CN116888818A

CN116888818A - Method for manufacturing battery

Info

Publication number: CN116888818A
Application number: CN202280014730.XA
Authority: CN
Inventors: 皇甫光洙; 金度均; 闵建宇; 林惠珍; 赵敏起; 崔修智; 姜宝炫
Original assignee: LG Energy Solution Ltd
Current assignee: LG Energy Solution Ltd
Priority date: 2021-10-15
Filing date: 2022-07-19
Publication date: 2023-10-13

Abstract

The battery manufacturing method according to the present application includes the steps of: preparing a battery case having one side with an opening and having a bottom on the other side, the bottom having a through hole; fixing the electrode terminal to the through hole; preparing an electrode assembly having a first electrode tab having a first uncoated portion and a second electrode tab having a second uncoated portion at top and bottom thereof; inserting the electrode assembly into the battery case through an open end portion provided at one side of the battery case such that the first electrode tab faces the bottom; (e) electrically connecting the first electrode tab and the electrode terminal; and covering the open end with a cover plate and finishing it.

Description

Method for manufacturing battery

Technical Field

The present disclosure relates to a method of manufacturing a battery, and more particularly, to a method of manufacturing a battery having a structure in which both a positive electrode terminal and a negative electrode terminal are arranged adjacent to each other on one side of a cylindrical battery without significantly changing the structure of the existing cylindrical battery.

The present application claims priority from korean patent application No. 10-2021-0137856 filed in korea on 10 month 15 of 2021, korean patent application No. 10-2021-0177741 filed in korea on 12 month 13 of 2021, and korean patent application No. 10-2021-0194593 filed in korea on 12 month 31 of 2021, the disclosures of which are incorporated herein by reference.

Background

When a battery pack is manufactured using cylindrical batteries, generally, a plurality of cylindrical batteries are vertically placed in a case and electrically connected to each other using the top and bottom of the cylindrical batteries as positive and negative terminals, respectively.

When the positive and negative terminals of the cylindrical batteries are disposed on opposite sides, electrical connection members, such as bus bars for electrically connecting the plurality of cylindrical batteries, need to be applied to both the top and bottom of the cylindrical batteries. This results in a complicated electrical connection structure of the battery pack.

In addition, since the conventional cylindrical battery structure requires separate application of the components for insulation and the components for waterproofing or sealability to the upper and lower parts of the battery pack, this results in an increase in the number of applied components and a complicated structure.

Therefore, in order to simplify the electrical connection structure of a plurality of cylindrical batteries, it is necessary to develop a cylindrical battery having a positive terminal and a negative terminal in the same direction.

In addition, while the cylindrical battery is configured to have a positive electrode terminal and a negative electrode terminal at one end in the axial direction, the cylindrical battery may have a complicated internal structure, which results in an increase in manufacturing cost and a limitation in energy density.

In addition, in a cylindrical battery having a positive electrode terminal and a negative electrode terminal at one end in the axial direction, it is necessary to secure an optimal area of each of the positive electrode terminal and the negative electrode terminal in a simple manner.

In addition, in a cylindrical battery having a positive terminal and a negative terminal at one end in the axial direction, the two terminals need to provide surfaces to which an electrical connection member is easily connected.

Further, when manufacturing a battery pack including vertically placed cylindrical batteries, each of which has a first electrode terminal and a second electrode terminal at one end and the other end in the axial direction, respectively, insulation between the bottom surface of the cylindrical battery serving as a terminal and the bottom of the battery pack case is essentially necessary, which is another factor that increases manufacturing costs.

Disclosure of Invention

Technical problem

The present disclosure is designed to solve the above-described problems, and therefore, the present disclosure is directed to providing a cylindrical battery having a structure in which a positive electrode terminal and a negative electrode terminal are applied in the same direction.

The present disclosure is intended to secure a sufficient area for welding of an electrical connection member such as a bus bar for manufacturing a battery pack and an electrode terminal of a cylindrical battery when a plurality of cylindrical batteries are electrically connected in the same direction.

The present disclosure is directed to providing a cylindrical battery including both a positive terminal and a negative terminal on the bottom of a battery case, which may be first manufactured regardless of whether an electrode assembly is inserted in the battery case having an open end and a bottom.

The present disclosure is directed to providing a cylindrical battery having a positive terminal and a negative terminal having an optimal area on the bottom of a battery case and having surfaces to which an electrical connection member is easily connected, the battery case can be manufactured first regardless of whether an electrode assembly is inserted.

The present disclosure is directed to a structure in which a positive electrode terminal and a negative electrode terminal are exposed on one side of a cylindrical battery but are not exposed on the other side of the cylindrical battery.

The present disclosure is directed to providing a cylindrical battery in which an electrode assembly may be placed in close contact with a bottom having two terminals to increase energy density.

The objects of the present disclosure are not limited to the above objects, and these and other objects and advantages of the present disclosure can be understood by the following description, and will be more clearly understood by the embodiments of the present disclosure. Further, it is apparent that the objects and advantages of the present disclosure can be achieved by means and combinations thereof set forth in the appended claims.

Technical proposal

In order to solve the above-described problems, the cylindrical battery of the present disclosure has two electrode terminals at the bottom of a cylindrical battery case having an opening at one side and a bottom at the other side.

The bottom of the battery case may be treated before the electrode assembly received in the battery case is inserted. That is, the two electrode terminals to be placed on the bottom have a high degree of freedom in processing.

Therefore, the bottom portion can be flattened by a simple process, and when the outer surface of the bottom portion is used as the first electrode terminal, the electric wiring operation is easily performed with the electric connection member for connection.

In addition, when a through-hole is formed in the bottom and an electrode terminal serving as a second electrode terminal is fixed and mounted in the through-hole, two electrodes may be placed on the bottom of the battery case.

Since the electrode terminals can also be processed before being inserted into the electrode assembly, the electrode terminals can be flattened by a simple process, and an electrical wiring operation can be easily performed using the electrical connection members for connection.

The portion of the electrode terminal exposed more outward than the bottom may extend more outward than the inner circumferential surface of the through hole in the radial direction. In addition, a portion of the electrode terminal that extends more outwardly than the through-hole in the radial direction may be treated first when preparing the electrode terminal itself.

Therefore, the size of the portion of the electrode terminal extending more outwardly than the through-hole in the radial direction can be precisely determined in a simple manner. In addition, in mass production of cylindrical batteries, the difference between products in the regions of the two electrode terminals on the bottom of the battery case can be minimized in a simple manner.

In the present disclosure, when two electrode terminals have been positioned on the bottom of the battery case, the electrode assembly may be inserted into the battery case. Accordingly, the electrode assembly may be received as close to or in close contact with the bottom of the battery case as possible.

The present disclosure may simply form an electrical connection structure between an electrode assembly and two electrode terminals on the bottom of a battery case having the two electrode terminals. This structure can increase the energy density in the battery case.

The battery of the present disclosure has two electrode terminals on the bottom of a cylindrical battery case, so that the open end of the cylindrical battery case can be closed in a simple manner.

The open end of the battery case may be closed by a cap plate, and the cap plate may be polar or nonpolar.

In particular, a cylindrical battery according to an embodiment of the present disclosure may include: a cylindrical battery case having an opening at one side and a bottom at the other side; an electrode assembly accommodated in the battery case and including a first electrode tab and a second electrode tab; an electrode terminal fixed to the bottom of the battery case through a through-hole in the bottom of the battery case; and a cover plate covering the opening at one side of the battery case.

In addition, a cylindrical battery according to another embodiment of the present disclosure may include: a cylindrical battery case having an opening at one side and a bottom at the other side; an electrode terminal fixed to the bottom of the battery case through a through-hole in the bottom of the battery case; an electrode assembly including a first electrode tab and a second electrode tab, and being accommodated in the battery case through an opening side of the battery case such that the first electrode tab faces a bottom of the battery case and the electrode terminal; and a cap plate covering the opening at one side of the battery case when the electrode assembly is received in the battery case.

The cap plate may not be electrically connected to the first electrode tab and the second electrode tab.

The first electrode tab may be electrically connected to the electrode terminal, and the second electrode tab may be electrically connected to the battery case.

Here, the side wall and the bottom of the battery case may be combined into one piece.

In an example, the sidewall and the bottom may be integrally formed by a drawing process using a sheet metal press.

The first electrode tab may face the bottom, and the first electrode tab may be electrically connected to the electrode terminal.

An insulator may be interposed between the first electrode tab and the bottom portion.

The insulator may not be interposed between the portion of the electrode terminal received in the battery case and the first electrode tab.

The insulator may have a through-hole, and an inner circumferential surface of the through-hole may surround the electrode terminal.

The portion of the electrode terminal, which is received in the battery case, may face the insulator in the radial direction, and may not face the insulator in the axial direction.

The outer diameter of the electrode terminal exposed outward through the bottom may be greater than the inner diameter of the through-hole in the bottom of the battery case.

The cross section of the through hole in the bottom of the battery case may be included in the cross section of the electrode terminal exposed outward through the bottom.

The portion of the electrode terminal exposed outward through the bottom may cover at least a portion of the bottom of the battery case in the axial direction.

The electrode terminal may include: a terminal exposure portion extending outwardly from the battery case; and a terminal insertion part passing through an upper surface of the battery case.

The cylindrical battery may further include an insulating gasket between the through-hole of the battery case and the electrode terminal to insulate the electrode terminal from the battery case.

The insulating gasket may include: a gasket exposure portion extending outwardly from the battery case; and a gasket insertion portion passing through the bottom of the battery case.

The electrode terminal may be riveted to the inner surface of the bottom of the battery case.

