Battery device for a motor vehicle and motor vehicle with a battery device

Abstract

Battery device (10) for a motor vehicle, comprising a plurality of battery cells (12) accommodated in a housing, which battery cells rest at least on a thermally conductive casting compound (20) or a thermally conductive pad, which rests on at least one structural component (22) of the battery device (10), whereby heat (14) can be dissipated from the battery cells (12) to the structural component (22) via the thermally conductive casting compound (20) or the thermally conductive pad, wherein at least two battery cells (12) rest on opposite sides of the at least one structural component (22) via respective thermally conductive casting compounds (20) or thermally conductive pads,such that the at least one structural component (22) is arranged centrally between the at least two battery cells (12) and the at least two battery cells (12) are each connected to the at least one structural component (22) arranged between the battery cells (12) via the thermally conductive potting compound (20) or the thermally conductive pad, characterized in that each of the battery cells (12) is thermally insulated from at least one further battery cell (12) via an insulation element (18).

Description

[0001] The invention relates to a battery device for a motor vehicle and a motor vehicle with a battery device.

[0002] If a battery cell in a battery device is defective, particularly in a high-voltage storage device, this battery cell can fail, which is also known as thermal runaway. This runaway of the battery cell can lead to enormous heat development, particularly over 1,000 degrees Celsius in the affected battery cell. In a battery module in which several battery cells are arranged in a row, the heat from the affected battery cell can spread to neighboring cells and cause these neighboring cells to also fail. This can create a chain reaction in which a cell defect in a single battery cell can lead to the propagation of several battery cells or the entire high-voltage storage device.

[0003] DE 10 2007 010 742 A1 describes a cell assembly consisting of battery cells for a battery, in which the battery cells are secured by means of a potting compound. The cell assembly comprises cells whose outer surfaces are designed to enhance the form fit with the potting compound. Heat-conducting rods can be arranged between the cells. This cell assembly is intended to offer cost-effective manufacturing, a space-saving design, and improved mechanical strength.

[0004] DE 20 2018 104 526 U1 describes a battery module with two cell holders. The cell holders have recesses facing each other in pairs, each of which holds a battery cell. The recesses are arranged such that the longitudinal extensions of the battery cells held therein run parallel to each other and are inclined relative to a normal to the holder perpendicular to parallel holder planes of the cell holders.

[0005] DE 10 2014 210 572 A1 describes a multi-cell battery module designed to reduce the risk of fire in the event of a crash. For this purpose, a module housing has a metallic base wall, and several plate-like, deformable pouch battery cells are arranged parallel to one another within the module housing. Adjacent to the base wall and in thermal contact with it, a non-adhesive and uncured thermally conductive compound is filled, which thermally contacts the lower ends of the pouch battery cells.

[0006] DE 197 21 348 A1 describes a multi-cell accumulator with a temperature control device designed to prevent the propagation of thermally induced cell destruction. Individual cells are separated from one another by a heat-insulating solid layer, the thermal resistance of the solid layer being a factor of K greater than the thermal resistance of the individual cell. The individual cell is connected to a heat exchanger in an area free of insulating material, the thermal resistance of which towards the neighboring cell is a factor of K greater than the thermal resistance of the individual cell. The thermal resistance of the heat exchanger towards the temperature control medium is a factor of 10 lower than the thermal resistance of the individual cell. K is the ratio of the energy content of the individual cell to the amount of energy required to trigger thermally induced cell failure.

[0007] DE 10 2013 220 690 A1 describes a method for producing a battery module. The battery module comprises several battery cells combined to form a cell stack. The method involves applying an electrically insulating thermally conductive compound to the base of the cell stack. This method is intended to provide a simple and cost-effective method for producing a battery module that reduces the number of layers for thermal conduction and electrical insulation of the battery module, provides good thermal connection of the cell stack, and can be used to compensate for manufacturing-related tolerances and component tolerances on the battery module.

[0008] WO 2015 / 179625 A1 discloses a lithium-ion battery with thermal runaway protection. For this purpose, a cooling mechanism can be implemented by means of which energy is actively removed from an affected area of ​​the battery and transported to another area, usually outside the battery. Furthermore, the provision of insulation between battery cells of the lithium-ion battery is described. Phase-change material is also mentioned as a further option for runaway protection.

