JP2005116342A - Battery pack - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact battery pack which can easily provide a cooling channel for uniformly cooling cells in the battery pack. <P>SOLUTION: The battery pack 100 comprises single cells 10<SB>1</SB>-10<SB>12</SB>and a module case 40 for housing the single cells. The single cells are arranged at specific intervals. The battery pack 100 further comprises a cooling air supply channel 30 formed along the top surfaces of the single cells 10<SB>1</SB>-10<SB>12</SB>, for supplying cooling air to the spaces between adjacent cells. The battery pack 100 further comprises case-side straightening vanes 21<SB>1</SB>-21<SB>6</SB>provided on the module case 40, and single-cell-side straightening vanes 22<SB>1</SB>-22<SB>6</SB>provided on the single cells. The case-side straightening vanes 21 and the single-cell-side straightening vanes 22 are alternately arranged. By providing these straightening vanes, the cooling air flowing in the cooling air supply channel 30 is allowed to meander. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an assembled battery formed by combining a plurality of batteries. More specifically, the present invention relates to an assembled battery that includes a flow path (hereinafter referred to as “cooling flow path”) through which a cooling medium flows, and that suppresses an increase in the temperature of each battery.

  Conventionally, assembled batteries obtained by connecting a plurality of batteries are used in various electronic devices. Examples of the battery that is a constituent element of the assembled battery include a storage battery such as a lithium ion battery or a nickel metal hydride battery. In recent years, assembled batteries are attracting attention as power sources not only for electronic devices such as portable PCs but also for hybrid vehicles and electric vehicles.

  The assembled battery can supply high energy, but has a problem that it tends to become high temperature due to heat generated during charging and discharging of each battery. Further, since the assembled battery is usually stored in a module case or the like, heat tends to be trapped in the case, and the temperature rise tends to be remarkable. Thus, each battery exposed to high temperature is affected by charging and discharging, and energy efficiency is reduced. Therefore, in a general assembled battery, as shown in FIG. 6, a cooling medium supply passage 35 is provided in the assembled battery, and cooling of each battery 15 is performed by supplying cooling air or the like as a cooling medium.

Furthermore, the assembled battery shown in FIG. 6 has a problem in that the cooling air hardly flows between the batteries in the vicinity of the inlet of the cooling medium supply system path, and the respective batteries 15 are not uniformly cooled. For this reason, as shown in FIG. 7, a plurality of rectifying plates 25 having different lengths are provided in the cooling medium supply passage 35 and the cooling air is uniformly guided between the batteries (for example, Patent Document 1). These rectifying plates 25 uniformly cool each battery 15 in the assembled battery.
JP 2000-67934 A

  However, the above-described conventional assembled battery has the following problems. That is, in the assembled battery shown in FIG. 7, the height and the installation angle of the rectifying plate 25 are required to be accurate. Therefore, it is required to manufacture each battery 15 and the current plate 25 with high accuracy. Further, even if the battery 15 is manufactured with high accuracy in the manufacturing stage, the effect of uniform cooling is significantly reduced due to a shift in the arrangement of the batteries 15 in the use stage.

  Further, the number of the rectifying plates 25 described in Patent Document 1 increases in proportion to the number of the batteries 15, and the length thereof needs to be longer toward the downstream side of the cooling medium supply passage 35. Therefore, the larger the number of batteries 15 constituting the assembled battery, the more space is required in the cooling medium supply passage 35. This hinders the compactness of the entire assembled battery.

  The present invention has been made to solve the problems of the above-described conventional assembled battery. That is, an object of the present invention is to provide a compact assembled battery in which a cooling flow path for uniformly cooling each battery in the assembled battery can be easily provided.

  An assembled battery formed for the purpose of solving this problem is an assembled battery in which a plurality of batteries are arranged, and is formed along one side of each arranged battery, and a cooling medium that supplies a cooling medium between the batteries. A medium supply passage, provided on one side of the battery, provided on a surface facing the one side of the arranged batteries, a first rectifying plate for changing the flow direction of the cooling medium in the cooling medium supply passage, and cooled And a second rectifying plate that changes the flow direction of the cooling medium in the medium supply passage, and the first rectifying plate and the second rectifying plate are alternately arranged in the cooling medium supply passage.

