Battery and battery pack and vehicle comprising the same

Abstract

The present invention provides a battery pack, characterized in that the battery pack comprises: a battery housing having a sidewall member, a bottom member connected to one end of the sidewall member in the axial direction, and an opening disposed at the other end of the sidewall member in the axial direction; an electrode assembly in which a first electrode, a second electrode, and a diaphragm inserted between the first electrode and the second electrode are wound around a winding axis, and the electrode assembly is housed in the battery housing such that the tab of the second electrode faces the opening; and a cover disposed on the outer surface of the other end of the sidewall member in the axial direction to cover the opening of the battery housing, wherein a connecting portion is formed such that the edge of the inner surface of the cover and the edge of the other end of the sidewall member in the axial direction engage with each other, and the connecting portion is recessed inward in the radial direction.

Description

Technical Field

[0001] This disclosure relates to batteries, battery packs including such batteries, and vehicles.

[0002] This application is based on and claims priority to Korean Patent Application No. 10-2024-0088247 filed with the Korean Intellectual Property Office on July 4, 2024 and Korean Patent Application No. 10-2025-0073787 filed on June 5, 2025, the disclosures of which are incorporated herein by reference in their entirety. Background Technology

[0003] Due to their high applicability to various product types and outstanding electrical characteristics such as high energy density, rechargeable batteries are widely used in portable electronic devices and electrically powered transportation devices such as electric vehicles (EVs) or hybrid electric vehicles (HEVs). Rechargeable batteries significantly reduce the use of fossil fuels and produce no byproducts from energy consumption; therefore, they are attracting attention as an eco-friendly and highly energy-efficient alternative energy source.

[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. The operating voltage of rechargeable battery cells typically ranges from approximately 2.5 V to 4.5 V. When a higher output voltage is required, battery cells are connected in series to form battery modules or battery packs. Depending on the required charge / discharge capacity, battery cells can be connected in parallel to form battery modules or battery packs. Therefore, the number of batteries included in a battery pack or module and the type of electrical connection can vary depending on the required voltage and capacity conditions.

[0005] Secondary battery cells can be cylindrical, square, or pouch-shaped. Cylindrical batteries are manufactured by winding electrode assemblies into a core shape and placing the electrode assemblies along with an electrolyte solution within a battery casing. The electrode assemblies include a positive plate and a negative plate, with a separator inserted between them. In some embodiments, the battery casing may have an open side, and a cap may be welded to the corresponding open end to seal the battery casing. However, insufficient contact area between the battery casing and the cap can lead to poor welding and consequently low weld strength, resulting in electrolyte leakage.

[0006] Therefore, research is currently underway on using seam welding instead of crimping and pressing to attach the cover to the battery housing. Seam welding can be performed in a direction parallel or perpendicular to the axial direction of the battery housing to join the battery housing to the cover. However, when welding is performed in a direction perpendicular to the axial direction, weld beads may form at the weld location, resulting in uneven outer diameter of the battery housing. This outer diameter deviation may affect the contact area between the battery and the heat sink within the battery pack, potentially leading to a reduction in the vehicle's heat dissipation performance and overall performance. Summary of the Invention

[0007] Technical issues

[0008] This disclosure is designed to solve the above-mentioned problems, and therefore aims to provide a battery for preventing uneven outer diameter of the battery casing due to weld beads during the manufacture of a cylindrical secondary battery including a seam welding process, thereby ensuring contact stability between the battery and the heat sink and preventing a reduction in the heat dissipation performance of the battery pack and the overall performance of the system.

[0009] This disclosure also aims to minimize or prevent the influence of weld beads at the joint between the cover and the battery housing on the outer diameter of the battery housing, thereby improving the shape accuracy of the battery housing, reducing the product defect rate and ensuring the stability and reliability of the manufacturing process.

[0010] The technical problems 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.

[0011] Technical solution

[0012] To achieve the above objectives, according to one aspect of this disclosure, a battery, a battery pack including the battery, and a vehicle are provided according to the following embodiments.

[0013] According to a first embodiment, a battery is provided, the battery comprising: a battery housing having a sidewall, a bottom, and an opening, the bottom being connected to an axially oriented end of the sidewall, the opening being at an opposite axially oriented end of the sidewall; an electrode assembly including a first electrode and a second electrode wound around a winding axis, and a diaphragm inserted between the first electrode and the second electrode, the electrode assembly being housed in the battery housing such that the tab of the second electrode faces the opening; and a cover configured to cover the opening of the battery housing when mounted on an outer surface of an opposite axially oriented end of the sidewall, wherein an edge of an inner surface of the cover and an edge of an opposite axially oriented end of the sidewall are joined to form a joint, and wherein the joint is radially recessed inward.

[0014] According to the second embodiment, in the first embodiment, the cover and sidewall can be joined by welding, and a weld bead can be formed at the joint by welding, and the weld bead does not protrude radially outward from the battery casing.

[0015] According to the third embodiment, in either the first or second embodiment, the joint may have a closed-loop shape along the circumferential direction.

[0016] According to the fourth embodiment, in any one of the first to third embodiments, the radial diameter of the cover may be equal to the radial diameter of the battery casing at opposite ends in the axial direction.

[0017] According to the fifth embodiment, in any one of the first to fourth embodiments, the other end of the sidewall in the axial direction may include a first inclined portion on the outer side in the radial direction and a first flat portion connected to the first inclined portion and perpendicular to the sidewall.

[0018] According to the sixth embodiment, in the fifth embodiment, the first inclined portion can extend axially inward and radially outward as the first inclined portion moves inward.

[0019] According to the seventh embodiment, in either the fifth or sixth embodiment, the angle α between the first inclined portion and the first flat portion can be 100° or greater and 170° or less.

