Battery module, battery pack, and power tool

Abstract

To provide a battery module which can be miniaturized while securing sealing performance.SOLUTION: The battery module A1 includes a plurality of battery cells 10. Each of the plurality of battery cells 10 includes a flat plate-shaped battery part 20 and an exterior body 30. The exterior body 30 includes a battery sealing portion 33, a first sealing portion 31, and a second sealing portion 32. The battery sealing portion 33 seals the battery portion 20. The first sealing portion 31 is a sealing portion which includes a first end portion of both ends of the exterior body 30 along a direction D2 orthogonal to the thickness direction D1 of the battery portion 20 and seals the battery portion 20 with a battery sealing portion 33. The second sealing portion 32 is a sealing portion for sealing the battery portion 20 with the battery sealing portion 33, including the second end portion of the both ends in the exterior body 30. The first sealing portion 31 and the second sealing portion 32 are bent in opposite directions to each other with respect to the battery portion 20 sealed by the battery sealing portion 33 in the thickness direction D1 of the battery portion 20.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure generally relates to a battery module, a battery pack, and a power tool, and more particularly to a battery module including a plurality of battery cells, a battery pack including a battery module, and a power tool including a battery pack. [Background technology]

[0002] An example of a battery pack is described in Patent Document 1. The battery pack described in Patent Document 1 includes multiple film-covered batteries (battery modules) and a metal case. The multiple film-covered batteries are stacked and housed inside the metal case.

[0003] Each of the film-covered batteries includes a battery element, a housing made of two laminate films, a positive electrode tab, and a negative electrode tab. The housing surrounds the battery element by sandwiching it from both sides in the thickness direction. The positive electrode tab and the negative electrode tab each protrude from the housing.

[0004] The exterior packaging material has a pair of rolled-up portions, which are formed by bending portions of the exterior packaging material in the same direction at locations where the positive electrode tab and the negative electrode tab do not protrude. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-110117 Summary of the Invention [Problem to be solved by the invention]

[0006] It is desirable that the film-covered batteries in the battery pack described in Patent Document 1 be made smaller while still maintaining sealing performance.

[0007] An object of the present disclosure is to provide a battery module, a battery pack, and a power tool that can be miniaturized while ensuring sealing performance. [Means for solving the problem]

[0008] A battery module according to one aspect of the present disclosure includes a plurality of battery cells. Each of the plurality of battery cells has a flat battery section and an exterior body. The exterior body seals the battery section. The exterior body has a battery sealing section, a first sealing section, and a second sealing section. The battery sealing section seals the battery section. The first sealing section includes a first end of both ends of the exterior body along a direction perpendicular to the thickness direction of the battery section, and is a sealing section for sealing the battery section with the battery sealing section. The second sealing section includes a second end of both ends of the exterior body along the direction perpendicular to the thickness direction of the battery section, and is a sealing section for sealing the battery section with the battery sealing section. The first sealing section and the second sealing section are bent in opposite directions to each other in the thickness direction of the battery section with respect to the battery section sealed with the battery sealing section.

[0009] A battery pack according to an aspect of the present disclosure includes the battery module and a case that houses the battery module.

[0010] An electric power tool according to one aspect of the present disclosure includes the battery pack, a drive unit, and a tool body. The drive unit drives the tool. The tool body houses the drive unit. The battery pack is configured to be detachable from the tool body. The battery pack supplies power to the drive unit when attached to the tool body. [Effects of the Invention]

[0011] According to one aspect of the present disclosure, it is possible to achieve miniaturization while ensuring sealing performance. [Brief explanation of the drawings]

[0012] [Figure 1]FIG. 1 is a perspective view of a battery module according to a first embodiment, in which a plurality of battery cells are stacked. [Figure 2] FIG. 2 is a side view of the battery module shown in FIG. 1, in which a plurality of battery cells are stacked. [Figure 3] FIG. 3 is a cross-sectional view of one battery cell in the battery module. [Figure 4] FIG. 4 is a plan view of the battery module in the state before the first sealing portion and the second sealing portion of one battery cell are folded. [Figure 5] FIG. 5 is a side view of a battery module of a comparative example, in which a plurality of battery cells are stacked. [Figure 6] FIG. 6 is a perspective view of one battery cell in a battery module of a comparative example. [Figure 7] FIG. 7 is a side view of a power tool including the battery pack according to the first embodiment. [Figure 8] FIG. 8 is a side view of a battery module according to the second embodiment, in which a plurality of battery cells are stacked. [Figure 9] FIG. 9 is a side view of one battery cell in the battery module. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, a battery module, a battery pack, and a power tool according to embodiments 1 and 2 will be described with reference to the drawings. The figures described in the following embodiments are schematic diagrams, and the ratios of the sizes and thicknesses of the components do not necessarily reflect the actual dimensional ratios. Furthermore, the configurations described in the following embodiments are merely examples of the present disclosure. The present disclosure is not limited to the following embodiments, and various modifications are possible depending on the design, etc., as long as the effects of the present disclosure can be achieved.

