Method for manufacturing an electrochemical cell interconnection device, interconnection device and associated electrical assembly

Abstract

Method for manufacturing an electrochemical cell interconnection device, interconnection device and associated electrical assembly. The invention relates to a method for manufacturing an electrochemical cell interconnection device (10), comprising the following steps: - providing a substantially flat initial part, comprising: two tabs (30, 32), arranged along two parallel axes; and a connecting portion disposed between said tabs and having a C-shape delimited by an inner edge and an outer edge; such that, between the tabs, a distance between the outer edge and the inner edge is within an interval [dmin; dmax] such that a ratio dmax / dmin is less than or equal to 1.5; then - forming a straight fold (24) on the connecting portion, so as to obtain a parallel upper layer (20) and lower layer (22), the upper layer including the tabs (30, 32). Figure for the abstract: Figure 1

Description

Title of the invention: Method for manufacturing an electrochemical cell interconnection device, interconnection device and associated electrical assembly

[0001] The present invention relates to a method for manufacturing a device for interconnecting electrochemical cells.

[0002] The invention is particularly applicable to the manufacture of batteries for electric or hybrid vehicles.

[0003] An electrochemical cell comprises an electrolyte contained in a closed external housing, generally of substantially parallelepiped shape. The electrochemical cell generally comprises terminals in contact with the electrolyte and fixed to the outside of the housing.

[0004] For example, the electrochemical cell comprises a stack of positive electrodes connected to each other and a stack of negative electrodes connected to each other, separated by a separator. Such an assembly, known as a "stack", is received in the housing.

[0005] It is known to assemble, in series and / or in parallel, a plurality of electrochemical cells in order to produce electrical modules, using an interconnection device ensuring electrical contact between the terminals of two neighboring cells.

[0006] The interconnection devices used include metal parts welded to the terminals to ensure optimal electrical contact. Such interconnection devices are described in particular in document WO2023126400, on behalf of the Applicant.

[0007] Conventionally, electrochemical cells are arranged in at least one row and electrically connected to their immediate neighbors in that row. To arrange the electrical input and output at the same end of the row, a return busbar is therefore necessary along the row. Such a configuration increases the overall size and the risk of poor electrical transmission.

[0008] Moreover, in such an arrangement, the overheating of one of the cells disrupts the operation of its immediate neighbors, which compromises the efficiency of the electric battery.

[0009] In order to solve these problems, the invention relates to a method for manufacturing an interconnection device of the aforementioned type, comprising the following steps: supplying a substantially flat initial part, said initial part comprising: a first and a second leg, arranged respectively along a first and a second axis, substantially parallel; and a connecting portion, adjacent to the first and second legs and arranged between said first and second legs, said connecting portion having a C-shape delimited by an inner edge and an outer edge; the connecting portion being configured so that, between the first and second legs, a distance between the outer edge and the inner edge is within an interval [dmin; dmax] such that a ratio dmax / dmin is less than or equal to 1.5; then forming a substantially straight fold on the connecting portion of the initial part, said fold being substantially perpendicular to the first and second axes, so as to obtain a top layer and a bottom layer substantially parallel, the top layer including the first and second legs.

[0010] An interconnection device thus obtained makes it possible in particular to electrically connect electrochemical cells spaced apart in their row, without increasing the overall size.

[0011] According to other advantageous aspects of the invention, the method comprises one or more of the following features, taken individually or in all technically possible combinations:

[0012] - the fold is positioned away from the inner edge of the connecting portion;

[0013] - the fold is configured so that part of an edge of the lower layer is positioned opposite the inner edge of the connecting portion;

[0014] - each of the internal and external edges of the connecting portion of the initial part comprises several roughly straight segments, arranged successively between the first and second legs.

[0015] The invention further relates to an electrochemical cell interconnection device, comprising: a first and a second assembly zone; and a linking zone, disposed between said first and second assembly zones and electrically connecting said assembly zones; each of said first and second assembly zones being able to assemble to an electrical terminal (82, 84) of electrochemical cell; the interconnection device being produced by a manufacturing process as described above, the first and second assembly zones comprising respectively the first and second legs, the linking zone comprising the folded linking portion.