[0020] According to the eighth embodiment, in any one of the fifth to seventh embodiments, the radial length of the first inclined portion may be smaller than the radial length of the first flat portion.

[0021] According to the ninth embodiment, in any one of the first to eighth embodiments, the edge of the inner surface of the cover may include a second inclined portion on the outer side in the radial direction and a second flat portion connected to the second inclined portion and perpendicular to the axial direction.

[0022] According to the tenth embodiment, in the ninth embodiment, the second inclined portion can extend outward along the axial direction and then outward along the radial direction.

[0023] According to the eleventh embodiment, in either the ninth or tenth embodiment, the radial length of the second inclined portion may be smaller than the radial length of the second flat portion.

[0024] According to the twelfth embodiment, in any of the ninth to eleventh embodiments, the angle β between the second inclined portion and the second flat portion can be 100° or greater and 170° or less.

[0025] According to the thirteenth embodiment, in any one of the first to twelfth embodiments, the cover may further include an exhaust recess.

[0026] According to the fourteenth embodiment, in any one of the first to thirteenth embodiments, the battery may further include a second current collector connected to the second electrode, and the second current collector may be connected to the battery casing.

[0027] According to the fifteenth embodiment, in the fourteenth embodiment, the cover may be axially spaced from the second collector plate at its outer side in the radial direction.

[0028] According to the sixteenth embodiment, a battery pack is provided, which includes a battery according to any one of the first to fifteenth embodiments.

[0029] According to the seventeenth embodiment, a vehicle is provided that includes a battery pack according to the sixteenth embodiment.

[0030] Beneficial effects

[0031] The battery according to the embodiments of this disclosure can prevent uneven outer diameter of the battery casing caused by weld lines in battery manufacturing processes including seam welding, thereby ensuring contact stability between the battery and the heat sink. Therefore, poor heat dissipation performance of the battery pack can be effectively prevented.

[0032] Furthermore, this disclosure can minimize or prevent the influence of weld beads at the joint between the cover and the battery housing on the outer diameter of the battery housing, thereby improving the shape accuracy of the battery housing and reducing the product defect rate.

[0033] Furthermore, because the battery of this disclosure is side-welded through a joint formed on the side, damage to the electrode assembly can be minimized.

[0034] 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

[0035] The accompanying drawings illustrate exemplary embodiments of this disclosure and are used together with the foregoing disclosure to provide a better understanding of the technical aspects of this disclosure; therefore, this disclosure should not be construed as limited to the exemplary aspects shown in the drawings.

[0036] Figure 1 A battery according to one aspect of this disclosure is shown.

[0037] Figure 2a A battery according to one aspect of this disclosure is shown.

[0038] Figure 2bA battery according to one aspect of this disclosure is shown.

[0039] Figure 3a A cross-section of a battery according to one aspect of this disclosure is shown.

[0040] Figure 3b The sidewall of a battery according to one aspect of this disclosure is shown.

[0041] Figure 3c A cover for a battery according to one aspect of this disclosure is shown.

[0042] Figure 4 A cross-section of a battery according to another aspect of this disclosure is shown.

[0043] Figure 5 A cross-section of a battery according to another aspect of this disclosure is shown.

[0044] Figure 6 A cross-section of a battery according to one aspect of this disclosure is shown.

[0045] Figure 7 An electrode assembly according to one aspect of this disclosure is shown.

[0046] Figure 8 An electrode assembly according to one aspect of this disclosure is shown.

[0047] Figure 9 A wound-core type electrode assembly according to one aspect of this disclosure is shown.

[0048] Figure 10 A wound-core type electrode assembly according to one aspect of this disclosure is shown.

[0049] Figure 11 A battery according to one aspect of this disclosure is shown.

[0050] Figure 12 A battery according to one aspect of this disclosure is shown.

[0051] Figure 13 A battery according to one aspect of this disclosure is shown.

[0052] Figure 14 A second current collector is shown according to one aspect of this disclosure.

[0053] Figure 15 A second current collector is shown according to one aspect of this disclosure.

[0054] Figure 16 The process for placing an electrode assembly in a battery housing according to one aspect of the present disclosure is illustrated schematically.

[0055] Figure 17The process for soldering a first electrode terminal to a first current collector is schematically illustrated according to one aspect of the present disclosure.

[0056] Figure 18 A battery pack according to one aspect of this disclosure is shown.

[0057] Figure 19 A battery pack according to one aspect of this disclosure is shown.

[0058] Figure 20 A vehicle according to one aspect of this disclosure is shown. Detailed Implementation

[0059] 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 or dictionary meanings, but should be interpreted according to their meanings and concepts corresponding to the technical aspects of this disclosure, based on the principle that inventors are allowed to define terms appropriately for the best interpretation.

[0060] The terminology used herein is for describing exemplary embodiments of this disclosure and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms include the plural forms.

[0061] <Definition>

[0062] The terms “comprising,” “including,” or “having” as used in this specification specify the presence of the said element, but do not exclude the presence or addition of one or more other elements unless the context clearly indicates otherwise.

[0063] Throughout this specification, unless otherwise stated, each element may be singular or plural.

[0064] Throughout the specification, when an element is referred to as "on (or below) another element" or "above (or below) another element," the element may be positioned to contact the upper (or lower) surface of the other element, and an intermediate element may be present.

[0065] Throughout the specification, when an element is referred to as “connected to” or “linked to” another element, it should be understood that these elements are directly connected or linked to each other, but each element may be “connected to” or “linked to” another element, or there may be an intermediate element.