[0009] Furthermore, US Pat. No. 8,541,126 B2 discloses a battery pack comprising one or more thermal barrier elements, wherein the thermal barrier elements separate cells within the battery pack into groups of cells. These thermal barrier elements, which separate the cells into groups, prevent thermal runaway initiated in one group of cells from propagating to cells in an adjacent group of cells.

[0010] The object of the present invention is to provide a solution by means of which a chain reaction of the respective runaway of adjacent battery cells of a battery device can be avoided or at least contained.

[0011] This object is achieved according to the invention by the subject matter of the independent patent claim. Further possible embodiments of the invention are disclosed in the subclaims, the description, and the figures.

[0012] The invention relates to a battery device for a motor vehicle, in particular a high-voltage storage device. The battery device comprises a plurality of battery cells accommodated in a housing, which are in contact with at least one thermally conductive encapsulant or a thermally conductive pad. This means that the battery cells are connected in planar contact with the at least one thermally conductive encapsulant and / or the at least one thermally conductive pad.The at least one thermally conductive encapsulant or the at least one thermally conductive pad has a particularly high thermal conductivity coefficient, whereby heat can be absorbed particularly well and, in particular, particularly quickly by the respective adjacent battery cells by means of the at least one thermally conductive encapsulant or the at least one thermally conductive pad, whereby the adjacent battery cells can be cooled particularly well by means of the at least one thermally conductive encapsulant or the at least one thermally conductive pad. The thermally conductive encapsulant or the thermally conductive pad, in turn, bears against at least one structural component of the battery device, whereby heat can be dissipated from the battery cells to the structural component via the thermally conductive encapsulant or the thermally conductive pad.Thus, if one of the battery cells runs through the thermally conductive encapsulation compound or the thermally conductive pad, a particularly large amount of heat can be dissipated particularly quickly to the at least one structural component, allowing the continuous battery cell to be cooled particularly effectively. Furthermore, the particularly effective cooling of the continuous battery cell can limit the transfer of heat from the continuous battery cell to battery cells adjacent to the continuous battery cell. This can minimize the risk of the battery cells adjacent to the continuous battery cell running through and thus of a chain reaction.

[0013] The invention provides that at least two battery cells rest on opposite sides of the at least one structural component via respective thermally conductive encapsulants or thermally conductive pads. This means that the at least one structural component is arranged centrally between at least two battery cells and the at least two battery cells are each connected to the at least one structural component arranged between the battery cells via the thermally conductive encapsulant or the thermally conductive pad. As a result, heat can be transported away from the battery cells centrally between the battery cells by means of the at least one structural component, whereby a transfer of heat between these battery cells arranged on opposite sides of the at least one structural component can be avoided or at least limited.Heat from the interior of the battery device can be dissipated particularly effectively via the at least one structural component, which is surrounded on opposite sides by respective battery cells. This can minimize the risk of a chain reaction in the event of a battery cell in the battery device running through.

[0014] According to the invention, each of the battery cells is thermally insulated from at least one other battery cell via an insulation element. In a stacked arrangement of several battery cells, respective battery cells arranged within the stack can be thermally insulated from respective adjacent battery cells, in particular from two further battery cells arranged on opposite sides of the respective inner battery cell, via respective insulation elements. The insulation elements are in particular a so-called heat shield. Each insulation element is thus arranged between two adjacent battery cells and designed to thermally insulate the adjacent battery cells from one another. The respective insulation element can thus be designed to prevent or at least limit the transport of heat between mutually insulated adjacent battery cells.A chain reaction within the battery device in the event of a runaway of one of the battery cells of the battery device can thus be particularly well limited.

[0015] In a further embodiment of the invention, it is provided that the at least one structural component is the housing or a module frame of the battery device. In this case, the housing and / or the module frame can, for example, be formed at least partially from aluminum, whereby the heat received via the at least one thermally conductive potting compound and / or the at least one thermally conductive pad can be transported away from the continuous battery cell and in particular from other battery cells of the battery device via the housing or the module frame particularly quickly. The at least one structural component can thus, on the one hand, stabilize the effect of the battery device and, on the other hand, serve to transport temperature away from a continuous battery cell of the battery device.