[0016] According to an advantageous aspect of the invention, the first and second assembly zones comprise respectively a first and a second substantially flat assembly surfaces, each of said assembly surfaces being suitable for assembly to an electrical terminal of an electrochemical cell; the first and second assembly surfaces being substantially coplanar and carried respectively by the first and by the second lugs.

[0017] The invention further relates to an electrical assembly comprising: a first, a second and a third electric battery cell, each of said cells comprising a housing and at least one first terminal, each housing comprising an upper face carrying said first terminal; the first terminals of the first, second and third cells being aligned along a third axis, the third cell being disposed between the first and second cells along said third axis; and a first interconnection device as described above, the first and second assembly areas of the first interconnection device being assembled to the first terminal, respectively, of the first and second electrochemical cells.

[0018] According to other advantageous aspects of the invention, the electrical assembly comprises one or more of the following features, taken individually or in all technically possible combinations:

[0019] - the electrical assembly further comprises: a fourth battery cell electrical, comprising a housing and at least one first terminal, the housing comprising a top face bearing said first terminal; the first terminal of the fourth cell being disposed on the third axis, the second cell being disposed between the third and fourth cells along said third axis; and a second interconnection device as described above, the first and second assembly zones of the second interconnection device being assembled to the first terminal, respectively, of the fourth and third electrochemical cells; the linking zones of the first and second interconnection devices being disposed on either side of the third axis;

[0020] - each of the first, second and third cells further comprises a second terminal carried by the upper face of the corresponding housing, said second terminals being aligned along a fourth axis, parallel to the third axis; the electrical assembly further comprises a fifth electric battery cell, said fifth cell comprising a housing and a first and a second terminal, the housing comprising an upper face carrying said first and second terminals; the first and second terminals of the fifth cell being arranged respectively on the third axis and on the fourth axis, the first cell being arranged between the fifth cell and the third cell along said third and fourth axes;and the electrical assembly further comprises a third interconnection device as described above, the first and second assembly zones of the third interconnection device being assembled to the second terminal, respectively, of the fifth and third electrochemical cells;

[0021] - the electrical assembly further comprises a terminal interconnection device, electrically connecting the second terminals of the second and fourth electrochemical cells;

[0022] - the electrical assembly includes an enclosure receiving the cells electrochemicals and the first interconnection device;

[0023] - the electrical assembly further comprises at least one separator arranged between two of the electrochemical cells along the third axis.

[0024] 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:

[0025] [Fig-1] [Fig.1] is a perspective view of an interconnection device according to a method of implementing the invention;

[0026] [Fig.2] [Fig.2] is a view of intermediate manufacturing steps of interconnection devices according to embodiments of the invention;

[0027] [Fig. 3] [Fig. 3] is a partial view of an electrical assembly comprising the interconnection device of [Fig. 1]; and

[0028] [Fig.4] [Fig.4] is a cross-sectional view of the electrical assembly of [Fig.3].

[0029] Fig. 1 shows an interconnection device 10 according to an embodiment of the invention.

[0030] As will be detailed later, the interconnection device 10 is intended to electrically connect two electrical terminals of electrochemical cells. To this end, the interconnection device 10 comprises: a first 12 and a second 14 assembly zones, each of said assembly zones being intended to be assembled to an electrical terminal; and a linking zone 16, disposed between said first 12 and second 14 assembly zones and electrically connecting said assembly zones.

[0031] More specifically, the device 10 comprises an upper layer 20 and a lower layer 22, arranged opposite each other. These layers 20 and 22 are substantially flat and parallel to each other. The device 10 further comprises a fold 24 connecting the upper layer 20 and the lower layer 22.

[0032] The upper layer 20 has an upper face 25 and a lower face 26, oriented respectively opposite to and towards the lower layer 22.