[0066] Throughout this specification, unless otherwise stated, “A and / or B” means A or B, or both, and unless otherwise stated, “C to D” means C or greater and D or less.

[0067] Throughout this specification, the term "axial direction" refers to the axial direction in which the winding axis extends, and the winding axis is the axis around which the core-type electrode assembly is wound. The term "radial direction" refers to the direction toward or away from the winding axis. The term "axial direction" refers to the direction about an axis.

[0068] The embodiments described herein and the illustrations shown in the accompanying drawings are exemplary embodiments of this disclosure to describe the technical aspects of this disclosure, but are not intended to be limiting. Therefore, it should be understood that various other equivalents and modifications may be made thereto when this application is filed.

[0069] This disclosure provides a battery.

[0070] According to one aspect of the present disclosure, the battery 1 of the present disclosure includes: a battery housing 10 having a sidewall 11, a bottom 12 connected to one end of the sidewall 11 in the axial direction, and an opening at the other end of the sidewall 11 in the axial direction; an electrode assembly 20 including a first electrode 21 and a second electrode 22 wound around a winding axis, and a diaphragm 28 inserted between the first electrode 21 and the second electrode 22, the electrode assembly 20 being housed in the battery housing such that the tab of the second electrode 22 faces the opening; and a cover 40 mounted on the outer surface of the other end of the sidewall 11 in the axial direction and configured to cover the opening of the battery housing, wherein the edge of the inner surface of the cover 40 and the edge of the other end of the sidewall 11 in the axial direction are joined to form a joint 16, and the joint 16 is recessed radially inward.

[0071] A detailed description will be provided below.

[0072] The battery 1 disclosed herein may, for example, be a cylindrical battery 1 with a shape factor ratio (defined as a value obtained by dividing the diameter Φ of the cylindrical battery cell by the height H, i.e., the ratio of height to diameter) that is approximately greater than 0.4.

[0073] Here, the shape factor refers to the values ​​representing the diameter and height of the cylindrical battery 1. The cylindrical battery used in the pressure tester can be, for example, a 46110 cell, a 48750 cell, a 48110 cell, a 48800 cell, or a 46800 cell. In the shape factor values, the first two digits represent the diameter of the cell, the last two digits represent the height of the cell, and the last digit, 0, indicates that the cross-section of the cell is circular.

[0074] The cylindrical battery used in the pressure tester can be a cylindrical battery with a generally cylindrical shape having a diameter of about 46 mm, a height of about 110 mm, and a form factor ratio of 0.418.

[0075] According to another embodiment, the battery 1 can be a cylindrical battery cell with a generally cylindrical shape having a diameter of about 48 mm, a height of about 75 mm, and a form factor ratio of 0.640.

[0076] According to another embodiment, the battery 1 can be a cylindrical battery cell with a generally cylindrical shape having a diameter of about 48 mm, a height of about 110 mm, and a form factor ratio of 0.418.

[0077] According to another embodiment, the battery 1 can be a cylindrical battery cell with a generally cylindrical shape having a diameter of about 48 mm, a height of about 80 mm, and a form factor ratio of 0.600.

[0078] According to another embodiment, the battery 1 can be a cylindrical battery cell with a generally cylindrical shape having a diameter of about 46 mm, a height of about 80 mm, and a form factor ratio of 0.575.

[0079] The pressure tester disclosed herein can be applied to battery cells having a form factor ratio of about 0.4 or less, such as 18650 cells or 21700 cells. An 18650 cell has a diameter of about 18 mm, a height of about 65 mm, and a form factor ratio of 0.277. A 21700 cell has a diameter of about 21 mm, a height of about 70 mm, and a form factor ratio of 0.300.

[0080] Reference Figure 1 The battery casing 10 disclosed herein has a cylindrical sidewall 11, a bottom 12 connected to one end of the sidewall 11 in the axial direction, and an opening at the other end of the sidewall 11 in the axial direction.

[0081] The bottom 12 and the sidewall 11 can be manufactured by forming a conductive metal sheet by deep drawing, holding the front end of the sidewall 11 with a blank holder, and finishing it with a punch.

[0082] Alternatively, the bottom 12 and the sidewall 11 can be manufactured by forming a conductive metal sheet by deep drawing, supporting the front end of the sidewall 11 by a jig, and machining it perpendicular to the bottom 12 using a cutting machine.

[0083] In embodiments of this disclosure, the conductive metal sheet may include, for example, aluminum, steel, or stainless steel, but is not limited thereto.

[0084] The bottom 12 may have a hole in the center, into which the first electrode terminal 13 may be fitted. The first electrode terminal 13 may be riveted to the bottom 12, and a terminal washer 14 may be located between the first electrode terminal 13 and the bottom 12. The terminal washer 14 may be located between the first electrode terminal 13 and the bottom 12 to seal the inside and outside of the battery housing 10, thereby preventing electrolyte leakage and electrically insulating the first electrode terminal 13 from the bottom 12.

[0085] However, the method for connecting the first electrode terminal 13 to the bottom 12 is not limited thereto. For example, when it comes to a structure for forming a seal between the first electrode terminal 13 and the bottom 12 and electrically insulating the first electrode terminal 13 from the bottom 12, any other fastening method may be used, such as bolt-nut connection, glass seal, or chrome coating & PP-MAH heat bonding.

[0086] The first electrode terminal 13 may have a first polarity, and the battery casing 10 may have a second polarity. Therefore, the bottom 12 of the battery casing 10 and the sidewall 11 connected to the bottom 12 may have a second polarity.

[0087] Therefore, the first electrode terminal 13 and the second electrode terminal 15 can be disposed at one end of the battery housing 10 in the axial direction. In this case, the busbar connected to the first electrode terminal 13 and the busbar connected to the second electrode terminal 15 can be located at one end of the battery housing 10 in the axial direction.

