JP5169471B2 - Power storage device and vehicle - Google Patents

Description

  The present invention relates to a power storage device and a vehicle having a power storage group in which a plurality of power storage elements are stacked.

  2. Description of the Related Art A power storage device having a power storage group in which a plurality of power storage elements are electrically connected is known as a drive power source or auxiliary power source for a hybrid vehicle or an electric vehicle. As this type of power storage device, Patent Document 1 discloses a battery module in which rectangular power storage elements and partition walls (spacers) are alternately stacked. With the partition, the interval between the adjacent power storage elements can be kept constant.

On the end surface of the partition wall, an uneven portion for forming a moving path for the refrigerant flowing along the outer surface of the power storage element is formed. The partition wall may be made of a resin from the viewpoint of ease of molding and cost reduction.
JP 2007-48750 A

  However, when the power storage element generates heat due to overcharge or overdischarge, the heat of the power storage element may be transferred to the partition wall and thermally deformed. Therefore, the interval between adjacent power storage elements cannot be kept constant.

  Therefore, an object of the present invention is to prevent thermal deformation of a spacer member disposed between adjacent power storage elements.

In order to solve the above problems, a power storage device according to the present invention includes (1) a power storage group in which power storage elements each having a power generation element housed in a case are stacked, and a spacer member disposed between adjacent power storage elements. The spacer member includes a spacer main body and a plurality of protrusions that form a movement path of a refrigerant that flows along the outer surface of the case, and at least one of the plurality of protrusions includes the protrusion The heat-resistant part having a melting point higher than that of the spacer main body and a non-heat-resistant part having a melting point lower than that of the heat-resistant part. The non-heat-resistant part is more than the heat-resistant part before the spacer member is assembled between the power storage elements. It is formed so as to protrude toward the case side, and is formed of a material that is more easily compressed in the stacking direction of the power storage element than the heat-resistant portion . When compressive force is applied to the power storage group in the stacking direction of the power storage elements, the non-heat resistant part has a larger amount of compressive deformation than the heat resistant part by the amount of protrusion. Therefore, the variation in the applied pressure applied to the case can be suppressed.

  (2) In the configuration of (1), the at least one protrusion may be constituted by the heat-resistant portion and a non-heat-resistant portion made of the same material as the spacer body portion. Since the heat-resistant portion is formed only on a part of the protruding portion, the cost can be reduced.

( 3 ) In the configuration of (1) or (2) , when viewed from the stacking direction of the power storage elements, the heat-resistant portion is provided at a position corresponding to the center position of the case. Thereby, a heat-resistant part can be made to contact the area | region which becomes the easiest to expand | swell in a case at the time of a temperature rise. Therefore, the thermal deformation of the spacer member can be effectively suppressed.

( 4 ) In the configurations of (1) to ( 3 ), the heat-resistant portion is provided at positions corresponding to the four corners of the case when viewed from the stacking direction of the power storage elements. Thereby, the thermal deformation of the spacer member can be effectively suppressed.

( 5 ) In the configurations of (1) to ( 4 ), the spacer main body portion is formed with an opening penetrating in the stacking direction of the power storage elements, and the heat-resistant portion is inserted into the opening portion. And protrudes from the opening. Thereby, the spacer member provided with the heat-resistant function can be manufactured easily.

  According to the present invention, it is possible to make the thermal deformation of the spacer member arranged between the adjacent power storage elements difficult to occur.

Examples of the present invention will be described below.
Example 1
The configuration of the power storage device of this embodiment will be described in detail. FIG. 1 is a perspective view of the power storage device. FIG. 2 is an exploded perspective view of the power storage module. FIG. 3 is an exploded perspective view of the power storage device, with the intake and exhaust chambers omitted. The X axis, the Y axis, and the Z axis are three axes that are orthogonal to each other. The power storage device of the present embodiment can be used for driving an electric vehicle, a hybrid vehicle, a fuel cell vehicle or an auxiliary power source.

