battery

Abstract

To provide a battery in which the cell holder can be easily molded. [Solution] The battery 10 comprises a cell 32 and a first cell holder unit 31 and a second cell holder unit having a plurality of housing sections 37 for housing the cell 32. The housing section 37 has a first bottom 53 that abuts against the first end 32a of the cell 32 and a wall section 58 that surrounds the cell 32. The wall section 58 has a first bulge 62 that is continuous with the first bottom 53 and bulges inward from the housing section 37, abutting against the side wall of the cell 32.

Description

Technical Field

[0001] The present invention relates to a battery.

Background Art

[0002] In recent years, in order to enable more people to access energy that is affordable, reliable, sustainable, and advanced, research and development on batteries that contribute to energy efficiency have been carried out. For example, as a battery, there is known one provided with a honeycomb heat insulating plate having a hexagonal shape in a top view and accommodating cells therein, and a fixing block for fixing the cells inside the honeycomb heat insulating plate (see, for example, Patent Document 1). Hereinafter, the honeycomb heat insulating plate may be referred to as a "cell holder".

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in the technology related to batteries, the fixing block is provided near the middle in the longitudinal direction of the cell holder. Therefore, when molding the cell holder, it is necessary to provide the fixing block inside the cell holder, and it is difficult to mold the cell holder.

[0005] In order to solve the above problems, an object of the present invention is to be able to easily mold the cell holder. And by extension, it contributes to the improvement of energy efficiency.

Means for Solving the Problems

[0006] In order to solve the above problems, the present invention proposes the following means. (1) The battery according to the present invention comprises a cell (for example, a cell 32 in the embodiment) and a cell holder (for example, a first cell holder unit 31, a second cell holder unit 42 in the embodiment) having a plurality of housing sections (for example, a housing section 37 in the embodiment) for housing the cell, wherein the housing section has a bottom section (for example, a first bottom section 53 in the embodiment) that abuts against one end of the cell (for example, a first end section 32a in the embodiment) and a wall section (for example, a wall section 58 in the embodiment) that surrounds the cell, and the wall section has a bulge section (for example, a first bulge section 62 in the embodiment) that is continuous with the bottom section and bulges inward from the housing section and abuts against the side wall of the cell.

[0007] This configuration creates a bulge that is continuous with the bottom of the housing section. The bulge extends inward from the housing section so as to contact the side wall of the cell. Here, for example, the housing section is divided in the axial direction, and an opening is provided on the opposite side of the bulge. Therefore, for example, the mold can be closed and opened in the axial direction with the bulge as a reference, and the bulge can be easily molded into the wall of the housing section. This makes it easy to mold the cell holder.

[0008] (2) In the above embodiment, the cell holder may have a recess (for example, the recess 64 in the embodiment) that is recessed inward from the bottom side of the housing portion, and the bulging portion may be configured to consist of a surface that is exposed inward to the housing portion corresponding to the recess.

[0009] This configuration allows the bulge to be exposed on the inside of the housing, corresponding to the recess that curves inward from the bottom. This makes it possible to reduce the thickness of the bulge. As a result, when inserting a cell into the housing, the bulge can be deformed to match the shape of the cell. Therefore, the cell can be held in place by the bulge under appropriate pressure.

[0010] (3) In the above embodiment, the thickness of the bulge may be thinner than the portion of the bottom and the wall other than the bulge.

[0011] This configuration makes the thickness of the bulge thinner than that of the bottom and walls. Therefore, when inserting the cell into the containment section toward the bulge, the bulge becomes easier to deform. As a result, the bulge can hold the cell with more appropriate pressure.

[0012] (4) In the above embodiment, the cell is cylindrical in shape, and in a view perpendicular to the bottom, the wall portion is polygonal in shape, and the bulge portion is formed at the intersection where the wall portions intersect (for example, the intersection 59 in the embodiment), and the portion of the wall portion other than the bulge portion and the side wall of the cell may be spaced apart.

[0013] This configuration creates bulges at intersections where the walls of the containment sections meet, separating the non-bulging portions of the walls from the side walls of the cells. As a result, an air layer can be secured between the non-bulging portions of the containment section walls and the side walls of the cells. This allows the portions of the cell side walls that do not come into contact with the bulges to be adjacent to the adjacent containment section via the air layer. Therefore, the transfer of heat generated in the cells to the adjacent containment section can be suppressed.