[0088] In embodiments of this disclosure, the first electrode terminal 13 may be a positive terminal, and the second electrode terminal 15 may be a negative terminal, and the first electrode terminal 13 may be a negative terminal, while the second electrode terminal 15 may be a positive terminal.

[0089] In embodiments of this disclosure, the cover 40 can be manufactured by pressing a circular metal sheet into shape.

[0090] In embodiments of this disclosure, the cover 40 has a generally disc-shaped form to close the opening of the battery housing 10 when mounted on the outer surface of the other end in the axial direction.

[0091] Reference Figure 2a The edge of the inner surface of the cover 40 and the edge of the other end of the sidewall 11 in the axial direction are joined to form a joint 16, and the joint 16 is recessed radially inward.

[0092] like Figure 3a As shown, the battery 1 of this disclosure is radially recessed inward at the contact area between the cover 40 and the sidewall 11.

[0093] Figure 3bA sidewall 11 according to one aspect of this disclosure is shown.

[0094] Reference Figure 3b The other end of the sidewall 11 in the axial direction may have a first inclined portion 111 on the outer side in the radial direction and a first flat portion 112 connected to the first inclined portion and perpendicular to the sidewall.

[0095] In embodiments of this disclosure, the other end of the sidewall 11 in the axial direction may have a first inclined portion 111 on the outer side in the radial direction and a first flat portion 112 connected to the first inclined portion 111 and perpendicular to the sidewall. That is, the first inclined portion 111 may be connected to the outer peripheral surface of the sidewall 11, and the first flat portion 112 may be connected to the first inclined portion 111 and connected to the inner peripheral surface of the sidewall 11.

[0096] In embodiments of this disclosure, the first inclined portion 111 may extend radially outward as it travels axially inward. That is, the first inclined portion 111 may have a surface whose outer diameter increases radially outward as it travels axially inward. In this case, the first inclined portion 111 may be a flat surface or a curved surface.

[0097] When the first inclined portion 111 is a flat surface, the angle (α) between the first inclined portion 111 and the first flat surface is not limited to a specific range, but can be, for example, 100° to 170°, 105° to 165°, 110° to 160°, 115° to 155°, 120° to 150°, 125° to 145°, 130° to 140° or 45°.

[0098] In embodiments of this disclosure, the first inclined portion 111 may be chamfered, rounded, or inclined to be inclined by a cutting machine.

[0099] In embodiments of this disclosure, the radial length of the first inclined portion 111 may be less than the radial length of the first flat portion 112. In this case, sufficient contact area between the sidewall 11 and the cover 40 can be ensured, thereby achieving high weld strength.

[0100] Figure 3c Cover 40 is shown according to one aspect of this disclosure.

[0101] Reference Figure 3c The edge of the inner surface of the cover 40 may have a second inclined portion 401 on the outer side in the radial direction and a second flat portion 402 connected to the second inclined portion 401 and perpendicular to the axial direction.

[0102] In embodiments of this disclosure, the second inclined portion 401 may extend radially outward as it travels axially outward. That is, the second inclined portion 401 may have a surface whose outer diameter increases radially outward as it travels axially outward. In this case, the second inclined portion 401 may be a flat surface or a curved surface.

[0103] In embodiments of this disclosure, when the second inclined portion 401 is a flat surface, the angle (β) between the second inclined portion 401 and the second flat portion 402 is not limited to a specific range, but can be, for example, 100° to 170°, 105° to 165°, 110° to 160°, 115° to 155°, 120° to 150°, 125° to 145°, 130° to 140° or 45°.

[0104] In embodiments of this disclosure, the second inclined portion 401 may be chamfered, rounded, or inclined to be inclined by a cutting machine.

[0105] In embodiments of this disclosure, the radial length of the second inclined portion 401 may be less than the radial length of the second flat portion 402. In this case, sufficient contact area between the sidewall 11 and the cover 40 can be ensured, thereby achieving high weld strength.

[0106] In embodiments of this disclosure, such as Figure 3a As shown, the joint 16 may have a first inclined portion 111 of the battery housing 10 and a second inclined portion 401 of the cover 40.

[0107] In another embodiment of this disclosure, such as Figure 4 As shown, the joint 16 may have a first inclined portion 111 of the battery housing 10, and may not have a second inclined portion 401 of the cover 40.

[0108] In yet another embodiment of this disclosure, such as Figure 5 As shown, the joint 16 may not have the first inclined portion 111 of the battery housing 10, but may have the second inclined portion 401 of the cover 40.

[0109] In embodiments of this disclosure, the angle (γ) between the sidewall 11 of the battery housing 10 and the cover 40 at the joint 16 can be, for example, 10° to 170°, 20° to 160°, 30° to 150°, 40° to 140°, 50° to 130°, 60° to 120°, 70° to 110°, 80° to 100° or 90°.

[0110] In embodiments of this disclosure, the joint 16 may be formed in a closed-loop shape along the circumferential direction, such as... Figure 2aAs shown. That is, the joint 16 can be continuously formed between the battery housing 10 and the cover 40. In this case, the mechanical bonding strength between the battery housing 10 and the cover 40 can be further improved.

[0111] In another embodiment of this disclosure, the joint 16 may be formed discontinuously between the battery housing 10 and the cover 40. In this case, the joint 16 may be formed regularly or irregularly along the circumferential direction.

