WO2016031121A1

WO2016031121A1 - Battery cooling structure, battery module, and battery module case

Info

Publication number: WO2016031121A1
Application number: PCT/JP2015/003509
Authority: WO
Inventors: 井口　豊樹; 弘明斉藤; 加藤　浩二; 清田　茂之; 弘志岩田; 博之小山; 那由他山地; 諭森山; 幸典根本
Original assignee: 日産自動車株式会社; 日立オートモティブシステムズ株式会社
Priority date: 2014-08-29
Filing date: 2015-07-10
Publication date: 2016-03-03
Also published as: JP6208887B2; JPWO2016031121A1

Abstract

A battery cooling structure for efficiently cooling battery cells in a battery module is provided. Multiple columnar battery cells are housed in the battery module and are arranged in parallel to each other with gaps formed therebetween so as to form a cooling medium passage through which a cooling medium passes inside of the battery module. On the first lateral surface of the battery module, inlets for introducing the cooling medium into battery module open upstream of the cooling medium passage and are provided along gaps between the battery cells arranged nearest to the first lateral surface. On the second lateral surface of the battery module, outlets for discharging the cooling medium to outside of the battery module open downstream of the cooling medium passage and are provided along the centers in the width direction of the battery cells arranged nearest to the second lateral surface.

Description

Battery cooling structure, battery module, and battery module housing

The present invention relates to a battery cooling structure for cooling a battery.

In an electric vehicle that uses an electric motor as a drive source, an automobile that combines an electric motor and an internal combustion engine as a drive source (a so-called hybrid vehicle), a battery for supplying electricity as energy to the electric motor is mounted. As this battery, a secondary battery such as a lithium ion battery that can be repeatedly charged and discharged is used. The secondary battery is configured by a battery module in which battery cells are stacked, and the battery module is mounted on a vehicle in a state where the battery module is housed in a battery case. A battery pack including the battery case, the battery module housed in the battery case, and other internal components is referred to as a battery pack. In order to manage the temperature of the battery module accommodated in the battery pack, a cooling device such as a fan or a duct for taking in cooling air is attached to the battery pack.

In recent years, as a place where a secondary battery is mounted in a passenger car, a battery pack may be disposed in a center console box disposed between a driver's seat and a passenger seat due to ambient temperature and layout requirements.
Currently, for the battery pack arranged in the center console box arranged between the driver's seat and the passenger seat, in the cooling structure for flowing cooling air to the cooling air passage between the inner wall of the battery case and the battery module, There is a technology for improving the cooling performance by cooling the entire secondary battery more uniformly by making the passage cross-sectional area of the cooling air passage larger on the inlet side and smaller on the outlet side (see Patent Document 1).

JP 2013-251158 A

In the battery pack disposed in the center console box disposed between the driver seat and the passenger seat as described above, in order to further enhance the cooling performance, only the cooling performance for the battery module in the battery case is increased. It is considered that it is necessary to improve the cooling performance for the battery cells in the battery module.

An object of the present invention is to provide a battery cooling structure for efficiently cooling battery cells in a battery module.

In order to solve the above problem, in the battery cooling structure according to one aspect of the present invention, a plurality of columnar battery cells accommodated in the battery module are formed with a cooling medium passage through which the cooling medium passes. They were arranged parallel to each other with a gap. The first side surface of the battery module has an inlet for opening the upstream side of the cooling medium passage and introducing the cooling medium into the battery module, in a gap between the battery cells arranged closest to the first side surface. It is provided along. On the second side surface of the battery module, there is an outlet on the downstream side of the cooling medium passage, and an outlet for discharging the cooling medium out of the battery module is arranged in the width direction of the battery cell arranged closest to the second side surface. It is provided along the center. For example, when the cooling medium is cooling air, the inlet is an inlet and the outlet is an outlet. Further, the first side surface and the second side surface of the battery module are not limited to a part of the battery module, and may be a member that covers or surrounds the battery module.

According to one aspect of the present invention, the cooling medium efficiently enters between the battery cells from the inlet of the battery module, and the cooling medium passes through the cooling medium passage formed by the battery cells accommodated in the battery module. Thus, when the cooling medium passes, the battery cell that becomes the passage is cooled, and finally the cooling medium becomes a flow that is discharged from the outlet along the shape of the battery cell arranged closest to the outlet. The battery cells in the module can be efficiently cooled.

