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

Abstract

A power supply device (100) is equipped with: a battery laminate (10) that is obtained by laminating a plurality of battery cells (1), each of which is provided with, on the upper surface thereof, a gas discharge valve (1c) that opens when the internal pressure of an exterior can (1a) rises; a first cover (41) that is provided to the upper surface of the battery laminate (10) and defines a first gas duct (43) that is in communication with the gas discharge valves (1c); and a second cover (42) that is provided to the upper surface of the first cover (41) and defines a second gas duct (44) on the upper surface of the first gas duct (43). A plurality of through holes (51) are formed in the upper surface of the first cover (41), and are in communication with the first gas duct (43) and the second gas duct (44).

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] BACKGROUND 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 power storage systems for factories, homes, etc. (see, for example, Patent Document 1).

[0003] The battery cells that make up such power supplies are equipped with gas exhaust valves that open to release gas if the internal pressure of the outer casing becomes too high due to an abnormality. If internal pressure becomes too high for some reason, such as thermal runaway, in any of the battery cells, high-temperature, high-pressure gas is released from the gas exhaust valve. Therefore, power supplies are equipped with gas ducts to release such gas to the outside. If a large amount of hot gas is released outside the power supply, it may ignite. However, if the hot gas is prevented from being released outside the power supply and remains in the gas duct, it could heat other battery cells and cause thermal runaway to worsen. Therefore, a configuration that can avoid both of these situations is required, but achieving this has not been easy. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2014 / 024452 Summary of the Invention [Problem to be solved by the invention]

[0005] An object of one embodiment of the present invention is to provide a power supply device that can safely discharge gas to the outside when gas is discharged from a battery cell, and a vehicle and a power storage device including the power supply device. [Means for solving the problem]

[0006] A power supply device according to one aspect of the present invention is a power supply device comprising: a battery stack formed by stacking multiple battery cells, each of which has a gas exhaust valve on its upper surface that opens when the internal pressure of the outer can rises; a first cover provided on the upper surface of the battery stack and defining a first gas duct that communicates with the gas exhaust valve; and a second cover provided on the upper surface of the first cover and defining a second gas duct on the upper surface of the first gas duct, wherein the upper surface of the first cover has multiple communication holes that communicate between the first gas duct and the second gas duct. [Effects of the Invention]

[0007] With the above configuration, when gas is discharged from a battery cell, it is branched into the first gas duct and the second gas duct, and the gas is dispersed and discharged, thereby preventing the gas from accumulating inside the power supply device and suppressing the risk of the gas being discharged to the outside catching fire. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a perspective view showing a power supply device according to a first embodiment of the present invention. [Figure 2] FIG. 2 is an exploded perspective view of the power supply device shown in FIG. [Figure 3] FIG. 10 is an enlarged schematic cross-sectional view showing a gas duct portion of a power supply device according to a comparative example. [Figure 4] 3 is an enlarged schematic cross-sectional view showing a gas duct portion of the power supply device according to the first embodiment. FIG. [Figure 5] 3 is an exploded perspective view showing a state in which a reinforcing cover is removed from the cover assembly of FIG. 2. FIG. [Figure 6] FIG. 6 is an exploded perspective view of FIG. 5. [Figure 7] FIG. 7 is an exploded perspective view of FIG. 6 as seen obliquely from below. [Figure 8] 2 is an exploded perspective view showing the power supply device of FIG. 1 with a reinforcing cover removed. FIG. [Figure 9] 2 is a plan view of the power supply device of FIG. 1 with a reinforcing cover seen through; FIG. [Figure 10]FIG. 10 is a cross-sectional view with an enlarged view of a main part taken along line XX in FIG. 9. [Figure 11] FIG. 10 is an enlarged schematic cross-sectional view showing a gas duct portion of a power supply device that does not have a communication rib. [Figure 12] FIG. 10 is an enlarged schematic cross-sectional view showing a gas duct portion of a power supply device provided with a communication rib. [Figure 13] FIG. 1 is a block diagram showing an example in which a power supply device is mounted on a hybrid vehicle that runs on an engine and a motor. [Figure 14] FIG. 1 is a block diagram showing an example in which a power supply device is mounted on an electric vehicle that runs solely on a motor. [Figure 15] FIG. 10 is a block diagram showing an example of application to a power supply device for power storage. DETAILED DESCRIPTION OF THE INVENTION

[0009] The embodiment of the present invention may be specified by the following configurations.

