Patent Grant
11990636
This application is a U.S. national stage application of the PCT International Application No. PCT/JP2020/028023 filed on Jul. 20, 2020, which claims the benefit of foreign priority of Japanese patent application No. 2019-145724 filed on Aug. 7, 2019, the contents all of which are incorporated herein by reference.
The present invention relates to a power supply device, and an electric vehicle and a power storage device using the same.
The power supply device is used for a power supply device for driving an electric vehicle, a power supply device for power storage, and the like. Such a power supply device has a plurality of chargeable and dischargeable battery cells that are stacked. As in power supply device 900 shown in a perspective view of
In recent years, with the demand for higher capacity, the number of stacked battery cells constituting a battery stack tends to increase. As a result, the overall length of the battery stack becomes longer in accordance with the number of battery cells, and the length of the top cover also becomes longer accordingly. However, when the length becomes longer with respect to the width of the top cover, the aspect ratio between height and width gets worse, and undulation and warpage of the resin-molded top cover are increased. As a result, there has been a problem that the positions of the screws and the claws change and fitting cannot be performed. When the top cover has undulation or warpage, a gap is provided between the top cover and the battery stack. When any of the battery cells thermally runs away, air may enter through this gap, and oxygen may burn to generate flame.
In order to avoid such a decrease in molding accuracy, it is conceivable to divide the top cover, but in this case, there has been a problem that the number of components increases, the number of assembly steps increases, and the cost increases.
An object of the present invention is to provide a power supply device that can be stably attached to a battery stack even when a top cover covering the battery stack is long, and an electric vehicle and a power storage device using the same.
A power supply device according to a first aspect of the present invention includes: a battery assembly including a plurality of battery cells and extended in one direction; and an insulating cover part covering one surface extended in one direction of the battery assembly, in which the cover part includes a plurality of fixtures for fixing the cover part to an upper surface of the battery assembly, the fixtures provided in an extension direction, and the cover part can include a metal core material. With the above configuration, even when the insulating cover part has an extended elongated shape, warpage and undulation can be suppressed by the metal core material, and the fixtures can be provided at predetermined positions, so that the reliability of fixing to the battery assembly can be enhanced.
In the power supply device according to a second aspect, in addition to the above configuration, the plurality of battery cells each have a prismatic outer covering can, the battery assembly is a stack in which a plurality of battery cells are stacked, the power supply device further includes a pair of end plates covering both side end surfaces of the battery stack in which the plurality of battery cells are stacked, and a separator held between the battery cells in a state where the plurality of battery cells are stacked, and the separator can include a reception part receiving the fixture at a position corresponding to the fixture in a state where the cover part is fixed.
In the power supply device according to a third aspect, in addition to any of the above configurations, the power supply device can further include a holder part provided between the cover part and an upper surface of the stack of the battery cells, and the holder can include a reception part receiving the fixture at a position corresponding to the fixture in a state where the cover is fixed.
In the power supply device according to a fourth aspect, in addition to any of the above configurations, the plurality of battery cells each include a safety valve that opens in response to an internal pressure change, and an upper surface of the battery assembly can be a surface of the plurality of battery cells on which the safety valve is provided. With the above configuration, even when the safety valve is opened and high pressure gas is released from the upper surface of the battery stack, deformation of the cover part is suppressed by the core material, and the safety is improved.
The power supply device according to a fifth aspect, in addition to any of the above configurations, the cover part is made of resin, and the core material can be formed into a plate shape. With the above configuration, since the core material has a plate shape, the entire upper surface of the battery assembly can be covered without a gap. This can increase the strength of the upper surface side of the battery assembly, and enhance the reliability of the battery assembly. It is possible to suppress warpage and undulation of the cover part by the plate-like core material even when the cover part has an elongated shape in which the cover part is extended while securing insulation properties by the cover part made of resin.
According to the power supply device according to a sixth aspect, in addition to any of the above configurations, at least a part of the plate-shaped core material can be exposed from the cover part. The above configuration can enhance the heat dissipation to the outside from the part of the core material exposed from the cover part.
According to the power supply device according to a seventh aspect, in addition to any of the above configurations, the plate-shaped core material can include, at both ends thereof, an exposed part that is exposed from the cover part and is extended and fixed to upper surfaces of the pair of end plates. With the above configuration, since the core material is also fixed to the end plate in addition to the fixture of the cover part, the cover part is hardly detached from the battery stack.
The power supply device according to an eighth aspect, in addition to any of the above configurations, the cover part is made of resin, and the core material can be provided into a plurality of rod shapes embedded apart in the resin. The above configuration can reduce the volume of the core material, and suppress an increase in weight due to the addition of the core material.
