WO2013084756A1

WO2013084756A1 - Power source device, vehicle equipped with same and electricity storage device

Info

Publication number: WO2013084756A1
Application number: PCT/JP2012/080658
Authority: WO
Inventors: 河野　剛
Original assignee: 三洋電機株式会社
Priority date: 2011-12-10
Filing date: 2012-11-27
Publication date: 2013-06-13

Abstract

[Problem] To maintain substantially uniform temperature for stacked rectangular cells which constitute a stacked-cell body. [Solution] A power source device is provided with a stacked-cell body (10) constituted by a plurality of stacked rectangular cells (11), metallic endplates (5) arranged at both end faces of the stacked-cell body (10) to hold said stacked-cell body (10) in the stacking direction, insulating separators (12) arranged between each of the rectangular cells (11), insulating end separators (13) arranged to insulate the rectangular cells (11) positioned at both ends of the stacked-cell body (10) from said endplates (5), a cooling plate (21) thermally coupled to one surface of said stacked-cell body (10) to cool down the stacked-cell body, and a flexible thermal conducting sheet (22) arranged between said stacked-cell body (10) and said cooling plate (21). The power source device can include spacers (13A, 13B, 13C) which prevent the thermal coupling between said cooling plate (21) and said endplate (5) through said thermal conducting sheet (22).

Description

Power supply device, vehicle including the same, and power storage device

The present invention relates to a power supply device in which a plurality of prismatic battery cells are stacked, a vehicle including the power supply device, and a power storage device, and more particularly, a motor that is mounted on an electric vehicle such as a hybrid vehicle, a fuel cell vehicle, an electric vehicle, and an electric motorcycle. Of prismatic battery cells constituting a power supply device that supplies power to a large-current power supply used in power storage devices for home use, factories, etc. Related to improvements.

The power supply device can increase the output voltage by connecting a large number of rectangular battery cells in series, and can increase the charge / discharge current by connecting them in parallel. Therefore, a high-current, high-output power supply device used for the power supply of a motor that runs an automobile or the like has a plurality of battery cells connected in series to increase the output voltage. A power supply device used for this type of application has a metal end plate fastened with a bind bar as a battery stack in which a plurality of rectangular battery cells are stacked.

The prismatic battery cell used as a power supply device needs to be cooled because it may generate heat due to charge and discharge and deteriorate. For this reason, conventionally, a cooling air passage is provided between adjacent prismatic battery cells of the battery stack, and air cooling is performed to cool the prismatic battery cells from the side by heat exchange with the cooling air. The method was adopted. Further, in recent years, a refrigerant cooling system that performs cooling more efficiently by placing a battery stack on the upper surface of a cooling plate in which a refrigerant is circulated and thermally connecting the bottom surface of the rectangular battery cell and the cooling plate. Has also been developed (see, for example, Patent Document 1). An example of a battery stack using such a refrigerant cooling system is shown in FIG. Note that the thermal coupling or the thermal coupling state referred to here indicates a state where the two members are in contact with each other so that heat transfer occurs.

18 includes a plurality of separators 920. The assembled battery 911 illustrated in FIG. The separator 920 is interposed between the rectangular battery cells 910 to insulate them. Each square battery cell 910 is sandwiched between separators 920 on both sides. Therefore, each separator 920 is formed in a size and shape that can cover the rectangular battery cell 910. Further, metal end plates are arranged on both end faces of the assembled battery 911. The assembled battery 910 is fastened by fixing the end plates at both ends with a bind bar.

On the other hand, the separator 920 is in a state where the upper electrode portion and the bottom portion of the rectangular battery cell 910 are opened. Further, the assembled battery 911 has a heat conductive sheet 940 disposed at the bottom of the stacked rectangular battery cells 910 and a cooling plate 912 disposed at the bottom of the heat conductive sheet 940. Thereby, each square battery cell 910 can release heat to the cooling plate 912 side via the heat conductive sheet 940. As a result, the plurality of prismatic battery cells 910 can stabilize the temperature.

However, when the present inventors conducted a test, in this cooling method, the prismatic battery cells located on the end faces of the battery stack are particularly easily cooled compared to other prismatic battery cells located in the middle portion. Thus, it has been found that a temperature distribution occurs in the stacking direction of the rectangular battery cells. This is because, in the battery laminate 811 shown in the side view of FIG. 14, the rectangular battery cell 810A located on the end face is adjacent to the metal end plate 830 via the end separator 821, as shown in the sectional view of FIG. The metal end plate 830 is thermally coupled to the cooling plate 812, which is considered to cause heat dissipation from the end face side of the prismatic battery cell 810A.

