Vehicle battery

Abstract

Vehicle battery (2, 2') comprising a battery housing with a pot- or trough-shaped battery box and a housing cover (6) closing the battery box, and a number of battery cells (8) arranged in the battery housing, wherein the battery box has a housing base (4) arranged opposite the housing cover (6), wherein the battery cells (8) are arranged side by side along a row direction (R) as a cell pack (10), wherein the battery cells (8) have first hook-and-loop surfaces (16) on a top surface (12) facing the housing cover (6) and on a bottom surface (14) facing the housing base (4), wherein the housing cover (6) and the housing base (4) each have second hook-and-loop surfaces (18) which are designed to be complementary to the first hook-and-loop surfaces (16) of the top surface (12) or bottom surface (14),and- wherein the battery cells (8) of the cell pack (10) are connected to both the housing base (4) and the housing cover (6) by means of Velcro.

Description

[0001] The invention relates to a vehicle battery comprising a battery housing with a housing base and a housing cover, and a number of battery cells arranged in the battery housing.

[0002] Electric or electric-powered vehicles, such as electric or hybrid vehicles, typically include an electric motor that can drive one or both axles. To supply electrical energy, the electric motor is typically connected to an on-board (high-voltage) battery that serves as an electrical energy storage device.

[0003] An electrochemical battery, in particular, is understood here and below to mean a so-called secondary battery (secondary battery) of a motor vehicle. In such a (secondary) vehicle battery, consumed chemical energy can be recovered by means of an electrical charging process. Such vehicle batteries are designed, for example, as electrochemical accumulators, in particular as lithium-ion accumulators.

[0004] To generate or provide a sufficiently high operating voltage, such vehicle batteries typically have at least one battery module (battery cell module) in which several individual battery cells are interconnected in a modular fashion. Alternatively, a so-called Cell2Pack or Cell2Car design is possible, in which the battery cells are directly interconnected to form the vehicle battery, particularly in parallel, rather than being pre-assembled into modules.

[0005] During assembly, the individual battery cells are bonded into a module or pack using adhesives or gap fillers. Furthermore, a so-called gap pad is typically arranged between adjacent battery cells as an intermediate element. This pad compensates for the volume changes of the battery cells in the assembly (cell stack) 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). The battery cells are bonded with a gap filler, particularly on a cooling connection side, and arranged with gap pads in the swelling direction and otherwise mechanically arranged in the battery system (welded, mounted, etc.), so that subsequent repositioning of the battery cell in the cell stack is not possible.

[0006] US 2007 / 0224498 A1 discloses providing the mutually facing end faces of the battery cells with Velcro surfaces and stacking them vertically to form a Velcro-connected cell stack. JP 2012-119131 A describes how such a vertically oriented cell stack is connected at its end face to a cover-side and a base-side housing surface using Velcro.

[0007] The invention is based on the object of providing a particularly suitable vehicle battery. In particular, the vehicle battery is to be as stable and crash-proof as possible, while simultaneously allowing for simple and effort-reduced installation.

[0008] The object is achieved according to the invention with the features of claim 1. Advantageous embodiments and further developments are the subject of the dependent claims.

[0009] The vehicle battery (battery system) according to the invention is designed in particular as a traction battery of an electrically powered or drivable motor vehicle, for example, an electric or hybrid vehicle. The vehicle battery comprises a battery housing with a pot- or tub-shaped battery box (battery compartment) and with a housing cover (battery cover) closing or covering the latter. The battery box has a housing base (battery base) arranged opposite the housing cover, which, when installed, forms the underlying housing surface of the battery housing. A number of battery cells, i.e., several battery cells, are arranged in the battery housing. The vehicle battery is designed according to a Cell2Pack or Cell2Car design, so that the battery cells are inserted directly into the battery housing and are not combined into (battery) modules.However, the following explanations and examples can also be applied analogously to a battery module with a module housing with a module base and a module cover.

[0010] The battery cells are arranged end-to-end in a row direction to form a cell pack (cell row, cell bundle). For this purpose, the battery cells are arranged next to one another in a row, particularly in the manner of a series installation. The cell pack formed in this way has two battery cells arranged on the outside at the end and at least one battery cell arranged in between. The housing surfaces of each battery cell that are opposite one another in the row direction are referred to below as the end faces of the respective battery cell. The housing surfaces of the battery cells facing the housing cover are referred to as the top sides, and the housing surfaces facing the housing base are referred to as the bottom sides. The remaining housing surfaces that face the housing walls of the battery housing or battery box are also referred to below as the wall sides.

