Battery for an electrically powered motor vehicle

Abstract

Battery (2) for an electrically powered motor vehicle, comprising - a battery housing (4) with a housing base (6) and with a housing cover (8), and - a battery cell (10) arranged in the battery housing (4), - wherein the battery cell (10) is connected to the housing base (6) by means of a first Velcro connection (12) and / or to the housing cover (8) by means of a second Velcro connection (14), and - wherein a thermally conductive colloid, a thermally conductive gel (24), and / or a thermally conductive paste is introduced between Velcro units (16) of the first Velcro connection (12) and / or between Velcro units (16) of the second Velcro connection (14).

Description

[0001] The invention relates to a battery, in particular a traction battery, for an electrically driven motor vehicle, which has a battery housing with a housing base and a housing cover, as well as a battery cell arranged in the battery housing.

[0002] An electrically powered motor vehicle typically has a traction battery (high-voltage battery, HV battery) that supplies energy to an electric motor to drive the motor vehicle. An electrically powered motor vehicle is understood to mean, in particular, an electric vehicle that stores the energy required for propulsion solely in the traction battery (BEV, battery electric vehicle), an electric vehicle with a range extender (REEV, range extended electric vehicle), a hybrid vehicle (HEV, hybrid electric vehicle), a plug-in hybrid vehicle (PHEV, plug-in hybrid electric vehicle), and / or a fuel cell vehicle (FCEV, fuel cell electric vehicle), which temporarily stores the electrical energy generated by a fuel cell in the traction battery.

[0003] Such a traction battery typically comprises a large number of battery cells that are connected in series and / or parallel. For example, the battery cells are grouped into modules, with the battery cells only being connected within the module, and the modules being connected in series and / or parallel. Alternatively, in the so-called Cell2Pack or Cell2Car design, the battery cells are directly connected together, i.e., not pre-assembled into modules.

[0004] For example, the individual battery cells are bonded together with adhesives or gap fillers during assembly into a module or pack. Furthermore, a so-called gap pad is typically arranged between adjacent battery cells as an intermediate element, which compensates for the volume changes of the battery cells and cell stacks during charging and discharging (so-called cell breathing). The gap pads also compensate for the age-related increase in thickness of the battery cells over their service life (so-called cell swelling). Furthermore, the battery cells can be bonded to a cooling connection side with a gap filler.

[0005] Due to the way the battery cells or modules are attached, for example by welding or using a bearing, cooling is disadvantageously difficult.

[0006] From US 2007 / 0 224 498 A1 it is known to provide the mutually facing end faces of the battery cells with Velcro surfaces and to stack them to form a Velcro-connected cell stack.

[0007] WO 2020 / 192196 A1 discloses that a cooling gel can be inserted between a cooling plate and the battery cells.

[0008] DE 10 2009 051 213 A1 discloses an electrochemical cell in which a hook-and-loop fastener is attached. A cooling coil is threaded between the hook-and-loop fasteners.

[0009] DE 10 2018 102 989 A1 discloses a thermal contact and filler material comprising at least one thermally conductive filler and at least one silicone-free base oil. The thermally conductive filler is a metal hydroxide, and the thermal contact and filler material comprises at least one chemically crosslinkable prepolymer mixture.

[0010] The teaching of DE 10 2020 203 876 A1 relates to a battery module with several galvanic cells arranged along a stacking direction. A connecting body connects the galvanic cells to one another in the stacking direction.

[0011] DE 10 2020 130 751 A1 discloses a battery assembly comprising a support structure with at least one electrically conductive first contact point and at least one battery cell with a first terminal. The at least one electrically conductive first contact point of the support structure and the first terminal of the at least one battery cell are electrically connected to one another via a detachable connection, wherein the detachable connection is an adhesive connection and / or a hook-and-loop connection.

[0012] The invention is based on the object of providing a particularly suitable battery for an electrically powered motor vehicle that enables the best possible cooling of the battery cells and / or is as stable and crash-resistant as possible. Furthermore, an electrically powered motor vehicle with such a battery is to be provided.

[0013] With regard to the battery, the object is achieved according to the invention by the features of claim 1. With regard to the electrically powered motor vehicle, the object is achieved according to the invention by the features of claim 8. Advantageous embodiments and further developments are the subject of the subclaims. The statements made in connection with the battery also apply mutatis mutandis to the motor vehicle, and vice versa.

[0014] The battery is intended and configured for an electrically powered motor vehicle. In particular, the battery is a traction battery of the motor vehicle. Thus, the battery supplies electrical energy to a (traction) electric motor for driving the motor vehicle. Suitably, the battery is a secondary battery.

