Power supply device

Abstract

A spacer part of a power supply device according to Embodiment 1 forms, between the spacer part and a first battery block, a first airflow passage for allowing first cooling air to flow through for cooling the first battery block, and forms, between the spacer part and a second battery block, a second airflow passage for allowing second cooling air to flow through for cooling the second battery block. The spacer part has a first air inlet and a second air inlet that are each open at one lengthwise end thereof, the first air inlet being in communication with one end of the first airflow passage, the second air inlet being in communication with one end of the second airflow passage. The spacer part has a first air outlet and a second air outlet that are each open at an opposite lengthwise end thereof, the first air outlet being in communication with an opposite end of the first airflow passage, the second air outlet being in communication with an opposite end of the second airflow passage. An exterior case has a case air inlet that is open in a first surface thereof facing the lengthwise one end inside the exterior case and a case air outlet that is open in a second surface facing the opposite lengthwise end inside the exterior case, the case air inlet being in communication with the first air inlet and the second air inlet, the case air outlet being in communication with the first air outlet and the second air outlet.

Description

power supply

[0001] The present disclosure relates to a power supply device.

[0002] Power supply devices in which multiple rechargeable secondary battery cells, such as lithium-ion secondary batteries, are connected in series or parallel are used as power sources for electrical equipment. In recent years, with the demand for higher output and capacity in power supply devices, the number of secondary battery cells used in power supply devices has tended to increase. For this reason, power supply devices are being used in which battery blocks, each of which is connected in series or parallel, are stacked in multiple stages.

[0003] The secondary battery cells generate heat when they are discharged or charged. Therefore, when the power supply device is in a discharged state, the cell temperature rises, and so the cell temperature must be cooled before charging can begin.

[0004] However, when multiple secondary battery cells are used, it is difficult to cool them efficiently, and waiting times for cooling can occur. In particular, the middle secondary battery cells are surrounded by other secondary battery cells, making it difficult for heat to escape. Therefore, the more secondary battery cells there are, the longer it takes to cool them. Furthermore, cooling by forced air from the exterior case is inefficient, and further shortening the cooling time requires increasing the rotation speed of the forced air fan or using a refrigerant, which increases energy consumption.

[0005] JP 2013-084558 A

[0006] The present disclosure provides a power supply device that allows for efficient cooling.

[0007] A power supply device according to one embodiment of the present disclosure includes a first battery block including a plurality of first secondary battery cells and a first battery holder that houses the plurality of first secondary battery cells, and a second battery block including a plurality of second secondary battery cells and a second battery holder that houses the plurality of second secondary battery cells. The power supply device also includes an insulating spacer portion extending in the longitudinal direction interposed between the first battery block and the second battery block, and an exterior case that houses the first battery block, the second battery block, and the spacer portion. The spacer portion forms a first ventilation passage between the first battery block and the second battery block for flowing a first cooling airflow that cools the first battery block, and a second ventilation passage between the second battery block and the spacer portion for flowing a second cooling airflow that cools the second battery block. The spacer portion has, at one longitudinal end thereof, a first inlet communicating with one end of the first ventilation passage and a second inlet communicating with one end of the second ventilation passage, and has, at the other longitudinal end thereof, a first outlet communicating with the other end of the first ventilation passage and a second outlet communicating with the other end of the second ventilation passage. The exterior case has, at a first surface facing the one longitudinal end and inside thereof, a case inlet communicating with the first inlet and the second inlet, and a case outlet communicating with the first outlet and the second outlet, on a second surface facing the other longitudinal end and inside thereof.

[0008] According to a power supply device according to one embodiment of the present disclosure, the first secondary battery cell and the second secondary battery cell housed inside the outer case of the power supply device can be efficiently cooled by flowing cooling air from the case inlet to the case outlet.

[0009] FIG. 1 is a perspective view showing a power supply device according to a first embodiment. FIG. 2 is a perspective view of the power supply device of FIG. 1 as seen from the rear side. FIG. 3 is a longitudinal cross-sectional view of the power supply device of FIG. 1 taken along line III-III. FIG. 4 is an exploded perspective view of the power supply device of FIG. 1. FIG. 5 is an exploded perspective view of the power supply device of FIG. 4 as seen from the rear side. FIG. 6 is a further exploded perspective view of the power supply device of FIG. 4. FIG. 7 is a further exploded perspective view of the power supply device of FIG. 6. FIG. 8 is an exploded perspective view of the power supply device of FIG. 6 as seen obliquely from below. FIG. 9 is an exploded perspective view of the battery block of FIG. 6. FIG. 10 is a front view of the battery module of FIG. 4. FIG. 11 is a rear view of the battery module of FIG. 5. FIG. 12 is a cross-sectional view showing the ventilation path for cooling air in the power supply device of FIG. 3. FIG. 13 is an enlarged cross-sectional view of a main portion of the power supply device of FIG. 3. FIG. 14 is a perspective view of the spacer portion of FIG. 7 as seen obliquely from below. FIG. 15 is an enlarged cross-sectional view of a main portion of the power supply device of FIG. 3. FIG. 16 is an enlarged cross-sectional view of a main portion of the power supply device of FIG. 3. Figure 17 is a cross-sectional view showing high-pressure gas being discharged from the power supply device of Figure 3. Figure 18 is an enlarged perspective view of the power supply device of Figure 8. Figure 19 is an exploded perspective view of the first battery block of Figure 18. Figure 20 is an enlarged perspective view showing the top surface of the second battery block. Figure 21 is an exploded perspective view of the second battery block of Figure 20. Figure 22 is a cross-sectional view of the power supply device of Figure 1 taken along line XXII-XXII.