In particular, the heat conductive sheet 840 interposed between the bottom surface of the battery stack 811 and the cooling plate 812 is pressed in order to eliminate the gap between the bottom surface of the rectangular battery cell 810 and the cooling plate 812 to enhance thermal coupling. The elastic member which is easy to deform is used. For this reason, when the pressing force to the cooling plate 812 of the battery laminated body 811 is small, as shown in the expanded sectional view of FIG. 16, the deformation amount of the heat conductive sheet 840 is also small. However, when the pressing force increases, the heat conductive sheet 840 is compressed and the amount of deformation increases as shown in the enlarged cross-sectional view of FIG. 17, and as a result, the heat conductive sheet 840 extends in the stacking direction of the rectangular battery cells 810. End up. For this reason, the end plate 830 and the cooling plate 812 disposed on the end surface of the battery stack 811 are thermally connected to each other by the stretched heat conductive sheet 840, and this is combined with the fact that the end plate 830 is made of metal. As shown by the arrows in the cross-sectional view of FIG. 15, the heat of the prismatic battery cell 810 A is taken from the side surface from the end face with which the end plate 830 is in contact. There was a problem of going too far. As shown in the graph of the temperature distribution in the stacking direction shown superimposed on the battery stack of FIG. 14, the temperature of the prismatic battery cells 810 A on both end faces of the battery stack 811 drops more than the other prismatic battery cells 810, A temperature difference is generated depending on the position of the prismatic battery cell 810, and this non-uniform temperature affects the life and performance of the assembled battery.

JP 2011-34775 A

The present invention has been made to solve such conventional problems. A main object of the present invention is to provide a power supply device that maintains a substantially uniform temperature of stacked rectangular battery cells, a vehicle including the power supply device, and a power storage device.

Means for Solving the Problems and Effects of the Invention

In order to achieve the above object, according to the power supply device of the first aspect of the present invention, a battery stack formed by stacking a plurality of rectangular battery cells and the battery stack are fastened in the stacking direction. Insulates the end plate made of metal disposed on both end faces, the separator having insulating properties disposed between the square battery cells, and the square battery cell located at both ends of the battery stack and the end plate. Insulating end separators arranged for cooling, cooling plates for cooling by being thermally coupled to one surface of the battery stack, and flexibility arranged between the battery stack and the cooling plates It is a power supply device provided with the heat conductive sheet which has, The spacer part which inhibits the thermal coupling with the said cooling plate and the said end plate through the said heat conductive sheet can be provided.
Thereby, the power supply device can prevent the prismatic battery cells adjacent to the end plate from being cooled via the end plate by suppressing the thermal contact between the end plate and the heat conductive sheet. That is, heat dissipation from the end plate to the cooling plate can be prevented, and heat can be radiated only by the cooling plate via the heat conductive sheet on which the battery stack is placed, so that the battery stack can be at a substantially uniform temperature. it can.

Further, according to the power supply device according to the second aspect, the spacer portion is integrally formed at the bottom portion of the end separator, the spacer portion is provided toward the bottom portion of the end plate, and the cooling plate via the heat conductive sheet is provided. The spacer portion can be disposed on the end plate, and the end plate can be placed on the spacer portion.
As a result, the end plate can suppress the thermal contact between the cooling plate and the end plate via the heat conductive sheet by the spacer portion formed integrally with the end separator. Heat can be reduced.

Furthermore, according to the power supply device which concerns on a 3rd side surface, the said spacer part thicker than the thickness of the said end separator between the said square battery cell and the said end plate can be provided.
As a result, the heat transfer amount decreases in proportion to the distance by increasing the thickness of the spacer portion while suppressing the extension of the battery stack in the stacking direction, so that the heat of the adjacent rectangular battery cells passes through the end plate. And it can suppress transmitting to a cooling plate via a heat conductive sheet.

Furthermore, according to the power supply device which concerns on a 4th side surface, in order to form a space in the said spacer part, multiple protrusion pieces can be provided in the direction of the said cooling plate.
As a result, a space can be formed for each protruding piece, and since the thermal conductivity of air is small, the thermal conductivity can be reduced by the space formation, and the heat generation of the adjacent rectangular battery cells passes through the end plate to generate heat. Propagation to the cooling plate via the conductive sheet can be further suppressed.

Furthermore, according to the power supply device which concerns on a 5th side surface, the thermal conductivity of the said end separator can be made into resin lower than the said separator.
Thereby, the heat conductivity to an end plate can be reduced by reducing the heat conductivity from the adjacent square battery cell. In addition, the heat conduction to the cooling plate can be further reduced by having the spacer portion.

Furthermore, according to the power supply device which concerns on a 6th side surface, a refrigerant | coolant can be circulated through the inside of the said cooling plate.
Thereby, the square battery cell which comprises a battery laminated body can be efficiently cooled by thermally couple | bonding a part of battery laminated body with a cooling plate.

Furthermore, according to the power supply device which concerns on a 7th side surface, it can be set as the sheet | seat which can compress and deform | transform the said heat conductive sheet.
Thereby, a heat conductive sheet can compress-deform by being pressed between a square battery cell and a cooling plate, can raise an adhesion degree, and can be in a heat-bonded state efficiently.

