Battery

Abstract

To provide a battery that can reduce contact resistance between the electrode body and the battery terminals, and can also be made smaller. [Solution] The battery terminal comprises a cylindrical housing 10, a battery terminal 11 having a cylindrical portion 12 housed inside the housing 10, an electrode body 40 consisting of a positive electrode plate 41, a negative electrode plate 44 and a separator 47, which is electrically connected to the battery terminal 11, and external terminals 21, 22 which are electrically connected to the battery terminal 11, wherein the battery terminal 11 has a positive electrode terminal portion 14 provided on one end of the cylindrical portion 12 and a negative electrode terminal portion provided on the other end of the cylindrical portion 12 The electrode body 40 has a terminal portion 15 and an insulating portion 16 that insulates the positive electrode terminal portion 14 and the negative electrode terminal portion 15. The electrode body 40 is a laminate 48 in which a positive electrode plate 41 and a negative electrode plate 44 are stacked with a separator in between. The tab 42 of the positive electrode plate 41 is in contact with the outer peripheral surface 14b of the positive electrode terminal portion 14, and the tab 45 of the negative electrode plate 44 is in contact with the outer peripheral surface 15a1 of the negative electrode terminal portion 15, and the laminate 48 is wound around the cylindrical portion 12.

Description

Technical Field

[0001] The present invention relates to a battery.

Background Art

[0002] In recent years, batteries such as lithium-ion secondary batteries have been suitably used as power sources for driving vehicles such as battery electric vehicles (BEVs), hybrid electric vehicles (HEVs), and plug-in hybrid electric vehicles (PHEVs). This type of battery is disclosed in Patent Document 1 below.

[0003] Patent Document 1 discloses the structure of a lithium-ion secondary battery. Specifically, in the lithium-ion secondary battery, one center rod is provided inside the battery can, and two lead-out terminals are respectively connected to both ends of the center rod. In addition, a wound electrode is wound around the circumferential surface of the center rod, and the end of the wound electrode and the lead-out terminal are electrically connected by one binding member, and the battery member and the battery can are fixed by two mounting nuts.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Cylindrical batteries are sometimes assembled using adhesives or by welding the electrode body (the "polarized winding" in Patent Document 1) to the battery terminals (the "lead-out terminals" in Patent Document 1). One of the problems with using adhesives or welding the electrode body to the battery terminals when assembling batteries is that it makes them difficult to disassemble for battery replacement or disposal. In the battery described in Patent Document 1, the polarized winding and the lead-out terminals can be electrically connected without welding. However, in the battery described in Patent Document 1, the contact resistance between the polarized winding and the lead-out terminals cannot be sufficiently reduced, and because the lead-out terminals protrude from the ends, the battery tends to be large. Therefore, there was room for improvement in the battery described in Patent Document 1.

[0006] This invention has been made in view of the above circumstances, and its purpose is to provide a battery that can reduce the contact resistance between the electrode body and the battery terminals and can be made smaller. [Means for solving the problem]

[0007] The characteristic configuration of the battery according to the present invention for achieving the above objective is: A cylindrical housing, A battery terminal housed inside the aforementioned housing and having a cylindrical portion whose outer diameter is at least smaller than the inner diameter of the housing, An electrode body consisting of a positive electrode plate, a negative electrode plate, and a separator, which is electrically connected to the battery terminals, The battery terminals are electrically connected to external terminals, The battery terminal has a positive terminal portion provided on one end of the cylindrical portion, a negative terminal portion provided on the other end of the cylindrical portion, and an insulating portion that insulates the positive terminal portion and the negative terminal portion. The electrode body is a laminate in which the positive electrode plate and the negative electrode plate are stacked with the separator in between, and the tab of the positive electrode plate is in contact with the outer circumferential surface of the positive electrode terminal portion, and the tab of the negative electrode plate is in contact with the outer circumferential surface of the negative electrode terminal portion, with the laminate being wound around the cylindrical portion.

[0008] According to the above-described configuration, by making the tabs of the positive electrode plate and the tabs of the negative electrode plate in contact with the outer circumferential surfaces of the parts corresponding to the positive and negative electrode terminals, it becomes easier to secure the contact area (current-carrying area) between the electrode body and the battery terminals, and it is possible to reduce the electrical contact resistance between them. By providing the positive and negative electrode terminals inside the housing, the battery can be made smaller compared to a case where the battery terminals protrude to the outside, as the electrode body and battery terminals are housed inside the housing.

