External Thermal Battery Cover

Abstract

The present invention provides an external thermal battery cover for a battery housing, comprising: This cover must be at least 0.070m 2 Thermal resistance (R-value) in K / W, preferably at least 0.078 m 2 comprises at least one insulating layer with a thermal resistance of K / W; The insulating layer is at least one of a fibrous layer, an open-cell foam layer, and a closed-cell foam layer. External thermal battery cover for battery housing.

Description

[Technical Field]

[0001] The present invention relates to an external thermal battery cover for a battery housing system used in a battery electric vehicle, particularly for a battery housing system located externally, facing the road, underneath the vehicle. [Background technology]

[0002] Rechargeable batteries are used for electric driving. Generally, these batteries include an electrode assembly including a positive electrode, a negative electrode, and a separator interposed between the positive and negative electrodes, a case that receives (or houses) the electrode assembly, and electrode terminals electrically connected to the electrode assembly. An electrolyte solution is poured into the case, allowing the battery to be charged and discharged via an electrochemical reaction between the positive electrode, the negative electrode, and the electrolyte solution. The shape of the case can be varied depending on the purpose.

[0003] The battery cases, also called cells, can be used in battery modules, in which multiple battery cell units are coupled together in series and / or parallel to provide a relatively high energy density, for example for driving electricity in hybrid vehicles. To obtain a relatively high-power rechargeable battery module for electric vehicles, the electrode terminals of multiple battery cell units are interconnected to form a battery module.

[0004] Battery modules can be constructed using a block design or a modular design. In a block design, multiple batteries are disposed within a housing, with each battery cell coupled to a common current collector structure and battery management system. In a modular design, multiple battery cells are connected in the form of sub-modules, and multiple sub-modules are connected to each other to form a module. In a modular design, various battery management functions can be implemented at the module or sub-module level, which provides advantages such as improved interchangeability.

[0005] The modules are generally installed in and fixed to a suitable housing in the form of a casing with a cover, which can be attached to the underside of the vehicle, preferably to a carrier beam of the main structure of the vehicle. The battery housing can be made of metal, SMC (sheet molding compound), or thermoplastic composite material.

[0006] A thermal management system is required to efficiently release, exhaust, and / or dissipate heat generated by rechargeable batteries to ensure safe use of the battery module. If heat is not released, exhausted, and / or dissipated sufficiently, temperature deviations will occur between the individual battery cells, preventing the battery module from generating the desired amount of power. Furthermore, an increase in internal temperature can cause abnormal reactions to occur, ultimately degrading the charging and discharging performance of the rechargeable cells and shortening the lifespan of the rechargeable battery. Therefore, a cooling device may be required to effectively release, exhaust, and / or dissipate heat from the cells. The cooling / heating device, for example, in the form of a liquid cooling and heating system, can be integrated into the casing adjacent to the battery module.

[0007] A battery's range depends on its temperature during use, with temperatures between 10°C and 40°C being optimal for the system. However, the battery's total electric range may be reduced during periods outside of the optimal temperature range, while battery life may also be adversely affected by operation outside of the optimal temperature range. The total range of an electric vehicle is defined as the total distance the vehicle can be driven starting from a single full battery load.

[0008] For structural reasons, the battery cells, battery modules, cooling plates, carrier plates, and stiffening structures may be tightly coupled to the battery housing, such as structural panels, effectively forming a thermal bridge, i.e., a direct heat conduction path into the housing and to the exterior of the housing.

[0009] The battery housing can be disposed on the underside of the vehicle body as a single component, and therefore the battery housing can be designed with an overall height such that the outer contour of the traction battery protrudes outward from the underside of the body of the body-floor assembly toward the road surface, and therefore the battery housing, together with the conduction path formed by the connection to the battery housing, is exposed to the aerodynamic resistance of the underside of the vehicle along the lower surface of the housing, creating a source of temperature loss that hinders the battery's thermal management system and ultimately increasing energy consumption for this thermal management.

[0010] Measures to provide thermal treatment, such as insulating patches in the form of, for example, felt or foam layers on the inside surface of the battery housing wall, may reduce temperature loss across that surface, but do not prevent temperature loss across the structural connections required to keep internal components from moving during use and assembly. Summary of the Invention [Problem to be solved by the invention]

[0011] The purpose of the present invention is to overcome these problems, provide a better thermal management system, and ultimately improve the range of the battery. [Means for solving the problem]

[0012] The object of the present invention is achieved by an external thermal battery cover for a battery housing as claimed in claim 1 and by a battery electric vehicle having at least one battery cell housed in a battery housing comprising an external thermal battery cover according to the present invention and at least one sub-module having a fixing part connected to the battery housing.

