Battery pack and electric tool

Abstract

The purpose of the present disclosure is to suppress a rise in temperature. This battery pack (10) is provided with a battery case (11) that houses: an all-solid-state battery cell (20); a first terminal mounting member (30); a second terminal mounting member (40); and a plurality of connection members (50). The first terminal mounting member (30) includes a first electric circuit to which a cell terminal (T1) of the all-solid-state battery cell (20) is electrically connected. The second terminal mounting member (40) includes a second electric circuit to which a battery terminal (T2) is electrically connected. The plurality of connection members (50) electrically connect the first electric circuit to the second electric circuit. In a second direction that intersects a first direction in which a current flows between the all-solid-state battery cell (20) and the plurality of connection members (50), the width of each of the plurality of connection members (50) is greater than the width of the cell terminal (T1).

Description

Battery packs and power tools

[0001] The present disclosure relates to a battery pack and a power tool. More particularly, the present disclosure relates to a battery pack that can be attached to an electrical device and a power tool including the battery pack.

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

[0003] In the battery pack described in Patent Document 1, when the current value of the current flowing through the lead plates increases, the amount of heat generated in the lead plates increases, which may result in an increase in the temperature of the battery pack.

[0004] Japanese Patent Application Laid-Open No. 2001-43839

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

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

[0007] The power 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 attached to the tool body. When the battery pack is attached to the tool body, the drive unit can operate using the battery pack as a power source.

[0008] Fig. 1 is a schematic side view of a battery pack according to an embodiment of the present disclosure with a battery case removed. Fig. 2 is a schematic plan view of the battery pack according to the same with the battery case removed. Fig. 3 is a schematic block circuit diagram of the battery pack according to the same. Fig. 4 is a side view of a power tool including the battery pack according to the same. Fig. 5 is a schematic side view of a battery pack according to a first modification with the battery case removed. Fig. 6 is a schematic plan view of the battery pack according to the first modification with the battery case removed. Fig. 7 is a side view of the battery pack according to the first modification.

[0009] Hereinafter, a battery pack according to an embodiment and a power tool including the same will be described in detail with reference to the drawings. However, the drawings described in the following embodiments are schematic diagrams, and the dimensional ratios of the sizes 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.

[0010] (Embodiment) (1) Overview A battery pack 10 and a power tool 1 according to this embodiment will be described below with reference to FIGS. 1 to 4. FIG.

[0011] As shown in FIGS. 1 to 3, the battery pack 10 includes a sheet-shaped all-solid-state battery cell 20, a cell terminal T1, a battery case 11, and a battery terminal T2.

[0012] The cell terminals T1 include 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.

[0013] The battery case 11 accommodates the all-solid-state battery cell 20 .

[0014] The battery terminals T2 include a first battery terminal T21 on the positive electrode side and a second battery terminal T22 on the negative electrode side.

[0015] At least a portion of the first battery terminal T21 and at least a portion of the second battery terminal T22 are exposed on the surface of the battery case 11.

[0016] The battery case 11 further houses a first terminal mounting member 30 , a second terminal mounting member 40 , and a plurality of connecting members 50 .

[0017] The first terminal mounting member 30 is provided with a first electric circuit 31 to which the cell terminal T1 is electrically connected.

[0018] The second terminal mounting member 40 is provided with a second electric circuit 41 to which the battery terminal T2 is electrically connected.

[0019] 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 the first electric circuit 31 and the second electric circuit 41 .

[0020] In a second direction (e.g., a direction parallel to the X-axis direction in FIG. 2 ) intersecting with a first direction (e.g., a direction parallel to the Y-axis direction in FIG. 2 ) in which a 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.

