Secondary battery

Abstract

Provided is a secondary battery, the secondary battery including: a case; an electrode assembly in the case and including a first tab protruding in the first direction and a second tab protruding in the first direction; a first current collector plate electrically connected to the first tab; a second current collector plate electrically connecting the second tab to the case; and a crimp terminal electrically connected to the first current collector plate and passing through the housing.

Description

[0001] This application claims priority to and the benefit of Korean Patent Application No. 10-2023-0082635 filed on June 27, 2023, in the Korean Intellectual Property Office, and Korean Patent Application No. 10-2023-0172087 filed on December 1, 2023, in the Korean Intellectual Property Office, the disclosures of which are incorporated herein in their entirety by reference. Technical Field

[0002] Embodiments relate to a secondary battery. Background Art

[0003] Unlike primary batteries, secondary batteries are rechargeable. Among these secondary batteries, low-capacity batteries including battery cells in the form of battery packs can be used in portable small electronic devices such as smart phones and digital cameras, and high-capacity battery modules including tens to hundreds of battery packs connected to each other can be used as a power source for driving motors (e.g., motors of hybrid vehicles, electric vehicles, etc.).

[0004] A rechargeable secondary battery includes: an electrode assembly in which a separator is interposed between a positive electrode plate and a negative electrode plate; a current collector plate electrically connected to the electrode assembly; a terminal electrically connected to the current collector plate; and a case accommodating the electrode assembly and the current collector plate and through which the terminal passes to be combined.

[0005] The above information is provided as background technology for the present disclosure and is only used to improve understanding of the background technology of the present disclosure and therefore may include information that does not constitute relevant technology. Summary of the invention

[0006] Aspects of some embodiments of the present disclosure provide a secondary battery, wherein a first tab (e.g., a positive electrode tab) and a second tab (e.g., a negative electrode tab) of an electrode assembly are arranged in the same direction so as to be electrically connected to a first terminal (e.g., a riveted terminal) and a second terminal (e.g., a shell), so that the resistance is low and the current path is short.

[0007] Other aspects of some embodiments of the present disclosure provide a secondary battery, wherein a first current collector plate (e.g., a positive electrode current collector plate) and a second current collector plate (e.g., a negative electrode current collector plate) are three-dimensionally combined and arranged on the same area to occupy a relatively small volume in the internal space of the shell, so that a relatively large electrode assembly can be accommodated in the shell.

[0008] Other aspects of some embodiments of the present disclosure provide a secondary battery, wherein a conductive ring plate is disposed on a second terminal (eg, a housing) to achieve good flatness between a first terminal (eg, a riveted terminal) and the second terminal.

[0009] According to some embodiments, a secondary battery includes: a shell; an electrode assembly, which is in the shell and includes a first terminal tab protruding in a first direction and a second terminal tab protruding in the first direction; a first collector plate, which is electrically connected to the first terminal tab; a second collector plate, which electrically connects the second terminal tab to the shell; and a riveted terminal, which is electrically connected to the first collector plate and passes through the shell.

[0010] The first terminal lug may have a planar circular sector shape having a center, an outer arc, and an inner arc, or may have a planar rectangular shape.

[0011] A central angle of the first tab may be less than about 180 degrees.

[0012] The second tab may be spaced apart from the first tab and may have a planar circular sector shape having a center, an outer arc, and an inner arc or may have a planar rectangular shape.

[0013] A central angle of the second tab may be less than about 180 degrees.

[0014] The first collector plate may include: a first collector plate first connection region electrically connected to the first terminal tab; a first collector plate connection region bent and extended from the first collector plate first connection region; and a first collector plate second connection region bent and extended from the first collector plate connection region and electrically connected to the riveted terminal.

[0015] The first connection region of the first current collector plate may have a planar circular sector shape having a center, an outer arc, and an inner arc, wherein the second connection region of the first current collector plate has a disk shape with a center.

[0016] The second collector plate may include: a second collector plate first connection region electrically connected to the second terminal tab; a second collector plate connection region bent and extended from the second collector plate first connection region; and a second collector plate second connection region bent and extended from the second collector plate connection region and electrically connected to the housing.

[0017] The first connection region of the second current collector plate may have a planar circular sector shape having a center, an outer arc, and an inner arc, wherein the second connection region of the second current collector plate has a circular ring plate shape with a center.

[0018] The secondary battery may further include an insulating plate between the first current collector plate and the second current collector plate and having a partial area in a gap between the second current collector plate and the electrode assembly.

[0019] The secondary battery may further include a conductive ring plate coupled to a partial area of ​​the case around the riveted terminal.

[0020] The first collector plate may include: a first connection area of ​​the first collector plate, electrically connected to the first terminal tab; a first collector plate connection area, bent and extended from the first connection area of ​​the first collector plate along a first direction; and a second connection area of ​​the first collector plate, bent and extended from the first collector plate connection area, and electrically connected to the riveted terminal, wherein the second collector plate includes: a first connection area of ​​the second collector plate, electrically connected to the second terminal tab; a second collector plate connection area, bent and extended from the first connection area of ​​the second collector plate along the first direction; and a second connection area of ​​the second collector plate, bent and extended from the second collector plate connection area, and electrically connected to the shell.

[0021] The first current collector plate first connection region and the second current collector plate first connection region may be on the same plane, wherein the first current collector plate second connection region is closer to the electrode assembly than the second current collector plate second connection region.

[0022] A partial area of ​​the second connection region of the second current collector plate may overlap the first connection region of the first current collector plate.

[0023] The housing may include: a riveting plate coupled to the riveting terminal; a side wall integrally extending from the riveting plate in a second direction opposite to the first direction; and a termination plate blocking an end of the side wall.

[0024] The termination plate may include a safety vent.

[0025] The terminating plate may be fixed to the side wall by means of a crimping portion and a compression portion provided on the side wall.

[0026] The termination plate may be secured to the side wall by welding.

[0027] The housing may include: a riveting plate coupled to the riveting terminal; a side wall welded to the riveting plate and extending in a second direction opposite to the first direction; and a termination plate integrally extending from the side wall.