According to the power supply device according to a ninth aspect, in addition to any of the above configurations, the cover part can be insert-molded in the core material.
According to the power supply device according to a tenth aspect, in addition to any of the above configurations, the cover part includes a rectangular shape, and the rectangular shape can have an aspect ratio of 5 or more.
According to a vehicle according to an eleventh aspect of the present invention, the vehicle including any of the above power supply devices, and can include the power supply device, a running motor to which electric power is supplied from the power supply device, a vehicle body on which the power supply device and the motor are mounted, and wheels that are driven by the motor to cause the vehicle body to travel.
A power storage device according to a twelfth aspect of the present invention, the power storage device including any of the above power supply devices, includes: the power supply device; and a power supply controller that controls charging to and discharging from the power supply device, in which the power supply controller enables charging to the battery cell with electric power from an outside, and controls charging to the battery cell.
Exemplary embodiments of the present invention will be described below with reference to the drawings. However, the exemplary embodiments described below are examples that allow a technical idea of the present invention to be embodied, and the present invention is not limited to the exemplary embodiments described below. In the present description, components described in the scope of claims are not limited to the components of the exemplary embodiments. In particular, it is not intended to limit the scope of the present invention to sizes, materials, shapes of components, relative arrangement of the components, and the like that are described in the exemplary embodiments, unless otherwise specified. The sizes, materials, shapes of the components, and the relative arrangement of the components are mere explanation examples. Note that the sizes, the positional relation, and the like of the components in the drawings may be exaggerated for clarifying the explanation. Furthermore, in the following description, the same names or the same reference marks denote the same components or components of the same type, and detailed description is appropriately omitted. Regarding the elements constituting the present invention, a plurality of elements may be formed of the same component, and one component may serve as a plurality of elements. In contrast, the function of one component may be shared by a plurality of components. Contents described in some examples or exemplary embodiments can be used, for example, in other examples or exemplary embodiments.
The power supply device according to exemplary embodiments can be used in various applications including a power source that is mounted in a hybrid automobile, an electric automobile, or another electric vehicle to supply electric power to a running motor, a power source that stores power generated by natural energy such as photovoltaic power generation and wind power generation, and a power source for storing late-night power. In particular, the power supply device can be used as a power supply suitable for high power and high current applications. In an example below, exemplary embodiments in which the power supply device is applied to a power supply device for driving an electric vehicle will be described.
A power supply device according to a first exemplary embodiment of the present invention is shown in
(Battery Cell 1)
As shown in
The plurality of battery cells 1 are stacked with the thickness direction of each battery cell 1 being the stacking direction to constitute battery stack 2. At this time, by providing more stacks than usual, it is possible to increase output of battery stack 2. In such a case, battery stack 2 is long and extended in the stacking direction. Terminal surfaces 10 provided with positive and negative electrode terminals 11 are arranged on the same plane, and thus the plurality of battery cells 1 are stacked to constitute battery stack 2. The upper surface of battery stack 2 is a surface provided with gas discharge valves 13 of the plurality of battery cells 1.
(Separator 30)
As shown in
Mounting plate part 31 is a part held between battery cells 1 adjacent to each other. Mounting plate part 31 has a plate shape having substantially the same size as the facing surface of battery cells 1, and separator 12 is stacked between battery cells 1 adjacent to each other to insulate battery cells 1 adjacent to each other. Substantially similarly to the facing surface of battery cells 1, mounting plate part 31 has a rectangular shape having long sides that are long in a width W and short sides.
Upper peripheral wall 32 is provided at an upper end of mounting plate part 31, and is locked to sealing plate 1b of battery cell 1. The upper surface of upper peripheral wall 32 includes a separator-side locking piece 34 described later.
On the other hand, longitudinal peripheral wall 33 is provided to be orthogonal to narrowly held plate part 31. One end part on the lower side of longitudinal peripheral wall 33 slightly protrudes toward one of battery cells 1 adjacent to each other, and is partially bent along the bottom side of narrowly held plate part 31. With such a shape, separator 30 can easily stand by itself, and the lower corner parts of battery cells 1 adjacent to each other can be held by the protruding part and the bent part, so that battery cells 1 adjacent to each other can be more reliably narrowly held.
(Battery Stack 2)
In battery stack 2, bus bar 14 made of metal is connected to positive and negative electrode terminals 11 of battery cells 1 adjacent to each other, and the plurality of battery cells 1 are connected in series or in parallel or in series and in parallel by bus bar 14. A bus bar holder may be disposed between battery stack 2 and the bus bar. Use of the bus bar holder makes it possible to dispose the plurality of bus bars at fixed positions on the upper surface of the battery stack while insulating the plurality of bus bars from each other and insulating the terminal surfaces of the battery cells from the bus bars.
