Electrode assembly, battery cell, and battery pack and vehicle including the same

Abstract

Provided are an electrode assembly, a battery cell, a battery pack including the battery cell, and a vehicle, the electrode assembly having a first electrode, a second electrode, and a separator interposed between the first electrode and the second electrode, the first electrode, the second electrode, and the separator being wound about a winding axis to define a core portion and an outer circumferential surface of the electrode assembly, wherein the first electrode includes a first uncoated portion to which an active material layer is not applied, the first uncoated portion being located at a long side end portion along a length direction of the first electrode, and a first coated portion to which the active material layer is applied, the first coated portion being a region other than the first uncoated portion, and the second electrode has a portion forming the outer circumferential surface of the electrode assembly and includes a second uncoated portion to which the active material layer is not applied, the second uncoated portion being a region including the portion, and a second coated portion coated with the active material layer, the second coated portion being a region other than the second uncoated portion.

Description

Technical Field

[0001] This disclosure relates to electrode assemblies, battery cells, battery packs including battery cells, and vehicles, and more specifically, to an electrode assembly, battery cell, and battery pack and vehicle including battery cells for improving the performance of battery cells.

[0002] This application is based on and claims priority to Korean Patent Application No. 10-2024-0178733, filed in Korea on December 4, 2024, the disclosure of which is incorporated herein by reference in its entirety. Background Technology

[0003] Due to their applicability to various products and electrical characteristics such as high energy density, rechargeable batteries are commonly used not only in portable devices but also in electric vehicles (EVs) or hybrid electric vehicles (HEVs) powered by electrical sources. Rechargeable batteries significantly reduce the use of fossil fuels, and in addition to their main advantages, they do not produce byproducts from energy use. From this perspective, batteries are considered a new energy source with energy-saving and energy-efficient properties.

[0004] Currently widely used types of rechargeable batteries include lithium-ion batteries, lithium polymer batteries, nickel-cadmium batteries, nickel-metal hydride batteries, and nickel-zinc batteries. A single rechargeable battery cell, or individual battery cell, has an operating voltage of approximately 2.5V to 4.5V. Therefore, when a higher output voltage is required, multiple battery cells can be connected in series to form a battery pack. Alternatively, battery packs can be manufactured by connecting multiple battery cells in parallel according to the required charge / discharge capacity of the battery pack. Therefore, the number of battery cells included in a battery pack can be set differently depending on the required output voltage or charge / discharge capacity.

[0005] Meanwhile, battery cell structures have been enhanced to increase energy density and improve output characteristics. However, traditional battery cell structures have many problems. In particular, as the internal resistance of the battery cell increases, its output characteristics deteriorate, failing to meet the required performance. Furthermore, during discharge, the battery cell generates a high current instantaneously, significantly affecting its internal resistance. Therefore, energy efficiency may decrease, and the stability of the battery cell may be adversely affected. This drawback may be particularly critical in electric vehicle applications.

[0006] Therefore, it is necessary to study a new battery cell structure to effectively reduce the internal resistance of the battery cell and improve its output characteristics. Summary of the Invention

[0007] Technical issues

[0008] This disclosure aims to provide an electrode assembly for improving the performance of a battery cell, a battery cell, and a battery pack and vehicle including the battery cell.

[0009] This disclosure also aims to provide an electrode assembly for reducing the internal resistance of a battery cell, a battery cell, and a battery pack and vehicle including the battery cell.

[0010] This disclosure also aims to provide an electrode assembly for improving the output of a battery cell, a battery cell, and a battery pack and vehicle including the battery cell.

[0011] The technical problems to be solved by this disclosure are not limited to those described above, and those skilled in the art will clearly understand these and other problems from the following description.

[0012] Technical solution

[0013] To achieve the above objectives, this disclosure provides an electrode assembly comprising: a first electrode and a second electrode, wherein the first electrode and the second electrode are wound around a winding axis with a diaphragm located between the first electrode and the second electrode to define a core and an outer peripheral surface, wherein the first electrode comprises: a first uncoated portion at each end of its two long sides along the length direction of the first electrode where no active material layer is coated; and a first coated portion in a region other than the first uncoated portion where an active material layer is coated, and wherein the second electrode comprises: a second uncoated portion in a region including at least a portion of the outer peripheral surface where no active material layer is coated, and the second uncoated portion constituting the outer peripheral surface of the electrode assembly; and a second coated portion in a region other than the second uncoated portion where an active material layer is coated.

[0014] For example, the first uncoated portion may be located at both ends of the electrode assembly in the direction of the winding axis.

[0015] For example, the first uncoated portion may be bent along the radial direction of the electrode assembly to form a curved surface at the two ends of the electrode assembly in the direction of the winding axis.

[0016] For example, the second uncoated portion may include at least one of the following: a first portion located at one end of the second electrode in the length direction; and a second portion located at the other end of the second electrode in the length direction.

[0017] For example, in the length direction of the second electrode, the first portion may have a length equal to or less than the outer perimeter length of the electrode assembly.

[0018] For example, in the length direction of the second electrode, the length of the second electrode can be longer than that of the first electrode.

[0019] For example, the first uncoated portion may be bent along the radial direction of the electrode assembly to form a curved surface at the two ends of the electrode assembly in the direction of the winding axis.