[0014] (5) In the above embodiment, the bulge may have a vertical portion extending substantially vertically from the bottom portion (for example, vertical portions 65, 67 in the embodiment) and an inclined portion connecting from the vertical portion to the portion of the wall other than the bulge portion and having a surface inclined with respect to the vertical portion (for example, inclined portions 66, 68 in the embodiment).

[0015] This configuration provides a slanted section in the bulging portion, with the slanted section being a surface inclined relative to the vertical section. Therefore, when inserting a cell into the housing section toward the bulging portion, the cell can be moved inward from the vertical section while contacting the slanted section. This allows the cell to be easily inserted into the housing section while suppressing strong interference between the cell and the bulging portion. [Effects of the Invention]

[0016] According to the present invention, an object is to be able to easily mold a cell holder.

Brief Description of the Drawings

[0017] [Figure 1] It is a perspective view of a battery in an embodiment of the present invention. [Figure 2] It is an exploded perspective view showing the battery of FIG. 1. [Figure 3] It is a cross-sectional view taken along line III-III of FIG. 2 and broken. [Figure 4] It is a cross-sectional view of a first battery module in an embodiment. [Figure 5] It is a perspective view showing a state where the first battery module in an embodiment is attached to a bottom case. [Figure 6] It is a perspective view of a second cell holder of a first cell holder unit in an embodiment as viewed from above. [Figure 7] It is a bottom view showing the second cell holder of the first cell holder unit in an embodiment. [Figure 8] It is a bottom view showing an enlarged VIII in the second cell holder of FIG. 7.

Mode for Carrying Out the Invention

[0018] Hereinafter, a battery according to an embodiment of the present invention will be described with reference to the drawings. <Battery> FIG. 1 is a perspective view of a battery in an embodiment. As shown in FIG. 1, the battery 10 is configured to be detachable from various power devices, for example. The power devices from which the battery 10 is detached are, for example, electric vehicles, electric moving bodies, electric machines, power supply devices, and various electrical appliances. The electric vehicle includes, for example, an electric vehicle, a saddle-type vehicle, and a kick scooter that are powered by a rotating electric machine driven by the power of the battery 10, a hybrid vehicle that combines a rotating electric machine and an internal combustion engine, and a fuel cell vehicle that combines the battery 10 and a fuel cell. The electric moving body includes, for example, a robot, an aircraft, and moving bodies on water and underwater. The electric machine includes, for example, a construction machine that is powered by a rotating electric machine. The power supply device includes, for example, a stationary or mobile power supply device that discharges and charges the battery 10.

[0019] FIG. 2 is an exploded perspective view showing the battery of FIG. 1. As shown in FIGS. 1 and 2, the outer shape of the battery 10 is, for example, a box shape having a gripping portion 21a in a top case 21 described later. The battery 10 is a so-called cassette-type battery pack (secondary battery) configured to be replaceable. The battery 10 includes, for example, a battery case 12, a battery module unit 14, a bus bar unit 16, and a control unit 18.

[0020] <Battery case> The battery case 12 includes a top case 21, a bottom case 22, and a middle case 23. The outer shape of each of the top case 21 and the bottom case 22 is, for example, an open box shape. The outer shape of the middle case 23 is, for example, a cylindrical shape. The top case 21 and the bottom case 22 close the open ends at both ends in the axial direction along the central axis of the middle case 23. Hereinafter, in the battery 10, the top case 21 side will be described as the "upper side" and the bottom case 22 side will be described as the "lower side". Also, the direction of the plane perpendicular to the vertical direction will be described as the "plane direction". Note that the vertical direction may be referred to as the "orthogonal direction" perpendicular to the plane direction. <00In this embodiment, the orientation of the battery 10 is described as having the top case 21 facing upwards and the bottom case 22 facing downwards, but the orientation of the battery 10 can be arbitrarily selected.

[0021] <Battery Module Unit> The battery module unit 14 is located inside the battery case 12 (specifically, the middle case 23). The battery module unit 14 includes, for example, a first battery module 25 and a second battery module 26.