Furthermore, the vehicle according to the eighth aspect can be provided with the power supply device described above.

Furthermore, the power storage device according to the ninth aspect can include the power supply device described above.

It is a general | schematic disassembled perspective view of the power supply device which concerns on embodiment of this invention. It is a perspective view of one battery laminated body shown in FIG. It is a block diagram which shows the flow of the refrigerant | coolant to the cooling plate of the battery laminated body shown in FIG. It is the disassembled perspective view which looked at the battery laminated body shown in FIG. 2 from the downward direction. It is a disassembled perspective view of the battery laminated body shown in FIG. It is the schematic sectional drawing which looked at the battery laminated body shown in FIG. 2 from the side surface. 1 is a perspective view showing a structure of an end separator according to Example 1. FIG. 6 is a perspective view showing a structure of an end separator according to Embodiment 2. FIG. 6 is a perspective view showing a structure of an end separator according to Embodiment 3. FIG. FIG. 3 is a schematic enlarged cross-sectional view in the stacking direction on one side end plate side of the battery stack according to Example 1; It is a block diagram which shows an example of the vehicle carrying a power supply device. It is a block diagram which shows the other example of the vehicle carrying a power supply device. It is a block diagram which shows the example applied to the power supply device for electrical storage. It is a schematic side view to the lamination direction of the battery laminated body which removed the bind bar in an experiment example. It is a schematic sectional drawing to the lamination direction by the one side end plate side of the battery laminated body in an experiment example. 4 is a schematic enlarged cross-sectional view in the stacking direction on one end plate side of the battery stack in Experimental Example 1. FIG. 6 is a schematic enlarged cross-sectional view in the stacking direction on one end plate side of the battery stack in Experimental Example 2. FIG. It is a schematic sectional drawing which shows the conventional assembled battery.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the embodiment described below exemplifies a power supply device for embodying the technical idea of the present invention, a vehicle including the power supply device, and a power storage device, and the present invention includes a power supply device, a vehicle including the power supply device, The power storage device is not specified as follows. Further, in the present specification, in order to facilitate understanding of the scope of claims, numbers corresponding to the members shown in the embodiments are indicated in the “claims” and “means for solving problems” sections. It is appended to the members shown. However, the members shown in the claims are not limited to the members in the embodiments. In particular, the dimensions, materials, shapes, relative arrangements, and the like of the constituent members described in the embodiments are not intended to limit the scope of the present invention only to the description unless otherwise specified. It is just an example. Note that the size, positional relationship, and the like of the members shown in each drawing may be exaggerated for clarity of explanation. Furthermore, in the following description, the same name and symbol indicate the same or the same members, and detailed description thereof will be omitted as appropriate. Furthermore, each element constituting the present invention may be configured such that a plurality of elements are constituted by the same member and the plurality of elements are shared by one member, and conversely, the function of one member is constituted by a plurality of members. It can also be realized by sharing. In addition, the contents described in some examples and embodiments may be used in other examples and embodiments.
(Example)

Hereinafter, a battery stack of a power supply apparatus applicable to in-vehicle use or power storage as an embodiment will be described with reference to FIGS. In these drawings, FIG. 1 is a schematic exploded perspective view of the power supply device according to the embodiment, FIG. 2 is a perspective view of one battery stack shown in FIG. 1, and FIG. 3 is a cooling of the battery stack shown in FIG. FIG. 4 is an exploded perspective view of the battery stack shown in FIG. 2 as viewed from below, FIG. 5 is an exploded perspective view of the battery stack shown in FIG. 2, and FIG. The schematic sectional drawing which looked at the battery laminated body shown in FIG.
(Power supply device 100)

As shown in the schematic exploded perspective view of FIG. 1, the external appearance of the power supply device 100 is a box shape having a rectangular upper surface. In the power supply device 100 of this embodiment, four battery stacks 10 are installed on the outer bottom case 3, and the battery stack 10 is formed by the outer upper case 1 having a U-shaped cross section and the outer bottom case 3 having a U-shaped cross section. In addition to covering, both end edges of the outer case 1 are covered with the end cover 2. Further,

flanges

4A and 4B projecting vertically are provided on both side surfaces in the longitudinal direction of the outer case 1 and the outer case 3 so as to be easily fixed when mounted on the vehicle. The flange 4A and the flange 4B are provided with screw holes to facilitate screwing using the screw holes.
(Battery laminate 10)

As shown in FIG. 2, the battery stack 10 has a substantially rectangular parallelepiped shape. The top cover 7 is disposed at the top and the cooling plate 21 is disposed at the bottom. Moreover, the battery laminated body 10 arrange | positions the end plate 5 on both end surfaces, and has arrange | positioned the bind bar 6 on both side surfaces.
(Bind bar 6)

The bind bar 6 is a member for fixing the battery stack 10 by fixing the end plates 5 on both end faces. The bind bar 6 has a substantially rectangular shape with an area substantially the same as the side surface of the battery stack 10. The bind bar 6 has a bent portion 6A in which both end surfaces of the battery stack 10 are bent substantially vertically. The bent portion 6A shown in FIG. 5 is fixed by screwing a set screw 19 into the female screw holes 5A of the end plates 5 at both ends. Thereby, the battery laminated body 10 has fastened the end plate 5 with the bind bar 6.

