Power supply device, vehicle equipped with same, and power storage device

Abstract

A power source device (100) comprises: a battery laminate (10) in which a plurality of battery cells (1) are laminated; a plurality of busbars (50) connecting battery terminals (2) to each other; a busbar holder (41) holding the busbars (50); and a duct plate (49) disposed on an upper surface of the busbar holder (41) and defining a gas duct (43). The busbar holder (41) is divided into a plurality of sub-holders (42). The duct plate (49) has, formed therein, elongated holes (49b) by which the duct plate (49) can be screwed to the sub-holders (42). Each sub-holder (42) forms, at a position corresponding to an elongated hole (49b), a support surface (61) that is longer than the elongated hole (49b) and a coupling part (63) opened in the support surface (61). In a state in which the duct plate (49) is placed on the support surface (61) so as to straddle the plurality of divided sub-holders (42), the duct plate (49) is screwed to the coupling parts (63) through the elongated holes (49b), thereby coupling the plurality of sub-holders (42) and the duct plate (49).

Description

[Technical field]

[0001] The present disclosure relates to a power supply device, a vehicle including the same, and a power storage device. [Background technology]

[0002] 2. Description of the Related Art Power supply devices such as battery modules and battery packs each having a plurality of battery cells are used as power sources for vehicles such as hybrid cars and electric cars, and as power sources for factory and home power storage systems (see, for example, Patent Documents 1 to 3).

[0003] Such a power supply device has a plurality of stacked battery cells that can be charged and discharged. For example, as shown in the schematic cross-sectional view of Fig. 21, a power supply device 900 has end plates 903 arranged on both end faces of a battery stack 910 in which rectangular exterior can battery cells 901 are stacked, and the end plates 903 are fastened together by a bind bar 904. Furthermore, the rectangular battery cells 901 have positive and negative electrode terminals 902 spaced apart on their top faces. The electrode terminals 902 of adjacent battery cells 901 are connected by a bus bar. Generally, the bus bar is held in position by a bus bar holder 941. Such a bus bar holder 941 is made of resin such as polypropylene.

[0004] Furthermore, the battery cell 901 is provided with a gas exhaust valve 901c that opens to release gas when the inside of the exterior can becomes highly pressurized in the event of an abnormality. The gas exhaust valve 901c is formed, for example, between the positive and negative electrode terminals 902 on the upper surface of the exterior can of the battery cell 901. In a power supply device 900 in which many such battery cells 901 are stacked, if the inside of any battery cell becomes highly pressurized for some reason, such as thermal runaway, high-temperature, high-pressure gas is released from the gas exhaust valve 901c. For this reason, a gas duct is provided above the battery stack 910. The gas duct is formed, for example, by screwing a duct plate 949 to the upper surface of the bus bar holder 941 in FIG. 20.

[0005] When a battery cell is repeatedly charged and discharged, the exterior can expands and contracts. In particular, in response to the demand for higher capacity in recent years, the capacity of each secondary battery cell is increasing, and as a result, the amount of expansion tends to increase. In a battery stack in which many such secondary battery cells are stacked and fastened, the expansion of each battery cell causes mutual displacement between adjacent battery cells, so it is necessary to absorb the displacement between the electrode terminals with the bus bar holder 941. For example, a stretchable structure is formed using a resin hinge or spring to absorb the displacement between the electrode terminals. In order to make such a resin hinge or spring, the bus bar holder needs to be made of a flexible resin such as polypropylene, as described above.

[0006] On the other hand, as the capacity of battery cells increases, a gas duct is formed above the battery stack to safely exhaust gas that is released in the event of an internal short circuit in a cell. The gas duct is formed by fixing a duct plate 949 to the upper surface of a bus bar holder 941 as shown in Fig. 20.

[0007] However, as described above, bus bar holder 941 needs to have flexibility that can absorb the expansion of battery cells 901, and at the same time, duct plate 949 needs to be firmly fixed to resin bus bar holder 941 with bolts 967 so that it will not come off even when exposed to high gas pressure, and so high rigidity is required. Thus, bus bar holder 941 is required to have the conflicting properties of flexibility against deformation and resistance to high pressure, and it has been difficult to achieve both of these properties at the same time. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Patent No. 6344362 [Patent Document 2] Patent No. 6465196 [Patent Document 3] Patent No. 5668555 Summary of the Invention [Problem to be solved by the invention]

[0009] An object of one embodiment of the present invention is to provide a power supply device that can handle a situation in which the overall length of a battery stack in which a plurality of battery cells are stacked expands or contracts, and a vehicle and a power storage device including the power supply device. [Means for solving the problem]

[0010] A power supply device according to one aspect of the present invention comprises a battery stack formed by stacking a plurality of battery cells, each of which has a gas exhaust valve that opens when the internal pressure of an outer can rises and electrode terminals formed on its upper surface, a plurality of bus bars that connect the electrode terminals to each other, a bus bar holder that holds the bus bars, and a duct plate that is arranged on the upper surface of the bus bar holder and defines a gas duct, wherein the bus bar holder is divided into a plurality of sub-holders, and the duct plate has elongated holes formed therein that are coupled to the sub-holders, and each sub-holder has a support surface that is longer than the elongated hole at a position corresponding to the elongated hole, and a connecting portion that opens into the support surface, and with the duct plate placed on the support surface so as to straddle the divided sub-holders, the duct plate is coupled to the connecting portion through the elongated hole to connect the sub-holders and the duct plate. Effect of the Invention