The cylindrical battery may further include a first current collecting plate having one surface coupled to the first electrode tab and the other surface coupled to the electrode terminal.

The cylindrical battery may further include an insulator between the first current collecting plate and the battery case.

The electrode terminal may be coupled to the first current collecting plate through an insulator.

At least one of the first electrode tab and the second electrode tab may be bent toward a winding center of the electrode assembly.

The cap plate may include a vent portion that breaks to discharge gas into the atmosphere when the internal pressure of the battery case rises above a predetermined level.

A battery pack according to an embodiment of the present disclosure includes: a plurality of batteries and a battery pack case accommodating the plurality of batteries according to an embodiment of the present disclosure.

A vehicle according to an embodiment of the present disclosure includes a battery pack according to an embodiment of the present disclosure.

To achieve the above technical object, a method of manufacturing a battery according to the present disclosure may include: (a) Preparing a battery case having an opening at one side and a bottom at the other side, the bottom having a through hole; (b) fixing an electrode terminal to the through hole; (c) Preparing an electrode assembly including a first electrode tab and a second electrode tab at upper and lower portions, respectively, the first electrode tab being formed of a first uncoated portion, and the second electrode tab being formed of a second uncoated portion; (d) Inserting the electrode assembly into the battery case through the opening at one side of the battery case such that the first electrode tab faces the bottom; (d) Inserting the electrode assembly into the battery case through an opening at one side of the battery case such that the first electrode tab faces the bottom; (e) electrically connecting the first electrode tab to the electrode terminal; and (f) covering the opening with a cover plate.

The electrode terminal may include a terminal insertion part inserted into the battery case through the through-hole. In addition, step (b) may include: (b 1) placing an insulating gasket between the electrode terminal and the through-hole; and (b 2) performing plastic working on an end edge of the terminal insertion portion in a radial direction so that a diameter of the edge is larger than a diameter of the through hole.

Step (b 2) may include applying pressure to the end edge in the axial direction of the electrode assembly using a jig having a structure conforming to the final shape of the plastic working.

Step (b 2) may include causing the plastically worked end edge to compress the insulating gasket against the inner surface of the bottom of the battery case.

Step (c) may comprise: preparing a first electrode having the first uncoated portion at a long side end and a second electrode having the second uncoated portion at a long side end; forming a plurality of slit grooves in the first and second uncoated portions along a winding direction of the electrode assembly to divide the first and second uncoated portions into a plurality of sections; disposing the first electrode and the second electrode such that the first uncoated portion is opposite to the second uncoated portion in an axial direction, and winding the first electrode and the second electrode around an axis with a separator interposed therebetween to form the electrode assembly in which a core and a peripheral surface are defined; and bending the first and second uncoated portions in a radial direction of the electrode assembly to form a bent surface region having a structure in which the uncoated portions are stacked in a plurality of layers in the axial direction.

Step (c) may include coupling the first current collecting plate to the bent surface region of the first uncoated portion, and step (e) may include coupling the electrode terminal to the first current collecting plate to electrically connect the electrode terminal to the first electrode tab.

Step (e) may include welding the electrode terminal to the first current collecting plate using a hollow at the core of the electrode assembly.

Step (e) may include irradiating welding laser toward a welding region of the first current collecting plate facing the electrode terminal through the hollow at the core of the electrode assembly.

The method of manufacturing a battery according to the present disclosure may further include placing an insulator between the first current collecting plate and the inner surface of the bottom of the battery case.

The method of manufacturing a battery according to the present disclosure may further include: prior to step (d), preparing an insulator having a through hole at the center and a shape corresponding to the inner surface of the bottom of the battery case; and mounting an insulator on an inner surface of the bottom of the battery case such that the through-hole of the insulator surrounds the fixing portion of the electrode terminal.

The method of manufacturing a battery according to the present disclosure may further include: prior to step (d), preparing an insulator having a through hole at the center and a shape corresponding to the inner surface of the bottom of the battery case; and fixing the insulator to the first current collecting plate such that the through-hole of the insulator is disposed on the core of the electrode assembly.

The method of manufacturing a battery according to the present disclosure may further include: coupling a second current collecting plate to a second electrode tab of the electrode assembly; and coupling at least a portion of the second current collector plate to an inner surface of the battery case.

The method of manufacturing a battery according to the present disclosure may further include: pressing the outer peripheral surface of the open end of the battery case toward the inside of the battery case to form a curled portion; welding at least a portion of the second current collector plate to the second electrode tab; and contacting a predetermined region of the edge of the second current collecting plate with the inner surface of the beading part.

The method of manufacturing a battery according to the present disclosure may further include: an edge region of the second current collecting plate adjacent to the predetermined region is bent such that the predetermined region reaches an inner surface of the beading portion.

The method of manufacturing a battery according to the present disclosure may further include: a predetermined region is welded to the inner surface of the hemming portion.

The method of manufacturing a battery according to the present disclosure may further include: placing a sealing gasket between the edge of the cover plate and the open end of the cell housing; and bending the open end of the battery case in a centripetal direction to form a crimp portion, thereby fixing the edge of the cap plate to the open end together with the sealing gasket.

The crimp portion may compress the sealing gasket to bring the predetermined region and the inner surface of the crimp portion into close contact with each other.

The method of manufacturing a battery according to the present disclosure may further include: a vent groove is formed in at least one of the two surfaces of the cover plate.

The method of manufacturing a battery according to the present disclosure may further include: before step (f), standing the battery case so that the bottom of the battery case faces the ground; and injecting an electrolyte into the battery case.

The method of manufacturing a battery according to the present disclosure may further include: after step (f), standing the battery case so that the bottom of the battery case faces upward; and performing electrical wiring through the outer surface of the bottom of the battery case and the electrode terminals using an area other than the exposed area of the electrode terminals.

Advantageous effects

According to an aspect of the present disclosure, it is possible to provide a cylindrical battery having a structure in which a positive electrode terminal and a negative electrode terminal are in the same direction, thereby simplifying an electrical connection structure of a plurality of cylindrical batteries.

According to another aspect of the present disclosure, it is possible to provide a sufficient area for welding electrode terminals of a cylindrical battery to an electrical connection member such as a bus bar, thereby ensuring sufficient bonding strength between the electrode terminals and the electrical connection member, and reducing resistance at a bonding portion between the electrical connection member and the electrode terminals to a desired level.

According to another aspect of the present disclosure, the electrode terminal and the electrode assembly may be placed in close contact with each other in the battery case, thereby increasing the amount of energy stored per volume, i.e., energy density.

According to another aspect of the present disclosure, the positive and negative terminals are exposed on one side of the cylindrical battery but not on the other side surface, thereby providing insulation design advantages.

According to another aspect of the present disclosure, since the positive and negative electrode terminals are positioned on the bottom of the battery case, which may be first manufactured before the electrode assembly is inserted, the sealing and insulating structure may be easily manufactured, and since the electrode assembly is accommodated in close contact with the bottom, the battery capacity density per volume may be increased, and by minimizing errors in manufacturing and assembling the positive and negative electrode terminals, a subsequent process of connecting the generated battery with the bus bar may be easily performed.

According to another aspect of the present disclosure, a structure may be provided in which the outer circumferential surface of the positive electrode extends more outwardly than the inner circumferential surface of the through hole on the bottom of the battery case, which is first manufactured regardless of whether the electrode assembly is inserted, thereby arbitrarily designing the exposed regions of the positive and negative electrode terminals.

These and other effects of the present disclosure will be described in conjunction with the detailed description of the embodiments of the present disclosure.

Drawings

The accompanying drawings illustrate exemplary embodiments of the present disclosure and, together with the detailed description below, serve to provide further understanding of technical aspects of the present disclosure, and thus the present disclosure should not be construed as limited to the accompanying drawings.

Fig. 1 is a diagram illustrating an external appearance of a cylindrical battery according to an embodiment of the present disclosure.

Fig. 2 is a sectional view illustrating an internal structure of a cylindrical battery according to an embodiment of the present disclosure.

Fig. 3 and 4 are partial sectional views illustrating an upper structure of a cylindrical battery according to an embodiment of the present disclosure.

Fig. 5 and 6 are diagrams illustrating a coupling structure between a first current collecting plate and an electrode assembly applied to the present disclosure.

Fig. 7 is a partial sectional view illustrating a lower structure of a cylindrical battery according to an embodiment of the present disclosure.

Fig. 8 is a diagram illustrating a lower surface of a cylindrical battery according to an embodiment of the present disclosure.

Fig. 9 is a diagram illustrating a second current collecting plate applied to the present disclosure.

Fig. 10 is a schematic view illustrating a battery pack according to an embodiment of the present disclosure.

Fig. 11 is a schematic diagram illustrating a vehicle according to an embodiment of the present disclosure.

Detailed Description

The above objects, features and advantages will be described in detail with reference to the drawings, and thus, those skilled in the art will readily practice the technical solutions of the present disclosure. In describing the present disclosure, a detailed description is omitted when it is determined that a particular detailed description of related known techniques may unnecessarily obscure the subject matter of the present disclosure. Hereinafter, exemplary embodiments according to the present disclosure will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals are used to designate the same or similar elements.

The terms "first," "second," and the like are used to describe various elements and these elements are not limited by these terms. These terms are used to distinguish one element from another element and a first element may be a second element unless the context clearly indicates otherwise.

In the description, each element may be in the singular or the plural unless the context clearly indicates otherwise.

In the following, it will be understood that an element is referred to as being "above (or below)" or "on (or below)" another element, which may be on the upper surface (or lower surface) of the other element, and intervening elements may be present between the element and the other element on (or below).

