WO2012118015A1

WO2012118015A1 - Electrical power supply and vehicle using forced-cooling stacked storage cell

Info

Publication number: WO2012118015A1
Application number: PCT/JP2012/054789
Authority: WO
Inventors: 智一高品; 橋本　裕之
Original assignee: 三洋電機株式会社
Priority date: 2011-02-28
Filing date: 2012-02-27
Publication date: 2012-09-07

Abstract

[Problem] To reduce a temperature difference between electrical cells on a cooling plate, and cool to a uniform state. [Solution] An electrical power supply comprising: a cell block (2) obtained by stacking a plurality of electrical cells (1), an external canister (11) being made of metal; a cooling plate (30) for cooling the cell block (2), the cooling plate connected to the cell block (2) in a heat-conducting state; and an insulating yet thermally conductive heat transfer member (40) interposed between the cooling plate (30) and the cell block (2); wherein a distribution of heat resistance of the heat transfer member(40) is adjusted according to a cooling capacity at which the electrical cell (1) is cooled by the cooling plate (30) so that, in a region of high cooling capacity, the heat resistance of the heat transfer member (40) in contact with the electrical cell (1) is higher than the heat resistance of the heat transfer member (40) in contact with the electrical cell (1) in a region of low cooling capacity.

Description

[Name of invention determined by ISA based on Rule 37.2] Power supply device and vehicle using forced cooling stacked battery

The present invention relates to a power supply device including a battery stack in which a plurality of battery cells are stacked.

A vehicle power supply device has a large number of battery cells connected in series to increase output voltage and output power. Further, in order to increase the charging capacity with respect to the volume, a power supply device including a battery stack in which a large number of rectangular battery cells are arranged in a stacked state has been developed. Since this power supply device is discharged with a large current to accelerate and drive the vehicle, the discharge current becomes extremely large at 100 A or more. Further, since the power supply device for a vehicle is charged by regenerative braking of the vehicle, the charging current is considerably increased. The assembled battery charged and discharged with a large current generates heat and causes deterioration of the battery. In order to prevent deterioration of the battery that has generated heat, the assembled battery for the vehicle is forced to blow cooling air to cool it, thereby preventing temperature rise.

On the other hand, a cooling method using a refrigerant has been proposed in order to increase the cooling capacity and uniformly cool the battery cells (see Patent Documents 1 to 3). In this cooling method, as shown in FIG. 20, the battery block 202 is placed on the cooling plate 230 and thermally coupled thereto, and the refrigerant is circulated through the cooling plate 230 to be cooled. Specifically, the assembled battery for a vehicle in FIG. 20 includes a battery block 202 to which a plurality of battery cells 201 are connected, a refrigerant channel 203 that is thermally coupled to the battery block 202 and cools the battery cells 201, and a refrigerant channel. A cooling mechanism 204 that supplies a refrigerant to 203 and an electronic component case 205 containing an electronic circuit connected to the battery block 202 are provided. The battery block 202 is cooled by the refrigerant supplied from the cooling mechanism 204 to the refrigerant flow path 203. With this method, it was expected that the battery cells could be cooled more uniformly than the method of circulating cooling air.

JP 2010-15788 A JP-A-6-338334 JP-A-5-151980

In order to cool a plurality of battery blocks using such a refrigerant circulation type cooling method, the refrigerant is circulated sequentially through the cooling plate in which each battery block is installed. As a refrigerant piping system in this case, a parallel type in which refrigerant pipes are connected in parallel as shown in FIG. 8 and a serial type in which the refrigerant pipes are connected in series as shown in FIG. 7 can be considered. Among these, in the parallel connection type, since the refrigerant before heat exchange can be supplied to each cooling plate 30, temperature variation between battery cells can be suppressed.

However, when there is a restriction on the installation space, such as a power supply device mounted on a vehicle, it may be difficult to connect the pipes in parallel. In this case, the pipes are connected in series. In this system, the temperature of the refrigerant rises as a result of the heat exchange of the refrigerant. As a result, the temperature rises as the refrigerant is transferred. As a result, there is a difference in cooling capacity depending on the position of the refrigerant piping, which may cause temperature variations in the battery cells to be cooled.

In order to reduce such a difference in cooling capacity, in the assembled battery for a vehicle in FIG. 20, the battery block 202 cooled by the refrigerant includes an outward path battery 202 </ b> A that is thermally coupled to the outward path side of the refrigerant flow path 203, and A return path battery 202B that is thermally coupled to the return path side of the refrigerant flow path 203 is partitioned, and an electronic component case 205 that is a heat source is disposed close to the forward path battery 202A. In order to realize this structure, two rows of battery blocks 202 are disposed on the forward path side of the refrigerant flow path 203 and are configured to be thermally coupled to the forward path refrigerant path 203. The battery is disposed on the return path side of the refrigerant flow path 203 and is divided into a return path side battery 202B that is disposed so as to be thermally coupled to the refrigerant flow path 203 on the return path side.

However, such an arrangement is not always possible, and in order to be able to appropriately combine the piping pattern of the refrigerant flow path, the arrangement state of the battery block, the size of the electronic component case, and the heat generation amount, There are restrictions such as the need for flexibility. Further, there may be a case where a heat source such as an electronic component case does not exist.