[0033] As detailed below, the upper layer 20 and lower layer 22 are considered to be thin layers. More precisely, a thickness 28 of each of said layers is less than or equal to 5% of a maximum dimension of the device 10 in a plane parallel to the upper layer 20 and lower layer 22.

[0034] The upper layer 20 of the device 10 comprises a first 30 and a second 32 legs, arranged respectively along a first 34 and a second 35 axes substantially parallel. The first 34 and second 35 axes are separated by an interaxial distance of 36 ([Fig.3]).

[0035] In the embodiment shown, each of the first 30 and second 32 legs comprises: an inner lateral edge 37 and an outer lateral edge 38, substantially parallel to the first 34 and second 35 axes; and a terminal edge 39, substantially perpendicular to the first 34 and second 35 axes. The inner lateral edges 37 of the first 30 and second 32 legs are opposite each other.

[0036] At the lower face 26, the upper layer 20 of the device 10 comprises a first 40 and a second 42 assembly surfaces, substantially coplanar, supported respectively by the first 30 and the second 32 tabs. Each of the first 40 and second 42 assembly surfaces is delimited by the lateral edges 37, 38 and the terminal edge 39 of the corresponding tab 30, 32.

[0037] The upper layer 20 further comprises an internal connecting edge 44, linking the internal lateral edges 37 of the first 30 and second 32 legs. The internal connecting edge 44 has a concave shape between said internal lateral edges 37.

[0038] The fold 24 extends substantially in a straight line along a fold axis 46, substantially perpendicular to the first 34 and second 35 axes. The fold 24 is positioned away from the first 30 and second 32 tabs. Preferably, the fold 24 is also positioned away from the inner connecting edge 44.

[0039] The fold extends between a first 48 and a second 50 extremities, respectively close to the first 30 and the second 32 legs.

[0040] The upper layer 20 further comprises a first 52 and a second 54 external connecting edges. The first external connecting edge 52 connects the external lateral edge 38 of the first leg 30 and the first end 48 of the fold 24. The second external connecting edge 54 connects the external lateral edge 38 of the second leg 32 and the second end 50 of the fold 24.

[0041] The lower layer 22 of the device 10 is defined by the fold 24 and by a straight edge 56. Preferably, a projection of the lower layer 22 onto the upper layer 20 is entirely included in said upper layer 20. More preferably, a part 58 of the straight edge 56 is substantially opposite the internal bonding edge 44 of the upper layer 20.

[0042] Preferably, as in the embodiment shown, the device 10 has a plane of symmetry, perpendicular to the fold axis 46. The first 30 and second 32 legs are symmetrical to each other with respect to said plane of symmetry.

[0043] Figure 2 represents an initial part 60 according to a first embodiment. This initial part 60 enables the manufacture of the device 10 as described later. Figure [Fig. 2] further represents an initial part 160 according to a second embodiment, allowing the manufacture of a variant of the device 10.

[0044] The initial parts 60, 160 will be described simultaneously below, the common elements being designated by the same reference numbers.

[0045] The initial part 60, 160 is substantially flat and has an upper face (not shown) and a lower face 62, 162.

[0046] Preferably, the initial part 60, 160 is formed as a single piece, for example by cutting a flat metal plate. The metal plate is, for example, made of aluminum.

[0047] The initial part 60, 160 comprises: the first 30 and second 32 legs, previously described for the device 10; and a connecting portion 64, 164.

[0048] The connecting portion 64, 164 is adjacent to the first 30 and second 32 legs and is located between said first and second legs. Said connecting portion has a C-shaped form, delimited by an initial inner edge 66, 166 and an initial outer edge 68, 168. The initial inner edge 66, 166 has a generally concave shape, the initial outer edge 68, 168 has a generally convex shape.

[0049] The initial inner edge 66, 166 extends between two extremities, opening onto the inner lateral edge 37, respectively of the first 30 and the second 32 legs. The initial outer edge 68, 168 extends between two extremities, opening onto the outer lateral edge 38, respectively of the first 30 and the second 32 legs.

