, aluminum (Al) can be used, but is not limited thereto.

[0061] The second electrode plate 112 can be formed by coating a second electrode active material (such as graphite or carbon) onto a second electrode current collector plate (or second electrode current collector) formed of a metal foil (such as copper, copper alloy, nickel, or nickel alloy). The second electrode plate 112 can include a second active material layer on which the second electrode active material is coated. The second electrode plate 112 can include a second electrode uncoated portion 112a that is an area where the second electrode active material is not coated.

[0062] In some examples, the second electrode uncoated portion 112a can be a second substrate tab. The second substrate tab 112a can be formed by cutting the second electrode plate 112 during the manufacture of the second electrode plate 112 such that the tab 112a protrudes from one side of the second electrode plate 112. In additional examples, the second substrate tab 112a can protrude further from one side of the second electrode plate 112 than the separator 113 without separate cutting. Multiple second substrate tabs 112a can be formed such that when the second electrode plates 112 are stacked, at least some of the tabs 112a overlap, thereby forming a multi-tab structure. The second substrate tab 112a can also be referred to as a second current collecting tab. The second substrate tab 112a is configured to be integrally formed with the second electrode plate 112 and protrude from each of the stacked second electrode plates 112, thereby increasing the current collecting efficiency of the electrode assembly 110. In some examples, multiple second substrate tabs 112a can be provided on each electrode plate and can protrude in the same direction (e.g., the second direction) from a side of the electrode assembly 110 opposite to the side from which the first substrate tab 111a protrudes.

[0063] The negative electrode active material for the second active material can include a material capable of reversibly intercalating / deintercalating lithium ions, lithium metal, an alloy of lithium metal, a material capable of doping and undoping lithium, or a transition metal oxide.

[0064] The material capable of reversibly intercalating / deintercalating lithium ions can be a carbon-based negative electrode active material, which can include, for example, crystalline carbon, amorphous carbon, or a combination thereof. Examples of crystalline carbon can include graphite, such as natural graphite or artificial graphite, and examples of amorphous carbon can include soft carbon, hard carbon, pitch carbide (e.g., mesophase pitch carbide), calcined coke, etc.

[0065] Si-based negative electrode active material or Sn-based negative electrode active material can be used as the material capable of doping and undoping lithium. The silicon-based negative electrode active material can be silicon, silicon-carbon composite, SiO x (0 < x ≤ 2), Si-based alloy, or a combination thereof.

[0066] Silicon-carbon composites can be a combination of silicon and amorphous carbon. For example, a silicon-carbon composite can be in the form of silicon particles and amorphous carbon coated on the surface of the silicon particles.

[0067] The silicon-carbon composite may further include crystalline carbon. For example, the silicon-carbon composite may include a core comprising crystalline carbon and silicon particles, and an amorphous carbon coating on the surface of the core.

[0068] The negative electrode for a lithium secondary battery may include a current collector and a negative electrode active material layer disposed 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.

[0069] For example, the negative electrode active material layer may include about 90 wt% to about 99 wt% of negative electrode active material, about 0.5 wt% to about 5 wt% of binder and about 0 wt% to about 5 wt% of conductive material.

[0070] Non-aqueous adhesives, aqueous adhesives, dry adhesives, or combinations thereof can be used as adhesives. When an aqueous adhesive is used as a negative electrode adhesive, it may further include cellulose compounds capable of imparting viscosity.

[0071] As the negative electrode current collector, one can be selected from copper foil, nickel foil, stainless steel foil, titanium foil, nickel foam, copper foam, polymer substrate coated with conductive metal, and combinations thereof.

[0072] Electrolytes used in lithium secondary batteries may include non-aqueous organic solvents and lithium salts.

[0073] Non-aqueous organic solvents are used as a medium through which ions participating in the electrochemical reactions of the battery can move.

[0074] 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.

[0075] In addition, when using carbonate solvents, a mixture of cyclic carbonates and chain carbonates can be used.

[0076] The diaphragm 113 is located between the first electrode plate 111 and the second electrode plate 112 to prevent the circuit between them.

[0077] Depending on the type of lithium secondary battery, a separator may be present between the first electrode plate (e.g., the positive electrode) and the second electrode plate (e.g., the negative electrode). As the separator, polyethylene, polypropylene, polyvinylidene fluoride, or multilayer films of two or more layers thereof may be used.

[0078] The diaphragm 113 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.

[0079] Organic materials may include polyvinylidene fluoride polymers or (meth)acrylic acid polymers.

[0080] 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.

[0081] Organic and inorganic materials can be mixed in a single coating, or they can be in the form of coatings containing organic materials and coatings containing inorganic materials stacked on top of each other.

[0082] The first current collector plate 120 and the second current collector plate 130, which are electrically connected to the first electrode plate 111 and the second electrode plate 112 respectively, are located at both ends of the electrode assembly 110.

[0083] The first current collector plate 120 is made of metal (e.g., aluminum) and is electrically connected to the first electrode plate 111. The first current collector plate 120 may be located on one side of the electrode assembly 110 and may be welded to the uncoated portion 111a of the first electrode. In some examples, multiple uncoated portions 111a of the first electrode may be bent in one direction and laser-welded to the first current collector plate 120. The structure of the first current collector plate 120 will be described in more detail below.

