JP2022126974A - Power storage pack - Google Patents

Abstract

To provide a power storage pack capable of ensuring sufficient cooling efficiency for a power storage module and other objects to be cooled, and capable of compactly structuring the entire device.SOLUTION: A power storage pack 1 includes a first channel K1 provided in a first direction between storage cells 3, 3 and a second channel K2 connected to the downstream side of the first channel K1, and the second channel K2 includes a first portion 31 for advancing a cooling gas G in the first direction continuously to the first channel K1, and a bending portion 32 that bends the traveling direction of the cooling gas G by 90° or more to the second direction. In the bending portion 32, an object P to be cooled other than the storage cell 3 is fixed on the outer surface 35a side of a wall portion 35 against which the cooling gas G for traveling through the first portion 31 collides.SELECTED DRAWING: Figure 4

Description

The present disclosure relates to an electricity storage pack.

BACKGROUND ART In recent years, from the viewpoint of promoting environmental friendliness, development of automobiles and industrial vehicles equipped with power storage packs such as lithium-ion secondary batteries has been promoted. For example, a lithium-ion secondary battery has a great advantage in that it can be charged more rapidly than a conventional lead-acid battery. On the other hand, charging a battery is generally accompanied by heat generation, and the amount of heat generated during charging increases with the square of the charging current. Since an increase in battery temperature can be a factor in shortening the life of the battery, it is important to study the cooling structure of the electricity storage pack.

As a technology related to the cooling structure of an electricity storage pack, for example, a battery pack described in Patent Literature 1 can be cited. In this conventional battery pack, a plurality of battery modules in which battery cells are assembled are accommodated in a case having an air inlet and an air outlet. A control device for controlling the current supplied to the battery module is housed in the case together with the battery module. These control devices are arranged on the downstream side of the flow of cooling air with respect to the battery modules.

JP 2014-151722 A

In the electric storage pack as described above, it is important to ensure sufficient cooling efficiency for the electric storage modules, and at the same time, it is necessary to ensure sufficient cooling efficiency for other objects to be cooled such as control devices related to the electric storage modules. there is In addition, when applying the cooling structure to the electricity storage pack, it is also required to make the electricity storage pack more compact from the viewpoint of avoiding restrictions on the layout when it is mounted on automobiles and industrial vehicles.

The present disclosure has been made to solve the above problems, and an object of the present disclosure is to provide an electricity storage pack that can ensure sufficient cooling efficiency for an electricity storage module and other objects to be cooled, and that can make the entire device compact. do.

An electricity storage pack according to one aspect of the present disclosure is an electricity storage pack in which an electricity storage module configured to include an array of a plurality of electricity storage cells is accommodated in a case, and a cooling gas is circulated in the case. A flow path is provided, and the flow path includes a first flow path provided in a first direction between the storage cells and a second flow path connected downstream of the first flow path. , wherein the second flow path includes a first portion that is continuous with the first flow path and causes the cooling gas to advance in a first direction, and a second portion that bends the traveling direction of the cooling gas to form a second portion. and a second portion for allowing cooling gas traveling through the bending portion to travel in a second direction, wherein the cooling gas traveling through the first portion collides with the wall at the bending portion. An object to be cooled other than the storage cell is fixed to the outer surface side of the portion.

In this power storage pack, the power storage cells can be preferentially cooled by circulating the cooling gas through the first flow path provided between the power storage cells, and the second flow path connected to the downstream side of the first flow path can be cooled. By fixing the object to be cooled to the flow path, cooling of the object to be cooled can be realized at the same time. The object to be cooled is fixed to the outer surface side of the wall on which the cooling gas traveling through the first portion collides in the bent portion where the direction of travel of the cooling gas is bent. The walls are cooled more efficiently than other parts due to the impingement of the cooling gas. Therefore, it is possible to sufficiently secure the cooling efficiency for the object to be cooled via the wall portion. In addition, by changing the direction of the cooling gas in the second channel, it is possible to prevent the channel from extending long in one direction, and the entire device can be made compact.

