JP2014112479A - Cooling structure of battery cell and battery pack including the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cooling structure of a battery cell which inhibits variations in battery cell temperatures and prevents increases in the weight and the cost.SOLUTION: A cooling structure of a battery cell includes: a battery exterior material 21 which encloses a power generation element; and a sealing part 22 which is formed by heat sealing a periphery of the battery exterior material 21, seals the power generation element in the battery exterior material 21, and has a heat radiation part 22a which extends in a flow direction of air flowing at the outer side of the battery exterior material 21. A contact area between the heat radiation part 22a at the downstream side of the air flow and the air is formed so as to be larger than a contact area between the heat radiation part 22a at the upstream side and the air.

Description

  The present invention relates to a battery cell cooling structure including a sealing portion around a battery exterior material that encloses a power generation element, and an assembled battery including the same.

  Conventionally, in a battery unit formed by arranging a plurality of battery cells in series, a spacer having a refrigerant passage capable of circulating a refrigerant between adjacent battery cells is interposed, and the battery cell area facing the refrigerant passage of this spacer is reduced. There is known a cooling structure for battery cells that is sequentially increased from the upstream side to the downstream side of the refrigerant flow (see, for example, Patent Document 1).

JP 2004-47426 A

By the way, in the conventional battery cell cooling structure, the heat radiation amount on the downstream side is made larger than the heat radiation amount on the upstream side by sequentially increasing the battery cell area facing the refrigerant passage of the spacer toward the downstream side of the refrigerant flow. Enlarge. Thereby, although the refrigerant | coolant temperature rises by the heat receiving from a battery cell, the downstream of the flow of a refrigerant | coolant, the whole battery unit can be cooled uniformly.
However, since it is necessary to interpose a spacer having a refrigerant passage between adjacent battery cells, the spacer becomes indispensable, and there is a problem that the entire battery unit becomes large and the weight and cost of the spacer increase. It was.

  The present invention has been made paying attention to the above problem, and an object of the present invention is to provide a battery cell cooling structure capable of preventing an increase in weight and cost while suppressing variations in battery cell temperature.

In order to achieve the above object, the battery cell cooling structure of the present invention includes a battery exterior material and a sealing portion.
The battery exterior material wraps the power generation element.
The sealing portion is formed by heat-sealing the periphery of the battery exterior material, encloses the power generation element inside the battery exterior material, and a flow direction of the refrigerant flowing outside the battery exterior material And a heat radiating portion extending along the line.
Then, the contact area between the heat radiation part on the downstream side and the refrigerant is made larger than the contact area between the heat radiation part on the upstream side of the flow of the refrigerant and the refrigerant.

In the cooling structure of the battery cell of the present invention, the sealing portion formed around the battery exterior material that encloses the power generation element has a heat dissipation portion that extends along the flow direction of the refrigerant that flows outside the battery exterior material. . Furthermore, the contact area between the heat radiating portion and the refrigerant is made larger on the downstream side than on the upstream side of the refrigerant flow.
Here, the heat radiating part is a part of the battery exterior material that wraps the power generating element, and heat from the power generating element is conducted to the heat radiating part. Therefore, the heat from the power generation element can be radiated by the heat radiating portion coming into contact with the refrigerant. That is, since heat is dissipated using a part of the battery exterior material, no separate parts such as spacers are required. Therefore, an increase in weight and cost can be prevented.
Further, the contact area between the heat radiating portion and the refrigerant extending along the refrigerant flow direction is larger on the downstream side than on the upstream side of the refrigerant flow, so that the discharge on the downstream side from the heat radiating portion is increased. The amount of heat can be improved more than the amount of heat released on the upstream side. Therefore, even if the refrigerant temperature rises toward the downstream side of the refrigerant flow due to heat received from the power generation element, a high heat dissipation amount can be secured on the downstream side of the refrigerant flow, and the temperature variation of the battery cells can be suppressed. it can.
As a result, an increase in weight and cost can be prevented while suppressing variations in battery cell temperature.

1 is an exploded perspective view showing an assembled battery of Example 1. FIG. It is an external appearance perspective view which shows the cooling device to which the battery cell of Example 1 is applied. 3 is an external perspective view showing a first battery unit of Example 1. FIG. It is a figure which shows the 1st battery cell of Example 1, (a) shows an external appearance perspective view, (b) shows a top view. 4 is an external perspective view showing a second battery unit of Example 1. FIG. It is a figure which shows the 2nd battery cell of Example 1, (a) shows an external appearance perspective view, (b) shows a top view. 3 is an external perspective view showing a third battery unit of Example 1. FIG. It is a figure which shows the 3rd battery cell of Example 1, (a) shows an external appearance perspective view, (b) shows a top view. FIG. 3 is an explanatory diagram showing an air flow in the assembled battery of Example 1. It is a side view when the 2nd battery cell of Example 1 is seen along the flow of air. It is a side view when the 3rd battery cell of Example 1 is seen along the flow of air. 6 is a perspective view showing the inside of an assembled battery of Example 2. FIG. 6 is a plan view showing the inside of an assembled battery of Example 3. FIG. It is a figure which shows the 1st modification of the battery cell of this invention, (a) shows a perspective view, (b) shows a side view. It is a perspective view which shows the 2nd modification of the battery cell of this invention. It is a figure which shows the 3rd modification of the battery cell of this invention, (a) shows a perspective view, (b) shows a side view. It is a perspective view which shows the 4th modification of the battery cell of this invention.

  Hereinafter, the form for implementing the cooling structure of the battery cell of this invention is demonstrated based on Example 1 and Example 2 shown in drawing.

Example 1
The configuration of the cooling structure of the battery cell of Example 1 is “configuration of application example of cooling structure of battery cell”, “configuration of assembled battery”, [configuration of first battery unit and first battery cell], [second configuration] [Configuration of Battery Unit and Second Battery Cell] and [Configuration of Third Battery Unit and Third Battery Cell] will be described separately.