[0013] In particular, an object of the present invention is an external thermal battery cover for a battery housing, the external thermal battery cover having a thickness of at least 0.070 mm. 2 Thermal resistance (R-value) in K / W, preferably at least 0.078 m 2 This is achieved by an external thermal battery cover for a battery housing, which includes at least one insulating layer having a thermal resistance of 1.5K / W, and the insulating layer is at least one of a fibrous layer, an open-cell foam layer, or a closed-cell foam layer.

[0014] Surprisingly, the introduction of such an external thermal cover can reduce energy losses due to the heat sink effect, thereby increasing the battery range by 1% to 15%, depending on the battery load, ambient temperature, and vehicle speed.

[0015] Preferably, the cover comprises at least a thermal insulating layer of porous fibrous material, wherein the porous fibrous material comprises staple fibers and / or filaments and a binder. The porous fibrous layer is thermally formed into the cover, and the cover has a thermal resistance of 150 to 600 kg / m. 3 The resulting rigid panel has a density of 0.03 to 0.06 W / mK, a thermal conductivity of 0.03 to 0.06 W / mK, and a thickness of 2.5 to 10 mm, preferably 2 to 6 mm.

[0016] Surprisingly, a thermal battery cover attached to the outside of the battery housing, preferably 150-600 k g / m 3 A thermal battery cover with a fibrous felt material having a density of 1000 psi and a thickness of 2.0 to 10 mm is sufficient to reduce energy loss due to the thermal bridging effect of the housing and internal structure. This primarily reduces thermal convection by reducing aerodynamic resistance along the surface of the battery housing, including the structural heat sink area, thus reducing forced convection due to wind movement.

[0017] A further benefit of this cover is that it protects the underside of the battery housing against stone chipping. Surprisingly, it has a resistance of 150-600 kg / m 3 Porous fibrous felt compressed to a density of 100 mm can withstand stone chipping effects while still reducing energy loss due to the heat sink effect. For example, a 3 mm compressed felt battery cover according to the present invention demonstrated range savings of 2-15%, depending on the battery load, ambient temperature, and vehicle speed. Range is defined as the distance a vehicle can travel on one full battery charge, and range savings means an increase in the vehicle's maximum range.

[0018] Surprisingly, when comparing a 20mm thick, low-compression felt battery cover with the claimed thin, compressed material, the increase in range is not as great as expected for high ambient temperatures. Thus, even the thin, compressed material can reduce the effectiveness of the battery housing's heat sink structure. On the other hand, the 20mm low-compression felt material cannot withstand stone chipping and will quickly disintegrate if placed on the underside of a vehicle facing the road.

[0019] From a heat sink perspective, other insulating materials can be used to obtain a reduced heat sink effect. However, due to the location, i.e., on the exterior surface of the battery housing facing the road, most materials may not be able to withstand the harsh conditions. In particular, stone chipping forces may cause parts to peel off. For this reason, foam may prove to be less beneficial.

[0020] When using an insulating material with low stone chipping resistance, a protective layer can be used on the outer surface of the insulating layer facing the road. This protective layer can be made of a plastic or plastic-fiber composite material, such as glass fibers embedded in a thermoplastic matrix, which matrix is ​​preferably polyolefin- or polyester-based. The protective layer can be constructed so that it functions as a rigid shell or carrier layer, with the insulating layer either located on top and in contact with both the protective layer and the outer surface of the battery housing, or with at least a partial gap between the insulating layer and the outer surface of the battery housing.

[0021] Preferably, the heat insulating layer has a density of 700 to 2000 g / m 2 , preferably 850 to 1600 g / m 2 It has an area weight of

[0022] The battery cover can include at least an insulating layer of porous fibrous material, where the porous fibrous layer includes staple fibers and / or filaments and a binder.

[0023] Preferably, the staple fibers and / or filaments are at least one of the following: organic materials, such as cotton, kenaf, hemp, or thermoplastic materials, such as polyesters, preferably polyethylene terephthalate (PET), or polyamides, preferably polyamide-6 or polyamide 6,6, or polyolefins, preferably polypropylene or polyethylene, or An inert material, preferably glass fiber, carbon fiber, ceramic fiber, or Normex fiber, or a mixture thereof.

[0024] 10. An external thermal battery cover for a battery housing according to any one of the claims, wherein the fibres and / or filaments have a hollow or solid cross section.

