Power storage device

Abstract

This power storage device comprises a power storage element, a circuit board, electrical equipment and a busbar. The circuit board comprises a substrate, and a board terminal electrically connected to the power storage element and fixed to the board. An equipment terminal and the busbar fixed to the electrical equipment are electrically connected to the board terminal by being collectively fixed to the board terminal.

Description

[Technical Field]

[0001] The present invention relates to an electricity storage device including a circuit board and an electric device. [Background technology]

[0002] Patent Document 1 discloses the structure of a battery pack including multiple battery cells (energy storage elements). This battery pack includes a BMS (Battery Management System) circuit board for controlling the charging and discharging of the energy storage elements, and a current sensor unit for measuring current. The current sensor unit is soldered to the BMS circuit board in a state where it stands vertically on the BMS circuit board. A bus bar is fastened to the end of the current sensor unit with a bolt and a nut. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2020-517075 Summary of the Invention [Problem to be solved by the invention]

[0004] Generally, like the conventional battery pack described above, an energy storage device includes a circuit board such as a BMS circuit board and an electrical device such as a relay or a current sensor unit, and the circuit board, the electrical device, and an external terminal are electrically connected via a bus bar. The connection between these multiple conductive elements (circuit board, electrical device, bus bar, etc.) is desired to have high connection strength, low electrical resistance, and ease of connection work. In the conventional battery pack described above, the bus bar is connected to a portion of the current sensor unit that is different from the connection portion with the BMS circuit board using bolts and nuts. Therefore, an external force applied to the current sensor unit by the bus bar easily causes stress concentration at the soldered connection portion between the current sensor unit and the BMS circuit board. Furthermore, when multiple conductive elements are connected in series, the resistance values ​​of multiple connections accumulate in the current path between the energy storage element and the external terminal. This can lead to a decrease in the performance of the energy storage device.

[0005] The present invention was made by the inventors of the present application by focusing on the above-mentioned problems, and has an object to provide a power storage device with improved reliability. [Means for solving the problem]

[0006] An energy storage device according to one embodiment of the present invention is an energy storage device comprising an energy storage element, a circuit board, an electrical device, and a bus bar, wherein the circuit board has a substrate and a substrate terminal electrically connected to the energy storage element and fixed to the substrate, and the device terminal and bus bar fixed to the electrical device are fixed collectively to the substrate terminal, thereby being electrically connected to the substrate terminal. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a power storage device with improved reliability. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view showing the appearance of a power storage device according to an embodiment. [Figure 2] FIG. 2 is an exploded perspective view of the electricity storage device according to the embodiment. [Figure 3] FIG. 3 is a perspective view showing a state in which the circuit board, the electric device, and the bus bar according to the embodiment are connected to each other. [Figure 4] FIG. 4 is an exploded perspective view corresponding to FIG. [Figure 5] FIG. 5 is a side view corresponding to FIG. DETAILED DESCRIPTION OF THE INVENTION

[0009] An energy storage device according to one embodiment of the present invention is an energy storage device comprising an energy storage element, a circuit board, an electrical device, and a bus bar, wherein the circuit board has a substrate and a substrate terminal electrically connected to the energy storage element and fixed to the substrate, and the device terminal and bus bar fixed to the electrical device are fixed collectively to the substrate terminal, thereby being electrically connected to the substrate terminal.

[0010] This configuration allows the bus bar and an electrical device, such as a relay, to be fixed together to the circuit board, and allows electrical continuity between the electrical device and the circuit board at a single location. Therefore, even if the bus bar applies a mechanical load to the electrical device, the possibility of stress concentrating at the connection between the electrical device and the circuit board is reduced. Because the circuit board and the electrical device are essentially directly attached to the bus bar, the resistance of the current paths connecting the bus bar to the circuit board and the electrical device can be relatively small. Thus, the energy storage device according to this aspect has improved reliability.

[0011] When the circuit board is positioned above the energy storage element, the device terminal and bus bar may be fixed to the board terminal in a state where they are stacked on top of each other in this order.

[0012] With this configuration, the bus bar is located at the top of the connection between the board terminal, the device terminal, and the bus bar. Therefore, when a cover member such as an inner lid or an outer lid is placed over the circuit board, the bus bar can be placed while being fixed to the cover member. In other words, by placing the cover member in a predetermined position, the bus bar can be positioned. This allows for efficient production of a reliable energy storage device.

