Energy storage device and method for manufacturing a cooling device for an energy storage device

Abstract

Energy storage device (14) with - several cooling devices (15a - 15f), - several energy storage devices (1a, 1b) arranged on the cooling devices (15a - 15f), each cooling device (E3, E8, E10) being designed to cool at least one energy storage device (1a, 1b) for storing electrical energy for a vehicle and is each equipped with: - a cooling plate (7) for mounting and cooling the at least one energy storage device (1a, 1b) and - a cooling channel (9) formed integrally with and adjacent to the cooling plate (7) for receiving a coolant, wherein the cooling channel (9) runs along one side of the cooling plate (7), wherein the cooling channels (9) of the cooling devices (15a - 15f) serve as spacers between the cooling devices (E3, E8, E10), and - a coolant distributor (16a, 16b) which is connected to the cooling channels (9) of the cooling devices (E3, E8, E10).

Description

[0001] The present invention relates to a cooling device for cooling at least one energy storage device for storing electrical energy for a vehicle, and to an energy storage device with several such cooling devices. Furthermore, the invention relates to a method for manufacturing such a cooling device.

[0002] To reduce fuel consumption and pollutant emissions, modern motor vehicles increasingly use electric motors as a power source. These electric motors are usually supplied with electrical energy using high-performance energy storage devices, such as electrochemical energy storage devices (e.g., batteries) and / or electrostatic energy storage devices (e.g., capacitors or double-layer capacitors).

[0003] In an electrochemical energy storage device, such as a battery with preferably a plurality of energy storage cells connected in series and / or parallel, (a) in the case of charging, electrical energy is converted into chemical energy, and (b) in the case of discharging, chemical energy is converted into electrical energy. Thus, electrical energy is stored by conversion into chemical energy. In an electrostatic energy storage device, such as a so-called double-layer capacitor, an electrical charge or discharge occurs on preferably several double-layer capacitors.

[0004] In particular, the electrochemical energy conversion processes are subject to losses depending on the type of accumulator used and its respective cell chemistry, resulting in heating and thus a change in the enthalpy of the energy storage device in question.

[0005] Additionally, waste heat is generated (a) during the cyclic operation of electrochemical energy storage devices and (b) due to the constantly present ohmic resistances, for example, the internal resistance of the cells and / or electrical inter-cell connections. Therefore, depending on the electrical power loss in an electrochemical energy storage device, heating and a temperature increase during operation are unavoidable unless efficient cooling is used.

[0006] As the maximum power output and storage capacity of energy storage systems continue to increase, while the available installation space for these systems decreases, the power density (power output per unit volume) increases significantly. Particularly in electrochemical energy storage systems, exothermic side reactions or energy losses due to the internal resistance of the cells during charging and discharging result in high heat release. To prevent critical temperature conditions, which are not only essential for safety reasons but also drastically reduce the lifespan of individual energy storage devices, efficient cooling concepts are necessary. These cooling concepts must meet very high standards in terms of compact design, simple and cost-effective construction, and cooling efficiency.

[0007] One method of heat dissipation is to connect the energy storage unit to a cooling fin via an electrically insulating heat transfer layer. Cooling fins represent a good compromise between thermal conductivity and weight, while also offering good mechanical strength. Previous connections of the cell via the cooling fin were typically achieved by inserting or mounting the cooling fins onto a heat sink. The disadvantage of this method is the high thermal resistance between the cooling fin and the heat sink, which can lead to insufficient heat dissipation from the cell despite the very low inlet temperature, thus significantly increasing the cooling requirements.

[0008] German patent application DE 10 2011 109 484 A1 discloses a thermal regulation system for a battery pack. The system comprises a plurality of main bodies arranged in a stack, an inlet line and an outlet line in fluid communication with the plurality of main bodies, and a retaining plate coupled to the plurality of main bodies. The main bodies include a thermal fin and a line and are formed using an extrusion process.

[0009] DE 10 2011 109 286 A1 describes an integrated cooling fin and an integrated frame. The cooling fin is arranged with a cooling channel adjacent to at least one edge, the cooling channel comprising an inlet and an outlet. The frame is arranged around the cooling fin and covers the edges of the cooling fin. The frame also has an opening for the inlet and outlet of the cooling channel.