[0021] Here, the first electric circuit 31 only needs to have at least the function of electrically connecting the cell terminal T1 including the first cell terminal T11 and the second cell terminal T12 to the plurality of connection members 50. The first electric circuit 31 may have a function such as a protection circuit that switches the cell terminal T1 and the plurality of connection members 50 from a conductive state to a non-conductive state when an overcurrent flows. The second electric circuit 41 may be a circuit that has the function of electrically connecting the battery terminal T2 including the first battery terminal T21 and the second battery terminal T22 to the plurality of connection members 50, but may also have the function of a charge control circuit that controls the charging current flowing through the all-solid-state battery cell 20. The second electric circuit 41 may also have the function of a temperature compensation circuit that adjusts the charging current in accordance with the temperature of the all-solid-state battery cell 20, a protection circuit that switches the cell terminal T1 and the plurality of connection members 50 from a conductive state to a non-conductive state when an overcurrent flows, etc. In the present disclosure, the state in which two directions are "parallel" is not limited to a state in which the two directions are completely parallel, but may include a state in which the angle between the two directions is a few degrees (for example, 10 degrees or less). Furthermore, the state in which two directions "intersect" is, for example, a state in which the two directions are perpendicular to each other, but is not limited to a state in which the two directions are completely perpendicular to each other, and may be any state in which the angle between the two directions is 80 degrees or more and 100 degrees or less, for example.

[0022] In the battery pack 10 of this embodiment, the width W2 of each of the multiple connection members 50 in the second direction (e.g., the direction parallel to the X-axis direction) is greater than the width W1 of the cell terminal T1. Therefore, the electrical resistance of the multiple connection members 50 can be reduced compared to when the width W2 of each of the multiple connection members 50 in the second direction is equal to or less than the width W1 of the cell terminal T1. This can suppress temperature rise in the multiple connection members 50, thereby suppressing temperature rise in the battery pack 10. Furthermore, because the electrical resistance of the multiple connection members 50 can be reduced, the voltage drop in the multiple connection members 50 can be reduced.

[0023] The power tool 1 of this 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.

[0024] Since the power tool 1 includes the battery pack 10, it is possible to realize a power tool 1 including the battery pack 10 that can suppress temperature rise.

[0025] (2) Details The battery pack 10 and the power tool 1 according to this embodiment will be described in detail below 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. Furthermore, the positive direction of the X-axis direction is defined as the right side, the positive direction of the Y-axis direction as the front side, and the positive direction of the Z-axis direction as the up side. However, these directions are merely examples and are not intended to limit the directions of the battery pack 10 and the power tool 1 when in use. Furthermore, the arrows indicating the respective directions in the drawings are merely shown for explanatory purposes and do not have any substance.

[0026] (2.1) Configuration The battery pack 10 of this embodiment can be attached to the power tool 1. When the battery pack 10 is attached to the power tool 1, the power tool 1 can operate using the battery pack 10 as a power source. The power tool 1 and the battery pack 10 attached to the power tool 1 will be described below.

[0027] (2.1.1) Power Tool As shown in FIG. 4, the power tool 1 according to this embodiment is a handheld power tool, such as an electric screwdriver, an electric drill, an electric wrench, or an electric grinder.

[0028] The power tool 1 includes a tool body 2 to which a battery pack 10 is detachably attached.

[0029] The tool body 2 includes a cylindrical portion 3 , a grip portion 4 , and a battery mounting portion 5 .

[0030] The cylindrical portion 3 is, for example, a molded product made of electrically insulating synthetic resin. The cylindrical portion 3 is formed in a cylindrical shape with its axial direction extending in the front-rear direction.

[0031] A tool attachment portion 61 for attaching a tool 60 such as a tool tip is provided at the front end of the cylindrical portion 3. 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, and the like are housed.

[0032] The tool attachment portion 61 is provided on the cylindrical portion 3 in a state where it can rotate about a rotation axis that extends in the front-to-rear direction. A plurality of types of tools 60 are prepared to correspond to a plurality of types of work using the power tool 1, and the desired type of tool 60 is attached to the tool attachment portion 61 for use. Examples of this type of tool 60 include a driver bit for screwing, a drill bit for drilling, and a socket for tightening nuts.

[0033] The drive unit 62 includes, for example, an electric motor that is driven by power supplied from the battery pack 10 .

[0034] The transmission unit 63 transmits the driving force of the drive unit 62 to the tool attachment unit 61. The transmission unit 63 is connected to the output shaft of the drive unit 62, and rotates the tool attachment unit 61 by transmitting the rotation of the drive unit 62 to the tool attachment unit 61. The transmission unit 63 may include a speed reduction mechanism, a clutch mechanism, an impact mechanism, etc.

