Battery module

Abstract

Battery Module The present invention relates to a battery module comprising: at least one electrochemical cell (12), each electrochemical cell (12) comprising an outer casing (18) defining a bottom (28) extending in a plane perpendicular (XY) to an elevation direction (Z); each bottom (28) comprising at least one through-hole (38) and at least one boss (40), and a cooling plate comprising an upper face and a lower face opposite each other along the elevation direction (Z), the upper face of the cooling plate being arranged opposite the bottom (28) of the outer casing (18) of each electrochemical cell (12). Figure for the abstract: Figure 2

Description

Title of the invention: Battery module

[0001] The present invention relates to a battery module comprising at least one electrochemical cell and a cooling plate.

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

[0003] An electrochemical cell comprises an electrolyte contained within a closed outer casing, generally of substantially parallelepiped shape. The electrochemical cell generally comprises terminals in contact with electrodes that are in contact with the electrolyte. The terminals are fixed to the outer casing, on the outside of said casing.

[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.

[0005] Such an assembly, known as a "stack", is received in the outer envelope.

[0006] Generally, a shim, known as a "bottom shim", is arranged on the base of the outer casing to support the "stack".

[0007] In particular, this wedge stiffens the outer casing to support the stack, especially during its inflation. Furthermore, this wedge raises the stack to prevent interference with the bottom of the outer casing.

[0008] However, such a wedge is not entirely satisfactory, as it generates additional costs, particularly for manufacturing and assembly.

[0009] Moreover, such a wedge limits the evacuation of gases generated inside the outer casing during the operation of the electrochemical cell.

[0010] Furthermore, it is known to assemble, in series and / or in parallel, a plurality of electrochemical cells in order to produce modules, using interconnection devices ensuring electrical contact between the terminals of two neighboring cells.

[0011] Such modules, however, generate significant heat during operation. For safety reasons, it is therefore necessary to efficiently cool each of the electrochemical cells constituting the module.

[0012] The aim of the invention is to provide a battery module that ensures sufficient cooling and satisfactory gas flow, while remaining inexpensive and space-saving.

[0013] To this end, the invention relates to a battery module comprising:

[0014] - at least one electrochemical cell, each electrochemical cell comprising an outer envelope defining a background extending in a plane perpendicular to an elevation direction; each base comprising at least one through opening and at least one boss,

[0015] - a cooling plate comprising an upper face and a face lower opposite each other along the direction of elevation, the upper face of the cooling plate being arranged opposite the bottom of the outer casing of each electrochemical cell.

[0016] According to other advantageous aspects of the invention, the battery module comprises one or more of the following features, taken individually or in any technically possible combination:

[0017] - Each base comprises at least two bosses arranged on either side of the through opening.

[0018] - Each electrochemical cell comprises a stack of electrodes received in the outer envelope and resting on a support surface of the boss(es) of the bottom of the electrochemical cell.

[0019] - The module comprises at least two connected electrochemical cells electrically between them.

[0020] - The electrochemical cells are arranged so that the or each opening through-opening of each electrochemical cell is aligned with a corresponding through-opening of each of the other cells along a longitudinal direction perpendicular to the direction of elevation.

[0021] - The electrochemical cells are arranged so that the or each boss of each electrochemical cell is aligned with a corresponding boss of each of the other cells along a longitudinal direction perpendicular to the direction of elevation.

[0022] - The upper face of the cooling plate includes at least one boss, each boss of the cooling plate extending opposite a corresponding boss among the bosses of the or one of the electrochemical cells.

[0023] - The cooling plate includes a fluid circulation conduit cooling.

[0024] - The cooling plate includes at least one through opening, each through opening of the cooling plate extending opposite a corresponding through opening among the through opening(s) of the or one of the electrochemical cells.

[0025] - The module includes a bonding layer between the cooling plate and the base of the outer envelope of each electrochemical cell.

[0026] The invention will become clearer upon reading the following description, given solely by way of non-limiting example, and made with reference to the drawings in which:

[0027] [Fig.1] [Fig.1] is a schematic perspective view of a battery module according to the invention comprising electrochemical cells;

[0028] [Fig.2] [Fig.2] is a perspective view of an external envelope of one of the electrochemical cells of the module of [Fig.1];

[0029] [Fig. 3] [Fig. 3] is a cross-sectional view of the battery module of [Fig. 1]; and

[0030] [Fig.4] [Fig.4] is a schematic top view of a cooling plate of a battery module according to the invention.

