JP2009252473A - Cooling structure of power storage device and vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cooling structure capable of effectively cooling a power storage elements and their terminals. <P>SOLUTION: The device is provided with power storage modules 12 each laminating a plurality of storage elements 11, first coolant channels 13d formed between two storage elements 11, and a second coolant channel 31a fitted to an outside part of the storage module 12 and formed along a first outer face at a side where terminals 11a, 11b of the storage elements 11 are located, out of outer faces of the storage module 12. An air-intake chamber 17 is provided for supplying coolants in branching to the first coolant channels 13d and the second coolant channel 31a. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a cooling structure for a power storage device that cools the power storage device using a refrigerant.

  Electric vehicles, hybrid vehicles, and fuel cell vehicles are equipped with a power storage device as a drive or auxiliary power source. An electric vehicle drives an electric motor using electric power stored in an electric storage device to drive the vehicle, or assists an engine with the electric motor to drive the vehicle. A fuel cell vehicle operates a motor by operating an electric motor using electric power from the fuel cell, or drives an electric motor using electric power stored in a power storage device in addition to electric power from the fuel cell to drive the vehicle. .

  This type of power storage device generates heat during charging and discharging, and battery deterioration progresses if this heat generation state is left unattended, so it is necessary to cool it using a refrigerant. As a cooling structure for a power storage device, Patent Document 1 discloses a cooling structure including a power generation module in which power generation elements are stacked without gaps and a cooling passage for cooling terminal members of these power generation elements.

  The terminal members are connected by a bus bar, and a fin for heat dissipation is formed on the bus bar. The heat generated in the power generation element is transferred to the fins by heat conduction. The generated fins are cooled by the refrigerant flowing into the refrigerant passage.

As another cooling structure, Patent Document 2 discloses an assembled battery in which a refrigerant passage is formed between unit cells. FIG. 3 of Patent Document 2 is a perspective view of the assembled battery, and a terminal is installed on the outer surface of the assembled battery on the side where the refrigerant outlet of the refrigerant passage is located. Moreover, FIG. 5 of patent document 2 is a perspective view of another assembled battery, and the terminal is installed in the surface orthogonal to the surface in which the inflow port and outflow port of the refrigerant path were formed.
Japanese Patent Laying-Open No. 2005-71674 (see FIG. 5 etc.) JP-A-10-106637

  However, in the configuration of Patent Document 1, only the bus bar provided with the fins and the terminal member are cooled, so that the power generation element is not sufficiently cooled.

  Further, in the configuration shown in FIG. 3 of Patent Document 2, the refrigerant that has flowed out of the refrigerant discharge port goes straight as indicated by the arrow, and the terminal is located at a position retracted from the refrigerant outflow path. Insufficient cooling.

  Furthermore, in the configuration illustrated in FIG. 5 of Patent Document 2, the terminal is positioned on a surface orthogonal to the surface on which the inlet and outlet of the refrigerant passage are formed, and therefore the terminal is directly cooled with the refrigerant. I can't.

  Accordingly, an object of the present invention is to provide a cooling structure for a power storage device that can cool both the power storage element and the terminal more effectively.

  In order to solve the above problems, a cooling structure for a power storage device according to the present invention includes a power storage module in which a plurality of power storage elements are stacked, a first refrigerant passage formed between the power storage elements, and an exterior of the power storage module. And a second refrigerant passage formed along a first outer surface on a side where a terminal of the power storage element is located in the outer surface of the power storage module.

  Thereby, both an electrical storage element and a terminal can be cooled more effectively.

  Here, as a first method of supplying the refrigerant to the first and second refrigerant passages, a refrigerant supply pipe that branches and flows the refrigerant into the first and second refrigerant passages can be used. Thereby, it is not necessary to provide independent refrigerant supply means for each refrigerant passage, and cost reduction and size reduction can be achieved.

  A spacer member may be disposed between the power storage elements, and a plurality of guide members may be provided on the spacer member so as to contact the power storage element to form the first refrigerant passage. Thereby, a 1st refrigerant path can be reliably formed between electrical storage elements. Further, since the spacer member is provided with the guide member, the spacer member can be unitized, so that the assembly of the power storage module having the first refrigerant passage is facilitated.

  The power storage element may be pressed by the guide member. Thereby, it can prevent that an active material peels from the electrical power collector of an electrical storage element, and can suppress the performance fall of an electrical storage element.