[0010] In addition to the above configuration, in a power supply device according to one embodiment of the present invention, the first cover has the communication hole open at a position offset from the gas release valve of the battery cell.

[0011] In a power supply device according to another embodiment of the present invention, in addition to any of the configurations described above, the first cover has a communication rib that protrudes toward the second cover around the communication hole. With this configuration, the communication rib can prevent the first cover from being pressed by gas pressure and deforming in such a way that the opening to the second gas duct is blocked.

[0012] In addition to any of the above configurations, in a power supply device according to another embodiment of the present invention, the first cover may be provided with a partition rib that partitions the spaces between adjacent ones of the plurality of communication holes. With the above configuration, it is possible to prevent high-pressure gas introduced into the second gas duct from the communication holes from being discharged in a concentrated manner in one place.

[0013] Furthermore, in addition to any of the configurations described above, a power supply device according to another embodiment of the present invention is configured such that the communication hole is formed in a slit shape.

[0014] Furthermore, in addition to any of the configurations described above, the power supply device according to another embodiment of the present invention is such that the first cover is made of resin.

[0015] Furthermore, in addition to any of the configurations described above, the power supply device according to another embodiment of the present invention is configured such that the second cover is made of metal.

[0016] In addition to any of the above configurations, a power supply device according to another embodiment of the present invention has the battery cells each having a rectangular outer can that is open at the top and a sealing plate that closes the opening of the outer can, the gas exhaust valve is provided in the center of the sealing plate, and the first gas duct is configured to exhaust gas in the stacking direction of the battery cells and in a lateral direction perpendicular to the stacking direction. With this configuration, gas can be exhausted not only in the stacking direction of the battery cells but also in a direction that intersects this direction, thereby enabling efficient gas exhaust.

[0017] Furthermore, an electric vehicle according to another embodiment of the present invention includes any of the power supply devices described above, a driving motor supplied with power from the power supply device, a vehicle body equipped with the power supply device and the motor, and wheels driven by the motor to propel the vehicle body.

[0018] Furthermore, a power 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 of 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.

[0019] Embodiments of the present invention will be described below with reference to the drawings. However, the embodiments described below are merely examples for embodying the technical concept of the present invention, and the present invention is not limited to these. Furthermore, this specification in no way specifies the components set forth in the claims as components of the embodiments. The dimensions, materials, shapes, and relative positions of components described in the embodiments are not intended to limit the scope of the present invention, and are merely illustrative unless otherwise specified. The size and relative positions of components shown in the drawings may be exaggerated for clarity. Furthermore, in the following description, the same names and symbols indicate identical or similar components, and detailed descriptions will be omitted as appropriate. Furthermore, the elements constituting the present invention may be configured with the same components, so that one component serves multiple functions, or conversely, the function of one component may be shared by multiple components. Furthermore, the content described in some examples and embodiments may be applicable to other examples and embodiments.

[0020] The power supply device according to the embodiment is used in a variety of applications, such as a power supply mounted on an electrically powered vehicle such as a hybrid car or an electric car to supply power to the driving motor, a power supply for storing power generated by natural energy sources such as solar power generation or wind power generation, or a power supply for storing late-night power, and is particularly suitable for applications requiring large power and large current. In the following example, an embodiment applied to a power supply device for driving an electrically powered vehicle will be described. [Embodiment 1]

[0021] 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 is an exploded perspective view of the power supply device 100 according to the first embodiment, and Figure 2 is an exploded perspective view of the power supply device 100 shown in Figure 1.

[0022] 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 end faces of the battery stack 10, multiple fastening members 15 fastening the end plates 20 together, and a cover assembly 40 provided on the top surface of the battery stack 10.