[0022] Figure 3 is a cross-sectional view broken along the line III-III in Figure 2. Figure 4 is a cross-sectional view of the first battery module. As shown in Figures 2 to 4, the first battery module 25 includes, for example, a first cell holder unit (cell holder) 31 and a plurality of cells 32. The first cell holder unit 31 includes a first cell holder 33 and a second cell holder 34. The first cell holder unit 31 has the first cell holder 33 and the second cell holder 34 stacked sequentially from the bottom case 22 upwards.

[0023] The first cell holder unit 31 is configured as a honeycomb structure 36 by, for example, a first cell holder 33 and a second cell holder 34. The honeycomb structure 36 has a plurality of arranged storage sections 37. The storage section 37 has walls 58 (described later) that are polygonal in shape when viewed from a perpendicular direction (i.e., in a direction perpendicular to the bottom section 45, which will be described later). In this embodiment, for example, a regular hexagon is used as the polygon. That is, the storage section 37 is formed as, for example, a hollow regular hexagonal prism. Note that the shape of the polygon is not limited to a regular hexagon and can be arbitrarily selected. The housing section 37 is oriented with its axis in the vertical direction. The housing section 37 holds the cells 32, which will be described later, by housing them within it. That is, the first cell holder unit 31 holds multiple cells 32 by housing them within it. The housing section 37 will be described in detail later.

[0024] Figure 5 is a perspective view showing the first battery module mounted on the bottom case. Figure 6 is a perspective view of the second cell holder of the first cell holder unit, viewed from above. As shown in Figures 5 and 6, the second cell holder 34 has a bottom portion 45, a positive electrode hole portion 46, a negative electrode hole portion 47, a contact portion 48, and an opening 49. The bottom portion 45 is formed at the top of the second cell holder 34.

[0025] The positive electrode hole 46 penetrates the bottom 45 in the thickness direction (i.e., vertical direction). The positive electrode hole 46 exposes the positive electrode terminal 32P (described later) of the cell 32 in the thickness direction. The negative electrode hole 47 penetrates the bottom 45 in the thickness direction. The negative electrode hole 47 exposes the negative electrode terminal 32N (described later) of the cell 32 in the thickness direction. The contact portion 48 contacts the first busbar 55, which will be described later. The opening 49 is opened at the bottom of the second cell holder 34.

[0026] As shown in Figures 4 and 5, the first cell holder 33 has a bottom 51 and an opening 52. The bottom 51 is formed at the lower part of the first cell holder 33. The opening 52 is formed at the top of the first cell holder 33.

[0027] Figure 7 is a bottom view showing the second cell holder of the first cell holder unit. As shown in Figures 3, 4, and 7, the housing portion 37 has a first bottom portion (bottom) 53, a second bottom portion 54, and a wall portion 58. The first bottom portion 53 is formed by the bottom portion 45 of the second cell holder 34. The first bottom portion 53 abuts against the first end portion 32a of the cell 32, which will be described later. The second bottom portion 54 is formed by the bottom portion 51 of the first cell holder 33. The second bottom portion 54 abuts against the second end portion 32b of the cell 32, which will be described later.

[0028] The wall portion 58 is formed, for example, as a hollow regular hexagonal prism. The wall portion 58 has, for example, a plurality of intersecting intersections 59. The wall portion 58 extends vertically from the first bottom portion 53 and the second bottom portion 54. The wall portion 58 is formed to surround the cell 32 (described later). The wall portion 58 has a plurality of first bulges (bulges) 62 and a plurality of second bulges 63.

[0029] Figure 8 is a bottom view showing an enlarged view of cell VIII in the second cell holder of Figure 7. As shown in Figures 4 and 8, the multiple first bulges 62 are formed in an annular shape, continuous with the first bottom 53 of the housing 37. The multiple first bulges 62 are provided at, for example, the intersections 59 of the multiple intersections 59, with one space between them in the circumferential direction of the wall 58. Specifically, for example, three first bulges 62 are provided at the intersections 59 with one space between them in the circumferential direction of the wall 58. The multiple first bulges 62 are formed to bulge inward from the housing 37 and abut against the side walls of the cell 32 (described later). In this embodiment, an example is described in which three first bulges 62 are provided at the intersection 59 of the wall portion 58 as multiple first bulges 62, but the number of first bulges 62 can be arbitrarily selected.