[0084] The second current collector plate 130 is made of metal (e.g., copper) and is electrically connected to the second electrode plate 112. The second current collector plate 130 may be located on the other side of the electrode assembly 110 and may be welded to the uncoated portion 112a of the second electrode. A plurality of uncoated portions 112a of the second electrode may be bent in one direction and laser welded to the second current collector plate 130.

[0085] The first terminal portion 140 is electrically connected to the first current collector plate 120. The first terminal portion 140 may include a connecting plate 141, a terminal post 142, and a terminal plate 143.

[0086] The connecting plate 141 is located above the electrode assembly 110 and is electrically connected to the first current collector plate 120. The connecting plate 141 may be formed perpendicular to the first current collector plate 120. The connecting plate 141 may include a hole 141a to which a terminal post 142 is coupled. In some examples, the connecting plate 141 may be integrally formed with the first current collector plate 120, or may be part of the first current collector plate 120.

[0087] Terminal post 142 may have a lower portion that connects to a hole 141a in the connecting plate 141 and an upper portion that passes through and projects upward from the cover plate 170. A laterally extending flange 142a may be formed below the cover plate 170 to prevent the terminal post 142 from falling out of the cover plate 170. In some examples, terminal post 142 may be electrically connected to the cover plate 170.

[0088] Terminal plate 143 may include a hole 143a to which terminal post 142 is coupled. Terminal plate 143 may be coupled to an upper portion of terminal post 142 that protrudes above cover plate 170. In some examples, terminal post 142 may be coupled to hole 143a of terminal plate 143 and riveted and / or soldered.

[0089] The second terminal portion 150 is electrically connected to the second current collector plate 130 and may have the same shape as the first terminal portion 140. The second terminal portion 150 may include a connecting plate 151, a terminal post 152, and a terminal plate 153.

[0090] A connecting plate 151 is located above the electrode assembly 110 and is electrically connected to the second current collector plate 130. The connecting plate 151 may be formed perpendicular to the second current collector plate 130. The connecting plate 151 may include a hole 151a to which a terminal post 152 is coupled. In some examples, the connecting plate 151 may be integrally formed with the second current collector plate 130, or may be part of the second current collector plate 130.

[0091] Terminal post 152 may have a lower portion that connects to a hole 151a in the connecting plate 151 and an upper portion that passes through and projects upward from the cover plate 170. A laterally extending flange 152a may be formed under the cover plate 170 to prevent the terminal post 152 from falling out of the cover plate 170. In some examples, terminal post 152 may be electrically isolated from the cover plate 170.

[0092] Terminal plate 153 may include a hole 153a to which terminal post 152 is coupled. Terminal plate 153 may be coupled to an upper portion of terminal post 152 that protrudes above cover plate 170. In some examples, terminal post 152 may be coupled to hole 153a of terminal plate 153 and riveted and / or soldered.

[0093] The housing 160 may be made of a conductive metal such as aluminum, aluminum alloy, or nickel-plated steel. The housing 160 may be shaped as a substantially hexahedron with openings into which the electrode assembly 110 may be inserted and disposed. For example, the housing 160 may include a bottom surface 161 and a pair of long side surfaces 162 and a pair of short side surfaces 163 extending upward from the bottom surface 161. Here, the long side surfaces 162 may refer to surfaces having a relatively larger area than the short side surfaces 163. A cover plate 170 may be coupled to the openings of the housing 160 to seal the housing 160. The inner surface of the housing 160 is substantially insulated to prevent internal short circuits. Additionally, in some cases, one electrode of the electrode assembly 110 may be electrically connected to the housing 160 via the cover plate 170. Even in this case, internal short circuits within the housing 160 can be prevented by an insulation process within the housing 160. For example, the housing 160 may serve as a positive electrode.

[0094] The cover plate 170 can be attached to the housing 160. The cover plate 170 seals the opening of the housing 160 and can be made of the same material as the housing 160. In some examples, the cover plate 170 can be attached to the housing 160 by laser welding. Here, as described above, because the cover plate 170 can have the same polarity as the first terminal portion 140, the cover plate 170 and the housing 160 can have the same polarity. The cover plate 170 may include an electrolyte injection port 171, a plug 172, a safety vent 173, a gasket 174, and a connecting member 175.

[0095] An electrolyte injection hole 171 can be formed through a cover plate 170. The electrolyte injection hole 171 is a hole for injecting electrolyte into the housing 160. A plug 172 can be connected to the electrolyte injection hole 171. That is, after the electrolyte is injected, the electrolyte injection hole 171 can be sealed by the plug 172.

[0096] A safety vent 173 may be formed at the substantially central portion of the cover 170. The safety vent 173 may be formed to be relatively thinner than the cover 170. Additionally, a notch may be formed in the safety vent 173 to open under a set pressure. In some examples, when the pressure inside the housing 160 exceeds a set pressure due to overcharging of the secondary battery 100, the notch ruptures, and the gas inside the housing 160 is released to the outside through the safety vent 173. Therefore, ignition or explosion of the secondary battery 100 can be prevented.

[0097] The gasket 174 may be made of an insulating material. The gasket 174 is formed at the lower portion of the cover plate 170 between the terminal posts 142, 152 and the cover plate 170 to seal the portion between the terminal posts 142, 152 and the cover plate 170. The gasket 174 prevents external moisture from penetrating into the secondary battery 100, or prevents the electrolyte contained in the secondary battery 100 from leaking to the outside.