[0023] The fastening members 15 are formed in the shape of plates that extend in the stacking direction of the multiple battery cells 1. The fastening members 15 are placed on opposing side surfaces of the battery stack 10 and fasten the end plates 20 together. (battery stack 10)

[0024] As shown in FIG. 2, a battery stack 10 includes multiple battery cells 1 with positive and negative electrode terminals 2, and bus bars connected to the electrode terminals 2 of the multiple battery cells 1 to connect the multiple battery cells 1 in parallel and in series. The multiple battery cells 1 are connected in parallel and in series via these bus bars. The battery cells 1 are rechargeable secondary batteries. In a power supply device 100, multiple battery cells 1 are connected in parallel to form parallel battery groups, and multiple parallel battery groups are connected in series, so that many battery cells 1 are connected in parallel and in series. The power supply device 100 shown in FIG. 2 is configured by stacking multiple battery cells 1 to form the battery stack 10. A pair of end plates 20 is also arranged on both end faces of the battery stack 10. The ends of fastening members 15 are fastened to the end plates 20, thereby pressing the stacked battery cells 1 together. (Battery cell 1)

[0025] As shown in FIG. 2, the battery cells 1 are rectangular batteries whose width is greater than their thickness—in other words, whose width is 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. Alternatively, the battery cells can be any rechargeable secondary battery, such as nickel-metal hydride batteries or nickel-cadmium batteries. The battery cells 1 contain positive and negative electrode plates together with an electrolyte in a sealed outer can 1a. The outer can 1a is formed by pressing a metal plate, such as aluminum or an aluminum alloy, into a rectangular shape, and its 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 positive and negative electrode terminals 2 are fixed to both ends of the sealing plate 1b. Furthermore, the sealing plate 1b has gas release valves 1c, safety valves that open in response to pressure changes inside each of the battery cells 1, between the positive and negative electrode terminals 2.

[0026] A plurality of 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 this case, by stacking more battery cells than usual, it is possible to increase the output of the battery stack 10. In such a case, the battery stack 10 is elongated in the stacking direction. The battery cells 1 are stacked to form the battery stack 10 with the terminal surfaces 1X, on which the positive and negative electrode terminals 2 are provided, arranged on the same plane. The top 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)

[0027] As shown in Figure 2 etc., the battery cell 1 has a terminal surface 1X, which is the sealing plate 1b on 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.

[0028] 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 in a mirror image, and adjacent positive and negative electrode terminals 2 are connected by a bus bar, allowing adjacent battery cells 1 to be connected in series. Note that the present invention does not specify the number of battery cells constituting the battery stack or their connection state. The number of battery cells constituting the battery stack and their connection state can be changed in various ways, including in other embodiments described below.

[0029] The multiple battery cells 1 are stacked so that the thickness direction of each battery cell 1 is the stacking direction, forming a battery stack 10. The multiple battery cells 1 are stacked in the battery stack 10 so that the terminal surfaces 1X on which the positive and negative electrode terminals 2 are provided, or the sealing plate 1b in FIG. 2, are flush with each other.

[0030] The battery stack 10 may include insulating spacers 16 between adjacent stacked battery cells 1. The insulating spacers 16 are made of an insulating material such as resin and are in the form of thin plates or sheets. The insulating spacers 16 are plate-shaped and approximately the same size as the opposing surfaces of the battery cells 1. By stacking these insulating spacers 16 between adjacent battery cells 1, the adjacent battery cells 1 can be insulated from each other. Note that the spacers placed between adjacent battery cells may also be shaped to form a flow path for cooling gas between the battery cells and the spacer. The surfaces of the battery cells may also be coated with an insulating material. For example, the surfaces of the outer cans, excluding the battery cell electrodes, may be covered with shrink film such as PET resin. In this case, the insulating spacers may be omitted. Furthermore, in power supplies 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. However, since there is no voltage difference between the adjacent outer cans of battery cells connected in parallel, the insulating spacers between these battery cells may be omitted.

[0031] Furthermore, the power supply device 100 shown in Figure 2 has end plates 20 placed on both end surfaces of the battery stack 10. End surface spacers 17 may be placed between the end plates 20 and the battery stack 10 to insulate them. The end surface spacers 17 can also be made into thin plate or sheet shapes using insulating material such as resin.

[0032] In the power supply device 100 according to the first embodiment, a battery stack 10 is formed by stacking a plurality of battery cells 1 on top of one another. The electrode terminals 2 of adjacent battery cells 1 are connected by bus bars, connecting the battery cells 1 in parallel and in series. A bus bar holder may be disposed between the battery stack 10 and the bus bars. By using the bus bar holder, the bus bars can be positioned in fixed positions on the top surface of the battery stack while insulating the bus bars from each other and insulating the terminal surfaces 1X of the battery cells from the bus bars. The cover assembly 40, which will be described later, may also be integrated with the bus bar holder.

