Battery cell for immersion in a coolant

Abstract

Battery Cell for Immersion in a Coolant. The invention relates to a battery cell (12) comprising a cell casing (20), said casing comprising: a first (30) and a second principal face, parallel and opposite; and an upper face (38), perpendicular to the principal faces; a casing axis (40) being perpendicular to the upper face. The first principal face (30) comprises a first series of grooves (42), substantially straight and parallel to each other; the second principal face (32) comprises a second series of grooves (44), substantially straight and parallel to each other. The grooves (42, 44) of the first and second series form respectively a first (α) and a second (β) angle with the casing axis (40), each of the first and second angles being strictly greater than 0° and strictly less than 90°. Figure for the abstract: Figure 2

Description

Title of the invention: Battery cell for immersion in a coolant

[0001] The present invention relates to an electric battery cell.

[0002] The invention is particularly applicable to battery cells intended to be immersed in a coolant. In particular, a battery device comprising a plurality of battery cells and a cooling circuit for circulating a coolant in contact with the battery cells is known in the prior art.

[0003] It is also known to provide parallel grooves on the main faces of battery cases to form channels for the circulation of the coolant. Such cells are notably known from document JP4830289.

[0004] However, in known devices, the grooves are arranged parallel to a housing axis. For optimal formation of the flow channels, it is therefore desirable to adhere to a precise arrangement and dimensioning of the grooves.

[0005] The present invention aims to provide a battery cell that facilitates the manufacturing process of the cell as well as the production of an electric battery using such a cell.

[0006] To this end, the invention relates to a battery cell of the aforementioned type, comprising a cell casing, said casing comprising: a first and a second principal face, substantially parallel and opposite to each other; and an upper face, substantially perpendicular to the first and second principal faces; the first and second principal faces of the casing comprising respectively a first and a second principal edge, substantially straight and parallel, said first and second principal edges defining the upper face. A casing axis is perpendicular to the upper face of said casing. The first principal face comprises a first series of grooves, substantially straight and parallel to each other, extending from the first principal edge; the second principal face comprising a second series of grooves, substantially straight and parallel to each other, extending from the second principal edge.The grooves of the first and second series form respectively a first and a second angle with the case axis, each of the first and second angles being strictly greater than 0° and strictly less than 90°.

[0007] According to other advantageous aspects of the invention, the battery cell comprises one or more of the following characteristics, taken individually or in any technically possible combination:

[0008] - each of the first and second angles is between 1° and 89°, preferably between 1° and 60°, more preferably between 5° and 30°;

[0009] - the first series of grooves forms a third non-zero angle with the second series of grooves, the third angle preferably being between 2° and 178°;

[0010] - projected onto a plane substantially parallel to the first and second faces main, the grooves of the first and second series are inclined in opposite directions to each other with respect to the case axis;

[0011] - the first and second main faces of the case are substantially symmetrical one from the other relative to the case axis;

[0012] - the battery cell further comprises a first and a second terminal electrical, arranged on the top face of the case.

[0013] The invention further relates to a battery device comprising: a plurality of battery cells; and a cooling circuit; the plurality of cells being arranged in the form of at least one row, the row or rows extending along a stacking axis; at least one first cell of the plurality of battery cells being such as described above, the first and second main faces of the casing of said first cell being arranged perpendicular to the stacking axis of the corresponding row; the cooling circuit being capable of circulating a coolant in contact with the first and second main faces of the casing of said first cell.

[0014] According to other advantageous aspects of the invention, the battery device comprises one or more of the following features, taken individually or in any technically possible combination:

[0015] - at least one second cell of the plurality of battery cells is such that described above; and the first and second cells are adjacent in the same row;

[0016] - the first principal faces of the first and second cells are opposite each other one from the other;

[0017] - the first main face of the first cell is opposite the second main face of the second cell;

[0018] - the battery device further comprises a sheet of solid material arranged between the first and second cells.

