Battery module and battery pack

Abstract

Battery module (60), comprising several battery cells (2), each having a negative terminal (11) and a positive terminal (12), two end plates (58) between which the battery cells (2) are arranged, and a negative contact element (41) and a positive contact element (42) for electrically contacting the battery module (60), wherein the contact elements (41, 42) are designed as plug contacts, wherein each of the contact elements (41, 42) is mechanically connected to a fixing element (31, 32) which serves to fix the battery cells (2) to the end plates (58), characterized in that the contact elements (41, 42) extend along the battery cells (2) arranged in a row in a longitudinal direction (x), and the negative contact element (41) forms a guide for the positive contact element (42), and / or that the positive contact element (42) forms a guide for the negative contact element (41), so that two contact elements (41, 42) which are in contact with one another are translationally displaceable relative to one another in the longitudinal direction (x).

Description

The invention relates to a battery module which comprises a plurality of battery cells, each of which has a negative terminal and a positive terminal, two end plates, between which the battery cells are arranged, and also a negative contact element and a positive contact element for making electrical contact with the battery module. The invention also relates to a battery pack which comprises at least two battery modules which are in contact with one another.Prior ArtElectrical energy can be stored by means of batteries. Batteries convert chemical reaction energy into electrical energy. Here, primary batteries and secondary batteries are distinguished. Primary batteries are only functional once, while secondary batteries, which are also referred to as rechargeable batteries, are rechargeable. A battery comprises one or more battery cells.In particular, so-called lithium-ion battery cells are used in a rechargeable battery. These are distinguished, inter alia, by high energy densities, thermal stability and an extremely low self-discharge. Lithium-ion battery cells are used in motor vehicles, in particular in electric vehicles (EV), hybrid vehicles (HEV) and plug-in hybrid vehicles (plug-in hybrid electric vehicle, PHEV), among other things.A battery cell of the generic type is disclosed in DE 10 2012 217 451 A1. The battery cell has a cell housing which is manufactured from a metal, for example. The cell housing is designed prismatically, in particular cuboidally, and is pressure-resistant. The battery cell has a positive terminal and a negative terminal for electrical contacting.A plurality of battery cells are mechanically combined to form a battery module. In this case, the battery cells are also electrically interconnected with one another. For this purpose, the terminals of the battery cells are electrically connected to one another by means of cell connectors.A plurality of battery modules are combined to form a battery pack and arranged in a common housing. In this case, the battery modules are also electrically interconnected with one another. For this purpose, one terminal each of the battery cells of a battery module located on the edge is electrically connected to one terminal of a battery cell of another battery module by means of a contact element.The publication KR 10-0771223 B1 discloses a battery module having a plurality of battery cells, wherein the terminals of the battery cells are connected by means of screwable cell connectors. The battery cells are mechanically connected by means of circumferential tension straps.The publication DE 10 2012 222 712 A1 discloses a battery cell whose terminals have a contoured depression. For connecting terminals, cell connectors are provided which engage in a form-fitting manner in the depression of a terminal.From the publication JP 2013-41774 A, a battery pack having a plurality of battery modules, each having a plurality of battery cells, is known. For the electrical contacting of a battery module with another battery module, contact elements are provided which are designed as elastically deformable plug contacts.The publication US 2012 / 0156537 A1 also discloses a battery pack having a plurality of battery modules, each of which has a plurality of battery cells. The battery modules are connected to one another electrically and mechanically.Disclosure of the InventionA battery module is proposed which comprises a plurality of battery cells, each of which has a negative terminal and a positive terminal, two end plates, between which the battery cells are arranged, and also a negative contact element and a positive contact element for making electrical contact with the battery module. The contact elements are designed as plug contacts.According to the invention, each of the contact elements is mechanically connected to a fixing element which serves for fixing the battery cells to the end plates. The battery module preferably comprises a plurality of fixing elements for mechanically fixing or fastening the battery cells between the end plates.According to an advantageous embodiment of the invention, the negative contact element and the positive contact element are designed as plug contacts which are complementary to one another. For the mechanical and electrical connection of two battery modules in a battery pack, the negative contact element of one battery module can then be connected mechanically and electrically to the positive contact element of the other battery module by plugging in.According to the invention, the contact elements extend along the battery cells arranged in a row in a longitudinal direction. The fixation elements, which extend from one end plate to the other end plate, also extend in the longitudinal direction along the battery cells.According to the invention, the negative contact element forms a guide for the positive contact element and / or the positive contact element forms a guide for the negative contact element. Thus, two contact elements contacted with each other are translationally displaceable relative to each other in the longitudinal direction. Thus, during assembly, two battery modules to be contacted with one another can be translationally displaced relative to one another in the longitudinal direction and thereby positioned or aligned relative to one another.According to an advantageous development of the invention, the negative contact element and the positive contact element can be inserted into one another in a direction which extends at right angles to the longitudinal direction. Thus, during assembly, two battery modules to be contacted with one another can first be mechanically and electrically connected to one another by plugging and then aligned in the longitudinal direction by translation relative to one another.According to an advantageous embodiment of the invention, the end plates each have a connection element which is electrically connected to a terminal of a battery cell. Here, the terminal element of the one end plate is electrically connected to the negative terminal of one battery cell, and the terminal element of the other battery cell is electrically connected to the positive terminal of another battery cell.Advantageously, the connection element of the end plate is electrically connected to one of the contact elements. Specifically, the positive contact element is electrically connected to the positive terminal of one battery cell via the terminal element of the one end plate, and the negative contact element is electrically connected to the negative terminal of another battery cell via the terminal element of the other end plate.Preferably, the fixing elements are mechanically connected to the end plates. The battery module thus forms a relatively stable composite of the two end plates, the battery cells and the fixing elements.The invention also relates to a battery pack which comprises at least two battery modules according to the invention which are in contact with one another. In this case, the negative contact element of one battery module is in contact with the positive contact element of the other battery module.A battery module according to the invention and a battery pack according to the invention are advantageously used in particular in an electric vehicle (EV), in a hybrid vehicle (HEV), in a plug-in hybrid vehicle (PHEV), in a stationary battery or in a battery in a marine application.Advantages of the InventionDue to