Thermally decoupled HV battery storage arrangement

Abstract

The invention relates to a battery arrangement for a battery-electric vehicle, comprising a cell space (1) for accommodating one or more battery cells, a cell frame (3) surrounding the cell space (1), and a battery housing (5) with elements for connection to a further vehicle structure (7), wherein the cell frame (3) has a layer of voluminous material (9) with individual air chambers, wherein the cell frame (3) and the battery housing (5) are mechanically connected to one another, and wherein the cell space (1) is delimited by a housing cover (11) on its side facing the ground when the battery arrangement is mounted on the vehicle.

Description

The invention relates to a battery arrangement for a battery-electric vehicle.Housings of high-voltage batteries ("HV batteries" for short) are frequently produced from aluminum components for weight reasons. Aluminum has a good thermal conductivity, which can be utilized in particular when cooling the battery. In the case of housing components which form the cell construction space and do not have a thermal task such as, for example, active cooling, this property also leads, however, to the cell construction space cooling out rapidly at low external temperatures or heating up at high temperatures. These thermal influences from the environment must be compensated for in an energy-intensive manner in the case of the undesired heating with the cell cooling. Furthermore, in the case of faster journeys, not negligible wind influences occur, which cool the battery to undesirably low temperatures, in particular at low temperatures. Adjusting to operating temperature additionally requires energy and leads to increased energy consumption, which reduces the remaining range of an electric vehicle. Methods for avoiding thermal losses are known from the prior art:DE 4309621 A1 relates to a vehicle with an electric drive and with a high-temperature battery serving for supplying the same, which has a thermally insulating housing to avoid thermal losses and a cooling system to limit the operating temperature during charging and during the extraction of current, wherein the waste heat of the cooling system can be used to heat the vehicle, wherein the vehicle can be preheated during charging of the battery and the heating of the vehicle already achieved by the preheating is substantially only maintained during driving operation.DE 10 2011 052 513 A1 also relates to a battery housing part for receiving a traction battery of an electric vehicle, wherein the battery housing part has at least one wall which consists at least partially of a thermoplastic or thermosetting plastic material, and wherein the wall has at least one cavity which is provided within the wall.DE 10 2017 000 266 A1 furthermore relates to a battery module carrier for receiving a traction battery of a motor vehicle, comprising a housing tray and a housing cover, which are each designed as sandwich structures, which each have an upper side and an underside made of an organic sheet or aluminum sheet, between which a thermoplastic plastic foam is arranged.US 2022 / 0294058 A1 further relates to a modular composite battery housing containing a plurality of individual composite structures connected together. The individual composite structures form covers that enclose an open area for the accommodation of a battery system of battery cells and cooling devices. The composite battery casings are lightweight and are made of materials that can absorb energy and isolate the area of the battery casing. The composite structures contain a core material bonded and sandwiched between layers of fibers.It is an object of the invention to be able to achieve the setting of a desired thermal state of a battery of a battery-electric vehicle more easily.The invention results from the features of the independent claims. Advantageous refinements and refinements are the subject matter of the dependent claims.A first aspect of the invention relates to a battery arrangement for a battery-electric vehicle, having a cell space for receiving one or more battery cells, a cell frame surrounding the cell space, and a battery housing having elements for connection to a further vehicle structure, wherein the cell frame has a layer of bulky material having individual air chambers, wherein the cell frame and the battery housing are mechanically connected to one another, and wherein the cell space is delimited in a planar manner on its side which points toward the bottom in a state of the battery arrangement which is mounted on the vehicle by a housing cover, and the housing cover forms an air chamber between the housing cover and the cell space.The interaction of the thermally insulating components, in particular the formation of the cell frame from a layer of voluminous material with insulating individual air chambers, and also further insulating layers and air-filled volumes, leads to better thermal insulation of the individual battery cells within the cell chamber with respect to the environment of the vehicle. If, for example, the floor radiates intense heat radiation during hot summer days, this is shielded by the housing cover and prevented from heating the battery cells. This saves cooling power. In particular, the honeycomb material or the material of the cell frame formed as foam prevents convective heat transfer by air flowing past from the relative wind.This thermally optimized arrangement of the HV battery on the vehicle and the use of thermally insulating materials, which enclose the cell construction space, or air chambers, bring about a reduction in the thermal power required to operate the HV battery at its optimum temperature operating point. Thus, the cell space including any cooling installed there (for example by means of cooling channels) is insulated from thermal environmental influences and the cooling capacity can be reduced accordingly. Thus, the thermal influence of the external temperatures can be reduced. For example, heat remains stored within the battery for a longer time; this must be heated up to a lesser extent at too low temperatures.According to an advantageous embodiment, the layer of voluminous material has a honeycomb structure. Preferably, the bulky material layer is formed of a honeycomb structure. The structure is furthermore preferably made of plastic.According to a further advantageous embodiment, the layer of voluminous material comprises open-porous foam. Preferably, the layer of bulky material consists of open-porous foam. Furthermore, the open-porous foam is preferably made of plastic.According to a further advantageous embodiment, the cell space, in a state of the battery arrangement mounted on the vehicle, has a thermal insulation layer on its side facing the vehicle interior.According to a further advantageous embodiment, a surface cooling device is arranged between the insulation layer and the cell space.In this embodiment