[0011] In a power supply device according to one aspect of the present invention, the bus bar holder is divided into multiple pieces, making it possible to absorb expansion and contraction in the stacking direction of the battery cells, while being fixed to a non-expanding duct plate so that it can slide freely, thereby enabling the connection state to be maintained. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a perspective view showing a power supply device with an enlarged view of a main part according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is an exploded perspective view of the power supply device shown in FIG. [Diagram 3] 3 is an exploded perspective view of the cover assembly of FIG. 2 in which a bus bar holder and a duct plate are separated. FIG. [Figure 4]4 is an exploded perspective view of the bus bar holder of FIG. 3 from which the bus bar is separated. [Diagram 5] 5 is an exploded perspective view of the bus bar holder of FIG. 4 divided into sub-holders. FIG. [Figure 6] FIG. 3 is a plan view of the cover assembly of FIG. 2. [Figure 7] 7 is a plan view with an enlarged view of a main part showing the bus bar holder in FIG. 6 with the duct plate removed. [Figure 8] 8 is a plan view with an enlarged view of a main part showing the bus bar holder in FIG. 7 with the bus bar removed. [Figure 9] 9 is a plan view with an enlarged view of a main portion in which the bus bar holder in FIG. 8 is divided into sub-holders. [Figure 10] FIG. 7 is a schematic cross-sectional view taken along line XX in FIG. 6. [Figure 11] FIG. 2 is an enlarged exploded perspective view of a main portion of the bus bar holder. [Figure 12] 13 is a schematic cross-sectional view showing a connection structure between a duct plate and a sub-holder according to a modified example. FIG. [Figure 13A] 13 is a schematic cross-sectional view showing a connection structure between a duct plate and a sub-holder according to another modified example. FIG. [Figure 13B] 13B is a schematic cross-sectional view showing a state in which the connecting portion is heat-caulked from the state shown in FIG. 13A. [Figure 14A] FIG. 11 is a plan view showing a bush nut used to connect a duct plate and a sub-holder according to still another modified example. [Figure 14B] 14B is a schematic cross-sectional view showing a connection structure between the duct plate and the sub-holder in FIG. 14A. [Figure 15] 13 is a schematic cross-sectional view showing a connecting structure between a duct plate and a sub-holder according to still another modified example. FIG. [Figure 16] FIG. 11 is a plan view showing a bus bar holder of a power supply device according to a second embodiment. [Figure 17] 1 is a block diagram showing an example of a power supply device mounted on a hybrid vehicle that runs on an engine and a motor. [Figure 18] FIG. 1 is a block diagram showing an example in which a power supply device is mounted on an electric vehicle that runs only on a motor. [Figure 19]FIG. 11 is a block diagram showing an example of application to a power supply device for power storage. [Figure 20] FIG. 1 is a schematic plan view showing a conventional power supply device. [Figure 21] FIG. 13 is an exploded perspective view showing a conventional power supply device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] The embodiment of the present invention may be specified by the following configurations.

[0014] In addition to the above configuration, in a power supply device according to one embodiment of the present invention, the sub-holder forms a boss inside the gas duct, and the support surface is formed on an upper surface of the boss.

[0015] In addition to any of the above configurations, a power supply device according to another embodiment of the present invention has an annular frame that protrudes from the support surface around the connecting portion to be inserted into the elongated hole. With the above configuration, the annular frame can be inserted into the elongated hole and function as a guide for sliding the connecting portion along the elongated hole.

[0016] Furthermore, in addition to any of the configurations described above, a power supply device according to another embodiment of the present invention has an insert nut embedded in the boss.

[0017] Furthermore, in addition to any one of the configurations described above, a power supply device according to another embodiment of the present invention is arranged such that the support surface is formed in a track shape.

[0018] Furthermore, in addition to any one of the configurations described above, a power supply device according to another embodiment of the present invention has an interface between the sub-holders facing each other, which is formed in a stepped shape in a plan view.

[0019] Furthermore, in a power supply device according to another embodiment of the present invention, in addition to any of the configurations described above, the bus bar holder extends from one of the opposing surfaces of the sub-holders facing each other toward the other opposing surface, forming an overlap portion that closes the gap between the sub-holders. With the above configuration, even if gas is released from a gas release valve of one of the battery cells through a gap created by dividing the bus bar holder into sub-holders, the overlap portion can prevent gas from leaking from the gap.

[0020] Furthermore, in addition to any one of the configurations described above, a power supply device according to another embodiment of the present invention includes a busbar that includes a busbar main body that is extended into a rectangular column shape, and busbar branch portions that extend from the busbar main body and are connected to the electrode terminals.

[0021] Furthermore, in addition to any of the configurations described above, a power supply device according to another embodiment of the present invention is such that the bus bar holder is formed from PBT.

[0022] Furthermore, in a power supply device according to another embodiment of the present invention, in addition to any one of the configurations described above, the duct plate is made of SUS or iron.

[0023] Furthermore, an electric vehicle according to another embodiment of the present invention includes any of the power supply devices described above, a motor for driving supplied with power from the power supply device, a vehicle body mounting the power supply device and the motor, and wheels driven by the motor to drive the vehicle body.

[0024] Furthermore, an energy storage device according to another embodiment of the present invention comprises any of the power supply devices described above and a power supply controller that controls charging and discharging to the power supply device, and the power supply controller enables charging of the battery cells using external power and controls charging of the battery cells.

[0025] Hereinafter, an embodiment of the present invention will be described based on the drawings. However, the embodiment shown below is an example for embodying the technical idea of ​​the present invention, and the present invention is not limited to the following. In addition, this specification never specifies the members shown in the claims to the members of the embodiment. In particular, the dimensions, materials, shapes, and relative arrangements of the components described in the embodiment are not intended to limit the scope of the present invention to those, and are merely explanatory examples, unless otherwise specified. Note that the size and positional relationship of the components shown in each drawing may be exaggerated to clarify the explanation. Furthermore, in the following explanation, the same name and symbol indicate the same or similar components, and detailed explanations will be omitted as appropriate. Furthermore, each element constituting the present invention may be configured as a form in which multiple elements are composed of the same member, and one member serves multiple elements, or conversely, the function of one member can be shared and realized by multiple members. In addition, the contents described in some examples and embodiments may be applicable to other examples, embodiments, etc.