the configuration of a battery module according to the invention, a plurality of battery modules can be connected to one another electrically and mechanically to form a battery pack in a relatively simple manner. In particular, comparatively complicated connection techniques such as welding, bonding or screws for connecting battery modules are not required. As a result, the mounting of a battery pack can be realized in a shorter time and thus more cost-effectively than is known from the prior art. Further, the battery modules connected to form a battery pack are also relatively easily detachable from each other, if necessary.Brief Description of the DrawingsEmbodiments of the invention are explained in more detail on the basis of the drawings and the following description. The following are shown: FIG. 1 shows a perspective, schematic, partially cut-away illustration of an individual battery module, FIG. 2 shows a perspective, schematic illustration of a battery pack having two contacted battery modules, and FIG. 3 shows a schematic illustration of a first and a second fixing element with associated contact elements.Embodiments of the InventionIn the following description of the embodiments of the invention, identical or similar elements are denoted by identical reference symbols, wherein a repeated description of these elements is omitted in individual cases. The figures only schematically represent the subject matter of the invention.FIG. 1 shows a perspective, schematic, partially cut representation of an individual battery module 60. in the representation shown, an end plate 58 of the battery module 60 is cut in such a way that a connection element 56 provided within the end plate 58, the function of which will be discussed later, is visible.The battery module 60 comprises a plurality of battery cells 2 which extend in a row in a longitudinal direction x. At the beginning and at the end of said row, an end plate 58 is provided. The battery cells 2 are thus arranged between the end plates 58.For fixing the battery cells 2 to one another and to the end plates 58, a first fixing element 31 is provided. The first fixing element 31 extends in the longitudinal direction x from one end plate 58 to the other end plate 58 along the row of battery cells 2.Likewise, for fixing the end plates 58 and the battery cells 2, a second fixing element 32 is provided, which extends in the longitudinal direction x from one end plate 58 to the other end plate 58 along the row of battery cells 2.The first fixing element 31 and the second fixing element 32 both extend in the longitudinal direction x, i.e. parallel to one another. The first fixing element 31 and the second fixing element 32 are arranged spaced apart from one another in a transverse direction y.For the mechanical fixing of the end plates 58 and the battery cells 2, a third fixing element 33 is furthermore provided. The third fixing element 33 also extends in the longitudinal direction x and thus parallel to the first fixing element 31 and the second fixing element 32.Furthermore, a fourth fixing element 34 is provided, which likewise runs in the longitudinal direction x and thus parallel to the first fixing element 31, the second fixing element 32 and the third fixing element 33. Similarly, the fourth fixing element 34 is arranged spaced apart from the third fixing element 33 in the transverse direction y.The longitudinal direction x, the transverse direction y and the vertical direction z are each oriented at right angles to one another.Each of the battery cells 2 has a negative terminal 11 and a positive terminal 12. The battery cells 2 are arranged in such a way that the negative terminal 11 of one battery cell 2 is located next to the positive terminal 12 of the adjacent battery cell 2. A negative terminal 11 of a battery cell 2 is connected to the positive terminal 12 of the adjacent battery cell 2 by means of a cell connector, not shown here. In this way, a series connection of all battery cells 2 within the battery module 60 is produced.A connecting element 56 is arranged in each end plate 58. In the illustration shown, the connection element 56 is visible in the front end plate 58, which is illustrated in a correspondingly cut-away manner. The connection element 56 comprises a positive connection conductor 16, which extends from the connection element 56 in the vertical direction z upwards as far as an edge of the end plate 58. The positive connection conductor 16 of the connection element 56 is connected to the positive terminal 12 of the front battery cell 2 in the illustration shown.In the rear end plate 58 shown in the illustration, a connecting element 56 is likewise provided, which is not visible in the illustration shown. The connection element 56 in the rear end plate 58 is electrically connected to the negative terminal 11 of the rear battery cell 2 in the illustration shown by means of a negative connection conductor which is likewise not visible.The first fixing element 31 is mechanically connected to a negative contact element 41. Likewise, the second fixing element 32 is mechanically connected to a positive contact element 42. The contact elements 41, 42 are manufactured from an electrically conductive material, in particular a metal.The positive contact element 42 is connected by means of a positive contact pin 46 to the terminal element 56 in the front end plate 58. Likewise, the negative contact element 41 is electrically connected to the connection element 56 in the rear end plate 58 by means of a negative contact pin 45 which is not visible in this illustration.FIG. 2 shows a perspective schematic illustration of a battery pack 50 which comprises two battery modules 60 which are in contact with one another. The two battery modules 60 are arranged next to one another in the transverse direction y and are electrically and mechanically connected to one another.The two battery modules 60 shown are connected to one another in such a way that the first fixing element 31 of one battery module 60 engages in the second fixing element 32 of the other battery module 60. Further, by this type of connection, the negative contact element 41 of one battery module 60 is connected to the positive contact element 42 of the other battery module 60. The negative contact element 41 and the positive contact element 42 are designed as plug contacts that are complementary to one another.FIG. 3 shows a schematic illustration of a first fixing element 31 with an associated negative contact element 41 and a second fixing element 32 with an associated positive contact element 42.As already mentioned, the negative contact element 41 is fastened to the first fixing element 31. Furthermore, the aforementioned negative contact pin 45 is fastened to the first fixing element 31, said negative contact pin serving for connecting the first fixing element 31 to the connection element 56 in the rear end plate 58.The positive contact element 42 already mentioned is fastened to the second fixing elements 32. Likewise, the positive contact pin 46 is fastened to the second fixing element 32, said positive contact pin serving for connecting the second fixing element 32 to the connection element 56 in the front end plate 58.The negative contact element 41 and the positive contact element 42 are designed as plug contacts which are complementary to one another, as already mentioned. The negative contact element 41 and the positive contact element 42 can be inserted into one another in a direction perpendicular to the longitudinal direction x, in particular in the vertical direction z.The negative contact element 41 is designed in such a way that it represents a guide for the positive contact element 42 in the longitudinal direction x. The positive contact element 42 is likewise configured in such a way that it represents a guide for the negative contact element 41 in the longitudinal direction x. The contact elements 41, 42 connected to one another are thus translationally displaceable relative to one another in the longitudinal direction x.Said structure of the contact elements 41, 42 allows, during the assembly of the battery pack 50, two battery modules 60 to be contacted with one another to be connected to one another mechanically and electrically first of all by plugging the contact elements 41, 42 into one another. The battery modules 60 to be contacted with one another can then be aligned in the longitudinal direction x by a translatory displacement of the contact elements 41, 42 relative to one another.