[Configuration of application example of battery cell cooling structure]
FIG. 1 is an exploded perspective view showing the assembled battery of Example 1. FIG. FIG. 2 is an external perspective view showing a cooling device to which the battery cell of Example 1 is applied. Hereinafter, based on FIG.1 and FIG.2, the structure of the application example of the cooling structure of the battery cell of Example 1 is demonstrated.

  As shown in FIG. 1, the assembled battery 1 of Example 1 is formed by assembling a plurality of battery units (here, first to third battery units 2, 3, and 4). A secondary battery. Here, it is mounted on an electric vehicle (electric vehicle, hybrid vehicle, etc.) that uses a motor as a travel drive source. This assembled battery 1 is built in the cooling device 100 shown in FIG. 2, and is disposed under the floor of the vehicle, in the passenger compartment, in the trunk room, or the like.

  As shown in FIG. 2, the cooling device 100 includes an outer case 101 containing the assembled battery 1, an air introduction duct 102 for introducing air as a cooling refrigerant into the outer case 101, and air introduced into the outer case 101. An air discharge duct 103 for discharging the air.

  The outer case 101 is arranged such that the air inlet 7a of the battery pack 1 is on the windward side and the air outlet 7b is on the leeward side. Specifically, the air introduction port 7a of the assembled battery 1 is directed to the air introduction duct 102 side, and the air discharge port 7b of the assembled battery 1 is directed to the air discharge duct 103 side.

An exhaust fan 104 is attached to the outer case 101 side of the air discharge duct 103. The exhaust fan 104 includes a sensor that detects the temperature of the air discharged from the exterior case 101, and the rotational speed (exhaust amount) of the exhaust fan 104 is adjusted according to the temperature detected by the sensor by a control device (not shown). Is done.
When the exhaust fan 104 is driven, the air in the outer case 101 is forcibly discharged through the air discharge duct 103, and the inside of the outer case 101 becomes negative pressure. As a result, air is introduced into the exterior case 101 via the air introduction duct 102.
The air introduced into the exterior case 101 exchanges heat with the assembled battery 1 to cool the assembled battery 1.

[Configuration of assembled battery]
Hereinafter, based on FIG. 1, the structure of the assembled battery of Example 1 is demonstrated.

  As shown in FIG. 1, the assembled battery 1 includes a battery case 5 and first to third battery units 2, 3, and 4.

  The battery case 5 is a housing that houses the first to third battery units 2, 3, and 4 and is disposed in the outer case 101 of the cooling device 100, along the flow of air that is a cooling refrigerant. It has an elongated rectangular parallelepiped shape. The battery case 5 can be divided into two parts, and includes a lower housing 5a and an upper housing 5b.

  The lower housing 5a has a flat plate shape on which the first to third battery units 2, 3, and 4 are placed. At both ends in the longitudinal direction of the lower housing 5a, spacers 6 to be described later are placed, and spacer stands 5c and 5c are formed with screw holes (not shown) into which screws are screwed. Yes.

The upper housing 5b is a portion that covers the first to third battery units 2, 3, and 4 mounted on the lower housing 5a. The upper housing 5b has a so-called gate shape having an upper surface portion 5d and a pair of side surface portions 5e, 5e.
The upper surface portion 5d covers the top of the first to third battery units 2, 3, and 4. Screw through holes 5f,... Are formed in the vicinity of the four corners of the upper surface portion 5d. The pair of side surface portions 5e and 5e are formed by extending both end portions of the upper surface portion 5d in the short direction toward the lower housing 5a.

  In addition, a plurality of spacers 6 are arranged on the spacer stands 5c and 5c, respectively. The spacer 6 has a thickness dimension slightly thicker than the thickness of first to third battery cells 20, 30, 40, which will be described later, and is the same number as the battery cells 20, 30, 40 in the thickness direction (here, four). ) Are stacked. A pair of screw through holes 6a, 6a penetrating in the thickness direction is formed at both longitudinal ends of each spacer 6.

  Then, the first to third battery units 2, 3, and 4 are placed on the lower housing 5a, and a plurality of spacers 6 are placed on the spacer base 5c and then covered with the upper housing 5b. To fix the upper housing 5b to the lower housing 5a. At this time, a screw (not shown) passes through the screw through hole 5f and the screw through hole 6a and is screwed into a screw hole (not shown) formed in the spacer base 5c.

  At this time, the longitudinal dimension of the spacer 6 is shorter than the lateral dimension of the upper housing 5b. For this reason, gaps are respectively generated between the longitudinal end portions of the spacer 6 and the pair of side surface portions 5e, 5e of the upper housing 5b. Of the gap between the spacer 6 and the upper housing 5b, one of the battery case 5 in the longitudinal direction is an air inlet (refrigerant inlet) 7a, and the other in the longitudinal direction is an air outlet (refrigerant outlet). 7b. Note that a pair of air inlet 7a and air outlet 7b are formed on both sides of the first to third battery units 2, 3, and 4, respectively. Furthermore, a space from the air inlet 7a to the air outlet 7b becomes an air passage 8 through which air flows.

  The first to third battery units 2, 3, 4 are built in the battery case 5, and the heat radiating portions 22a, 32a, 42a of the sealing portions 22, 32, 42, which will be described later, are exhausted from the air inlet 7a. It arrange | positions in a serial state so that the flow direction of the air which flows toward the exit 7b may be followed. Here, the first battery unit 2, the second battery unit 3, and the third battery unit 4 are arranged in this order from the upstream side to the downstream side of the air flow, that is, from the air introduction port 7a to the air discharge port 7b. It is out.

[Configuration of first battery unit and first battery cell]
3 is an external perspective view showing the first battery unit of Example 1. FIG. 4A and 4B are diagrams showing the first battery cell of Example 1, wherein FIG. 4A is an external perspective view, and FIG. 4B is a plan view. Hereinafter, based on FIG.3 and FIG.4, the structure of a 1st battery unit and a 1st battery cell is demonstrated.