[0013] The energy storage device may further include an outer casing that houses the energy storage element, the outer casing having external terminals arranged thereon, and the bus bar being a single conductive member connected to the external terminals.

[0014] According to this configuration, the bus bar connected to the external terminal for exchanging power with devices external to the energy storage device is directly connected mechanically and electrically to the electrical devices and the circuit board. This reduces the resistance in the main current path (power line) when charging and discharging the energy storage device. This contributes to improving the reliability of the energy storage device.

[0015] The energy storage device may further include a fixing member that fixes the equipment terminal and the bus bar to the board terminal, and one of a nut and a bolt of the fixing member is fixed to the board terminal, and the other of the nut and the bolt is fastened to the one, thereby fixing the equipment terminal and the bus bar to the board terminal.

[0016] According to this configuration, since the nuts or bolts are fixed to the board terminals, the task of fixing the device terminals and the bus bars to the board terminals together can be easily performed.

[0017] The electrical device may be a relay that switches on and off an electrical connection between the energy storage element and the bus bar in response to a signal transmitted from the circuit board.

[0018] This configuration allows a relay on the main current path (power line) of the energy storage device to be fixed to the circuit board together with the bus bar. Generally, a mechanical relay switch is used for a relay on a power line, which is relatively heavy. Therefore, fixing the electrical device, which is a relay, to the bus bar and the circuit board together is useful for improving the vibration resistance or impact resistance of the relatively heavy electrical device. This contributes to improving the reliability of the energy storage device.

[0019] Hereinafter, with reference to the drawings, a description will be given of an energy storage device according to an embodiment of the present invention (including its modified examples). The embodiments described below are all comprehensive or specific examples. The numerical values, shapes, materials, components, component placement and connection configurations, manufacturing processes, and the order of manufacturing processes shown in the following embodiments are merely examples and are not intended to limit the present invention. In each drawing, dimensions and the like are not strictly illustrated. In each drawing, the same or similar components are designated by the same reference numerals.

[0020] In the following description and drawings, the longitudinal direction of the exterior body of the energy storage device, the arrangement direction of multiple energy storage elements, or the opposing direction of the long side surfaces of the containers of the energy storage elements is defined as the X-axis direction. The lateral direction of the exterior body of the energy storage device, the opposing direction of the short side surfaces of the containers of the energy storage elements, or the arrangement direction of a pair of electrode terminals of one energy storage element is defined as the Y-axis direction. The arrangement direction of the main body and lid of the exterior body of the energy storage device, the arrangement direction of the bus bar holder and the energy storage element unit, or the up-down direction is defined as the Z-axis direction. The X-axis, Y-axis, and Z-axis directions intersect each other (orthogonal in this embodiment). Depending on the usage mode, the Z-axis may not be the up-down direction, but for convenience of explanation, the following description will be made assuming that the Z-axis direction is the up-down direction.

[0021] In the following description, the positive X-axis direction refers to the direction of the arrow on the X-axis, and the negative X-axis direction refers to the direction opposite to the positive X-axis direction. The same applies to the Y-axis and Z-axis directions. When simply referring to the "X-axis direction," it means either one or both directions parallel to the X-axis. The same applies to terms related to the Y-axis and Z-axis.

[0022] Expressions indicating relative directions or attitudes, such as parallel and perpendicular, also include cases where the directions or attitudes are not strictly those. For example, "two directions are perpendicular" does not only mean that the two directions are completely perpendicular, but also means that the two directions are substantially perpendicular, i.e., that there is a difference of, for example, a few percent. In the following description, when the term "insulation" is used, it means "electrical insulation."

[0023] (Embodiment) [1. General description of the power storage device] First, a schematic configuration of an energy storage device 1 according to an embodiment will be described with reference to Fig. 1 and Fig. 2. Fig. 1 is a perspective view showing the appearance of the energy storage device 1 according to an embodiment. Fig. 2 is an exploded perspective view of the energy storage device 1 according to an embodiment. In addition to the components shown in Fig. 2 and subsequent figures, the exterior body 10 accommodates bus bars joined to electrode terminals 120 of the energy storage elements 100, wiring connected to electrical equipment 80, and the like, but illustrations and descriptions of these components will be omitted as appropriate.