[0112] In embodiments of this disclosure, the radial diameter of the cover 40 and the radial diameter of the battery housing 10 at the other end in the axial direction may be equal. In this case, "equal" may include "substantially equal," and "substantially equal" may mean that, based on the radial diameter of the battery housing 10 at the other end in the axial direction being 100%, the radial diameter of the cover 40 is in the range of 95% to 105%. Alternatively, based on the radial diameter of the cover 40 being 100%, the radial diameter of the battery housing 10 at the other end in the axial direction may be in the range of 95% to 10%.

[0113] Figure 6 A cross-section of a battery, including a cover and sidewalls welded together, is shown according to one aspect of this disclosure.

[0114] Reference Figure 6 The cover 40 and the sidewall 11 can be joined by welding, and a weld bead 16a can be formed at the joint by welding. The weld bead 16a may not protrude outward in the radial direction beyond the battery housing. That is, the weld bead 16a may not protrude beyond the outer diameter of the cover 40 and / or the outer diameter of the battery housing 10. In other words, the weld bead 16a may be located within the outer diameter of the cover 40 and the outer diameter of the battery housing 10.

[0115] In this case, the outer diameter of the battery casing 10 can remain constant without unevenness, thereby ensuring the contact stability between the battery and the heat sink.

[0116] Furthermore, the joint between the cover 40 and the sidewall 11 can be achieved by resistance welding, ultrasonic welding, or laser welding.

[0117] In embodiments of this disclosure, the cover 40 may further include a venting recess 41.

[0118] For example, such as Figure 3a As shown, a venting notch 41 may be formed in the upper and / or lower surface of the cover 40. When a thermal event occurs in the battery, the venting notch 41 may rupture due to the internal pressure of the high-temperature venting gas, thereby releasing the venting gas from the battery to the outside.

[0119] In embodiments of this disclosure, the cap 40 may further include an inlet 42 at the central portion of the cap 40, such as... Figure 2b As shown. With the opening end of the battery housing 10 covered by the cap 40, the injection port 42 can be aligned with the hollow core of the electrode assembly 20 housed in the battery housing 10.

[0120] In embodiments of this disclosure, the injection port 42 may be disposed in an inner position in the radial direction relative to the venting recess 41, and preferably disposed in the central portion.

[0121] In embodiments of this disclosure, the injection port 42 can be provided by, for example Figure 2a and Figure 2b The closure 50 shown covers and closes the opening. The edge portion of the closure 50 and the edge portion of the inlet 42 can be sealed together. The seal can be achieved using seam welding or any other known sealing method.

[0122] In embodiments of this disclosure, the closure 50 may have a plug shape and is formed by deep drawing a 0.3 mm thick metal sheet.

[0123] Furthermore, in another embodiment of this disclosure, the cover 40 may not include an injection port. In this case, during the manufacture of the battery cell, when there is no injection port at the bottom 12 of the battery casing 10, the electrolyte injection process can be performed before covering the battery casing 10 with the cover 40.

[0124] However, when the cover 40 further includes an injection port 42, after the cover 40 is pushed into the battery housing 10 and a weld and joint are formed, an electrolyte solution can be injected through the injection port 42. Therefore, the effect of heat during the joint on the electrolyte solution can be avoided compared to bonding the cover 40 to the filled battery housing 10.

[0125] On the other hand, in embodiments of this disclosure, the injection port 42 at the center of the cover 40 may be a channel through which a device for welding the first current collector 31 for welding the first electrode terminal 13 and the first electrode 21 enters and exits.

[0126] Therefore, after the cover 40 is attached to the battery housing 10, the first electrode 21 and the first electrode terminal 13 can be attached by inserting a welding device into the battery housing 10 through the injection port 42.

[0127] In embodiments of this disclosure, the electrode assembly 20 is housed within the battery casing 10. The electrode assembly 20 is manufactured by the following steps: preparing as... Figure 7 The first electrode 21, the second electrode 22, and the diaphragm 28, which have a predetermined width and extend along the length direction, are shown; Figure 8As shown, the first electrode 21, the diaphragm 28, the second electrode 22, and the diaphragm 28 are stacked sequentially to form a laminate; the first stage winds the laminate around the winding axis as shown. Figure 9 The shape of the core shown.

[0128] In embodiments of this disclosure, the first electrode 21 can be a positive electrode, and the second electrode 22 can be a negative electrode, and the first electrode 21 can be a negative electrode, while the second electrode 22 can be a positive electrode.

[0129] In embodiments of this disclosure, the first electrode 21 and the second electrode 22 are formed into sheet shapes. The electrode sheet can be manufactured by coating an active material layer 24 onto the surface of a metal foil 23. The electrode sheet may have a coated portion 25 in which the active material layer 24 is present and an uncoated portion 26 in which the active material layer 24 is not present. The positive electrode sheet may have an uncoated portion 26 on one side in the width direction, and the negative electrode sheet may have an uncoated portion 26 on the other side in the width direction.

[0130] In embodiments of this disclosure, the positive electrode can be manufactured by coating a positive electrode composition comprising a positive electrode active material, a binder, a conductive material, and a solvent onto a positive electrode current collector.

[0131] In embodiments of this disclosure, the positive electrode active material may include any positive electrode active material commonly used in the positive electrode of an electrochemical device. For example, the positive electrode active material may include lithium manganese oxide, lithium cobalt oxide, lithium nickel oxide, lithium iron oxide, or lithium composite oxides thereof.

[0132] In this case, the positive electrode active material can be included in an amount of 80 wt% to 99 wt%, and preferably 85 wt% to 98 wt%, based on the total weight of the solid contents of the positive electrode composition. When the amount of positive electrode active material falls within the above range, excellent capacity characteristics can be exhibited.