  In these drawings, the power storage device 1 includes a power storage module (power storage group) 12A in which battery cells (power storage elements) 11 are stacked in the X-axis direction, and a power storage module (power storage group) 12B in which battery cells 11 are stacked in the X-axis direction. Including. The power storage modules 12A and 12B are juxtaposed in the Y-axis direction.

  The battery cell 11 has a square shape and includes a power generation element 15. As shown in FIG. 4, the power generation element 15 includes a positive electrode body 28, a negative electrode body 13, and a separator 14 disposed between the positive electrode body 28 and the negative electrode body 13. FIG. 4 is a schematic diagram of the power generation element 15. Here, the positive electrode body 28 includes a current collector and a positive electrode layer formed on the surface of the current collector. The positive electrode layer can be formed on one side or both sides of the current collector. The positive electrode layer is a layer containing an active material, a conductive agent, or the like corresponding to the positive electrode.

  Moreover, the negative electrode body 13 is comprised by the electrical power collector and the negative electrode layer formed in the surface of an electrical power collector. The negative electrode layer can be formed on one side or both sides of the current collector. The negative electrode layer is a layer containing an active material, a conductive agent, or the like corresponding to the negative electrode. The power generation element 15 is housed in a state where it is wound inside the battery case 41.

  Note that an electrode (a so-called bipolar electrode) in which a positive electrode layer is formed on one surface of the current collector and a negative electrode layer is formed on the other surface of the current collector can also be used.

Here, when the battery cell 11 is a nickel-hydrogen battery, nickel oxide is used as the active material of the positive electrode layer, and MmNi _(5-xyz) Al _x Mn is used as the active material of the negative electrode layer. A hydrogen storage alloy such as _y Co _z (Mm: Misch metal) can be used. When the battery cell 11 is a 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. As the conductive agent, acetylene black, carbon black, graphite, carbon fiber, or carbon nanotube can be used.

  A protruding positive electrode terminal 11 </ b> A and a negative electrode terminal 11 </ b> B are provided side by side in the Y-axis direction on one end surface of the battery cell 11 in the Z-axis direction. The battery cells 11 adjacent in the X-axis direction are arranged such 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. Further, the battery cells 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 destroyed when the internal pressure of the battery cell 11 is increased by the gas generated during overcharge or the like. Thereby, the gas inside the battery cell 11 is released to the outside of the battery cell 11, and an increase in the internal pressure of the battery cell 11 can be suppressed.

  A spacer member 13 is disposed between the battery cells 11 adjacent in the X-axis direction. End plates 19A are provided at both ends in the X-axis direction of the power storage module 12A. The upper restraint band 16A has a bent portion 160A in which both end portions are bent in the vertical direction. The upper restraining band 16A extends in the X-axis direction along the surface on the side where the terminals 11A and 11B are located on the outer surface of the power storage module 12A. The bending portion 160A of the upper restraining band 16A extends in the Z-axis direction along the end surface of the end plate 19A in the X-axis direction, and is fixed to the end plate 19A.

  The lower restraint band 17A has a bent portion 170A in which both end portions are bent in the vertical direction. The lower restraint band 17A extends in the X-axis direction along the surface opposite to the surface on which the terminals 11A and 11B are located on the outer surface of the power storage module 12A. The bent portion 170A of the lower restraint band 17A extends in the Z-axis direction along the end surface of the end plate 19A in the X-axis direction, and is fixed to the end plate 19A. The lower restraint band 17A is provided in a pair with the upper restraint band 16A.

  The bent portions 160A and 170A partially overlap each other in the X-axis direction, and the overlapped portions are riveted to the end plate 19A, whereby the upper restraint band 16A and the lower restraint band 17A are integrated to form the end plate 19A. Can be fixed to. As a result, the power storage module 12A can be compressed in the X-axis direction.

  A foot portion 190A is formed at the lower end of one end surface of the end plate 19A in the Y-axis direction. The foot portion 190A protrudes in the Y-axis direction with respect to the power storage module 12A. The foot portion 190A is placed on a lower case (not shown). A through hole 191A is formed in the foot portion 190A. The lower case and the foot portion 190A can be fixed by fastening a fastening bolt (not shown) in the through hole 191A.