[0016] In a further embodiment of the invention, all battery cells of the battery device are in contact with at least one structural component of the battery device via the thermally conductive encapsulant or the thermally conductive pad. This ensures that, regardless of which of the battery cells of the battery device passes through, heat is dissipated from the continuous battery cell via the at least one thermally conductive encapsulant or the at least one thermally conductive pad to the at least one structural component of the battery device.In other words, each of the battery cells of the battery device is in direct planar contact with at least one thermally conductive encapsulant or at least one thermally conductive pad, whereby heat can be dissipated from the respective battery cell to the at least one structural component resting on the thermally conductive encapsulant or the thermally conductive pad via the at least one thermally conductive encapsulant or the at least one thermally conductive pad.

[0017] In a further embodiment of the invention, it is provided that the respective lowest battery cells of the battery device rest via a heat-conducting element on a cooling device that is different from the structural component. In particular, the heat-conducting element can be provided by an additional heat-conducting casting compound or an additional heat-conducting pad. The heat-conducting element enables particularly good heat transfer from the lowest battery cells of the battery device to the cooling device, whereby the battery cells of the battery device can be cooled particularly well by means of the cooling device. The cooling device can be a cooling plate, for example. By means of the cooling device, heat can be transported away from the battery cells of the battery device, in particular during normal operation of the battery device.This ensures that an operating temperature range is maintained in the battery cells of the battery device.

[0018] In a further embodiment of the invention, it is provided that each battery cell rests on the thermally conductive potting compound or the thermally conductive pad on at least one first side and on the insulating element on at least one second side, which is different from the first side. In this case, the respective battery cell rests on the thermally conductive potting compound or the thermally conductive pad on its side facing the at least one structural component and on the insulating element on its side facing another battery cell. This arrangement makes it possible to limit the transfer of heat from one battery cell to an adjacent battery cell of the battery device by means of the insulating element arranged between the adjacent battery cells, whereas heat can be particularly well transferred from the respective battery cells to the at least one structural component via the thermally conductive potting compound or the thermally conductive pad.Heat can thus be dissipated particularly well and quickly from the respective battery cells via the at least one structural component, to which the respective battery cells are thermally conductively connected via the thermally conductive encapsulation compound or the thermally conductive pad. The at least one first side and the at least one second side of the respective battery cell can, for example, be arranged adjacent to one another. As a result, the battery cell can, for example, be thermally insulated upwards from an adjacent battery cell via a respective insulation element and can be cooled laterally via the thermally conductive encapsulation compound resting on the at least one structural component or the thermally conductive pad resting on the at least one structural component.

[0019] In a further embodiment of the invention, it is provided that the thermally conductive encapsulant has a thermal conductivity coefficient of greater than or equal to 1.5 watts per square meter Kelvin. In this case, it has proven particularly advantageous if the thermally conductive encapsulant has a thermal conductivity coefficient of approximately 10 watts per square meter Kelvin. By means of the thermally conductive encapsulant, a particularly large amount of heat can be transported particularly quickly from the respective battery cells of the battery device, in particular a continuous battery cell, to the at least one structural component adjacent to the thermally conductive encapsulant, whereby the battery cells or the continuous battery cell can be cooled particularly effectively via the thermally conductive encapsulant.

[0020] In a further embodiment of the invention, it is provided that at least one battery cell rests on opposite sides against respective thermally conductive encapsulants or thermally conductive pads, or rests on opposite sides against the thermally conductive encapsulant and the thermally conductive pad. Thus, the respective battery cell can rest on its opposite sides against respective thermally conductive encapsulants or respective thermally conductive pads, whereby the battery cell can be cooled particularly well via the opposite sides, in particular in the event of a runaway. Alternatively, the respective battery cell can rest on one side against the thermally conductive encapsulant and on the other, opposite side against the thermally conductive pad, wherein heat can be dissipated from the battery cell to respective structural components resting on the thermally conductive encapsulant or the thermally conductive pad via the thermally conductive pad and the thermally conductive encapsulant.This means that the respective battery cell can be cooled particularly well on the opposite sides, which makes it particularly easy to avoid a complete runaway of the battery device as a result of a chain reaction.