[0133] The positive current collector is not limited to a specific type and can include any material that is conductive without causing chemical changes in the corresponding battery. Positive current collectors can include, for example, stainless steel, aluminum, nickel, titanium, calcined carbon, or aluminum or stainless steel with a surface treated with carbon, nickel, titanium, or silver.

[0134] Binders are used to help hold the active and conductive materials together and bond them to the current collector, and are typically added in amounts from 1 wt% to 30 wt% based on the total solid weight of the cathode composition. Examples of binders may include polyvinylidene fluoride, polyvinyl alcohol, carboxymethyl cellulose (CMC), starch, hydroxypropyl cellulose, regenerated cellulose, polyvinylpyrrolidone, tetrafluoroethylene, polyethylene, polypropylene, ethylene propylene diene monomer (EPDM), sulfonated EPDM, styrene-butadiene rubber, fluororubber, or various copolymers.

[0135] Conductive materials can typically be added in amounts ranging from 1 wt% to 30 wt% based on the total solid weight of the positive electrode composition.

[0136] Conductive materials are not limited to a specific type and can include any material that is conductive without causing chemical changes in the corresponding battery. For example, conductive materials can include: graphite; carbon-based materials such as carbon black, acetylene black, Ketjen black, channel black, furnace black, lamp black, or thermally cracked black; conductive fibers such as carbon fibers or metal fibers; fluorocarbon compounds; metal powders such as aluminum powder or nickel powder; conductive whiskers such as zinc oxide whiskers and potassium titanate whiskers; conductive metal oxides, such as titanium oxide; or conductive materials such as polyphenylene derivatives. Specific examples of commercially available conductive materials include acetylene black from Chevron Chemical or Denka Singapore Private Limited, products from Gulf Oil, Ketjen black EC series (from Armak), Vulcan XC-72 (from Cabot), and Super P (Timcal).

[0137] In addition, if desired, the positive electrode active material layer may optionally include a dispersant.

[0138] The dispersant is not limited to a specific type and may include any dispersant for the positive electrode. For example, aqueous or organic dispersants may be used selectively as needed. Preferably, the dispersant may include any one or a mixture of two or more of the following: cellulose-based compounds, polyoxyethylene, polyvinyl alcohol, polyvinylpyrrolidone, polyvinyl acetal, polyvinyl ether, polyvinyl sulfonic acid, polyvinyl chloride (PVC), polyvinylidene fluoride, chitosan, starch, linear starch, polyacrylamide, poly-N-isopropylacrylamide, poly-N,N-dimethylacrylamide, polyethyleneimine, polyoxyethylene, poly(2-methoxyethoxyethylene), poly(acrylamide-co-diallyldimethylammonium chloride), acrylonitrile / butadiene / styrene (ABS) polymers, a mixture of acrylonitrile / styrene / acrylate (ASA) polymers and propylene carbonate, styrene / acrylonitrile (SAN) copolymers, methyl methacrylate / acrylonitrile / butadiene / styrene (MABS) polymers, styrene-butadiene rubber, nitrile rubber, and fluororubber. Hydrogenated nitrile rubber (H-NBR) may be used. When the positive electrode active material layer further includes a dispersant, the composition of the positive electrode active material layer, especially the dispersion of the conductive material, can be improved, but this is not the only benefit.

[0139] Additionally, the solvent may include any solvent commonly used in the relevant technical field, and may include, for example, any one of dimethyl sulfoxide (DMSO), isopropanol, N-methylpyrrolidone (NMP), acetone, or water, or a mixture of two or more thereof. The amount of solvent used is sufficient to dissolve or disperse the positive electrode active material, conductive material, and binder, taking into account the coating thickness and yield of the slurry, and varying the viscosity to achieve high thickness uniformity in subsequent coating processes for manufacturing the positive electrode.

[0140] The negative electrode according to this disclosure can be manufactured by coating a negative electrode composition comprising a negative electrode active material, a binder, a conductive material, and a solvent onto a negative electrode current collector. Furthermore, if desired, the negative electrode composition may optionally further comprise a dispersant.

[0141] The negative electrode active material may include compounds capable of reversibly inserting and deintercalating lithium. Preferably, the negative electrode may also include a negative electrode active material exhibiting high capacity characteristics, such as silicon-based negative electrode active materials; carbon-based negative electrode active materials; and metal composite oxides, such as Li. x Fe2O3 (0≤x≤1), Li x WO2 (0≤x≤1), Sn x Me 1-x Me' y O z(Me: Mn, Fe, Pb or Ge; Me': Al, B, P, Si, elements of Groups 1, 2 and 3 of the Periodic Table, halogens; 0 < x ≤ 1; 1 ≤ y ≤ 3; 1 ≤ z ≤ 8); lithium metal; lithium alloy; tin-based alloy; metal oxides such as SnO, SnO2, PbO, PbO2, Pb2O3, Pb3O4, Sb2O3, Sb2O4, Sb2O5, GeO, GeO2, Bi2O3, Bi2O4 and Bi2O5; conductive polymers, e.g., polyacetylene; Li-Co-Ni-based materials; titanium oxides; or lithium titanium oxides. The silicon-based anode active material may include at least one selected from the group consisting of Si, SiO x (0.1 < x < 5), Si-metal alloy, silicon oxide particles doped or chemically bonded with a metal such as Mg (SiO x , 0.1 < x < 5), and an alloy of Si and SiO x (0.1 < x < 5). The carbon-based anode active material may include at least one selected from the group consisting of natural graphite, artificial graphite, amorphous hard carbon, low-crystalline soft carbon, carbon black, acetylene black, Ketjen black, Super P, graphene, and fibrous carbon.