[0035] The grip portion 4 extends downward from a portion of the circumferential surface of the cylindrical portion 3. When a user uses the power tool 1, the user holds the grip portion 4 at a middle portion in the vertical direction (longitudinal direction) with his / her hand. One end (e.g., the upper end) of the grip portion 4 is connected to the cylindrical portion 3, and the battery attachment portion 5 is provided at the other end (e.g., the lower end). For example, when the battery pack 10 attached to the battery attachment portion 5 is placed on a support surface such as a floor, the longitudinal direction of the grip portion 4 is aligned with the vertical direction.

[0036] A trigger switch 64 is provided on the front side of the upper end of the grip unit 4. The trigger switch 64 is an operation unit that accepts user operations to control the rotation of the drive unit 62. The trigger switch 64 is located in a position that can be operated with the fingers of the user while holding the grip unit 4 in the hand.

[0037] The battery attachment section 5 is integrally provided at the lower end of the grip section 4. The battery attachment section 5 is formed, for example, in the shape of a rectangular parallelepiped with a vertical dimension smaller than its front-rear and left-right dimensions. The lower end of the grip section 4 is connected to the upper surface of the battery attachment section 5 so that the grip section 4 protrudes upward from the upper surface of the battery attachment section 5. The battery pack 10 is detachably attached to the lower part of the battery attachment section 5. A recess is provided on the lower surface of the battery attachment section 5 into which the upper part of the battery pack 10 is inserted. When the battery pack 10 is attached to the battery attachment section 5, the battery terminal T2 of the battery pack 10 is electrically connected to the tool-side terminal provided on the battery attachment section 5.

[0038] In this embodiment, for example, a control unit 65 having a circuit board on which circuits for controlling the drive unit 62 are mounted is housed inside the battery attachment unit 5. The control unit 65 can switch the drive unit 62 on and off by pulling the trigger switch 64. The control unit 65 also controls the rotation speed of the drive unit 62, i.e., the rotation speed of the tool 60 attached to the tool attachment unit 61, depending on the amount of pulling of the trigger switch 64. When the battery pack 10 is attached to the battery attachment unit 5 and the battery terminal T2 of the battery pack 10 is electrically connected to the tool-side terminal, the internal circuits of the power tool 1 (such as the control unit 65 and the drive unit 62) can operate with power supplied from the battery pack 10.

[0039] Furthermore, when the battery pack 10 is attached to the battery attachment section 5 and the bottom surface of the battery pack 10 opposite the grip section 4 is placed on a support surface (e.g., a floor surface), the tool body 2 of the power tool 1 can stand on its own.

[0040] (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 connecting members 50.

[0041] 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. An all-solid-state battery is a battery having a solid electrolyte layer between a positive electrode and a negative electrode. Since an all-solid-state battery does not use an electrolyte, it has the advantage of eliminating the possibility of leakage. The plurality of battery cells 21 have substantially the same shape and size in a top view. The shape of the plurality of battery cells 21 in a top view is, for example, rectangular. The plurality of battery cells 21 are stacked in positions where they overlap each other in the vertical direction, with a predetermined gap between them. The plurality of battery cells 21 are arranged parallel to each other so that the thickness direction is parallel to the vertical direction. Note that in this embodiment, the number of battery cells 21 is, for example, six. In the following description, when describing each individual battery cell 21, they may be referred to as battery cells 21A, 21B, 21C, 21D, 21E, and 21F.

[0042] The plurality of battery cells 21 are connected in series, for example, as shown in Fig. 3. The plurality of battery cells 21 may be connected in series or in parallel depending on the required voltage value or power storage capacity. In Fig. 1, the number of the plurality of battery cells 21 is, for example, six, but the number of battery cells 21 may be one or more, and the number of battery cells 21 can be changed as appropriate depending on the required voltage value or power storage capacity.