[0020] For example, the second uncoated portion may include at least one of the following: a first portion located at one end of the second electrode in the length direction; and a second portion located at the opposite end of the second electrode in the length direction.

[0021] For example, in the length direction of the second electrode, the first portion or the second portion may have a length equal to or less than the outer perimeter length of the electrode assembly.

[0022] For example, in the length direction of the second electrode, the second electrode may be longer than the first electrode.

[0023] For example, the second electrode may not be coated with an active material layer in at least a portion of the region where the second electrode is longer than the first electrode in the longitudinal direction.

[0024] For example, in the longitudinal direction of the diaphragm, the length of the diaphragm may be longer than the first electrode and shorter than the second electrode.

[0025] For example, in the direction of the winding axis of the electrode assembly, the width of the first electrode may be greater than the width of the second electrode.

[0026] For example, the first electrode may be arranged to have two ends that extend from the two ends of the second electrode respectively in the direction of the winding axis of the electrode assembly.

[0027] Additionally, this disclosure may provide a battery cell comprising: the aforementioned electrode assembly; a battery can including a bottom and a sidewall extending from the bottom along the winding axis direction of the electrode assembly, the battery can receiving the electrode assembly through an opening positioned opposite to the bottom, and an outer peripheral surface of the battery can contacting the sidewall for electrical connection with a second electrode; a first electrode terminal electrically connected to the electrode assembly through a through-hole in the bottom of the battery can; and a cover covering the opening of the battery can.

[0028] For example, the first electrode can be electrically connected to the first electrode terminal and the cover.

[0029] For example, the battery cell may further include a second electrode terminal riveted through a through hole in the cover, and the first electrode may be electrically connected to the first electrode terminal and the second electrode terminal.

[0030] In addition, this disclosure provides a battery pack including at least one battery cell.

[0031] Additionally, this disclosure provides a vehicle that includes at least one battery pack.

[0032] Beneficial effects

[0033] Electrode assemblies, battery cells, and battery packs and vehicles including battery cells according to various embodiments of this disclosure have the effect of improving the performance of battery cells.

[0034] Furthermore, the electrode assemblies, battery cells, and battery packs and vehicles including battery cells according to various embodiments of this disclosure have the effect of improving the output of the battery cells.

[0035] However, the effects that can be obtained through this disclosure are not limited to those described above, and those skilled in the art will clearly understand these and other technical effects through the following description. Attached Figure Description

[0036] Figure 1 This is a schematic diagram illustrating a wound-core type electrode assembly according to an embodiment of the present disclosure.

[0037] Figure 2 It is a schematic representation of the basis Figure 1 A diagram of the first electrode of the electrode assembly.

[0038] Figure 3 It shows the basis Figure 1 A diagram of another embodiment of the first electrode.

[0039] Figure 4 It is a schematic representation of the basis Figure 1 A diagram of the second electrode of the electrode assembly.

[0040] Figure 5 and Figure 6 It shows the basis Figure 1 A diagram showing the placement of each component of the electrode assembly.

[0041] Figure 7 This is a schematic diagram illustrating a battery cell according to an embodiment of the present disclosure.

[0042] Figure 8 It is a schematic representation of the basis Figure 7 A longitudinal cross-sectional view of the battery cell.

[0043] Figure 9 This is a schematic longitudinal cross-sectional view of a battery cell according to another embodiment of the present disclosure.

[0044] Figure 10 This is a schematic diagram illustrating a battery pack including battery cells according to embodiments of the present disclosure.

[0045] Figure 11 It is schematically shown that includes Figure 10 A picture of a vehicle with a battery pack. Detailed Implementation

[0046] In the following, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Before the description, it should be understood that the terms or words used in the specification and appended claims should not be construed as limited to their general and dictionary meanings, but should be interpreted based on the principle that allows the inventors to appropriately define terms for best interpretation, and based on the meanings and concepts corresponding to the technical aspects of the present disclosure.

[0047] Therefore, the embodiments described herein and the illustrations shown in the accompanying drawings are embodiments of the present disclosure used to describe the technical aspects of the present disclosure, but are not intended to be limiting, and it should be understood that various other equivalents and modifications may be made thereto at the time of filing of the application.

[0048] Furthermore, this disclosure includes many different embodiments. To avoid redundancy, descriptions of substantially the same or similar elements shared between each embodiment are omitted, and the following description will be based on the differences.

[0049] Additionally, to aid in understanding this disclosure, the drawings are not shown to scale, and some elements may be depicted at exaggerated dimensions. Furthermore, in different embodiments, the same reference numerals may be attached to the same elements.

[0050] Although terms such as "first" and "second" are used to describe different elements, these elements are not limited by these terms. These terms are used to distinguish one element from another, and unless otherwise stated, a "first" element can be a "second" element.

[0051] Throughout this specification, unless otherwise stated, each element may be singular or plural.

[0052] The terms “above (or below)” or “upper (or lower)” can indicate that an element is positioned in contact with the upper (or lower) surface of another element, and that an intermediate element may be present.

[0053] Additionally, it should be understood that when an element is referred to as being “connected to,” “joined to,” or “joined to” another element, it may be directly connected to or joined to the other element, or there may be an intermediate element, or each element may be connected, joined, or joined to another element.