[0028] The termination plate may include a safety vent. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The accompanying drawings are included to provide a further understanding of the present disclosure, and are incorporated in and constitute a part of this specification. The accompanying drawings illustrate embodiments of the present disclosure and together with the description serve to explain aspects of the present disclosure. In the drawings:

[0030] Figure 1A and Figure 1B respectively show a perspective view and a cross-sectional view of a secondary battery according to an embodiment;

[0031] Figure 2A and Figure 2BA plan view and a side view respectively show an electrode assembly in a secondary battery according to an embodiment;

[0032] Figure 3A and Figure 3B A cross-sectional view and a plan view respectively show a current collector plate assembly in a secondary battery according to an embodiment;

[0033] Figure 3C and Figure 3D 1 and 2 respectively show plan views of a first current collector plate and a second current collector plate in a current collector plate assembly according to an embodiment;

[0034] Figure 4 A schematic diagram showing a laser welding method in a secondary battery according to an embodiment;

[0035] Figure 5 shows a cross-sectional view of a secondary battery according to an embodiment;

[0036] Figure 6 A cross-sectional view showing a secondary battery according to an embodiment; and

[0037] Figure 7 A cross-sectional view of a secondary battery according to an embodiment is shown. DETAILED DESCRIPTION

[0038] By referring to the detailed description and drawings of the embodiments, it is easier to understand the aspects of some embodiments of the present disclosure and the methods for implementing them. The described embodiments are provided as examples so that the present disclosure will be thorough and complete, and the aspects of the present disclosure will be fully conveyed to those skilled in the art. Therefore, redundant, irrelevant or unrelated to the description of the embodiments, or processes, elements and techniques that are not necessary for a person of ordinary skill in the art to fully understand the aspects of the present disclosure can be omitted. Unless otherwise stated, throughout the drawings and written descriptions, the same reference numerals, characters or combinations thereof represent the same elements, and therefore, their repeated descriptions can be omitted.

[0039] The described embodiments may have various modifications and may be embodied in different forms, and should not be construed as being limited to the embodiments shown here. When describing an embodiment, the use of "may", "can" or "may not" corresponds to one or more embodiments of the present disclosure. The present disclosure encompasses all modifications, equivalents and substitutes within the conceptual and technical scope of the present disclosure. In addition, each of the features of the various embodiments of the present disclosure may be combined with each other in part or in whole, and various interlocks and drives are technically possible. Each embodiment may be implemented independently of one another, or may be implemented together in association.

[0040] In the drawings, the relative sizes of elements, layers, and regions may be exaggerated for clarity and / or descriptive purposes. In addition, the use of cross-hatching and / or shading is often provided in the drawings to make the boundaries between adjacent elements clear. As such, unless otherwise stated, the presence or absence of cross-hatching or shading does not convey or indicate any preference or requirement for specific materials, material properties, dimensions, proportions, commonalities between the elements shown, and / or any other characteristics, attributes, properties, etc. of the elements.

[0041] Various embodiments are described herein with reference to cross-sectional views as schematic diagrams of embodiments and / or intermediate structures. As such, variations in the shapes of the diagrams caused by, for example, manufacturing techniques and / or tolerances are anticipated. In addition, for the purpose of describing embodiments according to the concepts of the present disclosure, the specific structural or functional descriptions disclosed herein are merely illustrative. Therefore, the embodiments disclosed herein should not be interpreted as being limited to the illustrated shapes of elements, layers, or regions, but rather include shape deviations caused by, for example, manufacturing.

[0042] For ease of explanation, spatial relative terms such as "under...", "below...", "lower (lower part)", "lower side", "below...", "above...", "upper (upper part)", "upper side", etc. may be used here to describe the relationship of one element or feature to another (other) element or feature as shown in the drawings. It will be understood that, in addition to the orientation depicted in the drawings, the spatial relative terms are intended to cover different orientations of the device in use or operation. For example, if the device in the drawings is turned over, the element described as "under", "under" or "below" other elements or features will then be oriented to be "above" the other elements or features. Therefore, the example terms "under..." and "under..." can cover both upper and lower orientations. The device can be oriented otherwise (for example, rotated 90 degrees or in other orientations), and the spatial relative descriptors used here should be interpreted accordingly. Similarly, when a first part is described as being arranged "on" a second part, this means that the first part is arranged on the upper or lower side of the second part, and is not limited to the upper side of the second part based on the direction of gravity.

[0043] In addition, the phrase "in a plan view" means when the object portion is viewed from above, and the phrase "in a schematic cross-sectional view" means when a schematic cross-section taken by vertically cutting the object portion is viewed from the side. The term "superimposed" or "superimposed with..." means that the first object can be above or below the second object or on the side of the second object, and vice versa. In addition, the term "superimposed" may include stacking, facing (facing) or its variants, extending on ..., covering or partially covering or any other suitable term that a person of ordinary skill in the art will appreciate and understand. The expression "non-superimposed" may include meanings such as "separated from ..." or "beside ..." or "offset from ..." and any other suitable equivalents that a person of ordinary skill in the art will appreciate and understand. The term "facing (facing)" and its variants may mean that the first object may be directly or indirectly opposite to the second object. In the case where a third object is placed between the first object and the second object, the first object and the second object, although still facing each other, may be understood to be indirectly opposite to each other.

[0044] It will be understood that when an element, layer, region, or component is referred to as being "formed on," "on," "connected to," or "(operably or communicatively) coupled to" another element, layer, region, or component, it may be directly formed on, directly on, directly connected to, or directly coupled to the other element, layer, region, or component, or indirectly formed on, indirectly on, indirectly connected to, or indirectly coupled to the other element, layer, region, or component, such that one or more intervening elements, layers, regions, or components may be present. Additionally, this may collectively represent direct or indirect coupling or connection, as well as integral or non-integral coupling or connection. For example, when a layer, region, or component is referred to as being "electrically connected" or "electrically coupled" to another layer, region, or component, it may be directly electrically connected or directly electrically coupled to the other layer, region, and / or component, or there may be one or more intervening layers, regions, or components. One or more intervening components may include switches, resistors, capacitors, etc. When describing embodiments, unless explicitly described as being directly connected, the description of the connection indicates an electrical connection, and "directly connected / directly coupled" or "directly on..." means that one component is directly connected or directly coupled to another component, or is directly on another component, without intervening components.