  Further, as a second method of supplying the refrigerant to the first and second refrigerant passages, in the power storage module having two different second and third outer surfaces adjacent to the first outer surface, the first refrigerant A fourth refrigerant passage having a refrigerant inlet and a refrigerant outlet on the second and third outer surfaces, and a third refrigerant passage and a refrigerant outlet on the second and first outer surfaces, respectively. And a refrigerant passage.

  As a result, part of the refrigerant that has flowed into the first refrigerant passage flows into the second refrigerant passage, so there is no need to provide independent refrigerant supply means for each refrigerant passage, thereby reducing cost and size. Can be planned.

  A plurality of guide members that form a first refrigerant passage can be provided by arranging a spacer member between the power storage elements and abutting the spacer member against the power storage element. Thereby, a 1st refrigerant path can be reliably formed between electrical storage elements. Further, since the spacer member is provided with the guide member, the spacer member can be unitized, so that the assembly of the power storage module having the first refrigerant passage is facilitated.

  The power storage element may be pressed by the guide member. Thereby, it can prevent that an active material peels from the electrical power collector of an electrical storage element, and can suppress the performance fall of an electrical storage element.

  It is preferable to have a connecting member for connecting terminals of the power storage elements adjacent to each other, and to provide a convex heat radiating portion on the connecting member. Thereby, the thermal radiation area of a connection member increases and the thermal radiation amount of a terminal can be increased.

  The power storage element can be formed in a square shape. The cooling structure for the power storage device can be applied to vehicles such as hybrid vehicles, electric vehicles, and fuel cell vehicles.

  According to the present invention, both the power storage element and the terminal can be cooled more effectively.

  Examples of the present invention will be described below.

Example 1
A schematic configuration of a cooling structure for a power storage device according to an embodiment of the present invention will be described with reference to FIGS. Here, FIG. 1 is a perspective view of the power storage device, in which a top plate (see FIG. 3) connecting the intake chamber and the exhaust chamber is omitted. FIG. 2 is an exploded perspective view of the power storage device. FIG. 3 is a YZ cross-sectional view of the power storage device.

  In these drawings, the power storage device 1 includes a power storage module 12 in which power storage elements 11 and spacers 13 are alternately stacked, and two power storage modules 12 are provided side by side in the Y-axis direction. A positive electrode terminal 11 a and a negative electrode terminal 11 b are provided on the end face in the Z-axis direction of the electricity storage element 11.

  As illustrated in FIG. 1, end plates 14 and 15 are fixed to both end surfaces of the power storage module 12 in the X-axis direction. A restraining band 16 extending in the stacking direction of the power storage elements 11 is attached to the end plates 14 and 15. By attaching the restraining band 16 to the end plates 14 and 15, a compressive force in the stacking direction is applied to the power storage module 12.

  Here, the electricity storage element 11 generates heat due to charging / discharging, and if the heat generation state is left as it is, deterioration of the power generation element accommodated in the electricity storage element 11 proceeds. Further, the terminals 11a and 11b are heated to a temperature higher than that of the power generation element of the power storage element 11 due to chemical reaction and electrical resistance during charging and discharging, and the heat of the terminals 11a and 11b is transferred to the power generation element in the same manner. Problem arises. The problem of this temperature rise becomes more apparent as the power storage device has higher density and higher output. Therefore, in this embodiment, both the power generation element of the power storage element 11 and the terminals 11a and 11b are cooled by the following configuration.

  In the present embodiment, the refrigerant sucked into the intake chamber (refrigerant supply pipe) 17 is provided outside the power storage module 12 and the first refrigerant passage 13d formed between the adjacent power storage elements 11, and the power storage module 12 Branching into the second refrigerant passage 31a formed along the terminal installation surface (first outer surface) of the outer surface of the terminal. Thereby, both the electric power generation element accommodated in the electrical storage element 11 and terminal 11a, 11b can be cooled more effectively. Hereinafter, a detailed description will be given with reference to FIGS. 1 to 3.

  The electricity storage element 11 is rectangular and has a power generation element. The power generation element includes an electrode plate (a positive electrode plate and a negative electrode plate), a separator, and an electrolyte, and a known configuration can be appropriately applied.

  Here, as the positive electrode plate, a positive electrode layer formed on the surface of a current collector formed of a metal such as aluminum (including an alloy) is used. As the negative electrode plate, a metal such as aluminum (including an alloy) is used. What formed the negative electrode layer in the surface of the electrical power collector formed by 1 can be used. More specifically, in a nickel-hydrogen battery, nickel oxide is used as the active material of the positive electrode layer, and MmNi (5-xyz) AlxMnyCoz (Mm: Misch metal) is used as the active material of the negative electrode layer. The hydrogen storage alloy can be used. In the lithium ion battery, a lithium-transition metal composite oxide can be used as the active material for the positive electrode layer, and carbon can be used as the active material for the negative electrode layer.