[0024] The power storage device 1 is a device that can charge with electricity from an external source and discharge electricity to the outside, and in this embodiment, has a substantially rectangular parallelepiped shape. The power storage device 1 is, for example, a battery module (battery assembly) used for power storage or power supply purposes. Specifically, the power storage device 1 is used as a battery for driving or starting the engine of a moving object such as an automobile, motorcycle, personal watercraft, ship, snowmobile, agricultural machinery, construction machinery, or electric railway vehicle. Examples of the automobile include an electric vehicle (EV), a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV), and a fossil fuel (gasoline, diesel, liquefied natural gas, etc.) vehicle. Examples of the electric railway vehicle include a train, a monorail, a linear motor car, and a hybrid train equipped with both a diesel engine and an electric motor. The power storage device 1 can also be used as a stationary battery for home or business use.

[0025] 1 and 2, the energy storage device 1 includes an exterior body 10 and an energy storage element unit 150 housed in the exterior body 10. The exterior body 10 is disposed outside the energy storage element unit 150, fixes them in a predetermined position, and protects them from impacts and the like. In this embodiment, the exterior body 10 is a box-shaped (approximately rectangular parallelepiped) container (module case) that constitutes the housing of the energy storage device 1. The exterior body 10 is formed of an insulating material such as polycarbonate (PC), polypropylene (PP), polyethylene (PE), polystyrene (PS), polyphenylene sulfide resin (PPS), polyphenylene ether (PPE (including modified PPE)), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyether ether ketone (PEEK), tetrafluoroethylene-perfluoroalkyl vinyl ether (PFA), polytetrafluoroethylene (PTFE), polyethersulfone (PES), polyamide (PA), ABS resin, or a composite material thereof, or a metal or the like with an insulating coating. This prevents the energy storage element unit 150 and the like from coming into contact with external metal members and the like. The exterior body 10 may be formed of a conductive material such as a metal as long as electrical insulation between the exterior body 10 and the energy storage element unit 150 and the like is maintained.

[0026] In this embodiment, the exterior body 10 includes an exterior body main body 12 and a lid body 11. The exterior body main body 12 is a bottomed rectangular cylindrical housing with an opening 12a formed on the positive side of the Z axis, and houses the energy storage element unit 150 and other components. The lid body 11 is a rectangular member that closes the opening 12a of the exterior body main body 12. The lid body 11 is joined to the exterior body main body 12, preferably in an airtight or watertight manner, by adhesive, heat sealing, ultrasonic welding, laser welding, or the like. A pair of external terminals 13, which are a pair of module terminals for positive and negative electrodes, are disposed on the lid body 11. The energy storage device 1 is charged with electricity from the outside and discharges electricity to the outside via the pair of external terminals 13. The external terminals 13 are formed of a conductive metal material, such as aluminum, an aluminum alloy, copper, or a copper alloy. When the pair of external terminals 13 are distinguished as a positive electrode and a negative electrode, the positive external terminal 13 is referred to as an "external terminal 13a" and the negative external terminal 13 is referred to as an "external terminal 13b".

[0027] The energy storage element unit 150 has one or more energy storage elements 100. In this embodiment, the energy storage element unit 150 is configured by connecting eight energy storage elements 100 with a plurality of bus bars (not shown). These eight energy storage elements 100 are connected in series with, for example, seven bus bars. The electrical connection mode of the eight energy storage elements 100 is not limited to this. When two parallel-connected energy storage elements 100 are used as one sub-unit, four sub-units may be connected in series with three bus bars. The energy storage element unit 150 may further include members (not shown), such as spacers arranged between adjacent energy storage elements 100 and restraining members that restrain the plurality of energy storage elements 100 in the arrangement direction.

[0028] The energy storage element 100 is a secondary battery (single cell) capable of charging and discharging electricity, and specifically, a nonaqueous electrolyte secondary battery such as a lithium-ion secondary battery. As shown in FIG. 2, the energy storage element 100 has a flat rectangular (square) container 110 and a pair of electrode terminals 120 (positive and negative) fixed to the container 110. An electrode body, a current collector, an electrolyte, and the like (not shown) are housed inside the container 110. An example of the electrode body included in the energy storage element 100 is a wound-type electrode body formed by winding layers of positive and negative electrode plates with a separator sandwiched between them. The energy storage element 100 may also be provided with a stack-type electrode body formed by stacking multiple flat electrode plates, or a bellows-type electrode body formed by folding electrode plates in a bellows shape.