It is a figure which shows the structural example of a battery module. (A) is a figure which shows the main body of a battery module. (B) is a view of the intake side of the battery module. (C) is a figure of the exhaust side of a battery module. It is a schematic diagram for demonstrating the internal structure of a battery module. It is a figure which shows the example of a 1st cover board. It is a schematic diagram of the battery module when viewed from the intake side. (A) is an internal schematic diagram. (B) is a schematic diagram of an external appearance. It is a figure which shows the 1st example of a 2nd cover board. It is the 1st schematic diagram of a battery module at the time of seeing from the exhaust side. (A) is an internal schematic diagram. (B) is a schematic diagram of an external appearance. It is a figure which shows the 2nd example of a 2nd cover board. It is a 2nd schematic diagram of the battery module at the time of seeing from the exhaust side. (A) is an internal schematic diagram. (B) is a schematic diagram of an external appearance. It is a figure which shows the example which piled up 2 types of 2nd cover plates. It is a figure which shows the structural example of a battery pack. It is a schematic diagram of the battery pack when viewed from the exhaust side. It is explanatory drawing of the flow of the cooling air of the whole battery pack. (A) is a peripheral view of the battery pack when viewed from the exhaust side. (B) is a figure which shows the flow of the cooling air inside a battery pack. It is a figure which shows the example which forms a pseudo slit with a punch hole in a cover board. (A) is a figure of the state which opened all the holes. (B) is a figure of the state which is made into a slit with a part of holes being opened, and other holes are closed. It is a schematic diagram for demonstrating the internal structure of the battery module which provided the dummy cell.

Next, first to fifth embodiments of the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic and different from the actual ones. Therefore, specific components should be determined in consideration of the following description.
Further, the following first to fifth embodiments exemplify apparatuses and methods for embodying the technical idea of the present invention, and the technical idea of the present invention includes the shape of component parts, The structure and arrangement are not specified as follows. The technical idea of the present invention can be variously modified within the technical scope defined by the claims described in the claims.
In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of embodiments of the present invention. However, it will be apparent that one or more embodiments may be practiced without such specific details. In other instances, well-known structures and devices are schematically shown in order to simplify the drawing.

<First Embodiment>
Hereinafter, a first embodiment of the present invention will be described with reference to the accompanying drawings.
(Constitution)
The battery cooling structure according to the first embodiment is realized in a battery module 1 as shown in FIGS. As shown in FIGS. 1A and 2, the battery module 1 accommodates a plurality of columnar battery cells 2 inside a casing 1 a that is a rectangular parallelepiped as a whole. When viewed from the angle shown in FIG. 1A, among the six surfaces of the housing 1a, the first side surface on the intake side, the second side surface on the exhaust side, and both electrodes (end portions) of the battery cell 2 A total of four surfaces, an upper surface and a lower surface, located on the) side are open. Specifically, the housing 1a is provided with an intake-side opening 1b on a first side, and an exhaust-side opening 1c on a second side opposite to the first side. The side surface of the battery cell 2 is exposed at the opening 1b on the intake side and the opening 1c on the exhaust side. Further, the positive electrode 2a and the negative electrode 2b of the battery cell 2 are exposed on the upper surface and the lower surface of the housing 1a so that power can be taken out even in the state of being accommodated in the housing 1a. Since both the electrodes of the battery cell 2 are exposed, when the contents of the battery cell 2 flow out from either of the two electrodes of the battery cell 2, the flowed out contents are not inside the housing 1a but outside. Released. However, when it is not necessary to consider the outflow of the contents of the battery cell 2, only the lead wires connected to the positive electrode 2a and the negative electrode 2b are exposed instead of the positive electrode 2a and the negative electrode 2b of the battery cell 2. You may do it.

The battery cell 2 is a single battery. In the example shown in FIG. 2, the battery cell 2 is a cylindrical cell (columnar shape), and is housed in a staggered arrangement in order to be housed compactly in the housing 1 a of the battery module 1. However, actually, the battery cell 2 is not limited to a cylindrical cell. For example, a prismatic shape may be used. Moreover, it is not limited to the staggered arrangement. For example, it may be accommodated in a grid pattern. In addition, each of the plurality of battery cells 2 accommodated in the casing 1a of the battery module 1 is not completely in close contact, and is arranged at an appropriate interval, so that cooling air passes between the battery cells. Possible passages (cooling air passages) are formed. Here, since air cooling is common, cooling air (gas) is assumed as a cooling medium. However, when incorporated in a water-cooled system, cooling water (liquid) may be used as a cooling medium. That is, the cooling medium may be a fluid.

The first cover plate 3 is located on the first side surface (intake side) of the battery module 1. For example, the first cover plate 3 is a part of the casing 1 a of the battery module 1. Alternatively, the first cover plate 3 covers the opening 1b on the intake side of the casing 1a of the battery module 1 as an independent member. In this case, the first cover plate 3 is a panel such as a metal plate or an acrylic plate. In the first embodiment, as shown in FIGS. 1B and 3, the first cover plate 3 is provided with an intake port 4 for taking cooling air into the battery module 1. That is, the intake port 4 is an inlet for a cooling medium (fluid). Here, as an example, the first cover plate 3 is provided with four intake ports 4.

