Battery pack and electric power tool

Abstract

To provide a battery pack and an electric power tool, capable of suppressing an increase in temperature.SOLUTION: A battery case 11 houses an all-solid battery cell 20, a first terminal mounting member 30, a second terminal mounting member 40, and a plurality of connection members 50. A terminal T1 is provided on one end part of the all-solid battery cell 20. In the first terminal mounting member 30, a first electric circuit 31 to which the cell terminal T1 is electrically connected is provided. In the second terminal mounting member 40, a second electric circuit 41 to which a battery terminal T2 is electrically connected is provided. The plurality of connection members 50 are connected between the first terminal mounting member 30 and the second terminal mounting member 40, and electrically connects the first electric circuit 31 and the second electric circuit 41. In a second direction crossing a first direction where a current flows between the all-solid battery cell 20 and the plurality of connection members 50, a width W2 of each of the plurality of connection members 50 is larger than a width W1 of the cell terminal T1.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a battery pack and a power tool. More specifically, the present disclosure relates to a battery pack attachable to an electric device and a power tool including the battery pack.

Background Art

[0002] Patent Document 1 discloses a battery pack in which a plurality of battery cells are housed in a housing. The plurality of battery cells are connected in series via a lead plate. The plurality of battery cells are connected in series between a first battery terminal and a second battery terminal.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the battery pack described in Patent Document 1, when the current value of the current flowing through the lead plate increases, the amount of heat generated in the lead plate increases, and the temperature of the battery pack may rise.

[0005] An object of the present disclosure is to provide a battery pack and a power tool capable of suppressing temperature rise.

Means for Solving the Problems

[0006] A battery pack according to one aspect of the present disclosure includes a sheet-shaped all-solid-state battery cell, cell terminals, a battery case, and battery terminals. The cell terminals are provided at one end of the all-solid-state battery cell. The cell terminals include a first cell terminal on the positive electrode side and a second cell terminal on the negative electrode side. The battery case houses the all-solid-state battery cell. The battery terminals include a first battery terminal on the positive electrode side and a second battery terminal on the negative electrode side. At least a part of the first battery terminal and at least a part of the second battery terminal are exposed on the surface of the battery case. The battery case further houses a first terminal mounting member, a second terminal mounting member, and a plurality of connection members. A first electric circuit to which the cell terminals are electrically connected is provided in the first terminal mounting member. A second electric circuit to which the battery terminals are electrically connected is provided in the second terminal mounting member. The plurality of connection members are connected between the first terminal mounting member and the second terminal mounting member to electrically connect between the first electric circuit and the second electric circuit. In a second direction intersecting a first direction in which current flows between the all-solid-state battery cell and the plurality of connection members, the width of each of the plurality of connection members is larger than the width of the cell terminals.

[0007] An electric tool according to one aspect of the present disclosure includes the battery pack, a drive unit that drives the tool, and a tool body that houses the drive unit. The battery pack can be mounted on the tool body. With the battery pack mounted on the tool body, the drive unit can operate using the battery pack as a power source.

Advantages of the Invention

[0008] According to the present disclosure, an increase in the temperature of the battery pack can be suppressed.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

[0010] Hereinafter, the battery pack according to the embodiment and the power tool including the same will be described in detail with reference to the drawings. However, each drawing described in the following embodiment is a schematic diagram, and the dimensional ratios such as the size of each component do not necessarily reflect the actual dimensional ratios. In addition, the configuration described in the following embodiment is merely an example of the present disclosure. The present disclosure is not limited to the following embodiment, and various modifications can be made according to the design and the like as long as the effects of the present disclosure can be achieved.

[0011] (Embodiment) (1) Outline Hereinafter, the battery pack 10 and the power tool 1 according to the present embodiment will be described with reference to FIGS. 1 to 4.

[0012] As shown in FIGS. 1 to 3, the battery pack 10 includes a sheet-like all-solid-state battery cell 20, a cell terminal T1, a battery case 11, and a battery terminal T2.

[0013] The cell terminal T1 includes a first cell terminal T11 on the positive electrode side and a second cell terminal T12 on the negative electrode side. The first cell terminal T11 and the second cell terminal T12 are provided at one end of the all-solid-state battery cell 20.

[0014] The battery case 11 houses the all-solid-state battery cell 20.

[0015] The battery terminal T2 includes a first battery terminal T21 on the positive electrode side and a second battery terminal T22 on the negative electrode side.

[0016] At least a part of the first battery terminal T21 and at least a part of the second battery terminal T22 are exposed on the surface of the battery case 11.

[0017] The battery case further houses a first terminal mounting member 30, a second terminal mounting member 40, and a plurality of connection members 50.

[0018] The first terminal mounting member 30 is provided with a first electric circuit 31 to which the cell terminal T1 is electrically connected.

[0019] The second terminal mounting member 40 is provided with a second electric circuit 41 to which the battery terminal T2 is electrically connected.

[0020] The plurality of connection members 50 are connected between the first terminal mounting member 30 and the second terminal mounting member 40 to electrically connect between the first electric circuit 31 and the second electric circuit 41.

[0021] In a second direction (for example, a direction parallel to the X-axis direction in FIG. 2) intersecting a first direction (for example, a direction parallel to the Y-axis direction in FIG. 2) in which current flows between the all-solid-state battery cell 20 and the plurality of connection members 50, the width W2 of each of the plurality of connection members 50 is larger than the width W1 of the cell terminal T1.