[0098] A connecting member 175 may be formed at the upper portion of the cover plate 170 between the terminal plates 143, 153 and the cover plate 170. Additionally, the connecting member 175 may be in close contact with the gasket 174 and the cover plate 170. In some examples, the connecting member 175 formed on the terminal post 142 may electrically connect the cover plate 170 and the first terminal portion 140 to each other, and the connecting member 175 formed on the terminal post 152 may insulate the cover plate 170 and the second terminal portion 150 from each other.

[0099] An insulating member 180 is formed below the cover plate 170 to prevent unnecessary short circuits between the first current collector plate 120 and the second current collector plate 130 (or connecting plates 141, 151) and the cover plate 170.

[0100] Each electrode plate includes a protruding rectangular current collector of the uncoated mixture, referred to as the uncoated portion. This structure transfers electrons to the active material within the mixture via external circuitry, causing electrons and lithium ions to react within the active material. In electrode assemblies consisting of multiple stacked layers, the reactivity between the active material and lithium ions in the layers facing the center is relatively lower than that of the electrode plates located at the outer portions of the electrode assembly during battery cycling. When a cell is disassembled and the condition of the electrode plates is examined, it is confirmed that the amount of deposits gradually increases towards the center.

[0101] In some embodiments, electrochemical reactivity is improved by gradually increasing the number of tabs in the centrally located electrode plate of the secondary battery 100 to facilitate electron movement. In some examples of the secondary battery 100, the number of tabs in the provided electrode assembly 110 is greater in the center of the electrode plate than in the outer portion, thereby improving electrochemical reactivity. By increasing the number of tabs in the central electrode plate of the electrode assembly 110, the electrochemical reactivity of all electrode plates can be made more uniform compared to conventional electrode assemblies with the same number of tabs in all electrode plates. For example, in some embodiments, the secondary battery 100 may include an electrode assembly 110 having electrode plates with a tab at the outermost electrode plate, and the number of tabs increasing in the electrode plates toward the center of the electrode assembly. This configuration can be applied to all electrode plates, i.e., both positive and negative electrode plates, or to only one type of electrode plate, i.e., either a positive electrode plate or a negative electrode plate. For convenience, the first electrode plate 111 will be described below. However, although the description of the second electrode plate will be omitted, the same description applies to the second electrode plate 112.

[0102] Figure 3 This is a cross-sectional view of the terminal piece of an electrode assembly according to an embodiment of the present disclosure in a secondary battery from the side that protrudes from it. Figure 4This is a perspective view of a portion of an electrode assembly in a secondary battery according to an embodiment of the present disclosure. Figures 5-7 This is a perspective view of a portion of an electrode assembly in a secondary battery according to various embodiments of the present disclosure. In some examples, the electrode assembly 110 may be stacked in a Z-stack manner, wherein a first electrode plate 111 and a second electrode plate 112 are stacked with a separator 113 between them. For convenience, the second electrode plate 112 and the separator 113 may be shown as considerably reduced or omitted in the figure.

[0103] refer to Figure 3 and Figure 4 According to an embodiment of the present disclosure, a secondary battery 100 may include an electrode assembly 110, which is stacked to form a stack in such a state that a separator 113 is between a plurality of first electrode plates 111 and a plurality of second electrode plates 112 having a first substrate terminal piece 111a arranged in one direction.

[0104] In some examples, each of the plurality of first electrode plates 111 may have at least one first substrate tab 111a. A larger number of first substrate tabs 111a may be provided in the stack of the first electrode plates 111 (e.g., in...). Figure 3 On the first electrode plate 111 at the center (in the x-direction) of the stack. In some examples, a larger number of first substrate tabs 111a may be provided on the first electrode plate 111 at the center of the stack than on the first electrode plate 111 at the outer portion of the stack. For example, 16 first substrate tabs 111a may be provided at the center of the stack, and 12 first substrate tabs 111a may be provided in other portions of the stack. In some examples, the first substrate tabs 111a may be provided in the central region, such that the first substrate tabs 111a are densely packed in the central region. Figure 3 and Figure 4 In the example depicted, multiple first electrode plates 111 can be stacked such that the first substrate terminals 111a are arranged in a rhomboid shape.

[0105] In some examples, relative to the orientation of the stack, the plurality of first electrode plates 111 may include at least one first layer 1101 stacked on a first side of the center of the stack, at least one second layer 1102 stacked on the center of the stack, and at least one third layer 1103 stacked on a second side opposite to the first side of the center of the stack (see [reference]). Figure 3 In some examples, each of the first and third layers may include multiple electrode plates, and a greater number of substrate tabs may be provided toward the center. In some examples, the outermost layer of the multiple first electrode plates may include a first substrate tab.

[0106] refer to Figure 4The first layer is represented by 'a', the second layer by 'b', and the third layer by 'c'. Additionally, in some examples, in the width direction (e.g., ...), Figure 4 In the z-direction, each of the plurality of first electrode plates 111 may include, as shown in the following manner: Figure 4 The 'd' indicates the central area and the edge areas on both sides of the central area.

[0107] In some examples, more first substrate tabs 111a are provided in the second layer 1102 than in the first layer 1101 and the third layer 1103. In a further example, the number of first substrate tabs 111a in the first layer 1101 is the same as the number of first substrate tabs 111a in the third layer 1103. In an even further example, more substrate tabs may be provided toward the center of the stack.