[0011] According to the invention, the battery cells are each provided with first hook-and-loop surfaces on the top and bottom. The hook-and-loop surfaces preferably have a recess for a pressure relief valve of the battery cell. The housing base and the housing cover each have complementary second hook-and-loop surfaces, with the battery cells of the cell pack being connected (hook-and-loop-attached) to the housing base on the one hand and to the housing cover on the other. This creates a particularly suitable vehicle battery.

[0012] In contrast to the prior art, the row direction is therefore not arranged perpendicular to the housing base and housing cover, but is oriented parallel to the housing cover and the housing base according to the invention. Due to the horizontal arrangement of the battery cells in the cell pack, each of the battery cells is connected vertically via the top and bottom to the housing base and the housing cover with hook and loop fasteners. This gives the vehicle battery a structure that is essentially comparable to a double T-beam or a sandwich sheet. The arrangement and orientation of the battery cells and the hook and loop fasteners increase the stability and rigidity of the vehicle battery, thereby increasing safety in the event of a crash, as the battery cells in the Cell2Car design or even in smaller units, if necessary, do not slip.The housing base and housing cover are thus essentially fully connected with hook-and-loop fasteners, resulting in greater tensile strength for the battery housing due to the larger hook-and-loop surface. Furthermore, the use of hook-and-loop fasteners saves weight and material in the Cell2Car design, thereby significantly reducing costs.

[0013] The complete vehicle battery is preferably constructed in such a way that all mechanical connections between metallic structural components—essentially the battery cells, housing base, housing cover, stiffening plates, connecting plates, etc.—are realized with hook-and-loop fasteners. The hook-and-loop fasteners are conveniently applied or affixed to all overlapping connection surfaces on both sides. This eliminates the need for screwing, welding, or potting during assembly. The tightness of the vehicle battery is achieved, for example, with a sealing compound. For maintenance or repair purposes, the vehicle battery can be gradually removed, essentially without tools, by simply loosening the hook-and-loop fasteners.

[0014] "Hook and loop" or "Hook and loop" refers here and below to a reversibly detachable, positive and non-positive (quick-release) connection between the hook and loop surfaces. The hook and loop connection or hook and loop fastener is based on the principle of velcro. This means that the hook and loop surfaces have complementary hook and loop elements, which are held together in a positive and non-positive manner in the hook and loop connection and can be separated from each other, particularly by peeling.

[0015] A "positive connection" or a "positive connection" between at least two interconnected parts is understood here and below in particular to mean that the interconnected parts are held together at least in one direction by a direct interlocking of the contours of the parts themselves or by an indirect interlocking via an additional connecting part. The "blocking" of mutual movement in this direction is therefore due to the shape.

[0016] A "positive connection" or a "positive connection" between at least two interconnected parts is understood here and below in particular to mean that the interconnected parts are prevented from sliding against each other due to a frictional force acting between them. If a "connecting force" causing this frictional force (this means the force that presses the parts against each other, for example, a screw force or the force of gravity itself) is absent, the positive connection cannot be maintained and can therefore be released.

[0017] The complementary hook-and-loop fasteners can be designed, for example, as a hook and loop fastener (felt fastener, velour fastener), as a zip-head fastener and loop fastener, or as a mushroom-head fastener and mushroom-head fastener, or as a hook and mushroom-head fastener. The hook-and-loop fasteners can be made of polyamide, polyaramid, polyester, and polyolefin fibers, for example.

[0018] In an advantageous embodiment, the housing cover is attached to the battery housing or the housing base only by the Velcro connections with the battery cells.

[0019] This means that no additional tools are required to install the housing cover; the housing cover is simply pressed onto the battery cells or the Velcro surfaces and secured. This makes installation of the vehicle battery particularly easy.

[0020] In a suitable development, a head tensile load for releasing the hook-and-loop fasteners between the battery cells and the housing base and / or the housing cover is dimensioned to be greater than 5 MPa (megapascals). This results in a particularly reliable, crash-safe, and stable vehicle battery. Preferably, a suitable shear tensile load is also provided with regard to the shear forces that occur. The shear tensile load is suitably dimensioned to be approximately equal to the head tensile load. The shear tensile load is therefore dimensioned to be greater than 5 MPa, for example. The pressures and line loads for releasing the hook-and-loop fasteners by peeling are preferably dimensioned significantly smaller than the head tensile load and / or shear tensile load.