Or, conversely, if the heat generation amount of the heat source is too large, it may be considered that some of the battery cells are heated too much. For example, as shown in the plan view of FIG. 13, depending on the mode in which the power supply device is arranged in the vicinity of the heat generation source HG, the battery cell included in the power supply device may be used as a heat generation source as in the region indicated by cross hatching in the figure. Nearer battery cells are more likely to be heated.

As described above, adjustment for suppressing the temperature difference between the battery cells and cooling uniformly is not always easy. As a result, temperature variation may occur between battery cells depending on the location of the battery cells. If the variation in cooling occurs between the battery cells for various reasons as described above, the degree of deterioration of the battery cells differs, which is not preferable. In particular, since the deterioration of the deteriorated battery cell further progresses, the battery cell with the deteriorated performance of the power supply device is limited. For this reason, the cooling mechanism of the power supply device which can implement | achieve cooling of a battery cell as uniformly as possible was calculated | required.

The present invention has been made in view of such conventional problems. A main object of the present invention is to provide a power supply device capable of cooling battery cells in a uniform state in a cooling system in which a battery block is placed on a cooling plate.

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, the battery block 2 formed by laminating a plurality of battery cells 1 in which the outer can 11 is made of metal, and the battery block 2 and a cooling plate 30 for cooling the battery block 2, and interposed between the cooling plate 30 and the battery block 2. A heat supply device comprising: a heat member; and a heat capacity of the heat transfer member in contact with the battery cell in a portion having a high cooling capacity in accordance with a cooling capacity for cooling the battery cell by the cooling plate. The distribution of the heat resistance of the heat transfer member 40 can be adjusted so that the resistance is higher than the heat resistance of the heat transfer member 40 that is in contact with the battery cell 1 in a portion having a low cooling capacity. As a result, the battery cells arranged at positions that are difficult to be cooled by the cooling plate are relatively inferior in cooling performance. As a result, the deterioration of the battery cells proceeds more than the other battery cells, and the degree of deterioration is not uniform among the battery cells. With respect to the battery cells arranged at positions that are easily cooled by the cooling plate, the overall cooling capacity can be adjusted uniformly by lowering the thermal resistance of the heat transfer member relatively, and between the battery cells. There is an advantage that deterioration due to non-uniform cooling can be suppressed.

Further, according to the power supply device according to the second aspect, the cooling plate 30 includes a pipe for circulating the refrigerant therein, and can be configured to exhibit the cooling capacity by circulating the refrigerant through the pipe. Thereby, the effective and direct cooling using a refrigerant | coolant can be aimed at.

Furthermore, according to the power supply device according to the third aspect, a plurality of cooling plates 30 on which the battery block 2 is placed can be provided, and the pipes of the cooling plates 30 can be connected to each other in series. Thereby, the piping operation of the refrigerant | coolant between cooling plates can be made easy by connecting several cooling plates, and the cooling mechanism which can be installed also in space saving is realizable.

Furthermore, according to the power supply device which concerns on a 4th side surface, it intervenes between this battery cell 1 of the said battery block 2 comprised by laminating | stacking the said battery cells 1, and insulates these battery cells 1 mutually. A separator 5 is provided, and a part of the separator 5 is interposed between the cooling plate 30 and the bottom surface of the battery cell 1 to separate the cooling plate 30 from the battery cell 1 and to be generated by the separation. The heat transfer member 40 can be disposed in the gap. Thereby, the battery cell and the cooling plate can be connected to each other in a thermally coupled state via the heat transfer member while effectively insulating the bottom surface of the battery cell.

Furthermore, according to the power supply device according to the fifth aspect, the heat transfer member 40 can be configured in a sheet shape. Thereby, a sheet-like heat conductive member can be easily interposed between the battery block and the cooling plate.

Furthermore, according to the power supply device according to the sixth aspect, the heat transfer member 40 can change the distribution of thermal resistance by changing the thickness. Thereby, the distribution of thermal resistance can be easily changed partially.

Furthermore, according to the power supply device according to the seventh aspect, the heat transfer member 40 is formed by stacking a plurality of sheets, and the thickness can be changed by changing the number of stacked sheets. Thereby, the thickness of the heat transfer member, that is, the thermal resistance can be easily adjusted.

Furthermore, according to the power supply device according to the eighth aspect, the heat transfer member 40 can change the distribution of thermal resistance by using materials having partially different thermal conductivities. This makes it possible to partially change the thermal resistance while maintaining the height of the heat transfer member constant.

Furthermore, according to the power supply device according to the ninth aspect, the cooling plate 30 includes a pipe for circulating the coolant inside, and is configured to exhibit the cooling capacity by circulating the coolant through the pipe. it can. Thereby, a battery block can be cooled by a water cooling system.

Furthermore, the power supply device according to the tenth aspect further includes an intermediate heat exchanger for cooling the coolant, and the intermediate heat exchanger can be connected to an evaporator and a condenser. Thereby, the cooling water which cools a battery block can be cooled using the existing cooling mechanism, and an inexpensive and highly reliable cooling system can be realized.

Furthermore, according to the vehicle including the power supply device according to the eleventh aspect, any one of the power supply devices described above can be provided.