[0031] Fig. 1 is a perspective view of a battery module 10.

[0032] Module 10 is preferably intended to be assembled with other modules to form a battery pack (not shown). Such a battery pack is, for example, intended to be installed in an electric or hybrid vehicle (not shown).

[0033] The battery module 10 defines a longitudinal direction X which is for example the direction of movement of the vehicle, and a transverse direction Y perpendicular to the longitudinal direction X which is for example the transverse direction of the vehicle.

[0034] An elevation direction Z, perpendicular to the longitudinal direction X and the transverse direction Y, is also defined; it is intended, for example, to be substantially vertical when the vehicle is on a horizontal surface (not shown).

[0035] The battery module 10 comprises at least one electrochemical cell 12 and a cooling plate 14.

[0036] Preferably, the module 10 comprises at least two electrochemical cells 12, more particularly arranged side by side along the transverse direction You along the longitudinal direction X.

[0037] The electrochemical cells 12 of the module 10 are preferably mechanically joined and electrically connected to each other in parallel or in series, in particular by connection devices 15.

[0038] For example, in the embodiment of the invention illustrated in [Fig.1], the module 10 comprises four electrochemical cells 12 electrically connected in series.

[0039] Optionally, the battery module 10 also includes a bonding layer 16 arranged along the elevation direction Z between the electrochemical cell(s) 12 and the cooling plate 14.

[0040] Each electrochemical cell 12 comprises an external envelope 18 (visible in [Fig.2]) defining more particularly an internal volume 20.

[0041] For example, each electrochemical cell 12 comprises at least one stack of electrodes 22, called a "stack" in English, received in the internal volume 20.

[0042] As illustrated in [Fig.3], the stack 22, for example, has a general shape that is substantially parallelepiped-shaped.

[0043] Each electrochemical cell 12 further advantageously comprises at least one electrical terminal 24, 26, disposed outside said outer envelope 18. More specifically, each electrochemical cell 12 preferably comprises a positive terminal 24 and a negative terminal 26.

[0044] The outer casing 18 includes a bottom 28 extending in an XY plane perpendicular to the elevation direction Z and preferably also a cover 30 opposite the bottom 28 along the elevation direction Z.

[0045] The outer envelope 18 has, for example, a hollow, substantially parallelepiped shape defining the internal volume 20, which is preferably also generally substantially parallelepiped in shape.

[0046] As can be seen in [Fig.2], the outer envelope 18 comprises, for example, four side walls 32, in particular connecting the bottom 28 and the lid 30 so as to close the internal volume 20.

[0047] More particularly, the side walls 32 comprise two first side walls, each extending for example in an XZ plane, and two second side walls, each extending for example in a YZ plane.

[0048] The outer casing 18 is preferably made in one piece, for example by cutting, bending and welding a sheet, by stamping a sheet or by any other suitable sheet forming process.

[0049] For example, the outer casing 18 is made of aluminium or of a material with thermal and / or mechanical properties substantially equivalent to those of aluminium.

[0050] The bottom 28 defines for example an inner face 34 and an outer face 36 opposite along the elevation direction Z, the inner face 34 being oriented towards the inner volume 20 of the outer envelope 18.

[0051] The bottom 28 includes at least one through opening 38 and at least one boss 40.

[0052] In a particular embodiment, the bottom 28 includes at least two bosses 40 arranged on either side of the through opening 38, in particular along the longitudinal direction X.

[0053] In the particular example illustrated in [Fig.2], the bottom 28 comprises four bosses 40 and a through opening 38. The through opening 38 is, for example, substantially in the center of the bottom 28, and the two bosses 40 are arranged on each side of said through opening 38 along the longitudinal direction X.

[0054] In an unillustrated variant, the base 28 includes at least two through openings 38 arranged on either side of a boss 40, in particular along the longitudinal direction X.

[0055] Advantageously, each through opening 38 extends between the inner face 34 and the outer face 36 of the bottom 28, so as to allow a passage of gas between the inner volume 20 and the outside.

[0056] In other words, each through opening 38 defines a gas passage vent between the internal volume 20 and the outside.

[0057] The gases to be evacuated are gases generated during the operation of the electrochemical cell 12.

[0058] Each through opening 38 has, for example, a substantially ellipsoidal shape, preferably with a major axis along the longitudinal direction X, in particular between 2 cm and 15 cm.