[0025] In the external thermal battery cover for a battery housing according to any one of the claims, the fibers and / or filaments have a fineness (fiber fineness) of 3 to 10 dtex, preferably 3 to 8 dtex.

[0026] Preferably, at least 10 to 40% by weight of binder is used.

[0027] Preferably, the binder is either a thermoplastic binder, preferably a polyester, polyamide, or polypropylene, or a thermosetting binder, preferably an epoxy resin or a phenolic resin. The binder can be in the form of a powder, resin, or fiber. During thermoforming of the part, the binder melts and binds the fibers together to form a consolidated part.

[0028] Preferably, binder fibers based on bicomponent staple fibers or filaments are used with a polyester, preferably polyethylene terephthalate (PET), core and a PET copolymer sheath, where only the copolymer melts during the thermoforming process to form the binder. Preferably, the core to sheath ratio in the bicomponent filament or fiber is 60% core and 40% sheath to 80% core and 20% sheath, with the preferred filament composition being 70% core and 30% sheath. Preferably, water repellent and / or flame retardant additives are added to the sheath prior to melt spinning of the filaments.

[0029] Preferably, the water repellent is a polysiloxane-based or fluoro-based additive at a final concentration of 0.5-2% in the sheath polymer blend.

[0030] Preferably, a phosphorus-based additive is added as a flame retardant at a concentration of 3-5% relative to the sheath polymer blend.

[0031] All the fibers and / or filaments used can be based on virgin materials or recycled and / or reclaimed materials, preferably filaments or fibers based on flakes from polyester bottles or other recycled sources are used.

[0032] An example is a staple fiber blend based on 60% polyester fiber and 40% bicomponent staple fiber, preferably in an amount ranging from 30 to 70% of the total fiber used.

[0033] Alternatively, a fiberglass felt material bound with a polypropylene binder can be used. Finally, other fibers are mixed into the fiber felt.

[0034] In a preferred approach, the part is made entirely of composite filaments that are spun, webbed, cross-wrapped, and needled to form a blank material that can be used to form the part in a thermoforming-based conversion process.

[0035] By adjusting the density and / or amount of binder, the rigidity of the part and protection against stone impacts can be increased. Depending on the method of attachment of the external battery cover, with or without an air gap, the requirements may be slightly different.

[0036] Preferably, the part is rigid so that it can be attached to the bottom of the battery box without substantial sagging.

[0037] The part can be compressed so that areas of the part are more or less compressed and exhibit a varying thickness distribution over the length of the part, with stiffer areas having thinner thicknesses increasing the stiffness of the part and helping to prevent sagging, while less stiff areas increasing the thermal insulation of the part.

[0038] During driving, external thermal battery covers tend to experience a wind washing effect, which can be caused by the effect of wind passing through the porous fibrous material, leading to forced convection, which can be reduced by at least locally increasing the density of the panel and / or reducing airflow resistance.

[0039] Preferably, a wind barrier layer can be used to further reduce the window washing effect, which can be at least one of a micro-perforated or airtight barrier layer, for example a foam, film or foil layer, and / or a membrane type material the same as or similar to Goretex®, for example a microporous membrane of the PU or LDPE type.

[0040] The film or foil material is preferably a single or double layer, preferably made of polyester, polyamide, polyolefin, such as polypropylene (PP) or polyethylene (PE) or thermoplastic polyurethane (TPU). Alternatively, double or triple layer films or foils can be used, such as a PE / PA combination. The advantage of double or triple layer foils is that the materials can be combined during lamination, dividing the need for micro-perforated or airtight layers across different film layers. For example, the outer layer can soften and / or melt to form a laminate / bond to the adjacent surface layer, while the middle layer remains intact.

[0041] As a closed cell foam material, preferably a polyester closed cell foam layer can be used as the wind barrier layer, which has the advantage of further increasing the stiffness of the panel and thereby increasing stone chipping resistance.

[0042] If a non-porous film or foil is used on the outside of the external thermal battery cover, it can similarly provide a watertight seal and prevent the external thermal battery cover from getting wet. A wet battery cover reduces its insulating properties, thus helping to enhance overall thermal performance while driving in all types of weather conditions by preventing the layer from getting wet and / or remaining damp. A water barrier can be used to completely prevent water from reaching the outside of the battery housing, which further prevents any possible corrosion in this area, as the barrier not only prevents rainwater from entering, but also prevents debris and salt carried with the rainwater from the road.