  As shown in FIG. 3, the first battery unit 2 is formed by stacking a plurality (four in this case) of flat, rectangular parallelepiped first battery cells 20 in close contact with each other in the thickness direction. The first battery unit 2 is built in the battery case 5 in a state in which the longitudinal direction coincides with the flow direction of air flowing in the battery case 5 (the direction indicated by the arrow X in FIG. 3).

  The first battery cell 20 has a flat power generation element (not shown), and as shown in FIG. 4 (a), a positive electrode tab 23a for taking out electric power from both ends in the longitudinal direction of the power generation element. The negative electrode tab 23b is pulled out. Note that when the first battery unit 20 is formed by stacking the first battery cells 20, the positive electrode tab 23a and the negative electrode tab 23b are connected to the electrodes of the adjacent battery cells. It is omitted in FIG. Further, the first battery cell 20 includes a battery exterior material 21 and a sealing portion 22.

The battery outer packaging material 21 is a laminate film that wraps a power generation element (not shown) in a state where the positive electrode tab 23a and the negative electrode tab 23b are pulled out to the outside. Here, the battery exterior material 21 sandwiches the power generation element from above in the thickness direction and from below in the thickness direction. The battery outer packaging material 21 has a three-layer structure in which a heat sealing layer, a metal foil, and a protective layer are laminated in this order.
The metal foil is made of a metal that is excellent in ductility and malleability and requires flexibility, and is specifically made of aluminum or the like. The thickness of this metal foil is, for example, about 46 μm.
The heat-sealing layer located on the inner surface side of the metal foil is a thermoplastic resin layer such as polyethylene, polypropylene, ionomer, ethylene-methacrylate copolymer resin, ethylene- (meth) acrylate copolymer resin, etc., with an adhesive layer interposed therebetween. Alternatively, it is configured to be bonded by thermal fusion without using an adhesive layer.
The protective layer located on the outer surface side of the metal foil is made of a polyester resin such as polyethylene terephthalate or a nylon resin.

The sealing portion 22 is formed by heat-sealing the periphery (here, the entire circumference) of the battery exterior material 21, and encloses the power generation element inside the battery exterior material 21. Here, the sealing portion 22 is formed by superimposing a heat fusion layer of the battery exterior material 21 that covers the power generation element from above in the thickness direction and a heat fusion layer of the battery exterior material 21 that covers the power generation element from above in the thickness direction. It is formed by heat sealing. Thereby, the sealing part 22 will protrude and be formed in the direction orthogonal to the thickness direction of an electric power generation element.
Further, in the sealing portion 22, a portion protruding from the longitudinal side surface 20 a of the first battery cell 20 becomes a heat radiating portion 22 a extending along the flow direction of the air flowing in the battery case 5. That is, the sealing portion 22 has a heat radiating portion 22 a formed along the air path 8 formed inside the battery case 5.

  The heat radiating portion 22a is formed on a flat surface, and as shown in FIG. 4 (b), the first battery cell moves toward the downstream side of the air flow (right side in FIG. 4 (b)). The protrusion dimension from the longitudinal direction side surface 20a of 20 becomes large gradually. Thereby, the contact area of the thermal radiation part 22a and air becomes large as it goes to the downstream of the flow of air. That is, the contact area between the heat radiation part 22a on the upstream side of the air flow and the air and the contact area between the heat radiation part 22a on the downstream side and the air becomes larger.

[Configuration of Second Battery Unit and Second Battery Cell]
5 is an external perspective view showing a second battery unit of Example 1. FIG. 6A and 6B are diagrams showing a second battery cell of Example 1, wherein FIG. 6A is an external perspective view, and FIG. 6B is a plan view in a state where a sealing portion is developed. Hereinafter, based on FIG.5 and FIG.6, the structure of a 2nd battery unit and a 2nd battery cell is demonstrated.

  As shown in FIG. 5, the second battery unit 3 is formed by stacking a plurality of (here, four) second battery cells 30 having a flat rectangular parallelepiped shape in close contact with each other in the thickness direction. The second battery unit 3 has a longitudinal direction that coincides with the flow direction of air flowing in the battery case 5 (the direction indicated by the arrow X in FIG. 5) and is adjacent to the downstream side of the first battery unit 2. Built in the battery case 5.

  The second battery cell 30 has a flat power generation element (not shown), and as shown in FIG. 6 (a), a positive electrode tab 33a for taking out electric power from each of both ends in the longitudinal direction of the power generation element. The negative electrode tab 33b is pulled out. In addition, when this 2nd battery cell 30 is laminated | stacked and the 2nd battery unit 3 is formed, this positive electrode tab 33a and the negative electrode tab 33b are connected etc. to the electrode of an adjacent battery cell, but FIG. It is omitted in FIG. Further, the second battery cell 30 includes a battery exterior material 31 and a sealing portion 32.

  Since the battery exterior material 31 has the same configuration as the battery exterior material 21 in the first battery cell 20, description thereof is omitted here.

The sealing portion 32 is formed by heat-sealing the periphery (here, the entire circumference) of the battery exterior material 31, and encapsulates the power generation element inside the battery exterior material 31. Here, the sealing portion 32 is formed to project in a direction orthogonal to the thickness direction of the power generation element.
Furthermore, a portion of the sealing portion 32 that protrudes from the longitudinal side surface 30 a of the second battery cell 30 becomes a heat radiating portion 32 a that extends along the direction of the air flowing through the battery case 5. That is, the sealing portion 32 has a heat radiating portion 32 a formed along the air path 8 formed inside the battery case 5.