[0014] In the following description, unless otherwise specified, the first direction D1, second direction D2, and third direction D3 indicated by arrows in the drawings are defined as the up-down direction, left-right direction, and front-rear direction of the battery module A1, battery pack B1, and power tool C1. However, the up-down direction, left-right direction, and front-rear direction are used for convenience to facilitate understanding of the description of each embodiment, and do not define the directions when using the battery module A1, battery pack B1, and power tool C1. Furthermore, the arrows indicating "D1," "D2," and "D3" in the drawings are merely shown for the purpose of explanation and do not have any physical substance.

[0015] (Embodiment 1) A battery module A1, a battery pack B1, and a power tool C1 according to the first embodiment will be described below with reference to FIGS. 1 to 4 and 7. FIG.

[0016] (1) Battery module 1 and 2, the battery module A1 includes a plurality of (four in the example of FIGS. 1 and 2) battery cells 10. The plurality of battery cells 10 includes a first battery cell 10A, a second battery cell 10B, a third battery cell 10C, and a fourth battery cell 10D.

[0017] The first battery cell 10A is, for example, a laminate pack type battery cell (for example, an all-solid-state battery cell). The first battery cell 10A has a pair of terminals 21 and 22, a battery module 20, and an exterior body 30. The pair of terminals 21 and 22 includes a first terminal 21 and a second terminal 22.

[0018] The battery unit 20 has a flat plate shape. For example, the battery unit 20 is a sheet-shaped battery (for example, an all-solid-state battery). In other words, the battery unit 20 is a thin battery. The battery unit 20 has a first electrode 23, a second electrode 24, and an electrolyte layer 25, as shown in FIG. 3, for example.

[0019] The first electrode 23 is, for example, a positive electrode. The first electrode 23 is, for example, rectangular. The material of the first electrode 23 is, for example, a metal (for example, copper). The first terminal 21 (see FIG. 1) is connected to the first electrode 23. In other words, the first terminal 21 is a positive electrode terminal.

[0020] The second electrode 24 is, for example, a negative electrode. The second electrode 24 is, for example, rectangular. The area of ​​the second electrode 24 is, for example, the same as the area of ​​the first electrode 23. The thickness of the second electrode 24 is, for example, the same as the thickness of the first electrode 23. The material of the second electrode 24 is, for example, a metal (such as copper). The second terminal 22 (see FIG. 1) is connected to the second electrode 24. That is, the second terminal 22 is a negative electrode terminal.

[0021] Note that "the area of ​​the second electrode 24 is the same as the area of ​​the first electrode 23" is not limited to cases where the area of ​​the second electrode 24 and the area of ​​the first electrode 23 are exactly the same, but also includes, for example, a case where the difference between the area of ​​the second electrode 24 and the area of ​​the first electrode 23 (the absolute value of the difference) is a difference on the order of a manufacturing error between the first electrode 23 and the second electrode 24. Furthermore, "the thickness of the second electrode 24 is the same as the thickness of the first electrode 23" is not limited to cases where the thickness of the second electrode 24 and the thickness of the first electrode 23 are exactly the same, but also includes, for example, a case where the difference between the thickness of the second electrode 24 and the thickness of the first electrode 23 (the absolute value of the difference) is a difference on the order of a manufacturing error between the first electrode 23 and the second electrode 24.

[0022] The electrolyte layer 25 is, for example, a solid electrolyte, and is disposed between the first electrode 23 and the second electrode 24. The electrolyte layer 25 is in contact with the first electrode 23 and the second electrode 24. The electrolyte layer 25 is, for example, rectangular. The area of ​​the electrolyte layer 25 is, for example, the same as the area of ​​the first electrode 23. The thickness of the electrolyte layer 25 is, for example, greater than the thickness of the first electrode 23. Note that the phrase "the area of ​​the electrolyte layer 25 is the same as the area of ​​the first electrode 23" does not necessarily mean that the areas of the electrolyte layer 25 and the first electrode 23 are exactly the same, but also includes, for example, a case where the difference between the areas of the electrolyte layer 25 and the first electrode 23 (the absolute value of the difference) is on the order of a difference due to manufacturing errors of the electrolyte layer 25 and the first electrode 23.

[0023] The exterior body 30 seals the battery module 20. The exterior body 30 is made of, for example, two laminate films. The exterior body 30 has, for example, a rectangular shape. The area of ​​the exterior body 30 is larger than the area of ​​the first electrode 23, for example.

[0024] Each of the two laminate films has a structure including, for example, at least a first resin layer, a metal layer, and a second resin layer.

[0025] The first resin layer has, for example, impact resistance and chemical resistance. The material of the first resin layer is, for example, polyethylene terephthalate. The metal layer is disposed between the first resin layer and the second resin layer. The material of the metal layer is, for example, aluminum. The second resin layer has, for example, thermal welding properties. The material of the first resin layer is, for example, polyethylene.

[0026] The exterior body 30 seals the battery section 20 by welding the overlapping portions of the two laminate films (in this embodiment, the first sealing portion 31 and the second sealing portion 32 described below) together while sandwiching the battery section 20 between them.