[0050] The link portion 64, 164 is configured to present a substantially constant electrical current passage section between the first 30 and second 32 pins.

[0051] More specifically, the link portion 64, 164 is configured so that, between the first 30 and second 32 legs, a distance dh d2, d3 between the initial inner edge 66, 166 and the initial outer edge 68, 168 is within an interval [dmin ; dmax] such that a ratio dmax / dmin is less than or equal to 1.5.

[0052] By "distance between the initial inner edge and the initial outer edge", we mean: a minimum distance with the initial outer edge 68, 168 for a given point of the initial inner edge 66, 166; and / or a minimum distance with the initial inner edge 66, 166 for a given point of the initial outer edge 68, 168.

[0053] Preferably, the ratio dmax / dmin is less than or equal to 1.3; more preferably, the ratio dmax / dmin is less than or equal to 1.2.

[0054] Preferably, as in the embodiments shown, the initial part 60, 160 has a plane of symmetry 70, 170, the first 30 and second 32 legs being symmetrical to each other with respect to said plane of symmetry.

[0055] According to the first embodiment, each of the initial internal edge 66 and initial external edge 68 of the connecting portion 64 of the initial part 60 comprises several segments 72, 73, 74, 75 are substantially straight. These segments are arranged successively between the first 30 and second 32 legs.

[0056] More specifically, in the embodiment shown, the initial inner edge 66 comprises a central inner segment 72 and two oblique inner segments 73. The central inner segment 72 is perpendicular to the first 34 and second 35 axes and is crossed at its midpoint by the plane of symmetry 70. Each of the oblique inner segments 73 is located between the central inner segment 72 and the inner lateral edge 37 of one of the first 30 and second 32 legs. Each of the oblique inner segments 73 is inclined with respect to the first 34 and second 35 axes at an angle strictly greater than 0° and strictly less than 90°. For example, said angle is on the order of 45°.

[0057] Furthermore, in the embodiment shown, the initial outer edge 68 comprises a central outer segment 74 and two oblique outer segments 75. The central outer segment 74 is perpendicular to the first 34 and second 35 axes and is crossed at its midpoint by the plane of symmetry 70. Each of the oblique outer segments 75 is positioned between the central outer segment 74 and the outer lateral edge 38 of one of the first 30 and second 32 legs. Each of the oblique outer segments 75 is inclined with respect to the first 34 and second 35 axes at an angle strictly greater than 0° and strictly less than 90°. For example, said angle is on the order of 45°.

[0058] In an alternative not shown, each of the initial internal and external edges comprises a larger number of oblique segments, exhibiting different inclinations with respect to the first and second axes.

[0059] In the embodiment shown, a first intersection 76, between the central internal segment 72 and one of the oblique internal segments 73, and a second intersection 77, between the central external segment 74 and one of the oblique external segments 75, are separated by a first distance dh. Said first distance dh is greater than a second minimum distance d2 between the central internal segment 72 and external segment 74 and a third minimum distance d3 between neighboring oblique internal segment 73 and external segment 75. As indicated previously, the distances dh, d2, d3 are within the interval [dmin; dmax] such that a ratio dmax / dmin is less than or equal to 1.5.

[0060] According to the second embodiment, each of the initial internal edge 166 and initial external edge 168 of the connecting portion 164 of the initial part 160 has a curved shape.

[0061] A method for manufacturing the device 10 from the initial part 60 will now be described.

[0062] The fold 24 is formed in the connecting portion 64 of the initial part 60, along the fold axis 46 perpendicular to the first 34 and second 35 axes. More precisely, the lower face 62 of the initial part 60 is folded back on itself along the fold axis 46.

[0063] Preferably, the fold axis 46 is disposed away from the initial inner edge 66 and crosses each of the oblique external segments 75 of the initial outer edge 68. More preferably, the fold axis 46 is disposed substantially equidistant from the central inner segment 72 and the central outer segment 74.