[0142] The anode current collector is not limited to a specific type and may include any material having high electrical conductivity without causing chemical changes in the battery, and may include, for example, copper, stainless steel, aluminum, nickel, titanium, calcined carbon, copper or stainless steel treated with carbon, nickel, titanium or silver on the surface, or an aluminum cadmium alloy. In addition, the thickness of the anode current collector can generally be 3 μm to 500 μm, and in the same manner as the cathode current collector, the anode current collector may have a micro-textured surface to improve the bonding strength of the anode active material. The anode current collector may have different forms, e.g., film, sheet, foil, mesh, porous body, foam or non-woven fabric.

[0143] The conductive material, binder, solvent or dispersant included in the anode composition is not limited to a specific one and may include any commonly used one in the electrode composition, and may include, for example, the above conductive material, binder, solvent or dispersant in the cathode composition. [[ID=​​​​​​​​​​​ Figure 7 and Figure 8 The shape shown is an equilateral trapezoid. However, the notch tab 27 can have different shapes, such as semicircular, semi-elliptical, triangular, rectangular or parallelogram shapes.

[0147] In embodiments of this disclosure, the notched tabs 27 may have equal widths and be arranged along the length direction. However, the width of the notched tabs may gradually or progressively increase from the core to the outer periphery.

[0148] In embodiments of this disclosure, the height of the notched tab 27 can gradually increase outward from the core in the radial direction. However, the height of the notched tab 27 can be constant or gradually decrease.

[0149] In embodiments of this disclosure, the notched tabs 27 may not be present at predetermined portions of the inner end in the radial direction and the outer end in the radial direction of the uncoated portion 26. However, the notched tabs may not be removed from the inner end in the radial direction of the uncoated portion, nor may they be removed from the outer end in the radial direction of the uncoated portion.

[0150] In embodiments of this disclosure, the notched tab 27 of the wound electrode assembly 20 can be bent and flattened radially. The notched tab 27 can be bent radially inward or outward. For example, as Figure 9 and Figure 10 As shown, the notched tab 27 can be bent radially inward.

[0151] In embodiments of this disclosure, the notched tabs 27 can be bent one after another during the process of winding the laminate to form the wound electrode assembly 20. Conversely, the notched tabs 27 can be bent all at once after the laminate has been wound to form the wound electrode assembly.

[0152] In embodiments of this disclosure, the notched tabs 27 of the radially curved and overlapping first electrode 21 and the notched tabs 27 of the second electrode 22 can each provide a plane substantially perpendicular to the axial direction at both ends of the electrode assembly 20 in the axial direction, such as... Figure 10 As shown.

[0153] In embodiments of this disclosure, such as Figure 11 As shown, the first current collector 31 can be engaged with a substantially flat surface provided by bending the exposed notched tabs 27 at both ends of the electrode assembly 20 in the axial direction.

[0154] In embodiments of this disclosure, the first manifold 31 can be manufactured by stamping, trimming, perforating, and bending metal sheets. The first manifold 31 can be made of aluminum.

[0155] In embodiments of this disclosure, reference is made to Figure 11 The first current collector 31 may include a terminal connection portion 311 extending radially from a central portion, a ring portion 312 connecting the centrifugal edge of the terminal connection portion 311 in the circumferential direction, and an electrode connection portion 313 extending concentrically from the ring portion 312 but not connected to the terminal connection portion 311. The central portion of the terminal connection portion 311 may cover at least a portion of the hollow core of the electrode assembly 20.

[0156] In embodiments of this disclosure, before the electrode assembly 20 is placed in the battery housing 10, the electrode connection portion 313 can be laser welded to the notched tab 27 of the first electrode 21 of the electrode assembly 20.

[0157] In embodiments of this disclosure, reference is made to Figure 12 The second current collector 32 may not be connected to the notched tab 27 of the second electrode 22 of the electrode assembly 20. This disclosure is not limited to the structure in which the current collector is not connected to the notched tab 27 of the second electrode 22.

[0158] In embodiments of this disclosure, reference is made to Figure 13 The electrode assembly 20 may also include a second current collector 32 at the notched tab 27 of the second electrode 22 of the electrode assembly 20.

[0159] In embodiments of this disclosure, the second manifold 32 may be made of copper. The second manifold 32 may be manufactured by stamping, trimming, perforating, and bending metal sheets.

[0160] Reference Figures 13 to 15 The second collector plate 32 may include a main body portion 320 connected to the notched tab 27 of the electrode assembly 20 and an outer annular can connection portion 324. The can connection portion 324 is located more centrifugally than the main body portion 320 and is disposed around the edge of the second collector plate 32. The annular can connection portion 324 may be radially spaced from the main body portion 320.

[0161] The second manifold 32 may include a bridging portion 325 that is connected to the main body 320 on the centripetal side and to the tank connection portion 324 on the centrifugal side.

[0162] The main body 320 may include an inner ring portion 321 and an electrode tab connection portion 323. The inner ring portion 321 defines a hole 322 corresponding to the hollow core of the electrode assembly 20 and is disposed around the hollow core. The electrode tab connection portion 323 extends radially from the inner ring portion 321. The main body 320 can be welded and electrically connected to the notched tab 27 of the electrode assembly 20 by laser irradiation onto the electrode tab connection portion 323.

[0163] Before placing the electrode assembly 20 into the battery housing 10, the electrode tab connection 323 can be laser welded to the notched tab 27 of the second electrode 22 of the electrode assembly 20. The laser welding line can extend radially.

[0164] The can connection portion 324 can be electrically connected to the main body portion 320 via a radially extending bridging portion 325.

[0165] The bridging portion 325 and the electrode tab connection portion 323 can be arranged alternately in the circumferential direction. The bridging portion 325 can be connected to the inner ring portion 321.