[0027] 4, the exterior body 30 seals a portion of the first terminal 21 and a portion of the second terminal 22. That is, the remaining portion of the first terminal 21 (hereinafter referred to as the "tip") protrudes from the exterior body 30. The remaining portion of the second terminal 22 (hereinafter referred to as the "tip") protrudes from the exterior body 30. Hereinafter, the direction in which the tip portions of the first terminal 21 and the second terminal 22 protrude from the exterior body 30 is defined as the forward direction of the battery module A1, the battery pack B1, and the power tool C1.

[0028] The exterior body 30 includes, for example, a battery sealing portion 33, a first sealing portion 31, and a second sealing portion 32.

[0029] The battery sealing portion 33 seals the battery portion 20 (see FIG. 3). That is, the battery sealing portion 33 is a portion that hermetically seals the battery portion 20. The battery sealing portion 33 has, for example, a rectangular shape. Furthermore, the battery sealing portion 33 seals, for example, the portion of the first terminal portion 21 and the portion of the second terminal portion 22.

[0030] The first sealing portion 31 is a portion (sealing portion) for sealing the battery portion 20 with the battery sealing portion 33. In other words, the first sealing portion 31 is a portion to which the battery sealing portion 33 is welded in order to seal the battery portion 20. The first sealing portion 31 includes a first end (right end) of both ends of the exterior body 30 along a direction (second direction D2) perpendicular to the thickness direction (first direction D1) of the battery portion 20. In other words, the first sealing portion 31 includes the right end of the exterior body 30 in the left-right direction (second direction D2). The first sealing portion 31 is, for example, rectangular. More specifically, the first sealing portion 31 is a rectangular (oblong) shape that is elongated in the front-rear direction (third direction D3) of the first battery cell 10A.

[0031] The second sealing portion 32 is a portion for sealing the battery portion 20 with the battery sealing portion 33. In other words, the second sealing portion 32 is a portion to which the battery sealing portion 33 is welded in order to seal the battery portion 20. The second sealing portion 32 includes a second end (left end) of the two ends of the exterior body 30 along a direction perpendicular to the thickness direction of the battery portion 20. In other words, the second sealing portion 32 includes the left end in the left-right direction of the exterior body 30. The second sealing portion 32 is, for example, rectangular. More specifically, the second sealing portion 32 is a rectangular shape that is elongated in the front-rear direction of the first battery cell 10A.

[0032] 4, the first battery cell 10A has a battery sealing portion 33 that seals the battery portion 20, as well as a first sealing portion 31 and a second sealing portion 32 for sealing the battery portion 20 with the battery sealing portion 33, and therefore can improve sealing performance compared to when only the battery sealing portion 33 is included. In other words, the first battery cell 10A can ensure sealing performance.

[0033] 3, the first sealing portion 31 and the second sealing portion 32 are bent in opposite directions relative to the battery portion 20 sealed by the battery sealing portion 33. In other words, the first sealing portion 31 and the second sealing portion 32 are bent so as to be positioned on opposite sides relative to the battery portion 20 sealed by the battery sealing portion 33.

[0034] The first sealing portion 31 is bent, for example, upward in the thickness direction of the battery portion 20 with respect to the battery portion 20 sealed by the battery sealing portion 33. Furthermore, as shown in FIG. 2, for example, when the first battery cell 10A is stacked on another battery cell 10 (for example, the second battery cell 10B) in the thickness direction of the battery portion 20, the first sealing portion 31 is bent so that the first battery cell 10A can be easily stacked on the other battery cell 10. Specifically, as shown in FIG. 3, the first sealing portion 31 is bent so that the inclination angle θ1 with respect to a line L1 along a direction (second direction D2) perpendicular to the thickness direction of the battery portion 20 is an angle in the range of 85° or more and less than 90°. For example, the inclination angle θ1 of the first sealing portion 31 is 85°.

[0035] The second sealing portion 32 is bent downward in the thickness direction of the battery portion 20, for example, with respect to the battery portion 20 sealed by the battery sealing portion 33. Furthermore, the second sealing portion 32 is bent so that, for example, when the first battery cell 10A is stacked on another battery cell 10 in the thickness direction of the battery portion 20, the first battery cell 10A can be easily stacked on the other battery cells 10. Specifically, the second sealing portion 32 is bent so that the inclination angle θ2 with respect to a line L2 along a direction perpendicular to the thickness direction of the battery portion 20 is equal to or greater than 85° and less than 90°. For example, the inclination angle θ2 of the second sealing portion 32 is 85°. The line L2 is different from the line L1, but may also be the same line as the line L1.

[0036] Here, "bent in opposite directions" does not only mean that the first sealing portion 31 and the second sealing portion 32 are bent in opposite directions so that their inclination angles θ1 and θ2 are exactly the same, but also means that the first sealing portion 31 and the second sealing portion 32 are bent in opposite directions so that the difference (absolute value of the difference) between their inclination angles θ1 and θ2 is a predetermined angle (for example, 5°) or less.