The bending portion may bend the traveling direction of the cooling gas by 90° or more. In this case, it is possible to make the cooling gas strongly collide with the wall portion to which the object to be cooled is fixed, so that the cooling efficiency of the object to be cooled can be more sufficiently secured.

The electricity storage pack may include a fan for circulating the cooling gas through the channel, and the fan may be arranged in the first portion of the second channel. In this case, the wall portion to which the object to be cooled is fixed can be arranged close to the fan. Also, the pressure in the second flow path from the fan to the wall is positive. As a result, the cooling gas can more strongly collide with the wall portion to which the object to be cooled is fixed, and the efficiency of cooling the object to be cooled can be more sufficiently secured.

The object to be cooled may be arranged on the axis of the fan. As a result, the cooling gas can more strongly collide with the wall portion to which the object to be cooled is fixed, and the efficiency of cooling the object to be cooled can be more sufficiently secured.

The case may be provided with an openable/closable cover, and the object to be cooled may be arranged at a position exposed when the cover is opened. In this case, it is possible to further facilitate access to the object to be cooled from outside the case while the electricity storage pack is compactly configured. This contributes to improvement in maintainability of the electricity storage pack.

Advantageous Effects of Invention According to the present disclosure, it is possible to ensure sufficient cooling efficiency for the power storage module and other objects to be cooled, and to make the entire device compact.

1 is a perspective view showing an example of a vehicle to which an electricity storage pack according to an embodiment of the present disclosure is applied; FIG. 2 is an exploded perspective view showing the overall configuration of an electricity storage module that constitutes the electricity storage pack shown in FIG. 1. FIG. 1. It is a figure which shows typically the flow path of the cooling gas in the case in the electrical storage pack shown in FIG. 1, (a) is a top view, (b) is a front view, (c) is a side view. FIG. 4 is a diagram schematically showing a main part of FIG. 3; FIG. 10 is a diagram schematically showing flow paths of cooling gas in a case of an electricity storage pack according to a modification;

Hereinafter, preferred embodiments of an electricity storage pack according to one aspect of the present disclosure will be described in detail with reference to the drawings.

FIG. 1 is a perspective view showing an example of a vehicle to which an electricity storage pack according to an embodiment of the present disclosure is applied. The power storage pack 1 is a device mounted as a power source in a vehicle such as an electric vehicle or a hybrid vehicle, or an electric industrial vehicle. FIG. 1 illustrates a reach forklift 101 that can be operated by a standing worker as a vehicle to which the electricity storage pack 1 is applied.

The power storage pack 1 is arranged in a substantially rectangular parallelepiped accommodation space provided in the lower part of the machine base 102 of the reach forklift 101 . The accommodation space is defined by the cover panel 103 of the machine base 102 . One side surface 103 a of the cover panel 103 is provided with an opening 104 that exposes the charging port of the electricity storage pack 1 . An opening 105 is provided in the upper portion of the front face 103b of the cover panel 103 to expose the cover 36 (described later) of the case H of the electricity storage pack 1 . An exhaust port 106 for exhausting the cooling gas G for cooling the electricity storage pack 1 is provided at the lower portion of the front surface 103 b of the cover panel 103 . Here, the cooling gas G is air (outside air).

The electricity storage pack 1 is configured by housing an electricity storage module M shown in FIG. In this embodiment, the power storage modules M are arranged in two stages, upper and lower, in the case H. As shown in FIG. The case H is made of metal, for example, and has a rectangular parallelepiped shape corresponding to the size of the accommodation space of the reach forklift 101 . The case H has an intake port 21 for taking in the cooling gas G from the outside and an exhaust port 22 for discharging the cooling gas G to the outside (see FIG. 3). The intake port 21 is arranged to face, for example, one side surface 103 a of the cover panel 103 , and the exhaust port 22 is arranged to face the exhaust port 106 of the cover panel 103 .