[0010] The embodiments of the present disclosure may be specified by the following configurations and features.

[0011] In another form of the power supply device of the present disclosure, in the above-described form, the spacer portion is provided with a partition plate, and the first inlet and first outlet are opened on the upper surface side of the partition plate, and the second inlet and second outlet are opened on the lower surface side of the partition plate.

[0012] In addition, in another form of the power supply device of the present disclosure, in any of the above forms, the first inlet is formed by cutting out the upper end of the first wall surface formed in an intersecting position from one end of the partition plate, and the second inlet is formed by cutting out the lower end of the first wall surface.

[0013] Furthermore, in a power supply device according to another aspect of the present disclosure, in any of the above aspects, the partition plate is formed as a plate without any through-holes that penetrate the top and bottom sides. This configuration insulates the first battery block from the second battery block and prevents liquid from crossing the first ventilation passage and the second ventilation passage when the device is submerged in water, for example, and causing a short circuit.

[0014] In yet another embodiment of the power supply device according to the present disclosure, in any of the above embodiments, the exterior case defines, on its inner surface, a third ventilation passage between it and the first battery block, and a fourth ventilation passage between it and the second battery block. One end of the third ventilation passage is connected to the case inlet and the other end is connected to the case outlet, and one end of the fourth ventilation passage is connected to the case inlet and the other end is connected to the case outlet. With this configuration, the third and fourth ventilation passages, in addition to the first and second ventilation passages, allow cooling air to be sent into the interior of the exterior case through multiple paths, making it possible to more efficiently cool the first and second rechargeable battery cells inside.

[0015] Furthermore, in a power supply device according to another aspect of the present disclosure, in any of the above aspects, the plurality of first secondary battery cells and the plurality of second secondary battery cells each include a safety valve that opens in response to an increase in internal pressure of the exterior can. The first ventilation passage and the second ventilation passage are gas exhaust paths that exhaust gas released when either safety valve opens from the exterior case to the outside. With the above configuration, there is no need to provide a separate gas exhaust path for exhausting high-temperature, high-pressure gas released in the event of an abnormality in the secondary battery cells to the outside of the power supply device. This allows the gas exhaust path to also serve as a ventilation path for cooling air, thereby efficiently utilizing the limited space within the exterior case and contributing to a simpler configuration and a lower profile.

[0016] In yet another aspect of the power supply device according to the present disclosure, in any of the above aspects, the first battery holder has one or more first protrusions on the surface facing the spacer portion, and the second battery holder has one or more second protrusions on the surface facing the spacer portion. The one or more first protrusions abut the upper surface of the partition plate to form a first ventilation passage, and the one or more second protrusions abut the lower surface of the partition plate to form a second ventilation passage. This configuration makes it possible to easily form ventilation passages using the battery holders.

[0017] Furthermore, in a power supply device according to another aspect of the present disclosure, in any of the above aspects, the first protrusions and the second protrusions are arranged in a line along a direction intersecting the longitudinal direction of the outer case. In a cross-sectional view intersecting the longitudinal direction of the outer case, the first protrusions and the second protrusions are arranged alternately. With this configuration, by arranging the first protrusions and the second protrusions in a line, it is possible to stably hold the partition plate in a straight line from above and below. Furthermore, by arranging the first protrusions and the second protrusions in an alternating abutting position above and below, in the unlikely event that high-pressure gas is discharged into either the first ventilation passage or the second ventilation passage, the partition plate can be easily deformed in a direction expanding the ventilation passage at the portion of the back side that is not pressed. This allows for smooth discharge of high-pressure gas.

[0018] Furthermore, in a power supply device according to another aspect of the present disclosure, in any of the above aspects, the direction in which the first cooling air flows in the first ventilation duct and the direction in which the second cooling air flows in the second ventilation duct are opposite to the exhaust direction of the gas released when either the safety valve in the first ventilation duct or the second ventilation duct is opened.

[0019] Furthermore, a power supply device according to another aspect of the present disclosure is any of the above-described aspects, further including first connection terminals connected to input / output terminals of the first battery block and second connection terminals connected to input / output terminals of the second battery block. The first connection terminal and the second connection terminal are each disposed at either the case inlet or the case outlet. This configuration enables cooling of the connection terminals in addition to cooling of the secondary battery cells.

[0020] Furthermore, a power supply device according to another embodiment of the present disclosure, in any of the above embodiments, further includes a first insulating plate arranged between the first battery block and the upper surface of the spacer portion, and a second insulating plate arranged between the second battery block and the lower surface of the spacer portion.