[0064] The upper 20 and lower 22 layers of the device 10 are thus formed. The internal bonding edge 44 of the upper layer 20 corresponds to the initial internal edge 66 of the initial part 60. The central outer segment 74 and the adjacent parts of the oblique outer segments 75 form the sharp edge 56 of the lower layer 22. The remaining parts of the oblique outer segments 75 form the first 52 and second 54 external bonding edges of the upper layer 20.

[0065] In the embodiment shown, the interconnection device 10 is thus directly obtained. The first 30 and second 32 pins form respectively the first 12 and second 14 assembly zones; and the folded connecting portion 64 forms the connecting zone 16.

[0066] In an alternative not shown, in addition to the making of the fold 24 in the connecting portion 64, the initial part 60 undergoes further modifications to lead to the device 10. For example, a clipping device (not shown) is adapted to the edges 37, 38, 39 of the first 30 and second 32 tabs for a clipping assembly with electrical terminals.

[0067] An interconnection device similar to the device 10 is also obtained by the folding process described above, adapted to the initial part 160, the fold being made around a fold axis 146.

[0068] The folding of the connecting portion 64, 164 makes it possible to reduce the bulk of the device 10 in the direction of the first 34 and second 35 axes, while maintaining a substantially constant section between the first 30 and second 32 legs for the passage of the electric current.

[0069] Figures 3 and 4 show an electrical assembly 200 according to an embodiment of the invention.

[0070] The electrical assembly 200 comprises: a plurality of electrochemical cells 201, 202, 203, 204, 205, 206; and a plurality of interconnecting devices 10, 210, 211, 212. In the embodiment shown, the electrical assembly 200 further comprises: a terminal interconnecting device 214; an enclosure 216, not shown in [Fig. 3]; and a plurality of separators 218.

[0071] The electrochemical cells 201, 202, 203, 204, 205, 206 of the electrical assembly 200 are considered to be substantially identical. The number of cells in the assembly 200 is, for example, between four and two hundred.

[0072] A first cell 201 will be described below under the name "cell 201", said description applying to the other cells 202, 203, 204, 205, 206 of the assembly 200.

[0073] The cell 201 comprises: a housing 80; and a first 82 and a second 84 electrical terminals. The housing includes an upper face 86 bearing said first 82 and second 84 terminals.

[0074] In the embodiment shown, the housing 80 is substantially parallelepiped-shaped, the upper face 86 having a rectangular shape.

[0075] The housing 80 further comprises two principal faces 88, substantially parallel and opposite to each other, extending from the upper face 86. The principal faces 88 present the largest surfaces of the faces of the housing 80.

[0076] We consider an orthonormal basis (X, Y, Z) associated with the case 80. The upper face 86 extends in a plane (X, Y) and the principal faces 88 extend in planes (X, Z).

[0077] Each of the first 82 and second 84 electrical terminals of the cell 201 is arranged on the upper face 86 of the housing 20. The first 82 and second 84 electrical terminals are preferably aligned parallel to X.

[0078] Each terminal 82, 84 has a connection surface 90, substantially flat and parallel to the upper face 86 of the housing. In the embodiment shown, each connection surface 90 has a substantially rectangular outline. Alternatively, the outline of one or each of the connection surfaces has a different shape, for example, circular.

[0079] The cells 201, 202, 203, 204, 205, 206 of the assembly 200 are arranged in one or more rows, each row extending along a stacking axis parallel to Y. In the embodiment shown, the cells 201, 202, 203, 204, 205, 206 of the assembly 200 are arranged in a single row.

[0080] The first 82 and the second 84 electrical terminals of the cells 201, 202, 203, 204, 205, 206 of the assembly 200 are aligned, respectively along a first 222 and along a second 224 connection axes, parallel to Y.

[0081] The electrical assembly 200 comprises in particular the first cell 201 as well as a second 202, a third 203 and a fourth 204 cell. In the example shown, the fourth cell 204 is arranged at one end along Y of the row formed by said cells.

[0082] According to the Y direction, the third cell 203 is arranged between the first 201 and second 202 cells; and the second cell 202 is arranged between the third 203 and fourth 204 cells.