In addition, it will be further understood that when an element is referred to as being "connected to," "coupled to," or "joined to" another element, it can be directly connected or joined to the other element or intervening elements may be present, or each element may be "connected," "coupled," or "joined" to each other by the other element.

As used herein, the singular forms also include the plural unless the context clearly indicates otherwise. It will be understood that the term "comprising" when used in this specification, specify the presence of stated elements or steps, but do not preclude the presence or addition of one or more other elements or steps.

In addition, as used herein, the singular forms also include the plural forms unless the context clearly indicates otherwise. It will be understood that the term "comprising" when used in this specification, specify the presence of stated elements or steps, but do not preclude the presence or addition of one or more other elements or steps.

In the specification, "a and/or B" means a or B or both a and B, and "C to D" means greater than C and less than D unless the context clearly indicates otherwise.

For convenience of description, in the specification, a direction following a length direction of a winding shaft of an electrode assembly wound in a jelly-roll shape is referred to as an axial direction Z. In addition, the direction around the winding axis is referred to as the circumferential direction. In addition, the direction facing or facing away from the winding axis is referred to as the radial direction (X, Y). Specifically, the direction facing the winding axis is referred to as the centripetal direction, and the direction facing away from the winding axis is referred to as the centrifugal direction.

The axial direction Z may correspond to the width direction of the electrode before winding. The circumferential direction may correspond to the length direction of the electrode before winding. In addition, the radial direction X, Y can correspond to a normal direction of the electrode prior to winding.

Hereinafter, exemplary embodiments of the present disclosure will be described with reference to the accompanying drawings.

Referring to fig. 1 to 4, a cylindrical battery 1 according to an embodiment of the present disclosure has two electrode terminals at the bottom of a cylindrical battery case 20, the cylindrical battery case 20 having an opening at one side (lower side in the drawing) and a bottom at the other side (upper side in the drawing).

The bottom of the battery case 20 may be treated before the electrode assembly 10 received in the battery case 20 is inserted. The bottom of the battery case 20 may be integrally formed with the side walls by sheet metal stretching using a press. The bottom may be formed with a flat profile.

The battery case 20 may have a through-hole in the bottom (upper side in the drawing). The through hole may be provided at an approximate center of the bottom. The center of the bottom may be concentric with the center of the through hole. The electrode terminal 40 may be inserted into and fixed to the through-hole.

The electrode terminal 40 includes: a terminal exposing portion 41 exposed outward through the bottom; and a terminal insertion part 42 connected to the terminal exposure part 41 and inserted into the battery case 20 through a through-hole.

The insulating gasket 50 is interposed between the electrode terminal 40 and a member forming the bottom of the battery case 20. Accordingly, a gap between the electrode terminal 40 and the battery case 20 is sealed, and the electrode terminal 40 and the battery case 20 are electrically insulated from each other.

The bottom of the battery case 20 itself may be a first electrode terminal having polarity. In addition, the electrode terminal 40 may be a second electrode terminal having an opposite polarity.

The electrode terminals 40 may be exposed outward through the bottom of the battery case 20. When the electrode terminals 40 are fixedly mounted at the through-holes in the bottom, both electrode terminals may be located at the bottom of the battery case 20.

The two electrode terminals located at the bottom may be processed before the electrode assembly 10 is received in the battery case 20, thereby providing a high degree of freedom in processing. Both electrode terminals may have surfaces to which external electrical connection members are easily and conveniently connected.

The bottom of the battery case 20 may be manufactured flat by a simple process, and when the bottom is used as the first electrode terminal, a connection operation with an electrical connection member for connection may be easily performed.

The electrode terminal 40 may also be processed before being inserted into the electrode assembly 10, and thus the electrode terminal 40 may be flattened by a simple process, thereby making it easy to perform a connection operation with an electrical connection member for connection.

The terminal exposing portion 41 of the electrode terminal 40 may have a flange shape extending more outwardly than the inner circumferential surface of the through-hole in the radial direction. In addition, the terminal exposing portion 41 may be first processed in preparing the electrode terminal 40 member. Therefore, the size and shape of the terminal exposing portion 41 of the electrode terminal 40 can be precisely determined in a simple manner.

In mass production of the cylindrical battery 1, since both the bottom of the battery case 20 and the electrode terminals 40 mounted at the bottom of the battery case 20 are handled and assembled before the electrode assembly 10 is received in the battery case 20, the difference between products in the regions of the two electrode terminals on the bottom of the battery case 20 can be minimized in a simple manner.

In the present disclosure, the electrode assembly 10 may be inserted into the battery case 20 when two electrode terminals have been positioned on the bottom of the battery case 20. Accordingly, the electrode assembly 10 may be received as close to the bottom of the battery case 20 as possible or in close contact with the bottom of the battery case 20. The present disclosure may provide a simple electrical connection structure between the electrode assembly 10 and two electrode terminals on the bottom of the battery case 20 having the two electrode terminals. This structure increases the energy density in the battery case 20.

The electrode assembly 10 may have a first electrode tab 11 at one end in the axial direction and a second electrode tab 12 at the other end in the axial direction.

The first electrode tab 11 may face the bottom of the battery case 20, and then the electrode assembly 10 may be inserted into the battery case 20.

The first electrode tab 11 may be electrically connected to the terminal insertion part 42 of the electrode terminal 40. Accordingly, the electrode terminal 40 may have the first polarity.

The first electrode tab 11 is connected to the electrode terminal 40 through a first current collecting plate 60.

The second electrode tab 12 may face the open end of the battery case 20. The second electrode tab 12 may be electrically connected to the battery case 20 through the inner surface of the battery case 20. Accordingly, the bottom of the battery case 20 surrounding the electrode terminal 40 may have the second polarity.

Since the battery 1 of the present disclosure has two electrode terminals on the bottom of the cylindrical battery case 20, the open end of the cylindrical battery case 20 can be closed in a simple manner as shown in fig. 7.

The open end of the battery case 20 may be closed by the cap plate 30, and the cap plate 30 may be polar or nonpolar.

In summary, the cylindrical battery 1 of an embodiment may include: a cylindrical battery case 20 having an opening at one side and a bottom at the other side; an electrode assembly 10 which is accommodated in a battery case 20 and has a first electrode tab 11 and a second electrode tab 12; an electrode terminal 40 fixed to the bottom of the battery case 20 through a through-hole in the bottom of the battery case 20; and a cap plate 30 covering the open end of the battery case 20.

In other words, the cylindrical battery 1 of an embodiment may include: a cylindrical battery case 20 having an opening at one side and a bottom at the other side; an electrode terminal 40 fixed to the bottom of the battery case 20 through a through-hole in the bottom of the battery case 20; an electrode assembly 10 having a first electrode tab 11 and a second electrode tab 12, and being received in the battery case 20 through an opening of one side of the battery case 20 such that the first electrode tab 11 faces the bottom of the battery case 20 and the electrode terminal 40; and a cap plate 30 covering an open end of the battery case 20 having the electrode assembly 10 received in the battery case 20.

Here, the side wall and the bottom of the battery case 20 may be combined into one piece before accommodating the electrode assembly 10. The side walls and bottom of the battery case 20 may be combined into one piece in any manner before accommodating the electrode assembly 10. That is, the side walls and the bottom of the battery case 20 may be manufactured as one piece from the beginning through a molding process (e.g., a drawing process using a sheet metal press), or each of the side walls and the bottom may be manufactured as each piece and then assembled as one piece before accommodating the electrode assembly 10. The side wall forming part and the bottom forming part may be coupled to each other by welding.

The first electrode tab 11 may be electrically connected with the electrode terminal 40, and the second electrode tab 12 may be electrically connected with the battery case 20. In contrast, the cap plate 30 may not be electrically connected to the first electrode tab 11 and the second electrode tab 12. Technical aspects of the present disclosure do not preclude the cover plate 30 from being electrically connected to the second electrode tab 12. That is, the cover plate 30 may be polar or nonpolar. However, since the present disclosure has two electrode terminals at the bottom of the battery case 20, the cap plate 30 covering the open end opposite to the bottom may be nonpolar. The non-polar cover plate 30 has a number of advantages.

The first electrode tab 11 may face the bottom, and the first electrode tab 11 may be electrically connected with the electrode terminal 40.

An insulator 70 may be interposed between the first electrode tab 11 and the bottom. Accordingly, the bottom of the battery case 20 may be electrically insulated from the first electrode tab 11.

The insulator 70 may be interposed in close contact between the bottom of the battery case 20 and the first electrode tab 11. Accordingly, the contact between the first current collecting plate 60 and the first electrode tab 11 as described below may be improved.

The first current collecting plate 60 is a member that electrically connects the first electrode tab 11 of the electrode assembly 10 with the electrode terminal 40. Referring to fig. 3 and 4, one surface of the center of the first current collecting plate 60 is in close contact with or engaged with the electrode terminal 40, and the other surface of the first current collecting plate 60 is in close contact with or engaged with the first electrode tab 11. The joining may be performed by welding. Therefore, the resistance of the current flowing through the electrode terminal 40 can be minimized. In addition, the close contact structure increases the internal space utilization of the battery case 20, thereby increasing the energy density.

The insulator 70 may not be interposed between the portion of the electrode terminal 40 accommodated in the battery case 20 and the first electrode tab 11.

The insulator 70 has a hole vertically passing therethrough, and an inner circumferential surface of the hole may be disposed around the fixing portion of the electrode terminal 40.

The portion of the electrode terminal 40 accommodated in the battery case 20 may face the insulator 70 in the radial direction, and may not face the insulator 70 in the axial direction.