[0045] In addition, in this specification, when a part of a layer, film, region, plate, etc. is formed on another part, the formation direction is not limited to the upper direction, but includes forming the part on the side surface or in the lower direction. On the contrary, when a part of a layer, film, region, plate, etc. is formed "below" another part, this includes not only the case where the part is "directly under" another part, but also the case where there is another part between the part and the other part. At the same time, other expressions describing the relationship between components (such as "between...", "directly between..." or "adjacent to..." and "directly adjacent to...") can be similarly interpreted. It will be understood that when an element or layer is referred to as "between" two elements or layers, it can be the only element or layer between the two elements or layers, or one or more intermediate elements or layers may also be present.

[0046] For the purposes of this disclosure, expressions such as "at least one of..." or "any one of..." or "one or more of..." when following a list of elements modify the entire list of elements, rather than the individual elements in the list. For example, "at least one of X, Y, and Z," "at least one of X, Y, or Z," "at least one selected from the group consisting of X, Y, and Z," and "at least one selected from the group consisting of X, Y, or Z" may be interpreted as any combination of only X, only Y, only Z, two or more of X, Y, and Z (such as XYZ, XYY, YZ, and ZZ for example), or any variation thereof. Similarly, expressions such as "at least one of A and B" and "at least one of A or B" may include A, B, or A and B. As used herein, "or" generally means "and / or," and the term "and / or" includes any and all combinations of one or more of the relevant listed items. For example, the expression "A and / or B" may include A, B, or A and B. Similarly, expressions such as "at least one of," "a plurality of," "one of," and other prepositional phrases, when preceding (preceding) a list of elements, modify the entire list of elements rather than the individual elements in the list.

[0047] It will be understood that, although the terms "first", "second", "third", etc. can be used here to describe various elements, components, regions, layers and / or parts, these elements, components, regions, layers and / or parts should not be limited by these terms. These terms do not correspond to a specific order, position or priority, and are only used to distinguish an element, member, component, region, area, layer, section or part from another element, member, component, region, area, layer, section or part. Therefore, without departing from the spirit and scope of the present disclosure, the first element, component, region, layer or section described below can be referred to as the second element, component, region, layer or section. Describing an element as a "first" element may not require or imply the presence of a second element or other elements. The terms "first", "second", etc. can also be used here to distinguish elements of different categories or sets. For simplicity, the terms "first", "second", etc. can respectively represent "first category (or first set)", "second category (or second set)", etc.

[0048] The terms used herein are only for the purpose of describing the embodiments and are not intended to limit the present disclosure. As used herein, unless the context clearly indicates otherwise, the singular forms "one" and "one (kind / person)" are also intended to include plural forms, and the plural forms are also intended to include singular forms. It will also be understood that when the terms "including", "having", "comprising" and variations thereof are used in this specification, the features, integers, steps, operations, elements and / or components stated are indicated, but the presence or addition of one or more other features, integers, steps, operations, elements, components and / or their groups are not excluded.

[0049] As used herein, the terms "substantially", "about", "roughly" and similar terms are used as approximate terms rather than as terms of degree, and are intended to explain the inherent deviations of measured or calculated values ​​that will be recognized by those of ordinary skill in the art. For example, "substantially" may include a range of + / -5% of the corresponding value. As used herein, "about" or "roughly" includes the stated values ​​and is expressed within an acceptable deviation range of a specific value as determined by those of ordinary skill in the art taking into account the measurement in question and the errors associated with the measurement of a specific amount (i.e., the limitations of the measurement system). For example, "about" may be expressed within one or more standard deviations, or within ±30%, ±20%, ±10%, ±5% of the stated value. In addition, when describing embodiments of the present disclosure, the use of "may" refers to "one or more embodiments of the present disclosure".

[0050] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as those commonly understood by those skilled in the art to which the present disclosure belongs. It will also be understood that terms (such as those defined in commonly used dictionaries) should be interpreted as having a meaning consistent with their meaning in the context of the relevant art and / or this specification, and should not be interpreted in an idealized or overly formal sense, unless explicitly defined as such herein.

[0051] Figure 1A and Figure 1B 1 and 2 respectively show a perspective view and a cross-sectional view of a secondary battery 100 according to an embodiment. Figure 1A and Figure 1B As shown in , a secondary battery 100 according to an embodiment may include a case 110 , an electrode assembly 120 , a current collector plate assembly 130 , and a terminal (eg, a rivet terminal 140 ).

[0052] The housing 110 may be configured to have a generally cylindrical shape. The housing 110 may include a riveted plate 111, a side wall 112, and a termination plate 113, wherein the riveted plate 111 has a generally disc shape having a terminal hole 1111 at its center, the side wall 112 extends downward from the riveted plate 111, and the termination plate 113 blocks the lower end of the side wall 112. The housing 110 may include or may be referred to as a can, a shell, or a housing. The housing 110 may include steel, a steel alloy, nickel-plated steel, aluminum, an aluminum alloy, copper, or a copper alloy. The housing 110 may be manufactured by a drawing process, an extrusion process, or a bending and welding process, in which a metal plate is placed on a die having an opening and pressed by a punch to manufacture a cylindrical housing, in which a molten metal is placed in an extrusion die and extruded into a tubular housing, and in which a thin metal plate is rolled to be bent and welded to manufacture a housing. The case 110 may house the electrode assembly 120 , the current collector plate assembly 130 , and the electrolyte to isolate the assembly from the external environment, and the case 110 may be optional.

[0053] In some embodiments, the riveted plate 111 and the side wall 112 may be provided as one body. In some embodiments, the riveted plate 111 and the side wall 112 may be provided separately and then combined and welded to each other. In some embodiments, the side wall 112 and the termination plate 113 may be provided as one body. In some embodiments, the side wall 112 and the termination plate 113 may be provided separately and then welded and combined to each other (e.g., no curling design).