[0059] Each through opening 38 is for example manufactured by cutting, in particular by laser cutting, the bottom 28 of the outer envelope 18.

[0060] In the particular embodiment in which the module 10 comprises a plurality of electrochemical cells 12, said electrochemical cells 12 are arranged so that the or each through-opening 38 of each electrochemical cell 12 is aligned with a corresponding through-opening 38 of each of the other electrochemical cells 12 along the longitudinal direction X.

[0061] In other words, the through openings 38 of the electrochemical cells 12 of the module 10 form at least one row extending along the longitudinal direction X.

[0062] Each boss 40 extends for example in projection towards the interior of the internal volume 20 along the elevation direction Z.

[0063] In particular, the thickness of the bottom 28, that is to say the distance measured along the elevation direction Z between its inner face 34 and its outer face 36, remains constant, and is for example between 0.3 cm and 1.5 cm.

[0064] More specifically, the height of the internal volume 20, that is to say the distance measured along the elevation direction Z between the internal face 34 of the bottom 28 and the cover 30, is lower at the level of each boss 40 than in the rest of the bottom 28.

[0065] Each boss 40 defines in particular a raised area on the inner face 34 and a hollow on the outer face 36 of the bottom 28.

[0066] More particularly, each boss 40 defines on its inner face, a bearing surface 41 parallel to the inner face 34 of the rest of the bottom 28 and at a distance from it (measured along the elevation direction Z) which is for example between 0.3 cm and 3.5 cm.

[0067] Each boss 40 is preferably manufactured by plastic deformation of the bottom 28, for example by stamping.

[0068] Advantageously, each boss 40 has a shape adapted so as to guide the generated gases towards the through opening 38, in order to facilitate their evacuation.

[0069] In the particular embodiment illustrated in [Fig.2], each boss 40 has, for example, in the XY plane, a right-angled triangle shape with rounded edges.

[0070] Alternatively, each boss 40 has, for example, an ellipsoidal shape.

[0071] As illustrated in [Fig.3], the electrode stack 22 advantageously rests on the bearing surface 41 of each boss 40, which in particular makes it possible to raise the lower corners of the electrode stack 22 and thus prevent them from touching the lower edges of the outer casing 18.

[0072] In the particular embodiment in which the module 10 comprises a plurality of electrochemical cells 12, said electrochemical cells 12 are arranged so that the or each boss 40 of each electrochemical cell 12 is aligned with a corresponding boss 40 of each of the other electrochemical cells 12 along the longitudinal direction X.

[0073] In other words, the bosses 40 of the electrochemical cells 12 of the module 10 form at least one row extending along the longitudinal direction X.

[0074] The cooling plate 14 comprises an upper face 44 and a lower face 46 opposed to each other along the elevation direction Z.

[0075] As illustrated in [Fig.3], the upper face 44 of the cooling plate 14 is arranged opposite the bottom 28 of the outer casing 18 of each electrochemical cell 12, and more particularly opposite the outer face 36 of the bottom 28.

[0076] Preferably, the upper face 44 of the cooling plate 14 includes at least one boss 48, particularly extending upwards in the elevation direction Z, i.e. in the direction of the electrochemical cells 12 in the module 10.

[0077] Advantageously, each boss 48 of the cooling plate 14 extends opposite a corresponding boss 40 of one of the electrochemical cells 12.

[0078] Each boss 48 defines in particular a raised area on the upper face 44 of the cooling plate 14, more precisely towards the bottom 28 of the outer casing 18 of the electrochemical cells 12.

[0079] More specifically, each boss 48 of the cooling plate 14 fits, for example, into the hollow formed by one of the corresponding bosses 40 of one of the electrochemical cells 12.

[0080] Each boss 48 has, for example, an ellipsoidal shape or a right-angled triangle shape with rounded corners.

[0081] In the particular embodiment in which the module 10 comprises a plurality of electrochemical cells 12, the cooling plate 14 comprises at least one boss 48 per electrochemical cell.

[0082] In the particular embodiment illustrated in [Fig.4], the cooling plate 14 comprises two rows of bosses 48. Each row of bosses 48 comprises two bosses 48 per electrochemical cell, each arranged opposite one of the corresponding bosses 40 of the associated electrochemical cell 12.

[0083] In addition, the cooling plate 14 preferably includes at least one through opening 50.