[0026] The power supply device according to the embodiment is used for various purposes, such as a power supply mounted on an electric vehicle such as a hybrid car or an electric car to supply power to a driving motor, a power supply for storing power generated by natural energy such as solar power generation or wind power generation, or a power supply for storing late-night power, and is particularly used as a power supply suitable for large power and large current applications. In the following example, an embodiment applied to a power supply device for driving an electric vehicle will be described. [Embodiment 1]

[0027] A power supply device 100 according to a first embodiment of the present invention is shown in Figures 1 and 2. In these figures, Figure 1 shows an exploded perspective view with an enlarged view of a main part of the power supply device 100 according to the first embodiment, and Figure 2 shows an exploded perspective view of the power supply device 100 shown in Figure 1.

[0028] The power supply device 100 shown in these figures comprises a battery stack 10 made up of multiple stacked battery cells 1, a pair of end plates 20 covering both side ends of the battery stack 10, a number of fastening members 15 fastening the end plates 20 together, and a cover assembly 40 provided on the top surface of the battery stack 10.

[0029] The fastening members 15 are formed in a plate shape that extends along the stacking direction of the multiple battery cells 1. The fastening members 15 are disposed on opposing side surfaces of the battery stack 10 and fasten the end plates 20 together. (Battery stack 10)

[0030] As shown in FIG. 2, the battery stack 10 includes a plurality of battery cells 1 each having positive and negative electrode terminals 2, and bus bars 50 that are connected to the electrode terminals 2 of the battery cells 1 and connect the battery cells 1 in parallel and in series. The battery cells 1 are connected in parallel and in series via the bus bars 50. The battery cells 1 are rechargeable secondary batteries. In the power supply device 100, the battery cells 1 are connected in parallel to form parallel battery groups, and the parallel battery groups are connected in series to connect many battery cells 1 in parallel and in series. The power supply device 100 shown in FIG. 2 stacks the battery cells 1 to form the battery stack 10. A pair of end plates 20 are arranged on both end faces of the battery stack 10. The ends of fastening members 15 are fixed to the end plates 20 to fix the stacked battery cells 1 in a pressed state. (Battery cell 1)

[0031] As shown in FIG. 2, the battery cells 1 are rectangular batteries that are wider than their thickness, in other words thinner than their width, and are stacked in the thickness direction to form a battery stack 10. The battery cells 1 can be, for example, lithium-ion secondary batteries. The battery cells can also be any rechargeable secondary batteries, such as nickel-metal hydride batteries and nickel-cadmium batteries. The battery cells 1 house positive and negative electrode plates together with an electrolyte in an outer can 1a with a sealed structure. The outer can 1a is formed by pressing a metal plate such as aluminum or an aluminum alloy into a rectangular shape, and the opening is airtightly sealed with a sealing plate 1b. The sealing plate 1b is made of the same aluminum or aluminum alloy as the rectangular outer can 1a, and has positive and negative electrode terminals 2 fixed to both ends. Furthermore, the sealing plate 1b is provided with a gas exhaust valve 1c, which is a safety valve that opens in response to pressure changes inside the battery cells 1, between the positive and negative electrode terminals 2.

[0032] A plurality of battery cells 1 are stacked such that the thickness direction of each battery cell 1 is the stacking direction to form a battery stack 10. In this case, by stacking a larger number of battery cells than usual, it is possible to increase the output of the battery stack 10. In such a case, the battery stack 10 becomes elongated in the stacking direction. The battery cells 1 are arranged with their terminal surfaces 1X, on which the positive and negative electrode terminals 2 are provided, on the same plane, and the plurality of battery cells 1 are stacked to form the battery stack 10. The upper surface of the battery stack 10 is the surface on which the gas release valves 1c of the plurality of battery cells 1 are provided. (electrode terminal 2)

[0033] 2 etc., the battery cell 1 has a terminal surface 1X formed by a sealing plate 1b, which is the top surface, and positive and negative electrode terminals 2 are fixed to both ends of this terminal surface 1X. The electrode terminals 2 have cylindrical protrusions. However, the protrusions do not necessarily have to be cylindrical, and can also be polygonal or elliptical.

[0034] The positions of the positive and negative electrode terminals 2 fixed to the sealing plate 1b of the battery cell 1 are such that the positive and negative electrodes are symmetrical. As a result, as shown in Fig. 2, the battery cells 1 are stacked with the left and right sides reversed, and adjacent positive and negative electrode terminals 2 that are close to each other are connected by a bus bar 50, so that adjacent battery cells 1 can be connected in series. Note that the present invention does not specify the number of battery cells that make up the battery stack and their connection state. The number of battery cells that make up the battery stack and their connection state can be changed in various ways, including other embodiments that will be described later.

[0035] Multiple battery cells 1 are stacked so that the thickness direction of each battery cell 1 is the stacking direction to form a battery stack 10. In the battery stack 10, multiple battery cells 1 are stacked so that the terminal surfaces 1X on which the positive and negative electrode terminals 2 are provided, that is, the sealing plate 1b in FIG. 2, are on the same plane.