  That is, in the assembled battery of the present invention, the first rectifying plate attached to the battery side and the second rectifying plate attached to the surface facing the battery are provided in the cooling medium supply passage. Further, these rectifying plates are alternately arranged in the cooling medium supply passage. As a result, the flow direction of the cooling medium supplied into the cooling medium supply passage is changed by the first rectifying plate to the side facing the battery, and the flow direction is changed to the battery side by the second rectifying plate. Is done. That is, the cooling medium flows in a meandering manner in the cooling medium supply passage. Thereby, the dispersion | variation in the flow volume of the cooling medium supplied between each battery becomes small, and each battery can be cooled uniformly. In the assembled battery of the present invention, the first rectifying plates and the second rectifying plates need only be arranged alternately, and it is not required to arrange them with high accuracy. Moreover, in the assembled battery of this invention, even if many batteries are arranged, the length of each rectifying plate is not affected. Therefore, the entire assembled battery can be made compact.

  Further, the first rectifying plate and the second rectifying plate of the assembled battery of the present invention are inclined toward the downstream side of the flow path of the cooling medium, and the first rectifying plate and a normal line on one side of the battery are formed. The angle downstream of the cooling medium flow path is smaller, and the angle between the second rectifying plate and the normal of the surface facing the one side of the battery is larger toward the downstream of the cooling medium flow path. Then better. That is, the resistance of the first rectifying plate is increased toward the downstream side. On the other hand, the resistance of the second rectifying plate is reduced toward the downstream side. By adjusting the angle of each current plate, the cooling medium can be guided more uniformly between the batteries.

  In the assembled battery of the present invention, the width of the region between the line connecting the leading ends of the first rectifying plate and the line connecting the leading ends of the second rectifying plate is closer to the downstream side of the flow path of the cooling medium. It is better if it is narrow. By adjusting the width, the cooling medium can be uniformly guided between the batteries.

  The assembled battery of the present invention is preferably provided with a bypass passage that bypasses a part of the cooling medium from the upstream side to the downstream side of the flow path of the cooling medium. Thereby, the flow rate of the cooling medium to the downstream side can be secured, and the temperature of each battery can be made uniform. Further, the downstream battery can be cooled earlier.

  In the assembled battery of the present invention, it is preferable that at least one of the first rectifying plate and the second rectifying plate is provided with a cut opening through which a part of the cooling medium passes. Also with this cut, the flow rate of the cooling medium to the downstream side can be secured, and the temperature of each battery can be made uniform. Further, the downstream battery can be cooled earlier.

  According to the present invention, the first rectifying plate and the second rectifying plate are alternately arranged in the cooling medium supply passage, so that the cooling medium meanders and moves in the cooling medium supply passage. Thereby, a cooling medium can be uniformly induced | guided | derived between each battery. Therefore, a compact assembled battery can be provided which can easily provide a cooling flow path for uniformly cooling each battery in the assembled battery.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments embodying the present invention will be described below in detail with reference to the accompanying drawings. In this embodiment, the present invention is applied to a lithium ion assembled battery mounted on an electric vehicle or the like.

[First embodiment]
As shown in FIG. 1, the assembled battery 100 according to the first embodiment includes twelve unit cells 10 ₁ to 10 ₁₂ and a module case 40 that houses these unit cells. Each unit cell is arranged at a predetermined interval. The assembled battery 100 is provided with a cooling air supply passage 30 that is formed along the upper surfaces of the single cells 10 ₁ to 10 ₁₂ and supplies cooling air between the batteries. The cooling medium fed into the cooling air supply passage 30 may be a fluid that can cool each unit cell. That is, it is not limited to cooling air (gas) but may be cooling water (liquid) or the like. Further, in the unit cell of this embodiment, the upstream side of the cooling flow path in the cooling air supply passage 30 (hereinafter, “upstream side” and “downstream side” in this specification are the cooling flow paths of the cooling air supply passage 30). 1 to 12 in order.

