BATTERY CELL MODULE AND ARRANGEMENT

Abstract

A battery cell module (10) having a plurality of flat battery cells (1) arranged side by side in a stack, a layer of a compressible aerogel (17) between al least two of the battery cells (1), at least one phase change material (PCM) layer (18), and a circuit arrangement with battery cell management electronics (14a) in operative connection with said plurality of battery cells. At least two compression plates (11) are arranged on opposite sides of said stack and are operable in a cell compression direction (CD) to hold said stack together therebetween. A separation layer (19) is arranged between the stack and the circuit arrangement. A battery cell arrangement from such modules is also provided.

Claims

1. A battery cell module (10), comprising: a plurality of flat battery cells (1) arranged side by side in a stack; a layer of a compressible aerogel (17) between at least two of said battery cells (1); at least one phase change material (PCM) layer (18); a circuit arrangement with battery cell management electronics (14a) in operative connection with said plurality of battery cells (1); compression plates (11) arranged on opposite sides of said stack that are operable in a cell compression direction (CD) to hold said stack together between said compression plates (11); and a separation layer (19) arranged between said stack and said circuit arrangement.

2. The battery cell module (10) according to claim 1, wherein there is a limited number, n, of battery cells (1) within said battery cell module (10), and n<=20.

3. The battery cell module (10) according to claim 1, wherein two layers of the compressible aerogel (17) are located between every pair of the battery cells (1), and an additional layer of the compressible aerogel (17) is located between an outmost one of the battery cells (1) in said stack and an adjacent one of the compression plates (11).

4. The battery cell module (10) according to claim 3, wherein the at least one PCM layer (18) includes a PCM layer arranged between every pair of the battery cells (1), and one additional PCM layer (18) located between an outmost one of the battery cells (1) and an adjacent one of the compression plate (11), and the PCM layer between every pair of the battery cells (1) is located between the two layers of aerogel (17).

5. The battery cell module (10) according to claim 1, wherein the compression plates (11) are held together by compression rods (12).

6. The battery cell module (10) according to claim 1, wherein the at least one PCM layer (18) includes a PCM layer arranged between every pair of the battery cells (1), and one additional PCM layer (18) is located between an outmost one of the battery cells (1) and an adjacent one of the compression plates (11).

7. The battery cell module (10) according to claim 1, wherein said circuit arrangement is located outside said stack in a plane parallel to said compression direction (CD).

8. The battery cell module (10) according to claim 1, wherein said separation layer (19) comprises a layer of thermo-mechanical insulation between said stack and said circuit arrangement.

9. The battery cell module (10) according to claim 8, wherein the layer of thermo-mechanical insulation comprises a sandwiched electrically non-conductive panel.

10. The battery cell module (10) according to claim 1, wherein said separation layer (19) has through-holes through which cell tabs (16) pass, said cell tabs (16) operatively connect respective ones of the battery cells (1) with the circuit arrangement.

11. The battery cell module (10) according to claim 10, wherein said separation layer (19) is coated with a fire barrier coating.

12. The battery cell module (10) according to claim 10, further comprising an additional PCM layer (15) is arranged in or on said separation layer (19), in contact with said cell tabs (16).

13. The battery cell module (10) according to claim 1, wherein said additional PCM layer (15) has two phase change temperatures, one for low temperatures and another for high temperatures, that are higher than the low temperatures.

14. The battery cell module (10) according to claim 1, further comprising a lid (13) located outside said stack, said lid (13) having a plurality of holes (13a).

15. The battery cell module (10) according to claim 14, wherein an outer surface of said lid (13) is covered with a film.

16. The battery cell module (10) according to claim 14, wherein said lid (13), in a cross-section thereof, has bi-directional corrugated channels (13d) that extend between said holes (13a).

17. A battery cell arrangement (100), comprising a plurality of battery cell modules (10) according to claim 1.

18. The battery cell arrangement (100) according to claim 17, wherein said battery cell modules (10) are arranged in a planar configuration of rows and columns, wherein in every row said battery cell modules (10) are in contact with an adjacent one of the battery cell modules (10) via a respective one of the compression plate (11, 11′), and wherein adjacent ones of the rows are separated from each other by an intermodule wall (101).

19. The battery cell arrangement (100) according to claim 18, wherein the intermodule wall (101) has a H-shape, with outside ones of the rows being separated from an exterior by respective sidewalls (23) that have a U-shape.