Bus bar 14 is manufactured into a predetermined shape by cutting and processing a metal sheet. As the metal sheet constituting the bus bar, a metal having low electrical resistance and light weight, for example, an aluminum sheet, a copper sheet, or an alloy of them can be used. However, for the metal sheet for the bus bar, another metal having low electrical resistance and light weight or an alloy of them can be used.
(End Surface Spacer 12)
End plates 3 are disposed on both end surfaces of battery stack 2 across end surface spacer 12. As shown in
(End Plate 3)
As shown in
End plate 3 has a quadrangular outer shape, and is disposed facing the end surface of battery stack 2. End plate 3 shown in
A method for fixing this end plate is not particularly limited. For example, end plate 3 shown in
(Fastening Member 4)
As shown in
Fastening member 4 includes fastening member body part 40 disposed along the side surface of battery stack 2, and fastening member-side fixing part 41 bent at both ends of fastening member body part 40 and fixed to the outer surface of end plate 3. Fastening member body part 40 has a rectangular shape with a size that covers battery stack 2 and almost entire end plates 3 disposed at both ends of battery stack 2. Fastening member body part 40 shown in
(Cover Part 60)
As shown in
As shown in the exploded perspective view of
(Locking Claw Part 62)
Locking claw part 62 is one form of the fixture for fixing cover part 60 to separator 30. The position and number of locking claw parts 62 are not particularly limited. As an example, as shown in
As shown in the cross-sectional view of
The protruding orientation of locking claw protruding part 62b is not particularly limited, as long as it can be engaged with a corresponding reception part (details will be described later). For example, in cover part 60 of
(Separator-Side Locking Piece 34)
On the other hand, separator 30 includes the reception part that receives locking claw part 62 of cover part 60 on the upper surface of upper peripheral wall 32. Separator-side locking piece 34 is one aspect of the reception part that receives locking claw part 62. As shown in
As shown in
(Holder Part 50)
The present invention is not limited to an aspect in which a separator is used as a structure for fixing cover part 60 to battery stack 2. For example, a holder part may be provided to fix cover part 60 to the holder part. As an example, holder part 50 of modified example 1 is provided between the upper surface of battery stack 2 and cover part 60 as shown in
Use of holder part 50 also as a bus bar holder that holds the bus bar makes it possible to further simplify the configuration. A voltage detector or the like that detects the voltage of battery cell 1 may be provided in holder part 50. Holder part 50 is preferably made of an insulating resin so as not to short-circuit battery stack 2.
In modified example 1, since holder part 50 fixes cover part 60, it is not necessary to provide the separator with a separator-side locking piece. Therefore, the separator may be manufactured in a thin plate shape or sheet shape with an insulating material. This makes it possible to simplify the configuration of the separator. However, the size and shape of the separator are not particularly limited. For example, the separator may have a shape in which a flow path for a cooling gas is provided between battery cell 1 and the spacer. The surface of battery cell 1 can also be covered with an insulating material. For example, the surface of outer covering can 1a excluding the electrode part of the battery cell may be thermally welded with a shrink tube or a shrink film made of such as a polyethylene terephthalate (PET) resin.
(Core Material 63)
As shown in
Usually, when a long cover part having a high aspect ratio is molded with a resin in order to impart insulation properties, undulation and warpage are likely to occur. As a result, the position of the locking claw part may be deviated, and the fixing to the holder part may be hindered. External air easily enters from the undulating or warped part. In a case where gas discharge valve 13 of battery cell 1 is opened and a high-pressure gas is released from the upper surface of battery stack 2, external air is supplied to the inside of battery stack 2, and the state gets worse. Therefore, in the present exemplary embodiment, by core material 63 embedded in cover part 60, even when cover part 60 made of resin has an extended elongated shape, warpage and undulation can be suppressed by core material 63 made of metal, and locking claw parts 62 can be provided at expected positions, so that the reliability of fixing to battery assembly 2 can be enhanced. It is possible to avoid external air from being supplied due to warpage or undulation of cover part 60 and to improve safety.
Core material 63 is a metal sheet having excellent heat transfer properties and rigidity. For example, core material 63 is an iron sheet, stainless steel, a high-tensile steel sheet, an aluminum sheet, or the like. In addition to the metal sheet in a plate shape, core material 63 may have a mesh shape or a lattice shape.