[0022] Here, the first electrical circuit 31 only needs to have at least the function of electrically connecting between the cell terminal T1 including the first cell terminal T11 and the second cell terminal T12 and the plurality of connection members 50. When an overcurrent flows, the first electrical circuit 31 may have functions such as a protection circuit that switches the connection between the cell terminal T1 and the plurality of connection members 50 from a conductive state to a non-conductive state. Further, the second electrical circuit 41 may be a circuit having the function of electrically connecting between the battery terminal T2 including the first battery terminal T21 and the second battery terminal T22 and the plurality of connection members 50, or may have the function of a charge control circuit that controls the charging current flowing through the all-solid-state battery cell 20. Further, the second electrical circuit 41 may have functions such as a temperature compensation circuit that adjusts the charging current according to the temperature of the all-solid-state battery cell 20, and a protection circuit that switches the connection between the cell terminal T1 and the plurality of connection members 50 from a conductive state to a non-conductive state when an overcurrent flows. Also, in the present disclosure, the state where two directions are "parallel" is not limited to the state where the two directions are completely parallel, and may include a state where the angle formed by the two directions is about several degrees (for example, 10 degrees or less). Further, the state where two directions "intersect" is, for example, a state where the two directions are orthogonal, but is not limited to the state where the two directions are completely orthogonal, and it is sufficient that the angle formed by the two directions is, for example, 80 degrees or more and 100 degrees or less.

[0023] In the battery pack 10 of the present embodiment, in the second direction (for example, a direction parallel to the X-axis direction), the width W2 of each of the plurality of connection members 50 is larger than the width W1 of the cell terminal T1. Therefore, in the second direction, the electrical resistance of the plurality of connection members 50 can be reduced as compared with the case where the width W2 of each of the plurality of connection members 50 is less than or equal to the width W1 of the cell terminal T1. Thus, the temperature rise in the plurality of connection members 50 can be suppressed, and the temperature rise of the battery pack 10 can be suppressed. Also, since the electrical resistance of the plurality of connection members 50 can be reduced, the voltage drop in the plurality of connection members 50 can be reduced.

[0024] In addition, the power tool 1 of the present embodiment includes a battery pack 10, a drive unit 62 that drives the tool 60, and a tool body 2 that houses the drive unit 62. The battery pack 10 can be attached to the tool body 2. With the battery pack 10 attached to the tool body 2, the drive unit 62 can operate using the battery pack 10 as a power source.

[0025] Since the power tool 1 includes the battery pack 10, it is possible to realize a power tool 1 equipped with a battery pack 10 capable of suppressing temperature rise.

[0026] (2) Details Hereinafter, the battery pack 10 and the power tool 1 according to the present embodiment will be described in detail with reference to the drawings. In the following description, the X-axis direction in FIGS. 1, 2, and 4 is defined as the left-right direction, the Y-axis direction as the front-rear direction (depth direction), and the Z-axis direction as the up-down direction. Further, the positive direction of the X-axis is defined as the right side, the positive direction of the Y-axis as the front side, and the positive direction of the Z-axis as the upper side. However, these directions are merely examples and are not intended to limit the directions during the use of the battery pack 10 and the power tool 1. Also, the arrows indicating the respective directions in the drawings are merely shown for the purpose of explanation and do not have an actual entity.

[0027] (2.1) Configuration The battery pack 10 of the present embodiment can be attached to the power tool 1. With the battery pack 10 attached to the power tool 1, the power tool 1 can operate using the battery pack 10 as a power source. Hereinafter, the power tool 1 and the battery pack 10 attached to the power tool 1 will be described respectively.

[0028] (2.1.1) Power Tool As shown in FIG. 4, the power tool 1 according to the present embodiment is a hand-held power tool, and examples thereof include an electric driver, an electric drill, an electric wrench, and an electric grinder.

[0029] The power tool 1 includes a tool body 2 to which the battery pack 10 is detachably attached.

[0030] The tool body 2 includes a cylindrical portion 3, a grip portion 4, and a battery mounting portion 5.

[0031] The cylindrical portion 3 is, for example, a molded product of synthetic resin having electrical insulation. The cylindrical portion 3 is formed in a cylindrical shape with the front-rear direction as the axial direction.

[0032] At the front end of the cylindrical portion 3, a tool mounting portion 61 for mounting a tool 60 such as a tip tool is provided. Inside the cylindrical portion 3, a drive portion 62 for driving the tool 60, a transmission portion 63 for transmitting the driving force of the drive portion 62 to the tool 60, etc. are accommodated.

[0033] The tool mounting portion 61 is provided on the cylindrical portion 3 in a rotatable state about a rotation axis along the front-rear direction. A plurality of types of tools 60 are prepared according to a plurality of types of operations using the power tool 1, and a desired type of tool 60 is mounted on the tool mounting portion 61 and used. Examples of this type of tool 60 include a driver bit for screwing work, a drill bit for drilling, a socket for tightening nuts, etc.

[0034] The drive portion 62 includes, for example, an electric motor driven by electric power supplied from the battery pack 10.

[0035] The transmission portion 63 transmits the driving force of the drive portion 62 to the tool mounting portion 61. The transmission portion 63 is connected to the output shaft of the drive portion 62, and rotates the tool mounting portion 61 by transmitting the rotation of the drive portion 62 to the tool mounting portion 61. Note that the transmission portion 63 may include a reduction mechanism, a clutch mechanism, an impact mechanism, etc.