[0019] The invention further relates to a method for manufacturing a battery cell as described above, comprising the following steps: providing a receptacle comprising a first and a second main wall, intended to form respectively the first and second main faces of the casing; said first and second main walls of the receptacle comprising respectively a first and a second main edge, defining an opening of the receptacle; the receptacle extending along a receptacle axis substantially perpendicular to said opening; insertion into the opening of a first and a second internal element, each of the first and second internal elements comprising: an external grooved surface; and an internal face, inclined with respect to the receptacle axis; insertion into the opening of a movable part comprising two inclined faces; then displacement of the movable part along the receptacle axis so that each inclined face slides along the internal face of the first or the second internal element, to bring said internal element closer to the corresponding main wall; and application, on each of the first and second main walls, of a grooved surface of an external wedge;so that compression of each of the first and second main walls, between the grooved external surface of one of the internal elements and the grooved surface of one of the external wedges, leads by stamping to the formation of the grooves of the first and second main faces of the housing.

[0020] According to other advantageous aspects of the invention, each internal element comprises an internal wedge and an insert, the internal face and the grooved external face being carried respectively by said internal wedge and by said insert; and during the stamping step, the insert of each internal element is secured to the first or second main wall of the receptacle.

[0021] The invention will be better understood upon reading the following description, given solely by way of non-limiting example and made with reference to the drawings in which:

[0022] [Fig-1] [Fig.1] is a partial schematic view of a battery device according to an embodiment of the invention;

[0023] [Fig.2] [Fig.2] is a front view of a battery cell forming part of the battery device of the [Fig. 1]; and

[0024] [Fig.3] [Fig.4] Figures 3 and 4 are schematic, cross-sectional views of steps of manufacturing processes of the cell of [Fig.2], according respectively to a first and a second embodiment of the invention.

[0025] Fig. 1 represents a battery device 10 according to an embodiment of the invention.

[0026] The device 10 comprises: a plurality of battery cells 12, 14, 16; and a cooling circuit 18 for said cells.

[0027] A first cell 12 of the plurality of cells is shown in [Fig.2]. The first cell 12 will be described below as "cell 12".

[0028] Cell 12 comprises: a housing 20; and a first 22 and a second 24 electrical terminals. In the embodiment shown, cell 12 further comprises a vent 26.

[0029] The housing 20 comprises a first 30 and a second 32 principal faces, substantially parallel and opposite to each other. Said first 30 and second 32 principal faces comprise respectively a first 34 and a second 36 principal edges, substantially straight and parallel to each other.

[0030] The housing 20 further comprises an upper face 38, delimited by the first 34 and second 36 main edges.

[0031] In the embodiment shown, the housing 20 is substantially parallelepiped, the first 30 and second 32 main faces have the largest surfaces of the faces of said housing 20 and the first 34 and second 36 main edges are part of the longest edges of the edges of said housing 20.

[0032] We consider an orthonormal basis (X, Y, Z) associated with said case 20, the direction X being parallel to the first 34 and second 36 principal edges.

[0033] We consider an axis 40 of the housing, perpendicular to the upper face 38 and parallel to the direction Z.

[0034] The first main face 30 of the housing 20 comprises a first series of grooves 42, substantially straight and parallel to each other, extending from the first main edge 34 and / or from an edge opposite said first main edge. The grooves 42 of the first series form a first angle α with the axis 40 of the housing.

[0035] The second main face 32 of the housing 20 includes a second series of grooves 44, substantially straight and parallel to each other, extending from the second main edge 36. The grooves 44 of the second series form a second angle [3 with the axis 40 of the housing.

[0036] Each of the first and second [3 angles is strictly greater than 0° and strictly less than 90°. Preferably, each of the first and second [3 angles is between 1° and 89°.

[0037] More preferably, each of the first and second angles is between 1° and 60°. Even more preferably, each of the first and second angles is between 5° and 30°.

[0038] The grooves 42 of the first series form a third angle y with the grooves 44 of the second series. Preferably, said third angle y is non-zero, that is to say that the grooves 42 of the first series are not parallel to the grooves 44 of the second series.