[0030] As shown in Figures 4 and 6, the second cell holder 34 has a plurality of recesses 64 that are recessed into the inside of the housing portion 37 from the bottom portion 45 side. A first bulge 62 is provided corresponding to the recesses 64. That is, the first bulge 62 is formed to consist of a surface that is exposed to the inside of the housing portion 37 corresponding to the recesses 64. Furthermore, the thickness of the first bulge 62 is formed to be thinner than the portions of the first bottom portion 53 and the wall portion 58 of the housing portion 37 other than the first bulge 62.

[0031] Furthermore, the first bulge 62 has a vertical portion 65 and an inclined portion 66. The vertical portion 65 extends from the first bottom portion 53 of the housing portion 37 in a substantially vertical direction (i.e., substantially axial direction of the housing portion 37). The vertical portion 65 is formed in a cylindrical (ring) shape. Note that the substantially vertical direction also includes the vertical direction. The inclined portion 66 is connected from the vertical portion 65 to the portion of the wall portion 58 other than the first bulge 62 and has a surface inclined with respect to the vertical portion 65. In other words, the inclined portion 66 is formed in an annular (ring) shape that gradually decreases in diameter from the wall portion 58 toward the vertical portion 65.

[0032] As shown in Figure 4, the multiple second bulges 63 are formed in an annular shape, continuous with the second bottom 54 of the housing 37. The second bulges 63, like the first bulges 62, have a vertical portion 67 and an inclined portion 68. The multiple second bulges 63 are formed approximately symmetrically in the vertical direction with respect to the multiple first bulges 62. Therefore, a detailed explanation of the second bulges 63 is omitted.

[0033] Thus, the wall portion 58 of the housing portion 37 has a plurality of first bulges 62 continuous with the first bottom portion 53 and a plurality of second bulges 63 continuous with the second bottom portion 54. Therefore, when the cell 32 (described later) is housed in the housing portion 37, the side walls of the cell 32 are held by the plurality of first bulges 62 and the plurality of second bulges 63. As a result, the portion of the wall portion 58 of the housing portion 37 other than the plurality of first bulges 62 and the plurality of second bulges 63 is kept separated from the side walls of the cell 32.

[0034] Furthermore, the storage section 37 is divided into an upper half and a lower half in the vertical direction by the division of the first cell holder 33 and the second cell holder 34. The upper half of the storage section 37 is provided in the second cell holder 34. The lower half of the storage section 37 is provided in the first cell holder 33.

[0035] The upper half of the storage section 37 has a first bulge 62 that is continuous with the bottom 45 of the second cell holder 34. The upper half of the storage section 37 also has an opening 49 on the opposite side of the first bulge 62. The lower half of the storage section 37 has a second bulge 63 that is continuous with the bottom 51 of the first cell holder 33. The lower half of the storage section 37 also has an opening 52 on the opposite side of the second bulge 63. Therefore, when the first cell holder 33 and the second cell holder 34 are assembled, the opening 49 in the upper half of the housing section 37 and the opening 52 in the lower half of the housing section 37 abut against each other. This forms the housing section 37.

[0036] In the above embodiment, an example is described in which the first bottom 53 of the housing section 37 abuts against the first end 32a of the cell 32 and the second bottom 54 of the housing section 37 abuts against the second end 32b of the cell 32, but the embodiment is not limited to this. As another example, for instance, only the first bottom 53 of the housing section 37 may abut against the first end 32a (i.e., one end) of the cell 32. Alternatively, the second end 32b of the cell 32 may be used as one end, and only the second bottom 54 of the housing section 37 may abut against the second end 32b.

[0037] As shown in Figures 3 and 4, the cell 32 is arranged (housed) inside the housing 37 in a vertical direction along the axial direction of the housing 37. The cell 32 is formed in a cylindrical shape. The cell 32 comprises a first end (one end) 32a and a second end 32b, and a positive terminal 32P and a negative terminal 32N. The first end 32a and the second end 32b are provided at both ends in the vertical direction. Specifically, the first end 32a is provided at the upper end of the cell 32. The second end 32b is provided at the lower end of the cell 32. Therefore, the multiple cells 32 are arranged along a predetermined plane with the orientation of the first end 32a and the second end 32b aligned. The positive terminal 32P and the negative terminal 32N are located (provided) on the side of the first end 32a.