[0043] Each of the multiple battery cells 21 has a pair of cell terminals T1 at one end (e.g., 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 spaced apart 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 each protrude forward from one end (e.g., front end) of the battery cell 21. The first cell terminal T11 and the second cell terminal T12 are made of a metal material such as copper, nickel, or aluminum. The first cell terminal T11 and the second cell terminal T12 are, for example, conductive metal foil members having a rectangular shape in a plan view, but may also be metal bars having a rectangular shape in a plan view. The width W1 of the first cell terminal T11 and the second cell terminal T12 in the second direction (a direction parallel to the X-axis direction) is the same. In the present disclosure, the term "two dimensions being the same" does not necessarily mean that the two dimensions are exactly the same, but may also mean that the two dimensions differ by a margin of error on the order of a manufacturing error.

[0044] 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. Each of the pair of battery terminals T2 is, for example, a metal bar formed into a rectangular shape in a plan view. A 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 in the battery case 11 with at least a portion of its second end exposed on a surface (e.g., 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) so that, for example, the thickness direction is parallel to the Z-axis direction.

[0045] 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. Each of the pair of battery terminals T2 is, for example, a metal bar formed into a rectangular shape in a plan view. The pair of battery terminals T2 are arranged at a predetermined interval in the second direction (left-right direction) so that their thickness directions are parallel to the Z-axis direction. The first ends (e.g., rear ends) 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 (e.g., front ends) 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 widths W1 of the first cell terminal T11 and the second cell terminal T12 in the second direction.

[0046] The first terminal mounting member 30 is a circuit board 32 such as a printed wiring board. The circuit board 32, which is the first terminal mounting member 30, is arranged so that the normal direction of the circuit board 32 is parallel to a first direction (the front-to-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, for example, soldering or welding. 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, for example, soldering or welding. The first terminal mounting member 30 also is provided with a terminal portion PD3 to which a first connecting member 51 is joined by, for example, soldering or welding, and a terminal portion PD4 to which a second connecting member 52 is joined by, for example, soldering or welding. The first terminal mounting member 30 is provided with a first electric circuit 31 between the terminal portion PD3 and the terminal portion PD4, which connects in series the plurality of battery cells 21 connected to the plurality of terminal portions PD1, PD2, respectively, via printed wiring formed on the circuit board 32. The terminal portions PD1 to PD4 may be surface mounting pads or through holes.

[0047] 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 so that the normal direction of the circuit board 42 is parallel to the first direction (the front-to-rear direction in this embodiment). The second terminal mounting member 40 is provided with a terminal portion PD5 to which the first connecting member 51 is joined by, for example, soldering or welding, and a terminal portion PD6 to which the second connecting member 52 is joined by, for example, soldering or welding. The second terminal mounting member 40 also is provided with a terminal portion PD7 to which the first battery terminal T21 is joined by, for example, soldering or welding, and a terminal portion PD8 to which the second battery terminal T22 is joined by, for example, soldering or welding. The second terminal mounting member 40 also has a second electric circuit 41 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 when the battery pack 10 is connected to a charger after being removed from the power tool 1. The second electric circuit 41 may also include a charging protection circuit that limits an overcurrent that flows when the battery pack 10 is being charged, or a discharging protection circuit that limits an overcurrent that flows when the all-solid-state battery cell 20 is being discharged when the battery pack 10 is connected to the power tool 1.

[0048] The battery case 11 is a box-shaped molded product made of electrically insulating synthetic resin. A holding structure is provided on the top surface of the battery case 11, which holds the battery case 11 in the battery mounting section 5 by sliding the battery case 11, for example, backward, relative to the battery mounting section 5. A pair of tool-side terminals is provided on the front end of the battery mounting section 5. When the battery case 11 is mounted in the battery mounting section 5, the tool-side terminals are electrically connectable to a pair of battery terminals T2 exposed on the front surface of the battery case 11. By connecting the 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. The battery mounting section 5 may be provided with a terminal cover (not shown) that covers the pair of tool-side terminals when the pair of tool-side terminals are connected to the pair of battery terminals T2 of the battery pack 10.