[0033] Busbars are manufactured by cutting and processing metal sheets into a predetermined shape. The metal sheets that make up the busbars can be made of metals that have low electrical resistance and are lightweight, such as aluminum or copper, or alloys of these. However, other metals and alloys of these that have low electrical resistance and are lightweight can also be used for the metal sheets of busbars. (End plate 20)

[0034] As shown in Figure 2, the end plates 20 are positioned at both ends of the battery stack 10 and are fastened via a pair of left and right fastening members 15 that are arranged along both side surfaces of the battery stack 10. The end plates 20 are positioned at both ends of the battery stack 10 in the stacking direction of the battery cells 1, outside the end spacers 17, and sandwich the battery stack 10 from both ends. (Fastening member 15)

[0035] Both ends of the fastening members 15 are fixed to end plates 20 located on both end faces of the battery stack 10. The end plates 20 are fixed using multiple fastening members 15, thereby fastening the battery stack 10 in the stacking direction. As shown in Figure 2 and other figures, each fastening member 15 is made of metal and has a specified width and thickness that fits along the side of the battery stack 10, and is positioned opposite both sides of the battery stack 10. These fastening members 15 can be made of metal plate such as iron, preferably steel plate. The fastening members 15 made of metal plate are formed into a specified shape by bending using press forming or other methods.

[0036] The fastening member 15 has a plate-shaped main fastening surface 15a, and the top and bottom of the surface 15a are bent in 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 sides of the battery stack 10. The fastening member 15 is fixed to the outer periphery of the end plate 20 by threading bolts 15f into multiple screw holes opened in the main fastening surface 15a. Note that the method of fixing the main fastening surface 15a to the end plate 20 is not limited to using bolts, and pins, rivets, etc. may also be used.

[0037] A power supply device 100 having many stacked battery cells 1 is configured to restrain the battery cells 1 by connecting end plates 20 arranged at both ends of a battery stack 10 made up of the battery cells 1 with fastening members 15. By restraining the battery cells 1 via the highly rigid end plates 20 and fastening members 15, it is possible to suppress malfunctions due to expansion, deformation, relative movement, and vibration of the battery cells 1 caused by charging / discharging and deterioration. (Insulation sheet 30)

[0038] 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. The insulating sheet 30 shown in Figure 2 and elsewhere is composed of a flat plate 31 that covers the side of the battery stack 10 and folded covering portions 32 provided above and below this flat plate 31. The folded covering portions 32 are folded in a U-shape from the flat plate 31 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 to the side and bottom with the insulating folded covering portions, preventing unintended electrical conduction between the battery cells 1 and the fastening members 15.

[0039] Additionally, the bent pieces 15d press against the top and bottom surfaces of the battery cells 1 of the battery stack 10 via the bent covering portions 32. This allows the bent pieces 15d to press against each battery cell 1 from above and below, holding it in the height direction, and preventing the battery cells 1 from shifting in position in the vertical direction even if vibrations, shocks, etc. are applied to the battery stack 10.

[0040] Note that an insulating sheet may not be necessary if the battery stack or its surface is insulated, for example, if the battery cells are housed in an insulating case or covered with a resin heat-shrinkable film, if the surfaces of the fastening members are coated with an insulating paint or other material, or if the fastening members are made of an insulating material. Furthermore, if insulation between the insulating sheet 30 and the bent pieces 15d of the fastening members 15 on the underside of the battery stack 10 does not need to be considered, the bent covering portion 32 may be formed only on the upper end. For example, this would be the case if the battery cells 1 are covered with a heat-shrinkable film. (Cover assembly 40)

[0041] The power supply device 100 has a cover assembly 40 on the top surface of the battery stack 10. The cover assembly 40 forms a gas exhaust path that exhausts high-temperature, high-pressure gas to the outside of the power supply device 100 when it is exhausted from any of the battery cells 1 that make up the battery stack 10. The cover assembly 40 may also be configured to double as a busbar holder that holds the busbars.