[0054] Unless the context clearly specifies otherwise, the singular form used herein includes the plural form. In this specification, the terms “comprising” or “including” should not necessarily be construed as including all elements or steps described herein, and should be construed as excluding some elements or steps, or further including additional elements or steps.

[0055] In addition, in this specification, terms indicating direction such as up, down, left, right, front, and back may be used, but these terms are provided for ease of description and it will be apparent to those skilled in the art that these terms may change depending on the position, placement, rotation, or positioning of the object or the position of the observer.

[0056] This disclosure may independently include each of the following embodiments. Furthermore, this disclosure may include a combination of at least two of the following embodiments. The various embodiments described below may be independent of each other and may be freely combined together.

[0057] For ease of description, in this specification, the direction along the length of the winding axis of the electrode assembly wound into a core shape is referred to as the winding axis direction (Z). Furthermore, the direction in which the electrode assembly is wound along the winding axis is referred to as the winding direction (X). Additionally, the direction away from or towards the winding axis of the electrode assembly is referred to as the radial direction.

[0058] Figure 1 This is a schematic diagram illustrating a wound-core type electrode assembly 20 according to an embodiment of the present disclosure. Figure 2 It is a schematic representation of the basis Figure 1 A diagram of the first electrode 21 of the electrode assembly 20. Figure 3 It shows the basis Figure 1 A diagram of another embodiment of the first electrode 21, and Figure 4 It is a schematic representation of the basis Figure 1 A diagram of the second electrode 22 of the electrode assembly 20.

[0059] Reference Figures 1 to 4 The electrode assembly 20 according to embodiments of the present disclosure may include a first electrode 21 and a second electrode 22, and may be in a core shape when wound about a winding axis. Here, the electrode assembly 20 may include a core and an outer peripheral surface defined relative to the winding axis.

[0060] When viewed from the top or bottom in the XY plane, the electrode assembly 20 can be circular in the circumferential direction. However, the structure of the electrode assembly 20 is not limited to this embodiment and can have a known winding structure.

[0061] Each of the first electrode 21 and the second electrode 22 may have a predetermined width along the winding axis direction Z and extend to a predetermined length along the winding direction X. For example, the first electrode 21 and the second electrode 22 may be made of sheet metal foil.

[0062] The first electrode 21 may include a first uncoated portion 212 in which the active material layer 2111 is not coated and a first coated portion 211 in which the active material layer 2111 is coated.

[0063] The first uncoated portion 212 may extend along the length direction of the first electrode 21 at each end of the long side of the first electrode 21, and the first coated portion 211 may be located in the region other than the first uncoated portion 212.

[0064] The second electrode 22 may include a second uncoated portion 222 in which the active material layer 2211 is not coated and a second coated portion 221 in which the active material layer 2211 is coated.

[0065] The second uncoated portion 222 may be located in a predetermined region at at least one shorter side end of the second electrode 22, and the second coated portion 221 may be located in a region other than the second uncoated portion 222.

[0066] The first electrode 21 can be a positive electrode plate, and the second electrode 22 can be a negative electrode plate, or vice versa. Here, the positive electrode active material applied to the positive electrode plate and the negative electrode active material applied to the negative electrode plate can be, but is not limited to, any known active material.

[0067] According to this embodiment, the second electrode 22 can form the outer peripheral surface of the electrode assembly 20. Here, the outer peripheral surface can be a curved surface that forms the cylindrical shape of the electrode assembly 20.

[0068] Therefore, the second uncoated portion 222 can be disposed in a region including at least a portion of the outer peripheral surface of the electrode assembly 20. Thus, at least a portion of the outer peripheral surface of the electrode assembly 20 can be exposed in a metal foil state, and the corresponding portion can serve as a path for current flow, thereby causing a potential to be generated.

[0069] In other words, at least a portion of the outer peripheral surface of the electrode assembly 20 can be used as the electrode tab of the second electrode 22.

[0070] The electrode assembly 20 according to this embodiment has a structure in which a first electrode 21 and a second electrode 22 are wound around a winding axis with a diaphragm 23 inserted therebetween. The outermost part is not covered by the diaphragm 23 or any coating, and the second electrode 22 may form the outer peripheral surface of the electrode assembly 20.

[0071] Therefore, the electrode assembly 20 according to this embodiment can have a structure electrically connected via an outer peripheral surface, thereby reducing the current path. Thus, the resistive component occurring in the electrical connection with the second electrode 22 can be effectively reduced.

[0072] Furthermore, since a relatively large area is used as the electrode tab of the second electrode 22, a path that allows for uniform current distribution can be provided, thereby preventing localized overheating and reduced battery life caused by unbalanced current density.

[0073] According to the embodiment, the first electrode 21 may have a first uncoated portion 212 at both ends in the winding axis direction Z. For example, based on the winding axis direction Z, the first uncoated portion 212 may include an upper uncoated portion 2121 located at one end of the electrode assembly 20 and a lower uncoated portion 2122 located at the other end of the electrode assembly 20.

[0074] In other words, the first electrode 21 may include tabs at the upper and lower parts based on the winding axis direction Z to establish an electrical connection.

[0075] By forming slits at predetermined intervals along the winding direction X, the first uncoated portion 212 can have a plurality of flag-shaped slit tabs 2123. The plurality of slit tabs 2123 can be in the shape of an equilateral trapezoid arranged along the winding direction X. However, the shape is not limited to this and can include various shapes, including semicircular, semi-elliptical or semi-oval, triangular, rectangular or parallelogram.