[0049] (2.2) Advantages In the present embodiment, the width W2 of each of the plurality of connection members 50 is larger than the width W1 of the cell terminal T1 in a second direction (parallel to the X-axis direction) intersecting with a first 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. This increases the cross-sectional area of ​​each of the plurality of connection members 50 in the second direction compared to when the width W2 of each of the plurality of connection members 50 is equal to or smaller than the width W1 of the cell terminal T1, thereby reducing the electrical resistance of the plurality of connection members 50. Therefore, in the present embodiment, the temperature rise of the plurality of connection members 50 can be suppressed, thereby realizing a battery pack 10 capable of suppressing temperature rise. Furthermore, by reducing the electrical resistance of the plurality of connection members 50, the voltage drop across the plurality of connection members 50 can be suppressed.

[0050] Furthermore, in this embodiment, the thickness dimension in the Z direction of each of the multiple connection members 50 and the thickness dimension in the Z direction of each of the multiple cell terminals T1 are approximately the same. Therefore, in this embodiment, in a cross section (e.g., a Z-X plane) normal to the first direction (a direction parallel to the Y-axis direction), the cross-sectional area of ​​each of the multiple connection members 50 is larger than the cross-sectional area of ​​the cell terminal T1. This allows for a lower electrical resistance of the multiple connection members 50 compared to when the cross-sectional area of ​​each of the multiple connection members 50 is equal to or smaller than the cross-sectional area of ​​the cell terminal T1 in the cross section normal to the first direction. Therefore, a battery pack 10 capable of suppressing temperature rise can be realized, which can suppress temperature rise. Furthermore, by reducing the electrical resistance of the multiple connection members 50, the voltage drop across the multiple connection members 50 can also be reduced.

[0051] In the present embodiment, since it is possible to suppress a temperature rise of the battery pack 10, it is possible to increase the charging current of the all-solid-state battery cell 20. For example, the maximum value of the charging rate of the all-solid-state battery cell 20 can be set to 10 C or more. Note that even if the charging current when charging the theoretical capacity of the all-solid-state battery cell 20 in one hour is 1 C and the maximum value of the charging rate is set to 10 C or more in the present embodiment, it is possible to suppress the temperature of the battery pack 10 to an upper limit value of a predetermined operating temperature range or less. By setting the maximum value of the charging rate of the all-solid-state battery cell 20 to 10 C or more, it is possible to charge the all-solid-state battery cell 20 in a short time, and by shortening the time required to charge the all-solid-state battery cell 20, it is possible to extend the time during which work can be performed using the power tool 1.

[0052] 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 on each of the plurality of battery cells 21. The cell terminal T1 provided on each of the plurality of battery cells 21 is electrically connected to the first terminal mounting member 30.

[0053] Furthermore, each of the plurality of battery cells 21 includes a plurality of cell terminals T1, and the cell terminals T1 provided on each of the plurality of battery cells 21 are electrically connected to the first terminal mounting member 30. Therefore, the cell terminals T1 provided on each of the plurality of battery cells 21 can be aggregated and connected to the plurality of connection members 50 in the first electric circuit 31 of the first terminal mounting member 30, and the work of connecting the cell terminals T1 of the all-solid-state battery cells 20 to the plurality of connection members 50 can be simplified. Note that in the present embodiment, the cell terminals T1 of the all-solid-state battery cells 20 are connected to the plurality of connection members 50 via the first terminal mounting member 30.

[0054] Furthermore, in the present embodiment, 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 order in a plane (e.g., the Y-Z plane) along the first direction (e.g., a direction parallel to the Y-axis direction). Because 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, the length of the plurality of connection members 50 can be shortened compared to, for example, a case in which the plurality of connection members 50 are bent midway. 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.

[0055] (3) Modifications The above embodiment is merely one of various embodiments of the present disclosure. The above embodiment can be modified in various ways depending on the design, etc., as long as the object of the present disclosure can be achieved. Hereinafter, the above embodiment may also be referred to as a basic example.

[0056] Modifications of the above embodiment are listed below. The modifications described below can be applied in appropriate combination with the basic example described above, and the basic example can also be applied in appropriate combination with multiple modifications described below.

[0057] (3.1) Modification 1 A battery pack 10 according to modification 1 will be described with reference to FIGS.