[0021] Embodiments of the present disclosure will be described below with reference to the drawings. However, the embodiments described below are merely examples for embodying the technical concepts of the present disclosure, and the present disclosure is not limited to the following. Furthermore, this specification does not in any way specify the components set forth in the claims to be those of the embodiments. The dimensions, materials, shapes, relative positions, etc. of components described in the embodiments are not intended to limit the scope of the present disclosure, and are merely illustrative examples, unless otherwise specified. The size and positional relationships of components shown in the drawings may be exaggerated for clarity. Furthermore, in the following description, the same names and symbols indicate components that are identical or of the same quality, and detailed descriptions will be omitted as appropriate. Furthermore, the elements constituting the present disclosure may be configured with the same components, such that multiple elements are served by a single component, or conversely, the functions of a single component may be shared by multiple components.

[0022] The power supply device of the present disclosure can be used as a driving power source for mobile objects such as electric carts, electric scooters, and assisted bicycles, and as a power source for portable electrical devices such as radios, electric cleaners, and power tools. Alternatively, the power supply device of the present disclosure can be used as a backup power source for servers in stationary power storage applications, as a power supply device for home, office, and factory use, and even as a driving power source for vehicles such as hybrid cars and electric automobiles. Below, a power supply device 100 used as a driving power source for an electric cart will be described as one embodiment of the present disclosure.

[0023] [Embodiment 1] A power supply device 100 according to Embodiment 1 of the present disclosure will be described with reference to Figures 1 to 22. In these figures, Figure 1 is a perspective view showing the power supply device 100 according to Embodiment 1, Figure 2 is a perspective view of the power supply device 100 of Figure 1 as seen from the rear, Figure 3 is a longitudinal cross-sectional view of the power supply device 100 of Figure 1 taken along line III-III, and Figure 4 is an exploded perspective view of the power supply device 100 of Figure 1. Also, Figure 5 is an exploded perspective view of the power supply device 100 of Figure 4 as seen from the rear, Figure 6 is a further exploded perspective view of the power supply device 100 of Figure 4, Figure 7 is a further exploded perspective view of the power supply device 100 of Figure 6, and Figure 8 is an exploded perspective view of the power supply device 100 of Figure 6 as seen obliquely from below. Also, Figure 9 is an exploded perspective view of the battery block 20 of Figure 6, Figure 10 is a front view of the battery module 2 of Figure 4, and Figure 11 is a rear view of the battery module 2 of Figure 5. Fig. 12 is a cross-sectional view showing the ventilation path for cooling air in the power supply device 100 of Fig. 3, Fig. 13 is an enlarged cross-sectional view of a main portion of the power supply device 100 of Fig. 3, Fig. 14 is a perspective view of the spacer portion 30 of Fig. 7 viewed obliquely from below, and Fig. 15 is an enlarged cross-sectional view of a main portion of the power supply device 100 of Fig. 3. Fig. 16 is an enlarged cross-sectional view of a main portion of the power supply device 100 of Fig. 3, Fig. 17 is a cross-sectional view showing how high-pressure gas is discharged in the power supply device 100 of Fig. 3, Fig. 18 is an enlarged perspective view of the power supply device 100 of Fig. 8, and Fig. 19 is an exploded perspective view of the first battery block 20A of Fig. 18. Fig. 20 is an enlarged perspective view showing the top surface of the second battery block 20B, Fig. 21 is an exploded perspective view of the second battery block 20B of Fig. 20, and Fig. 22 is a cross-sectional view of the power supply device 100 of Fig. 1 taken along line XXII-XXII. The power supply device 100 shown in these figures comprises an outer case 10 , a battery module 2 , and a circuit board 3 .

[0024] (External Case 10) The external case 10 houses the battery modules 2 and the circuit board 3. The external shape of the external case 10 can be any shape that has an internal storage space. In the example shown in Figures 1 to 3, the external case 10 has a box-like appearance that extends in one direction. The box-shaped external case 10 is composed of a top surface 14 and a bottom surface 15 that are spaced apart from each other above and below, and side surfaces 16 that connect these surfaces. The external case 10 also has a case inlet 17 and a case outlet 18 opening at each end surface in the longitudinal direction.

[0025] As shown in Figures 3 to 7, the exterior case 10 is divided into an upper case 11 and a lower case 12. The exterior case 10 is preferably made of a resin with excellent insulating properties, such as polycarbonate or a PC-ABS (Polycarbonate-Acrylonitrile Butadiene Styrene resin) alloy, but may also be made of a metal material such as aluminum or its alloy. As shown in Figures 4 to 7, an internal space is provided inside the exterior case 10 to house the battery module 2 and circuit board 3.

[0026] (Battery module 2) The battery module 2, also called a core pack, is composed of multiple battery blocks 20. In the example shown in Figures 6 to 8, the battery module 2 is composed of a first battery block 20A and a second battery block 20B. The first battery block 20A and the second battery block 20B are each composed of multiple secondary battery cells 1. Here, of the multiple secondary battery cells 1, the secondary battery cell 1 housed in the first battery block 20A is referred to as the first secondary battery cell 1A, and the secondary battery cell 1 housed in the second battery block 20B is referred to as the second secondary battery cell 1B.