The intake 4 is a slit. By using the inlet 4 as a slit, the pressure loss can be reduced while increasing the flow velocity of the cooling air. Moreover, the entrance of the protrusion (occupant's finger etc.) to the air inlet 4 can be suppressed by using the air inlet 4 as a slit.

As shown in FIGS. 4A and 4B, the air inlet 4 is provided along the gap between the battery cells arranged closest to the first cover plate 3. For example, when the first cover plate 3 that covers the opening 1b on the intake side of the housing 1a of the battery module 1 is viewed from the front, the air inlet 4 is positioned so as to overlap with the gap between the parallel cylindrical cells. It is open.

Here, as an example, the number of battery cells 2 arranged closest to the first cover plate 3 is five, and the intake ports 4 are formed in four gaps between adjacent cells in the parallel five battery cells 2. It is provided along. Actually, the number of battery cells 2 arranged closest to the first cover plate 3 is not limited to five and is arbitrary.

Thus, it is preferable that the air inlet 4 is provided only at a position along the gap between the battery cells arranged closest to the first cover plate 3. In practice, in the first cover plate 3, a part of the air inlet 4 may be provided at a place other than the position along the gap between the battery cells. However, even in this case, the flow of the cooling air passing through the air inlet 4 provided at the position along the gap between the battery cells is made mainstream.

The second cover plate 5 is located on the second side surface (exhaust side) of the battery module 1. For example, the second cover plate 5 is a part of the casing 1 a of the battery module 1. Alternatively, the second cover plate 5 covers the exhaust-side opening 1c of the casing 1a of the battery module 1 as an independent member. In this case, the second cover plate 5 is a panel such as a metal plate or an acrylic plate. Here, the second cover plate 5 faces the first cover plate 3 with the battery module 1 interposed therebetween. However, actually, the second cover plate 5 may not be opposed to the first cover plate 3. In the first embodiment, as shown in FIGS. 1C and 5, the second cover plate 5 is provided with an exhaust port 6 for discharging cooling air to the outside of the battery module 1. That is, the exhaust port 6 is an outlet for the cooling medium (fluid). Here, as an example, the second cover plate 5 is provided with three exhaust ports 6.

The exhaust port 6 is a slit. By making the exhaust port 6 into a slit, the flow passage area of the cooling air can be increased while guiding the direction in which the cooling air flows. Further, by making the exhaust port 6 into a slit, it is possible to prevent the protrusion (such as a passenger's finger) from entering the exhaust port 6.

6 (a) and 6 (b), the exhaust port 6 is provided along the center in the width direction of the battery cell arranged closest to the second cover plate 5. For example, when the second cover plate 5 that covers the opening 1c on the exhaust side of the casing 1a of the battery module 1 is viewed from the front, the exhaust port 6 opens at a position that overlaps the apex of the curved surface of the cylindrical cell. Yes. Since the exhaust port 6 is opened at a position overlapping the apex of the curved surface of the cylindrical cell, the cooling air can be clung to the cylindrical cell when the cooling air is discharged.

Here, as an example, the number of battery cells 2 arranged closest to the second cover plate 5 is five, and the exhaust port 6 is a central side excluding two of the two battery cells 2 in parallel. The three battery cells 2 are provided along the center in the width direction. This is because the three battery cells 2 on the center side tend to be hotter than others, and the necessity for cooling is particularly high. Actually, the number of battery cells 2 arranged closest to the second cover plate 5 is not limited to five and is arbitrary. However, when the intake port 4 and the exhaust port 6 have the same shape and the same size, the number of the exhaust ports 6 arranged is smaller than the number of the intake ports 4 arranged. In other words, the total opening area of all the exhaust ports 6 is smaller than the total opening area of all the intake ports 4.

Thus, it is preferable that the exhaust port 6 is provided only at a position along the center in the width direction of the battery cell arranged closest to the second cover plate 5. In practice, in the second cover plate 5, a part of the exhaust port 6 may be provided at a location other than the position along the center in the width direction of the battery cell. However, also in this case, the flow of the cooling air passing through the exhaust port 6 provided at the position along the center in the width direction of the battery cell is set to be the mainstream.

(Cooling air flow)
Although not shown, in the first embodiment, an exhaust fan installed on the exhaust side of the casing 1 a of the battery module 1 is connected to the air inside the casing 1 a from the exhaust port 6 provided in the second cover plate 5. As a result, the cooling air is sucked into the housing 1a from the air inlet 4 provided in the first cover plate 3 on the air intake side of the housing 1a of the battery module 1. For example, the cooling air is air in the vehicle cooled by an air conditioner or the like. The cooling air is sucked from the intake port 4, passes through the inside of the housing 1 a, and is sucked from the exhaust port 6. Thereafter, for example, the air may circulate in the vehicle and be sucked from the air intake 4 again.

