Energy storage device

Abstract

The condensed water generated inside the case is quickly drained. [Solution] The energy storage device 1 comprises a battery stack 10, a case 20, and a guide plate 30. The battery stack 10 includes a plurality of battery cells 11 stacked on top of each other. The case 20 houses the battery stack 10. The case 20 includes a bottom surface 21, an inclined portion 27, and a through hole 28. The bottom surface 21 supports the battery stack 10 from below. The inclined portion 27 extends diagonally downward from the bottom surface 21. The through hole 28 extends from the lower end of the inclined portion 27 and connects the housing space in the case 20 that houses the battery stack 10 with the external space. The guide plate 30 is configured to guide the cooling air flowing inside the case 20 toward the bottom surface 21 or the inclined portion 27.

Description

Technical Field

[0001] This disclosure relates to a power storage device.

Background Art

[0002] Japanese Unexamined Patent Application Publication No. 2014-165004 (Patent Document 1) discloses a conventional battery pack. In this battery pack, condensation occurs due to cooling the assembled battery with cooling air, and the condensed water generated by this condensation drops onto the support plate and is discharged. Specifically, the water that has dripped directly, the water that has flowed down along the insulating member, and the water that has flowed in from the width-side inclined surface inside the groove portion flow along the inclination of the groove bottom surface of the groove portion by its own weight toward the outside and downward in the width direction, and is discharged from the second through-hole of the side wall portion to the outside in the width direction of the support plate.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The condensed water in the power storage device can reduce the insulation resistance between the members in the power storage device and cause leakage, so it is preferably discharged promptly. However, in a conventional battery pack (power storage device), the induction of condensed water (condensation water) is only due to its own weight. Therefore, the efficiency of discharging the condensed water is low.

[0005] This disclosure has been made in view of the above problems, and an object thereof is to provide a power storage device capable of promptly discharging the condensed water generated in the case.

Means for Solving the Problems

[0006] An energy storage device according to a certain aspect of the present disclosure comprises a battery stack, a case, and a guide plate. The battery stack includes a plurality of battery cells stacked on top of each other. The case houses the battery stack. The case includes a bottom, a slanted section, and a through hole. The bottom supports the battery stack from below. The slanted section extends diagonally downward from the bottom. The through hole extends from the lower end of the slanted section and connects the housing space in the case that houses the battery stack with the outside space. The guide plate is configured to guide cooling air flowing inside the case toward the bottom or the slanted section. [Effects of the Invention]

[0007] With the above configuration, condensed water generated inside the case can be quickly drained. [Brief explanation of the drawing]

[0008] [Figure 1] This is a perspective view showing an energy storage device according to one embodiment of the present disclosure. [Figure 2] This diagram shows part of the case and internal structure of the energy storage device. [Figure 3] Figure 2 is a cross-sectional view of the energy storage device as seen along the line III-III. [Figure 4] Figure 2 is a cross-sectional view of the energy storage device as seen in the direction of the arrow between lines IV and IV. [Figure 5] Figure 2 is a cross-sectional view of the energy storage device as seen in the direction of the VV arrow. [Modes for carrying out the invention]

[0009] Hereinafter, an energy storage device according to one embodiment of the present disclosure will be described with reference to the drawings. The same or corresponding parts in the drawings are denoted by the same reference numerals, and their descriptions will not be repeated. In addition, the drawings show "U" and "D". "U" indicates upward, and "D" indicates downward.

[0010] Figure 1 is a perspective view showing a power storage device according to one embodiment of the present disclosure. The power storage device 1 shown in Figure 1, according to one embodiment of the present disclosure, may be installed in an electric vehicle such as a plug-in hybrid electric vehicle (PHEV) or a battery electric vehicle (BEV). The power storage device 1 may supply power to drive the vehicle.

[0011] Figure 2 shows a portion of the case and internal structure of the energy storage device. As shown in Figures 1 and 2, the energy storage device 1 comprises a battery stack 10, a case 20, and a guide plate 30. In Figure 2, a portion of the case 20 is shown for convenience.

[0012] The battery stack 10 includes a plurality of battery cells 11 stacked on top of each other and a plurality of flow path sections 12.

[0013] Each of the multiple battery cells 11 may be a secondary battery such as a lithium-ion secondary battery or a nickel-metal hydride battery. Each of the multiple battery cells 11 may also be a solid-state battery. The multiple battery cells 11 are stacked while being separated from each other in a first direction D1 that is perpendicular to the vertical direction DV.