[0036] The grip portion 4 extends downward from a part of the circumferential surface of the cylindrical portion 3. When the user uses the power tool 1, the user uses it while holding the middle portion in the vertical direction (longitudinal direction) of the grip portion 4 by hand. One end (for example, the upper end) of the grip portion 4 is connected to the cylindrical portion 3, and a battery mounting portion 5 is provided at the other end (for example, the lower end). For example, when the battery pack 10 mounted on the battery mounting portion 5 is placed on a placement surface such as a floor surface, the longitudinal direction of the grip portion 4 is along the vertical direction.

[0037] Also, a trigger switch 64 is provided on the front side of the upper end of the grip portion 4. The trigger switch 64 is an operation portion that receives an operation by the user for controlling the rotation of the drive portion 62. The trigger switch 64 is disposed at a position where it can be operated by the fingers of the hand while the grip portion 4 is held by hand.

[0038] The battery mounting portion 5 is integrally provided at the lower end of the grip portion 4. The battery mounting portion 5 is formed, for example, in a rectangular parallelepiped shape having a smaller dimension in the vertical direction than the dimensions in the front-rear direction and the left-right direction. The lower end of the grip portion 4 is connected to the upper surface of the battery mounting portion 5 so that the grip portion 4 protrudes upward from the upper surface of the battery mounting portion 5. A battery pack 10 is detachably attached to the lower portion of the battery mounting portion 5. A recess into which the upper portion of the battery pack 10 is inserted is provided on the lower surface of the battery mounting portion 5. When the battery pack 10 is mounted on the battery mounting portion 5, the battery terminal T2 of the battery pack 10 is electrically connected to the tool-side terminal provided on the battery mounting portion 5.

[0039] In addition, in the present embodiment, for example, inside the battery mounting portion 5, a control unit 65 having a circuit board on which a circuit for controlling the drive unit 62 and the like is mounted is accommodated. The control unit 65 can switch the on / off state of the drive unit 62 by an operation of pulling the trigger switch 64. Further, the control unit 65 controls the rotation speed of the drive unit 62, that is, the rotation speed of the tool 60 attached to the tool mounting portion 61, according to the operation amount of the operation of pulling in the trigger switch 64. When the battery pack 10 is mounted on the battery mounting portion 5 and the battery terminal T2 of the battery pack 10 is electrically connected to the tool-side terminal, the internal circuit (such as the control unit 65 and the drive unit 62) of the power tool 1 can be operated by the power supplied from the battery pack 10.

[0040] Note that with the battery pack 10 mounted on the battery mounting portion 5, the tool body 2 of the power tool 1 can stand on its own when the bottom surface of the battery pack 10 on the side opposite to the grip portion 4 is placed on a placement surface (such as a floor surface).

[0041] (2.1.2) Battery Pack As described above, the battery pack 10 includes the all-solid-state battery cell 20, the cell terminal T1, the battery case 11, the battery terminal T2, the first terminal mounting member 30, the second terminal mounting member 40, and a plurality of connection members 50.

[0042] The all-solid-state battery cell 20 includes a plurality of battery cells 21 each formed in a sheet shape. Each of the plurality of battery cells 21 is an all-solid-state battery. The all-solid-state battery is a battery having a solid electrolyte layer between a positive electrode and a negative electrode. Since the all-solid-state battery does not use an electrolytic solution, there is an advantage that liquid leakage does not occur. The shapes and sizes of the plurality of battery cells 21 in top view are substantially the same. The shape of the plurality of battery cells 21 in top view is, for example, rectangular. The plurality of battery cells 21 are arranged so as to overlap each other in the vertical direction with a predetermined gap therebetween. The plurality of battery cells 21 are arranged parallel to each other such that the thickness direction is parallel to the vertical direction. In this embodiment, the number of battery cells 21 is, for example, six. When describing each individual battery cell 21 in the following explanation, it may be described as battery cells 21A, 21B, 21C, 21D, 21E, and 21F.

[0043] The plurality of battery cells 21 are connected in series as shown in FIG. 3, for example. The plurality of battery cells 21 may be connected in series or in parallel according to the required voltage value or storage capacity. In FIG. 1, the number of the plurality of battery cells 21 is, for example, six, but the number of the plurality of battery cells 21 may be one or more than one, and the number of the plurality of battery cells 21 can be appropriately changed according to the required voltage value or storage capacity.

[0044] Each of the plurality of battery cells 21 has one cell terminal T1 at one end (for example, the front end). The pair of cell terminals T1 includes a first cell terminal T11 on the positive electrode side and a second cell terminal T12 on the negative electrode side. The first cell terminal T11 and the second cell terminal T12 are arranged at intervals in the left - right direction at the front end of the battery cell 21. The first cell terminal T11 and the second cell terminal T12 protrude forward from one end (for example, the front end) of the battery cell 21 respectively. The first cell terminal T11 and the second cell terminal T12 are formed of a metal material such as copper, nickel, aluminum, etc. The first cell terminal T11 and the second cell terminal T12 are, for example, metal foil - shaped conductive members formed in a rectangular shape in plan view, but may also be metal bars or the like formed in a rectangular shape in plan view. The widths W1 of the first cell terminal T11 and the second cell terminal T12 in the second direction (the direction parallel to the X - axis) are the same. In the present disclosure, the fact that two dimensions are the same is not limited to the case where the two dimensions are exactly the same, and the two dimensions may differ by a difference of the degree of manufacturing error.