[0054] In some embodiments, the inwardly concave curling portion 1121 and the inwardly bent crimping portion 1122 may be optionally provided at the lower end of the side wall 112. In some embodiments, the terminating plate 113 may be coupled between the curling portion 1121 and the crimping portion 1122. In some embodiments, the insulating gasket 114 may be located on the curling portion 1121 and the crimping portion 1122, and the terminating plate 113 may be coupled in a state where the insulating gasket 114 is placed between the curling portion 1121 and the crimping portion 1122. As described above, instead of providing the curling portion 1121 and the crimping portion 1122, the terminating plate 113 may be directly welded and coupled to the side wall 112, or the terminating plate 113 may be coupled to the side wall 112 in a curling or seaming manner.

[0055] In some embodiments, the termination plate 113 may include a relatively thin vent recess 1134 in its upper surface. In some embodiments, the termination plate 113 may include a peripheral region 1131 sandwiched between the curling portion 1121 and the crimping portion 1122, an inner region 1132 connected to the peripheral region 1131 and lower than the peripheral region 1131, and a central region 1133 connected to the inner region 1132 and higher than the inner region 1132. The vent recess 1134 may be disposed in the inner region 1132. In some embodiments, the central region 1133 may be closer to the electrode assembly 120 than the peripheral region 1131 and the inner region 1132. The vent recess 1134 may include or may be referred to as a safety vent. If the internal pressure of the secondary battery is higher than the reference pressure, the vent recess 1134 may rupture to release the internal gas.

[0056] The electrode assembly 120 may be arranged in a generally cylindrical shape. The electrode assembly 120 may be wound into a cylindrical shape and then coupled to the housing 110. The electrode assembly 120 may include or may be referred to as an electrode group or a pole core. The electrode assembly 120 may include a first electrode plate 121 (e.g., a positive electrode plate), a second electrode plate 122 (e.g., a negative electrode plate), and a separator 123. In some embodiments, the first electrode plate 121 (e.g., a positive electrode plate), the separator 123, and the second electrode plate 122 (e.g., a negative electrode plate) may be stacked and wound into a generally cylindrical shape. The first electrode plate 121 may include a plurality of first tabs 1211 extending upward. The second electrode plate 122 may include a plurality of second tabs 1221 extending upward. Here, the upward direction may be defined as a first direction, and the downward direction opposite to the upward direction may be defined as a second direction.

[0057] In some embodiments, the first electrode plate 121 may be provided by applying a first active material 1213 (such as a transition metal oxide) to a first current collector 1212 made of a metal (such as aluminum) foil, and may include a first tab 1211 extending and protruding toward the upper side of the first current collector 1212 (e.g., a region where the first active material 1213 is not coated). The first tab 1211 extending and protruding as described above may be referred to as a first uncoated portion tab or a first matrix tab, and the first tabs 1211 may be aligned at the same or similar positions by a winding process, a matrix stamping process, or a matrix notch process to constitute a multi-tab. In some embodiments, the first tab 1211 may include a lead tab that is separately provided and welded to the first current collector 1212.

[0058] In some embodiments, a compound capable of reversibly intercalating and deintercalating lithium (lithiated intercalation compound) may be used as the first active material. In some embodiments, one or more types of composite oxides of lithium and a metal selected from cobalt, manganese, nickel, iron, or a combination thereof may be used.

[0059] The composite oxide may be a lithium transition metal composite oxide, and 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.

[0060] For example, a compound represented by any one of the following chemical formulas may 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 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 Nib Co c L1 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 NeG 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 Mn 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);Li a FePO4(0.90≤a≤1.8).

[0061] In the above chemical formula: A can be Ni, Co, Mn or a combination thereof; X can be Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, a rare earth element or a combination thereof; D can be O, F, S, P or a combination thereof; G can be Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V or a combination thereof; and L1 can be Mn, Al or a combination thereof.

[0062] In some embodiments, the positive electrode of the lithium secondary battery may include a current collector (e.g., a first current collector) and a positive electrode active material layer (e.g., a first active material layer) located on the current collector. The positive electrode active material layer may include a positive electrode active material and may also include a binder and / or a conductive material.

[0063] The positive electrode active material may be contained in an amount of about 90 wt % to about 99.5 wt % based on 100 wt % of the positive electrode active material layer, and the binder and the conductive material may each be contained in an amount of about 0.5 wt % to about 5 wt % based on 100 wt % of the positive electrode active material layer.

[0064] The first tab 1211 may be electrically connected to the first current collector plate 131 and a terminal (eg, a rivet terminal 140 ) to provide a path for current flow between the first electrode plate 121 and the rivet terminal 140 .

[0065] In some embodiments, the second electrode plate 122 may be provided by applying a second active material 1223 (such as graphite or carbon) to a second current collector 1222 made of a metal (such as copper or nickel) foil, and may include a second tab 1221 (for example, an area not coated with the second active material 1223) that extends and protrudes upward from the second current collector 1222. The second tab 1221 that extends and protrudes as described above may be referred to as a second non-coated tab or a second matrix material tab, and the second tab 1221 may be aligned at the same or similar positions by a winding process, a matrix material stamping process, or a matrix material notching process to form a multi-tab. In some embodiments, the second tab 1221 may include a lead tab that is separately provided and welded to the second current collector 1222. The second tab 1221 may be electrically connected to a second terminal (for example, the case 110) to provide a path for current flow between the second electrode plate 122 and the case 110.

[0066] In some embodiments, the second active material may 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.

[0067] The material capable of reversibly intercalating / deintercalating lithium ions may be a carbon-based negative electrode active material, and 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, mesophase pitch carbide, calcined coke, etc.

[0068] As the material capable of doping and undoping lithium, a Si-based negative electrode active material or a Sn-based negative electrode active material may be used. The Si-based negative electrode active material may be silicon, a silicon-carbon composite, SiO x (0 < x < 2), a Si-based alloy, or a combination thereof.

[0069] The silicon-carbon composite may be a composite of silicon and amorphous carbon. According to some embodiments, the silicon-carbon composite may be in the form of silicon particles and amorphous carbon coated on the surface of each silicon particle.