If the flow rate of the cooling air passing through the inside of the housing 1a can be simply increased, it is thought that the cooling efficiency of the battery cell 2 can be improved. As a result, it is necessary to increase the size, to deal with noise, increase power consumption, increase the volume of the duct, and the like, and thus have limitations. Therefore, in the battery cooling structure according to the first embodiment, a cooling structure that improves the cooling efficiency by adjusting the flow path and the flow velocity without increasing the flow rate of the cooling air is configured as described above. It was realized. The flow of cooling air inside the housing 1a in this cooling structure will be described in detail below.

Since the five battery cells 2 arranged closest to the first cover plate 3 are close to the intake side (upstream side of the cooling air) of the casing 1a of the battery module 1, the battery cells 2 in the casing 1a are arranged. A relatively low temperature cooling air before cooling can be received. Therefore, the five battery cells 2 arranged closest to the first cover plate 3 can obtain a sufficient cooling effect even if the contact time of the cooling air is short. Therefore, the intake ports 4 are provided along the four gaps between adjacent cells in the five battery cells 2 arranged closest to the first cover plate 3. As a result, the cooling air sucked into the housing 1 a from the air inlet 4 comes into contact with the side surfaces of the five battery cells 2 arranged closest to the first cover plate 3 and is lightly cooled in a short time. Then, it is sucked into the back of the housing 1a as it is. The sucked cooling air clings to the side surface of the battery cell 2 installed in the back of the housing 1a and cools it.

On the other hand, the five battery cells 2 arranged closest to the second cover plate 5 are close to the exhaust side (downstream of the cooling air) of the casing 1a of the battery module 1, so The cooling air which received the temperature rise after cooling the battery cell 2 is received. In addition, among the five battery cells 2 arranged closest to the second cover plate 5, the two battery cells 2 at both ends have side surfaces adjacent to the inner wall of the casing 1a of the battery module 1, As high as the three battery cells 2 on the center side surrounded by the battery cells 2, the temperature is unlikely to increase. That is, among the battery cells 2 in the housing 1a, the three battery cells 2 on the central side arranged closest to the second cover plate 5 tend to be hottest. Therefore, the exhaust port 6 is provided along the center in the width direction of the three battery cells 2 on the center side. As a result, before the cooling air flows out from the exhaust port 6, it clings to the side surfaces of the three battery cells 2 on the central side and takes a relatively longer time than the four battery cells 2 nearest to the intake port 4. And sufficiently cooled, the air is sucked out by a fan outside the housing 1a.

By doing in this way, the flow velocity of the cooling air around the battery cell 2 that is likely to be the highest temperature on the exhaust side (downstream side of the cooling air) of the casing 1a of the battery module 1 is increased, and the battery cell 2 Only prevents it from becoming extremely hot.
In addition, the battery cell 2 that is likely to become the highest temperature can be prevented from exceeding the threshold value, and the threshold value of the laterality diagnosis of the temperature of the battery cell 2 can be optimized, so that the detectability of the battery cell abnormality can be improved. .
Moreover, the maximum temperature by heat_generation | fever of the battery cell 2 in the housing | casing 1a can be reduced.

(Effect of 1st Embodiment)
According to 1st Embodiment, there exist the following effects.
(1) In the battery cooling structure according to the first embodiment, a plurality of columnar battery cells are housed in a battery module, and are spaced from each other so as to form a cooling medium passage through which the cooling medium passes. They are arranged in parallel. The first side surface of the battery module has an inlet for opening the upstream side of the cooling medium passage and introducing the cooling medium into the battery module, in a gap between the battery cells arranged closest to the first side surface. It is provided along. On the second side surface of the battery module, there is an outlet on the downstream side of the cooling medium passage, and an outlet for discharging the cooling medium out of the battery module is arranged in the width direction of the battery cell arranged closest to the second side surface. It is provided along the center. For example, when the cooling medium is cooling air, the inlet is an inlet and the outlet is an outlet. Further, the first side surface and the second side surface of the battery module are not limited to a part of the battery module, and may be a member that covers or surrounds the battery module.
As a result, the cooling medium efficiently enters between the battery cells from the inlet of the battery module, and the cooling medium passes through the cooling medium passage formed by the battery cells accommodated in the battery module. When the battery cell that becomes the passage is cooled, the cooling medium is finally discharged from the outlet along the shape of the battery cell that is arranged closest to the outlet. It can cool well.
Further, by providing the inlet and the outlet only at the positions as described above, the flow rate of the cooling medium around the downstream battery cell can be increased, and the cooling efficiency for the downstream battery cell can be increased. .
Furthermore, the temperature of the downstream battery cell that tends to become the highest temperature among the battery cells in the battery module can be lowered, and the threshold value of the battery cell temperature laterality diagnosis can be optimized. be able to.
Further, it is possible to reduce the frequency at which the battery cell on the downstream side becomes hot and the input / output restriction of the battery occurs.