In addition, the bind bar 6 is fixed using a connector 8 for locking the top cover 7 at the top of the battery stack 10 and further fixing the cooling plate 21 at the bottom of the battery stack 10. The specific bind bar 6 has a locking portion 6B whose upper end portion is bent substantially vertically, and is locked to the side end portion of the top cover 7. Furthermore, the bind bar 6 has connecting pieces 6C that protrude at three locations on the lower end. As shown in FIG. 4, the connecting piece 6 C is connected to a bent portion 8 C in which the connecting tool 8 is bent substantially vertically. In the connection method, the engagement hook 6D protruding from the connection piece 6C is connected to the connection hole 8D opened in the bent portion 8C. Thereby, the battery stack 10 locks the top cover 7 by the locking portion 6B of the bind bar 6 and fixes the cooling plate 21 by the connecting piece 6C of the bind bar 6 and the bent portion 8C of the connecting tool 8. Therefore, it is fastened while achieving integration in the vertical direction.
(Cooling plate 21)

The battery stack 10 has a plurality of prismatic battery cells 11 stacked as shown in FIG. Since the square battery cell 11 generates heat by charging and discharging, it needs to be cooled. Therefore, a cooling plate 21 is disposed at the bottom of the heated battery stack 10. The cooling plate 21 is arranged to cool the heat generated by the rectangular battery cells 11 of the battery stack 10. As shown in FIG. 3, the cooling plate 21 includes a refrigerant path 23. The refrigerant path 23 is provided at two places as an entrance and exit, and is connected to a pipe meandering inside the cooling plate 21. In the cooling plate 21, the refrigerant is circulated from the cooling mechanism 20 to the refrigerant path 23 of the cooling plate 21. The refrigerant path 23 is supplied with a refrigerant such as carbon dioxide in a liquid state, vaporizes the refrigerant inside, and cools the cooling plate 21 with heat of vaporization. As a result, the plurality of rectangular battery cells 11 in the battery stack 10 are cooled by the cooling plate 21.

The cooling mechanism 20 includes a compressor 26 that pressurizes the gaseous refrigerant vaporized in the refrigerant path 23, a cooling heat exchanger 27 that cools and liquefies the refrigerant compressed by the compressor 26, and the cooling heat exchanger 27. And an expansion valve 28 for supplying the refrigerant liquefied to the refrigerant path 23. The liquid refrigerant supplied through the expansion valve 28 is vaporized in the refrigerant path 23 in the cooling plate 21, cools the cooling plate 21 with heat of vaporization, and is discharged to the cooling mechanism 20. Therefore, the refrigerant circulates through the refrigerant path 23 of the cooling plate 21 and the cooling mechanism 20 to cool the cooling plate 21. The cooling mechanism 20 cools the cooling plate 21 to a low temperature with the heat of vaporization of the refrigerant, but the cooling plate can also be cooled regardless of the heat of vaporization. The cooling plate supplies a refrigerant such as brine cooled to a low temperature to the refrigerant path, and cools the cooling plate by releasing heat to the refrigerant.

The cooling mechanism 20 controls the cooling capacity of the cooling plate 21 with a temperature sensor (not shown) that detects the temperature of the rectangular battery cells 11 in the battery stack 10. That is, when the temperature of the prismatic battery cell becomes higher than the preset cooling start temperature, the coolant is supplied to the cooling plate 21 for cooling, and when the prismatic battery cell becomes lower than the cooling stop temperature, The supply of the refrigerant is stopped, and the rectangular battery cell is controlled to a preset temperature range.
(Thermal conductive sheet 22)

The cooling plate 21 and the prismatic battery cell 11 are not in direct contact with each other, but as shown in a perspective view seen from below shown in FIG. 4, the heat conductive sheet 22 is interposed between the cooling plate 21 and the prismatic battery cell 11. It has. The bottom surface of the prismatic battery cell 11 is in an exposed state. The battery stack 10 is mounted in a state in which a deformable heat conductive sheet 22 is attached to the bottom of the exposed rectangular battery cell 11 and pressed by the cooling plate 21 from below to compress the heat conductive sheet 22. . As a result, the heat conductive sheet 22 is deformed to eliminate a gap between the prismatic battery cell 11 and the cooling plate 21, eliminate the heat insulation effect by the air layer, and efficiently transfer the heat of the prismatic battery cell 11 to the cooling plate 21. It can dissipate heat.