[0014] Figure 3 is a cross-sectional view of the energy storage device shown in Figure 2, taken along the line III-III. As shown in Figures 2 and 3, the flow path section 12 is provided between a plurality of adjacent battery cells 11. The plurality of battery cells 11 and the plurality of flow path sections 12 are arranged alternately in the first direction D1. The flow path section 12 located between a pair of adjacent battery cells 11 may be composed of a plurality of members spaced apart from each other, or it may be composed of a single integrated member. The flow path section 12 forms a flow path 12a. Details of the flow path 12a will be described later.

[0015] As shown in Figures 1 to 3, the case 20 houses the battery stack 10. The case 20 is also called a pack.

[0016] The case 20 includes a bottom surface portion 21, a first wall portion 22, a second wall portion 23, a first side wall portion 24, a second side wall portion 25, a recessed portion 26, an inclined portion 27, a through hole 28, and an upper case 29. In the present embodiment, the bottom surface portion 21, the first wall portion 22, the second wall portion 23, the first side wall portion 24, the second side wall portion 25, the recessed portion 26, the inclined portion 27, and the through hole 28 are formed of an integral member, and more specifically, are formed by aluminum die casting.

[0017] The bottom surface portion 21 supports the battery stack 10 from below. The first wall portion 22 stands upright upward from the bottom surface portion 21 on one side of the battery stack 10 in the first direction D1. The second wall portion 23 stands upright upward from the bottom surface portion 21 on the other side of the battery stack 10 in the first direction D1. The bottom surface portion 21, the first wall portion 22, and the second wall portion 23 partition the accommodation space for accommodating the battery stack 10 in the case 20 and the external space of the case 20.

[0018] The first side wall portion 24 stands upright upward from the bottom surface portion 21 on one side of the battery stack 10 in the second direction D2 that is orthogonal to both the vertical direction DV and the first direction D1. The first side wall portion 24 partitions the accommodation space for accommodating the battery stack 10 in the case 20 and the external space of the case 20.

[0019] The second side wall portion 25 stands upright upward from the bottom surface portion 21 on the other side of the battery stack 10 in the second direction D2. The second side wall portion 25 is located in the accommodation space for accommodating the battery stack 10 in the case 20.

[0020] The recessed portion 26 is formed to be recessed from the bottom surface portion 21 below the battery stack 10. The recessed portion 26 partitions the accommodation space for accommodating the battery stack 10 in the case 20 and the external space of the case 20.

[0021] FIG. 4 is a cross-sectional view of the power storage device of FIG. 2 as viewed in the direction of the arrow along line IV-IV. FIG. 5 is a cross-sectional view of the power storage device of FIG. 2 as viewed in the direction of the arrow along line V-V. As shown in FIGS. 2 to 5, the inclined portion 27 extends obliquely downward from the bottom surface portion 21.

[0022] The inclined portion 27 is positioned so as not to overlap with the battery stack 10 in the vertical direction DV. The inclined portion 27 is inclined downward as it extends from the bottom surface portion 21 toward the through hole 28 along the first direction D1. The inclined portion 27 is adjacent to the first side wall portion 24 or the second side wall portion 25 when viewed from the vertical direction DV. Specifically, the inclined portion 27 is adjacent to the second side wall portion 25.

[0023] The through hole 28 extends from the lower end of the inclined portion 27 and communicates the accommodation space for accommodating the battery stack 10 in the case 20 with the external space of the case 20. The through hole 28 is positioned so as not to overlap with the battery stack 10 in the vertical direction DV. The through hole 28 is adjacent to the first side wall portion 24 or the second side wall portion 25 when viewed from the vertical direction DV. The through hole 28 is adjacent to the first wall portion 22 or the second wall portion 23 when viewed from the vertical direction DV. Specifically, the through hole 28 is adjacent to the second wall portion 23 when viewed from the vertical direction DV.

[0024] The upper case 29 covers the upper sides of the bottom surface portion 21, the first wall portion 22, the second wall portion 23, the first side wall portion 24, the second side wall portion 25, the concave portion 26, the inclined portion 27, and the through hole 28. The upper case 29 partitions the accommodation space for accommodating the battery stack 10 in the case 20 from the external space of the case 20.

[0025] The guide plate 30 is configured to guide the cooling air flowing inside the case 20 toward the bottom surface portion 21 or the inclined portion 27. Specifically, the guide plate 30 extends from the first side wall portion 24 or the second side wall portion 25 along the second direction D2 toward the battery stack 10 and is in contact with the battery stack 10. More specifically, the guide plate 30 extends from the first side wall portion 24.