The outer diameter of the electrode terminal 40 exposed outward through the bottom may be greater than the inner diameter of the through-hole in the bottom of the battery case 20. In other words, the first cross-section of the through-hole in the bottom of the battery case 20 may be included in the second cross-section of the electrode terminal 40 exposed outward through the bottom. The first cross section and the second cross section are perpendicular to the axial direction. The first cross-section being included in the second cross-section means that when the first cross-section is projected onto the second cross-section, the projected area of the first cross-section is included in the area of the second cross-section. Accordingly, the portion of the electrode terminal 40 exposed through the bottom may cover at least a portion of the bottom of the battery case 20 in the radial direction. Therefore, the surface area of the bottom and the surface area of the electrode terminal 40 can be appropriately ensured.

The cylindrical battery 1 may be manufactured as follows.

First, a cylindrical battery case 20 having an opening at one side and a bottom having a through-hole at the other side is prepared. Thereafter, the electrode terminal 40 is fixed to the through-hole. When the electrode terminal 40 is fixed to the through-hole, the insulating gasket 50 may be inserted in close contact between the electrode terminal 40 and the through-hole in the bottom of the battery case 20.

Subsequently, an electrode assembly 10 having a first electrode tab 11 and a second electrode tab 12 at both ends, respectively, was prepared.

The first current collecting plate 60 may be stacked on the first electrode tab 11 in the axial direction before the electrode assembly 10 is inserted into the battery case 20. As shown in fig. 6, the first electrode tab 11 may be bent in a radial direction, and the first current collecting plate 60 may be coupled with the bent first electrode tab 11 by welding. In order to facilitate bending of the first electrode tab 11, slit grooves may be formed at predetermined intervals along the winding direction in the uncoated portion where the first electrode tab 11 is formed. The direction in which the cutout groove extends may be the axial direction of the electrode assembly 10. As shown in fig. 5, the first current collecting plates 60 may be stacked without bending the first electrode tab 11.

Subsequently, the electrode assembly 10 is inserted through the open end at one side in the axial direction of the battery case 20, with the electrode terminal 40 fixed to the bottom. In this case, the electrode assembly 10 is inserted such that the first electrode tab 11 of the electrode assembly 10 faces the bottom. In addition, an insulator 70 may be interposed between the first electrode tab 11 and the first current collecting plate 60 and the inner surface of the bottom of the battery case 20.

The insulator 70 may be mounted on the inner surface of the bottom of the battery case 20 before the electrode assembly 10 is inserted. Alternatively, the insulator 70 may be attached to the end of the electrode assembly 10 engaged with the first current collecting plate 60. An adhesive or tape may be used to attach the insulator 70. When the insulator 70 is made of a heat-shrunk polymer resin, the insulator 70 may be fixed to the end of the electrode assembly 10 by heating. The insulator 70 may include a sleeve structure extending in an axial direction along the outer circumferential surface of the electrode assembly 10 to cover the top of the outer circumferential surface of the electrode assembly 10.

After the electrode assembly 10 is inserted into the battery case 20, the first electrode tab 11 is electrically connected with the electrode terminal 40, and the second electrode tab 12 is electrically connected with the battery case 20.

The electrode terminal 40 may be aligned with the hollow at the winding center C of the electrode assembly 10. Accordingly, the terminal insertion part 42 of the electrode terminal 40 and the center of the first current collecting plate 60 may be coupled by inserting a welding device through the open end of the battery case 20 and the hollow part of the electrode assembly 10. Since the terminal insertion part 42 of the electrode terminal 40 has a flat bottom, the centers of the terminal insertion part 42 of the electrode terminal 40 and the first current collecting plate 60 may be welded in tight contact with each other. When the first current collecting plate is coupled to the terminal insertion part 42 of the electrode terminal 40 by laser welding, a laser beam may be irradiated through the hollow part of the electrode assembly 10. In this case, it may not be necessary to insert the welding device into the hollow.

The second current collecting plate 80 may be coupled with the second electrode tab 12, and an edge of the second current collecting plate 80 may be connected with the inner surface of the battery case 20. As shown in fig. 5 and 6, the second current collecting plate 80 may be joined with the second electrode tab 12 in a state in which the second electrode tab 12 may or may not be bent in the radial direction. In order to facilitate bending of the second electrode tab 12, slit grooves may be formed at predetermined intervals along the winding direction in the uncoated portion where the second electrode tab 12 is formed. The direction in which the cutout groove extends may be the axial direction of the electrode assembly 10.

As shown in fig. 5, 6 and 9, the second current collecting plate 80 may have a hole at the center. The hole may be a passage for inserting a device for bonding the first current collecting plate 60 to the electrode terminal 40 or allowing a laser beam to pass through. That is, the second current collecting plate 80 may be coupled to the second electrode tab 12 before the electrode assembly 10 is inserted into the battery case 20. Alternatively, the second current collecting plate 80 may be coupled to the second electrode tab 2 after the electrode assembly 10 is inserted into the battery case 20.

Subsequently, the open end of the battery case 20 may be covered by the cap plate 30. In this case, the cap plate 30 and the battery case 20 may be insulated from each other by placing the sealing gasket 90 between the open end of the battery case 20 and the edge of the cap plate 30 and pressing the cap plate 30 together with the sealing gasket 90 by the crimp 22 of the battery case 20.

Before the electrode assembly 10 is inserted into the battery case 20 and the crimping part 22 is formed, the crimping part 21 may be formed to support the bottom edge of the electrode assembly 10, thereby preventing the electrode assembly 10 from sliding from the battery case 20.

The edge of the second current collecting plate 80 may be engaged with the beading part 21. Specifically, when the crimping part 22 is formed with the edge of the second current collecting plate 80 interposed between the beading part 21 and the cap plate 30, the second current collecting plate 80 may be in close contact with the battery case 20. A sealing gasket 90 may be interposed between the cap plate 30 and the edge of the second current collecting plate 80 to maintain the non-polarity of the cap plate 30. In this case, the edge of the second current collecting plate 80 may be fixed between the sealing gasket 90 and the inner circumferential surface of the beading part 21.

At least a portion of the edge of the second current collecting plate 80 may be welded to the inner circumferential surface of the beading part 21 before the open end of the battery case 20 is covered with the cap plate 30. The welding surface of the hemming portion 21 may be a lower surface based on the outermost point of the hemming portion 21.

Referring to fig. 1 to 3, a cylindrical battery 1 according to an embodiment of the present disclosure includes an electrode assembly 10, a battery case 20, a cap plate 30, and an electrode terminal 40. In addition to the above-described components, the cylindrical battery 1 may further include an insulating gasket 50 and/or a first current collecting plate 60 and/or an insulator 70 and/or a second current collecting plate 80 and/or a sealing gasket 90.

The electrode assembly 10 includes a first electrode having a first polarity, a second electrode having a second polarity, and a separator between the first electrode and the second electrode. The first electrode corresponds to a positive electrode or a negative electrode, and the second electrode corresponds to an electrode having a polarity opposite to that of the first electrode.

The electrode assembly 10 may have, for example, a jelly roll shape.

The electrode assembly 10 may be manufactured by winding a stack formed by sequentially stacking a first separator, a first electrode, a second separator, and a second electrode at least once around a winding center C. The electrode assembly 10 may have a jelly-roll structure. The outermost convolution of the separator may be provided on the outer circumferential surface of the electrode assembly 10 for insulation from the battery case 20.

The first electrode includes a first electrode current collector and a first electrode active material coated on one or both surfaces of the first electrode current collector. One end of the first electrode current collector in the width direction (parallel to the Z axis) has a first uncoated portion that is not coated with the first electrode active material. The first uncoated portion extends along the winding direction of the electrode assembly 10.

The first uncoated portion serves as the first electrode tab 11. The first electrode tab 11 is located at the upper part of the height direction (parallel to the Z axis) of the electrode assembly 10 accommodated in the battery case 20.

The second electrode includes a second electrode current collector and a second electrode active material coated on one or both surfaces of the second electrode current collector. The other end of the second electrode current collector in the width direction (parallel to the Z axis) has a second uncoated portion that is not coated with the second electrode active material. The second uncoated portion extends along the winding direction of the electrode assembly 10.

The second uncoated portion serves as a second electrode tab 12. The second electrode tab 12 is located at the lower part of the height direction (parallel to the Z axis) of the electrode assembly 10 accommodated in the battery case 20.

The first electrode tab 11 and the second electrode tab 12 extend and protrude in opposite directions from the separator in the axial direction of the electrode assembly 10. Accordingly, each of the first uncoated portion of the first electrode and the second uncoated portion of the second electrode, which are exposed through one side and the other side of the electrode assembly 10, respectively, may serve as an electrode tab.

The first electrode tab 11 and the second electrode tab 12 have a spirally wound structure. The first and second uncoated portions may have a plurality of cut grooves at predetermined intervals along the winding direction of the electrode assembly 10. The plurality of kerf grooves are used to divide the first and second uncoated portions into a plurality of sections so that the uncoated portions are easily bent.

In the present disclosure, the positive electrode active material coated on the positive electrode plate and the negative electrode active material coated on the negative electrode plate may include any type of active material known in the art.

In one example, the positive electrode active material may include a material represented by formula A [ A ] _x M _y ]O _2+z (A comprises at least one of Li, na or K; M comprises at least one element selected from Ni, co, mn, ca, mg, al, ti, si, fe, mo, V, zr, zn, cu, al, mo,At least one selected from Sc, zr, ru and Cr; x is more than or equal to 0, x+y is more than or equal to 1 and less than or equal to 2, and z is more than or equal to 0.1 and less than or equal to 2; the stoichiometric coefficients x, y, and z are selected to maintain compound electroneutrality).