2 is an exploded perspective view showing the overall configuration of an electricity storage module that constitutes the electricity storage pack shown in FIG. 1. FIG. As shown in FIG. 2, the storage module M includes an array 2 including a plurality of storage cells, a pair of end plates 4, 4 sandwiching the array 2 in the array direction of the storage cells 3, an array 2 in the array direction, and a plurality of separators 6 arranged between the storage cells 3 and 5 in the array 2. In FIG. 1, for convenience of explanation, the arrangement direction of the storage cells 3 in the array 2 is shown as the x direction, the width direction of the storage cells 3 as the y direction, and the height direction of the storage cells 3 as the z direction.

The storage cell 3 is, for example, a non-aqueous electrolyte secondary battery such as a lithium ion secondary battery. The storage cell 3 is configured by housing an electrode assembly in a case 11 filled with a non-aqueous electrolytic solution. Here, the case 11 has a rectangular parallelepiped shape that is flat in the arrangement direction. An electrode assembly is obtained by laminating a positive electrode, a negative electrode, and a separator in a predetermined order. In the present embodiment, for example, a sheet-shaped positive electrode is accommodated in a bag-shaped separator, and the bag-shaped separator in which the positive electrode is accommodated and the sheet-shaped negative electrode are alternately laminated to form an electrode. An assembly is constructed.

A pair of electrode terminals 12 , 12 are provided on one side of the storage cell 3 in the height direction. One electrode terminal 12 is a positive terminal and the other electrode terminal 12 is a negative terminal. In the array 2, each storage cell 3 is arranged with the pair of electrode terminals 12, 12 oriented in the same direction. Moreover, in the storage cells 3, 3 adjacent to each other in the arrangement direction, the polarity of the electrode terminals 12, 12 is reversed. In array 2 , the positive terminal of one storage cell 3 is connected to the negative terminal of one adjacent storage cell 3 by bus bar 13 , and the negative terminal of one storage cell 3 is connected to the other adjacent storage cell by bus bar 13 . Each electric storage cell 3 is electrically connected in series by connecting to the positive terminal of 3 .

A pair of end plates 4, 4 are arranged at both ends of the array body 2 in the array direction. The end plate 4 is made of metal, for example. The end plate 4 has a rectangular parallelepiped shape that is slightly flatter in the arrangement direction than the case 11 of the storage cell 3, for example. Both the first band 5A and the second band 5B are formed of metal in a plate shape. In this embodiment, the first band 5A extends in the array direction on the other side of the storage cell 3 in the height direction, and the second band 5B extends on the one side in the height direction of the storage cell 3. in the array direction.

The first band 5A is arranged on the other surface side of the storage cell 3 in the height direction with a width approximately equal to the width of the case 11 of the storage cell 3 . The second band 5B is arranged on the other side of the storage cell 3 in the height direction with a width smaller than the interval between the electrode terminals 12 of the storage cell 3 . Both ends in the arrangement direction of the first band 5A and the second band 5B are fixed to a pair of end plates 4, 4 using bolts (not shown) or the like. A restraining load is applied to the array body 2 in the array direction by fastening the pair of end plates 4, 4 with the first band 5A and the second band 5B.

The separators 6 are arranged in the array 2 between the storage cells 3 and between the storage cells 3 and the end plates 4 . The separator 6 is formed in a plate shape, for example, from an insulating resin. The shape of the main surface 6a of the separator 6 when viewed from the arrangement direction corresponds to the shape of the case 11 of the storage cell 3 when viewed from the arrangement direction. This electrically insulates between the storage cells 3 and 3 and between the storage cell 3 and the end plate 4 .

The separator 6 has leg portions 6b projecting in the arrangement direction. In the separator 6 arranged between the storage cells 3 , leg portions 6 b protrude from the edge of the main surface 6 a of the separator 6 on the side of the first band 5 A to both sides of the array body 2 in the array direction. In the separator 6 arranged between the storage cell 3 and the end plate 4, the leg portion 6b protrudes inward in the arrangement direction of the array body 2 from the edge of the main surface 6a of the separator 6 on the side of the first band 5A. there is By positioning the leg portion 6b between the storage cell 3 and the first band 5A, the storage cell 3 and the first band 5A are electrically insulated.