[0021] The conjunction “and / or” is to be understood here and in the following in such a way that the features linked by this conjunction can be formed both together and as alternatives to one another.

[0022] An additional or further aspect of the invention provides that mutually complementary third hook-and-loop surfaces are arranged on the end faces of the battery cells oriented perpendicular to the row direction, wherein the battery cells are connected to one another in the row direction by pressing them together. Preferably, the third hook-and-loop surfaces are arranged flatly on the mutually facing end faces, so that the end faces of the battery cells are essentially completely covered with a hook-and-loop surface. Alternatively, only strips or sections / regions of the end faces are provided with the third hook-and-loop surfaces. During cell construction, the battery cells can preferably still be mechanically gripped with manipulators on the housing surfaces to which no hook-and-loop tape is applied.

[0023] Before being installed in the battery housing, the battery cells are thus connected to the cell pack using hook and loop fasteners, for example, so that the cell pack can be inserted into the battery housing as an assembly group. Once battery cells have been connected to one another using hook and loop fasteners, they are very easy to handle during assembly because they are already force-fitted and no longer need to be laboriously held in position. If the battery cells are not aligned flush, they can be removed and repositioned. The battery cells are inserted / installed in the battery housing as a fixed cell pack; if the positioning is not flush, the cell pack can be repositioned. It is also conceivable, for example, to insert the battery cells individually or as partial cell packs or bundles piece by piece into the battery housing and then to press the housing base and housing cover on vertically.

[0024] The frontal arrangement of the third hook and loop surfaces is advantageous because these are the housing surfaces that deform the most during cell expansion (swelling). In other words, the third hook and loop surfaces are oriented perpendicular to the swelling direction. The hook and loop connections thus enable tolerance compensation between the battery cells in the cell stack. The hook and loop connections thus replace gap pads and absorb cell breathing and cell swelling over the service life. Expansion or counterforce can be limited or stopped by appropriately dimensioning the hook and loop connection when the hook and loop pins with heads (hook / mushroom head) cannot be pushed further into one another. The desired dimensioning can thus be adjusted, for example, by changing the length of the hook and loop pins.

[0025] In a preferred embodiment, the Velcro surfaces are designed as mushroom-shaped fasteners, since a hook-and-loop fastener design cannot ensure the absorption of cellular respiration and cell swelling. The mushroom-shaped fasteners are made of polyolefin or polypropylene, for example. Alternatively, metallic Velcro surfaces in the form of hook fasteners are provided. The hooks in the Velcro connection adhere to each other and, like the mushroom-shaped fasteners, can be slightly moved relative to each other to compensate for cellular respiration and cell swelling.

[0026] In a suitable refinement, the hook-and-loop fasteners are designed to be electrically non-conductive. In other words, the battery cells are arranged so that they are electrically insulated from one another by the third hook-and-loop fastener surfaces. Furthermore, the battery cells are preferably arranged so that they are electrically insulated from the housing cover and the housing base by the first and second hook-and-loop fastener surfaces. The hook-and-loop fasteners thus act as electrical insulation between the battery cells and the battery housing, as well as insulation from the installation space in the vehicle, eliminating the need for additional insulation foils. This ensures a particularly component-reduced design of the vehicle battery.

[0027] The Velcro surfaces are therefore preferably used both for cell fixation and for insulation, as gap pads, or for tolerance compensation. This allows for particularly advantageous functional integration within the vehicle battery structure.

[0028] In one possible design, the housing cover is constructed in several parts, with each part being connected to at least one battery cell of the cell pack using Velcro. The multi-part design of the housing cover allows for simplified disassembly with reduced force, thus simplifying maintenance, service, and repair work on the vehicle battery.

[0029] In a suitable refinement, the cover sections are designed as parallel struts arranged parallel to the top surfaces of the battery cells and connected to a corresponding battery cell with Velcro fasteners. This means that the number of cover sections of the housing cover corresponds to the number of battery cells in the cell pack. This enables particularly simple and targeted removal of the housing cover for maintenance, service, and repair work.

[0030] In a practical embodiment, the cover parts are sealed against each other by a sealing compound, in particular a fluid-tight seal. This allows for a simple and cost-effective sealing of the battery housing or the housing cover. Preferably, the housing cover is also sealed against the battery box by means of a circumferential sealing compound.