[0029] The energy storage element 100 is not limited to a non-aqueous electrolyte secondary battery, but may be a secondary battery other than a non-aqueous electrolyte secondary battery, or may be a capacitor. The energy storage element 100 may not be a secondary battery, but may be a primary battery that can use stored electricity without the user having to charge it. The energy storage element 100 may be a battery that uses a solid electrolyte. The energy storage element 100 may be a pouch-type energy storage element. Furthermore, the shape of the energy storage element 100 is not limited to the above-mentioned rectangular shape, but may be other shapes such as a polygonal prism, a cylindrical shape, an elliptical cylindrical shape, or an oblong cylindrical shape.

[0030] In this embodiment, the container 110 has a pair of long side surfaces 110a, a pair of short side surfaces 110b, and a terminal arrangement surface 110c, as shown in Fig. 2. The terminal arrangement surface 110c is a surface on which positive and negative electrode terminals 120 are arranged. In this embodiment, a gas release valve 105 is also arranged on the terminal arrangement surface 110c. The gas release valve 105 is a part that opens in response to an excessive increase in internal pressure of the container 110, thereby releasing gas inside the container 110 to the outside. In the energy storage element unit 150, the multiple energy storage elements 100 are arranged with their long side surfaces 110a facing the arrangement direction (X-axis direction).

[0031] A circuit board 50 and an electric device 80 are disposed between the energy storage element unit 150 and the cover 11. In this embodiment, the circuit board 50 is a control circuit board called a BMU (Battery Management Unit). The circuit board 50 detects the voltage and the like of each of the energy storage elements 100 and controls the charging state of the energy storage elements 100. Specifically, the circuit board 50 is electrically connected to each of the energy storage elements 100 via voltage detection wiring (detection lines) not shown, and can measure the voltage of each energy storage element 100 via the detection lines. The circuit board 50 has a plurality of electronic components mounted on a board 51, which is, for example, a printed circuit board, but these electronic components are not shown in the figure.

[0032] In this embodiment, the electrical device 80 is a relay having a mechanical relay switch. The electrical device 80 has a function of switching on and off the charging or discharging of the multiple energy storage elements 100 under the control of the circuit board 50. The electrical device 80 is connected to the general positive terminal of the energy storage element unit 150 via the bus bar 75, and is also connected to the positive external terminal 13 (external terminal 13a) via the bus bar 70. The general positive terminal of the energy storage element unit 150 is, for example, the positive electrode terminal 120 of the energy storage element 100 at the end in the positive direction of the X axis in FIG. 2.

[0033] The circuit board 50 and the electric device 80 configured in this manner are housed inside the exterior housing 10 in a state where they are fixed to an insulating member such as a bus bar holder (not shown) arranged above the energy storage elements 100 (in the positive direction of the Z axis). The circuit board 50 and the electric device 80 are electrically connected, and the electric device 80 is also electrically connected to the bus bar 70. In the energy storage device 1 configured in this manner, in this embodiment, the three members, the circuit board 50, the electric device 80, and the bus bar 70, are electrically and mechanically connected at one location. In other words, the connections of the three members are concentrated at one location. Features of such a connection structure will be described below with reference to FIGS. 3 to 5.

[0034] [2. Connection structure for circuit boards, electrical equipment, and bus bars] Fig. 3 is a perspective view showing a state in which a circuit board 50, an electric device 80, and a bus bar 70 according to an embodiment are connected to each other. Fig. 4 is an exploded perspective view corresponding to Fig. 3. Fig. 5 is a side view corresponding to Fig. 3. Fig. 5 shows a side view of the circuit board 50, the electric device 80, and the bus bar 70 in a connected state, as viewed from the negative direction of the X axis, and the external terminals 13a shown in Figs. 3 and 4 are not shown. In Fig. 5, the electric device 80 is shown in a state in which it is supported only by the board terminals 52, but the electric device 80 may also be supported by an insulating member such as a bus bar holder arranged above the energy storage element unit 150.