[0076] Furthermore, the multiple notched tabs 2123 can be bent and flattened in the radial direction of the electrode assembly 20. Alternatively, during the formation of the rolled-core electrode assembly 20, the multiple notched tabs 2123 can be bent one after another. Alternatively, the notched tabs 2123 can be bent all at once after the rolled-core electrode assembly 20 has been formed.

[0077] As described above, the cut tabs 2123 of the first electrode 21, which are bent and overlapped in the radial direction, can form curved surfaces for electrical connection at both ends of the electrode assembly 20 in the winding axis direction Z.

[0078] The second uncoated portion 222 may include at least one of the following: a first portion 2221 located at one end of the second electrode 22 in the length direction; and a second portion 2222 located at the other end of the second electrode 22 in the length direction. Here, one end may be located on the outer peripheral surface side, and the other end may be located on the core side.

[0079] The first portion 2221 may form at least a portion of the outer peripheral surface of the electrode assembly 20. Thus, the first portion 2221 can be used as an electrode tab of the second electrode 22 to transmit current or establish an electrical connection.

[0080] In the length direction of the second electrode 22, the length d1 of the first part 2221 can be equal to or less than the outer perimeter length L1 of the electrode assembly 20.

[0081] For example, in the length direction of the second electrode 22, when the length d1 of the first portion 2221 is equal to the outer peripheral length L1 of the electrode assembly 20, the first portion 2221 can be formed over the entire area of ​​the outer peripheral surface of the electrode assembly 20. This can help simplify the structure of the electrode assembly 20 and increase electrical connection efficiency.

[0082] For example, in the longitudinal direction of the second electrode 22, when the length d1 of the first portion 2221 is less than the outer peripheral length L1 of the electrode assembly 20, the first portion 2221 can be formed in a portion of the outer peripheral surface of the electrode assembly 20. As described above, even if the metal foil type second electrode 22 is not exposed to the entire area of ​​the outer peripheral surface of the electrode assembly 20, an area for electrical connection to the outside can be provided. Therefore, the length of the first portion 2221 does not need to be much greater than the outer peripheral length L1 of the electrode assembly 20.

[0083] Therefore, properly designing the length d1 of the first part 2221 can save unnecessary materials used for performing functions and improve the efficiency of the manufacturing process.

[0084] Optionally, the second portion 2222 may be formed in at least a portion of the core-side region of the electrode assembly 20. When the active material layer 2211 is coated to the core-side end, breakage or peeling of the active material layer 2211 may occur during the winding or stacking of the second electrode 22. Furthermore, the active material layer 2211 undergoes repeated expansion and contraction during charging / discharging, and when the active material layer 2211 is coated up to the core-side end, the internal stress of the battery may increase due to volume changes.

[0085] Therefore, according to this embodiment, the second electrode 22 may have a second portion 2222 in at least a portion of the core side region of the electrode assembly 20, thereby reducing damage to the active material layer 2111 and improving assembly efficiency.

[0086] The second coating portion 221 may have an active material layer 2211 coated on the area other than the second uncoated portion 222. The active material layer 2211 may be coated on the area other than at least one end of the second electrode 22 in the length direction.

[0087] The second coated portion 221 and the second uncoated portion 222 may be in various shapes along the length of the second electrode 22, and the shape is not limited to the exemplary shape shown in this specification.

[0088] As an example, the active material layer 2211 may be coated in a specific pattern along the length of the second electrode 22. In this case, the active material layer 2211 may not be coated on at least a portion of the area including the outer peripheral surface of the electrode assembly 20.

[0089] For example, the active material layer 2211 can be linearly coated along the length direction of the second electrode 22 in the winding direction X and the winding axis direction Z at predetermined intervals. Therefore, the diffusion path of lithium ions can be optimized and the charging / discharging speed can be improved.

[0090] As described above, the active material layer 2211 can be formed in various patterns, such as grid, linear, or dotted coatings. Patterned coating methods can be designed to improve electrochemical reaction efficiency and optimize battery capacity and output characteristics.

[0091] Figure 5 and Figure 6 It shows the basis Figure 1 A diagram showing the placement of each component of the electrode assembly 20.

[0092] refer to Figure 5 The electrode assembly 20 may include a first electrode 21 and a second electrode 22 wound around a winding axis along the winding direction X, wherein a diaphragm 23 is inserted between the first electrode 21 and the second electrode 22.

[0093] In the length direction of the second electrode 22, for example in the winding direction X, the second electrode 22 may be longer than the first electrode 21 by a predetermined length d2. For example, in at least a portion of the region (d2) in which the second electrode 22 is longer than the first electrode 21 in the length direction (e.g., in the winding direction X), the second electrode 22 may not be coated with an active material layer.

[0094] As described above, the first electrode 21, the diaphragm 23 and the second electrode 22 can be formed together as a plurality of winding turns based on the winding axis of the electrode assembly 20, and the second uncoated portion 222 in which the active material layer 2222 is not coated can be located in at least a portion of the outer peripheral surface of the electrode assembly 20.

[0095] The diaphragm 23 may be longer than the first electrode 21 by a predetermined length d3 in the length direction of the diaphragm 23 (e.g., in the winding direction X).