[0058] The battery pack 10 of the first modification differs from the basic example described above in that at least a portion of the 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. Note that components common to the basic example described above are denoted by the same reference numerals, and descriptions thereof will be omitted.

[0059] In the first modification, 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 parallel to the sheet-shaped all-solid-state battery cell 20. The 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. At least a portion of the pair of battery terminals T2 is exposed from the upper surface of the battery case 11. A pair of terminal portions PD5 and PD6 to which second ends of the pair of connecting members 50 are respectively connected is provided at the front end portion of the circuit board 42, which is the second terminal mounting member 40.

[0060] The first terminal mounting member 30 is disposed on the front side of the all-solid-state battery cell 20. The circuit board 32, which is the first terminal mounting member 30, is disposed so that the normal direction of the circuit board 32 is parallel to the first direction. A pair of terminal portions PD3 and PD4, to which first ends of a pair of connection members 50 are respectively connected, are provided on the upper part of the circuit board 32.

[0061] The pair of connecting members 50 connected between the first terminal mounting member 30 and the second terminal mounting member 40 have an L-shape in side view. First ends of the pair of connecting members 50 are connected to a pair of terminal portions PD3 and PD4 provided on the upper part of the circuit board 32 by soldering, welding, or other methods. Second ends of the pair of connecting members 50 are connected to a pair of terminal portions PD5 and PD6 provided on the front end of the circuit board 42 by soldering, welding, or other methods.

[0062] In the first modification, a pair of battery terminals T2 (a first battery terminal T21 and a second battery terminal T22) are partially exposed from the top surface of the battery case 11. A pair of tool-side connection terminals connected to the pair of battery terminals T2 are arranged on the bottom surface of the battery mounting section 5 of the tool body 2. Therefore, when the battery pack 10 is mounted in the battery mounting section 5, the pair of battery terminals T2 and the pair of tool-side terminals are electrically connected, and the internal circuits of the power tool 1 (such as the control section 65 and the drive section 62) can operate using power from the battery pack 10.

[0063] In the battery pack 10 of the first modification, at least a portion 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 in which current flows between the all-solid-state battery cell 20 and the first terminal mounting member 30 (Y-axis direction) can be reduced.

[0064] Furthermore, since the circuit board 42, which is the second terminal mounting member 40, is arranged parallel to the sheet-like all-solid-state battery cells 20, the dimensions of the battery pack 10 in the thickness direction (Z-axis direction) of the all-solid-state battery cells 20 can be made smaller than when the circuit board 42 is arranged obliquely with respect to the sheet-like all-solid-state battery cells 20.

[0065] 5 and 6 , the second terminal mounting member 40 is disposed at a position where the entire second terminal mounting member 40 overlaps with the all-solid-state battery cell 20 in the thickness direction of the all-solid-state battery cell 20, but the position of the second terminal mounting member 40 can be changed as appropriate. For example, the second terminal mounting member 40 may be disposed at a position where a part of the second terminal mounting member 40 overlaps with the all-solid-state battery cell 20 in the thickness direction of the all-solid-state battery cell 20.

[0066] 5 and 6 , the second terminal mounting member 40 is disposed between the center 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 in such a position, the length of the multiple connecting members 50 can be shortened compared to when the second terminal mounting member 40 is disposed on the opposite side of the first terminal mounting member 30 from the center position P1 of the all-solid-state battery cell 20. Therefore, the electrical resistance of the multiple connecting members 50 can be reduced, and a temperature rise in the multiple connecting members 50 can be suppressed, thereby suppressing a temperature rise in the battery pack 10.

[0067] (3.2) Other Modifications In the above-described basic example and modification 1, the sum of the cross-sectional areas of the multiple connection members 50 in a cross section (e.g., a Z-X plane) normalized in the first direction (e.g., a direction parallel to the Y-axis direction) may be larger than the sum of the cross-sectional areas of the multiple cell terminals T1 provided on the multiple battery cells 21 in a cross section (e.g., a Z-X plane) normalized in the first direction (e.g., a direction parallel to the Y-axis direction). That is, the widths and thicknesses of the multiple connection members 50 and the multiple cell terminals T1 may be designed so that the sum of the cross-sectional areas of the multiple connection members 50 is larger than the sum of the cross-sectional areas of the multiple cell terminals T1 in a cross section (e.g., a Z-X plane) normalized in the first direction (e.g., a direction parallel to the Y-axis direction). This reduces the electrical resistance of the multiple connection members 50, making it possible to suppress temperature increases in the multiple connection members 50 and also suppress voltage drops in the multiple connection members 50.