[0038] In other words, a positive terminal 32P and a negative terminal 32N are formed on the upper side of cell 32. Therefore, when multiple cells 32 are arranged in a planar direction, the positive terminal 32P and the negative terminal 32N are provided on the upper side of multiple cells 32. The positive terminal 32P protrudes above the negative terminal 32N and is located above the negative terminal 32N in a direction perpendicular to it. The positive terminal 32P is exposed to the outside of the second cell holder 34 through the positive terminal hole 46 (see Figure 6). The negative terminal 32N is exposed to the outside of the second cell holder 34 through the negative terminal hole 47 (see Figure 6).

[0039] As shown in Figures 1 and 2, the second battery module 26 is stacked on top of the first battery module 25. The first battery module 25 and the second battery module 26 are formed to be generally symmetrical, for example, in the vertical direction. The second battery module 26 comprises, for example, a second cell holder unit (cell holder) 42 and a plurality of cells 32. The second cell holder unit 42 comprises a third cell holder 43 and a fourth cell holder 44. The third cell holder 43 and the fourth cell holder 44 of the second cell holder unit 42 are stacked sequentially downwards from the top case 21.

[0040] As shown in Figures 2 and 7, the second cell holder unit 42, like the first battery module 25, has a plurality of housing sections (not shown). Cells 32 are held in the housing sections of the second cell holder unit 42 by being housed there, similar to the housing section 37 of the first cell holder unit 31. That is, the second cell holder unit 42 is held in place by a plurality of cells 32 being housed there, similar to the first battery module 25. The plurality of cells 32 housed in the second cell holder unit 42 are arranged along a predetermined plane with the orientation of their first end 32a and second end 32b aligned. The plurality of cells 32 housed in the second cell holder unit 42 have their first end 32a facing downwards. In this embodiment, a first battery module 25 and a second battery module 26 are used as an example to describe the battery module unit 14, but the number of battery modules can be arbitrarily selected.

[0041] <Bus bar unit> As shown in Figures 2 and 5, the busbar unit 16 is provided in the first battery module 25 and the second battery module 26 (see Figure 2). The busbar unit 16 comprises a plurality of first busbars 55, a plurality of second busbars 56, and a plurality of third busbars 57. In this embodiment, as a plurality of second bus bars 56, for example, two second bus bars 56 will be described. The number of second bus bars 56 can be arbitrarily selected to match the number of first battery modules 25 and second battery modules 26. Furthermore, as a plurality of third bus bars 57, for example, two third bus bars 57 will be described. The number of third bus bars 57 can be arbitrarily selected to match the number of control units 18 (described later).

[0042] Multiple first busbars 55 are provided in the first battery module 25 and the second battery module 26. The first busbars 55 of the first battery module 25 electrically connect the multiple cells 32 provided in the first battery module 25. Hereinafter, "electrically connect" may be referred to as "connect". Multiple first busbars 55 connect the electrodes of one cell 32 to the electrodes of other cells 32 adjacent to that cell 32 in the first battery module 25.

[0043] The electrodes of one cell 32 are one of the electrodes of the positive terminal 32P and the negative terminal 32N in that cell 32. The electrodes of other cells 32 are the other electrode of the positive terminal 32P and the negative terminal 32N in that cell 32. In other words, the first busbar 55 electrically connects adjacent cells 32. Furthermore, the multiple first busbars 55 in the second battery module 26 electrically connect adjacent cells 32 to each other, similar to the first battery module 25.

[0044] The two second busbars 56 electrically connect, for example, the cell 32 of the first battery module 25 and the cell 32 of the second battery module 26. Here, the positive terminal 32P and negative terminal 32N of the cell 32 in the first battery module 25 and the positive terminal 32P and negative terminal 32N of the cell 32 in the second battery module 26 are positioned opposite each other in the vertical direction, for example.

[0045] In this state, one of the two second busbars 56 is connected, for example, to the positive terminal 32P of the cell 32 in the first battery module 25. The other second busbar 56 is connected, for example, to the negative terminal 32N of the cell 32 in the second battery module 26. Furthermore, the other second busbar 56 is connected, for example, to the negative terminal 32N of the cell 32 in the first battery module 25. The other second busbar 56 is connected to the positive terminal 32P of the cell 32 in the second battery module 26. Therefore, the cells 32 of the first battery module 25 and the cells 32 of the second battery module 26 are electrically connected to each other by two second busbars 56.

[0046] The two third busbars 57 electrically connect the first battery module 25 and the second battery module 26 to the control unit 18 (described later). The two third busbars 57 consist of a positive busbar 57A and a negative busbar 57B. Here, the control unit 18 is located below the first battery module 25.