Then, as shown in FIG. 6 (b), the heat radiating portion 32a is formed in the longitudinal direction of the second battery cell 30 in the downstream portion of the air flow from the middle position in the longitudinal direction (right side in FIG. 6 (b)). The protrusion dimension from the direction side surface 30a is large. That is, the projecting dimension of the heat radiating portion 32a from the longitudinal side surface 30a is increased by one step toward the downstream side of the air flow. As a result, the contact area between the heat radiation portion 32a on the downstream side of the air flow and the air becomes larger than that on the upstream side.
Further, the heat radiating portion 32a has an increased protruding portion directed toward the upper housing 5b from the air flow direction (arrow X shown in FIG. 5), that is, from the bent portion α along the longitudinal direction of the second battery unit 3. It is three-dimensionally shaped by bending 90 degrees.

  Further, in the second battery cell 30, the projecting dimension from the longitudinal side surface 30a of the heat radiating portion 32a is increased stepwise toward the downstream side of the air flow, thereby forming a flat surface shown in FIG. The total contact area between the heat dissipating part 32a and the air is larger than that of the heat dissipating part 22a of the first battery cell 20 thus formed. For this reason, the contact area of the heat radiating part 32a and air becomes larger in the second battery unit 3 arranged on the downstream side of the air flow than in the first battery unit 2 arranged on the upstream side.

[Configuration of Third Battery Unit and Third Battery Cell]
7 is an external perspective view showing a third battery unit of Example 1. FIG. 8A and 8B are diagrams showing a third battery cell of Example 1, wherein FIG. 8A is an external perspective view, and FIG. 8B is a plan view in a state where a sealing portion is developed. Hereinafter, based on FIG.7 and FIG.8, the structure of a 3rd battery unit and a 3rd battery cell is demonstrated.

  As shown in FIG. 7, the third battery unit 4 is formed by laminating a plurality (four in this case) of flat, rectangular parallelepiped third battery cells 40 in close contact with each other in the thickness direction. The third battery unit 4 has a longitudinal direction that coincides with the flow direction of air flowing in the battery case 5 (the direction indicated by the arrow X in FIG. 7) and is adjacent to the downstream side of the second battery unit 4. Built in the battery case 5.

  The third battery cell 40 has a flat power generation element (not shown), and as shown in FIG. 8 (a), a positive electrode tab 43a for taking out electric power from both ends in the longitudinal direction of the power generation element. The negative electrode tab 43b is pulled out. When the third battery unit 40 is formed by stacking the third battery cells 40, the positive electrode tab 43a and the negative electrode tab 43b are connected to the electrodes of the adjacent battery cells. It is omitted in FIG. Further, the third battery cell 40 includes a battery exterior material 41 and a sealing portion 42.

  Since the battery exterior material 41 has the same configuration as the battery exterior material 21 in the first battery cell 20 and the battery exterior material 31 in the second battery cell 30, description thereof is omitted here.

The sealing portion 42 is formed by heat-sealing the periphery (here, the entire circumference) of the battery exterior material 41, and encloses the power generation element inside the battery exterior material 41. Here, the sealing portion 42 is formed so as to protrude in a direction orthogonal to the thickness direction of the power generation element.
Further, a portion of the sealing portion 42 that protrudes from the longitudinal side surface 40 a of the third battery cell 40 becomes a heat radiating portion 42 a that extends along the flow direction of the air flowing in the battery case 5. That is, the sealing portion 42 has a heat radiating portion 42 a formed along the air path 8 formed inside the battery case 5.

And as shown in FIG.8 (b), this thermal radiation part 42a is the longitudinal direction of the 3rd battery cell 40 in the part of the downstream of the airflow (right side in FIG.8 (b)) from the middle position of a longitudinal direction. The projecting dimension from the directional side surface 40a is gradually increased. That is, the projecting dimension of the heat radiation part 42a from the longitudinal side surface 40a is increased by two steps toward the downstream side of the air flow. Thereby, the contact area between the heat radiation portion 42a on the downstream side of the air flow and the air becomes larger than that on the upstream side.
Further, the heat radiating portion 42a has an increased protruding portion directed from the bent portion α1 along the air flow direction (arrow X shown in FIG. 7), that is, the longitudinal direction of the third battery unit 4, toward the upper housing 5b. Is bent 90 degrees. Furthermore, the increased protruding portion is bent 90 ° toward the longitudinal side surface 40a from the bent portion α2. Thereby, this heat radiation part 42a is three-dimensionally molded. At this time, both the bent portion α1 and the bent portion α2 are so-called valley folds, and the bending direction in each is constant.

  Further, in the third battery cell 40, the protrusion dimension from the longitudinal side surface 40a of the heat radiating part 42a is increased in two stages toward the downstream side of the air flow, thereby the bent part shown in FIG. The total contact area with air is larger than that of the heat radiating part 32a in the second battery cell 30 bent from α. For this reason, the third battery unit 4 arranged on the downstream side of the air flow has a larger contact area between the heat radiation part 42a and the air than the second battery unit 3 arranged on the upstream side.

  Next, the operation will be described. The operation of the battery cell cooling structure according to the first embodiment will be described by dividing it into “uniform cooling operation” and “air path expansion suppressing operation”.

[Uniform cooling]
FIG. 9 is an explanatory diagram showing air flow in the assembled battery of Example 1. Hereinafter, the uniform cooling operation of the first embodiment will be described with reference to FIG.

  In the cooling device 100 according to the first embodiment, when the exhaust fan 104 is driven, air is forcibly sucked from the air introduction duct 102 and flows through the exterior case 101 and then discharged from the air discharge duct 103 to the atmosphere. At this time, as shown in FIG. 9, the air that has flowed into the outer case 101 flows into the battery case 5 from the air inlet 7 a formed in the battery case 5 of the assembled battery 1 and flows through the air path 8. The air flowing through the air passage 8 flows out of the battery case 5 from the air discharge port 7 b and flows into the air discharge duct 103.

  On the other hand, inside the battery case 5, as shown in FIG. 9, the heat radiation portions 22a, 32a, and 42a in the first to third battery units 2, 3, and 4 are arranged in series so as to follow the air flow. Thus, the heat radiating portions 22 a, 32 a, and 42 a are along the air path 8 formed inside the battery case 5.

