Battery module with direct cell cooling via coolant distribution device

Abstract

Battery module comprising a plurality of electrochemical cells and a coolant distribution device guided along the cells, wherein the coolant distribution device has a plurality of openings in the area of ​​the cells which are arranged and dimensioned such that coolant is discharged directly along the cells.

Description

[0001] The invention relates to a battery module with direct cell cooling by means of a coolant distribution device.

[0002] German patent application DE 10 2015 111 194 A1 discloses a battery module with several prismatic cells. The battery module includes a coolant distribution device for directly cooling the cells.

[0003] The battery module according to the invention comprises a plurality of electrochemical cells and a coolant distribution device guided along the cells, wherein the coolant distribution device has a plurality of openings in the area of ​​the cells which are arranged and dimensioned in such a way that coolant is discharged directly along the cells.

[0004] This combination of features enables targeted local cooling of heat-prone cell surfaces, reduces axial and lateral temperature gradients across the module, allows for faster thermal response to load changes, enables more efficient use of the coolant flow rate through direct injection at the point of heat input, and allows for scalability to different cell formats, module geometries, and packing geometries. Suitable cell formats include cylindrical cells, prismatic cells, and pouch cells.

[0005] In another preferred embodiment, the coolant distribution device is directly connected to the cells to mechanically fix them. This design enables precise positioning of the cells relative to the outlet openings, reduces the number of separate holding components and thus the number of parts, ensures stable positioning under vibration and crash stress, and allows for an efficient assembly sequence with a predefined date position.

[0006] The connection of the coolant distribution to the cells can be achieved via integrated clips, tongue-and-groove geometries or overmolded ribs; contact zones can be electrically insulated to comply with creepage and air gaps.

[0007] The openings can be pitched with the cell division, the opening lengths and widths can preferably be in areas suitable for the manufacturing process, and the coolant can advantageously be selected as a dielectric fluid with defined viscosity and cleanliness specification; upstream filtration and cleanliness requirements contribute to the long-term stability of the opening function.

[0008] In another preferred embodiment, the openings are oriented towards the electrical connections of the cells. This orientation minimizes direct flow to sensitive connection and terminal areas, improves electrical safety through increased fluid distances, reduces potential erosion or corrosion effects at contact points, and enables more stable long-term insulation in the dielectric.

[0009] In a further preferred embodiment, the openings along a longitudinal direction of the coolant distribution device have a progressive opening area that increases from the inlet end to the outlet end. This progression enables a hydraulically balanced distribution despite axial pressure drop, allows for an approximation of uniform cell-to-cell volume flows, enables a reduction in the required pump head while maintaining homogeneity, and allows for an increase in the effectively coolable pipe or module lengths.

[0010] The progression can be continuous or stepwise; design parameters such as opening width, length, spacing and pipe cross-section are adjusted to the target ΔT and the permissible pressure loss.

[0011] In another preferred embodiment, the coolant distribution device is made of a polymeric material. This variant enables inherent electrical insulation without additional layers, allows for corrosion-free operation in the cooling medium, enables weight and potential cost savings, and allows for integrated manufacturing processes with the formation of clips and baffles in a single component.

[0012] Suitable polymers can be, for example, glass fiber reinforced PPA / PA or PEEK; manufacturing routes can include injection molding (e.g., half-shells) with ultrasonic welding or extrusion with subsequent opening.

[0013] In another preferred embodiment, the coolant distribution device is made of metal. This choice of material enables high dimensional and shape stability across the operating temperature range, allows for rigid coupling for cell fixation, and enables good recyclability at the end of its life.

[0014] Suitable materials include, for example, aluminium or stainless steels; joining technologies include in particular laser welding or brazing; corrosion protection can be achieved through conversion coatings or overmolding.

[0015] In another preferred embodiment, the coolant distribution device is fed from both sides. This topology enables a significant reduction in the maximum axial pressure gradient, allows for more symmetrical temperature fields along the cell array, enables shorter cooling start-up times during transients, and allows for increased operational robustness even with partial narrowing of individual openings.

[0016] In addition to double-sided feeding, variants with separate return or central collecting channel are possible; coupling interfaces can be standardized.

[0017] In another preferred embodiment, the coolant distribution device is fluidically connected to a main cooling line. This connection enables a standardized interface to the module or vehicle system, allows the use of commercially available quick couplings with defined sealing systems, enables easy servicing of the module, and allows for simple scaling of the throughput for platform variants.

[0018] Suitable sealing and connection concepts include, for example, O-ring or FIPG solutions; leakage rate targets and IP protection levels can be specified per application.

[0019] The inventive cooling structure is applicable, for example, in the automotive sector for traction battery modules in electric vehicles, for plug-in hybrid battery modules, for 48-volt on-board storage systems, for fuel cell hybrid buffers, and for high-performance storage systems in motorsport and special vehicles.