[0036] The battery stack 10 may have an insulating spacer 16 between adjacent stacked battery cells 1. The insulating spacer 16 is made of an insulating material such as resin in the shape of a thin plate or sheet. The insulating spacer 16 is in the shape of a plate having a size almost equal to the size of the opposing surfaces of the battery cells 1. The insulating spacer 16 can be stacked between adjacent battery cells 1 to insulate the adjacent battery cells 1 from each other. Note that, as the spacer to be placed between adjacent battery cells, a spacer having a shape that forms a flow path for cooling gas between the battery cell and the spacer can also be used. The surface of the battery cell can also be covered with an insulating material. For example, the surface of the exterior can excluding the electrode terminal portion of the battery cell can be covered with a shrink film such as PET resin. In this case, the insulating spacer may be omitted. In addition, in a power supply device in which multiple battery cells are connected in parallel or in series, insulating spacers are interposed between the battery cells connected in series to insulate them from each other, while no voltage difference occurs between adjacent exterior cans between battery cells connected in parallel to each other, so the insulating spacer between these battery cells can also be omitted.

[0037] Furthermore, the power supply device 100 shown in Fig. 2 has end plates 20 disposed on both end faces of the battery stack 10. Note that end plate 20 and battery stack 10 may be insulated by interposing end spacers 17 between them. The end spacers 17 can also be made into thin plate or sheet shapes from an insulating material such as resin.

[0038] In the power supply device 100 of embodiment 1, a battery stack 10 is formed in which a number of battery cells 1 are stacked on top of each other, and the electrode terminals 2 of adjacent battery cells 1 are connected to each other by bus bars 50, thereby connecting the battery cells 1 in parallel and in series. (End plate 20)

[0039] 2, the end plates 20 are arranged on both ends of the battery stack 10 and are fastened via a pair of left and right fastening members 15 arranged along both side surfaces of the battery stack 10. The end plates 20 are located on the outsides of the end spacers 17, at both ends of the battery stack 10 in the stacking direction of the battery cells 1, and sandwich the battery stack 10 from both ends. (Fastening member 15)

[0040] Both ends of the fastening members 15 are fixed to end plates 20 arranged on both end faces of the battery stack 10. The end plates 20 are fixed using a plurality of fastening members 15, thereby fastening the battery stack 10 in the stacking direction. As shown in FIG. 2 etc., each fastening member 15 is made of metal and has a predetermined width and thickness that fits along the side of the battery stack 10, and is arranged facing both side faces of the battery stack 10. These fastening members 15 can be made of a metal plate such as iron, preferably a steel plate. The fastening members 15 made of metal plate are bent by press forming or the like to be formed into a predetermined shape.

[0041] The fastening member 15 is formed by bending the top and bottom of the plate-shaped fastening main surface 15a into a U-shape to form bent pieces 15d. The top and bottom bent pieces 15d cover the top and bottom corners of the left and right side surfaces of the battery stack 10. The fastening member 15 is fixed to the outer circumferential surface of the end plate 20 by screwing bolts 15f into multiple fastening screw holes opened in the fastening main surface 15a. Note that the method of fixing the fastening main surface 15a to the end plate 20 is not necessarily limited to screwing using bolts, and pins, rivets, etc. may also be used.

[0042] A power supply device 100 in which many battery cells 1 are stacked is configured to restrain the multiple battery cells 1 by connecting end plates 20 arranged on both ends of a battery stack 10 made up of the multiple battery cells 1 with fastening members 15. By restraining the multiple battery cells 1 via the highly rigid end plates 20 and fastening members 15, it is possible to suppress the expansion, deformation, relative movement, and malfunction due to vibration of the battery cells 1 that accompanies charging / discharging and deterioration. (Insulation sheet 30)

[0043] An insulating sheet 30 is interposed between the fastening members 15 and the battery stack 10. The insulating sheet 30 is made of an insulating material, such as resin, and provides insulation between the metal fastening members 15 and the battery cells 1. The insulating sheet 30 shown in FIG. 2 and other figures is made of a flat plate 31 that covers the side surfaces of the battery stack 10, and folded covering portions 32 provided above and below the flat plate 31. The folded covering portions 32 are folded in a U-shape from the flat plate 31 so as to cover the folded pieces 15d of the fastening members 15, and then folded back again. In this way, the folded pieces 15d are covered from the top surface to the side surfaces and bottom surface with the insulating folded covering portions, thereby preventing unintended electrical connection between the battery cells 1 and the fastening members 15.

[0044] Additionally, the bent pieces 15d press against the top and bottom surfaces of the battery cells 1 of the battery stack 10 via the folded covering portions 32. As a result, each battery cell 1 is pressed from above and below by the bent pieces 15d to hold it in the height direction, and even if vibrations, shocks, etc. are applied to the battery stack 10, each battery cell 1 can be kept from shifting position in the vertical direction.

[0045] Note that if the battery stack or the surface of the battery stack is insulated, for example if the battery cells are housed in an insulating case or covered with a resin heat-shrinkable film, or if the surfaces of the fastening members are coated with an insulating paint or coating, or if the fastening members are made of an insulating material, then the insulating sheet may be unnecessary. Also, for the insulating sheet 30, if there is no need to consider insulation from the folded pieces 15d of the fastening members 15 on the underside of the battery stack 10, the folded covering portion 32 may be formed only on the upper end side. For example, this would be the case if the battery cells are covered with a heat-shrinkable film. (Busbar holder 41)

[0046] The busbars 50 are held by busbar holders 41. The busbar holders 41 are fixed to the top surface of the battery stack 10. By using the busbar holders 41, the multiple busbars 50 can be arranged in fixed positions on the top surface of the battery stack 10 while insulating the multiple busbars 50 from each other and from the terminal surfaces 1X of the battery cells 1. (Cover assembly 40)

