High-voltage battery arrangement and method for temperature control of individual cells

Abstract

The invention relates to a high-voltage battery arrangement (1) for a vehicle, comprising a plurality of individual cells (3), a housing (4) for accommodating the individual cells (3), and a latent heat accumulator (2). According to the invention, the latent heat accumulator (2) is connected to a temperature-controlled positioning device (5) which is designed to automatically position the latent heat accumulator (2) in at least two positions (P1, P2), wherein the latent heat accumulator (2) is thermally coupled to the individual cells (3) in a first position (P1) and is thermally coupled to the housing (4) in a second position (P2). The invention further relates to a method for controlling the temperature of the individual cells (3) of the high-voltage battery arrangement (1).

Description

[0001] The invention relates to a high-voltage battery assembly for a vehicle, comprising a plurality of individual cells, a housing for accommodating the individual cells, and a latent heat storage device. Furthermore, the invention relates to a method for controlling the temperature of the individual cells of the high-voltage battery assembly.

[0002] DE 10 2014 017 989 A1 discloses a high-voltage battery arrangement with a latent heat storage device for a motor vehicle. The high-voltage battery arrangement comprises a plurality of battery cells, a battery housing for accommodating the battery cells, a heat exchange device for the one-way or reciprocal exchange of thermal energy between battery cells and an environment outside the high-voltage battery arrangement, and a latent heat storage device consisting of a phase-change material for thermally coupling the battery cells and the heat exchange device. A separating element is arranged between the battery cells and the heat exchange device. In the liquid state of the phase-change material, this separating element supports the formation of a circular circulation of the phase-change material from the heat exchange device to the battery cells and back as a result of a temperature gradient created by heat input or heat extraction at the heat exchange device.

[0003] The invention is based on the object of specifying a novel high-voltage battery arrangement and a method for temperature control of individual cells of the high-voltage battery arrangement.

[0004] The object is achieved according to the invention by a high-voltage battery arrangement which has the features specified in claim 1 and by a method which has the features specified in claim 8.

[0005] Advantageous embodiments of the invention are the subject of the subclaims.

[0006] A high-voltage battery arrangement for a vehicle comprises a plurality of individual cells, a housing for accommodating the individual cells, and a latent heat accumulator. According to the invention, the latent heat accumulator is connected to a temperature-controlled positioning device configured to automatically position the latent heat accumulator in at least two positions, wherein the latent heat accumulator is thermally coupled to the individual cells in a first position and thermally coupled to the housing in a second position.

[0007] Using the positionable latent heat storage device, the individual cells can be passively tempered, particularly cooled, thus increasing the efficiency of the individual cells. Passive temperature control using the latent heat storage device, which can be positioned using the positioning device, can be implemented with a small number of comparatively inexpensive components.

[0008] In addition, the latent heat storage can be recycled relatively easily.

[0009] In one embodiment, the housing has a heat sink to which the latent heat storage device can be thermally coupled. For example, the heat sink has cooling fins to efficiently dissipate heat transferred to the heat sink by the latent heat storage device, for example, by exposing the heat sink to airflow during vehicle operation.

[0010] In another embodiment, the latent heat storage device is arranged between the individual cells and a housing base, so that any heat loss generated during charging and discharging of the individual cells can be transferred to the housing base. Typically, the high-voltage battery assembly is located near the vehicle floor, so that the housing base is exposed to the wind during vehicle operation, allowing the heat to be dissipated.

[0011] In one possible design, the latent heat storage device is coated with a thermally conductive material to optimize thermal coupling between individual cells and the latent heat storage device or between the housing and the latent heat storage device. The thermally conductive material forms a thermal interface between the respective components.

[0012] In one possible embodiment, the positioning device comprises a gear and / or an electromagnetic actuator. Thus, the latent heat storage device can be positioned in the first position or the second position in order to dissipate the heat transferred from the individual cells to the latent heat storage device and stored by the latter to the outside of the housing.