[0037] Each of the second battery cell 10B, the third battery cell 10C, and the fourth battery cell 10D is, for example, a laminate pack type battery cell (for example, an all-solid-state battery cell) similar to the first battery cell 10A. Each of the second battery cell 10B, the third battery cell 10C, and the fourth battery cell 10D has the same configuration as the first battery cell 10A, and therefore detailed description thereof will be omitted.

[0038] The multiple battery cells 10 are connected in at least one of series and parallel connection depending on the output voltage or storage capacity. The multiple battery cells 10 are electrically connected in series and parallel in the thickness direction of the battery module 20, as shown in Fig. 1, for example. More specifically, a parallel circuit (first parallel circuit) of the first battery cell 10A and the second battery cell 10B and a parallel circuit (second parallel circuit) of the third battery cell 10C and the fourth battery cell 10D are connected in series.

[0039] The first battery cell 10A and the second battery cell 10B are connected, for example, by soldering, welding, or another connection method at the respective tips of the first terminal portion 21 of the first battery cell 10A and the second battery cell 10B, and the respective tips of the second terminal portion 22 of the first battery cell 10A and the second battery cell 10B are connected by the above-mentioned connection method. The third battery cell 10C and the fourth battery cell 10D are connected, for example, by the respective tips of the first terminal portion 21 of the third battery cell 10C and the fourth battery cell 10D, and the respective tips of the second terminal portion 22 of the third battery cell 10C and the fourth battery cell 10D are connected by the above-mentioned connection method.

[0040] The first parallel circuit and the second parallel circuit are formed, for example, by connecting the tip of the first terminal portion 21 of the second battery cell 10B and the tip of the second terminal portion 22 of the third battery cell 10C using the above-mentioned connection method, or by connecting the tip of the second terminal portion 22 of the second battery cell 10B and the tip of the first terminal portion 21 of the third battery cell 10C using the above-mentioned connection method.

[0041] A battery module 100 of the comparative example will now be described with reference to Fig. 5. The battery module 100 of the comparative example includes a plurality of (four in the example of Fig. 5) battery cells 90. The plurality of battery cells 90 includes a first battery cell 90A, a second battery cell 90B, a third battery cell 90C, and a fourth battery cell 90D.

[0042] As shown in FIG. 6 , the first battery cell 90A of the comparative example has a first terminal 85, a second terminal 86, a battery 84, and an exterior body 80. The first terminal 85 is a positive terminal. The second terminal 86 is a negative terminal. The tip of the first terminal 85 protrudes from the exterior body 80. The tip of the second terminal 86 protrudes from the exterior body 80.

[0043] The exterior body 80 seals the battery 84. The exterior body 80 is made of two laminate films, and includes a battery sealing portion 83, a first sealing portion 81, and a second sealing portion 82. The battery sealing portion 83 seals the battery 84.

[0044] The first sealing portion 81 is a portion for sealing the battery 84 with the battery sealing portion 83. The second sealing portion 82 is a portion for sealing the battery 84 with the battery sealing portion 83.

[0045] As shown in FIG. 6, the first sealing portion 81 and the second sealing portion 82 are bent in the same direction relative to the battery 84 sealed by the battery sealing portion 83 in the first direction D1 of the battery 84.

[0046] The second battery cell 90B, the third battery cell 90C, and the fourth battery cell 90D of the comparative example each have the same configuration as the first battery cell 90A of the comparative example, and therefore detailed description thereof will be omitted.

[0047] In the battery module 100 of the comparative example, when multiple battery cells 90 are stacked so that they are electrically connected in series and parallel in the first direction D1 of the battery 84 of the first battery cell 90A (see FIG. 6), as shown in FIG. 5, the tip 81a of the first sealing portion 81 of the second battery cell 90B may interfere with the tip 82a of the second sealing portion 82 of the third battery cell 90C, or the tip 82a of the second sealing portion 82 of the second battery cell 90B may interfere with the tip 81a of the first sealing portion 81 of the third battery cell 90C.

[0048] 2, in the battery module A1 of this embodiment, the first sealing portion 31 and the second sealing portion 32 are bent in opposite directions relative to the battery portion 20 (see FIG. 3) sealed by the battery sealing portion 33 in the thickness direction of the battery portion 20 (see FIG. 3). As a result, in the battery module A1 of this embodiment, when the battery cells 10 are stacked so that the battery cells 10 are electrically connected in series and parallel in the thickness direction of the battery portion 20 of the first battery cell 10A, for example, the leading end 31a of the first sealing portion 31 of the second battery cell 10B does not interfere with the leading end 32a of the second sealing portion 32 of the third battery cell 10C, and the leading end 32a of the second sealing portion 32 of the second battery cell 10B does not interfere with the leading end 31a of the first sealing portion 31 of the third battery cell 10C.

[0049] Therefore, in the battery module A1 of this embodiment, it is easier to stack multiple battery cells 10 compared to the battery module 100 of the comparative example. Therefore, in the battery module A1 of this embodiment, it is possible to achieve a smaller size while ensuring sealing performance compared to the battery module 100 of the comparative example.