[0027] The multiple secondary battery cells 1 are connected in series or in parallel via lead plates 4. The number of series connections and the number of parallel connections can be set arbitrarily according to the required specifications. Preferably, the first battery block 20A and the second battery block 20B use the same number of secondary battery cells 1. It is also preferable that the first battery block 20A and the second battery block 20B have the same number of series connections and parallel connections. In the examples shown in FIGS. 3 and 5 , the first battery block 20A and the second battery block 20B each use a total of 90 first secondary battery cells 1A and 90 second secondary battery cells 1B (9 series x 10 parallel connections), and the entire battery module 2 uses a total of 180 secondary battery cells 1 (18 series x 10 parallel connections). However, the first battery block 20A, the second battery block 20B, and the battery module 2 are not limited to this configuration.

[0028] Each battery block 20 includes multiple rechargeable battery cells 1. For example, the battery block 20 includes battery holders 21 that house the rechargeable battery cells 1. Specifically, the first battery block 20A includes a first battery holder 21A that houses multiple first rechargeable battery cells 1A. The second battery block 20B includes a second battery holder 21B that houses multiple second rechargeable battery cells 1B. Each battery holder 21 includes multiple storage cylinders that house the individual rechargeable battery cells 1. For example, each battery holder 21 is divided into two, an upper and lower section, and the two storage cylinders hold the rechargeable battery cells 1 from above and below. Such battery holders 21 can be made of resin such as polycarbonate, which has excellent insulating properties.

[0029] 3, 9, and other examples, each battery block 20 is configured with 90 secondary battery cells 1, but in the present disclosure, the number of secondary battery cells configuring each battery block is not limited to this and can be any number. Also, in the present disclosure, the number of secondary battery cells may be changed in some battery blocks. Furthermore, in the examples shown in FIGS. 6 to 8, an example is described in which a battery module 2 is configured with two battery blocks, a first battery block 20A and a second battery block 20B. However, it goes without saying that the present disclosure does not limit the number of battery blocks to two and may include three or more.

[0030] (Secondary battery cells 1) Each secondary battery cell 1 can be a secondary battery cell with a cylindrical or rectangular outer shape. In the examples shown in Figures 3 and 9, cylindrical secondary battery cells 1 are used in a staggered arrangement in a vertical orientation. Note that the number and arrangement of the secondary battery cells 1 are not limited to this example, and any number and arrangement can be used as appropriate. For example, cylindrical secondary battery cells may be arranged in a matrix.

[0031] Each secondary battery cell 1 has a positive and negative electrode, which are preferably provided on one end surface of the secondary battery cell 1. The secondary battery cell 1 may be any known secondary battery, such as a lithium-ion secondary battery, a nickel-metal hydride battery, or a nickel-cadmium battery.

[0032] (Safety valve 1a) The exterior can of each secondary battery cell 1 is provided with a safety valve 1a. The safety valve 1a opens in response to an increase in internal pressure of the exterior can, releasing gas inside the exterior can to the outside. For example, as shown in Figure 9, this type of safety valve 1a is provided on the positive electrode side of the secondary battery cell 1.

[0033] (Gas vent hole 13) Meanwhile, the exterior case 10 has a gas vent hole 13 formed in part for releasing high-pressure gas to the outside when the safety valve 1a of the secondary battery cell 1 is opened and the gas is discharged, as shown in Figures 10, 11, etc. In the example shown in Figures 1 to 5, etc., the gas vent hole 13 is provided near the center of the top surface 14 of the exterior case 10.

[0034] (Lead Plates 4) Lead plates 4 are arranged on the side surfaces of the battery holder 21. The lead plates 4 connect the electrodes of the end surfaces 1c of the rechargeable battery cells 1 together, connecting multiple rechargeable battery cells 1 in series or parallel. In the examples of Figures 3 and 9, the end surfaces 1c of 90 rechargeable battery cells 1 are connected together with lead plates 4, connecting the rechargeable battery cells 1 in a 9-in-10 parallel configuration. Note that the number and arrangement of rechargeable battery cells 1, and the number of series or parallel connections, are not limited to this example, and any number and arrangement can be used as appropriate. These lead plates 4 are made of a metal plate with excellent conductivity, such as a nickel plate.

[0035] (Insulating Plates 40) Insulating plates 40 are also disposed on the end surfaces of the lead plates 4. In the examples shown in Figures 6 to 8, the insulating plates 40 include a first insulating plate 40A and a second insulating plate 40B. The first insulating plate 40A is interposed between the underside of the first battery block 20A and the spacer portion 30. The second insulating plate 40B is interposed between the spacer portion 30 and the second battery block 20B. The first insulating plate 40A and the second insulating plate 40B are formed to a size sufficient to cover the entire surface of the lead plates 4 of the first battery block 20A and the second battery block 20B. Electrode windows 41 are also partially opened to expose the electrode portions of the lead plates 4. These insulating plates 40 are made of a material with excellent insulating properties, such as paper or mica.