[0035] As shown in FIGS. 3 to 5 , the circuit board 50 includes a board 51 and board terminals 52 protruding from the board 51 in the positive direction of the Z axis. The electric device 80 includes a flat-plate-shaped device terminal 82, which is fixed to the board terminal 52 by a fixing member 90. In this embodiment, the fixing member 90 includes a bolt 91 and a nut 95. That is, the device terminal 82 is mechanically and electrically connected to the board terminal 52 by fastening the bolt 91, which passes through the device terminal 82 and the board terminal 52, to the nut 95. Specifically, as shown in FIG. 4 , the board terminal 52 is formed in a box shape to accommodate the nut 95 therein, and has a through hole 52a formed in a position facing the screw hole of the nut 95. The bolt 91, which is inserted into the through hole 82a provided in the device terminal 82, passes through the through hole 52a and is fastened to the nut 95. The board terminal 52 also functions as a rotation stopper for the nut 95, making it easy to tighten the bolt 91. In FIG. 4 , the nut 95 is shown separated from the board terminal 52 to clearly illustrate the nut 95, but the nut 95 and the board terminal 52 do not have to be separable. In this embodiment, the nut 95 is fixed to the board terminal 52 by welding or the like, which allows the board terminal 52 to be treated as a single component to which the nut 95 is fixed. Alternatively, the nut 95 may be provided integrally with the board terminal 52 as a part of the board terminal 52. In other words, the nut 95 may have a lead portion that is joined to the wiring of the board 51.

[0036] In this embodiment, the fixing member 90 also serves to mechanically and electrically connect the bus bar 70 to the electric device 80. That is, the bus bar 70 and the device terminal 82 are fixed together to the board terminal 52 by a bolt 91 and a nut 95. Specifically, the bus bar 70 has a through hole 70a at one end through which the bolt 91 passes, and a through hole 70b at the other end through which the external terminal 13a is fixed. That is, the bolt 91 of the fixing member 90 is inserted through the through hole 70a of the bus bar 70, the through hole 82a of the device terminal 82, and the through hole 52a of the board terminal 52 in this order, and then fastened to the nut 95. As a result, the external terminal 13a is electrically connected to the electric device 80 and the circuit board 50 via the bus bar 70. The circuit board 50, with the electrical device 80 and the bus bar 70 fixed to the board terminals 52, may be fixed to a member such as a bus bar holder on which the circuit board 50 is placed, by screws passing through each of the multiple screw holes 50a (see Figure 4).

[0037] The circuit board 50, which is a control circuit board, is electrically connected to the negative external terminal 13 (external terminal 13b) via a bus bar (not shown) and operates using power received via the external terminals 13a and 13b. The electric device 80, which is a relay, is disposed midway along the current path between the external terminal 13a and the energy storage element unit 150 and is connected to the circuit board 50 via a signal line (not shown). Specifically, the signal line extending from the circuit board 50 has a connector at its end, and the connector is inserted into a socket 85 of the electric device 80, thereby connecting the signal line to the electric device 80. Therefore, the electric device 80 can receive a signal (control signal) from the circuit board 50 via the signal line and can switch a relay switch on and off in accordance with the control signal. This allows the charging and discharging of the energy storage device 1 to be switched on and off.

[0038] As described above, the energy storage device 1 according to this embodiment includes the energy storage elements 100, the circuit board 50, the electric device 80, and the bus bar 70. The circuit board 50 has the board 51 and the board terminal 52 that is electrically connected to the energy storage elements 100 and fixed to the board 51. The device terminal 82 and the bus bar 70 that are fixed to the electric device 80 are fixed collectively to the board terminal 52, and are thereby electrically connected to the board terminal 52.

[0039] This configuration allows the electric device 80 and the bus bar 70 to be fixed together to the circuit board 50, and allows the electric device 80 and the circuit board 50 to be electrically connected to the bus bar 70 at a single location. Therefore, even if the bus bar 70 applies a mechanical load to the electric device 80, the possibility of stress concentration at the connection between the electric device 80 and the circuit board 50 is reduced. Because the circuit board 50 and the electric device 80 are essentially directly attached to the bus bar 70, the resistance of the current paths connecting the bus bar 70 to the circuit board 50 and the electric device 80 can be relatively small. By consolidating the connections of the three components in one location, the energy storage device 1 can be manufactured efficiently. The circuit board 50, the electric device 80, and the bus bar 70 are each fixed to the other two components, and the other two components are fixed to each other. Therefore, resistance to shock or vibration is improved. Thus, the energy storage device 1 according to this embodiment is an energy storage device with improved reliability.

[0040] In this embodiment, when the circuit board 50 is positioned above the energy storage element 100, the device terminal 82 and the bus bar 70 are fixed to the board terminal 52 in a state where they are stacked on top of each other in this order.