[0020] The dependent claims describe further advantageous embodiments of the invention.

[0021] Preferred embodiments are explained in more detail with reference to the following figures. These show Fig. 1 a first embodiment of a battery module according to the invention, Fig. 2 a section of the first embodiment, showing the coolant flow and Fig. 3 a second embodiment of a battery module according to the invention.

[0022] Fig. Figure 1 shows a first embodiment of a battery module according to the invention. The battery module 1 comprises a plurality of electrochemical cells 2 in the form of cylindrical cells. A coolant distribution device 3 is guided along the cells 2. The coolant distribution device 3 has a plurality of openings 4 in the area of ​​the cells 2, which are arranged and dimensioned such that coolant 5 is discharged directly along the cells 2. The coolant distribution device 3 is designed as a coolant distribution pipe and is directly connected to the cells 2 in order to mechanically fix them. For this purpose, integrated clips and guide geometries are provided on the coolant distribution device 3, which interact with lateral recesses of the cylindrical cells. The coolant distribution device 3 also serves as a mounting rail for the cells 2.

[0023] The openings 4 are designed as slots. The openings 4 are oriented towards the electrical connections of the cells 2. The openings 4 have a progressive opening area along the longitudinal direction of the coolant distribution device 3, which increases from the inlet end to the outlet end. This progression compensates for the axial pressure drop and promotes uniform cell-to-cell volume flows.

[0024] The coolant distribution device 3 is made of a polymeric material, preferably glass fiber reinforced PPA. Two half-shells are joined by ultrasonic welding. The clip geometries and flow guide baffles are integrated. The coolant distribution device 3 is supplied from both sides. A central return line carries heated coolant 5 away from the module cavity. The coolant distribution device 3 is fluidically connected to a main cooling line (not shown).

[0025] Fig. Figure 2 shows a cross-section of the battery module 1. Furthermore, the coolant 5, which exits from the openings 4 of the coolant distribution device 3 and is guided directly along the walls of the cells 2 from one end of the cells 2 to the other end, is shown by arrows. The cells 2 are positively enclosed in the base region by the coolant distribution device 3, which ensures mechanical fixation.

[0026] Fig. Figure 3 shows a second embodiment of a battery module according to the invention. The battery module 1 comprises a plurality of electrochemical cells 2 in the form of prismatic cells.

[0027] The coolant distribution device 3 is designed as a cooling distribution frame directly connected to the cells 2 to mechanically fix them. Integrated clips, tongue-and-groove geometries, and overmolded ribs provide the mechanical reference and ensure the position of the cells 2 relative to the openings 4. The openings 4 are designed as bores. The coolant distribution device 3 is made of metal, preferably aluminum. Metallic surfaces of the coolant distribution device 3 in the contact area with the cells 2 are insulated by an electrically insulating layer. A polymer overmold is suitable for the contact zones. The coolant distribution device 3 is manufactured as an extruded aluminum frame. The frame seam is joined by laser welding. End caps are metallurgically bonded. A dielectric oil is used as the coolant.The coolant distribution device 3 is fluidically connected to a main cooling line (not shown here). The connection is made via a standardized quick-release coupling with a sealing system.

[0028] All other features of the second embodiment correspond to those of the first embodiment. QUOTES INCLUDED IN THE DESCRIPTION

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

[0000] DE 10 2015 111 194 A1

[0002]

Claims

[1] Battery module (1) comprising a plurality of electrochemical cells (2) and a coolant distribution device (3) guided along the cells (2), wherein the coolant distribution device (3) has a plurality of openings (4) in the region of the cells (2) which are arranged and dimensioned such that a coolant (5) is discharged directly along the cells (2). [2] Battery module (1) according to one of the preceding claims, wherein the coolant distribution device (3) is directly connected to the cells (2) to mechanically fix the cells (2). [3] Battery module (1) according to one of the preceding claims, wherein the openings (4) are oriented towards the electrical terminals of the cells (2). [4] Battery module (1) according to one of the preceding claims, wherein the openings (4) along a longitudinal direction of the coolant distribution device (3) have a progressive opening area which increases from the inlet end to the outlet end. [5] Battery module (1) according to any of the preceding claims, wherein the coolant distribution device (3) is made of metal and / or plastic. [6] Battery module (1) according to one of the preceding claims, wherein the coolant distribution device (3) is supplied from both sides. [7] Battery module (1) according to one of the preceding claims, wherein the coolant distribution device (3) is designed as a coolant distribution pipe or coolant distribution frame. [8] Battery module (1) according to one of the preceding claims, wherein the coolant distribution device (3) is fluidically connected to a main cooling line. [9] Battery module (1) according to one of the preceding claims, wherein the openings (4) are designed as slots or bores. [10] Vehicle comprising a battery module (1) according to any of the preceding claims.

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