Cell module for an electrical energy storage system

Abstract

The invention relates to a cell module (1) for an electrical energy storage device comprising a plurality of electrically interconnected individual cells (2) and a temperature control device (5), wherein the individual cells (2) and the temperature control device (5) are arranged in a common housing (4). According to the invention, the cell module (1) is formed from a plurality of layers (L1 to L4), each with a number of prismatically shaped individual cells (2) arranged lying on a flat side (F), wherein each layer (L1 to L4) has at least one row (R1, R2) of individual cells (2) arranged side by side, and a temperature control device (5) designed as an inter-cell cooler is arranged between a predetermined number of layers (L1 to L4).

Description

[0001] The invention relates to a cell module for an electrical energy storage device comprising a plurality of electrically interconnected individual cells and a temperature control device, wherein the individual cells and the temperature control device are arranged in a common housing.

[0002] From EP 3 499 635 B1, a manufacturing method and a manufacturing apparatus for a battery pack are known. The battery pack comprises a cell stack, which is a stack of a plurality of individual cells, and a cooler containing a coolant flow channel. A cooled section of the coolant flow channel is a portion of the surface of the cell stack extending along a stacking direction of the individual cells, to which the cooler is attached, with a viscous body layer arranged between the cooled section and the cooler.The manufacturing process comprises: forming the viscous body layer on the cooler such that an opposite surface of the viscous body layer facing the cooled section has a vertex at which a perpendicular distance from a surface of the viscous body layer opposite the opposite surface is longest, and such that the perpendicular distance decreases continuously and monotonically in directions away from the vertex, as seen in a sectional view of the viscous body layer from a longitudinal side direction of the viscous body layer; and before the hardening of the viscous body layer on the cooler is complete, fixing the cell stack to the cooler while the opposite surface is pressed with the cooled section.

[0003] The invention is based on the objective of providing a cell module for an electrical energy storage device.

[0004] The problem is solved according to the invention by a cell module which has the features specified in claim 1.

[0005] Advantageous embodiments of the invention are the subject of the dependent claims.

[0006] A cell module for an electrical energy storage device comprises a plurality of electrically interconnected individual cells and a temperature control device, wherein the individual cells and the temperature control device are arranged in a common housing. According to the invention, the cell module is designed such that it has a plurality of layers, each with a number of prismatically shaped individual cells arranged on a flat side, wherein each layer has at least one row of adjacent individual cells, and a temperature control device designed as an inter-cell cooler is arranged between a predetermined number of layers.

[0007] In such a cell module, operational and / or age-related cell thickness growth of the individual cells can be optimally distributed relative to the module. The horizontal arrangement of the individual cells and the multiple layers allow the cell thickness growth to be distributed over a larger area, thereby reducing expansion along the longitudinal axis of the cell module. Furthermore, the cell thickness growth does not affect the mechanical structure of the cell module but is compensated for within the existing space of the module, which is already available for venting gases in the individual cells.

[0008] For example, the service life of the electrical energy storage system can also be increased, as the risk of failure of mechanical components of the cell module can be reduced by the fact that the cell thickness growth has a particular effect in the direction of a vertical axis of the cell module.

[0009] Such a horizontal arrangement of the individual cells allows for a simple construction of the cell module with relatively few components, which simplifies the manufacturing of the cell module.

[0010] Furthermore, such a cell module can increase the utilization of space for active material in the housing of the electrical energy storage device, enabling a high degree of integration into an existing installation space for the cell module.

[0011] In one embodiment, the individual cells of an outer layer are positioned with their end faces abutting each other, so that a longitudinal axis of the individual cells is parallel to a longitudinal axis of the row. Based on such an arrangement, the electrical poles of each individual cell are freely accessible for the electrical interconnection of the individual cells of the cell module, since the electrical poles are located on a narrow side of each individual cell.

[0012] In another embodiment, the electrical poles are arranged on the same narrow side of the individual cells, and the narrow sides are aligned in the same direction. This makes electrically connecting the individual cells relatively simple and straightforward, and can even be automated.

[0013] In one possible embodiment of the cell module, a single cell is positioned at one end of an inner layer located between two outer layers, with its longitudinal axis perpendicular to the longitudinal axis of an adjacent single cell in the same row, and is flush with the end-mounted single cells of at least the outer layers. This flush finish along the longitudinal axis largely prevents any overhang and thus the formation of a practically unusable gap.

[0014] In one embodiment, a narrow side of the single cell, which has the electrical poles and is arranged transversely with its longitudinal axis to the longitudinal axis of the adjacent single cell, is exposed, so that a comparatively simple electrical connection of this transversely arranged single cell is possible without hindrance.

[0015] In another embodiment, a space is formed between the end-arranged individual cells of the outer layers on an opposite side. This space can be used for the space-saving arrangement of a high-voltage terminal and / or for the arrangement of connection elements of the temperature control device(s) and / or for the arrangement of a control unit and / or for the arrangement of low-voltage connectors, etc.