[0043] Alternatively, two layers of insulating material can be used with a wind barrier in between. The density of the outer layer can be higher than the density of the inner layer. Both layers can be made of the same material or different materials, for example, the outer layer facing the road can be a fibrous layer and the inner layer facing the battery housing can be a foam layer.

[0044] The part can be manufactured by forming at least one insulating (thermal insulating) material, such as a felt material or slab foam layer, into a final shape by an initial heating step and / or mechanically, and finally pre-densifying it. Additional layers can be added during the same forming step or applied before or after the forming step. If necessary, the part can be cut to shape and any fittings, such as fixtures, fasteners, etc., can be attached.

[0045] In lieu of mounting hardware, the components can be adhered to the exterior surface of the battery housing and / or adjacent structure using a water-resistant adhesive known in the art, preferably with an adhesive layer that can withstand harsh conditions.

[0046] Alternatively, mechanical attachments alone or in combination with adhesives are used.

[0047] The present invention further includes a battery electric vehicle having at least one battery cell housed in a battery housing having a fastener coupled to the battery housing, wherein the external thermal battery cover disclosed herein is attached to at least the road-facing bottom surface of the battery housing.

[0048] Preferably, the external thermal battery cover is attached with an enclosed air gap between at least a portion of the surface of the battery housing and the top surface of the external thermal battery cover, the air gap between the surface of the battery housing and the top surface of the battery cover acting as an additional thermal layer by creating a fixed, immobile air gap.

[0049] Preferably, the insulation layer and the trapped air layer combined are at least 0.070 m 2 Composite thermal resistance (R-value) in K / W, preferably at least 0.078 m 2 · Forms an insulating multi-layer with a combined thermal resistance of K / W.

[0050] Increasing density increases thermal conductivity, but also increases resistance to stone chipping and reduces the effect of windshield washing, providing an already excellent overall insulation that translates into increased vehicle range, but also helps preserve battery life.

[0051] The surface of the battery cover can include ribs to create spacers that ensure a dedicated area for the trapped air layer. Preferably, the trapped air layer or layers are coextensive with the structural connections inside the battery housing that create thermal bridges. This has the advantage that the air in the trapped air layer further improves localized insulation by creating an additional layer that is not disturbed by any window washing effect due to the cover.

[0052] Preferably, the battery cover also covers the sides of the battery housing and / or any adjacent structures, e.g., forming a partial encapsulation of the battery housing, with the battery cover covering and contacting the sides of the battery housing.

[0053] The external thermal battery cover may provide a seal to the surface of the battery housing and ultimately to adjacent structures and / or the body-in-white, forming a partial encapsulation of the battery housing. Alternatively, the battery cover may further include means for sealing the battery cover to the battery housing and / or adjacent structures and / or the body-in-white.

[0054] The battery housing may have a textured surface design, so that the battery cover of the present invention can be molded to follow the shape of the battery housing, or the textured shape can be used to introduce localized trapped air spaces to further optimize the thermal resistance of the combined air spaces and battery cover.

[0055] Thermal insulation properties may be measured as thermal conductivity according to ASTM C518-91 (ISO 8301), and unless otherwise indicated, measurements and / or results are at 20°C. [Brief explanation of the drawings]

[0056] [Figure 1] Figure 1 shows a schematic diagram of the state of the art. [Figure 2] FIG. 2 shows a schematic diagram of the approach proposed in this invention. [Figure 3] FIG. 3 shows a schematic diagram of the approach proposed in this invention. [Figure 4] FIG. 4 shows a schematic diagram of the approach proposed in this invention. [Figure 5] FIG. 5 shows a schematic diagram of the approach proposed in this invention. [Figure 6] FIG. 6 shows a schematic diagram of the approach proposed in this invention. DETAILED DESCRIPTION OF THE INVENTION

[0057] Below are examples illustrating possible implementations of the battery cover of the present invention, the examples and data of which may be adapted or combined with the teachings given as part of the disclosure herein. [Example]

[0058] Example 1 A composite filament based felt material was moulded to form an external thermal battery cover according to the present invention. The felt had a weight of 850 g / m 2 The resulting thermal resistance is 0.079m 2 ·K / W and the measured thermal conductivity of this material is 0.038 W / mK.

[0059] Example 2 A composite filament based felt material was moulded to form an external thermal battery cover according to the present invention. The felt had a weight of 1200 g / m 2 The resulting thermal resistance is 0.171 m 2 ·K / W and the measured thermal conductivity of this material is 0.035 W / mK.