The separator 6 has ribs 6c for forming the first flow paths K1 for the cooling gas. In this embodiment, the ribs 6c are arranged in the height direction of the separator 6 on both surfaces of the main surface 6a. Each rib 6 c has, for example, a rectangular cross section and extends in the width direction of the separator 6 . In the separator 6 arranged between the storage cells 3, 3, the tips of the ribs 6c contact the storage cells 3, 3 adjacent to the separator 6, so that the first flow of the cooling gas is generated between the storage cells 3, 3. A road K1 is formed. Ribs 6c are also provided on the main surface 6a of the separator 6 arranged between the storage cell 3 and the end plate 4 to form the first flow path K1 for the cooling gas between the storage cell 3 and the end plate 4. You may

FIG. 3 is a diagram schematically showing flow paths of cooling gas in the case of the electricity storage pack shown in FIG. FIG. 3(a) is a plan view (xy plane view), and FIG. 3(b) is a front view (xz plane view). FIG. 3(c) is a side view (yz plane view). As shown in these figures, the case H of the electricity storage pack 1 has a pair of side faces Ha and Hb in the x direction, a pair of side faces Hc and Hd in the y direction, and a pair of side faces He and Hf in the z direction. is doing. In the case H, as described above, the power storage modules M are arranged in two stages, upper and lower.

Side Ha is a surface facing one side 103a of cover panel 103 in reach forklift 101 . The above-described intake port 21 is provided at the edge of the side surface Ha on the side of the side surface Hd. The side Hc faces the front face 103b of the cover panel 103 of the reach forklift 101 , and the side Hd faces the back of the reach forklift 101 . The exhaust port 22 described above is provided in the lower portion of the side surface Hc.

The cooling gas G taken into the case H through the intake port 21 on the side face Ha advances in the case H in the x direction, and moves through the first flow paths K1 between the storage cells 3, 3 in the y direction ( first direction). The cooling gas G that has passed through the first flow path K travels in the -z direction toward the exhaust port 22 on the side surface Hc, and is discharged to the outside of the case H from the exhaust port 22 below the side surface Hc.

Inside the case H, as shown in FIG. 4, a second flow path K2 connected to the downstream side of the first flow path K1 is provided. In FIG. 4, the second flow paths K2 connected to the first flow paths K1 of the power storage modules M arranged on the upper side of the case H are illustrated. For the power storage module M arranged on the lower side of the case H, for example, a flow path having the same configuration as the second flow path K2 may be formed, and the power storage module M and the exhaust port 22 of the case H may be connected. A channel may be formed that connects linearly.

As shown in FIG. 4, the second flow path K2 is formed by, for example, a duct D having a rectangular cross section. The second flow path K2 has a first portion 31, a bent portion 32, and a second portion 33. As shown in FIG. The first portion 31 is a portion that continues the first flow path K1 and causes the cooling gas G to advance in the y direction (first direction). The first portion 31 extends in the y-direction. The first portion 31 is provided with a fan 34 that circulates the cooling gas G through the flow path from the intake port 21 to the exhaust port 22 .

The bending portion 32 is positioned downstream of the first portion 31 . In the example of FIG. 4, the bending section 32 bends the traveling direction of the cooling gas G from the y direction to the −z direction by 90°. The second portion 33 is a portion that causes the cooling gas G that has passed through the bent portion 32 to travel in the -z direction (second direction). The second portion 33 is positioned downstream of the bent portion 32, extends in the −z direction up to the height of the exhaust port 22, and then bends in the y direction to connect to the exhaust port 22. FIG.

In the bent portion 32 described above, an object P to be cooled other than the storage cell 3 is fixed on the outer surface 35a side of the wall portion 35 against which the cooling gas G traveling in the y direction collides. Examples of the object to be cooled P include a control device that controls current supply to the storage cell 3, a monitoring device that monitors the state of the storage cell 3, and the like. The object to be cooled P may be a switch system board or the like.