[0016] In one embodiment, the individual cells of the outer layers and the individual cells of at least one inner layer, whose longitudinal axes run in the same direction, are arranged laterally offset from one another in a masonry bond pattern, thereby increasing the mechanical stability and stiffness of the cell module. For example, due to the horizontal arrangement of the individual cells, it is also possible to dispense with additional mechanical components to increase the stability and stiffness, particularly of the cell module.

[0017] In another embodiment, the individual cells, whose flat sides contact a plate-shaped temperature control device, are bonded to the temperature control device over their entire surface. This largely prevents any displacement of the temperature control device and / or the individual cells contacting it.

[0018] In one embodiment, the individual cells are bonded to the temperature control device using a thermally conductive adhesive, thus optimizing thermal coupling between the individual cells and the temperature control device and efficiently transferring waste heat generated during operation of the individual cells to the temperature control device.

[0019] Furthermore, one embodiment provides that the individual cells are electrically interconnected by means of cell connectors, whereby, depending on a planned electrical interconnection of the individual cells, either two electrical poles of the same electrical polarity are connected together, or two electrical poles of different electrical polarity.

[0020] Exemplary embodiments of the invention are explained in more detail below with reference to the drawings.

[0021] This shows: Fig. 1. Schematic perspective view of a cell module according to the state of the art and Fig. 2 schematically a perspective view of a cell module with several layers of horizontally arranged individual cells.

[0022] Corresponding parts are marked with the same reference symbols in all figures.

[0023] Fig. Figure 1 shows a perspective view of a prior art cell module 1' for an electrical energy storage device not shown in detail. The electrical energy storage device is, in particular, a vehicle battery, especially a traction battery, for an electric vehicle, a hybrid vehicle, or a fuel cell-powered vehicle.

[0024] The cell module 1' has a predetermined number of individual cells 2 that form a cell stack, wherein in Fig. The two flat surfaces F of adjacent individual cells 2, shown in more detail, lie flat against each other in the stacking direction R, i.e., in the axial direction of the cell stack, that is, in the direction of its longitudinal axis. An end plate 3 is arranged at each end of the cell stack for axial compression of the cell stack. Pressure is exerted on the individual cells 2 by means of a clamping device and the end plates 3, so that the individual cells 2 are operated in an optimized manner. The cell module 1' also has a housing 4 in which the cell stack is arranged.

[0025] During operation of the individual cells 2, that is, particularly during charging, and with increasing age, the individual cells 2 exhibit cell thickness growth, which accumulates axially across the cell stack. This results in fluctuations in the dimensions of the cell stack, especially in the axial direction. Due to an increase in the length of the cell stack caused by the accumulated cell thickness growth, particularly in the axial direction, the end plates 3 can deform, especially bend, and the welds N of the housing 4 of the cell module 1' can be subjected to high loads.

[0026] Furthermore, the electrochemical active material of the individual cells 2 is comparatively aggressive, resulting in a higher energy content, but also in a higher cell thickness growth for the individual cells 2, which is increasingly difficult to handle mechanically.

[0027] The following is in accordance with Fig. 2 a cell module 1 is described in which a construction space for an arrangement of the electrochemical active material is efficiently used, the cell module 1 can be manufactured simply in comparison, a lifetime can be optimized and represents a cost-effective solution, especially with regard to a compensation of the cell thickness growth of the individual cells 2.

[0028] In Fig. Figure 2 shows a cell module 1 which comprises several layers L1 to L4 of individual cells 2, which are arranged side by side lying on one of their flat sides F.

[0029] According to the in Fig. In the embodiment shown in Figure 2, each layer L1 to L4 of the cell module 1 has a predetermined number of individual cells 2, wherein a first layer L1 and a fourth layer L4 form outer layers L1, L4, between which a second layer L2 and a third layer L3, i.e., two inner layers L2, L3, are arranged. The number of layers L1 to L4 of the cell module 1 can vary.

[0030] Each layer L1 to L4 comprises two rows R1, R2 in the axial direction of cell module 1, with each row R1, R2 having six individual cells 2. Both the number of rows R1, R2 and the number of individual cells 2 can vary.

[0031] The individual cells 2 of the outer layers L1, L4 lie with their end faces S against each other, with narrow sides M of the individual cells 2 of each row R1, R2, on which electrical poles P of the individual cells 2 are arranged, being aligned in one and the same direction.

[0032] In Fig.Figure 2 shows that a plate-shaped temperature control device 5, a so-called cell intercooler, is arranged between the individual cells 2 of a respective outer layer L1, L4 and the individual cells 2 of a respective inner layer L2, L3. The individual cells 2 are connected to the temperature control device 5 with their flat side F facing the respective temperature control device 5 by means of a material bond, in particular by means of a thermally conductive adhesive.

[0033] The individual cells 2 of the two inner layers L2, L3 are arranged in a masonry-like pattern offset laterally to the individual cells 2 of the two outer layers L1, L4, thereby increasing the stiffness of the cell module 1 and thus of the electrical energy storage.