[0009] Further characteristic features of the battery according to the present invention are: The positive terminal portion is characterized by having a longer axial length of the cylindrical portion than the negative terminal portion.

[0010] According to the above characteristic configuration, the contact area between the positive terminal and the tab on the positive plate is larger than the contact area between the negative terminal and the tab on the negative plate. As a result, the battery can more easily draw current, improving its performance.

[0011] Further characteristic features of the battery according to the present invention are: The cylindrical portion of the battery terminal has a mounting hole formed along the axial direction of the cylindrical portion and opening on at least one end face of the positive terminal portion side and the negative terminal portion side. The key feature is that the mounting portion provided on the external terminal is inserted into the mounting hole, and the external terminal is mounted in a state where it is electrically connected to the battery terminal.

[0012] According to the above-described configuration, by providing a mounting portion corresponding to the mounting hole on the external terminal, it becomes possible to attach the external terminal to the terminal portion on the side where the mounting hole is open (positive terminal portion or negative terminal portion), making it easy to remove when replacing or disposing of the battery, thus improving the disassembly and assembly of the battery. In addition, when the mounting portion is inserted into the mounting hole, it is easier to secure the contact area between the battery terminal and the external terminal, and it is possible to reduce the electrical contact resistance between them.

[0013] Further characteristic features of the battery according to the present invention are: A seal member is provided between the external terminal to which the mounting portion is attached to the mounting hole and the housing.

[0014] According to the above characteristic configuration, in the battery, the airtightness between the external terminal and the housing can be ensured, and liquid leakage and the like can be prevented.

[0015] A further characteristic configuration of the battery according to the present invention is The battery terminal has a flange portion at at least one end of either the positive terminal portion side or the negative terminal portion side.

[0016] According to the above characteristic configuration, by joining the interface between the flange portion and the housing by laser welding or the like, the airtightness of the housing can be ensured in the battery without providing a seal member or the like.

Effect of the Invention

[0017] As described above, according to the battery according to the present invention, the contact resistance between the electrode body and the battery terminal can be effectively reduced and the size can be reduced.

Brief Description of the Drawings

[0018] [Figure 1] It is a side sectional view of the secondary battery of the first embodiment. [Figure 2] It is an exploded view of the electrode body. [Figure 3] It is a view showing the laminated electrode body. [Figure 4] It is a view showing the process of winding the laminate around the battery terminal. [Figure 5] It is a view showing the process of inserting the battery material into the battery case. [Figure 6] It is a view showing the process of attaching the lid portion to the battery case. [Figure 7] It is a side sectional view of the secondary battery of the second embodiment.

Mode for Carrying Out the Invention

[0019] The battery according to this embodiment will be described below with reference to the drawings. In the following description, the example of a lithium-ion secondary battery will be used. Furthermore, in order to clarify the explanation, the descriptions and drawings have been simplified as appropriate.

[0020] [First Embodiment] A first embodiment of secondary battery 1 (an example of a battery) will be described based on Figures 1 to 6. Figure 1 is a side cross-sectional view of secondary battery 1. In the following description, the direction parallel to the height direction of secondary battery 1 is defined as the Z-axis direction. The Z-axis direction is parallel to the vertical direction.

[0021] As shown in Figure 1, the secondary battery 1 comprises a cylindrical battery case 10 (an example of a housing), battery terminals 11, two external terminals 21 and 22, and an electrode body 40.

[0022] [Configuration of battery case 10] The battery case 10 houses the battery terminals 11 and the electrode body 40 inside the cylinder. The battery case 10 is made of an insulating material, such as ceramic or resin. In addition, if insulation can be ensured between the battery terminals 11, external terminals 21, 22 (at least the negative electrode external terminal 22 described later in this embodiment), and the electrode body 40 by coating it with an insulating material to ensure safety, a conductive material can also be used as the main material of the battery case 10.