[0050] In addition, in the battery module A1, the multiple battery cells 10 are electrically connected in series and parallel in the thickness direction of the battery section 20, so that the output voltage or storage capacity can be made larger than, for example, when the multiple battery cells are electrically connected in parallel in the thickness direction of the battery section. In addition, in the battery module A1, the multiple battery cells 10 are electrically connected in series and parallel in the thickness direction of the battery section 20, so that power can be supplied for a longer period of time than, for example, when the multiple battery cells are electrically connected in series in the thickness direction of the battery section.

[0051] Furthermore, in the battery module A1, the battery section 20 is a sheet-shaped battery, which allows the battery module A1 to be made smaller while still ensuring sealing performance.

[0052] The first sealing portion 31 of the first battery cell 10A may be bent so that the leading end 31a of the first sealing portion 31 of the first battery cell 10A contacts the battery sealing portion 33 of the first battery cell 10A. The first sealing portion 31 of the second battery cell 10B may be bent so that the leading end 31a of the first sealing portion 31 of the second battery cell 10B contacts the first sealing portion 31 of the first battery cell 10A. The first sealing portion 31 of the fourth battery cell 10D may be bent so that the leading end 31a of the first sealing portion 31 of the fourth battery cell 10D contacts the battery sealing portion 33 of the fourth battery cell 10D. The first sealing portion 31 of the third battery cell 10C may be bent so that the leading end 31a of the first sealing portion 31 of the third battery cell 10C contacts the first sealing portion 31 of the fourth battery cell 10D. This allows the battery module A1 of this embodiment to be further miniaturized while maintaining sealing performance.

[0053] (2) Battery pack The battery pack B1 includes a battery module A1 and a case 40, as shown in FIG.

[0054] The case 40 houses the battery module A1. The case 40 is, for example, box-shaped (e.g., rectangular box-shaped). The case 40 is made of, for example, an electrically insulating material (e.g., synthetic resin). The case 40 is configured to be detachable from the tool main body 50, which will be described later. In other words, the battery pack B1 is configured to be detachable from the tool main body 50.

[0055] The battery pack B1 may include a cushioning material (e.g., cushioning rubber) that absorbs external shocks or vibrations. For example, the cushioning material is disposed between the inner peripheral wall of the case 40 and the battery module A1. This allows the battery pack B1 to improve the shock resistance and vibration resistance of the battery module A1.

[0056] The battery pack B1 includes the battery module A1 and the case 40, and therefore can be made smaller while maintaining sealing performance compared to the battery pack including the battery module 100 of the comparative example.

[0057] (3) Power tools The power tool C1 is a handheld power tool, such as an electric screwdriver, and includes a battery pack B1, a drive unit 62, a tool body 50, a tool 60, and a control device 65, as shown in FIG.

[0058] The drive unit 62 drives the tool 60. The drive unit 62 includes, for example, an electric motor. The drive unit 62 drives the tool 60 using power supplied from the battery pack B1. The tool 60 is, for example, a driver bit for screw tightening.

[0059] The tool body 50 houses the drive unit 62. The tool body 50 includes, for example, a cylindrical portion 51, an attachment portion 61, a transmission portion 63, a grip portion 52, a trigger switch 64, and a battery mounting portion 53.

[0060] The tubular portion 51 is, for example, tubular (e.g., cylindrical) in shape. The tubular portion 51 is made of, for example, an electrically insulating material. The central axis of the tubular portion 51 is, for example, parallel to the front-rear direction (third direction D3) of the power tool C1.

[0061] An attachment part 61 is provided at one end (front end) in the front-rear direction of the tubular part 51. The attachment part 61 is configured to allow the tool 60 to be attached and detached. The attachment part 61 is attached to the tubular part 51 in a state where it can rotate around the central axis of the tubular part 51.

[0062] A drive unit 62 and a transmission unit 63 are housed inside the cylindrical portion 51. The transmission unit 63 is connected to the rotation shaft of the drive unit 62 (i.e., the rotation shaft of the electric motor). The transmission unit 63 transmits the driving force of the drive unit 62 to the attachment unit 61. In other words, the transmission unit 63 transmits the rotation by the drive unit 62 to the attachment unit 61, thereby rotating the attachment unit 61. The transmission unit 63 may include, for example, a reduction mechanism, a clutch mechanism, an impact mechanism, etc.

[0063] The grip portion 52 is, for example, cylindrical (e.g., cylindrical). The material of the grip portion 52 is, for example, an electrically insulating material. The central axis of the grip portion 52 is, for example, parallel to the up-down direction (first direction D1) of the power tool C1.

[0064] An upper end portion of the grip portion 52 in the vertical direction is connected to a part of the outer peripheral wall of the tubular portion 51. A lower end portion of the grip portion 52 in the vertical direction is connected to the battery mounting portion 53. When the user uses the power tool C1, the user holds the grip portion 52 in his / her hand.