[0060] Example 3 If the dedicated space for the battery cover is 6 mm, it can be decided to fill this space completely, for example with a felt material according to Example 1 or Example 2, or it can be decided to combine this felt material with an enclosed air layer. Adding a 3 mm enclosed air layer to the material of Example 1 adds 0.115 m to the already obtained thermal resistance of Example 1. 2 Additional thermal resistance of 0.194 m² / W can be added for a total of 0.194 m² 2 ·K / W.

[0061] Increasing density increases thermal conductivity, but also increases resistance to stone chipping and reduces the effect of window washing, while providing overall superior insulation, which surprisingly still translates into increased vehicle range. This also helps preserve battery life by maintaining a more constant temperature while reducing the energy required to do so.

[0062] Example 4 The external thermal cover of the present invention was used on a vehicle with a battery housing installed on the bottom of the passenger compartment, parallel to the floor of the passenger compartment. The external thermal cover was installed on the surface of the battery housing facing the road. The cover was made of polyethylene terephthalate composite filaments containing up to 100% recycled polyethylene terephthalate. The filaments were spun into a mat and needled prior to thermal forming of the cover parts. The thermal forming was carried out by a molding process. Preferably, the thickness was 850 to 1600 g / m. 2 , preferably 1000 g / m 2 The filament mat thus formed was thermally formed into more or less compressed areas, with an areal weight of 150 kg / m 3 ~800kg / m 3The resulting cover had a final density of 1000 psi. When tested on a vehicle, this cover was found to significantly improve the insulation of the battery during both the heating and cooling phases. Furthermore, due to its rigidity (tensile strength), this single-layer structure was found to be able to deform upon impact of the cover by an obstacle and still substantially return to its original, intended shape. Thus, this cover not only improved the regulation of the thermal conditions of the battery pack, but also substantially prevented impact damage to the underside of the battery housing due to the high elongation of the compacted material used. Compared to state-of-the-art fiber matrix structures made of glass fiber and polymer, the elongation factor was found to be approximately 10 times higher, which allowed the edges of the molded part to rise and fall more easily. Thus, the polyester filament cover of the present invention elastically deforms and provides excellent protection against stone impacts on the front tire.

[0063] BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram of the state of the art. FIG. 2 is a schematic diagram of the approach proposed in this invention.

[0064] Figure 1 shows a vehicle with a body structure (2) and wheels (1). A battery housing is attached to the bottom of the body structure, facing the road (5). The battery housing (3) can be made of a sturdy material that can withstand impacts, such as composites or metals, and inside the housing, some kind of frame structure (6) can be attached to the inner wall of the battery housing to ensure proper fixation of the battery cells and / or modules within the battery housing. Side beams (4) can be installed along the walls of the battery housing and preferably fixed to the body structure to form stiffening zones that can withstand impacts to the vehicle, especially to the battery boxes in the event of a vehicle breakage, reducing the risk to the battery modules.

[0065] In the state of the art, the battery modules inside the battery housing are cooled or heated to maintain a temperature within a predetermined range, but the frame structure (6) structurally connected to the battery housing forms a temperature bridge (thermal bridge) to the other side of the battery housing wall, thus allowing heat (7) to radiate from the outside of the wall to the surroundings. This is independent of any insulating material (not shown) placed within the battery housing structure.

[0066] Since the battery housing is directly exposed to the external environment, especially during driving, the airflow (8) passing through the lower area of ​​the battery box further cools or heats the outside of the battery box, thereby reducing the thermal management efforts inside the battery housing, and in particular, this increases the energy used to maintain a constant temperature of the battery elements and / or modules.

[0067] 2-6 show various design possibilities for how the external battery cover disclosed thus far can be combined with the vehicle battery housing. All materials or material combinations mentioned above and below can be freely combined depending on the advantageous features they provide.

[0068] Figures 2 and 3 show the same spatial arrangement as shown in the state of the art, but the battery housing is covered with an external thermal battery cover (9) according to the invention. The battery cover may be made of fibrous or foam material. Alternatively, the battery cover may consist of a plastic shell with an insulating inlay made of foam or felt between the shell and the outer surface of the battery housing.

[0069] In a first embodiment (FIG. 2), an external thermal battery cover is placed adjacent to the battery housing. The external cover can be bonded over the entire surface or just around the rim, leaving a minimal trapped air gap between the surfaces. Even a minimal trapped air gap is already sufficient to separate the external cover from the heat-radiating surfaces of the battery housing.