[0013] In one embodiment, the positioning device is coupled to a temperature detection unit arranged within the housing, so that the positioning unit is activated in a temperature-controlled manner to thermally couple the latent heat storage device either to the individual cells or to the housing. In particular, a temperature threshold is specified for this purpose, so that when the temperature threshold is exceeded, the positioning device of the latent heat storage device is positioned in the first position to cool the individual cells by transferring heat to the latent heat storage device.

[0014] In one embodiment, the heat sink is arranged on the housing base so that the heat stored by the latent heat storage is transferred to the housing base and from there to the heat sink in order to dissipate the heat efficiently, in particular with the help of the airflow when the vehicle is moving.

[0015] Furthermore, the invention relates to a method for controlling the temperature of the individual cells of the high-voltage battery assembly according to one of the preceding claims using the latent heat storage device. According to the invention, the latent heat storage device is thermally coupled either to the individual cells or to the housing by means of the positioning device, depending on the temperature of the individual cells.

[0016] The latent heat storage device is positioned in the first position or the second position by means of the positioning device so that heat loss from the individual cells is efficiently dissipated via the latent heat storage device and the housing in order to cool the individual cells and thereby optimize their functioning.

[0017] Embodiments of the invention are explained in more detail below with reference to drawings.

[0018] Showing: Fig. 1 schematically shows a sectional view of a high-voltage battery arrangement with a latent heat storage device in a first position, Fig. 2 schematically shows a sectional view of the high-voltage battery arrangement with the latent heat storage device in a second position, Fig. 3 schematically shows a sectional view of a first embodiment of the latent heat storage device, Fig. 4 schematically shows a sectional view of a second embodiment of the latent heat storage device, Fig. 5 schematically shows a sectional view of a third embodiment of the latent heat storage device and Fig. 6 schematically shows a diagram with a charging profile and different operating states in relation to time.

[0019] Corresponding parts are provided with the same reference numerals in all figures.

[0020] Fig. 1 shows a sectional view of a high-voltage battery arrangement 1 with a latent heat storage device 2 in a first position P1 and Fig. 2 shows a sectional view of the high-voltage battery arrangement 1 with the latent heat storage device 2 in a second position P2.

[0021] The Fig. 1 and Fig. The high-voltage battery arrangement 1 shown in Figure 2 has a plurality of individual cells 3 arranged in a common housing 4.

[0022] The latent heat storage device 2 is arranged between a housing base 4.1 and the individual cells 3 and is connected to a positioning device 5.

[0023] With regard to the individual cells 3, according to the Fig. 1 and Fig. 2 a plate-shaped temperature control unit 6 is arranged on the head side, which can form a housing cover for closing the housing 4.

[0024] Outside the housing 4, a heat sink 7, for example with cooling fins, is arranged on the housing base 4.1, extending, for example, over an entire surface of the housing base 4.1.

[0025] It is generally known that when individual cells 3 are charged and discharged, heat loss occurs, which should be dissipated to prevent overheating of the individual cells 3 as far as possible. An electrical energy storage device, in particular a traction battery, of an electric vehicle with a plurality of individual cells 3 is often actively cooled using what is known as liquid cooling. This requires a delivery unit, a coolant circuit, a cooler, and a chiller. Such liquid cooling is therefore relatively complex, which can lead to a high probability of failure and high costs. The weight of the energy storage device is also comparatively high.

[0026] Furthermore, passive cooling of the individual cells 3 of an electrical energy storage system is known. Such passive cooling is comparatively energy-efficient because no cooling power is required. However, if the individual cells 3 are passively cooled, rapid charging of the individual cells 3 is not possible.

[0027] In order to passively cool the individual cells 3 and still enable rapid charging of the individual cells 3, the high-voltage battery arrangement 1 is designed as described below.