[0015] The battery has a battery housing, also referred to as a housing for short, with a housing base and a housing cover opposite the housing base, in particular extending parallel to the housing base. A battery cell, in particular a lithium-ion battery cell, is arranged in the battery housing, thus between the housing base and the housing cover. Expediently, several such battery cells are arranged in the battery housing between the housing base and the housing cover. In particular, the battery cell(s) is / are inserted directly into the battery housing according to the Cell2Pack or Cell2Car design, with the battery cells preferably being arranged next to one another in a row.

[0016] Here and in the following, the side of the respective battery cell facing the housing cover is referred to as the top side and the side facing the housing base is referred to as the bottom side.

[0017] The battery cell is (or each battery cell is) connected to the housing base by means of a first hook-and-loop connection. Thus, the battery cell is fixed and held to the housing base by means of the first hook-and-loop connection. The first hook-and-loop connection is formed by two mutually complementary hook-and-loop units, in particular by two hook-and-loop strips, one of which is attached, in particular glued, to the underside of the battery cell, and the other is attached, in particular glued, to the side of the housing base facing the battery cell.

[0018] Alternatively, or preferably additionally, the battery cell (or each battery cell) is connected to the housing cover by means of a second hook-and-loop connection. Thus, the battery cell is fixed and held to the housing cover by means of the second hook-and-loop connection. The second hook-and-loop connection is formed in an analogous manner by two (further) complementary hook-and-loop units, in particular by two (further) hook-and-loop strips, one of which is attached, in particular glued, to the top of the battery cell, and the other is attached, in particular glued, to the side of the housing cover facing the battery cell.

[0019] "Hook and loop" or "Hook and loop" refers here and below to a reversibly detachable, positive and / or non-positive connection between the hook and loop units. The hook and loop connection (the hook and loop fastener) is based on the principle of velcro. Thus, the hook and loop units have complementary hook and loop elements, which are held together in a positive and / or non-positive manner in the hook and loop connection. The complementary hook and loop units can be designed, for example, as a hook and loop fastener (felt fastener, velour fastener), or as a mushroom-shaped fastener and loop fastener, or as a mushroom-shaped fastener and mushroom-shaped fastener, or as a hook and loop fastener and mushroom-shaped fastener.

[0020] Furthermore, a thermally conductive colloid is inserted between the two hook-and-loop units of the first hook-and-loop connection and / or between the two hook-and-loop units of the second hook-and-loop connection. A colloid is a mixture of particles, in particular solid particles, or droplets in a dispersion medium, where the dispersion medium can be a solid, a gas, or a liquid. The particles or droplets are distributed, in particular homogeneously, in the dispersion medium. The particles or droplets preferably have a diameter between 1 nm and 1000 nm, particularly preferably a diameter between 10 nm and 500 nm.

[0021] Alternatively or in addition to the colloid, a thermally conductive gel (thermally conductive gel, thermally conductive gel, cooling gel) and / or a, in particular non-flowable, thermally conductive paste is introduced between the two Velcro units of the first Velcro connection and / or between the two Velcro units of the second Velcro connection.

[0022] In summary, thermally conductive colloid, thermally conductive gel, or thermal paste, or a mixture thereof, is incorporated into the first hook-and-loop connection and / or the second hook-and-loop connection. In other words, the gel, colloid, or thermal paste is arranged in an (intermediate) space formed between the complementary hook-and-loop units in the assembled state. In particular, this space is filled with the gel, colloid, or thermal paste.

[0023] For example, the thermal paste is cured, so the connection between the hook-and-loop fasteners is comparatively secure and stable. In contrast, a paste-like thermal paste, i.e., a non-cured thermal paste, as well as a gel, advantageously allows for non-destructive opening (removal) of the first or second hook-and-loop fastener, thus simplifying maintenance, which involves removing the housing cover and / or the housing base from the battery cell.

[0024] In summary, the first and / or second hook-and-loop fasteners enable a comparatively simple joining of the battery cell to the housing. A comparatively secure hold of the (housing) cover or the (housing) base is provided by the first and / or second hook-and-loop fasteners, respectively. Furthermore, the space formed by the hook-and-loop fasteners is advantageously used for the thermally conductive colloid, the (heat-conducting) gel, or the thermal paste. The gel or the thermal paste improves heat transfer from the battery cell to the housing base or the housing cover.