  A protruding positive electrode terminal 11 a and negative electrode terminal 11 b are provided side by side in the Y-axis direction on one end surface in the Z-axis direction of the electricity storage element 11. The storage elements 11 adjacent in the X-axis direction are arranged so that the directions of the positive electrode terminal 11a and the negative electrode terminal 11b are opposite to each other in the Y-axis direction. In addition, the storage elements 11 adjacent in the Y-axis direction are arranged so that the directions of the positive electrode terminal 11a and the negative electrode terminal 11b are the same in the Y-axis direction.

  A gas release valve 11c is formed between the positive terminal 11a and the negative terminal 11b (see FIG. 2). The gas release valve 11c is configured to be destroyed when the internal pressure of the energy storage device 11 is increased by gas generated by electrolysis of the electrolyte during overcharge or the like. Thereby, the gas inside the electricity storage element 11 is released to the outside of the electricity storage element 11, and an increase in the internal pressure of the electricity storage element 11 can be suppressed.

  Adjacent power storage elements 11 are connected in series by a bus bar (connection member) 19 (see FIG. 3). In FIG. 1 and FIG. 2, the bus bar 19 is omitted. FIG. 4A is a perspective view of the bus bar. As shown in the figure, the bus bar 19 has two through holes 19a and 19b, and the terminals 11a and 11b of the power storage element 11 are inserted into the through holes 19a and 19b. Female screws are formed on the outer peripheral surfaces of the terminals 11a and 11b, and a bus bar 19 is fixed to the terminals 11a and 11b by fastening a nut (not shown) to the female screws.

  On the upper surface of the bus bar 19, heat radiation fins (convex heat radiation portions) 21 are formed at positions (three locations) facing each other with the through holes 19 a and 19 b interposed therebetween. A material excellent in thermal conductivity can be used for the heat radiation fin 21. For example, copper, aluminum, stainless steel and the like. The bus bar 19 and the radiation fins 21 can be integrally formed by press molding, extrusion molding, casting, or the like. Moreover, you may connect the thermal radiation fin 21 to the bus-bar 19 by means, such as brazing and welding.

  According to the above configuration, since the heat radiation area of the bus bar 19 is increased by providing the plurality of heat radiation fins 21, the heat radiation amount of the terminals 11a and 11b radiated from the bus bar 19 can be increased.

  Here, as illustrated in FIG. 4B, a louver-shaped heat radiation portion 22 may be provided on the bus bar 19 instead of the heat radiation fin 21. Even when the louver-shaped heat radiation portion 22 is used, the heat radiation area of the bus bar 19 is increased, so that the heat radiation amount can be increased. Further, the heat dissipation layer may be provided by applying heat dissipation grease to the bus bar 19.

  Next, the configuration of the spacer 13 will be described in detail. As shown in FIG. 2, a plurality of protrusions (guide members) 13 c are formed in a comb shape on both end faces of the spacer 13 in the X-axis direction (the stacking direction of the power storage elements 11). Resin can be used for the spacer 13.

  The protrusions 13c extend in the Y-axis direction, and are arranged in parallel at a certain interval in the Z-axis direction. When the protrusion 13 c abuts on the outer surface of the power storage element 11, a first refrigerant passage 13 d is formed between the power storage element 11 and the spacer 13. The refrigerant that has flowed into the first refrigerant passage 13 d from the intake chamber 17 moves in the Y-axis direction along the outer surface of the power storage element 11. Thereby, the electric power generation element of the electrical storage element 11 can be cooled more effectively.

  The protrusion 13c and the power generation element of the electricity storage element 11 are set to have substantially the same dimension in the Y-axis direction. In the assembled state of the power storage module 12 (see FIG. 1), the end surface in the X-axis direction of the protrusion 13c is in contact with the outer surface of the power storage element 11 and presses the power generation element of the power storage element 11. Thereby, it is possible to prevent the active material of the positive electrode layer and the negative electrode layer from being peeled from the current collector, and to suppress the performance deterioration of the power storage device 1.

  Next, the configuration of the intake chamber 17 and the exhaust chamber 18 will be described in detail with reference to FIGS. 1 and 3. The upper ends of the intake chamber 17 and the exhaust chamber 18 are connected by a top plate 31. A second refrigerant passage 31 a is formed between the top plate 31 and the terminal installation surface of the power storage module 12.