[0039] More preferably, the third angle is between 2° and 178°.

[0040] Preferably, in projection in a plane substantially parallel to the first 30 and second 32 main faces, the grooves 42 and 44 of the first and second series are inclined opposite to each other with respect to the axis 40 of the housing.

[0041] More preferably, the first a and second [3 angles are equal in absolute value and the third angle y is equal to twice the said first and second angles. In other words, as in the embodiment shown, the first 30 and second 32 main faces of the case 20 are substantially symmetrical to each other with respect to the case axis 40.

[0042] Each of the first 22 and second 24 electrical terminals of the cell 12 is arranged on the upper face 38 of the housing 20. The first 22 and second 24 electrical terminals are preferably aligned parallel to X.

[0043] For example, the first terminal 22 is considered to be a positive terminal and the second terminal 24 to be a negative terminal. The first 30 and second 32 main faces of the housing 20 are thus distinguished from each other according to the arrangement of the first 22 and second 24 terminals.

[0044] In the embodiment shown, the vent 26 is located on the upper face 38 of the housing 20, between the first 22 and second 24 terminals.

[0045] The battery device 10 of [Fig.1] will now be described in more detail.

[0046] In the following description, cells 12, 14, 16 of the device are considered 10 are substantially identical and correspond to the above description of the first cell 12.

[0047] The cells 12, 14, 16 of the device 10 are arranged in the form of one or more rows 50. Each of said rows 50 extends along a stacking axis 52.

[0048] Consider a second cell 14 belonging to the same row 50 as the first cell 12 described above. The stacking axis 52 of the row 50 is parallel to Y and perpendicular to the first 30 and second 32 principal faces of the casings of the first 12 and second 14 cells.

[0049] The plurality of cells 12, 14, 16 of the device 10 are intended to form one or more battery modules. The cells forming a single battery module are considered to be electrically connected to each other, in series and / or in parallel.

[0050] For example, in the embodiment shown, the first 12 and second 14 cells are intended to be connected in series. More precisely, the first main faces 30 of the housings of the first 12 and second 14 cells are arranged opposite each other. The first terminal 22 of the first cell 12 is thus aligned along Y with the second terminal 24 of the second cell 14, allowing a series connection.

[0051] In case of contact between the first 12 and second 14 cells in the row 50, the inclination of the grooves 42 with respect to the axis 40 of the housing limits the contact surface into a mesh of distinct zones 54. On the rest of the surface of the first main faces 30, a gap is maintained between the first 12 and second 14 cells.

[0052] In an unrepresented variant, the first 12 and second 14 cells are intended to be connected in parallel and the first main face 30 of the first cell 12 is opposite the second main face 32 of the second cell 14.

[0053] In the case where the grooves 42 and 44 of the first and second series are inclined in opposite directions to each other with respect to the housing axis 40, such a parallel arrangement also leads to possible contact between the two cells 12, 14 in the form of a mesh of distinct zones. In particular, in the case of axial symmetry between the first 30 and second 32 principal faces, the parallel arrangement leads to contact between the two cells 12, 14 in the form of the mesh of distinct zones 54 similar to that of the series arrangement.

[0054] The housing 20 having an axial symmetry between the first 30 and second 32 main faces thus makes it possible to obtain an identical interface between two adjacent cells 12, 14, regardless of the connection configuration.

[0055] According to a first embodiment, two adjacent cells of the device 10 are directly opposite each other, such as the first 12 and second 14 cells. According to a second embodiment, the device 10 further comprises a sheet 56 of solid material disposed between two adjacent cells, such as the first cell 12 and a third cell 16. Such a sheet 56 of solid material is, for example, a separator or a thermal insulator.

[0056] The cooling circuit 18 of the device 10 will now be described. The cooling circuit 18 comprises: a housing 60; a coolant inlet 62 and outlet 64; a reservoir 66; and a circulation pump 68.

[0057] The enclosure 60 receives the plurality of cells 12, 14, 16 of the device 10, arranged as described previously in the form of one or more rows 50.