[0025] In a preferred embodiment, the thermal conductivity of the colloid, the gel, and / or the thermal paste is greater than 4 W / (m·K), in particular greater than 7 W / (m·K). Preferably, the thermal conductivity of the gel is between 4 W / (m·K) and 20 W / (m·K), in particular between 7 W / (m·K) and 13 W / (m·K).

[0026] The gel is, for example, a polymer-solvent mixture. In particular, the gel is a viscoelastic fluid, with the polymer, especially a solid one, expediently forming a sponge-like, three-dimensional network in whose pores the solvent is absorbed. For example, a gel containing macromolecular polymers is used. In particular, these polymers have a dimension or diameter greater than 1000 nm.

[0027] For example, a block polymer, particularly a styrene block copolymer or an ester block copolymer, is used for the gel's polymer. Oils or organic solvents are suitably used as solvents or swelling agents for the production of the gel. As a specific example, styrene-butadiene-styrene is used as a block copolymer with mineral oil as a plasticizer. The proportion of oil is selected according to a desired or specified viscosity and is between 30 vol.% and 85 vol.%.

[0028] According to a suitable embodiment, the thermally conductive gel has a viscosity, based on room temperature (20°C), of between 150,000 mPa s (millipascals per second) and 5,000,000 mPa s, in particular between 500,000 mPa s and 2,000,000 mPa s, preferably between 500,000 mPa s and 1,000,000 mPa s. Preferably, the colloid also has a viscosity, based on room temperature (20°C), of between 150,000 mPa s (millipascals per second) and 5,000,000 mPa s, in particular between 500,000 mPa s and 2,000,000 mPa s, preferably between 500,000 mPa s and 1,000,000 mPa s.

[0029] Even during operation of a device containing the battery, especially an electrically powered motor vehicle, and any vibrations or shocks that may occur, the thermally conductive colloid, the gel (and, analogously, the more viscous thermal paste) is held relatively securely in the spaces between the hook-and-loop fasteners. Thus, leakage of the gel or colloid from the hook-and-loop fastener area due to such viscosity is prevented, or the risk of such leakage is at least reduced.

[0030] According to an advantageous embodiment, the first and / or the second hook and loop connection is designed such that a head tensile load for opening the first hook and loop connection, i.e. for releasing the connection of the battery cell from the housing base due to the first hook and loop connection, or for opening the second hook and loop connection, i.e. for releasing the connection of the battery cell from the housing cover due to the second hook and loop connection, is in each case greater than 5 MPa (megapascals). In other words, a tensile load greater than 5 MPa must be applied in a direction perpendicular to the plane spanned by the hook and loop units of the first or second hook and loop connection, so that the first and / or the second hook and loop connection is opened. In this way, a particularly operationally and crash-safe as well as stable battery is realized, in particular for an electrically powered motor vehicle.

[0031] Preferably, the first and / or second hook-and-loop fasteners are further configured such that their shear strength is greater than 5 MPa. The pressures and line loads required to release the hook-and-loop fasteners by means of a peeling movement are preferably dimensioned significantly smaller than the head tensile load and / or shear strength.

[0032] Suitably, the hook-and-loop unit of the first and / or the hook-and-loop units of the second hook-and-loop connection are each made of or comprise a polymer, in particular polypropylene, polyamide, polyaramid, polyester, and polyolefin. This variant of the hook-and-loop units is advantageously comparatively lightweight and cost-saving.

[0033] Alternatively, the hook-and-loop unit of the first and / or the hook-and-loop units of the second hook-and-loop connection are each formed from or comprise a metal or an alloy, such as steel. Due to the metal or alloy, the hook-and-loop units each exhibit a comparatively high thermal conductivity, further improving cooling of the battery cell. Furthermore, high tensile and / or shear strengths, in particular greater than 5 MPa, are relatively easy to achieve with hook-and-loop units made of or with metal or with or with an alloy.

[0034] In a preferred embodiment, the housing base and / or the housing cover are coolable. Preferably, the housing base and / or the housing cover are actively coolable by means of a cooling device. In particular, the housing base and / or the housing cover each have a cooling channel for a cooling medium. In other words, a cooling channel for controlling the temperature of the battery cell is preferably integrated into the housing base and / or the housing cover. The housing base or the housing cover thus serves as a heat sink for the heat conducted away from the battery cell by means of the (cooling) gel, the colloid, the thermal paste, and / or the Velcro units.

[0035] A further aspect of the invention relates to an electrically powered motor vehicle with a battery configured according to one of the variants described above. In particular, the battery is a traction battery of the motor vehicle, which provides electrical energy for driving the motor vehicle.