[0083] Preferably, the electrical assembly 200 further comprises at least a fifth 205 and a sixth 206 cells, the fifth cell 205 being arranged along Y between the first 201 and the sixth 206 cells.

[0084] A first interconnection device 10 of the assembly 200 corresponds to the device 10 of [Fig. 1] previously described. In the embodiment shown, the assembly 200 further comprises a second 210, a third 211 and a fourth 212 interconnection devices, considered to be identical to the device 10 of [Fig. 1].

[0085] The first 12 and second 14 assembly zones of the first interconnecting device 10 are assembled to the first terminal 82 of the first 201 and second 202 electrochemical cells, respectively. The linking zone 16 of the first device 10 is positioned opposite the upper face 86 of the housing 80 of the third cell 203 and bypasses the first terminal 82 of said third cell 203.

[0086] In particular, the inner edge 44 of the upper layer 20 of the first device 10 bypasses the first terminal 82 of said third cell 203; and the lower layer 22 of said first device 10 is in contact with or near the upper face 86 of the housing 80 of said third cell 203.

[0087] The interaxial distance 36 of the first device 10 and the dimension along Y of the upper faces 86 of the housings are chosen to allow such a configuration of the assembly 200. The thin lower layer 22 fits into the space provided along Z by the first terminals 82 in contact with the corresponding upper layer 20.

[0088] In the embodiment shown, the first 40 and second 42 assembly surfaces of the first device 10 are in contact with the connection surface 90 of the first terminal 82, respectively of the first 201 and the second 202 electrochemical cells.

[0089] In particular, in the embodiment shown, each of the first 40 and second 42 mounting surfaces of the first device 10 is fixed to the corresponding connection surface 90 of the first terminal 82, preferably by welding, or alternatively by clipping. Preferably, the edges 37, 38, 39 of each tab 30, 32 substantially follow the contour of the corresponding connection surface 90.

[0090] In an alternative not shown, the first 12 and second 14 assembly zones are assembled to the corresponding first terminals 82 by clipping or by another means of fastening.

[0091] Furthermore, the first 12 and second 14 assembly zones of the second interconnecting device 210 are assembled to the first terminal 82 of the fourth 204 and third 203 electrochemical cells, respectively. The linking zone 16 of the second device 210 is positioned opposite the upper face 86 of the housing 80 of the second cell 202 and bypasses the first terminal 82 of said second cell 202. The linking zones 16 of the first 10 and second 210 interconnecting devices are positioned on either side of the first connecting axis 222.

[0092] The assembly of the second interconnecting device 210 and the fourth 204 and third 203 cells is similar to the assembly of the first interconnecting device 10 and the first 201 and second 202 cells described above.

[0093] Furthermore, the first 12 and second 14 assembly zones of the third interconnecting device 211 are assembled to the second terminal 84 of the fifth 205 and third 203 electrochemical cells, respectively. The linking zone 16 of the third interconnecting device 211 is positioned opposite the upper face 86 of the housing 80 of the first cell 201 and bypasses the second terminal 84 of said first cell 201.

[0094] The assembly of the third interconnecting device 211 and the fifth 205 and third 203 cells is similar to the assembly of the first interconnecting device 10 and the first 201 and second 202 cells described above.

[0095] Furthermore, the first 12 and second 14 assembly zones of the fourth interconnecting device 212 are assembled to the second terminal 84 of the first 201 and sixth 206 electrochemical cells, respectively. The linking zone 16 of the fourth interconnecting device 212 is positioned opposite the upper face 86 of the housing 80 of the fifth cell 205 and bypasses the second terminal 84 of said fifth cell 205. The linking zones 16 of the third 211 and fourth 212 interconnecting devices are positioned on either side of the second connecting axis 224.

[0096] Each of the interconnection devices 10, 210, 211, 212 has a small footprint along X due to the fold 24, and a small thickness along Z due to the thinness of the upper 20 and lower 22 layers. The compactness of the assembly 200 is thus improved.