[0036] (Circuit Board 3) Each first battery block 20A and second battery block 20B is connected to the circuit board 3 via lead plates 4. The circuit board 3 is equipped with a charge / discharge circuit that charges and discharges the rechargeable battery cells 1, and a protection circuit that monitors the voltage and temperature of the rechargeable battery cells 1 and cuts off the current in the event of an abnormality. The circuit board 3 is made of a glass epoxy board or the like. A board holder for holding such a circuit board 3 may also be provided.

[0037] (Spacer 30) A spacer 30 is interposed between the first battery block 20A and the second battery block 20B. The spacer 30 extends in the longitudinal direction of the first battery block 20A and the second battery block 20B. In the example shown in Figures 6 to 8, the spacer 30 includes a partition plate 32 extending in the longitudinal direction of the first battery block 20A and the second battery block 20B, and a spacer wall 35 disposed around the partition plate 32 and extending in a direction intersecting the partition plate 32. As shown in Figures 6 to 7, the spacer wall 35 is formed slightly larger than the first battery holder 21A of the first battery block 20A and the second battery holder 21B of the second battery block 20B so as to cover a portion of the side surface of these holders. Preferably, the partition plate 32 and the spacer wall 35 are integrally molded. The spacer portion 30 is made of a material with excellent insulating properties, for example, a resin such as polycarbonate or PC-ABS alloy.

[0038] The partition plate 32 is preferably formed as a plate without any through holes penetrating the top and bottom sides, which insulates the first battery block 20A from the second battery block 20B and prevents conductive liquids such as salt water from shorting across the first ventilation channel FP1 and the second ventilation channel FP2 when the battery block 20A is submerged in water.

[0039] (First Inlet 33A; Second Inlet 33B) Between the spacer portion 30 and the first battery block 20A, a first ventilation passage FP1 is formed for flowing a first cooling airflow to cool the first battery block 20A. A second ventilation passage FP2 is formed between the spacer portion 30 and the second battery block 20B for flowing a second cooling airflow to cool the second battery block 20B. In the example shown in FIGS. 3 , 12 , and 13 , the first ventilation passage FP1 is provided on the upper surface side along the longitudinal direction of the partition plate 32, and the second ventilation passage FP2 is provided on the lower surface side. A first inlet 33A and a second inlet 33B are opened at one longitudinal end of the spacer portion 30. Examples of the first inlet 33A and the second inlet 33B are shown in the front view of the battery module 2 in FIG. 10 . As shown in this figure, the first inlet 33A is formed by cutting out the upper end of a first wall surface of the spacer wall portion 35, which is located at the longitudinal end face of the spacer portion 30. The second inlet 33B is formed by cutting out the lower end of the first wall surface. As shown in Figures 3 and 12, the first inlet 33A is connected to one end of the first ventilation passage FP1. The second inlet 33B is connected to one end of the second ventilation passage FP2.

[0040] (First Outlet 34A; Second Outlet 34B) Meanwhile, a first outlet 34A and a second outlet 34B are respectively opened at the other longitudinal end of the spacer portion 30. Examples of the first outlet 34A and the second outlet 34B are shown in the rear view of the battery module 2 in FIG. 11. As shown in FIGS. 3, 6, and 12, the first outlet 34A communicates with the other end of the first ventilation passage FP1. Furthermore, as shown in FIGS. 3, 8, 12, and 14, the second outlet 34B communicates with the other end of the second ventilation passage FP2. In this way, the first inlet 33A and the first outlet 34A are opened on the upper surface side of the partition plate 32, and the second inlet 33B and the second outlet 34B are opened on the lower surface side of the partition plate 32.

[0041] Meanwhile, the exterior case 10 has a case inlet 17 and a case outlet 18. The case inlet 17 opens on a first case surface inside the side surface 16, facing one longitudinal end of the exterior case 10. The case outlet 18 is connected to the first inlet 33A and the second inlet 33B. The case outlet 18 also opens on a second case surface inside the side surface 16, facing the other longitudinal end of the exterior case 10. As shown in FIGS. 3 and 12 , the case outlet 18 is connected to the first outlet 34A and the second outlet 34B. This configuration enables efficient cooling of the multiple secondary battery cells 1 housed inside the exterior case 10 of the power supply device 100 by flowing cooling air from the case inlet 17 to the case outlet 18. In particular, in power supply devices that house a large number of secondary battery cells in a storage case with limited internal space, it is not easy to cool the secondary battery cells that generate heat during charging and discharging, and heat tends to accumulate in the secondary battery cells located in the middle. If it takes a long time to cool the secondary battery cells, the amount of time the secondary battery cells cannot be used increases, reducing usage efficiency. Even in such cases, providing a path for cooling air between the battery blocks 20 has the advantage of allowing cooling air to be blown into the interior, thereby enabling efficient heat exchange.