(2) Each of the first side surface and the second side surface faces the outer peripheral surface of the battery cell (the side surface of the cylindrical cell).
That is, each of the first side surface and the second side surface is a surface that faces the outer peripheral surface of the battery cell among the side surfaces of the battery module.
In this way, the first side surface and the second side surface provided with the inflow port and the outflow port are opposed to the outer peripheral surface of the battery cell, so that the outer peripheral surface of the battery cell is cooled instead of the end portion of the battery cell. The medium can be brought into contact and cooled.

(3) Each of the inflow port and the outflow port is a slit parallel to the longitudinal direction of the battery cell.
Thus, by making the inflow port and the outflow port into slits parallel to the longitudinal direction of the battery cell, it is possible to suppress the intrusion of protrusions (occupants' fingers, etc.) into the inflow port and the outflow port. In addition, by using the slit as the inlet, the pressure loss can be reduced while increasing the flow rate of the cooling medium. Further, by forming the outlet at the slit, the flow path area of the cooling medium can be increased while guiding the direction in which the cooling medium flows.

(4) The total opening area of the outlet is smaller than the total opening area of the inlet.
For example, the inflow port is provided along four gaps between adjacent cells in five battery cells arranged in parallel near the second side surface. The outflow port is provided along the center in the width direction of the three battery cells 2 on the center side excluding the two battery cells at both ends of the five battery cells arranged in parallel near the second side surface. .
By providing the inflow port and the outflow port in this manner, it is possible to increase the flow rate of the cooling medium around the battery cell on the downstream side of the cooling medium passage as compared with the case where the inflow port and the outflow port are provided uniformly.

(5) Each of the inflow port and the outflow port is directly provided in the casing of the battery module.
Thus, by providing the inlet and outlet directly in the casing of the battery module, the inlet and outlet can be provided simultaneously with the creation of the casing members.

(6) Each of the inflow port and the outflow port is provided on a cover plate that covers the opening of the casing of the battery module.
Thus, by providing the inlet and outlet in the cover plate, the arrangement of the inlet and outlet can be freely adjusted and changed by replacing the cover plate. In addition, even when the inflow port, the outflow port, or the cover plate is damaged, it can be dealt with by simply replacing the cover plate, so that the repair is facilitated.

(7) The battery cell is a cylindrical cell and is accommodated in a staggered arrangement in the battery module.
By doing in this way, a battery cell can be accommodated in a battery module compactly. In the battery cooling structure according to the first embodiment, an optimal cooling medium passage can be formed.

Second Embodiment
The second embodiment of the present invention will be described below.
When the battery cell 2 is a cylindrical cell, both ends (terminal side) of the cylindrical cell tend to be high temperature. Therefore, in order to efficiently cool both ends of the cylindrical cell while improving the flow velocity of the cooling air, two small intake ports are divided and arranged on one end side and the other end side of one battery cell 2. However, actually, the number is not limited to two, and may be three or more. That is, a plurality of intake ports are divided and arranged for one battery cell 2.

In the second embodiment, as shown in FIG. 7, two small exhaust ports are provided at a position corresponding to one of the exhaust ports 6 shown in FIG. Here, the two small exhaust ports are referred to as a first small exhaust port 6a and a second small exhaust port 6b, respectively. Thus, in the second embodiment, in the second cover plate 5, six small exhaust ports are provided instead of the three exhaust ports 6 shown in FIG.

For example, as shown in FIGS. 8A and 8B, the exhaust port 6 has two small intake ports along the center in the width direction of the battery cell 2 arranged closest to the second side wall portion. The battery cell 2 is divided and arranged on one end side and the other end side. Both the first small exhaust port 6 a and the second small exhaust port 6 b are provided along the center in the width direction of the same battery cell 2.

The first small exhaust port 6 a is provided on one end side of the battery cell 2 along the center in the width direction of the battery cell 2. The second small exhaust port 6 b is provided on the other end side of the battery cell 2 along the center in the width direction of the battery cell 2. Although not shown, the first cover plate 3 can be the same as the second cover plate 5 shown in FIG.