[0097] The terminal interconnection device 214 electrically connects the second terminals 84 of the second 202 and fourth 204 electrochemical cells.

[0098] In the embodiment shown, the terminal interconnection device 214 has a C-shaped form, analogous to the first 10, second 210, third 211 and fourth 212 interconnection devices described previously. In particular, the terminal device 214 has two pins 230, 232 analogous to pins 30, 32 previously described. However, the interaxial distance between said two legs 230, 232 is adapted to the connection of two immediately adjacent cells.

[0099] In an alternative not shown, the terminal interconnection device 214 is replaced by another interconnection device capable of linking two adjacent cells, as described for example in the previously cited document WO2023126400.

[0100] Thus, in assembly 200, the electrochemical cells are arranged in series according to the following sequence: sixth cell 206; first cell 201; second cell 202; fourth cell 204; third cell 203; fifth cell 205.

[0101] In the present description, the first 82 and second 84 terminals of each cell are designated along the connection axis 222, 224 along which they are aligned. However, in order to achieve the series arrangement described above, the positioning of each electrochemical cell 201, 202, 203, 204, 205, 206 is chosen such that each of the said first 82 and second 84 terminals has the appropriate positive or negative polarity. For example, if the first 82 terminals of the first 201 and fourth 204 cells are positive, the first 82 terminals of the second 202 and third 203 cells are negative.

[0102] Such a positioning of the electrochemical cells is chosen differently in a variant (not shown) of the assembly 200, in which at least some of said cells are arranged in parallel.

[0103] The enclosure 216 receives the plurality of electrochemical cells 201, 202, 203, 204, 205, 206 of the assembly 200, arranged as described above. Preferably, the enclosure 216 has a substantially parallelepiped shape. According to one embodiment (not shown), the enclosure 216 further contains a cooling liquid that immerses the housings 80 of the electrochemical cells.

[0104] In assembly 200, due to the configuration of the series arrangement described above, the electrical input and output can be provided on the same side along Y (not shown) of the enclosure 216, opposite the fourth cell 204. It is therefore not necessary to equip assembly 200 with a bulky return busbar.

[0105] Each of the plurality of separators 218 comprises a sheet 226 of solid material, disposed between the main faces 88 opposite the housings 80 of two adjacent electrochemical cells. Said solid material is, for example, a thermal insulator.

[0106] In the embodiment shown, each separator 218 further comprises a first 227 and a second 228 lugs, aligned respectively with the first 82 and with the second 84 terminals of the electrochemical cells.

[0107] The electrical assembly 200 is considered to operate as an electric battery. If an electrochemical cell, such as the first cell 201, becomes overheated, the heat is preferentially transferred to the cells directly adjacent, that is to say the third cell 203 and the fifth cell 205. However, these cells are not the direct neighbors of the first cell 201 in the serial arrangement described above.

[0108] The operation of the battery is therefore less affected than in the prior art, in which several electrically directly connected cells are likely to overheat at the same time.

[0109] As previously stated, another advantage of the electrical assembly 200 is to implement connection devices 10 combining a good current passage cross-section with a small space footprint.

Claims

Demands

1. A method for manufacturing a device (10) for interconnecting electrochemical cells, the method comprising the following steps: - providing a substantially planar initial part (60, 160), said initial part comprising: a first (30) and a second (32) tabs, arranged respectively along a first (34) and a second (35) axis, substantially parallel; and a connecting portion (64, 164), adjacent to the first and second tabs and disposed between said first and second tabs, said connecting portion having a C-shape delimited by an inner edge (66, 166) and an outer edge (68, 168); the connecting portion being configured such that, between the first and second tabs, a distance (db d2, d3, d4) between the outer edge and the inner edge is within an interval [dmin; dmax] such that a ratio dmax / dmin is less than or equal to 1.5;then - formation of a substantially straight fold (24) on the connecting portion (64, 164) of the initial part, said fold being substantially perpendicular to the first and second axes, so as to obtain a substantially parallel upper layer (20) and lower layer (22), the upper layer including the first (30) and second (32) legs.;

2. A manufacturing method according to claim 1, wherein the fold (24) is disposed away from the inner edge (66, 166) of the connecting portion.