[0058] The coolant inlet 62 and outlet 64 open into the enclosure 60 and are connected to the reservoir 66, which contains, for example, a buffer quantity of coolant. In one embodiment, the reservoir includes a heat exchanger 70 for cooling the coolant. In another embodiment, the cooling circuit 18 does not include a reservoir 66, and the coolant inlet 62 and outlet 64 are directly connected to the heat exchanger 70.

[0059] The circulation pump 68 is intended to circulate a flow of coolant in the enclosure 60, in contact with the housings 20 of the cells 12, 14, 16. The electric battery cells are thus cooled during their use.

[0060] In particular, the coolant circulates in the grooves 42, 44 of the first 30 and second 32 main faces of each housing 20. As described previously, said grooves 42, 44 provide a space between two directly adjacent cells 12, 14, with the possible exception of the mesh of distinct zones 54 in In the case of contact between the cells, the coolant therefore has the necessary space to circulate in contact with the main faces 30, 32, so as to cool the housings 20.

[0061] If a sheet 56 of solid material separates two adjacent cells 12, 16, said sheet defines channels with the grooves 42, 44 of the main face 30, 32 located opposite.

[0062] The configuration of the housings 20 of the cells 12, 14, 16, as described above, therefore ensures the circulation of the coolant, even in the event of contact between two adjacent cells 12, 14. The arrangement and dimensions of the grooves 42, 44 thus require a lower degree of precision than in other prior art configurations.

[0063] Figures 3 and 4 represent an installation 100, 200 for manufacturing the housing 20 of the cells 12, 14, 16 described above, according respectively to a first and a second embodiment of the invention.

[0064] Installations 100 and 200 will be described, the common elements being designated by the same reference numbers.

[0065] The installation 100, 200 comprises: a receptacle 102; two internal wedges 104, 106, 204; a movable part 108; and two external wedges 110, 112. In the embodiment of [Fig.4], the installation 200 further comprises two inserts 214, 216.

[0066] The receptacle 102 is intended to form the housing 20, by adding a cover (not shown) intended to form the upper face 38. Preferably, the receptacle 102 has a substantially parallelepiped shape.

[0067] In particular, the receptacle 102 comprises a first 120 and a second 122 main walls, intended to form respectively the first 30 and the second 32 main faces of the housing 20.

[0068] In an initial state of the receptacle 102, visible in [Fig. 3], each of the first 120 and second 122 main walls is substantially flat. In a final state of the receptacle 102, visible in [Fig. 4], each of the first 120 and second 122 main walls has the grooves 42, 44 previously described for the main faces 30, 32 of the housing 20.

[0069] The first 120 and second 122 main walls of the receptacle 102 comprise respectively a first 124 and a second 126 main edges, defining an opening 127 intended to receive the lid (not shown).

[0070] In contrast to the first 124 and second 126 main edges, the receptacle 102 further comprises a bottom 128 connecting the first 120 and second 122 main walls.

[0071] The receptacle 102 extends along an axis 130, perpendicular to the first 124 and second 126 principal edges and to the bottom 128. An orthonormal base is considered (X, Y, Z) associated with receptacle 102, the X direction corresponding to the first 124 and second 126 principal edges and the Z direction corresponding to axis 130.

[0072] The internal shims 104, 106, 204 are intended to be placed in the receptacle 102 during a manufacturing process for the housing 20, which will be described below. The internal shims 104, 106, 204 will be described in relation to the orthonormal basis (X, Y, Z) associated with the receptacle 102.

[0073] Each of the inner wedges 104, 106, 204 has an outer face 132, 134, 232 and an inner face 136.

[0074] In the embodiment of [Fig.3], the outer face 132, 134 of a first 104 and a second 106 of the inner wedges is intended to come into contact, respectively, with the first 120 and the second 122 main wall of the receptacle 102. More specifically, the outer face 132, 134 of each of the first 104 and second 106 inner wedges has a grooved shape, adapted to the formation of the grooves 42, 44 of each of the first 30 and second 32 main faces of the housing 20, as described below.