Furthermore, the heat conductive sheet 22 is made of a material that is insulative and excellent in heat conduction, and more preferably has a certain degree of elasticity. Examples of such a material include acrylic, urethane, epoxy, and silicone resins. By doing in this way, the cooling performance by the cooling plate 21 can be improved, electrically insulating between the battery laminated body 10 and the cooling plate 21. FIG. In particular, when the outer can of the rectangular battery cell 11 is made of metal and the cooling plate 21 is made of metal, it is necessary to insulate the battery so as not to be electrically connected to the bottom surface of the rectangular battery cell 11. Moreover, in order to maintain insulation reliably, an additional insulating film can also be interposed. For example, a rectangular battery cell can improve insulation by covering an outer can with an insulating shrink tube (heat shrink film) or the like.
(Square battery cell 11)

Here, the stacked rectangular battery cell 11 shown in FIG. 5 has a thin and substantially box shape made of a rectangular battery, and a pair of positive and negative electrode terminals 14 protrude upward at both ends of the upper surface, and between the electrode terminals 14. Is provided with a safety valve 15. The safety valve 15 is configured to open when the internal pressure of the rectangular battery cell 11 rises to a predetermined value or more, and to release the internal gas. By opening the safety valve 15, the increase in the internal pressure of the rectangular battery cell 11 can be stopped.

The unit cell constituting the rectangular battery cell is a rechargeable secondary battery such as a lithium ion secondary battery, a nickel-hydrogen battery, or a nickel-cadmium battery. In particular, when a lithium ion secondary battery is used for a thin battery, there is an advantage that the charging capacity with respect to the capacity of the entire battery stack can be increased.
(Separator 12)

Here, the rectangular battery cell 11 is made of a metal outer can. In this rectangular battery cell 11, an insulating separator 12 is interposed to prevent the outer cans of the adjacent rectangular battery cells 11 from coming into contact with each other and shorting out. Here, both surfaces of the rectangular battery cell 11 are sandwiched between two separators 12. This separator 12 is provided with a peripheral wall in which the rectangular battery cells 11 can be arranged on both side surfaces. As shown in FIG. 5, the peripheral wall covers both end surfaces and both side surfaces of the rectangular battery cell 11 with two separators 12, and includes a pair of electrode terminals 14 and a safety valve 15 disposed on the upper surface of the rectangular battery cell. It is formed so as to cover the removed part. Further, the bottom surface of the separator 12 is provided with an opening through which the bottom of the rectangular battery cell 11 can be exposed and the heat conductive sheet 22 can be disposed. Further, the separator 12 is provided with a protruding piece 12 a for insulating between the rectangular battery cell 11 and the cooling plate 21. The outer can of the square battery cell can be made of an insulating material such as plastic. In this case, the prismatic battery cell does not need to be laminated by insulating the outer can, and therefore the separator can be made of metal.

In addition, a separator can also connect a square battery cell by the fitting structure on both surfaces. By interposing the separator connected to the prismatic battery cell with the fitting structure, it is possible to prevent the displacement of the adjacent prismatic battery cells.
(End separator 13)

Furthermore, as shown in the side sectional view of FIG. 6, the battery stack 10 has a plurality of prismatic battery cells 11 and separators 12 stacked. On the other hand, in order to insulate the rectangular battery cell 11A disposed on the end face from the metal end plate 5, an insulating end separator 13 is disposed. In other words, the end separator 13 is interposed between the end face prismatic battery cell 11 A and the end plate 5. The end separator 13 is formed of an insulating resin in order to insulate the end plate 5 formed of a metal and the rectangular battery cell 11A in order to increase the strength. The material has a relatively low conductivity.

The battery stack 10 includes a plurality of prismatic battery cells 11, a plurality of separators 12, prismatic battery cells 11 A disposed at both ends thereof, and end separators 13 to form a battery block 9. Here, the end separator 13 is formed in the same structure as the separator 12 in the shape of the prismatic battery cell 11 A disposed on the end face of the battery block 9. Further, the end separator 13 is provided with a protruding piece 13a for insulating between the rectangular battery cell 11A on the end face and the cooling plate 21. On the other hand, the shape of the end separator 13 on the end plate 5 side is provided with a spacer portion 13A having an area substantially equal to the bottom surface of the end plate 5, and further provided with guide portions 13b for holding both upper end surfaces of the end plate 5. ing.

In the conventional end separator 830 as shown in FIG. 17, the heat conductive sheet 840 is stretched, the bottom of the end separator 830 comes into contact with the cooling plate 812, and heat may be transmitted. In contrast, in the embodiment of the present invention, as shown in FIG. 6, a spacer portion 13 A that is bent substantially perpendicularly to the end plate 5 side at the bottom of the end separator 13 is provided. By interposing this spacer portion 13A, it is possible to avoid the end plate 5 from transferring heat to the cooling plate 21 or the heat conductive sheet 22. Thereby, it can avoid that the bottom face of the end plate 5 and the heat conductive sheet 22 contact directly. This end plate 5 suppresses heat transfer from the end plate 5 to the cooling plate 21 by interposing a resin spacer portion 13 A having a thermal conductivity smaller than that of the heat conductive sheet 22 between the end plate 5 and the cooling plate 21. can do. As a result, the rectangular battery cell 11 A at the end of the adjacent battery stack 10 can prevent an extreme temperature drop via the end plate 5.