[0108] refer to Figure 4 Each of the first substrate tabs 111a in the first layer 1101, second layer 1102, and third layer 1103 may protrude from the stack by the same length. In some examples, when the first electrode connection portion 122 is soldered to the first substrate tab 111a, the first substrate tab 111a may be pressed by the solder load applied by the first electrode connection portion 122, such that the first substrate tab 111a may be compressed or bent. In some examples, the first substrate tab 111a of each of the first layer 1101, second layer 1102, and third layer 1103 may be bent and soldered to the first electrode connection portion 122. Because the first substrate tabs 111a are dense in the central region d, even when pressed, the first substrate tabs 111a may be pressed into a generally rhomboid shape.

[0109] refer to Figure 5 and Figure 6 In some examples, the first substrate tab 111a of each of the first layer 1101 and the third layer 1103 may protrude from the stack by the same length. In some examples, the first substrate tab 111a of the first layer 1101 and the third layer 1103 may protrude from the stack by a different length than the first substrate tab 111a of the second layer 1102. In a further example, the first substrate tab 111a of each of the first layer 1101, the second layer 1102, and the third layer 1103 may protrude to the same length.

[0110] refer to Figure 5In some examples, the protruding length of the first substrate tab of the second layer is longer than the protruding length of the first substrate tabs of each of the first and third layers. In some examples, when the first electrode connection portion 122 is soldered to the first substrate tab 111a, the first substrate tab 111a of the second layer 1102 can be pressed by the solder load applied by the first electrode connection portion 122, such that the first substrate tab 111a of the second layer 1102 can be compressed or bent. In some examples, the first substrate tab 111a of the second layer 1102 can be bent and soldered to the first current collector 120 (e.g., the first electrode connection portion 122 of the first current collector 120).

[0111] refer to Figure 6 In some examples, the protruding length of the first substrate tab of the second layer may be shorter than the protruding length of the first substrate tabs of each of the first and third layers. In some examples, when the first electrode connection portion 122 is soldered to the first substrate tab 111a, the corresponding first substrate tabs 111a of the first layer 1101 and the third layer 1103 may be pressed by the soldering load applied by the first electrode connection portion 122, such that the corresponding first substrate tabs 111a of the first layer 1101 and the third layer 1103 may be compressed or bent. In some examples, the corresponding first substrate tabs 111a of the first layer 1101 and the third layer 1103 may be bent and soldered to the first current collector 120 (e.g., the first electrode connection portion 122 of the first current collector 120). In some examples, the corresponding pressed first substrate tabs 111a of the first layer 1101, the second layer 1102, and the third layer 1103 may have the same end position.

[0112] refer to Figure 7 In some examples, the side surface of the stack may have a central region and an edge region. A first substrate tab of the first electrode plate protrudes from the side surface of the stack. A first substrate tab of the second layer may be provided in both the central and edge regions, and the first substrate tab in the central region of the second layer and the first substrate tab in the edge region of the second layer may have the same or different protrusion lengths. In other examples, the first substrate tab in the edge region of the second layer protrudes longer than the first substrate tab in the central region of the second layer.

[0113] In some examples, when the first electrode connection portion 122 is soldered to the first substrate tab 111a, the first substrate tab provided in the edge region of the second layer can be pressed by the soldering load applied by the first electrode connection portion 122, such that the first substrate tab provided in the edge region of the second layer can be compressed or bent. In some examples, the first substrate tab provided in the edge region of the second layer can be bent and soldered to the first current collector 120 (e.g., the first electrode connection portion 122 of the first current collector 120).

[0114] Figure 8 A side view showing the combined state of the current collector plate and electrode assembly of a secondary battery according to an embodiment of the present disclosure. Figure 9 This is a side view showing the combined state of the current collector plate and electrode assembly of a secondary battery according to another embodiment of the present disclosure. In this disclosure, the first current collector plate 120 and the second current collector plate 130 have the same structure. Therefore, only the first current collector plate 120 will be described below. Additionally, the first current collector plate 120 may be referred to as a current collector plate.

[0115] refer to Figure 8 and Figure 9 The first current collector 120 may include a first terminal connection portion 121 and a first electrode connection portion 122. The first electrode connection portion 122 may include a side that contacts the first substrate tab 111a and an opposite side facing the short side surface 163 of the housing 160. The first electrode connection portion 122 may be positioned parallel to the short side surface 163 of the housing 160.

[0116] The first terminal connection portion 121 is connected to the connecting plate 141 and may be located at the upper end of the first current collector plate 120. In some examples, the first terminal connection portion 121 may be electrically connected to the connecting plate 141 by soldering. In other examples, the first terminal connection portion 121 may be integrally formed with the connecting plate 141. Soldering between the first terminal connection portion 121 and the connecting plate 141 may be unnecessary. Compared to the first electrode connection portion 122, the first terminal connection portion 121 may protrude toward the short side surface 163 of the housing 160.

[0117] The first electrode connection portion 122 is the portion connected to the first substrate terminal piece 111a, and may additionally include a portion for laser welding the first substrate terminal piece 111a. The first electrode connection portion 122 may be formed in a rhomboid shape, such that the laser welding portion W protrudes towards one side of the first electrode plate 111 and can be welded to the rhomboid-shaped first substrate terminal piece 111a. The first electrode connection portion 122 may be positioned closer to the electrode assembly 110 than the first terminal connection portion 121. That is, a step may be formed between the first terminal connection portion 121 and the first electrode connection portion 122. With this configuration, by positioning the first electrode connection portion 122 closer to the electrode assembly 110, the internal space of the housing 160 can be better utilized, and the capacity per unit volume of the electrode assembly 110 can be increased.