[0034] The individual cells 2 of a first row R1 and a second row R2 of the first layer L1 are electrically connected to the individual cells 2 of a first row R1 and a second row R2 of the second layer L2 by means of cell connectors 6, wherein the electrical connection of the individual cells 2 can be in series or in parallel.

[0035] The single cell 2 at one end of the respective inner layers L2, L3, arranged between the two outer layers L1, L4, is arranged with its longitudinal axis transverse to the longitudinal axis of an adjacent single cell 2 of the same row R1, R2 and is essentially flush with the end-arranged single cells 2 of each row R1, R of the two outer layers L1, L2.

[0036] Because the last individual cells 2 of both rows R1, R2 of the inner layers L2, L3 are arranged transversely to the adjacent individual cells 2, the electrical interconnection of the individual cells 2 of the first row R1 can be carried out on the individual cells 2 of the second row 2.

[0037] At one end opposite the two transversely arranged individual cells 2, a free space FR is formed due to the lateral offset of the individual cells 2 of the outer layers L1, L4 to the individual cells 2 of the inner layers L2, L3. This free space FR can be used, for example, for the arrangement of a high-voltage terminal and / or for the arrangement of connection elements of the temperature control device 5 or devices 5 and / or for the arrangement of a control unit and / or for the arrangement of low-voltage connectors, etc. This allows for a space-saving arrangement of the components required for the operation of the electrical energy storage system.

[0038] Due to the horizontal arrangement of the individual cells 2 within the cell module 1, the cell thickness growth of the individual cells 2 can be distributed over a larger area formed by the flat sides F of the individual cells 2. The cell thickness growth does not act in the axial and / or transverse direction of the cell module 1, but rather in the direction of a vertical axis z. Space is available for cell thickness growth in the housing 4 of the cell module 1 in the direction of the vertical axis z, as this space is already available for outgassing of the individual cells 2 during operation and can therefore be used additionally. Reference symbol list 1', 1 cell module 2 single cells 3 End plate 4 cases 5 Temperature control device 6 cell connectors F Flat side FR Free Space L1 first / outer layer L2 second / inner layer L3 third / inner layer L4 fourth / outer layer M Narrow side N weld seam P electric pole R1, R2 series S Front z vertical axis 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] EP 3 499 635 B1

[0002]

Claims

[1] Cell module (1) for an electrical energy storage device comprising a plurality of electrically interconnected individual cells (2) and a temperature control device (5), wherein the individual cells (2) and the temperature control device (5) are arranged in a common housing (4), characterized by a plurality of layers (L1 to L4) with a respective number of prismatically shaped individual cells (2) arranged lying on a flat side (F), wherein each layer (L1 to L4) has at least one row (R1, R2) of individual cells (2) arranged next to each other and a temperature control device (5) designed as an inter-cell cooler is arranged between a predetermined number of layers (L1 to L4). [2] Cell module (1) according to claim 1, characterized by , that the individual cells (2) of an outer layer (L1, L4) are adjacent to each other with their end faces (S), so that a longitudinal axis of the individual cells (2) is arranged parallel to a longitudinal axis of the row (R1, R2). [3] Cell module (1) according to claim 1 or 2, characterized by , that electrical poles (P) are arranged on one and the same narrow side (M) of the individual cells (2) and the narrow sides (M) are arranged in one and the same direction. [4] Cell module (1) according to claim 2 or 3, characterized by , that a single cell (2) is arranged at one end of an inner layer (L2, L3) arranged between two outer layers (L1, L4) with its longitudinal axis perpendicular to the longitudinal axis of an adjacent single cell (2) of the same row (R1, R2) and is flush with the end-arranged single cells (2) of at least the outer layers (L1, L4). [5] Cell module (1) according to claim 4, characterized by , that a narrow side (M) having the electrical poles (P) of the single cell (2) arranged transversely with its longitudinal axis to the longitudinal axis of the adjacent single cell (2) is exposed. [6] Cell module (1) according to claim 4 or 5, characterized by, that between end-arranged individual cells (2) of the outer layers (L1, L4) a free space (FR) is formed on an opposite side. [7] Cell module (1) according to any one of the preceding claims, characterized by , that the individual cells (2) of the outer layers (L1, L4) and the individual cells (2) of the at least one inner layer (L2, L3), whose longitudinal axes run in the same direction, are arranged laterally offset from each other in the manner of a masonry bond. [8] Cell module (1) according to any one of the preceding claims, characterized by , that the individual cells (2) which contact a plate-shaped temperature control device (5) with their flat sides (F) are fully bonded to the temperature control device (5). [9] Cell module (1) according to any one of the preceding claims, characterized by, that the individual cells (2) are connected to the temperature control device (5) by means of a thermally conductive adhesive. [10] Cell module (1) according to any one of the preceding claims, characterized by , that the individual cells (2) are electrically connected by means of cell connectors (6).

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