[0042] (Third ventilation passage FP3) Furthermore, on the inner surface of the exterior case 10, a third ventilation passage FP3 is formed between the exterior case 10 and the first battery block 20A, and a fourth ventilation passage FP4 can also be formed between the exterior case 10 and the second battery block 20B. One end of the third ventilation passage FP3 is connected to the case inlet 17 and the other end is connected to the case outlet 18. Similarly, one end of the fourth ventilation passage FP4 is connected to the case inlet 17 and the other end is connected to the case outlet 18. In the examples shown in the vertical cross-sectional views of Figures 3, 12, 15, and 16, the third ventilation passage FP3 is provided between the inner surface of the top surface 14 of the exterior case 10 and the first battery block 20A, and the fourth ventilation passage FP4 is provided between the inner surface of the bottom surface 15 of the exterior case 10 and the second battery block 20B. In this way, in addition to the first ventilation passage FP1 and the second ventilation passage FP2, the third ventilation passage FP3 and the fourth ventilation passage FP4 are used to send cooling air into the interior of the outer case 10 via multiple paths, making it possible to cool the first secondary battery cell 1A and the second secondary battery cell 1B inside more efficiently.

[0043] The power supply device 100 may also be provided with a blower fan for forcibly blowing cooling air. The blower fan may be provided, for example, on the case inlet 17 side or the case outlet 18 side.

[0044] (Gas Exhaust Path) Furthermore, the first ventilation passage FP1 and the second ventilation passage FP2 can also function as gas exhaust paths for exhausting gas released when the safety valve 1a provided in each secondary battery cell 1 is open from the exterior case 10 to the outside through the gas exhaust holes 13. With this configuration, the gas exhaust path for exhausting high-temperature, high-pressure gas released in the event of an abnormality in the secondary battery cell 1 to the outside of the power supply device 100 can be used as a ventilation path for cooling air without having to be provided separately within the exterior case 10, thereby efficiently utilizing the limited space within the exterior case 10 and contributing to a simpler configuration and a lower profile.

[0045] In the example shown in the longitudinal cross-section of FIG. 17 , the exterior case 10 defines a gas exhaust path within itself. In the event that gas is released from one of the secondary battery cells 1, the gas exhaust path guides the gas to the gas exhaust hole 13. The gas exhaust path includes a first space 31A, a second space 31B, a third space 31C, and a fourth space 31D, each extending longitudinally across the interior of the exterior case 10. The first space 31A forms a first ventilation passage FP1 formed between the first battery block 20A and the second battery block 20B. The second space 31B forms a second ventilation passage FP2. The third space 31C is formed between the bottom surface of the second battery block 20B and the inner surface of the bottom surface 15 of the lower case 12. The fourth space 31D is formed between the top surface of the first battery block 20A and a circuit board 3 located on the inner surface of the top surface 14 of the upper case 11. Furthermore, on the inner surface of the side surface 16 of the exterior case 10, the first space 31A, second space 31B, third space 31C, and fourth space 31D are connected to a fifth space 31E that extends to one surface in the shorter direction of the exterior case 10 (the up-down direction of the left side surface 16 in FIG. 17 ). The fifth space 31E is also connected to a sixth space 31F formed on the inner surface of the top surface 14 of the exterior case 10. The sixth space 31F extends along the longitudinal direction on the back surface of the upper case 11 to the gas exhaust hole 13. With this configuration, as shown in FIG. 17 , when high-temperature, high-pressure gas is exhausted from any of the secondary battery cells 1, it is exhausted to one of the first space 31A, second space 31B, third space 31C, or fourth space 31D depending on the exhaust position, i.e., the position of the safety valve 1a provided in the secondary battery cell 1. Gas discharged into any of the first space 31A, second space 31B, third space 31C, and fourth space 31D is guided to the sixth space 31F through the fifth space 31E, and is finally discharged to the outside of the outer case 10 through the gas discharge hole 13. Note that while this structure has been described with reference to Fig. 17 with the fifth space 31E provided on the left side of the inner surface of the outer case 10, the present disclosure is not limited to this structure, and a separate gas discharge path may also be formed on the right side of the inner surface of the outer case.

[0046] Furthermore, it is desirable that the end faces of the rechargeable battery cells 1 constituting the first battery block 20A and the end faces of the rechargeable battery cells 1 constituting the second battery block 20B are arranged facing each other via the spacers 30. Furthermore, it is desirable that a safety valve 1a be provided on either the end face of the rechargeable battery cells 1 of the first battery block 20A or the end face of the rechargeable battery cells 1 of the second battery block 20B, which are facing each other via the spacers 30. For example, it is desirable that one of the opposing end faces of the rechargeable battery cells 1 of the first battery block 20A and the second battery block 20B is a positive electrode and the other is a negative electrode. Since a safety valve is generally provided on either the positive or negative electrode, providing a safety valve 1a on only one of the opposing electrode surfaces prevents high-temperature, high-pressure gas from escaping from both end faces, ensuring safety.

[0047] 17, the gas discharge direction when the safety valve 1a of either the secondary battery cell 1 facing the first ventilation passage FP1 or the second ventilation passage FP2 is opened is designed to run from right to left. Meanwhile, the cooling air blowing direction, i.e., the direction of the first cooling air in the first ventilation passage FP1 and the direction of the second cooling air in the second ventilation passage FP2, is designed to run from left to right as shown in FIG. 12. In this way, the gas discharge direction and the cooling air blowing direction are designed to be opposite to each other.