[0041] As described above, in this embodiment, the bus bar 70 is located at the top of the connection between the board terminals 52, the device terminals 82, and the bus bar 70. Therefore, when the lid 11 is placed on top of the circuit board 50 housed in the exterior body main body 12, the bus bar 70 can be placed in a state where it is fixed to the lid 11. If the bus bar 70 is integrated with the lid 11 by insert molding, the bus bar 70 can be positioned by attaching the lid 11 to the exterior body main body 12. This allows for efficient manufacture of an energy storage device 1 with improved reliability. In this case, by providing an opening in the lid 11 at a position facing the board terminals 52 in the Z-axis direction, the bolt 91 can be tightened through the opening after the lid 11 is joined to the exterior body main body 12. Furthermore, the airtight state of the exterior body 10 can be maintained by closing the opening with a cover plate made of, for example, a resin material.

[0042] In this embodiment, the energy storage device 1 includes an exterior body 10 that houses energy storage elements 100. External terminals 13 are arranged on the exterior body 10, and the bus bar 70 is a single conductive member connected to the external terminals 13. Specifically, in this embodiment, as shown in FIGS. 3 and 4 , a positive electrode external terminal 13 (external terminal 13a) is fixed to the end of the bus bar 70 opposite to the end fixed by the fixing member 90.

[0043] According to this configuration, the bus bar 70 connected to the external terminal 13 that exchanges power with devices external to the energy storage device 1 is directly electrically connected to the electrical device 80 and the circuit board 50. This reduces the resistance value in the main current path (power line) when the energy storage device 1 is charged or discharged. This contributes to improving the reliability of the energy storage device 1.

[0044] In this embodiment, the energy storage device 1 includes a fixing member 90 that fixes the device terminal 82 and the bus bar 70 to the board terminal 52. A nut 95 of the fixing member 90 is fixed to the board terminal 52, and the device terminal 82 and the bus bar 70 are fixed to the board terminal 52 by being fastened with a bolt 91 of the fixing member 90.

[0045] According to this configuration, since the nut 95 is fixed to the board terminal 52, the device terminal 82 and the bus bar 70 can be easily fixed together to the board terminal 52. This effect is also achieved when the bolt 91 is fixed to the board terminal 52 and the nut 95 is fastened to the bolt 91. In other words, if one of the nut 95 and the bolt 91 of the fixing member 90 is fixed to the board terminal 52 and the other of the nut 95 and the bolt 91 is fastened to the one, the above-mentioned fixing operation can be facilitated.

[0046] In the present embodiment, electrical device 80 is a relay that switches the electrical connection between energy storage elements 100 and bus bar 70 on and off in response to a signal transmitted from circuit board 50.

[0047] According to this configuration, the relay on the main current path (power line) of the energy storage device 1 can be fixed to the circuit board 50 together with the bus bar 70. Generally, a mechanical relay switch is used as a relay on a power line, and therefore is relatively heavy. Therefore, fixing the electrical device 80, which is a relay, to the bus bar 70 and the circuit board 50 together is useful for improving the vibration resistance or impact resistance of the relatively heavy electrical device 80. This contributes to improving the reliability of the energy storage device 1.

[0048] [3. Modifications] Although the energy storage device 1 according to the embodiment of the present invention has been described above, the present invention is not limited to this embodiment. The embodiment disclosed herein is illustrative in all respects and is not restrictive, and the scope of the present invention includes all modifications within the meaning and scope of the claims.

[0049] The board terminals 52, device terminals 82, and bus bars 70 do not have to be stacked vertically (in the Z-axis direction). The board terminals 52, device terminals 82, and bus bars 70 may be stacked horizontally (in a direction parallel to the XY plane). In this case, the bolt 91 is fastened to the nut 95 while passing through these three components, with its axial direction parallel to the stacking direction of these three components. This mechanically and electrically connects these three components together.