Here, each heat radiating part 22a, 32a, 42a is a part of the battery outer packaging material 21, 31, 41 that encloses the power generation element, respectively, and is thermally connected to the power generation element. Note that “thermally connected” means a connection or contact capable of heat transfer by heat conduction.
Thereby, the heat of an electric power generation element is conducted to each thermal radiation part 22a, 32a, 42a. On the other hand, when the air flowing through the air passage 8 comes into contact with the heat radiating portions 22a, 32a, and 42a, heat exchange is performed between the air and the heat radiating portions 22a, 32a, and 42a.

  At this time, if the temperature of the air is lower than the temperature of each of the heat radiating portions 22a, 32a, 42a, the heat of the power generation element is radiated to the air via the heat radiating portions 22a, 32a, 42a. Moreover, since the air temperature rises due to the heat received from the heat radiating unit toward the downstream side of the air flow, the cooling efficiency decreases as the battery cell is located on the downstream side.

  On the other hand, in Example 1, in each heat radiating part 22a, 32a, 42a which radiates the heat of the power generation element, the contact area between these heat radiating parts 22a, 32a, 42a and air is from the upstream side of the air flow. Is also larger on the downstream side. Here, the amount of heat released from each heat radiating portion 22a, 32a, 42a increases as the contact area with air increases. For this reason, in each heat radiating part 22a, 32a, 42a, the heat radiation amount on the downstream side of the air flow is greater than that on the upstream side, and the heat radiation performance on the downstream side is improved.

That is, on the upstream side of the air flow with a low air temperature and a relatively high cooling efficiency, in each of the heat radiating portions 22a, 32a, and 42a, the contact area with air is kept small so that the heat radiating performance does not become too high. . On the other hand, on the downstream side of the air flow having a high air temperature and a relatively low cooling efficiency, the contact area with the air is increased in each of the heat radiating portions 22a, 32a, and 42a, thereby improving the heat radiating performance.
Thereby, even if the air temperature increases toward the downstream, it is possible to suppress variation between the heat release amount on the upstream side and the heat release amount on the downstream side of the air flow, and each battery cell 20, 30, 40 is evenly distributed. Can be cooled to. Moreover, the battery life can be improved by suppressing variations in battery cell temperature.

  Furthermore, as shown in FIG. 9, a plurality of battery cells 20, 30, and 40 are stacked in the thickness direction to form a first battery unit 2, a second battery unit 3, and a third battery unit 4. In addition, the heat radiating portions 22a, 32a, and 42a protrude from the longitudinal side surfaces 20a, 30a, and 40a, respectively. Therefore, the heat radiation from each heat radiation part 22a, 32a, 42a is not inhibited. Thereby, the dispersion | variation in the amount of heat radiation can be suppressed by changing the contact area of each thermal radiation part 22a, 32a, 42a and air. That is, it is not necessary to provide a flow path space through which air as a cooling refrigerant flows between adjacent battery cells. As a result, a separate part such as a spacer for forming the flow path space becomes unnecessary, and an increase in weight and cost can be suppressed.

  In particular, in the assembled battery 1 of Example 1, as shown in FIG. 9, the battery unit arranged on the downstream side of the air flow is sealed more than the battery unit arranged on the upstream side of the air flow. The contact area between the heat dissipating part of the stopper and the air is increased. Specifically, the heat radiating portion 32a of the second battery cell 30 in the second battery unit 3 disposed on the downstream side of the contact area between the heat radiating portion 22a of the first battery cell 20 and the air in the first battery unit 2. The contact area between air and air is larger. Furthermore, the heat radiating portion 42a of the third battery cell 40 and the air in the third battery unit 4 disposed further downstream than the contact area between the heat radiating portion 32a of the second battery cell 30 and the air in the second battery unit 3. The contact area is larger.

  Thereby, even if the air temperature rises due to heat exchange with the first battery unit 2, the heat radiation amount in the second battery unit 3 is higher, so that necessary heat radiation performance can be ensured. Furthermore, even if the air temperature further rises due to heat exchange with the second battery unit 3, the heat radiation amount in the third battery unit 4 is further increased, so that necessary heat radiation performance can be ensured. As a result, the temperature variations of the battery units 2, 3, and 4 can be suppressed and cooling can be performed uniformly.

[Airway expansion suppression action]
FIG. 10 is a side view of the second battery cell of Example 1 when viewed along the air flow. FIG. 11 is a side view of the third battery cell of Example 1 as viewed along the air flow. Hereinafter, based on FIG.10 and FIG.11, the air path expansion suppression effect | action of Example 1 is demonstrated.

  In the heat radiating part 32a of the second battery cell 30 of the first embodiment, the protruding dimension from the longitudinal side surface 30a is large in the downstream portion of the air flow from the midway position in the longitudinal direction. The increased protruding portion is bent 90 ° from the bent portion α.

  Therefore, as shown in FIG. 10, this projecting portion rises from the bent portion α, and the contact area between the heat radiating portion 32 a and the air is increased without increasing the cross-sectional area of the air passage 8. Can do. That is, even if the contact area between the heat radiating portion 32a and the air is increased, the heat radiating portion 32a can be accommodated in the air passage 8 and an increase in the cross-sectional area of the air passage 8 can be suppressed.

  Moreover, in the thermal radiation part 42a of the 3rd battery cell 40 of Example 1, the protrusion dimension from the longitudinal direction side surface 40a is gradually increased in the downstream part of the air flow from the middle position of the longitudinal direction. The increased protruding portion is bent by 90 ° at each of the bent portion α1 and the bent portion α2.

  Therefore, as shown in FIG. 11, the protruding portion stands from the bent portion α1 and is directed from the bent portion α2 to the longitudinal side surface 40a. Thereby, even if the contact area of the heat radiating part 42a and the air is increased, the heat radiating part 42a can be accommodated in the air path 8 without increasing the cross-sectional area of the air path 8.