[0047] Cover assembly 40 in Fig. 2 is composed of busbar holder 41 and duct plate 49. Fig. 3 shows an exploded perspective view of cover assembly 40 in Fig. 2 with busbar holder 41 and duct plate 49 separated, Fig. 4 shows a state in which busbar 50 has been further separated from busbar holder 41 in Fig. 3, and Fig. 5 shows a state in which busbar holder 41 in Fig. 4 has been divided into sub-holders 42. Fig. 6 is a plan view of cover assembly 40 in Fig. 2, Fig. 7 is a plan view showing busbar holder 41 in Fig. 6 without duct plate 49, Fig. 8 is a plan view showing busbar holder 41 in Fig. 7 without busbar 50, and Fig. 9 is a plan view showing busbar holder 41 in Fig. 8 divided into sub-holders 42. (Busbar 50)

[0048] As shown in the exploded perspective views of Figs. 4 and 5, the busbar 50 is composed of a busbar main body 51 and busbar branches 52 extending from the busbar main body 51 and connected to the electrode terminals 2. The busbar main body 51 is extended into a prismatic shape, and the busbar branches 52 are fixed at predetermined intervals along the extension direction. The busbar main body 51 is a metal rod having excellent electrical conductivity. The busbar branches 52 are preferably made of the same material, such as copper or aluminum. The prismatic shape increases the cross-sectional area, thereby improving electrical conductivity. Moreover, the shape is rectangular rather than square, thereby reducing the height and avoiding an increase in the size of the power supply device.

[0049] The busbar branches 52 are manufactured into a predetermined shape by cutting and processing a metal plate. Here, they are bent in a stepped manner so as to fit the surface of the rectangular column-shaped busbar body 51. This increases the contact area between the busbar branches 52 and the busbar body 51, reducing contact resistance and maintaining high conductivity. Furthermore, by having the busbar branches 52 protrude from the side surface of the busbar body 51, they can be easily brought into contact with the electrode terminals 2 of the battery cells 1, improving the ease of welding work.

[0050] The metal plate constituting the busbar branch 52 can be a metal that has low electrical resistance and is lightweight, such as an aluminum plate or a copper plate, or an alloy of these. However, the metal plate of the busbar branch 52 can also be another metal that has low electrical resistance and is lightweight, or an alloy of these.

[0051] 4 and 5 is just an example, and does not necessarily have to be composed of busbar main body 51 and busbar branches 52. Typically, a busbar made of a single plate material is used. (Gas Duct 43)

[0052] The cover assembly 40 also constitutes a gas exhaust path, i.e., a gas duct 43, for exhausting high-temperature and high-pressure gas to the outside of the power supply device 100 when the gas is exhausted from any of the battery cells 1 constituting the battery stack 10. As shown in the exploded perspective view of FIG. 3, the bus bar holder 41 has a gas duct 43 formed in the center along the extension direction, and bus bars 50 are arranged on the left and right. With this arrangement, a gas exhaust path can be secured on the upper surface of the battery stack 10 while arranging the bus bars 50 that connect the electrode terminals. In the example shown in FIG. 6, the bus bar holder 41 has a pair of walls 46 formed in the center to define the gas duct 43. Also, a wiring section 44 is provided on the outside of the gas duct 43, in which harnesses such as output lines and signal lines of a circuit board are arranged. Furthermore, a bus bar guide section 45 is formed on the outside of the wiring section 44, in which the bus bar 50 is arranged. The bus bar holder 41 is made of resin with excellent insulating properties. For example, it is made of polybutylene terephthalate (PBT).

[0053] The wall portions 46 partition the gas duct 43 with the duct surface 48 of the bus bar holder 41 sandwiched between the wall portions 46 and a duct plate 49 that closes the top surface, preventing the gas from flowing into other areas and defining a gas exhaust path for safely exhausting the gas to the outside. In addition, multiple gas inlets 48b are formed in the duct surface 48 of the bus bar holder 41. The gas inlets 48b are formed in positions corresponding to the gas exhaust valves 1c of each battery cell 1 in the battery stack 10.

[0054] Note that multiple baffles may be provided on duct surface 48 of bus bar holder 41. The baffle plates lengthen the exhaust path of the gas exhausted into gas duct 43, thereby reducing the pressure and temperature, and allowing the gas to be safely exhausted. (Duct plate 49)

[0055] Furthermore, a duct plate 49 is fixed to the bus bar holder 41. As shown in the exploded perspective view of Fig. 3, the gas duct 43 is defined by left and right wall parts 46, a duct surface 48 on the floor surface, and a duct plate 49 on the top surface. In order to increase rigidity, the duct plate 49 is preferably made of a metal plate such as sheet metal. For example, it may be made of SUS or iron. Alternatively, the duct plate 49 may be made of insulating resin such as PBT, like the bus bar holder 41. (Subholder 42)

[0056] Furthermore, the bus bar holder 41 is divided into multiple sub-holders 42 as shown in Figures 5 and 7. This makes it possible to accommodate changes in the overall length of the battery stack 10 caused by battery cell expansion, as shown in the plan views of Figures 8 and 9.

[0057] As in the power supply device 900 shown in FIG. 20, if the duct plate 949 is fixed to the upper surface of the sub-holder 942 obtained by dividing the bus bar holder 941 with the bolt 967, the bus bar holder 941 is stretched by the duct plate 949, and the expansion and contraction structure of the bus bar holder 941, which is divided into the sub-holders 942 to absorb the expansion and contraction of the battery stack 910, does not function. Therefore, the fixing structure of the duct plate and the bus bar holder is devised so that the expansion and contraction function of the bus bar holder is not impaired even when the duct plate is attached to the bus bar holder. Specifically, as shown in the enlarged exploded perspective view of the main part in FIG. 11, the duct plate 49 has an elongated hole 49b that is screwed into the sub-holder 42 with a bolt 67. Furthermore, each sub-holder 42 has a support surface 61 that is longer than the elongated hole 49b at a position corresponding to the elongated hole 49b. A screw hole is opened as a connecting part 63 in the support surface 61. The sub-holder 42 forms a boss 60 inside the gas duct 43. The boss 60 has a top surface formed in a track shape, and this top surface serves as a support surface 61.