20. The battery cell arrangement (100) according to claim 18, further comprising a cooling plate (22) arranged at least on one side parallel to a plane of said rows and columns in contact with said circuit arrangement.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Further characteristics and advantageous of the invention can be gathered from the following description of preferred and non-limiting embodiments with reference to the drawings.

[0060] FIG. 1 shows considerations for reducing the risk of cascading thermal runaway by reducing the number of battery cells (or simply “cells”) in a module;

[0061] FIG. 2 shows a sectional view of the basic structure of a battery cell module;

[0062] FIG. 3 shows the lid comprised in FIG. 2;

[0063] FIG. 4 shows a battery cell arrangement composed of a plurality of cell modules assembled in a planar configuration of rows and columns;

[0064] FIG. 5 shows the basic structure of a single battery cell module in an exploded view;

[0065] FIG. 6 shows a single battery cell module in another representation with a view of its underside; and

[0066] FIG. 7 shows a battery cell arrangement in an exploded view.

DETAILED DESCRIPTION

[0067] The illustration of FIG. 1 is based on the assumption that 20% (rounded up—RU) of the battery cells in a corresponding battery cell module (as called “cell module” or simply “module”) are triggered. This is shown in FIG. 1 for three cases, i.e., 10 cells per module (or “sub-pack”), 11 cells per module, and 16 cells per module. The individual cells are designated in FIG. 1 with the reference numeral 1. Not all cells are explicitly designated.

[0068] Reference signs R1 to R6 denote different risk levels for triggering: R1 denotes triggered cells 1; R2 denotes cells 1 that have a very high triggering risk; R3 denotes cells 1 that have a high triggering risk; R4 denotes cells 1 that have a medium triggering risk; R5 denotes cells 1 that have a low triggering risk; and R6 denotes cells 1 that have a very low triggering risk. It can be seen that the risk of cells 1 triggering simultaneously decreases with lower number of cells 1 per module.

[0069] According to FIG. 1, a number of ten (10) cells 1 per module can be regarded as an optimal value.

[0070] FIG. 2 shows in a sectional view the basic structure of a battery cell module, which module as a whole is provided with the reference numeral 10. Ten flat battery cells 1 in the form of so-called pouch cells are arranged in the module 10 in the form of a stack. The stack is held together by two compression plates 11 made of, e.g., CFRP (Carbon Fibre Reinforced Polymer) or materials having similar properties, which are held together on both sides of the stack by two compression rods 12, which can only be seen on one side of the assembly due to the chosen method of representation. A cell compression direction (cf. FIG. 4) runs parallel to said compression rods 12. Compression rods 12 serve as a form of compression means operable in said cell compression direction for to hold the stack together between said compression plates 11.

[0071] A lid 13 with exhaust holes 13a is arranged above the stack, the exact design of which will be discussed in more detail below with reference to FIG. 3. Reference numeral 13b indicates a shortest path from a battery cell 1 to an exhaust hole 13a.

[0072] Below the stack is an electric circuit arrangement in the form of a printed circuit board (PCB) 14 with corresponding battery cell management electronics 14a, which can be seen better in FIG. 6. Elements 15 made of a phase change material (PCM) are arranged laterally next to the electronics 14a. These elements 15 are thermally conductively connected to the individual battery cells 1 via flexible connections 16 (so-called cell tabs).

[0073] Two layers 17 of a compressible aerogel are arranged between each pair of battery cells 1, between which aerogel layers 17 a layer 18 of phase change material (PCM) is arranged in turn. At the end faces of the stack, adjacent said compression plates 11, there is again a layer 17 of aerogel followed by a layer 18 of phase change material.

[0074] A separation/insulating layer 19 is arranged between the printed circuit board 14, i.e., the circuit arrangement and the stack of battery cells 1, which separation/insulating layer 19 separates the battery cell stack from the electronics 14a and the printed circuit board 14 both thermally and mechanically.

[0075] The separation/insulating layer 19 can take the form of a sandwiched electrically non-conductive panel (e.g., a woven ceramic) including an insulating material (e.g., an aerogel) encapsulating a PCM layer, which PCM layer can absorb high temperature residual heat. The separation layer 19 has through-holes (not shown) through which pass said cell tabs 16.

[0076] Reference numeral 20 denotes a burstable anti flame sleeve made of high strength, low weight, non-conductive material, and reference numerals 21 denote thermal runaway clearances for easy degassing in the case of a thermal event in order to avoid the fire impacting other neighbouring components and/or bursting of the triggered cell.

[0077] Underneath the electronics 14a and the PCM elements 15, a cooling plate 22 is arranged for additional cooling action.