[0042] As shown in the schematic cross-sectional view of Figure 4, the cover assembly 40 includes a first cover 41 and a second cover 42. The first cover 41 is attached to the top surface of the battery stack 10 and defines a first gas duct 43 that communicates with the gas exhaust valves 1c of the battery cells 1 that make up the battery stack 10. The second cover 42 is attached to the top surface of the first cover 41 and defines a second gas duct 44 on the top surface of the first gas duct 43. Furthermore, the top surface of the first cover 41 has multiple communication holes 51 that communicate between the first gas duct 43 and the second gas duct 44. The communication holes 51 open in the first cover 41 at positions offset from the gas exhaust valves 1c of the battery cells 1.

[0043] With this configuration, when gas GS is discharged from the battery cell 1, it can be branched into the first gas duct 43 and the second gas duct 44 through the communication holes 51, and the gas can be dispersed and discharged. This prevents the gas GS from accumulating inside the power supply device and suppresses the risk of ignition of gas discharged to the outside. Furthermore, by providing multiple gas discharge ports, the opening area of ​​each port can be reduced, reducing the risk of ignition even if high-temperature gas is discharged.

[0044] In a configuration with a single gas duct, such as the power supply device 800 according to the comparative example shown in the schematic cross-sectional view of FIG. 3, if high-temperature, high-pressure gas GS from one battery cell 1 is ejected from the gas exhaust valve 1c and remains in the gas duct without being discharged to the outside of the power supply device 800, other battery cells adjacent to that battery cell 1 may be heated, potentially leading to a chain reaction of thermal runaway. In particular, if there is only one gas exhaust port, the gas tends to concentrate at that port, preventing smooth discharge. Furthermore, the inventors' tests have revealed that if a large amount of gas is discharged from one location, the risk of fire increases. However, if the opening area of ​​the exhaust port is reduced, the gas is less likely to be discharged to the outside, potentially resulting in gas remaining inside the power supply device 800.

[0045] Therefore, in this embodiment, by forming multiple exhaust ports 45a, 45b for discharging gas, the gas discharge amount is ensured while the opening area per exhaust port is reduced, thereby reducing the possibility of fire. Specifically, as shown in the schematic cross-sectional view of Figure 4, the gas duct is divided into two stages, first gas duct 43 and second gas duct 44, each of which is provided with gas exhaust ports 45a, 45b, to disperse and discharge the gas. With this configuration, it is possible to reduce the opening area per gas exhaust port while maintaining the same total opening area, thereby improving safety while avoiding an increase in the size of the power supply device.

[0046] The specific configuration of the cover assembly 40 will be described below with reference to FIGS. 5 to 10. In these figures, FIG. 5 is an exploded perspective view showing the cover assembly 40 of FIG. 2 with the reinforcing cover 60 removed, FIG. 6 is an exploded perspective view of FIG. 5, FIG. 7 is an exploded perspective view of FIG. 6 viewed obliquely from below, FIG. 8 is an exploded perspective view showing the power supply device 100 of FIG. 1 with the reinforcing cover 60 removed, FIG. 9 is a plan view of the power supply device 100 of FIG. 1 with the reinforcing cover seen through, and FIG. 10 is a cross-sectional view with an enlarged view of a main portion taken along line XX in FIG. 9. The cover assembly 40 shown in these figures includes a lower cover 46, an upper cover 50, and a reinforcing cover 60. The upper cover 50 corresponds to the first cover 41 described above, and the reinforcing cover 60 corresponds to the second cover 42. (Lower cover 46)

[0047] The lower cover 46 is attached to the top surface of the battery stack 10 and defines a first gas duct 43 that communicates with the gas exhaust valve 1c. As shown in Figures 6 to 7, the lower cover 46 has a gas inlet 47 at a position corresponding to the gas exhaust valve 1c of the battery cell 1. As shown in Figures 6 to 7 and 10, the lower cover 46 also has multiple baffles 48 that change the direction of the high-temperature, high-pressure gas before it is discharged, thereby reducing its momentum and lowering its temperature. Gas exhaust paths are provided not only in the stacking direction of the battery cells 1, but also in a direction that intersects this direction. The lower cover 46 is made of resin with excellent insulating properties, such as polycarbonate. (Intermediate plate 49)