[0058] Then, with duct plate 49 placed on support surface 61 so as to straddle the multiple divided sub-holders 42, bolts 67 are screwed into screw holes 63, which serve as connecting parts, through oblong holes 49b to connect the multiple sub-holders 42 to duct plate 49. With this configuration, the bus bar holder 41 is divided into multiple parts so that it can absorb expansion and contraction in the stacking direction of the battery cells, while being slidably fixed to duct plate 49, which does not expand and contract, making it possible to maintain the connected state.

[0059] The boss 60 has a track-shaped support surface 61 on the top surface. A connecting portion 63 is formed at the center of this support surface 61. It is preferable to have an annular frame 62 to be inserted into the elongated hole 49b protruding from the periphery of the connecting portion 63. With this configuration, the annular frame 62 can be inserted into the elongated hole 49b and function as a guide for sliding the screw-fitting portion along the elongated hole 49b.

[0060] In the example shown in the schematic cross-sectional view of Fig. 10, an insert nut 64 into which a bolt 67 is screwed is embedded in a boss 60. The upper surface of the insert nut 64 protrudes from a support surface 61 to form an annular frame 62. In addition, it is preferable that the boss 60 is provided integrally with the wall portion 46 as shown in Figs. 3, 4, 11, etc. This also provides the effect of increasing the strength of the wall portion 46 with the boss 60.

[0061] In the above example, the duct plate 49 and the sub-holder 42 are connected by screwing the bolt 67 into the long hole 49b and the screw hole of the connecting portion 63. However, the present invention does not limit the connection between the duct plate 49 and the sub-holder 42 to screwing, and any known configuration that connects the duct plate to the sub-holder in a manner that allows some displacement can be appropriately adopted. For example, as shown in the exploded perspective view of Figure 12, an anchor 67B having an arrowhead at its tip is used instead of a bolt and is inserted into the long hole 49b of the duct plate 49 and the connecting portion 63B of the sub-holder 42B. The connecting portion 63 is an opening into which the arrowhead of the anchor 67B can be press-fitted instead of a screw hole.

[0062] Alternatively, connection by crimping may be used. For example, as shown in the cross-sectional view of Fig. 13A, a resin boss is protruded as connection portion 63C of sub-holder 42C, and after being inserted into long hole 49b of duct plate 49 from the underside, the tip surface of the boss is heated and pressed with a heater HT or the like to crush it, so that the tip of the boss can be made larger than long hole 49b for connection as shown in Fig. 13B.

[0063] Alternatively, a bush nut 67D may be used as shown in the plan view of Fig. 14A. In this case, the connecting portion 63D of the sub-holder 42D is formed in a pin shape as shown in the cross-sectional view of Fig. 14B. Then, with this pin inserted into the long hole 49b of the duct plate 49 from below, the bush nut 67D is engaged with the tip of the pin, and the duct plate 49 is sandwiched and fixed between the bush nut 67D and the sub-holder 42D.

[0064] Alternatively, as shown in the cross-sectional view of Fig. 15, the connecting portion 63E of the sub-holder 42E may be formed in a claw shape. In this case as well, the claw-shaped connecting portion 63E can be inserted from the underside of the long hole 49b of the duct plate 49 to lock the claw shape, thereby clamping and fixing the duct plate 49 with the claw-shaped connecting portion 63E.

[0065] In the example of Fig. 3 etc., the joint interface between the divided sub-holders 42 is formed in a stepped shape. This makes it easier to position the sub-holders 42 at the joint interface, and allows the bus bar guide portions 45 on which the bus bars 50 are arranged to be linearly connected between the sub-holders 42 as shown in Fig. 6 and Fig. 7. The stepped joint interface is formed so as to divide a portion of the gas inlet port 48b in two as shown in Fig. 8.

[0066] Also, a locking structure may be provided to maintain the connection between the sub-holders 42. In the example of Fig. 8 and Fig. 9, the locking structure is configured with a frame 65 and a pin 66 inserted into the frame 65. The frame 65 is formed in a track shape with a slit provided therein, and the pin 66 can be inserted into the slit to move it. The inner diameter of the slit is designed to be the same as the outer diameter of the pin 66 or to be slightly larger than this, taking a margin into consideration.

[0067] In addition, since the amount of movement between the sub-holders 42 is small, the frame 65 does not need to be provided over the entire length of the sub-holders 42, and may be provided with a length sufficient to cover the distance that the pin 66 moves. (Overlap part 47)

[0068] It is preferable to prevent gaps at the joint interfaces where the busbar holder 41 is divided into sub-holders 42 by overlapping the joint interfaces so that gas does not leak from the joint interfaces between the sub-holders 42 even if a gas exhaust valve of one of the battery cells opens. For this reason, the busbar holder 41 forms an overlapping portion 47 that extends from one of the opposing faces of the sub-holders 42 toward the other opposing face. The overlapping portion 47 closes the gap between the sub-holders 42 when the battery stack expands and the sub-holders 42 are separated from each other.

[0069] In the example shown in the exploded perspective view of Fig. 5 and the enlarged exploded perspective view of a main part of Fig. 11, an overlapping portion 47 is formed on the wall portion 46 at the joint interface. The overlapping portion 47 is configured to extend from a side surface of one of the wall portions 46 that abut at the joint interface and abut against the side surface of the other wall portion 46. As a result, even when the sub-holders 42 are abutted against each other, the overlapping portion 47 is located on the side surface of the wall portion 46 without interfering with the abutment of the sub-holders 42 against each other. Furthermore, when the sub-holders 42 are separated from each other, it is possible to close the gap with the overlapping portion 47.