[0021] The invention further relates to a motor vehicle with a battery device, as already described in connection with the battery device according to the invention. The motor vehicle is particularly designed to be powered by electrical energy from the battery device. The motor vehicle is thus, in particular, an electric vehicle or a hybrid vehicle. Advantages and advantageous developments of the battery device according to the invention are to be regarded as advantages and advantageous developments of the motor vehicle according to the invention, and vice versa.

[0022] Further features of the invention may emerge from the claims, the figures, and the description of the figures. The features and combinations of features mentioned above in the description, as well as the features and combinations of features shown below in the description of the figures and / or in the figures alone, can be used not only in the respective combinations specified, but also in other combinations or on their own, without departing from the scope of the invention.

[0023] The drawing shows in: Fig. 1 a schematic interior view of a battery device for a motor vehicle, with several battery cells arranged next to one another, which are each thermally insulated from one another via respective insulation elements, wherein each of the battery cells is in contact with at least one structural component of the battery device via at least one thermally conductive casting compound, whereby heat can be dissipated from the respective battery cell to the respective structural component via the thermally conductive casting compound.

[0024] Fig. 1 shows a battery device 10 for a motor vehicle, which is in particular a high-voltage storage device. The battery device 10 is designed to store electrical energy and provide it for an electric drive of the motor vehicle, whereby the motor vehicle can be driven with the electrical energy provided by the battery device 10. The battery device 10 comprises a plurality of battery cells 12 accommodated in a housing. If a so-called thermal runaway occurs in one of the battery cells 12, which means that this battery cell runs away, a chain reaction can occur in which, by means of heat 14 from the continuous battery cell, which is designated below by the reference numeral 16, further battery cells 12 of the battery device 10 are stimulated to also run away.In particular, the respective additional battery cells 12 can be stimulated to break through by intense heating. It is thus necessary to avoid so much heat being transferred from the continuous battery cell 16 to additional battery cells 12 that the additional battery cells 12 also break through.

[0025] In order to minimize heat transfer from the continuous battery cell 16 to further battery cells 12 of the battery device 10, each battery cell 12 is thermally insulated from at least one further battery cell 12, in particular from respective adjacent battery cells 12, by means of an insulating element 18. This insulating element 18 is a so-called heat shield. Each insulating element 18 is arranged between two adjacent battery cells 12 and is configured to thermally insulate the adjacent battery cells 12 from one another.

[0026] In order to enable particularly good dissipation of heat 14 from the continuous battery cell 16, it is provided that the battery cells 12 each rest on at least one side against a thermally conductive potting compound 20, which in turn rests against at least one structural component 22. Via the thermally conductive potting compound 20, heat 14 from the battery cells 12 can be dissipated particularly well and quickly to the adjacent structural component 22, whereby the respective battery cells 12, in particular the continuous battery cell 16, can be cooled particularly well. In order to be able to dissipate the heat 14 from the respective battery cells 12 particularly well, it is provided that the thermally conductive potting compound 20 in this case has a thermal conductivity coefficient of greater than or equal to 1.5 watts per square meter Kelvin. The thermally conductive potting compound 20 is in particular a plastic.In the present case, all battery cells 12 of the battery device 10 are connected to at least one structural component 22 via at least one thermally conductive encapsulant 20. The at least one structural component 22 can be a housing component of the housing of the battery device 10 or a module frame of the battery device 10.

[0027] The respective lowest battery cells 12 can be connected via a Fig. 1, a heat conducting element not shown may be applied to a cooling device different from the structural components 22, whereby the battery cells 12 can be adjusted to operating temperature via the cooling device during normal operation of the battery device 10.

[0028] As in Fig. 1, the respective battery cells 12 in this case rest on respective thermally conductive encapsulants 20 on opposite first sides 24. In this case, the respective battery cells 12 can be connected via the thermally conductive encapsulants 20 to outer structural components 22 or to respective inner structural components 22 arranged between the battery cells 12. In the present case, the battery device 10 is provided with at least one inner structural component 22, against which respective battery cells 12 rest with their first sides 24 on the opposite sides thereof via respective thermally conductive encapsulants 20. Heat 14 can thus be dissipated particularly well from an interior of the battery device 10 via the inner structural component 22, which is thus arranged between the respective battery cells 12.