[0068] 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 changed as appropriate. Furthermore, the plurality of battery cells 21 included in the all-solid-state battery cell 20 are connected in series, but the plurality of battery cells 21 may be connected in parallel. Furthermore, the all-solid-state battery cell 20 may include a plurality of cell blocks, each of which has a plurality of battery cells 21 connected in series, and the plurality of cell blocks may be connected in parallel. Furthermore, the shape of the battery cells 21 included in the all-solid-state battery cell 20 is rectangular in a plan view, but the shape of the battery cells 21 is not limited to rectangular and can be changed as appropriate.

[0069] Furthermore, in the basic example and the modified example described above, 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 can be attached is not limited to the power tool 1. The electrical device to which the battery pack 10 can be attached may be a rechargeable vacuum cleaner, a lawnmower, or other electrical device.

[0070] In the basic example and modified examples described above, the cell terminal T1 has a rectangular foil or plate shape, but the cell terminal T1 may also be a round pin or an electric wire such as a twisted 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 with the first direction in which current flows is the diameter of the cell terminal T1.

[0071] Furthermore, in the basic example and modified examples described above, the shape of the connection member 50 is a rectangular foil or plate, but the connection member 50 may be a round pin or an electric wire such as a twisted 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 with the first direction in which the current flows is the diameter of the connection member 50.

[0072] (Summary) The above-described embodiments and the like disclose the following aspects.

[0073] 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) accommodates 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 portion of the first battery terminal (T21) and at least a portion 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 connecting members (50). The first terminal mounting member (30) is provided with a first electric circuit (31) to which a cell terminal (T1) is electrically connected. The second terminal mounting member (40) is provided with a second electric circuit (41) to which a battery terminal (T2) is electrically connected. The plurality of connecting members (50) are connected between the first terminal mounting member (30) and the second terminal mounting member (40) to electrically connect the first electric circuit (31) and the second electric circuit (41). In a second direction intersecting a first direction in which current flows between the all-solid-state battery cell (20) and the plurality of connecting members (50), the width (W2) of each of the plurality of connecting members (50) is larger than the width (W1) of the cell terminal (T1).

[0074] According to this aspect, the electrical resistance of the plurality of connection members (50) can be reduced compared to when the width (W2) of each of the plurality of connection members (50) in the second direction is equal to or less 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 in the battery pack (10) can be suppressed.

[0075] In the battery pack (10) of the second aspect, in the first aspect, the cross-sectional area of ​​each of the plurality of connecting members (50) is larger than the cross-sectional area of ​​the cell terminal (T1) in a cross section normal to the first direction.

[0076] According to this aspect, the electrical resistance of the plurality of connection members (50) can be reduced compared to when the cross-sectional area of ​​each of the plurality of connection members (50) is equal to or smaller than the cross-sectional area of ​​the cell terminal (T1) in a cross section normal to the first direction, thereby suppressing a temperature rise in the plurality of connection members (50) and a temperature rise in the battery pack (10).

[0077] 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 on each of the plurality of battery cells (21). The cell terminal (T1) provided on each of the plurality of battery cells (21) is electrically connected to a first terminal mounting member (30).

[0078] According to this aspect, the cell terminals (T1) provided on 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).

[0079] In the battery pack (10) of the fourth aspect, the sum of the cross-sectional areas of the plurality of connection members (50) in a cross section normal to the first direction is greater than the sum of the cross-sectional areas of the plurality of cell terminals (T1) in a cross section normal to the first direction. The plurality of cell terminals (T1) are provided on the plurality of battery cells (21).

[0080] According to this aspect, the electrical resistance of the plurality of connection members (50) can be reduced, and the temperature rise in the plurality of connection members (50) can be suppressed, thereby suppressing the temperature rise of the battery pack (10).