[0028] For this purpose, the latent heat accumulator 2 is provided, which can be positioned in the first position P1 and in the second position P2 by means of the positioning device 5.

[0029] In the Fig. 3 to 5 each show a sectional view of an embodiment of the latent heat storage device 2. In particular, Fig. 3 a sectional view of a first embodiment, Fig. 4 a sectional view of a second embodiment and Fig. 5 a sectional view of a third embodiment of the latent heat storage device 2.

[0030] The latent heat storage device 2 has a structure that enables efficient heat transfer from the outside into the chambers K filled with a phase change material 8. A chamber element 9 is formed, for example, from aluminum and / or another material suitable for heat conduction. As shown in the Fig. 3 to 5, a size and / or arrangement of the chambers K filled with the phase change material 8 can vary.

[0031] In addition, the latent heat storage device 2 is encased in a thermally conductive material 10, wherein the thermally conductive material 10 forms a thermal interface between the individual cells 3 and the latent heat storage device 2 or the housing 4, in particular the housing base 4.1, and the latent heat storage device 2. The thermally conductive material 10 is comparatively thermally conductive, with relatively low thermal radiation.

[0032] The positioning device 5 connected to the latent heat storage device 2 is controlled depending on the temperature prevailing within the housing 4, in particular when the temperature exceeds a predetermined temperature threshold. For this purpose, a control unit of the positioning device 5 is connected to a temperature detection unit, for example, a battery monitoring unit.

[0033] If it is determined that the temperature in the housing 4 exceeds the temperature threshold, the latent heat storage device 2 is positioned in the first position P1 by means of the positioning unit 5, which can also be referred to as a lifting device and has a gear and / or an electromagnetic actuator.

[0034] In the first position P1, the latent heat storage device 2 is thermally coupled to the individual cells 3, whereby the heat generated by the individual cells 3 is transferred from the individual cells 3 to the latent heat storage device 2. The heat transfer occurs comparatively quickly, with heating of the individual cells 3 slowed, and the latent heat storage device 2, in particular the phase-change material 8, stores the heat. In particular, the phase-change material 8 changes its state of aggregation from solid to liquid.

[0035] If the temperature in the housing 4 of the high-voltage battery assembly 1 then falls below the predetermined temperature threshold, the positioning device 5 is activated and positioned in the second position P2. In the second position P2, the latent heat accumulator 2 is thermally coupled to the housing 4, i.e., to the housing base 4.1, and thus indirectly to the heat sink 7. The heat stored by the phase change material 8 is then dissipated comparatively slowly from the latent heat accumulator 2 to the housing base 4.1 and via the latter to the outside of the housing 4, with the heat transfer being assisted by the heat sink 7.

[0036] When the vehicle is in operation, the heat sink 7 is exposed to an air flow so that a cooling process of the latent heat storage device 2 can be accelerated.

[0037] Fig.Figure 6 shows a diagram D with a charging profile relating to various operating states B1 to B4 of the latent heat storage device 2 over time t. A charging power P is plotted on the ordinate and time t on the abscissa.

[0038] To generate a charging profile, the vehicle, i.e. the high-voltage battery arrangement 1, is electrically connected to a charging station, in particular to a rapid charging station.

[0039] In a first operating state B1, a rapid charging process of the high-voltage battery assembly 1 starts, with the charging power P being comparatively high. If the individual cells 3 are at their operating temperature when the rapid charging process starts, the latent heat storage device 2 is positioned in the first position P1, so that the latent heat storage device 2 is thermally coupled to the individual cells 3.

[0040] If a temperature value of the individual cells 3 falls below a further predefined temperature threshold, i.e., if the individual cells 3 are comparatively cold, the latent heat storage device 2 is positioned in the second position P2. The latent heat storage device 2 is thus thermally coupled to the housing base 4.1. The latent heat storage device 2 is only positioned in the first position P1 when there is a cooling requirement for the individual cells 3, i.e., when the temperature of the individual cells 3 exceeds the predefined temperature threshold mentioned above. This allows the efficiency of the individual cells 3 to be increased.