As shown in FIG. 6, the battery stack 10 is sandwiched between end plates 5 at both ends of the battery block 9. Furthermore, the square battery cell 11 has a bottom exposed from the opened portion of each separator 12. The exposed bottom portion of the rectangular battery cell 11 is thermally coupled to the cooling plate 21 via the heat conductive sheet 22. On the other hand, the heat conductive sheet 22 is slightly stretched in the stacking direction of the prismatic battery cells 11 by the pressing of the prismatic battery cells 11 and the cooling plate 21. For this reason, in order to prevent the end plate 5 and the heat conductive sheet 22 from being thermally coupled by such an extended portion, a spacer 13A is provided on the end plate 5 side at the bottom of the end separator 13. According to this configuration, the end plate 5 can be prevented from being cooled by the cooling plate 21. Therefore, for example, in order to insulate the square battery cells 11A located at both ends of the battery stack 10 and the end plate 5, it is not necessary to provide the end plate 5 with a heat insulating structure. Furthermore, it is not necessary to increase the thickness of the end separator 5 in the stacking direction of the battery stack 10 in order to suppress heat conduction from the prismatic battery cell 11A to the end plate 5. In the end separator 13 in this embodiment, by providing the spacer 13 A instead of the above-described aspect, it is possible to prevent an extreme temperature drop of the rectangular battery cells 11 A at both ends of the battery block 9. That is, the power supply device having the above-described configuration can achieve uniform temperature distribution of the battery stack without increasing the dimension of the power supply device in the stacking direction. For this reason, the temperature of all the rectangular battery cells in the battery stack 10 can be controlled to the same level by the cooling plate 21 via the heat conductive sheet 22.

The structure of the end separator 13 as Example 1 is shown in the perspective view of FIG. The end separator 13 is provided with a spacer portion 13 A protruding toward the bottom surface of the end plate 5 by integral molding. Furthermore, the end separator 13 includes a guide portion 13b that holds both ends of the upper portion of the end plate 5, and the end plate 5 is held by the guide portion 13b and the spacer portion 13A. The spacer portion 13 A has substantially the same area as the bottom surface of the end plate 5, and has a thickness substantially equal to the thickness of the end separator 13 between the rectangular battery cell 11 A on the end surface and the end plate 5. Furthermore, a positioning hole 13c that can screw the end plate 5 and the cooling plate 21 is formed in the spacer portion 13A. Furthermore, as described above, the material of the end separator 13 provided with the spacer portion 13A is preferably made of a resin having high insulation properties and high heat insulation properties in order to avoid conduction between the end face prismatic battery cells 11A and the cooling plate 21. . Since the end plate 5 can be suppressed from being cooled by the cooling plate 21 by providing the spacer portion 13 A, the prismatic battery cell 11 A at the end of the battery stack 10 is cooled via the end plate 5. Can be prevented.

The distance between the end plate 5 and the cooling plate 21 changes according to the thickness of the spacer portion 13A. As described above, the spacer portion 13A is formed of a resin having a relatively low thermal conductivity. However, heat transfer from the spacer portion 13A to the cooling plate 21 is not completely eliminated. By increasing the thickness of the spacer portion 13A, the cooling of the end plate 5 can be further suppressed. Therefore, in Example 1 described above, the thickness of the spacer portion 13A is substantially equal to the thickness of the end separator 13, but the present invention is not limited to such a configuration. For example, the heat transfer between the end plate 5 and the cooling plate 21 can be further inhibited by forming the spacer portion thicker than the end separator. Such an example is shown as a second embodiment in the perspective view of FIG. The end separator 13 is integrally formed with a spacer portion 13B having a partition wall thicker than the above-described spacer portion 13A. For example, the thickness of the spacer portion 13B can be two to three times that of the spacer portion 13A.

Furthermore, in Examples 1 and 2 above, the end plate 5 is brought into contact with almost the entire surface of the spacer portion, but the present invention is not limited to this configuration. For example, heat transfer through the spacer portion can be suppressed by bringing a part of the spacer portion into contact with the heat conductive sheet 22 or the cooling plate 21. Such an example is shown in FIG. The end separator 13 has a spacer portion 13C in which a plurality of protruding legs 13d are formed below the spacer portion 13A. The protruding leg 13d of the spacer portion 13C can reduce the contact area with the heat conductive sheet 22 or the cooling plate 21. Furthermore, a space is formed between the protruding legs 13d of the spacer portion 13C. Thereby, since the thermal conductivity of the air in this space is extremely smaller than other solid materials, the heat transfer between the end plate 5 and the heat conductive sheet 22 or the cooling plate 21 can be further reduced.