The assembled battery 100 includes six case-side rectifying plates 21 _{1 to} 21 ₆ attached to the module case 40 and six unit-cell rectifying plates 22 _{1 to} 22 ₆ attached to the unit cells. doing. In addition, the code | symbol of 1-6 is attached | subjected to the case side rectifier plate and the cell side rectifier plate of this form in order from the upstream side. The case side rectifying plates 21 and the cell side rectifying plates 22 are alternately arranged on the cooling flow path. Specifically, as shown in FIG. 1, the unit cell side rectifying plates 22 _{1 to} 22 on the upper surfaces of the unit cell 10 ₂ , unit cell 10 ₄ , unit cell 10 ₆ , unit cell 10 ₈ , unit cell 10 ₁₂ , respectively. ₆ is provided. Further, a case side rectifying plate 21 ₁ is provided upstream of the unit cell side rectifying plate 22 ₁ . Further, a case side rectifying plate 21 ₂ is provided at a position between the single cell side rectifying plate 22 ₁ and the single cell side rectifying plate 22 ₂ . Thereafter, one case-side rectifying plate is provided between the single cell-side rectifying plates.

In addition, in order to transmit cooling air efficiently, each baffle plate of this form is inclined and arranged by a predetermined angle as shown in FIG. Specifically, the case side rectifying plates 21 _{1 to} 21 ₆ are arranged so that the angle θa becomes smaller toward the downstream side (Condition 1). That is, the resistance by the current plate is increased toward the downstream side. On the other hand, the cell-side rectifying plates 22 _{1 to} 22 ₆ are arranged so that the angle θb becomes larger toward the downstream side (condition 2). That is, the resistance by the rectifying plate is reduced toward the downstream side. By adjusting the angle of each current plate, the cooling air can be preferentially guided between the cells toward the downstream side where the flow rate of the cooling air is smaller. Therefore, the flow rate of the cooling air flowing between the single cells is kept uniform. Fine adjustment of each rectifying plate can be performed, for example, by experiment or CAE analysis.

  Further, the width L of the region between the line connecting the tip portions of the case side rectifying plates and the line connecting the tip portions of the single cell side rectifying plates is made narrower toward the downstream side (Condition 3). . Even by adjusting the width L, the cooling air can be preferentially guided between the cells toward the downstream side where the flow rate of the cooling air is small. Therefore, the flow rate of the cooling air flowing between the single cells is kept uniform. These adjustments (angle θa, angle θb, width L) may be accurate to satisfy the above-described conditions 1 to 3, and do not require high-level adjustment.

Next, the flow of cooling air in the assembled battery 100 will be described. First, as shown in FIG. 2, the cooling air is sent into the cooling air supply passage 30. The direction of the cooling air is directed toward the unit cell by the case side rectifying plate 21 ₁ disposed on the most upstream side. A part of the cooling air flows into the gap between the case 40 and the single cell 10 ₁ or the gap between the single cell 10 ₁ and the single cell 10 ₂ . On the other hand, most of the cooling air that does not flow between the unit cells is directed toward the case by the unit cell side rectifying plate 22 ₁ . That is, it is directed to the opposite side with respect to the unit cell. Subsequently, the cooling air flows in a meandering manner in the cooling air supply passage 30 by repeating the change in the air direction at the case side rectifying plate and the change in the air direction at the single cell side rectifying plate. Then, when the direction of the cooling air is directed toward the single cells, the cooling air is sent into the gap between the single cells. Thereby, suppression of the high temperature of each cell is achieved. In addition, the cooling air meanders and moves in the cooling air supply passage 30 to induce a uniform flow rate of cooling air between the cells, so that the temperature of each unit cell is made uniform.

FIG. 3 shows a comparison of the temperature of the assembled battery (with a rectifying plate) of this embodiment and a conventional assembled battery (without a rectifying plate, see FIG. 6). There was no difference in the average temperature of the entire assembled battery, but there was a difference in the temperature of each unit cell. That is, in the case of the assembled battery of this embodiment (A in FIG. 3), the temperature difference Δa between the cells 10 ₁ to 10 ₁₂ is small. On the other hand, in the case of the conventional assembled battery (B in FIG. 3), the temperature difference Δb between the cells 10 ₁ to 10 ₁₂ is large. That is, it can be seen that the unit cell upstream of the cooling air supply passage 30 has a higher temperature and a lower cooling effect. Specifically, in this example, the temperature difference Δa was about 1/3 of the temperature difference Δb. In the assembled battery of this embodiment, the temperature of the upstream unit cell is low, but the temperature difference can be further reduced by finely adjusting the angle of each rectifying plate.