[0023] [Configuration of battery terminal 11] As shown in Figure 1, the battery terminal 11 is housed inside the battery case 10 and has a cylindrical portion 12 whose outer diameter is smaller than at least the inner diameter of the battery case 10. The battery terminal 11 has a positive terminal portion 14 provided on one end of the cylindrical portion 12, a negative terminal portion 15 provided on the other end of the cylindrical portion 12, and an insulating portion 16 that insulates the positive terminal portion 14 and the negative terminal portion 15. In this embodiment, the positive terminal portion 14 has a cylindrical portion 14a that constitutes part of the cylindrical portion 12, and the negative terminal portion 15 is configured to have a cylindrical portion 15a that constitutes part of the cylindrical portion 12 and a flange portion 15b. In other words, in this embodiment, the flange portion 15b is formed on the negative terminal portion 15 of the positive terminal portion 14 and the negative terminal portion 15. Furthermore, in the battery terminal 11 of this embodiment, the length L1 of the cylindrical portion 14a of the positive terminal portion 14 is longer than the length L2 of the cylindrical portion 15a of the negative terminal portion 15. In other words, in this embodiment, the positive terminal portion 14 is set so that the length of the cylindrical portion 12 in the axial direction (Z-axis direction) is longer than that of the negative terminal portion 15 (see Figure 4).

[0024] In this embodiment, the battery terminal 11 is a dissimilar material jointed member. Specifically, in this embodiment, it consists of a first member that becomes the positive electrode terminal portion 14, a second member that becomes the negative electrode terminal portion 15, and a third member that becomes the insulating portion 16. The first and second members are made of conductive materials, and the third member is made of an insulating material, and these are joined together. Aluminum can be used as the first member, copper as the second member, and ceramic as the third member, but it is not limited to these.

[0025] As shown in Figure 1, the cylindrical portion 12 of the battery terminal 11 has a hole 17 (an example of a mounting hole) formed along the axial direction (Z-axis direction) of the cylindrical portion 12 and opening on at least one end face on the side of the positive terminal portion 14 and the side of the negative terminal portion 15. In this embodiment, the entire cylindrical portion 12 is formed in a cylindrical shape, and the hole 17 opens on both end faces on the side of the positive terminal portion 14 and the side of the negative terminal portion 15 (see Figure 4). In this embodiment, the positive external terminal 21 is attached to the hole 17. In this embodiment, a screw groove 17a is formed on the inner surface of the hole 17 on the side of the positive terminal portion 14 (the cylindrical portion 14a of the positive terminal portion 14), and the cylindrical portion 21a of the positive external terminal 21, which will be described later, is inserted into the hole 17.

[0026] [Configuration of external terminals 21 and 22] As shown in Figure 1, the secondary battery 1 is equipped with a positive external terminal 21 and a negative external terminal 22 as external terminals. The positive external terminal 21 is electrically connected to the positive terminal portion 14 of the battery terminal 11, and these positive external terminals 21 and 14 constitute the positive terminal PS. The negative external terminal 22 is electrically connected to the negative terminal portion 15 of the battery terminal 11, and these negative external terminals 22 and 15 constitute the negative terminal NS.

[0027] In this embodiment, the positive external terminal 21 has a cylindrical portion 21a and a flange portion 21b. The cylindrical portion 21a has a screw groove 61a formed on its outer surface 61. As described above, the cylindrical portion 21a of the positive external terminal 21 is inserted into the hole 17 of the battery terminal 11.

[0028] In this embodiment, the negative electrode external terminal 22 is a disc-shaped member made of aluminum. The negative electrode external terminal 22 is electrically connected to the flange portion 15b of the negative electrode terminal portion 15.

[0029] [Configuration of electrode body 40] Figure 2 is an exploded view of the electrode body 40. Figure 3 is a diagram showing the laminate 48. As shown in Figures 2 and 3, the electrode body 40 consists of a laminate 48 in which rectangular positive electrode plates 41 and negative electrode plates 44 are laminated with rectangular separators 47 in between. In this embodiment, the positive electrode plate 41 is aluminum foil and the negative electrode plate 44 is copper foil.

[0030] The positive electrode plate 41 has positive electrode active material coated on both sides and has a tab 42 (positive electrode tab) extending from one end in the winding direction (R direction). The negative electrode plate 44 has negative electrode active material coated on both sides and has a tab 45 extending from the lower end in the Z-axis direction. The tab 42 is rectangular in shape with its longitudinal direction parallel to the Z-axis direction of the electrode body 40. The tab 45 is rectangular in shape with its longitudinal direction parallel to the winding direction (R direction) of the electrode body 40. The length of the tab 42 of the positive electrode plate 41 in the Z-axis direction should be greater than or equal to the length of the cylindrical portion 14a of the positive electrode terminal portion 14 of the battery terminal 11, and the length in the R direction should be greater than or equal to the circumference of the outer surface 61 of the cylindrical portion 14a. In this way, a sufficient contact area between the positive electrode plate 41 and the positive electrode terminal portion 14 can be secured. Furthermore, the tab 45 of the negative electrode plate 44 should have a length in the R direction that is greater than or equal to the circumference of the outer surface 15a1 of the cylindrical portion 15a of the negative electrode terminal portion 15, and a length in the Z-axis direction that is greater than or equal to the length of the cylindrical portion 15a. In this way, a sufficient contact area between the negative electrode plate 44 and the negative electrode terminal portion 15 can be ensured.