[0075] In the embodiment of [Fig.4], an insert 214, 216 is intended to be interposed between the outer face 232 of each of the inner wedges 204 and, respectively, the first 120 and the second 122 main walls of the receptacle 102.

[0076] More specifically, each insert 214, 216 is formed from a thin plate, one face of which has a grooved shape, adapted to the formation of the grooves 42, 44 described above, and a second face of which is flat. The outer face 232 of each of the inner wedges 204 is flat and intended to come into contact with said second face of one of the inserts 214, 216.

[0077] The inner face 136 of each of the inner wedges 104, 106, 204 is inclined with respect to the corresponding outer face 132, 134, 232 and with respect to the Z direction. Preferably, each inner face 136 is inclined with respect to Z by an angle ô between 0.5° and 10.0°.

[0078] The movable part 108 comprises two opposing flat faces 138, inclined relative to each other and meeting at a tapered end 139. Each of said faces 138 is designed to slide along the inner face 136 of one of the inner wedges 104, 106, 204, as described below. Preferably, each of said faces 138 is inclined at an angle θ with respect to Z.

[0079] Each of the outer wedges 110, 112 has a pressure face 140, 142, intended to come into contact, respectively, with the first 120 and the second 122 main walls of the receptacle 102. Each of the pressure faces 140, 142 has a grooved shape, adapted to the formation of the grooves 42, 44 of each of the first 30 and second 32 main faces of the housing 20, as described below.

[0080] A manufacturing process for the housing 20 will now be described.

[0081] First, the receptacle 102 is in the initial state visible in [Fig. 3]. The wedges inner shims 104, 106, 204 are introduced into said receptacle through the opening 127 and butted against the bottom 128. In the embodiment of [Fig.4], each insert 214, 216 is interposed between the outer face 232 of each of the inner shims 204 and, respectively, the first 120 and the second 122 main walls of the receptacle 102.

[0082] Next, the tapered end 139 of the movable part 108 is interposed between the two inner wedges 104, 106, 204, and said movable part is moved along the axis 130, towards the bottom 128 of the receptacle. When the faces 138 of the movable part come into contact with the inner faces 136 of the inner wedges 104, 106, 204, the movement of the movable part pushes said inner wedges 104, 106, 204 in the direction, respectively, of the first 120 and the second 122 main walls of the receptacle 102.

[0083] In parallel, the outer wedges 110, 112 are brought closer along Y to the receptacle 102 so that the pressure faces 140, 142 come into contact, respectively, with the first 120 and the second 122 main walls.

[0084] In the embodiment of [Fig.3], each of the first 120 and second 122 main walls of the receptacle 102 is thus compressed along Y between the pressure face 140, 142 of an outer wedge 110, 112 and the outer face 132, 134 of an inner wedge 104, 106. Similarly, in the embodiment of [Fig.4], each of the first 120 and second 122 main walls of the receptacle 102 is compressed between the pressure face 140, 142 of an outer wedge 110, 112 and the first face of one of the inserts 214, 216.

[0085] The grooved shape of said faces, previously described, leads by stamping to deform the first 120 and second 122 main walls, so as to form the grooves 42, 44 previously described.

[0086] The outer wedges 110, 112 are then moved apart along Y from the receptacle 102 and the moving part is moved along the axis 130 in the opposite direction to that of the bottom 128. The inner wedges 104, 106, 204 are thus moved apart from the main walls 120, 122. In the embodiment of [Fig.4], each insert 214, 216 remains fixed inside the corresponding main wall 120, 122.

[0087] The inner wedges 104, 106, 204 are then extracted from the receptacle 102 through the opening 127. The receptacle 102 in the final state is thus obtained, ready to form the housing 20 by adding the cover (not shown) to close the opening 127.

[0088] The process described above makes it easy to obtain the grooved shape of the main faces 30, 32 of the housing 20, as described previously.