[0084] Advantageously, each through opening 50 of the cooling plate 14 extends opposite a corresponding through opening 38 of one of the electrochemical cells 12.

[0085] Advantageously, each through opening 50 extends between the upper face 44 and the lower face 46 of the cooling plate 14, so as to allow the passage of gas between the internal volume 20 of the corresponding electrochemical cell 12 and the outside.

[0086] In other words, each through opening 50 defines a vent for the evacuation of gas from the internal volume 20 of the corresponding electrochemical cell 12 to the outside.

[0087] Each through opening 50 has, for example, a shape substantially identical to that of the corresponding through opening 38 of the electrochemical cell 12.

[0088] In the particular embodiment in which the module 10 comprises a plurality of electrochemical cells 12, the cooling plate 14 comprises at least one through opening 50 per electrochemical cell.

[0089] In the particular embodiment illustrated in [Fig.4], the cooling plate 14 comprises a row of through openings 50, each through opening 50 being opposite a through opening 38 of one of the electrochemical cells 12.

[0090] The cooling plate 14 is preferably configured to facilitate the evacuation of thermal energy generated by each electrochemical cell 12 during its operation.

[0091] For this purpose, the cooling plate 14 includes, for example, a circulation conduit 52 for a cooling fluid.

[0092] More specifically, the circulation conduit 52 extends between the upper face 44 and the lower face 46 of the cooling plate 14.

[0093] For example, the cooling plate 14 is formed by two sheets fixed to each other and defining between them the circulation conduit 52.

[0094] The circulation conduit 52 includes a fluid inlet 54 and a fluid outlet (not visible on [Fig.4]) and allows a flow of cooling fluid illustrated by the arrows on [Fig.4] from the fluid inlet 54 to the fluid outlet.

[0095] Advantageously, the circulation conduit 52 passes at the level of each of the bosses 48 of the cooling plate 14, as illustrated in [Fig. 4], so that to ensure that the cooling fluid passes as close as possible to each boss 40 of the bottom 28 of the outer casing 18 of the electrochemical cells 12, and thus enhances the cooling of the electrode stack 22 resting on the boss(es) 40 of the bottom 28 of the outer casing 18 of the corresponding electrochemical cell 12.

[0096] For example, in the particular embodiment illustrated in [Fig. 4], the circulation conduit 52 divides into two sub-conduits for this purpose, each sub-conduit passing under one of the rows of bosses 48 of the cooling plate 14.

[0097] The cooling fluid circulating in the circulation conduit 52 is, for example, a mixture of glycol and demineralized water or a specific cooling oil.

[0098] The cooling plate 14 is advantageously made of metal, in particular aluminum.

[0099] As can be seen in [Fig.3], the bonding layer 16 is arranged along the elevation direction Z between the bottom 28 of the outer shell 18 of each electrochemical cell 12 and the cooling plate 14.

[0100] More particularly, the bonding layer 16 is arranged along the elevation direction Z between the outer face 36 of the bottom 28 of the outer shell 18 of each electrochemical cell 12 and the upper face 44 of the cooling plate 14.

[0101] The bonding layer 16 ensures, for example, the filling of the space between the cooling plate 14 and the bottom 28 of the outer shell 18 of each electrochemical cell 12.

[0102] Preferably, the bonding layer 16 is not arranged opposite the through openings 38, 50.

[0103] The bonding layer 16 has, for example, a thickness between 0.5 cm and 2.5 cm.

[0104] For example, the bonding layer 16 is formed with a flexible polymer exhibiting high thermal conductivity.

[0105] Alternatively, the bonding layer 16 is formed in a semi-liquid gap filler material having high thermal conductivity.

[0106] The definition of the bosses 40 in the bottom 28 of the outer envelope 18 of each electrochemical cell 12 makes it possible to define a support for the stacking of electrodes 22, without the need to arrange an additional wedge.

[0107] Thus, the number of parts constituting module 10 is reduced and its manufacturing and assembly process is simplified, which makes it possible to reduce the cost of modules 10.

[0108] Furthermore, said bosses 40 prevent interference between the stack of electrodes 22 and the lower corners of the outer casing 18. A Reinforcement to protect the corners of the electrodes is therefore no longer necessary, which further reduces costs.

[0109] In addition, the through opening(s) 38 defined in the bottom 28 of the outer envelope 18 of each electrochemical cell 12 allow passage of the gases generated during operation, in particular guided by the corresponding boss(es) 40.