[0070] In a second embodiment (FIG. 3), the outer cover is installed with a dedicated trapped air space (12). The dedicated trapped air space can be realized by attachment means (10) including spacer parts to the attachment and / or by a molded shape design, e.g., with at least one recess, to create such a dedicated trapped air space. To prevent airflow from entering through the trapped air space between the underside of the battery housing and the adjacent surface of the outer cover, a sealing (11) surrounding at least a portion of the rim can be advantageous for closing the trapped air space, preferably while keeping its closed area as large as possible. The spacer function and the sealing can be integrated into a solution using the same material.

[0071] Alternatively, the outer cover (9) can extend to include surrounding structures parallel to the battery housing, such as stiffening beams (FIG. 4). Preferably, the outer cover is made of a porous fibrous material according to the present invention, compressed to withstand stone impacts, also known as stone chipping. The material can be thermoformed to form a shape that fits over the battery housing structure and possible adjacent structures.

[0072] The cover design can also help smooth out battery housing structures, such as beams, to create a more aerodynamic surface on the bottom of the cover or optimize drag performance. Optionally, a dedicated trapped air layer (12) in the form of a recess or recesses can be integrated into the molded shape. While not required for thermal function, high bending stiffness is a priority for maintaining the part's shape during use and for improving resistance to stone chipping. Surprisingly, high-density fibrous materials can keep the battery's temperature more constant while still providing very good performance. It has been shown that using such panel structures, with or without trapped air layers, can reduce the amount of energy required to maintain a constant temperature.

[0073] The heat sink effect can be further reduced by extending the external battery cover along and over the corners of the part, also covering the sides of the battery housing and / or adjacent structures, further sealing the lower area and preventing wind from blowing through structures that could act as heat sinks.

[0074] 5 and 6 show different material approaches for the same battery housing situation depicted in FIGS. 1-3.

[0075] The engine cover shield (9) includes at least one insulating layer (14) of porous fibrous material. It may further include a second layer (13) capable of blocking wind and / or water. This layer may be any one of a film, foil, impermeable foam layer, or microporous membrane layer. The film or foil layer may be a single-layer film or a double-layer film. It must be watertight or airtight, but may still be a breathable film or foil to allow condensation that forms in the area between the battery housing and the cover to escape. The membrane may have similar behavior and may be the same or similar to membranes sold under the Goretex® trademark. By preventing wind from pressing into the porous fibrous material, the stationary air within the undercover material, and ultimately within the trapped air layer, is not disturbed. This further enhances insulation, especially under higher speed driving conditions. This windproof and / or waterproof layer can be placed facing the battery housing or facing the road. Optionally, films can be placed on both sides of the porous fibrous layer. Finally, the porous fibrous layer can be wrapped and sealed within such layers to form a windproof and / or waterproof pouch.

[0076] In a further preferred approach, a windproof and / or waterproof layer (16) is placed between the two fibrous layers to form a sandwich structure. The first fibrous layer (14) may be the same as or different from the second fibrous layer (15). The fibrous layers may differ in fiber composition, mix, and / or fineness, and / or the amount of binder used. For example, the outer fibrous layer (14) may have a higher binder content than the inner fibrous layer to achieve better stone chipping performance, and there may be a difference in thermal conductivity between the layer near and / or adjacent to the battery housing and the layer facing the road. Furthermore, the inner fibrous layer (15) and the outer fibrous layer (14) may be further treated differently; for example, it may be beneficial to apply a flammable and / or water-repellent treatment to only one side. For example, both layers may be made of the same or similar basic fibrous material, but the outer layer may be treated with a water-repellent treatment and the inner layer with a flame-retardant treatment.