  Furthermore, in Example 1, the bending direction in the two bent portions α1 and α2 is constant. Therefore, the shape of the sealing part 42 can be simplified, the productivity can be increased to reduce the manufacturing cost, and the cross-sectional area of the air passage 8 can be reliably prevented from increasing.

Next, the effect will be described.
In the cooling structure of the battery cell of Example 1, the effects listed below can be obtained.

(1) a battery outer packaging material 21 that encloses a power generation element;
A sealing portion 22 formed by heat-sealing the periphery of the battery outer packaging material 21 and enclosing the power generating element inside the battery outer packaging material 21;
The sealing part 22 has a heat radiating part 22a extending along the flow direction of the refrigerant (air) flowing outside the battery exterior material 21,
The contact area between the heat radiation part 22a on the downstream side and the refrigerant (air) is made larger than the contact area between the heat radiation part 22a on the upstream side of the flow of the refrigerant (air) and the refrigerant (air). The configuration.
Thereby, an increase in weight and cost can be prevented while suppressing variations in temperature of the battery cell (first battery cell) 20.

(2) By forming a three-dimensional shape of the downstream side of the flow of the refrigerant (air) of the heat radiating portion 32a, the contact area between the heat radiating portion 32a and the refrigerant (air) is changed to the refrigerant (air). The downstream side is larger than the upstream side of the flow.
Thereby, the contact area of the thermal radiation part 32a and a refrigerant | coolant (air) can be enlarged, without expanding the cross-sectional area of the air path 8 through which a refrigerant | coolant (air) flows.

(3) By bending the heat radiating portion 32a from a bent portion α extending along the flow direction of the refrigerant (air), the contact area between the heat radiating portion 32a and the refrigerant (air) is changed to the refrigerant (air). ), The downstream side of the flow is increased stepwise from the upstream side.
Thereby, the enlargement of the cross-sectional area of the air path 8 through which the refrigerant (air) flows can be reliably prevented while increasing the contact area between the heat radiation part 32a and the refrigerant (air).

(4) A plurality of the bent portions α1 and α2 are provided, the heat dissipating portion 42a is bent at 90 ° at the bent portions α1 and α2, and the bending direction is made constant.
Thereby, while simplifying the shape of the thermal radiation part 42a and improving productivity and reducing a manufacturing cost, the expansion of the cross-sectional area of the air path 8 can be prevented reliably.

(5) The battery outer packaging material 21 that wraps the flat power generation element and the outer periphery of the battery outer packaging material 21 are heat-sealed so as to protrude in a direction perpendicular to the thickness direction. A heat dissipating part 22a extending along the flow direction of the refrigerant (air) flowing outside, and a sealing part 22 for enclosing the power generating element inside the battery exterior material 21,
The contact area between the heat radiation part 22a on the downstream side and the refrigerant (air) is made larger than the contact area between the heat radiation part 22a on the upstream side of the flow of the refrigerant (air) and the refrigerant (air). The battery cell (first battery cell) 20 is configured to have a battery unit (first battery unit) 2 in which a plurality of battery cells (first battery cells) 20 are stacked in close contact in the thickness direction of the power generation element.
Thereby, even in the assembled battery, heat can be radiated using the heat radiating part 22a which is a part of the sealing part 22, and a space in which the refrigerant (air) flows between the adjacent battery cells (first battery cells) 20 can be obtained. There is no need to provide it, and weight reduction and cost reduction can be achieved.

(6) A battery case 5 having a refrigerant inlet (air inlet) 7a on one side and a refrigerant outlet (air outlet) 7b on the other side facing the one side,
The flow direction (arrow) of the refrigerant | coolant (air) which the said thermal radiation part 22a, 32a, 42a flows toward the said refrigerant | coolant discharge port (air discharge port) 7b from the said refrigerant | coolant inlet (air inlet) 7a in the said battery case 5 X), a plurality of battery units (first to third battery units) 2, 3, and 4 are arranged in series, and battery units (on the downstream side of the refrigerant (air) flow) The third battery unit (4) is configured to increase the contact area between the heat radiation part 42a and the refrigerant (air).
Thereby, even if the refrigerant (air) temperature rises due to heat exchange with the battery cell (first battery cell 20) arranged on the upstream side, in the battery cell (third battery cell 40) arranged on the downstream side. Since the amount of heat radiation is improved, variation in battery cell temperature can be suppressed and the entire assembled battery 1 can be cooled uniformly.

(Example 2)
The assembled battery of Example 2 is an example in which a plurality of battery units are arranged in parallel with respect to the refrigerant flow.

First, the configuration will be described.
12 is a perspective view showing the inside of the assembled battery of Example 2. FIG. FIG. 13 is a plan view showing the inside of the assembled battery of Example 3. FIG. Hereinafter, based on FIG.12 and FIG.13, the structure of the assembled battery of Example 2 is demonstrated.

  As shown in FIG. 12, the assembled battery 1 </ b> A according to the second embodiment includes a battery case 10 and four third battery units 4.

  The battery case 10 is a housing that houses the four third battery units 4,... And is disposed in the outer case 101 of the cooling device 100 as shown in the first embodiment. As shown in FIG. 12, the battery case 10 has an air introduction port 11a formed on one side surface 10a in the longitudinal direction and an air discharge port 11b formed on the other side surface 10b in the longitudinal direction. Here, as shown in FIG. 13, the air inlet port 11a and the air outlet port 11b are arranged diagonally when viewed in plan.

  When the four third battery units 4,... Are built in the battery case 10, the flow direction of the air in which the heat radiating portion 42 a in each battery unit 4 flows from the air inlet 11 a toward the air outlet 11 b ( They are arranged in a parallel state so as to intersect the direction indicated by the broken line arrow Y in FIG.