In another example, the positive electrode active material may be an alkali metal compound xLiM disclosed by US6,677,082 and US6,680,143 ¹ O ₂ -(1-x)Li ₂ M ² O ₃ (M ¹ Comprising at least one element having an average trivalent oxidation state; m is M ² Comprising at least one element having an average tetravalent oxidation state; x is more than or equal to 0 and less than or equal to 1).

In yet another example, the positive electrode active material may be represented by formula Li _a M ¹ _x Fe _1-x M ² _y P _1-y M ³ _z P _1-y M ³ _z O _4-z (M ¹ Comprises at least one selected from Ti, si, mn, co, fe, V, cr, mo, ni, nd, al, mg and Al; m is M ² Comprising at least one selected from Ti, si, mn, co, fe, V, cr, mo, ni, nd, al, mg, al, as, sb, si, ge, V and S; m is M ³ Comprising a halogen radical element optionally comprising F; 0<a≤2，0≤x≤1，0≤y<1，0≤z<1, a step of; the stoichiometric coefficients a, x, y and z being chosen to maintain compound electroneutrality) or Li ₃ M ₂ (PO ₄ ) ₃ [ M comprises at least one selected from Ti, si, mn, fe, co, V, cr, mo, ni, al, mg and Al]Lithium metal phosphate represented.

Preferably, the positive electrode active material may include primary particles and/or secondary particles formed by agglomeration of the primary particles.

In one example, the anode active material may include a carbon material, lithium metal or lithium metal compound, silicon or silicon compound, tin or tin compound. Such as TiO ₂ And SnO ₂ And the like having a potential of less than 2V may be used for the anode active material. The carbon material may include low crystalline carbon, high crystalline carbon, and the like.

The separator may include, for example, a porous polymer film made of polyolefin-based polymers such as ethylene homopolymers, propylene homopolymers, ethylene/butene copolymers, ethylene/hexene copolymers, and ethylene/methacrylate copolymers, used alone or in a stack. In another example, the separator may include a commonly used porous nonwoven fabric, such as a nonwoven fabric made of high-melting glass fibers and polyethylene terephthalate fibers.

The separator may include a coating of inorganic particles on at least one surface. In addition, the separator itself may be formed of a coating of inorganic particles. The particles forming the coating may be combined with a binder such that interstitial volumes exist between adjacent particles.

The inorganic particles may include an inorganic substance having a dielectric constant of 5 or more. Non-limiting examples of the inorganic particles may include at least one material selected from the group consisting of: pb (Zr, ti) O ₃ (PZT)、Pb _1-x La _x Zr _1-y Ti _y O ₃ (PLZT)、PB(Mg ₃ Nb _2/3 )O _3- PbTiO ₃ (PMN-PT)、BaTiO ₃ Hafnium oxide (HfO) ₂ )、SrTiO ₃ 、TiO ₂ 、Al ₂ O ₃ 、ZrO ₂ 、SnO ₂ 、CeO ₂ MgO, caO, znO and Y ₂ O ₃ 。

The electrolyte may be a polymer having a ⁺ B ^- Salts of the structure. Here, A ⁺ Comprising alkali metal cations, e.g. Li ⁺ 、Na ⁺ 、K ⁺ Or a combination thereof. B (B) ^- Comprising at least one anion selected from the group consisting of: f (F) ^- 、Cl ^- 、Br ^- 、I ^- 、NO ₃ ^- 、N(CN) ₂ ^- 、BF ₄ ^- 、ClO ₄ ^- 、AlO ₄ ^- 、AlCl ₄ ^- 、PF ₆ ^- 、SbF ₆ ^- 、AsF ₆ ^- 、BF ₂ C ₂ O ₄ ^- 、BC ₄ O ₈ ^- 、(CF ₃ ) ₂ PF ₄ ^- 、(CF ₃ ) ₃ PF ₃ ^- 、(CF ₃ ) ₄ PF ₂ ^- 、(CF ₃ ) ₅ PF ^- 、(CF ₃ ) ₆ P ^- 、CF ₃ SO ₃ ^- 、C ₄ F ₉ SO ₃ ^- 、CF ₃ CF ₂ SO ₃ ^- 、(CF ₃ SO ₂ ) ₂ N ^- 、(FSO ₂ ) ₂ N ^- 、CF ₃ CF ₂ (CF ₃ ) ₂ CO ^- 、(CF ₃ SO ₂ ) ₂ CH ^- 、(SF ₅ ) ₃ C ^- 、(CF ₃ SO ₂ ) ₃ C ^- 、CF ₃ (CF ₂ ) ₇ SO ₃ ^- 、CF ₃ CO ₂ ^- 、CH ₃ CO ₂ ^- 、SCN ^- (CF) ₃ CF ₂ SO ₂ ) ₂ N ^- 。

The electrolyte may be used by being dissolved in an organic solvent. The organic solvent may include at least one of: propylene Carbonate (PC), ethylene Carbonate (EC), diethyl carbonate (DEC), dimethyl carbonate (DMC), dipropyl carbonate (DPC), dimethyl sulfoxide, acetonitrile, dimethoxyethane, diethoxyethane, tetrahydrofuran, N-methyl-2-pyrrolidone (NMP), methylethyl carbonate (EMC) or gamma-butyrolactone.

Referring to fig. 1 to 4, the battery case 20 is a generally cylindrical container having an open end at a lower portion thereof, and is made of, for example, a material having conductive properties such as metal. The material of the battery case 20 may be, for example, steel, stainless steel, and aluminum.

The side surfaces (outer peripheral surfaces) and the upper surface of the battery case 20 may be integrally formed. The upper surface of the housing 20 (parallel to the X-Y plane) may have an approximately flat shape. The bottom of the cell casing 20 opposite the open end forms a closed end. The battery case 20 accommodates the electrode assembly 10 through an open end at a lower portion, and also accommodates an electrolyte. The closed end supports an electrode assembly inserted through the open end.

The battery case 20 is electrically connected to the electrode assembly 10. For example, the battery case 20 is electrically connected to the second electrode tab 12 of the electrode assembly 10. In this case, the battery case 20 has the same polarity as the second electrode tab 12.

Referring to fig. 2 and 7, the battery case 20 may include a crimping part 21 and a crimping part 22 at a lower end. The beading part 21 is disposed under the electrode assembly 10. The beading portion 21 is formed by pressing the outer peripheral surface of the battery case 20 inward. The beading part 21 may prevent the electrode assembly 10 having a size substantially corresponding to the inner space of the battery case 20 from sliding through the open end at the lower part of the battery case 20, and may serve as a support on which the edge of the second current collecting plate 80 and the cap plate 30 are seated.

The crimping portion 22 is provided below the hemming portion 21. The crimp portion 22 extends and is bent to surround portions of the outer peripheral surface of the cap plate 30 and the lower surface of the cap plate 30 below the crimping portion 21.

However, the present disclosure does not exclude that the battery case 20 does not include the crimping portion 21 and/or the crimping portion 22. In the present disclosure, when the battery case 20 does not include the crimping part 21 and/or the press-fit part 22, the fixing of the electrode assembly 10 and/or the fixing of the cap plate 30 and/or the sealing of the battery case 20 may be accomplished, for example, by additionally applying a member that may serve as a stopper of the electrode assembly 10, and/or additionally applying a structure on which the cap plate 30 may be seated, and/or welding between the battery case 20 and the cap plate 30.

The thickness of the region forming the bottom of the battery case 20 may be in the range of about 0.5mm to 1.0mm, and more preferably in the range of about 0.6mm to 0.8 mm. The thickness of the side wall of the battery case 20 forming the outer circumferential surface may be in the range of about 0.3mm to 0.8mm, and more preferably in the range of about 0.40mm to 0.60 mm. According to an embodiment of the present disclosure, the battery case 20 may have a plating layer. In this case, the plating layer may include, for example, nickel (Ni). The thickness of the plating layer may be in the range of about 1.5 μm to 6.0 μm.

Since the thickness of the battery case 20 is small, the inner space is large, and thus, the cylindrical battery 1 having improved energy density and high capacity can be manufactured.

In contrast, as the thickness increases, flame propagation to adjacent cells in an explosion accident can be prevented, thereby improving safety.

The smaller the thickness of the plating layer is, the more susceptible to corrosion, and the greater the thickness of the plating layer is, the more complicated the manufacturing process may be, or the higher the likelihood that delamination of the plating layer may occur. In view of these conditions, it is necessary to set an optimal thickness of the battery case 20 and an optimal thickness of the plating layer. In addition, it is necessary to control each of the thickness of the bottom and the thickness of the side wall of the battery case 20 in consideration of all conditions.

Referring to fig. 2 and 7, the cover plate 30 may be made of, for example, metal to ensure strength. The cap plate 30 covers the open end of the lower portion of the battery case 20. That is, the cap plate 30 forms the lower surface of the cylindrical battery 1. In the cylindrical battery 1 of the present disclosure, even when the cap plate 30 is made of a metal having conductive properties, the cap plate 30 is nonpolar. Non-polarity may mean that the cap plate 30 is electrically insulated from the battery case 20 and the electrode terminals 40. Therefore, the cap plate 30 does not function as a positive terminal or a negative terminal. Accordingly, the cap plate 30 does not need to be electrically connected to the electrode assembly 10 and the battery case 20, and the material thereof does not need to be conductive metal.

When the battery case 20 of the present disclosure includes the beading part 21, the cap plate 30 may be seated on the beading part 21 of the battery case 20. In addition, when the battery case 20 of the present disclosure includes the crimp portion 22, the cap plate 30 is fixed by the crimp portion 22. A sealing gasket 90 may be interposed between the cap plate 30 and the crimp 22 of the battery case 20 to ensure sealability of the battery case 20.