[0048] Furthermore, by arranging the terminals of the battery modules 2 midway through the ventilation passage, it is possible to cool the connection terminals in addition to cooling the rechargeable battery cells 1. In the examples of Figures 10, 12, 17, etc., the first connection terminals 24A connected to the input / output of the first battery block 20A are arranged near the case inlet 17. In the examples of Figures 11-12, etc., the second connection terminals 24B connected to the input / output of the second battery block 20B are arranged near the case outlet 18. This also makes it possible to cool the terminals through which a large current flows and generates Joule heat. This configuration is not limited to this; the positions of the first connection terminals 24A and the second connection terminals 24B may be reversed, or both may be arranged on the case inlet 17 side or the case outlet 18 side. Furthermore, they may be arranged in any of the first space 31A, second space 31B, third space 31C, and fourth space 31D.

[0049] (Check valve) Furthermore, an openable / closable lid or a check valve may be provided at the case inlet 17 or the case outlet 18 of the outer case 10. In particular, safety can be enhanced by allowing cooling air to be taken in from the outside to the inside of the outer case 10 through the case inlet 17 as shown in Fig. 12 under normal circumstances, while preventing high-temperature, high-pressure gas from leaking from the outer case 10 through the case inlet 17 in the event of an abnormality as shown in Fig. 17. In this way, an openable / closable lid or a check valve can be used to restrict the gas flow to one direction.

[0050] 13 and 17, the partition plate 32 of the spacer section 30 defines a first ventilation passage FP1 on the side facing the first battery block 20A and a second ventilation passage FP2 on the side facing the second battery block 20B. The partition plate 32 is preferably formed so that the height of the first ventilation passage FP1 and the height of the second ventilation passage FP2 are approximately equal.

[0051] (First Protrusions 25A, Second Protrusions 25B) The first battery holder 21A has one or more first protrusions 25A on the surface facing the spacer portion 30. The second battery holder 21B also has one or more second protrusions 25B on the surface facing the spacer portion 30. In the examples shown in FIGS. 8, 18, and 19, the first battery holder 21A has multiple first protrusions 25A on the underside of the spacer portion 30, facing the upper surface of the partition plate 32. In the examples shown in FIGS. 20 and 21, the second battery holder 21B has multiple second protrusions 25B on the upper side, facing the lower surface of the partition plate 32. As shown in the enlarged cross-sectional view of FIG. 13, each first protrusion 25A abuts against the upper surface of the partition plate 32, forming a first ventilation passage FP1, and each second protrusion 25B abuts against the lower surface of the partition plate 32, forming a second ventilation passage FP2. In this way, it is possible to easily form ventilation passages using the battery holder 21. As shown in Figures 18 to 21, the first protrusions 25A and second protrusions 25B are each formed in a block shape with a flat upper surface.

[0052] As shown in the enlarged cross-sectional view of Figure 13, the first protrusions 25A and the second protrusions 25B are arranged in the same straight line along a transverse direction intersecting the longitudinal direction of the outer case 10. This allows the partition plate 32 to be clamped and supported from above and below in a straight line, with multiple straight lines spaced apart and intersecting the longitudinal direction of the partition plate 32, allowing for stable support of the partition plate 32. However, as shown in the transverse cross-sectional view of Figure 22, it is preferable to alternately arrange the first protrusions 25A and the second protrusions 25B in a cross-sectional view intersecting the longitudinal direction of the outer case 10. With this configuration, the partition plate 32 is stably supported in a straight line from above and below, while the contact positions at the top and bottom are alternately offset. This makes it possible that in the unlikely event that high-pressure gas is discharged into either the first ventilation passage FP1 or the second ventilation passage FP2, the partition plate 32 is easily deformed in the direction of expanding the ventilation passage at the portion on the back side that is not being pressed, thereby enabling the high-pressure gas to be discharged smoothly.

[0053] 18 to 21, the insulating plate 40 has openings 42 for allowing the first protrusions 25A and the second protrusions 25B to pass through. The first protrusions 25A and the second protrusions 25B are formed to be approximately the same size, and the openings 42 are formed to be approximately the same as or slightly larger than the outer shapes of the first protrusions 25A and the second protrusions 25B. This allows the insulating plate 40 to use the openings 42 as guides for positioning.

[0054] In the above example, the power supply device 100 is attached to the electrical device to be driven and supplies power to the electrical device. When the remaining capacity of the power supply device 100 becomes low or when the power supply device 100 deteriorates over time, the power supply device 100 can be replaced to continue using the electrical device. However, the present disclosure is not limited to replaceable power supply devices that mainly house secondary battery cells, but can also be applied to configurations in which secondary battery cells are housed within the housing of the electrical device. In the present disclosure, a power supply device is sufficient as long as it houses secondary battery cells in a case, and also includes power supply devices in which driving secondary battery cells are built into the housing of the electrical device itself. In other words, the present disclosure is not limited to replaceable power supply devices, but can also be applied to electrical devices that house secondary battery cells.

[0055] The power supply device according to the present disclosure can be suitably used, for example, as a power source for driving mobile objects such as electric carts, electric scooters, etc. The power supply device according to the present disclosure can also be suitably used, for example, as a power source for wireless devices or as a power source for portable electrical devices such as electric cleaners and power tools.