  In addition, although the assembled battery 100 of this form is provided with 12 unit cells and 12 rectifying plates, it is not limited to this. That is, it is only necessary to increase the number of cells and the number of rectifying plates. At that time, the rectifying plate may be formed by alternately arranging the case-side rectifying plate 21 and the unit cell-side rectifying plate 22 on the cooling flow path, and does not require a wide space for installing the rectifying plate. That is, the arrangement pattern of the rectifying plates is simple, and the more cells, the more effective. Further, it is not always necessary to have the same number of 12 unit cells and 12 rectifying plates. In other words, the case-side rectifying plates 21 and the cell-side rectifying plates 22 need only be alternately arranged on the cooling flow path. For example, the cell-side rectifying plates may be arranged for every three cells.

[Second form]
As shown in FIG. 4, the assembled battery 200 according to the second embodiment includes 12 unit cells 10 ₁ to 10 ₁₂ and a module case 40 that houses each unit cell. A distribution plate 23 is provided in the cooling air supply passage 30 at a position facing the upper surface of each unit cell. Further, the distribution plate 23 is provided with openings 231 and 232 on the upstream side of the cooling air supply passage 30 and openings 233 and 234 on the downstream side, respectively. Thereby, a bypass passage 31 for cooling air is formed. The assembled battery 200 includes six case-side rectifying plates 21 _{1 to} 21 ₆ attached to the distribution plate 23 and six unit-cell rectifying plates 22 _{1 to} 22 ₆ attached to the unit cells. doing.

  In the assembled battery 200, a part of the cooling air sent into the cooling air supply passage 30 is sent to the bypass passage 31 through the openings 231 and 232. Then, it moves in the bypass passage 31 and is sent again into the cooling air supply passage 30 through the openings 233 and 234. Thereby, the flow volume of the cooling air to the downstream side can be ensured. In addition, since it does not meander in the bypass, the cooling air can be transmitted early to the downstream side, and the temperature difference from the upstream side can be shortened early.

[Third embodiment]
As shown in FIG. 5, the assembled battery 300 according to the third embodiment includes six unit cells 10 ₁ to 10 ₁₂ and a module case 40 that houses each unit cell. The assembled battery 300 includes six case-side rectifying plates 21 _{1 to} 21 ₆ attached to the module case 40 and six unit-cell rectifying plates 22 _{1 to} 22 ₆ attached to the unit cells. doing. Further, each case-side rectifying plate is provided with a slit 211. Thereby, a part of the cooling air sent into the cooling air supply passage 30 passes through the slit 211 without losing pressure. Therefore, it is possible to secure the flow rate of the cooling air to the downstream side.

In the assembled battery 300 shown in FIG. 5, the slit 211 is provided in the case side rectifying plates 21 _{1 to} 21 ₆ , but is not limited thereto. In other words, it may be provided in single cell-side regulating plate 22 _{1-22 6.} Moreover, it is good also as providing in both the baffle plates. In any arrangement, it is possible to secure a sufficient flow rate of the cooling air to the downstream side.

As described in detail above, the assembled battery 100 of the first embodiment is provided with the cooling air supply passage 30 that is formed along the upper surfaces of the unit cells 10 ₁ to 10 ₁₂ and supplies the cooling air between the batteries. It is said. In the cooling air supply passage 30, six case-side rectifying plates 21 _{1 to} 21 ₆ attached to the module case 40 and six unit cell-side rectifying plates 22 _{1 to} 22 ₆ attached to the unit cells are provided. And will be established. These rectifying plates are alternately arranged in the cooling air supply passage 30. As a result, the cooling air snakes and flows in the cooling air supply passage 30, and a uniform flow rate of cooling air can be supplied between the single cells. Therefore, each unit cell can be cooled uniformly. Further, it is only necessary to alternately arrange the case side rectifying plates and the single cell side rectifying plates, and it is not required to arrange them with high accuracy. Even if the number of cells is increased, high-precision adjustment is not required. Further, even when the number of single cells is large, there is no need to provide a long rectifying plate. Therefore, the battery pack as a whole is compact.