[0047] In this state, the positive busbar 57A connects the positive terminal 32P of cell 32 in the first battery module 25 to the positive terminal (not shown) of the control unit 18. The negative busbar 57B connects the negative terminal 32N of cell 32 in the second battery module 26 to the negative terminal (not shown) of the control unit 18.

[0048] Here, the cell 32 of the first battery module 25 and the cell 32 of the second battery module 26 are electrically connected by two second busbars 56. Therefore, the cell 32 of the first battery module 25 and the cell 32 of the second battery module 26 are electrically connected to the control unit 18 by a positive busbar 57A and a negative busbar 57B.

[0049] <Control Unit> The control unit 18 is located on the underside of the first battery module 25. The control unit 18 is, for example, a so-called BMU (Battery Management Unit). The control unit 18 monitors and controls the state of the cells 32 of the first battery module 25 and the cells 32 of the second battery module 26. The control unit 18 is a software function unit that operates when a predetermined program is executed by a processor, for example, a CPU (Central Processing Unit).

[0050] The software function unit is an ECU (Electronic Control Unit) equipped with a processor such as a CPU, a ROM (Read Only Memory) for storing programs, a RAM (Random Access Memory) for temporarily storing data, and electronic circuits such as timers. At least a part of the control unit 18 may be an integrated circuit such as an LSI (Large Scale Integration).

[0051] The control unit 18 includes, for example, various sensors for detecting the state of cells 32 of the first battery module 25 and cells 32 of the second battery module 26, and a storage unit for storing information about the battery 10 and predetermined programs, etc. The state of cell 32 of the first battery module 25 and cell 32 of the second battery module 26 is, for example, voltage, current, and temperature. Information regarding the battery 10 includes, for example, identification information such as a battery ID (IDentifier) ​​exclusively assigned to the battery 10, manufacturing date and time, initial capacity, information regarding the state of cell 32 based on sensor output, charging and discharging history, storage time in the replacement unit and usage history.

[0052] The battery 10 according to the embodiment described above provides the following functions and effects. The first battery module 25 and the second battery module 26 are formed to be generally symmetrical in the vertical direction. Therefore, the first battery module 25 will be described below, and the description of the second battery module 26 will be omitted.

[0053] As shown in Figure 4, in the first cell holder unit 31, the lower half of a plurality of housing sections 37 is provided in the first cell holder 33, and the upper half of a plurality of housing sections 37 is provided in the second cell holder 34. In the upper half of the plurality of housing sections 37, a first bulge 62 is provided in the wall section 58, continuous with the first bottom 53 of the housing section 37. In addition, an opening 49 is provided in the upper half of the plurality of housing sections 37 on the opposite side of the first bulge 62. Therefore, for example, when molding the second cell holder 34, the mold can be closed and opened vertically along the axial direction of the housing section 37, using the first bulge 62 as a reference. This makes it easy to mold the first bulge 62 in the wall section 58 in the upper half of the housing section 37.

[0054] Furthermore, in the lower half of the multiple storage sections 37, a second bulge 63 is provided in the wall section 58, continuous with the second bottom section 54. Also, in the lower half of the multiple storage sections 37, an opening 52 is provided on the opposite side of the second bulge 63. Therefore, for example, when molding the first cell holder 33, the mold can be closed and opened vertically using the second bulge 63 as a reference. This makes it easy to mold the second bulge 63 in the wall section 58 in the lower half of the storage section 37.

[0055] Here, with the first cell holder 33 and the second cell holder 34 assembled, the opening 49 in the upper half of the housing section 37 and the opening 52 in the lower half of the housing section 37 abut against each other. This forms the housing section 37. Therefore, the first cell holder unit 31 can be easily molded.

[0056] Furthermore, a recess 64 is provided at the bottom 45 of the second cell holder 34, and the first bulge 62 is exposed to the inside of the housing 37 in accordance with the recess 64. This allows the thickness of the first bulge 62 to be reduced. In addition, the thickness of the second bulge 63 in the second cell holder 34 can be reduced in the same way as the first bulge 62. As a result, when inserting the cell 32 into the housing 37 toward the first bulge 62 and the second bulge 63, the first bulge 62 and the second bulge 63 can be deformed to match the shape of the cell 32. Therefore, the cell 32 can be held with appropriate pressure.