[0031] The separator 47 is positioned to insulate the positive electrode coating portion of the positive electrode plate 41 from the negative electrode coating portion of the negative electrode plate 44. The separator 47 can be made of an insulating material that allows ions to pass through (for example, a porous insulating resin material). Although Figures 2 and 3 only show the separator 47 positioned between the positive electrode plate 41 and the negative electrode plate 44, in reality, a separator 47 is also positioned on the far side of the negative electrode plate 44 in Figure 2, or on the near side of the positive electrode plate 41 in Figure 2. In other words, one laminate 48 is made up of a positive electrode plate 41, a negative electrode plate 44, and two separators 47 stacked together.

[0032] [Manufacturing procedure for secondary battery 1] Next, the manufacturing procedure for the secondary battery 1 will be explained with reference to Figures 4 to 6. Figure 4 shows the process of winding the laminate 48 around the battery terminals 11. Figure 5 shows the process of inserting the battery material into the battery case 10. Figure 6 shows the process of attaching the lid 51 to the battery case 10. As shown in Figure 4, the laminate 48 is wound around the cylindrical portion 12 with the tab 42 of the positive electrode plate 41 in contact with the outer circumferential surface 14b of the positive electrode terminal portion 14, and the tab 45 of the negative electrode plate 44 in contact with the outer circumferential surface 15a1 of the negative electrode terminal portion 15. More specifically, the laminate 58 is wound with the tab 42 of the positive electrode plate 41 in contact with the outer circumferential surface 14b of the cylindrical portion 14a of the positive electrode terminal portion 14, and the tab 45 of the negative electrode plate 44 in contact with the outer circumferential surface 15a1 of the cylindrical portion 15a of the negative electrode terminal portion 15. As a result, the tab 42 of the positive electrode plate 41 is electrically connected to the positive electrode terminal portion 14, and the tab 45 of the negative electrode plate 44 is electrically connected to the negative electrode terminal portion 15, forming an electrode body 40.

[0033] As shown in Figure 5, the battery material (battery terminals 11 and electrode body 40) is inserted into the cylinder of the battery case 10. The negative electrode terminal portion 15 is joined to the battery case 10 by laser welding or the like at the interface between the outer peripheral edge of the flange portion 15b of the negative electrode terminal portion 15 and the inner peripheral edge of the battery case 10. As a result, one side of the battery case 10 in the Z-axis direction is hermetically sealed.

[0034] Next, as shown in Figure 6, a circular cover portion 51 (an example of a sealing member) is assembled to the tip side 14c of the positive terminal portion 14. A through hole 52 is formed in the center of the cover portion 51. The cover portion 51 is made of an insulating material such as resin.

[0035] Next, the external terminals 21 and 22 are attached to both sides of the battery terminal 11 in the Z-axis direction, and the external terminals 21 and 22 are electrically connected to the battery terminal 11. Specifically, the positive external terminal 21 is attached to the positive terminal portion 14 of the battery terminal 11, and the negative external terminal 22 is attached to the negative terminal portion 15 (flange portion 15b) of the battery terminal 11.

[0036] In this embodiment, the positive terminal portion 14 of the battery terminal 11 has a hole 17 formed in the cylindrical portion 14a, and a screw groove 17a is formed on the inner surface of the hole 17. Also, the cylindrical portion 21a of the positive external terminal 21 has a screw groove 61a formed on its outer surface 61. Therefore, by inserting the cylindrical portion 21a (mounting portion) provided on the positive external terminal 21 into the hole 17 (mounting hole), the positive external terminal 21 is mounted in a state in which it is electrically connected to the positive terminal portion 14 of the battery terminal 11. In this embodiment, the positive external terminal 21 and the battery terminal 11 are fixed by screw fastening. As a result, the other side of the battery case 10 in the Z-axis direction is hermetically sealed by the positive external terminal 21 with the cylindrical portion 21a (mounting portion) attached to the hole 17 (mounting hole) and the cover portion 51. In this way, the secondary battery 1 shown in Figure 1 can be manufactured.