In the example of FIG. 4 , the object P to be cooled is arranged on the axis L of the fan 34 . Here, the wall portion 35 against which the cooling gas G traveling in the y direction collides is a wall portion parallel to the side surface Hc of the case H on the side of the side surface Hc among the walls constituting the duct D. The object to be cooled P is arranged on the axis L of the fan 34 by being positioned in a portion facing the fan 34 on the wall portion 35 . Grease or the like having good thermal conductivity may be interposed between the object to be cooled P and the outer surface 35 a of the wall portion 35 .

In addition, for fixing the object P to be cooled to the wall portion 35, an openable and closable cover 36 is provided on the upper portion of the side surface Hc of the case H corresponding to the position of the opening portion 105 of the cover panel 103 of the reach forklift 101. It is The object P to be cooled is arranged at a position exposed when the cover 36 is opened, and can be accessed from the outside through the opening 105 of the cover panel 103 by opening the cover 36 . When the cover 36 is opened, the entire object to be cooled P may be exposed, or a part of the object to be cooled P may be exposed within an accessible range from the outside through the opening 105 .

As described above, in the electricity storage pack 1, the electricity storage cells 3 can be preferentially cooled by circulating the cooling gas G through the first flow path K1 provided between the electricity storage cells 3, and the first By fixing the cooling object P to the second flow path K2 connected to the downstream side of the flow path K1, the cooling of the cooling object P can be realized at the same time. The object to be cooled P is fixed to the outer surface 35a side of the wall portion 35 with which the cooling gas G traveling in the first portion 31 collides in the bending portion 32 where the traveling direction of the cooling gas G is bent. The wall portion 35 is cooled more efficiently than other portions due to the collision of the cooling gas G. As shown in FIG. Therefore, it is possible to sufficiently secure the cooling efficiency for the object to be cooled P via the wall portion 35 . In addition, by changing the direction of the cooling gas G in the second flow path K2, it is possible to suppress the flow path from extending long in one direction, and the entire device can be configured compactly.

In the electricity storage pack 1 , the traveling direction of the cooling gas G is bent by 90° by the bent portion 32 . As a result, the cooling gas G can strongly collide with the wall portion 35 to which the object P to be cooled is fixed, and the cooling efficiency of the object P to be cooled can be sufficiently ensured.

In the electricity storage pack 1, a fan 34 that circulates the cooling gas G through the channel is arranged in the first portion 31 of the second channel K2. In this case, the wall portion 35 to which the object P to be cooled is fixed can be arranged close to the fan 34 . Further, the pressure in the second flow path K2 from the fan 34 to the wall portion 35 becomes positive. Therefore, the cooling gas G can collide with the wall portion 35 more strongly, and the cooling efficiency for the object P to be cooled can be sufficiently secured. Further, in the electricity storage pack 1 , the object P to be cooled is arranged on the axis L of the fan 34 . As a result, the cooling gas G can more strongly collide with the wall portion 35 to which the cooling object P is fixed, and the cooling efficiency for the cooling object P can be more sufficiently secured.

In the electricity storage pack 1, an openable/closable cover 36 is provided on the case H, and the object to be cooled P is arranged at a position exposed when the cover 36 is opened. As a result, access to the object to be cooled P from outside the case H can be facilitated while the electricity storage pack 1 is configured compactly. This contributes to improvement in maintainability of the electricity storage pack 1 .

The present disclosure is not limited to the above embodiments. For example, in the above-described embodiment, the configuration in which the power storage modules M are arranged in two stages, upper and lower, in the case H is illustrated, but the arrangement configuration of the power storage modules M is not limited to this. The second flow path K2 may be formed for each of the plurality of power storage modules M. As shown in FIG. When a plurality of second flow paths K2 are provided, the object to be cooled P may be fixed to some of the second flow paths K2, and the object to be cooled may be fixed to all the second flow paths K2. P may be fixed.

In the above embodiment, the fan 34 is arranged in the first portion 31 of the second flow path K2, but the position of the fan 34 is not limited to this. For example, the fan 34 may be arranged in the second portion 33 of the second flow path K2, or the fan 34 may be arranged upstream of the first flow path K1. In the above embodiment, the bending angle of the cooling gas G by the bending portion 32 is 90°, but the bending angle may be 90° or more.