[0057] Furthermore, in the housing section 37, the thickness of the first bulge 62 and the second bulge 63 is made thinner than the first bottom 53, the second bottom 54, and the wall 58. Therefore, when inserting the cell 32 towards the first bulge 62 and the second bulge 63 inside the housing section 37, the first bulge 62 and the second bulge 63 are made easier to deform. This allows the cell 32 to be held at a more appropriate pressure.

[0058] Furthermore, when the cell 32 is housed in the housing section 37, the side walls of the cell 32 are held by the first bulge section 62 and the second bulge section 63. Therefore, the portion of the wall 58 of the housing section 37 other than the first bulge section 62 and the second bulge section 63 can be kept separated from the side walls of the cell 32. Thus, an air layer can be secured between the portion of the wall 58 of the housing section 37 other than the first bulge section 62 and the second bulge section 63 and the side walls of the cell 32. This allows the portion of the side wall of the cell 32 that does not come into contact with the first bulge 62 and the second bulge 63 to be adjacent to the adjacent housing 37 with an air layer in between. Therefore, the heat generated in the cell 32 can be suppressed from being transmitted to the adjacent housing 37.

[0059] Furthermore, the first bulge 62 has an inclined portion 66, with the inclined portion 66 being a surface inclined with respect to the vertical portion 65. Also, the second bulge 63 has an inclined portion 68, with the inclined portion 68 being a surface inclined with respect to the vertical portion 67. Therefore, when housing the cell 32 inside the housing portion 37, the cell 32 can be moved to the inside of the vertical portion 65 of the first bulge 62 and the vertical portion 67 of the second bulge 63 while abutting (contacting) the inclined portion 66 of the first bulge 62 and the inclined portion 68 of the second bulge 63. This allows the cell 32 to be easily inserted into the housing portion 37 while suppressing strong interference between the cell 32 and the first bulge 62 and the second bulge 63.

[0060] It should be noted that the technical scope of the present invention is not limited to the embodiments described above, and various modifications can be made without departing from the spirit of the invention.

[0061] Furthermore, without departing from the spirit of the present invention, the components in the above embodiments may be replaced with well-known components as appropriate, and the above-described modifications may be combined as appropriate. [Explanation of Symbols]

[0062] 10…Battery 31…First cell holder unit (cell holder) 32...cell 32a...First end (one end) 37...Detention Unit 42...Second cell holder unit (cell holder) 53...1st bottom (bottom) 54...Second bottom 58...Wall part 59... Intersection 62...First bulge (bulge) 63...Second bulge 64…recess 65,67…Vertical part 66,68…slope part

Claims

1. Cell (32) and, A battery (10) comprising a cell holder (31, 42) having a plurality of housing sections (37) for housing the aforementioned cell (32), The housing portion (37) has a bottom portion (53) that abuts against one end (32a) of the cell (32), The cell (32) has a wall portion (58) surrounding it, The wall portion (58) has a bulge portion (62) that is continuous with the bottom portion (53) and bulges inward into the housing portion (37) and abuts against the side wall of the cell (32). A battery (10) characterized by the following features.

2. The cell holders (31, 42) have recesses (64) that are recessed into the inside of the housing portion (37) from the bottom portion (53) side. The bulging portion (62) consists of a surface that is exposed to the inside of the housing portion (37) in correspondence with the recess (64). The battery (10) according to feature 1.

3. The thickness of the bulging portion (62) is thinner than the portion of the bottom portion (53) and the wall portion (58) other than the bulging portion (62). The battery (10) according to claim 2, characterized in that

4. The cell (32) is cylindrical in shape. In a view perpendicular to the bottom portion (53), the wall portion (58) has a polygonal shape. The bulging portion (62) is formed at the intersection (59) where the wall portions (58) intersect. The portion of the wall portion (58) other than the bulging portion (62) and the side wall of the cell (32) are separated. The battery (10) according to feature 1.

5. The bulging portion (62) has vertical portions (65, 67) extending substantially vertically from the bottom portion (53), The vertical portion (65, 67) is connected to the portion of the wall portion (58) other than the bulging portion (62), and the inclined portion (66, 68) has a surface that is inclined with respect to the vertical portion (65, 67), The battery (10) according to feature 1.

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