Battery module

Abstract

Battery module (1) with a battery cell stack (3) formed from several battery cells (2), with deformable foam plates (4) arranged between adjacent battery cells (2) to compensate for deformations of the battery cells (2) during charging and discharging or due to their aging, as well as with a cooling medium passed between each adjacent battery cells (2) for cooling the battery cells (2), characterized by the fact that the cooling medium is a coolant (5) that directly contacts the battery cells (2), A cooling structure (6) for directing the coolant (5) to the battery cell (2) and along the battery cell (2) is arranged between the respective battery cell (2) and the foam plate (4) facing it, wherein this foam plate (4) contacts this cooling structure (6) and the cooling structure (6) contacts this battery cell (2), the respective cooling structure (6) has a plate (7) on its side facing the battery cell (2), which rests against this battery cell (2), wherein this plate (7) has passages for the cooling liquid (5), the respective cooling structure (6) has a closed plate (8) on the side facing away from this battery cell (2), which rests against the foam plate (4) facing this battery cell (2) on this side of the battery cell (2).

Description

[0001] The invention relates to a battery module with a battery cell stack formed from a plurality of battery cells, with deformable foam plates arranged between adjacent battery cells to compensate for deformations of the battery cells during their charging and discharging or due to their aging, and with a cooling medium passed between adjacent battery cells to cool the battery cells.

[0002] Such a battery module is known from US 2013 / 0 071 718 A1. In this battery module, a deformable foam plate is arranged between each two adjacent battery cells, which directly contacts these two battery cells. The deformable foam plate has these passages for the passage of a cooling medium, which is cooling air. The passages are positioned parallel to the contact surfaces of the deformable foam plate on the two battery cells. This battery module is used in electric vehicles, for example, passenger cars, buses, and trucks.

[0003] US 2017 / 0 194 681 A1 discloses a battery module with a battery stack formed from several battery cells and cooling structures arranged between adjacent battery cells. Each cooling structure is designed as a closed structure with an inlet and outlet for a cooling fluid. The cooling structure arranged between adjacent battery cells directly contacts these battery cells. The battery module has an insulating plate made of a foamed material in the region of one end of the battery cell stack to absorb shocks for the battery cell stack.

[0004] DE 10 2018 133 004 A1 discloses a battery module consisting of multiple battery cells. Spacers are arranged between adjacent battery cells. The spacers form a flow channel for a cooling medium between each two cells and, together with the respective cell wall, form. The spacers are made of or comprise an elastic material. The elastic material can be a foam.

[0005] US 2018 / 0 034 116 A1 discloses a battery with battery cells, foam plates, and a cooling structure for the battery cells. The foam plates consist of a metal foam, in particular aluminum.

[0006] The object of the present invention is to further develop a battery module of the type mentioned at the outset, which has the features of the preamble of patent claim 1, in such a way that optimal compensation of deformations of the battery cells during their charging and discharging or due to their aging as well as optimal cooling of the battery cells is ensured.

[0007] The problem is solved by a battery module having the features of patent claim 1.

[0008] In the battery module according to the invention, it is provided that the cooling medium is a cooling liquid which directly contacts the battery cells, wherein a cooling structure for conducting the cooling liquid to the battery cell and along the battery cell is arranged between the respective battery cell and the foam plate facing it, wherein this foam plate contacts this cooling structure and the cooling structure contacts this battery cell.

[0009] The battery cells can therefore expand, for example, during charging, which causes the battery cells to act on the cooling structures, which in turn affect the foam plates. Since the foam plates are deformable, they can change their shape according to the space required by the battery cells' expansion, thus compressing them more strongly. However, if the battery cells are deformed in a different operating state to reduce their thickness, the foam plates relax more and return to their original state.

[0010] The coolant can cool the battery cells particularly effectively because it is in direct contact with the battery cells. Due to the arrangement of the cooling structure between the foam plate and the associated battery cell, the foam plate cannot become blocked, particularly in the area of ​​the cooling structure facing the battery cell. This risk would arise if the foam plate and battery cell were in direct contact.

[0011] Each cooling structure has a plate on its side facing the battery cell that rests against the battery cell, with this plate having passages for the coolant. This design ensures advantageous support of the cooling structure on the battery cell while simultaneously ensuring favorable flow of coolant through the plate. Furthermore, each cooling structure has a plate on its side facing away from the battery cell that rests against the foam plate facing this battery cell on this side of the battery cell. This design of the cooling structure allows forces when the battery cells are deformed to be transferred over a large area from the generally softer foam plate to the usually rigid cooling structure, and from there to the battery cell.The plate that comes into contact with the foam plate is closed and therefore has no passages because it is not necessary to pump the cooling liquid into the area of ​​the foam plate.

[0012] In particular, it is intended that the respective battery cell be a pouch cell. This is characterized by a relatively small thickness and a relatively large width and length, with an essentially rectangular shape of the area formed by the width and length, and, in particular, by electrical connections in the region of one narrow side of the pouch cell.

[0013] Preferably, the respective plate is formed from sheet metal. This allows it to transport heat from the associated battery cell particularly effectively to the cooling structure and thus to the coolant.

[0014] Preferably, the respective plate is designed as a profiled plate. The profiling allows the cooling structure to be positioned, particularly with respect to the associated battery cell, such that the plate only contacts the battery cell in protruding profile areas of the plate. The cooling fluid can thus be passed between the plate and the battery cell between the protruding areas of the plate.

[0015] In particular, it is provided that the plates of the cooling structure are connected to one another and form a stable unit. In particular, the plates are corrugated and directly connected to one another.