[0118] refer to Figure 8 and Figure 9 The first current collector plate 120 and the first substrate terminal piece 111a can be connected by laser welding. The welding area W can be formed in the form of multiple lines by a laser beam irradiating the first electrode connection portion 122.

[0119] In some examples, the first substrate terminal block 111a may be bent toward the second layer 1102. For example, multiple substrate terminal blocks arranged in multiple layers may be bent from both sides toward the center. As described above, the first current collector 120 may be soldered to the bent first substrate terminal block 111a, and the soldering area W of the current collector 120 may be a rhomboid shape corresponding to the shape of the bent first substrate terminal block 111a.

[0120] In some examples, such as Figure 4 As shown, the protrusion length of the first substrate terminal piece 111a in each of the first layer 1101, the second layer 1102, and the third layer 1103 can all be the same. Because the protrusion lengths are all the same, the soldering area can be formed to correspond to the shape of the protrusion of the first substrate terminal piece 111a when the first electrode connection portion 122 contacts the first substrate terminal piece 111a, such as... Figure 8 As shown in the image.

[0121] In other examples, such as Figure 5As shown, the protruding length of the first substrate terminal block 111a in the second layer 1102 can be greater than the protruding length of the first substrate terminal block 111a in each of the first layer 1101 and the third layer 1103. Because the protruding length of the substrate terminal block 111a in the center is greater than the protruding length of the substrate terminal blocks 111a on both sides, when pressed towards the central axis, the substrate terminal block 111a on the central axis can protrude longer than the substrate terminal blocks 111a on both sides. By bending the substrate terminal block 111a in one direction towards the central axis and making the substrate terminal block 111a in close contact with the first electrode connection portion 122, and by irradiating the surface opposite to the surface of the substrate terminal block 111a in contact with the first electrode connection portion 122 with a laser beam, the first substrate terminal block 111a can be electrically connected to the first current collector plate 120. Here, the soldering area W can be approximately rectangular in shape.

[0122] In some other examples, the protruding length of the first substrate terminal block 111a of the second layer 1102 may be shorter than the protruding length of the first substrate terminal block 111a in each of the first layer 1101 and the third layer 1103 (see [reference]). Figure 6 Because the protruding length of the substrate terminals 111a on both sides is longer than that of the substrate terminal 111a in the center, when pressed towards the central axis, the longer substrate terminals 111a on both sides are partially bent and converge towards the central axis. Therefore, the first substrate terminals 111a being pressed can have the same end position. In some examples, because the ends of the first substrate terminals 111a are identical, as... Figure 8 As shown, a welding area can be formed corresponding to the shape of the first substrate terminal piece 111a that is pressed when the first electrode connection portion 122 contacts the first substrate terminal piece 111a that is pressed.

[0123] like Figure 7As shown, the first substrate connector 111a provided in the edge region of the second layer 1102 may protrude longer than the first substrate connector 111a provided in the central region d. For example, the first substrate connector 111a in the edge region where the first substrate connector 111a is least present may be the longest. In some examples, the first substrate connector 111a is pressed based on the second layer 1102, and the pressed first substrate connector 111a provided in the edge region of the second layer 1102 may be bent to one side and soldered to the first current collector 120. When pressed by the first current collector 120, the first substrate connector 111a in the edge region where the first substrate connector 111a is longest may be bent to one side. For example, by bending the substrate terminal block 111a at its edge in one direction, the substrate terminal block 111a contacts the first electrode connection portion 122, and a laser beam is irradiated onto the surface opposite to the surface of the substrate terminal block 111a that contacts the first electrode connection portion 122, the first substrate terminal block 111a can be electrically connected to the first current collector plate 120. Here, as... Figure 9 As shown, the welding area W can be biased towards the general bending direction.

[0124] Regarding the longest protruding first substrate tab 111a, in some examples, by bending multiple first substrate tabs 111a in one direction so that tabs 111a contact the first electrode connection portion 122, and the laser beam irradiates the surface opposite to the surface of the substrate tab 111a that contacts the first electrode connection portion 122, the first substrate tab 111a can be electrically connected to the first current collector plate 120. In some examples, when multiple first substrate tabs 111a are bent in one direction, the bent portion can first protrude outward from the first electrode connection portion 122, and the protruding portion can be bent again to contact the outer surface (i.e., the housing side) of the first electrode connection portion 122.

[0125] As described above, in this disclosure, by varying the number of terminals on each electrode plate, the reactivity of the electrode plate located at the center of the electrode assembly can be improved, thereby allowing for uniform reaction across all electrode plates in the assembly. When the number of terminals is the same, the electrochemical reactivity of the electrode plate located at the center of the electrode assembly is poor due to increased in-plane resistance, intensified ion concentration gradients, and localized heat buildup. These conditions lead to higher polarization and increased parasitic side reaction rates, as evidenced by the large amount of deposits observed towards the core region during post-cycle disassembly analysis. However, in this disclosure, uniform reaction is achieved between the electrode plates at the outer and center of the electrode assembly, thereby improving battery life and cycle performance.