[0037] According to this embodiment, the secondary battery 1 can be configured to be electrically connected and detachable and fixable without using adhesive or welding the battery terminals 11 and the electrode body 40. Therefore, the secondary battery 1 is improved in terms of disassembly and assembly. In addition, a helical screw groove 17a is formed on the inner surface of the hole 17 (mounting hole) of the cylindrical portion 12 of the battery terminal 11, and a screw groove 61a is formed on the outer surface 61 of the cylindrical portion 21a of the positive electrode external terminal 21. As a result, the positive electrode external terminal 21 is electrically connected to and fixed to the battery terminal 11 in the manner of screw fastening, so the positive electrode external terminal 21 can be easily removed when replacing the battery or when disposing of it.

[0038] Furthermore, by providing a screw groove 17a in the hole 17 of the cylindrical portion 12 of the battery terminal 11, the contact area between the battery terminal 11 and the positive electrode external terminal 21 is increased. In addition, since the positive electrode external terminal 21 can be fixed to the battery terminal 11 in the manner of screw fastening, the contact pressure between the positive electrode external terminal 21 and the battery terminal 11 is increased. As a result, the electrical contact resistance in the secondary battery 1 can be reduced.

[0039] Furthermore, by arranging the battery terminals 11 inside the battery case 10, the secondary battery 1 can be made smaller. Also, by directly wrapping the tabs 42 and 45 of the electrode body 40 around the positive terminal portion 14 and the negative terminal portion 15, sufficient contact area is ensured between the positive terminal portion 14 and the negative terminal portion 15 and the tabs 42 and 45. This reduces the electrical contact resistance between the battery terminals 11 and the tabs 42 and 45.

[0040] Furthermore, in the secondary battery 1, by positioning the battery terminals 11 inside the battery case 10, the battery terminals 11 do not protrude to the outside. Therefore, it becomes difficult for other objects to come into contact with the battery terminals 11 from the outside, thereby reducing the risk of short circuits caused by accidental contact of other objects such as tools with the battery terminals 11, and electric shocks caused by inadvertently touching the battery terminals 11 with one's hand.

[0041] [Second Embodiment] A second embodiment will be described based on Figure 7. In the second embodiment, the following will mainly describe the configurations that differ from the first embodiment, and the same reference numerals will be used for components that are the same as in the first embodiment, and detailed descriptions will be omitted.

[0042] In the second embodiment, as shown in Figure 7, the negative electrode terminal portion 15 is composed only of a cylindrical portion 15a and does not have a flange portion. In this embodiment, a screw groove 17b is also formed on the inner surface of the hole portion 17 on the side of the negative electrode terminal portion 15 (the cylindrical portion 15a of the negative electrode terminal portion 15). In this embodiment, a cover portion 53 is also arranged on the side of the negative electrode terminal portion 15, just as on the side of the positive electrode terminal portion 14. A through hole 54 is formed in the center of the cover portion 53. The negative electrode external terminal 22 is also composed of a cylindrical portion 22a and a flange portion 22b, just like the positive electrode external terminal 21, and a screw groove 62a is formed on the outer surface 62 of the cylindrical portion 22a. Therefore, the cylindrical portion 22a of the negative electrode external terminal 22 is inserted into the hole 17 (see Figure 4) of the cylindrical portion 15a of the negative electrode terminal portion 15 of the battery terminal 11, and the negative electrode external terminal 22 is fixed to the battery terminal 11 by screw fastening.

[0043] (Other embodiments) In the first embodiment, an example was shown in which the negative terminal portion 15 is composed of a cylindrical portion 15a and a flange portion 15b, but instead of the negative terminal portion 15, the positive terminal portion 14 may be composed of a cylindrical portion and a flange portion.

[0044] In the above embodiment, the positive terminal portion 14 was described in which the length of the cylindrical portion 12 in the axial direction (Z-axis direction) is longer than that of the negative terminal portion 15, but the embodiment is not limited to this. The positive terminal portion 14 and the negative terminal portion 15 may be the same length, or the negative terminal portion 15 may be longer. In other words, the length L1 of the cylindrical portion 14a of the positive terminal portion 14 and the length L2 of the cylindrical portion 15a of the negative terminal portion 15 may be the same, or the length L2 of the negative terminal portion 15 may be longer.