It is a perspective view which shows the power supply device which concerns on one embodiment of this invention. FIG. 2 is a longitudinal sectional view taken along line II-II in FIG. FIG. 3 is a cross-sectional view taken along line III-III in FIG. It is a model horizontal sectional view which shows an example of a refrigerant flow path. It is a model horizontal sectional view which shows the other example of a refrigerant flow path. It is a disassembled perspective view which shows the state which fixes a some battery block on one cooling plate. It is a schematic diagram which shows the example which connected the piping of the refrigerant | coolant in series. It is a schematic diagram which shows the example which connected piping of the refrigerant | coolant in parallel. It is a schematic diagram which shows the other example which connects the piping of a refrigerant | coolant in series. It is a schematic diagram which shows the further another example which connects the piping of a refrigerant | coolant in series. It is a perspective view which shows the part from which the temperature becomes high by arrangement | positioning of piping in the battery block of FIG. FIG. 7 is a perspective view showing a portion where the temperature increases due to the proximity of the battery blocks in the battery block of FIG. 6. It is a top view which shows the example which arrange | positions a power supply device in the vicinity of a heat source. FIG. 4 is an exploded cross-sectional view of FIG. 3. It is an exploded sectional view showing a power supply device concerning a modification. It is an exploded sectional view showing a power supply device concerning other modifications. It is a block diagram which shows the example which mounts a power supply device in the hybrid vehicle which drive | works with an engine and a motor. It is a block diagram which shows the example which mounts a power supply device in the electric vehicle which drive | works only with a motor. It is a block diagram which shows the example applied to the power supply device for electrical storage. It is a schematic diagram which shows the cooling system using the conventional refrigerant | coolant. It is a schematic diagram which shows another cooling mechanism. It is an exploded sectional view of a power supply device concerning a modification. It is an exploded sectional view of a power supply device concerning other modifications.

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 and a vehicle using the same, and the present invention describes the power supply device and a vehicle using the power supply device as follows. Not specific to anything. In addition, the member shown by the claim is not what specifies the member of embodiment. 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's 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.

1 to FIG. 16, an example in which the present invention is applied to an in-vehicle power supply device will be described as a power supply device according to an embodiment of the present invention. The power supply apparatus shown in these drawings is most suitable for the power source of an electric vehicle such as a hybrid vehicle that travels by both an engine and a motor and an electric vehicle that travels by only a motor. However, the power supply device of the present invention can be used for vehicles other than hybrid vehicles and electric vehicles, and can also be used for applications requiring high output other than electric vehicles.

A vehicle power supply device 100 shown in the perspective view of FIG. 1, the longitudinal sectional view of FIG. 2, and the transverse sectional view of FIG. 3 includes a battery block 2 in which a plurality of battery cells 1 are connected in series or in parallel, and the battery block. And a heat transfer member 40 interposed between the cooling plate 30 and the battery block 2. The cooling plate 30 includes a refrigerant flow path 3 for flowing a refrigerant therein. A cooling mechanism 4 that supplies a refrigerant to the refrigerant flow path 3 is connected to the cooling plate 30. This power supply device cools the battery block 2 with the refrigerant supplied from the cooling mechanism 4 to the refrigerant flow path 3.
(Battery block 2)

The battery block 2 is arranged such that a plurality of battery cells 1 are stacked with separators 5 interposed therebetween, and both ends are sandwiched and fixed by end plates. In the battery block 2, a plurality of battery cells 1 are arranged adjacent to each other, and electrode terminals of the adjacent battery cells 1 are connected. The electrode terminals of the adjacent battery cells 1 are stacked on each other, and are electrically connected by fixing the stacked portion with a connector.

In the battery block 2 in FIG. 1, the battery cell 1 is a square battery. The prismatic battery can be arranged more efficiently than the cylindrical battery, and the energy density per unit volume can be increased. Particularly, in-vehicle use, there is a high demand for space saving, which is preferable. For such a battery cell 1, a rectangular secondary battery such as a lithium ion secondary battery can be used. Moreover, it can also be set as secondary batteries, such as a nickel metal hydride battery, and a secondary battery is good also as a cylindrical shape. The electrode terminals of the battery cell 1 are connected in series or in parallel. In this example, the outer can of the battery cell 1 is made of metal.

A separator 5 is sandwiched between adjacent battery cells 1 to insulate them from each other. The separator 5 is a quadrangle having the same size as the outer shape of the battery cell 1 and is sandwiched and insulated between adjacent battery cells 1. The separator 5 is made of an insulating material having excellent heat resistance and heat insulation, and is preferably made of a light and inexpensive resin. For example, a synthetic resin such as polypropylene or polyurethane having a low thermal conductivity (preferably 0.5 W / m or less) can be used. Thereby, while protecting the battery cell 1 with the separator 5, the adjacent battery cells 1 are insulated and insulated.