[0126] Figure 10 A perspective view of a battery module 20a according to one or more embodiments of the present disclosure is shown. (See reference...) Figure 10A battery module 20a according to one or more embodiments of the present disclosure includes terminal portions 14 and 15, a plurality of battery cells 100A arranged in one direction, a connecting tab 22 connecting the battery cells 100A to adjacent battery cells 100b, and a protection circuit module 23 having one end connected to the connecting tab 22. The protection circuit module 23 may include a battery management system (BMS). Further, the connecting tab 22 may include a body portion that contacts the terminal portions 14 and 15 between adjacent battery cells 100a and 100b, and an extension portion extending from the body portion and connected to the protection circuit module 23. The connecting tab 22 may be, for example, a busbar.

[0127] Each battery cell 100A may include a battery casing, an electrode assembly received (or housed) within the battery casing, and an electrolyte. The electrode assembly and electrolyte undergo an electrochemical reaction to store and release (e.g., generate) energy. Terminals 14, 15 electrically connected to connecting tabs 22 and an exhaust portion 17 serving as an exhaust channel for gases generated inside the battery casing may be provided on one side (e.g., the upper side) of the battery cell 100A. Terminals 14, 15 of the battery cell 100A may be positive electrode terminals 14 and negative electrode terminals 15 having different polarities from each other, and the terminals 14, 15 of adjacent battery cells 100a, 100b may be electrically connected to each other in series or in parallel via connecting tabs 22, which will be described in more detail below. Although a series connection has been described as an example, the connection structure is not limited thereto, and various connection structures may be employed as desired or required. Furthermore, the number and arrangement of battery cells are not limited to... Figure 10 The structure shown is available and can be changed as desired or required.

[0128] Multiple battery cells 100A may be arranged in one direction (e.g., stacked in one direction) such that the wide surfaces of the battery cells 100A face each other, and the multiple battery cells 100A may be secured by housings 26-1, 26-2, 26-3, and 26-4. Housings 26-1, 26-2, 26-3, and 26-4 may include a pair of end plates 26-1, 26-2 facing the wide surfaces of the battery cells 100A, and a side plate 26-3 and a bottom plate 26-4 connecting the pair of end plates 26-1, 26-2 to each other. The side plate 26-3 may support the side surfaces of the battery cells 100A, and the bottom plate 26-4 may support the bottom surfaces of the battery cells 100A. Additionally, the pair of end plates 26-1, 26-2, the side plate 26-3, and the bottom plate 26-4 may be connected by bolts 26-5 and / or any other suitable fastening members and methods known to those skilled in the art.

[0129] The protection circuit module 23 may have electronic components and protection circuitry mounted thereon, and may be electrically connected to connection tabs 22, which will be described in more detail later. The protection circuit module 23 includes a first protection circuit module 23a and a second protection circuit module 23b extending along a direction in which the plurality of battery cells 100A are arranged at different locations. The first protection circuit module 23a and the second protection circuit module 23b may be appropriately spaced apart (e.g., a predetermined interval) and arranged parallel to each other to be electrically connected to adjacent connection tabs 22, respectively. For example, the first protection circuit module 23a extends along the direction in which the plurality of battery cells 100A are arranged on one side of the upper portion of the plurality of battery cells 100A, and the second protection circuit module 23b extends along the direction in which the plurality of battery cells 100A are arranged to the other upper side of the plurality of battery cells 100A. The second protection circuit module 23b may be appropriately spaced apart (e.g., a predetermined interval) from the first protection circuit module 23a with an exhaust portion 17 between them, but may be configured to be parallel to the first protection circuit module 23a. Thus, the two protection circuit modules are arranged side-by-side and spaced apart from each other along the direction in which multiple battery cells 100A are arranged, thereby reducing or minimizing the area of ​​the printed circuit board (PCB) constituting the protection circuit module. By configuring the protection circuit module as two separate protection circuit modules, the unnecessary protection circuit module area can be reduced or minimized. In addition, the first protection circuit module 23a and the second protection circuit module 23b can be connected to each other via a conductive connecting member 25-1. One side of the conductive connecting member 25-1 is connected to the first protection circuit module 23a, and the other side is connected to the second protection circuit module 23b, so that the two protection circuit modules 23a and 23b can be electrically connected to each other.

[0130] The connection can be performed by any one of brazing, resistance welding, laser welding, projection welding and / or any other suitable connection method known to those skilled in the art.

[0131] Additionally, the connecting member 25-1 can be, for example, an electrical wire. Furthermore, the connecting member 25-1 can be made of a resilient or flexible material. Through the connecting member 25-1, the voltage, temperature, and / or current of multiple battery cells 100A can be checked and managed to ensure they are normal. For example, information (such as voltage, current, and / or temperature) received by the first protection circuit module from the connecting tab adjacent to the first protection circuit module, and information (such as voltage, current, and / or temperature) received from the connecting tab adjacent to the second protection circuit module, can be integrated and managed by the protection circuit module through the connecting member 25-1.

[0132] In addition, when the battery cell 100A expands, the impact can be absorbed by the elasticity or flexibility of the connecting member 25-1, thereby preventing damage to the first protection circuit module 23a and the second protection circuit module 23b.

[0133] Furthermore, the shape and structure of the connecting member 25-1 are not limited to... Figure 10 The shapes and structures shown.