[0010] It is an object of the present invention to provide a cooling device for cooling at least one energy storage device for storing electrical energy, as well as an energy storage device based thereon, which exhibit improved heat dissipation characteristics. Furthermore, it is a further object of the present invention to provide a simple but effective manufacturing method for such a cooling device.

[0011] These problems are solved by an energy storage device according to claim 1, a manufacturing method according to claim 5, and a manufacturing method according to claim 8. The dependent claims specify embodiments of the present invention.

[0012] Accordingly, the invention comprises an energy storage device with multiple cooling devices, each cooling device for cooling at least one energy storage device for storing electrical energy for a vehicle, comprising a cooling plate for mounting and cooling the at least one energy storage device and a cooling channel integrally connected to and adjacent to the cooling plate for receiving a coolant, the cooling channel extending along one side of the cooling plate. The cooling channel can be manufactured, in particular, by means of bending. The integral design of the cooling plate with the cooling channel ensures efficient heat dissipation from the cooling plate into the cooling channel. Typically, such a cooling device has only a single cooling channel. The cooling plate and the cooling channel can, for example, be made of aluminum. The cooling plate essentially has six sides.The energy storage devices can be arranged on two of the sides. The remaining sides are referred to below as the edges of the cooling plates. Furthermore, according to the invention, the cooling channels of the cooling devices serve as spacers between the cooling devices. The energy storage device also comprises several energy storage devices arranged on the cooling devices and a coolant distributor connected to the cooling channels of the cooling device.

[0013] The coolant distributor can not only supply the cooling channels with coolant, but can also hold the cooling devices together with the energy storage units, thus eliminating the need for an additional base plate. This saves costs.

[0014] In one embodiment, the cooling plate extends in a reference plane, and the cooling channel runs within this reference plane. The cooling channel thus runs along an edge of the cooling plate. This results in a compact design that is particularly space-saving when combining multiple cooling devices.

[0015] Preferably, the cooling channel has a larger outer circumference perpendicular to the reference plane than the cooling plate. The outer circumference of the cooling channel can be substantially rectangular. Due to its larger size compared to the cooling plate, the cooling channel can act as a spacer when multiple cooling devices are combined.

[0016] To increase the turbulence level of the coolant in the cooling channel, a turbulence element can be arranged in the cooling channel.

[0017] Preferably, the transitions between the coolant distributor and the cooling channels of the cooling devices are sealed by means of sealing sleeves, which preferably have double sealing rings. The sealing sleeves allow for the compensation of manufacturing tolerances. The double sealing ring design ensures sufficient sealing even under vibration loads.

[0018] In one embodiment, the energy storage device comprises a housing, wherein the cooling devices have fixing aids to facilitate screwing the cooling devices to the housing. In this way, the cooling devices can be screwed together easily and efficiently. The housing can be made of aluminum, for example.

[0019] The present invention further comprises a method for manufacturing a cooling device according to the invention. In this method, a sheet metal part is first provided, comprising a cooling plate for mounting and cooling the at least one energy storage device, as well as a further section. The sheet metal part can, for example, be made of aluminum. The further section of the sheet metal is processed by bending to produce a cooling channel integrally connected to and adjacent to the cooling plate for receiving a coolant, such that the cooling channel runs along one side of the cooling plate. Typically, only a single cooling channel is produced per cooling device. The bending step can be carried out, in particular, by roll bending. Bending is a simple, efficient, and cost-effective method for manufacturing the cooling channel. Heating the sheet metal can be omitted to save energy.

[0020] In one embodiment, the bending forming step is carried out such that the cooling plate extends in a reference plane and the cooling channel runs within the reference plane. The cooling channel can have a larger extent than the cooling plate at its outer circumference orthogonal to the reference plane, and in particular, the cooling channel can have a substantially rectangular shape at its outer circumference.

[0021] The cooling channel can be sealed along its length, particularly by soldering or welding one end of the remaining sheet metal section to a portion of the sheet metal. This prevents the coolant from leaking out of the cooling channel due to pressure.

[0022] In one embodiment, grooves are created in the further part of the sheet metal to facilitate bending.