[0016] In principle, according to an alternative design, the cooling structure can also comprise a single profiled plate, in particular a single profiled sheet metal plate. This profiled plate rests against both the battery cell and the foam plate. In this case, the cooling fluid contacts both the battery cell and the foam plate. The profiled plate of the cooling structure prevents the cooling structure from clogging up towards the battery cell, thus ensuring continuous flow of the cooling fluid between the cooling structure and the battery cell.

[0017] The foam board is preferably made of a microcellular polyurethane. This is commercially available, for example, under the brand name "PORON" (Rogers Corporation, AZ 85224 Chandler, USA).

[0018] Further features of the invention emerge from the subclaims, the attached drawing and the description of the embodiment shown in the drawing, without being limited thereto.

[0019] It shows: Fig. 1 in a highly simplified representation of a battery module with illustrated flow through the battery module, Fig. 2 shows a schematic representation of the structure of the battery module in the area between two battery cells.

[0020] The Fig. The battery module 1 shown in Figure 1 is used in particular in an electrically driven vehicle, for example a passenger car, for driving an electric machine of the vehicle.

[0021] The battery module 1 has a battery cell stack 3 formed from several battery cells 2. The battery cells 2 are designed as pouch cells. Deformable foam plates 4 are arranged between adjacent battery cells 2 of the battery cell stack 3 to compensate for deformations of the battery cells 2 during charging and discharging or due to aging. A cooling medium, which is a cooling liquid 5, is passed between adjacent battery cells 2 to cool the battery cells 2.

[0022] Fig. 2 shows a schematic representation of the structure of the battery module 1 in the area of ​​two adjacent battery cells 2. The same applies correspondingly to the other adjacent battery cells 2 of the battery cell stack 3: The coolant 5 directly contacts the battery cells 2. A cooling structure 6 for conducting the coolant 5 to the battery cell 2 and along the battery cell 2 is arranged between the respective battery cell 2 and the foam plate 4 facing it. This foam plate 4 contacts this cooling structure 6 and the cooling structure 6 contacts this battery cell 2. The cooling structure 6 has a plate 7 on its side facing the battery cell 2, which plate rests against this battery cell 2. The plate 7 has flow passages (not shown) for the coolant 5.The cooling structure 6 has a plate 8 on its side facing away from this battery cell 2, which plate rests against the foam plate 4 facing this battery cell 2 on this side of the battery cell 2.

[0023] The respective plates 7, 8 are formed from sheet metal and are also profiled. The cooling structure 6, arranged between each battery cell 2 and the foam plate 4, is designed such that its plates 7, 8 are connected to one another and form a stable unit. The plates 7, 8 are corrugated and directly connected to one another. This ensures that the cooling structure 6 rests against the associated battery cell 2 and the associated foam plate 4, and that coolant 5 flows through the cooling structure 6.

[0024] The foam plate 4 is made of a microcellular polyurethane.

[0025] The described arrangement of the battery cells 2, the foam plates 4 and the cooling structures 6 of the battery module 1 allows optimal compensation of deformations of the battery cells 2 during their charging and discharging or due to their aging, as well as optimal cooling of the battery cells 2.

[0026] Fig. 1 illustrates the flow conditions of the cooling liquid 5 in the battery module 1. Due to the formed battery cell stack 3, the cuboid-shaped battery module 1 has a first end face 9, a second end face 10 opposite this, a front side face 11, a rear side face 12, a bottom surface 13, and a top surface 14. Via an inlet for the cooling liquid 5, the cooling liquid flows into the interior of the battery module 1 in the region of its end face 9 along battery cell terminals, which are thus forcibly flowed over to also ensure their cooling. The cooling liquid 5 passes from the region of the end face 9 into the region of the bottom surface 13 and from there flows through the various cooling structures 6 to the top surface 14. Heated cooling liquid 5 passes from the region of the top surface 14 to the end face 10 and is discharged from the battery module 1 there.The flow directions of the cooling liquid 5 are indicated by the arrows shown with a thick line in . Fig. 1 illustrates.

Claims

[1] Battery module (1) with a battery cell stack (3) formed from several battery cells (2), with deformable foam plates (4) arranged between adjacent battery cells (2) to compensate for deformations of the battery cells (2) during charging and discharging or due to their ageing, and with a cooling medium passed between adjacent battery cells (2) for cooling the battery cells (2), characterized by , that the cooling medium is a cooling liquid (5) which directly contacts the battery cells (2), a cooling structure (6) for conducting the cooling liquid (5) to the battery cell (2) and along it is arranged between the respective battery cell (2) and the foam plate (4) facing it, wherein this foam plate (4) contacts this cooling structure (6) and the cooling structure (6) contacts this battery cell (2), the respective cooling structure (6) has, on the side facing the battery cell (2), a plate (7) which bears against this battery cell (2), said plate (7) having passages for the cooling liquid (5), the respective cooling structure (6) has, on the side facing away from this battery cell (2), a closed plate (8) which bears against the foam plate (4) facing this battery cell (2) on this side of the battery cell (2). [2] Battery module (1) according to claim 1, characterized by that the respective battery cell (2) is a pouch cell. [3] Battery module (1) according to claim 1 or 2, characterized by that the respective plate (7, 8) is designed as a sheet metal. [4] Battery module (1) according to one of claims 1 to 3, characterized by that the respective plate (7, 8) is designed as a profiled plate. [5] Battery module (1) according to one of claims 1 to 4, characterized bythat the plates (7, 8) of the cooling structure (6) are connected to one another and form a stable unit. [6] Battery module (1) according to claim 5, characterized by that the plates (7, 8) are corrugated and are directly connected to one another. [7] Battery module (1) according to one of claims 1 to 6, characterized by that the respective foam plate (4) is made of a microcellular polyurethane.

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