[0070] The silicon-carbon composite may also include crystalline carbon. For example, the silicon-carbon composite may include: a core containing crystalline carbon and silicon particles; and an amorphous carbon coating located on the surface of the core.

[0071] The negative electrode for a lithium secondary battery may include a current collector (for example, the second current collector) and a negative electrode active material layer (for example, the second active material layer) located on the current collector. The negative electrode active material layer includes a negative electrode active material, and may also include a binder and / or a conductive material.

[0072] For example, the negative electrode active material layer may include about 90% to about 99% by weight of the negative electrode active material, about 0.5% to about 5% by weight of the binder, and about 0% to about 5% by weight of the conductive material. The binder may be a non-aqueous binder, an aqueous binder, a dry binder, or a combination thereof. If an aqueous binder is used as the negative electrode binder, the negative electrode binder may also include a cellulose compound capable of imparting viscosity.

[0073] The diaphragm 123 may be placed between the first electrode plate 121 and the second electrode plate 122 to reduce or prevent the possibility of a short circuit between the first electrode plate 121 and the second electrode plate 122, and to enable lithium ions to move. The diaphragm 123 may be slightly wider than the surface area of ​​each of the first electrode plate 121 and the second electrode plate 122, so as to further protrude in the upward, downward, leftward and / or rightward directions than each of the first electrode plate 121 and the second electrode plate 122. In some embodiments, the diaphragm 123 may reduce or prevent the possibility of the first electrode plate 121 and the second electrode plate 122 directly contacting the housing 110 in the upward, downward, leftward and / or rightward directions of the electrode assembly 120. In some embodiments, the diaphragm 123 may protrude and extend a corresponding length in the upward and / or downward directions of the electrode assembly 120 without the first tab 1211 and the second tab 1221.

[0074] In some embodiments, the electrode assembly 120 may be substantially hollow in the central region, which may also be referred to as a core 124. The core 124 may serve as a passage for discharging the pressure if the internal pressure of the secondary battery becomes greater than a reference pressure. In some embodiments, the internal pressure may be applied to the termination plate 113 through the core 124 to rupture the vent recess 1134 of the termination plate 113, thereby reducing the internal pressure.

[0075] In some embodiments, the electrode assembly 120 may be housed in the housing 110 together with an electrolyte. In some embodiments, the electrolyte may include an organic solvent such as ethylene carbonate (EC), propylene carbonate (PC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), and / or dimethyl carbonate (DMC) and a lithium salt such as LiPF6 or LiBF4. In some embodiments, the electrolyte may be a liquid, a solid, or a gel.

[0076] The current collector plate assembly 130 may include a first current collector plate 131 and a second current collector plate 132. The current collector plate assembly 130 may further include an insulating plate 133.

[0077] The first collector plate 131 may electrically connect the first electrode plate 121 of the electrode assembly 120 to the riveted terminal 140. The first collector plate 131 may include or may be referred to as a collector, a conductor, or a conductive lead. The first collector plate 131 may be made of aluminum or an aluminum alloy. The first collector plate 131 may be manufactured by stamping a metal plate using a mold and a punch or by casting a molten metal. In some embodiments, the first collector plate 131 may include a first collector plate first connection region 1311, a first collector plate connection region 1312, and a first collector plate second connection region 1313. The first collector plate first connection region 1311 may be electrically connected to the above-mentioned plurality of first tabs 1211 by a method such as laser welding. The first collector plate connection region 1312 may be bent and may extend upward from the first collector plate first connection region 1311. The first collector plate second connection region 1313 may be bent and may extend from the first collector plate connection region 1312, and may be electrically connected to the riveted terminal 140 by a method such as laser welding. In some embodiments, the first current collector plate 131 may become a current flow path between the electrode assembly 120 and the rivet terminal 140 .

[0078] The second collector plate 132 may electrically connect the second electrode plate 122 of the electrode assembly 120 to the housing 110 (e.g., the riveted plate 111). The second collector plate 132 may include or may be referred to as a collector, a conductor, or a conductive lead. The second collector plate 132 may be made of copper, a copper alloy, nickel, or a nickel alloy. The second collector plate 132 may be manufactured by stamping a metal plate using a mold and a punch or by casting a molten metal. In some embodiments, the second collector plate 132 may include a second collector plate first connection region 1321, a second collector plate connection region 1322, and a second collector plate second connection region 1323. The second collector plate first connection region 1321 may be electrically connected to the above-mentioned plurality of second tabs 1221 by a method such as laser welding. The second collector plate connection region 1322 may be bent and may extend upward from the second collector plate first connection region 1321. The second collector plate second connection region 1323 may be bent and may extend from the second collector plate connection region 1322 and may be electrically connected to the housing 110 (e.g., electrically connected to the rivet plate 111) by a method such as laser welding. In some embodiments, the second collector plate 132 may become a current flow path between the electrode assembly 120 and the housing 110.

[0079] The insulating plate 133 may be placed between the first collector plate 131 and the second collector plate 132. In some embodiments, a portion of the insulating plate 133 may be placed between the first connection region 1311 of the first collector plate and the second connection region 1323 of the second collector plate to reduce or prevent the possibility of the first collector plate 131 and the second collector plate 132 being electrically shorted to each other. In some embodiments, a portion of the insulating plate 133 may be placed between the second connection region 1323 of the second collector plate and the electrode assembly 120. The insulating plate 133 may include or may be referred to as an insulator, an insulating block, or an insulating panel. The insulating plate 133 may be made of polypropylene, polyethylene, dual synthetic rubber (EPDM), or nylon that does not react with the electrolyte. In some embodiments, the first collector plate 131, the second collector plate 132, and the insulating plate 133 may be manufactured by a double injection method.