(Effect of 2nd Embodiment)
According to 2nd Embodiment, there exists an effect similar to the battery cooling structure which concerns on 1st Embodiment, and there exist the following effects further.
(1) In the battery cooling structure according to the second embodiment, the outlet is divided and arranged in the longitudinal direction of the battery cell. For example, the outflow port is divided and arranged on one end side and the other end side of the battery cell along the center in the width direction of the battery cell arranged closest to the second side surface.
As a result, a flow of a cooling medium for cooling both ends (terminal side) of the cylindrical cell can be generated.

<Third Embodiment>
The third embodiment of the present invention will be described below.
If the positions of the exhaust ports 6 coincide with each other, a plurality of second cover plates 5 can be used in an overlapping manner. For example, as shown in FIG. 9, the second cover plate 5 shown in FIG. 5 according to the first embodiment and the second cover plate 5 shown in FIG. 7 according to the second embodiment are overlapped. Can also be used.

In the third embodiment, the position of the exhaust port 6 shown in FIG. 5 and the first small exhaust port 6a and the second small exhaust port 6b shown in FIG. Match the position of. Thereby, it is possible to improve the durability against the input (collision, impact, pressurization, etc.) to the second cover plate 5 and suppress the deformation amount.

In FIG. 9, the second cover plate 5 shown in FIG. 5 is on the outside and the second cover plate 5 shown in FIG. 7 is on the inside, but actually, the second cover plate shown in FIG. 5 can be the inside, and the second cover plate 5 shown in FIG. 7 can be the outside. Although not shown, the first cover plate 3 can be the same as the second cover plate 5 shown in FIG. For example, if the positions of the intake ports 4 coincide with each other, a plurality of first cover plates 3 can be used in an overlapping manner.

Note that the second cover plate 5 may be a single plate-like member that collectively covers the openings of the plurality of battery modules 1. For example, as shown in FIGS. 10 and 11, the second cover plate 5 may be a side plate (side plate) of the battery pack 10 in which the plurality of battery modules 1 are accommodated. It can be said that the side plate of the battery pack 10 is a side plate of the battery case. In this case, the second cover plate 5 is formed by sheet metal processing (laser processing, punching, bending, pressing, welding, etc.).

Here, the battery pack 10 shown in FIG. 10 accommodates three battery modules 1 as shown in FIG. 11, and the exhaust port 6, the first small exhaust port 6 a and the first small exhaust port 6 corresponding to each battery module 1. Two small exhaust ports 6b are provided. In the battery pack 10, each of the three battery modules 1 may be partitioned by a partition plate or the like.

In the example shown in FIGS. 10 and 11, as shown in FIG. 9, the second cover plate 5 shown in FIG. 5 according to the first embodiment and the second cover plate shown in FIG. 7 according to the second embodiment. The cover plate 5 is used in an overlapping manner. However, actually, only one of the second cover plate 5 shown in FIG. 5 according to the first embodiment and the second cover plate 5 shown in FIG. 7 according to the second embodiment may be used. . Although not shown, the first cover plate 3 can be the same as the second cover plate 5 shown in FIGS. 10 and 11.

As shown in FIG. 12A, on the exhaust side of the battery pack 10, an exhaust port 6, a first small exhaust port 6 a, and a second small exhaust are provided on the surface of the second cover plate 5 of the battery pack 10. A thin exhaust duct 8 is attached so as to cover the opening 6b. The exhaust duct 8 may be a plate-like member having a passage formed on the surface by sheet metal processing. The exhaust duct 8 is provided so that the cooling air flows toward the lower floor side. The exhaust duct 8 is connected to an exhaust fan 9 provided on the floor surface.

As shown in FIG. 12 (b), the exhaust fan 9 sucks and discharges the cooling air, so that the cooling air is sucked into the intake port 4 from the lower floor side and passes through the inside of the battery module 1. Then, the air flows from the exhaust port 6 toward the lower floor side and is sucked out by the exhaust fan 9 on the floor surface. For example, the cooling air is air in the vehicle cooled by an air conditioner or the like. The cooling air is sucked from the intake port 4, passes through the inside of the battery module 1, and is sucked from the exhaust port 6. Thereafter, for example, the air may circulate in the vehicle and be sucked from the air intake 4 again. The “cooling air flow” described in the first embodiment may be realized in this way.

(Effect of the third embodiment)
According to 3rd Embodiment, there exists an effect similar to the battery cooling structure which concerns on 1st and 2nd embodiment, and also there exist the following effects.
(1) In the battery cooling structure according to the third embodiment, each of the inflow port and the outflow port is provided on the side plate of the battery pack that houses the battery module.
As a result, just by storing the battery module in the battery pack, the side plate of the battery pack replaces the cover plate, and the opening of the battery module is covered by the side plate of the battery pack. The work of attaching the plate is not necessary. Further, since it is not necessary to prepare a cover plate for each battery module, the labor and cost of managing the cover plate are reduced.