  The intake chamber 17 is formed with an opening 17a for discharging the refrigerant sucked by an unillustrated intake fan. The opening 17a is connected to the first refrigerant passage 13d and the second refrigerant passage 31a from the Y-axis direction. Since the front end portion (the front end portion in the X-axis direction) of the intake chamber 17 is closed, all the refrigerant sucked into the intake chamber 17 is discharged from the opening portion 17a.

  According to the above-described configuration, the refrigerant sucked into the intake chamber 17 can be branched into the first refrigerant passage 13d and the second refrigerant passage 31a. In this way, since both the power generation element of the power storage element 11 and the terminals 11a and 11b can be cooled using a refrigerant having a high cooling capacity before coming into contact with the heat generating element, the cooling effect on the power storage element 11 can be enhanced.

  The exhaust chamber 18 is formed in the same shape as the intake chamber 17 and has an opening 18a. The opening 18a of the exhaust chamber 18 is connected to the first refrigerant passage 13d and the second refrigerant passage 31a from the Y-axis direction. The refrigerant that has flowed into the first refrigerant passage 13d and the second refrigerant passage 31a cools the heat generating elements such as the terminals 11a and 11b, and is then exhausted from the opening 18a to the exhaust chamber 18.

  According to the above-described configuration, both the power generation element of the power storage element 11 and the terminals 11 a and 11 b can be cooled by the single intake chamber 17. As a result, it is not necessary to provide independent cooling means for cooling the power generation element of the power storage element 11 and the terminals 11a and 11b, respectively, and the cost can be reduced and the size can be reduced.

  In the above-described embodiment, the chambers 17 and 18 and the top plate 31 are formed as separate members. However, they can be integrally formed by press molding, extrusion molding, casting, or the like.

(Example 2)
Next, the power storage device of Example 2 will be described with reference to FIG. Here, FIG. 5 is a YZ sectional view of the power storage device, and the direction in which the refrigerant flows is indicated by arrows. For convenience of explanation, a refrigerant passage and the like are projected and illustrated, and the same components as those in the first embodiment are denoted by the same reference numerals.

  Here, the surface (terminal installation surface) on which the terminals 11a and 11b are located on the outer surface of the power storage module 12 corresponds to the “first outer surface” recited in the claims. Of the outer surface of the electricity storage module 12, the surface on which the refrigerant inlets 41a and 42a are formed corresponds to the “second outer surface” recited in the claims. Of the outer surface of the electricity storage module 12, the surface on which the refrigerant discharge port 41b is formed corresponds to the “third outer surface” recited in the claims.

  A plurality of guide members 43 extending in the Y-axis direction are juxtaposed in the Z-axis direction on both end surfaces of the spacer 13 in the X-axis direction. The third refrigerant passage 41 is formed when these guide members 43 abut against the outer surface of the electricity storage element 11. The inlet 41 a of the third refrigerant passage 41 is connected to the opening 51 a of the intake chamber 51, and the outlet 41 b is connected to the opening 52 a of the exhaust chamber 52.

  The refrigerant that has flowed into the third refrigerant passage 41 from the intake chamber 51 moves on the outer surface of the power storage element 11 in the Y-axis direction while being guided by the guide member 43. Thereby, the electric power generation element of the electrical storage element 11 can be cooled more effectively.

  Further, guide members 44 for guiding the refrigerant flowing from the intake chamber 51 toward the terminal installation surface are provided on both end surfaces in the X-axis direction of the spacer 13. When these guide members abut on the outer surface of the electricity storage element 11, the fourth refrigerant passage 42 is formed.

  A top plate 61 whose both ends are bent in an L shape is provided on the upper portion of the terminal installation surface of the power storage module 12, and the bent portion 61 a of the top plate 61 is provided on both end surfaces of the spacer 13 in the Y-axis direction. It is fixed. As the fixing means, a known method such as welding can be used. A region along the terminal installation surface, which is formed between the top plate 61 and the terminal installation surface of the power storage module 12, becomes the second refrigerant passage 62.

  The top plate 61 is formed with a discharge port (not shown) for discharging the refrigerant flowing into the second refrigerant passage 62. This discharge port can be formed at the end of the top plate 61 in the Y-axis direction (end on the exhaust chamber 52 side).

  The refrigerant that has flowed into the fourth refrigerant passage 42 from the intake chamber 51 moves toward the outlet 42 b and flows into the second refrigerant passage 62 while being guided by the guide member 44. The refrigerant flowing into the second refrigerant passage 62 moves along the terminal installation surface while moving in the Y-axis direction. Thereby, the terminals 11a and 11b of the electricity storage element 11 can be cooled more effectively.