[0096] Therefore, since the end of the first electrode 21 is not directly exposed, the electrode assembly 20 can prevent the first electrode 21 and the second electrode 22 from making direct contact (short circuit) due to charging / discharging or external impact.

[0097] Additionally, the diaphragm 23 may be shorter than the second electrode 22 in its length direction (e.g., in the winding direction X). Therefore, the second electrode 22 can be exposed on the outer peripheral surface of the electrode assembly 20 without wasting material.

[0098] Here, the diaphragm 23 may comprise a porous polymer membrane, for example, a porous polymer membrane made alone or in a laminated manner from a polyolefin-based polymer such as ethylene homopolymer, propylene homopolymer, ethylene / butene copolymer, ethylene / hexene copolymer, or ethylene / methacrylate copolymer. As another example, the diaphragm 23 may comprise a commonly used porous nonwoven fabric, for example, a nonwoven fabric made of high-melting-point glass fiber or polyethylene terephthalate fiber.

[0099] At least one surface of the diaphragm 23 may include a coating of inorganic particles. Alternatively, the diaphragm 23 itself may be formed from a coating of inorganic particles. The particles forming the coating may have a structure in which they are bonded to an adhesive to create interstitial volumes between adjacent particles.

[0100] Reference Figure 6 In the winding axis direction Z of the electrode assembly 20, the width d4 of the first electrode 21 can be greater than the width d5 ​​of the second electrode 22.

[0101] The first electrode 21 may extend beyond the ends of the two long sides of the second electrode 22 by a predetermined length in the winding axis direction Z of the electrode assembly 20. That is, the two ends of the first electrode 21 in the winding axis direction Z may each have an extension length exceeding the two ends of the second electrode 22.

[0102] For example, in the winding axis direction Z of the electrode assembly 20, the upper uncoated portion 2121 of the first uncoated portion 212 can be provided at the top of the end of one long side of the second electrode 22, and the lower uncoated portion 2122 of the first uncoated portion 212 can be provided at the bottom of the end of the other long side of the second electrode 22.

[0103] In this case, the width d6 of the diaphragm 23 in the winding axis direction Z of the electrode assembly 20 can be greater than the width d5 ​​of the second electrode 22. Therefore, the metal foil exposed on the outer peripheral surface of the electrode assembly 20 can be only the second electrode 22.

[0104] Therefore, the electrode assembly 20 according to this embodiment can prevent direct contact between the first electrode 21 and the second electrode 22 within the electrode assembly 20 and effectively suppress electrical short circuits that may occur during charging / discharging. Furthermore, the first uncoated portion 212 at the ends of the two long sides of the first electrode 21 can be bent radially to provide a sufficiently large area for use as an electrode tab.

[0105] The above reference Figures 1 to 6 The described electrode assemblies 20, 20a, and 20b can be components of the battery cell 1. Hereinafter, a battery cell 1 including electrode assemblies 20, 20a, and 20b according to embodiments of this disclosure will be described.

[0106] Figure 7 This is a schematic diagram illustrating a battery cell 1 according to an embodiment of the present disclosure, and Figure 8 It is a schematic representation of the basis Figure 7 Longitudinal cross-sectional view of battery cell 1.

[0107] First, the battery cell 1 can be a cylindrical battery cell. For example, the battery cell 1 can be a cylindrical battery cell with a shape factor ratio (defined as the height-to-diameter ratio, i.e., the value obtained by dividing the diameter of the cylindrical battery cell by its height) greater than about 0.4.

[0108] Here, the form factor can refer to the values ​​representing the diameter and height of a cylindrical battery cell. By applying the numerical value representing the form factor, a cylindrical battery cell can be a 46110 cell, a 48750 cell, a 48110 cell, a 48800 cell, or a 46800 cell. Here, the first two numbers represent the diameter of the cell, the next two numbers represent the height of the cell, and the last number 0 indicates that the cross-section of the cell is circular.

[0109] Furthermore, the battery cell 1 can be, for example, a cylindrical battery cell with a shape factor ratio (the ratio of its diameter in the radial direction to its height in the winding axis direction) greater than about 0.4. For example, the diameter of the battery cell 1 can be 40 mm to 50 mm, and the height can be 60 mm to 130 mm. The shape factor of the battery cell 1 can be, for example, 46110, 4875, 48110, 4880, or 4680. However, the shape of the battery cell 1 is not limited to these and can include any other shape.

[0110] according to Figures 1 to 6 And refer to Figure 7 and Figure 8 According to the embodiment, the battery cell 1 may mainly include a battery canister 10, the aforementioned electrode assembly 20, a first electrode terminal 30, and a cover 60.

[0111] The battery canister 10 can be a cylindrical structure for cylindrical battery cells. In this case, the sidewall 11 can form the cylindrical side surface of the battery canister 10, and the bottom 12 can be connected to the sidewall 11 to form one end of the cylinder.

[0112] In other words, the bottom 12 can be the closed part of the battery can 10, and the other end of the battery can 10, which is positioned opposite to the bottom 12, can be the open part.

[0113] The battery cell 1 can accommodate the electrode assembly 20 in the battery can 10 through the opening of the battery can 10.