Claims

Battery module (60) comprising a plurality of battery cells (2) which each have a negative terminal (11) and a positive terminal (12), two end plates (58) between which the battery cells (2) are arranged, and a negative contact element (41) and a positive contact element (42) for electrically contacting the battery module (60), wherein the contact elements (41, 42) are designed as plug contacts, wherein each of the contact elements (41, 42) is mechanically connected to a fixing element (31, 32) which serves for fixing the battery cells (2) to the end plates (58), characterized in that the contact elements (41, 42) extend along the battery cells (2) arranged in a row in a longitudinal direction (x), and the negative contact element (41) forms a guide for the positive contact element (42), and / or in that the positive contact element (42) forms a guide for the negative contact element (41), such that two contact elements (41, 42) contacted with one another are translationally displaceable relative to one another in the longitudinal direction (x).Battery module (60) according to Claim 1, characterized in that the negative contact element (41) and the positive contact element (42) are designed as plug contacts which are complementary to one another.Battery module (60) according to one of the preceding claims, characterized in that the negative contact element (41) and the positive contact element (42) can be inserted into one another in a direction (y, z) which extends at right angles to the longitudinal direction (x).Battery module (60) according to one of the preceding claims, characterized in that the end plates (58) each have a connection element (56) which is electrically connected to a terminal (11, 12) of a battery cell (2).Battery module (60) according to Claim 4, characterized in that the connection element (56) is electrically connected to one of the contact elements (41, 42).Battery module (60) according to one of the preceding claims, characterized in that the fixing elements (31, 32) are mechanically connected to the end plates (58).Battery pack (50) comprising at least two battery modules (60) which are contacted with one another according to one of the preceding claims, wherein the negative contact element (41) of the one battery module (60) is contacted with the positive contact element (42) of the other battery module (60).Use of a battery module (60) according to any of claims 1 to 6 and / or a battery pack (50) according to claim 7 in an electric vehicle (EV), in a hybrid vehicle (HEV), in a plug-in hybrid vehicle (PHEV), in a stationary battery or in a battery in a marine application.

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