Further, the angle θa formed by the case-side rectifying plates 21 _{1 to} 21 ₆ and the normal line of the upper surface of the module case 40 is made smaller as the downstream side becomes smaller. On the other hand, the angle θb formed by the cell-side rectifying plates 22 _{1 to} 22 ₆ and the normal line of the upper surface of the battery is increased as the downstream side increases. As a result, the cooling air can be transmitted more efficiently. Further, the width L of the region between the line connecting the tip portions of the case side rectifying plates and the line connecting the tip portions of the unit cell side rectifying plates is made narrower toward the downstream side. This also allows the cooling air to be transmitted more efficiently. Therefore, each battery in the assembled battery can be easily cooled uniformly, and a compact assembled battery is realized.

  In the assembled battery 200 of the second embodiment, the bypass passage 31 is provided. Thereby, the flow volume of the cooling air to the downstream side can be secured. In addition, the downstream battery can be cooled early. Moreover, in the assembled battery 300 of the 3rd form, it is supposed that the slit 211 is provided in each case side rectification | straightening board. This also ensures the flow rate of the cooling air to the downstream side. In addition, the downstream battery can be cooled early.

  Note that this embodiment is merely an example and does not limit the present invention. Therefore, the present invention can naturally be improved and modified in various ways without departing from the gist thereof. For example, the battery that is a component of the assembled battery is not limited to a lithium ion battery. That is, the present invention can be applied to a nickel metal hydride battery or a nickel cadmium battery.

It is sectional drawing which shows the structure of the assembled battery which concerns on a 1st form. It is sectional drawing which shows the flow of the cooling air in an assembled battery. It is a graph which shows the example which compared the temperature of the assembled battery which concerns on a 1st form, and the assembled battery which concerns on the conventional form. It is sectional drawing which shows the structure of the assembled battery which concerns on a 2nd form. It is sectional drawing which shows the structure of the assembled battery which concerns on a 3rd form. It is sectional drawing which shows the structure of the assembled battery which concerns on the conventional form. It is sectional drawing which shows the structure (with a baffle plate) of the assembled battery which concerns on the conventional form.

Explanation of symbols

10 ₁ -10 ₁₂ cells (batteries)
21 _{1 to} 21 ₆ Case side current plate (second current plate)
22 _{1 to} 22 ₆ single cell side rectifier (first rectifier)
211 Slit (Cut)
30 Cooling air supply passage (cooling medium supply passage)
31 Bypass passage 40 Module case 100 Battery pack

Claims (5)

In an assembled battery comprising a plurality of batteries arranged,
A cooling medium supply passage formed along one side surface of each of the arranged batteries and supplying a cooling medium between the batteries;
A first rectifying plate that is provided on one side of the battery and changes a flow direction of the cooling medium in the cooling medium supply passage;
A second baffle plate provided on a surface facing one side surface of the arranged batteries and changing a flow direction of the cooling medium in the cooling medium supply passage;
The assembled battery, wherein the first rectifying plate and the second rectifying plate are alternately arranged in the cooling medium supply passage. The assembled battery according to claim 1,
The first rectifying plate and the second rectifying plate are inclined toward the downstream side of the flow path of the cooling medium,
The angle formed by the first rectifying plate and the normal of one side of the battery is smaller toward the downstream side of the cooling medium flow path,
An assembled battery, wherein an angle formed between the second rectifying plate and a normal line of a surface facing one side of the battery is larger toward a downstream side of the flow path of the cooling medium. In the assembled battery according to claim 1 or 2,
The group characterized in that the width of the region between the line connecting the tip portions of the first rectifying plate and the line connecting the tip portions of the second rectifying plate is narrower toward the downstream side of the flow path of the cooling medium. battery. In the assembled battery according to any one of claims 1 to 3,
An assembled battery comprising a bypass passage for bypassing a part of the cooling medium from the upstream side to the downstream side of the flow path of the cooling medium. In the assembled battery according to any one of claims 1 to 4,
An assembled battery, wherein at least one of the first rectifying plate and the second rectifying plate is provided with a cut opening through which a part of the cooling medium passes.

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