[0077] This can also be beneficial for the environment, as the outer fibrous layer will have more contact with rainwater and the material treatment may leach into it, whereas the inner fibrous layer is mostly protected by a windproof and / or waterproof layer, and the treatment material is unlikely to be exposed to high levels of water. Some of the embodiments of the invention related to the present invention are shown below. [Embodiment 1] 1. An external thermal battery cover for a battery housing, comprising: The cover is at least 0.070 m 2 Thermal resistance (R-value) in K / W, preferably at least 0.078 m 2 At least one insulating layer having a thermal resistance of K / W; The heat insulating layer is at least one of a fibrous layer, an open-cell foam layer, and a closed-cell foam layer. External thermal battery cover for battery housing. [Embodiment 2] The porous fibrous layer contains staple fibers and / or filaments and a binder, and the porous fibrous layer has a strength of 150 to 600 kg / m 3 2. The external thermal battery cover for a battery housing according to embodiment 1, wherein the battery cover is molded to form a panel having a density of 0.02 to 0.06 W / mK, a thermal conductivity of 0.03 to 0.06 W / mK, and a thickness of 2.5 to 10 mm. [Embodiment 3] 3. An external thermal battery cover for a battery housing according to embodiment 1 or 2, wherein the fibers and / or filaments of the porous fibrous material are preferably of organic origin, such as cotton, kenaf, hemp, or a thermoplastic material, such as polyester, preferably PET or PBT, or a polyamide, preferably polyamide-6 or polyamide 6,6, or a polyolefin, preferably polypropylene or polyethylene, or an inert material, preferably based on at least one of glass, carbon, kenaf, Nomex, or ceramics, or a fiber and / or filament mixture thereof. [Embodiment 4] 4. An external thermal battery cover for a battery housing according to any one of embodiments 1 to 3, wherein the fibers and / or filaments have a fineness of 3 to 10 dtex, preferably 3 to 8 dtex. [Embodiment 5] 5. An external thermal battery cover for a battery housing according to any one of embodiments 1 to 4, wherein the fibers and / or filaments have a hollow or solid cross section. [Embodiment 6] 6. An external thermal battery cover for a battery housing according to any one of embodiments 1 to 5, wherein the binder of the porous fibrous material is either a thermoplastic binder, preferably polyester, polyamide, polyethylene, or polypropylene, or a thermosetting binder, preferably epoxy resin or phenolic resin. [Embodiment 7] 7. An outer thermal battery cover for a battery housing according to any one of embodiments 1 to 6, further comprising at least one of a micro-perforated or airtight wind barrier layer. [Embodiment 8] 8. An external thermal battery cover for a battery housing as described in any one of embodiments 1 to 7, wherein the wind barrier layer is at least one of a foam, a film or foil layer, and / or a membrane-type material. [Embodiment 9] 9. An external thermal battery cover for a battery housing according to any one of the preceding embodiments, wherein the porous fibrous layer is treated with a water repellent agent and / or a water repellent additive is mixed into at least one of the materials forming the fibers and / or filaments, preferably an agent based on at least one of polysiloxanes, such as polydimethylsiloxane, or polysiloxanes such as polydimethylsiloxanes having aminoalkyl groups and polyether groups, or an agent based on polyethylene glycol, or an agent based on fluoropolymers, such as fluoroalkyl derivatives. [Embodiment 10] 10. An external thermal battery cover for a battery housing according to any one of embodiments 1 to 9, wherein the porous fibrous layer is treated with a flame retardant and / or a flame retardant additive is mixed into at least one of the materials forming the fibers and / or filaments, preferably a phosphorus- or bromine-based agent is used. [Embodiment 11] 11. An external thermal battery cover for a battery housing according to any one of the preceding embodiments, further comprising a protective layer formed from a plastic or plastic-fiber composite material, preferably glass fibers embedded in a thermoplastic matrix, said matrix preferably being based on polyolefin or polyester. [Embodiment 12] 12. An external thermal battery cover for a battery housing according to any one of embodiments 1 to 11, further comprising a means for attaching the external thermal battery cover under the battery housing on the road-facing side. [Embodiment 13] A battery electric vehicle having at least one battery cell stored in a battery housing, the battery housing having a fixing part connected to the battery housing, characterized in that the external thermal battery cover described in any one of embodiments 1 to 12 is attached to at least the bottom surface of the battery housing facing the road. [Embodiment 14] The insulating layer includes an enclosed air layer between the battery housing and the insulating layer, and the insulating layer and the enclosed air layer combined have a thickness of at least 0.070 m 2 Composite thermal resistance (R-value) in K / W, preferably at least 0.078 m 2 14. The battery electric vehicle of claim 13, wherein the battery electric vehicle is formed with a thermal insulating multilayer having a composite thermal resistance of 1000 K / W. [Embodiment 15] 15. The battery electric vehicle of embodiment 13 or 14, wherein the external thermal battery cover is attached with an enclosed air space between a surface of the battery housing and a top surface of the external thermal battery cover. [Embodiment 16] 16. The battery electric vehicle of any one of embodiments 13 to 15, wherein the battery cover also at least partially covers the battery housing and / or adjacent structure and / or a side of the body-in-white. [Embodiment 17] 17. The battery electric vehicle of any one of embodiments 1 to 16, wherein a seal is used between the battery cover and at least a portion of the side of the battery housing and / or adjacent structure and / or body-in-white.