  In addition, air is introduced into the battery case 10 on one side (upper side of each third battery unit 4 in FIG. 13) that is orthogonal to each heat radiation part 42a of the four third battery units 4,. An inflow-side refrigerant flow path 12a continuous from the port 11a is formed. Further, on the other side of the four third battery units 4,... Orthogonal to the heat radiating portions 42a (on the lower side of each third battery unit 4 in FIG. 13), a discharge-side refrigerant that continues to the air discharge port 11b. A flow path 12b is formed.

And the flow path area of this inflow side refrigerant flow path 12a becomes small toward the downstream (right side in FIG. 13) of the flow of air. That is, the third battery unit 4 gradually approaches one side surface 10c in the short direction of the battery case 10 as it goes downstream of the air flow.
Moreover, the flow path area of the discharge-side refrigerant flow path 12b becomes larger toward the downstream side of the air flow. That is, the third battery unit 4 gradually moves away from the other side surface 10d in the short direction of the battery case 10 as it goes downstream of the air flow.

Next, the uniform cooling operation in the second embodiment will be described with reference to FIG.
In Example 2, the air that has flowed into the battery case 10 from the air inlet port 11a flows in the longitudinal direction of the battery case 10 (the direction indicated by the arrow A) along the inflow-side refrigerant flow path 12a.

  On the other hand, the four third battery units 4,... Are arranged so that the heat radiating portion 42a is orthogonal to the direction of the arrow A, and the third battery unit 4 becomes a battery as it goes downstream of the air flow. The case 10 gradually approaches one side surface 10c in the short direction. That is, the 3rd battery unit 4 will protrude in steps with respect to the flow of air.

  Therefore, the air flowing through the inflow side refrigerant flow path 12a collides with the longitudinal side surface 40a of the third battery unit 4 and enters a gap between the adjacent third battery units 4. And it flows along the heat radiating part 42a protrudingly formed from this longitudinal direction side surface 40a, and flows into the discharge side refrigerant flow path 12b. Furthermore, if it flows in the longitudinal direction (direction shown by arrow B) of the battery case 10 along the discharge side refrigerant flow path 12b, it flows out of the battery case 10 from the air discharge port 11b.

  Thus, when the air flows from the inflow side refrigerant flow path 12a to the discharge side refrigerant flow path 12b, the heat radiating portion 42a comes into contact with the air, and heat can be radiated from each third battery unit 4.

  At this time, the third battery unit 4 gradually approaches one side surface 10c in the short direction of the battery case 10 while the other side surface in the short direction of the battery case 10 approaches the downstream side of the air flow. Gradually away from 10d.

  Therefore, the plurality of third battery units 4 are arranged in a state where the positions of the adjacent third battery units 4 are shifted. Thereby, the flow volume dispersion | variation in the air flow in the battery case 10 can be improved, and the temperature dispersion | variation in each 3rd battery unit 4 can be made small. As a result, the battery life of the assembled battery 1A can be improved.

  That is, in the assembled battery of Example 2, the effects listed below can be obtained.

(7) A refrigerant introduction port (air introduction port) 11a is provided on one side surface (one side surface in the longitudinal direction) 10a, and a refrigerant discharge port is provided on the other side surface (the other side surface in the longitudinal direction) 10b facing the one side surface 10a. A battery case 10 having an (air discharge port) 11b;
In the battery case 10, the heat radiating portion 42a flows in the flow direction (broken arrow Y) of the refrigerant (air) flowing from the refrigerant inlet (air inlet) 11a toward the refrigerant outlet (air outlet) 11b. A plurality of battery units (third battery units) 4,... Are arranged in parallel so as to intersect with each other, and are orthogonal to the heat radiation portion 42 a of the plurality of battery units (third battery units) 4,. An inflow side refrigerant flow path 12a continuous from the refrigerant introduction port (air introduction port) 11a is formed on one side, and is orthogonal to the heat radiation part 42a of the plurality of battery units (third battery units) 4,. A discharge-side refrigerant flow path 12b that is continuous with the refrigerant discharge port (air discharge port) 11b is formed on the other side.
The flow area of the inflow side refrigerant flow path 12a is reduced as it goes to the downstream side of the flow of the refrigerant (air),
The flow path area of the discharge-side refrigerant flow path 12b is configured to increase toward the downstream side of the flow of the refrigerant (air).
Thereby, the flow volume dispersion | variation in the air flow in the battery case 10 can be improved, and the temperature dispersion | variation in each 3rd battery unit 4 can be made small.

  As described above, the cooling structure and the assembled battery of the battery cell according to the present invention have been described based on the first embodiment and the second embodiment. However, the specific configuration is not limited to this embodiment, and the scope of the claims is as follows. Design changes and additions are allowed without departing from the spirit of the invention according to each claim.

In the heat radiating part 22a in the first battery cell 20 of the first embodiment, an example is shown in which the projecting dimension from the longitudinal side surface 20a of the first battery cell 20 is gradually increased toward the downstream side of the air flow. However, the present invention is not limited to this. For example, like the battery cell 50A shown in FIG. 14A, the projecting dimension of the heat radiating part 51 from the battery cell 50A is gradually increased toward the downstream side of the air flow. You may round so that 51 may curve.
As a result, as shown in FIG. 14 (b), even if the contact area between the heat radiating portion 51 and the air is increased, the heat radiating portion 51 is placed inside the air passage 8 without increasing the cross-sectional area of the air passage 8. Can fit in.

Furthermore, in Example 1, the heat radiating part 32a in the second battery cell 30 and the heat radiating part 42a in the third battery cell 40 are three-dimensionally shaped toward the downstream side of the air flow, so that the heat radiating part 32a or The example which enlarges the contact area of the thermal radiation part 42a and air was shown. In particular, in the first embodiment, an example in which the bending angle at the bent portion α or the like is 90 ° is shown.
However, in addition to the bent shape shown in the first embodiment, for example, the bent angle at the bent portion may be less than 90 ° (about 45 °), and the cross-sectional shape of the heat radiating portion may be a so-called triangular shape. Further, two or more bent portions may be provided.

