Automotive traction battery module

Abstract

To provide an automotive traction battery module having a pouch battery cell and an effective cooling structure.SOLUTION: An automotive traction battery module having a rigid battery housing in which a plurality of plate-shaped pouch battery cells 20, 20' are arranged parallel to each other, the cooling liquid 50 flows between two studded plates 32, 33, and each directly adjacent battery cell side wall 22, 22' in the stud valley 45 between the stud peaks 44, and as a result, each battery cell side wall 22, 22' is directly cooled by the cooling liquid 50.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a liquid-cooled automotive traction battery module having an essentially rigid battery housing. [Background technology]

[0002] Automobile traction battery modules are so-called high-voltage battery modules with terminal voltages of up to more than 1000 V. To ensure a permanently high power output during charging and discharging of the traction battery module, the traction battery module must have an internal liquid cooling system. German Patent Application Publication No. DE 10 2017 221 347 A1, International Patent Application Publication No. WO 2020 212 652 A1, and European Patent Application Publication No. EP 3 780 147 A1 disclose various battery assemblies suitable as automobile traction battery modules with internal liquid cooling systems, in which a plurality of plate-shaped battery cells are arranged in an essentially rigid battery housing. The internal liquid cooling is achieved by a plate-shaped cooling structure through which a cooling liquid flows, the cooling liquid being arranged in each case between two plate-shaped battery cells. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] German Patent Application Publication No. 10 2017 221347 A1 [Patent Document 2] International Publication No. 2020 212 652A1 Brochure [Patent Document 3] European Patent Application Publication No. 3 780 147 A1 Summary of the Invention [Problem to be solved by the invention]

[0004] So-called pouch battery cells are commonly used as battery cells, and because of their simple structure, they have high electrical efficiency, low manufacturing costs, long lifespans, and high internal thermal conductivity. However, pouch battery cells naturally exhibit significant volume growth over their lifespans.

[0005] The problem addressed by the present invention is to create an automotive traction battery module with pouch battery cells and an effective cooling structure.

[0006] This problem is solved according to the invention by a vehicle traction battery module having the features of claim 1. [Means for solving the problem]

[0007] The automotive traction battery module according to the present invention is a so-called high-voltage traction battery module, having a terminal voltage in the high-voltage range of more than 100 V to more than 1000 V. The traction battery module comprises an essentially rigid, impact-resistant battery housing, preferably a metal battery housing. Within the battery housing, a plurality of plate-shaped pouch battery cells are arranged parallel to one another. In this case, the pouch battery cells do not necessarily have to be a specific type of cell defined physically or chemically, but rather are understood to mean any type of cell that expands significantly during operation, especially upon heating and / or aging.

[0008] A plate-shaped cooling structure is provided between two adjacent pouch battery cells for active and direct liquid cooling of the two pouch battery cells adjacent to the cooling structure, and the plate-shaped cooling structure is configured to be compressible in a transverse direction perpendicular to a base plane of the plate-shaped cooling structure or a base plane of the plate-shaped pouch battery cells to provide space for expansion of the pouch battery cells.

[0009] The cooling structure includes an essentially rigid first studded plate having a constant plate thickness using a plurality of shaped hollow studs, the outwardly convexly rounded stud peaks or stud peak apexes of which contact the sidewalls of adjacent pouch battery cells. The cooling structure further includes an essentially rigid second studded plate having the same shape as the first studded plate. The stud peaks of the second studded plate contact one sidewall of another adjacent pouch battery cell. The hollow studs are preferably arranged in a regular distribution pattern. Preferably, each hollow stud has the same lateral distance from three or four laterally adjacent hollow studs.

[0010] An elastic pressure structure is disposed between the two studded plates, and the elastic pressure structure presses the two studded plates away from each other across their entire surfaces so that the stud peaks of the two studded plates are each pressed against the battery cell sidewalls with a specific biasing force. Because the pressure structure is elastically compliant, adjacent battery cells can expand laterally and compress the pressure structure, but the two studded plates do not significantly deform. The elastic pressure structure can generally be realized in a variety of ways.