[0023] In another embodiment, the method for manufacturing a cooling device according to the invention comprises the following steps. First, a sheet metal part is again provided, comprising a cooling plate for mounting and cooling the at least one energy storage device, as well as a further component. The sheet metal part can again be made of aluminum, in particular. In a further step, a bore is drilled through the further component of the sheet metal part, extending along one side of the cooling plate, thus creating a cooling channel integrally connected to and adjacent to the cooling plate for receiving a coolant. Typically, only one bore is drilled, so that there is only a single cooling channel per cooling device. In this way, too, a cooling device according to the invention can be manufactured simply and efficiently.

[0024] Furthermore, the invention comprises a method for manufacturing an energy storage device. In this method, several cooling devices are equipped with multiple energy storage elements and connected to a coolant distributor. Transitions between the coolant distributor and the cooling channels can be sealed using sealing sleeves. Subsequently, the cooling devices can be screwed to a housing.

[0025] The invention was disclosed partly with reference to a device and partly with reference to a manufacturing process. Unless otherwise stated, process features can be applied analogously to the devices and the device features analogously to the processes. In embodiments, the devices thus include the features that necessarily arise from the manufacturing process.

[0026] Further features and advantages of embodiments of the invention are explained below with reference to the figures. These show: Fig. 1A a state-of-the-art energy storage device; Fig. 1B another energy storage device according to the state of the art; Fig. 2A a first embodiment of a method according to the invention for manufacturing a cooling device; Fig. 2B Intermediate products or the final product of the first embodiment of the process according to the invention; Fig. 3A a second embodiment of a method according to the invention for manufacturing a cooling device; Fig. 3B Intermediate products or the final product of the second embodiment of the process according to the invention; Fig. 4A a third embodiment of a method according to the invention for manufacturing a cooling device; Fig. 4B Intermediate products or the final product of the third embodiment of the process according to the invention; Fig. 5 an embodiment of a cooling device according to the invention with corresponding energy storage devices; Fig. 6 an embodiment of an energy storage device according to the invention in an exploded view; Fig. 7 the embodiment from Fig. 6 in an assembled state in a side view; Fig. 8A a partial section through the in Fig. 7 embodiment shown and Fig. 8B is an embodiment of a sealing sleeve.

[0027] Unless otherwise specified, identical and equivalent elements are referred to by the same reference symbols in the following text.

[0028] Fig. Figure 1A shows a prior art energy storage device. Two energy storage devices 1a, 1b are connected to two cooling plates 2a, 2b. Each energy storage device 1a, 1b has a heat sink element 3a, 3b, the heat sink elements being connected by a laser or ultrasonic weld 4. Each cooling plate 2a, 2b has a base 5a, 5b. These bases 5a, 5b are connected, for example, by means of an adhesive to a heat sink 6.

[0029] Fig. Figure 1B illustrates a second energy storage device known from the prior art. This time, the two energy storage devices 1a and 1b are mounted on a single cooling plate 2a from opposite sides. The energy storage devices 1a and 1b are connected to each other via corresponding heat sink elements 3a and 3b and a corresponding laser or ultrasonic weld 4. The cooling plate 2a is connected to the heat sink 6 via a base 5a. A significant thermal resistance occurs between the base 5a and the heat sink 6.

[0030] Fig. Figure 2A shows a first embodiment of a method according to the invention for manufacturing an embodiment of a cooling device according to the invention. The intermediate products and the final product of this first embodiment are in Fig. Figure 2B shows that in step S1, a sheet metal plate E1 is provided, which has a cooling plate 7 for attaching and cooling the at least one energy storage device, as well as a further part 8. In step S2, this further part 8 is bent. This can be done, for example, by roll bending. In this way, the [part] is created. Fig. 2B, the intermediate product designated E2, has a cooling channel 9. This cooling channel 9 is integrally connected to the cooling plate and is adjacent to it. It runs along one side of the cooling plate. This means that the cooling channel does not pass through the cooling plate. In step S3, the cooling channel 9 is sealed along its direction of travel. This can be done, for example, by soldering one end 10 of the further part to a section of the sheet metal. Fig. Figure 2B shows that the final product E3 has solder 11 between the end 10 of the further part and the sheet that seals the cooling channel.