[0078] Reference numerals 11′ and 12′, respectively, denote a compression plate and a compression rod of a neighbouring cell module.

[0079] The compression plates 11, 11′ have high inertia ribs 11a, 11a′ to increase stiffness.

[0080] As will be further shown in FIG. 7, a plurality of cell modules 10 are surrounded by U-shaped sidewalls 23, which sidewalls are devised as high strength low weight double walls made of a sandwich composed of an inside wall 23a which serves as fire resistance wall and can be coated with CFRP (Carbon Fibre Reinforced Polymer) or Ceramic Fibre Reinforced Polymer, while an outer wall 23b is devised as a structural thin layer. A space 23c between said walls 23a, 23b can be filled with a thermal insulation material, e.g., aerogel or a combination of PCM and aerogel, or can be evacuated.

[0081] FIG. 3 shows the lid 13 of FIG. 2. As already mentioned, said lid 13 has a plurality of exhaust holes 13a, the edges 13b of which are each bulged or angled outwardly, and they are each flattened plateau-like at their free ends 13c. Between and around the exhaust holes 13a, bi-directional channels 13d of V-shaped cross-section extend in a square pattern. Reference numeral 13e marks adhesive edges for adhering a bursting foil, which foil is not shown in FIG. 3. In this way, an arrangement can be created in which the bursting foil easily bursts or tears in the event of overpressure on the underside of the lid 13, while it is relatively stable in the opposite direction due to an abutment against the edges 13b, 13c of the exhaust holes 13a. Said bursting foil is preferably made of a polymer reinforced with glass fibre.

[0082] Alternatively, said bursting foil (or a plurality of small bursting foil pieces) could be adhered to said plateau-like free ends 13c of the exhaust holes 13a.

[0083] FIG. 4 shows a battery cell arrangement 100 composed of a plurality of cell modules 10 assembled in a planar configuration of rows and columns as an example of one of the possibilities to connect the cell modules 10 (cf. FIG. 2). By way of example, FIG. 4 shows an arrangement of cell modules 10, each of which cell modules 10 comprises ten (10) battery cells that are connected in series within a given cell module 10, thus forming a 100S1P configuration that is physically arranged in U-shape, as shown by each one of arrows S1-S4 in the FIG. 4. These 100S1P configurations are then connected in parallel, for example four (4) times, to form a 100S4P configuration as shown in FIG. 4. Assume the compression direction CD being horizontal (left to right), as shown. Individual battery cells (not shown) are connected via the PCB (FIG. 2) which can be easily modified or designed to incorporate power wiring and slave components. Therefore, the modules 10 can be connected in direction CD of the compression of the cells or perpendicular to this direction, as shown in FIG. 4.

[0084] FIG. 5 once again shows the basic structure of a single battery cell module 10 in an exploded view. The individual compression plates 11, 11′ with their respective reinforcing ribs 11a, 11a′ and the compression rods 12, 12′ can be seen particularly well. It can also be seen in FIG. 5 that the compression plates 11, 11′ have bent or angled edges 11b, 11b′ with which they partially surround the battery cell stacks laterally.

[0085] In addition, FIG. 5 shows an intermodule wall 101 of H-shape separating adjacent rows of battery cell modules 10. Said intermodule wall 101 can further be devised in analogy to the sidewalls 23 described earlier in connection with FIG. 2.

[0086] FIG. 6 shows a single battery cell module 10 in another representation with a view of the circuit board 14 on its underside (cf. FIG. 2) together with the electronics 14a. Two PCM elements 15 can also be seen, cf. FIG. 2. The two compression plates 11 belonging to the module 10 are also shown, together with a further compression plate 11′ belonging to an adjacent module (not shown in its entirety). At the lower edge of the figure, an intermediate module wall or a side wall is depicted.

[0087] As can further be gathered from FIG. 6, the printed circuit board 14 or the corresponding circuit arrangement has various terminal lugs 14b which serve to supply the module 10 with electrical power and/or electrical signals. As has already been noted, the various terminal lugs 14b serve to interconnect the individual modules 10 in various ways, in particular in the direction of compression or perpendicular thereto, cf. FIG. 4.

[0088] The whole pack is finally enclosed and held in place by the lid 13 (cf. FIG. 3), the sidewalls 23, the intermodule wall 101 and the cooling plate 22 via adhesive and/or detachable connectors (e.g., screws) as shown in FIG. 7, which shows the mechanical containment structure of a battery cell arrangement 100 (i.e., without said battery cells and without said lid) in an exploded view.