[0114] The bottom 12 may be in the shape of a disc with a through hole H1 in the central portion, and the sidewalls 11 may be disposed around the bottom 12 and have a cylindrical shape with a constant radius along the circumferential direction. The battery canister 10 including the bottom 12 and the sidewalls 11 may be formed by deep drawing a sheet of metal made of nickel-plated steel. The materials of the bottom 12 and the sidewalls 11 are not limited to this.

[0115] In this configuration, the first electrode terminal 30 can be fitted into the through hole H1 of the bottom 12. For example, the first electrode terminal 30 can be riveted to the bottom 12, wherein a washer 31 is positioned between the first electrode terminal 30 and the bottom 12.

[0116] The gasket 31 can be positioned between the first electrode terminal 30 and the bottom 12 to seal the inside of the battery canister 10 to prevent electrolyte leakage and to electrically insulate the first electrode terminal 30 from the bottom 12.

[0117] However, the connection method between the first electrode terminal 30 and the bottom 12 is not limited to this. For example, any other fixing method can be used to form a seal between the first electrode terminal 30 and the bottom 12 and to electrically insulate the first electrode terminal 30 from the bottom 12, such as bolt and nut connection, glass sealing or chrome coating and PP-MAH thermal bonding.

[0118] The first electrode terminal 30 can be connected to the first electrode 21 via a first current collector 40 located at one end in the winding axis direction Z. The first current collector 40 can be engaged with one of the two ends of the electrode assembly 20 in the winding axis direction Z. For example, the first current collector 40 can be engaged with the first uncoated portion 212 of the first electrode 21 located at the upper part of the electrode assembly 20 in the winding axis direction Z.

[0119] The first current collector 40 can be a negative current collector made of copper. However, the material of the first current collector 40 is not limited to this, and it can be omitted.

[0120] Therefore, the first electrode terminal 30 can be electrically connected to the first electrode 21 and has a first polarity.

[0121] The sidewall 11 of the battery can 10 can directly contact the outer peripheral surface of the electrode assembly 20, be electrically connected to the second electrode 22, and have a second polarity. For example, the sidewall 11 of the battery can 10 can be welded (W) to the second uncoated portion 222 of the second electrode 22, the second uncoated portion 222 forming at least a portion of the outer peripheral surface of the electrode assembly 20.

[0122] In this case, the insulator 70 can be disposed between the bottom 12 and the electrode assembly 20 to insulate the first electrode 21 from the bottom 12.

[0123] Therefore, the bottom 12 can be connected to the sidewall 11 and has a second polarity.

[0124] The cover 60 can be configured to cover the opening of the battery can 10. For example, the cover 60 can have a cover structure for effectively sealing the opening of the battery can 10. Therefore, the sealing of the battery cell 1 can be ensured, the electrolyte and electrode assembly 20 can be protected from the influence of the external environment, and the long-term performance of the battery cell 1 can be maintained.

[0125] The connection point between the opening of the battery can 10 and the cover 60 can be joined by welding. For example, the cover 60 can be joined to the battery can 10 by butt welding. However, the connection method between the battery can 10 and the cover 60 is not limited to welding, and the battery can 10 and the cover 60 can be joined by any other connection method (e.g., crimping and press-fitting).

[0126] The cover 60 may be made primarily of a metallic material used for electrical connection with the second current collector 50. Therefore, the cover 60 may be conductive. For example, the cover 60 may include copper.

[0127] The cap 60 can be circular, allowing it to be secured to the opening of the battery can 10 or the opening of the sealed can, but its shape is not limited to this. Furthermore, the thickness of the cap 60 can be designed to provide sufficient strength to prevent deformation in high-temperature or high-pressure environments and to ensure durability to prevent electrolyte leakage.

[0128] The cover 60 can be connected to the first electrode 21 via a second current collector 50 located at the other end in the winding axis direction Z. For example, the cover 60 can be electrically connected via the second current collector 50 to the first uncoated portion 212 of the first electrode 21 located at the lower part in the winding axis direction Z.

[0129] The cover 60 can be insulated from the side wall 11 of the battery can 10 having a second polarity via a gasket 61. Alternatively, the cover 60 can be directly connected to the first electrode 21 without the second current collector 50. For example, the first uncoated portion 212 of the first electrode 21 (see...) Figure 2 It can be connected to cover 60.

[0130] Therefore, the cover 60 can be electrically connected to the first electrode 21 and has a first polarity.

[0131] In other words, the first electrode terminal 30 and the cover 60 of the battery cell 1 according to this embodiment can have a first polarity, such as negative polarity, and the sidewall 11 and the bottom 12 can have a second polarity, such as positive polarity, and vice versa.

[0132] Therefore, since the outer peripheral surface of the electrode assembly 20 and the sidewall 11 are welded together in contact with each other, the battery cell 1 according to this embodiment can have an increased welding area and electrical contact area, thereby reducing contact resistance. As described above, when the contact resistance is reduced, electrical losses in the current transmission path can be reduced, thereby improving the output characteristics of the battery cell 1. Furthermore, a stable electrical connection can be maintained during repeated charging / discharging, thereby improving the performance of the battery cell 1.

[0133] Figure 9 This is a schematic longitudinal cross-sectional view of a battery cell 1a according to another embodiment of the present disclosure.

[0134] Here, refer to the above. Figure 7 and Figure 8 The description shared between the battery cell 1 described and the battery cell 1a of this embodiment will be understood equivalently and omitted to avoid redundancy.