[0050] The positions of the nut 95 and the bolt 91 may be interchanged. For example, in FIG. 4 , the shank of the bolt 91 may be inserted through the through hole 52a of the board terminal 52 from below, thereby attaching the bolt 91 to the board 51. In this case, the board terminal 52 and the bolt 91 may be joined by welding or the like. Alternatively, for example, a lead portion joined to the wiring of the board 51 may be provided at the head of the bolt 91, so that a part of the bolt 91 functions as the board terminal 52. In either case, the shank of the bolt 91 erected on the board 51 can be inserted through the through hole 82a of the device terminal 82 and the through hole 70a of the bus bar 70 and fastened to the nut 95. This allows the electric device 80 and the bus bar 70 to be fixed to the circuit board 50 collectively, and allows the electric device 80 and the circuit board 50 to be electrically connected to the bus bar 70 at one location.

[0051] The method by which the fixing member 90 fixes the bus bar 70 and the device terminal 82 of the electric device 80 to the board terminal 52 is not limited to fastening with the bolt 91 and the nut 95. The bus bar 70 and the device terminal 82 may be fixed to the board terminal 52 by other methods such as welding, crimping, or press fitting.

[0052] The board terminals 52, the device terminals 82, and the bus bars 70 may be detachably fixed, or the board terminals 52, the device terminals 82, and the bus bars 70 may be non-detachably fixed.

[0053] The board terminals 52 may protrude from the peripheral edge of the board 51. In this case, the board terminals 52 may protrude from the peripheral edge of the board 51 in a direction perpendicular to the board 51 or in a direction parallel to the board 51.

[0054] The electrical device 80 is not limited to a relay, but may be another type of electrical device, such as a protection circuit including a fuse or a current measuring instrument including a shunt resistor. The circuit board 50 is also not limited to a control circuit board, but may be another type of circuit board, such as a measurement circuit board for simply measuring voltage or temperature, or a communication circuit board forming an electronic circuit for communication. The external terminal 13 connected to the electrical device 80 via the bus bar 70 may be a negative external terminal 13 (external terminal 13b).

[0055] The energy storage device 1 does not need to have a sealed exterior body such as the exterior body 10 shown in FIG. 1. The energy storage device 1 may have an exterior body having a plurality of openings (through holes) in the wall portion for heat dissipation. A restraining member that restrains the plurality of energy storage elements 100 of the energy storage element unit 150 in the arrangement direction may hold the energy storage element unit 150 and function as an exterior body on which a pair of external terminals 13 and the like are arranged. The energy storage device 1 does not need to have an exterior body.

[0056] 1 and other drawings is not necessarily fixed to the exterior body 10. For example, an end of the bus bar 70 may protrude from the exterior body 10 to serve as an external terminal. A cable connected to the bus bar 70 inside the exterior body 10 may be drawn out to the outside of the exterior body 10, and the cable may serve as an external terminal.

[0057] Any combination of the components included in the above-described embodiments and their modifications is also included within the scope of the present invention. [Industrial Applicability]

[0058] The present invention can be applied to an electricity storage device including an electricity storage element such as a lithium ion secondary battery. [Explanation of symbols]

[0059] 1. Energy storage device 10. Exterior body 13, 13a, 13b external terminal 50 Circuit Board 51 PCB 52 PCB terminal 70, 75 busbar 80 Electrical Equipment 82 Equipment terminal 90 Fixing member 91 volts 95 Nut 100 Energy storage element

Claims

1. An energy storage device including an energy storage element, a circuit board, an electric device, and a bus bar, the circuit board includes a substrate and a substrate terminal electrically connected to the power storage element and fixed to the substrate; The device terminal fixed to the electrical device and the bus bar are collectively fixed to the board terminal, and are thereby electrically connected to the board terminal. Energy storage device.

2. When the circuit board is positioned above the energy storage element, the device terminal and the bus bar are stacked on the board terminal in this order and fixed to the board terminal. The electricity storage device according to claim 1.

3. Further, an exterior body that houses the power storage element is provided, an external terminal is disposed on the exterior body; The bus bar is a single conductive member connected to the external terminal. The electricity storage device according to claim 1 or 2.

4. a fixing member for fixing the device terminal and the bus bar to the board terminal; One of a nut and a bolt of the fixing member is fixed to the board terminal, and the other of the nut and the bolt is fastened to the one, thereby fixing the device terminal and the bus bar to the board terminal. The electricity storage device according to any one of claims 1 to 3.

5. the electrical device is a relay that switches on and off an electrical connection between the energy storage element and the bus bar in response to a signal transmitted from the circuit board. The electricity storage device according to any one of claims 1 to 4.

6. The substrate terminals protrude from the peripheral edge of the substrate. The electricity storage device according to any one of claims 1 to 5.

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