(2) In the battery cooling structure according to the third embodiment, the outflow port is divided and arranged in the longitudinal direction of the battery cell in the side plate of the battery pack that houses the battery module. For example, the side plate of the battery pack includes two side plates, a side plate provided with three outlets and a side plate provided with six small outlets, with respect to one outlet. The two small outlets are overlapped so as to overlap each other, thereby forming a single side plate.
As a result, a flow of a cooling medium for cooling both ends (terminal side) of the cylindrical cell can be generated. Further, by stacking a plurality of side plates to form one side plate, the thickness of the side plate of the battery pack is increased, the durability against the input to the side plate of the battery pack is improved, and the deformation amount is suppressed. It becomes possible. Moreover, an outlet and a small outlet can be arbitrarily switched by attaching and detaching each side plate. That is, it becomes easy to change a normal outflow port to a small outflow port, and conversely to change a small outflow port into a normal outflow port.

<Fourth embodiment>
The fourth embodiment of the present invention will be described below.
As shown in FIG. 13 (a), a through hole (hereinafter referred to as a punch hole) is formed on the entire surface of a panel such as a metal plate or an acrylic plate by a punching process using a punching punch or a laser. As shown in (b), the unnecessary punch holes are closed while leaving the necessary punch holes. Or, only the necessary punch holes are made from the beginning. For example, the punch hole is a dot hole. With such punch holes, it is possible to form the air inlet 4 of the first cover plate 3 and the air outlet 6 of the second cover plate 5. At this time, one pseudo slit may be formed by connecting punch holes after opening in one direction. Further, when a pseudo slit is formed by a punch hole, it is easy to provide the first small exhaust port 6a and the second small exhaust port 6b shown in FIG.

(Effect of 4th Embodiment)
According to 4th Embodiment, there exists an effect similar to the battery cooling structure which concerns on 1st Embodiment, and also there exist the following effects.
(1) In the battery cooling structure according to the fourth embodiment, each of the inlet and the outlet of the cooling medium is formed by a plurality of holes arranged in the longitudinal direction of the battery cell.
For example, by forming pseudo slits with such a plurality of holes, slit-shaped inlets and outlets can be easily provided on the first side surface and the second side surface of the battery module. Moreover, the shape of an inflow port and an outflow port can be easily changed by changing the hole to open or close.

<Fifth Embodiment>
The fifth embodiment of the present invention will be described below.
For example, when the battery cells 2 are arranged in a staggered arrangement as shown in FIG. 2, due to the layout of the battery cells 2 accommodated in the battery module 1, a place where the battery cells 2 are not arranged occurs and a dead space is generated. There is. The place where the battery cell 2 is not disposed is, for example, a place where there is no space and the battery cell 2 cannot be disposed.

In this case, there is a possibility that the cooling air stays in a place where the battery cell 2 is not arranged in the cooling air passage. Moreover, since the flow path area is larger than the other locations where the battery cells 2 are not disposed, the cooling air pressure and the contact area with respect to the battery cells 2 around the locations where the battery cells 2 are not disposed are reduced. Battery cell 2 may not be sufficiently cooled by the cooling air. As a countermeasure, as shown in FIG. 14, as a substitute for the battery cell 2, a part of the shape of the battery cell 2 or a place where the battery cell 2 is not arranged in the layout of the battery cell 2 accommodated in the battery module 1. A dummy cell 7 having a shape imitating the whole is arranged. That is, the dummy cell 7 is disposed in a dead space inside the casing of the battery module 1 and forms a cooling air passage together with the battery cell 2. As described above, the dummy cell 7 is arranged in the dead space inside the casing of the battery module 1, and the cooling air passage is formed by the battery cell 2 and the dummy cell 7, so that the cooling air passage is formed only by the battery cell 2. The location where the cooling air stays can be reduced more than when.

Here, a semi-cylindrical member is provided as the dummy cell 7 on the inner wall of the casing 1a of the battery module 1. The size of the semi-cylindrical member corresponds to the size of a cylindrical cell used as the battery cell 2 divided into two along the center in the width direction to form a semi-cylindrical member. The material of the dummy cell 7 is not particularly limited, but it is more preferable if it does not deteriorate the cooling performance of the cooling air. That is, what is necessary is just a thing which does not inhibit cooling of the battery cell 2 by cooling air. Further, the dummy cell 7 may be a part of the casing 1a of the battery module 1 or may be an independent member.

As described above, by disposing the dummy cells 7 at the places where the battery cells 2 are not arranged, the cooling performance of the battery cells 2 around the places where the battery cells 2 are not arranged is different from that of the other battery cells 2. The cooling air passage can be formed so as not to be.