of the HV battery with surface cooling device, the arrangement of the latter takes place below the vehicle floor. The influencing factors of cooling out during journeys or the heat radiation from the road can thus be decoupled from the cooling circuit.According to a further advantageous embodiment, cooling channels for conducting cooling fluid are arranged between the battery cells.According to a further advantageous embodiment, the housing cover is made of an insulating material, e.g. plastic. In an alternative embodiment of the housing cover made of aluminum material, an insulation layer (e.g. porous foam structures) is additionally introduced on the inside in order to shield the thermal radiation of the road / ground from the interior.According to a further advantageous embodiment, the cell frame and the battery housing are separated from one another in a thermally insulated manner by an additional frame insulation.According to a further advantageous embodiment, the frame insulation between the cell frame and the battery housing is formed by adhesive.A further aspect of the invention relates to a vehicle having a battery arrangement as described above and below.Advantages and preferred refinements of the proposed vehicle result from an analogous and analogous transfer of the explanations given above in connection with the proposed battery arrangement.Further advantages, features and details are evident from the following description, in which--possibly with reference to the drawing--at least one exemplary embodiment is described in detail. Identical, similar and / or functionally identical parts are provided with the same reference numerals.The following are shown: FIG. 1 : shows a battery arrangement according to an exemplary embodiment of the invention. FIG. 2 : shows a battery arrangement according to a further exemplary embodiment of the invention. FIG. 3 : shows a detailed section of the connection of a battery housing to a cell frame according to an exemplary embodiment of the invention. FIG. 4 : shows a detailed section of the connection of a battery housing to a cell frame according to a further exemplary embodiment of the invention.The representations in the figures are schematic and not to scale.FIG. 1 shows an example battery arrangement for a battery electric vehicle. The battery assembly is intended to be disposed under a vehicle structure 7, i.e., below an underbody that defines an interior of the vehicle. A cell space 1 forms a volume for accommodating individual cylindrical battery cells. The cell space 1 is surrounded laterally by a cell frame 3. The cell frame 3 is in turn mechanically connected to a battery housing 5, which is connected to the vehicle structure 7. The cell frame 3 is formed of bulky material 9 itself to have thermally insulating properties. The battery housing 5 has a mechanical connection to the further vehicle structure 7. On the underside, i.e. on the side of the cell chamber 1 facing the bottom, a housing cover 11 is arranged, which forms an air chamber 19. The air chamber 19 has particular thermally insulating properties; the housing cover 11 likewise consists for this purpose of materials which are highly thermally insulating. Moreover, the air chamber 19 is thus provided for mounting reasons. If the housing cover 11 is formed from aluminum, an insulating material, for example porous foam, is introduced on the inside in order to shield the thermal radiation emanating from the bottom into the cell space, in order not to increase the temperature in the cell space 1 unnecessarily by absorbing the thermal radiation from the bottom as a result of the thermal radiation from the bottom. In addition, this arrangement only produces significantly reduced cooling effects due to wind. A surface cooling device 15 is oriented in the direction of the vehicle interior. This is separated from the surface cooling device 15 in a thermally insulated manner by an insulation layer 13. The temperature prevailing in the battery housing 5 can thus be kept for a longer time without external supply of energy (in particular cooling), and cooling power can thus be reduced.FIG. 2 shows another example battery arrangement for a battery electric vehicle. Analogously to FIG. 1, a sectional view from a side view is shown, wherein the floor is drawn at the bottom in FIG. 2, whereas the further vehicle structure 7 in the region of an underbody of a vehicle interior is shown at the upper end. In contrast to the battery arrangement of FIG. 1, however, the voluminous material 9 is supplemented by a frame insulation 21 which produces a connection of the cell frame 3 to the battery housing 5. The frame insulation 21 is formed from adhesive. In contrast to the battery arrangement of FIG. 1, no surface cooling device 15 is provided, but only the insulation layer 13 on the upper side of the cell space 1, but instead cooling channels 17 which produce intermediate cell cooling.FIG. 3 shows a detailed illustration in section of the arrangement, which merges from the cell space 1 to the battery housing 5. Between the honeycomb structure of the cell frame 3 and the battery case 5, frame insulation 21 formed of adhesive is provided. The material 9 is formed from plastic.FIG. 4 shows an alternative of connecting the cell space 1 as far as the battery housing 5: in this case, the cell frame 3 is directly connected to the battery housing 5, and the cell frame 3 has open-porous foam as a bulky material 9, which, like the honeycomb structure, has thermally good insulating properties.Although the invention has been illustrated and explained in more detail by preferred exemplary embodiments, the invention is not restricted by the disclosed examples and other variations can be derived therefrom by the person skilled in the art without departing from the scope of protection of the invention. It is therefore clear that a large number of possible variations exist. It is also clear that embodiments mentioned by way of example represent only examples which are not to be understood in any way as limiting, for example, the scope of protection, the possible applications or the configuration of the invention. Rather, the preceding description and the description of the figures enable the person skilled in the art to implement the exemplary embodiments in concrete terms, wherein the person skilled in the art, knowing the disclosed inventive concept, can make various changes, for example with regard to the function or the arrangement of individual elements mentioned in an exemplary embodiment, without departing from the scope of protection defined by the claims and their legal equivalents, such as further explanations in the description.List of reference characters1 Cell chamber 3 Cell frame 5 Battery housing 7 Further vehicle structure 9 Voluminous material with individual air chambers 11 Housing cover 13 Insulation layer 15 Surface cooling device 17 Cooling channels 19 Air chamber 21 Frame insulation