[0070] The overlap portion 47 is preferably provided on the side of the wall portion 46 facing the gas duct 43. This eliminates any protruding portion on the side of the wire passage portion 44, and prevents the placement of a harness or the like from being hindered. However, the overlap portion may also be provided on the side of the wall portion that faces the outside of the gas duct. This prevents the end face of the overlap portion from hindering the discharge of gas.

[0071] The overlapping portion may be provided not only on the wall portion but also on, for example, the duct surface of a sub-holder that constitutes the bottom side of the gas duct. [Embodiment 2]

[0072] 8 and 9, the joint interface between the sub-holders is stepped, but the present invention is not limited to this shape and may have other shapes. For example, in bus bar holder 41B of power supply device 200 according to embodiment 2 shown in FIG. 16, the joint interface between sub-holders 42B is linear. By making the joint interface linear, there is a concern that sub-holders 42B may be misaligned in the width direction (vertical direction in FIG. 16). However, by providing the locking structure described above, the distance between sub-holders 42B can be stably changed while gas duct 43B, wire portion 44B, and bus bar guide portion 45B are kept linear.

[0073] Further, in the above example, the bus bar holder 41 is divided into two sub-holders 42. However, it goes without saying that the present invention is not limited to limiting the number of divided sub-holders to two, and may be three or more.

[0074] The above power supply device 100 can be used as a vehicle power source that supplies power to a motor that runs an electric vehicle. Electric vehicles that can be equipped with the power supply device 100 include hybrid cars and plug-in hybrid cars that run on both an engine and a motor, and electric cars that run only on a motor, and the power supply device 100 is used as a power source for these vehicles. Note that an example will be described in which a large-capacity, high-output power supply device is constructed by connecting a large number of the above-mentioned power supply devices 100 in series or parallel to obtain power to drive an electric vehicle, and further adding a necessary control circuit. (Power supply unit for hybrid vehicles)

[0075] FIG. 17 shows an example in which the power supply device 100 is mounted on a hybrid vehicle that runs on both an engine and a motor. The vehicle HV equipped with the power supply device 100 shown in this figure includes a vehicle body 91, an engine 96 and a motor 93 for running the vehicle body 91, wheels 97 driven by the engine 96 and the motor 93 for running, the power supply device 100 that supplies power to the motor 93, and a generator 94 that charges the battery of the power supply device 100. The power supply device 100 is connected to the motor 93 and the generator 94 via a DC / AC inverter 95. The vehicle HV runs on both the motor 93 and the engine 96 while charging and discharging the battery of the power supply device 100. The motor 93 is driven in an area where the engine efficiency is poor, such as during acceleration or low-speed running, to run the vehicle. The motor 93 is driven by power supplied from the power supply device 100. The generator 94 is driven by the engine 96 or by regenerative braking when braking the vehicle, and charges the battery of the power supply device 100. 17, the vehicle HV may be provided with a charging plug 98 for charging the power supply device 100. The power supply device 100 can be charged by connecting this charging plug 98 to an external power source. (Power supply unit for electric vehicles)

[0076] FIG. 18 shows an example in which the power supply device 100 is mounted on an electric vehicle that runs only by a motor. The vehicle EV equipped with the power supply device 100 shown in this figure includes a vehicle body 91, a motor 93 for driving the vehicle body 91, wheels 97 driven by the motor 93, the power supply device 100 that supplies power to the motor 93, and a generator 94 that charges the battery of the power supply device 100. The power supply device 100 is connected to the motor 93 and the generator 94 via a DC / AC inverter 95. The motor 93 is driven by power supplied from the power supply device 100. The generator 94 is driven by energy generated when the vehicle EV is regeneratively braked, and charges the battery of the power supply device 100. The vehicle EV also includes a charging plug 98, which can be connected to an external power source to charge the power supply device 100. (Power supply device for power storage device)

[0077] Furthermore, the present invention does not limit the use of the power supply device to a power supply for a motor that runs a vehicle. The power supply device according to the embodiment can also be used as a power supply for a power storage device that charges a battery with power generated by solar power generation, wind power generation, or the like and stores the power. Fig. 19 shows a power storage device that charges a battery of a power supply device 100 with a solar cell 82 and stores the power.

[0078] The power storage device shown in FIG. 19 charges a battery of a power supply device 100 with power generated by a solar cell 82 arranged on the roof or rooftop of a building 81 such as a house or a factory. This power storage device charges the battery of the power supply device 100 with a charging circuit 83 using the solar cell 82 as a charging power source, and then supplies power to a load 86 via a DC / AC inverter 85. For this reason, this power storage device has a charging mode and a discharging mode. The power storage device shown in the figure connects the DC / AC inverter 85 and the charging circuit 83 to the power supply device 100 via a discharge switch 87 and a charge switch 84, respectively. The discharge switch 87 and the charge switch 84 are switched ON / OFF by a power storage device power supply controller 88. In the charge mode, the power supply controller 88 switches the charge switch 84 to ON and the discharge switch 87 to OFF to allow charging from the charging circuit 83 to the power supply device 100. Furthermore, when charging is completed and the battery is fully charged, or when a predetermined charged capacity or more has been reached, the power supply controller 88 switches the charging switch 84 OFF and the discharging switch 87 ON to switch to a discharging mode, permitting discharging from the power supply device 100 to the load 86. Furthermore, if necessary, the charging switch 84 can be turned ON and the discharging switch 87 can be turned ON to supply power to the load 86 and charge the power supply device 100 at the same time.