[0045] The pair of battery terminals T2 (the first battery terminal T21 and the second battery terminal T22) are formed of a metal material such as copper or nickel, etc. Each of the pair of battery terminals T2 is, for example, a metal bar formed in a rectangular shape in plan view. The first end of each of the pair of battery terminals T2 (the first battery terminal T21 and the second battery terminal T22) is connected to the second terminal mounting member 40. Each of the pair of battery terminals T2 is held by the battery case 11 with at least a part of the second end exposed on the surface (for example, the front surface) of the battery case 11. The pair of battery terminals T2 are arranged at a predetermined interval in the second direction (left - right direction) such that, for example, the thickness direction is parallel to the Z - axis direction.

[0046] The pair of connection members 50 (the first connection member 51 and the second connection member 52) are formed of a metal material such as copper or nickel, for example. Each of the pair of battery terminals T2 is, for example, a metal bar having a rectangular shape in plan view. Each of the pair of battery terminals T2 is arranged at a predetermined interval in the second direction (left - right direction) such that the thickness direction is parallel to the Z - axis direction. The first ends (for example, the rear ends) of each of the first connection member 51 and the second connection member 52 are connected to the first terminal mounting member 30, and the second ends (for example, the front ends) of each of the first connection member 51 and the second connection member 52 are connected to the second terminal mounting member 40. The widths W2 of the first connection member 51 and the second connection member 52 in the second direction (the direction parallel to the X - axis direction) are the same. The widths W2 of the first connection member 51 and the second connection member 52 in the second direction are larger than the width W1 of the first cell terminal T11 and the second cell terminal T12 in the second direction.

[0047] The first terminal mounting member 30 is a circuit board 32 such as a printed wiring board, for example. The circuit board 32 which is the first terminal mounting member 30 is arranged such that the normal direction of the circuit board 32 is parallel to the first direction (front - rear direction in this embodiment). The first terminal mounting member 30 is provided with a plurality of terminal portions PD1 to which a plurality of first cell terminals T11 of a plurality of battery cells 21 are respectively joined by a method such as soldering or welding, for example. The first terminal mounting member 30 is provided with a plurality of terminal portions PD2 to which a plurality of second cell terminals T12 of a plurality of battery cells 21 are respectively joined by a method such as soldering or welding, for example. Further, the first terminal mounting member 30 is provided with a terminal portion PD3 to which the first connection member 51 is joined by a method such as soldering or welding, for example, and a terminal portion PD4 to which the second connection member 52 is joined by a method such as soldering or welding, for example. And the first terminal mounting member 30 is provided with a first electric circuit 31 that connects a plurality of battery cells 21 respectively connected to the plurality of terminal portions PD1 and PD2 in series via printed wiring formed on the circuit board 32 between the terminal portion PD3 and the terminal portion PD4. Note that the terminal portions PD1 - PD4 may be surface - mounting pads or through - holes.

[0048] The second terminal mounting member 40 is a circuit board 42 such as a printed wiring board. The circuit board 42 which is the second terminal mounting member 40 is arranged such that the normal direction of the circuit board 42 is parallel to the first direction (the front-rear direction in this embodiment). On the second terminal mounting member 40, there are provided a terminal portion PD5 to which a first connection member 51 is joined by a method such as soldering or welding, and a terminal portion PD6 to which a second connection member 52 is joined by a method such as soldering or welding. Further, on the second terminal mounting member 40, there are provided a terminal portion PD7 to which a first battery terminal T21 is joined by a method such as soldering or welding, and a terminal portion PD8 to which a second battery terminal T22 is joined by a method such as soldering or welding. Also, on the second terminal mounting member 40, a second electric circuit 41 is provided between the terminal portions PD7, PD8 and the terminal portions PD5, PD6. The second electric circuit 41 may include, for example, a charging circuit that controls a charging current supplied from a charger via the battery terminal T2 in a state where the battery pack 10 removed from the power tool 1 is connected to the charger. Further, the second electric circuit 41 may include a charging protection circuit that limits an overcurrent flowing during charging of the battery pack 10, or a discharge protection circuit that limits an overcurrent flowing during discharge of the all-solid-state battery cell 20 in a state where the battery pack 10 is connected to the power tool 1.

[0049] The battery case 11 is a molded product of a synthetic resin having electrical insulation and is formed in a box shape. On the upper surface of the battery case 11, a holding structure is provided for holding the battery case 11 in the battery mounting portion 5 by sliding the battery case 11, for example, backward with respect to the battery mounting portion 5. At the front end portion of the battery mounting portion 5, a pair of tool-side terminals that can be electrically connected to a pair of battery terminals T2 exposed on the front surface of the battery case 11 in a state where the battery case 11 is mounted on the battery mounting portion 5 are provided. By connecting the pair of tool-side terminals to the pair of battery terminals T2 of the battery case 11 respectively, power is supplied from the battery pack 10 to the internal circuits (such as the control unit 65 and the drive unit 62) of the power tool 1. Note that the battery mounting portion 5 may be provided with a terminal cover (not shown) that covers the pair of tool-side terminals in a state where the pair of tool-side terminals are connected to the pair of battery terminals T2 of the battery pack 10.

[0050] (2.2) Advantages In the present embodiment, in a second direction (a direction parallel to the X-axis direction) intersecting a first direction (a direction parallel to the Y-axis direction) in which current flows between the all-solid-state battery cell 20 and the plurality of connection members 50, the width W2 of each of the plurality of connection members 50 is made larger than the width W1 of the cell terminal T1. As a result, in the second direction, the cross-sectional area of the plurality of connection members 50 becomes larger than that in the case where the width W2 of each of the plurality of connection members 50 is equal to or less than the width W1 of the cell terminal T1, and the electrical resistance of the plurality of connection members 50 can be reduced. Therefore, in the present embodiment, the temperature rise of the plurality of connection members 50 can be suppressed, and the battery pack 10 capable of suppressing the temperature rise can be realized. Further, by reducing the electrical resistance of the plurality of connection members 50, the voltage drop in the plurality of connection members 50 can be suppressed.