The battery block 2 is formed by alternately laminating separators 5 and battery cells 1 and sandwiching and fixing both end surfaces between a pair of end plates. The end plate is manufactured by molding the whole with plastic or reinforcing it by insert molding metal. The end plate is formed in a size capable of covering the battery cell 1 exposed at both end surfaces, with the outer shape being the outer shape of the battery cell 1. The pair of end plates are connected by tie rods (not shown), and the battery cells 1 and the separators 5 stacked therebetween are sandwiched and fixed.
(Cooling plate 30)

The battery block 2 is fixed on the cooling plate 30 by a method such as screwing. The cooling plate 30 is composed of a plate-shaped metal plate, and is provided with a refrigerant flow path 3 for flowing a refrigerant therein. The refrigerant flow path 3 is made of copper, aluminum, or the like, and supplies the liquefied refrigerant to the refrigerant flow path 3, vaporizes the refrigerant in the refrigerant flow path 3, and forcibly cools with the heat of vaporization of the refrigerant. The battery cell 1 is cooled via the heat transfer member 40. This refrigerant flow path 3 is connected to an external cooling mechanism 4.
(Cooling mechanism 4)

The cooling mechanism 4 that forcibly cools the cooling plate 30 with the heat of vaporization of the refrigerant includes a circulation pump 21, a radiator 22, and a control circuit 20 that controls the operation of the circulation pump 21 and the fan 23 of the radiator 22. The circulation pump 21 circulates the liquid refrigerant through the refrigerant path 3 and the radiator 22. The control circuit 20 detects the temperature of the battery block 2 with a temperature sensor, and operates the circulation pump 21 when the detected temperature becomes higher than the set temperature. The control circuit 20 detects the temperature of the refrigerant with a temperature sensor, and operates the fan 23 of the radiator 22 when the temperature of the refrigerant becomes higher than a set value. The refrigerant circulated to the refrigerant path 3 by the circulation pump 21 is insulating oil or antifreeze. Silicon oil or the like can be used as the insulating oil. In this specification, the cooling with the refrigerant is used in the meaning including water cooling in which water or a coolant is circulated.

Furthermore, the cooling mechanism can also supply a Freon-based refrigerant that is vaporized inside the refrigerant path and cooled by heat of vaporization to the refrigerant path. Such a cooling mechanism 4B is shown in FIG. This refrigerant is vaporized inside the refrigerant path to cool the refrigerant path. The cooled refrigerant path cools the battery block 2 from the bottom surface. This cooling mechanism can cool the battery block 2 to a low temperature. The cooling mechanism includes a compressor 26 that pressurizes the vaporized refrigerant, a condenser 27 that cools and liquefies the refrigerant pressurized by the compressor 26, and supplies the refrigerant liquefied by the condenser 27 to the refrigerant path 3. And an inflator 28.

The expander 28 is, for example, a capillary tube or an expansion valve. A capillary tube or an expansion valve made of a thin tube is limited to a predetermined flow range of the refrigerant. These expanders 28 are designed to have a flow rate at which all of the refrigerant is vaporized while being discharged from the refrigerant path 3. This is because the compressor 26 is designed to suck in and compress the gaseous refrigerant, and if liquid refrigerant is sucked in, it causes a failure. The state in which the refrigerant is vaporized in the refrigerant path 3 varies depending on the temperature of the battery block 2. When the temperature of the battery block 2 is high, the refrigerant is easily vaporized, and when the temperature is low, the refrigerant is difficult to vaporize. Therefore, when the flow rate of the expander 28 such as a capillary tube is controlled so that all the refrigerant is vaporized in a state where the temperature of the battery block 2 is low, in the state where the temperature of the battery block 2 is high, in the middle of the refrigerant path 3. All the refrigerant is vaporized and the cooling efficiency by the heat of vaporization is lowered. This state is likely to occur in the refrigerant path 3 on the return path side, and the temperature of the refrigerant path 3 on the return path side tends to increase. In other words, the battery block 2 on the forward path side is efficiently cooled and enters a supercooled state. Therefore, the temperature difference between the battery cells is reduced by the heat transfer member 40 (described later).

The refrigerant flow path 3 has a U-shaped pattern in the example shown in FIG. The refrigerant flow path 3 is configured in a pipe shape, and two refrigerant paths 3 are arranged in parallel on the forward path side and the return path side. Liquid refrigerant is supplied from the cooling mechanism 4 to the refrigerant flow path 3 to be cooled. In addition, the pattern of a refrigerant flow path is not restricted to this, Arbitrary patterns can be utilized, for example, it is good also considering the refrigerant flow path 3B as a wavy pattern like the cooling plate 30B shown in FIG. The cooling plate 30B shown in FIG. 5 supplies the liquefied refrigerant to the refrigerant flow path 3B provided therein, vaporizes the refrigerant in the refrigerant flow path 3B, and forcibly cools it with the heat of vaporization of the refrigerant. Cell 1 is cooled. The cooling mechanism 35 forcibly cooling the cooling plate 30B with the heat of vaporization of the refrigerant includes a compressor 36 that pressurizes the refrigerant in a gaseous state, a condenser 37 that cools and liquefies the gas pressurized by the compressor 36, And an expansion valve 38 for supplying the refrigerant liquefied by the condenser 37 to the refrigerant flow path 3B of the cooling plate 30B. The cooling mechanism 35 supplies the liquefied refrigerant to the cooling plate 30B via the expansion valve 38, vaporizes the supplied refrigerant inside the cooling plate 30B, and cools the cooling plate 30B with heat of vaporization. The vaporized refrigerant is pressurized by the compressor 36, supplied to the condenser 37, liquefied by the condenser 37, and circulated through the expansion valve 38 to the refrigerant flow path 3B of the cooling plate 30B to pass through the cooling plate 30B. Cooling.