[0080] The riveted terminal 140 may pass through the housing 110. In some embodiments, the riveted terminal 140 may pass through a terminal hole 1111 provided in the riveted plate 111. In some embodiments, an insulating gasket 1431 may be placed between the riveted terminal 140 and the terminal hole 1111. In some embodiments, the riveted terminal 140 may include a relatively wide head 141 and a relatively narrow body 142 extending downward from the head 141 to pass through the terminal hole 1111. In some embodiments, the riveted terminal 140 may further include a recess 1411 that is retracted from the upper surface of the head 141 toward the body 142 by a corresponding depth. Due to the recess 1411, the thickness between the bottom surface of the body 142 and the corresponding lowest surface of the recess 1411 may become relatively thin, and the energy of the laser beam may be smoothly transmitted to the first collector plate 131 (e.g., the first collector plate second connection region 1313), so that the riveted terminal 140 and the first collector plate 131 are welded to each other by laser welding. In some embodiments, the upper insulator 1432 may be further disposed between the head 141 and the riveted plate 111. In some embodiments, the lower insulator 1433 may be further disposed around the body portion 142 passing through the riveted plate 111. In some embodiments, the lower insulator 1433 may be disposed between the collector plate assembly 130 and the riveted plate 111. In some embodiments, the recess 1411 may be completed with a substantially flat member (e.g., metal) after the welding process. In some embodiments, after the welding process, the metal member may be bonded to the recess 1411, or the upper end of the recess 1411 may be closed.

[0081] In some embodiments, the present disclosure may provide a secondary battery 100, wherein the first tab 1211 (e.g., positive electrode tab) and the second tab 1221 (e.g., negative electrode tab) of the electrode assembly 120 are arranged in the same direction (e.g., upward direction) so as to be electrically connected to the first terminal (e.g., rivet terminal 140) and the second terminal (e.g., housing 110), so that the resistance is low and the current path is short. In some embodiments, the present disclosure may provide a secondary battery 100, wherein the first collector plate 131 (e.g., positive electrode collector plate) and the second collector plate 132 (e.g., negative electrode collector plate) are three-dimensionally combined and arranged on the same area to occupy a relatively small volume in the internal space of the housing 110, so that a relatively large electrode assembly 120 is accommodated in the housing 110.

[0082] Figure 2A and Figure 2B 1 and 2 respectively show a plan view and a side view of an electrode assembly 120 in a secondary battery 100 according to an embodiment. Figure 2A and Figure 2B As shown in , the electrode assembly 120 according to the embodiment may include a plurality of first tabs 1211 and a plurality of second tabs 1221 protruding and extending upward. In some embodiments, the plurality of first tabs 1211 and the plurality of second tabs 1221 may be arranged in a shape symmetrical to each other about a central core 124 (e.g., an empty space).

[0083] In some embodiments, the plurality of first tabs 1211 may have a planar circular sector shape or a planar sector shape having a center C, an outer arc 1211a, and an inner arc 1211b. The length of the outer arc 1211a may be longer than the length of the inner arc 1211b. In some embodiments, the center angle of the plurality of first tabs 1211 may be in the range of about 10 degrees to about 180 degrees, in the range of about 40 degrees to about 160 degrees, or in the range of about 80 degrees to about 120 degrees. If the center angle of the plurality of first tabs 1211 is greater than about 180 degrees, the first tab 1211 may contact the second tab 1221, and if the center angle of the plurality of first tabs 1211 is less than about 10 degrees, the contact area or welding area with the first current collector plate 131 may be relatively small. In some embodiments, the plurality of first tabs 1211 may have a substantially rectangular planar shape. In some embodiments, the plurality of first tabs 1211 may have a rectangular shape having a center C, an outer arc 1211 a , and an inner arc 1211 b .

[0084] In some embodiments, the plurality of second tabs 1221 may be disposed at relative positions spaced apart from the plurality of first tabs 1211, and the plane may have a circular sector shape or a sector shape having a center C, an outer arc 1221a, and an inner arc 1221b. The length of the outer arc 1221a may be longer than the length of the inner arc 1221b. In some embodiments, the center angle of the plurality of second tabs 1221 may be in the range of about 10 degrees to about 180 degrees, in the range of about 40 degrees to about 160 degrees, or in the range of about 80 degrees to about 120 degrees. If the center angle of the plurality of second tabs 1221 is greater than about 180 degrees, the second tab 1221 may contact the first tab 1211, and if the center angle of the plurality of second tabs 1221 is less than about 10 degrees, the contact area or welding area with the second current collector plate 132 may be relatively small. In some embodiments, the plurality of second tabs 1221 may have a substantially rectangular planar shape. In some embodiments, the plurality of second tabs 1221 may have a rectangular shape having a center C, an outer arc 1221 a , and an inner arc 1221 b .

[0085] Figure 3A and Figure 3B 1 and 2 respectively show a cross-sectional view and a plan view of a current collector plate assembly 130 in a secondary battery 100 according to an embodiment, and Figure 3C and Figure 3D Plan views of a first current collector plate 131 and a second current collector plate 132 in a current collector plate assembly 130 according to an embodiment are respectively shown.

[0086] As described above, the collector plate assembly 130 may include a first collector plate 131, a second collector plate 132, and an insulating plate 133 (optional). In some embodiments, as described above, the first collector plate 131 may include a first collector plate first connection region 1311, a first collector plate connection region 1312, and a first collector plate second connection region 1313.

[0087] In some embodiments, the first connection area 1311 of the first collector plate may be a planar circular sector shape or a planar sector shape having a center C, an outer arc 1311a, and an inner arc 1311b. The length of the outer arc 1311a may be longer than the length of the inner arc 1311b. In some embodiments, the second connection area 1313 of the first collector plate may have a disc shape with a center. In some embodiments, a plurality of welding lines WL may be arranged in a straight line on the first connection area 1311 of the first collector plate, and the first tab 1211 and the first connection area 1311 of the first collector plate may be electrically connected to each other through the welding line WL. In some embodiments, the first tab 1211 may be compressed or bent in an inward or outward direction and may be welded to the first connection area 1311 of the first collector plate. In some embodiments, a plurality of welding lines WL may be arranged in a ring shape on the second connection area 1313 of the first collector plate, and the rivet terminal 140 and the second connection area 1313 of the first collector plate may be electrically connected to each other through the welding line WL. In some embodiments, the planar shape of the first current collector plate first connection region 1311 may be the same as or similar to the planar shape of the first tab 1211. In some embodiments, the first current collector plate first connection region 1311 may overlap with the first tab 1211.