[0051] Also, in the present embodiment, the thickness dimension of each of the plurality of connection members 50 in the Z direction and the thickness dimension of each of the plurality of cell terminals T1 in the Z direction are substantially the same dimension. Therefore, in the present embodiment, in a cross section (for example, the Z-X plane) having the first direction (a direction parallel to the Y-axis direction) as a normal line, the cross-sectional area of each of the plurality of connection members 50 is larger than the cross-sectional area of the cell terminal T1. As a result, in the cross section having the first direction as a normal line, the electrical resistance of the plurality of connection members 50 can be reduced as compared with the case where the cross-sectional area of each of the plurality of connection members 50 is equal to or less than the cross-sectional area of the cell terminal T1. Therefore, the temperature rise in the plurality of connection members 50 can be suppressed, and the battery pack 10 capable of suppressing the temperature rise can be realized. Further, by reducing the electrical resistance of the plurality of connection members 50, the voltage drop in the plurality of connection members 50 can also be reduced.

[0052] In this embodiment, since the temperature rise of the battery pack 10 can be suppressed, the charging current of the all-solid-state battery cell 20 can be increased. For example, the maximum value of the charging rate of the all-solid-state battery cell 20 can be set to 10C or more. Note that the charging current when charging the theoretical capacity of the all-solid-state battery cell 20 in one hour is 1C. In this embodiment, even when the maximum value of the charging rate is set to 10C or more, the temperature of the battery pack 10 can be suppressed to be equal to or lower than the upper limit value of the operating temperature range. By setting the maximum value of the charging rate of the all-solid-state battery cell 20 to 10C or more, the all-solid-state battery cell 20 can be charged in a short time. By shortening the time required for charging the all-solid-state battery cell 20, the time during which work can be performed using the power tool 1 can be extended.

[0053] Also, in this embodiment, the all-solid-state battery cell 20 includes a plurality of battery cells 21 (21A to 21F) each formed in a sheet shape. The plurality of battery cells 21 are arranged in a stacked manner in the thickness direction. A cell terminal T1 is provided for each of the plurality of battery cells 21. The cell terminal T1 provided for each of the plurality of battery cells 21 is electrically connected to the first terminal mounting member 30.

[0054] Also, each of the plurality of battery cells 21 includes a plurality of cell terminals T1, and the cell terminals T1 provided for each of the plurality of battery cells 21 are electrically connected to the first terminal mounting member 30. Therefore, in the first electric circuit 31 of the first terminal mounting member 30, the cell terminals T1 provided for each of the plurality of battery cells 21 can be aggregated and connected to the plurality of connection members 50, and the work of connecting the cell terminals T1 of the all-solid-state battery cell 20 to the plurality of connection members 50 can be simplified.

[0055] In addition, in the present embodiment, in a plane along the first direction (for example, a direction parallel to the Y-axis direction) (for example, the Y-Z plane), the battery terminal T2, the second terminal mounting member 40, the plurality of connection members 50, the first terminal mounting member 30, the cell terminal T1, and the all-solid-state battery cell 20 are arranged in this order. Since the battery terminal T2, the second terminal mounting member 40, the plurality of connection members 50, the first terminal mounting member 30, the cell terminal T1, and the all-solid-state battery cell 20 are arranged along the first direction in which current flows, for example, compared with the case where the plurality of connection members 50 are bent in the middle, the length of the plurality of connection members 50 can be shortened. Therefore, the electrical resistance of the plurality of connection members 50 can be reduced, and the temperature rise of the battery pack 10 can be suppressed.

[0056] (3) Modification The above embodiment is merely one of various embodiments of the present disclosure. The above embodiment can be variously modified according to design and the like as long as the object of the present disclosure can be achieved. Hereinafter, the above embodiment may sometimes be referred to as a basic example.

[0057] Hereinafter, modification examples of the above embodiment will be listed. The modification examples described below can be applied in appropriate combination with the above basic example, and the above basic example and a plurality of the modification examples described below can also be applied in appropriate combination.

[0058] (3.1) Modification Example 1 The battery pack 10 of Modification Example 1 will be described with reference to FIGS. 5 to 7.

[0059] The battery pack 10 of Modification Example 1 is different from the above basic example in that at least a part of the second terminal mounting member 40 is arranged at a position overlapping the all-solid-state battery cell 20 in the thickness direction of the all-solid-state battery cell 20. Note that the same reference numerals are given to the components common to the above basic example, and the description thereof is omitted.

[0060] In Modification 1, a second terminal mounting member 40 having a pair of battery terminals T2 provided thereon is disposed above the all-solid-state battery cell 20. The second terminal mounting member 40 has a circuit board 42 on which the battery terminals T2 are mounted, and the circuit board 42 is disposed in parallel with the sheet-like all-solid-state battery cell 20. A pair of battery terminals T2 (a first battery terminal T21 and a second battery terminal T22) are mounted on the circuit board 42, and the pair of battery terminals T2 protrude upward from the upper surface of the second terminal mounting member 40. And at least a part of the pair of battery terminals T2 is exposed from the upper surface of the battery case 11. At the front end portion of the circuit board 42 which is the second terminal mounting member 40, a pair of terminal portions PD5, PD6 to which the second ends of the pair of connection members 50 are respectively connected are provided.