The cooling plate is not necessarily cooled by the heat of vaporization of the refrigerant. For example, the cooled plate can be cooled by circulating the cooled liquid inside. Further, the cooling plate can be cooled by providing a cooling gas passage inside and forcibly blowing the gas cooled in this passage.

In the above example, one battery block is cooled by one cooling plate. However, it goes without saying that a plurality of battery blocks can be cooled by using one cooling plate. For example, in the example of FIG. 6, four battery blocks 2 are fixed and cooled on one large cooling plate 30.

Furthermore, it goes without saying that a plurality of battery blocks can be cooled using a plurality of cooling plates. In this case, it is preferable that the cooling mechanism 4 can be shared by connecting the refrigerant flow paths of the cooling plates and circulating the refrigerant. The connection form between the cooling plates may be either a series connection as shown in FIG. 7 or a parallel connection as shown in FIG. The serial connection facilitates the connection of the refrigerant flow path, simplifies the piping work, and is advantageous in terms of the installation space of the piping. Further, the serial connection is not limited to the example of FIG. 7, and any connection form corresponding to the installation form of the cooling plate such as connection examples as shown in FIGS. 9 and 10 can be used as appropriate.
(Heat transfer member 40)

The heat transfer member 40 is interposed between the cooling plate 30 and the battery block 2 and thermally conducts while insulating them to cool the heat generated in the battery cell 1 with the cooling plate 30. In a power supply device in which adjacent prismatic battery cells are connected in series, the adjacent prismatic battery cells have a potential difference. Therefore, if a rectangular battery cell composed of a metal outer can is electrically connected to the cooling plate as it is, a short circuit occurs and a large short current flows. Therefore, the battery cells must be insulated. On the other hand, in order to efficiently dissipate heat with the cooling plate, it is necessary to bring the battery cell and the cooling plate into a thermally coupled state. For this reason, the heat transfer member 40 is made of a material having an insulating property for preventing a short circuit between adjacent battery cells while exhibiting high thermal conductivity so as to be thermally coupled to the outer can of the battery cell. As such a material, acrylic resin, urethane resin, epoxy resin, silicone resin, or the like can be used.

Between the bottom surface of the battery cell 1 and the top surface of the cooling plate 30, a gap GP for arranging the heat transfer member 40 is provided as shown in FIG. Therefore, the separator 5 is bent at the bottom so as to partially cover the bottom of the battery cell 1. By interposing the separator bottom surface 5b between the bottom surface of the battery cell 1 and the top surface of the cooling plate 30, a gap GP corresponding to the thickness of the separator bottom surface 5b is formed.

Further, in the example of FIG. 3, the heat transfer member 40 is formed in a sheet shape. Preferably, the member is slightly elastically deformed. The sheet-like heat transfer member 40 is formed slightly higher than the height of the gap GP. As a result, the sheet-like heat transfer member 40 arranged in the gap GP is pressed and compressed by the bottom surface of the battery cell 1 and the top surface of the cooling plate 30, and an air layer is formed at the joining interface between them. Avoid this and make it heat-bonded.

Furthermore, the heat transfer member 40 partially changes the thermal resistance in the plane. For example, as shown in FIG. 11, in the configuration in which four battery blocks 2 are placed on one cooling plate 30, when the refrigerant flow path 3 is piped in a U shape, the lower side in the figure is relatively lower. It can be said that the battery block is easily heat-exchanged with the refrigerant and is easily cooled. On the other hand, the upper battery block is cooled after the heat exchange of the refrigerant proceeds. It can be said that the block is hardly cooled. Alternatively, when considering the arrangement state of the battery blocks, if four battery blocks are arranged close to each other as shown in FIG. 12, heat is easily trapped between the battery blocks. The cell temperature tends to increase. Furthermore, as shown in FIG. 13, when the heat source is disposed close to the power supply device, the battery cells in the vicinity are similarly heated and the temperature tends to increase.

As described above, when some battery cells tend to be less likely to dissipate heat than other battery cells due to the arrangement state of the battery cells, the piping state of the refrigerant path, or the presence of a heat source. In order to suppress this, the thermal resistance of the heat transfer member is partially changed, so that such non-uniformity can be alleviated and the temperature of the battery cell can be brought close to a constant level. For this reason, the heat transfer member has a configuration that partially changes the thermal resistance.

For example, let us consider temperature correction when the temperature rises at the central portion of the battery cell arranged on one cooling plate 30. In this case, the heat transfer member 40 is prepared so that the heat resistance is relatively low at the center of the battery cell and the heat resistance of other portions is relatively high, and the heat conduction is improved at the center portion where the heat resistance is low. Thus, the heat dissipation is improved, the temperature is lowered, and the heat conduction in the peripheral portion is relatively lowered, thereby reducing the temperature difference between the peripheral portion where the temperature is likely to be lowered and the central portion where the temperature is likely to be raised. Specifically, as shown in FIG. 14, the thickness is reduced at the central portion 40b of the heat transfer member 40, and the thickness of the other portion 40a is increased. Thereby, the heat transfer member of the thin part of the center part 40b has low thermal resistance, and heat resistance becomes high in the other part 40a. As a result, heat dissipation is relatively lowered in the area around the battery block, and a difference from the cooling capacity of the central portion occurs. By adjusting this difference in cooling capacity so that it approaches or matches the temperature difference between battery cells depending on the location, the temperature difference between battery cells is reduced to avoid partial deterioration, and a highly reliable power supply A device can be realized.