Further, as described above, the battery case 20 of the present disclosure may not include the crimping part 21 and/or the crimping part 22, and in this case, the sealing gasket 90 may be interposed between the cap plate 30 and the structure for fixing the cap plate 30 at the open end of the battery case 20 to ensure sealability of the battery case 20.

Referring to fig. 7 and 8, the cap plate 30 may further include a vent portion 31 to prevent the internal pressure from rising above a preset pressure due to gas generated in the battery case 20. The exhaust portion 31 corresponds to a region having a smaller thickness than other regions in the cover plate 30. The exhaust portion 31 is structurally weaker than any other region. Therefore, when the internal pressure of the battery case 20 rises above a predetermined level due to an abnormality in the cylindrical battery 1, the vent 31 breaks to force the gas generated in the battery case 20 to be discharged. For example, the exhaust portion 31 may be formed by grooving on either or both surfaces of the cover plate 30 to partially reduce the thickness of the cover plate 30.

The cylindrical battery 1 according to the embodiment of the present disclosure has a structure in which both the positive electrode terminal and the negative electrode terminal are present in the upper portion, and thus the upper structure is more complex than the lower structure. Therefore, in order to smoothly discharge the gas generated in the battery case 20, the gas discharge portion 31 may be formed in the cap plate 30 forming the lower surface of the cylindrical battery 1. As shown in fig. 7, the lower end of the cap plate 30 is preferably disposed higher than the lower end of the battery case 20. In this case, even when the lower end of the battery case 20 is in contact with the ground or the bottom surface of the case for forming the module or the battery pack, the cap plate 30 is not in contact with the ground or the bottom surface of the case for forming the module or the battery pack. Therefore, it is possible to prevent a phenomenon in which the pressure required for the rupture of the exhaust part 31 is different from the design pressure due to the weight of the cylindrical battery 1, thereby allowing the smooth rupture of the exhaust part 31.

Further, when the exhaust portion 31 has a closed loop shape as shown in fig. 7 and 8, the exhaust portion 31 may be more easily broken as the distance from the center of the cover plate 30 to the exhaust portion 31 is longer. When the same exhaust pressure is applied, as the distance from the center of the cover plate 30 to the exhaust portion 31 is longer, the force acting on the exhaust portion 31 is larger, and the exhaust portion 31 is more easily ruptured. In addition, as the distance from the center of the cover plate 30 to the exhaust portion 31 is longer, more smooth exhaust of the exhaust gas can be achieved. From this point of view, the exhaust portion 31 may be preferably formed along the edge of a substantially flat region extending downward (in a downward direction based on fig. 7) from the edge region of the cover plate 30.

Although fig. 8 shows that the exhaust part 31 is continuously formed in an approximately circular shape on the cover plate 30, the present disclosure is not limited thereto. The exhaust portion 31 may be discontinuously formed in an approximately circular shape on the cover plate 30, and may be formed in an approximately straight line or any other shape.

Referring to fig. 1 to 3, the electrode terminal 40 is made of metal having conductive properties, and passes through an upper surface (parallel to the X-Y plane) of the battery case 20 opposite to the open end of the battery case 20. For example, the electrode terminal 40 is electrically connected with the first electrode tab 11 of the electrode assembly 10. In this case, the electrode terminal 40 has a first polarity. Thus, in the cylindrical battery 1 of the present disclosure, the electrode terminal 40 may serve as the first electrode terminal. When the electrode terminal 40 has the first polarity, the electrode terminal 40 is electrically insulated from the battery case 20 having the second polarity. The electrical insulation between the electrode terminals 40 and the battery case 20 may be accomplished in various ways. For example, insulation may be achieved by inserting an insulation gasket 50 between the electrode terminal 40 and the battery case 20. In contrast, insulation may be achieved by forming an insulating coating in a portion of the electrode terminal 40. Alternatively, the electrode terminal 40 may be structurally firmly fixed to prevent contact between the electrode terminal 40 and the battery case 20. Alternatively, two or more of the above methods may be applied together.

The electrode terminal 40 includes a terminal exposing portion 41 and a terminal inserting portion 42. The terminal exposing portion 41 is exposed outward through the battery case 20. The terminal exposing portion 41 may be disposed at an approximate center of the upper surface of the battery case 20. The maximum width of the terminal exposing portion 41 may be greater than the maximum width of the through-hole of the battery case 20. The terminal insertion part 42 may be electrically connected to the first electrode tab 11 through the approximate center of the upper surface of the battery case 20. The end edge of the terminal insertion part 42 may be bent toward the inner surface of the battery case 20 by plastic working and riveted to the inner surface. Plastic working is a technique of causing deformation by applying pressure to the lower end of the electrode terminal 40 using a jig. By plastic working, the end edge of the terminal insertion portion 42 extends in the radial direction, and thus the diameter increases. The jig has a structure conforming to the final shape of the terminal insertion portion 42. Plastic working is a metal working technique that uses ductility and toughness of a metal. The plastic working may be caulking. The application of pressure using the jig may be performed a plurality of times during plastic working. The bent portion of the terminal insertion part 42, which faces the inner surface, may compress the insulating gasket 50 onto the inner surface, thereby providing sealability between the electrode terminal 40 and the battery case 20. Since the end edges of the terminal insertion parts 42 are bent toward the inner surface of the battery case 20, the maximum width of the end parts of the terminal insertion parts 42 is greater than the maximum width of the through-holes of the battery case 20.

Further, when the cylindrical battery 1 of the present disclosure includes the first current collecting plate 60, the central region of the terminal insertion part 42 may be coupled to the first current collecting plate 60. The center region of the terminal insertion portion 42 may have, for example, an approximately cylindrical shape. The diameter of the bottom surface of the center region of the terminal insertion part 42 may be set to about 6.2mm.

The coupling between the bottom surface of the central region of the terminal insertion part 42 and the first current collecting plate 60 may be accomplished, for example, by laser welding or ultrasonic welding.

The laser welding may be performed by forming a laser welding line on one surface of the first current collecting plate 60 through the hollow at the winding center C of the electrode assembly 10 by laser irradiation. The laser welding line may form an approximately concentric circle shape on one surface of the first current collecting plate 60 with the bottom surface of the central region of the terminal insertion part 42. The weld line may be continuous or partially discontinuous.

The diameter of the weld line having the concentric circle shape may be about 60% to 80% of the diameter of the bottom surface of the center region of the terminal insertion part 42. For example, when the diameter of the bottom surface of the center region of the terminal insertion portion 42 is about 6.2mm, the diameter of the circle drawn by the weld line may preferably be about 4.0mm or more. When the diameter of the circle drawn by the weld line is too small, the joint strength of the weld may be insufficient. Conversely, when the diameter of the circle drawn by the weld line is too large, there may be a higher risk of damaging the electrode assembly 10 due to heat and/or weld spatter.

The ultrasonic welding may be performed by inserting a welding rod for ultrasonic welding through the hollow at the winding center C of the electrode assembly 10. A welded portion formed by ultrasonic welding is formed in a contact interface between the bottom surface of the center region of the terminal insertion part 42 and the first current collecting plate 60. The welding portion formed by ultrasonic welding may be formed over the entire concentric circle having a diameter of about 30% to 80% of the diameter of the bottom surface of the central region of the terminal insertion portion 42. For example, when the diameter of the bottom surface of the center region of the terminal insertion part 42 is about 6.2mm, the diameter of the circle occupied by the ultrasonic-welded welding part may be preferably about 2.0mm or more. When the diameter of the circle occupied by the ultrasonic-welded portion is too small, the joint strength of the weld may be insufficient. In contrast, when the diameter of the circle occupied by the ultrasonically welded joint is too large, there may be a higher risk of damaging the electrode assembly 10 by heat and/or vibration.

In the embodiment of the present disclosure, the upper surface of the battery case 20 and the electrode terminals 40 exposed outward through the battery case 20 have opposite polarities and face in the same direction. In addition, there may be a step between the electrode terminal 40 and the upper surface of the battery case 20. Specifically, when the entire upper surface of the battery case 20 is flat or protrudes at the center, the terminal exposing part 41 of the electrode terminal 40 may extend higher than the upper surface of the battery case 20. In contrast, when the upper surface of the battery case 20 is concavely depressed downward from the central portion, i.e., toward the electrode assembly 10, the upper surface of the battery case 20 may protrude higher than the terminal exposure parts 41 of the electrode terminals 40.

Further, when the upper surface of the battery case 20 is concavely recessed downward from the central portion, i.e., toward the electrode assembly 10, the upper surface of the battery case 20 and the upper surface of the terminal exposing portion 41 may form substantially the same plane according to the recess depth and thickness of the terminal exposing portion 41 of the electrode terminal 40. In this case, there may be no step between the upper surface of the battery case 20 and the terminal exposing portion 41.

The insulating gasket 50 is interposed between the battery case 20 and the electrode terminal 40 to prevent contact between the battery case 20 and the electrode terminal 40 having opposite polarities.

Therefore, the upper surface 20a of the battery case 20 having an approximately flat shape may serve as the second electrode terminal of the cylindrical battery 1.

The insulating washer 50 includes a washer exposure portion 51 and a washer insertion portion 52.

The gasket exposure portion 51 is interposed between the terminal exposure portion 41 of the electrode terminal 40 and the battery case 20. The gasket insertion part 52 is inserted between the terminal insertion part 42 of the electrode terminal 40 and the through-hole of the battery case 20. The gasket insertion part 52 may be deformed together with the terminal insertion part 42 and be in close contact with the inner surface of the battery case 20 during plastic working of the terminal insertion part 42. The insulating washer 50 may be made of, for example, a resin material having insulating properties.