[0048] An intermediate plate 49 is provided on the top surface of the lower cover 46. The intermediate plate 49 is located in the center of the width of the battery stack 10 and is positioned to face the gas exhaust valve 1c. The intermediate plate 49 is made of a strong material, such as metal. This prevents the gas from being directly ejected through the power supply device 100, even if high-temperature, high-pressure gas is exhausted from the gas exhaust path, as it is received by the metal intermediate plate 49, which is stronger than a plastic cover. (Top cover 50)

[0049] The upper cover 50 is provided on the upper surface of the lower cover 46 and defines the second gas duct 44 on the upper surface of the first gas duct 43. The upper cover 50 is made of resin. The upper surface of the upper cover 50 is also formed with multiple communication holes 51 that connect the first gas duct 43 and the second gas duct 44. By providing the gas duct with a two-layer structure consisting of the first gas duct 43 and the second gas duct 44, even if gas is discharged from a battery cell, the gas is branched into the first gas duct 43 and the second gas duct 44 and discharged separately. This prevents the gas from accumulating inside the power supply device and reduces the risk of ignition of gas discharged to the outside. Furthermore, by providing multiple gas discharge ports, the cross-sectional area of ​​each port can be reduced, reducing the risk of ignition even if high-temperature gas is discharged. (Communication hole 51)

[0050] It is preferable that the communication holes 51 are not opened to correspond to all the battery cells, but are opened discretely to cover multiple battery cells. In the example of Fig. 6 etc., communication holes 51 are opened at three locations in the stacking direction for a battery stack 10 in which 12 battery cells 1 are stacked.

[0051] Furthermore, it is preferable to provide the communication hole 51 at an offset position rather than facing the gas release valve 1c. By not having the communication hole 51 directly open to the gas release valve 1c, it is possible to facilitate gas dispersion. In the example shown in Figure 2, the gas release valve 1c is provided in the center of the sealing plate 1b of the battery cell 1. Meanwhile, as shown in Figure 6 and other figures, the communication holes 51 are opened at positions corresponding to the left and right of the sealing plate 1b of the battery cell 1.

[0052] The communication holes 51 are preferably formed in a slit shape. The width and length of the slit and the height of the second gas duct 44 are adjusted to set the path area of ​​the second gas duct 44, thereby controlling the amount of gas discharged. In the example shown in Fig. 10, the height of the second gas duct 44 is determined by the height of the communication rib 52, which will be described later. (Communicating rib 52)

[0053] The upper cover 50 has a communicating rib 52 protruding toward the reinforcing cover 60 around the communicating hole 51. This prevents the path for introducing gas into the second gas duct 44 from being blocked. In a configuration without a communicating rib, as in the power supply device 700 shown in the schematic cross-sectional view of FIG. 11, when high-pressure gas is discharged from the gas exhaust valve 1c, the gas pressure may cause the periphery of the communicating hole 51 in the upper cover 50 to deform, blocking the gas exhaust path. In this state, the gas is not guided to the second gas duct 44, and the gas cannot be dispersed and discharged through the second gas duct 44. In contrast, as shown in the schematic cross-sectional view of FIG. 12, by providing a communicating rib 52 around the communicating hole 51, deformation around the communicating hole 51 is prevented, the open end to the second gas duct 44 is secured, and high-pressure gas can be guided to the second gas duct 44.

[0054] Furthermore, the communicating ribs 52 are provided only around a portion of the communicating hole 51, rather than around the entire circumference, so as not to impede the flow of gas into the second gas duct 44. Preferably, as shown in the plan view of FIG. 9, a pair of communicating ribs 52 are provided facing each other on both sides of the communicating hole 51. In the case of a slit-shaped communicating hole 51, it is preferable to arrange the pair of communicating ribs 52 so as to intersect the longitudinal direction of the slit. In this example, the communicating ribs 52 are integrally molded with the resin upper cover 50. With this configuration, the communicating ribs 52 can be easily formed by positioning them around the communicating hole 51. However, it goes without saying that the communicating ribs may also be provided on the reinforcing cover. In particular, by forming the communicating ribs protruding from a metal reinforcing cover using a punching process or the like, the communicating ribs can be formed to be stronger and less prone to deformation. (Dividing rib 53)

[0055] Furthermore, the upper cover 50 is provided with partitioning ribs 53 that separate adjacent communication holes 51. This allows the second gas duct 44 to be partitioned by each communication hole 51, and prevents the high-pressure gas introduced into the second gas duct 44 from the communication holes 51 from being discharged in one place.