[0135] refer to Figure 9 According to the embodiment, the battery cell 1a may mainly include a battery canister 10, the aforementioned electrode assembly 20, a first electrode terminal 30, a cover 60a, and a second electrode terminal 90.

[0136] The cover 60a can be configured to cover the opening of the battery can 10. That is, the cover 60a can have a cover structure for effectively sealing the opening of the battery can 10. Therefore, the sealing of the battery cell 1 can be ensured, the electrolyte and electrode assembly 20 can be protected from the influence of the external environment, and the long-term performance of the battery cell 1 can be maintained.

[0137] The connection point between the opening of the battery can 10 and the cover 60a can be joined by welding. For example, the cover 60a can be joined to the battery can 10 by butt welding. However, the connection method between the battery can 10 and the cover 60a is not limited to welding, and the battery can 10 and the cover 60a can be joined by any other connection method (e.g., crimping and press-fitting).

[0138] The cover 60a may be made primarily of a metallic material used for electrical connection with the second current collector 50. Therefore, the cover 60a may be conductive. For example, the cover 60a may include copper.

[0139] The cover 60a can be in the shape of a disc with a through hole H2 in the center portion. Therefore, the second electrode terminal 90 can be fitted into the through hole H2 of the cover 60a.

[0140] For example, the second electrode terminal 90 can be riveted to the cover 60a, with a gasket 91 located between the second electrode terminal 90 and the cover 60a. The gasket 91 can be positioned between the second electrode terminal 90 and the cover 60a to seal the interior of the battery can 10 to prevent electrolyte leakage and to electrically insulate the second electrode terminal 90 from the cover 60a.

[0141] However, the connection method between the second electrode terminal 90 and the cover 60a is not limited to this. For example, any other fixing method can be used to form a seal between the second electrode terminal 90 and the cover 60a and to electrically insulate the second electrode terminal 90 from the cover 60a, such as bolt and nut connection, glass sealing or chrome coating and PP-MAH thermal bonding.

[0142] The second electrode terminal 90 can be connected to the first electrode 21 via a second current collector 50 located at the other end in the winding axis direction Z. For example, the second electrode terminal 90 can be connected to the first uncoated portion 212 of the first electrode 21 via a second current collector 50 located at the lower part in the winding axis direction Z.

[0143] Therefore, the second electrode terminal 90 can be electrically connected to the first electrode 21 and has a first polarity.

[0144] The sidewall 11 of the battery can 10 can directly contact the outer peripheral surface of the electrode assembly 20, be electrically connected to the second electrode 22, and have a second polarity. For example, the sidewall 11 of the battery can 10 can be welded (W) to the second uncoated portion 222 of the second electrode 22, the second uncoated portion 222 forming at least a portion of the outer peripheral surface of the electrode assembly 20.

[0145] In this configuration, the insulator 80 can be positioned between the cover 60a and the electrode assembly 20 to insulate the first electrode 21 from the sidewall 11.

[0146] Therefore, in the same manner as the bottom 12, the cover 60a can be connected to the sidewall 11 and has a second polarity.

[0147] In other words, the first electrode terminal 30 and the second electrode terminal 90 of the battery cell 1 according to this embodiment can have a first polarity, such as negative polarity, and the sidewall 11, bottom 12 and cover 60a can have a second polarity, such as positive polarity, and vice versa.

[0148] However, with Figure 9Conversely, the cover 60a may not be electrically connected to the sidewall 11. For example, a sealing element may be positioned between the outer periphery of the cover 60 and the sidewall 11, and the cover 60 and the sidewall 11 may be electrically insulated by the sealing element.

[0149] As described above, since the outer peripheral surface and sidewall 11 of the electrode assembly 20 are welded to each other in direct contact (W), the contact resistance of the battery cell 1 and battery cell 1a according to the embodiments of this disclosure can be reduced. This design can improve the efficiency of the electrical connection and minimize energy loss that may occur in the current transmission path, thereby improving the output characteristics of the battery cell 1 and battery cell 1a.

[0150] In addition, it can provide a stable and large contact area, ensuring uniform current transmission and eliminating the need for any additional connectors or media for bonding, resulting in a simple structure, which in turn helps to improve the efficiency of the manufacturing process of battery cells 1, 1a.

[0151] Figure 10 This is a schematic diagram illustrating a battery pack P including battery cell 1 and battery cell 1a according to an embodiment of the present disclosure. Figure 11 This is a schematic diagram of a vehicle V including a battery pack P according to an embodiment of the present disclosure.

[0152] Reference Figure 10 The battery pack P according to the embodiments of the present disclosure may include at least one battery cell 1, 1a according to the foregoing embodiments and a battery pack housing C that houses the battery cell 1, 1a.

[0153] The battery pack P according to embodiments of this disclosure may also include any other components of the battery pack P known at the time of filing of this disclosure. For example, the battery pack P according to embodiments of this disclosure may also include a current sensor, a fuse, or a service plug.

[0154] Battery pack P can freely use any cooling method, such as bottom cooling or side cooling, according to the desired design requirements, regardless of the placement orientation of battery cells 1 and 1a. Therefore, battery pack P allows for various structural designs that can be combined with a thermal management system to achieve optimal performance of battery cells 1 and 1a and adaptability to various environments.