[0041] In a second operating state B2, the rapid charging process is carried out, with the charging power P being high, as in the first operating state B1. In this second operating state B2, the latent heat storage device 2 is positioned in the first position P1, so that the latent heat storage device 2 is thermally coupled to the individual cells 3 of the high-voltage battery assembly 1. As a result, the phase-change material 8 in the chambers K of the chamber element 9 of the latent heat storage device 2 heats up and changes its state of aggregation from solid to liquid.

[0042] In a third operating state B3, the charging power P decreases, which also reduces the cooling requirement of the individual cells 3. The latent heat accumulator 2 is moved from the first position P1 to the second position P2 by controlling the positioning device 5, so that a thermal coupling is established between the latent heat accumulator 2 and the housing 4, in particular the housing base 4.1. The heat of the individual cells 3 absorbed and stored by the latent heat accumulator 2 is dissipated to the housing base 4.1 and, if present, to the heat sink 7.

[0043] In a fourth operating state B4, the rapid charging process is completed and the vehicle starts driving, so that the high-voltage battery arrangement 1 is cooled by air, for example by means of laminar flow, and in stationary operation by convection (position P2).

[0044] Once the high-voltage battery assembly 1 and thus also the latent heat storage device 2 have cooled sufficiently, the phase-change material 8 is ready to absorb the heat loss generated during charging and discharging of the individual cells 3, so that the latent heat storage device 2 is moved from the second position P2 to the first position P1 by controlling the positioning device 5. For example, cooling may be required due to a subsequent rapid charging process and / or due to dynamic driving of the vehicle. List of reference symbols 1 high-voltage battery arrangement 2 latent heat storage 3 single cells 4 housings 4.1 Case back 5 Positioning device 6 Temperature control unit 7 heat sinks 8 Phase change material 9 chamber element 10 Thermal conductive material B1 to B4 operating status D diagram K Chamber P charging power P1 first position P2 second position t time QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2014 017 989 A1

[0002]

Claims

[1] High-voltage battery arrangement (1) for a vehicle with a plurality of individual cells (3), a housing (4) for accommodating the individual cells (3) and a latent heat storage device (2), characterized by in that the latent heat accumulator (2) is connected to a temperature-controlled positioning device (5) which is designed to automatically position the latent heat accumulator (2) in at least two positions (P1, P2), wherein the latent heat accumulator (2) is thermally coupled to the individual cells (3) in a first position (P1) and is thermally coupled to the housing (4) in a second position (P2). [2] High-voltage battery arrangement (1) according to claim 1, characterized by that the housing (4) has a heat sink (7) to which the latent heat accumulator (2) can be thermally coupled. [3] High-voltage battery arrangement (1) according to claim 1 or 2, characterized bythat the latent heat storage device (2) is arranged between the individual cells (3) and a housing base (4.1). [4] High-voltage battery arrangement (1) according to one of the preceding claims, characterized by that the latent heat accumulator (2) is covered with a heat-conducting material (10). [5] High-voltage battery arrangement (1) according to one of the preceding claims, characterized by that the positioning device (5) has a gear and / or an electromagnetic actuator. [6] High-voltage battery arrangement (1) according to one of the preceding claims, characterized by that the positioning device (5) is coupled to a temperature detection unit arranged within the housing (4). [7] High-voltage battery arrangement (1) according to one of claims 3 to 6, characterized by that the heat sink (7) is arranged on the housing base (4.1). [8] Method for tempering the individual cells (3) of the high-voltage battery arrangement (1) according to one of the preceding claims by means of the latent heat storage device (2), characterized by that the latent heat storage device (2) is thermally coupled either to the individual cells (3) or to the housing (4) by means of the positioning device (5) depending on a temperature of the individual cells (3).

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