Here, as the material of the end separator 13 of Examples 1 to 3, a material having a lower thermal conductivity than the separator 12 disposed between the rectangular battery cells 11 can be used. For example, a material such as polypropylene, which has a low thermal conductivity and a high insulating property, can be used. According to this configuration, the amount of heat transferred from the rectangular battery cell 11 adjacent to the end plate 5 to the end plate 5 can be reduced by the end separator 13.

The power supply device described above can be used as an in-vehicle battery system. As a vehicle equipped with a power supply device, an electric vehicle such as a hybrid car or a plug-in hybrid car that runs with both an engine and a motor, or an electric vehicle that runs only with a motor can be used, and is used as a power source for these vehicles .
(Power supply for hybrid vehicles)

FIG. 11 shows an example in which a power supply device is mounted on a hybrid car that travels with both an engine and a motor. A vehicle HV equipped with the power supply device shown in this figure includes an engine 96 and a running motor 93 that run the vehicle HV, a battery system 100B that supplies power to the motor 93, and a generator that charges the battery of the battery system 100B. 94. The battery system 100B is connected to a motor 93 and a generator 94 via a DC / AC inverter 95. The vehicle HV travels by both the motor 93 and the engine 96 while charging / discharging the battery of the battery system 100B. The motor 93 is driven to drive the vehicle when the engine efficiency is low, for example, during acceleration or low-speed driving. The motor 93 is driven by power supplied from the battery system 100B. The generator 94 is driven by the engine 96 or is driven by regenerative braking when braking the vehicle, and charges the battery of the battery system 100B.
(Power supply for electric vehicles)

FIG. 12 shows an example in which a power supply device is mounted on an electric vehicle that runs only with a motor. A vehicle EV equipped with the power supply device shown in this figure includes a traveling motor 93 for traveling the vehicle EV, a battery system 100C for supplying electric power to the motor 93, and a generator 94 for charging a battery of the battery system 100C. And. The motor 93 is driven by power supplied from the battery system 100C. The generator 94 is driven by energy when regeneratively braking the vehicle EV, and charges the battery of the battery system 100C.
(Power storage device for power storage)

Furthermore, this power supply device can be used not only as a power source for a moving body but also as a stationary power storage device. For example, as a power source for home and factory use, a power supply system that is charged with sunlight or midnight power and discharged when necessary, or a streetlight power supply that charges sunlight during the day and discharges at night, or during a power outage It can also be used as a backup power source for driving signals. Such an example is shown in FIG. The power supply device 100A shown in this figure forms a battery unit 82 by connecting a plurality of battery stacks 81 in a unit shape. Each battery stack 81 has a plurality of prismatic battery cells connected in series and / or in parallel. Each battery stack 81 is controlled by a power controller 84. The power supply device 100A drives the load LD after charging the battery unit 82 with the charging power supply CP. For this reason, the power supply device 100A includes a charge mode and a discharge mode. The load LD and the charging power source CP are connected to the power supply device 100A via the discharging switch DS and the charging switch CS, respectively. ON / OFF of the discharge switch DS and the charge switch CS is switched by the power supply controller 84 of the power supply apparatus 100A. In the charging mode, the power controller 84 switches the charging switch CS to ON and the discharging switch DS to OFF to permit charging from the charging power supply CP to the power supply device 100A. Further, when the charging is completed and the battery is fully charged, or in response to a request from the load LD in a state where a capacity of a predetermined value or more is charged, the power controller 84 turns off the charging switch CS and turns on the discharging switch DS to discharge. The mode is switched to permit discharge from the power supply device 100A to the load LD. If necessary, the charge switch CS can be turned on and the discharge switch DS can be turned on to simultaneously supply power to the load LD and charge the power supply device 100A.

The load LD driven by the power supply device 100A is connected to the power supply device 100A via the discharge switch DS. In the discharge mode of the power supply device 100A, the power supply controller 84 switches the discharge switch DS to ON, connects to the load LD, and drives the load LD with the power from the power supply device 100A. As the discharge switch DS, a switching element such as an FET can be used. ON / OFF of the discharge switch DS is controlled by the power supply controller 84 of the power supply apparatus 100A. The power controller 84 also includes a communication interface for communicating with external devices. In the example of FIG. 13, the host device HT is connected according to an existing communication protocol such as UART or RS-232C. Further, if necessary, a user interface for the user to operate the power supply system can be provided.