[0026] Here, the flow path 12a will be described with reference to Figure 3. In Figure 3, the cooling air is indicated by a white arrow. In the flow path 12a, the cooling air that flows upward from the space formed by the recess 26 in the housing space is sent between the battery stack 10 and the first side wall 24, and between the battery stack 10 and the second side wall 25. The cooling air sent between the battery stack 10 and the first side wall 24, and between the battery stack 10 and the second side wall 25, is further directed toward the bottom surface 21, the inclined portion 27, and the through hole 28 by the guide plate 30, etc. As a result, the condensed water generated in the case 20 is guided by the cooling air and quickly discharged from the through hole 28. The cooling air may be generated by a blower (not shown), or it may be generated by the movement of a vehicle equipped with the energy storage device 1. The cooling air may also be cooled by a heat exchanger (not shown). The heat exchanger may be provided in the energy storage device 1, or in the vehicle on which the energy storage device 1 is installed.

[0027] As described above, an energy storage device 1 according to one embodiment of the present disclosure comprises a battery stack 10, a case 20, and a guide plate 30. The battery stack 10 includes a plurality of battery cells 11 stacked on top of each other. The case 20 houses the battery stack 10. The case 20 includes a bottom portion 21, an inclined portion 27, and a through hole 28. The bottom portion 21 supports the battery stack 10 from below. The inclined portion 27 extends diagonally downward from the bottom portion 21. The through hole 28 extends from the lower end of the inclined portion 27 and connects the housing space in the case 20 that houses the battery stack 10 with the external space. The guide plate 30 is configured to guide the cooling air flowing inside the case 20 toward the bottom portion 21 or the inclined portion 27.

[0028] According to the above configuration, condensed water generated in the cooling air flowing inside the case 20 is guided by the cooling air, guided by the guide plate 30, to the bottom surface 21 or the inclined surface 27. The condensed water generated at the bottom surface 21 or the inclined surface 27 flows from the bottom surface 21 to the inclined surface 27, and then flows from the inclined surface 27 to the through hole 28. The condensed water is then discharged from the through hole 28. In this way, the above configuration allows for the rapid discharge of condensed water generated inside the case 20. Furthermore, the condensed water can be dried by the cooling air.

[0029] Furthermore, in this embodiment, the inclined portion 27 and the through hole 28 are positioned so as not to overlap with the battery stack 10 in the vertical direction DV.

[0030] With the above configuration, it is possible to prevent the discharge of condensate from being hindered by the battery stack 10. Therefore, the condensate generated in the case 20 can be discharged even more quickly.

[0031] Furthermore, in this embodiment, the plurality of battery cells 11 are stacked in a first direction D1 perpendicular to the vertical direction DV. The case 20 further includes a first wall portion 22, a second wall portion 23, a first side wall portion 24, and a second side wall portion 25. The first wall portion 22 rises upward from the bottom portion 21 on one side of the battery stack 10 in the first direction D1. The second wall portion 23 rises upward from the bottom portion 21 on the other side of the battery stack 10 in the first direction D1. The first side wall portion 24 rises upward from the bottom portion 21 on one side of the battery stack 10 in a second direction D2 perpendicular to both the vertical direction DV and the first direction D1. The second side wall portion 25 rises upward from the bottom portion 21 on the other side of the battery stack 10 in the second direction D2.

[0032] Furthermore, the inclined portion 27 is tilted downward along the first direction D1 from the bottom portion 21 toward the through hole 28. This allows the inclined portion 27 to be formed over a relatively wide area without overlapping with the battery stack 10.

[0033] Furthermore, the inclined portion 27 is adjacent to either the first side wall portion 24 or the second side wall portion 25 when viewed from the vertical direction DV. As a result, condensed water adhering to either the first side wall portion 24 or the second side wall portion 25 can be quickly discharged through the through hole 28 via the inclined portion 27.

[0034] Furthermore, the through-hole 28 is adjacent to either the first side wall portion 24 or the second side wall portion 25 when viewed from the vertical direction DV. This allows condensed water adhering to either the first side wall portion 24 or the second side wall portion 25 to be quickly discharged through the through-hole 28.

[0035] Furthermore, the through-hole 28 is adjacent to either the first wall portion 22 or the second wall portion 23 when viewed from the vertical direction DV. This allows condensed water adhering to the first wall portion 22 or the second wall portion 23 to be quickly discharged through the through-hole 28.

[0036] Furthermore, in this embodiment, the plurality of battery cells 11 are stacked in a first direction D1 perpendicular to the vertical direction DV. The case 20 further includes a first side wall portion 24 and a second side wall portion 25. The first side wall portion 24 rises upward from the bottom portion 21 on one side of the battery stack 10 in a second direction D2 perpendicular to both the vertical direction DV and the first direction D1. The second side wall portion 25 rises upward from the bottom portion 21 on the other side of the battery stack 10 in the second direction D2. The guide plate 30 extends from the first side wall portion 24 or the second side wall portion 25 toward the battery stack 10 along the second direction D2 and is in contact with the battery stack 10.