Referring to fig. 4, the gasket exposure portion 51 of the insulating gasket 50 may extend to cover the outer circumferential surface of the terminal exposure portion 41 of the electrode terminal 40.

When the insulating gasket 50 covers the outer circumferential surface of the electrode terminal 40, it is possible to prevent a short circuit from occurring during the coupling of an electrical connection member, such as a bus bar, to the upper surface of the battery case 20 and/or the electrode terminal 40. Although not shown in the drawings, the gasket exposure portion 51 of the insulating gasket 50 may extend to cover not only the outer peripheral surface of the terminal exposure portion 41 but also a portion of the upper surface.

When the insulating gasket 50 is made of a resin material, the insulating gasket 50 may be coupled to the battery case 20 and the electrode terminal 40 by thermal fusion.

In this case, sealability at the coupling interface between the insulating gasket 50 and the electrode terminal 40 and sealability at the coupling interface between the insulating gasket 50 and the battery case 20 may be enhanced. Further, when the gasket exposure portion 51 of the insulating gasket 50 extends to the upper surface of the terminal exposure portion 41, the electrode terminal 40 may be coupled to the insulating gasket 50 by insert molding.

According to embodiments of the present disclosure, the insulating gasket 50, the insulator 70, and the sealing gasket 90 may be made of the same material. However, this is not necessary. The thickness of the insulating washer 50 may be equal to the thickness of the insulator 70. However, this is not necessary. Their thicknesses may be different, and in such a case, the thickness of the insulator 70 may be less than the thickness of the insulating washer 50, and vice versa.

The entire remaining area on the upper surface of the battery case 20 except for the area occupied by the electrode terminal 40 and the insulating gasket 50 corresponds to the second electrode terminal 20a having the opposite polarity to the electrode terminal 40. In contrast, in the present disclosure, when the insulating gasket 50 is omitted and the electrode terminal 40 is partially provided with an insulating coating, the entire remaining area on the upper surface of the battery case 20 except for the area occupied by the electrode terminal 40 provided with the insulating coating may be used as the second electrode terminal 20a.

The cylindrical sidewall of the battery case 20 may be formed integrally with the second electrode terminal 20a to avoid discontinuity between the sidewall of the battery case 20 and the second electrode terminal 20a. The connection from the side wall of the battery case 20 to the second electrode terminal 20a may be a gently curved line. However, the present disclosure is not limited thereto, and the connection portion may include at least one angle having a predetermined angle.

Referring to fig. 2 to 4, a first current collecting plate 60 is coupled to an upper portion of the electrode assembly 10. The first current collecting plate 60 is made of metal having conductive characteristics, and is connected to the first electrode tab 11. Although not shown in the drawings, the first current collecting plate 60 may have a plurality of protrusions radially arranged on a lower surface. The protrusion may be pushed into the first electrode tab 11 by pressing the first current collecting plate 60.

Referring to fig. 5, a first current collecting plate 60 may be coupled to an end of the first electrode tab 11. The coupling between the first electrode tab 11 and the first current collecting plate 60 may be performed by, for example, laser welding. The laser welding may be performed by partially melting the base material of the first current collecting plate 60, and may be performed by inserting solder for welding between the first current collecting plate 60 and the first electrode tab 11. In this case, it is preferable that the solder has a lower melting point than the first current collecting plate 60 and the first electrode tab 11.

Referring to fig. 6, the first current collecting plate 60 may be coupled to a coupling surface formed by bending an end portion of the first electrode tab 11 in a direction parallel to the first current collecting plate 60. The bending direction of the first electrode tab 11 may be, for example, a direction toward the winding center C of the electrode assembly 10. When the first electrode tab 11 is bent, the uncoated portion forming the first electrode tab 11 may form a bent surface area. The bending surface region has a structure in which uncoated portions are stacked in a plurality of layers along the axial direction of the electrode assembly 10. When the first electrode tab 11 is bent in this way, the space occupied by the first electrode tab 11 can be reduced, thereby improving energy density. In addition, the coupling area between the first electrode tab 11 and the first current collecting plate 60 may be increased, thereby improving the bonding strength and reducing the resistance.

Referring to fig. 2 to 4, an insulator 70 is disposed between the upper end of the electrode assembly 10 and the inner surface of the battery case 20 or between the first current collecting plate 60 coupled to the electrode assembly 10 and the inner surface of the battery case 20. The insulator 70 prevents contact between the first electrode tab 11 and the battery case 20 and/or between the first current collecting plate 60 and the battery case 20. The insulator 70 may be interposed between the upper end of the outer circumferential surface of the electrode assembly 10 and the inner surface of the battery case 20. The first current collecting plate 60 may be a plate extending across the upper end of the electrode assembly 10. However, the present disclosure is not limited thereto, and the first current collecting plate 60 may extend only partially across the upper end of the electrode assembly 10.

When the cylindrical battery 1 according to the embodiment of the present disclosure includes the insulator 70, the terminal insertion portion 42 of the electrode terminal 40 is coupled to the first current collecting plate 60 or the first electrode tab 11 through the insulator 70.

The insulator 70 may have a through hole adjacent to the winding center C. The through-holes may allow the terminal insertion parts 42 of the electrode terminals 40 and the first current collecting plate 60 to directly contact each other.

In the embodiment of the present disclosure, the terminal insertion part 42 may have a circular shape on a plane, but is not limited thereto. The terminal insertion part 42 may optionally have a polygonal shape, a star shape, and a shape having a leg portion extending from the center.

Referring to fig. 2 and 7, a second current collecting plate 80 is coupled under the electrode assembly 10. The second current collecting plate 80 is made of metal having conductive characteristics and is connected to the second electrode tab 12. In addition, the second current collecting plate 80 is electrically connected to the battery case 20. As shown in fig. 7, the second current collecting plate 80 may be fixed between the inner surface of the battery case 20 and the sealing gasket 90.

Alternatively, the second current collecting plate 80 may be welded to the inner surface of the battery case 20.

Although not shown in the drawings, the second current collecting plate 80 may have a plurality of protrusions radially arranged on one surface. The protrusion may be pushed into the second electrode tab 12 by pressing the second current collecting plate 80.

Referring to fig. 5, a second current collecting plate 80 is coupled to an end of the second electrode tab 12. The coupling between the second electrode tab 12 and the second current collecting plate 80 may be performed by, for example, laser welding. The laser welding may be performed by partially melting the base material of the second current collecting plate 80, and may be performed by inserting solder for welding between the second current collecting plate 80 and the second electrode tab 12.

In this case, it is preferable that the solder has a lower melting point than the second current collecting plate 80 and the second electrode tab 12.

Referring to fig. 6, the second current collecting plate 80 may be coupled to a coupling surface formed by bending an end portion of the second electrode tab 12 in a direction parallel to the second current collecting plate 80. The bending direction of the second electrode tab 12 may be, for example, a direction toward the winding center C of the electrode assembly 10. When the second electrode tab 12 is bent, the uncoated portion forming the second electrode tab 12 may form a bent surface area. The bending surface region has a structure in which uncoated portions are stacked in a plurality of layers along the axial direction of the electrode assembly 10. When the second electrode tab 12 is bent in this way, the space occupied by the second electrode tab 12 can be reduced, thereby improving energy density. In addition, the coupling area between the second electrode tab 12 and the second current collecting plate 80 may be increased, thereby improving the bonding strength and reducing the resistance.

Referring to fig. 7 and 9, at least a portion 81a of the second current collecting plate 80 may be coupled to the second electrode tab 12 by welding. In addition, a predetermined region of the edge of the second current collecting plate 80 may be in contact with the inner surface of the beading part 21. The predetermined region may be welded to the inner surface of the hemming portion 21. The edge region 81b of the second current collecting plate 80 adjacent to the predetermined region may be bent toward the inner surface of the beading part 21 such that the predetermined region reaches the inner surface of the beading part 21.

In an example, the second current collecting plate 80 may include a plurality of sub-plates 81 extending radially from a center and spaced apart from each other. In this case, each of the plurality of sub-boards 81 is coupled to the second electrode tab 12 and the battery case 20. The edge regions 81b of the plurality of sub-plates 81 may be bent and extended toward the junction with the battery case 20.

When the second current collecting plate 80 includes a plurality of sub-plates 81 spaced apart from each other, the second current collecting plate 80 partially covers the lower surface of the electrode assembly 10. Therefore, it is possible to secure a sufficient space for moving the gas generated from the electrode assembly 10 to the cap plate 30, and to achieve smooth gas discharge downward of the cylindrical battery 1. Further, the structure of the second current collecting plate 80 including the plurality of sub-plates 81 as described above may be applied to the previously described first current collecting plate 60 in the same manner.

Referring to fig. 3 and 7, the cylindrical battery 1 according to the embodiment of the present disclosure includes an electrode terminal 40 having a first polarity and a second electrode terminal 20a having a second polarity, which is electrically insulated from the electrode terminal 40, on one side in the axial direction. That is, since the cylindrical battery 1 according to the embodiment of the present disclosure includes the pair of electrode terminals 30, 20a in the same direction, when a plurality of cylindrical batteries 1 are electrically connected, an electrical connection member such as a bus bar may be placed on only one side of the cylindrical batteries 1. This may result in a simple battery structure and improved energy density.

In addition, since the cylindrical battery 1 has a structure in which one surface of the battery case 20 having an approximately flat shape can be used as the second electrode terminal 20a, a sufficient junction region can be ensured when an electrical connection member such as a bus bar is joined to the second electrode terminal 20 a. Therefore, the cylindrical battery 1 can have sufficient bonding strength between the electrical connection member and the second electrode terminal 20a, and the resistance at the bonding portion is reduced to a desired level.