[0079] Furthermore, although not shown, the power supply device can also be used as a power source for a power storage device that uses late-night power at night to charge and store electricity in a battery. A power supply device that is charged with late-night power is charged with late-night power, which is surplus electricity from power plants, and outputs electricity during the day when the power load is high, making it possible to limit daytime peak power to a low level. Furthermore, the power supply device can also be used as a power source that charges with both the output of solar cells and late-night power. This power supply device effectively uses both the power generated by solar cells and the late-night power, and can efficiently store electricity while taking into account the weather and power consumption.

[0080] The above-described power storage system can be suitably used for applications such as a backup power supply device that can be mounted on a computer server rack, a backup power supply device for wireless base stations for mobile phones and the like, a power storage power source for home or factory use, a power source for street lights, a power storage device combined with a solar cell, and a backup power supply for traffic lights and road traffic indicators. [Industrial Applicability]

[0081] The power supply device and the vehicle and power storage device equipped therewith according to the present invention can be suitably used as a large current power supply used for the power supply of motors driving electric vehicles such as hybrid cars, fuel cell cars, electric cars, and electric motorcycles. Examples include power supply devices for plug-in hybrid electric cars, hybrid electric cars, electric cars, etc. that can switch between EV driving mode and HEV driving mode. They can also be suitably used for applications such as backup power supply devices that can be mounted on the racks of computer servers, backup power supply devices for wireless base stations for mobile phones, etc., power supplies for home and factory storage, power supplies for street lights, power storage devices combined with solar cells, and backup power supplies for traffic lights, etc. [Explanation of symbols]

[0082] 100, 200, 900…power supply 1. Battery cell 1X…Terminal surface 1a…Outer can 1b...Sealing plate 1c…Gas exhaust valve 2...Electrode terminal 10...Battery stack 15... fastening member; 15a... fastening main surface; 15d... bent piece 15f…Bolt 16…Insulating spacer 17...End face spacer 20…End plate 30: Insulation sheet; 31: Flat plate; 32: Folded covering portion 40…Cover assembly 41, 41B…Busbar holder 42, 42B, 42C, 42D, 42E...Sub holder 43, 43B…Gas duct 44, 44B...Wiring section 45, 45B... Busbar guide section 46...Wall part 47…Overlap section 48...duct surface; 48b...gas inlet 49...Duct plate; 49b...Slotted hole 50…Busbar 51…Busbar body 52…Busbar branch 60…Boss 61...Support surface 62...Ring frame 63, 63B, 63C, 63D, 63E...Connection part 64…Insert nut 65…Frame shape 66…Pin 67...Bolt; 67B...Anchor; 67D...Bush nut 81…Building 82…Solar cell 83…Charging circuit 84…Charging switch 85…DC / AC inverter 86…Load 87…Discharge switch 88…Power supply controller 91…Vehicle body 93…Motor 94…Generator 95…DC / AC inverter 96…Engine 97...Wheel 98…Charging plug 901...battery cell; 901c...gas exhaust valve 902...Electrode terminal 903…End plate 904…Binding bar 910...Battery stack 941…Busbar holder 942…Sub holder 949…Duct plate 967...Bolt HT…Heater HV, EV...Vehicles

Claims

1. a gas release valve that opens when the internal pressure of the outer casing rises, and a battery stack formed by stacking multiple battery cells on the upper surface of the battery cells that have electrode terminals formed thereon; A plurality of bus bars connecting the electrode terminals to each other; a bus bar holder for holding the bus bar; a duct plate disposed on an upper surface of the bus bar holder and defining a gas duct; Equipped with the bus bar holder is divided into a plurality of sub-holders, the duct plate has a slot formed therein to be coupled with the sub-holder; Each sub-holder has a support surface longer than the elongated hole at a position corresponding to the elongated hole, and a connecting portion opening on the support surface, A power supply device in which the duct plate is placed on the support surface so as to straddle the divided sub-holders, and is then connected to the connecting portion through the long hole to connect the multiple sub-holders and the duct plate.

2. 2. The power supply device according to claim 1, The sub-holder defines a boss in the gas duct; The power supply device has the support surface formed on an upper surface of the boss.

3. 3. The power supply device according to claim 2, A power supply device in which an annular frame that is inserted into the elongated hole protrudes from the support surface around the connecting portion. With the above-described configuration, the annular frame can be inserted into the elongated hole and function as a guide for sliding the threaded portion along the elongated hole.

4. 4. The power supply device according to claim 2 or 3, The power supply device further comprises an insert nut embedded in the boss.

5. The power supply device according to any one of claims 1 to 4, The power supply device, wherein the support surface is formed in a track shape.

6. The power supply device according to any one of claims 1 to 5, The interface between the sub-holders facing each other is formed in a stepped shape in a plan view. Device.

7. The power supply device according to any one of claims 1 to 6, The bus bar holder extends from one of the opposing surfaces of the sub-holders facing each other toward the other opposing surface, forming an overlap portion that closes the gap between the sub-holders.

8. The power supply device according to any one of claims 1 to 7, The bus bar is A busbar body extended in a prismatic shape; busbar branches extending from the busbar body and connected to the electrode terminals; A power supply device comprising:

9. The power supply device according to any one of claims 1 to 8, The power supply device, wherein the bus bar holder is made of PBT.

10. The power supply device according to any one of claims 1 to 9, The power supply device, wherein the duct plate is made of stainless steel or iron.

11. A vehicle equipped with the power supply device according to any one of claims 1 to 10, A vehicle comprising the power supply device, a motor for driving supplied with power from the power supply device, a vehicle body mounting the power supply device and the motor, and wheels driven by the motor to drive the vehicle body.

12. A power storage device comprising the power supply device according to any one of claims 1 to 10, A power storage device comprising the power supply device and a power supply controller that controls charging and discharging to the power supply device, the power supply controller enabling charging of the battery cells using external power and controlling the charging of the battery cells.

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