In the first exemplary embodiment described above, an example in which core material 63 is embedded in cover body part 61 has been described. However, the core material of the present invention is not limited to the above aspect. For example, a part of the core material may be exposed from the cover body part. The part to be exposed can be an end part in the longitudinal direction of the cover body part or a side surface. As an example, a cover part according to a second exemplary embodiment is shown in a longitudinal cross-sectional view of
When core material 63B is fixed to the upper surface of end plate 3, a fixing structure using locking claw part 62 can be omitted.
The position where the core material is exposed from the cover body part is not limited to the circumferential direction of the cover body, and may be on the main surface. Such an example is shown in
Furthermore, the metal core material of the present invention is not limited to the above-described plate shape. For example, a wire material such as an iron wire or a rod-like wire can be adopted. In core material 63D shown in
On the other hand, in the above-described first to third exemplary embodiments, the plate-shaped core material is spread to cover the upper surface of battery assembly 2, and a gap is not provided between the wire materials unlike the core material of a fourth exemplary embodiment. Therefore, even when a high-pressure gas is released, it is possible to avoid the gas from passing through the gap to blow out to the outside of the power supply device.
Power supply device 100 described above can be used as a power source for a vehicle that supplies electric power to a motor that causes an electric vehicle to travel. As an electric vehicle on which power supply device 100 is mounted, an electric vehicle such as a hybrid automobile or a plug-in hybrid automobile that travels by both an engine and a motor, or an electric automobile that travels only by a motor can be used, and is used as a power source of these vehicles. Note that an example will be described in which in order to obtain electric power for driving the electric vehicle, a large number of power supply devices 100 described above are connected in series or in parallel, and a large-capacity, high-output power supply device to which a necessary controlling circuit is further added is constructed.
(Power Supply Device for Hybrid Automobile)
(Power Supply Device for Electric Automobile)
(Power Supply Device for Power Storage Device)
The application of the power supply device of the present invention is not limited to a power source for a motor that causes the vehicle to travel. The power supply device according to the exemplary embodiments can be used as a power source for a power storage device that performs power storage by charging the battery with electric power generated by photovoltaic power generation, wind power generation, or other methods.
The power storage device shown in
Although not illustrated, the power supply device can also be used as a power source of a power storage device that performs power storage by charging a battery using midnight electric power at night. The power supply device charged with midnight electric power is charged with the midnight electric power, which is surplus electric power generated by a power station, and outputs the electric power during the daytime when an electric power load increases. Thus, peak electric power during the daytime can be limited to a small value. The power supply device can also be used as a power source charged with both output of a solar battery and the midnight electric power. This power supply device can efficiently perform power storage effectively using both electric power generated by the solar battery and the midnight electric power in consideration of weather and electric power consumption.
The power storage system as described above can be suitably used in applications such as a backup power supply device that can be installed in a rack of a computer server, a backup power supply device for a radio base station for a cellular phone or the like, a power storage power source for use in a house or a factory, a power storage device combined with a solar battery such as a power source for street lights, and a backup power source for traffic lights and traffic indicators on roads.
The power supply device according to the present invention and a vehicle including the same are suitably used as a large-current power supply used for a power source of a motor for driving an electric vehicle such as a hybrid automobile, a fuel cell automobile, an electric automobile, and an electric motorcycle. Examples include a power supply device for a plug-in hybrid electric automobile and a hybrid type electric vehicle that can switch between an EV running mode and a HEV running mode and an electric automobile.
Furthermore, the power storage system can also be appropriately used in applications such as a backup power supply device that can be installed in a rack of a computer server, a backup power supply device for a radio base station for a cellular phone or the like, a power storage power source for use in a house or a factory, a power storage device combined with a solar battery such as a power source for street lights, and a backup power source for traffic lights and the like.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2019-145724 | Aug 2019 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2020/028023 | 7/20/2020 | WO |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2021/024771 | 2/11/2021 | WO | A |
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|---|---|---|---|
| 20110229754 | Zhao | Sep 2011 | A1 |
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| 20200243830 | Tanaka et al. | Jul 2020 | A1 |
| 20210050572 | Omura et al. | Feb 2021 | A1 |
| Number | Date | Country |
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| 105190934 | Dec 2015 | CN |
| 2012-084447 | Apr 2012 | JP |
| 2012084447 | Apr 2012 | JP |
| 2013031613 | Mar 2013 | WO |
| 2014103007 | Jul 2014 | WO |
| 2018012224 | Jan 2018 | WO |
| 2018168982 | Sep 2018 | WO |
| Entry |
|---|
| International Search Report of PCT application No. PCT/JP2020/028023 dated Sep. 24, 2020. |
| English translation of Search Report dated Oct. 14, 2023, issued in counterpart CN Application No. 202080056401.2. (3 pages). |
| Number | Date | Country | |
|---|---|---|---|
| 20220247029 A1 | Aug 2022 | US |