[0065] The trigger switch 64 is an operation unit for controlling the rotation (for example, the rotation speed) of the drive unit 62. The trigger switch 64 is provided on a part of the outer circumferential wall of the grip unit 52. The trigger switch 64 is also located in a position that can be operated by the user's finger while the user is holding the grip unit 52 in his / her hand.

[0066] The battery mounting section 53 holds the battery pack B1. The battery mounting section 53 is connected to the lower end of the grip section 52. The battery mounting section 53 has, for example, a flat rectangular parallelepiped shape. The material of the battery mounting section 53 is, for example, an electrically insulating material.

[0067] The upper end of the battery mounting section 53 in the vertical direction (first direction D1) is connected to the lower end of the grip section 52. The lower end of the battery mounting section 53 in the vertical direction holds the battery pack B1. In other words, the battery pack B1 is attached to the lower end of the battery mounting section 53. More specifically, the lower end of the battery mounting section 53 is provided with a recess into which a part of the battery pack B1 is inserted or removed. In the power tool C1 of this embodiment, when the battery pack B1 is mounted in the battery mounting section 53, the battery module A1 and the drive section 62 are electrically connected.

[0068] A control device 65 is also provided inside the battery attachment section 53. The control device 65 controls the drive unit 62. For example, the control device 65 activates the drive unit 62 when the user operates the trigger switch 64. More specifically, the control device 65 supplies power to the drive unit 62 for operating the drive unit 62 when the user operates the trigger switch 64. In other words, when the user operates the trigger switch 64 while the battery pack B1 is attached to the tool body 50, the battery pack B1 supplies power to the drive unit 62 via the control device 65. In other words, the battery pack B1 supplies power to the drive unit 62 while attached to the tool body 50.

[0069] Furthermore, the control device 65 controls the rotation speed of the drive unit 62, that is, the rotation speed of the tool 60 attached to the attachment unit 61, according to the amount of operation of the trigger switch 64, for example.

[0070] The power tool C1 includes the battery pack B1, the drive unit 62, and the tool body 50, and therefore can be made compact while ensuring sealing performance.

[0071] (4) Variations The plurality of battery cells 10 are electrically connected in series and parallel in the thickness direction of the battery section 20, but may also be electrically connected in series in the thickness direction of the battery section 20. This allows the battery module A1 to have a higher output voltage or storage capacity than when the plurality of battery cells 10 are electrically connected in series and parallel in the thickness direction of the battery section 20.

[0072] Furthermore, the plurality of battery cells 10 are electrically connected in series and parallel in the thickness direction of the battery section 20, but may also be electrically connected in parallel in the thickness direction of the battery section 20. This allows the battery module A1 to supply power for a longer period of time than when the plurality of battery cells 10 are electrically connected in series and parallel in the thickness direction of the battery section 20.

[0073] Each of the two laminate films may include a ceramic layer containing a ceramic material (eg, alumina (aluminum oxide)) instead of including a metal layer.

[0074] The power tool C1 is not limited to an electric screwdriver, but may be, for example, an electric drill, an electric wrench, an electric grinder, or the like.

[0075] The tool 60 is not limited to a driver bit, but may be, for example, a drill bit for drilling a hole, or a socket for tightening a nut.

[0076] (Embodiment 2) 8, the battery module A2 according to the second embodiment differs from the battery module A1 according to the first embodiment (FIGS. 1 to 4) in that the first sealing portion 31 has a folded portion 34 and the second sealing portion 32 has a folded portion 35. Note that, with respect to the battery module A2 according to the second embodiment, the same components as those of the battery module A1 according to the first embodiment are denoted by the same reference numerals and description thereof will be omitted.

[0077] The battery module A2 according to the second embodiment will be described below with reference to FIG.

[0078] The battery module A2 includes, for example, a plurality (four in the example of FIG. 8) of battery cells 10. The plurality of battery cells 10 includes a first battery cell 10A, a second battery cell 10B, a third battery cell 10C, and a fourth battery cell 10D.

[0079] The first sealing portion 31 of the first battery cell 10A has a folded portion (first folded portion) 34. As shown in FIG. 9, the first folded portion 34 is formed by folding the central portion of the first sealing portion 31 back in a U-shape in side view. In other words, the first folded portion 34 is folded back so as to have rounded corners. More specifically, the first folded portion 34 is configured so that the peak portion folded on the outside (outer periphery side) and the valley portion folded on the inside (inner periphery side) have rounded corners.

[0080] The first folded portion 34 is folded back at an angle within a predetermined range (hereinafter referred to as the "folding angle"). The folding angle of the first folded portion 34 is, for example, an angle within a range of 110° or more and less than 170°. In other words, the first folded portion 34 is folded back so that the tip end 31a of the first sealing portion 31 changes direction at an angle within the above-mentioned predetermined range.

[0081] The first folded portion 34 is folded back so that the tip portion 31a of the first sealing portion 31 is away from the battery portion 20. In other words, the first folded portion 34 is folded back so that the tip portion 31a of the first sealing portion 31 is folded back toward the opposite side of the battery sealing portion 33 (toward the outside of the battery sealing portion 33).