For changing the thickness of the heat transfer member 40, a plurality of heat transfer members having different thicknesses are combined. Further, a plurality of sheet-like heat transfer members can be laminated and adjusted. In this method, since the height can be changed by adjusting the number of thin sheet-like heat transfer members prepared in advance, there is an advantage that adjustment work can be facilitated. Further, preferably, as shown in FIG. 14, by projecting a portion where the heat transfer member of the central portion 40 b is disposed on the cooling plate 30, the height of the surface facing the battery cell 1 of the heat transfer member is aligned, While adhering to the battery cell surface, it is possible to position the heat transfer member in the peripheral portion 40a. However, it is not always necessary to project the cooling plate, and for example, a cooling plate having a flat surface facing the battery cell of the cooling plate can be used. When electric heating members having different thicknesses are arranged on the cooling plate, the height of the facing surface of the heat transfer member to the battery cell does not match, so when fixing the battery block to the cooling plate, the heat transfer member A heat transfer member that is compressed and fits in the gap GP is used. Alternatively, a plurality of heat transfer members having the same thickness and different thermal conductivity can be arranged on a cooling plate having a flat surface facing the battery cell.

In the above example, the example in which the thickness is made in two stages has been described, but it is needless to say that it can be adjusted in three stages or more as in the heat transfer member 40B shown in FIG. Absent. By dividing into a plurality of regions, finer adjustment is possible. Furthermore, in addition to a configuration in which the thickness is uniform for each region, a configuration in which the thickness is continuously changed as in the heat transfer member 40C illustrated in FIG. 16 may be employed. The height can be changed by inclining the upper surface of the heat transfer member 40C, and the cooling capacity can be continuously changed in accordance with the state in which the temperature difference between the battery cells is continuously changed.

Moreover, although the above demonstrated the structure which comprises the heat-transfer member 40 with the same raw material, and changed thermal resistance by varying thickness, it comprises a heat conductive member combining the raw material from which heat conductivity differs. You can also. For example, in the example of FIG. 6, the heat transfer member in the center portion is made of a first material having a high thermal conductivity, and the heat transfer member in the surrounding portion is made of a second material having a lower heat conductivity. And while forming a 2nd raw material in a rectangular shape, the center is opened and the elliptical 1st raw material shape | molded separately is inserted, and the heat-transfer member 40 is comprised. If it is this structure, since the thickness of the heat-transfer member 40 can be made uniform, the advantage which can fix a battery block and the cooling plate 30 smoothly will be acquired.

Furthermore, in the above example, the heat transfer member is in the form of a sheet, but is not limited thereto, and may be in the form of a paste, for example. The paste-like heat transfer member can avoid a situation in which a space between the bottom surface of the battery cell outer can and the top surface of the cooling plate is filled without any gap and a heat insulating layer such as an air layer is formed. Or the adhesive which adhere | attaches a battery cell and a cooling plate can also be used as a heat-transfer member. For example, uncured resin is applied to the bottom surface of the battery cell outer can and the top surface of the cooling plate, and the two are bonded together. Thereby, fixation of a battery block and a thermal coupling state are realizable.

On the other hand, in the above example, the battery block is configured by interposing a separator between the battery cells, but the separator can be omitted. For example, by covering the outer can surface of the battery cell with an insulating layer such as a shrink tube, a short circuit between adjacent battery cells can be avoided even if the battery cells are stacked. In this case, a spacer is separately arranged between the bottom surface of the battery cell and the cooling plate to form a space for arranging the heat transfer member. Alternatively, the spacer may be omitted, and the battery cell may be directly fixed on the cooling plate with the heat transfer member interposed.

In the above example, the cooling plate is arranged on the battery block. However, the present invention is not limited to this configuration. For example, the cooling plate can be arranged on the side surface of the rectangular battery cell.

In the above example, the configuration for reducing the thermal resistance of the central portion of the battery cell has been described. However, the configuration is not limited to this configuration, and for example, the configuration can be configured to reduce one of the thermal resistances. In the example of FIG. 22, the heat resistance of the heat transfer member facing the inflow side (left side refrigerant path 3 in FIG. 22) of the refrigerant flow path 3 arranged at both ends of the cooling plate 30 is increased, and the outflow side (FIG. In FIG. 22, the thickness of the heat transfer member 40D is changed so that the heat resistance of the heat transfer member facing the right refrigerant path 3) is lowered. That is, by increasing the thickness on the left side of the heat transfer member 40D in the figure, the thermal resistance is increased in the side region of the battery cell 1 facing the refrigerant path 3 on the inflow side. On the other hand, the thickness on the right side of the heat transfer member 40D is reduced to reduce the thermal resistance on the outflow side of the refrigerant path 3. As a result, in the region cooled by the low-temperature refrigerant on the inflow side of the refrigerant path 3, the heat resistance is increased to suppress the temperature decrease, and on the outflow side, the heat exchange proceeds and the refrigerant is cooled by the higher temperature. Therefore, the temperature difference between the two can be reduced by reducing the thermal resistance and increasing the cooling of the battery cells. In this example, the heat transfer member 40D is composed of three members. However, the present invention is not limited to this, and the thickness change may be made finer by using two members or by using four or more members. Alternatively, as in the heat transfer member 40E shown in FIG. 23, the thickness can be changed continuously.