  End plates 19B are provided at both ends in the X-axis direction of the power storage module 12B. The upper restraint band 16B has a bent portion 160B in which both end portions are bent in the vertical direction. The lower restraint band 17B has a bent portion 170B in which both end portions are bent in the vertical direction. Since the structure and assembly method of the upper restraint band 16B are the same as those of the upper restraint band 16A, detailed description thereof is omitted. Since the configuration and assembling method of the lower restraint band 17B are the same as those of the lower restraint band 17A, detailed description thereof is omitted.

  A foot 190B is formed at the lower end of one end face of the end plate 19B in the Y-axis direction. The foot portion 190B protrudes in the Y-axis direction with respect to the power storage module 12B. The foot 190B is placed on a lower case (not shown). A through hole (not shown) is formed in the foot portion 190B. The lower case and the foot 190B can be fixed by fastening a fastening bolt (not shown) to the through hole.

  The power storage modules 12A and 12B are accommodated in a battery pack including an upper case and a lower case (not shown). An insulating sheet 24 is disposed between the lower case and the power storage modules 12A and 12B. The insulating sheet 24 can prevent the electricity storage modules 12A and 12B from leaking.

  An intake chamber 31 is attached to one end side of the power storage module 12A in the Y-axis direction. An exhaust chamber 32 is attached to one end side of the power storage module 12B in the Y-axis direction.

  Next, the configuration of the spacer member 13 will be described. The spacer member 13 is disposed between the battery cells 11 adjacent in the X-axis direction. As shown in FIG. 2, the spacer member 13 includes a spacer main body 130. The spacer main body 130 is formed in a flat plate shape. The spacer main body 130 is made of resin.

  A foot 130X is formed at the lower end of one end surface of the spacer main body 130 in the Y-axis direction. The foot portion 130X is placed on the lower case. A through hole 130 </ b> Y is formed in the foot part 130 </ b> X of some spacer main body parts 130. The foot 130X can be fixed to the lower case by fastening a fastening bolt (not shown) to the through hole 130Y.

  First to fifth protrusions 131 to 135 are arranged side by side in the Z-axis direction on both end faces of the spacer main body 130 in the X-axis direction (stacking direction of the battery cells 11). The intervals between the first to fifth protrusions 131 to 135 are constant. Each of the first to fifth protrusions 131 to 135 extends in the Y-axis direction, and the dimensions in the Y-axis direction are the same. The XZ cross sections of the first to fifth protrusions 131 to 135 are rectangular.

  The first protrusion 131 is located on the uppermost side among the first to fifth protrusions 131 to 135. As shown in FIGS. 2 and 5, the first protrusion 131 includes a non-heat resistant portion 131A and heat resistant portions 131B located at both ends of the non-heat resistant portion 131A in the Y-axis direction. FIG. 5 is a front view of the battery cell 11 when viewed from the X-axis direction. However, in order to facilitate the following description, the first to fifth protrusions 131 to 135 are projected on the outer surface of the battery cell 11 and illustrated.

  The heat resistant part 131B is made of a material having a higher melting point than the non-heat resistant part 131A. Resin can be used for the non-heat resistant portion 131 </ b> A, as with the spacer main body 130. A thermosetting resin or ceramic can be used for the heat-resistant portion 131B. By forming only a part of the first protrusion 131 with a heat-resistant material, the cost can be reduced as compared with the case where the entire first protrusion 131 is formed with a heat-resistant material.

  As illustrated in FIG. 6A, the non-heat resistant portion 131A protrudes to the outer surface side of the battery case 41 with respect to the heat resistant portion 131B. 6A illustrates the spacer member 13 positioned between the battery cells 11, and illustrates a state before the upper restraint band 16A and the lower restraint band 17A are attached. The non-heat resistant portion 131 </ b> A is in contact with the outer surface of the battery case 41, and the heat resistant portion 131 </ b> B is not in contact with the outer surface of the battery case 41.