[0088] As described above, the second current collector plate 132 may include a second current collector plate first connection region 1321 , a second current collector plate connection region 1322 , and a second current collector plate second connection region 1323 .

[0089] In some embodiments, the first connection area 1321 of the second current collector plate may be a planar circular sector shape or a planar sector shape having a center C, an outer arc 1321a, and an inner arc 1321b. In some embodiments, the first connection area 1321 of the second current collector plate may be symmetrical with the first connection area 1311 of the first current collector plate relative to the core 124 of the electrode assembly 120 or relative to the second connection area 1313 of the first current collector plate. In some embodiments, the second connection area 1323 of the second current collector plate may be in the form of a circular ring plate with a center. In some embodiments, the center C of the second connection area 1323 of the second current collector plate may coincide with the core 124 of the electrode assembly 120 or with the center C of the second connection area 1313 of the first current collector plate. In some embodiments, a portion of the second connection area 1323 of the second current collector plate may overlap with a portion of the first connection area 1311 of the first current collector plate in the vertical direction. A portion of the insulating plate 133 may be placed between overlapping regions (such as between a portion of the first connection area 1311 of the first current collector plate and a portion of the second connection area 1323 of the second current collector plate). As described above, a partial area of ​​the insulating plate 133 may also be disposed between the second current collector plate second connection area 1323 and the electrode assembly 120. In some embodiments, a plurality of welding lines WL may be disposed in a straight line on the second current collector plate first connection area 1321, and the second terminal tab 1221 and the second current collector plate first connection area 1321 may be electrically connected to each other through the welding lines WL. In some embodiments, the second terminal tab 1221 may be compressed or bent in an inward or outward direction and may be welded to the second current collector plate first connection area 1321. In some embodiments, a plurality of welding lines WL may be disposed in the second current collector plate second connection area 1323 in the form of a circular dotted line, and the housing 110 (e.g., the rivet plate 111) and the second current collector plate second connection area 1323 may be electrically connected to each other through the welding lines WL. In some embodiments, the planar shape of the second current collector plate first connection area 1321 may be the same or similar to the planar shape of the second terminal tab 1221. In some embodiments, the second current collector plate first connection area 1321 may overlap with the second terminal tab 1221.

[0090] In some embodiments, the first current collector plate first connection region 1311 and the second current collector plate first connection region 1321 may be located on the same or similar plane, and the first current collector plate second connection region 1313 may be closer to the electrode assembly 120 than the second current collector plate second connection region 1323. In some embodiments, the current collector plate assembly 130 may be provided with a relatively compact thickness to occupy a relatively small volume inside the secondary battery 100. In some embodiments, a relatively large electrode assembly 120 may be provided inside the secondary battery 100.

[0091] Figure 4 FIG. 2 is a schematic diagram showing a laser welding method in a secondary battery 100 according to an embodiment. Figure 4 As shown in , a laser beam may be provided to the concave portion 1411 of the riveted terminal 140 so that the main body 142 of the riveted terminal 140 is electrically connected to the first connection region 1311 of the first current collector plate. Figure 4 As shown in , the laser beam may be provided in the form of an approximately circular dotted line along the circumference of the case 110 (eg, the rivet plate 111 ) so that the rivet plate 111 is electrically connected to the second connection region 1323 of the second current collector plate.

[0092] In some embodiments, a first current path may be provided by a first terminal (e.g., a riveted terminal 140), a first current collector plate 131, and a first electrode plate 121. A second current path may be provided by a second terminal (e.g., a housing 110 or a riveted plate 111), a second current collector plate 132, and a second electrode plate 122. In some embodiments, relatively short first and second current paths may be provided to reduce the internal resistance of the secondary battery 100.

[0093] Figure 5 1 shows a cross-sectional view of a secondary battery according to an embodiment. In addition to the liquid injection port 1135 and the plug 210 provided in the termination plate 113, Figure 5 The secondary battery 200 shown in FIG. Figure 1A and Figure 1B The secondary battery 100 shown in FIG. Figure 5 As shown in , a liquid injection port 1135 may be provided in the termination plate 113, for example, in the central region 1133, and the liquid injection port 1135 may be closed by the plug 210. In some embodiments, the electrolyte may be injected through the liquid injection port 1135, and the liquid injection port 1135 may be blocked by the plug 210 to reduce or prevent the possibility of electrolyte leakage. In some embodiments, the liquid injection port and the plug may be provided on the riveted plate 111.

[0094] Figure 6 FIG. 3 shows a cross-sectional view of a secondary battery 300 according to an embodiment. In addition to further providing a conductive ring plate 310, Figure 6 The secondary battery 300 shown in FIG. Figure 1A and Figure 1B The secondary battery 100 shown in FIG. Figure 6As shown in , the conductive ring plate 310 can be mechanically / electrically attached to a partial area of ​​the housing 110 surrounding the riveted terminal 140 (e.g., attached to the riveted plate 111). In some embodiments, the conductive ring plate 310 can be welded to the riveted plate 111 by a laser beam. The conductive ring plate 310 can be made of a material similar to or the same as the riveted plate 111. In some embodiments, the top surface of the conductive ring plate 310 can be similar to the top surface of the riveted terminal 140 or can form the same plane as the top surface of the riveted terminal 140. In some embodiments, the busbars connected to the riveted terminal 140 and the conductive ring plate 310 can have the same height. In some embodiments, the top surface of the conductive ring plate 310 can be lower than the top surface of the riveted terminal 140. In some embodiments, the busbars connected to the riveted terminal 140 and the conductive ring plate 310 can have different heights.

[0095] In some embodiments, the present disclosure may provide a conductive ring plate 310 on the second terminal (eg, the riveted plate 111 of the housing 110 ) to provide a secondary battery 300 with good flatness between the first terminal (eg, the riveted terminal 140 ) and the second terminal / housing 110 .