[0134] As described above, since the protection circuit module 23 is provided as a first protection circuit module 23a and a second protection circuit module 23b, the area of ​​the PCB constituting the protection circuit module can be reduced or minimized, and the space inside the battery module can be ensured. This improves work efficiency by facilitating the fastening work for connecting the connecting tab 22 and the protection circuit module 23, as well as the maintenance work if (or when) an abnormality is detected in the battery module.

[0135] Figure 11 and Figure 12 This is a perspective view illustrating an example of a battery pack 30. The battery pack 30 may include a plurality of battery modules 20b and a housing 31 for housing the plurality of battery modules 20b. For example, the housing 31 may include a first housing 31-1 and a second housing 31-2 connected in opposite directions via the plurality of battery modules 20b. The plurality of battery modules 20b may be electrically connected to each other using busbars 25, and the plurality of battery modules 20b may be electrically connected to each other in series / parallel or a hybrid series-parallel method to obtain a desired (e.g., required) electrical output.

[0136] A battery pack according to one or more embodiments includes at least one battery module and a housing having a receiving space in which at least one battery module is received.

[0137] A battery module may include multiple battery cells and a module housing. The battery cells may be stacked (or arranged or configured in a stacked manner) and housed within the module housing. Each battery cell may have a positive electrode terminal and a negative electrode terminal, and may be circular, prismatic, or pouch-shaped depending on its shape. In this specification, a battery cell may also be referred to as a secondary battery, a battery, or a cell.

[0138] In a battery pack, a single stacked unit can form a stack that replaces a battery module. The stacked unit can be housed in the housing space of the pack casing, or in a housing space separated by frames, partitions, etc.

[0139] Individual battery cells can generate a significant amount of heat during charging / discharging. This heat can accumulate within the cells, accelerating their degradation. Accordingly, the battery pack may further include cooling components to remove the generated heat, thereby suppressing cell degradation. These cooling components may be located at the bottom of the housing where the battery cells are located, but are not limited to this, and may be located at the top or side depending on the battery pack.

[0140] The battery cell may be configured to allow exhaust gases generated inside the battery cell under abnormal operating conditions (also known as thermal runaway or thermal events) to be vented to the outside of the battery cell. The battery pack or battery module may include vents for discharging exhaust gases to prevent or reduce damage to the battery pack or module.

[0141] A battery pack may include batteries and a battery management system (BMS) for managing the batteries. The battery management system may include detection devices, balancing devices, and control devices. A battery module may include multiple individual cells connected in series and / or in parallel. Battery modules may be connected in series and / or in parallel.

[0142] The detection device can detect the state of the battery (e.g., voltage, current, temperature, etc.) to output state information indicating the battery's state. The detection device can detect the voltage of each individual cell or each battery module that makes up the battery. The detection device can detect the current flowing through each battery module that makes up the battery module or battery pack. The detection device can also detect the temperature of the individual cells and / or modules and / or the ambient temperature at at least one point on the battery.

[0143] The balancing device performs balancing operations on the battery module and / or the individual cells constituting the battery module. The control device receives state information (e.g., voltage, current, temperature, etc.) of the battery module from the detection device. Based on the state information received from the detection device, the control device monitors and calculates the state of the battery module (e.g., voltage, current, temperature, state of charge (SOC), lifespan (state of health (SOH)), etc.). Furthermore, based on the monitored state information, the control device performs control functions (e.g., temperature control, balancing control, charge / discharge control, etc.) and protection functions (e.g., over-discharge, overcharge, overcurrent protection, short circuit, fire suppression, etc.). Additionally, the control device can perform wired or wireless communication functions with external devices of the battery pack (e.g., higher-level controllers, vehicles, chargers, power conversion systems, etc.).

[0144] The control device can control the charging / discharging operation and protection operation of the battery. For this purpose, the control device may include a charging / discharging control unit, a balancing control unit, and / or a protection unit.

[0145] A battery management system is a system that monitors battery status and performs diagnostic and control, communication and protection functions. It can calculate charge / discharge status, calculate battery life or state of health (SOH), cut off battery power when necessary (e.g., relay control), control thermal management (e.g., cooling, heating, etc.), perform high-voltage interlock functions, and / or detect and / or calculate insulation and short-circuit conditions.

[0146] A relay can be a mechanical contactor that turns a coil on and off or a semiconductor switch (such as a metal-oxide-semiconductor field-effect transistor (MOSFET)).

[0147] The relay control has the function of cutting off the power supply from the battery if (or when) a problem occurs in the vehicle and battery system, and may include one or more relays and a pre-charge relay at the positive terminal and the negative terminal respectively.

[0148] In precharge control, there is a risk of inrush current in the high-voltage capacitor on the inverter input side when a battery load is connected. Therefore, to prevent inrush current when starting the vehicle, the precharge relay can be operated before the main relay, and a precharge resistor can be connected.

[0149] A high-voltage interlock is a circuit that uses a small signal to detect whether all high-voltage components of the entire vehicle system are connected, and may have the function of forcibly disconnecting the relay if (or when) a break occurs in even one part of the entire circuit.

[0150] Figure 13 and Figure 14 Perspective and side views of examples of the body 40 and vehicle components are shown respectively.