Further, in the above example, the example in which the heat conduction state is changed on one cooling plate 30 has been described. However, in the configuration using a plurality of cooling plates, the heat conduction coefficient of the heat transfer member of each cooling plate. By changing, temperature variation between different cooling plates can be suppressed. In this case, the material of the heat transfer member used in the cooling plate is changed, the thickness is changed, or the heat resistance of the heat transfer member used in each cooling plate is partially changed as described above. May be.
(Water cooling)

Furthermore, although cooling using a refrigerant has been described in the above example, water cooling in which water or a coolant is circulated can be employed as described above. In addition, the coolant used for water cooling may be cooled with a refrigerant. In particular, in a vehicle power supply device, an existing cooling mechanism used for an indoor air conditioner or the like can be used for cooling the coolant. A cooling mechanism employing such a configuration is shown in FIG. The cooling mechanism shown in this figure includes a first cooling mechanism 60 that cools the cooling plate 30C with a coolant by water cooling, and a second cooling mechanism 70 for cooling the vehicle interior that uses a refrigerant such as an indoor air conditioner. Connected with. In the first cooling mechanism 60, a pump 61, a three-way valve 64, an intermediate heat exchanger 67, a heater 66, and a cooling plate 30C are arranged in a first circulation path 65 indicated by a thick line. Further, the radiator 62 is also connected through the three-way valve 64. The radiator 62 is air-cooled by the outside air, and when the outside air temperature is low, the three-way valve 64 is switched from the intermediate heat exchanger 67 to the radiator 62 side, and energy consumption required for cooling such as power of the compressor 76 described later can be suppressed. The heater 66 is a member for adjusting the temperature by heating the coolant.

On the other hand, the second cooling mechanism 70 is provided with a compressor 76, an intermediate heat exchanger 67, an evaporator 71, and a condenser 77 in a second circulation path 75 indicated by a thin line. The intermediate heat exchanger 67 and the evaporator 71 are connected in parallel via expansion valves 73 and 72, respectively. A fan 63 is in close proximity to the condenser 77. The fan 63 can also be used for heat dissipation of the radiator 62. In the example of FIG. 21, water containing antifreeze is used as the coolant, and HFC is used as the refrigerant.

Thus, by connecting the first cooling mechanism 60 of the cooling plate 30C to the second cooling mechanism 70 via the intermediate heat exchanger 67, the coolant can be cooled more efficiently using the existing cooling mechanism, There is an advantage that the battery block can be cooled stably.

As described above, in the power supply device in which the plurality of battery cells 1 are arranged on the cooling plate 30, the temperature variation between the battery cells can be reduced by adjusting the thermal conductance between the battery cell 1 and the cooling plate 30. it can. Such a power supply device can be used as an in-vehicle power supply. As a vehicle equipped with a power supply device, an electric vehicle such as a hybrid vehicle or a plug-in hybrid vehicle that runs with both an engine and a motor, or an electric vehicle that runs only with a motor can be used, and it is used as a power source for these vehicles. .
(Power supply for hybrid vehicles)

FIG. 17 shows an example in which a power supply device is mounted on a hybrid vehicle that runs 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 travel motor 93 that travel the vehicle HV, a power supply device 100 that supplies power to the motor 93, and a generator that charges a battery of the power supply device 100. 94. The power supply apparatus 100 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 power supply device 100. 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 power supply device 100. The generator 94 is driven by the engine 96 or is driven by regenerative braking when the vehicle is braked to charge the battery of the power supply device 100.
(Power supply for electric vehicles)

FIG. 18 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 FIG. 1 is a motor 93 for running the vehicle EV, a power supply device 100 that supplies power to the motor 93, and a generator 94 that charges a battery of the power supply device 100. And. The motor 93 is driven by power supplied from the power supply device 100. The generator 94 is driven by energy when regeneratively braking the vehicle EV and charges the battery of the power supply device 100.
(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 facility. For example, as a power source for households and factories, a power supply system that is charged with solar power or midnight power and discharged when necessary, or a street light that is charged with solar power during the day and discharged at night It can also be used as a backup power source for traffic lights that are driven in the event of a power failure. Such an example is shown in FIG. The power supply apparatus 100 shown in this figure forms a battery unit 82 by connecting a plurality of battery packs 81 in a unit shape. Each battery pack 81 has a plurality of battery cells connected in series and / or in parallel. Each battery pack 81 is controlled by a power controller 84. The power supply apparatus 100 drives the load LD after charging the battery unit 82 with the charging power supply CP. For this reason, the power supply apparatus 100 includes a charging mode and a discharging mode. The load LD and the charging power source CP are connected to the power supply device 100 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 100. In the charging mode, the power supply 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 apparatus 100. 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 apparatus 100 to the load LD. Further, if necessary, the charge switch CS can be turned on and the discharge switch DS can be turned on to supply power to the load LD and charge the power supply device 100 at the same time.