[0031] Fig. Figure 3A shows a second embodiment of a method according to the invention for manufacturing an embodiment of a cooling device according to the invention. The corresponding intermediate products or the final product are produced in Fig. Figure 3B is shown. In step S4, a sheet E4 is again provided, which has a cooling plate 7 for attaching and cooling the at least one energy storage device, as well as a further part 8. The further part 8 is rolled in step S5 to make it thinner, so that the intermediate product E5 is created (see Figure 3B). Fig. 3B). Corresponding grooves 12a, 12b, 12c are produced in step S6 in the further part 8 of the sheet. Subsequently, in step S7, the further part is bent to create the intermediate product E7. This intermediate product E7 in turn has a corresponding cooling channel 9, which is integrally connected to and adjacent to the cooling plate 7. In step S8, the cooling channel is sealed along its direction. This can be done, for example, by soldering. As the final product E8 shows, solder 11 is arranged between one end 10 of the further part of the sheet 8 and a region of the sheet.

[0032] Fig. Figure 4A shows a third embodiment of a method according to the invention for manufacturing an embodiment of a cooling device according to the invention. The corresponding intermediate products and the final product are again shown in Fig. Figure 4B illustrates this. In step S9.1, a sheet E9.1 is prepared. In step S9.2, this sheet is rolled in a specific area to thin it, creating sheet E9.2. Sheet E9.2 thus comprises a cooling plate 7 for mounting and cooling the at least one energy storage device, as well as another part 8. In step S10, a hole is drilled through the other part of sheet 8, extending along one side of the cooling plate. This creates a cooling channel 9, integrally connected to and adjacent to the cooling plate 7, for receiving a coolant. Fig. Figure 5 shows an embodiment of a cooling device according to the invention with two energy storage elements 1a, 1b. The energy storage elements 1a, 1b are connected to each other by conductive elements 3a, 3b and a laser or ultrasonic weld 4. The energy storage elements 1a, 1b are arranged on the cooling plate 7, which is integrally connected to the adjacent cooling channel 9. The cooling channel 9 was produced by bending a further portion of the sheet metal 8 and soldering one end 10 of this further portion. Fixing aids 13a, 13b are arranged on the cooling plate 7 to facilitate screwing the cooling device to a housing.

[0033] Fig. Figure 6 illustrates an embodiment of an energy storage device 14 according to the invention in an exploded view. This energy storage device comprises several cooling devices 15a-15f on which corresponding energy storage elements are arranged. The coolant distributor 16a, 16b consists of two parts, one serving to supply coolant to the cooling channels and the other serving to discharge coolant from the cooling channels. The transitions between the coolant distributor 16a, 16b and the cooling channels of the cooling devices 15a-15f are sealed by means of sealing sleeves 17a-17i. A housing 18a-18d, consisting of four parts that are screwed to the cooling devices, encloses the energy storage device. Fig. Figure 7 shows the embodiment of an energy storage device 14 again in an assembled state in a side view.

[0034] Fig. Figure 8A shows part of the energy storage device 14. Fig. Figure 7 in a sectional view. The coolant distributor 16a is connected to a cooling channel 9 via a sealing sleeve 17a. The coolant distributor 16a is screwed to the cooling device 15a by means of a screw 19. The sealing sleeve 17a is in Fig. Figure 8B shows this figure in detail. It can be seen that the sealing sleeve 17a has a double sealing ring on each side. The individual sealing rings are designated with the reference numbers 20a - 20d.