[0151] exist Figure 13 In this configuration, the battery pack 30 may include a battery pack cover 30-1 that is part of the vehicle floor 41 and a frame 30-2 located below the vehicle floor 41. In some examples, the battery pack cover 30-1 may correspond to a first housing 31-1, and the frame 30-2 may correspond to a second housing 31-2. The frame 30-2 and the battery pack cover 30-1 may be integrally formed with the vehicle floor 42. The vehicle floor 41 separates the interior and exterior of the vehicle, and the frame 30-2 may be located on the exterior of the vehicle.

[0152] refer to Figure 14 The vehicle 50 can be formed by attaching additional components (such as the engine hood 51 at the front of the vehicle and the fenders 52 located at the front and rear of the vehicle, respectively) to the body 40.

[0153] The vehicle 50 may include a battery pack 30, which includes a battery pack cover 30-1 and a battery pack frame 30-2, and the battery pack 30 may be connected to the vehicle body 40.

[0154] Although some embodiments of this disclosure have been shown and described, those skilled in the art will understand that various changes and modifications may be made to these embodiments without departing from the principles and spirit of this disclosure, the scope of which is defined in the appended claims and their equivalents.

Claims

1. A secondary battery, comprising: An electrode assembly includes a first electrode plate and a second electrode plate, the first electrode plate including a first substrate terminal block arranged in a first direction, and the second electrode plate including a second substrate terminal block arranged in a second direction opposite to the first direction, and the first electrode plate and the second electrode plate are provided as a stack. Housing that houses the electrode assembly; as well as The cover assembly includes a pair of current collectors electrically connected to the first substrate terminal block and the second substrate terminal block, respectively, and the cover assembly seals the housing. The first electrode plate at the center of the stack has a greater number of first substrate tabs than the first electrode plate at the outer portion of the stack.

2. The secondary battery of claim 1, wherein the first substrate terminal block is provided at the center of the stack such that the first substrate terminal block is dense at the center of the stack.

3. The secondary battery according to claim 1, wherein the first electrode plates are stacked such that the first substrate terminals are arranged in a rhomboid shape.

4. The secondary battery according to claim 1, wherein the first electrode plate in the stack comprises at least one first layer on a first side of the center of the stack, at least one second layer at the center of the stack, and at least one third layer on a second side of the center of the stack opposite to the first side.

5. The secondary battery according to claim 4, wherein the number of first substrate terminals provided in the second layer is greater than the number of first substrate terminals provided in the first layer, and the number of first substrate terminals provided in the second layer is greater than the number of first substrate terminals provided in the third layer.

6. The secondary battery according to claim 5, wherein the number of the first substrate terminals in the first layer and the number of the first substrate terminals in the third layer are the same.

7. The secondary battery according to claim 4 or 5, wherein the first substrate terminal piece of each of the first layer, the second layer and the third layer protrudes from the stack by the same length.

8. The secondary battery according to claim 7, wherein one of the pair of current collector plates is welded to the first substrate terminal piece, and the welding area of ​​the one of the pair of current collector plates is diamond-shaped.

9. The secondary battery according to claim 4 or 5, wherein the first substrate terminal block of the first layer and the first substrate terminal block of the third layer protrude from the stack by the same length, and the first substrate terminal blocks of the first layer and the third layer protrude from the stack by different lengths than the first substrate terminal block of the second layer.

10. The secondary battery of claim 4, wherein the length of the first substrate terminal block in the second layer protruding from the stack is greater than the length of the first substrate terminal block in each of the first layer and the third layer protruding from the stack.

11. The secondary battery of claim 10, wherein the first substrate terminal piece of the second layer is bent and welded to one of the pair of current collectors.

12. The secondary battery according to claim 9, wherein the length of the first substrate terminal piece in the second layer protruding from the stack is shorter than the length of the first substrate terminal piece in the first layer and the third layer protruding from the stack.

13. The secondary battery of claim 12, wherein the first substrate terminal piece in the first layer and the third layer is bent and welded to one of the pair of current collectors.

14. The secondary battery according to claim 4 or 5, wherein the side surface of the stack has a central region and an edge region, the first substrate terminal block of the first electrode plate protrudes from the side surface of the stack, the first substrate terminal block in the second layer is provided in the central region and the edge region, and the first substrate terminal block in the second layer provided in the central region and the first substrate terminal block in the second layer provided in the edge region have the same protrusion length or different protrusion lengths.

15. The secondary battery of claim 14, wherein the first substrate terminal block provided in the edge region of the second layer protrudes longer than the first substrate terminal block provided in the center region of the second layer.

16. The secondary battery of claim 15, wherein the first substrate tab provided in the edge region of the second layer is bent and welded to one of the pair of current collectors.

17. The secondary battery according to claim 4 or 5, wherein each of the first layer and the third layer comprises a plurality of electrode plates, and more of the first substrate tabs are disposed toward the center of the stack.

18. The secondary battery of claim 1, wherein the housing comprises a bottom surface and a long side surface and a short side surface extending upward from the bottom surface. The cover assembly includes a first terminal portion electrically connected to the first electrode plate, and One of the pair of current collectors includes a first terminal connection portion connected to the first terminal portion and a first electrode connection portion extending from the first terminal connection portion, parallel to the short side surface, and connected to the first electrode plate.

19. The secondary battery of claim 1, wherein each of the second electrode plates includes at least one second substrate tab, and a greater number of second substrate tabs are provided on the second electrode plate at the center of the stack than on the second electrode plate at the outer portion of the stack.

20. The secondary battery according to claim 1, wherein the outermost layer of the first electrode plate has a first substrate terminal piece.

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