  6A, when the upper restraint band 16A and the lower restraint band 17A are fixed to the end plate 19A, the power storage module 12A is compressed in the X-axis direction. For this reason, the non-heat resistant portion 131A that is in contact with the outer surface of the battery case 41 is sandwiched between the battery case 41 and compressed in the X-axis direction. As illustrated in FIG. 6B, when the deformation amount of the non-heat resistant portion 131A reaches a predetermined amount, the heat resistant portion 131B comes into contact with the outer surface of the battery case 41, and the entire heat resistant portion 131B and the non heat resistant portion 131A are compressed.

  The heat resistant part 131B is made of a material that is less likely to deform in the X-axis direction than the non-heat resistant part 131A. Therefore, the heat resistant portion 131B can apply a large reaction force to the battery case 41 with a smaller deformation amount than the non-heat resistant portion 131A. As a result, it is possible to suppress variations in pressure applied to the battery case 41 of the non-heat resistant part 131A and the heat resistant part 131B. Thereby, the performance of the power generation element 15 can be maintained.

  The amount of protrusion of the non-heat-resistant portion 131A with respect to the heat-resistant portion 131B varies when the upper restraint band 16A and the lower restraint band 17A are fixed to the end plate 19A. It can set suitably from a viewpoint of suppressing.

  The second protrusion 132 is positioned below the first protrusion 131. The second protrusion 132 is formed of the same material as the non-heat resistant part 131A of the first protrusion 131. When the upper restraint band 16A and the lower restraint band 17A are fixed to the end plate 19A, the second protrusion 132 is clamped by the battery case 41 and presses the battery cell 11 with the same pressure as the first protrusion 131. To do.

  A space between the first protrusion 131 and the second protrusion 132 serves as a movement path through which the refrigerant moves. The cooling air supplied from the intake chamber 31 moves along this movement path, and cools the power generation element of the battery cell 11. Thereby, deterioration of the battery cell 11 can be suppressed.

  The third protrusion 133 is located below the second protrusion 132. The third protrusion 133 is composed of a heat-resistant part 133B and non-heat-resistant parts 133A located at both ends in the Y-axis direction of the heat-resistant part 131B. The heat resistant part 133B is made of a material having a higher melting point than the non-heat resistant part 133A. Resin can be used for the non-heat resistant portion 133 </ b> A as in the spacer main body portion 130. A thermosetting resin or ceramic can be used for the heat resistant portion 133B. By forming only a part of the third protrusion 133 with a heat resistant material, the cost can be reduced as compared with the case where the entire third protrusion 133 is formed with a heat resistant material.

  As illustrated in FIG. 7A, the non-heat resistant portion 133A protrudes to the outer surface side of the battery case 41 with respect to the heat resistant portion 133B. FIG. 7A illustrates the spacer member 13 positioned between the battery cells 11 and illustrates a state before the upper restraint band 16A and the lower restraint band 17A are attached. The non-heat resistant portion 133A is in contact with the outer surface of the battery case 41, and the heat resistant portion 133B is not in contact with the outer surface of the battery case 41.

  When the upper restraint band 16A and the lower restraint band 17A are fixed to the end plate 14 in the state illustrated in FIG. 7A, the power storage module 12A is compressed in the X-axis direction. Therefore, the non-heat resistant portion 133A that is in contact with the outer surface of the battery case 41 is compressed by the battery case 41 and compressed in the X-axis direction. As shown in FIG. 7B, when the deformation amount of the non-heat resistant portion 133A reaches a predetermined amount, the heat resistant portion 133B comes into contact with the outer surface of the battery case 41, and the entire heat resistant portion 133B and the non heat resistant portion 131A are compressed.

  The heat resistant portion 133B is made of a material that is less likely to be deformed in the X-axis direction than the non-heat resistant portion 133A. Therefore, the heat resistant part 133B can apply a large reaction force to the battery case 41 with a smaller deformation amount than the non-heat resistant part 133A. As a result, variations in the pressure applied to the battery case 16 by the non-heat resistant part 133A and the heat resistant part 133B can be suppressed.