[0036] In the following, exemplary embodiments of the invention are explained in more detail with reference to a drawing. In the drawings: Fig. 1 schematically and in detail a battery with a housing and with battery cells, wherein the battery cells are connected to a housing base of the housing by means of a first Velcro connection and to a housing cover of the housing by means of a second Velcro connection, Fig. 2a schematically and in detail the first Velcro connection, wherein a thermally conductive gel and / or a thermally conductive paste is arranged between the Velcro strips, and Fig. 2b schematically and in detail the second Velcro connection, wherein a thermally conductive gel and / or a thermal paste is arranged between its Velcro strips.

[0037] Corresponding parts and sizes are always provided with the same reference symbols in all figures.

[0038] In the Fig. 1 schematically illustrates a battery 2. It comprises a battery housing 4 (housing 4), with only its housing base 6 (base 6) and its housing cover 8 being shown. The housing base 6 and the housing cover 8 are arranged opposite one another and oriented parallel to one another.

[0039] A number of battery cells 10 are arranged in the battery housing 4 between the housing base 6 and the housing cover 8, of which only three are shown for the sake of clarity. The battery cells 10 are arranged next to one another in a row direction R, which runs parallel to the housing base. The battery cells 10 form a so-called cell pack.

[0040] In particular, the battery 2 is designed according to a Cell2Pack or Cell2Car design, so that the battery cells 10 are inserted directly into the battery housing 4, i.e. are not combined into modules.

[0041] Each of the battery cells 10 is connected (Velcro-) to the housing base 6 by a first Velcro connection 12 and to the housing cover 8 by a second Velcro connection 14. In other words, each of the battery cells 10 is joined to the housing base 6 by the first Velcro connection 12 and to the housing cover 8 by a second Velcro connection 14.

[0042] As in the Fig. 2a and Fig. 2b, the first hook-and-loop connection 12 is formed by two hook-and-loop units 16, each designed as a hook-and-loop strip. These hook-and-loop units 16 comprise a base body 18 glued to the battery cell 10 or to the housing base 6, on which a plurality of hook-and-loop fastener elements 20 are arranged, which protrude upwards from the base body 18. Accordingly, the second hook-and-loop connection 14 is formed by two hook-and-loop units 16, each designed as a hook-and-loop strip. These comprise a base body 18 glued to the battery cell 10 or to the housing cover 8, on which a plurality of hook-and-loop fastener elements 20 are arranged, which protrude upwards from the base body 18.

[0043] The hook and loop fastener elements 20 have, according to the Fig. 2a and Fig. The embodiment shown in Figure 2b has a mushroom-shaped design. In other words, the hook-and-loop units 16 are designed as complementary mushroom-shaped strips.

[0044] According to alternatives not shown in more detail, the hook and loop fastener units 16 are designed in an otherwise analogous manner as a hook and loop fastener tape complementary to this, as a mushroom head tape and loop fastener tape complementary to this, or as a hook tape and loop fastener tape complementary to this.

[0045] In the assembled state of the battery 2, a gap 22 is formed between the hook-and-loop units 16 of the first hook-and-loop connection 12, in particular between their base bodies 18 and / or between their hook-and-loop fastener elements 20. To improve heat conduction from the respective battery cell 10 to the housing base 6, a thermally conductive gel 24 is introduced into this gap 22. According to an alternative not further illustrated, a colloid or, according to a further alternative, a thermally conductive paste is introduced into this gap 22. In particular, the gap 22 is filled with the colloid, with the gel 24, or with the thermally conductive paste.

[0046] Analogously, in the assembled state of the battery 2, a (further) intermediate space 22 is formed between the hook-and-loop units 16 of the second hook-and-loop connection 14, in particular between their base bodies 18 and / or between their hook-and-loop fastener elements 20. To improve heat conduction from the respective battery cell 10 to the housing cover 8, thermally conductive gel 24 or, according to an alternative not further shown, thermally conductive paste is introduced into this (further) intermediate space 22. In particular, the intermediate space 22 is filled with the gel 24 or with the thermally conductive paste.

[0047] In summary, a thermally conductive gel 24 and / or a thermally conductive paste is inserted between the hook and loop units 16 of the first hook and loop connection 12 and between the hook and loop units 16 of the second hook and loop connection 14. Fig. 2a and Fig. In Figure 2b, the gel 24 is shown hatched for better visibility.