The load LD driven by the power supply device 100 is connected to the power supply device 100 via the discharge switch DS. In the discharge mode of the power supply apparatus 100, 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 apparatus 100. 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 100. The power controller 84 also includes a communication interface for communicating with external devices. In the example of FIG. 19, the host device HT is connected in accordance with 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 pack 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 packs 81 in series and in parallel. The battery units 82 are connected to the output line OL via the parallel connection switch 85 and are connected in parallel to each other.

A vehicle power supply device and a vehicle including the power supply device according to the present invention 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 an EV traveling mode and an 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. It can also be used as appropriate for applications such as a backup power source for traffic lights. Furthermore, the dustproof case is not limited to the case that houses the power supply device, and can be suitably used for other applications that require a dustproof structure.

DESCRIPTION OF SYMBOLS 100 ... Power supply device 1 ... Battery cell 2 ...

Battery block

3, 3B ...

Refrigerant flow path

4, 4B, 35 ... Cooling mechanism 5 ... Separator; 5b ... Separator bottom face 20 ... Control circuit 21 ... Circulation pump 22 ... Radiator 23 ... Fan 26 ... Compressor 27 ... Condenser 28 ...

Expander

30, 30B, 30C ... Cooling plate 36 ... Compressor 37 ... Condenser 38 ...

Expansion valve

40, 40B, 40C, 40D, 40E ... Heat transfer member 40a ... Parts other than the center; 40b ... Central part 60 ... First cooling mechanism 61 ... Pump 62 ... Radiator 63 ... Fan 64 ... Three-way valve 65 ... First circulation path 66 ... Heater 67 ... Intermediate heat exchanger 70 ... Second cooling mechanism 71 ... Evaporator 72 73 ... Expansion valve 75 ... Second circulation path 76 ... Compressor 77 ... Condenser 81 ... Battery pack 82 ... Battery unit 84 ... Power supply controller 85 ... Parallel connection switch 93 ... motor 94 ... generator 95 ... DC / AC inverter 96 ... engine 201 ... battery cell 202 ... battery block; 202A ... outward side battery; 202B ... return side battery 203 ... refrigerant flow path 204 ... cooling mechanism 205 ... electronic component case 230 ... Cooling plate HG ... Heat source; GP ... Gap; EV, HV ... Vehicle LD ... Load; CP ... Charging power supply; DS ... Discharge switch; CS ... Charge switch OL ... Output line;

Claims

A battery block (2) formed by laminating a plurality of battery cells (1) whose outer can is made of metal; and
A cooling plate (30) connected to the battery block (2) in a thermally coupled state to cool the battery block (2);
A heat transfer member (40) interposed between the cooling plate (30) and the battery block (2);
A power supply device comprising:
In accordance with the cooling capacity for cooling the battery cell (1) with the cooling plate (30), the heat resistance of the heat transfer member (40) in contact with the battery cell (1) at a portion with a high cooling capacity, the cooling capacity The power supply device is characterized in that the distribution of the thermal resistance of the heat transfer member (40) is adjusted so as to be higher than the thermal resistance of the heat transfer member (40) in contact with the battery cell (1) in a low-temperature region .
The power supply device according to claim 1,
The power supply device, wherein the cooling plate (30) includes a pipe for circulating a refrigerant therein, and exhibits cooling capacity by circulating the refrigerant through the pipe.
The power supply device according to claim 2,
With a plurality of cooling plates (30) on which the battery block (2) is placed,
A power supply device, wherein the piping of each cooling plate (30) is connected in series with each other.
The power supply device according to any one of claims 1 to 3, further comprising:
The battery block (2) configured by laminating the battery cells (1) includes a separator (5) interposed between the battery cells (1) to insulate the battery cells (1). And
A part of the separator (5) is interposed between the cooling plate (30) and the bottom surface of the battery cell (1) to separate the cooling plate (30) and the battery cell (1), and A power supply device, wherein the heat transfer member (40) is arranged in a gap generated by the above.
The power supply device according to any one of claims 1 to 4,
The power supply device, wherein the heat transfer member (40) is formed in a sheet shape.
The power supply device according to claim 5,
The power supply device, wherein the heat transfer member (40) has a distribution of thermal resistance changed by changing a thickness thereof.
The power supply device according to claim 6,
The heat transfer member (40) is configured by laminating a plurality of sheets, and the thickness is changed by changing the number of stacked sheets.
The power supply device according to any one of claims 1 to 7,
The power supply device according to claim 1, wherein the heat transfer member (40) is made of a material having partially different thermal conductivity to change the distribution of thermal resistance.
The power supply device according to claim 2, wherein
The power supply apparatus according to claim 1, wherein the cooling plate (30) includes a pipe for circulating a cooling liquid therein, and exhibits cooling capacity by circulating the cooling liquid through the pipe.
The power supply device according to claim 9, further comprising:
An intermediate heat exchanger for cooling the coolant,
The power supply apparatus, wherein the intermediate heat exchanger is connected to an evaporator and a condenser.
A vehicle comprising the power supply device according to any one of claims 1 to 10.