Claims

Demands

1. Electric battery cell (12, 14, 16), comprising a cell housing (20), said housing comprising: a first (30) and a second (32) principal faces, substantially parallel and opposite to each other; and an upper face (38), substantially perpendicular to the first and second principal faces; the first and second principal faces of the housing comprising respectively a first (34) and a second (36) principal edges, substantially straight and parallel, said first and second principal edges defining the upper face; a housing axis (40) being perpendicular to the upper face of said housing; the first principal face (30) comprising a first series of grooves (42), substantially straight and parallel to each other, extending from the first principal edge (34);the second main face (32) comprising a second series of grooves (44), substantially straight and parallel to each other, extending from the second main edge (36); characterized in that the grooves (42, 44) of the first and second series form respectively a first (a) and a second (|3) angle with the axis (40) of the housing, each of the first and second angles being strictly greater than 0° and strictly less than 90°.;

2. Battery cell according to claim 1, wherein each of the first (a) and second (|3) angles is between 1° and 89°, preferably between 1° and 60°, more preferably between 5° and 30°.

3. Battery cell according to any one of claims 1 or 2, wherein the first series of grooves (42) forms a third non-zero angle (y) with the second series of grooves (44), the third angle (y) preferably being between 2° and 178°.

4. Battery cell according to claim 3, wherein, in projection into a plane substantially parallel to the first (30) and second (32) principal faces, the grooves (42, 44) of the first and second series are inclined opposite to each other with respect to the axis (40) of the case.

5. Battery device (10), comprising: a plurality of battery cells (12, 14, 16); and a cooling circuit (18); the plurality of cells being arranged in the form of at least one row (50), the row or rows extending along a stacking axis (52); at least one first cell (12) of the plurality of battery cells being, according to any one of claims 1 to 4, the first (30) and second (32) principal faces of the casing (20) of said first cell being arranged perpendicular to the stacking axis (52) of the corresponding row; the cooling circuit (18) being capable of circulating a coolant in contact with the first and second principal faces of the casing of said first cell.

6. Battery device according to claim 5, wherein: at least a second cell (14, 16) of the plurality of battery cells is according to any one of claims 1 to 4; and the first (12) and second cells are adjacent in the same row (50).

7. Battery device according to claim 6, wherein the first principal faces (30) of the first (12) and second (14) cells are opposite each other.

8. Battery device according to claim 6, wherein the first main face (30) of the first cell (12) is opposite the second main face (32) of the second cell (14).

9. A method for manufacturing a battery cell according to any one of claims 1 to 4, comprising the following steps: - providing a receptacle (102) comprising a first (120) and a second (122) main walls, intended to form respectively the first (30) and the second (32) main faces of the casing (20); said first and second main walls of the receptacle comprising respectively a first (124) and a second (126) main edges, defining an opening (127) of the receptacle; the receptacle extending along a receptacle axis (130), substantially perpendicular to said opening; - introducing into the opening a first and a second internal elements (104, 106, 204, 214, 216), each of the first and second internal elements comprising: a grooved external surface; and an internal face (136), inclined with respect to the axis (130) of the receptacle; - insertion into the opening of a movable part (108) comprising two inclined faces (138); then displacement of the movable part along the axis (130) of the receptacle so that each inclined face (138) slides along the inner face (136) of the first or second inner element (104, 106, 204), to bring said inner element closer to the corresponding main wall; and - application, on each of the first (120) and second (122) main walls, of a grooved surface (140, 142) of an outer wedge (110, 112); so that a compression of each of the first (120) and second (122) main walls, between the grooved external surface of one of the internal elements (104, 106, 204, 214, 216) and the grooved surface (140, 142) of one of the external wedges (110, 112) leads by stamping to the formation of the grooves (42, 44) of the first (30) and second (32) main faces of the case.

10. A manufacturing method according to claim 9, wherein: - each inner element comprises an inner wedge (204) and an insert (214, 216), the inner face (136) and the grooved outer face being carried respectively by said inner wedge and by said insert; and - during the stamping step, the insert (214, 216) of each inner element is secured to the first (120) or the second (122) main wall of the receptacle (102).

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