[0056] In the example in Figure 6 etc., a battery stack 10 made up of 12 stacked battery cells 1 is divided into three sections of four cells each, and these are further divided into two sections on the left and right of the battery cells 1, for a total of six sections. Also, in the example in Figure 6, a dividing rib protrudes from the top surface of the upper cover 50, but it goes without saying that the present invention is not limited to this configuration, and the dividing rib may protrude from the reinforcing cover side, for example.

[0057] Furthermore, it is preferable to provide gas exhaust paths not only in the stacking direction of the battery cells 1 but also in a direction intersecting this direction. By exhausting gas in this intersecting direction, it is possible to efficiently exhaust gas to the outside of the power supply device, thereby improving safety. In the example of Figure 9, gas exhaust paths are formed in each of the first gas duct 43 and the second gas duct 44 so that gas can also be exhausted in the vertical direction in the figure. (Reinforcement cover 60)

[0058] The reinforcing cover 60 is provided on the upper surface of the upper cover 50. The second gas duct 44 is formed between the reinforcing cover 60 and the upper cover 50. The reinforcing cover 60 also abuts against the upper surface of the second cover via the communication rib 52. With this configuration, even if high-temperature, high-pressure gas is discharged from the gas discharge valve, deformation of the upper cover 50 can be suppressed by reinforcing the upper surface of the upper cover 50 with metal reinforcement. In particular, if the upper cover 50 is deformed, there is a risk that an unintended gas discharge path will be formed that avoids the baffle plate 48. However, by preventing deformation of the upper cover 50 with the reinforcing cover 60, such a situation can be avoided.

[0059] The above power supply device 100 can be used as a vehicle power supply that supplies power to a motor that runs an electric vehicle. Electric vehicles that can be equipped with 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 power supply device 100 is used as a power source for these vehicles. Note that this description will be given as an example of a large-capacity, high-output power supply device 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 the necessary control circuitry. (Power supply unit for hybrid vehicles)

[0060] FIG. 13 shows an example of a power supply device 100 mounted on a hybrid vehicle that runs on both an engine and a motor. The vehicle HV shown in this figure is equipped with a vehicle body 91, an engine 96 and a traction motor 93 that propel the vehicle body 91, wheels 97 driven by the engine 96 and the traction 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 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 to propel the vehicle in areas where the engine is inefficient, such as during acceleration or low-speed driving. 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 the vehicle is braked, and charges the battery of the power supply device 100. 13, the vehicle HV may be provided with a charging plug 98 for charging the power supply device 100. By connecting this charging plug 98 to an external power source, the power supply device 100 can be charged. (Power supply unit for electric vehicles)

[0061] FIG. 14 shows an example in which power supply device 100 is mounted on an electric vehicle that runs only on a motor. The vehicle EV equipped with power supply device 100 shown in this figure includes a vehicle body 91, a traction motor 93 that drives the vehicle body 91, wheels 97 driven by the motor 93, power supply device 100 that supplies power to motor 93, and a generator 94 that charges the battery of power supply device 100. Power supply device 100 is connected to motor 93 and generator 94 via a DC / AC inverter 95. Motor 93 is driven by power supplied from power supply device 100. Generator 94 is driven by energy generated when the vehicle EV is regeneratively braked, and charges the battery of power supply device 100. The vehicle EV also includes a charging plug 98 that can be connected to an external power source to charge power supply device 100. (Power supply device for power storage device)

[0062] Furthermore, the present invention does not limit the use of the power supply device to a power source for a motor that runs a vehicle. The power supply device according to the embodiment can also be used as a power source for a power storage device that charges a battery with power generated by solar power generation, wind power generation, etc. and stores the power. Figure 15 shows a power storage device that charges a battery of a power supply device 100 with a solar cell 82 and stores the power.

[0063] The power storage device shown in FIG. 15 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 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 the power to a load 86 via a DC / AC inverter 85. For this reason, this power storage device has a charge mode and a discharge mode. The power storage device shown in the figure has the DC / AC inverter 85 and the charging circuit 83 connected 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 and off by a power storage device power supply controller 88. In the charge mode, the power supply controller 88 switches the charge switch 84 on and the discharge switch 87 off, allowing 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 the battery capacity is charged to a predetermined value or more, the power supply controller 88 switches the charging switch 84 OFF and the discharging switch 87 ON to switch to discharging mode, allowing the power supply device 100 to discharge 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 simultaneously.