Claims

Battery arrangement for a battery-electric vehicle, having a cell space (1) for receiving one or more battery cells, a cell frame (3) surrounding the cell space (1), and a battery housing (5) having elements for connection to a further vehicle structure (7), wherein the cell frame (3) has a layer of bulky material (9) with individual air chambers, wherein the cell frame (3) and the battery housing (5) are mechanically connected to one another, and wherein the cell space (1) is delimited in a planar manner on its side pointing towards the floor in the state of the battery arrangement mounted on the vehicle by a housing cover (11), and the housing cover (11) forms an air chamber (19) between the housing cover (11) and the cell space (1).The battery assembly according to claim 1, wherein the bulky material layer (9) has a honeycomb structure.Battery arrangement according to one of the preceding claims, wherein the layer of voluminous material (9) comprises open-porous foam.Battery arrangement according to one of the preceding claims, wherein the cell space (1), in a state of the battery arrangement in which it is mounted on the vehicle, has an insulation layer (13) on its side facing the vehicle interior.Battery arrangement according to Claim 4, wherein a surface cooling device (15) is arranged between the insulation layer (13) and the cell space (1).Battery arrangement according to one of the preceding claims, wherein cooling channels (17) for conducting cooling fluid are arranged between the battery cells.Battery arrangement according to one of the preceding claims, wherein the housing cover (11) is made of an insulating material, e.g. plastic.Battery arrangement according to one of Claims 1 to 6, wherein the housing cover (11) is made from aluminium material and an insulating layer is arranged on the inner side in order to shield the thermal radiation of the road from the interior of the battery.Battery arrangement according to one of the preceding claims, wherein the cell frame (3) and the battery housing (5) are separated from one another in a thermally insulated manner by an additional frame insulation (21).The battery assembly according to claim 9, wherein the frame insulation (21) is formed between the cell frame (3) and the battery case (5) by adhesive.

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