[0061] Also, the first terminal mounting member 30 is disposed in front of the all-solid-state battery cell 20. The circuit board 32 which is the first terminal mounting member 30 is disposed such that the normal direction of the circuit board 32 is parallel to the first direction. At the upper portion of the circuit board 32, a pair of terminal portions PD3, PD4 to which the first ends of the pair of connection members 50 are respectively connected are provided.

[0062] The shape of the pair of connection members 50 when viewed from the side and connected between the first terminal mounting member 30 and the second terminal mounting member 40 is L-shaped. The first ends of the pair of connection members 50 are connected to the pair of terminal portions PD3, PD4 provided at the upper portion of the circuit board 32 by a method such as soldering or welding. Also, the second ends of the pair of connection members 50 are connected to the pair of terminal portions PD5, PD6 provided at the front end portion of the circuit board 42 by a method such as soldering or welding.

[0063] In Modification 1, a part of the pair of battery terminals T2 (a first battery terminal T11 and a second battery terminal T12) is exposed from the upper surface of the battery case 11. On the lower surface of the battery mounting portion 5 of the tool body 2, a pair of tool-side connection terminals connected to the pair of battery terminals T2 are disposed. Therefore, in a state where the battery pack 10 is mounted on the battery mounting portion 5, the pair of battery terminals T2 and the pair of tool-side terminals are electrically connected, and the internal circuits (such as the control unit 65 and the drive unit 62) of the power tool 2 can be operated with the power from the battery pack 10.

[0064] In the battery pack 10 of Modification 1, at least a part of the second terminal mounting member 40 is disposed at a position overlapping the all-solid-state battery cell 20 in the thickness direction (Z-axis direction) of the all-solid-state battery cell 20. Therefore, the size of the battery pack 10 in the direction (Y-axis direction) in which current flows between the all-solid-state battery cell 20 and the first terminal mounting member 30 can be reduced.

[0065] Further, since the circuit board 42, which is the second terminal mounting member 40, is disposed in parallel with the sheet-shaped all-solid-state battery cell 20, the dimensions of the battery pack 10 in the thickness direction (Z-axis direction) of the all-solid-state battery cell 20 can be reduced as compared with the case where the circuit board 42 is disposed obliquely with respect to the sheet-shaped all-solid-state battery cell 20.

[0066] In FIGS. 5 and 6, the entire second terminal mounting member 40 is disposed at a position overlapping the all-solid-state battery cell 20 in the thickness direction of the all-solid-state battery cell 20. However, the arrangement of the second terminal mounting member 40 can be changed as appropriate. For example, in the thickness direction of the all-solid-state battery cell 20, a part of the second terminal mounting member 40 may be disposed at a position overlapping the all-solid-state battery cell 20.

[0067] Further, in FIGS. 5 and 6, the second terminal mounting member 40 is disposed between the central position P1 of the all-solid-state battery cell 20 in the first direction and the first terminal mounting member 30. By disposing the second terminal mounting member 40 at such a position, the lengths of the plurality of connection members 50 can be shortened as compared with the case where the second terminal mounting member 40 is disposed on the side opposite to the first terminal mounting member 30 with respect to the central position P1 of the all-solid-state battery cell 20. Therefore, the electrical resistance of the plurality of connection members 50 can be reduced, the temperature rise in the plurality of connection members 50 can be suppressed, and the temperature rise of the battery pack 10 can be suppressed.

[0068] (3.2) Other Modifications In the above basic example and Modification Example 1, the sum of the cross-sectional areas of the plurality of connection members 50 in a cross-section (for example, the Z-X plane) having the first direction (for example, a direction parallel to the Y-axis direction) as the normal line may be larger than the sum of the cross-sectional areas of the plurality of cell terminals T1 in a cross-section having the first direction as the normal line provided on the plurality of battery cells 21. That is, in a cross-section (for example, the Z-X plane) having the first direction (for example, a direction parallel to the Y-axis direction) as the normal line, the widths and thicknesses of the plurality of connection members 50 and the plurality of cell terminals T1 may be designed such that the sum of the cross-sectional areas of the plurality of connection members 50 is larger than the sum of the cross-sectional areas of the plurality of cell terminals T1. Thereby, the electrical resistance of the plurality of connection members 50 can be reduced, the temperature rise in the plurality of connection members 50 can be suppressed, and the voltage drop in the plurality of connection members 50 can also be suppressed.

[0069] In the above embodiment, the all-solid-state battery cell 20 includes six battery cells 21, but the number of battery cells 21 included in the all-solid-state battery cell 20 is not limited to six and can be appropriately changed. Further, although the plurality of battery cells 21 included in the all-solid-state battery cell 20 are connected in series, the plurality of battery cells 21 may be connected in parallel. Further, the all-solid-state battery cell 20 may include a plurality of cell blocks in which a plurality of battery cells 21 are connected in series, and the plurality of cell blocks may be connected in parallel. Further, although the shape of the battery cell 21 in plan view included in the all-solid-state battery cell 20 is rectangular, the shape of the battery cell 21 is not limited to rectangular and can be appropriately changed.

[0070] Also, in the above basic example and modification examples, the battery pack 10 can be attached to the tool body of the power tool 1, but the electrical device to which the battery pack 10 is attached is not limited to the power tool 1. The electrical device to which the battery pack 10 is attached may be an electrical device such as a rechargeable vacuum cleaner or lawn mower.