[0064] 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 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 the power plant, and outputs electricity during the day when the power load is high, thereby minimizing daytime peak power. Furthermore, the power supply device can also be used as a power source that charges with both solar cell output and late-night power. This power supply device effectively utilizes both the power generated by the solar cell and the late-night power, and can efficiently store electricity while taking into account the weather and power consumption.

[0065] 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 supply for home or factory use, a power supply 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]

[0066] The power supply device and vehicle and power storage device equipped therewith according to the present invention can be suitably used as a large-current power supply for use in, for example, a motor that drives an electric vehicle such as a hybrid car, a fuel cell vehicle, an electric vehicle, or an electric motorcycle. Examples include power supply devices for plug-in hybrid electric vehicles, hybrid electric vehicles, and electric vehicles that can switch between EV and HEV driving modes. They can also be used as backup power supplies that can be mounted on computer server racks, backup power supplies for wireless base stations for mobile phones and the like, power storage power supplies for homes and factories, power supplies for street lights, power storage devices combined with solar cells, and backup power supplies for traffic lights and the like. [Explanation of symbols]

[0067] 100, 700, 800…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...insulating sheet; 31...flat plate; 32...folded covering portion 40...Cover assembly 41...First cover 42...Second cover 43...First gas duct 44...Second gas duct 45a, 45b...Gas outlet 46...Lower cover 47...Gas inlet 48...Baffle 49...Intermediate plate 50...Top cover 51...Communication hole 52...Communicating rib 53...Dividing rib 60...Reinforcement cover 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 GS...Gas HV, EV...Vehicles

Claims

1. a battery stack formed by stacking multiple battery cells, each of which has a gas release valve on its top surface that opens when the internal pressure of the outer casing increases; a first cover provided on an upper surface of the battery stack and defining a first gas duct communicating with the gas exhaust valve; a second cover provided on an upper surface of the first cover and defining a second gas duct on an upper surface of the first gas duct; A power supply device comprising: a plurality of communication holes that communicate between the first gas duct and the second gas duct are formed on an upper surface of the first cover; The power supply device is configured such that the first cover is provided with a partitioning rib that partitions spaces between adjacent ones of the plurality of communication holes.

2. 2. The power supply device according to claim 1, The power supply device, wherein the second cover is made of metal.

3. a battery stack formed by stacking multiple battery cells, each of which has a gas release valve on its top surface that opens when the internal pressure of the outer casing increases; a first cover provided on an upper surface of the battery stack and defining a first gas duct communicating with the gas exhaust valve; a second cover provided on an upper surface of the first cover and defining a second gas duct on an upper surface of the first gas duct; A power supply device comprising: a plurality of communication holes that communicate between the first gas duct and the second gas duct are formed on an upper surface of the first cover; The power supply device, wherein the second cover is made of metal.

4. The power supply device according to any one of claims 1 to 3, The first cover has the communication hole opened at a position offset from the gas release valve of the battery cell.

5. The power supply device according to any one of claims 1 to 4, The first cover has a communication rib that protrudes toward the second cover around the communication hole.

6. The power supply device according to any one of claims 1 to 5, The power supply device wherein the communication hole is formed in a slit shape.

7. The power supply device according to any one of claims 1 to 6, The power supply device, wherein the first cover is made of resin.

8. The power supply device according to any one of claims 1 to 7, The battery cell is a rectangular outer can having an opening at the top; a sealing plate that closes the opening of the outer can; It is equipped with The gas exhaust valve is provided in the center of the sealing plate, The power supply device is configured such that the first gas duct discharges gas in the stacking direction of the battery cells and in a lateral direction perpendicular to the stacking direction.

9. A vehicle equipped with the power supply device according to any one of claims 1 to 8, A vehicle comprising the power supply device, a driving motor supplied with power from the power supply device, a vehicle body equipped with the power supply device and the motor, and wheels driven by the motor to drive the vehicle body.

10. A power storage device comprising the power supply device according to any one of claims 1 to 8, A power storage device comprising the power supply device and a power supply controller that controls charging and discharging of the power supply device, wherein the power supply controller enables charging of the battery cells using external power and controls charging of the battery cells.

Images