  The amount of protrusion of the non-heat-resistant part 133A with respect to the heat-resistant part 133B is applied to the battery case 16 from the heat-resistant part 133B and the non-heat-resistant part 133A, respectively, when the upper restraint band 16A and the lower restraint band 17A are fixed to the end plate 19A. It can be set as appropriate from the viewpoint of reducing the pressure difference.

  A space sandwiched between the second protrusion 132 and the third protrusion 133 serves as a refrigerant passage. The cooling air supplied from the intake chamber 31 moves along this movement path, and cools the power generation element of the battery cell 11. Thereby, deterioration of the battery cell 11 can be suppressed.

  The fourth protrusion 134 is located on the lower side of the third protrusion 133. The fourth protrusion 134 has the same configuration as the second protrusion 132. When the upper restraint band 16A and the lower restraint band 17A are fixed to the end plate 19A, the fourth protrusion 134 is clamped by the battery case 41 and presses the battery case 41 with the same pressure as the second protrusion 132. .

  A space sandwiched between the third projecting portion 133 and the fourth projecting portion 134 serves as a refrigerant passage. The cooling air supplied from the intake chamber 31 moves along this movement path, and cools the power generation element of the battery cell 11. Thereby, deterioration of the battery cell 11 can be suppressed.

  The fifth protrusion 135 is located below the fourth protrusion 134. The fifth protrusion 135 has the same configuration as the first protrusion 131. That is, the fifth protrusion 135 includes a non-heat-resistant part 135A and heat-resistant parts 135B located at both ends of the non-heat-resistant part 135A in the Y-axis direction.

  A space between the fourth protrusion 134 and the fifth protrusion 135 serves as a refrigerant passage. The cooling air supplied from the intake chamber 31 moves along this movement path, and cools the power generation element of the battery cell 11. Thereby, deterioration of the battery cell 11 can be suppressed.

  In the configuration described above, the heat-resistant portion 131B of the first protrusion 131 and the heat-resistant portion 135B of the fifth protrusion 135 are in contact with the four corners of the outer surface of the battery case 41 when viewed in the X-axis direction. Thereby, a heat-resistant material can be reduced and an increase in cost can be suppressed. Further, the spacer main body 130 can be prevented from being thermally deformed, and the interval between the battery cells 11 can be kept constant.

  Further, the heat-resistant portion 133 </ b> B of the third protrusion 133 is in contact with the center of the battery case 41 as viewed in the X-axis direction. Since the central part of the battery case 41 is most easily expanded when the temperature rises, the thermal deformation of the spacer main body 130 can be effectively prevented by bringing the heat-resistant part 133B into contact with the central part. The same applies to the power storage module 12B.

  Next, a method for manufacturing the spacer member 13 will be described. First, the resin is poured into the mold, and the spacer main body 130, the non-heat resistant portion 131A of the first protrusion 131, the second protrusion 132, the non-heat resistant portion 133A of the third protrusion 133, and the fourth protrusion. 134 and the non-heat resistant part 135A of the fifth protrusion 135 are integrally formed. Openings 130A to 130E penetrating in the X-axis direction are formed in the spacer main body 130 (see FIG. 8). FIG. 8 is a perspective view of the spacer member 13.

  Next, the prismatic heat-resistant portion 131B is press-fitted into the openings 130A and 130B of the spacer body 130. The heat-resistant part 131B is fixed by being pressed against the inner surfaces of the openings 130A and 130B. Similarly, the prismatic heat-resistant portion 133 </ b> B is press-fitted into the opening 130 </ b> C of the spacer main body 130. The heat-resistant portion 133B is fixed by being pressed against the inner surface of the opening 130C. Similarly, the prismatic heat-resistant portion 135B is press-fitted into the openings 130D and 130E of the spacer main body 130. The heat-resistant part 135B is fixed by being pressed against the inner surfaces of the openings 130D and 130E.

  Thus, the spacer member 13 can be obtained simply by forming the heat-resistant portions 131B to 135B separately and press-fitting these heat-resistant portions 131B to 135B into the openings 130A to 130E. Therefore, the spacer member 13 can be easily manufactured. However, the spacer member 13 can be formed in two colors using two different molds.