[0035] The invention enables a thermal connection between the coolant and the cooling plate by integrally connecting the cooling plate to a cooling channel through which the coolant flows. In corresponding energy storage devices, the cooling channels can simultaneously serve as spacers between the individual cooling units. In contrast to the prior art, no additional cooling elements, such as a base block or core, are required to combine the cooling units into an energy storage device, resulting in a low weight for the energy storage device. At the same time, the space requirement can be minimized while maintaining high mechanical strength. The cooling units can be manufactured particularly cost-effectively, for example, by roll bending.Cost advantages can be achieved through the simple design of the cooling and energy storage devices, as well as the efficient manufacturing process. Efficient heat dissipation from the energy storage units and a low temperature gradient in the cooling plate can be achieved. The double sealing rings minimize the risk of leakage. Reference symbol list 1a, 1b Energy storage 2a, 2b Cooling plate 3a, 3b Conductor element 4 Laser or ultrasonic welding point 5a, 5b Foot section 6 heat sinks 7 Cooling plate 8 more parts of the sheet metal 9 Cooling channel 10 End (of the further part of the sheet metal) 11 solder 12a - 12c Nut 13a - 13b Fixing aid 14 Embodiment of an energy storage device according to the invention 15a - 15f Cooling device with energy storage 16a, 16b Coolant distributor 17a - 17i Sealing sleeve 18a - 18d Housing 19 screw 20a - 20d Sealing ring S1 Providing a sheet S2 Bending of the remaining part of the sheet metal S3 Sealing the cooling channel along its direction of travel S4 Providing a sheet S5 Rolling of the sheet metal S6 Creating grooves S7 Bending of the further part of the sheet metal S8 Sealing the cooling channel along its direction of travel S9.1 Providing a sheet S9.2 Rolling of sheet metal S10 Drilling a hole through the further part of the sheet metal E1 sheet metal E2 sheet metal with cooling channel E3 embodiment of a cooling device according to the invention E4 sheet metal E5 sheet metal with rolled additional part E6 E5 with grooves E7 sheet metal with cooling channel E8 embodiment of a cooling device according to the invention E9.1 Sheet metal E9.2 sheet metal with a cooling plate and another part E10 embodiment of a cooling device according to the invention

Claims

[1] Energy storage device (14) with - several cooling devices (15a - 15f), - several energy storage devices (1a, 1b) arranged on the cooling devices (15a - 15f), each cooling device (E3, E8, E10) being designed to cool at least one energy storage device (1a, 1b) for storing electrical energy for a vehicle and is each equipped with: - a cooling plate (7) for mounting and cooling the at least one energy storage device (1a, 1b) and - a cooling channel (9) formed integrally with and adjacent to the cooling plate (7) for receiving a coolant, wherein the cooling channel (9) runs along one side of the cooling plate (7), wherein the cooling channels (9) of the cooling devices (15a - 15f) serve as spacers between the cooling devices (E3, E8, E10), and - a coolant distributor (16a, 16b) which is connected to the cooling channels (9) of the cooling devices (E3, E8, E10). [2] Energy storage device (14) according to claim 1, wherein the cooling channel (9) has a larger extent at its outer circumference orthogonal to the reference plane than the cooling plate (7). [3] Energy storage device (14) according to claim 1 or 2, wherein transitions between the coolant distributor (16a, 16b) and the cooling channels (9) of the cooling devices (15a - 15f) are sealed by means of sealing sleeves (17a - 17i) which preferably have double sealing rings (20a - 20d). [4] Energy storage device (14) according to one of the preceding claims, comprising a housing (18a - 18d), wherein the cooling devices (15a - 15f) have fixing aids (13a, 13b) to facilitate screwing the cooling devices (15a - 15f) to the housing (18a - 18d). [5] Method for manufacturing a cooling device (E3, E8, E10) for an energy storage device (14) according to one of claims 1 or 2, comprising the steps - Providing a sheet (S1, S4) comprising a cooling plate (7) for mounting and cooling the at least one energy storage device (1a, 1b) and a further part (8), and - Bending forming (S2, S7) of the further part of the sheet (8) to produce a cooling channel (9) formed in one piece with the cooling plate (7) and adjacent to the cooling plate (7) for receiving a coolant, so that the cooling channel (9) runs along one side of the cooling plate (7). [6] Method according to claim 5, comprising the further step of sealing the cooling channel (S3, S8) along its direction of travel, wherein the sealing is carried out by soldering or welding an end (10) of the further part of the sheet (8) to a region of the sheet. [7] Method according to claim 5 or 6, comprising the further step of producing grooves (12a - 12c) in the further part of the sheet (8) to facilitate bending (S2, S7). [8] Method for manufacturing a cooling device (E3, E8, E10) for an energy storage device (14) according to one of claims 1 or 2, comprising the steps - Providing a sheet (S9.1, S9.2) comprising a cooling plate (7) for mounting and cooling the at least one energy storage device (1a, 1b) and a further part (8), and - Drilling a hole through the further part of the sheet (S10) extending along one side of the cooling plate (7) in order to produce a cooling channel (9) formed integrally with and adjacent to the cooling plate (7) for receiving a coolant.

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