[0031] In a preferred embodiment, at least one cooling channel for controlling the temperature of the cell pack is integrated into the housing cover and / or the housing base. Cooling channels are thus integrated, for example, in the battery base and / or the battery cover, which ensure that each battery cell is evenly cooled. For this purpose, the housing cover and / or housing base provided with the cooling channels or cooling coils have a sufficient thickness of, for example, 2 mm (millimeters) to 8 mm. The beginning and end of the cooling channels, which run from the housing cover and / or housing base, can be coupled to a cooling unit of the motor vehicle and are controlled, for example, by means of sensors.

[0032] Exemplary embodiments of the invention are explained in more detail below with reference to a drawing. In schematic and simplified representations, the drawings show: Fig. 1 shows a section view of a vehicle battery according to a first embodiment, Fig. 2 shows a section view of the vehicle battery according to the first embodiment, Fig. 3 shows a plan view of a vehicle battery according to a second embodiment, and Fig. 4 shows a section view of a vehicle battery according to the second embodiment.

[0033] Corresponding parts and sizes are always shown with the same reference numerals in all figures.

[0034] The Fig. 1 and the Fig. Figure 2 shows a schematic and simplified representation of a vehicle battery 2 for a motor vehicle. The vehicle battery 2 has a battery housing (not shown in detail) with a housing base 4 and a housing cover 6 arranged opposite it.

[0035] A number of battery cells 8 are arranged in the battery housing. The vehicle battery 2 is designed, for example, according to a Cell2Pack or Cell2Car design, so that the battery cells 8 are inserted directly into the battery housing and are not combined into (battery) modules.

[0036] The battery cells 8 are arranged end-on along a row direction R as a cell package (cell row, cell bundle) 10. In the Fig. 2 shows an example of a cell pack 10 with only three battery cells 8.

[0037] The battery cells 8 are each provided with hook-and-loop surfaces 14 on an upper side 10 facing the housing cover 6 and on an underside 12 facing the housing base 4. The housing base 4 and the housing cover 6 each have complementary hook-and-loop surfaces 16, whereby the battery cells 8 of the cell pack are connected by hook-and-loop to the housing base 4 on the one hand and to the housing cover 6 on the other hand.

[0038] The row direction R is arranged parallel to the planes of the housing cover 6 and the housing base 4. In other words, the row direction R is oriented horizontally or transversely, i.e. perpendicular to a vertical height direction H of the battery housing.

[0039] Due to the horizontal arrangement of the battery cells 8 in the cell pack 10, each of the battery cells 8 is connected vertically via the top side 12 and bottom side 10 to the housing base 4 and the housing cover 6 using hook-and-loop fasteners. As a result, the vehicle battery 2 has a structure that is essentially comparable to a double-T beam or a sandwich sheet. The arrangement and orientation of the battery cells 8 and the hook-and-loop fasteners thus increase the stability and rigidity of the vehicle battery 2, thereby realizing increased safety in the event of a crash. A head tensile load for releasing the hook-and-loop fasteners between the battery cells 8 and the housing base 4 and / or the housing cover 6 is dimensioned to be greater than 5 MPa.

[0040] For example, in the Fig. As can be seen in Figure 2, mutually complementary hook-and-loop surfaces 20 are arranged on the end faces of the battery cells 8 oriented perpendicularly to the row direction R, so that the battery cells 8 are connected to one another in the row direction R by means of hook-and-loop fasteners. The hook-and-loop surfaces 20 are provided with reference numerals merely as examples. The battery cells 8 are thus connected to the cell pack 10, for example, before installation in the battery housing, so that the cell pack 10 can be inserted into the battery housing as an assembly.

[0041] Preferably, the Velcro surfaces 16, 18, 20 are used both for cell fixation in the battery housing and additionally for insulation and as a gap pad or as tolerance compensation between the battery cells 8 and the battery housing.

[0042] Below is a second embodiment of the vehicle battery 2` based on the Fig. 3 and Fig. 4 is explained in more detail.