  According to the above-described configuration, both the power generation element of the power storage element 11 and the terminals 11a and 11b can be more effectively cooled. Moreover, since both the power generation element of the power storage element 11 and the terminals 11a and 11b can be cooled by one intake chamber 51, cooling means for cooling the power generation element of the power storage element 11 and the terminals 11a and 11b are provided independently. This eliminates the need for cost reduction and downsizing.

  Further, the outer surface of the electricity storage element 11 is pressed by the guide members 43 and 44. Accordingly, the active material of the positive electrode layer and the negative electrode layer can be prevented from being peeled from the current collector, and the performance degradation of the power storage device can be suppressed.

(Other examples)
In the above-described embodiment, the movement trajectory of the refrigerant moving in the intake chambers 17 and 51, the power storage module 12 and the exhaust chambers 18 and 52 is U-shaped in plan view, but is not limited thereto. For example, the present invention can also be applied to a cooling structure in which the moving direction of the refrigerant before flowing between the storage elements 11 and the moving direction of the refrigerant flowing out between the storage elements 11 are the same.

  Further, the spacer 13 can be omitted. In this case, guide members 13 c, 43, and 44 may be directly provided on the outer surface of the power storage element 11. In addition, the storage element 11 may be a secondary battery such as a lithium ion battery or a nickel metal hydride battery, or may be a capacitor. The capacitor is an electric double layer capacitor based on the principle of operation of the electric double layer generated at the interface between the activated carbon and the electrolyte. When activated carbon is used as a solid and an electrolytic solution (dilute sulfuric acid aqueous solution) is used as a liquid and brought into contact with each other, plus and minus electrodes are relatively distributed at very short intervals on the interface. When a pair of electrodes are immersed in an ionic solution and a voltage is applied to such an extent that electrolysis does not occur, ions are adsorbed on the surface of each electrode, and positive and negative electricity are stored (charging). When electricity is discharged to the outside, positive and negative ions leave the electrode and return to the neutralized state.

It is a perspective view of a power storage device. It is a disassembled perspective view of an electrical storage apparatus. It is YZ sectional drawing of an electrical storage apparatus. It is the schematic of the thermal radiation part formed in the bus-bar. It is YZ sectional drawing of the electrical storage apparatus of Example 2. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Spacer 12 Power storage module 13 Spacer 13d 1st refrigerant path 17 51 Intake chamber 18 52 Exhaust chamber 31a 62 2nd refrigerant path 41 3rd refrigerant path
42 4th refrigerant path

Claims (11)

A power storage module in which a plurality of power storage elements are stacked;
A first refrigerant passage formed between the storage elements;
And a second refrigerant passage formed along a first outer surface of the outer surface of the power storage module, on a side where a terminal of the power storage element is located, of the outer surface of the power storage module. Power storage device cooling structure.   The cooling structure for a power storage device according to claim 1, further comprising a refrigerant supply pipe that branches and supplies a refrigerant to the first and second refrigerant passages.   The cooling structure for a power storage device according to claim 2, wherein the first and second refrigerant passages are provided in the same direction. A spacer member disposed between the power storage elements;
A plurality of guide members provided on the spacer member and in contact with the power storage element to form the first refrigerant passage;
The cooling structure for a power storage device according to claim 2, wherein:   The cooling structure for a power storage device according to claim 4, wherein the guide member also serves as a pressing member that presses the power storage element. The power storage module has two different second and third outer surfaces adjacent to the first outer surface,
The first refrigerant passage includes a third refrigerant passage having a refrigerant inlet and a refrigerant outlet on the second and third outer surfaces, respectively, and a refrigerant inlet and a refrigerant outlet on the second and first outer surfaces, respectively. The cooling structure for a power storage device according to claim 1, comprising a fourth refrigerant passage having an outlet. A spacer member disposed between the power storage elements;
The cooling structure for a power storage device according to claim 6, further comprising: a plurality of guide members that are formed on the spacer member and that form the first refrigerant passage by contacting the outer surface of the power storage element. .   The cooling structure for a power storage device according to claim 7, wherein the guide member also serves as a pressing member that presses the power storage element.   The power storage device according to claim 1, further comprising a connection member that connects terminals of the power storage elements adjacent to each other, wherein the connection member includes a convex heat dissipation portion. Cooling structure.   The cooling structure for a power storage device according to any one of claims 1 to 9, wherein the power storage element has a rectangular shape. A vehicle comprising the power storage device cooling structure according to claim 1.

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