(Modification)
Actually, it is also possible to arrange dummy cells 7 instead of the battery cells 2. For example, for the purpose of reducing the number of battery cells 2 accommodated in the battery module 1 or for the purpose of preventing the battery cells 2 from being adjacent to each other in a region that tends to become high temperature, the battery module 1 accommodates the battery cell 1. It is also possible to replace a part of the battery cell 2 with the dummy cell 7.

(Effect of 5th Embodiment)
According to 5th Embodiment, there exists an effect similar to the battery cooling structure which concerns on 1st Embodiment, and there exist the following effects further.
(1) In the battery cooling structure according to the fifth embodiment, a dummy cell having a shape imitating at least a part of the shape of the battery cell housed in the battery module housing is provided inside the battery module housing. It is arranged at the place where the cell is not arranged. The dummy cells together with the battery cells form a cooling medium passage through which the cooling medium passes inside the housing of the battery module.
As a result, the dead space in the battery module is closed with dummy cells to adjust the flow of the cooling medium, and the battery cells around the dead space are also cooled by bringing them into contact with the cooling medium to the same extent as other battery cells. Will be able to.

Although the present invention has been described above with reference to specific embodiments, it is not intended that the present invention be limited by these descriptions. From the description of the invention, other embodiments of the invention will be apparent to persons skilled in the art, along with various variations of the disclosed embodiments. Therefore, it is to be understood that the claims encompass these modifications and embodiments that fall within the scope and spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 Battery module 1a Case 1b Inlet side opening 1c Exhaust side opening 2 Battery cell 2a Positive electrode 2b Negative electrode 3 First cover plate 4 Inlet (inlet)
5 Second cover plate 6 Exhaust port (outlet)
6a 1st small exhaust port 6b 2nd small exhaust port 7 Dummy cell 8 Exhaust duct 9 Exhaust fan 10 Battery pack

Claims

A plurality of columnar battery cells housed in the battery module and arranged in parallel with each other so as to form a cooling medium passage through which the cooling medium passes in the battery module;
An inlet provided on a first side of the battery module, opening upstream of the cooling medium passage, and for introducing the cooling medium into the battery module;
Provided on the second side surface of the battery module, opening downstream of the cooling medium passage, and an outlet for discharging the cooling medium out of the battery module,
The inlet is provided along a gap between battery cells arranged closest to the first side surface;
The battery cooling structure according to claim 1, wherein the outlet is provided along a center in a width direction of the battery cell arranged closest to the second side surface.
The battery cooling structure according to claim 1, wherein each of the first side surface and the second side surface is opposed to an outer peripheral surface of the battery cell.
The battery cooling structure according to claim 2, wherein each of the inlet and the outlet is a slit parallel to a longitudinal direction of the battery cell.
4. The battery cooling structure according to claim 2, wherein a total opening area of the outlet is smaller than a total opening area of the inlet.
The battery cooling structure according to any one of claims 2 to 4, wherein the outlet is divided and arranged in a longitudinal direction of the battery cell.
The battery cooling structure according to any one of claims 1 to 5, wherein each of the inflow port and the outflow port is directly provided in a housing of the battery module.
The battery cooling structure according to any one of claims 1 to 6, wherein each of the inflow port and the outflow port is provided on a cover plate that covers an opening of a housing of the battery module.
The battery cooling structure according to any one of claims 1 to 7, wherein each of the inflow port and the outflow port is provided on a side plate of a battery pack that houses the battery module.
The battery cooling structure according to any one of claims 1 to 8, wherein each of the inflow port and the outflow port is formed by a plurality of holes arranged in a longitudinal direction of the battery cell.
2. A dummy cell that has a shape imitating at least a part of the shape of the battery cell, is disposed in a location where the battery cell is not disposed in the battery module, and forms the cooling medium passage together with the battery cell. The battery cooling structure according to claim 9.
A housing,
A plurality of columnar battery cells that are housed in the housing and arranged in parallel with a gap therebetween so as to form a cooling medium passage through which the cooling medium passes.
The housing is
A first side opening an inlet for taking the cooling medium into the cooling medium passage;
A second side surface having an outlet opening for discharging the cooling medium from the cooling medium passage,
The inlet is provided along a gap between battery cells arranged closest to the first side surface;
The battery module is characterized in that the outlet is provided along the center in the width direction of the battery cells arranged closest to the second side surface.
A battery module housing, wherein dummy cells having a shape imitating at least a part of the shape of the battery cells accommodated therein are disposed at locations where the battery cells are not disposed in the interior.
The battery module casing according to claim 12, wherein the dummy cell and the battery cell form a cooling medium passage through which a cooling medium passes.