[0071] Also, in the above basic example and modification examples, the shape of the cell terminal T1 is a rectangular foil shape or plate shape, but the cell terminal T1 may be a round pin or an electric wire such as a stranded wire. When the cell terminal T1 is a round pin or an electric wire, the width W1 of the cell terminal T1 in the second direction intersecting the first direction in which the current flows is the diameter of the cell terminal T1.

[0072] In the above-described basic example and modified examples, the shape of the connection member 50 is a rectangular foil shape or a plate shape. However, the connection member 50 may be a round pin or an electric wire such as a stranded wire. When the connection member 50 is a round pin or an electric wire, the width W2 of the connection member 50 in the second direction intersecting the first direction in which the current flows is the diameter of the connection member 50.

[0073] (Summary) From the embodiments described above, the following aspects are disclosed.

[0074] The battery pack (10) of the first aspect includes a sheet-like all-solid-state battery cell (20), a cell terminal (T1), a battery case (11), and a battery terminal (T2). The cell terminal (T1) is provided at one end of the all-solid-state battery cell (20). The cell terminal (T1) includes a first cell terminal (T11) on the positive electrode side and a second cell terminal (T12) on the negative electrode side. The battery case (11) houses the all-solid-state battery cell (20). The battery terminal (T2) includes a first battery terminal (T21) on the positive electrode side and a second battery terminal (T22) on the negative electrode side. At least a part of the first battery terminal (T21) and at least a part of the second battery terminal (T22) are exposed on the surface of the battery case (11). The battery case (11) further houses a first terminal mounting member (30), a second terminal mounting member (40), and a plurality of connection members (50). A first electric circuit (31) to which the cell terminal (T1) is electrically connected is provided in the first terminal mounting member (30). A second electric circuit (41) to which the battery terminal (T2) is electrically connected is provided in the second terminal mounting member (40). The plurality of connection members (50) are connected between the first terminal mounting member (30) and the second terminal mounting member (40) to electrically connect between the first electric circuit (31) and the second electric circuit (41). In the second direction intersecting the first direction in which the current flows between the all-solid-state battery cell (20) and the plurality of connection members (50), the width (W2) of each of the plurality of connection members (50) is larger than the width (W1) of the cell terminal (T1).

[0075] According to this aspect, in the second direction, when the width (W2) of each of the plurality of connection members (50) is less than or equal to the width (W1) of the cell terminal (T1), the electrical resistance of the plurality of connection members (50) can be reduced as compared to the case where the width (W2) of each of the plurality of connection members (50) is greater than the width (W1) of the cell terminal (T1). Therefore, the temperature rise in the plurality of connection members (50) can be suppressed, and the temperature rise of the battery pack (10) can be suppressed.

[0076] In the battery pack (10) of the second aspect, in the first aspect, in a cross section having the first direction as a normal, the cross-sectional area of each of the plurality of connection members (50) is larger than the cross-sectional area of the cell terminal (T1).

[0077] According to this aspect, in a cross section having the first direction as a normal, the electrical resistance of the plurality of connection members (50) can be reduced as compared to the case where the cross-sectional area of each of the plurality of connection members (50) is less than or equal to the cross-sectional area of the cell terminal (T1). Therefore, the temperature rise in the plurality of connection members (50) can be suppressed, and the temperature rise of the battery pack (10) can be suppressed.

[0078] In the battery pack (10) of the third aspect, in the first or second aspect, the all-solid-state battery cell (20) includes a plurality of battery cells (21) each formed in a sheet shape. The plurality of battery cells (21) are arranged in a stacked manner in the thickness direction. A cell terminal (T1) is provided for each of the plurality of battery cells (21). The cell terminals (T1) provided for each of the plurality of battery cells (21) are electrically connected to the first terminal mounting member (30).

[0079] According to this aspect, the cell terminals (T1) provided for each of the plurality of battery cells (21) can be aggregated by the first terminal mounting member (30) and connected to the plurality of connection members (50).

[0080] In the battery pack (10) of the fourth aspect, in the third aspect, in a cross section having the first direction as a normal, the sum of the cross-sectional areas of the plurality of connection members (50) is larger than the sum of the cross-sectional areas of the plurality of cell terminals (T1) provided for the plurality of battery cells (21) in a cross section having the first direction as a normal.

[0081] According to this aspect, it is possible to reduce the electrical resistance of the plurality of connection members (50), suppress the temperature rise in the plurality of connection members (50), and suppress the temperature rise of the battery pack (10).

[0082] In the battery pack (10) of the fifth aspect, in any one of the first to fourth aspects, in a plane along the first direction, the battery terminal (T2), the second terminal mounting member (40), the plurality of connection members (50), the first terminal mounting member (30), the cell terminal (T1), and the all-solid-state battery cell (20) are arranged in this order.

[0083] According to this aspect, in the direction along the first direction, the dimensions of the plurality of connection members (50) can be shortened to reduce the electrical resistance. Therefore, it is possible to suppress the temperature rise in the plurality of connection members (50) and suppress the temperature rise of the battery pack (10).

[0084] In the battery pack (10) of the sixth aspect, in any one of the first to fourth aspects, at least a part of the second terminal mounting member (40) is arranged at a position overlapping the all-solid-state battery cell (20) in the thickness direction of the all-solid-state battery cell (20).

[0085] According to this aspect, it is possible to reduce the dimensions of the battery case (11) in the direction in which the all-solid-state battery cell (20), the cell terminal (T1), and the first terminal mounting member (30) are arranged in a line.