[0166] In embodiments of this disclosure, reference is made to Figure 3a The second current collector 32 can be connected to the battery housing 20. Specifically, the outer peripheral surface of the can connection portion 324 can be engaged with the battery housing 10.

[0167] In embodiments of this disclosure, reference is made to Figure 3a The cover 40 can be axially spaced from the second collector plate 32 at its outer side in the radial direction. That is, the second collector plate 32 may not contact the cover 40.

[0168] In embodiments of this disclosure, such as Figure 16 and Figure 17 As shown, the electrode assembly 20 can be housed in the battery housing 10 with the first current collector 31 positioned facing the bottom 12 of the battery housing 10. In this case, the insulator 19 can be located between the first current collector 31 and the bottom 12 of the battery housing 10 to electrically insulate the first current collector 31 from the bottom 12.

[0169] In embodiments of this disclosure, the terminal connection portion 311 of the first current collector 31 can be joined to the first electrode terminal 13 fixed to the battery casing 10 by resistance welding, ultrasonic welding, or laser welding. Figure 17 As shown, the welding apparatus for forming the welding portion of the first current collector 31 and the first electrode terminal 13 can perform welding from the other end of the electrode assembly 20 in the axial direction toward the back side of the terminal connection portion 311 of the first current collector 31 via the hollow core of the electrode assembly 20. The first current collector 31 can be joined to the first electrode terminal 13 using either hard soldering or soft soldering. That is, any other connection method can be used to electrically connect and hold the first current collector 31 and the first electrode terminal 13 together.

[0170] Reference Figure 18 and Figure 19The battery 1, including the aforementioned cover, can be housed within the battery pack housing 100. The battery pack P can be manufactured using battery modules or intermediate components, or it can be manufactured directly without the battery modules shown in the figure.

[0171] Because battery 1 has a large volume, battery pack P can be easily manufactured without using intermediate structures or battery modules. Furthermore, because the second electrode is connected via a cover, battery 1 can have lower internal resistance and higher energy density.

[0172] Furthermore, the battery pack P may include a heat sink 101 on either side of the battery pack housing 100. In this case, when the battery 1 has a uniform outer diameter unaffected by the weld bead 16a, the contact area between the battery 1 and the heat sink 101 can be maximized, and the heat exchange efficiency of the battery 1 can be increased by the heat sink 101.

[0173] A battery pack P with higher energy density can reduce the volume and load required to store the same amount of energy. Therefore, as... Figure 19 As shown, when a battery pack P, including battery 1, is installed in a vehicle V that uses electricity as an energy source, the vehicle's range relative to energy can be further increased.

[0174] While this disclosure has been described above with reference to a number of embodiments and accompanying drawings, it is not limited thereto, and those skilled in the art related to this disclosure will understand that various changes and modifications can be made within the technical scope of this disclosure and the appended claims and their equivalents. Therefore, it should be understood that the disclosed embodiments are provided by way of illustration and not intended to be limiting. In other words, the true scope of the technical aspects of this disclosure is set forth in the appended claims, and all differences within the scope of equivalents should be interpreted as including within this disclosure.

Claims

1. A battery, the battery comprising: A battery housing having a sidewall, a bottom, and an opening, the bottom being connected to an axial end of the sidewall, and the opening being located at the opposite end of the sidewall in the axial direction; An electrode assembly comprising a first electrode and a second electrode wound around a winding axis, wherein a diaphragm is inserted between the first electrode and the second electrode, the electrode assembly being housed in the battery casing such that the tab of the second electrode faces the opening; as well as A cover, configured to cover the opening of the battery housing when mounted on the outer surface of the opposite ends of the sidewall in the axial direction, The edges of the inner surface of the cover and the opposite ends of the sidewall in the axial direction are joined to form a joint. The joint portion is recessed radially inward.

2. The battery according to claim 1, in, The cover and the sidewall are joined together by welding. Wherein, the welding forms a weld bead at the joint, and The weld does not protrude radially outward from the battery casing.

3. The battery according to claim 1, in, The joint has a closed-loop shape along the circumferential direction.

4. The battery according to claim 1, in, The radial diameter of the cover is equal to the radial diameter of the battery housing at the opposite end in the axial direction.

5. The battery according to claim 1, in, The opposite ends of the sidewall in the axial direction include a first inclined portion on the outer side in the radial direction and a first flat portion connected to the first inclined portion and perpendicular to the sidewall.

6. The battery according to claim 5, in, The first inclined portion extends axially inward and then radially outward.

7. The battery according to claim 5, in, The angle α between the first inclined portion and the first flat portion is 100° or greater and 170° or less.

8. The battery according to claim 5, in, The radial length of the first inclined portion is smaller than the radial length of the first flat portion.

9. The battery according to claim 1, in, The edge of the inner surface of the cover includes a second inclined portion on the outer side in the radial direction and a second flat portion connected to the second inclined portion and perpendicular to the axial direction.

10. The battery according to claim 9, in, The second inclined portion extends outward along the axial direction and then outward in the radial direction.

11. The battery according to claim 9, in, The radial length of the second inclined portion is smaller than the radial length of the second flat portion.

12. The battery according to claim 9, in, The angle β between the second inclined portion and the second flat portion is 100° or greater and 170° or less.

13. The battery according to claim 1, in, The cover also includes an exhaust recess.

14. The battery according to claim 1, further comprising: The second current collector is connected to the second electrode. The second current collector is connected to the battery casing.

15. The battery according to claim 14, in, The cover is axially spaced from the second manifold at its outer side in the radial direction.

16. A battery pack comprising a battery according to any one of claims 1 to 15.

17. A vehicle comprising a battery pack according to claim 16.

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