[0082] The second sealing portion 32 of the first battery cell 10A has a folded portion (second folded portion) 35. As shown in FIG. 9, the second folded portion 35 is formed by folding the center portion of the second sealing portion 32 back in a U-shape in side view. In other words, the second folded portion 35 is folded back so as to have rounded corners. More specifically, the second folded portion 35 is configured so that the peak portion folded back on the outside (outer periphery side) and the valley portion folded back on the inside (inner periphery side) have rounded corners.

[0083] The second folded portion 35 is folded back at an angle within the above-mentioned predetermined range. The folding angle of the second folded portion 35 is, for example, an angle within a range of 110° or more and less than 170°. In other words, the second folded portion 35 is folded back so that the tip portion 32a of the second sealing portion 32 changes direction at an angle within the above-mentioned predetermined range.

[0084] The second folded portion 35 is folded back so that the tip portion 32a of the second sealing portion 32 is away from the battery portion 20. In other words, the second folded portion 35 is folded back so that the tip portion 32a of the second sealing portion 32 is folded back toward the opposite side of the battery sealing portion 33 (toward the outside of the battery sealing portion 33).

[0085] As shown in FIG. 8, each of the second battery cell 10B, the third battery cell 10C, and the fourth battery cell 10D has a first sealing portion 31 with a first folded portion 34 and a second sealing portion 32 with a second folded portion 35, similar to the first battery cell 10A.

[0086] In the battery module A2 of embodiment 2, similar to the battery module A1 of embodiment 1, the first sealing portion 31 and the second sealing portion 32 are bent in opposite directions relative to the battery assembly 20 sealed by the battery sealing portion 33. As a result, in the battery module A2 of embodiment 2, similar to the battery module A1 of embodiment 1, when the plurality of battery cells 10 are stacked so that the plurality of battery cells 10 are electrically connected in series and parallel in the thickness direction of the battery assembly 20, for example, the leading end 31 a of the first sealing portion 31 of the second battery cell 10B does not interfere with the leading end 32 a of the second sealing portion 32 of the third battery cell 10C, and the leading end 32 a of the second sealing portion 32 of the second battery cell 10B does not interfere with the leading end 31 a of the first sealing portion 31 of the third battery cell 10C.

[0087] Therefore, the battery module A2 of the second embodiment also makes it easier to stack multiple battery cells 10 compared to the battery module 100 of the comparative example. Therefore, the battery module A2 of the second embodiment also makes it possible to achieve a smaller size while maintaining sealing performance compared to the battery module 100 of the comparative example.

[0088] Furthermore, in the battery module A2 of the second embodiment, each of the first sealing portions 31 is provided with a first folded portion 34, and each of the second sealing portions 32 is provided with a second folded portion 35. Therefore, the first sealing portions 31 and the second sealing portions 32 have elasticity due to the restoring force of each of the first folded portions 34 and the restoring force of each of the second folded portions 35. This makes it possible for the battery module A2 to absorb, for example, external impacts (e.g., impacts applied in the left-right direction (second direction D2) of the battery module A2) or vibrations (e.g., vibrations of the tool body 50 caused by rotation of the drive unit 62, etc.). Therefore, the battery module A2 of the second embodiment can have improved impact resistance and vibration resistance compared to the battery module A1 of the first embodiment.

[0089] In the first folded portion 34, the tip portion 31a of the first sealing portion 31 is folded back toward the outside of the battery sealing portion 33, but the tip portion 31a of the first sealing portion 31 may be folded back toward the inside of the battery sealing portion 33. In other words, the first folded portion 34 may be folded back so that the tip portion 31a of the first sealing portion 31 approaches the battery portion 20. In addition, in the first folded portion 34, the central portion of the first sealing portion 31 is folded back in a U-shape in side view, but for example, the central portion of the first sealing portion 31 may be folded back in a V-shape in side view.

[0090] In the second folded portion 35, the tip portion 32a of the second sealing portion 32 is folded back toward the outside of the battery sealing portion 33, but the tip portion 32a of the second sealing portion 32 may be folded back toward the inside of the battery sealing portion 33. In other words, the second folded portion 35 may be folded back so that the tip portion 32a of the second sealing portion 32 approaches the battery portion 20. In addition, in the second folded portion 35, the central portion of the second sealing portion 32 is folded back in a U-shape in side view, but for example, the central portion of the second sealing portion 32 may be folded back in a V-shape in side view.

[0091] The above-described first and second embodiments and modifications are merely a part of the various embodiments and modifications of the present disclosure.

[0092] The present disclosure is not limited to the above-described embodiments, and at least some of the configurations of the embodiments and modified examples can be combined as appropriate and applied.

[0093] (Aspect) The present specification discloses the following aspects.