[0096] Figure 7 1 shows a cross-sectional view of a secondary battery according to an embodiment. In addition to the termination plate 113 being welded and fixed to the side wall 112 of the housing 110, Figure 7 The secondary battery 400 shown in FIG. 4 may be similar to Figure 6 The secondary battery 300 shown in FIG. Figure 7 As shown in , the termination plate 113 can be fixed to the side wall 112 of the housing 110 by laser welding. In some embodiments, after the termination plate 113 is bonded to the side wall 112 of the housing 110, a laser beam can be irradiated onto the portion where the circumference of the termination plate 113 and the side wall 112 contact each other. In some embodiments, the circumference of the termination plate 113 and a partial area of ​​the side wall 112 can be melted and cooled so that the termination plate 113 is finally bonded to the side wall 112 of the housing 110. In some embodiments, a curling-free secondary battery 400 can be provided to remove the space occupied by the curling portion and the crimping portion. In some embodiments, the present disclosure can accommodate a relatively large electrode assembly 120 in the housing 110 to provide a secondary battery 400 with a relatively high capacity.

[0097] Aspects of some embodiments of the present disclosure provide a secondary battery, wherein a first tab (e.g., a positive electrode tab) and a second tab (e.g., a negative electrode tab) of an electrode assembly are arranged in the same direction so as to be electrically connected to a first terminal (e.g., a riveted terminal) and a second terminal (e.g., a housing 110) so that resistance is low and a current path is short.

[0098] The present disclosure may provide a secondary battery, wherein a first current collector plate (e.g., a positive electrode current collector plate) and a second current collector plate (e.g., a negative electrode current collector plate) are three-dimensionally combined and arranged at approximately the same area to occupy a relatively small volume in the internal space of a shell, so that a relatively large electrode assembly can be accommodated in the shell.

[0099] The present disclosure may provide a secondary battery in which a conductive ring plate is disposed on a second terminal (eg, the housing 110 ) to achieve appropriate flatness between a first terminal (eg, a riveted terminal) and the second terminal.

[0100] The above embodiments are merely examples of secondary batteries, the present disclosure is not limited to the foregoing embodiments, and it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present disclosure as defined by the appended claims.

Claims

1. A secondary battery, comprising: case; an electrode assembly in the housing and comprising a first tab protruding in a first direction and a second tab protruding in the first direction; a first current collector plate electrically connected to the first terminal tab; a second current collector plate electrically connecting the second terminal tab to the housing; as well as A riveting terminal is electrically connected to the first current collector plate and passes through the case.

2. The secondary battery according to claim 1, wherein The first terminal piece has a planar circular sector shape or a planar rectangular shape, and the planar circular sector shape has a center, an outer arc, and an inner arc.

3. The secondary battery according to claim 2, wherein: The central angle of the first terminal piece is less than 180 degrees.

4. The secondary battery according to claim 1, wherein The second terminal lug is spaced apart from the first terminal lug and has a planar circular sector shape or has a planar rectangular shape, the planar circular sector shape having a center, an outer arc, and an inner arc.

5. The secondary battery according to claim 4, wherein The central angle of the second terminal piece is less than 180 degrees.

6. The secondary battery according to claim 1, wherein The first current collector plate comprises: a first connection region of the first current collector plate, electrically connected to the first terminal tab; a first collector plate connection region, bent and extending from the first collector plate first connection region; and The first collector plate second connection region is bent and extended from the first collector plate connection region and is electrically connected to the rivet terminal.

7. The secondary battery according to claim 6, wherein The first connection region of the first current collector plate has a planar circular sector shape, the planar circular sector shape includes a center, an outer arc and an inner arc, and The second connection region of the first current collector plate has a disk shape with a center.

8. The secondary battery according to claim 1, wherein The second current collector plate comprises: a first connection region of the second current collector plate, electrically connected to the second terminal tab; a second current collector plate connection region, bent and extending from the second current collector plate first connection region; and The second collector plate second connection region is bent and extended from the second collector plate connection region and is electrically connected to the case.

9. The secondary battery according to claim 8, wherein The first connection region of the second current collector plate has a planar circular sector shape having a center, an outer arc and an inner arc, and The second connection region of the second current collector plate has a circular ring shape with a center. 10 . The secondary battery of claim 1 , further comprising an insulating plate between the first current collector plate and the second current collector plate and having a partial area in a gap between the second current collector plate and the electrode assembly. 11 . The secondary battery according to claim 1 , further comprising a conductive ring plate coupled to a partial area of ​​the case around the riveted terminal.

12. The secondary battery according to claim 1, wherein The first current collector plate comprises: a first connection region of the first current collector plate, electrically connected to the first terminal tab; a first current collector plate connecting region, bent and extending from the first current collector plate first connecting region along the first direction; and a first collector plate second connection region, bent and extended from the first collector plate connection region, and electrically connected to the riveted terminal, and Wherein, the second current collector plate comprises: a first connection region of the second current collector plate, electrically connected to the second terminal tab; a second current collector plate connection region, bent and extending from the second current collector plate first connection region along the first direction; and The second collector plate second connection region is bent and extended from the second collector plate connection region and is electrically connected to the case.

13. The secondary battery according to claim 12, wherein: The first connection region of the first current collector plate and the first connection region of the second current collector plate are on the same plane, and The second connection region of the first current collector plate is closer to the electrode assembly than the second connection region of the second current collector plate.

14. The secondary battery according to claim 12, wherein: A portion of the second connection region of the second current collector plate overlaps the first connection region of the first current collector plate.

15. The secondary battery according to claim 1, wherein The housing comprises: a riveting plate coupled to the riveting terminal; a side wall integrally extending from the riveted plate in a second direction opposite to the first direction; and A termination plate blocks an end of the side wall.

16. The secondary battery according to claim 15, wherein The termination plate includes a safety vent.

17. The secondary battery according to claim 15, wherein The terminating plate is fixed to the side wall by a crimping portion and a crimping portion provided on the side wall.

18. The secondary battery according to claim 15, wherein The terminating plate is fixed to the side wall by welding.

19. The secondary battery according to claim 1, wherein The housing comprises: a riveting plate coupled to the riveting terminal; a side wall welded to the riveted plate and extending in a second direction opposite to the first direction; and A termination plate integrally extends from the side wall.

20. The secondary battery according to claim 19, wherein The termination plate includes a safety vent.

Images