(Modification)
Next, a modification of the above embodiment will be described. It is also possible to form all of the first to fifth protrusions 131 to 135 with a heat-resistant material (ceramic, thermosetting resin). In this case, the cost is higher than that in the above-described embodiment, but thermal deformation of the spacer member 13 can be prevented more effectively. Further, all of the first protrusion 131, the third protrusion 133, and the fifth protrusion 135 are formed of a heat-resistant material, and the second protrusion 132 and the fourth protrusion 134 are connected to the spacer main body 130. Similarly, it can be formed of resin.

  The first to fifth protrusions 131 to 135 may be configured as shown in FIG. FIG. 9 is a perspective view of a modified spacer member, and corresponds to FIG. In addition, the same code | symbol is attached | subjected to the part which has the same function as Example 1. FIG.

  In the drawing, the first protrusion 131 includes a non-heat resistant part 131A in which both ends in the Y-axis direction are thinned in the X-axis direction, and a heat-resistant part 131B located in the recess 1310A of the non-heat resistant part 131A. The second protrusion 132 is the same as in the first embodiment. The third protrusion 133 includes a non-heat resistant part 133A in which the central part in the Y-axis direction is thinned in the X-axis direction, and a heat-resistant part 133B located in the recess 1330A of the non-heat resistant part 133A. The fourth protrusion 134 is the same as that in the first embodiment. The fifth protrusion 135 is the same as the first protrusion 131 of this modification. According to the above-described configuration, the amount of the heat-resistant material can be reduced as compared with the above-described embodiment. Therefore, cost can be reduced.

  The 1st-5th projection parts 131-135 can also be formed in other shapes, such as a column shape.

It is a perspective view of a power storage device. It is a disassembled perspective view of an electrical storage module. It is a disassembled perspective view of an electrical storage apparatus. It is the schematic of an electric power generation element. It is a front view when a battery cell is seen from the X-axis direction. It is the schematic diagram which showed typically the operation | movement at the time of a deformation | transformation of a 1st projection part. It is the schematic diagram which showed typically the operation | movement at the time of a deformation | transformation of a 3rd projection part. It is a perspective view of a spacer member. It is a perspective view of the spacer member of a modification.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Battery cell 12A, 12B Power storage module 13 Spacer member 15 Power generation element 41 Battery case 130 Spacer main body part 131-135 1st-5th protrusion part 131B 133B 135B Heat-resistant part 131A 133A 135A Non-heat-resistant part

Claims (6)

A power storage group in which power storage elements in which power generation elements are housed are stacked, and
A spacer member disposed between adjacent power storage elements,
The spacer member has a spacer main body and a plurality of protrusions that form a movement path of a refrigerant flowing along the outer surface of the case.
At least one of the plurality of protrusions includes a heat resistant part having a higher melting point than the spacer body part and a non-heat resistant part having a lower melting point than the heat resistant part,
The non-heat-resistant portion is formed so as to protrude from the heat-resistant portion toward the case before the spacer member is assembled between the power storage elements, and is compressed in the stacking direction of the power storage elements from the heat-resistant portion. A power storage device characterized by being made of a material that can be easily processed.   The power storage device according to claim 1, wherein the at least one protrusion includes the heat-resistant portion and a non-heat-resistant portion made of the same material as the spacer main body. 3. The power storage device according to claim 1, wherein the heat-resistant portion is provided at a position corresponding to a center position of the case in the stacking direction of the power storage elements. In the stacking direction as viewed in the storage element, said refractory portion is a power storage device according to any one of claims 1 to 3, characterized in that provided in the positions corresponding to the four corners of the case. In the spacer main body, an opening that penetrates in the stacking direction of the power storage elements is formed,
Said refractory portion is inserted into the opening, the electricity storage device according to any one of claims 1 to 4, characterized in that projecting from the opening. Vehicle equipped with a power storage device according to any one of claims 1 to 5.

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