Each battery stack 81 includes a signal terminal and a power supply terminal. The signal terminals include a pack input / output terminal DI, a pack abnormality output terminal DA, and a pack connection terminal DO. The pack input / output terminal DI is a terminal for inputting / outputting signals from other pack batteries and the power supply controller 84, and the pack connection terminal DO is for inputting / outputting signals to / from other pack batteries which are child packs. Terminal. The pack abnormality output terminal DA is a terminal for outputting the abnormality of the battery pack to the outside. Furthermore, the power supply terminal is a terminal for connecting the battery stacks 81 in series and in parallel.

Furthermore, the power supply device 100A includes an equalization mode for equalizing the battery units 82. The battery units 82 are connected to the output line OL via the parallel connection switch 85 and connected in parallel to each other. For this purpose, an equalizing circuit 86 controlled by the power supply controller 84 is provided. The equalization circuit 86 suppresses variations in the remaining battery capacity among the plurality of battery units 82.

The power supply device according to the present invention, the vehicle including the power supply device, and the power storage device are suitably used as a power supply device for a plug-in hybrid electric vehicle, a hybrid electric vehicle, an electric vehicle, or the like that can switch between the EV traveling mode and the HEV traveling mode. it can. Also, a backup power supply device that can be mounted on a rack of a computer server, a backup power supply device for a wireless base station such as a mobile phone, a power storage device for home use and a factory, a power supply for a street light, etc. Also, it can be used as appropriate for applications such as a backup power source such as a traffic light.

DESCRIPTION OF

SYMBOLS

100, 100A ...

Power supply device

100B, 100C ... Battery system 1 ... Exterior upper case 2 ... End surface cover 3 ...

Exterior bottom case

4A, 4B ... Flange 5 ... End plate 5A ... Female screw hole 6 ... Bind bar 6A ... Bending part 6B ... Locking part 6C ... Connecting piece 6D ... Locking hook 7 ... Top cover 8 ... Connecting tool 8C ... Bending part 8D ... Connecting hole 9 ... Battery block 10 ...

Battery stack

11, 11A ... Square battery cell 12 ... Separator 12a ... Projection piece 13 ...

End separator

13A, 13B, 13C ... Spacer part 13a ... Projection piece 13b ... Guide part 13c ... Positioning hole 13d ... Projection leg 14 ... Electrode terminal 15 ... Safety valve 19 ... Set screw 20 ... Cooling mechanism 21 ... Cooling plate 22 ... Heat conduction sheet 23 ... Refrigerant path 26 ... Compressor 27 ... Cooling heat Exchanger 28 ... Expansion valve 81 ... Battery stack 82 ... Battery unit 84 ... Power supply controller 85 ... Parallel connection switch 86 ... Equalization circuit 93 ... Motor 94 ... Generator 95 ... Inverter 96 ...

Engine

810, 810A ... Rectangular battery cell 811 ... Battery stack 812 ... Cooling plate 821 ... End separator 830 ... End plate 840 ... Thermal conductive sheet 910 ... Square battery cell 911 ... Battery pack 912 ... Cooling plate 920 ... Separator 940 ... Thermal conductive sheet HV, EV ... Vehicle LD ... Load CP ... Power supply for charging; DS ... Discharge switch; CS ... Charge switch OL ... Output line; HT ... Host device DI ... Pack input / output terminal; DA ... Pack abnormal output terminal; DO ... Pack connection terminal

Claims

A battery laminate formed by laminating a plurality of rectangular battery cells;
Metal end plates disposed on both end faces for fastening the battery stack in the stacking direction;
A separator having insulating properties disposed between the respective square battery cells;
Insulating end separators arranged to insulate the prismatic battery cells located at both ends of the battery stack and the end plate;
A cooling plate for thermally bonding and cooling with one surface of the battery stack;
A power supply device comprising a heat conductive sheet disposed between the battery stack and the cooling plate,
A power supply apparatus comprising a spacer portion that inhibits thermal coupling between the cooling plate and the end plate via the heat conductive sheet.
The power supply device according to claim 1,
The spacer portion is integrally formed at the bottom of the end separator,
The spacer portion is provided toward the bottom of the end plate,
The spacer portion is disposed on the cooling plate via the heat conductive sheet,
A power supply device comprising the end plate placed on the spacer portion.
The power supply device according to claim 1 or 2,
A power supply apparatus comprising the spacer portion thicker than a thickness of the end separator between the rectangular battery cell and the end plate.
The power supply device according to any one of claims 1 to 3,
In the spacer portion, in order to form a space, a plurality of protruding pieces are provided in the direction of the cooling plate.
The power supply device according to any one of claims 1 to 4,
A power supply device, wherein the end separator is made of a resin having a lower thermal conductivity than the separator.
The power supply device according to any one of claims 1 to 5,
A power supply apparatus comprising a coolant passage through which a coolant passes inside the cooling plate.
The power supply device according to any one of claims 1 to 6,
A power supply device, wherein the heat conductive sheet is a sheet that is compressed and deformed.
A vehicle comprising the power supply device according to any one of claims 1 to 7.
A power storage device comprising the power supply device according to any one of claims 1 to 7.