[0081] In the battery pack (10) of a fifth aspect, in any of the first to fourth aspects, 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 order on a plane along the first direction.

[0082] According to this aspect, the dimensions of the plurality of connecting members (50) can be shortened in the first direction, thereby reducing electrical resistance, thereby suppressing temperature rise in the plurality of connecting members (50) and suppressing temperature rise in the battery pack (10).

[0083] In the battery pack (10) of a 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).

[0084] According to this aspect, 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 can be reduced.

[0085] 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 parallel to the sheet-like all-solid-state battery cell (20).

[0086] According to this aspect, the dimension of the battery pack (10) in the thickness direction of the all-solid-state battery cell (20) can be reduced compared to when the circuit board (42) is disposed obliquely with respect to the sheet-like all-solid-state battery cell (20).

[0087] 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 center position (P1) of the all-solid-state battery cell (20) in the first direction and the first terminal mounting member (30).

[0088] According to this aspect, the lengths of the multiple connection members (50) can be made shorter than when the second terminal mounting member (40) is disposed on the opposite side of the first terminal mounting member (30) with respect to the center position (P1) of the all-solid-state battery cell (20). Therefore, the electrical resistance of the multiple connection members (50) can be reduced, and a temperature rise in the multiple connection members (50) can be suppressed, thereby suppressing a temperature rise in the battery pack (10).

[0089] In the battery pack (10) of the ninth aspect, in any one of the first to eighth aspects, the maximum charge rate of the all-solid-state battery cell (20) is 10 C or more.

[0090] According to this embodiment, the charging time of the all-solid-state battery cell (20) can be shortened.

[0091] A power tool (1) of a 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.

[0092] According to this aspect, it is possible to realize a power tool (1) including a battery pack (10) capable of suppressing temperature rise.

[0093] The configurations according to the second to ninth aspects are not essential for the battery pack (10) and can be omitted as appropriate.

[0094] REFERENCE SIGNS LIST 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 Connection member 60 Tool 62 Drive unit 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 connection member W2 Width of cell terminal

Claims

a battery case accommodating the all-solid-state battery cell; and a battery terminal including a first cell terminal on a positive electrode side and a second cell terminal on a negative electrode side, the cell terminal being provided at one end of the all-solid-state battery cell; a battery case accommodating the all-solid-state battery cell; and a battery terminal including a first battery terminal on a positive electrode side and a second battery terminal on a negative electrode side, wherein at least a portion of the first battery terminal and at least a portion of the second battery terminal are exposed on a surface of the battery case, the battery case further accommodating: 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; and a plurality of connecting members connected between the first terminal mounting member and the second terminal mounting member and electrically connecting between the first electric circuit and the second electric circuit, the width of each of the plurality of connecting members being greater than a width of the cell terminal in a second direction intersecting a first direction in which a current flows between the all-solid-state battery cell and the plurality of connecting members.

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

3. The battery pack according to claim 1 or 2, wherein 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 in a stack in a thickness direction, the cell terminal is provided on each of the plurality of battery cells, and the cell terminal provided on each of the plurality of battery cells is electrically connected to the first terminal mounting member.

4. The battery pack described in claim 3, wherein the sum of the cross-sectional areas of the multiple connecting members in a cross section normal to the first direction is greater than the sum of the cross-sectional areas of the multiple cell terminals provided on the multiple battery cells in a cross section normal to the first direction.

5. The battery pack according to any one of claims 1 to 4, wherein 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 order on a plane along the first direction.

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

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

8. The battery pack according to claim 6 or 7, wherein the second terminal mounting member is disposed between a center position of the all-solid-state battery cell in the first direction and the first terminal mounting member.

9. The battery pack according to any one of claims 1 to 8, wherein the maximum charging rate of the all-solid-state battery cell is 10C or higher.

10. An electric power tool comprising: a battery pack according to any one of claims 1 to 9; a drive unit for driving the tool; and a tool body housing the drive unit, wherein the battery pack can be attached to the tool body; and, when the battery pack is attached to the tool body, the drive unit can operate using the battery pack as a power source.

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