[0048] In particular, the thermal conductivity of the gel 24 and / or the thermal paste is greater than 4 W / (m·K), in particular greater than 7 W / (m·K). Preferably, the thermal conductivity of the gel is between 4 W / (m·K) and 20 W / (m·K), in particular between 7 W / (m·K) and 13 W / (m·K). The gel 24 further has a viscosity that is greater than 150,000 mPa·s and less than 5,000,000 mPa·s.

[0049] The hook-and-loop units 16, i.e., their base body 18 and their hook-and-loop fastener elements 20, of the first hook-and-loop connection 12, as well as the hook-and-loop units 16 of the second hook-and-loop connection 14, are each made of a polymer, such as polypropylene, polyamide, polyaramid, polyester, and polyolefin. Alternatively, the hook-and-loop units 16, i.e., their base body 18 and their hook-and-loop fastener elements 20, are made of a metal, such as aluminum, or an alloy, such as steel. If the hook-and-loop units 16 are made of metal or an alloy, they are coated, for example, to reduce electrical conductivity.

[0050] Due to such an arrangement of the battery cells 10 and their hook-and-loop connections 12, 14 to the housing 4, the battery 2 has a structure that is essentially comparable to a double-T beam or a sandwich panel. The arrangement and orientation of the battery cells 10 and the hook-and-loop connections thus increases the stability and rigidity of the battery 2, thereby realizing increased safety in the event of a crash. A head tensile load for releasing the first and / or second hook-and-loop connections is dimensioned to be greater than 5 MPa.

[0051] As particularly in the Fig. As can be seen in Figure 1, the battery cells 10 are furthermore reversibly connected to one another and, in particular, can be detached from one another without tools by means of a further, third hook-and-loop connection 26. Preferably, the battery cells 10 are electrically insulated from one another by means of the third hook-and-loop connection 26.

[0052] Optional is, as still in the Fig. As can be seen in Figure 1, the housing base 6 and the housing cover 8 are coolable. For this purpose, the housing base 6 and the housing cover 8 each have a cooling channel 28 through which a cooling medium can flow.

[0053] In a manner not shown in detail, an electrically powered motor vehicle has battery 2 as a traction battery. Thus, battery 2 serves to provide electrical energy for an electric motor to drive the motor vehicle.

[0054] The invention is not limited to the exemplary embodiments described above. Rather, other variants of the invention can be derived from them by those skilled in the art within the scope of the claims without departing from the subject matter of the invention. In particular, all individual features described in connection with the exemplary embodiments and / or in the claims can also be combined with one another in other ways without departing from the subject matter of the invention. List of reference symbols 2 batteries 4 battery housings 6 Case back 8 housing cover 10 battery cells 12 first Velcro connection 14 second Velcro connection 16 Velcro unit 18 basic bodies 20 Velcro fasteners 22 space 24 Gel 26 third Velcro connection 28 cooling channel R Row direction

Claims

[1] Battery (2) for an electrically powered motor vehicle, comprising - a battery housing (4) with a housing base (6) and with a housing cover (8), and - a battery cell (10) arranged in the battery housing (4), - wherein the battery cell (10) is connected to the housing base (6) by means of a first Velcro connection (12) and / or to the housing cover (8) by means of a second Velcro connection (14), and - wherein a thermally conductive colloid, a thermally conductive gel (24), and / or a thermally conductive paste is introduced between Velcro units (16) of the first Velcro connection (12) and / or between Velcro units (16) of the second Velcro connection (14). [2] Battery (2) according to claim 1, characterized by that the thermal conductivity of the gel (24), the colloid, and / or the thermal paste is greater than 4 W / (m·K), in particular greater than 7 W / (m·K). [3] Battery (2) according to claim 1 or 2, characterized bythat the viscosity of the gel (24) is between 150000 mPa·s and 5000000 mPa·s. [4] Battery (2) according to one of claims 1 to 3, characterized by that a head tensile load for opening the first Velcro connection (12) and / or the second Velcro connection (14) is greater than 5 MPa. [5] Battery (2) according to one of claims 1 to 4, characterized by that the Velcro units (16) of the first Velcro connection (12) and / or the Velcro units (16) of the second Velcro connection (14) are each formed from a polymer. [6] Battery (2) according to one of claims 1 to 4, characterized by that the Velcro units (16) of the first Velcro connection (12) and / or the Velcro units (16) of the second Velcro connection (14) are each formed from metal or an alloy. [7] Battery (2) according to one of claims 1 to 6, characterized by that the housing base (6) and / or the housing cover (8) can be cooled. [8] Electrically driven motor vehicle with a battery (2) according to one of claims 1 to 7.

Images