[0029] As from Fig.1, the respective insulation elements 18 rest on second sides 26 of the respective battery cells 12, which adjoin the first sides 24. Thus, heat transfer between respective adjacent battery cells 12 within the battery device 10 is made more difficult, and heat dissipation from the respective battery cells 12 to the respective structural components 22 is supported via the respective thermally conductive encapsulants 20. A chain reaction of respective battery cells 12 when a battery cell 16 passes through in the battery device 10 can thus be limited, in particular avoided.

[0030] The described battery device 10 makes it possible to develop new heat conduction paths in addition to the respective heat shields as heat blockers. Via these newly developed heat conduction paths, heat 14 can be dissipated in components that are less critical than battery cells 12, such as the housing. By using the housing as a heat sink, a temperature in the critical, runaway battery cell 16 can drop and heat input into battery cells 12 adjacent to the runaway battery cell 16 can be reduced. This combination of heat blocker to respective battery cells 12 adjacent to the runaway battery cell 16 and heat distribution to the structural components 22, in particular the housing, can result in the battery cells 12 adjacent to the runaway battery cell 16 not reaching a temperature critical for runaway and consequently not entering a thermal runaway and thus not running away.This could stop the chain reaction and thus propagation in the continuous battery cell 16.

[0031] Overall, the invention shows how thermally conductive encapsulant 20 can be used for heat distribution in the event of a cell defect, in this case a runaway of the battery cell 16. List of reference symbols 10 Battery setup 12 battery cells 14 Heat 16 continuous battery cells 18 Insulation element 20 thermally conductive encapsulant 22 Structural component 24 first page 26 second page

Claims

[1] Battery device (10) for a motor vehicle, comprising a plurality of battery cells (12) accommodated in a housing, which battery cells bear against at least one thermally conductive casting compound (20) or a thermally conductive pad, which bears against at least one structural component (22) of the battery device (10), whereby heat (14) can be dissipated from the battery cells (12) to the structural component (22) via the thermally conductive casting compound (20) or the thermally conductive pad, wherein at least two battery cells (12) bear against opposite sides of the at least one structural component (22) via respective thermally conductive casting compounds (20) or thermally conductive pads,such that the at least one structural component (22) is arranged centrally between the at least two battery cells (12) and the at least two battery cells (12) are each connected to the at least one structural component (22) arranged between the battery cells (12) via the thermally conductive casting compound (20) or the thermally conductive pad, characterized by that each of the battery cells (12) is thermally insulated from at least one further battery cell (12) via an insulation element (18). [2] Battery device (10) according to claim 1, characterized by that the at least one structural component (22) is the housing or a module frame of the battery device (10). [3] Battery device (10) according to claim 1 or 2, characterized by that all battery cells (12) of the battery device (10) are in contact with at least one structural component (22) of the battery device (10) via the thermally conductive casting compound (20) or the thermally conductive pad. [4] Battery device (10) according to one of the preceding claims, characterized by that respective lowermost battery cells (12) of the battery device (10) are in contact via a heat-conducting element with a cooling device which is different from the structural component (22). [5] Battery device (10) according to one of the preceding claims, characterized by that each battery cell (12) rests on at least one first side (24) against the thermally conductive casting compound (20) or the thermally conductive pad and rests on at least one second side (26) different from the first side (24) against the insulation element (18). [6] Battery device (10) according to one of the preceding claims, characterized by that the thermally conductive casting compound (20) has a thermal conductivity coefficient of greater than or equal to 1.5 W / m 2 K. [7] Battery device (10) according to one of the preceding claims, characterized bythat at least one battery cell (12) rests on opposite sides against respective thermally conductive casting compounds (20) or thermally conductive pads or rests on opposite sides against the thermally conductive casting compound (20) and the thermally conductive pad. [8] Motor vehicle with a battery device (10) according to one of the preceding claims.

Images