[0037] With the above configuration, the cooling air below the guide plate 30 can be more reliably directed towards the bottom surface 21, and consequently, the condensed water can be reliably guided by the bottom surface 21 or the inclined surface 27.

[0038] In this embodiment, the battery stack 10 further includes a flow path 12. The case 20 further includes a recess 26. The flow path 12 is provided between a plurality of adjacent battery cells 11. The recess 26 is formed below the battery stack 10 so as to be recessed from the bottom surface 21. The flow path 12 forms a flow path 12a that directs cooling air flowing upward from the space formed by the recess 26 within the housing space to the space between the battery stack 10 and the first side wall 24, and between the battery stack 10 and the second side wall 25.

[0039] With the above configuration, the cooling air inside the case 20 can be reliably guided by the airflow path 12 to the space below the guide plate 30. Consequently, condensed water can be more reliably guided to the space below the guide plate 30, and the condensed water can be quickly discharged from the through-hole 28 via the bottom surface 21 and the inclined section 27. In addition, the airflow path for the cooling air inside the case 20 becomes clearer, which can make it easier to calculate the pressure loss of the cooling air.

[0040] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of this disclosure is indicated by the claims rather than the foregoing description, and all modifications within the meaning and scope equivalent to the claims are intended. [Explanation of Symbols]

[0041] 1 Energy storage device, 10 Battery stack, 11 Battery cell, 12 Flow path section, 12a Flow path, 20 Case, 21 Bottom section, 22 First wall section, 23 Second wall section, 24 First side wall section, 25 Second side wall section, 26 Recess, 27 Inclined section, 28 Through hole, 29 Upper case, 30 Guide plate, D1 First direction, D2 Second direction, DV Up and down direction.

Claims

1. It is an energy storage device, Battery stack and The case and Equipped with an information board, The battery stack includes a plurality of battery cells stacked on top of each other, The aforementioned case houses the battery stack, The case includes a bottom portion, an inclined portion, and a through hole. The bottom portion supports the battery stack from below. The inclined portion extends diagonally downward from the bottom surface, The through-hole extends from the lower end of the inclined portion and connects the housing space for housing the battery stack in the case with the external space. The aforementioned guide plate is configured to guide the cooling air flowing inside the case toward the bottom surface or the inclined portion, in an energy storage device.

2. The energy storage device according to claim 1, wherein the inclined portion and the through hole are positioned so as not to overlap with the battery stack in the vertical direction.

3. The plurality of battery cells are stacked in a first direction perpendicular to the vertical direction, The case further includes a first wall portion, a second wall portion, a first side wall portion, and a second side wall portion. The first wall portion rises upward from the bottom portion on one side of the battery stack in the first direction. The second wall portion rises upward from the bottom portion on the other side of the battery stack in the first direction. The first side wall portion rises upward from the bottom portion on one side of the battery stack in a second direction perpendicular to both the vertical direction and the first direction. The second side wall portion rises upward from the bottom portion on the other side of the battery stack in the second direction. The inclined portion is tilted downward along the first direction from the bottom surface towards the through hole, The inclined portion is adjacent to the first side wall portion or the second side wall portion when viewed from the vertical direction. The energy storage device according to claim 2, wherein the through hole is adjacent to the first side wall portion or the second side wall portion when viewed from the vertical direction, and is adjacent to the first wall portion or the second wall portion when viewed from the vertical direction.

4. The plurality of battery cells are stacked in a first direction perpendicular to the vertical direction, The case further includes a first side wall portion and a second side wall portion, The first side wall portion rises upward from the bottom portion on one side of the battery stack in a second direction perpendicular to both the vertical direction and the first direction. The second side wall portion rises upward from the bottom portion on the other side of the battery stack in the second direction. The energy storage device according to claim 1, wherein the guide plate extends from the first side wall portion or the second side wall portion toward the battery stack along the second direction and is in contact with the battery stack.

5. The battery stack further includes a flow path section, The aforementioned case further includes a recess, The aforementioned flow path is provided between the plurality of battery cells that are adjacent to each other. The recess is formed below the battery stack so as to be recessed from the bottom surface. The energy storage device according to claim 4, wherein the flow path portion forms a flow path that sends the cooling air flowing upward from the space formed by the recess in the storage space to the space between the battery stack and the first side wall portion, and between the battery stack and the second side wall portion.

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