[0056] REFERENCE SIGNS LIST 1 Secondary battery cell 1A First secondary battery cell 1B Second secondary battery cell 1a Safety valve 1c End surface 2 Battery module 3 Circuit board 4 Lead plate 10 Outer case 11 Upper case 12 Lower case 13 Gas exhaust hole 14 Top surface 15 Bottom surface 16 Side surface 17 Case inlet 18 Case outlet 20 Battery block 20A First battery block 20B Second battery block 21 Battery holder 21A First battery holder 21B Second battery holder 24A First connecting terminal 24B Second connecting terminal 25A First protrusion 25B Second protrusion 30 Spacer portion 31A First space 31B Second space 31C Third space 31D Fourth space 31E Fifth space 31F Sixth space 32 Partition plate 33A First inlet 33B Second inlet 34A First outlet 34B Second outlet 35 Spacer wall 40 Insulating plate 40A First insulating plate 40B Second insulating plate 41 Electrode window 42 Opening window 100 Power supply device FP1 First ventilation path FP2 Second ventilation path FP3 Third ventilation path FP4 Fourth ventilation path

Claims

1. A power supply device comprising: a first battery block including a plurality of first secondary battery cells and a first battery holder that houses the plurality of first secondary battery cells; a second battery block including a plurality of second secondary battery cells and a second battery holder that houses the plurality of second secondary battery cells; an insulating spacer portion extending in the longitudinal direction interposed between the first battery block and the second battery block; and an exterior case that houses the first battery block, the second battery block, and the spacer portion, wherein the spacer portion forms a first ventilation passage between the first battery block and the second battery block for flowing a first cooling air flow that cools the first battery block, and forms a second ventilation passage between the second battery block and the second battery block for flowing a second cooling air flow that cools the second battery block, and a first inlet opening that communicates with one end of the first ventilation passage and a second inlet opening that communicates with one end of the second ventilation passage are opened at one end of the longitudinal direction, and a first outlet opening that communicates with the other end of the first ventilation passage and a second outlet opening that communicates with the other end of the first ventilation passage are opened at the other end of the longitudinal direction. a second air outlet communicating with the other end of the second ventilation passage is opened, and the exterior case has a case inlet communicating with the first air inlet and the second air inlet, opened on a first face internally facing the one end in the longitudinal direction, and a case outlet communicating with the first air outlet and the second air outlet, opened on a second face internally facing the other end in the longitudinal direction.

2. A power supply device as described in claim 1, wherein the spacer portion is provided with a partition plate, and the first inlet and the first outlet are opened on the upper surface side of the partition plate, and the second inlet and the second outlet are opened on the lower surface side of the partition plate.

3. A power supply device as claimed in claim 2, wherein the first inlet is formed by cutting out an upper end of a first wall surface formed in a cross position from one end of the partition plate, and the second inlet is formed by cutting out a lower end of the first wall surface.

4. A power supply device according to claim 2, wherein the partition plate is formed in a plate shape having no through hole penetrating the upper surface side and the lower surface side.

5. A power supply device as claimed in claim 1, wherein the outer case forms, on its inner surface, a third ventilation passage between itself and the first battery block, and a fourth ventilation passage between itself and the second battery block, one end of the third ventilation passage being connected to the case inlet and the other end being connected to the case outlet, and the fourth ventilation passage being connected to the case inlet and the other end being connected to the case outlet.

6. A power supply device as described in claim 2, wherein the plurality of first secondary battery cells and the plurality of second secondary battery cells are each provided with a safety valve that opens in response to an increase in internal pressure of the outer casing, and the first ventilation passage and the second ventilation passage are gas exhaust paths that exhaust gas released when any of the safety valves are opened from the outer casing to the outside.

7. A power supply device as described in claim 6, wherein the first battery holder has one or more first protrusions on a surface facing the spacer portion, and the second battery holder has one or more second protrusions on a surface facing the spacer portion, the one or more first protrusions abutting the upper surface of the partition plate to form the first ventilation passage, and the one or more second protrusions abutting the lower surface of the partition plate to form the second ventilation passage.

8. A power supply device as claimed in claim 7, wherein the first protrusions and the second protrusions are arranged in the same straight line along a direction intersecting the longitudinal direction of the exterior case, and the first protrusions and the second protrusions are arranged alternately in a cross-sectional view intersecting the longitudinal direction of the exterior case.

9. A power supply device as claimed in claim 6, wherein the direction in which the first cooling air flows in the first ventilation duct and the direction in which the second cooling air flows in the second ventilation duct are opposite to the exhaust direction of the gas released when the safety valve in either the first ventilation duct or the second ventilation duct is opened.

10. A power supply device as claimed in any one of claims 1 to 9, further comprising: a first connection terminal connected to an input / output of the first battery block; and a second connection terminal connected to an input / output of the second battery block, the first connection terminal and the second connection terminal being respectively disposed on either the case inlet side or the case outlet side of the exterior case.

11. A power supply device as claimed in any one of claims 1 to 9, further comprising: a first insulating plate arranged between the first battery block and the upper surface of the spacer portion; and a second insulating plate arranged between the second battery block and the lower surface of the spacer portion.

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