In addition, in the above-described embodiment, the electricity storage pack 1 of the external air intake type cooling system is exemplified, but for example, a circulation cooling type electricity storage pack 41 as shown in FIG. FIG. 5 schematically shows the inside of the electricity storage pack 41 in an xy sectional view. In the example of FIG. 5, partition walls 42A and 42B are provided to partition the inside of the case H in the x direction, and the entire flow path of the cooling gas G is formed between the partition walls 42A and 42B. The power storage module M is arranged between the partition walls 42A and 42B. A heat exchanger 43 is arranged between one partition wall 42A and the side face Ha of the case H. As shown in FIG.

Assuming that the position of the heat exchanger 43 is the starting point of the circulation of the cooling gas G, the cooling gas G advances from the heat exchanger 43 in the x-direction and flows through the first flow path K1 (Fig. 2) in the y-direction (first direction). The second flow path K2 is provided downstream of the first flow path K1 by the side surface Hc of the case H and partition walls 42A and 42B. In the second flow path K2, the portion defined by the side surface Hc is the first portion 31, and the portion defined by the corner where the side surface Hc and the partition wall 42A intersect is the bent portion 32, A second portion 33 is defined by the partition wall 42A.

The cooling gas G that has passed through the first flow path K1 travels through the first portion 31 in the −x direction and is bent in the −y direction by the bending portion 32 . The cooling gas G that has passed through the bent portion 32 travels in the -y direction through the second portion 33 and exchanges heat with the heat exchanger 43 at the position of the heat exchanger 43 via the partition wall 42A. A fan 34 is arranged in the first portion 31 . The object to be cooled P is located on the side of the outer surface 42a of the wall portion (here, the partition wall 42A) on which the cooling gas G traveling to the first portion 31 collides in the bent portion 32, and is spaced apart from the heat exchanger 43. is fixed with

In this aspect, as in the above-described embodiment, sufficient cooling efficiency can be ensured for the power storage module M and other objects P to be cooled, and the entire device can be configured compactly. Further, in this aspect, a cover 36 that can be freely opened and closed is provided on the side face Ha of the case H, and the object to be cooled P is arranged at a position exposed when the cover 36 is opened. As a result, access to the object to be cooled P from outside the case H can be facilitated.

REFERENCE SIGNS LIST 1, 41 power storage pack 2 array 3 power storage cell 31 first portion 32 bent portion 33 second portion 34 fan 35 wall portion 35a outer surface 36 ... cover 42A ... partition wall (wall portion) 42a ... outer surface H ... case M ... power storage module G ... cooling gas K1 ... first flow path K2 ... second flow path L ... axis , P... object to be cooled.

Claims (5)

An electricity storage pack containing, in a case, an electricity storage module configured to include an array of a plurality of electricity storage cells,
A flow path for circulating a cooling gas is provided in the case,
The flow path includes a first flow path provided in a first direction between the storage cells, and a second flow path connected downstream of the first flow path,
The second flow path has a first portion that is continuous with the first flow path and allows the cooling gas to advance in the first direction, and a second portion that bends the traveling direction of the cooling gas to form a second flow path. and a second portion that causes the cooling gas that has passed through the bent portion to travel in the second direction,
An electricity storage pack in which an object to be cooled other than the electricity storage cell is fixed to an outer surface side of a wall portion of the bent portion against which the cooling gas traveling in the first portion collides. The electricity storage pack according to claim 1, wherein the bending portion bends the traveling direction of the cooling gas by 90° or more. A fan for circulating the cooling gas through the flow path,
The electricity storage pack according to claim 1 or 2, wherein the fan is arranged in the first portion of the second flow path. 4. The electricity storage pack according to claim 3, wherein the object to be cooled is arranged on the axis of the fan. The case is provided with an openable and closable cover,
The electricity storage pack according to any one of claims 1 to 4, wherein the object to be cooled is arranged at a position exposed when the cover is opened.

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