[0155] Reference Figure 11 A vehicle V according to an embodiment of the present disclosure may include one or more battery packs P according to the present disclosure. In addition to the battery packs P, a vehicle V according to an embodiment of the present disclosure may also include any other components included in a vehicle. For example, in addition to the battery packs P according to an embodiment of the present disclosure, a vehicle V according to an embodiment of the present disclosure may also include a body, a motor, or a controller, such as an electronic control unit (ECU).

[0156] Furthermore, the battery pack P according to embodiments of this disclosure can be installed in a vehicle V and any other device, instrument, or equipment (e.g., an energy storage system) that uses a secondary battery.

[0157] According to the various embodiments described above, an electrode assembly 20 with improved performance, as well as battery cells 1, 1a, battery pack P and vehicle V including the electrode assembly 20, can be provided.

[0158] Although the present disclosure has been described above with reference to certain embodiments and accompanying drawings, the present disclosure is not limited thereto, and various modifications and variations can be made by those skilled in the art to which this disclosure pertains within the scope of the technical aspects of the present disclosure, the appended claims and their equivalents.

[0159] [List of reference numerals] 1, 1a: Battery cell

[0160] 10: Battery can

[0161] 11: Sidewall

[0162] 12: Bottom

[0163] 20: Electrode assembly

[0164] 21: First electrode

[0165] 211: First Coating Section

[0166] 2111: Active material layer

[0167] 212: First uncoated part

[0168] 2121: Uncoated upper part

[0169] 2122: Lower uncoated area

[0170] 2123: Incisional ear

[0171] 22: Second electrode

[0172] 221: Second Coating Section

[0173] 2211: Active material layer

[0174] 222: Second uncoated area

[0175] 2221: Part One

[0176] 2222: Part Two

[0177] 23: Diaphragm

[0178] 30: First electrode terminal

[0179] 31: Washer

[0180] 40: First manifold

[0181] 50: Second manifold

[0182] 60, 60a: Cover

[0183] 61: Washer

[0184] 70, 80: Insulator

[0185] 90: Second electrode terminal

[0186] 91: Washer

[0187] W: Welding section

[0188] H1, H2: Through holes

[0189] W: Welding section

[0190] P: Battery pack

[0191] C: Battery pack casing

[0192] V: Vehicle

[0193] L1: Perimeter length

Claims

1. An electrode assembly, the electrode assembly comprising: A first electrode and a second electrode, wherein the first electrode and the second electrode are wound around a winding axis with a diaphragm inserted between the first electrode and the second electrode to define a core and an outer peripheral surface. The first electrode includes: A first uncoated portion at each end of the two long sides, along the length direction of the first electrode, where no active material layer is coated; and A first coated portion having an active material layer coated in the area excluding the first uncoated portion, and The second electrode includes: A second uncoated portion, in a region including at least a portion of the outer peripheral surface, is not coated with an active material layer, the second uncoated portion forming the outer peripheral surface of the electrode assembly; and A second coated portion is coated with an active material layer in the area other than the second uncoated portion.

2. The electrode assembly according to claim 1, in, The first uncoated portion is formed at both ends of the electrode assembly in the direction of the winding axis.

3. The electrode assembly according to claim 2, in, The first uncoated portion is bent along the radial direction of the electrode assembly to form a bent surface at the two ends of the electrode assembly in the direction of the winding axis.

4. The electrode assembly according to claim 1, in, The second uncoated portion includes at least one of the following: The first part is located at one end of the second electrode in the length direction; as well as The second part is located at the other end of the second electrode in the length direction.

5. The electrode assembly according to claim 4, in, In the length direction of the second electrode, the first portion has a length equal to or less than the outer perimeter length of the electrode assembly.

6. The electrode assembly according to claim 1, in, In the length direction of the second electrode, the length of the second electrode is longer than that of the first electrode.

7. The electrode assembly according to claim 6, in, The second electrode is not coated with an active material layer in at least a portion of the region where the second electrode is longer than the first electrode in the longitudinal direction.

8. The electrode assembly according to claim 1, in, In the longitudinal direction of the diaphragm, the length of the diaphragm is longer than that of the first electrode and shorter than that of the second electrode.

9. The electrode assembly according to claim 1, in, In the direction of the winding axis of the electrode assembly, the width of the first electrode is greater than the width of the second electrode.

10. The electrode assembly according to claim 9, in, The first electrode is configured to have two ends that extend from the two ends of the second electrode respectively in the direction of the winding axis of the electrode assembly.

11. A battery cell, the battery cell comprising: The electrode assembly according to any one of claims 1 to 10; A battery can, the battery can including a bottom and a sidewall extending from the bottom along the winding axis direction of the electrode assembly, the battery can receiving the electrode assembly through an opening positioned opposite the bottom, and the outer peripheral surface of the battery can contacting the sidewall for electrical connection with a second electrode; A first electrode terminal is electrically connected to the electrode assembly through a through-hole in the bottom of the battery can; as well as A lid that covers the opening of the battery can.

12. The battery cell according to claim 11, in, The first electrode is electrically connected to the first electrode terminal and the cover.

13. The battery cell according to claim 11, further comprising: The second electrode terminal is riveted through a through hole in the cover. The first electrode is electrically connected to the first electrode terminal and the second electrode terminal.

14. A battery pack comprising the battery cells according to claim 11.

15. A vehicle comprising at least one battery pack according to claim 14.

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