3. A manufacturing method according to claim 2, wherein the ply (24) is configured so that a portion (58) of an edge (56) of the lower layer (22) is arranged opposite the inner edge (44, 66) of the bonding portion.

4. A manufacturing method according to any one of the preceding claims, wherein each of the inner (66, 166) and outer (68, 168) edges of the connecting portion of the initial part comprises several substantially straight segments (72, 73, 74, 75), arranged successively between the first (30) and second (32) lugs.

5. Device (10, 210, 211, 212) for interconnecting electrochemical cells, comprising: a first (12) and a second (14) assembly zones; and a bonding zone (16), arranged between said first and second assembly zones and electrically connecting said assembly zones; each of said first and second assembly zones being able to assemble to an electrical terminal (82, 84) of electrochemical cell; the interconnection device being produced by a manufacturing process according to one of the preceding claims, the first (12) and second (14) assembly zones comprising respectively the first (30) and second (32) lugs, the linking zone (16) comprising the folded linking portion (64).

6. Interconnection device according to claim 5, wherein the first (12) and second (14) assembly areas comprise respectively a first (40) and a second (42) substantially planar assembly surfaces, each of said assembly surfaces being able to assemble to an electrical terminal (82, 84) of an electrochemical cell; the first and second assembly surfaces being substantially coplanar and carried respectively by the first (30) and by the second (32) legs.

7. Electrical assembly (200) comprising: - a first (201), a second (202) and a third (203) electric battery cells, each of said cells comprising a housing (80) and at least one first terminal (82), each housing comprising an upper face (86) carrying said first terminal; the first terminals (82) of the first, second and third cells being aligned along a third axis (222), the third cell (203) being disposed between the first and second cells along said third axis; and - a first interconnection device (10) according to claim 5 or 6, the first (12) and second (14) assembly areas of the first interconnection device being assembled to the first terminal (82), respectively, of the first (201) and second (202) electrochemical cells.

8. An electrical assembly according to claim 7, further comprising: - a fourth electric battery cell (204), comprising a housing (80) and at least one first terminal (82), the housing comprising an upper face (86) carrying said first terminal; the first terminal (82) of the fourth cell (204) being disposed on the third axis (222), the second cell (202) being disposed between the third (203) and fourth (204) cells along said third axis; and - a second interconnection device (210) according to claim 5 or 6, the first (12) and second (14) assembly zones of the second interconnection device being assembled to the first terminal, respectively, of the fourth (204) and third (203) electrochemical cells; the bonding zones (16) of the first (10) and second (210) interconnection devices being arranged on either side of the third axis (222).

9. Electrical assembly according to any one of claims 7 or 8, wherein: - each of the first (201), second (202) and third (203) cells further comprises a second terminal (84) carried by the upper face (86) of the corresponding housing, said second terminals being aligned along a fourth axis (224), parallel to the third axis; - the electrical assembly further comprises a fifth electric battery cell (205), said fifth cell comprising a housing (80) and a first (82) and a second (84) terminal, the housing comprising an upper face (86) carrying said first and second terminals; the first (82) and second (84) terminals of the fifth cell being arranged respectively on the third axis (222) and on the fourth axis (224), the first cell (201) being arranged between the fifth cell (205) and the third cell (203) according to the said third axis and fourth axes;and - the electrical assembly further comprises a third interconnection device (211) according to claim 5 or 6, the first (12) and second (14) assembly areas of the third interconnection device (211) being assembled to the second terminal (84), respectively of the fifth (205) and third (203) electrochemical cells.;

10. Electrical assembly according to claim 9 taken in combination with claim 8, further comprising a terminal interconnection device (214), electrically linking the second terminals (84) of the second (202) and fourth (204) electrochemical cells.

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