[0110] Such an external envelope 18 is also very simple to manufacture, for example by forming a metal sheet, in particular by stamping, a metal sheet.

[0111] The arrangement of the cooling plate 14 under the electrochemical cells 12 ensures satisfactory cooling of each of the electrochemical cells 12 of the module 10.

[0112] Furthermore, the definition of the bosses 48 in the cooling plate 14 and their arrangement relative to the corresponding bosses 40 of the electrochemical cells 12 allows for space savings by eliminating the need for a bottom shim. This also optimizes the cooling of each electrochemical cell 12.

[0113] Furthermore, the correspondence of the through openings of the cooling plate 14 and the electrochemical cells 12 allows for optimized evacuation of the gases generated during the operation of the module 10. NOMENCLATURE

[0114] 10 - Battery module

[0115] 12 - Electrochemical cell

[0116] 14 - Cooling plate

[0117] 15 - Connection device

[0118] 16 - Bonding layer

[0119] 18 - Outer casing

[0120] 20 - Internal Volume

[0121] 22 - Electrode stack

[0122] 24 - Positive terminal

[0123] 26 - Negative terminal

[0124] 28 - Background

[0125] 30-Lid

[0126] 32 - Side wall

[0127] 34 - Inner face (of the bottom of the outer casing)

[0128] 36 - Outer face (of the bottom of the outer casing)

[0129] 38 - Through opening (from the bottom of the outer casing)

[0130] 40 - Boss (of the bottom of the outer casing)

[0131] 41 - Bearing surface

[0132]

[0133]

[0134]

[0135]

[0136]

[0137] 44 - Upper face (of the cooling plate) 46 - Lower face (of the cooling plate) 48 - Boss (of the cooling plate) 50 - Through opening (of the cooling plate) 52 - Circulation channel 54 - Fluid inlet

Claims

Demands

1. Battery module (10), comprising: a. at least one electrochemical cell (12), each electrochemical cell (12) comprising an outer casing (18) defining a bottom (28) extending in a plane perpendicular (XY) to an elevation direction (Z); each bottom (28) comprising at least one through opening (38) and at least one boss (40), b. a cooling plate (14) comprising an upper face (44) and a lower face (46) opposite each other along the elevation direction (Z), the upper face (44) of the cooling plate (14) being arranged opposite the bottom (28) of the outer casing (18) of each electrochemical cell (12).

2. Module (10) according to claim 1, wherein each bottom (28) comprises at least two bosses (40) arranged on either side of the through opening (38).

3. Module (10) according to claim 1 or 2, wherein each electrochemical cell (12) comprises a stack of electrodes (22) received in the outer envelope (18) and resting on a bearing surface (41) of the boss(es) (40) of the bottom (28) of the electrochemical cell (12).

4. Module (10) according to any one of the preceding claims, comprising at least two electrochemical cells (12) electrically connected to each other.

5. Module (10) according to claim 4, wherein the electrochemical cells (12) are arranged so that the or each through-opening (38) of each electrochemical cell (12) is aligned with a corresponding through-opening (38) of each of the other cells (12) along a longitudinal direction (X) perpendicular to the elevation direction (Z).

6. Module (10) according to claim 4 or 5, wherein the electrochemical cells (12) are arranged so that the or each boss (40) of each electrochemical cell (12) is aligned with a corresponding boss (40) of each of the other cells (12) along a longitudinal direction (X) perpendicular to the elevation direction (Z).

7. Module (10) according to any one of the preceding claims, wherein the upper face (44) of the cooling plate (14) comprises at least one boss (48), each boss (48) of the cooling plate (14) extending opposite a corresponding boss (40) among the boss(es) (40) of the or one of the electrochemical cells (12).

8. Module (10) according to any one of the preceding claims, wherein the cooling plate (14) includes a circulation conduit (52) for a cooling fluid.

9. Module (10) according to any one of the preceding claims, wherein the cooling plate (14) comprises at least one through opening (50), each through opening (50) of the cooling plate (14) extending opposite a corresponding through opening (38) among the through opening(s) (38) of the or one of the electrochemical cells (12).

10. Module (10) according to any one of the preceding claims, comprising a bonding layer (16) between the cooling plate (14) and the bottom (28) of the outer shell (18) of each electrochemical cell (12).

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