[0011] A cooling liquid flows between the studded plate and each directly adjacent battery cell sidewall in the stud valleys between the stud peaks, resulting in each battery cell sidewall being directly wetted and cooled by the cooling liquid. All of the aforementioned studs are fluidly connected to one another, resulting in a full-surface cooling liquid cavity for the cooling liquid. Only in the region of the contact point between the stud peak and the directly adjacent battery cell sidewall is there direct cooling liquid contact with the battery cell sidewall, resulting in substantially full-surface cooling liquid contact with the battery cell sidewall.

[0012] The two studded plates of the cooling structure are formed to be rigid and flex-resistant so as not to deform significantly upon expansion of the two pouch battery cells adjacent to them, so that the cooling liquid cavity defined between each studded plate and the battery cell sidewall remains substantially unchanged.

[0013] The expansion of the battery cells in the transverse direction is substantially balanced or compensated only by the elastic pressure structure, which ensures that the maximum available cooling capacity remains substantially unchanged for the expanded pouch battery cells. For example, the cooling liquid can be a suitable non-conductive cooling oil.

[0014] Preferably, the two identical studded plates are oriented parallel to one another across their entire surfaces, so that the stud peaks of a first studded plate are aligned transversely with the corresponding stud valleys of a second studded plate, and all of the stud peaks of one studded plate are aligned transversely with the corresponding low points of the stud valleys of the other studded plate. In this way, the two studded plates are approximately the same distance from one another at each point in the transverse direction, so that the elastic pressure structure is also uniformly compressed and has approximately the same transverse expansion at all points.

[0015] Particularly preferably, the studded plates are configured so that the stud peaks and valleys of one studded plate can nest with the stud valleys and stud peaks of the other studded plate, i.e., could theoretically be pushed into each other if the pressure structure did not prevent this. The peaks and valleys of the plates are therefore conical in their widest or narrowest sense, or correspondingly curved. Without the pressure structure, the two studded plates would rest on top of each other without any spacing, resulting in no total surface distance between the two studded plates.

[0016] Particularly preferably, the alternating stud peaks and stud valleys of the studded plate form a generally sinusoidal profile in cross section.

[0017] In principle, the studded plate could be made from, for example, plastic, however it is particularly preferred that the studded plate is made from a metal sheet body which has high strength and rigidity, has good thermal conductivity properties and allows for inexpensive production of the studded plate.

[0018] In principle, the spring-elastic pressure structure can be constructed in various ways, for example, it can be formed by a plurality of individual spring elements. Preferably, the pressure structure is formed from a monolithic, inherently elastic pressure body, for example, a foam with high permanent elasticity. The monolithic pressure body exerts a perfectly uniform pressure on the two transverse studded plates. A monolithic plastic pressure body is inexpensive to obtain and easy to use. The pressure body can, for example, be glued to the two studded plates.

[0019] Exemplary embodiments of the invention are explained in more detail below with reference to the drawings. [Brief explanation of the drawings]

[0020] [Figure 1] 1 is a schematic longitudinal section of an automotive traction battery module according to the present invention. [Figure 2] FIG. 2 is an enlarged detail view of the traction battery module from FIG. 1. DETAILED DESCRIPTION OF THE INVENTION

[0021] The drawing shows a schematic longitudinal cross section of an automotive traction battery module 10, e.g., a high-voltage battery module having a terminal voltage of about 800 V. In this case, the traction battery module 10 is shown only diagrammatically, in which only three plate-shaped pouch battery cells 20, 20′ are shown in an essentially rigid, impact-resistant metal battery housing 12, as an example.

[0022] However, based on the residual tension of the pouch battery cells 20, 20', the desired terminal voltage, and the desired traction battery capacity, a corresponding number of pouch battery cells are installed in the traction battery module 10. For example, 5 to 10 pouch battery cells can be combined into a cell stack in the battery housing.

[0023] The plate-shaped pouch battery cells 20, 20' lie parallel to each other in the plate plane xz, are identical to each other, and can expand significantly due to heating and aging in the transverse direction Y. The plate-like cooling structure 30 is disposed between two adjacent pouch battery cells 20, 20'.

[0024] The plate-like cooling structure 30 is disposed between two adjacent pouch battery cells 20, 20′ so that the two side walls 22, 22′ of the two battery cells 20, 20′ are directly cooled over a large surface area by the flowing cooling liquid 50. In this case, the cooling liquid 50 is a non-conductive cooling oil.