Referring to fig. 1, a bus bar B is connected to each of the first electrode terminal 40 and the second electrode terminal 20a of the cylindrical battery 1 of the present disclosure. In each of the first electrode terminal 40 and the second electrode terminal 20a, in order to secure a sufficient area for connection of the bus bar B, a region of the first electrode terminal 40 exposed through the battery case 20, i.e., a width D1 of the upper surface of the terminal exposing part 41, may be set to about 10% to 60% of a width of the second electrode terminal 20a (i.e., a width D2 of the upper surface of the battery case 20).

Preferably, the cylindrical battery may be, for example, a cylindrical battery having a ratio of a shape factor (a value obtained by dividing the diameter of the cylindrical battery by its height, i.e., defined as a ratio of the diameter Φ to the height H) of greater than about 0.4.

Here, the form factor refers to a value indicating the diameter and height of the cylindrical battery. Cylindrical batteries according to embodiments of the present disclosure may be, for example, 46110, 4875, 48110, 4880, and 4680 batteries. Among the numbers indicating the form factor, the first two numbers represent the diameter of the battery, and the remaining numbers represent the height of the battery.

A battery according to embodiments of the present disclosure may be a battery having an approximately cylindrical shape with a diameter of about 46mm, a height of about 110mm, and a ratio of a shape factor of 0.418.

A battery according to another embodiment may be a battery having an approximately cylindrical shape with a diameter of about 48mm, a height of about 75mm, and a ratio of a shape factor of 0.640.

A battery according to another embodiment may be a battery having an approximately cylindrical shape with a diameter of about 48mm, a height of about 110mm, and a ratio of a shape factor of 0.436.

A battery according to another embodiment may be a battery having an approximately cylindrical shape with a diameter of about 48mm, a height of about 80mm, and a ratio of a shape factor of 0.600.

A battery according to another embodiment may be a battery having an approximately cylindrical shape with a diameter of about 46mm, a height of about 80mm, and a ratio of a shape factor of 0.575.

Generally, batteries having a ratio of a shape factor of about 0.4 or less have been used. That is, for example, 1865 batteries and 2170 batteries have been used. 1865 cells have a ratio of about 18mm diameter, about 65mm height, and a form factor of 0.277. 2170 cells have a ratio of a diameter of about 21mm, a height of about 70mm, and a form factor of 0.300.

Referring to fig. 10, a battery pack 3 according to an embodiment of the present disclosure includes a battery assembly including a plurality of cylindrical batteries 1 according to an embodiment of the present disclosure and a battery pack case 2 accommodating the battery assembly, which are electrically connected to each other. In the drawings, components such as bus bars for electrical connection, cooling units, and power terminals are omitted for convenience of description in the drawings.

Referring to fig. 11, a vehicle 5 according to an embodiment of the present disclosure may be, for example, an electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle, and includes a battery pack 3 according to an embodiment of the present disclosure. The vehicle 5 includes a four-wheel vehicle and a two-wheel vehicle. According to the embodiment of the present disclosure, the vehicle 5 is operated using the power supplied from the battery pack 3.

It should be understood that the above-described embodiments are provided for illustration in all aspects and are not intended to be limiting, and that the scope of the present disclosure is to be defined by the appended claims rather than the foregoing detailed description. Further, it is to be understood that the meaning and scope of the appended claims, as well as all modifications and changes made according to the equivalent concepts, are intended to be included within the scope of the present disclosure.

Although the present disclosure has been described above with reference to the accompanying drawings, the present disclosure is not limited to the disclosed embodiments and the accompanying drawings, and it is apparent that various modifications may be made thereto within the scope of the technical aspects of the present disclosure. Although the description of the embodiments of the present disclosure does not explicitly describe the effect of the operation of the elements of the present disclosure, it should be apparent that the predictable effect of the corresponding elements should be acknowledged.

Claims

1. A method of manufacturing a battery, the method comprising the steps of:

(a) Preparing a battery case having an opening at one side and a bottom at the other side, the bottom having a through hole;

(b) Fixing an electrode terminal to the through hole;

(c) Preparing an electrode assembly including a first electrode tab and a second electrode tab at upper and lower portions, respectively, the first electrode tab being formed of a first uncoated portion, and the second electrode tab being formed of a second uncoated portion;

(d) Inserting the electrode assembly into the battery case through the opening at one side of the battery case such that the first electrode tab faces the bottom;

(e) Electrically connecting the first electrode tab to the electrode terminal; and

(f) The open end is covered with a cover plate.

2. The method of manufacturing a battery according to claim 1, wherein the electrode terminal includes a terminal insertion portion that is inserted into the battery case through the through-hole, and

step (b) comprises the steps of:

(b1) Placing an insulating gasket between the electrode terminal and the through hole; and

(b2) Plastic working is performed on an end edge of the terminal insertion portion in a radial direction so that a diameter of the end edge is larger than a diameter of the through hole.

3. The method of manufacturing a battery according to claim 2, wherein step (b 2) includes applying pressure to the end edge in the axial direction of the electrode assembly using a jig having a structure conforming to the final shape of the plastic working.

4. The method of manufacturing a battery according to claim 2, wherein step (b 2) includes causing a plastically worked end edge to compress the insulating gasket onto an inner surface of the bottom of the battery case.

5. The method of manufacturing a battery according to claim 1, wherein the step (c) includes the steps of:

preparing a first electrode having the first uncoated portion at a long side end and a second electrode having the second uncoated portion at a long side end;

forming a plurality of slit grooves in the first and second uncoated portions along a winding direction of the electrode assembly to divide the first and second uncoated portions into a plurality of sections;

disposing the first electrode and the second electrode such that the first uncoated portion is opposite to the second uncoated portion in an axial direction, and winding the first electrode and the second electrode around an axis with a separator interposed therebetween to form the electrode assembly in which a core and a peripheral surface are defined; and

the first and second uncoated portions are bent in a radial direction of the electrode assembly to form a bent surface region having a structure in which the first and second uncoated portions are stacked in a plurality of layers in the axial direction.

6. The method of manufacturing a battery according to claim 5, wherein step (c) includes coupling a first current collecting plate to the folded surface region of the first uncoated portion, and

wherein step (e) includes coupling the electrode terminal to the first current collecting plate to electrically connect the electrode terminal to the first electrode tab.

7. The method of manufacturing a battery according to claim 6, wherein step (e) includes welding the electrode terminal to the first current collecting plate using a hollow at a core of the electrode assembly.

8. The method of manufacturing a battery according to claim 7, wherein step (e) includes irradiating welding laser through the hollow at the core of the electrode assembly toward a welding region of the first current collecting plate facing the electrode terminal.

9. The method of manufacturing a battery according to claim 6, the method further comprising the steps of:

an insulator is placed between the first current collector plate and an inner surface of the bottom of the battery case.

10. The method of manufacturing a battery according to claim 9, further comprising, before step (d), the steps of:

preparing the insulator having a through hole at a center and having a shape corresponding to an inner surface of the bottom of the battery case; and

The insulator is mounted on an inner surface of the bottom of the battery case such that the through-hole of the insulator surrounds a fixing portion of the electrode terminal.

11. The method of manufacturing a battery according to claim 9, further comprising, before step (d), the steps of:

preparing the insulator having a through hole at a center and a shape corresponding to an inner surface of the bottom of the battery case; and

the insulator is fixed to the first current collecting plate such that the through hole of the insulator is provided on the core of the electrode assembly.

12. The method of manufacturing a battery according to claim 1, the method further comprising the steps of:

coupling a second current collecting plate to the second electrode tab of the electrode assembly; and

at least a portion of the second current collector plate is coupled to an inner surface of the battery case.

13. The method of manufacturing a battery according to claim 12, the method further comprising the steps of:

pressing an outer peripheral surface of the open end of the battery case toward an inside of the battery case to form a curled portion;

welding at least a portion of the second current collector plate to the second electrode tab; and

A predetermined region of an edge of the second current collecting plate is brought into contact with an inner surface of the beading portion.

14. The method of manufacturing a battery according to claim 13, the method further comprising the steps of:

and bending an edge region of the second current collecting plate adjacent to the predetermined region such that the predetermined region reaches the inner surface of the beading part.

15. The method of manufacturing a battery according to claim 13, the method further comprising the steps of:

the predetermined region is welded to the inner surface of the hemming section.

16. The method of manufacturing a battery according to claim 13, the method further comprising the steps of:

placing a sealing gasket between an edge of the cover plate and the open end of the battery housing; and

the open end of the battery case is bent in a centripetal direction to form a crimp portion, thereby fixing the edge of the cap plate to the open end together with the sealing gasket.

17. The method of manufacturing a battery according to claim 16, wherein the press-fit portion compresses the sealing gasket to bring the predetermined region and the inner surface of the beading portion into close contact with each other.

18. The method of manufacturing a battery according to claim 1, the method further comprising the steps of:

a vent groove is formed in at least one of the two surfaces of the cover plate.

19. The method of manufacturing a battery according to claim 1, further comprising, before step (f), the steps of:

placing the battery housing upright such that the bottom of the battery housing faces the ground; and

electrolyte is injected into the battery case.

20. The method of manufacturing a battery according to claim 1, further comprising the following step after step (f):

placing the battery housing upright such that the bottom of the battery housing faces upward; and

an electric wiring is performed through the outer surface of the bottom of the battery case and the electrode terminals using an area other than the exposed area of the electrode terminals.