[0043] In this embodiment, the housing cover 6 is made up of several parts with several assembled cover parts 6a, 6b, 6c, 6d, 6e, whereby in the Fig. 3, five cover parts 6a, 6b, 6c, 6d, 6e are shown as examples. The cover parts 6a, 6b, 6c, 6d, 6e are designed as parallel struts, which are arranged parallel to the upper sides 12 of the battery cells 8 and are connected to a respective battery cell 8 by means of Velcro. The cover parts 6a, 6b, 6c, 6d, 6e are sealed against each other by means of a sealing compound 22, so that a fluid-tight housing cover 6 is formed. The cover parts 6a, 6b, 6c, 6d, 6e are fixed, for example, by means of optional fastening screws 24 to struts 26 of the battery housing. The sealing compounds 22 and the fastening screws 24 are in the Fig. 3 are provided with reference symbols merely as examples.

[0044] A cooling channel or cooling coil is integrated into each of the cover parts 6a, 6b, 6c, 6d, 6e for controlling the temperature of the cell pack 10 or the associated battery cell 8. The cooling channels are connected, for example, to a cooling unit of the motor vehicle and are traversed by a cooling medium, for example (cooling) water.

[0045] The claimed invention is not limited to the exemplary embodiments described above. Rather, other variants of the invention can also be derived therefrom by those skilled in the art within the scope of the disclosed claims without departing from the subject matter of the claimed invention. In particular, all individual features described in connection with the various exemplary embodiments can also be combined in other ways within the scope of the disclosed claims without departing from the subject matter of the claimed invention. List of reference symbols 2.2` vehicle battery 4 Case back 6 housing cover 6a, 6b, 6c, 6d, 6e cover parts 8 battery cells 10 cell pack 12 Top 14 Bottom 16 Velcro surface 18 Velcro surface 20 Velcro surface 22 Sealant 24 fixing screw 26 Strut R Row direction QUOTES CONTAINED IN THE DESCRIPTION

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

[0000] US 2007 / 0224498 A1

[0006] JP 2012119131 A

[0006]

Claims

[1] Vehicle battery (2, 2') comprising a battery housing with a housing base (4) and with a housing cover (6), and a number of battery cells (8) arranged in the battery housing, - wherein the battery cells (8) are arranged end-to-end along a row direction (R) as a cell pack (10), - wherein the battery cells (8) have first Velcro surfaces (16) on an upper side (12) facing the housing cover (6) and on an underside (14) facing the housing base (4), - wherein the housing cover (6) and the housing base (4) each have second Velcro surfaces (18) which are complementary to the first Velcro surfaces (16) of the top side (12) or bottom side (14), and - wherein the battery cells (8) of the cell pack (10) are connected to both the housing base (4) and the housing cover (6) by means of Velcro. [2] Vehicle battery (2, 2') according to claim 1, characterized bythat the housing cover (6) is only fixed to the battery housing by the Velcro connection with the battery cells (8). [3] Vehicle battery (2, 2') according to claim 1 or 2, characterized by that a head tensile load for releasing the Velcro connections between the battery cells (8) and the housing base (4) and / or the housing cover (6) is dimensioned to be greater than 5 MPa. [4] Vehicle battery (2, 2') according to one of claims 1 to 3, characterized by that mutually complementary third Velcro surfaces (20) are arranged on the end faces of the battery cells (8) oriented normal to the row direction (R), wherein the battery cells (8) are connected to one another in the row direction (R) by means of Velcro. [5] Vehicle battery (2, 2') according to claim 4, characterized by that the battery cells (8) are arranged electrically insulated from one another by the third Velcro surfaces (20). [6] Vehicle battery (2, 2') according to one of claims 1 to 5, characterized bythat the battery cells (8) are arranged electrically insulated from the housing cover (6) and the housing base (4) by the first and second Velcro surfaces (16, 18). [7] Vehicle battery (2') according to one of claims 1 to 6, characterized by that the housing cover (6) is designed in several parts with several assembled cover parts (6a, 6b, 6c, 6d, 6e), wherein each cover part (6a, 6b, 6c, 6d, 6e) is connected to at least one battery cell (8) of the cell pack (10) by means of Velcro. [8] Vehicle battery (2') according to claim 7, characterized by that the cover parts (6a, 6b, 6c, 6d, 6e) are designed as parallel struts which are arranged parallel to the upper sides (12) of the battery cells (8) and are connected to a respective associated battery cell (8) by means of Velcro. [9] Vehicle battery (2') according to claim 7 or 8, characterized by that the cover parts (6a, 6b, 6c, 6d, 6e) are sealed against each other by a sealing compound (22). [10] Vehicle battery (2') according to one of claims 1 to 9, characterized by that a cooling channel for tempering the cell pack (10) is integrated into the housing cover (6) and / or into the housing base (4).

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