[0086] In the battery pack (10) of the seventh aspect, in the sixth aspect, the second terminal mounting member (40) has a circuit board (42) on which the battery terminal (T2) is mounted. The circuit board (42) is arranged in parallel with the sheet-shaped all-solid-state battery cell (20).

[0087] According to this aspect, compared with the case where the circuit board (42) is arranged obliquely with respect to the sheet-shaped all-solid-state battery cell (20), it is possible to reduce the dimensions of the battery pack (10) in the thickness direction of the all-solid-state battery cell (20).

[0088] In the battery pack (10) of the eighth aspect, in the sixth or seventh aspect, a second terminal mounting member (40) is disposed between the central position (P1) of the all-solid-state battery cell (20) in the first direction and the first terminal mounting member (30).

[0089] According to this aspect, compared with the case where the second terminal mounting member (40) is disposed on the side opposite to the first terminal mounting member (30) with respect to the central position (P1) of the all-solid-state battery cell (20), the lengths of the plurality of connection members (50) can be shortened. Therefore, the electrical resistance of the plurality of connection members (50) can be reduced, the temperature rise in the plurality of connection members (50) can be suppressed, and the temperature rise of the battery pack (10) can be suppressed.

[0090] In the battery pack (10) of the ninth aspect, in any one of the first to eighth aspects, the maximum value of the charging rate of the all-solid-state battery cell (20) is 10C or more.

[0091] According to this aspect, the charging time of the all-solid-state battery cell (20) can be shortened.

[0092] The power tool (1) of the tenth aspect includes the battery pack (10) of any one of the first to ninth aspects, a drive unit (62) that drives the tool (60), and a tool body (2) that houses the drive unit (62). The battery pack (10) can be attached to the tool body (2). With the battery pack (10) attached to the tool body (2), the drive unit (62) can operate using the battery pack (10) as a power source.

[0093] According to this aspect, a power tool (1) including a battery pack (10) capable of suppressing temperature rise can be realized.

[0094] Regarding the configurations according to the second to ninth aspects, they are not essential configurations of the battery pack (10) and can be omitted as appropriate.

Explanation of Reference Numerals

[0095] 1 Power tool 2 Tool body 10 Battery pack 11 Battery case 20 All-solid-state battery cell 21 Battery cell 30 First terminal mounting member 31 First electric circuit 40 Second terminal mounting member 41 Second electric circuit 42 Circuit board 50 Connecting member 60 Tool 62 Driving part P1 Central position T1 Cell terminal T2 Battery terminal T11 First cell terminal T12 Second cell terminal T21 First battery terminal T22 Second battery terminal W1 Width of the connecting member W2 Width of the cell terminal

Claims

1. A sheet-shaped all-solid-state battery cell, A cell terminal including a first cell terminal on the positive electrode side and a second cell terminal on the negative electrode side provided at one end of the all-solid-state battery cell, A battery case for housing the all-solid-state battery cell, A battery terminal including a first battery terminal on the positive electrode side and a second battery terminal on the negative electrode side, and comprising: At least a part of the first battery terminal and at least a part of the second battery terminal are exposed on the surface of the battery case, The battery case, A first terminal mounting member provided with a first electric circuit to which the cell terminal is electrically connected, A second terminal mounting member provided with a second electric circuit to which the battery terminal is electrically connected, Further accommodating a plurality of connection members connected between the first terminal mounting member and the second terminal mounting member to electrically connect between the first electric circuit and the second electric circuit, In a second direction intersecting a first direction in which current flows between the all-solid-state battery cell and the plurality of connection members, the width of each of the plurality of connection members is larger than the width of the cell terminal, respectively, A battery pack.

2. In a cross section having the first direction as a normal line, the cross-sectional area of each of the plurality of connection members is larger than the cross-sectional area of the cell terminal, The battery pack according to claim 1.

3. The all-solid-state battery cell includes a plurality of battery cells each formed in a sheet shape, The plurality of battery cells are arranged stacked in the thickness direction, The cell terminal is provided for each of the plurality of battery cells, The cell terminals provided for each of the plurality of battery cells are electrically connected to the first terminal mounting member, The battery pack according to claim 1.

4. The sum of the cross-sectional areas of the plurality of connection members in a cross section having the first direction as a normal line is larger than the sum of the cross-sectional areas of the plurality of cell terminals provided for the plurality of battery cells in a cross section having the first direction as a normal line, The battery pack according to claim 3.

5. In a plane along the first direction, the battery terminal, the second terminal mounting member, the plurality of connection members, the first terminal mounting member, the cell terminal, and the all-solid-state battery cell are arranged in this order, The battery pack according to any one of claims 1 to 4.

6. In the thickness direction of the all-solid-state battery cell, at least a part of the second terminal mounting member is arranged at a position overlapping the all-solid-state battery cell, The battery pack according to any one of claims 1 to 4.

7. The second terminal mounting member has a circuit board on which the battery terminal is mounted. The circuit board is arranged in parallel with the sheet-shaped all-solid-state battery cell. The battery pack according to claim 6.

8. The second terminal mounting member is arranged between the central position of the all-solid-state battery cell in the first direction and the first terminal mounting member. The battery pack according to claim 6.

9. The maximum value of the charging rate of the all-solid-state battery cell is 10C or more. The battery pack according to any one of claims 1 to 4.

10. A battery pack according to any one of claims 1 to 4, a drive unit for driving a tool, and a tool body for housing the drive unit, and the battery pack can be mounted on the tool body, and the drive unit can operate using the battery pack as a power source when the battery pack is mounted on the tool body. An electric tool.

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