Claims

1. An external thermal battery cover for a battery housing of a battery electric vehicle, comprising: The cover is at least 0.070 m ２ Thermal resistance (R-value) in K / W, preferably at least 0.078 m ２ - includes at least one insulating layer with a thermal resistance of K / W; The heat insulating layer is a fibrous layer made of a porous fibrous material containing staple fibers and / or filaments and a binder, and the porous fibrous layer has a strength of 150 to 600 kg / m ３ a thermal conductivity of 0.03 to 0.06 W / mK, and a thickness of 2.5 to 10 mm. External thermal battery cover for battery housing.

2. 2. An external thermal battery cover for a battery housing of a battery electric vehicle according to claim 1, wherein the staple fibres and / or filaments of the porous fibrous material are preferably of organic origin, for example cotton, kenaf, hemp, or a thermoplastic material, for example polyester, preferably PET or PBT, or polyamide, preferably polyamide-6 or polyamide 6,6, or polyolefin, preferably polypropylene or polyethylene, or an inert material, preferably based on at least one of glass, carbon, kenaf, Nomex, or ceramics, or a fibre and / or filament blend thereof.

3. 3. An external thermal battery cover for a battery housing of a battery electric vehicle according to claim 1 or 2, wherein said staple fibres and / or filaments have a fineness of 3 to 10 dtex, preferably 3 to 8 dtex.

4. The external thermal battery cover for a battery housing of a battery electric vehicle according to any one of claims 1 to 3, wherein the staple fibres and / or filaments have a hollow or solid cross section.

5. 5. The external thermal battery cover for a battery housing of a battery electric vehicle according to claim 1, wherein the binder of the porous fibrous material is either a thermoplastic binder, preferably polyester, polyamide, polyethylene, or polypropylene, or a thermosetting binder, preferably epoxy resin or phenolic resin.

6. 6. The external thermal battery cover for a battery housing of a battery electric vehicle according to any one of claims 1 to 5, further comprising at least one of a micro-perforated or airtight wind barrier layer.

7. 7. The external thermal battery cover for a battery housing of a battery electric vehicle according to claim 6, wherein the wind barrier layer is at least one of a foam, a film or foil layer, and / or a membrane-type material.

8. 8. An external thermal battery cover for a battery housing of a battery electric vehicle according to any one of claims 1 to 7, wherein the porous fibrous layer is treated with a water repellent agent and / or a water repellent additive is mixed into at least one of the materials forming the staple fibres and / or filaments, preferably an agent based on at least one of polysiloxanes, such as polydimethylsiloxane or polydimethylsiloxanes having aminoalkyl groups and polyether groups, or an agent based on polyethylene glycol, or an agent based on fluoropolymers, such as fluoroalkyl derivatives.

9. 9. An external thermal battery cover for a battery housing of a battery electric vehicle according to any one of claims 1 to 8, wherein the porous fibrous layer is treated with a flame retardant and / or a flame retardant additive is mixed into at least one of the materials forming the staple fibers and / or filaments, preferably a phosphorus or bromine based agent is used.

10. 10. An external thermal battery cover for a battery housing of a battery electric vehicle according to any one of claims 1 to 9, further comprising a protective layer formed from a plastic or plastic-fiber composite material, preferably glass fibers embedded in a thermoplastic matrix, said matrix preferably being based on polyolefin or polyester.

11. 11. An external thermal battery cover for a battery housing of a battery electric vehicle according to any one of claims 1 to 10, further comprising means for mounting the external thermal battery cover under the battery housing on the road-facing side.

12. A battery electric vehicle having at least one battery cell housed in a battery housing having a fixing part connected to the battery housing, characterized in that the external thermal battery cover according to any one of claims 1 to 11 is attached to at least a bottom surface of the battery housing facing the road.

13. The insulating layer includes an enclosed air layer between the battery housing and the insulating layer, and the insulating layer and the enclosed air layer combined have a thickness of at least 0.070 m ２ Composite thermal resistance (R-value) in K / W, preferably at least 0.078 m ２ 13. The battery electric vehicle of claim 12, wherein the battery electric vehicle is provided with a thermal insulating multilayer having a combined thermal resistance of K / W.

14. 14. The battery electric vehicle of claim 12 or 13, wherein the external thermal battery cover is attached with an enclosed air gap between a surface of the battery housing and a top surface of the external thermal battery cover.

15. A battery electric vehicle according to any one of claims 12 to 14, wherein the battery cover also at least partially covers a side of the battery housing and / or adjacent structure and / or body-in-white.

16. A battery electric vehicle according to any one of claims 1 to 15, wherein a seal is used between the battery cover and at least a part of the side of the battery housing and / or adjacent structure and / or body-in-white.

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