  Further, as in the battery cell 50B shown in FIG. 15, the bending direction in the bent portion may not be constant, and the heat radiating portion 52 may be bent in a bellows shape. At this time, the contact area between the heat radiation part 52 and the air can be increased by gradually increasing the bending height toward the downstream side of the air flow.

Further, as in the battery cell 50C shown in FIG. 16 (a), the projecting dimension of the heat radiating portion 53 from the longitudinal side surface 50Ca of the battery cell 50C is gradually increased toward the downstream side of the air flow, and the air flow. You may bend from bending part (beta) 1, (beta) 2 along.
Even in this case, as shown in FIG. 16 (b), the heat dissipation portion 53 is connected to the air passage without increasing the cross-sectional area of the air passage 8 while increasing the contact area between the heat dissipation portion 53 and the air. 8 can be accommodated.

And you may form multiple protrusion part 54a from which the protrusion dimension becomes large gradually toward the downstream of the flow of air, like the battery cell 50D shown in FIG. By increasing the protruding dimension of the protruding portion 54a, the contact area between the heat radiating portion 54 and air can be increased on the downstream side.
In addition, in FIG. 17, although the protrusion part 54a becomes what is called a hemispherical dome shape, it is not restricted to this shape. For example, an oval shape that does not inhibit the flow of air may be used.

  In each of the above embodiments, air is used as the refrigerant. However, the present invention is not limited to this, and water, antifreeze liquid, gas refrigerant, or the like may be used as long as a flow is generated. Either may be sufficient.

  Further, as a method of supplying air as the refrigerant toward the heat radiating portion, in addition to forced convection using the exhaust fan 104 as shown in the first embodiment, for example, traveling wind generated when the vehicle travels is used. It may be introduced and used.

DESCRIPTION OF SYMBOLS 1 assembled battery 2 1st battery unit 20 1st battery cell 20a Longitudinal side surface 21 Battery exterior material 22 Sealing part 22a Heat dissipation part 23a Positive electrode tab 23b Negative electrode tab 3 Second battery unit 30 Second battery cell 30a Longitudinal side surface 31 Battery Exterior material 32 Sealing portion 32a Heat dissipation portion 33a Positive electrode tab 33b Negative electrode tab 4 Third battery unit 40 Third battery cell 40a Longitudinal side surface 41 Battery exterior material 42 Sealing portion 42a Heat dissipation portion 43a Positive electrode tab 43b Negative electrode tab 5 Battery case 5a Lower housing 5b Upper housing 5c Spacer base 6 Spacer 7a Air inlet (refrigerant inlet)
7b Air outlet (refrigerant outlet)
8 Airways

Claims (7)

A battery sheathing material that wraps the power generation element;
Formed by heat-sealing the periphery of the battery exterior material, and includes a sealing portion that encloses the power generation element inside the battery exterior material,
The sealing portion has a heat radiating portion extending along a flow direction of the refrigerant flowing outside the battery exterior material,
The cooling structure of the battery cell, wherein a contact area between the heat radiation part on the downstream side and the refrigerant is made larger than a contact area between the heat radiation part on the upstream side of the flow of the refrigerant and the refrigerant. In the cooling structure of the battery cell according to claim 1,
The downstream side of the refrigerant flow of the heat radiating portion is three-dimensionally molded so that the contact area between the heat radiating portion and the refrigerant is larger on the downstream side than on the upstream side of the refrigerant flow. A cooling structure for a battery cell. In the cooling structure of the battery cell according to claim 2,
By bending the heat dissipating part from a bent part extending along the flow direction of the refrigerant, the contact area between the heat dissipating part and the refrigerant is stepped on the downstream side from the upstream side of the refrigerant flow. The battery cell cooling structure is characterized by being made large. In the cooling structure of the battery cell according to claim 3,
A cooling structure for a battery cell, wherein a plurality of the bent portions are provided, the heat radiating portions are bent at 90 ° at each bent portion, and the bending direction is made constant. A battery outer packaging material that wraps a flat power generation element, and an outer periphery of the battery outer packaging material are formed by projecting in a direction orthogonal to the thickness direction of the power generation element by heat-sealing the outer surface of the battery outer packaging material. A heat dissipating part extending along the flow direction of the flowing refrigerant, and a sealing part enclosing the power generating element inside the battery exterior material,
In the thickness direction of the power generation element, a battery cell having a larger contact area between the heat radiation part on the downstream side and the refrigerant than the contact area between the heat radiation part on the upstream side of the refrigerant flow and the refrigerant is provided. A battery pack comprising a plurality of battery units stacked in close contact with each other. The assembled battery according to claim 5,
A battery case having a refrigerant inlet on one side and a refrigerant outlet on the other side facing the one side,
In the battery case, a plurality of battery units are arranged in series so that the heat radiating portion follows a flow direction of the refrigerant flowing from the refrigerant introduction port toward the refrigerant discharge port, and downstream of the flow of the refrigerant. The assembled battery is characterized in that the contact area between the heat radiating part and the refrigerant is increased as the battery unit is disposed closer to the battery unit. The assembled battery according to claim 5,
A battery case having a refrigerant inlet on one side and a refrigerant outlet on the other side facing the one side,
In the battery case, a plurality of battery units are arranged in parallel so that the heat radiating portion intersects the flow direction of the refrigerant flowing from the refrigerant introduction port toward the refrigerant discharge port. On one side orthogonal to the heat radiating part of the battery unit, an inflow side refrigerant flow path continuous from the refrigerant inlet is formed, and on the other side orthogonal to the heat radiating part of the plurality of battery units, Forming a discharge-side refrigerant flow path continuous with the refrigerant discharge port;
The flow area of the inflow side refrigerant flow path is reduced as it goes downstream of the flow of the refrigerant,
The assembled battery, wherein a flow passage area of the discharge-side refrigerant flow passage is increased toward a downstream side of the refrigerant flow.