[0045] In the above embodiment, a configuration in which a mounting hole 17 is formed in the battery terminal 11 has been described, but the embodiment is not limited to this configuration. For example, if both the positive terminal portion 14 and the negative terminal portion 15 have flange portions, these flange portions can be joined to the battery case 10, and the positive external terminal 21 and the negative external terminal 22 can be joined to these flange portions by welding or the like.

[0046] In the above embodiment, an example was shown in which the cylindrical portion 12 of the battery terminal 11 is formed in a cylindrical shape. However, the cylindrical portion 12 may also be configured such that the hole 17 (mounting hole) extends partway along the axial direction (Z-axis direction) of the cylindrical portion 12. That is, the hole 17 may be formed to open only on one end face, either the positive terminal portion 14 side or the negative terminal portion 15 side.

[0047] In the above embodiment, a screw groove 17a is formed in the hole 17 of the cylindrical portion 12 of the battery terminal 11, and screw grooves 61a and 62a are formed on the outer surfaces 61 and 62 of the cylindrical portions 21a and 22a of the external terminals 21 and 22, and the battery terminal 11 and the external terminals 21 and 22 are fixed together by screw fastening. However, the embodiment is not limited to this embodiment. Methods other than screw fastening may be used to fix the external terminals 21 and 22 to the battery terminal 11.

[0048] In the above embodiment, a configuration in which the secondary battery 1 is a lithium-ion battery was described, but the embodiment is not limited to this configuration. Other secondary batteries or primary batteries may be used as the secondary battery 1.

[0049] Furthermore, the configurations disclosed in the above embodiments (including other embodiments, the same applies hereinafter) can be applied in combination with configurations disclosed in other embodiments, as long as no inconsistencies arise. Moreover, the embodiments disclosed herein are illustrative, and the embodiments of the present invention are not limited thereto, and can be modified as appropriate without departing from the object of the present invention. [Explanation of symbols]

[0050] 1: Secondary battery (battery) 10: Battery case 11:Battery terminal 12: Cylindrical section 14: Positive terminal section 14b: External surface 15:Negative terminal part 15a1: External surface 15b: Flange section 16: Insulation 17: Hole (mounting hole) 21: Positive external terminal (external terminal) 21a: Cylindrical section (mounting section) 21b: Flange section 22: Negative external terminal (external terminal) 22a: Cylindrical section (mounting section) 22b: Flange section 40: Electrode body 41: Positive plate 42: Tab 44: Negative plate 45: Tab 47: Separator 48: Laminate 51, 53: Lid (sealing member)

Claims

1. A cylindrical housing, A battery terminal housed inside the aforementioned housing and having a cylindrical portion whose outer diameter is at least smaller than the inner diameter of the housing, An electrode body consisting of a positive electrode plate, a negative electrode plate, and a separator, which is electrically connected to the battery terminals, The battery terminals are electrically connected to external terminals, The battery terminal has a positive terminal portion provided on one end of the cylindrical portion, a negative terminal portion provided on the other end of the cylindrical portion, and an insulating portion that insulates the positive terminal portion and the negative terminal portion. The electrode body is a laminate in which the positive electrode plate and the negative electrode plate are stacked with the separator in between, and the tab of the positive electrode plate is in contact with the outer circumferential surface of the positive electrode terminal portion, and the tab of the negative electrode plate is in contact with the outer circumferential surface of the negative electrode terminal portion, and the laminate is wound around the cylindrical portion in this state.

2. The battery according to claim 1, wherein the positive terminal portion has a longer axial length of the cylindrical portion than the negative terminal portion.

3. The cylindrical portion of the battery terminal has a mounting hole formed along the axial direction of the cylindrical portion and opening on at least one end face of the positive terminal portion side and the negative terminal portion side. The battery according to claim 1, wherein the mounting portion provided on the external terminal is inserted into the mounting hole and the external terminal is electrically connected to the battery terminal.

4. The battery according to claim 3, wherein a sealing member is provided between the external terminal to which the mounting portion is attached to the mounting hole and the housing.

5. The battery according to claim 1 or 2, wherein the battery terminal has a flange portion at at least one end of the positive terminal portion side and the negative terminal portion side.

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