[0025] The battery housing 12 is large in area, flat, and comprises two metal side walls 14, 15 with their wall planes parallel to each other and to the plate plane xz of the battery cells 20, 20′ and to the plate-shaped cooling structure 30. The cooling structure 30, compressible in the transverse direction y, consists of a first, essentially rigid studded plate 32, an identical second studded plate 33, and a pressure structure 34, which spaces the two studded plates 32, 33 apart and connects them to each other, formed by a monolithic, essentially elastic pressure body 34′, to which the two studded plates 32, 33 are glued.

[0026] Each studded plate 32, 33 is formed by a respective metal sheet body 32', 33' and has a substantially constant plate thickness in the transverse direction y across its entire surface. The studded plates 32, 33 define a plurality of convexly formed hollow studs 40 arranged in a regular engineering pattern, with stud peaks 44 contacting the adjacent sidewalls 22, 22' of adjacent pouch battery cells 20, 20', respectively. As can be seen in the cross-section shown in the figure, each studded plate 32, 33 has a substantially sinusoidal profile in cross-section. When viewed in the transverse direction y, the stud peaks 44 of one studded plate 32, 33 are precisely aligned with the corresponding stud valleys 45 of the other studded plate 33, 32, so that the distance between the two studded plates 32, 33 in the transverse direction y is substantially equal at all points.

[0027] Because of the fluidly interconnected stud valleys 45, a continuous mesh-like cooling liquid cavity 38 is formed between each studded plate 32, 33 and the adjacent battery cell sidewall 22, 22' through which the cooling liquid 50 flows such that each battery cell sidewall 22, 22' is directly cooled by the cooling liquid 50 over substantially its entire surface.

[0028] When the pouch battery cells 20, 20′ are expanded in the transverse direction y, the pressure structure 34 is elastically compressed and the studded plates 32, 33 do not change shape substantially, resulting in a substantially unchanged cooling liquid cavity 38. This means that the maximum available cooling capacity of the expanded pouch battery cells 20, 20′ does not change substantially.

Claims

1. An automotive traction battery module (10) having a rigid battery housing (12) in which a plurality of plate-shaped pouch battery cells (20, 20') are arranged parallel to one another, a plate-shaped cooling structure (30) for directly cooling the pouch battery cells (20, 20') by a cooling liquid (50) is disposed between two adjacent pouch battery cells (20, 20'), the cooling structure (30) being compressible in a transverse direction (Y) and perpendicular to its plate plane (xz); a rigid first studded plate (32) having a constant plate thickness with a plurality of shaped hollow studs (40), wherein stud peaks (44) of the first studded plate (32) contact the sidewalls (22) of the adjacent pouch battery cells (20); a rigid second studded plate (33) of the same shape as the first studded plate (32), wherein the stud peaks (44) of the second studded plate (33) contact the sidewalls (22') of the adjacent pouch battery cells (20'); a resilient pressure structure (34) between the two studded plates (32, 33), via which the two studded plates (32, 33) are pressed away from each other over their entire surfaces, a cooling liquid (50) flows between the two studded plates (32, 33) and the battery cell side walls (22, 22') that contact the stud peaks (44) of each of the two studded plates (32, 33), so that the respective battery cell side walls (22, 22') are directly cooled by the cooling liquid (50).

2. 2. The automotive traction battery module (10) of claim 1, wherein the two studded plates (32, 33) are oriented toward each other over their entire surfaces so that the stud peaks (44) of the first studded plate (32) are aligned with the stud valleys (45) between the stud peaks (44) of the second studded plate (33) in the transverse direction (y).

3. 3. The automotive traction battery module (10) of claim 2, wherein the studded plates (32, 33) are configured such that the stud peaks (44) of one studded plate (32) can be nested with the stud valleys (45) of the other studded plate (33).

4. 2. The automotive traction battery module (10) of claim 1, wherein the two studded plates (32, 33) are formed by a sheet metal body (32', 33').

5. 2. The automotive traction battery module (10) of claim 1, wherein the studded plates (32, 33) having the stud peaks (44) and the stud valleys (45) between the stud peaks (44) have a generally sinusoidal profile in cross section.

6. 2. The vehicle traction battery module (10) of claim 1, wherein said pressure structure (34) is formed from a monolithic, essentially elastic pressure body (34').

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