[0094] A battery module (A1; A2) according to a first aspect includes a plurality of battery cells (10). Each of the plurality of battery cells (10) has a flat battery section (20) and an exterior body (30). The exterior body (30) seals the battery section (20). The exterior body (30) has a battery sealing section (33), a first sealing section (31), and a second sealing section (32). The battery sealing section (33) seals the battery section (20). The first sealing section (31) includes a first end of both ends of the exterior body (30) along a direction (D2) perpendicular to a thickness direction (D1) of the battery section (20), and is a sealing section for sealing the battery section (20) with the battery sealing section (33). The second sealing portion (32) includes a second end portion of the both ends of the exterior body (30) along a direction (D2) perpendicular to the thickness direction (D1) of the battery portion (20), and is a sealing portion for sealing the battery portion (20) with the battery sealing portion (33). The first sealing portion (31) and the second sealing portion (32) are bent in opposite directions to each other in the thickness direction (D1) of the battery portion (20) with respect to the battery portion (20) sealed with the battery sealing portion (33).

[0095] According to this aspect, it is possible to achieve miniaturization while ensuring sealing performance.

[0096] In the battery module (A1; A2) according to the second aspect, the plurality of battery cells (10) in the first aspect are electrically connected in series in the thickness direction (D1) of the battery section (20).

[0097] According to this embodiment, the output voltage or the storage capacity can be made larger than when the plurality of battery cells (10) are electrically connected in series and parallel in the thickness direction (D1) of the battery section (20).

[0098] In the battery module (A1; A2) according to the third aspect, the plurality of battery cells (10) in the first aspect are electrically connected in parallel in the thickness direction (D1) of the battery section (20).

[0099] According to this embodiment, power can be supplied for a longer period of time than when the plurality of battery cells (10) are electrically connected in series and parallel in the thickness direction (D1) of the battery section (20).

[0100] In the battery module (A1; A2) according to the fourth aspect, the plurality of battery cells (10) in the first aspect are electrically connected in series and parallel in the thickness direction (D1) of the battery section (20).

[0101] This embodiment can increase the output voltage or storage capacity compared to when the battery cells 10 are electrically connected in parallel in the thickness direction D1 of the battery unit 20. This embodiment can also supply power for a longer period of time compared to when the battery cells 10 are electrically connected in series in the thickness direction D1 of the battery unit 20.

[0102] A battery module (A2) according to a fifth aspect is the same as any one of the first to fourth aspects, in that the first sealing portion (31) and the second sealing portion (32) have folded portions (34, 35).

[0103] According to this aspect, it is possible to improve the shock resistance and vibration resistance.

[0104] A battery pack (B1) according to a sixth aspect includes the battery module (A1; A2) according to any one of the first to fifth aspects and a case (40). The case (40) houses the battery module (A1; A2).

[0105] According to this aspect, it is possible to achieve miniaturization while ensuring sealing performance.

[0106] A power tool (C1) according to a seventh aspect includes the battery pack (B1) according to the sixth aspect, a drive unit (62), and a tool body (50). The drive unit (62) drives the tool (60). The tool body (50) houses the drive unit (62). The battery pack (B1) is configured to be detachable from the tool body (50). When attached to the tool body (50), the battery pack (B1) supplies power to the drive unit (62).

[0107] According to this aspect, it is possible to achieve miniaturization while ensuring sealing performance. [Explanation of symbols]

[0108] 10 battery cells 20 Battery section 30 Exterior body 31 First sealing portion 32 Second sealing portion 33 Battery sealing part 34 First fold (fold) 35 Second fold (fold) 40 cases 50 Tool body 60 Tools 62 Drive unit A1 Battery Module A2 Battery Module B1 Battery Pack C1 power tools D1 First direction (thickness direction) D2 Second direction (perpendicular direction)

Claims

1. A plurality of battery cells are provided. Each of the plurality of battery cells a flat battery portion; an exterior body that seals the battery portion, The exterior body is a battery sealing portion that seals the battery portion; a first sealing portion including a first end portion of both ends of the exterior body along a direction perpendicular to a thickness direction of the battery portion, the first sealing portion being for sealing the battery portion with the battery sealing portion; a second sealing portion that includes a second end portion of both ends of the exterior body along the direction perpendicular to the thickness direction of the battery portion, and that seals the battery portion with the battery sealing portion; the first sealing portion and the second sealing portion are folded in opposite directions with respect to the battery portion sealed by the battery sealing portion in the thickness direction of the battery portion; Battery module.

2. The plurality of battery cells are electrically connected in series in the thickness direction of the battery section. The battery module according to claim 1 .

3. The plurality of battery cells are electrically connected in parallel in the thickness direction of the battery section. The battery module according to claim 1 .

4. the plurality of battery cells are electrically connected in series and parallel in the thickness direction of the battery section; The battery module according to claim 1 .

5. The first sealing portion and the second sealing portion have a folded portion. The battery module according to claim 1 .

6. The battery module according to any one of claims 1 to 5; a case for housing the battery module; Battery pack.

7. The battery pack according to claim 6; a drive unit that drives the tool; a tool body that houses the drive unit, The battery pack The tool body is configured to be detachable from the tool body, supplying power to the drive unit in a state where the drive unit is attached to the tool body; Power tools.

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